JPH09327920A - Liquid-discharging method and device with liquid discharging head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive to more stabilize the discharging amount and speed of liquid and more improve the controllability of the discharging amount of the liquid by a method wherein the environment, under which the pressure of the liquid is efficiently applied to a movable member, is formed in the discharging system of the liquid on the basis of a new discharging principle using the mov able member. SOLUTION: In a constitution, in which a movable member 31 is arranged so as to face to a bubble generating region 11, at which a bubble 40 is generated by the heat energy emitted from a heating element 2, so as to control the growing direction of the bubble 40 by the displacement of the movable plate 31, driving pulses applied to the heating element 2 are divided into first pulses and second pulses, the pulse width of the former first pulse is controlled, and liquid is preheated by the first pulses and then bubble 40 is generated in the liquid by the latter second pulses.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid discharge head for displacing a movable member by utilizing bubbles generated by applying thermal energy to a liquid and discharging a desired liquid by the generation of the bubbles. The present invention relates to a used liquid ejection method and a liquid ejection device.

The present invention relates to a printer, a copier, a facsimile having a communication system, and a printer unit for printing on print media such as paper, yarn, fiber, cloth, leather, metal, plastic, glass, wood, ceramics and the like. , And an industrial recording device combined with various types of processing devices.

[0003] In the present invention, "print" and "recording" mean not only giving an image having a meaning such as a character or a figure to a print medium, but also an image having no meaning such as a pattern. It also means giving.

[0004]

2. Description of the Related Art By giving energy such as heat to ink, a state change accompanied by a steep volume change (formation of bubbles) is caused in the ink, and the ink is ejected from an ejection port by an action force based on this state change. An ink jet recording method in which an image is formed by attaching the ink onto a recording medium, that is, a so-called bubble jet recording method, is conventionally known. A recording device using this bubble jet recording method is USP
As disclosed in Japanese Patent No. 4,723,129 and the like,
Generally, an ejection port for ejecting ink, an ink channel communicating with this ejection port, and an electrothermal converter as an energy generating means for ejecting the ink disposed in the ink channel are disposed. ing.

According to such a recording method, a high-quality image can be recorded at high speed and with low noise, and in a head performing this recording method, ejection ports for ejecting ink are arranged at a high density. Therefore, it has many advantages that a high-resolution recorded image and a color image can be easily obtained with a small device. For this reason, this bubble jet recording method has recently been used in many office devices such as printers, copiers, and facsimile machines, and has been used in industrial systems such as textile printing devices.

[0006] As the bubble jet technology is used for products in various fields, the following various requirements have been increasing in recent years.

[0007] For example, as a study on a demand for improvement in energy efficiency, optimization of a heating element such as adjusting the thickness of a protective film is mentioned. This method is effective in improving the efficiency of propagation of generated heat to the liquid.

In addition, in order to obtain a high quality image, a driving condition for providing a liquid discharging method or the like in which the ink discharging speed is high and a good ink discharging can be performed based on stable bubble generation has been proposed. From the viewpoint of high-speed printing, there has also been proposed a print head having an improved flow path shape in order to obtain a liquid discharge head having a high filling (refilling) speed of the discharged liquid into the liquid flow path.

FIG. 32 shows a flow path structure of this flow path shape.
(A) and (b) are disclosed in JP-A-63-199997.
No. 2, for example. The flow path structure and the head manufacturing method described in this publication are based on the back wave (pressure in the direction opposite to the direction toward the discharge port, that is, the pressure in the liquid chamber 12) generated by the generation of bubbles. It is an invention which pays attention to. This back wave is known as loss energy because it is not energy directed toward the ejection direction.

In the invention shown in FIGS. 32 (a) and 32 (b), the valve 1 is located farther from the bubble generating region formed by the heating element 2 and located on the opposite side of the discharge port 11 with respect to the heating element 2.
0 is disclosed.

In FIG. 32 (b), this valve 10
It is disclosed that it has an initial position as attached to the ceiling of the flow channel 3 and hangs down into the flow channel 3 with the generation of bubbles by a manufacturing method using a plate material or the like. The present invention is disclosed as controlling the energy loss by controlling a part of the back wave by the valve 10.

However, in this configuration, as will be understood from consideration of the case where air bubbles are generated inside the flow path 3 for holding the liquid to be discharged, suppression of a part of the back wave by the valve 10 is not possible with liquid discharge. Is not practical.

Originally, the back wave itself is not directly related to the ejection as described above. At the time when this back wave is generated in the flow path 3, as shown in FIG.
The pressure of the bubbles that is directly related to the discharge has already made the liquid dischargeable from the flow path 3. Therefore, it is clear that even if only a part of the back wave is suppressed, the ejection is not greatly affected.

On the other hand, in the bubble jet recording method, since heating is repeated while the heating element is in contact with the ink, deposits are generated on the surface of the heating element due to scorching of the ink. In some cases, the generation of bubbles causes the generation of bubbles to be unstable, making it difficult to discharge ink satisfactorily. Further, even in the case where the liquid to be discharged is a liquid which is easily deteriorated by heat or a liquid in which foaming is difficult to be sufficiently obtained, a method for discharging the liquid to be discharged without changing the quality is desired. .

[0015] From such a viewpoint, the liquid (foaming liquid) that generates bubbles by heat and the liquid (ejected liquid) to be ejected are separated liquids, and the ejected liquid is ejected by transmitting the pressure due to foaming to the ejected liquid. The method is described in JP-A-61-69467, JP-A-55-81172, US Pat.
No. 0,259, and the like. In these publications, the ink, which is the ejection liquid, and the foaming liquid are completely separated by a flexible film such as silicon rubber so that the ejection liquid does not come into direct contact with the heating element, and the pressure due to the foaming of the foaming liquid is controlled. The configuration is such that the liquid is transmitted to the discharge liquid by deformation of the flexible film.
Such a configuration achieves prevention of deposits on the surface of the heating element, improvement in the degree of freedom in selecting the liquid to be discharged, and the like.

However, as described above, in the head having a structure in which the discharge liquid and the foaming liquid are completely separated, the pressure at the time of foaming is transmitted to the discharge liquid by expansion and contraction deformation of the flexible film. Is considerably absorbed by the flexible membrane. Further, since the amount of deformation of the flexible film is not so large, the effect of separating the ejection liquid and the foaming liquid can be obtained, but there is a possibility that the energy efficiency and the ejection force are reduced.

[0017]

SUMMARY OF THE INVENTION Some of the present inventors have
First, from the viewpoint that was not considered in the past, the fundamental ejection characteristics of the method of ejecting liquid by forming bubbles (particularly bubbles accompanying film boiling) in the liquid flow path are raised to a level that cannot be predicted in the past. Proposed technology (Japanese Patent Application No. 1-4109).

That is, some of the inventors reverted to the principle of droplet discharge, and conducted intensive research to provide a novel droplet discharge method utilizing bubbles which could not be obtained conventionally and a head and the like used therefor. went. At this time, the first technology analysis starting from the operation of the movable member in the liquid flow path, which is to analyze the principle of the mechanism of the movable member in the flow path, and the second technology starting from the principle of discharging droplets by bubbles An analysis and further a third analysis starting from the bubble formation region of the heating element for bubble formation were performed.

According to these analyses, the positional relationship between the fulcrum and the free end of the movable member is determined to be such that the free end is located on the discharge port side, that is, on the downstream side, and the movable member faces the heating element or the bubble generation region. This has led to the establishment of a completely new technology for actively controlling air bubbles.

Next, when considering the energy that the bubble itself gives to the discharge amount, it has been found that considering the growth component on the downstream side of the bubble is the largest factor that can significantly improve the discharge characteristics. That is, it has been found that the efficient conversion of the growth component on the downstream side of the bubble in the ejection direction leads to the improvement of the ejection efficiency and the ejection speed. From this, the inventors have reached a very high technical level as compared with the prior art in which the growth component on the downstream side of the bubble is positively moved to the free end side of the movable member.

Further, a heating area for forming bubbles,
For example, a structural element such as a movable member or a liquid flow path that is involved in the growth of the downstream side of the bubble, such as the area center on the surface that controls foaming, downstream from the center line passing through the area center in the liquid flow direction of the electrothermal converter. It has been found that it is also preferable to take into account the above.

On the other hand, it has been found that the refill speed can be greatly improved by considering the arrangement of the movable member and the structure of the liquid supply path.

Some of the present inventors have proposed the above-mentioned proposal (Japanese Patent Laid-Open No. 7-4) by finding the superior principle of liquid ejection from the knowledge obtained through such research and from a comprehensive viewpoint.
No. 109).

The present invention has been made in relation to the above-mentioned proposal, and an object thereof is to make the liquid pressure more efficient in a liquid discharge system based on a new discharge principle using a movable member. The purpose of this is to create an environment in which the movable member is well acted on to further stabilize the discharge amount and discharge speed of the liquid and further improve the controllability of the discharge amount of the liquid.

[0025]

A first aspect of a liquid ejecting method using a liquid ejecting head of the present invention is an ejecting port for ejecting a liquid, a bubble generating region for generating bubbles in the liquid, and the bubble generating. A movable member, which is disposed facing the area and has a movable member that is displaceable between a first position and a second position farther from the bubble generation region than the first position, is used. Is displaced from the first position to the second position by the pressure based on the generation of bubbles in the bubble generation region, and is displaced downstream of the upstream in the direction toward the discharge port by the displacement of the movable member. A liquid ejecting method using a liquid ejecting head for ejecting a liquid by greatly expanding the liquid, wherein the first pulse and the second pulse are applied to a heating element that applies thermal energy to the bubble generation region. Is divided into A drive pulse is supplied via a turban time, the first pulse preheats the liquid to the extent that the liquid is not ejected from the ejection port, and the second pulse ejects the liquid from the ejection port. The liquid is heated to generate bubbles, and the degree of preheating of the liquid is controlled by changing at least one of the pulse width of the first pulse and the interval time.

A second mode of the liquid ejecting method using the liquid ejecting head of the present invention supplies the liquid from the upstream side of the heating element along the heating element arranged in the flow path of the liquid ejecting head, Bubbles are generated by applying heat generated by a heating element to the supplied liquid, and the pressure is generated due to the generation of the bubbles, and the bubbles are arranged so as to face the heating element and are free on the ejection port side of the liquid ejection head. A liquid discharge method using a liquid discharge head for discharging a liquid by displacing a free end of a movable member having an end and guiding the pressure to the discharge port side by the displacement of the movable member, wherein The drive pulse is divided into the first pulse and the next second pulse, and the drive pulse is supplied during the interval time, and the liquid is ejected to the extent that the liquid is not ejected from the ejection port by the first pulse. Preheat and the second The amount of preheating of the liquid is changed by heating the liquid so that the liquid is discharged from the discharge port to generate bubbles, and changing at least one of the pulse width of the first pulse or the interval time. It is characterized by controlling.

A third aspect of the liquid ejecting method using the liquid ejecting head of the present invention is: a first liquid passage communicating with an ejection port; a second liquid passage having a bubble generating region; A liquid discharge head having a free end on the outlet side and having a movable member arranged between the first liquid flow path and the bubble generation region is used to generate bubbles in the bubble generation region. Liquid by displacing the free end of the movable member toward the first liquid flow path side based on the pressure generated by the generation of the liquid and guiding the pressure toward the discharge port side of the first liquid flow path by the displacement of the movable member. A liquid ejecting method using a liquid ejecting head for ejecting, wherein a heating element for applying thermal energy to the bubble generation region is divided into a first pulse and a second pulse, and The drive pulse is supplied through the interval time, and the first pulse is supplied. The liquid to preheat the liquid to the extent that the liquid is not ejected from the ejection port, and the second pulse heats the liquid to eject the liquid from the ejection port to generate bubbles, and the first pulse The pulse width of the liquid or at least one of the interval times is changed to control the degree of preheating of the liquid.

A first embodiment of a liquid ejecting apparatus using a liquid ejecting head of the present invention is an ejection port for ejecting a liquid, a bubble generating region for generating bubbles in the liquid, and a face for the bubble generating region. And a movable member that is displaceable between a first position and a second position farther from the bubble generation region than the first position is used. By displacing the bubbles from the first position to the second position by the pressure based on the generation of bubbles in the above, and by expanding the bubbles in the direction toward the discharge port to the downstream side by the displacement of the movable member. A liquid ejecting apparatus using a liquid ejecting head for ejecting a liquid, wherein a heating element for applying thermal energy to the bubble generation region is divided into a first pulse and a second pulse, and At interval tie Drive pulse is supplied, the liquid is preheated to such an extent that the liquid is not ejected from the ejection port by the first pulse, and the liquid is ejected from the ejection port by the second pulse. A drive pulse supply means for heating to generate bubbles, and a control means for controlling the degree of preheating of the liquid by changing at least one of the pulse width of the first pulse or the interval time are provided. Characterize.

A second embodiment of the liquid ejecting apparatus using the liquid ejecting head of the present invention supplies liquid from the upstream side of the heating element along the heating element arranged in the flow path of the liquid ejecting head, Bubbles are generated by applying heat generated by a heating element to the supplied liquid, and the pressure is generated due to the generation of the bubbles, and the bubbles are arranged so as to face the heating element and are free on the ejection port side of the liquid ejection head. A liquid discharge device using a liquid discharge head that discharges liquid by displacing a free end of a movable member having an end and guiding the pressure to the discharge port side by the displacement of the movable member, wherein The drive pulse is divided into the first pulse and the second pulse, and the drive pulse is supplied during the interval time, and the liquid is preheated to the extent that the liquid is not ejected from the ejection port by the first pulse. The second package The liquid by changing at least one of a drive pulse supply unit that heats the liquid so as to discharge the liquid from the discharge port to generate bubbles, and a pulse width of the first pulse or the interval time. And a control means for controlling the degree of preheating.

A third embodiment of a liquid ejecting apparatus using the liquid ejecting head of the present invention is such that a first liquid passage communicating with an ejection port, a second liquid passage having a bubble generating region, A liquid discharge head having a free end on the outlet side and having a movable member arranged between the first liquid flow path and the bubble generation region is used to generate bubbles in the bubble generation region. Liquid by displacing the free end of the movable member toward the first liquid flow path side based on the pressure generated by the generation of the liquid and guiding the pressure toward the discharge port side of the first liquid flow path by the displacement of the movable member. A liquid ejecting apparatus using a liquid ejecting head for ejecting, wherein a first heating element for applying heat energy to the bubble generation region is divided into a first pulse and a second pulse, and The drive pulse is supplied through the interval time, and the first pulse is supplied. Drive pulse supply means for preheating the liquid to the extent that the liquid is not ejected from the ejection port, and for heating the liquid to eject the liquid from the ejection port by the second pulse to generate bubbles. And a control means for controlling the degree of preheating of the liquid by changing at least one of the pulse width of the first pulse or the interval time.

The terms “upstream” and “downstream” used in the description of the present invention refer to the flow direction of the liquid from the liquid supply source to the discharge port through the bubble generation region (or movable member).
Alternatively, it is expressed as an expression regarding this structural direction.

The “downstream side” of the bubble itself is as follows:
It mainly represents a portion on the ejection port side of a bubble which is considered to directly act on ejection of a droplet. More specifically, with respect to the center of the bubble, the downstream side with respect to the flow direction and the structural direction,
Alternatively, it means bubbles generated in a region downstream of the area center of the heating element.

The term “substantially sealed” used in the description of the present invention refers to a state in which bubbles do not slip through gaps (slits) around the movable member before the movable member is displaced when the bubbles grow. Means

Further, the "separation wall" in the present invention means a wall (which may include a movable member) interposed so as to separate a bubble generation region and a region directly communicating with the discharge port in a broad sense. In a narrow sense, it means that the flow path including the bubble generation area is separated from the liquid flow path that directly communicates with the discharge port, and mixing of the liquid in each area is prevented.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings by dividing them into (forms of the structure of a liquid ejection portion), (driving system), and (other embodiments). .

(Form 1 of Configuration of Liquid Ejecting Section) First, the ejection force and the ejection efficiency of the liquid are improved by controlling the propagation direction of the pressure based on the bubbles for ejecting the liquid and the growth direction of the bubbles. A case example will be described.

FIG. 1 shows a schematic sectional view of the liquid discharge head of this embodiment cut in the liquid flow path direction, and FIG. 2 shows a partially cutaway perspective view of the liquid discharge head. .

The liquid discharge head of the present embodiment is a heating element 2 (in the present embodiment, a heating resistor having a shape of 40 μm × 105 μm) that applies heat energy to the liquid as an ejection energy generating element for discharging the liquid. Are provided on the element substrate 1, and the liquid flow paths 10 are arranged on the element substrate 1 so as to correspond to the heating elements 2. Liquid flow path 10
Is connected to the discharge port 18 and has a plurality of liquid flow paths 1.
It is in communication with a common liquid chamber 13 for supplying liquid to the nozzles 0, and receives from the common liquid chamber 13 an amount of liquid corresponding to the liquid discharged from the discharge port 18.

On the element substrate 1 in the liquid flow path 10, a plate-like movable member facing the above-mentioned heating element 2 and made of an elastic material such as metal and having a flat surface portion. 31 is provided in the shape of a cantilever. One end of the movable member 31 is a base (supporting member) formed by patterning a photosensitive resin or the like on the wall of the liquid flow path 10 or on the element substrate 1.
It is fixed to 34 etc. Thereby, the movable member 31
Are held and constitute a fulcrum (fulcrum portion) 33.

The movable member 31 has a fulcrum (fulcrum portion; fixed end) 33 on the upstream side of a large flow flowing from the common liquid chamber 13 to the ejection port 18 side through the movable member 31 by the liquid ejecting operation. 15 μ from the heating element 2 in a state of covering the heating element 2 at a position facing the heating element 2 so as to have a free end (free end portion) 32 on the downstream side of 33.
They are arranged at a distance of about m. A bubble generation region 11 is between the heating element 2 and the movable member 31. Note that the types, shapes, and arrangements of the heating element 2 and the movable member 31 are not limited thereto, and may be any shape and arrangement that can control the growth of bubbles and the propagation of pressure as described later. The liquid flow path 10 described above is connected to the first liquid flow path 14 which is directly connected to the discharge port 18 with the movable member 31 as a boundary, for the purpose of describing the flow of the liquid to be described later. Area 1
1 and the second liquid flow path 16 in the portion having the liquid supply path 12 will be described separately.

The movable member 31 is generated by causing the heating element 2 to generate heat.
Heat is applied to the liquid in the bubble generation region 11 between the heating element 2 and the heating element 2 to generate bubbles in the liquid based on the film boiling phenomenon as described in US Pat. No. 4,723,129. The pressure based on the generation of the bubbles and the bubbles act on the movable member 31 preferentially, and the movable member 31 is moved toward the discharge port 18 side around the fulcrum 33 as shown in FIG. 1 (b), (c) or FIG. Displace to open widely. Depending on the displacement or the displaced state of the movable member 31, the propagation of pressure based on the generation of bubbles and the growth of the bubbles themselves are guided to the ejection port side.

Here, one of the basic ejection principles of the present invention will be described. One of the most important principles in the present invention
The first is that the movable member 31 arranged to face the air bubble has a first state in a steady state based on the pressure of the air bubble or the air bubble itself.
Is moved from the position to the second position, which is the position after the displacement, and the movable member 31 that is displaced guides the pressure caused by the generation of bubbles and the bubbles themselves to the downstream side where the discharge port 18 is arranged.

This principle will be described in more detail by comparing FIG. 3 schematically showing a conventional liquid flow path structure not using the movable member 31 and FIG. 4 of the present invention. Here, the propagation direction of the pressure toward the discharge port 18 is indicated as VA, and the propagation direction of the pressure toward the upstream side is indicated as VB.

In the conventional head as shown in FIG. 3, there is no structure for restricting the propagation direction of pressure by the bubble 40 generated. Therefore, the pressure propagation direction of the bubble 40 is V1
As shown in V8, the direction was perpendicular to the surface of the bubble, and was oriented in various directions. Among them, those having a component in the pressure propagation direction in the VA direction which has the most influence on the liquid discharge are V1-V
4, that is, a direction component of pressure propagation in a portion closer to the discharge port 18 than a position substantially half of the bubble 40, and is an important portion directly contributing to liquid discharge efficiency, liquid discharge force, discharge speed, and the like. Further, V1 works efficiently because it is closest to the ejection direction VA, while V4 has relatively little direction component toward VA.

On the other hand, in the case of the present invention shown in FIG. 4, the movable member 31 faces various directions as in the case of FIG. It is guided to the (discharge port side) and converted into the VA pressure propagation direction, whereby the pressure of the bubble 40 directly and efficiently contributes to the discharge. Then, the growth direction itself of the bubble 40 is also guided in the downstream direction in the same manner as the pressure propagation directions V1 to V4, and grows larger downstream than upstream. As described above, by controlling the growth direction itself of the bubble 40 by the movable member 31 and controlling the pressure propagation direction of the bubble 40, it is possible to achieve a fundamental improvement in ejection efficiency, ejection force, ejection speed, and the like. .

Next, returning to FIG. 1, the ejection operation of the liquid ejection head of this embodiment will be described in detail.

FIG. 1A shows a state before energy such as electric energy is applied to the heat generating element 2.
Is a state before generating heat. The important thing here is that
The movable member 31 is provided at a position facing at least a downstream portion of the bubble 40 generated by the heat generation of the heating element 2. That is, on the liquid flow path structure, at least downstream of the area center 3 of the heating element 2 (through the area center 3 of the heating element 2 in the length direction of the flow path so that the downstream side of the bubble 40 acts on the movable member 31). The movable member 31 is arranged to a position (downstream from the orthogonal line).

In FIG. 1 (b), electric energy or the like is applied to the heating element 2 to heat the heating element 2, and the generated heat heats a part of the liquid filling the bubble generating region 11 to cause film boiling. This is a state in which the accompanying bubbles 40 are generated.

At this time, the movable member 31 is displaced from the first position to the second position by the pressure based on the generation of the bubbles 40 so as to guide the propagation direction of the pressure of the bubbles 40 toward the ejection port 18. What is important here is that the movable member 3
1 is disposed on the downstream side (discharge port side), and the fulcrum 3
3 is located on the upstream side (common liquid chamber side),
That is, at least a part of the movable member 31 faces the downstream portion of the heating element 2, that is, the downstream portion of the bubble 40.

FIG. 1C shows a state in which the bubble 40 has further grown, but the movable member 31 is further displaced according to the pressure accompanying the generation of the bubble 40. The generated air bubbles 40
It grows greatly from the upstream to the downstream, and grows greatly beyond the first position (dotted line position) of the movable member 31. In this way, the movable member 31 is gradually displaced according to the growth of the bubbles 40, so that the pressure propagation direction of the bubbles 40 and the direction in which the accumulation movement is easy, that is, the bubbles 40 toward the free end 32 side.
The fact that the growth direction can be uniformly directed to the discharge port 18 is also considered to increase the discharge efficiency. Movable member 3
In the case of 1, even when the bubbles 40 and the bubbling pressure are guided toward the discharge port 18, this transmission is hardly hindered, and the pressure propagation direction and the growth direction of the bubbles 40 are efficiently changed according to the magnitude of the propagating pressure. Can be controlled.

FIG. 1D shows a state in which the bubble 40 contracts and disappears due to the decrease in the bubble internal pressure after the film boiling described above.

The movable member 31 displaced to the second position
The initial position (first position in FIG. 1A) of FIG.
Position). Further, at the time of defoaming, in order to supplement the contracted volume of the bubbles 40 in the bubble generation region 11 and to supplement the volume of the discharged liquid, VD1, VD1 of the flow from the upstream side (B), that is, from the common liquid chamber 13 side. Liquid flows in like VD2, and like Vc of the flow from the discharge port 18 side.

As described above, the movable member 31 associated with the generation of the bubbles 40
The operation of and the liquid ejection operation have been described.
The liquid refill in the liquid ejection head will be described in detail.

The liquid supply mechanism in the present invention will be described in more detail with reference to FIG.

After the state shown in FIG. 1 (c), when the bubble 40 enters the defoaming process after having reached the maximum volume state, the volume of the liquid that compensates for the defoamed volume is the discharge port 18 side of the first liquid flow path 14. And the second
The liquid flows into the bubble generation area 11 from the common liquid chamber side 13 of the liquid flow path 16. In the conventional liquid flow path structure having no movable member 31, the amount of liquid flowing from the discharge port side to the defoaming position and the amount of liquid flowing from the common liquid chamber side are common to the portion closer to the discharge port than the bubble generation region. This is due to the magnitude of the flow resistance with the portion close to the liquid chamber (based on the flow path resistance and the inertia of the liquid).

Therefore, when the flow resistance on the side close to the ejection port is small, a large amount of liquid flows into the defoaming position from the ejection port side, and the retreat amount of the meniscus increases. In particular, as the flow resistance on the side close to the discharge port is reduced to increase the discharge efficiency in order to increase the discharge efficiency, the meniscus M at the time of defoaming becomes larger, the refill time becomes longer, and the refill time becomes longer, and high-speed printing is performed. Was to hinder.

On the other hand, in this embodiment, the movable member 31 is used.
Is provided, the volume W of the bubble 40 is
When the upper side of the position is W1 and the side of the bubble generation region 11 is W2, the retreat of the meniscus stops when the movable member 31 returns to the original position at the time of defoaming, and then the remaining volume of W2 of the liquid. The supply is mainly performed by the liquid supply from the flow VD2 of the second flow path 16. Thus, while the amount corresponding to about half of the volume of the bubble W has conventionally been the meniscus retraction amount, it has become possible to suppress the meniscus retreat amount to a smaller amount, which is about half of W1.

Further, the supply of the liquid of the volume of W2 is forcibly made mainly from the upstream side (VD2) of the second liquid flow path along the surface of the movable member 31 on the heating element side by utilizing the pressure at the time of defoaming. Since it can be performed at any time, a faster refill could be realized.

What is characteristic here is that when refilling is performed with the conventional head using the pressure at the time of defoaming, the vibration of the meniscus becomes large, which leads to the deterioration of the image quality. In the high-speed refill, the movable member 31 suppresses the flow of the liquid between the region of the first liquid flow path 14 on the ejection port 18 side and the ejection port side of the bubble generation region 11, so that the vibration of the meniscus is extremely reduced. That is what you can do. As described above, the present invention provides the second flow path 1
6 was used in the fields of stable ejection, high-speed repetitive ejection, and recording by achieving forced refill to the bubbling region through the liquid supply passage 12 of No. 6 and high-speed refill by suppressing the above-mentioned meniscus retreat and vibration. In this case, improvement in image quality and high-speed recording can be realized.

The structure of the present invention further has the following effective functions. That is, the propagation of the pressure due to the generation of the bubble 40 to the upstream side (back wave) is suppressed. Of the bubbles 40 generated on the heating element 2, most of the pressure caused by the bubbles on the common liquid chamber 13 side (upstream side) is a force (back wave) for pushing back the liquid toward the upstream side. This back wave caused the pressure on the upstream side, the amount of liquid movement due thereto, and the inertia force accompanying the liquid movement, which reduced the refill of the liquid into the liquid flow path and hindered high-speed driving. . In the present invention, first, the movable member 31 suppresses these actions on the upstream side to further improve the refill supply property.

Next, further characteristic structures and effects of this embodiment will be described below.

The second liquid flow path 16 of this embodiment is provided with the heating element 2
Liquid supply path 1 having an inner wall that is substantially flat with the heating element 2 (the heating element surface is not greatly reduced) upstream of the liquid supply path 1
Two. In such a case, the supply of the liquid to the surface of the bubble generation region 11 and the surface of the heating element 2 is performed along the surface of the movable member 31 near the bubble generation region 11 like VD2. Therefore, stagnation of the liquid on the surface of the heating element 2 is suppressed, and deposition of gas dissolved in the liquid,
So-called residual air bubbles remaining without defoaming are easily removed,
Also, the heat storage in the liquid does not become too high. Therefore, more stable generation of bubbles can be repeated at high speed. In the present embodiment, the liquid supply path 12 having a substantially flat inner wall has been described.
However, the present invention is not limited to this. Any liquid supply path that smoothly connects to the surface of the heating element 2 and has a gentle inner wall may be used.
Any shape that does not cause stagnation of the liquid or large turbulence in the supply of the liquid may be used.

The liquid is supplied to the bubble generating region 11 through the side portion (slit 35) of the movable member 31 and VD.
Some are done from scratch. However, in order to guide the pressure at the time of bubble generation to the discharge port 18 more effectively, the entire bubble generation region 11 is covered (covers the surface of the heating element) as shown in FIG.
Movable member 31 as shown in FIG.
In the case where the flow resistance of the liquid between the bubble generation region 11 and the region near the discharge port 18 of the first liquid flow path 14 is increased by returning to the position shown in FIG. Incoming liquid flow is impeded. But,
In the head structure of the present invention, the flow VD1 for supplying the liquid to the bubble generation region 11 has a very high liquid supply performance.
Even if a structure that seeks to improve discharge efficiency that covers
There is no drop in liquid supply performance.

As for the positions of the free end 32 and the fulcrum 33 of the movable member 31, the free end 32 is relatively downstream of the fulcrum 33 as shown in FIG. 5, for example. With such a configuration, at the time of the above-described foaming, functions and effects such as guiding the pressure propagation direction and growth direction of the bubbles 40 to the ejection port 18 side can be efficiently realized. Further, this positional relationship achieves not only a function and an effect on discharge, but also an effect that the flow resistance to the liquid flowing through the liquid flow path 10 can be reduced and the refill can be performed at a high speed even when the liquid is supplied. This occurs when the meniscus M receded by the ejection of the liquid returns to the ejection port 18 by capillary force, as shown in FIG.
When the liquid is supplied for defoaming, the liquid flow path 10
This is because the free end 32 and the fulcrum 33 are arranged so as not to go against the flows S1, S2, and S3 flowing in (including the first liquid flow path 14 and the second liquid flow path 16).

Supplementally, in FIG. 1 of the present embodiment, as described above, the free end 32 of the movable member 31 divides the heating element 2 into the upstream side region and the downstream side region by the center 3 of the area.
It extends with respect to the heating element 2 so as to face a position downstream of (a line passing through the area center (center) of the heating element 2 and orthogonal to the length direction of the liquid flow path). Thereby, the movable member 31 receives a pressure or a bubble 40 that greatly contributes to the ejection of the liquid generated downstream of the area center position 3 of the heating element 2,
This pressure and bubbles can be guided to the discharge port 18 side, and the discharge efficiency and discharge force can be fundamentally improved.

Further, many effects are obtained by utilizing the upstream side of the bubble 40 in addition.

Further, in the structure of the present embodiment, it is considered that the free end 32 of the movable member 31 makes an instantaneous mechanical displacement, which effectively contributes to the ejection of the liquid.

(Form 2 of Structure of Liquid Ejecting Section) FIG. 6 shows a second embodiment of the structure of the liquid discharging section in the present invention. In FIG. 6, A indicates a state in which the movable member 31 is displaced (bubbles are not shown), B indicates a state in which the movable member 31 is in the initial position (first position), and in this B state, It is assumed that the bubble generation area 11 is substantially sealed with respect to the discharge port 18 (here, although not shown, A,
There is a channel wall between B and separates the channel from the channel.)

The movable member 31 in FIG. 6 is provided with two bases 34 on the side and the liquid supply path 12 is provided between them.
Thereby, along the surface of the movable member 31 on the heating element 2 side,
Further, the liquid can be supplied from a liquid supply path having a surface that is substantially flat or smoothly connected to the surface of the heating element 2.

Here, at the initial position (first position) of the movable member 31, the movable member 31 is close to or adjacent to the heating element downstream wall 36 and the heating element side wall 37 which are arranged downstream of the heating element 2 and in the lateral direction. The discharge port 18 of the bubble generation region 11 is closely attached
Side is substantially sealed. Therefore, the pressure of the bubbles at the time of foaming, particularly the pressure on the downstream side of the bubbles, is not released and the movable member 3
1 can be concentrated on the free end 32 side.

When defoaming, the movable member 31 returns to the first position, and when supplying liquid onto the heating element 2 at the time of defoaming,
Since the ejection port 18 side of the bubble generation region 11 is in a substantially sealed state, various effects described in the previous embodiment, such as suppression of meniscus retraction, can be obtained. In addition, the same function and effect as those of the previous embodiment can be obtained in the effect regarding the refill.

Further, in this embodiment, FIG. 2 and FIG.
As described above, the base 34 for supporting and fixing the movable member 31 is provided upstream of the heating element 2, and the base 34 having a width smaller than the liquid flow path 10 allows the liquid supply path 12 to the liquid supply path 12 as described above. Supplying liquid. Further, the shape of the base 34 is not limited to this, and any shape can be used as long as the refill can be performed smoothly.

In this embodiment, the movable member 31
The distance between the heating element 2 and the heating element 2 is set to about 15 μm.

(Form 3 of Configuration of Liquid Ejection Portion) FIG. 7 shows one of the basic concepts of the present invention, which is a third embodiment of the configuration of the liquid ejection portion of the present invention. FIG.
This is an embodiment in which a bubble generation region in one liquid flow path, a positional relationship between bubbles generated therein and a movable member, and a liquid discharge method and a refill method are more easily understood.

In most of the above-described embodiments, the pressure of the bubble 40 generated is concentrated on the free end 32 of the movable member 31, so that the bubble 40 moves simultaneously with the abrupt movement of the movable member 31. Has achieved to focus on the side. On the other hand, in the present embodiment, while giving the degree of freedom of the generated bubble 40, the downstream portion of the bubble 40 which is the discharge port 18 side of the bubble 40 directly acting on the discharge of the liquid is moved to the movable member 31.
Is regulated on the free end 32 side of the motor.

Explaining the structure, in FIG. 7, as a barrier located at the downstream end of the bubble generation region 11 provided on the element substrate 1 of FIG. 2, as compared with FIG. 2 (first embodiment) described above. No convex portion (hatched portion in the figure) is provided in this embodiment. In other words, the free end region and both side end regions of the movable member 31 are in the bubble generation region 1 with respect to the discharge port region.
1 is opened without being substantially closed, and this configuration is the present embodiment.

In this embodiment, since the bubble growth at the downstream tip portion of the downstream portion that directly affects the droplet discharge of bubbles is allowed, the pressure component is effectively used for the ejection. In addition, at least the upward pressure (VB, VB, VB of FIG. 3) of the downstream portion is applied to the movable member 31.
The free end side portion acts so as to be added to the bubble growth at the downstream end portion, so that the discharge efficiency is improved similarly to the above-described embodiment. In this embodiment, the responsiveness to driving of the heating element 2 is superior to that of the above embodiment.

In addition, this embodiment has a manufacturing advantage because it is structurally simple.

The fulcrum portion of the movable member 31 of this embodiment is fixed to one base 34 having a width smaller than the surface of the movable member 31. Therefore, the liquid is supplied to the bubble generation region 11 at the time of defoaming through both sides of the base 34 (see the arrow in the figure). The base 34 may have any structure as long as the liquid supply is ensured.

In the case of the present embodiment, the refill at the time of supplying the liquid controls the flow of the liquid flowing into the bubble generating region 11 from above in association with the defoaming of the bubbles in the case of the present embodiment. This is superior to the conventional bubble generating structure using only a heating element. Of course, this can also reduce the amount of meniscus retraction.

As a modified embodiment of the third embodiment,
It is preferable that only the both ends (one or both sides) of the movable member 31 with respect to the free end 32 be substantially sealed with respect to the bubble generation region 11. According to this configuration, the pressure directed to the side of the movable member 31 can be changed and used for the growth of the discharge port side end of the bubble as described above, so that the discharge efficiency is further improved.

(Form 4 of Configuration of Liquid Ejection Section) An example in which the liquid ejection force by the mechanical displacement described above is further improved will be described in this embodiment. FIG. 8 is a cross-sectional view of such a head structure. FIG. 8 shows an embodiment in which the movable member 31 extends such that the position of the free end 32 of the movable member 31 is located further downstream of the heating element 2. Thereby, the displacement speed of the movable member 31 at the position of the free end 32 can be increased, and the generation of the ejection force due to the displacement of the movable member 31 can be further improved.

Further, since the free end 32 comes closer to the ejection port 18 side as compared with the previous embodiment, it is possible to concentrate the growth of the bubble 40 on a more stable directional component and perform a better ejection. You can

Further, the movable member 31 is displaced at a displacement rate R1 according to the bubble growth rate at the center of pressure of the bubble 40, but the free end 32 at a position farther from the fulcrum 33 than this position is even faster. It is displaced at R2. As a result, the free end 32 is mechanically acted on the liquid at a high speed to cause the liquid to move, thereby increasing the discharge efficiency.

Further, the shape of the free end 32 is perpendicular to the liquid flow as in FIG. 7, so that the pressure of the bubble 40 and the mechanical action of the movable member 31 can be discharged more efficiently. Can be contributed to.

(Form 5 of Configuration of Liquid Ejection Section) FIG.
(A), (b), (c) is a fifth embodiment of the configuration of the liquid ejection unit in the present invention.

Unlike the previous embodiments, the structure of this embodiment does not have a flow path shape that communicates with the liquid chamber 13 side in the region that directly communicates with the discharge port 18, and therefore the structure can be simplified. .

All the liquid is supplied only from the liquid supply path 12 along the surface of the movable member 31 on the side of the bubble generation region 11, and the discharge end 1 of the free end 32 or the fulcrum 33 of the movable member 31 is supplied.
The positional relationship with respect to 8 and the configuration facing the heating element 2 are the same as those in the above-described embodiment.

The present embodiment realizes the above-mentioned effects such as the discharge efficiency and the liquid supply property, but in particular, the retreat of the meniscus is suppressed, and almost all the liquid supply is made use of the pressure at the time of defoaming. This is a forced refill.

FIG. 9A shows a state in which the liquid is foamed by the heating element 2, and FIG. 9B shows a state in which the bubble 40 is shrinking, and at this time, the movable member 31 is in the initial state. The return to the position and the liquid supply in S3 are performed.

In FIG. 9C, the slight meniscus retreat M when the movable member 31 returns to the initial position is refilled by the capillary force in the vicinity of the discharge port 18 after the bubble is eliminated.

(Form 6 of Configuration of Liquid Ejection Section) Next, a sixth embodiment of the configuration of the liquid ejection section of the present invention will be described.

In this embodiment as well, the main principle of liquid ejection is the same as that of the previous embodiment, but in this embodiment, the liquid flow path is made into a multi-flow path structure so that liquid is bubbled by applying heat. The (foaming liquid) and the liquid to be mainly discharged (discharge liquid) can be separated.

FIG. 10 is a schematic cross-sectional view of the liquid discharge head of this embodiment in the flow path direction, and FIG. 11 is a partially cutaway perspective view of the liquid discharge head.

In the liquid discharge head of this embodiment, the second liquid flow path 16 for foaming is provided on the element substrate 1 provided with the heat generating element 2 for giving heat energy for generating bubbles in the liquid. A first liquid flow path 14 for discharge liquid, which directly communicates with the discharge port 18, is arranged above.

The upstream side of the first liquid flow passage 14 communicates with the first common liquid chamber 15 for supplying the discharge liquid to the plurality of first liquid flow passages 14, and the upstream side of the second liquid flow passage 16. Side is a plurality of second
The liquid flow path 16 communicates with a second common liquid chamber for supplying a foaming liquid.

However, when the bubbling liquid and the discharge liquid are the same liquid, the common liquid chamber may be unified and made common.

Between the first and second liquid flow paths 14 and 16,
A separation wall 30 made of an elastic material such as a metal is provided, and separates the first liquid flow path 14 and the second liquid flow path 16. In the case where the foaming liquid and the discharge liquid are liquids that should not be mixed as much as possible, the first liquid flow path 14 and the second liquid flow path 1
Although it is better to separate the flow of the liquid of No. 6, if there is no problem even if the foaming liquid and the discharge liquid are mixed to some extent, the separation wall 30 need not have the function of complete separation.

A projection space above the heating element 2 in the plane direction (hereinafter, referred to as a discharge pressure generation region; regions A and B in FIG. 10).
Of the separation wall 30 located in the bubble generation region 11) of
Discharge port side (downstream side of liquid flow) by slit 35
Is a free end and a fulcrum 3 is on the common liquid chamber (15, 17) side.
The movable member 31 has a cantilever shape in which 3 is located.
Since the movable member 31 is disposed so as to face the bubble generation region 11 (B), the first liquid flow path 1 is formed by foaming of the foaming liquid.
4 to open toward the discharge port 18 side (in the direction of the arrow in the figure). In FIG. 11 as well, a second liquid flow path 16 is formed on the element substrate 1 on which the heating resistor as the heating element 2 and the wiring electrode 5 for applying an electric signal to the heating resistor are arranged. Separation wall 30 is arranged via a space to be formed.

The relationship between the arrangement of the fulcrum 33 and the free end 32 of the movable member 31 and the arrangement of the heating element 2 is the same as in the previous embodiment.

Although the structural relationship between the liquid supply passage 12 and the heating element 2 has been described in the previous embodiment, the structural relationship between the second liquid flow path 16 and the heating element 2 is the same in this embodiment. are doing.

Next, the operation of the liquid ejection head of this embodiment will be described with reference to FIG.

In driving the head, the same aqueous ink was used as the ejection liquid supplied to the first liquid flow path 14 and the bubbling liquid supplied to the second liquid flow path 16.

The heat generated by the heating element 2 is applied to the second liquid flow path 16
By acting on the foaming liquid in the bubble generation region 11, the foaming liquid is added to the foaming liquid in the same manner as described in the previous embodiment.
A bubble 40 is generated based on the film boiling phenomenon as described in U.S. Pat.

In this embodiment, the bubble generation area 11
Since there is no escape of foaming pressure from the three sides except the upstream side of
The pressure due to the bubble generation is concentrated and propagates to the movable member 6 arranged in the discharge pressure generating portion, and the movable member 6 is moved from the state of FIG.
As shown in (b), it is displaced to the first liquid flow path 14 side. The operation of the movable member 31 causes the first liquid flow path 14 and the second liquid flow path 1
6 communicates largely with each other, and the pressure based on the generation of the bubbles 40 is mainly transmitted in the direction (A direction) on the discharge port 18 side of the first liquid flow path 14. The liquid is discharged from the discharge port 18 by the propagation of the pressure and the mechanical displacement of the movable member 31 as described above.

Next, as the bubble 40 shrinks, the movable member 31 returns to the position shown in FIG. 12A, and in the first liquid flow path 14, the amount of ejected liquid commensurate with the amount of ejected liquid is ejected. Is supplied from the upstream side. Also in this embodiment,
Since the supply of the discharge liquid is in the direction in which the movable member 31 is closed, as in the above-described embodiment, the movable member 31 does not hinder the refill of the discharge liquid.

The present embodiment is the same as the first embodiment and the like in the operation and effect of the main part concerning the propagation of the foaming pressure due to the displacement of the movable member 31, the growth direction of the bubbles 40, the prevention of the back wave and the like. However, by adopting the two-channel structure as in the present embodiment, there are the following additional advantages.

That is, according to the configuration of the above-described embodiment, the discharge liquid and the foaming liquid can be different liquids, and the discharge liquid can be discharged by the pressure generated by the foaming of the foaming liquid. For this reason, even if a high-viscosity liquid such as polyethylene glycol, which has conventionally been insufficiently foamed even when heat is applied and discharge power is insufficient, the liquid is supplied to the first liquid flow path 14. , A liquid (ethanol:
Water = 4: 6 mixed liquid of about 1 to 2 cP) or a low-boiling liquid can be supplied to the second liquid flow path 16 for good ejection.

Further, by selecting, as the foaming liquid, a liquid which does not generate deposits such as kogation on the surface of the heat generating element 2 even when it receives heat, it is possible to stabilize the foaming and perform good discharge.

Furthermore, in the structure of the head of this embodiment, the effects as described in the previous embodiments are also produced, so that a liquid such as a highly viscous liquid can be ejected with higher ejection efficiency and ejection force. .

Further, even in the case of a liquid which is weak against heating, this liquid is supplied to the first liquid flow path 14 as a discharge liquid,
By supplying a liquid that is hard to thermally degenerate and favorably foams in the liquid flow path 16, it does not cause thermal harm to the liquid that is vulnerable to heating, and has high discharge efficiency and high discharge force as described above. Can be ejected.

(Driving Method) Next, the outline of the pulse width modulation of the divided pulse adopted as the driving method of the liquid ejection head of each of the above-described embodiments and the ejection amount control by this will be described. In the following, an ink jet print head that ejects ink (hereinafter, also referred to as “ink jet recording head” or “recording head”) will be described as an example of the liquid ejection head.

FIG. 33 is a diagram for explaining divided pulses in this embodiment.

In FIG. 33, V _OP is the drive voltage, P ₁ is the pulse width of the first pulse (hereinafter referred to as “preheat pulse”) of a plurality of divided heat pulses (drive pulses), P ₂ is the interval time, P ₃ is the pulse width of the second pulse (hereinafter referred to as “main heat pulse”). T ₁ , T ₂ and T ₃ indicate times for determining P ₁ , P ₂ and P ₃ . The driving voltage V _OP is one of the values indicating electric energy required for the heating element 2 as an electrothermal converter to which this voltage is applied to generate bubbles 40 in the ink. It is determined by the area, the resistance value, the film structure and the liquid path structure of the recording head. In the divided pulse width modulation driving method, a pulse is sequentially applied with a width of P ₁ , P ₂ , and P _3. The preheat pulse is a pulse for mainly controlling the ink temperature in the liquid path. The example plays an important role in discharge rate control. The pulse width P ₁ of the preheat pulse is changed by the application of the preheat pulse to the heating element 2.
Is set to such a value that the bubbling phenomenon does not occur in the ink as the liquid to be ejected due to the thermal energy generated.

The interval time P ₂ is provided in order to set a predetermined time interval so that the preheat pulse and the main heat pulse do not interfere with each other, and to make the temperature distribution of the ink in the ink liquid passage uniform. The main heat pulse is caused to foam in the ink in the liquid passage is for discharging ink from the discharge port 18, the width P ₃ is the heat generating element 2 area, resistance, film structure and the recording head It is determined by the structure of the ink liquid path.

FIG. 34 is a diagram showing the preheat pulse dependency of the ink ejection amount, where V ₀ is P ₁
= 0 [μsec], and this value is determined by the head structure. Incidentally, V _{0 in} this example is V ₀ = 18.0 [ng / do when the ambient temperature T _R = 25 ° C.
t].

As shown by the curve a in FIG. 34, the ejection amount V _d increases as the pulse width P ₁ of the preheat pulse increases.
Is that the pulse width P ₁ increases linearly from 0 to P _1LMT, and the change loses linearity in the range where the pulse width P ₁ is larger than P _1LMT and saturates at the pulse width P _1MAX and becomes maximum. .

As described above, the range up to the pulse width P _{1LMT in} which the change in the discharge amount V _d with respect to the change in the pulse width P ₁ shows linearity makes it easy to control the discharge amount by changing the pulse width P _1. This is an effective range. In the example shown in the curve a, P _1LMT = 1.87 (μs), and the discharge amount at this time was V _LMT = 24.0 [ng / dot]. Further, the pulse width P _1MAX when ejection amount V _d is saturated is, P _1MAX = 2.1 a [.mu.s], were ejection amount V _MAx = 25.5 at this time [ng / dot] .

The pulse width P _{1 of the} preheat pulse is P _1MAX
Greater than the discharge amount V _d is smaller than V _{MA X.}
This phenomenon occurs when a preheat pulse having a pulse width in the above range is applied, so that minute bubbling (a state immediately before film boiling) occurs on the heating element 2, and the next main heat pulse is applied before the bubble disappears. As a result, the ejection amount is reduced by the micro bubbles disturbing the bubbling by the main heat pulse. This region is called a pre-foaming region, and in this region, it becomes difficult to control the discharge amount via a preheat pulse.

If the slope of the straight line showing the relationship between the discharge amount and the pulse width in the range of P ₁ = 0 to P _1LMT [μs] shown in FIG. 34 is defined as the preheat pulse dependence coefficient, the preheat pulse dependence coefficient:

[0121]

[Equation 1]

Is obtained. This coefficient K _P is determined by the head structure, driving conditions, physical properties of the ink, and the like irrespective of the temperature. That is, curves b and c in FIG. 34 show the case of another print head, and it can be seen that the discharge characteristics change when the print head is different. Thus, if the recording head is different,
Since the upper limit value P _1LMT of the pulse width P ₁ of the preheat pulse is different, the upper limit value P _1LMT
And discharge amount control is performed. Incidentally, K _P = 3.2 in the print head and ink shown by the curve a in this example.
09 [ng / μsec · dot].

Another factor that determines the ejection amount of the ink jet recording head is the temperature of the recording head (ink temperature).

FIG. 35 is a diagram showing the temperature dependence of the discharge amount. As shown in curve a of Figure 35, ejection amount V with respect to an increase in environmental temperature T _R of the recording head (= head temperature T _H)
d increases linearly. If the slope of this line is defined as a temperature-dependent coefficient, the temperature-dependent coefficient:

[0125]

[Equation 2]

[0126] This coefficient K _T does not depend on the driving conditions, but is determined by the structure of the head, the physical properties of the ink, and the like. FIG.
Also in No. 5, curves b and c show cases of other recording heads. Incidentally, in the recording head of this example, K _T = 0.3
[Ng / ° C. · dot].

After all, the pulse width of the preheat pulse is set to PW.
By performing M control, it is possible to positively adjust the ejection amount of ink to improve the gradation of the print and to stabilize the ejection amount of ink.

For example, the preheat pulse causes the heating element 2 to generate heat so as to preheat the liquid so that the liquid is not ejected. Therefore, the operating environment of the movable member 31 is improved,
The ejection amount and ejection speed of the liquid are stabilized.
That is, the liquid in the bubble generation region 11 is preheated by the prepulse, the viscosity thereof is reduced, and the movable member 31
Environment with high transmission efficiency of pressure transmitted to Therefore, the intended starting of the movable member 31 when the main heat pulse is applied is reliably and efficiently performed, and the reliability of the movable member 31 is improved, and as a result, the liquid discharge condition is improved. Will be. In addition, since such a liquid ejection state is improved only when the liquid is ejected, a desired ejection state (when an image is printed by ejecting ink, the (Discharge state for ensuring the gradation property of the image) can be reliably obtained.

The pulse width of the preheat pulse can be PWM-controlled based on the temperature detected by a temperature sensor such as a diode provided in the head. In that case, it is preferable to weight the temperature detected by the temperature sensor in accordance with the temperature difference between the temperature sensor and the heating element 2 and the discharge port 18 caused by the positional relationship between the two. In addition, since the movable member 31 is made of a metal or a member having good thermal conductivity, preheating of the discharged liquid is performed smoothly. Also,
The movable member 31 can also absorb the heat of the liquid in the vicinity of the heating element 2 that has been heated for the preheat pulse or for the continuous discharge of the liquid. As a result, the heat of the liquid in the vicinity of the heating element 2 can be made uniform, and for example, the difference between the temperature detected by the temperature sensor provided in the head and the temperature of the heating element 2 can be kept small, and the precision of the PWM control of the preheat pulse can be reduced. You can also raise it.

A specific example of the drive pulse applied to the heating element 2 will be described.

In the nozzle structure of FIG. 36 (a), as shown in FIG.
6 (a) and 6 (b), the pulse width t1,
t2 and t3 were set as follows.

1 μsec ≦ t1 ≦ 1.4 μsec 1.5 μsec ≦ t2 ≦ 3 μsec 3 μsec <t3 ≦ 8 μsec (preferably 5 μse
c ≦ t3 ≦ 8 μsec) Under such setting conditions, the ejection amount can be controlled according to the shape of the drive pulse, and multi-gradation expression of the print image with ink can be realized.

The preheat pulse is 1.5 μsec.
By setting ≦ t1 ≦ 1.8 μsec longer and increasing the temperature of the liquid near the heating element 2 to some extent,
The discharge amount can be controlled in a range of about 10 ng or less of the liquid.

When the pulse width of the preheat pulse is controlled according to the temperature of the head in order to correct the liquid discharge amount, it is preferable to change the control content depending on the print medium. For example, transparent or translucent O
When printing such as printing by discharging ink as a liquid onto HP paper, it is important to correct the variation in the discharge amount, but it is often necessary to print at a high density. Therefore, when performing printing on OHP sheet, without performing the PWM control in accordance with the temperature of the recording head, for fixing the pulse width of P _3. By long as possible a pulse width of P ₁ at this time, to increase the discharge amount to achieve high density printing.

FIG. 37 is a block diagram for explaining the head drive control for such OHP sheets, and FIG.
8 is a timing chart of each signal in this configuration.

The pattern of the head drive signal waveform is R
It is stored in the OM 803. First, at the output timing of the head drive signal, a clock is applied to the counter 800C included in the controller of the printing apparatus, and the output of the counter is incremented by "1" every time this clock is input. As a result, the contents of the ROM 803 are output using the counter output as an address and become a head drive signal.

The head drive signal is output depending on which of the PWM control tables storing the pulse width P ₁ of the preheat pulse corresponding to each temperature is selected.
That is, as shown in FIG. 38, a head drive signal having a waveform according to the selected table is output. Which head drive signal table is selected is determined by the PWM control table selection signal input to the ROM 803. When the OHP paper selection signal is “H”, the OR gate 800A outputs the PWM table selection signal to the ROM 803. All input signals are H next, PWM table without table aN + α-1 table related to the selection signal is selected, the pulse width P ₁ of the pre-heat pulse shown at the top of FIG. 38 is a fixed value at the maximum. Specifically, P ₁ =
P _{3 was set to} 4.114 μsec at 2.618 μsec.

Further, in FIG. 38, the print ON signal is "H".
In has been described for head driving signal when the printing, when the printing ON signal is "L" (not printed), the distinction between the head driving signal pulse P ₃ shown in FIG. 38 is "L"
Become a level.

In the present embodiment, the ejection amount is increased only when the pulse width P ₁ of the preheat pulse is fixed at MAX, but the temperature control temperature of the head is raised more than usual to further increase the ejection amount. May be. Specifically, the temperature control temperature is increased from the normal 25 ° C. to 40 ° C. If the temperature is higher than this, the temperature rise during printing may be about 15 ° C., so that the limit temperature T _LIMIT of the recording head approaches 60 ° C., which is not preferable.

The above-described drive control is performed by shifting to the OHP mode processing when it is determined that the OHP mode is set when the paper type is detected, for example.

Next, another embodiment of the head drive control will be described with reference to FIGS. 39 to 41.

In FIG. 39, the image signal as the print data is stored in the RAM 805. Image signal is RAM8
When the image data is stored in 05, the CPU 800 sets the image data in the shift register 800R and generates the head drive signal. The details will be described with reference to the flowchart of FIG.

In FIG. 41, in step S1, the CPU
800 reads one pixel of image data from the RAM 805, and proceeds to step S2. In step S2, it is determined whether or not the read data of one pixel is a value to be printed, that is, whether or not ink ejection is to be performed. If printing is to be performed, the process proceeds to step S3.
Go to 9.

In step S3, the fact that the section of the main pulse width P ₃ is "H" is stored in the register 12 of the CPU 800, and the process proceeds to step S4. Step S4
In reads the PWM selection signal, the process proceeds to store the width P ₁ of the "H" level of the preheat pulse to the register 12 of the CPU800 to step S5. In step S5, the OHP selection signal is read, and the process proceeds to step S6 if the printing mode is for OHP paper, and to step S7 if the mode is for printing on paper other than OHP paper.

In step S6, the width P ₁ of the H level of the preheat pulse determined in step S4 is changed to the maximum width that can be set and stored in the register of the CPU 800,
Proceed to step S7. In step S7, the CPU
Create a head drive signal from the information of the pulse width P ₃ of the pulse width P ₁ and the main pulse of the pre-heat pulse which is stored in the 800 registers and stored in the shift register 800R, the process proceeds to step S8. The head drive signal stored in the shift register 800R is output from the shift register 800R in synchronization with a clock.

In step S8, it is determined whether all the image data stored in the RAM 805 has been output,
If all the data has been output, the process ends. If all the data has not been output, the process returns to step S1.

FIG. 42 is a waveform diagram showing drive pulses selectable in the above-mentioned PWM control.

When a general recording paper other than the recording medium having the light transmitting portion such as the OHP paper according to the embodiment of the present invention is used, the waveforms shown in FIGS. Select according to.

On the other hand, in the above-described embodiment of the present invention, when recording is performed on OHP paper, control is performed such that only the pulse indicated by 1 in FIG. 42 is used.

In the PWM control of 1 to 11 in FIG. 42, the liquid discharge amount is variably controlled by varying P ₁ and P ₂ , respectively. However, as shown by the pulse waveforms 1 and 1'in FIG. In addition, the discharge amount of the liquid can be variably controlled by changing the width of the interval P ₂ . in this case,
By setting the interval time to be long as in 1'of FIG. 42, the heat of preheating is sufficiently transmitted to the bubble generation region 11 and the movable member 31, and the effect of increasing the foaming and increasing the discharge amount of the liquid is enhanced. To be

Further, these 1 to 11 and 1'of FIG.
In the case of the PWM control, the larger bubbles are guided toward the discharge port by the presence of the movable member 31, so that the discharge amount of the liquid by the PWM control is increased as compared with the case where the conventional movable member is not provided. The rate increases.

FIG. 43 is an explanatory diagram of the relationship between the pulse waveform applied to the heating element 2 and the liquid ejection state. This figure is
This is a state corresponding to FIG. 1C, and the same reference numerals are used for each part. FIG. 43 (a) shows a liquid discharge state when the pulse waveform of 1 in FIG. 42 is applied to the heating element 2, and FIG. 43 (b)
42 shows a case where the pulse waveform 1 'in FIG. Also in FIG.
Is efficiently guided in the direction of the discharge port.
As described above, when the bubbles 40 increase due to the sufficient transfer of heat as described above, the growth of the bubbles 40 in the discharge port direction becomes more prominent than the increase in the displacement of the movable member 31, and the discharge amount becomes more growing. This is because the movement of the bubble 40 mainly includes a component in the direction of the discharge port having less resistance than the direction of the movable member 31 against the spring stress. Therefore, compared with the conventional liquid discharge head having no movable member 31, using a liquid head having a movable member 31 as in the present invention, further to control the width of the interval P ₂ between the pre-heat pulse and a main pulse As a result, FIG.
As shown by A in the figure, the rate of change of the liquid discharge amount can be made larger than B in the conventional case, and the controllability of the discharge amount is improved. Also, by controlling the width P ₁ of the pre-heat pulse, the discharge amount of change of the liquid becomes similarly large, controllability of the ejection amount is improved.

(Other Embodiments) The embodiments of the essential parts of the liquid ejection head and the liquid ejection method according to the present invention have been described above. The embodiments which can be preferably applied to these embodiments will be described below. This will be described with reference to the drawings. However, in the following description, there is a case where either one of the above-described embodiment of the one-passage form and the embodiment of the two-passage form is described. However, unless otherwise specified, the present invention is applied to both embodiments. It is a good thing.

<Ceiling Shape of Liquid Flow Path> FIG. 13 is a sectional view of the liquid discharge head of the present invention in the flow path direction.
A grooved member 50 provided with a groove for constituting 3 (or the liquid flow path 10 in FIG. 1) is provided on the separation wall 30. In the present embodiment example. The height of the flow path ceiling near the position of the free end 32 of the movable member 31 is increased, so that the operation angle θ of the movable member 31 can be increased. The operating range of the movable member 31 may be determined in consideration of the structure of the liquid flow path, the durability of the movable member 31, the bubbling force, and the like. Is considered desirable.

As shown in this figure, the discharge port 18
By making the displacement height of the free end 32 of the movable member 31 higher than the diameter of the movable member 31, a more sufficient discharge force can be transmitted. Also, as shown in this figure, the free end 3 of the movable member 31
The fulcrum 33 of the movable member 31 from the height of the liquid flow path ceiling at two positions
Since the height of the liquid flow path ceiling at the position is lower, the escape of the pressure wave to the upstream side due to the displacement of the movable member 31 can be more effectively prevented.

<Arrangement Relationship between Second Liquid Flow Path and Movable Member> FIG. 14 is a diagram for explaining the arrangement relationship between the movable member 31 and the second liquid flow path 16 described above. (a) is a view of the separation wall 30 and the vicinity of the movable member 31 as viewed from above, and (b) is a view of the second liquid flow path 16 with the separation wall 30 removed as viewed from above. FIG. 3C is a diagram schematically showing the arrangement relationship between the movable member 6 and the second liquid flow path 16 by overlapping these elements. In each of the drawings, the lower part of the drawing is the front side where the discharge port 18 is arranged.

The second liquid flow path 16 of the present embodiment is the upstream side of the heating element 2 (the upstream side here refers to the heating element position, the movable member, and the first flow path from the second common liquid chamber side). The upstream side of the large flow toward the discharge port) has a narrowed portion 19 so that the pressure at the time of foaming is prevented from easily escaping to the upstream side of the second liquid flow path 16. It has a unique chamber (foaming chamber) structure.

As in the conventional head, the flow path for bubbling and the flow path for discharging the liquid are the same, and the constricted portion is formed so that the pressure generated on the liquid chamber side from the heating element does not escape to the common liquid chamber side. In the case of the head provided with the above, it is necessary to adopt a configuration in which the cross-sectional area of the flow path in the constricted portion does not become so small in consideration of liquid refilling.

However, in the case of this embodiment, most of the discharged liquid can be used as the discharge liquid in the first liquid flow path,
Since the foaming liquid in the second liquid flow path provided with the heating element 2 can be prevented from being consumed so much, the filling amount of the foaming liquid into the bubble generation region 11 of the second liquid flow path may be small. Therefore, since the interval in the constricted portion 19 can be made very small, that is, several μm to several tens of μm, it is possible to further suppress the pressure at the time of foaming generated in the second liquid flow path from being released too much to the surroundings, and to concentrate and move. It can be directed to the member 31 side. Since this pressure can be used as the discharge force via the movable member 31, higher discharge efficiency and discharge force can be achieved. However, the shape of the first liquid flow path 16 is not limited to the above-mentioned structure, and may be any shape as long as the pressure associated with bubble generation is effectively transmitted to the movable member 31 side.

As shown in FIG. 14 (c), the side of the movable member 31 covers a part of the wall forming the second liquid flow path, whereby the second side of the movable member 31 is covered. It is possible to prevent the liquid from flowing into the liquid channel. This can further enhance the separability between the ejection liquid and the foaming liquid described above. In addition, since the escape of bubbles from the slits can be suppressed, the discharge pressure and the discharge efficiency can be further increased. further,
The effect of the refill from the upstream side by the pressure at the time of the defoaming can be enhanced.

Incidentally, in FIG. 12B and FIG.
Some of the bubbles generated in the bubble generation region of the second liquid flow path 4 along with the displacement of the movable member 31 toward the first liquid flow path 14 extend toward the first liquid flow path 14. However, by setting the height of the second flow path such that the bubbles extend as described above, the ejection force can be further improved as compared with the case where the bubbles do not extend. In order for the bubbles to extend into the first liquid flow path 14 in this manner, it is desirable that the height of the second liquid flow path 16 be lower than the height of the maximum bubble. μm to 3
Desirably, it is 0 μm. In this embodiment, the height is set to 15 μm.

<Movable Member and Separation Wall> FIG. 15 shows another shape of the movable member 31. Reference numeral 35 is a slit provided in the separation wall, and the slit forms the movable member 31. . FIG. 7A shows a rectangular shape, FIG. 7B shows a shape in which the fulcrum side is narrower and the movable member 31 is easy to operate, and FIG. The shape is such that the durability of the member 31 is improved. As a shape having good easiness of operation and durability, a shape in which the width on the fulcrum side is narrowed in an arc shape as shown in FIG. 14A is desirable, but the shape of the movable member 31 is the second shape. Any shape may be used as long as it has a shape that can easily operate without entering the liquid flow path side and has excellent durability.

In the previous embodiment, the plate-shaped movable member 31 and the separating wall 5 having this movable member 31 have a thickness of 5 mm.
Although the movable member 31 and the separation wall 5 are formed of nickel having a thickness of μm, the material constituting the movable member 31 and the separation wall 5 has solvent resistance to the foaming liquid and the discharge liquid, and works well as the movable member 31. Any material may be used as long as it has the above elasticity and can form fine slits.

As the material of the movable member 31, silver, nickel, gold, iron, titanium, aluminum, which has high durability,
Metals such as platinum, tantalum, stainless steel, phosphor bronze, and their alloys, or acrylonitrile, butadiene,
Resin having a nitrile group such as styrene, resin having an amide group such as polyamide, resin having a carboxyl group such as polycarbonate, resin having an aldehyde group such as polyacetal, resin having a sulfone group such as polysulfone, and other liquid crystal polymers. Resins and their compounds,
Metals with high ink resistance such as gold, tungsten, tantalum, nickel, stainless steel, and titanium, alloys of these, and those having ink resistance coated on the surface, resins having amide groups such as polyamide, polyacetal, etc. Resin having aldehyde group, resin having ketone group such as polyetheretherketone, resin having imide group such as polyimide, resin having hydroxyl group such as phenol resin, resin having ethyl group such as polyethylene, alkyl such as polypropylene Resin with a base,
A resin having an epoxy group such as an epoxy resin, a resin having an amino group such as a melamine resin, a resin having a methylol group such as a xylene resin and a compound thereof, and a ceramic such as silicon dioxide and a compound thereof are desirable. Examples of the material of the separation wall include polyethylene, polypropylene, polyamide, polyethylene terephthalate, melamine resin, phenol resin, epoxy resin, polybutadiene, polyurethane, polyetheretherketone, polyethersulfone, polyarylate, polyimide, polysulfone, and liquid crystal polymer (LCP). ) And other resins with good heat resistance, solvent resistance, and moldability represented by engineering plastics, and compounds thereof, or metals such as silicon dioxide, silicon nitride, nickel, gold, and stainless steel;
Alloys and their compounds, or those coated with titanium or gold on the surface are desirable.

The thickness of the separation wall may be determined in consideration of its material, shape, etc. from the viewpoint that the strength as the separation wall can be achieved and the movable member can operate satisfactorily.
A thickness of about 0.5 to 10 μm is desirable.

The width of the slit 35 for forming the movable member 31 is 2 μm in the present embodiment, but when the bubbling liquid and the discharge liquid are different liquids and it is desired to prevent the mixture of both liquids, The slit width may be set to an interval such that a meniscus is formed between the two liquids to suppress the flow of the respective liquids. For example, when a liquid of about 2 cP (centipoise) is used as the foaming liquid and a liquid of 100 cP or more is used as the discharge liquid, the liquid mixture can be prevented even with a slit of about 5 μm, but it is preferable that the slit be 3 μm or less. .

As the movable member 31 in the present invention, μm
The thickness is on the order of order (t μm), and the movable member 31 having a thickness on the order of cm is not intended. For the movable member 31 having a thickness on the order of μm, when a slit width (Wμm) on the order of μm is to be targeted, it is desirable to consider manufacturing variations to some extent.

When the thickness of the member facing the free end 32 and / or the side end of the movable member 31 forming the slit is equal to the thickness of the movable member 31 (FIG. 12, FIG. 13, etc.), the relationship between the slit width and the thickness. By considering the manufacturing variation in the following range, it is possible to stably suppress the mixture of the foaming liquid and the discharge liquid. Although this is a limited condition, when a high-viscosity ink (5 cp, 10 cp, etc.) is used for a foaming liquid having a viscosity of 3 cp or less, W / t ≦ 1 is satisfied from a design viewpoint. As a result, a configuration in which the mixing of the two liquids can be suppressed for a long period of time was obtained.

The slit providing the "substantially closed state" of the present invention is more certain if it is on the order of several μm.

As described above, when the foaming liquid and the discharge liquid are functionally separated, the movable member 31 serves as a substantial partitioning member for these. When the movable member 31 moves along with the generation of bubbles, it can be seen that the foaming liquid slightly mixes with the discharge liquid. In consideration of the fact that an ejection liquid for forming an image generally has a colorant density of about 3% to 5% in the case of ink jet recording, this foaming liquid is in a range of 20% or less with respect to the ejection droplet. Does not cause a large change in concentration. Therefore, the present invention includes such a mixed liquid as a mixture of a foaming liquid and an ejected liquid such that the amount thereof is 20% or less of the ejected liquid droplets.

In the implementation of the above configuration example, the foaming liquid is mixed at an upper limit of 15% even if the viscosity is changed. For a foaming liquid of 5 cP or less, this mixing ratio depends on the driving frequency, but is 10%. The upper limit was about%.

In particular, as the viscosity of the discharge liquid is set to 20 cP or less, this mixed liquid can be reduced (for example, 5% or less).

Next, the positional relationship between the heating element 2 and the movable member 31 in this head will be described with reference to the drawings. However, the shapes, dimensions, and numbers of the movable member 31 and the heating element 2 are not limited to the following. The optimal arrangement of the heating element 2 and the movable member 31 makes it possible to effectively use the pressure at the time of bubbling by the heating element 2 as the discharge pressure.
By giving energy such as heat to the ink, the ink undergoes a sharp volume change (generation of bubbles), and the ink is ejected from the ejection port by the action force based on this state change. In a conventional technique of an ink jet recording method in which an image is formed by being attached to a medium, that is, a so-called bubble jet recording method, as shown in FIG. 16, the area of the heating element 2 and the ink ejection amount are in a proportional relationship, but the ink ejection is performed. It can be seen that there is a non-foaming effective area S that does not contribute to In addition, from the appearance of the kogation on the heating element 2, it can be seen that the non-foaming effective area S exists around the heating element 2. From these results, it is considered that the width of about 4 μm around the heating element 2 is not involved in foaming.

Therefore, in order to effectively utilize the foaming pressure, the movable area of the movable member 31 covers the area immediately above the effective foaming area of about 4 μm or more from the periphery of the heating element 2.
It can be said that the arrangement of the movable member 31 is effective.
In the present embodiment, the effective foaming area is at least about 4 μm inward from the periphery of the heating element 2, but is not limited to this depending on the type of heating element 2 and the forming method.

FIG. 17 shows a movable member 301 ((a) having a total movable area different from that of the heating element 2 of 58 × 150 μm.
FIG. 2 is a schematic diagram viewed from above when the movable member 302 (FIG. 2B) is arranged.

The dimension of the movable member 301 is 53 × 145 μm.
m, which is smaller than the area of the heating element 2, but approximately the same as the effective foaming area of the heating element 2, and is arranged so as to cover the effective foaming area. On the other hand, the size of the movable member 302 is 53 × 220 μm, which is larger than the area of the heating element 2 (when the width is the same, the dimension between the fulcrum and the movable tip is longer than the length of the heating element). It is arranged so as to cover the effective foaming area in the same manner as the above. 2 above
The durability and discharge efficiency of the movable members 301 and 302 were measured. The measurement conditions are as follows.

Foaming liquid: 40% aqueous solution of ethanol Discharge ink: dye ink Voltage: 20.2 V Frequency: 3 kHz As a result of an experiment performed under these measurement conditions, regarding the durability of the movable member, (a) the movable member 301 In the case of 1 × 10 ⁷ pulses, the fulcrum of the movable member 301 was damaged when 1 × 10 ⁷ pulses were applied. (B) 3 × 10 ^{8 for the} movable member 302
No damage was seen when the pulse was applied. It was also confirmed that the kinetic energy based on the discharge amount and the discharge speed with respect to the input energy was improved by about 1.5 to 2.5 times.

From the above results, it can be seen from the viewpoint of both durability and discharge efficiency that the movable member is provided so as to cover directly above the effective foaming area, and that the area of the movable member is larger than the area of the heating element. It turns out that it is excellent.

FIG. 18 shows the movable member 3 from the edge of the heating element 2.
The relationship between the distance to one fulcrum and the amount of displacement of the movable member 31 is shown. FIG. 19 is a cross-sectional view showing the positional relationship between the heating element 2 and the movable member 31 as viewed from the side. Heating element 2
Used was 40 × 105 μm. As the distance l from the edge of the heating element 2 to the fulcrum 33 of the movable member 31 increases,
It can be seen that the displacement amount is large. Therefore, it is desirable to determine the optimal displacement amount and determine the fulcrum 33 position of the movable member 31 based on the required ink ejection amount, the ejection liquid flow path structure, and the shape of the heating element.

Also, the fulcrum 33 of the movable member 31 is the heating element 2.
In the case where the movable member 31 is located just above the effective foaming area, the foaming pressure is directly applied to the fulcrum in addition to the stress caused by the displacement of the movable member 31, so that the durability of the movable member 31 is reduced. According to the experiment of the present inventor, it was found that, in the case where the fulcrum was provided right above the effective foaming area, the movable wall was damaged by about 1 × 10 ⁶ pulses, and the durability was reduced. I have. Therefore, by arranging the fulcrum 33 of the movable member 31 just above the effective foaming area of the heating element 2, the practicability increases even if the movable member 31 has a shape or material whose durability is not so high. However, even if there is a fulcrum just above the effective foaming area, it can be used favorably if the shape and material are selected. With this configuration, a liquid ejection head having high ejection efficiency and excellent durability can be obtained.

<Element Substrate> The structure of the element substrate provided with a heating element for applying heat to the liquid will be described below.

FIG. 20 is a vertical sectional view of a liquid discharge head of the present invention. FIG. 20 (a) shows a head having a protective film described later, and FIG. 20 (b) shows one without a protective film.

On the element substrate 1, the second liquid flow path 16, the separation wall 3
0, a first liquid flow path 14, and a grooved member 50 provided with grooves forming the first liquid flow path.

A gas 107 such as silicon is provided on the element substrate 1.
A silicon oxide film or a silicon nitride film 106 for the purpose of insulation and heat storage is formed thereon, and hafnium boride (HfB ₂ ), tantalum nitride (TaN), tantalum aluminum ( An electric resistance layer 105 (having a thickness of 0.01 to 0.2 μm) such as TaAl) and a wiring electrode (having a thickness of 0.2 to 1.0 μm) such as aluminum are patterned as shown in FIG. These two wiring electrodes 1
From 04, a voltage is applied to the resistance layer 105, and a current flows through the resistance layer to generate heat. On the resistance layer between the wiring electrodes, a protective layer of 0.1 to 2.0 μm of silicon oxide or silicon nitride is formed.
A cavitation-resistant layer (0.1 to 0.6 μm thick) of tantalum or the like is further formed thereon to protect the resistance layer 105 from various liquids such as ink.

In particular, the pressure and shock waves generated when bubbles are generated and defoamed are extremely strong, and the durability of a hard and brittle oxide film is significantly reduced.
Are used as a cavitation-resistant layer.

Further, a constitution in which the above-mentioned protective layer is not necessary depending on the combination of liquid, liquid flow channel constitution and resistance material is shown in FIG. 20 (b). Examples of the material of the resistance layer that does not require such a protective layer include an iridium-tantalum-aluminum alloy.

As described above, the structure of the heating element in each of the above-described embodiments may be only the resistance layer (heat generating portion) between the electrodes described above, or may include a protective layer for protecting the resistance layer. .

In the present embodiment, as the heating element 2, the one having the heating portion composed of the resistance layer which generates heat in response to the electric signal is used, but the present invention is not limited to this, and the discharging liquid is discharged. What is necessary is just to generate sufficient bubbles in the foaming liquid. For example, a light-to-heat converter that generates heat by receiving light from a laser or the like, or a heat generator that has a heat generating unit that generates heat by receiving a high frequency may be used as the heat generating unit.

The above-mentioned element substrate 1 includes, in addition to the electrothermal transducer composed of the above-described resistance layer 105 constituting the heating section and the wiring electrode 104 for supplying an electric signal to this resistance layer, Functional elements such as a transistor, a diode, a latch, and a shift register for selectively driving the electrothermal conversion element may be integrally formed by a semiconductor manufacturing process.

Further, in order to drive the heat generating portion of the electrothermal converter provided on the element substrate 1 as described above and eject the liquid, the resistance layer 105 is connected to the resistance layer 105 via the wiring electrode 104 as shown in FIG. A rectangular pulse as shown by is applied to rapidly generate heat in the resistance layer 105 between the wiring electrodes.

<Head Structure with Two Flow Channels> A liquid discharge that can satisfactorily separate and introduce different liquids into the first and second common liquid chambers, can reduce the number of parts, and can reduce the cost. An example of the structure of the head will be described.

FIG. 22 is a schematic diagram showing the structure of such a liquid discharge head, and the same reference numerals are used for the same components as those of the previous embodiment, and detailed description thereof will be omitted here.

In this embodiment, the grooved member 50 is used.
Communicates in common with the orifice plate 51 having the discharge port 18, the plurality of grooves constituting the plurality of first liquid flow paths 14, and the plurality of liquid flow paths 14, and communicates with each of the first liquid flow paths 3. And a recess forming a first common liquid chamber 15 for supplying a liquid (ejection liquid).

The separation wall 30 is provided below the grooved member 50.
Can be formed to form a plurality of first liquid flow paths 14. Such a grooved member 50 has a first liquid supply path 20 that reaches the inside of the first common liquid chamber 15 from above. Further, the grooved member 50 penetrates the separation wall 30 from the upper part thereof and reaches the second common liquid chamber 17 in the second common liquid chamber 17.
The liquid supply path 21 of FIG.

The first liquid (discharge liquid) is the arrow C in FIG.
As shown in FIG. 22, the liquid is supplied to the first common liquid chamber 15 and then to the first liquid flow path 14 via the first liquid supply path 20, and the second liquid (foaming liquid) is indicated by an arrow D in FIG. As shown, the second
The second common liquid chamber 17 and then the second common liquid chamber 17 via the liquid supply passage 21.
The liquid is supplied to the liquid flow path 16.

In this embodiment, the second liquid supply passage 21
Is arranged in parallel with the first liquid supply passage 20, but is not limited to this, penetrates the separation wall 30 arranged outside the first common liquid chamber 15, and 17 may be arranged in any way as long as it is formed so as to communicate with 17.

The thickness (diameter) of the second liquid supply passage 21
Is determined in consideration of the supply amount of the second liquid.
The shape of the second liquid supply path 21 does not need to be round,
It may be rectangular or the like.

The second common liquid chamber 17 has the grooved member 50.
By the partition wall 30. As a forming method, as shown in an exploded perspective view of this embodiment example shown in FIG. 23, a common liquid chamber frame and a second liquid path wall are formed on an element substrate with a dry film, and a groove with fixed separation walls is formed. By bonding the combined body of the member 50 and the separation wall 30 to the element substrate 1, the second common liquid chamber 17 and the second liquid flow path 16 are bonded.
May be formed.

In the present embodiment, as described above, as the heating element 2 for generating heat for generating bubbles due to film boiling in the foaming liquid, on the support 70 formed of a metal such as aluminum. An element substrate 1 provided with a plurality of electrothermal conversion elements is arranged. On the element substrate 1, the plurality of grooves forming the liquid flow path 16 formed by the second liquid path wall are communicated with the plurality of foaming liquid flow paths, and the foaming liquid is supplied to the respective foaming liquid paths. The recessed portion that constitutes the second common liquid chamber (common bubbling liquid chamber) 17 and the separation wall 30 provided with the movable wall 31 described above are arranged.

Reference numeral 50 is a grooved member. The grooved member is joined to the separation wall 30 to form a discharge liquid flow path (first
A first common liquid chamber (common discharge liquid chamber) 15 which communicates with the groove forming the liquid flow path) 14 and the discharge liquid flow path to supply the discharge liquid to each discharge liquid flow path; Of the recess,
A first supply path (discharge liquid supply path) 20 for supplying discharge liquid to the first common liquid chamber, and a second supply path (foam liquid supply) for supplying foaming liquid to the second common liquid chamber 17. (Road) 21. The second supply passage 21 penetrates the separation wall 30 disposed outside the first common liquid chamber 15 and
7, the foaming liquid is not mixed with the discharge liquid by the communication path, and the foamed liquid is mixed with the second common liquid chamber 1.
5 can be supplied.

The arrangement relationship among the element substrate 1, the separation wall 30, and the grooved top plate 50 is that the movable member 31 is arranged corresponding to the heating element 2 of the element substrate 1, and corresponds to this movable member 31. The discharge liquid flow path 14 is arranged. Further, in the present embodiment, an example in which one second supply path is arranged in the grooved member is shown, but a plurality of second supply paths may be provided depending on the supply amount. Furthermore, the flow path cross-sectional area of the discharge liquid supply path 20 and the foaming liquid supply path 21 may be determined in proportion to the supply amount.

By optimizing the flow path cross-sectional area as described above, it is possible to further reduce the size of the parts constituting the grooved member 50 and the like.

As described above, according to the present embodiment, the second supply passage for supplying the second liquid to the second liquid passage,
Since the first supply path for supplying the first liquid to the first liquid flow path is formed of the same grooved top plate as the grooved member, the number of parts can be reduced, and the process can be shortened and the cost can be reduced. Become.

Further, the supply of the second liquid to the second common liquid chamber communicating with the second liquid flow passage is performed by the second liquid flow passage in the direction of penetrating the separation wall for separating the first liquid and the second liquid. Since the structure is performed, the step of attaching the separating wall, the grooved member, and the heating element forming substrate only needs to be performed once, and the easiness of making is improved, the attaching accuracy is improved, and good ejection is achieved. You can

Further, since the second liquid penetrates the separation wall and is supplied to the second liquid common liquid chamber, the second liquid can be reliably supplied to the second liquid flow path, and a sufficient supply amount can be secured.
Stable discharge is possible.

<Discharging Liquid, Foaming Liquid> As described in the above embodiment, in the present invention, due to the structure having the movable member 31 as described above, the discharging force and the discharging efficiency higher than those of the conventional liquid discharging head are obtained. Moreover, the liquid can be discharged at high speed. When the same liquid is used as the foaming liquid and the discharge liquid in the embodiment, the heat is not deteriorated by the heat applied from the heating element 2 and the deposit is hardly generated on the heating element 2 by heating. Thus, a reversible state change of vaporization and condensation can be performed, and various liquids can be used as long as the liquid does not deteriorate the liquid flow path, the movable member 31, the separation wall, and the like.

Among such liquids, as the liquid used for recording (recording liquid), the ink having the composition used in the conventional bubble jet device can be used.

On the other hand, when the head having the two-channel structure of the present invention is used and the discharge liquid and the foaming liquid are different liquids, the liquid having the above-mentioned properties may be used as the foaming liquid. , Methanol, ethanol, n-propanol, isopropanol, n-hexane, n-heptane, n-octane, toluene, xylene, methylene dichloride, trichlene, Freon TF, Freon BF, ethyl ether, dioxane, cyclohexane, methyl acetate, acetic acid ethyl,
Examples include acetone, methyl ethyl ketone, water, and the like, and mixtures thereof.

As the discharge liquid, various liquids can be used regardless of the presence or absence of foaming property and the thermal property. In addition, liquids having low foaming properties, liquids which are easily deteriorated or deteriorated by heat, high-viscosity liquids, and the like, which have been difficult to discharge conventionally, can be used.

However, as the properties of the discharge liquid, the discharge liquid itself,
Alternatively, it is desirable that the liquid is not a liquid that hinders ejection, foaming, operation of the movable member, or the like due to a reaction with the foaming liquid.

High-viscosity ink or the like can be used as the ejection liquid for recording. As other discharge liquids, liquids such as medicines and perfumes that are vulnerable to heat can be used.

In the present invention, recording was performed using an ink having the following composition as a recording liquid that can be used as both a discharge liquid and a foaming liquid. As a result, the droplet landing accuracy was improved and a very good recorded image could be obtained.

Composition of dye ink (viscosity 2 cP) (CI Food Black 2) Dye 3% by weight Diethylene glycol 10% by weight Thiodiglycol 5% by weight Ethanol 5% by weight Water 77% by weight Recording was performed by ejecting a combination of liquids having the compositions shown below. As a result, it was possible to satisfactorily eject a liquid having a viscosity as high as 150 cP as well as a liquid having a viscosity of more than 10 cP, which was difficult to eject with a conventional head, and to obtain a high-quality recorded matter.

Composition of foaming liquid 1 Ethanol 40% by weight Water 60% by weight Composition of foaming liquid 2 Water 100% by weight Composition of foaming liquid 3 Isopropyl alcohol 10% by weight Water 90% by weight Discharge liquid 1 Pigment ink (viscosity about 15 cP) Composition Carbon black 5% by weight Styrene-acrylic acid-ethyl acrylate copolymer 1% by weight (acid value 140, weight average molecular weight 8000) Monoethanolamine 0.25% by weight Glycerin 69% by weight Thiodiglycol 5% by weight Ethanol 3 % By weight Water 16.75% by weight Composition of ejection liquid 2 (viscosity 55 cP) Polyethylene glycol 200 100% by weight Composition of ejection liquid 3 (viscosity 150 cP) Polyethylene glycol 600 100% by weight By the way, it is said that the conventional ejection is difficult. If the liquid used was Because, the conducive variation in ejection directionality is poor landing accuracy of the dot on the recording paper, also by variation in the discharge amount due to unstable discharge occurs in these, high-quality image was difficult to obtain. However, in the configuration of the above-described embodiment, it is possible to generate bubbles sufficiently and stably by using the foaming liquid. As a result, it is possible to improve the landing accuracy of the droplets and stabilize the ink discharge amount, and it is possible to remarkably improve the quality of the recorded image.

<Manufacturing of Liquid Discharging Head> Next, the manufacturing process of the liquid discharging head of the present invention will be described.

In the case of the liquid discharge head as shown in FIG. 2, a base 34 for providing the movable member 31 on the element substrate 1 is formed by patterning a dry film or the like, and the movable member is mounted on the base 34. 31 was adhered or fixed by welding. Thereafter, a grooved member having a plurality of grooves constituting each liquid flow path 10, a discharge port 18, and a concave part constituting the common liquid chamber 13 is joined to the element substrate 1 in a state where the grooves correspond to the movable members 31. It was formed by doing.

Next, as shown in FIG. 10 and FIG.
The manufacturing process of the liquid discharge head having the flow path configuration will be described.

Roughly speaking, the second liquid flow path 1 is formed on the element substrate 1.
6, a separation wall 30 is mounted thereon, and a grooved member 50 provided with a groove or the like constituting the first liquid flow path 14 is further mounted thereon. Alternatively, the second liquid flow path 1
After forming the wall of No. 6, the head was manufactured by joining the grooved member 50 on which the separation wall 30 was attached to the wall.

Further, the method for producing the second liquid flow path will be described in detail.

24 (a) to 24 (e) are schematic sectional views for explaining the first embodiment of the method of manufacturing a liquid discharge head of the present invention.

In this embodiment, as shown in (a), using a manufacturing apparatus similar to that used in the semiconductor manufacturing process on the element substrate (silicon wafer) 1, hafnium boride, tantalum nitride, or the like is used. After forming the electrothermal conversion element having the heating element 2, the surface of the element substrate 1 was washed for the purpose of improving the adhesion with the photosensitive resin in the next step. Further, in order to improve the adhesion, after performing surface modification on the surface of the element substrate 1 with ultraviolet-ozone or the like,
For example, a silane coupling agent (manufactured by Nippon Yunika: A18
This is achieved by spin-coating a liquid obtained by diluting 9) to 1% by weight with ethyl alcohol on the modified surface.

Next, as shown in (b), an ultraviolet-sensitive resin film (manufactured by Tokyo Ohka: Dry Film Audyl SY) was washed on the surface of the substrate 1 having improved adhesion.
-318) DF was laminated.

Next, as shown in (c), a photomask PM is arranged on the dry film DF, and the portion of the dry film DF left as the second flow path wall is exposed to ultraviolet rays through the photomask PM. Was irradiated. This exposure step
Manufactured by Canon Inc .: MPA-600, about 6
The exposure amount was 00 mJ / cm ² .

Next, as shown in (d), the dry film DF is developed with a developing solution (BMRC-3 manufactured by Tokyo Ohka Kabushiki Kaisha) made of a mixed solution of xylene and butyl cellosolve acetate, and the unexposed portion is exposed. The portion which was dissolved, exposed and cured was formed as the wall portion of the second liquid flow path 16. Further, the residue remaining on the surface of the element substrate 1 is removed by treating it with an oxygen plasma ashing apparatus (MAS-800, manufactured by Alcantech) for about 90 seconds, and subsequently, at 150 ° C. for 2 hours, and further 100 mJ / cm ^{2 of} ultraviolet irradiation. The exposure was completely cured.

By the above method, the second liquid flow path can be uniformly and accurately formed on a plurality of heater boards (element substrates) divided and manufactured from the silicon substrate. A dicing machine (manufactured by Tokyo Seimitsu:
(AWD-4000) to cut and separate each heater board 1. An adhesive (made by Toray:
(SE4400) on the aluminum base plate 70 (FIG. 27). Next, the aluminum base plate 70
An aluminum wire (not shown) having a diameter of 0.05 mm is formed by connecting the printed wiring board 71 bonded above and the heater board 1 to each other.
Connected with.

Next, as shown in FIG. 24 (e), the joined body of the grooved member 50 and the separating wall 30 was positioned and joined to the heater board 1 thus obtained, as shown in FIG.
That is, the grooved member having the separating wall 30 and the heater board 1 are positioned and engaged and fixed by the pressing spring 78, and then the ink / foaming liquid supply member 80 is joined and fixed on the aluminum base plate 70, and the aluminum wire is fixed. , Grooved member 50, heater board 1, and ink / foaming liquid supply member 80
Silicone sealant (Toshiba Silicone:
It was completed by sealing with TSE399).

By forming the second liquid flow path by the above manufacturing method, it is possible to obtain a highly accurate flow path with no positional deviation with respect to the heater of each heater board. In particular, by joining the grooved member 50 and the separation wall 30 in the previous step in advance, the positional accuracy of the first liquid flow path 14 and the movable member 31 can be improved.

By these high-precision manufacturing techniques, the ejection is stabilized and the printing quality is improved. Further, since it can be formed on a wafer all at once, a large amount can be manufactured at low cost.

In this example, an ultraviolet-curable dry film was used to form the second liquid flow path.
It can also be obtained by using a resin having an absorption band in the ultraviolet region, particularly around 248 nm, curing after laminating, and directly removing the resin in a portion serving as the second liquid flow path with an excimer laser.

25 (a) to 25 (d) are schematic sectional views for explaining the second embodiment of the method for manufacturing a liquid discharge head of the present invention.

In this example, as shown in (a), the resist 10 having a thickness of 15 μm was formed on the SUS substrate 100.
1 was patterned in the shape of the second liquid flow path.

Next, as shown in (b), the SUS substrate 1
00 was electroplated to grow a nickel layer 102 on the SUS substrate 100 by 15 μm. As a plating solution, a stress reducing agent (manufactured by World Metal Co., Ltd .: Zerool), boric acid, a pit inhibitor (World Metal Co., Ltd .: NP-APS), and nickel chloride were used in nickel sulphomate. As for the method of applying an electric field at the time of electrodeposition, an electrode was attached to the anode side, the already patterned SUS substrate 100 was attached to the cathode side, and the temperature of the plating solution was set to 50 ° C.
And the current density was 5 A / cm ² .

Next, as shown in (c), an ultrasonic vibration is applied to the SUS substrate 100 which has been plated as described above, and the nickel layer 102 is peeled off from the SUS substrate 100, and the desired second A liquid flow path was obtained.

On the other hand, a heater board provided with an electrothermal conversion element was formed on a silicon wafer using the same manufacturing apparatus as that for semiconductors. This wafer was separated into each heater board by a dicing machine as in the previous embodiment. The heater board 1 is joined to an aluminum base plate 70 to which a printed board 104 has been joined in advance, and the printed board 7
1 and an aluminum wire (not shown) to form an electrical wiring. On the heater board 1 in such a state, as shown in FIG. 25D, the second liquid flow path obtained in the previous step was positioned and fixed. At the time of this fixing, as in the first embodiment, since the top plate on which the separation wall is fixed is engaged with and tightly attached to the top plate by the pressing spring in the subsequent step, it is fixed to the extent that no positional displacement occurs at the time of joining the top plate. Is enough.

In this embodiment, an ultraviolet curable adhesive (made by Grace Japan: Amicon UV-3 is used for the positioning and fixing.
00), and using an ultraviolet irradiation device, the exposure amount is 10
Fixation was completed in about 3 seconds at 0 mJ / cm ² .

According to the manufacturing method of this embodiment, it is possible to obtain a highly accurate second liquid flow path with no positional deviation with respect to the heating element, and since the flow path wall is formed of nickel, It is possible to provide a highly reliable head that is resistant to alkaline liquids.

FIGS. 26A to 26D are schematic sectional views for explaining the third embodiment of the method of manufacturing a liquid discharge head of the present invention.

In this example, as shown in (a), a resist 31 was applied to both sides of a 15 μm thick SUS substrate 100 having alignment holes or marks 100a. Here, as the resist, P made by Tokyo Ohka
MERP-AR900 was used.

Thereafter, as shown in (b), the element substrate 1
Exposure was performed using an exposure apparatus (MPA-600, manufactured by Canon Inc.) in accordance with the alignment hole 100a of No. 00, and the resist 103 in the portion where the second liquid flow path was to be formed was removed. The exposure was performed at an exposure amount of 800 mJ / cm ² .

Next, as shown in (c), the SUS substrate 100 having the resist 103 on both sides patterned is immersed in an etching solution (an aqueous solution of ferric chloride or cupric chloride) to expose it from the resist 103. After etching the affected portion, the resist was peeled off.

Next, as shown in (d), the etched SUS substrate 100 is positioned and fixed on the heater board 1 and the second liquid flow path 4 is formed in the same manner as in the above embodiment of the manufacturing method. Was assembled.

According to the manufacturing method of this embodiment, the second liquid flow path 4 can be obtained with high accuracy without any positional deviation with respect to the heater. In addition, since the flow path is formed of SUS, acid or alkaline And a highly reliable liquid ejection head can be provided.

As described above, according to the manufacturing method of this embodiment, the electrothermal transducer and the second liquid flow path are formed by disposing the walls of the second liquid flow path in advance on the element substrate. Positioning can be performed with high accuracy. Further, since the second liquid flow paths can be simultaneously formed on a large number of element substrates on the substrate before cutting and separating, it is possible to provide a large amount and low cost of the liquid ejection head.

Further, in the liquid discharge head obtained by carrying out the method of manufacturing the liquid discharge head of the manufacturing method of this embodiment, since the heating element and the second liquid flow path are positioned with high precision, The pressure of foaming due to the heat generation of the electrothermal converter can be efficiently received, and the discharge efficiency becomes excellent.

<Liquid Ejection Head Cartridge> Next, a liquid ejection head cartridge equipped with the liquid ejection head according to the above-described embodiment will be schematically described.

FIG. 27 is a schematic exploded perspective view of a liquid discharge head cartridge including the above-described liquid discharge head. The liquid discharge head cartridge is mainly composed of a liquid discharge head portion 200 and a liquid container 80. There is.

The liquid discharge head section 200 comprises the element substrate 1,
It comprises a separation wall 30, a grooved member 50, a pressing spring 78, a liquid supply member 90, a support 70 and the like. As described above, the element substrate 1 is provided with a plurality of heating resistors for applying heat to the foaming liquid in a row, and a functional element for selectively driving the heating resistors. Are provided. This element substrate 1 and the aforementioned separation wall 3 having a movable wall
0, a foaming liquid passage is formed, and the foaming liquid flows. By joining the separation wall 30 and the grooved top plate 50, a discharge flow path (not shown) through which the discharged liquid to be discharged flows is formed.

The pressing spring 78 is a member for exerting an urging force on the grooved member 50 in the direction of the element substrate 1, and the urging force causes the element substrate 1, the separation wall 30, the grooved member 50, and a support member described later. 70 and 70 are well integrated.

The support body 70 is for supporting the element substrate 1 and the like, and on the support body 70, a circuit board 71 for connecting to the element substrate 1 and supplying an electric signal,
Contact pads 72 are provided for exchanging electrical signals with the device side by connecting to the device side.

The liquid container 90 contains the ejection liquid such as ink and the bubbling liquid for generating bubbles, which are supplied to the liquid ejection head, separately. Outside the liquid container 90, a positioning portion 94 for arranging a connection member for connecting the liquid ejection head and the liquid container and a fixed shaft 95 for fixing the connection portion are provided. The discharge liquid is supplied from the discharge liquid supply path 92 of the liquid container to the discharge liquid supply path 81 of the liquid supply member 80 via the supply path 84 of the connection member.
And the discharge liquid supply paths 83, 71, 21 of each member
To the first common liquid chamber. Similarly, the foaming liquid is supplied from the supply path 93 of the liquid container to the foaming liquid supply path 82 of the liquid supply member 80 via the supply path of the connecting member, and is supplied via the foaming liquid supply paths 84, 71, and 22 of the respective members. The liquid is supplied to the second liquid chamber.

In the liquid ejection head cartridge described above, the supply form and the liquid container capable of supplying even when the bubbling liquid and the ejection liquid are different liquids have been described. However, when the ejection liquid and the bubbling liquid are the same. In addition, it is not necessary to separate the supply path and container for the foaming liquid and the discharge liquid.

The liquid container may be refilled with the liquid after the consumption of each liquid. For this purpose, it is desirable to provide a liquid inlet in the liquid container. Further, the liquid discharge head and the liquid container may be integrated or may be separable.

<Liquid Ejecting Device> FIG. 28 shows a schematic structure of a liquid ejecting device equipped with the above-mentioned liquid ejecting head. In the present embodiment, a carriage HC of a liquid ejection apparatus, which will be described using an ink ejection recording apparatus using ink as an ejection liquid, is a head cartridge in which a liquid tank section 90 containing ink and a liquid ejection head section 200 are detachable. And reciprocate in the width direction of the recording medium 150 such as recording paper conveyed by the recording medium conveying means.

When a drive signal is supplied from the drive signal supply means (not shown) to the liquid discharge means on the carriage, the recording liquid is discharged from the liquid discharge head onto the recording medium in response to this signal.

Further, in the liquid ejecting apparatus of this embodiment, the motor 111 as a drive source for driving the recording medium conveying means and the carriage, and the gears 112, 113 carriage for transmitting the power from the drive source to the carriage. It has a shaft 115 and the like. With this recording apparatus and the liquid ejection method performed by this recording apparatus, a recorded matter of a good image could be obtained by ejecting liquid to various recording media.

FIG. 29 is a block diagram of the entire apparatus for operating ink discharge recording to which the liquid discharge method and liquid discharge head of the present invention are applied.

The recording apparatus receives print information as a control signal from the host computer 300. The print information is temporarily stored in an input interface 301 inside the printing apparatus, and at the same time, is converted into data that can be processed in the printing apparatus, and is input to the CPU 302 also serving as a head drive signal supply unit. The CPU 302 processes data input to the CPU 302 using a peripheral unit such as the RAM 304 based on a control program stored in the ROM 303,
Convert to print data (image data).

Further, the CPU 302 produces drive data for driving a drive motor that moves the recording sheet and the recording head in synchronization with the image data in order to record the image data at an appropriate position on the recording sheet. The image data and the motor drive data are respectively supplied to the head driver 307,
The image is formed by being transmitted to the head 200 and the drive motor 306 via the motor driver 305 and being driven at respective controlled timings.

The recording medium which can be applied to the recording apparatus as described above and to which liquid such as ink is applied is various kinds of papers, OHP sheets, plastic materials, cloths, aluminum used for compact discs, decorative plates and the like. Metal materials such as copper and copper, leather materials such as cowhide, pigskin and artificial leather, wood materials such as wood and plywood, bamboo materials, ceramic materials such as tiles, and three-dimensional structures such as sponges can be targeted.

As the recording device described above, various types of paper and O
A printer device for recording on an HP sheet or the like, a recording device for a plastic for recording on a plastic material such as a compact disc, a recording device for a metal for recording on a metal plate,
Leather recording device for recording on leather, wood recording device for recording on wood, ceramic recording device for recording on ceramics material, recording device for recording on three-dimensional mesh structure such as sponge, and cloth It also includes a printing device and the like for recording on.

As the ejection liquid used in these liquid ejection devices, liquids suitable for each recording medium and recording conditions may be used.

<Recording System> Next, an example of an ink jet recording system for recording on a recording medium using the liquid discharge head of the present invention as a recording head will be described.

FIG. 30 is a schematic diagram for explaining the structure of an ink jet recording system using the above-described liquid discharge head 201 of the present invention. The liquid ejection head in this embodiment is a full line type head in which a plurality of ejection ports are arranged at intervals of 360 dpi in a length corresponding to the recordable width of the recording medium 150, and is yellow (Y), magenta (M). , Cyan (C), and black (Bk) are fixedly supported in parallel by a holder 202 at predetermined intervals in the X direction.

A signal is supplied to each of these heads from a head driver 307 which constitutes a drive signal supply means, and each head is driven based on this signal.

Each head is supplied with Y, M, C, and
Bk four color inks are supplied from ink containers 204a to 204d, respectively. Reference numeral 204e denotes a foaming liquid container in which a foaming liquid is stored, and the foaming liquid is supplied from the container to each head.

A head cap 203 having an ink absorbing member such as a sponge inside is disposed below each head.
a to 203d are provided, and the maintenance of the head can be performed by covering the ejection openings of each head during non-printing.

Reference numeral 206 is a conveyor belt which constitutes a conveying means for conveying various kinds of non-recording media as described in the above embodiments. The conveyor belt 206 is wound around a predetermined path by various rollers, and is driven by a driving roller connected to a motor driver 305.

In the ink jet recording system of the present embodiment, a pre-processing device 251 and a post-processing device 252, which perform various kinds of processing on the recording medium before and after recording, are provided upstream and downstream of the recording medium conveying path, respectively. It is provided.

The contents of the pre-treatment and the post-treatment differ depending on the type of recording medium on which recording is performed and the type of ink. For example, for a recording medium such as metal, plastic or ceramics, As pretreatment, ultraviolet rays and ozone are irradiated to activate the surface of the material, so that the adhesion of the ink can be improved. Further, in a recording medium such as plastic which easily generates static electricity, dust easily adheres to the surface due to the static electricity, and good recording may be hindered by the dust. For this reason, it is preferable to remove dust from the recording medium by removing static electricity from the recording medium using an ionizer device as a pretreatment.
When a cloth is used as the recording medium, an alkaline substance is added to the cloth in order to prevent bleeding and improve the first-arrival rate.
A treatment for providing a substance selected from a water-soluble substance, a synthetic polymer, a water-soluble metal salt, urea, and thiourea may be performed as pretreatment. The pre-processing is not limited to these, and may be a process of setting the temperature of the recording medium to a temperature suitable for recording.

On the other hand, the post-treatment is a fixing treatment for accelerating the fixing of the ink by heat treatment, ultraviolet irradiation or the like on the recording medium to which the ink has been applied, or washing of the unreacted residual treatment agent applied in the pre-treatment. The processing is performed.

Although the full line head is used as the head in the present embodiment, the present invention is not limited to this, and the small head as described above is conveyed in the width direction of the recording medium to perform recording. It may be one.

<Head Kit> A head kit having the liquid ejection head of the present invention will be described below. FIG.
FIG. 2 is a schematic view showing such a head kit. The head kit includes a head 510 of the present invention having an ink ejection unit 511 for ejecting ink, and an ink container 520 which is an inseparable or separable liquid container from the head. When,
An ink filling means holding the ink for filling the ink container with ink is contained in a kit container 501.

When the ink has been consumed, the insertion portion of the ink filling means (such as an injection needle) is inserted into the atmosphere communication port 521 of the ink container, the connection portion with the head, or the hole formed in the wall of the ink container. ) A part of 531 may be inserted, and the ink in the ink filling means may be filled in the ink container via the insertion portion.

In this way, the liquid discharge head of the present invention,
By packing the ink container and ink filling means into one kit container to make a kit, even if the ink is consumed, the ink can be quickly and easily filled into the ink container as described above. Recording can be started quickly.

Although the head kit of this embodiment is described as including the ink filling means, the head kit does not have the ink filling means and is a separable type ink container filled with ink. The head and the head may be housed in the kit container 510.

Further, although FIG. 31 shows only the ink filling means for filling the ink container with the ink, a foaming liquid filling means for filling the foaming liquid container with the foaming liquid is provided in addition to the ink container. It may be in the form of being housed in a kit container.

[0277]

As described above, according to the present invention,
Bubbles are generated in a liquid discharge method based on a new discharge principle that uses a movable member, that is, in a discharge method that can efficiently discharge the liquid in the vicinity of the discharge port due to the synergistic effect of the generated bubbles and the movable member that is displaced by the generated bubbles. The heating element for driving is driven by the drive pulse divided into the first pulse and the second pulse, the pulse width of the first pulse is controlled, and the liquid is not ejected by the first pulse. Since it is preheated to a certain degree, it is possible to create an environment in which the pressure of the liquid acts on the movable member more efficiently, and to further stabilize the discharge amount and discharge speed of the liquid, and to control the discharge amount of the liquid. Can be improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a liquid ejection head of a first embodiment used in the present invention.

FIG. 2 is a partially cutaway perspective view of a liquid ejection head of a first embodiment used in the present invention.

FIG. 3 is a schematic diagram showing pressure propagation from bubbles in a conventional head.

FIG. 4 is a schematic diagram showing pressure propagation from bubbles in the head of the first embodiment used in the present invention.

FIG. 5 is a schematic diagram for explaining the flow of liquid in the head of the first embodiment used in the present invention.

FIG. 6 is a partially cutaway perspective view of a liquid ejection head of a second embodiment used in the present invention.

FIG. 7 is a partially cutaway perspective view of a liquid ejection head of a third embodiment used in the present invention.

FIG. 8 is a cross-sectional view of a liquid ejection head of a fourth embodiment used in the present invention.

FIG. 9 is a schematic sectional view of a liquid ejection head of a fifth embodiment used in the present invention.

FIG. 10 is a sectional view of a liquid discharge head (two flow paths) of a sixth embodiment used in the present invention.

FIG. 11 is a partially cutaway perspective view of a liquid ejection head of a sixth embodiment used in the present invention.

FIG. 12 is a diagram for explaining an operation of a movable member in a liquid ejection head of a sixth embodiment used in the present invention.

FIG. 13 is a view for explaining a structure of a movable member and a first liquid flow path of a liquid ejection head used in the present invention.

FIG. 14 is a diagram illustrating the structure of a movable member and a liquid flow path of a liquid ejection head used in the present invention.

FIG. 15 is a view for explaining another shape of the movable member of the liquid ejection head used in the present invention.

FIG. 16 is a diagram showing a relationship between a heating element area of a liquid ejection head used in the present invention and an ink ejection amount.

FIG. 17 is a diagram illustrating an arrangement relationship between a movable member and a heating element of a liquid ejection head used in the present invention.

FIG. 18 is a diagram showing the relationship between the distance to the edge and the fulcrum of the heating element of the liquid ejection head used in the present invention and the amount of displacement of the movable member.

FIG. 19 is a diagram for explaining an arrangement relationship between a heating element and a movable member of a liquid ejection head used in the present invention.

FIG. 20 is a longitudinal sectional view of a liquid ejection head used in the present invention.

FIG. 21 is a schematic diagram showing a shape of a driving pulse of a liquid ejection head used in the present invention.

FIG. 22 is a cross-sectional view for explaining a supply path of a liquid ejection head used in the present invention.

FIG. 23 is an exploded perspective view of a liquid ejection head used in the present invention.

FIG. 24 is a process chart for describing a method of manufacturing a liquid discharge head used in the present invention.

FIG. 25 is a process chart for describing a method of manufacturing a liquid discharge head used in the present invention.

FIG. 26 is a process chart for describing a method of manufacturing a liquid discharge head used in the present invention.

FIG. 27 is an exploded perspective view of a liquid ejection head cartridge used in the present invention.

FIG. 28 is a schematic configuration diagram of a liquid ejection device according to the present invention.

FIG. 29 is a block diagram of a liquid ejection apparatus according to the present invention.

FIG. 30 is a diagram showing a system configuration of a liquid ejection apparatus according to the present invention.

FIG. 31 is a schematic diagram of a head kit.

FIG. 32 is a view for explaining a liquid flow path structure of a conventional liquid discharge head.

FIG. 33 is a diagram showing a pulse waveform of a driving pulse for a liquid ejection head used in the present invention.

FIG. 34 is a diagram showing a relationship between a discharge amount of a liquid discharge head used in the present invention and a pulse width.

FIG. 35 is a diagram showing the relationship between the ejection amount of the liquid ejection head used in the present invention and the head temperature.

FIG. 36 is a diagram illustrating a specific example of a driving pulse of the liquid ejection head used in the present invention.

FIG. 37 is a block diagram showing an example of a main part of the liquid ejection apparatus according to the present invention.

FIG. 38 is a timing chart of each signal in the configuration shown in FIG. 37.

FIG. 39 is a block diagram showing another example of the main part of the liquid ejection apparatus according to the present invention.

40 is a timing chart of each signal in the configuration shown in FIG. 39.

41 is a flowchart showing a processing procedure in the configuration shown in FIG. 39. FIG.

FIG. 42 is a diagram showing a pulse waveform of another example of a driving pulse of the liquid ejection head used in the present invention.

FIG. 43 (a) is an explanatory view of a liquid discharge state when one pulse waveform in FIG. 42 is applied to a heating element, and FIG. 43 (b) is a drawing in which a 1 ′ pulse waveform in FIG. 42 is applied to a heating element. FIG. 4 is an explanatory diagram of a liquid discharge state when voltage is applied.

FIG. 44 is an explanatory diagram of a relationship between an interval time of a drive pulse of a liquid ejection head used in the present invention and an ejection amount.

[Explanation of symbols]

 Reference Signs List 1 element substrate 2 heating element 3 area center 10 liquid flow path 11 bubble generation area 12 supply path 13 common liquid chamber 14 first liquid flow path 15 first common liquid chamber 16 second liquid flow path 17 second common liquid chamber 18 Outlet 19 Narrowed part 20 First supply path 21 Second supply path 22 First liquid flow path wall 23 Second liquid flow path wall 24 Convex part 30 Separation wall 31 Movable member 32 Free end 33 Support point 34 Support member 35 Slit 36 Bubble generation Area front wall 37 Bubble generation area side wall 40 Bubble 45 Droplet 50 Grooved member 51 Orifice plate 70 Support 78 Spring 80 Supply member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Kashino 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshie Nakata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (16)

[Claims] 1. A discharge port for discharging a liquid, a bubble generation region for generating bubbles in the liquid, a bubble generation region disposed facing the bubble generation region, and a first position and a bubble generation region more than the first position. A liquid discharge head having a movable member that is displaceable between a second position far from the first position, and a movable member that moves from the first position to the movable member by a pressure based on the generation of bubbles in the bubble generation region. A liquid ejecting method using a liquid ejecting head that ejects a liquid by displacing the bubble to a second position and expanding the air bubbles to a downstream side rather than an upstream side in a direction toward an ejection port by the displacement of the movable member, In the heating element that applies heat energy to the bubble generation region,
The driving pulse is divided into the first pulse and the second pulse, and the driving pulse is supplied during the interval time, and the liquid is preheated to the extent that the liquid is not ejected from the ejection port by the first pulse. Then, by the second pulse, the liquid is heated so as to be ejected from the ejection port to generate bubbles, and at least one of the pulse width of the first pulse or the interval time is changed. A liquid ejection method using a liquid ejection head, characterized in that the degree of preheating of the liquid is controlled. 2. A bubble is produced by supplying a liquid from an upstream side of the heating element along a heating element arranged in a flow path of the liquid discharge head and applying heat generated by the heating element to the supplied liquid. Is generated, and the pressure based on the generation of the bubbles displaces the free end of a movable member that is arranged facing the heating element and has a free end on the ejection opening side of the liquid ejection head, and the displacement of the movable member A liquid discharge method using a liquid discharge head that discharges liquid by guiding the pressure to the discharge port side by the method, wherein the heating element is divided into a first pulse and a second pulse. , A driving pulse is supplied during an interval time, the liquid is preheated by the first pulse to the extent that the liquid is not ejected from the ejection port, and the liquid is ejected from the ejection port by the second pulse. To let the liquid Liquid ejection using a liquid ejection head, characterized in that a degree of preheating of the liquid is controlled by heating to generate bubbles and changing at least one of the pulse width of the first pulse or the interval time. Method. 3. A first liquid flow path communicating with a discharge port, a second liquid flow path having a bubble generation region, a first liquid flow path having a free end on the discharge port side and the first liquid flow path. A liquid discharge head having a movable member disposed between the movable member and a bubble generation region is used, bubbles are generated in the bubble generation region, and the free end of the movable member is moved to the first end based on the pressure generated by the generation of the bubbles. A liquid discharge method using a liquid discharge head that discharges liquid by displacing the liquid to the liquid flow path side and guiding the pressure to the discharge port side of the first liquid flow path by the displacement of the movable member, For a heating element that gives heat energy to the bubble generation area,
The drive pulse is divided into the first pulse and the second pulse, and the drive pulse is supplied during the interval time, and the liquid is ejected to the extent that the liquid is not ejected from the ejection port by the first pulse. Preheating, heating the liquid by the second pulse so as to eject the liquid from the ejection port to generate bubbles, and changing at least one of the pulse width of the first pulse or the interval time. A method for ejecting liquid using a liquid ejection head, characterized in that the degree of preheating of the liquid is controlled by the method. 4. The pulse width of the first pulse or at least one of the interval times is changed according to the temperature detected by the liquid ejection head. A liquid ejection method using a liquid ejection head. 5. The liquid ejection head according to claim 3, wherein the liquid supplied to the first liquid flow path and the liquid supplied to the second liquid flow path are the same liquid. A liquid ejection method using. 6. The liquid ejection head according to claim 3, wherein the liquid supplied to the first liquid flow path and the liquid supplied to the second liquid flow path are different liquids. A liquid ejection method using. 7. The liquid supplied to the second liquid flow path is
Compared with the liquid supplied to the first liquid flow path, it has a low viscosity,
The liquid ejecting method using a liquid ejecting head according to claim 3, wherein the liquid is excellent in at least one of foaming property and thermal stability. 8. The liquid ejecting method using a liquid ejecting head according to claim 1, wherein the bubble is a bubble generated by a film boiling phenomenon of a liquid. 9. A discharge port for discharging a liquid, a bubble generation region for generating bubbles in the liquid, a bubble generation region disposed facing the bubble generation region, and at a first position and a bubble generation region more than the first position. A liquid discharge head having a movable member that is displaceable between a second position far from the first position, and a movable member that moves from the first position to the movable member by a pressure based on the generation of bubbles in the bubble generation region. A liquid ejecting apparatus using a liquid ejecting head that ejects a liquid by displacing the bubble to a second position and expanding the bubble to a downstream side rather than an upstream side in a direction toward an ejection port by the displacement of the movable member, In the heating element that applies heat energy to the bubble generation region,
The drive pulse is divided into the first pulse and the next second pulse, and the drive pulse is supplied during the interval time, and the liquid is ejected to the extent that the liquid is not ejected from the ejection port by the first pulse. Drive pulse supply means for preheating and heating the liquid by the second pulse so as to eject the liquid from the ejection port to generate bubbles; and at least one of the pulse width of the first pulse or the interval time. And a control means for controlling the degree of preheating of the liquid by changing one of the two. 10. A bubble is produced by supplying a liquid from an upstream side of the heating element along a heating element arranged in a flow path of the liquid discharge head, and applying heat generated in the heating element to the supplied liquid. And the pressure due to the generation of the bubbles causes
The liquid is disposed by facing the heating element and displacing a free end of a movable member having a free end on the ejection port side of the liquid ejection head, and guiding the pressure to the ejection port side by the displacement of the movable member. A liquid ejecting apparatus using a liquid ejecting head for ejecting, wherein the heating element is divided into a first pulse and a second pulse, and a driving pulse is supplied via an interval time therebetween. The first pulse preheats the liquid to the extent that the liquid is not ejected from the ejection port, and the second pulse heats the liquid to eject the liquid from the ejection port to generate bubbles. It is provided with a supply means and a control means for controlling the degree of preheating of the liquid by changing at least one of the pulse width of the first pulse or the interval time. A liquid discharge apparatus using the body discharge head. 11. A first liquid flow path communicating with a discharge port, a second liquid flow path having a bubble generation region, a first liquid flow path having a free end on the discharge port side and the first liquid flow path. A liquid discharge head having a movable member disposed between the movable member and a bubble generation region is used, bubbles are generated in the bubble generation region, and the free end of the movable member is moved to the first end based on the pressure generated by the generation of the bubbles. A liquid ejecting head that ejects liquid by displacing the liquid to the liquid channel side and guiding the pressure to the ejection port side of the first liquid channel by the displacement of the movable member, For a heating element that gives heat energy to the bubble generation area,
The drive pulse is divided into the first pulse and the next second pulse, and the drive pulse is supplied during the interval time, and the liquid is ejected to the extent that the liquid is not ejected from the ejection port by the first pulse. Drive pulse supply means for preheating and heating the liquid by the second pulse so as to eject the liquid from the ejection port to generate bubbles; and at least one of the pulse width of the first pulse or the interval time. And a control means for controlling the degree of preheating of the liquid by changing one of the two. 12. A temperature detecting means for detecting the temperature of the liquid discharge head is provided, and the control means sets at least one of the first pulse width and the interval time in accordance with the detected temperature of the temperature detecting means. 12. A liquid ejecting apparatus using the liquid ejecting head according to claim 9, wherein the liquid ejecting head is controlled. 13. The liquid ejection head according to claim 11, wherein the liquid supplied to the first liquid flow path and the liquid supplied to the second liquid flow path are the same liquid. A liquid ejecting apparatus using. 14. The liquid ejection head according to claim 11, wherein the liquid supplied to the first liquid flow path and the liquid supplied to the second liquid flow path are different liquids. A liquid ejecting apparatus using. 15. The liquid supplied to the second liquid flow path has at least one property of low viscosity, foaming property and thermal stability as compared with the liquid supplied to the first liquid flow path. A liquid ejecting apparatus using the liquid ejecting head according to claim 11, which is an excellent liquid. 16. The bubble according to claim 9, wherein the bubble is generated by a film boiling phenomenon of a liquid.
A liquid ejecting apparatus using the liquid ejecting head according to claim 1.