JP2005138601A - Color inkjet recording device and color inkjet reproduction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device configuration which ensures that a large amount of ink used inside the device does not soil the interior of the device or its electrical system is not damaged, even when the ink is scattered by an unforeseeable accident, in a multi-nozzle inkjet recording device with a plurality of ink discharge apertures which are continuously long in order to cover the printing width of a recording medium. <P>SOLUTION: In this color inkjet recording device, a recording part 26 has a plurality of multi-nozzle inkjet recording heads 26 arranged which are continuously long in order to cover the part where data are recorded of the recording medium Pa, and data are recorded by injecting ink liquid droplets to the recording medium to be conveyed to an opposite position to the nozzle surfaces of the multi-nozzle inkjet recording heads 26. In addition, an ink supply means which has an ink vessel 27 connected to the recording heads through a communications means 24, and at least the ink vessel 27 of the ink supply means is arranged below the multi-nozzle inkjet recording heads 26. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a color ink jet recording apparatus and a color ink jet copying apparatus using the color ink jet recording apparatus. More specifically, the present invention relates to an ink supply means for a multi-nozzle ink jet recording head in which ink discharge ports are arranged over the entire width of a recording medium. The present invention also relates to a color ink jet recording apparatus characterized by its installation apparatus and a color ink jet copying apparatus using the color ink jet recording apparatus.

  2. Description of the Related Art Inkjet recording apparatuses that perform a recording operation by ejecting and adhering ink to a recording surface of a recording medium have been widely used. In general, an ink jet recording apparatus includes a recording head having an ink discharge port forming surface for discharging ink to a recording surface of a recording medium.

  The recording head, for example, causes ink droplets formed by pressure of an electromechanical transducer or heating energy of an electrothermal transducer controlled based on a drive control signal supplied according to image data to pass through an ink ejection port formation surface. The ink is discharged onto the recording surface of the recording medium. In the recording head, in order to achieve high image quality and high recording speed, the ink discharge ports formed on the ink discharge port forming surface are arranged at a relatively high density, for example, 400 dpi to 600 dpi, The number of ink discharge ports is several tens to several hundreds. By the way, in recent years, for the purpose of further increasing the speed, a so-called multi-nozzle and elongated one in which the ink discharge port is formed over the entire recording area of the recording medium, for example, the entire width of the recording medium is being studied.

  In such a long recording head, the number of ink discharge ports (nozzles, orifices) is several thousand to several tens of thousands, and the amount of ink used is about several tens to several hundreds of conventional ones. Is not comparable. The ink jet recording technology in which the recording head using such a large amount of ink is lengthened has just been developed, and the ink supply means and the like are still unknown and include research elements. Not established. In particular, it is an issue for the future to ensure the safety of the entire device when an accident occurs.

  The present invention has been made in view of the above circumstances, and an object thereof is a multi-nozzle ink jet recording apparatus in which a plurality of ink discharge ports are elongated so as to cover the print width of a recording medium. However, it is an object of the present invention to propose a device configuration that does not contaminate the inside of the device or damage the electrical system of the device even when a large amount of ink used in the device is scattered due to an accident.

  The present invention has been made to achieve the above object, and the invention of claim 1 is directed to a recording surface of a recording medium on which a fine powder that suppresses the spread of printed dots is coated on the surface based on image data. Recording means for performing a recording operation on the recording medium, recording medium conveying means for conveying the recording medium to the recording means at a predetermined timing, means for drying the recording surface after recording, and supplying ink to the recording means In a color ink jet recording apparatus comprising an ink supply means, the recording means arranges a plurality of nozzles at an arrangement density of 400 to 2400 dpi so as to cover the recording portion of the recording medium, and 1 A multi-nozzle ink jet recording head that ejects ink on demand at a frequency of up to 30 kHz per nozzle. A plurality of inks of three or more colors are applied to the fine powder coating surface of the recording medium conveyed to a position opposite to the nozzle surface of the multi-nozzle ink jet recording head. A recording means for performing ink droplet ejection recording by superposition, wherein the recording medium conveying means is a means for flatly conveying the recording medium when recording on the recording medium and when the recording surface after recording is dried. And the means for drying the recording surface after recording has a heating capability to cover a range larger than the width of the recording portion of the recording medium, and the multi-nozzle ink jet recording head in the transport path of the recording medium And a non-contact heating unit that is disposed on the downstream side of the recording medium and above the recording medium and that supplies ink to the recording unit. Means, more it becomes a tube that connects them with the ink container and the pump in the recording unit, of which at least the ink container is obtained is characterized in that disposed from below the multi-nozzle type ink jet recording head.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the ink container is placed on a member having an independent placement structure for each color through a gap.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the color ink jet recording apparatus supplies ink to the multi-nozzle ink jet recording head that ejects ink of each color of yellow, magenta, cyan, and black. The ink containers are separated and placed on the holding means, and the ink container groups of the respective colors are replaced or refilled with ink on the side wall of the portion where the ink container groups of the color ink jet recording apparatus are arranged. It is characterized by being opened and closed.

  According to a fourth aspect of the present invention, there is provided a scanner unit for reading a document image placed on a document table and forming image data in the color inkjet recording apparatus according to any one of the first to third aspects, and the scanner unit. In the color inkjet copying apparatus provided with the data sending means for sending the image data from the recording means to the recording means, the scanner unit is composed of a document scanning unit combining an exposure light source and a line sensor, and the ink container and the ink supply path In addition, the present invention is characterized in that it is a scanner unit that performs exposure movement scanning in a region that is located above the region where the ink is formed of a multi-nozzle ink jet recording head.

  According to a fifth aspect of the present invention, in the recording medium according to any one of the first to fourth aspects, the recording medium is stacked on a paper feeding unit, and the paper feeding unit is disposed above the ink container. It is a feature.

  The invention of claim 6 is characterized in that, in the invention of any one of claims 1 to 5, a bottom plate is provided at the bottom of the apparatus.

  In a multi-nozzle color inkjet recording apparatus that is long to cover the printing width of the recording medium and consumes a large amount of ink, the water-sensitive electrical system parts / units are located above the consumable ink container. Because it is arranged, even if ink leaks from an ink container due to an unexpected accident, etc., the inside of the device will not be soiled or the electrical system of the device will not be damaged. The multi-nozzle color ink jet recording apparatus can be realized.

FIG. 1 is a partial perspective view for explaining an example of a multi-nozzle ink jet recording head used in the ink jet recording apparatus of the present invention. The structure of the ink jet recording head shown here is an example of a thermal ink jet that can easily realize a high-density arrangement of 400 to 2400 dpi, but is not necessarily limited to this structure.
In FIG. 1, 16 is a flow path, 17 is a nozzle, 18 is a common liquid chamber, 19 is a ceiling plate, 20 is a bonding layer, and 21 is a flow path barrier. In this example, only three nozzles are shown, but in actuality, as will be described later, this is a multi-nozzle type ink jet recording head that is elongated so as to cover the print width of the recording medium. Thousands to tens of thousands of nozzles are arranged in the printing width direction of the medium.

FIG. 2 shows a heating element substrate used in a thermal ink jet recording head, FIG. 2 (A) is a perspective view, and FIG. 2 (B) is a cross-sectional view taken along line AA in FIG. 2 (A). It is sectional drawing which shows the detail of a heat generating body part vicinity in a figure.
In FIG. 2, 1 is a heating element substrate, 2 is a first electrode (control electrode), 3 is a second electrode (ground electrode), 4 and 5 are bonding pads, 7 is a substrate, 8 is a heat storage layer (SiO ₂ ), 9 is a heating element (HfB ₂ ), 10 is an electrode (Al), 11 is a protective layer (SiO ₂ ), 12 is an electrode protective layer (Resin), 13 is another protective layer, 14 is a heating element part, 15 is It is an electrode part. In order to avoid complication, FIG. 2A shows only the heating element and the electrode part which are the main parts.

As shown in FIG. 2 (B), the heating element substrate 1 is formed on a substrate 7 made of ceramic such as alumina, glass or Si by a thin film forming technique such as sputtering or a pattern forming technique such as photoetching. SiO ₂ ) 8, heating element (HfB ₂ ) 9, electrode (Al) 10, protective layer (SiO ₂ ) 11, electrode protective layer 12, another protective layer 13 are sequentially formed, and the heat generating part 14 and the electrode are formed on the surface part. Part 15 is configured. As shown in FIG. 2A, each heating element 9 is connected to a first electrode (control electrode) 2 and a second electrode (earth electrode) 3, respectively. The first electrode 2 has a bonding pad 4 and the second electrode 3 has a bonding pad 5. The bonding pads 4 and 5 are connected to other image information input means (not shown). 9 can be driven independently. The second electrode 3 may be a common second electrode for the plurality of heating elements 9, that is, the first electrode 2.
Further, as in this example, instead of a configuration in which each heating element is driven independently, a configuration in which matrix driving is performed may be employed. Such a row of the heating elements 9 has an arrangement density of, for example, 400 dpi to 2400 dpi, and several thousand to several tens of thousands are provided according to the required printing width of the recording medium.

A heat storage layer 8 is formed on the substrate 7. The heat storage layer 8 is for preventing heat generated by a heating element 9 described later from escaping toward the substrate 7. That is, the generated heat is efficiently transmitted to the ink so that stable bubbles are generated in the ink. Usually, as the heat storage layer 8, SiO ₂ is used to form a SiO ₂ film thickness of 1μm~5μm using a deposition technique such as sputtering.

As shown in FIG. 2B, a layer of a heating element 9 is formed on the storage layer (SiO ₂ ) 8. A material useful as a material for the heating element 9 is tantalum-SiO _{2. And} a boride of a metal such as tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor, or hafnium, lanthanum, zirconium, titanium, tantalum, tungsten, molybdenum, niobium, chromium, and vanadium. Among metal borides, hafnium boride (HfB ₂ ) has the most excellent characteristics, followed by zirconium boride, lanthanum boride, tantalum boride, vanadium boride, and niobium boride. ing.

The heating element 9 can be formed using the above-described materials by a technique such as electron beam evaporation or sputtering. The film thickness of the heating element 9 is determined according to the area, material, shape and size of the heat acting part, and actual power consumption, etc. so that the amount of heat generated per unit time becomes as desired. However, in the usual case, the film thickness is 0.001 to 5 μm, preferably 0.01 to 1 μm.
In the embodiment of the present invention, an example in which HfB ₂ was sputtered to a thickness of 2000 mm (0.2 μm) was shown.

  As the material constituting the electrode 10, many commonly used electrode materials are effectively used, and specific examples thereof include Al, Ag, Au, Pt, Cu and the like. Using these, it is provided in a predetermined position with a predetermined size, shape and thickness by a technique such as vapor deposition. In the present invention, Al is formed to have a thickness of 1.4 μm by sputtering.

The properties required for the protective layer 11 are ink corrosion resistance and protection from impact force due to the disappearance of bubbles (cavitation resistance), and the heat generated by the heating element 9 is transferred to thermal paper, an ink ribbon, Alternatively, it is effectively transmitted to the ink that is the recording liquid.
Examples of useful materials for forming the protective layer 11 include silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, tantalum oxide, and zirconium oxide, which are formed using a technique such as electron beam evaporation or sputtering. can do. Ceramic materials such as silicon carbide and aluminum oxide (alumina) are also preferably used materials.
The thickness of the protective layer 11 is usually 0.01 μm to 10 μm, preferably 0.1 μm to 5 μm, and most preferably 0.1 μm to 3 μm. In the present invention, 1.2 μm of SiO ₂ is formed by sputtering.

  FIG. 2B shows an example of the electrode protective layer 12 and another protective layer 13, but a Resin layer of 2 μm was formed as the electrode protective layer 12. This is provided as necessary, but is not necessarily required and may be omitted. As the material of the protective layer 13, tantalum (Ta) is preferably used in consideration of cavitation resistance. Since a cavitation impact force due to the generation of bubbles is applied in the heating element region, good performance can be obtained by forming Ta with a thickness of 4000 μm (0.4 μm) by sputtering in order to protect against destruction.

An ink jet recording head can be constructed using such a heating element substrate 1, and specifically, it can be manufactured by a process as shown in FIG. 3.
In FIG. 3, 19 is a ceiling plate, 20 is a bonding layer, 21 is a flow path barrier, 22 is a photoresist, and 23 is a photomask.

The manufacturing process of the ink jet recording head will be described with reference to FIGS.
(1) A heating element substrate is prepared (FIG. 3A).
In the heating element substrate 1, a heating layer 9 and a protective layer 11 made of a thin film for protecting and insulating the heating element 9 are formed on the substrate 7.
(2) A photoresist is coated on the heating element substrate (FIG. 3B).
For example, a photoresist 22 having a viscosity of 1000 to 2000 cP (centipoise) is coated on the heating element substrate 1 shown in FIG. 3A to a thickness of about 5 μm to 30 μm by spin coating, dip coating or roller coating. . This thickness finally becomes the height of the flow path barrier 21, and the height varies depending on the arrangement density (printing density) of the heating elements 9. In order to obtain a layer of photoresist 22 having a thickness of 20 μm or more, a dry film type photoresist may be used instead of a liquid photoresist. Subsequently, as shown in FIG. 3B, after a photomask 23 having a predetermined pattern is overlaid on a photoresist 22 provided on the surface of the heating element substrate 1, exposure is performed from above the photomask 23. . At this time, it is necessary to align the installation position of the heating element 9 and the pattern.

(3) A flow path barrier is formed (FIG. 3C).
The photoresist 22 and the unexposed portion of the exposed photoresist 22 are removed with an alkali developer such as an aqueous sodium carbonate solution to form the flow path barrier 21. The removed portion becomes a recess having the heating element 9 and constitutes the flow path 16 and the common liquid chamber 18.
(4) A substrate serving as a ceiling of the flow path and the common liquid chamber is created (FIG. 3D).
The substrate serving as the ceiling of the flow path 16 and the common liquid chamber 18 is obtained by bonding the bonding layer 20 and the glass substrate, and the glass substrate becomes the ceiling plate 19.

(5) The substrate is bonded to the flow path barrier (FIG. 3E).
The heating element substrate 1 and the glass substrate serving as the ceiling plate 19 are bonded with the photoresist 22 and the bonding layer 20 facing each other. At that time, thermosetting treatment (for example, heating at 150 to 250 ° C. for 30 to 60 minutes) or ultraviolet irradiation (for example, 50 mW / cm ^{2 to} 200 mW / cm ² , or higher ultraviolet intensity) Improve ink properties and bond strength.

(F) A discharge port is formed (FIG. 3 (F)).
Finally, the yy line portion in the vicinity of the opening on the heating element 9 side is cut by dicing to form nozzles (ejection ports) 17 to complete the ink jet recording head.
As another manufacturing means, there is a method of manufacturing the flow path and the common liquid chamber by integral molding of a resin such as polysulfone, polyethersulfone, polyphenylene oxide, polypropylene, and polyimide.
In addition, a means for forming a nozzle by arranging a resin film at the tip of the flow path, perforating the discharge port by means such as excimer laser, and the like is also suitably used. With the excimer laser ejection port drilling method, nozzles of any shape can be formed depending on the mask shape, so the shape can be changed in consideration of the relationship with the ink ejection characteristics such as round shape, polygonal shape, or star-shaped radial shape. This is an advantageous method because it can be determined. Also in this case, resins such as polysulfone, polyethersulfone, polyphenylene oxide, polypropylene, and polyimide can be used favorably.

Next, the principle of ink ejection by such an ink jet recording head will be briefly described with reference to FIG.
In FIG. 4, 31 is ink, 32 is a bubble, 33 is a discharge port, 34 is a flow path, 35 is a heating element substrate, 36 is a heating element, 37 is a first electrode (control electrode), and 38 is a second electrode (ground). Electrode), 39 is an ink droplet. A signal pulse is input to the heating element 36 in accordance with image information via the first electrode 37 and the second electrode 38, and bubbles 32 are generated in the ink in response to the input pulses. Due to the acting force of the bubbles, A part of the ink 31 in the flow path 34 is ejected as an ink droplet 39 from the ejection port 33 and recorded on a recording medium (for example, paper).

  Here, the duration of the signal pulse is preferably several μs to several tens μs, and is set to 30 μs at the longest. This is because once the bubble 32 is generated on the heating element 36, the bubble 32 blocks the heat of the heating element 36, so that the size of the bubble 32 hardly changes and is unnecessarily long. This is because energization not only wastes but also damages the heating element 36. After the energization is stopped, the bubbles 32 are deprived of heat by the heating element substrate 35 and the surrounding ink 31 and contract and disappear. As is clear from this explanation, the bubbles 32 acting on the ink jetting principle in the present invention are bubbles obtained by abrupt heating in a very short time, and so-called membranes in the field of heat transfer engineering. It is a bubble of a phenomenon called boiling, and the reproducibility of generation to disappearance is very good.

Further, as another ejection principle, the position of the heating element 36 shown in FIG. 4 is brought close to the ejection port 33 so that a finer ink droplet is ejected, or the generated bubbles protrude to the outside of the ejection port 33. Or you may make it burst.
Further, the above description has been made based on the example of the thermal ink jet method including the method of manufacturing the ink jet recording head. However, an ink jet method using a piezo element may be used.

FIG. 5 shows a recording unit of a multi-nozzle type ink jet recording apparatus in which a plurality of ink ejection openings as described above are elongated so as to cover the printing width of a recording medium.
The recording unit 26 includes a head block 72 that incorporates the respective recording heads 70C, 70M, 70Y, and 70B and a heating-type fixing device 76 described later. The head block 72 is supported inside the recording unit 26 via protrusions 72A provided at both ends along the conveyance path of the recording medium (paper Pa).

  The recording heads 70C, 70M, 70Y, and 70B are sequentially arranged with a predetermined mutual interval from the upstream side to the downstream side of the paper Pa conveyance path. At that time, the recording heads 70C, 70M, 70Y, and 70B are positioned and fixed to the head block 72 so that the flatness of the plane formed by all the ejection port surfaces of these heads is within about several tens of microns. .

  Each of the recording heads 70C, 70M, 70Y, and 70B is, for example, the thermal ink jet method as described above, and ejects cyan, magenta, yellow, and black inks. That is, each of the recording heads 70C, 70M, 70Y, and 70B has a heater as an electrothermal converter in a liquid flow path that communicates with the discharge port, and ink droplets that are formed when the ink is heated by the heater. To be discharged. Each of the recording heads 70C, 70M, 70Y, and 70B has a plurality of ejection openings arranged along a direction substantially orthogonal to the conveyance direction of the paper Pa. The plurality of ejection openings are formed over the entire width in a direction substantially orthogonal to the conveyance direction on the recording surface of the paper Pa.

  Each of the recording heads 70C, 70M, 70Y, and 70B is connected to the ink supply path 24 and receives ink supply from an ink container described later. In the drawing, although shown by one line, it goes without saying that the ink supply path 24 is independent for each color. Here, the ink supply path 24 is required to have ink corrosion resistance, and a resin tube such as Teflon (registered trademark) or polyethylene, a stainless steel pipe, or the like is used.

The recording operations of the recording heads 70C, 70M, 70Y, and 70B are performed on the same sheet of paper Pa. For example, the recording head 70C performs recording first, and the recording head 70C performs second. Are recorded on the recording surface or recorded at a new position, and thirdly, the recording head 70Y further records in the same manner, and finally, the recording head 70B records.
In a color ink jet recording apparatus in which the recording head is composed of ink jet recording heads of three colors of yellow, magenta, and cyan, the ink jet recording heads for each color are arranged in the order of yellow, magenta, and cyan. At this time, the arrangement of the ink containers for supplying the respective color inks to the three color ink jet recording heads is also arranged in the order of yellow, magenta, and cyan.
The recording heads 70C, 70M, 70Y, and 70B are not limited to those that eject ink, and for example, at least one recording head may eject a treatment liquid that insolubilizes ink. Alternatively, the processing liquid may be discharged to prevent the pixels from spreading or blurring more than necessary on the paper Pa before ink discharge.

In such an ink jet recording system, ink adhered to a recording material permeates into the recording member, and the ink is fixed to the recording member. Alternatively, the adhered ink is fixed on the recording material through an evaporation process of the ink solvent.
However, the time from the ink adhesion to fixing, that is, the fixing speed, not only greatly depends on the configuration and physical properties of the recording material, but also greatly depends on the state of the external atmosphere. Also, the natural fixing speed cannot be shorter than a certain time due to physical characteristics.
As described above, the speed at which the ink adheres to and penetrates the recording material also varies greatly depending on the composition of the ink used.

  Usually, the ink composition is often distinguished by the degree of permeability of the ink to the recording material. In general, ink with high penetrability is advantageous from the viewpoint of fixability because of its high penetrating speed with respect to the recording material. The problem is that the quality deteriorates. Further, since the ink penetrates deeply into the recording material, it tends to lead to a decrease in image density.

On the other hand, when an ink with low penetrability is used, as described above, it takes time to penetrate, and from the viewpoint of fixability, a recording medium that requires high speed as in the present invention. In a multi-color printing device that uses a multi-nozzle inkjet recording head that is elongated to cover the printing width, ink mixing and bleeding between ink colors, and recording material discharge Scratching of the image at the time, a so-called scratch resistance problem arises. Therefore, it is important to configure the apparatus in consideration of fixability, image density, bleeding, and scratch resistance.
In conventional serial scan recording apparatuses, such fixability can often be dealt with with a somewhat simple configuration because of the recording speed.

However, in particular, when high-speed recording and color recording are performed as in the embodiments of the present invention, as described above, in order to fix the ink applied to the recording material to a desired state on the recording material. A heating type fixing device 76 as described below for reducing the fixing speed and increasing the efficiency is required.
For example, as shown in FIG. 5, the heating type fixing device 76 is provided on the downstream side of the recording head 70 </ b> B in the conveyance path and corresponding to a relatively close position. Here, an example in which the heating type fixing device 76 includes a halogen heater 84 and a reflection plate 82 that reflects heat rays from the halogen heater 84 is shown.

As in this example, in the present invention, the printing surface side of the recording medium (paper Pa) is heated in a non-contact manner. That is, since the printing part is heated from the surface, volatile components in the ink such as water can be efficiently dried.
Here, as the heating-type fixing device 76, a halogen heater 84 as a heating unit, a reflection plate 82 that reflects heat rays from the halogen heater 84, a heating unit shielding member 86 that partitions the halogen heater 84 and the conveyance path, Although an example has been described that includes a heat insulating device 78 as a heat insulating portion that cuts off heat transfer from the halogen heater 84 to the recording head 70B, a ceramic heater may be used as another example. Fixing can be performed satisfactorily.

  In the above embodiments, the heating / drying is described after printing. However, various heating means as described above are arranged in the transport path of the recording medium Pa before printing, and the recording medium Pa is heated in advance. A method of performing printing after the state is kept is also a good method for effective ink drying.

Next, the overall configuration of a color ink jet copying apparatus to which a multi-nozzle ink jet recording head elongated so as to cover the printing width of a recording medium as in the present invention is applied will be described.
Conventionally, what is called a copying machine generally refers to an electrophotographic system. Although such an electrophotographic system is widely used, there is a drawback that the principle is complicated and the apparatus becomes very large. On the other hand, the principle of ink jet recording is simple, and if a copying apparatus is configured using this as a recording principle, an epoch-making simple copying apparatus that has never been achieved can be realized.

  FIG. 6 shows a color ink jet copying apparatus according to the present invention. The color ink jet copying apparatus reads an image of a surface to be copied on a document Bo placed on the document table 116, and thereby the document Bo is scanned. Sequentially, a scanner unit 102 that forms image data, and a recording unit 26 that performs a recording operation by ejecting and adhering ink to the recording surface of paper Pa as a recording medium based on the image data from the scanner unit 102. And a transport unit 134 that is disposed below the recording unit 26 and transports the paper Pa to a later-described discharge transport unit 136 at a predetermined timing according to the recording operation of the recording unit 26, and printing transported by the transport unit 134 Discharged paper Pa ′ is discharged onto the paper discharge tray 138, and the paper Pa from the paper supply unit 130 is sent to the recording unit 26 one by one. A paper feed conveyance unit 132 for sending is configured to include a recovery processing unit 140 selectively perform the recovery processing for the recording head of the recording unit 26.

  In such a color inkjet copying apparatus, driving / control of the recording unit 26, the scanner unit 102, the paper feeding unit 130, and the like is performed by the electrical system unit 60. Here, since the electrical system unit 60 is weak against water, it is desirable that the electrical unit 60 be installed as far as possible from moisture such as ink. In the present invention, in view of this point, the electrical unit 60 is configured to be above the ink container 27. As a result, even if ink leaks from the ink container 27, the electrical system unit 60 is above the ink container 27, so that the electrical system unit 60 is immersed in the ink, thereby causing the electrical system unit 60 to malfunction. Accidents can be avoided.

  FIG. 6 shows an example in which the electrical system unit 60 is above the ink container 27 and further above the recording unit 26. However, the basic concept of such failure / accident avoidance is a large amount. That is, the ink container 27 for containing ink is arranged at the bottom. Since the recording unit 26 is not without the risk of ink leakage, it is desirable to arrange the electrical unit 60 above the recording unit 26 as shown in FIG. 6, but the most dangerous one is arranged at the bottom. This prevents flooding (ink) of the electrical system unit 60 due to an accident.

  Note that the recording unit 26 includes the recording heads 70C, 70M, 70Y, and 70B that discharge ink of each color as described above, and these receive ink supply from the ink containers 27 of each color connected to the ink supply path 24. The ink container 27 includes a yellow ink container 27Y, a magenta ink container 27M, a cyan ink container 27C, and a black ink container 27B, and these are placed on the ink container tray 29. Here, the ink container tray 29 has an independent barrier structure so that the respective ink containers are placed separately. Although FIG. 6 shows a low independent barrier structure, the structure is not necessarily limited to this structure. For example, it is also a good method to have a completely independent barrier structure for each color so as to cover all the upper part of the ink container.

  By adopting such a structure, for example, when ink is used up and ink is replenished, or when the ink container itself is replaced, ink spills or overflows to contaminate the surroundings, or It is possible to prevent the ejected ink from contaminating the adjacent ink container. In particular, when each color has a completely independent barrier structure, it is possible to avoid a situation in which ink is mixed into an adjacent ink container when ink is ejected for some unexpected reason.

  In the present invention, since a large amount of ink is used, it is desirable to provide a pump 25 for supplying the ink. When the recording head drive frequency (ink droplet ejection frequency) is very slow (for example, several Hz to several hundred Hz per nozzle), the ink is discharged by capillary action without using pump means. However, in the case where the nozzle is used by being driven at several kHz to 30 kHz, it is necessary to forcibly supply the ink to the recording head by a pump unit.

FIG. 6 shows an example in which a pump 25 is provided in the middle of the ink supply path 24 connecting the recording head and the ink container. Needless to say, the pump 25 does not show a detailed structure, but can be independently driven and supplied for each color.
The scanner unit 102 includes a document scanning unit 104 that reads an image to be copied on the document Bo, and a guide rail 112 that supports the document scanning unit 104 so as to be movable in the direction indicated by the arrow S in FIG. Although not shown, the document scanning unit 104 supported by the guide rail 112 is reciprocated at a predetermined speed between, for example, a position indicated by a solid line and a position indicated by a two-dot chain line in FIG. And a drive unit.

The document scanning unit 104 includes, as main components, a rod array lens 106, a line sensor 110 of equal color separation as a color image sensor which is a color information reading sensor, and an exposure unit 108 such as a lamp light source. It consists of
When the document scanning unit 104 is moved and scanned in the direction of the arrow S to read the image of the document Bo on the document table 116 made of a transparent material by the driving unit, the exposure lamp in the exposure unit 108 is turned on, Reflected light from the original document Bo is guided by the rod array lens 106 and condensed on the line sensor 110. The line sensor 110 reads color image information represented by the reflected light for each color, converts it into an electrical digital signal, and supplies it as image data to a control unit in an inkjet printer unit 118 described later. Accordingly, each recording head for each color in the recording unit 26 to be described later discharges a liquid used for recording, for example, inks of different colors, in accordance with drive control pulse signals based on these image data. Is done.

  In the present invention, as described above, the scanner unit 102 is composed of a lamp light source that is weak against water, and the above-described basic concept of failure / accident avoidance by ink of the electrical unit 60 should be applied. . That is, as apparent from FIG. 6, in the present invention, the scanner unit 102 is laid out so as to be above the ink container 27 that accommodates a large amount of ink. Further, it is disposed above the recording unit 26 that ejects ink droplets to prevent flooding (ink) of the scanner unit 102 due to an accident and damage / failure caused by the accident.

Sheets Pa of a predetermined standard size loaded and stored in the sheet feeding unit 130 are taken out one by one by the pickup roller unit 130RA when a driving motor (not shown) is activated, and is supplied. The paper is supplied to the paper transport unit 132.
In the ink jet recording method, small droplets of ink fly and are attached to the surface of recording paper such as paper for recording, so paper Pa can be blurred because the ink is more than necessary on the paper surface. It is necessary not to. Further, it is preferable that the paper Pa has such a characteristic that the ink adhering to the paper Pa is quickly absorbed into the paper Pa. The paper Pa does not have the phenomenon of ink flowing out and exuding even when inks of different colors overlap and adhere to the same location in the paper Pa within a short time, and the print dots spread and the image quality becomes clear. Those having characteristics that can be suppressed to such an extent that they are not impaired are preferred.

These characteristics may not be fully satisfied with copying paper called plain paper used in electrophotographic copying machines or the like or other general recording paper. In these papers, when only one color is printed or two colors are superposed, an image quality that is satisfactory to some extent is often obtained. However, for example, a full color image by superposing three or more inks is obtained. When the amount of ink adhering to the paper increases as in printing and recording, a sufficiently satisfactory image quality record may not be obtained.
As the paper satisfying the above-described characteristics, a paper on which a coating (for example, fine powder silicic acid) is obtained on the base paper so as to obtain the above-mentioned characteristics may be used.

  The ink jet copier of the present invention has an ink heating type fixing device that covers a range larger than the width of the recording portion of the recording medium. Therefore, since the ink can be dried / fixed instantaneously, it is possible to obtain a high-speed, high-quality, high-quality printed / copied material without the show-through of undried ink even during continuous printing / copying. it can. In particular, the multi-nozzle ink jet principle in which a plurality of ink discharge ports are elongated so as to cover the printing width of the recording medium enables very high speed printing / copying in principle. By adopting a configuration in which the fixing capability is sufficient as in the present invention, a high-speed copying machine that can sufficiently exhibit the capability can be realized.

7 and 8 are diagrams for explaining another embodiment of the present invention.
As described above, in the present invention, the ink container 27 is disposed at the lower part of the apparatus, and the electrical system unit 60 and the scanner unit 102 are flooded (ink) due to an accident, thereby preventing damage / failure. However, here, as still another safety measure, a configuration example in which the ink container 27 is reliably separated from the electrical system unit 60 and the scanner unit 102 of the apparatus is shown.
FIG. 7 shows an example in which the first separation wall 52A is arranged in the apparatus, and FIG. 8 shows an example in which the second separation wall 52B is used and the ink container 27 is completely separate.
If the separation wall structure is a completely separate chamber as shown in FIG. 8, ink replenishment to the ink container 27 only needs to be performed by opening and closing the side wall of the apparatus. Therefore, since it is not necessary to open the inside of the apparatus to an unnecessary portion when refilling ink, the electrical system unit 60 and the scanner unit 102 are more surely protected by an accident such as ink leakage or ink ejection.

Next, still another embodiment of the present invention will be described.
6 to 8 show examples in which the bottom plate 51 is provided in the present invention. In general, such a bottom plate 51 is not necessary if the electrophotographic copying machine or printer is configured so long as the rigidity of the apparatus can be maintained. However, in the present invention, since a large amount of liquid called ink is handled, in the unlikely event that ink leaks, the leaked ink falls to the floor and soils the floor, so the bottom plate 51 is provided to prevent this. When the bottom plate 51 is provided in this way, not only can the ink fall to the floor with the bottom plate 51 even if ink leaks, but also the ink container 27 or the ink container 27 is held as shown in FIGS. There is an advantage that the ink container tray 29, the pump 25, and the like, such as the recording apparatus of the present invention and the parts / units constituting the copying machine can be installed.

1 is a partial perspective view showing a multi-nozzle type ink jet recording head applied to a color ink jet recording apparatus of the present invention. It is a figure for demonstrating the heat generating body board | substrate of the thermal inkjet recording head applied as one Example of a multi nozzle type inkjet recording head. It is a figure for demonstrating the manufacturing process of a thermal inkjet recording head. It is a figure for demonstrating operation | movement of a thermal color inkjet recording head. 1 is a side sectional view showing a recording portion and its peripheral portion of a multi-nozzle color ink jet recording apparatus of the present invention. 1 is a side sectional view showing a copying apparatus using a multi-nozzle color ink jet recording apparatus of the present invention. FIG. 6 is a side sectional view showing another embodiment of a copying apparatus using the multi-nozzle color ink jet recording apparatus of the present invention. FIG. 7 is a side sectional view showing still another embodiment of a copying apparatus using the multi-nozzle color ink jet recording apparatus of the present invention.

Explanation of symbols

1 ... heating element substrate, 2 ... first electrode (control electrode), 3 ... second electrode (ground electrode), 4,5 ... bonding pad, 7 ... substrate, 8 ... heat storage layer (SiO _2), 9 ... heating element (HfB ₂ ), 10 ... Electrode (Al), 11 ... Protective layer (SiO ₂ ), 12 ... Electrode protective layer (Resin), 13 ... Another protective layer, 14 ... Heat generating part, 15 ... Electrode part, 16 ... Current 17: nozzle, 18: common liquid chamber, 19: ceiling plate, 20 ... bonding layer, 21 ... flow path barrier, 22 ... photoresist, 23 ... photomask, 24 ... ink supply path, 25 ... pump, 26 ... Recording unit, 27 ... ink container, 27Y ... yellow ink container, 27M ... magenta ink container, 27C ... cyan ink container, 27B ... black ink container, 29 ... ink container tray, 31 ... ink, 32 ... air bubbles, 33 ... discharge port, 34 ... flow path 35 ... heating element substrate, 36 ... heating element, 37 ... first electrode (control electrode), 38 ... second electrode (ground electrode), 39 ... ink droplet, 51 ... bottom plate, 52A ... first separation wall, 52B ... Second separation wall, 60 ... electric unit, 72 ... head block, 72Y ... yellow ink head block, 72M ... magenta ink head block, 72C ... cyan ink head block, 72B ... black ink head block, 78 DESCRIPTION OF SYMBOLS ... Thermal insulation apparatus, 80 ... Air layer, 84 ... Halogen heater, 102 ... Scanner part, 104 ... Document scanning unit, 106 ... Rod array lens, 108 ... Exposure unit, 110 ... Line sensor, 112 ... Guide rail, 116 ... Document table 118 ... Inkjet printer unit, 130 ... Paper feed unit, 132 ... Paper feed conveyance unit, 134 ... Conveyance unit, 136 Discharge transport section, 138 ... discharge tray, 140 ... recovery processing unit.

Claims (6)

  Recording means for performing a recording operation on a recording surface of a recording medium coated with fine powder for suppressing the spread of printed dots on the surface based on image data, and conveying the recording medium to the recording means at a predetermined timing In a color ink jet recording apparatus comprising: a recording medium conveying unit that performs recording; a unit that dries a recording surface after recording; and an ink supply unit that supplies ink to the recording unit. 3 multi-nozzle type ink jet recording heads that are arranged to be long and cover the recording portion of the recording medium at an array density of ˜2400 dpi and that eject ink on demand at a frequency of up to 30 kHz per nozzle. A multi-nozzle in which a plurality of inks of a plurality of colors or more are arranged and fixed so as to be ejected according to each color. A recording means for performing ink droplet ejection recording by superimposing three or more colors on a fine powder coating surface of the recording medium conveyed to a position opposite to a nozzle surface of an inkjet recording head, the recording medium conveying means Is means for transporting the recording medium in a flat manner when recording on the recording medium and when the recording surface after recording is dried, and means for drying the recording surface after recording is a means for covering the recording medium. A means for heating non-contactingly and having a heating capability to cover a range larger than the width of the recording unit, being arranged on the downstream side of the multi-nozzle ink jet recording head and on the upper side of the recording medium in the recording medium conveyance path The ink supply means for supplying ink to the recording means includes an ink container, a pump, and a tube for connecting them to the recording section; Rinari, of which at least the ink container, the color ink jet recording apparatus being characterized in that disposed from below the multi-nozzle type ink jet recording head.   The color ink jet recording apparatus according to claim 1, wherein the ink container is placed on a member having an independent placement structure for each color through a gap.   The color ink jet recording apparatus separates an ink container for supplying ink to the multi-nozzle ink jet recording head that ejects ink of each color of yellow, magenta, cyan, and black, and places the ink container on a holding unit. 3. The ink container group for each color is replaced or refilled with ink by opening and closing a side wall of a portion of the color ink jet recording apparatus where the ink container group is disposed. Color ink jet recording apparatus.   A color ink jet recording apparatus according to any one of claims 1 to 3, wherein a scanner unit that reads a document image placed on a document table and forms image data, and image data from the scanner unit In the color ink jet copying apparatus provided with the data sending means for sending to the recording means, the scanner section is composed of a document scanning unit combining an exposure light source and a line sensor, and the ink container, the ink supply path, and the multi-nozzle ink jet recording head. A color ink-jet copying apparatus, comprising: a scanner unit that performs exposure movement scanning in a region separated from an ink existing region.   5. The color inkjet recording apparatus according to claim 1, wherein the recording medium is stacked on a paper feeding unit, and the paper feeding unit is disposed above the ink container. Color inkjet copier.   6. A color ink jet recording apparatus or a color ink jet copying apparatus according to claim 1, wherein a bottom plate is provided at the bottom of the apparatus.