JPH11348300A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of executing an operation for supplying ink to an ink tank without stopping a printing operation of a print head. SOLUTION: Levels of inks are grasped by means of sensors 23, 24, 25 for detecting the levels of the inks in ink tanks 4, 5. By maintaining each of the levels of the inks in a predetermined range, an inner section of a print head 205a (205b) is maintained in a negative pressure. As a result, it is possible to execute an operation for supplying ink to the ink tank even when the print head 205a (205b) is driven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing apparatus having an ink supply device for supplying a large amount of ink. Here, the print includes the application of ink to all of the ink, such as cloth, thread, paper, and sheet material, etc., and the printing apparatus includes all of various information devices or a printer as an output device thereof. The present invention can be applied to these.

[0002]

2. Description of the Related Art Conventionally, ink jet recording apparatuses for recording using ink have been widely used as printers and copiers for personal computers. The demand for this ink jet recording apparatus is increasing because it is inexpensive and can perform full-color recording. These days,
Ink jet recording apparatuses are used not only for general-purpose ink jet printers for personal use, but also for plotters that record photographic images on large sheets such as A1 and A0 plates. It is also used in textile printing systems that print on fabric.

Further, application of ink jet recording to medical multi-tone image recording such as X-ray film or CT scan image is being studied.

In order to realize multi-gradation expression with high image quality similar to that of a silver halide film using an ink jet recording apparatus, the types of ink jet inks tend to increase.
For example, in a photo-like color plotter, normal cyan,
In addition to magenta, yellow and black, thin cyan,
It has been proposed to use inks of six or more colors, such as adding magenta. It is considered that at least six dark and light black inks are necessary for a medical image recording apparatus to produce an image that requires 1000 or more gradations, such as an X-ray image. That is, in such a medical image recording apparatus, a plurality of types of inks having different densities are combined, and the ink is recorded twice and three times, thereby expressing a much larger number of gradations than the number of ink types. It becomes possible.

However, in the above-described plotter, textile printing system, and recording apparatus for medical images, a large amount of ink is used. Therefore, if a large-capacity ink tank is mounted on a carriage together with a recording head, the weight of the carriage increases.
Carriage drive control becomes difficult. Conversely, if the capacity of the ink tank is small, it is necessary to frequently replace the ink tank, which is inconvenient.

Accordingly, a small-capacity tank is provided on the carriage, and a large ink tank is provided outside the carriage.
There has been proposed an ink supply system in which a tube through which ink flows is arranged between tanks.

However, in the known ink supply system, air bubbles are generated in the tube due to gas permeability of the tube, and when the air bubbles enter the recording head, a printing defect or the like occurs, and stable recording can be performed. There are no inconveniences.

In order to solve this problem, an ink supply system using a tube as shown in FIG. 8 has been proposed.

In FIG. 8, reference numeral 101 denotes a recording head.
A first ink tank 02 stores ink to be supplied to the print head 101. The recording head 101 and the first ink tank 102 are mounted on a carriage 103 movable with respect to the apparatus main body. 104 and 105 are second and third ink tanks fixed to the apparatus main body.

At the top of the second ink tank 104, an air communication hole 126 is provided. First ink tank 1
02 and the second and third ink tanks 104 and 105 are connected by first and third ink flow paths 106 and 107 formed by tubes, joints, and the like. The first ink flow path 106 sends the ink stored in the second ink tank 104 to the first ink tank 102. The third ink flow path 107 is provided in the first ink tank 1.
02 is sent to the third ink tank 105, and a third valve 122 is provided in the middle of the third ink flow path 107.
Is provided.

The second ink tank 104 and the third ink tank 105 are adjacent to each other, and their bottoms are connected by a second ink flow path 108. In the middle of the second ink flow path 108, a first valve 109 is provided. The first valve 109 is a so-called check valve that allows ink to flow only from the third ink tank 105 to the second ink tank 104.

The second ink tank 105 has a second
Air communication path 11 having the valve 110 of the third type, and an air chamber suction path 11 for sucking air in the air chamber portion of the third ink tank.
Two ends are attached. The second valve 110 is opened and closed by crushing the atmosphere communication passage 111 with a cam member (not shown). The opening and closing of the second valve 110 allows the air chamber portion of the third ink tank 105 to communicate with the atmosphere and not communicate with the atmosphere. Can be switched. A tube pump 150 is provided in the middle of the air chamber suction path 112, and the third ink tank 105 is provided.
The air in the air chamber is sucked. The other end of the air chamber suction path 112 is guided to a waste ink tank 113. In addition, the third
One end of a fourth ink flow path 114 is connected to the ink tank 105, and a tubular first needle member 115 having a hole at the other end of the fourth ink flow path 114 is provided.

The first needle member 115 is provided with a supply tank 116.
Is loaded into a predetermined position, the cartridge is inserted into the ink supply port 117 of the supply tank 116. Reference numeral 128 denotes an atmosphere communication passage for a replenishing tank, and one end thereof is provided with a tubular second needle member 118 also having a hole at the tip, and the other end extends to the waste ink tank 113. Since the waste ink tank 113 is provided with an atmosphere communication hole 119, when the second needle member 118 is inserted into the atmosphere communication port 120 of the supply tank 116, the air chamber of the supply tank 116 is communicated with the atmosphere to supply the air. The movement of the ink from the tank 116 to the third ink tank 105 becomes possible. A fourth valve 121 that allows ink to flow in only one direction is provided in the middle of the fourth ink flow path 114, and the fourth valve 121 supplies ink from the third ink tank 105 to the supply tank 116. Prevents backflow.

The second ink tank 104 is provided with an ink level detecting means 124, and the third ink tank 10
5 is provided with an ink level detecting means 123.
The ink level detecting means 124 is provided in the second ink tank 10.
4 and the ink level detecting means 123 detects the maximum ink level of the third ink tank 105.

In the ink supply system shown in FIG. 8, when circulating the ink, first, the second valve 110 is used.
Is closed and the third valve 122 is opened to open the tube pump 150
Is driven in the direction of arrow A. As a result, air is sucked from the air chamber of the third ink tank 105, and the pressure in the third ink tank 105 decreases, so that ink (including air bubbles) from the first ink tank 102 becomes the third ink tank. Channel 10
7, the ink is guided into the third ink tank 105. As a result, the pressure in the air chamber in the first ink tank 102 also decreases, and instead, ink is supplied from the second ink tank 104 to the first ink tank 102 through the first flow path 106. Thus, the second ink tank 104
The ink inside moves through the first ink tank 102 to the third ink tank 105. At this time, the fourth valve 1
21 is urged in the closing direction by an elastic member 127. This is to prevent the ink in the supply tank 116 from flowing into the third ink tank 105 via the fourth ink flow path 114 by opening the fourth valve 121.

Here, when the ink level detecting means 124 detects the minimum ink level of the second ink tank or the ink level detecting means 125 detects the maximum ink level of the third ink tank, the second By opening the valve 110, the air chamber of the third ink tank 105 communicates with the atmosphere, and the first valve 109 opens due to the head difference between the ink in the second ink tank 104 and the ink in the third ink tank 105. The third ink tank 1 through the second flow path 108
From 05, the ink can flow into the second ink tank 104. The second and third ink tanks 104,
When the ink levels at 105 become approximately equal, this ink flow stops. The second valve 110 is opened until the ink levels of the second and third ink tanks 104 and 105 become substantially equal, for example, for 10 seconds.
Of course, this opening time is not limited to the second and third ink tanks 10.
4, 105 ink capacity, cross-sectional area of the second flow path 108,
It is appropriately determined according to the positions of the ink level detecting means 124 and 125.

As described above, by the simple operation of driving the tube pump 150 and opening and closing the second valve 110,
First, second, and third ink tanks 103, 104, and 10
It is possible to circulate the ink between the five spaces.

According to the above configuration, the first ink flow path 1
Even if a bubble is generated in the ink tank 06, the ink is circulated as described above, so that the bubble once enters the first ink tank 102 and then passes through the third ink flow path 107 to the third ink channel 107. Is discharged into the ink tank 105. Therefore, the air bubbles generated on the way do not enter the inside of the recording head, and the printing failure does not occur.

[0019]

In the ink supply method of the ink supply system having the structure shown in FIG. 8, the second and third ink tanks control the negative pressure of the recording head during printing. 104 and 105 are ink levels. In this case, when the ink runs out, the printing is stopped, and the third ink tank 105 is filled with ink, the ink is moved from the third ink tank 105 to the second ink tank 104, and the like. Third ink tank 10
4, 105 must be refilled with ink.
At this time, the recording pause state in which printing cannot be performed continues. Although this state varies depending on the capacity of the ink tank, the second and third ink tanks 104, 10
5 is small, the second and third ink tanks 10
The ink supply to the ink tanks 4 and 105 is frequently performed. Conversely, if the capacity of the ink tank is large, the recording pause time is long as described above. If there is an interval for replenishing ink during continuous printing, print output cannot be performed quickly.

An object of the present invention is to provide an ink supply system with ink circulation for preventing bubbles from entering a recording head (hereinafter, also referred to as a print head) as described above, without stopping printing by the print head and supplying ink to an ink tank. It is an object of the present invention to provide a printing apparatus provided with an ink supply device for performing the above-described ink supply operation.

[0021]

In order to achieve the above object, the present invention provides a print head for discharging ink, a discharge control means for controlling the discharge of ink from the print head, and a supply to the print head. A first ink tank that stores ink, a second ink tank that supplies ink to the first ink tank, a third ink tank that receives ink overflowed in the first ink tank, A pump for sucking an air chamber portion in the third ink tank, detecting means for detecting respective ink levels in the second ink tank and the third ink tank, and the second ink by the detecting means. An ink level maintaining means for maintaining the respective ink levels in the tank and the third ink tank within a predetermined range; Characterized in that it comprises a driving control means for simultaneously driving said discharge control means and means.

According to the above configuration, it is possible to prevent air bubbles from entering the print head, to stop the printing by the print head even during the ink supply operation to the ink tank, and to perform a stable operation without a recording pause state. Can be improved.

Here, the ink level maintaining means includes first detecting means for detecting a high ink level and a low ink level in the second ink tank, and detecting an ink level in the third ink tank. And second detection means for detecting an ink level higher than the low ink level in the second ink tank.

In addition, the apparatus further includes a first valve provided in a path from the third ink tank to the second ink tank, and driving the pump with the first valve closed. The ink in the first ink tank may be guided into the third ink tank, and the ink in the second ink tank may be supplied into the first ink tank. The first valve may be a backflow prevention valve that allows only the flow of ink from the third ink tank to the second ink tank.

The opening of the first valve may be based on a difference between the ink level in the third ink tank and the ink level in the second ink tank.

The apparatus further includes a second valve for switching between communication with the atmosphere and shutoff of the air chamber portion of the third ink tank, and opening the first and second valves to open the third ink tank. May be moved to the second ink tank.

[0027] A replaceable refill ink tank for refilling the third ink tank with ink may be further connected.

Here, the print head may include a thermal energy generator for applying thermal energy to the ink as energy used for discharging the ink.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing the appearance of a printing system as a printing apparatus including an ink supply device (hereinafter also referred to as an ink supply system) of the present invention. Reference numeral 199 denotes an ink jet printer main body, and the ink jet printer 199 is schematically constituted by an ink supply unit 100, a printer unit 200, and a cloth transport unit 300.

A practical printing operation in the above configuration will be described step by step with reference to FIG.

A cloth 301 as a recording medium is set on a cloth supply roller 302 in a roll state. This cloth 30
1 passes under the printer unit 200 while being guided by various guide rollers 303 and 304, and also reaches the cloth winding roller 307 after being given an appropriate tension by the guide rollers 305 and 306. These rollers 3
02 to 307 constitute the cloth transport unit 300. The printer frame 201 is located above the cloth transport unit 300.
The printer frame 201 has two guide rails 20.
2, 203 are supported and fixed in parallel with each other along the direction of arrow A. The carriage 204 has two guide rails 2
02 and 203 are movably supported in the direction of arrow A. On the carriage 204, 16 print heads (205a and 205b are shown as representatives) are
It is attached at a position facing 1. Carriage 2
04 is moved in the direction of arrow A by a drive motor (not shown), for example, the print heads 205a and 205b
Is issued with an ink ejection command as necessary to perform printing. At the end of the movement of the carriage 204, one line of printing is performed at a predetermined position on the cloth 301 according to the ejected ink. After printing one line on the cloth 301,
The cloth 301 is conveyed by a cloth feed belt (not shown) by a predetermined amount in the direction of arrow B (sub-scanning direction) in FIG. Next, when the carriage 204 moves in the direction A while, for example, the print heads 205a and 205b perform ejection as needed, a second line of printing is performed on the cloth 301. By repeating such a series of operations, desired continuous printing is performed on the cloth 301.

Incidentally, for example, the print heads 205a,
An ink tube group 206 is connected to 205b and the like, and the used ink is replenished from the ink supply unit 100 to the print heads 205a and 205b through the ink tube group 206 every time ejection is repeated.

FIG. 2 is a schematic sectional view showing the configuration of an ink supply section 100 as an ink supply device in the textile printing system shown in FIG.

The ink supply unit 100 includes the print head 2
05a (or 205b), the first ink tank 2 containing the ink supplied thereto, and the first ink tank 2
A second ink tank 4 for supplying ink to the
And a third ink tank 5 for supplying ink to the first ink tank 4 and storing the overflowed ink in the first ink tank 2.

The first ink tank 2 includes a carriage 204 movable together with the print head 205a (or 205b) with respect to an apparatus main body constituting the system.
It is installed in. Further, the second ink tank 4 and the third ink tank 5 are fixed to an apparatus main body constituting the system.

At the top of the second ink tank 4, an air communication hole 26 is provided. First ink tank 2 and second ink tank 2
The ink tank 4 and the third ink tank 5 are connected to each other by a first ink flow path 6 and a third ink flow path 7 which are constituted by tubes, joints, and the like. The first ink flow path 6 sends the ink stored in the second ink tank 4 to the first ink tank 2 as shown by an arrow A. The third ink flow path 7 sends the ink in the first ink tank 2 to the third ink tank 5, and a third valve 22 is provided in the middle of the third ink flow path 7. Have been.

The bottoms of the second ink tank 4 and the third ink tank 5 are connected to each other by a second ink flow path 8. A first valve 9 is provided in the middle of the second ink flow path 8. The first valve 9 may be a so-called check valve that allows ink to flow only from the third ink tank 5 to the second ink tank 4 (the direction of arrow C). An air communication passage 11 having a second valve 10 is provided above the third ink tank 5, and an air chamber suction passage 12 for sucking air in an air chamber portion of the third ink tank 5 in the direction of arrow D.
One end is attached. Both the atmosphere communication passage 11 and the air chamber suction passage 12 are made of a flexible material, for example, a silicon tube. The second valve 10 has an atmosphere communication passage 11
Can be opened and closed by crushing a cam member (not shown). By opening and closing the second valve 10, communication between the air chamber portion of the third ink tank 5 and the air can be switched.
In the middle of the air chamber suction passage 12, the tube pump 50 described above is used.
Is provided to suck the air in the air chamber portion of the third ink tank 5.

The rollers 51 of the tube pump 50 are arranged concentrically with the roller holder 52, for example, six in this embodiment. The roller holder 52 is supported rotatably about a rotation shaft 53, and the rollers 51 are also supported rotatably about a roller rotation shaft 54 fixed to the roller holder 52, respectively. The pressing member 55 is urged toward the roller 51 by the compression spring 56 and crushes the tube 12. When the roller holder 52 is rotated by a motor (not shown) in the direction of arrow E, the roller 51 performs a revolving motion.
Air is sucked from the first ink tank 2 directly connected to the head 205a (205b) through the air chamber portion of the ink tank 5 and the third ink flow path 7.

The other end of the air chamber suction path 12 is the waste ink tank 1
3 so that even if the ink in the third ink tank 5 is discharged through the air chamber suction passage 12, the ink is prevented from leaking out of the apparatus.

One end of a fourth ink flow path 14 is connected to the upper part of the third ink tank 5, and the other end of the fourth ink flow path 14 is provided with a tubular first end provided with a hole at the tip. Needle member 15 is provided.

When the supply tank 16 is loaded at a predetermined position, the first needle member 15 is inserted into the ink supply port 17 of the supply tank 16. Reference numeral 28 denotes an atmosphere communication passage for a supply tank, and at one end thereof, a tubular second needle member 18 also having a hole at the tip is provided, and is connected to the supply tank 16 through an opening 20.

The waste ink tank 13 is provided with an air communication hole 19. In the middle of the fourth ink flow path 14, a fourth valve 2 that allows ink to flow only in one direction (the direction of arrow F).
1 is provided, and the third ink tank 5 is
6 is prevented from flowing back.

The second ink tank 4 is provided with an ink level sensor 24 and an ink level sensor 25 as first detecting means, and the third ink tank is provided with an ink level sensor 23 as second detecting means. Is provided.
The ink level sensor 24 detects the minimum ink level of the second ink tank 4, and the ink level sensor 25 detects
The ink level sensor 23 detects the maximum ink level of the third ink tank 5.

In such a configuration, the pressure in the ink chamber of the print head 205a (205b) is determined by the ink level of the second ink tank 4, and the discharge port of the print head 205a (205b) and the second ink tank in FIG. The height difference from the ink level of No. 4 is preferably in the range of 20 to 100 mm. When the height difference is less than 20 mm, the difference is too small, and the fluctuation of the liquid level of the second ink tank 4 causes the unstable discharge performance or the inconvenience that the ink leaks from the discharge port. On the other hand, when the height difference exceeds 100 mm, the negative pressure in the head is too large, which may cause ejection failure.

In the figure, reference numeral 30 denotes a cap which is in close contact with the nozzle surface of the print head 205a (205b) to prevent clogging due to ink drying of the nozzle when the carriage 204 stops at a position called a normal home position outside the recording area. It is a member.

Here, the cap member 30 and the cap means including the accompanying means will be described in detail below.

The capping means is supported by a cap support member (not shown), and includes a print head 205a.
(205b) has a mechanism for making it possible to make contact / separation. Further, one end of a tube 31 for communicating with the atmosphere is attached to the cap member 30, and the other end is in communication with the upper portion of the waste ink tank 13.

The reason why the air communication state is formed in the cap member 30 by using the air communication hole 19 of the waste ink tank 13 is that the air inside the cap is released from the print head 205a (205b) at the time of contact with the print head 205a (205b). 2
This is because it is not pushed into the nozzle 05b).

The tube 31 is provided with a suction pump 32 having both a valve function and an ink suction function. Reference numeral 33 denotes a tube pressure roller, which is a rotation center 35 of the roller holder 34.
And is rotated in the direction of arrow G by the arm 36. Closing the tube 31 can be realized with the tube 31 crushed and the pressure roller 33 stopped. The pressing member 35 is urged toward the pressure roller side by the compression spring 36 to crush the tube 31.

Next, the operation of the ink supply system of the present invention will be described with reference to FIGS.

First, as shown in FIG. 3, when the power is turned on (S1), the ink level sensor 24 provided in the second ink tank 4 detects the presence or absence of ink in the ink tank 4 (S2). Note that “sensor ON” in S2 in the figure indicates “ink present”. same as below. If there is no ink, an initial operation for filling the first, second, and third ink tanks 2, 4, and 5 with ink is started.

First, the valves 22, 9, and 10 are sequentially closed (S
3, S4, S5). The tube pump 50 starts driving (S6), and sucks and decompresses the air chamber of the third ink tank 5. The pressure in the air chamber of the third ink tank 5 is reduced, and the ink in the supply tank 16 is injected into the third ink tank 5 through the tube 14. When the ink level sensor 23 in the third ink tank 5 detects the ink level (liquid level) (S7), the valve 10 is opened (S8), and the inside of the third ink tank 5 is returned to the atmospheric pressure. After opening the valve 10, the driving of the tube pump 50 is stopped (S9). The tube pump 50 does not necessarily need to be stopped because the valve 10 is open, but is preferably stopped to reduce power consumption.

Next, when the valve 9 is opened (S10), the ink is transferred from the third ink tank 5 to the second ink tank 4, and the ink is leveled. Here, leveling means that the connected second ink tank 4 and third ink tank 5
Means that the ink inside does not move to either tank.

Whether the inks in the second ink tank 4 and the third ink tank 5 have been completely leveled depends on the shapes of the second ink tank 4 and the third ink tank 5 and the tubes 8. Although the conditions differ depending on the diameter and the pipe diameter of the valve 9, the leveling time is estimated, and the completion of the leveling is determined by a standby time from the time when the valve 9 is opened to a supply system control unit (not shown) as an ink level maintaining unit. Send a signal (S1
1).

When the ink level sensor 25 of the second ink tank 4 detects ink (S12), the first ink tank 2 is filled with the ink and circulated to expel bubbles in the tube as shown in FIG. Move to operation. If the ink level sensor 25 does not detect ink even after leveling, the process returns to step S3, and after the third ink tank 5 is filled with ink again, leveling is performed (S3 to S11). The above operation is repeated until the sensor 25 detects the ink (S12).

Next, filling of the first ink tank 2 with ink will be described with reference to FIG. First, after the ink level sensor 25 detects ink (S12), the valve 22 is opened (S13), and the valves 9 and 10 are further closed (S1).
4, S15).

At this time, the print head 205a
The capping member 30 of the print head 205a (205b) prevents bubbles from entering from the nozzle (205b).
Performs a contact operation with the print head 205a (205b) (S16), and drives the suction pump 32 to
The tube 31 is crushed by using to close the tube (S17). When the tube pump 50 is driven (S
18), the air chamber of the third ink tank 5 is sucked.
At the same time, the ink in the first ink tank 2 is sucked through the tube 7 and the ink in the second ink tank 4 is sucked through the tube 6.

As described above, the third operation is performed by the tube pump 50.
By sucking the ink tank 5, the ink in the second ink tank 4 can be transferred to the first ink tank 2 and the third ink tank 5, and all the tanks can be filled with the ink.

The above operation determines whether the ink level sensor 24 of the second ink tank 4 detects "no ink" (S1).
9) Alternatively, the operation is stopped depending on whether the ink level sensor 23 of the third ink tank 5 detects "ink present" (S20). Thereafter, the valve 22 was closed (S21).
Thereafter, the valve 10 is opened (S22), and the third ink tank 5 is opened.
To atmospheric pressure. Further, the driving of the tube pump 50 is stopped (S23), the suction pump 32 is driven, the tube is opened to the atmosphere (S24), and the cap 30 is separated from the print head 205a (205b) (S25).
Open the valve 9 (S26) and wait for a certain time (S27)
Perform ink leveling. When the ink leveling is completed, the valve 9
Is closed (S28), the image is ready to be printed (print standby state), and a print standby signal is sent to an ink supply system control unit (not shown) (S29).

After the print standby state (S29), it is possible to select whether to end or continue the recording (S30).
When the printing is ended and the apparatus is stopped, an ink supply system ending operation for quickly shifting to the printing operation at the next startup of the apparatus is performed. In the case of continuous printing operation, the remaining amount of ink in each ink tank is detected, and the presence or absence of ink in the supply tank 16 and the presence or absence of ink in the second and third ink tanks 4 and 5 are constantly determined. The ink supply system is controlled so that the print head 205a (205b) can be stably printed.

Here, the supply system driving operation in the case of performing continuous printing will be described in detail.

In this apparatus, an image is printed on a recording medium on which the print head 205a (205b) is driven based on an image signal of a print instruction from a computer as an ejection control means (not shown) (S31). When the image recording is completed (S3
2) After a timer for detecting the presence or absence of ink in the supply tank 16 is reset (S33), the process is started (S34). The presence or absence of ink in the third ink tank 5 is determined by the ink level sensor 23 (S35), and after the presence of ink is detected, the process proceeds to the next step S36. The ink level sensor 24 of the second ink tank 4 determines the presence or absence of ink (S36). If "ink out" is detected, the process returns to step S26 to perform leveling, and ink is stored in the second ink tank 4. refill.

The ink level sensor 24 of the second ink tank 4 detects "ink present" (S45), and if there is ink, returns to the print standby state (S29).

In step S35, the presence or absence of ink in the third ink tank 5 is determined by the ink level sensor 23. If the third ink tank 5 is not filled with ink, it is within a time sufficient for refilling with ink. If so, the process returns to step S35. If the ink level sensor 23 does not detect ink even after a sufficient time for refilling the ink has passed, it is determined that a time-out has occurred (S37).
Since it is indicated that the ink in the ink supply tank 16 has run out of ink, "out of ink" of the ink supply tank 16 is displayed on a device display panel (not shown) or a computer connected to the device (S38).

Further, in this state, the second ink tank 4
The ink level sensor 24 determines whether ink is present (S
39) If “no ink” is detected, step S
49, stopping all driving (S50-S5
3) Turn off the device power. Second ink tank 4
The ink level sensor 24 detects "ink present" (S39), and if there is ink, returns to the print standby state (S29).

Even if the ink level sensor 24 detects "no ink" during printing, the ink level of the second ink tank 4 is changed from the ink bottom surface to the sensor level surface so that the minimum amount of ink used per sheet can be secured. By taking the required volume up to the required volume, the ink in the second ink tank 4 during printing can be prevented from running out, and bubbles can be prevented from entering the tube.

In the ink supply method of the present invention, the third
It is necessary that the ink level sensor 23 of the ink tank 5 detects that there is ink when shifting from the end of printing to the printing standby state.

In order to realize this state, a print standby signal is output from an ink supply system control unit (not shown) (S29), and at the same time, the state of the presence or absence of ink in the third ink tank 5 is detected. If the ink is not filled, the operation of filling the third ink tank 5 with ink is started.

FIG. 7 shows an operation for filling the third ink tank 5 with ink. When the print standby signal is output as described above (S29), the ink level sensor 23 detects the presence or absence of ink (S54). If there is ink, the operation is terminated. If the state of no ink is detected, the valve 10 is closed. (S
55) The tube pump 50 is driven (S56), and the third ink tank 5 is refilled with ink until the ink level sensor 23 detects the ink level (liquid level) (S56).
57). When the third ink tank 5 is filled with ink, the valve 10 is opened (S58), and the driving of the tube pump 50 is stopped (S59). By these operations, the third ink tank 5 can be maintained in a state of being filled with ink as long as the replenishment tank 16 has ink. In the present ink supply system, ink is supplied to each ink tank. The recording can be performed smoothly without stopping the recording without taking the standby time of the recording.

After the print standby state (S29), if the recording end is selected in the recording end judgment (S30),
An ink supply end operation is performed.

In the present invention, a supply control unit (not shown) for controlling the ink supply operation and a computer (not shown) for controlling the discharge operation of the print head are simultaneously driven by drive control means (not shown). This drive control means may be shared by a computer (not shown).

Hereinafter, the end operation of the ink supply system will be described in detail.

When the end of recording is selected (S30), the third
The presence or absence of ink is detected by the ink level sensor 23 of the ink tank 5 (S40). If there is no ink, the third ink tank 5 is refilled with ink.

First, the valve 10 of the air communication port is closed (S4).
1) The tube pump 50 is driven (S42). After the timer for detecting the presence or absence of ink in the supply tank 16 is reset (S43), the operation is started (S4).
4). The presence or absence of ink in the third ink tank 5 is determined by the ink level sensor 23 (S45), and after the presence of ink is detected, the flow proceeds to the next step S48.

In step S45, the presence or absence of ink in the third ink tank 5 is determined by the ink level sensor 23. If the third ink tank 5 is not filled with ink, it is within a time sufficient for refilling with ink. If so, the process returns to step S45. If the ink level sensor 23 does not detect ink even after a sufficient time for refilling the ink has passed, it is determined that a time-out has occurred (S46).
Since it is indicated that the ink in the ink supply tank 16 has run out, "out of ink" is displayed on the supply tank 16 on a device display panel (not shown) or a computer connected to the device (S47), and the process proceeds to step S48.

Subsequently, the operation of the tube pump 50 is stopped (S48), and the valves 10 and 9 are opened (S49, S5).
0), the ink is transferred to the second ink tank 4, leveling is performed, and after waiting for a predetermined time (S51), the valve 22 is opened (S52), the apparatus power is turned off (S53), and the apparatus is operated. To end.

When the apparatus is restarted to perform the next image recording by the end operation as described above, since each ink tank is already filled with ink, the power is turned on to remove bubbles in the ink supply system. After that, the operation starts from step S13 in which the ink level sensor 24 detects that there is ink in the second ink tank 4, thereby removing bubbles to the ink nozzles, and enabling a stable image output. It can be.

(Others) The present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body and the ink from the apparatus main body are mounted on the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, for example, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

Further, the form of the ink jet recording apparatus of the present invention is not limited to the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0088]

As described above, according to the present invention,
It is possible to prevent air bubbles from entering the head, and to improve the stable operation without stopping the recording without stopping printing on the recording head even during the ink supply operation for filling the ink tank. it can.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a textile printing system as a printing apparatus of the present invention.

FIG. 2 is a schematic sectional view showing an embodiment of the printing apparatus of the present invention.

FIG. 3 is a flowchart for explaining an operation in the embodiment of the printing apparatus of the present invention shown in FIG. 2;

FIG. 4 is a flowchart following the flowchart shown in FIG. 3;

FIG. 5 is a flowchart following the flowchart shown in FIG. 4;

FIG. 6 is a flowchart following the flowchart shown in FIG. 5;

FIG. 7 is a flowchart following the flowchart shown in FIG. 6;

FIG. 8 is a schematic sectional view showing a printing apparatus including a conventional ink supply system.

[Explanation of symbols]

 1, 205a, 205b Print head 2 First ink tank 3,204 Carriage 4 Second ink tank 5 Third ink tank 6 First flow path 7 Third ink flow path 8 Second ink flow path 9 1st valve 10 2nd valve 11 air communication path 12 air chamber suction path 13 waste ink tank 14 fourth ink flow path 15 first needle member 16 supply tank 17 ink supply port 18 second needle member 19 atmosphere Communication hole 20 Atmospheric communication port 21 Fourth valve 22 Third valve 23 Ink level detecting means 24 Ink level detecting means 25 Ink level detecting means 26 Atmospheric communication port 27 Elastic member 28 Atmospheric communication path 50 Tube pump 51 Roller 52 Roller holder 53 rotating shaft 54 roller drive shaft 35, 55 pressing member 36, 56 compression spring 31, 57 tube 100 ink supply Department

Claims (8)

[Claims] A print head that discharges ink; a discharge control unit that controls discharge of ink from the print head; and a first control unit that stores ink supplied to the print head.
An ink tank, a second ink tank that supplies ink to the first ink tank, a third ink tank that receives ink that overflows in the first ink tank, A pump for sucking the air chamber portion, detecting means for detecting the respective ink levels in the second ink tank and the third ink tank, and the second ink tank and the third A printing apparatus comprising: an ink level maintaining unit that maintains each ink level in an ink tank within a predetermined range; and a drive control unit that simultaneously drives the ink level maintaining unit and the ejection control unit. 2. The ink level maintaining means according to claim 2, wherein
First detecting means for detecting a high ink level and a low ink level in the ink tank, and detecting an ink level in the third ink tank and higher than the low ink level in the second ink tank. 2. The printing apparatus according to claim 1, further comprising second detection means for detecting an ink level. A first valve provided in a path from the third ink tank to the second ink tank, wherein the pump is driven in a state where the first valve is closed. Wherein the ink in the first ink tank is guided into the third ink tank, and the ink in the second ink tank is supplied into the first ink tank. Or the printing device according to 2. 4. The printing apparatus according to claim 3, wherein the first valve is a check valve that allows only ink to flow from the third ink tank to the second ink tank. 5. The method according to claim 1, wherein the opening of the first valve is based on a height difference between an ink level in the third ink tank and an ink level in the second ink tank. Item 5. The printing device according to Item 4. 6. The apparatus according to claim 6, further comprising a second valve configured to switch between communication and shutoff of the air chamber portion of the third ink tank with the atmosphere, wherein the first valve and the second valve are opened by opening the first valve and the second valve. 4. The printing apparatus according to claim 3, wherein the ink in the third ink tank is moved to the second ink tank. 7. The printing apparatus according to claim 1, further comprising a replaceable refill ink tank for refilling the third ink tank with ink. 8. The print head according to claim 1, wherein the print head includes a thermal energy generator that applies thermal energy to the ink as energy used to discharge the ink. The printing device according to the above.