JPH1120179A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To collect ink discharged during the non-printing and to facilitate the handling of the ink. SOLUTION: In this printer, a waste ink cassette 70 having a cassette body 71, an absorbing body 72 housed in the cassette body 71 and a check valve 771 is detachably attached to a waste ink tube 58 at the side of a print head. Ink discharged from the print head through an ink discharge means (a waste ink tube 58) during the non-printing is absorbed by the absorbing body 72 to be in an airtight condition, then it is collected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet printer capable of printing an image while jetting ink from a print head to a medium.

[0002]

2. Description of the Related Art In a so-called serial type ink jet printer shown in FIG. 4, a print head 20P and an ink cassette (not shown) are mounted on a carrier 151 which can reciprocate along a guide bar 150, and a medium (paper P) is mounted. The ink is jetted from each nozzle while moving the print head 20P in the row (X) direction (the horizontal direction in the figure) to form an image. Each color ink nozzle of the print head 20P is single in the X direction, and the ink cassette is very large. Therefore, for example, it takes 10 minutes (0.1 PPM) for color printing of one A4 size sheet.

On the other hand, there has been proposed an ink jet printer capable of increasing the printing speed of, for example, 20 PPM (for example, Japanese Patent Application No. 8-296959). In FIG.
The print head units 20C (cyan), 20Y (yellow), 20M (magenta), and 20B (black) for the respective color inks forming the print head unit 20U have the following nozzles:
In the row (X) direction of the medium (paper P), for example, a plurality of pixels are arranged and arranged at a pitch corresponding to the resolution or 1/2 to 1/4 of the pitch corresponding to the resolution. It is possible to reciprocate. The medium (P) is carried on a drum 10 rotatable around the axis Z at, for example, 120 rpm, and moves at a high speed in the R direction. Thus, for example, one A4 size sheet can be color-printed in 2-3 sec.

In addition, since each print head 20 is almost stationary and each ink cassette need not be formed integrally with each print head 20, a large number of separate ink tanks capable of filling a large amount of ink are used. Sheets can be printed continuously.

[0005]

In the ink jet printer, maintenance is performed by discharging ink from each nozzle during non-printing in order to prevent nozzle clogging and to remove gas (bubbles) in any type of ink jet printer. is necessary. When the ejected ink adheres to the surrounding dirt or the print surface, the print sharpness is reduced. However, for example, printing several sheets a day has not been regarded as a problem.

However, when printing a large number of, for example, thousands of sheets continuously for one day, it is difficult to discharge the ink ejected for maintenance to a predetermined location in the printer body. . This is because cleaning is difficult and handling is difficult from the viewpoint of reducing the size and weight. In addition, in high-speed printing as in the previously proposed printer, there is a strong possibility that paper dust generated from the medium (P) adheres to the nozzle tip or tip end face of the print head. Therefore, it is desirable to perform maintenance even during continuous printing operation. In addition, the amount of ejected ink tends to increase.

An object of the present invention is to provide an easy-to-handle ink jet printer capable of collecting ink ejected during non-printing in a sealed state.

[0008]

According to a first aspect of the present invention, there is provided an ink jet printer capable of printing an image while jetting ink from a print head to a medium. Provided with a removable ink cassette that can collect ink ejected through a check valve in the ink discharge tube via a check valve, and this ink cassette can be collected by absorbing ink stored in the cassette body. In addition, the ink jet printer is formed so as to prevent the ink collected by the check valve on the cassette body side from leaking to the outside when detached from the ink discharge tube.

In this invention, the ink discharged during non-printing is discharged through the discharge ink tube, and is recovered by the absorber in the discharge ink cassette attached thereto through the check valve. On the other hand, when the full discharged ink cassette is removed (removed) from the discharged ink tube, the check valve on the cassette body side operates, so that the ink does not leak to the outside. That is, it can be handled in the same manner as in the case of an ink cassette that supplies ink to the print head.

Therefore, the ink ejected during non-printing can be collected in a sealed state, the handling is easy, and there is no need to provide an ink cleaning space. Cost can be reduced.

The invention according to claim 2 is an ink jet printer in which a storage area for ink dropped from the absorber is provided at a position of the cassette body opposite to a position where the check valve is mounted.

In this invention, the ejected ink is collected in the discharge ink cassette through the check valve, and when the absorber becomes saturated with the ink, a part of the ink is disposed at a position opposite to the check valve. Fall into the storage area and save. Therefore,
In addition to providing the same operation and effect as the case of the first aspect of the present invention, it is possible to know the replacement timing of the ink discharge cassette by visually confirming the ink storage condition, for example.

[0013] The invention according to claim 3 is an ink jet printer having a built-in sensor for detecting ink stored in the storage area.

According to the invention, the ink stored in the storage area can be detected by a sensor (for example, a micro level switch). Therefore, in addition to providing the same operation and effect as in the case of the second aspect of the present invention, the replacement time can be known even at a place remote from the printer.

Further, the invention according to claim 4 is an ink jet printer in which a sensor for detecting the ink stored in the storage area is provided outside.

According to this invention, the ink stored in the storage can be detected by a sensor (for example, a photoelectric level detector). Therefore, in addition to providing the same operation and effect as in the case of the second aspect of the present invention, it is possible to know the replacement time even in a place away from the printer and to use the sensor in common with a discharge ink cassette for replacing the sensor. be able to.

Further, the invention according to claim 5 is an ink jet printer in which the lower storage area is horizontally displaced from the upper check valve.

In this invention, the ink collected through the upper check valve goes around the absorber and falls into the lower storage area. That is, it is possible to increase the absolute amount of ink absorbed by the absorber while preventing the absorbent from directly dropping from the check valve to the storage area. Therefore, in addition to providing the same operation and effect as in the inventions of claims 2 to 4, it is possible to further extend the replacement time of the discharged ink cassette or to further reduce the size of the discharged ink cassette.

Further, the invention according to claim 6 is an ink jet printer wherein the ink stored in the storage is formed so as to be visible from the outside.

According to this invention, the storage field is formed of, for example, a transparent material, and the ink stored therein can be visually observed from the outside. Therefore, in addition to providing the same operation and effect as the inventions of the first to fifth aspects, it is possible to more accurately and easily estimate in advance the state of collecting and replacing the discharged ink in the discharged ink cassette. Can be.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. This ink jet printer has the same basic configuration (10, 20) as that of the previous proposal (FIG. 5), except that the cassette main body 71, the absorber 72 housed in the cassette main body 71, and the check valve 100I A detachable ink cassette 70 having the following configuration is detachably attached to the discharge ink tube 58 on the print head (20C) side, and is ejected from the print head (20C) during non-printing and the ink discharge means 50
The ink discharged (through) the (discharged ink tube 58) is oozed into the absorber 72 in the cassette main body 71 and can be collected in a sealed state so as to be recoverable.

A storage area 74 is provided below the cassette body 71, and an external (or built-in) sensor (8) is provided.
0), the saturated state of the absorber 72 can be grasped by detecting the discharged ink stored in the storage field 74.

First, the overall configuration will be described with reference to FIG. As shown in FIG. 3, for example, a print head 20 </ b> C for cyan C color which constitutes a part of the print head unit 20 </ b> U,
A plurality of (four) nozzle units 20CA, 20CB, 20CC, 20CD attached in a staggered manner to a connecting member 29 extending in the row (X) direction of the medium (P),
The ink chambers 21 of each nozzle unit (20) are communicated with each other, and the pitch of each nozzle 22 in the X direction is twice the pitch corresponding to the printing resolution (for example, 400 dpi).

The print head 20C is supplied with ink from the ink cassette 2 to the nozzle unit 20CA via the ink supply system 40, and the ink from the nozzle unit 20CD is returned to the ink tank 2 via the ink return system 46.

The ink cassette 1 can be attached to and detached from the ink tank 2. When mounted, the seal on the ink cassette 1 side is broken. Therefore, the ink I1 can be supplied from the mounted ink cassette 1. Ink in tank I
The liquid level 2 is maintained at a constant level by the level stabilizing means 1L. The liquid level of the ink I2 in the tank is lower than the nozzle height. In addition, 3 is a vent pipe.

The ink supply system 40 includes an ink supply pipe 41,
The print head 20C (2) includes a supply pump 42, an ink adjusting means 43 including a heater, a filter, and the like, and a switching valve 44, and switches the switching valve 44 to one port 44A.
Ink can be supplied to 1). Other port 44B
Is switched to the ink tank 2 via the circulation system (circulation pipe 45). Used for ink temperature adjustment in the initial state. The ink return system 46 includes a return pipe 4
7. The suction pump 48 returns excess ink in the print head 20C to the ink tank 2.

In an ink jet printer, each nozzle 2
The ink Ij is forcibly ejected from Step 2 to perform maintenance for preventing nozzle clogging and degassing. In this embodiment, paper dust adhering to the tip surface 24 of the nozzle units 20CA, 20CB, 20CC, and 20CD and the tip of the nozzle can be removed by effectively utilizing the ejected ink Ij.

That is, the ink receiver is formed from the wash board 30, and the gap between the front surface 24 and the opposing surface 32 which is surrounded by the convex portion 31 and faces the front surface 24 is, for example, 0.1 to 0.5 mm (preferably, 0.1 to 0.5 mm). Is maintained at 0.3 mm) to generate an ink flow between the two 24 and 32, and the ink flow is used to remove paper dust.

The ink discharging means 50 includes an ink collecting chamber 51.
And a discharge pipe 52, a gas-liquid separation chamber 53, a suction pump 54, a discharge ink tube 58, and a discharge pump 57. The discharge ink separated in the chamber 53 is discharged from the discharge ink tube 58 to the outside. The gas (air) is released from the suction pump 54 to the atmosphere.

In this embodiment, the discharge pump 57 can be operated to discharge the waste ink collected in the chamber 62 through the overflow pipe 61 connected to the ink tank to the outside.

Incidentally, in order to continuously perform high-speed printing, maintenance of the print head 20C and removal of paper dust are important, so that the chance of ink discharge tends to increase. Therefore, if the discharged ink is discharged as it is to the outside, the surroundings are soiled and the cleaning work becomes troublesome.

The waste ink cassette 70 introduced to solve these conventional problems pays attention to the convenience of the ink cassette 1 and can handle the same as it. It is possible.

In FIG. 1, the discharge ink cassette 70 is
The ink is soaked in an absorbent (for example, a sponge) 72 which is stored in the cassette body 71 and has a high ink absorbability, and is collected.

On the upper side, two check valves 77I and 77G
A storage area 74 for storing the ink Id that has spilled due to the saturation of the absorber 72 is provided below.

One check valve 77I includes a valve element 78 slidable by a guide 76 and urged upward by a spring 79, and includes a connector 100I on the ink discharge tube 58 side.
To prevent the internal ink from leaking to the outside when it is detached from the printer.

On the other hand, it is attached (attached) to the connector 100I.
In other words, when the skirt 101 is fitted to the check valve 77I (more specifically, when the skirt 101 is pushed further downward in FIG. 1), the rod 104
8 is pushed downward against the urging force of the spring 79, so that the discharged ink Ii is discharged from the discharge ink tube 58 into the cassette body 71 through the through hole 103 provided in the connection portion 105 and the holding plate 102 ( Collection).

The left check valve 100G is connected to the right check valve 1
00I, but the cassette body 71
It is provided to release gas (air) inside to the atmosphere via a discharge tube 59.

In other words, when sucking the discharged ink from the chamber 53 (62), a relatively large amount of air is sucked due to its small amount, and the discharged ink is sent into the closed space (71). I have to get rid of it. That is, it is provided to send out the existing air in the space and the air sent in at the time of discharge to the outside.

In any case, the check valves 77I and 77G are preferably opened and closed simultaneously. Therefore, both connecting devices 10
0I and 100G are attached to the attachment / detachment operation plate 110, and are synchronously detachably attached to both tubes 58 and 59.

The storage area 74 is provided below the inclined surface 73 at the inner lower portion of the cassette body 71, and stores the ink Id that has fallen from the saturated absorber 72. The bottomed cylindrical body 75 forming the storage area 74 is made of a transparent member so that the stored ink Is can be visually checked.

Further, for automatic discrimination of the presence or absence of the stored ink Is, a sensor (photoelectric level detector) 80 comprising a light emitting device 81, a light receiving device 82 and a detecting circuit 83 attached to the base 9 of the printer main body is provided. Is provided. The sensor 80 may be formed of, for example, a micro-level switch or the like, and all or some of its components may be provided on the cassette main body 71 side. In any case, it is preferable to form the detection signal so that it can be externally output.

The location of the storage 74 on the lower side of the cassette body 71 is displaced in the horizontal direction (left and right direction in FIG. 1) from the upper check valve 77I. In the case of FIG. 1, a guide 7 is provided so that the ink Ii can be discharged and fed from the right corner.
6, and a storage area 74 is provided at the center along the center line. Therefore, the sent ink Ii
Can be prevented from falling into the storage 74 through the shortest distance.

In this sense, in order to make the absorber 72 totally and uniformly saturated, for example, the check valve 77
It is preferable that the ink Ii sucked from I is formed so as to be uniformly fed into the inner peripheral surface of the cassette main body 71 using the guide 76.

According to the embodiment having such a configuration, the ink supply system 40 shown in FIG. 2 is driven to increase the ink pressure in each of the ink chambers 21 to perform forcible ejection, or to drive an ink jet controller (not shown) to perform printing. In the same manner as described above, the nozzle 22 is prevented from being clogged and degassing is performed. That is, maintenance is performed. Further, the ink flow is generated by using the wash board 30 and the leading end surface 2 thereof is formed.
4. Remove the paper dust adhering to 4.

The ejected ink Ij is stored in the ink recovery chamber 51 through each outlet 33. Specifically, each nozzle 22
During the period during which the ink is being ejected from or after the end of the ink ejection, the ink discharging means 50 is operated.

That is, when the suction pump 54 is driven to rotate, the ink Ih in the ink recovery chamber 51 is discharged together with the gas through the discharge pipe 52 to the chamber 53, where it is separated into a gas stream. Gas (air) is released to the atmosphere and ink (liquid)
Is stored at the bottom of the chamber 53. And the discharge pump 5
By operating 7, the ink (liquid) is sucked and discharged from the chamber 53.

Here, the drainage tube 58 is connected to the connector 1
The ink discharged through 00I is fed into the cassette main body 71 through the check valve 77I shown in FIG. At this time, the cassette body 7
Excess air (gas) in 1 is checked by the check valve 77G
OG is emitted to the atmosphere through the emission tube 59.

When the number of prints is large, the storage place 74 is visually checked from the outside by removing the base 9 from the base 9 if necessary. The replacement time of the discharged ink cassette 70 can be estimated earlier from the amount of the stored ink Is.

The ink Ii sent one after another is absorbed by the absorber 7
2 is oozed along a two-dot chain line shown on the right side in FIG. Therefore, since the ink does not fall directly to the storage site 74, a large amount of ink can be collected in a sealed state.

When the absorber 72 is saturated for a long time in the printing operation, the ink Is falls from below and is stored in the storage 74. When it reaches a certain level, the sensor 80
Performs the detection operation. Therefore, it is possible to know that it is time to replace the discharge ink cassette 70.

At the time of non-printing and in a state where ink is not ejected, the discharge ink cassette 70 is connected to each tube 58,
Pull out from 59. Then, each check valve 77I, 77G (7
8, 78) is closed by the urging force of the spring 79,
Even if the absorber 72 is in a saturated state, the collected ink does not leak to the outside.

By operating the discharge pump 57, the ink separated in the chamber 62 can be collected in the discharge ink cassette 70.

Thus, the inside of the printer main body and the medium (P) can be completely prevented from being stained with the ink, and the cleaning operation of the stained ink can be eliminated. Therefore, the degree of freedom of the layout inside the printer main body is expanded, so that further reduction in size, weight, and cost can be achieved.

According to this embodiment, the ink discharged from the print head (20C) during non-printing and discharged through the discharge ink tube 58 can be collected, and the ink can be recovered to the discharge ink tube through the check valve 77I. A detachable ink cassette 70 is provided so that the ink can be collected by absorbing the ink into the absorber 72 housed in the cassette main body 71 and the cassette main body 7 can be removed when detached from the ink discharge tube 58.
Since the ink collected by the one-side check valve 77I (77G) can be prevented from leaking to the outside,
The ink ejected during non-printing can be collected in a sealed state, handling is easy, and there is no need to provide an ink cleaning space, so that the degree of freedom in layout within the printer body can be increased and cost can be reduced. .

Further, since a storage area 74 for the ink dropped from the absorber 72 is provided at a position on the opposite side of the position of the check valve 77I of the cassette body 71, the storage state of the ink can be visually checked, for example. Then, it is possible to know the replacement timing of the drainage ink cassette.

Further, since the sensor 80 for detecting the ink stored in the storage area 74 is provided externally, it is possible to know the replacement time even in a place away from the printer and to exchange the sensor 80 with the discharged ink cassette. 70 can be used in common. The sensor 80 is connected to the cassette body 7.
2 may be provided.

Further, since the lower storage area 74 is displaced in the horizontal direction with respect to the upper check valve 77I, the collected ink goes around the absorber 72 and is stored in the lower storage area. Fall to place 74. That is, from the check valve 77I to the storage 7
4, it is possible to increase the absolute amount of ink absorbed by the absorber 72 while preventing the ink from dropping directly on the ink container. Therefore, it is possible to further extend the replacement time of the discharge ink cassette 70 or to further reduce the size of the discharge ink cassette 70.

The storage area 74 is made of a transparent bottomed cylinder 7.
Since the stored ink formed from 5 is made visible from the outside, it is possible to preliminarily estimate the state of collecting and replacing the discharged ink in the discharged ink cassette 70.

Further, since the ink overflowing in the ink cassette 2 can be collected in the discharge ink cassette 70, the inside of the printer main body is not stained from this point, and the ink supply can be stabilized.

Further, the ink ejected from each nozzle 22 is made to flow using the wash board 30 during maintenance or exclusively for removing paper dust, so that the paper dust attached to the front end face 24 can be removed and this ink is also discharged. Since the ink is collected in the ink tank 70, high quality printing can be stably and continuously performed.

Further, since the discharge ink cassette 70 is provided with a check valve 77G for discharging the internal air to the atmosphere,
The discharged ink from the ink discharging means 50 can be sent in a stable manner.

Further, both connecting members 100I, 100G
Is integrally mounted on the detachable operation plate 110, so that the opening and closing of the two check valves 77I and 77G can be performed synchronously. From this point as well, external leakage of the collected ink can be prevented more reliably and handling is further facilitated. It is.

[0063]

According to the first aspect of the invention, it is possible to collect ink discharged from the print head during non-printing and discharged through the discharge ink tube, and to detachably attach to the discharge ink tube via the check valve. The ink collected by the check valve on the cassette body leaks to the outside when the discharged ink cassette oozes into the absorber accommodated in the cassette body and ink can be collected and is detached from the ink discharge tube. Is formed so that ink discharged during non-printing can be collected in a sealed state, handling is easy, and there is no need to provide an ink cleaning space. And the cost of the printer can be reduced.

According to the second aspect of the present invention, the storage space for the ink dropped from the absorber is provided at a position opposite to the position where the check valve is mounted on the cassette body. In addition to providing the same effects as those of the invention, it is possible to know the replacement timing of the discharged ink cassette by visually checking the ink storage condition, for example.

According to the third aspect of the present invention, since the sensor for detecting the ink stored in the storage area is built in,
In addition to providing the same effects as in the case of the second aspect of the present invention, the replacement time can be known even at a place remote from the printer.

Further, according to the fourth aspect of the invention, since the sensor for detecting the ink stored in the storage area is provided outside, the same effect as that of the second aspect of the invention can be obtained. In addition to being able to do so, it is possible to know the replacement time even at a place remote from the printer, and it is possible to use it in common for a discharge ink cassette for replacing a sensor.

Further, according to the fifth aspect of the present invention, since the lower storage area is displaced in the horizontal direction with respect to the upper check valve, the second to fourth aspects of the present invention. In addition to having the same effect as in the case of,
It is possible to further extend the replacement time of the discharge ink cassette or to further reduce the size of the discharge ink cassette.

Furthermore, according to the invention of claim 6, since the stored ink is formed so that the stored ink can be seen from the outside, the same as in the inventions of claims 1 to 5 is provided. In addition to the effect, it is possible to estimate in advance the state of collecting and replacing the discharged ink of the discharged ink cassette.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view for explaining an ink discharge cassette according to an embodiment of the present invention.

FIG. 2 is a system diagram for explaining the entire printer.

FIG. 3 is a view for explaining a print head for one color.

FIG. 4 is a diagram for explaining a conventional example.

FIG. 5 is a diagram for explaining a previously proposed printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink cassette 2 Ink tank 10 Drum 20C-20B Print head 20CA-20CD Nozzle unit 21 Ink chamber 22 Nozzle 24 Tip surface 29 Connecting member 30 Washing board 32 Opposite surface 33 Discharge port 40 Ink supply system 44 Switching valve 45 Circulation pipe 46 Ink Return system 50 Ink discharge means 51 Ink collection chamber 53 Chamber 54 Suction pump 57 Drain pump 58 Drain ink tube 70 Drain ink cassette 71 Cassette body 72 Absorber 74 Storage area 75 Bottomed cylinder 77 Check valve 78 Valve 79 Spring 80 Sensor 100 Connector 104 Rod P Paper (medium)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Sato 570 Ohito, Oni-cho, Takata-gun, Shizuoka Prefecture Inside Tech Ohi Works, Inc.

Claims (6)

[Claims] 1. An ink-jet printer capable of printing an image while jetting ink from a print head to a medium, wherein the ink discharged from the print head and discharged through a discharge ink tube during non-printing can be collected and discharged. A detachable ink cassette is provided on the tube via a check valve, and this ink cassette can be collected by absorbing ink absorbed in the absorber housed in the cassette body and detached from the ink tube. An ink jet printer formed so as to prevent the ink collected by the check valve on the cassette body side from leaking to the outside. 2. The ink jet printer according to claim 1, wherein a storage area for the ink dropped from the absorber is provided at a position of the cassette body opposite to a position where the check valve is mounted. 3. The ink jet printer according to claim 2, further comprising a sensor for detecting ink stored in said storage area. 4. The ink jet printer according to claim 2, wherein a sensor for detecting ink stored in the storage area is provided outside. 5. The storage space on the lower side is displaced in the horizontal direction from the check valve on the upper side.
The inkjet printer according to any one of claims 1 to 4. 6. The ink jet printer according to claim 1, wherein the ink is stored in the storage area so that the stored ink can be viewed from the outside.