JPH02122937A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To ensure that an ink discharge recovery action is performed and obtain an ink jet recording device which can be easily manufactured by pressing part of an ink pouch during discharge recovery action and at the same time, moving its pressure point, then allowing ink to run through the ink flow path due to pressure following the movement of the pressure point. CONSTITUTION:When discharge is recovered, an ink absorber 104 is allowed to come in contact with an orifice section 103 and a squeezing member 106 is pushed in. The tip of the squeezing member 106 swivels so that the outlet of the ink pouch is squeezed and the ink is forcibly injected into an ink jet head 101. The injected ink discharges bubbles and sticking materials to the outside of a nozzle. The discharged ink penetrates and becomes absorbed into the ink absorber 104 pressed against the orifice section 103. This prevents the ink from dripping or being scattered from the orifice section 103.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inkjet recording apparatus equipped with a recovery means for preventing clogging of nozzles that eject ink.

[Conventional technology]

In an inkjet recording apparatus, ink is supplied from a recording ink tank to a recording head, and ink droplets are ejected from ejection ports of nozzles provided in the recording head. Incidentally, in such an inkjet recording apparatus, dust or air bubbles may get mixed into the ink tank or the communication portion between the tank and the nozzle. For recording/Gutter nozzles are generally thin, with an inner diameter of several tens of microns, so when the dust and air bubbles reach the nozzles of the recording head, they stick inside the nozzles and obstruct the flow of ink, reducing ink ejection efficiency. This may cause the ink to become clogged, reduce the ejection response to the recording signal, or eventually cause clogging, making it impossible to eject ink. Further, even if an inkjet recording device is filled with ink and no ink is ejected for a long time, constituent components of the ink may precipitate and similarly cause ink ejection abnormalities.

In order to prevent this, it is necessary to restore ink ejection from the nozzle, and there are a pressure recovery method and a negative pressure recovery method as recovery means for this purpose. The negative pressure recovery method is to close the ink discharge port of the nozzle with a cap, and use a suction pump or the like to draw suction through the cap to remove obstructions such as ink particles, bubbles, and dust that accumulate inside the nozzle. It is to be removed from

On the other hand, the pressurization recovery method is a method in which ink is force-fed to a nozzle using a pressure pump or the like, and the ink adherents, air bubbles, dust, etc. are removed by the pressure.

However, in the negative pressure recovery method, it is necessary to create an ink ejection recovery device separately from the print head, which makes it difficult to make the printing device more compact. The problem is that it takes a lot of effort to assemble the device because it is necessary to determine the positional accuracy of the suction hole attached to the device, and if the positional accuracy is poor, the discharge port may be damaged during use. Ta.

In addition, in the above pressurizing method, a pressurizing mechanism is provided in the ink accommodating part or in the ink flow path between the ink accommodating part and the head, and a gear pump, a tube pump, etc. is used for the latter pressurizing mechanism. In this case, since it is provided in the ink flow path, it is difficult to miniaturize it.

A configuration in which the pressure mechanism is provided in the ink storage section has the advantage of being able to be made smaller, and there is, for example, the configuration shown in FIGS. 16 to 18.

FIG. 16 is a sectional view of a pressure mechanism used in a conventional inkjet recording apparatus.

In FIG. 16, l is a nozzle part that ejects ink droplets;
2 is an ink storage part that stores ink 3 to be supplied to the nozzle part 1; 4 is an air layer formed on the top of the ink storage part 2; and 5 is provided on the top plate of the ink storage part 2 to be used when ejection is recovered. a diaphragm that supplies the ink 3 under pressure to the nozzle;
Reference numeral 6 indicates a communication hole formed in the lower part of the diaphragm 5 for communicating the air 7 with the air layer 4, and reference numeral 8 indicates a ventilation hole provided in the ceiling of the diaphragm 5 for communicating the air 7 with the atmosphere.

In the above configuration, when performing discharge recovery, the diaphragm 5 is pressed down while blocking the ventilation hole 8 with a finger. By this operation, the air in the air 7 flows into the air N4 through the communication hole 6 and compresses the air layer 4. As a result, the ink 3 is pressurized and press-fitted into the nozzle portion 1, and air bubbles, adhered substances, dust, etc. inside the nozzle are discharged from the nozzle.

FIG. 17 is a sectional view showing another example of a conventional pressurizing mechanism. In FIG. 17, the same reference numerals are used for the same parts as in FIG. 16, so redundant explanation will be omitted. In FIG. 17, 9 is a push button provided on the top of the ink tank case 11, 10 is a compression coil spring fitted onto the shaft of the push button 9, and 11 is a built-in ink bag 14 that communicates with the nozzle portion 1. 12 is a lever that forms the ceiling of the ink tank case 11 and is formed by having one end broken when the push button 9 is pressed; 13 is a fulcrum that allows the lever 12 to rotate; 14;
is an ink bag.

In the configuration shown in FIG. 17, when the push button 9 is pressed down against the compression coil spring 10, one end of the ink tank case 11 is broken by the pressing pressure, and a lever 12 is formed. The lever X2 rotates downward about the fulcrum 13, and its free end pressurizes a portion of the ink bag 14. By pressurizing the ink bag 14, the ink 3 is press-fitted into each nozzle of the nozzle portion l, recovery of ejection from the nozzles is achieved, and ink ejection abnormality is prevented.

Moreover, FIG. 18 is a sectional view showing a third example of a conventional pressurizing mechanism. Also in FIG. 18, the same reference numerals are used for the same parts as in FIG. 16 or FIG. 17, so redundant explanation will be omitted. In FIG. 18, reference numeral 15 is a pressing member having a flange at the lower end and having a length extending to the center of the ink storage section 2, and whose operating end protrudes outside the ink storage section 2, and 16 is a pressing member 15. This is an O-ring that connects the ink storage portion 2 in a slidable and airtight manner. Reference numeral 17 is an atmospheric release valve provided on the ceiling of the ink storage section 2 to communicate the atmosphere with the air layer 4 during printing and during a recovery operation, and 18 is provided to cover the inlet of the ink supply path to the nozzle section 1. a diaphragm 2, which is also provided with an opening 19 in the ceiling;
0 is a coil spring that is provided between the outer peripheral portion of the diaphragm 18 and the pressing member 15 and always urges the pressing member upward.

In the configuration shown in FIG. 18, the pressing member 1 during the discharge recovery operation
5 is pressed down, the lower end surface of the pressing member 15 comes into contact with the diaphragm 18 so as to close the opening 19. When the pressing member 15 is pressed down in this state, the diaphragm 18
The ink inside the nozzle is force-fed to the nozzle part 1 through the ink supply path, and the ink stuck inside the nozzle, air bubbles, dust, etc. are ejected to the outside of the nozzle, and ejection recovery is completed. Then the pressing member 15
When you release your finger, the coil spring 20 causes the pressing member 15 to
is pushed back upwards. Since the shape recovery of the diaphragm 18 is slow with respect to the return of the pressing member 15, the opening 19
quickly communicates with the ink 3 and does not generate negative pressure in the nozzle section 1.

However, the conventional pressurizing mechanism shown in FIGS. 16 to 18 has the following problems.

The configuration shown in FIG. 16 has a problem in that as the amount of ink in the ink storage section 2 decreases, the pressurizing ability of the diaphragm 18 changes and the ejection recovery force becomes unstable.

Here, in order to maintain sufficient pressurizing capacity even when the ink 3 is consumed and the volume of the air layer 4 increases, it is necessary to increase the pressurizing capacity by the diaphragm 5. The second problem of increasing the size of the unit also arises, and the first problem of not being able to perform stable ejection recovery still remains unsolved.

Further, in the configuration shown in FIG. 17, there is a problem that as the ink 3 is consumed, the amount of pressure applied to the ink bag 14 by the lever 12 changes greatly, and the pressure recovery force becomes unstable. especially,
When almost no ink 3 remains in the ink bag 14, pressure recovery may become impossible.

Furthermore, in the configuration shown in FIG. 18, as the pressing member 15 moves up and down, the liquid tightness of the O-ring 16 may deteriorate, and there is a risk that the ink 3 may leak out of the ink tank case 11. Further, if the lower end of the pressing member 15 returns to its original state while remaining in close contact with the opening 19 of the diaphragm 18, a problem arises in that negative pressure is generated in the nozzle portion 1 and atmospheric air is drawn into the nozzle.

〔the purpose〕

It is an object of the present invention to provide an inkjet recording apparatus that can solve the problems of the prior art, can be made smaller, can reliably perform an ink ejection recovery operation, and is easy to manufacture.

[Means to achieve the purpose]

The present invention is configured such that a part of the ink bag is pressed during the ejection recovery operation, and the pressing point is moved, so that the ink in the ink flow path is force-fed to the head as a result of this movement. The goal is to achieve the following.

〔Example〕

The present invention will be specifically described below with reference to FIGS. 1 to 15.

FIG. 1 is a schematic perspective view showing an embodiment of an ink jet recording apparatus according to the present invention.

In FIG. 1, 101 is a recording head, 102 is an ink cartridge, 303 is a carrier that carries the recording head 101 and the ink cartridge 102 and moves in the main scanning direction (print digit direction), 304 is a recording head O1. a platen roller facing and arranged along its moving direction;
305 is a recording medium such as paper that is in close contact with the platen roller 304.

2 and 3 are schematic perspective views showing an example of the structure of the ink cartridge 102 in FIG. 1, respectively.

Note that the ink cartridge 102 in FIGS. 2 and 3
A recording head 101 is integrally incorporated in both of them.

In FIG. 2, 101 is a head that ejects ink droplets during recording, 102 is an ink cartridge that supplies ink to the liquid chamber of the head 101, 103 is an orifice portion of a nozzle of the head 101, and 104 is a head that is sent to the orifice portion 103 when ejection recovery is completed. The ink absorber 106 that comes into contact with the ink absorber 106 is a squeezing member that moves in the direction of the arrow shown in the figure and squeezes an ink bag (described later) built into the ink cartridge.

In FIG. 2, when performing ejection recovery, the ink absorber 1
04 to the orifice part 103, and the squeezing member 106
Push in. The tip of the squeezing member 106 swings as if squeezing the ink outlet of the ink bag, and presses ink into the head 101. The press-filled ink discharges air bubbles, stuck substances, etc. inside the nozzle to the outside of the nozzle. The discharged ink is transferred to the ink absorber 104 that is pressed against the orifice portion 103? +'lt and absorbed. Therefore, there is no possibility that it will fall or scatter from the orifice portion 103.

Next, the configuration shown in FIG. 3 will be explained. In FIG. 3, the same reference numerals are used for the same parts as in FIG. 2, so redundant explanations will be omitted.

This embodiment uses a cap 105 that can be brought into close contact with the orifice section 103 instead of the ink absorber 104 having the structure shown in FIG. The present invention is characterized in that a pressing member 109 connected to 108 for suctioning waste ink is provided, and ejection recovery is performed by suctioning the ink.

In the configuration shown in FIG. 3, when performing discharge recovery, the cap 105 is brought into close contact with the orifice portion 103, and then the squeezing member 106 is pushed in. As a result, the ironing member 10
The tip of 6 moves while squeezing the specified area of the ink bag,
The ink at the outlet of the ink bag is forced into the head to restore ejection. The waste ink discharged from the orifice portion 103 passes through the space formed by the camp 105 and is sucked into the waste ink suction hole 108. Waste ink suction hole 10
The waste ink sucked into the ink cartridge 8 is sucked into the waste ink storage section in the ink cartridge.

The recording head 101 includes the ink cartridge 10
Although it is possible to make it separate from 2, it is preferable to make it integral as shown in the figure, since everything around the ink can be made disposable and the reliability of the device can be improved.

Next, the detailed configuration of FIG. 3 will be explained with reference to FIG. 4.

FIG. 4 is a sectional view taken along the line IV-rV in FIG. 3. In FIG. 4, 110 is a waste ink absorber, 111 is a waste ink suction port connected to the waste ink suction hole 108, 112 is an ink bag containing ink 120 to be supplied to the head 101, and 117 is an outlet of the ink bag 112. 118 is a suction pump, 118A is a valve of the suction pump 118, and 119 is a tube connecting the suction pump 118 and the storage portion of the waste ink absorber 110. .

FIG. 5 is a sectional view taken along the line V-V in FIG. 4, and shows the ink bag 1.
The lower part of the joint part 117 forms an ink flow path.
is connected to. In addition, the tip of the squeezing member 106 is disposed so as to face the ink flow path, and a space is provided for accommodating the tip that swings downward while squeezing the ink bag in the ink flow path as it is inserted. It is secured in front of the ink flow path.

6 and 7 are a plan view and a front view showing the detailed configuration of the squeezing member 106. FIG. In each figure, 200 is a main body that becomes an operating rod, 201 is a pair of roller supports that are rotatably attached to the tip of the main body, and 202 is a roller support that is engaged between the roller support 201 and the main body 200. body 20
A spring 203 that urges the ink bag 112 in the counterclockwise direction is rotatably supported between the roller supports 201.
An ironing roller 204 presses against the roller support 201
This is a stopper that locks the

Next, the operation of the embodiment with the above configuration will be explained in FIGS. 8 to 11.
This will be explained with reference to the figures.

The ink cartridge 102 is mounted by being pushed from above into a carriage that moves the head, and during the mounting process, a needle joint (not shown) provided on the carriage pierces the joint portion 117. This allows the ink in the ink bag 112 to be supplied to the head 1.

During normal times (during recording), the squeezing member 106 is
As shown in FIG. 1, the squeezing roller 203 is kept separated from the surface of the ink bag 112, and
The second ink flow path F is open. Therefore, ink is supplied to the nozzles of the head 1 according to its consumption.

Next, a recovery operation is performed after a recording operation is performed for a certain period of time, or when a paused state continues for a long time.

First, after the recording operation is interrupted, the squeezing member 106 is pushed in as shown in FIG. 8, and the squeezing roller 203 presses the ink bag 112 in the ink flow path section F, thereby blocking the ink flow path section F. As a result, ink is retained in the ink flow path between the blocking portion and the joint portion 117.

This ink is used for ejection recovery.

When the squeezing member 106 is further pushed in from the state shown in FIG. 8, the roller support 201 rotates against the spring 202 as shown in FIG. 9, so that the squeezing roller 203 descends while squeezing the ink bag 112. Therefore, as the squeezing roller 203 descends, the ink in the ink bag 112 is force-fed to the head 1 via the joint portion 117.
A discharge recovery operation is performed.

As the squeezing roller 203 continues to descend, the roller support 201 gradually angles from the horizontal position, and finally exceeds 90 degrees and is pulled by the spring 202, as shown in FIG. It comes into contact with the wall. In this state, the squeezing roller 203 is completely separated from the ink bag 112, so
The ink flow path is formed again, and the ejection recovery operation ends.

Then, in the process of pulling back the squeezing member 106, the roller support 201 is pushed by the wall and rotated counterclockwise, and when it is returned to near the horizontal position, the spring 202 returns it to the state shown in FIG. It will look like Figure 11. The roller support body 201 is locked by a stopper 204 and stably held.

Next, the operation of the suction pump 118 will be explained in FIGS.
This will be explained with reference to FIG. 12 to 14 show cross-sectional views taken along the line X11-X11 in FIG. 4. FIG. 12 shows a normal recording state, in which the bellows portion of the suction pump 118 is extended.

FIG. 13 shows a state in which the pressing member 109 is pushed in the direction of the arrow shown in the figure, and the bellows portion of the suction pump 118 is contracted while the valve 118A remains open. In this state, the valve 11
Since 8A is open, negative pressure and pressurization are not generated in the tube 119 even though the suction pump 118 is operated. FIG. 14 shows a state in which the pressing member 109 is pulled back from the state shown in FIG. 13. The valve 118A closes when the pressing member 109 begins to pull back, and the bellows portion expands in this state, so that the tube 119
Negative pressure is generated in the storage part of the waste ink absorber 110 through
The waste ink discharged into the cap 105 is sucked into the waste ink suction hole 108 and further into the waste ink absorber 110. The pressing member 109 is operated in conjunction with the squeezing member 106.

FIG. 15 is a front view showing another embodiment of the laddering member 106.

In FIG. 15, reference numeral 205 denotes a rotating body supported at the tip of the main body 200 so as to be able to swing freely and rotatably in the length direction thereof, and 206 is disposed near the shaft of the rotating body 205. 207 is a ratchet gear coaxially attached to the side surface of the rotating body 205, 208 is an ironing roller rotatably attached to the periphery of the rotating body 205, and 209 is a A driving body slidably installed on the top surface of the main body 205;
210 is a claw pivotally supported at the tip of the driving body 209; 211
is a spring that is engaged with the shaft of the pawl 210 and biases the pawl 210 clockwise.

In the configuration shown in FIG. 15, when performing the discharge recovery operation, the main body portion 200 is advanced by a certain distance, and then the driver 209 is reciprocated within a predetermined distance range, so that the pawl 210 engages the ratchet gear 207. Rotate. In response, the rotating body 205 rotates, and the squeezing roller 208 descends while being pressed against the ink bag 112, squeezing the ink bag 112 in the ink flow path and forcing the ink inside to the joint portion 117. Rotating body 205 and squeezing roller 2
08 is perpendicular to the ink bag 112, the rotating body 205 swings to the left in the figure, and the rotating body 205
can be rotated easily.

When the rotating body 205 rotates to this angle, the squeezing roller 208 separates from the surface of the ink bag 112, an ink flow path is formed, and the ejection recovery operation ends.

According to each of the above embodiments, the ink for ejection recovery is force-fed to the head by pressurizing the ink bag, so the ejection recovery operation can be achieved with a simple configuration. Unlike squeezing a circular tube, for example, squeezing an ink bag completely blocks the flow path and completely restores itself after squeezing, making the ejection recovery operation and recording operation after this operation ideal. can be done.

Furthermore, in the above explanation, the squeezing roller was moved in the direction of the joint portion 117, but conversely, by moving the squeezing roller from the head direction toward the ink storage portion, the meniscus in the nozzle is pushed back. It is also possible to allow air to enter the nozzle.

〔Effect of the invention〕

As is clear from the above description, according to the inkjet recording apparatus of the present invention, a part of the ink bag in the ink cartridge is pressed during ejection recovery, and the ink is force-fed to the recording head by moving the pressing point. Since the pressurizing means is provided, the ejection recovery mechanism can have a simple configuration, and the recording apparatus can be downsized.

The pressure means includes a rotating roller that can come into contact with the entire ink bag forming the ink flow path, and a driving means that moves the rotating roller a predetermined distance in the direction of the recording head while keeping the rotating roller in pressure contact. It is preferable to have a configuration that includes the following.

Furthermore, it is preferable that an absorber for absorbing waste ink is brought into contact with the waste ink ejection surface of the recording head in conjunction with the operation of the pressure means.

Furthermore, a cap that is brought into close contact with the waste ink ejection surface of the recording head while forming a space in conjunction with the operation of the pressure means, and a suction means that sucks the waste ink in the cap into the waste ink storage section. It is preferable that the discharge recovery system be integrated into the device so as to make the device more compact and reduce the number of assembly steps during production.

Furthermore, since the recording head is integrated into the ink cartridge, the so-called "ink surroundings" including the ejection recovery system are all disposable, and the conventional ejection recovery system is disposed on the main body of the printing apparatus. It has become possible to improve the reliability of the device compared to the configuration.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing essential parts of an inkjet recording apparatus according to an embodiment of the present invention, FIG. 2 is a schematic perspective view showing an example of the configuration of an ink cartridge in FIG. 1, and FIG. 1 is a schematic perspective view showing another configuration example of the ink cartridge in FIG. 1, FIG. 4 is a sectional view taken along line It/-IV in FIG. 3, and FIG. A cross-sectional view along V,
FIG. 6 is a plan view of the ironing member in FIGS. 2 and 3;
7 is a front view of FIG. 6, FIGS. 8 to 11 are schematic sectional views explaining the operation of the squeezing means in FIG. 5, and FIGS. 12 to 14 are suction A schematic sectional view taken along the line X1l-XII in FIG. 4 explaining the operation of the pump, the first
FIG. 5 is a schematic front view showing another structural example of the laddering member, and FIGS. 16 to 18 are schematic cross-sectional views showing the main parts of a pressurized ejection recovery device of a conventional inkjet recording apparatus. 101---------1 Record Hesod, 102--1-
----- Ink cartridge, 103------
Orifice part, 104 --- Ink absorber, 10
5---------Head cap, 106------
--L member, 109-----One pressing member, l O
8------Waste ink suction hole, 110Waste ink absorber, 112---Ink bag, 1i 3------
----Ink flow path, 115-------Ink pressure section, 117---Joint section, 200---
-Main body, 201-----1--Roller support,
202.206.211----- Spring, 203.208--Stringing roller, 205-------
--One rotating body, 209.--One--Driver, 210--
------One claw, 207~...-Ratchet gear. Agent Patent Attorney Yasushi Oto ■ Ichikuω Otsu - Hi

Claims (5)

[Claims] (1) In an inkjet recording apparatus that includes a recording head equipped with a nozzle for ejecting ink droplets, an ink bag containing ink to be supplied to the head, and an ink cartridge containing the ink bag, the An inkjet recording apparatus comprising a pressurizing means that presses a part of the ink bag and moves the press point to forcefully feed ink to the head. (2) The pressure means includes a rotating roller that can be pressed against the entire width of the ink bag forming the ink flow path, and a driving means that moves the rotating roller a predetermined distance in the direction of the recording head while keeping the rotating roller in pressure contact. 2. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus comprises: (3) The inkjet recording apparatus according to claim 1, wherein an absorber for absorbing waste ink is brought into contact with the waste ink ejection surface of the nozzle in conjunction with the operation of the pressurizing means. (4) A cap that is brought into close contact with the waste ink ejection surface of the nozzle with a space formed in conjunction with the operation of the pressurizing means, and a suction means that sucks the waste ink in the cap into the waste ink storage section. The inkjet recording apparatus according to claim 1, further comprising: an inkjet recording apparatus; (5) The inkjet recording apparatus according to claim 1, wherein the recording head is integrally assembled with the ink cartridge.