JP3843651B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes an ink jet recording head that is mounted on a carriage that moves in the width direction of a recording sheet and that discharges ink onto the recording sheet, and a filter member for removing foreign matter contained in the ink supplied to the recording head. More particularly, the present invention relates to an ink jet recording apparatus configured so that bubbles remaining on the upstream side of a filter member can be easily eliminated.
[0002]
[Prior art]
Inkjet recording devices are used for many printing including color printing in recent years because noise during printing is relatively small and small dots can be formed with high density. Such an ink jet recording apparatus includes an ink jet recording head that receives ink supplied from an ink cartridge, and a paper feeding unit that moves the recording paper relative to the recording head. The recording head is recorded on the carriage. Recording is performed by ejecting ink droplets onto the recording paper while moving in the width direction of the paper.
[0003]
A recording head capable of ejecting black ink and yellow, cyan, and magenta color inks is mounted on the carriage, and full color printing is possible by changing the ejection ratio of each ink as well as text printing with black ink. It is possible.
[0004]
The ink jet recording head has a relationship in which ink pressurized in a pressure generating chamber is ejected from a nozzle as ink droplets onto a recording sheet for printing, so that the ink viscosity increases due to evaporation of the solvent from the nozzle opening, There is a problem that the nozzle opening is clogged due to solidification of dust, adhesion of dust, mixing of bubbles, and the like, resulting in poor printing.
[0005]
For this purpose, the ink jet recording apparatus includes a capping unit for sealing the nozzle opening of the recording head during non-printing, and a wiping member for cleaning the nozzle plate as necessary. The capping means not only functions as a lid for preventing the ink of the nozzle opening from drying when printing is suspended, but also seals the nozzle plate with a cap member when the nozzle opening is clogged. It also has a function of discharging ink from the nozzle openings by negative pressure from the suction pump to eliminate clogging due to solidification of the ink in the nozzle openings and ink ejection failure due to air bubbles entering the ink flow path.
[0006]
The forcible suction / discharge process of ink that is performed to eliminate clogging of the recording head and the inclusion of bubbles in the ink flow path is called a cleaning operation, and this restarts printing after a long pause of the device. Or when the user recognizes that the quality of the recorded image has deteriorated and operates a cleaning switch, for example, and after discharging ink by negative pressure, a wiping member made of an elastic plate such as rubber This is a process involving a wiping operation of the nozzle forming surface.
[0007]
On the other hand, in this type of recording apparatus for consumer use, each ink cartridge enclosing the black ink and the color ink is configured to be detachably mounted on the carriage on which the recording head is mounted, from above. Each cartridge is configured to be supplied with ink to the recording head via a hollow ink supply needle mounted upward on the carriage.
[0008]
[Problems to be solved by the invention]
By the way, in the recording apparatus as described above, the flow path of the ink in the recording head is configured very finely. Therefore, the ink supplied from the ink cartridge to the recording head is free of foreign matters such as dust. It is required to be in a normal state with no contamination. In other words, when foreign matter such as dust is mixed, there is a problem that foreign matter is clogged in the narrow ink supply port or nozzle opening portion in the ink flow path of the recording head. Ink ejection cannot be performed, and in many cases, it is impossible to restore the function of the recording head.
[0009]
Therefore, in general, a filter member for removing foreign matter is disposed in the ink flow path between the recording head and the ink supply needle, and this filter member is configured to prevent foreign matter from entering the recording head side. Yes.
[0010]
On the other hand, in recent years, in order to increase the printing speed, the number of nozzles for ejecting ink has been increased, and driving signals applied to actuators for ejecting ink are increasingly being used. . For this reason, the ink consumption per unit time is also increasing rapidly.
[0011]
Accordingly, the amount of ink passing through the filter member naturally increases, and the area of the filter member needs to be increased in order to suppress the dynamic pressure (pressure loss) of the filter member. For this reason, there is a problem that air bubbles always stay in the space portion upstream of the filter member and cannot be discharged.
[0012]
Therefore, for example, when the upstream side of the filter member is formed into a taper shape, the ink is first filled into the flow path of the recording head, or at the time of replacement cleaning performed when the ink cartridge is replaced, recording is performed. Attempts have been made to discharge the residual bubbles by driving a suction pump that sucks the nozzle forming surface of the head to a negative pressure at a high speed to increase the flow rate of ink. However, the increase in the area of the filter member for suppressing the dynamic pressure of the filter member and the problem with the residual bubbles are based on incompatible actions, and it is difficult to fundamentally remove the residual bubbles. .
[0013]
The present invention has been made in view of the technical problems as described above, and in particular reduces the amount of bubbles remaining upstream of the filter member as much as possible, and at the time of actual use of the recording apparatus, An object of the present invention is to provide an ink jet recording apparatus that can eliminate the occurrence of printing defects due to the influence of bubbles.
[0014]
[Means for Solving the Problems]
An ink jet recording apparatus according to the present invention made to solve the above-described problems includes an ink jet recording head that receives ink supplied from an ink cartridge and ejects ink droplets from nozzle openings, and the ink cartridge and the recording head. An ink jet type comprising a filter member for removing foreign matter, and a capping means for sealing a nozzle opening of the recording head and receiving a negative pressure from a negative pressure generating means The recording apparatus includes a filter chamber composed of an opposing surface that is the filter member and the deformable member and a bowl-shaped space, and the opposing surface is pushed toward the filter chamber by an operating body from the outside of the filter chamber. The effective flow area of the filter member is reduced.
[0015]
At this time, the opposing surface of the filter member can be composed of a deformable member that can be displaced toward the filter member and an operating member for displacing the deformable member.
[0016]
At this time, a configuration in which the deformable member is disposed on the upstream side of the filter member and is in contact with the filter member from the upstream side of the filter member may be employed.
[0017]
Furthermore, it is more preferable that the deformable member arranged on the upstream side of the filter member is positioned immediately above the filter member in the direction of gravity.
[0018]
Furthermore, the filter in which the ink supplied from the horizontal direction orthogonal to the gravitational direction is supplied to the space portion between the filter member and the deformable member and the ink supplied to the space portion is arranged in the horizontal direction. A configuration that passes through the member is more preferable.
[0019]
Furthermore, a configuration in which the deformable member is disposed on the downstream side of the filter member and is in contact with the filter member from the downstream side of the filter member may be employed.
[0020]
At this time, the deformable member disposed on the downstream side of the filter member includes a stretchable film-like member, and a contact member that is formed on the film-like member and comes into contact with the filter member. A configuration in which an ink circulation groove is partially formed can also be adopted.
[0021]
The deformable member is preferably formed of a stretchable laminate film, and the negative pressure generated when the contact of the actuating member is released and the deformable member returns is the meniscus strength at the nozzle opening of the ink jet recording head. It is more preferable to make it smaller.
[0022]
In any form, when the deformable member is displaced toward the filter member, the ink supply path is completely closed, or when the deformable member is displaced toward the filter member, ink supply is performed. A configuration in which a part of the ink can be circulated without closing the path is also appropriately employed.
[0023]
Furthermore, it is possible to adopt a configuration in which the deformation member displacement means displaces the deformation member in synchronization with the contact and separation of the capping means.
[0024]
According to the ink jet recording apparatus configured as described above, the effective area of the filter of the filter member installed in the ink path can be made as variable as possible, and the capping means can negatively affect the nozzle forming surface of the recording head. In the state where pressure is applied, the flow area of the ink passing through the filter member can be increased by reducing the filter area, thereby allowing air bubbles remaining upstream of the filter member to pass downstream of the filter member and recording. It can be discharged from the head.
[0025]
As a result, the amount of bubbles remaining upstream of the filter member is reduced, and the occurrence of printing defects due to the influence of the remaining bubbles can be eliminated during actual use of the recording apparatus.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an ink jet recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. FIG. 1 shows a basic configuration of an ink jet recording apparatus to which the present invention can be applied. In FIG. 1, reference numeral 1 denotes a carriage. The carriage 1 is guided by a guide member 4 through a timing belt 3 driven by a carriage motor 2 and is reciprocated in the axial direction of the platen 5. .
[0027]
An ink jet recording head 7 is mounted on the side of the carriage 1 facing the recording paper 6, and a black ink cartridge 8 and a color ink cartridge 9 for supplying ink to the recording head 7 are attached to and detached from the ink jet recording head 7. It is loaded as possible.
[0028]
Reference numeral 10 in the figure denotes a capping unit arranged in a non-printing area (home position), and is configured to seal the nozzle formation surface of the recording head 7 when the recording head 7 moves directly above. Yes. A suction pump 11 as a negative pressure generating means for applying a negative pressure to the internal space of the capping means 10 is installed below the capping means 10.
[0029]
The capping means 10 functions as a lid for preventing the nozzle openings of the recording head 7 from drying during the rest period of the recording apparatus, and applies a driving signal unrelated to printing to the recording head 7 to apply ink droplets. It functions as an ink receiver at the time of flushing operation to perform idle discharge, and also functions as an ink suction means for sucking ink by applying a negative pressure from the suction pump 11 to the recording head 7.
[0030]
A wiping member 12 made of an elastic body such as rubber is installed in the vicinity of the capping device 10 and wipes the nozzle forming surface of the recording head 7 when the carriage 1 reciprocates toward the capping means 10. A wiping operation is performed.
[0031]
FIG. 2 schematically shows the configuration of the capping means 10 mounted on the recording apparatus shown in FIG. 1 and the suction pump 11 connected thereto. The capping means 10 includes a rectangular cap case 10a having an open upper surface and a cap member 10b made of a flexible material such as a rubber material housed in the cap case 10a. The upper edge is formed so as to protrude slightly from the cap case 10a. An ink absorbing material 10c formed of a porous material is accommodated in the inner bottom portion of the cap member 10b, and the ink absorbing material 10c is held by a holding body 10d formed integrally with the cap member 10b.
[0032]
In addition, a supply port 10e and an air release port 10f are formed in the lower bottom portion of the cap case 10a so as to penetrate the cap case 10a and the cap member 10b, respectively. A suction pump 11 is connected to the suction port 10e of the cap case 10a via a tube T1, and a discharge side of the suction pump 11 is connected to a waste ink tank 13. Furthermore, the atmosphere release valve 14 is connected to the atmosphere release port 10f of the cap case 10a via a tube T2.
[0033]
On the other hand, reference numeral 7 in FIG. 2 indicates a recording head. When the recording head 7 is positioned above the capping means 10 as the carriage moves, the cap means 10 moves to the recording head 7 side, and the nozzle The formation surface 7a is configured to be sealed (capped) by the cap member 10b. A plurality of nozzle openings 7b are formed on the nozzle forming surface 7a, and each of black ink, yellow, cyan, magenta, and the like is generated by the vibration action of the piezoelectric vibrator 7c arranged corresponding to each nozzle opening 7b. Color ink is ejected.
[0034]
In the above configuration, the ink sucking action for discharging the residual bubbles in the recording head or the ink supply path and eliminating the clogging of the nozzle openings is performed by using the cap member 10b as shown in FIG. This is performed in a state in which the air release valve 10 is closed while being brought into close contact with the plate 7a.
[0035]
By operating the suction pump 11 in this state, a negative pressure is applied to the internal space of the cap member 10b, and ink is sucked and discharged from the nozzle openings 7b of the recording head 7. When the negative pressure inside the cap member is reduced to some extent, when the atmosphere release valve 14 is opened, the atmosphere is introduced into the cap member and the internal negative pressure is released. Subsequently, by operating the suction pump 11 again with the air release valve 14 closed, the ink discharged into the cap member is sent into the waste ink tank 13 via the tube T1.
[0036]
Next, FIG. 3 schematically shows a first embodiment according to the present invention in a path from the ink cartridge (black ink cartridge 8 in the figure) to the suction pump 11. In FIG. 3, the parts corresponding to the parts already described are denoted by the same reference numerals.
[0037]
As shown in FIG. 3, the ink supply path 21 between the ink cartridge 8 and the recording head 7 is provided with a filter chamber for removing foreign matter. The filter chamber includes a filter member 22, a facing surface 23 that is a deformable member, and a bowl-shaped space portion 24. The filter member 22 is formed in a flat plate shape, and has a mesh shape in which fine openings are formed throughout. This allows the ink to flow and prevents foreign matter. A counter surface 23, which is a deformable member formed of a stretchable elastic material (laminate film), is disposed immediately above the filter member 22 in the gravitational direction. Between the members 22, a bowl-shaped space 24 is formed.
[0038]
FIG. 4 shows a state seen through in the direction of arrow A in FIG. 3. In the space 24 formed between the facing surface 23 and the filter member 22, the ink is introduced from a horizontal direction perpendicular to the direction of gravity. An introduction hole 25 is formed to receive the supply.
[0039]
On the other hand, an actuating body 31 as an actuating means is arranged above the opposing surface 23 arranged just above the filter member 22 in the direction of gravity. The operating body 31 functions to change the effective flow path area of the filter member 22, and is preferably an elastic body such as a rubber material.
[0040]
According to the above-described configuration, when the operating body 31 abuts against the opposing surface 23 and is further pushed in, the bubbles staying in the upper direction of the gravity disappear and are pushed to the filter member 22 side. In addition, since the effective filter area is reduced, the flow rate of ink passing through the filter is increased, and bubbles remaining in the space 24 pass through the filter member 22 and are discharged to the outside via the recording head 7. (FIG. 5).
[0041]
As shown in FIG. 6, when the operating body 31 is further pushed in and in close contact with the wall surface of the bowl-shaped space 24, the flow path is completely closed, so that the flow path to the suction pump below the filter is maximally decompressed. I can do it. Thereafter, the operating body 31 is slightly returned to unblock the flow path, so that the ink flows vigorously. By this flow, the remaining bubbles can be more completely eliminated. In addition, according to this, there is a secondary merit that foreign matter or the like firmly adhered in the vicinity of the ejection port can be removed by a strong ink flow. By appropriately combining the two states described above, it is possible to properly use appropriate cleaning as required.
[0042]
The components and the operating body from the ink cartridge to the recording head are mounted on the carriage 1, and therefore the operating body 31 can be configured to operate by movement of the carriage. In other words, the operating body can be set to be in a pressed state in conjunction with the carriage moving to the home position and the capping means 10 sealing the nozzle forming surface 7a of the recording head 7.
[0043]
At this time, the negative pressure generated by the repulsive force of the opposing surface 23 when the operating body 31 is separated from the opposing surface 23 is determined based on the pressure at which the recording head does not draw outside air from the ejection port, that is, the meniscus strength of the recording head. If a material with a flexible repulsive force on the opposite surface is used so that the pressure becomes small, the speed when the carriage 1 moves from the home position to the print area side (that is, the capping means 10 is separated and the operating body 31 is also separated). Management can be made unnecessary.
[0044]
Further, at the home position, as shown in FIG. 5, the flow path is not completely blocked, and the carriage 1 is set so as to be completely blocked by moving further away from the printing area than the home position of the carriage 1. Is more preferable. According to this, even if the non-use state at the home position continues for a long time, the ink is supplied from the ink cartridge every time the volatile component such as moisture in the ink evaporates and diverges through the wall surface of the capping means 10. Obstacles such as clogging can be suppressed, and if necessary, the flow path can be completely closed only by the operation of the carriage.
[0045]
Next, FIG. 7 is a schematic view showing a second embodiment of the present invention. In FIG. 7, parts corresponding to the parts already described are denoted by the same reference numerals.
[0046]
In the embodiment shown in FIG. 7, the facing surface 23 formed by a stretchable thin film member (laminate film) is disposed on the downstream side of the filter member 22, and the operating member 31 is further installed on the back surface of the facing surface 23. ing. A contact member 32 that is in contact with the filter member 22 is attached to the inner surface of the facing surface 23. The contact member 32 is configured, for example, in a disk shape, and an ink circulation hole 32a is formed so as to communicate in the circumferential direction from the central portion of the upper surface thereof.
[0047]
In the above configuration, when the operating member 31 is pressed toward the filter member, the contact member 32 comes into contact with the filter member 22 from the lower surface so as to cover almost the entire surface of the filter member 22.
[0048]
Since an ink circulation hole 32a communicating with the circumferential direction is formed in the central portion of the contact member 32, when the suction pump is operated in this state, the ink flows quickly in the filter member 22 corresponding to the ink circulation hole 32a. Occurs locally. Therefore, bubbles existing on the upstream side of the filter member 22 pass through the filter member 22 by this flow and are discharged from the recording head 7.
[0049]
In the embodiment shown in FIG. 7, the ink circulation hole 32a is formed at the center of the contact member 32. The arrangement of the ink circulation hole 32a can be selected as appropriate. Further, the same action can be obtained by setting the diameter of the contact member 32 slightly smaller than the effective area (diameter) of the filter member 22 without providing the ink circulation hole 32a.
[0050]
In this configuration, the pressure and separation of the capping means 10 on the ink ejection surface 7a and the pressure separation of the operating body can be set in the same direction, so that the number of components can be reduced.
[0051]
【The invention's effect】
As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the filter member is provided with the filter member composed of the filter member, the opposing surface as the deformable member, and the bowl-shaped space portion, and from the outside of the filter chamber by the operating body. By reducing the effective flow path area of the filter member by pushing the opposing surface toward the filter chamber, air bubbles upstream of the filter member can be discharged through the filter member. Accordingly, the bubbles staying upstream of the filter member can be greatly reduced, and the occurrence of printing defects due to the influence of the residual bubbles can be eliminated during the actual use of the recording apparatus, and the printing reliability of the recording apparatus can be eliminated. Is guaranteed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a basic configuration of an ink jet recording apparatus to which the present invention is applied.
FIG. 2 is a cross-sectional view showing an example of capping means mounted on the recording apparatus shown in FIG. 1 and its peripheral devices.
FIG. 3 is a schematic diagram showing a first embodiment in a path from an ink cartridge to a suction pump.
4 is a perspective view seen in the direction of arrow A in FIG. 3;
FIG. 5 is a cross-sectional view illustrating the operation in the first embodiment.
FIG. 6 is a cross-sectional view for explaining an operation in the first embodiment.
FIG. 7 is a schematic diagram illustrating a second embodiment in a path from an ink cartridge to a suction pump.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Carriage 6 Recording paper 7 Recording head 7a Nozzle formation surface 7b Nozzle opening 8 Black ink cartridge 9 Color ink cartridge 10 Capping means 11 Suction pump (negative pressure generating means)
12 Wiping member 13 Waste ink tank 14 Air release valve 22 Filter member 23 Opposing surface (deformation member)
24 Space part 25 Ink introduction hole 31 Actuator 32 Contact member 32a Ink flow hole

Claims (6)

An ink jet recording head that receives ink supplied from an ink cartridge and ejects ink droplets from nozzle openings; and a filter member disposed in an ink supply path between the ink cartridge and the recording head for removing foreign matter. An ink jet recording apparatus comprising a capping unit that seals a nozzle opening of the recording head and receives a negative pressure from a negative pressure generating unit,
A filter chamber comprising an opposing surface that is the filter member and the deformable member and a bowl-shaped space,
An ink jet recording apparatus, wherein an effective flow area of the filter member is reduced by pushing the opposing surface toward the filter chamber by an operating body from the outside of the filter chamber.   2. The ink jet recording apparatus according to claim 1, wherein the deformable member is disposed on the upstream side of the filter member and is configured to contact the filter member from the upstream side of the filter member.   The ink jet recording apparatus according to claim 1, wherein the deformable member is formed of a stretchable laminate film.   4. The ink jet recording apparatus according to claim 3, wherein the deformable member disposed on the upstream side of the filter member is positioned directly above the filter member in the direction of gravity.   The ink is supplied to the filter chamber from a horizontal direction orthogonal to the direction of gravity, and the ink supplied to the filter chamber is configured to pass through the filter member arranged in the horizontal direction. An ink jet recording apparatus according to claim 4. The deformable member disposed on the downstream side of the filter member includes a stretchable membrane member and a contact member that is formed on the filter member side surface of the membrane member and contacts the filter member. And
2. The ink jet recording apparatus according to claim 1, wherein an ink circulation groove is formed in a part of the contact member.

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