JP2001018414A - Ink jet recording device - Google Patents

Abstract

(57) [Problem] To effectively eliminate bubbles remaining upstream of a filter member arranged in an ink supply path, and to secure printing reliability of a recording apparatus. SOLUTION: A deformable film-shaped facing surface 23 is provided immediately above a filter member 22 arranged in an ink supply path 21.
And an operating body 31 on the back surface of the facing surface 23. The nozzle forming surface of the recording head 7 is sealed by the capping unit 10, and suction is performed by the suction pump 11 while the operating body 31 is pressed against the facing surface 23. As a result, the residual air bubbles are pushed to the filter member 22 side and are eliminated downstream of the filter member by the strong ink flow generated by the reduction of the effective area of the filter member 22, and are discharged from the recording head 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type recording head mounted on a carriage which moves in the width direction of a recording sheet and ejects ink to the recording sheet, and a foreign matter contained in the ink supplied to the recording head. The present invention relates to a recording apparatus having a filter member for removing, and more particularly, to an ink jet recording apparatus configured so that air bubbles remaining on the upstream side of the filter member can be easily removed.

[0002]

2. Description of the Related Art Ink jet recording apparatuses have been used in many printings including color printing in recent years, because noise at the time of printing is relatively small and small dots can be formed at a high density. Such an ink jet recording apparatus includes an ink jet recording head that receives supply of ink from an ink cartridge, and a paper feeding unit that moves recording paper relative to the recording head, and records the recording head on a carriage. Recording is performed by ejecting ink droplets onto the recording paper while moving in the width direction of the paper.

On the carriage, a recording head capable of discharging black ink and each color ink of yellow, cyan, and magenta is mounted, and by changing not only the text printing with black ink but also the discharge ratio of each ink, Enables full-color printing.

In the ink jet type recording head, the ink pressurized in the pressure generating chamber is ejected from a nozzle as an ink droplet onto a recording sheet to perform printing, so that the ink viscosity increases due to evaporation of a solvent from a nozzle opening. Also, there is a problem that the nozzle openings are clogged due to solidification of ink, adhesion of dust, and mixing of air bubbles, resulting in poor printing.

For this purpose, the ink jet recording apparatus is provided with a capping means for sealing the nozzle openings of the recording head during non-printing, and a wiping member for cleaning the nozzle plate if necessary. The capping means not only functions as a lid for preventing drying of the ink in the nozzle openings when printing is stopped, but also when the nozzle openings are clogged, seals the nozzle plate with a cap member, Due to the negative pressure from the suction pump,
It also has a function of sucking and discharging ink from the nozzle opening to eliminate clogging due to solidification of the ink in the nozzle opening and ink ejection failure due to air bubbles entering the ink flow path.

[0006] Forcible suction and discharge processing of ink for eliminating clogging of the recording head and mixing of air bubbles into the ink flow path is called a cleaning operation, which is performed after a long period of suspension of the apparatus. This is executed when printing is restarted, or when the user recognizes that the quality of the recorded image has deteriorated and operates, for example, a cleaning switch.After discharging ink by negative pressure, the ink is discharged from an elastic plate such as rubber. This is a process involving a wiping operation of the nozzle forming surface by the wiping member.

On the other hand, this type of consumer printing apparatus is configured such that each of the ink cartridges enclosing the black ink and the color ink can be detachably mounted on a carriage on which a printing head is mounted from above. Each of the cartridges is configured to supply ink to the recording head via a hollow ink supply needle mounted upward on the carriage.

[0008]

By the way, in the above-described printing apparatus, the flow path of the ink in the print head is very fine, and therefore, the ink is supplied from the ink cartridge to the print head. Ink
It is required to be in a normal state in which foreign matter such as dust is not mixed. That is, in the case where foreign matter such as dust is mixed in, there is a problem that the foreign matter is clogged in the ink supply port and the nozzle opening portion which are particularly narrow in the ink flow path of the recording head. Ink ejection cannot be performed, and in many cases, the function of the print head cannot be restored.

Therefore, generally, a filter member for removing foreign matter is arranged in an ink flow path between the recording head and the ink supply needle so that foreign matter can be prevented from entering the recording head by this filter member. It is configured.

On the other hand, recently, in order to increase the printing speed, the number of nozzles for ejecting ink has been increased, and drive signals applied to an actuator for ejecting ink have been increasingly used at higher frequencies. Is being done. For this reason, the amount of ink consumption per unit time is also rapidly increasing.

Accordingly, the amount of ink passing through the filter member naturally increases, and the area of the filter member must 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 and cannot be discharged in the space upstream of the filter member.

Therefore, the upstream side of the filter member is formed into a tapered shape, for example, at the time of initial filling when ink is firstly filled into the flow path of the recording head, or at the time of replacement cleaning performed when the ink cartridge is replaced. Attempts have been made to increase the flow rate of the ink by driving a suction pump that suctions the nozzle forming surface of the recording head to a negative pressure at a high speed to discharge the residual air bubbles. However, the problem with the increase in the area of the filter member for suppressing the dynamic pressure of the filter member and the problem with the residual air bubbles are based on incompatible actions, and it is difficult to fundamentally remove the residual air bubbles. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned technical problems. In particular, the present invention reduces the amount of air bubbles remaining upstream of a filter member as much as possible, and at the time of actual use of a recording apparatus. It is an object of the present invention to provide an ink jet recording apparatus which can eliminate the occurrence of printing defects due to the influence of the residual air bubbles.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an ink-jet recording apparatus according to the present invention is configured to receive ink from an ink cartridge and discharge ink droplets from nozzle openings. A head, a filter member disposed in an ink supply path between the ink cartridge and the recording head, for removing foreign matter, and sealing a nozzle opening of the recording head to reduce a negative pressure from a negative pressure generating unit. An ink jet recording apparatus comprising: a capping means for receiving the ink; a filter area of a filter member is made as variable as possible.

At this time, the filter member can be constituted by a deformable member whose opposing surface can be displaced toward the filter member, and an operating member for displacing the deformable member.

At this time, it is possible to adopt a configuration in which the deformable member is arranged on the upstream side of the filter member, and is brought into contact with the filter member from the upstream side of the filter member.

Further, it is more preferable that the deformable member arranged on the upstream side of the filter member is located immediately above the filter member in the direction of gravity.

Further, ink is supplied to a space between the filter member and the deformable member from a horizontal direction orthogonal to the direction of gravity, and the ink supplied to the space is arranged in a horizontal direction. Further, a configuration in which the filter member passes through the filter member is more preferable.

Further, it is possible to adopt a configuration in which the deformable member is disposed downstream of the filter member, and the deformable member contacts the filter member from the downstream side of the filter member.

At this time, the deformable member disposed downstream of the filter member is constituted by a stretchable film-like member and a contact member formed on the film-like member and contacting the filter member. A configuration in which an ink circulation groove is formed in a part of the contact member may be adopted.

Preferably, the deformable member is formed of a stretchable laminate film, and further, a negative pressure generated when the contact of the operating member is released and the deformable member returns is applied to the nozzle opening of the ink jet recording head. More preferably, it is smaller than the meniscus strength in the above.

In any of the embodiments, 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. Also, a configuration in which a part of the ink can be circulated without setting the ink supply path to the closed state is appropriately adopted.

Further, a configuration may be adopted in which the deforming member displacement means displaces the deforming member in synchronization with the contact and separation of the capping means.

According to the ink jet recording apparatus constructed 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 nozzles of the recording head are formed by the capping means. In a state where a negative pressure is applied to the surface, the flow velocity of the ink passing through the filter member can be increased by reducing the filter area, so that bubbles remaining upstream of the filter member pass to the downstream side of the filter member. And discharge it from the recording head.

As a result, the amount of bubbles remaining upstream of the filter member is reduced, and the occurrence of printing defects due to the effects of the remaining bubbles can be eliminated during the actual use of the recording apparatus.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 configured to be reciprocated in the axial direction of a platen 5 by being guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2. .

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 for supplying ink to the recording head 7 and a color ink cartridge 9 is removably mounted.

In the drawing, reference numeral 10 denotes capping means arranged in a non-printing area (home position), which can seal the nozzle forming surface of the recording head 7 when the recording head 7 moves directly above. It is configured. Below the capping means 10, the capping means 1 is provided.
A suction pump 11 is provided as a negative pressure generating means for applying a negative pressure to the internal space of No. 0.

The capping means 10 functions as a lid for preventing the nozzle openings of the recording head 7 from drying during the pause of the recording apparatus, and also applies a driving signal unrelated to printing to the recording head 7. It functions as an ink receiver at the time of a flushing operation for idly discharging ink droplets, and also has a function as ink suction means for sucking ink by applying a negative pressure from the suction pump 11 to the recording head 7.

In the vicinity of the capping device 10, a wiping member 12 made of an elastic material such as rubber is provided. When the carriage 1 reciprocates toward the capping means 10, the nozzle forming surface of the recording head 7 is formed. Is configured to perform a wiping operation for wiping.

FIG. 2 schematically shows the structure of the capping means 10 mounted on the recording apparatus shown in FIG. 1 and the suction pump 11 and the like 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 stored in the cap case 10a.
The upper end of the cap member 10b is formed to project slightly from the cap case 10a. An ink absorbing material 10c formed of a porous material is accommodated in the inner bottom of the cap member 10b, and the ink absorbing material 10c is held by a holder 10d formed integrally with the cap member 10b.

A supply port 10e and an atmosphere opening port 10f are formed in the lower bottom 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 a 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. further,
An atmosphere opening valve 14 is connected to the atmosphere opening port 10f of the cap case 10a via a tube T2.

On the other hand, reference numeral 7 in FIG. 2 denotes a recording head. When the recording head 7 is positioned above the capping means 10 with the movement of the carriage, the cap means 10 moves to the recording head 7 side. The nozzle forming surface 7a is configured to be sealed (capped) by the cap member 10b. A plurality of nozzle openings 7b are formed in the nozzle forming surface 7a, and black ink and each of yellow, cyan, magenta, and the like are generated by the vibration action of a piezoelectric vibrator 7c arranged corresponding to each nozzle opening 7b. It is configured to eject color ink.

In the above configuration, the ink suction operation for discharging the residual air bubbles in the recording head or the ink supply path and eliminating the clogging of the nozzle openings is shown in FIG.
As shown in FIG. 5, the cap member 10b is brought into close contact with the nozzle plate 7a of the
This is performed with 0 closed.

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 atmosphere release valve 14 is opened when the negative pressure inside the cap member has decreased to some extent, 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 atmosphere opening valve 14 closed, the ink discharged into the cap member is sent to the waste ink tank 13 via the tube T1.

Next, FIG. 3 is a schematic diagram showing a first embodiment according to the present invention in a path from an ink cartridge (the black ink cartridge 8 in the figure) to the suction pump 11. In FIG. 3, parts corresponding to the parts described above are denoted by the same reference numerals.

As shown in FIG. 3, a filter chamber for removing foreign matter is provided in the ink supply path 21 between the ink cartridge 8 and the recording head 7. The filter chamber includes a filter member 22, a facing surface 23 as a deformable member, and a bowl-shaped space 24. The filter member 22 is formed in a flat plate shape, and is formed in a mesh shape in which fine openings are formed throughout. This allows the ink to flow and acts to prevent foreign matter. The opposing surface 23 which is a deformable member formed of an elastic material (laminate film) that can be expanded and contracted is attached immediately above the filter member 22 in the direction of gravity. Between the member 22, a bowl-shaped space portion 24 is formed.

FIG. 4 shows a state seen through in the direction of arrow A in FIG. 3, in which the space 24 formed between the opposing surface 23 and the filter member 22 has a horizontal direction perpendicular to the direction of gravity. Inlet 2 to receive ink supply from
5 are formed.

On the other hand, above an opposing surface 23 disposed immediately above the filter member 22 in the direction of gravity, an operating body 31 as operating means is disposed. The operating body 31 functions to change the effective flow area of the filter member 22, and is preferably an elastic body such as a rubber material.

According to the above-described structure, when the operating body 31 comes into contact with the opposing surface 23 and is further pushed in, the air bubbles staying upward in the direction of gravity lose their location and are pushed to the filter member 22 side. In addition, since the area of the effective filter is reduced, the flow velocity of the ink passing through the filter is increased, and the 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).

As shown in FIG. 6, when the operating body 31 is further pushed in and is brought into close contact with the wall surface of the bowl-shaped space 24, the flow path is completely closed. The pressure can be reduced to a minimum. Then, by slightly returning the operating body 31, the blockage of the flow path is released, and the ink flows vigorously. With this flow,
Stagnant air bubbles can be more completely eliminated. In addition, according to this, there is a secondary merit that foreign matters and the like firmly attached near the ejection port can be removed by strong ink flow. By appropriately combining the above two states, it is possible to properly use appropriate cleaning as needed.

The components from the ink cartridge to the recording head and the operating body are mounted on the carriage 1, so that the operating body 31 can be configured to operate by moving the carriage. In other words, the carriage moves to the home position and the capping means 1
By setting 0, the operating body can be set to be pressed in conjunction with the nozzle forming surface 7a of the recording head 7 being sealed.

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 changed to a pressure enough for the recording head not to draw in the outside air from the discharge port, that is, the pressure of the recording head When a flexible material is used for the repelling force of the opposing surface so that the pressure becomes smaller than the meniscus strength, the carriage 1 moves from the home position to the printing area side (that is, the capping unit 10 is separated and the operating body 31 is also separated). It is not necessary to manage the speed at the time.

In the home position, as shown in FIG. 5, the flow path is not completely closed, and the carriage 1 is moved further away from the print area than the home position so that the carriage 1 is completely closed. It is more preferable to set. 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 the water in the ink evaporates and diffuses through the wall surface of the capping unit 10 or the like. Obstacles such as clogging can be suppressed, and the flow path can be completely closed if necessary only by the operation of the carriage.

FIG. 7 is a schematic view showing a second embodiment of the present invention. In FIG. 7, parts corresponding to the parts described above are denoted by the same reference numerals.

In the embodiment shown in FIG. 7, an opposing surface 23 formed of a stretchable thin film member (laminated film) is disposed downstream of a filter member 22 and further an operating member 31 is provided on the back of the opposing surface 23. Is installed. A contact member 32 that is in contact with the filter member 22 is attached to the inner surface of the facing surface 23. This contact member 32
Is formed, for example, in a disk shape, and has an ink circulation hole 32a formed so as to communicate in the circumferential direction from the center of the upper surface.

In the above arrangement, when the operating member 31 is pressed toward the filter member, the contact member 32 is
, From the lower surface so as to cover almost the entire surface of the filter member 22.

An ink circulation hole 32a is formed at the center of the contact member 32 so as to communicate in the circumferential direction.
When the suction pump is operated in this state, the ink circulation holes 32a
In the filter member 22 corresponding to (1), a rapid flow of the ink locally occurs. Therefore, the filter member 22
The bubbles existing on the upstream side pass through the filter member 22 by this flow and are discharged from the recording head 7.

In the embodiment shown in FIG. 7, the ink circulation holes 32a are formed at the center of the contact member 32, but the arrangement of the ink circulation holes 32a can be appropriately selected. A similar effect 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 making the ink circulation holes 32a.

In this configuration, the pressing and separating of the capping means 10 against the ink ejection surface 7a and the pressing and separating of the operating body can be set in the same direction, so that the number of components can be reduced.

[0051]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the filter area of the filter member in the ink supply path is made as variable as possible, so Upstream air bubbles can be discharged through the filter member. Therefore, bubbles staying upstream of the filter member can be significantly reduced, and the occurrence of printing defects due to the influence of the residual bubbles can be eliminated during actual use of the recording apparatus, and the printing reliability of the recording apparatus can be reduced. Is guaranteed.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a basic configuration of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a sectional view showing an example of capping means mounted on the recording apparatus shown in FIG. 1 and peripheral devices thereof.

FIG. 3 is a schematic diagram illustrating a first embodiment of a path from an ink cartridge to a suction pump.

FIG. 4 is a perspective view seen in the direction of arrow A in FIG. 3;

FIG. 5 is a cross-sectional view illustrating an operation in the first embodiment.

FIG. 6 is a cross-sectional view illustrating an operation in the first embodiment.

FIG. 7 is a schematic diagram illustrating a second embodiment of 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 Atmospheric release valve 22 Filter Member 23 Opposing surface (deformable member) 24 Space portion 25 Ink introduction hole 31 Actuator 32 Contact member 32a Ink circulation hole

Claims (12)

[Claims] 1. An ink jet recording head that receives ink supplied from an ink cartridge and discharges ink droplets from nozzle openings, and is disposed in an ink supply path between the ink cartridge and the recording head to remove foreign matter. And a capping means for sealing the nozzle opening of the recording head and receiving a negative pressure from a negative pressure generating means, wherein the filter area of the filter member is as large as possible. An ink jet recording apparatus characterized in that it is variable. 2. The ink jet recording apparatus according to claim 1, wherein the opposing surface of the filter member has a deformable member displaceable toward the filter member, and an operating member for displacing the deformable member. 3. The ink jet recording apparatus according to claim 2, wherein the deformable member is disposed upstream of the filter member, and is configured to contact the filter member from the upstream side of the filter member. 4. The ink jet recording apparatus according to claim 2, wherein the deformable member is disposed downstream of the filter member, and is configured to contact the filter member from downstream of the filter member. 5. The apparatus according to claim 2, wherein said deformable member is formed of a stretchable laminate film.
The ink-jet recording apparatus as described in the above. 6. The ink jet recording apparatus according to claim 3, wherein the deformable member disposed on the upstream side of the filter member is located immediately above the filter member in the direction of gravity. 7. A method according to claim 7, wherein ink is supplied to a space between said filter member and said deformable member from a horizontal direction orthogonal to the direction of gravity, and the ink supplied to said space is arranged in a horizontal direction. 7. The ink jet recording apparatus according to claim 6, wherein the ink jet recording apparatus is configured to pass through the filter member. 8. A deformable member disposed on the downstream side of the filter member includes a stretchable film member and a contact member formed on the film member and contacting the filter member. The ink jet recording apparatus according to claim 4, wherein an ink circulation groove is formed in a part of the ink jet recording apparatus. 9. The ink-jet system according to claim 2, wherein a negative pressure generated when said deformable member returns when said operating member is separated is smaller than a meniscus strength at a nozzle opening of said ink-jet recording head. Recording device. 10. The ink jet recording apparatus according to claim 2, wherein the ink supply path is completely closed when the deformable member is displaced toward the filter member. 11. The ink jet printer according to claim 2, wherein when the deformable member is displaced toward the filter member, a part of the ink can flow without closing the ink supply path. Ink jet recording device. 12. The ink jet recording apparatus according to claim 2, wherein the deforming member displacing means displaces the deforming member in synchronization with the contact and separation of the capping means.