JPH08169120A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE: To prevent the generation of non-emission and abnormal emission caused by the accumulation of ink by arranging the ink absorbing material of a cleaning and wiping device in a non-contact state with respect to an ink emitting surface. CONSTITUTION: A cleaning and wiping device consists of an absorbing material 11 having high ink absorbing capacity and the spacer 8b being the container including and supporting the absorbing material 11 and the surface position of the absorbing material 11 is prescribed by the spacer 8b and, when the cleaning and wiping device is present at the position opposed to the emitting surface of an ink head at the time of cleaning, the interval between the emitting surface 2 and the surface of the absorbing material 11 is held to a definite distance (d). After restoration operation is performed by the pump connected to a cap in order to avoid the generation of abnormal emission, the emission number of times not generating wetting by the formation of an image is predetermined from experiment and the cleaning and wiping device is operated at every definite period corresponding thereto to perform the cleaning of the emitting surface. Therefore, non-wipen parts can be reduced and good absorbing capacity can be always kept.

Description

Detailed Description of the Invention

[0001]

[Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording material such as paper with ink ejected from nozzles, and more particularly to an ink jet recording apparatus therefor.

In an ink jet recording apparatus of this type of image forming apparatus, a cap is attached to the tip of a nozzle for ejecting ink during non-recording to prevent evaporation of ink, and a small amount of ink is pumped by a pump as needed. It is usually configured to suck the ink to recover the ink discharge ability.

On the other hand, when ink is continuously ejected for image formation, small droplets bounced from the recording material adhere to the ink ejection surface to wet the ejection surface, and further solidify to block the ink ejection port. In addition, there is a problem that the ink ejection direction is changed and the image quality is deteriorated.

Therefore, it has already been proposed to provide an elastic blade for rubbing and cleaning the ink ejection surface. However, even with such means, it is difficult to obtain a stable wiping function due to the dimensional accuracy of the blade made of an elastic material such as rubber, temperature change, etc., and uneven ejection due to ink accumulation, irregular ejection Was inevitable.

The present invention has been made to cope with such a situation, and an object thereof is to solve the above situation with a simple structure at a low cost.

[0006]

Configuration of the Invention

In order to achieve the above object, the present invention provides an ink jet recording having an ink ejection surface for ejecting ink, and a wiping device for wiping the ink ejection surface. In the inkjet recording device (1), wherein the ink absorbing material of the wiping device is arranged in a non-contact state with the ink ejection surface, or in the above (1), the ink absorbing material of the wiping device. In the ink jet recording apparatus (2) in which the non-contact distance between the ink absorbing material and the ejection surface is constant, or in the above (1) or (2), the means for making the ink absorbing material and the ejection surface non-contact is An ink jet recording apparatus (3) in which an end surface of a casing for housing the ejection surface is closer to the ejection surface than the surface of the ink absorbing material, or (1) or (2) above.
In the inkjet recording device (4), the means for bringing the ink absorbing material and the ejection surface out of contact with each other is formed by forming the outer periphery of a roller supporting the ink absorbing material closer to the ejection surface than the ink absorbing material surface, or In any one of the above (1) to (4), an ink jet recording device (5) in which the ink absorbing material changes permeability in a portion near the wiping surface and a portion holding the wiped ink, or Above (1)
In any one of (1) to (5), the inkjet recording device (6) is provided in which at least a part of the ejection surface is water repellent, or an ink ejection surface for ejecting ink is provided, and the ink ejection surface is wiped. In an inkjet recording apparatus having a wiping device, the wiping device is provided in the non-printing areas on both sides of the ink head, or in the above (7), the wiping device. In the ink jet recording apparatus (8) in which the ink absorbing material of (4) is in non-contact with all ink ejection surfaces, or in the above (8), the non-contact distance between the ink absorbing material and the ejection surface of the wiping device is constant. In the inkjet recording apparatus (9) or the above (8) or 89), the means for bringing the ink absorbing material and the ejection surface into non-contact with each other,
Either the ink jet recording apparatus (10), in which the ejection surface side edge of the casing containing the ink absorbing material is closer to the ejection surface than the ink absorbing material surface, or the above (8) or (9) In such an ink jet recording apparatus (11), means for bringing the ink absorbing material and the ejection surface out of contact with each other forms the outer periphery of the roller supporting the ink absorbing material closer to the ejection surface than to the ink absorbing material surface. Alternatively, in any one of the above (8) to 811, the ink jet recording apparatus (1) in which the permeability is changed between the ink absorbent, the area near the wiping surface, and the area holding the wiped ink.
2) Or, the inkjet recording device (13) according to any one of (7) to (11), in which at least a part of the ejection surface is made water repellent.

With this structure, the ink ejection surface of the ink jet recording apparatus can be always cleaned in good condition.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows that ink heads (four ink heads in the drawing) for accommodating ink are held by a carriage 4 and are in a home position. Each of the illustrated ink heads 1A, 1B, 1C and 1D contains cyan, magenta, yellow and black inks, respectively. At this position, the ink ejection surface of the ink head is
On the other hand, the caps 5 provided on the support plate 6 that can be contacted and separated from each other are closed, and a small amount of ink is sucked by the pump 7 so that the ejection capacity can be recovered. There is.

At the time of image formation, the support plate 6 retreats downward from the position shown in the figure and moves in the direction of the white arrow shown in FIG. In accordance with the above, the ink is ejected from the ejection port 3 opening on the ejection surface 2 to form an image. In order to prevent the ink from adhering to the ejection surface, an appropriate water repellent having poor wettability is applied to a silicon-based or fluorine-based water-based ink.

If the ejection of ink for image formation is continued, the ejection surface of the ink head is inevitably contaminated. Therefore, in order to clean the ejection surface, the apparatus of this embodiment shows "FIG. 3". Such a wiping device 8 is provided.
“FIG. 3” is a view of the wiping device 8 of “FIG. 1” as seen from the direction of arrow F. The wiping device 8 can selectively take a cleaning position close to the ejection surface of each ink head and an inoperative position retracted from the cleaning position.

As shown in FIG. 3, the wiping device 8 is composed of an absorbent material 11 having a high ink absorption capacity and a spacer 8b which is a container for internally supporting the absorbent material 11. The spacer 8b serves to absorb the absorbent material. The surface position of 11 is restricted,
At the time of cleaning, when the wiping device 8 is at a position facing the ejection surface 2 of the ink head, the distance between the ejection surface 2 and the surface of the absorbent material 11 is kept at a constant distance d. Further, a blade 8c made of urethane rubber or the like is provided near the spacer 8b.

As described above, when the ink is repeatedly ejected for a certain period of time, the ink adheres and accumulates on the ejection surface 2, and when the ink droplet grows, it is combined with the adjacent ink droplets and the ink droplets are adhering to several tens to several hundreds μ.
It grows up to m and becomes a wet state, blocking the discharge port,
Irregular discharge may occur.

In order to avoid such a situation, after the recovery operation by the pump connected to the cap is performed, or the number of discharges that does not cause wetting due to image formation is determined in advance from an experiment, and at a constant period corresponding to this. The wiping device 8 is activated to clean the ejection surface.

When performing the wiping operation, the wiping device 8 is used.
As shown in "Fig. 2", the tip of the spacer of
Is lifted up to a position where it abuts against and is moved relative to the carriage 4 in the direction of arrow X (about 150 mm / sec) to clean the ejection surface.

FIG. 4 is an enlarged explanatory view showing a mode of cleaning. When the cleaning operation is started, the absorbing member 11 first travels with respect to the ejection surface 2 with a minute gap, and a relatively large ink. The ink is absorbed and removed, and then the fine ink droplets are wiped off by the blade 8c that is in pressure contact with the ejection surface.

By such a wiping action, as in the case where the ejection surface is wiped and cleaned by only the blade which is conventionally used, a part of the ink which cannot be wiped off remains on the ejection surface. It is possible to reliably prevent the cleaning effect from being diminished. In addition, since the amount of ink wiped off is reduced, it is possible to prevent ink from scattering when the blade returns to its original position after the cleaning operation is completed.

5 to 7 show another embodiment of the present invention. The carriage 4 on which the ink heads are loaded advances from the home position on the right side in FIG. 5 to the recording material 10 placed on the platen 9 while performing printing and image formation, and moves to the left side in the drawing to reach the non-printing area. Then, the carriage 4 is reversed to return to the home position, and the recording material moves to the next printing position.

In such a device, a wiping device including a spacer roller 8d for cleaning the ejection surface and the ink absorbing material 11 is also arranged in the non-printing area on the left side of the drawing. Therefore, each time the carriage 4 advances to the left non-printing area, the ink ejection surface is cleaned by the absorbing material 11. Needless to say, a gap d is formed between the surface of the ink absorbing member 11 and the ejection surface 2 of the wiping device in this case, as in the above embodiment.

As described above, since the contamination of the ejection surface is gradually aggravated by repeated ejection, it is desirable to wipe the ejection surface as frequently as possible. At the same time, after wiping for wiping, thickening ink or different color ink adhering to the blade is mixed in the ejection port, so ejecting it several times in the non-printing area to eliminate such ink. Therefore, it is inevitable that the recording operation is interrupted and the workability is deteriorated.

When a wiping device is provided for cleaning as in the apparatus of this embodiment, the ink adhering to the ejection surface is frequently removed before it grows. In addition to the existence of the gap d, the wiping interval for preventing non-ejection can be increased, workability is improved, and there is no fear of color mixing.

Further, since the roller is used as the spacer member of the wiping device in the device of this embodiment, the relative movement between the wiping device and the ejection surface abutting against the wiping device can be smoothly performed, and there is little risk of damage. The durability is also improved.

FIGS. 8A, 8B, 9 and 10 show examples in which the ink absorbing material of the wiping device is attached to the casing that also serves as the spacer.

"FIG. 8" has the same structure as that shown in "FIG. 3", and the absorbent 11a has an upper bottom L2> a lower bottom L1.
It has a trapezoidal cross section formed in
Is formed in the casing 12 having an opening width L3 (L1 ≧ L3).

With this structure, in the mounted state, the absorbent material 11a has a larger degree of compression from the surface to the bottom portion, in other words, the suction action due to the capillary phenomenon becomes stronger toward the bottom portion, so that the discharge is improved. The ink absorbed from the surface side moves to the bottom side, and the surface of the absorbent 11a is always maintained in a state where it is easy to absorb the ink due to the action of gravity.

In FIG. 9, the absorbent material housed in the casing 12 has a three-layered structure as indicated by reference numerals 11b, 11c, and 11d. It is configured to have a large action. It will be readily understood that such a structure exhibits the same operation as that shown in FIG. Needless to say, the absorbent material is not limited to three layers.

FIG. 10 shows a case in which a width l4 is provided in a casing 12 constructed as "upper opening width L5> bottom width L6".
The absorbent material 11e of (l4 ≧ L5) is mounted and configured. With such a structure, the density of the absorbent 11e increases as it goes to the bottom, and the same effect as that shown in "FIG. 8" and "FIG. 9" can be obtained.

【The invention's effect】

As described above, according to the present invention, when cleaning the ink ejection surface of the ink jet recording apparatus, the absorbent material that absorbs the ink adhering to the ejection surface is wiped off without contacting the ink ejection surface. Since this is done, the amount of wiping residue can be reduced as much as possible. Further, when the ink is absorbed by the ink absorbing material, the absorbing material is configured so that it can move positively from the absorbing surface to the back side, so that it is possible to maintain good absorbing ability at all times and effectively prevent image quality deterioration. is there.

[Brief description of drawings]

FIG. 1 is a schematic front view of an inkjet recording apparatus showing an embodiment of the present invention.

[FIG. 2] An enlarged view of the main part of the same as above.

[Fig. 3] Enlarged view of the wiping device

FIG. 4 is an explanatory diagram showing a mode in which ink is wiped by a wiping device.

FIG. 5 is a schematic front view showing the operation of the inkjet recording apparatus.

FIG. 6 is an enlarged view of a part of the same as above.

FIG. 7 is an exploded side view showing a mode in which the absorber is attached to a roller that also serves as a stopper.

FIG. 8 is a side view showing another embodiment of mounting the absorbent material on the casing.

FIG. 9 is a side view showing still another embodiment in which the absorbent is mounted on the casing.

FIG. 10 is a side view showing still another embodiment of mounting the absorbent material on the casing.

[Explanation of symbols]

 1A, 1B, 1C, 1D Ink head 2 Ejection surface 4 Carriage 5 Cap 6 Support plate 7 Recovery pump 8 Wiping device 8b Spacer / casing 8c Elastic blade

Claims (13)

[Claims] 1. An ink ejection surface for ejecting ink is provided,
An inkjet recording apparatus comprising a wiping device for wiping the ink ejection surface, wherein the ink absorbing material of the wiping device is arranged in a non-contact state with the ink ejection surface. 2. The ink jet recording apparatus according to claim 1, wherein the non-contact distance between the ink absorbing material and the ejection surface of the wiping device is constant. 3. A means for bringing the ink absorbing material and the ejection surface into non-contact with each other, wherein the ejection surface side edge of the casing containing the ink absorbing material is closer to the ejection surface than the ink absorbing material surface. 2. The inkjet recording device according to claim 1, or claim 2. 4. A means for bringing the ink absorbing material and the ejection surface out of contact with each other, wherein the outer periphery of the roller supporting the ink absorbing material is formed closer to the ejection surface than the ink absorbing material surface.
Alternatively, the inkjet recording apparatus according to claim 2. 5. The ink jet recording apparatus according to any one of claims 1 to 4, wherein the ink absorbing material changes its permeability between a portion near a wiping surface and a portion holding the wiped ink. . 6. The ink jet recording apparatus according to claim 1, wherein at least a part of the ejection surface is made water repellent. 7. An ink ejection surface for ejecting ink is provided,
An inkjet recording apparatus comprising a wiping device for wiping the ink ejection surface, wherein the wiping device is arranged in a non-printing area on both sides of an ink head. 8. The ink jet recording apparatus according to claim 7, wherein the ink absorbing material of the wiping device is in non-contact with all ink ejection surfaces. 9. The ink jet recording apparatus according to claim 8, wherein the non-contact distance between the ink absorbing material and the ejection surface of the wiping device is constant. 10. The means for bringing the ink absorbing material and the discharge surface into non-contact with each other is such that the discharge surface side edge of the casing containing the ink absorbing material is closer to the discharge surface than the ink absorbing material surface. The ink jet recording apparatus according to claim 8 or claim 9. 11. The method according to claim 8, wherein the means for bringing the ink absorbing material and the ejection surface out of contact with each other is formed by forming the outer periphery of the roller supporting the ink absorbing material closer to the ejection surface than the ink absorbing material surface. The inkjet recording device according to claim 9. 12. The ink jet recording apparatus according to any one of claims 8 to 11, wherein the permeability is changed between the ink absorbent, the area near the wiping surface and the area holding the wiped ink. 13. The ink jet recording apparatus according to claim 7, wherein at least a part of the ejection surface is made water repellent.