JPH09216372A - Image-forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesiveness between the ink discharge surface of an ink head and an cap disposed on a recovery unit by arranging the ink discharge surface slantly with respect to the traveling direction of the ink head, and disposing an ink discharge surface sealing cap set on the recovery unit In parallel with the ink discharge surface. SOLUTION: An ink discharge surface 5a is provided slantwise relative to the traveling direction of an ink head 5. On the other hand, a leaf spring 11 is put on a recovery unit 8, and a cap 9 is positioned thereon such that the part to be in contact with the ink discharge surface 5a becomes in parallel to the ink discharge surface 5a. Accordingly, when the ink head 5 moves leftward, the ink discharge surface 5a of the ink head 5 comes in contact with the cap 9. Inasmuch as the cap 9 is supported by the leaf spring 11 at this time, even when some height directional errors exist between the ink head 5 and the cap 9, the occurrence of an interstice is precluded by the cap 9 being pressed and sealed against the ink discharge surface 5a of the ink head 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer or a plotter which forms an image by an inkjet method.

[0002]

2. Description of the Related Art Ink is ejected in accordance with an image signal from an ink head which runs in a predetermined direction with respect to a recording material such as paper to maintain a constant distance to form an image. Image forming apparatuses have been widely put into practical use.

The ink used in this type of image forming apparatus is liquid, and a large number of ink ejection nozzles are arranged side by side to form an ink ejection surface, and ink is ejected from a predetermined nozzle according to an image signal. I am doing it.

Due to such a structure, mist is unavoidably generated at the time of ink ejection, which adheres to the ink ejection surface and is further solidified by evaporation of water to cause defective ejection of ink, resulting in deterioration of image quality. There is a problem of being invited. In addition, air bubbles and the like may be mixed in the nozzles, which may cause defective ejection of ink and deterioration of image quality due to the defective ejection of ink.

In order to deal with such a problem, the ink head is brought to the position of the recovery unit outside the image area at regular time intervals during image formation, and the cap disposed there is turned upward or rotated. In the direction of the ink head to prevent the ink from evaporating and drying by adhering to the ink ejection surface of the ink head, and sucking the ink in the nozzle with a suction pump to remove solidified ink that has adhered, bubbles in the nozzle, dust, etc. It has been proposed to configure it for removal.

[0006] At the same time, with such a structure,
When bringing the cap to the position where it comes into close contact with the nozzle surface, it is necessary to move the cap upward to make it come in close contact.
Although the error in the vertical direction of the ink head is tolerable, the contact angle of the contact surface of the cap with the ink ejection surface is not stable due to rattling of parts. Further, the structure in which the cap is rotated to come into contact with the ink ejection surface cannot cope with the error in the vertical direction of the ink head. As described above, the adhesion of the cap to the ink ejection surface of the known ink head at the position of the recovery unit is unreliable and the recovery function is deteriorated due to the occurrence of the gap, and the deterioration of the image quality due to this cannot be prevented. Was the reality.

The present invention has been made to cope with such a situation, and in the image forming apparatus as described above, the adhesion between the ink ejection surface of the ink head and the cap arranged in the recovery unit is improved. It is an object of the present invention to provide an image forming apparatus that contributes to the above and can obtain a high quality image.

[0008]

In order to achieve the above object, the present invention provides an image forming apparatus for forming an image with ink ejected from an ink head, in which the ink is ejected in the traveling direction of the ink head. An image forming apparatus (1), wherein the surface is provided so as to be inclined, and a cap for sealing an ink ejection surface provided in a recovery unit of the image forming apparatus is provided in parallel with the ink ejection surface. Alternatively, in the above item (1), the cap provided in the recovery unit is elastically provided in the axial direction thereof, or the image forming apparatus (2) or the item (2). In the image forming apparatus (3), characterized in that the cap is attached to a leaf spring, or in the above (2), the cap is formed of an elastic member. The image forming apparatus according to symptoms (4).

With this configuration, the ink head at the recovery position can be maintained in a good sealed state, so that the recovery function works well and contributes to obtaining a good quality image.

[0010]

EXAMPLE FIG. 1 is a schematic front view of a main part of an apparatus for forming an image using an ink head. It is assumed that the recording material 3 travels on the platen 4 provided in the main body of the apparatus in the direction perpendicular to the paper surface.

A guide rail 6 is arranged above the platen, and a carriage 7 moves along the rail 6 in the left-right direction in the drawing. An ink head 5 is attached to the carriage 7 so that the ink ejection surface of the ink head 5 runs on the recording material 3 at a constant distance.

With such a configuration, the ink head 5 mounted on the carriage 7 runs along the guide rail 6 with respect to the recording material 3 which is stopped, and is applied to the ink head 5 during this time. Depending on the image signal
Ink is ejected from the nozzles corresponding to this and the recording material 3
An image is formed thereon. When the image formation for one line is completed,
After the ink head 5 has returned to the old position, the same image forming process as described above is performed again. By this time, it is assumed that the recording material 3 has been conveyed by the conveying roller 1 and the pinch roller 2 by one line in the direction perpendicular to the paper surface.

While such an image forming process is in progress, the ink head 5 is advanced to the position of the recovery unit 8 disposed on the left side in the drawing, outside the image area, at a proper time. The recovery unit 8 is provided with a cap 9 at a position corresponding to the ink ejection surface of the ink head 5 coming to this position, and the ink ejection surface is kept in contact with the cap 9 to maintain a hermetic state. .

Hereinafter, FIG. 2 shows the carriage 7 and the ink head 5 attached to the carriage 7 in the vicinity of the recovery unit 8. The ink head 5 moves in the left-right direction in FIG. The ejection surface is arranged to be inclined with respect to the direction.

The recovery unit 8 is provided with a leaf spring 11, on which the cap 9 is arranged so that its portion contacting the ink ejection surface is parallel to the ink ejection surface. The cap 9 is connected via a pipe 10a to a recovery pump 10 having a piston 10b.

With this structure, when the ink head 5 moves leftward and reaches the position shown in FIG. 3, the ink ejection surface 5a of the ink head 5 contacts the cap 9, and at this time, Since the cab 9 is supported by the leaf spring 11, even if there is a slight height difference between the ink head 5 and the cap 9, the cap 9 is brought into pressure contact with and closely adheres to the ink ejection surface 5a of the ink head 5. This prevents the generation of gaps.

After that, the piston 10b moves to the right from the position shown in the figure, and the ink in the nozzle of the ink head 5 is sucked through the cap 9 and the pipe 10a to adhere to the ink ejection surface 5a, the solidified ink, Aspirate air bubbles in the nozzle.

FIG. 4 shows another embodiment of the present invention. Portions corresponding to those of the apparatus of the above embodiment are designated by the same reference numerals, and description thereof will be omitted unless necessary. To do.

In this apparatus, a cap 9 is arranged at a fixed portion of the recovery unit 8, and the cap 9 is made of an elastic material such as rubber having an appropriate elasticity, as shown in the drawing. In this case, the annular recess 9a is provided on the side of the cap body.
Is formed, and due to the presence of this portion, it is relatively displaceable in the direction of the axis T.

With such a structure, when the ink head 5 mounted on the carriage 7 further moves from the position (a) in the figure to the position (b) in the figure, the ink ejection surface 5a is formed. While contacting the cap 9, the cap 9 is pressed against the ink ejection surface by the action of the annular recess 9a, and even if there is a slight error in the height direction, this is compensated for and the close contact between the cap 9 and the ink head 5 is secured. Will be done.

[0021]

As described above, according to the present invention,
In an image forming apparatus that forms an image by ejecting ink from a recording head in accordance with an image signal from an ink head, an ink ejection surface, and a cap disposed in a recovery unit for sealing the ink ejection surface, Since it is configured to contact elastically in a direction inclined with respect to the running direction of the ink head, even if there is a mounting error or processing error in the height direction between the ink head and the cap, this can be compensated for. Both can be hermetically sealed, the deterioration of the image quality due to the ink ejection failure can be effectively prevented, and there is a remarkable effect in obtaining a high quality image.

[Brief description of drawings]

FIG. 1 is a front view of a main part of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is a front view of the main part showing the ink head close to the cap of the recovery unit.

FIG. 3 is a front view of a main part showing a state where an ink ejection surface of the ink head is in contact with a cap.

FIG. 4 is a front view of a main part showing another embodiment.

[Explanation of symbols]

1 Conveyor Roller 8 Recovery Unit 2 Pinch Roller 9 Cap 3 Recording Material 10 Recovery Pump 4 Platen 11 Leaf Spring 5 Ink Head 6 Guide Rail 7 Carriage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kunitoshi Hayashi 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Copier Co., Ltd. (72) Tomohiro Ishizu 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo No. Copia Co., Ltd. (72) Inventor Yasushi Sawada 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Copia Co., Ltd. (72) Inventor Shigehiko Ito 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Inside Copier Co., Ltd. (72) Inventor Yasuhiro Kawamoto 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Within Copier Co., Ltd. (72) Keno Sasaki 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo No. Copier Co., Ltd. (72) Inventor Yutaka Kawamata 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Copier Co., Ltd. (72) Inventor Fumitaka Aoki 6-3-3 Shimorenjaku, Mitaka-shi, TokyoPeer inside, Inc.

Claims (4)

[Claims] 1. An image forming apparatus for forming an image with ink ejected from an ink head, the ink ejecting surface of which is inclined with respect to the running direction of the ink head, and which is arranged in a recovery unit of the image forming apparatus. An image forming apparatus, wherein a cap for sealing an ink ejection surface is arranged in parallel with the ink ejection surface. 2. An image forming apparatus according to claim 1, wherein the cap provided in the recovery unit is elastically provided in the axial direction. 3. The image forming apparatus according to claim 2, wherein the cap is attached to the leaf spring. 4. The image forming apparatus according to claim 2, wherein the cap is formed of an elastic member.