JPH09300641A - Ink-jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the movement of the residual ink in a cap to a communicating hole by a method wherein the bottom part including the surroundings of the hole communicating with a pumping means and the side wall part adjacent to the bottom part in the inner surface of a cap, which moves under the condition being bonded to an ink-jet recording head, are turned into surfaces having good wettability by ink. SOLUTION: The surfaces of the bottom part including at least the surroundings of a communicating hole and of the side wall part adjacent to the bottom part in the inner surface of a cap are turned into surfaces having good wettability by ink. Concretely, in the inner surface of the cap 1, the surface in the neighborhood of the communicating hole 10 is roughened with a sandpaper of 500 mesh so as to obtain a mechanically roughened surface 22. Thus, the surface having good wettability by ink is formed. At blank sucking, residual ink is moved to the communicating hole 10, resulting in leaving no dropwise liquid in a cap 1. Further, as for the mechanical roughening as the means for forming a surface having good wettability by ink, a roughening with sandpapers with numbers different from one another, a roughening by sandblasting or the like is exampled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus provided with a cleaning means for initially filling ink in an ink jet recording head (hereinafter abbreviated as a recording head) and eliminating nozzle clogging.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing an essential part of an ink jet recording apparatus, and FIG. 5 is a block diagram showing the vicinity of its cleaning means. A recording head 2 (not shown) is mounted on the carriage 17. Carriage 17 is belt 16
The belt 16 is driven by the pulley 12 attached to the motor 11, so that the belt 16 can be guided by the spacing shaft 18 to reciprocate in the axial direction. On the other hand, the recording medium 15 is arranged on the platen 13 and can be moved vertically in the scanning direction of the recording head 2 by at least a pair of paper feeding rollers 14. Therefore, printing can be performed on the recording medium 15 by repeating the operation of moving the carriage 17 to print one line and then feeding the paper.

When no printing is performed on the recording medium 15, the recording head 2 is in the non-printing area, and therefore the carriage 17
Is not located on the recording medium 15 but on the cleaning means outside the recording medium 15. The cleaning means is composed of a cap 1, a wiper 4, an elevating part 5, and a pump (not shown). When no printing is performed, the recording head 2 is used.
The nozzle surface 3 is covered with a cap 1 in order to prevent the nozzle surface 3 from drying. The cap 1 covers and separates the nozzle surface 3 by the elevating part 5. The cleaning means further performs an ink initial filling operation for guiding the ink into the recording head 2 and the ink supply tube 19 when using the inkjet recording apparatus for the first time, and removes air bubbles in the recording head 2 and dust attached to the nozzle portion. It is also intended to perform a cleaning operation for removing the ink, in which case the ink is sucked by the pump.

When the pump is driven for this purpose, the cap 1 covers the nozzle surface 3 of the recording head 2. This state is shown in FIG. As a pump,
For example, a pump that generates a negative pressure by the reciprocating motion of the bellows is used. When the pump is driven, the space formed by the cap 1 and the nozzle surface 3 of the recording head 2 becomes negative pressure,
Ink is sucked into the cap 1 from the recording head 2, and the ink is discarded through the ink tube 6 and the pump. After sucking the ink from the recording head 2 for a predetermined time, the pump is stopped and the cap 1 is separated from the recording head 2.

FIG. 6 is a view showing a state in which the cap 1 is separated from the recording head 2, after which the ink attached to the nozzle surface 3 of the recording head 2 is wiped off by the wiper 4. FIG. 7 is a diagram showing a state of the inside of the cap 1 after the ink is sucked, and the ink is left as a residual ink droplet 23 in the cap 1 away from the communication port 10 with the pump (hereinafter, simply referred to as the communication port 10). Remains in the area where At this point, the operation of driving the pump again, called an idle suction, to remove the ink remaining in the cap 1 is performed. In this operation, if ink droplets remain only around the communication port 10 of the cap 1, it is possible to completely remove the ink droplets, but as shown in FIG. In such a case, it is not possible to generate a force for sucking the ink against the surface tension of the ink, so that the ink droplets often remain in the cap 1.

If the ink droplets in the cap 1 cannot be completely removed and the ink droplets remain in the cap 1, the recording head 2 is brought into close contact with the cap 1 in order to prevent the ink from drying during non-printing. Nozzle surface 3 of the recording head 2
If the residual ink droplets in the cap 1 adhere to the above, and when printing is performed again, troubles such as staining the surface of the recording medium 15 may occur.

Even if the bottom portion of the cap 1 is tilted toward the communication port 10, it is not possible to prevent ink droplets from remaining. FIG. 8 is a cross-sectional view of a cap showing a conventional example for preventing the ink from remaining. The communication port 10 in the cap 1 is covered with a sheet-shaped porous body 21. By doing so, the residual ink is completely removed by the capillary phenomenon of the porous body 21. However, this method increases the number of parts and the number of assembling steps, resulting in high cost.

[0008]

As described in the description of the prior art, in the prior art, after cleaning the inside of the recording head 2, the ink droplets remaining in the cap 1 are completely removed by idle suction. However, there is a concern that the recording medium 15 may be contaminated by the subsequent printing operation. As a means for completely removing the ink droplets, there is a method of introducing the sheet-shaped porous body 21 into the cap 1, but the number of parts is increased and the number of assembling steps is also increased, so the cost is increased. It is an object of the present invention to provide an inexpensive cap that solves these drawbacks.

[0009]

In order to solve the above-mentioned problems, according to the present invention, the surface of the bottom portion of the inner surface of the cap including at least the periphery of the communication port and the side wall portion adjacent to the bottom portion is provided with a wettability of ink. It has a good surface. At least the ink around the communication port has good wettability, so that the residual ink can be easily moved to the communication port, so that the ink droplets can be completely removed by idle suction.

As the surface having good wettability of ink, a mechanically roughened surface or a surface coated with a paint having good wettability of ink is effective. Further, in order to enhance the effect of removing the residual ink, a groove communicating with the communication port is provided at the bottom of the inner surface of the cap.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An object of the present invention is to prevent ink droplets from remaining in the cap after the ink is sucked from the recording head into the cap. Therefore, the inner surface of the cap has a good wettability. The point is to prevent the residual ink in the cap from being easily transferred to the communication port and remaining in the form of droplets during idle suction.

An embodiment will be described below. (First Embodiment) FIG. 1 is a sectional view showing the structure of a cap in a first embodiment of an ink jet recording apparatus according to the present invention. The cap 1 of this embodiment is different from the cap of the prior art in that the inner surface of the cap 1 around the communication port 10 is roughened with 500 mesh sandpaper (in FIG. 1, mechanically). It was written as surface 22). A surface with good wettability of ink is formed by roughening with sandpaper, and the residual ink does not move to the communication port and remain in a droplet form in the cap during idle suction. A photograph showing this state is shown in FIG. No ink droplets are found inside the cap 1.

In this embodiment, as the means for forming the surface having good wettability of ink, the roughening with the 500 mesh sandpaper is explained, but other mechanical roughening,
The same effect can be obtained by, for example, vandalism or sandblasting with sandpaper of different counts. Further, if the surface having good wettability of the ink is spread to the entire bottom surface or the side wall portion adjacent to the bottom portion, the removal of ink droplets becomes more complete.

(Second Embodiment) Although not shown in the drawing,
In the second example, a paint having good wettability of ink was applied to the inner surface of the cap, the bottom including the periphery of the communication port, and the surfaces of the side walls adjacent to the bottom. Also in this case, the same effect as that of the first embodiment could be obtained. (Third Embodiment) FIG. 3 is a perspective view showing the structure of a cap in a third embodiment of the present invention. A groove 9 communicating with the communication port 10 is provided at the bottom of the inner surface of the cap 1 so that the residual ink can be easily moved by the communication port 10 during idle suction.

[0015]

According to the present invention, the surface of the bottom portion of the inner surface of the cap including at least the periphery of the communication port and the side wall portion adjacent to the bottom portion is a surface having good ink wettability. At least the ink around the communication port has good wettability, so that the residual ink can be easily moved to the communication port, so that the ink droplets can be completely removed by idle suction.

Further, a groove communicating with the communication port is provided at the bottom of the inner surface of the cap to enhance the effect of removing the residual ink. In this way, it is possible to provide a low-cost cap in which ink drops do not remain on the inner surface of the cap.

[Brief description of drawings]

FIG. 1 shows a first inkjet recording apparatus according to the present invention.
Sectional view showing the structure of the cap in the embodiment of FIG.

FIG. 2 is a diagram showing an ink removal state in the cap according to the first embodiment.

FIG. 3 is a perspective view showing a structure of a cap according to a third embodiment of the present invention.

FIG. 4 is a perspective view showing a main part of the inkjet recording apparatus.

FIG. 5 is a configuration diagram in the vicinity of a cleaning unit of an inkjet recording device.

FIG. 6 is a configuration diagram in the vicinity of cleaning means showing a state in which a cap is separated from a recording head.

FIG. 7 is a diagram showing a state inside the cap after the ink is sucked.

FIG. 8 is a sectional view of a cap in a conventional example.

[Explanation of symbols]

 1 Cap 2 Recording Head 3 Nozzle Surface 4 Wiper 5 Lifting Unit 6 Ink Tube 7 Frame 8 Side Plate 9 Groove 10 Communication Hole 11 Motor 12 Pulley 13 Platen 14 Roller 15 Recording Medium 16 Belt 17 Carriage 18 Spacing Axis 19 Ink Supply Tube 20 Ink Tank 21 Porous body 22 Mechanically roughened surface 23 Residual ink drops

Claims (4)

[Claims] 1. An inkjet recording head, a cap that can move in close contact with the head, and a cleaning unit that removes air bubbles and dust in the head by negative pressure generated by a pump unit that communicates with the cap. In the inkjet recording apparatus, the bottom surface of the inner surface of the cap, including at least the periphery of the opening communicating with the pump means, and the side wall portion adjacent to the bottom surface are surfaces having good ink wettability. . 2. The ink jet recording apparatus according to claim 1, wherein the surface having good wettability of ink is a mechanically roughened surface. 3. The ink jet recording apparatus according to claim 1, wherein the surface having good wettability of the ink is a surface coated with a paint having good wettability of the ink. 4. The ink jet recording apparatus according to any one of claims 1 to 3, wherein a groove communicating with the mouth is provided around the mouth communicating with the pump means on the inner surface of the cap. An inkjet recording device characterized by the above.