JPH1044447A - Maintenance apparatus of ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning apparatus of an ink jet head having high cleaning effect and preventing the mixing of a plurality of color inks. SOLUTION: Ink nozzles 28 corresponding to a plurality of ink colors are provided in the nozzle plate 29 of an ink jet head 2. A wiping part 16 has the surfaces corresponding to the respective ink colors. The wiping part 16 is rotated by 90 deg. in a predetermined timing in an 'A' direction and the ink of the corresponding color is wipen off by the surface coming into contact with the head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maintenance device for an ink jet head, and more particularly to a maintenance device for an ink jet head which is attached to an ink jet printer and cleans the head at a predetermined timing.

[0002]

2. Description of the Related Art A nozzle hole of a head of an ink-jet printer has a small diameter and may be clogged. In addition, ink may adhere to the vicinity of the nozzles, or the ink may fly in an unstable manner due to dirt. In order to prevent such a situation, conventionally, the nozzle surface of the head is treated with a water-repellent coat film, and the nozzle surface is rubbed with a rubber blade at a predetermined timing.

[0003]

[Problems to be solved by the invention]

(1) First problem However, even when the nozzle surface is rubbed with a rubber blade, the nozzle surface cannot be completely cleaned in some cases. It is due to the following reasons.

FIG. 6A is a plan view of one form of a nozzle portion of an ink jet head, and FIG. 6B is a sectional view thereof. Referring to the figure, the nozzle has a nozzle hole 28,
A concave portion 27 provided around the nozzle hole 28 for the purpose of discharging ink droplets satisfactorily.

FIG. 7 is a plan view showing a state in which the ink jet head is cleaned with a rubber blade.
The cleaning is performed by moving the rubber blade 54 pressed by the head in the “C” direction.

FIG. 8 is a cross-sectional view showing a state in which the rubber blade 58 has reached the recess 27. Referring to the drawing, the rubber blade 54 has a length in a direction penetrating the drawing,
Since both ends are in contact with the surface of the head other than the recess 27,
The rubber blade 54 does not touch the bottom of the recess 27. Therefore, the dirt in the recess 27 cannot be removed.

(2) Second Problem In addition, when the color head is wiped with one blade, the ink of the nozzle on the upstream side of the wiping may enter the nozzle on the downstream side, and color mixing may occur.

In order to solve this problem, it is conceivable to use a different rubber blade for each color of the head, but there is a problem that the cost is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet head maintenance apparatus which can perform cleaning properly even if nozzles have irregularities. .

A second object of the present invention is to provide a maintenance device for an ink jet head which does not cause color mixture even when the color head is cleaned.

[0011]

In order to achieve the above object, a maintenance device for an ink jet head according to the present invention has a surface arranged in parallel with a nozzle forming surface of an ink jet head for wiping the nozzle forming surface. It is characterized by the following.

Further, the surface may be a plurality of surfaces, and the number of the plurality of surfaces may be equal to or more than the number of colors of ink ejected by the inkjet head.

Further, the surface may be formed of a porous material. According to such an invention, since the ink jet head is wiped by the surface, the cleaning can be accurately performed even if the nozzle has irregularities.

Further, by setting the number of the plurality of surfaces to be equal to or more than the number of colors of the ink ejected by the ink jet head, it is possible to provide a maintenance device which does not cause color mixture even when the color head is cleaned. .

[0015]

FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a perspective view of an ink jet recording apparatus of FIG.

Referring to the drawings, a recording sheet (recording medium) 1 such as a sheet of paper or a thin plastic sheet is fed into a printer unit by a paper feeding device such as a manual feed sheet or a cut sheet feeder, and is fed to a paper feed roller (not shown). By controlling the amount of rotation, the sheet is conveyed to a recording unit (a cueing position) and set to a recording state. The recording section (recording head) 2 is an ink jet head, and this head 2 is mounted on a carriage 3.

The ink jet head 2 is an ink jet recording apparatus using a piezoelectric element. The ink is ejected from a nozzle provided in a channel portion by a change in the volume of the channel caused by distortion generated by applying a voltage to the piezoelectric element. The recording is performed by discharging.

In the ink jet recording apparatus, a plurality of ejection holes are provided vertically on the front surface (ejection hole forming surface) of the head 2. The carriage 3 is supported by sliding shafts 4 and 5 so as to be able to reciprocate, and is driven by a driving motor 6.
It is reciprocated via a timing belt 8 stretched between the motor and the idle pulley 7. This carriage 3
The main scanning is performed in the digit direction of the recording sheet 1 (a direction crossing the recording sheet 1) to record an image for one line, and every time one line is recorded, the next line is recorded by sub-scanning by feeding paper.

At a position facing the head 2, a platen 9 serving as a guide plate for guiding the recording sheet 1 along the transport path is arranged. The platen 9 may also serve as a fixing device by attaching a heater wire (not shown) to a sheet metal to form a surface heater. The recording sheet 1 is pressed against a platen 9 by a paper holding plate 10 at a portion as close as possible to a recording area below (upstream) the recording area where the head 2 performs main scanning.
Floating is prevented. The recording sheet 1 that has passed through the recording unit is discharged by a discharge roller 11 that is disposed on the downstream side in the transport direction.
And the spur roller 12 pressed against it.

On the other hand, at a position facing the head 2,
At a position deviated from the platen 9, a recovery system 13 is provided for recovering an ink ejection failure of the head 2 to a favorable state. The paper feed roller (conveyance roller) is provided with a paper feed knob 14 for manually conveying the recording sheet 1.

A cleaning device (also called a wiping device) 15 for performing maintenance and cleaning of the head 2 is provided beside the recovery system 13. The wiping device 15 is provided with a wiping unit 16. The wiping unit 16 has a rectangular parallelepiped shape.

The cleaning device 15 is connected to a piston pump 17 via a tube 18.

FIG. 2 is a view showing a part of the ink jet head 2 viewed from the direction "P" in FIG.

Referring to FIG. 1, a plurality of ink nozzles 28 for discharging ink, an ink channel 26 for storing ink, a piezoelectric element 42 for discharging ink, and an ink And an ink inlet 32. The surface of the inkjet head 2 is constituted by a nozzle plate 29. The nozzle plate 29 is covered with a water-repellent coat film.

The ink jet head 2 is formed symmetrically with a symmetrical line 34 interposed therebetween. One is a large diameter head section 14 for printing large diameter dots, and the other is a small diameter head for printing small diameter heads. The head 12 is provided. The ink nozzles 28 of the large-diameter head unit 14 are made larger than the ink nozzles 28 of the small-diameter head unit 12 for printing large-diameter dots. FIG. 2 shows a head for printing one color. When a full-color head is configured, four colors for yellow, magenta, cyan, and black may be arranged in the vertical direction with respect to the drawing. .

FIG. 3 is a perspective view of the wiping unit 16 of FIG. Referring to the figure, wiping unit 16 includes a sponge (a porous substance, also referred to as a porous material) 71 having a rectangular parallelepiped shape, a support 72 for supporting sponge 71, and an attachment to support 72. And a rotating shaft 73 having a hollow portion. The support 72 also has a hollow portion, and the hollow portion of the rotating shaft 73 and the hollow portion of the support 72 are connected. A plurality of holes are formed on the side of the support 72 that contacts the sponge 71. By applying a negative pressure to the hollow portion of the rotating shaft 73, the hollow portion of the support 72 is decompressed,
As a result, ink residue, fine dust, and the like are sucked through the sponge 71.

As shown in the figure, in this embodiment, the sponge 71 has four faces.

One end of the rotating shaft 73 is connected to the piston pump 17 via the tube 18.

FIG. 4 is a diagram for explaining the relationship between the print head 2 and the wiping unit 16.

Referring to the figure, wiping section 16 is driven to rotate in the direction "A" by drive gear 74. In addition, the wiping unit 16 is set to “B” by a driving device (not shown).
Move in the direction. Such a driving device is realized by combining a gear, a clutch, a clamp, a cam, or the like. Further, if the inkjet head 2 and the wiping unit 16 can be relatively moved,
Any configuration may be used.

Further, the wiping device or the print head can relatively move in the direction "C". Accordingly, the wiping unit 16 can move relative to the inkjet head 2 by following the route of II → III → IV → V.

FIG. 5 shows the ink jet head 2 shown in FIG.
FIG. 6 is a diagram illustrating a relationship between the wiping unit 16 and the wiping unit 16 viewed from above.

In the figure, I is the wiping unit 16 in FIG.
Indicates the position of. And II, III, IV and V are
These correspond to those in FIG.

Referring to the figure, the wiping unit 71 has A,
It has B, C and D faces. At the position I, the surface A and the nozzle plate 29 are in more contact with each other. At the time of cleaning, in this state, the wiping unit 71 moves to the position II. Thereby, the periphery of the ink nozzles 28a and 28b is cleaned. Next, the wiping unit 71 moves to the position III. In this state, the wiping unit 71 rotates 90 ° about the rotation shaft 73 in the direction of the arrow. Thereby, the surface B faces the nozzle plate 29 side. In this state, the wiping unit 71
Moves to the position IV. During this movement, the wiping unit 71 and the nozzle plate 29 do not come into contact with each other.

Next, the wiping unit 71 moves to the position V, whereby the nozzle plate 29 comes into contact with the surface B. Thereafter, the wiping unit 71 further moves in the direction of the arrow, thereby cleaning the ink nozzles 28c and 28d. At this time, the ink nozzles 28a, 28b
Cleaning surface (surface A) and the ink nozzle 28
This is different from the surface (surface B) where c and 28d are cleaned.
Therefore, even if the color of the ink ejected from the ink nozzles 28a and 28b is different from the color of the ink ejected from the ink nozzles 28c and 28d, the ink does not mix. For example, yellow, magenta,
When four systems of ink nozzles for ejecting inks of cyan and black are provided, surface A is a surface for yellow ink, surface B is a surface for magenta ink, surface C is a surface for cyan ink, and surface D is a black ink. , It is possible to prevent color mixing of ink.

In the example shown in FIG. 5, the wiping unit 71 is moved with respect to the nozzle plate 29. However, the nozzle plate 29 is moved relatively, and the wiping unit 71 moves between II and III. You may make it reciprocate. Thereby, the driving mechanism of the wiping unit 71 can be simplified.

FIG. 9 shows the sponge 71 of the wiping unit 16.
FIG. 3 is a diagram for explaining a contact relationship between the ink nozzle and the ink nozzle; FIG. 9 corresponds to FIG.

Referring to the figure, the periphery of ink nozzle 28 is cleaned by moving sponge 71 in the "C" direction. At this time, even if there is the concave portion 27 around the ink nozzle 28, the sponge 71 is easily deformed, so that it goes deeply into the concave portion 27. Thus, even when the nozzle plate has irregularities, the cleaning can be accurately performed.

In the above embodiment, the wiping portion 16 has four surfaces. However, if the purpose is only to increase the cleaning efficiency, the number of surfaces may be one.

Further, if the wiping unit 16 is provided with a number of surfaces equal to or greater than the number of colors of the ink ejected from the ink jet head, it is possible to prevent the ink from being mixed.

Furthermore, although a sponge has been described as an example of the porous substance, any substance may be used as long as it has fine holes and can suck ink scum and the like through the holes.

Further, in the above embodiment, suction is performed by the piston pump, but the pump is not limited to this. Also, without using a pump,
Even if suction is not performed, it is possible to enhance the wiping effect and to prevent color mixing of ink.

Further, the average pore diameter D of the surface of the porous material,
It is more effective to make the viscosity N of the ink in contact with the surface proportional to the viscosity, and to increase the porous diameter when the viscosity of the ink is high.

In the case where the head nozzle has large-diameter and small-diameter regions as shown in FIG. 2, when the same ink is ejected from each of the large-diameter and small-diameter regions, the large-diameter nozzle has a small-pore diameter. It is preferable that a porous material having a large diameter be brought into contact with the small-diameter nozzle. In this case, since the amount of water absorbed by the ink is constant at each of the large diameter and the small diameter, it is possible to stabilize the same cleaning effect.

A filter material or the like can be used as the porous material. It is effective to use a porous material that has water absorbency and returns to its original state when squeezed after being sucked.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ink jet recording apparatus according to one embodiment of the present invention.

FIG. 2 is a plan view of the inkjet head 2 of FIG.

FIG. 3 is a perspective view of the wiping unit 16 of FIG.

FIG. 4 is a diagram for explaining a relationship between the wiping unit 16 and the inkjet head 2.

5 is a view of the state of FIG. 4 as viewed from above.

FIG. 6 is a diagram illustrating one embodiment of an ink nozzle of an inkjet head.

FIG. 7 is a view for explaining a state in which the ink nozzle of FIG. 6 is cleaned by a rubber blade;

FIG. 8 is a diagram for explaining a problem in FIG. 7;

FIG. 9 is a diagram for explaining one of the effects of the present invention.

[Explanation of symbols]

 2 Inkjet head 15 Cleaning device 16 Wiping unit 17 Piston pump 18 Tube 71 Sponge A to D surface

Claims (3)

[Claims] 1. A maintenance device for an ink jet head, comprising: a surface for wiping the nozzle forming surface, which is disposed in parallel with the nozzle forming surface of the ink jet head. Maintenance device. 2. The inkjet head maintenance device according to claim 1, wherein the surface is a plurality of surfaces, and the number of the plurality of surfaces is equal to or greater than the number of colors of ink ejected by the inkjet head. 3. The inkjet head maintenance device according to claim 1, wherein the surface is formed of a porous material.