JPS63224958A - Actuation of ink jet recorder - Google Patents

Abstract

PURPOSE:To enable fine bubbles to be easily removed, by a method wherein a comparatively large bubble is formed in a nozzle by jamming air into the nozzle from an ink discharge port, and fine bubbles in the nozzle are entrapped into this large bubble and thereafter, this large bubble is removed as ink is sucked. CONSTITUTION:An elastic cap 15 is compressed to be deformed via a rod 30 and a cap 14 by rotating an air jamming cam 27 under a state where an ink discharge port of a recording head 6 is sealed up by the elastic cam 15, and a portion of air in this elastic cap 15 is pressed into the inside of the recording head 6 from the ink discharge port by suddenly raising its inner pressure. Then, pressure in the elastic cap 15 is returned to atomospheric pressure by opening a vent switching valve with a vent cam 26 and the jammed air is made to remain in the ink inside the nozzle. Fine bubbles in the ink is entrapped to be combined into the large bubble generated in the nozzle by this air jamming. Thereafter, ink is sucked by ink recovery operation and discharged favorably by removing the large bubble in which fine bubbles are taken.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an operating method of an inkjet recording apparatus, and particularly to an operating method during an ink cycle fjj operation.

[Prior art]

An inkjet recording device supplies ink into a recording head, drives driving elements corresponding to a plurality of ink ejection ports formed on the front surface of the recording head based on a data signal,
In this method, flying ink droplets are formed from an ink ejection port toward a recording medium, and the ink droplets are attached to record.

In this type of inkjet recording device, when unpacking,
To maintain good ink ejection by filling the ink supply system seamlessly when replacing ink or recording heads, or when ink ejection ports are clogged due to dust, thickened ink adhesion, or air bubbles. In order to eliminate this problem and maintain image quality, in addition to sealing the ink discharge port with a camp, an ink recovery operation is performed in which a suction pump generates negative pressure suction force within the cap to suck ink through the ink discharge port. It is being said.

By the way, air may get mixed into the ink inside the ink ejection port, creating microbubbles, but these microbubbles are difficult to remove by simply suctioning the ink as in the conventional recovery operation. However, in the prior art, microbubbles remained even after the recovery operation, often causing instability in ink ejection.

〔the purpose〕

The purpose of the present invention is to solve the problems of the prior art, to reliably remove microbubbles within the ink ejection port, to reliably stabilize ink ejection after a recovery operation, and to produce high-quality recorded images. An object of the present invention is to provide a method for operating an inkjet recording device that can be maintained.

[Means to achieve the purpose]

In the present invention, with the ink ejection opening of the recording head sealed with an elastic cap member, the elastic cap member is further pressed and elastically deformed to increase the internal pressure, and then the inside of the elastic camp member is communicated with the atmosphere. The above object is achieved by performing a post-ink recovery operation.

[Effect]

Air is forced through the ink ejection port to form relatively large bubbles inside the nozzle, and the microbubbles inside the nozzle are trapped in the large bubbles, and then the large bubbles are removed together with ink suction.

This makes it possible to easily remove microbubbles that would otherwise be difficult to remove.

〔Example〕

The method of the present invention will be specifically explained below with reference to the drawings.

FIG. 2 shows an inkjet recording apparatus suitable for carrying out the method of the present invention.

In FIG. 2, the sheet (recording medium) 3 is moved along a guide shaft 4.4 in front of the sheet (recording medium) 3, which is fed in the direction of arrow A through sheet feeding rollers 1.2 installed vertically at a predetermined interval. A recording head (inkjet head) 6 is mounted on the carriage.

This recording head faces the sheet 3 with an interval of, for example, about 0.8w.

A plurality of ink ejection ports for forming dots are formed on the front surface of the recording head 6.

The carriage 5 is reciprocated in the direction of the arrow by a carriage drive motor 8 via a belt transmission mechanism 9.

During recording, in synchronization with the movement of the carriage 5 in the width direction of the sheet 3, driving elements of each ink ejection port of the recording head 6 are driven to form flying ink droplets directed from the ink ejection ports toward the sheet 3. I will record it.

After recording is completed, the recording head 6 moves to the home position H outside the recording range.
Stopped by P. A pump suction type ink recovery device 10 is provided at the home position HP.

No. 38 Kl indicates the ink recovery device 10.

In FIG. 3, a motor 12 as a driving source and a suction pump 13 for ink recovery are mounted on a frame 11, and the ink ejection opening of the recording hood 6 is sealed airtight at the front (on the recording head side). A cap 14 that seals in this state is guided and supported so that it can move forward and backward (in the direction of arrow F).

An elastic cap 15 made of an elastically deformable material such as rubber is mounted inside the cap 14 . The periphery of this elastic cap 15 protrudes from the main body of the cap 14, and the ink discharge port is sealed by this elastic cap 15 during camping.

Further, the elastic cap 15 is compressed and deformed by moving the cap 14 further forward from the camping state, thereby increasing the pressure (internal pressure) in the internal space when the cap is sealed.

The elastic cap 15 and the suction pump 13 are connected by a suction tube 16, and a waste ink tube 17 for discharging the suctioned ink is connected to the discharge side of the suction pump.

A cap drive gear 19 having an inner cam 18 for driving the cap 14 back and forth is disposed on the frame 11,
A pump drive gear 21 having an end face cam 20 that drives the suction pump 13 is pivotally supported, and these gears 19
．． 21 is driven by the motor 12 via a gear train.

A swing lever 22 is pivotally supported between the pump drive gear 21 and the suction pump 13, and is configured to drive the suction pump 13 with the lift of the end cam 20.

A ventilation tube 25 is connected to the elastic cap 15, and an on-off valve (not shown) is provided in the middle of the ventilation tube 25. By opening the on-off valve, the elastic cap 1
The inside of the elastic cap 15 is sealed by communicating the inside of the elastic cap 5 with the atmosphere and closing the on-off valve.

Two circular cams 26 and 27 are provided coaxially with the pump drive gear 21 and rotate together with the gear, and one of the cams 26 opens the on-off valve of the ventilation tube 25 at a predetermined timing to vent the atmosphere. The other cam 27 is a ventilation cam for communicating with the elastic cap 15, and the other cam 27 moves the cap 14 in the capped state further forward by a partial stroke at a predetermined timing, thereby increasing the internal pressure of the elastic cap 15 and blowing air into the ink discharge port. It is an air pushing cam for pushing.

FIG. 1 shows the camping state of the elastic camp 15 (A
) and air pushing state (B) are shown.

The cap 14 moves a movable plate 28 disposed on its back side forward by the inner cam 18, and enters the capping state.

In this camping state, the elastic cap 15 is brought into close contact with a predetermined pressure set by the spring 29, sealing the ink discharge port from the outside.

When the air pushing cam 27 rotates and presses the rod 30 forward in the above-mentioned capping state, the cap 14 is further advanced as shown in FIG. rise to This increased pressure forces some of the air within the cap into the ink discharge port.

When the vent opening/closing valve (not shown) is opened (ventilated) by the vent cam 26 in a state where the internal pressure has increased, the pressure inside the elastic cap 15 can be returned to atmospheric pressure (decreased).

In this way, by returning the pressure within the elastic cap 15 to atmospheric pressure, the aforementioned forced air can remain in the ink within the ink discharge (inside the nozzle).

Therefore, by generating large air bubbles inside the nozzle by pushing air as described above, if there are microbubbles in the ink that are difficult to remove by ink suction alone, these microbubbles can be trapped and merged into larger bubbles. It can be put away.

Since large bubbles can be easily removed by ink suction, by performing the recovery operation after coalescing the microbubbles as described above, the microbubbles could be easily and reliably removed.

FIG. 4 is a timing chart of the recovery operation (one cycle) according to the present invention.

At the reference position (0 degrees), recording is possible, the cap 14 is open, the ventilation means 25 is open, the pump 13 is off, and air pushing is also off.

When the gear 19.21 begins to rotate by the motor 12 due to the recovery operation, first the camp is closed and the ventilation of the cap is also closed. Next, air pushing cam 2
7 compresses the elastic cap 15 to generate air bubbles in the ink within the nozzle.

Next, the ventilation is opened to return the pressure inside the elastic cap 15 to atmospheric pressure, and the air pushing cam 27 passes through to release the compressive deformation of the elastic cap 15.

After that, the ventilation means 25 is closed again to seal the inside of the cap 15, and in this state, the suction pump 13 is operated to suck ink, and a recovery operation is performed.

Next, the ventilation means is opened to communicate the inside of the canister to the atmosphere, and the operation of the suction pump 130 is stopped.

Finally, open the cap to complete one cycle of the recovery operation.

The above recovery operation can be repeated in multiple cycles as necessary.

〔effect〕

As is clear from the above description, according to the present invention, with the ink ejection ports of the recording head sealed with the elastic cap member, the elastic camp member is further pressed and elastically deformed to increase the internal pressure, and then the elastic cap member is The inside of the member is communicated with the atmosphere, and then the ink recovery operation is performed, so even if there are microbubbles in the ink inside the nozzle, the air can be used to push them in and incorporate them, allowing the ink to be easily and reliably removed. A method for operating an inkjet recording device is obtained that can remove air bubbles and ensure good ink ejection.

[Brief explanation of the drawing]

FIG. 1 shows the state in which the method of the present invention is carried out, (A) is a schematic cross-sectional view showing the time of camping, (B) is a schematic cross-sectional view showing the time of air pushing, and FIG. 2 is an inkjet suitable for carrying out the method of the present invention. FIG. 3 is a perspective view of the recording device, FIG. 3 is a perspective view of the recovery device in FIG. 2, and FIG. 4 is a timing chart of operations when carrying out the method of the present invention. 6.--.--recording head, 10--.
...Recovery device, 12--m---1--Motor (recovery system), 13-...--Suction pump, 14-
・−1−−−−Camping, 15−・−・−・−・・Elastic cap, 25−・・−・−・−Vent tube, 26−
−−−−・・・−・Vent cam, 27・−1−−−−−
---Air push cam. Agent: Yasushi Ooto, Patent Attorney Figure 1 (B)

Claims (1)

[Claims] (1) With the ink ejection opening of the recording head sealed with an elastic cap member, the elastic cap member is further pressed and elastically deformed to increase the internal pressure, and then the inside of the elastic cap member is communicated with the atmosphere, and then A method of operating an inkjet recording device, characterized by performing an ink recovery operation.