JP2000135798A - Recovering device for ink jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recovering device for an ink jet device which exhibits high recovery performance, is highly reliable, and is capable of altering the form of the suction of ink according to the condition of the nozzle of a recording head and an ink passage. SOLUTION: In the case where the speed of the rotation of a cam 43 making a first rotation is high and the speed of the rotation of the cam making a second rotation is low, time required for a sucking cap 41 to be separated from a nozzle face is short in the first rotation, therefore in the course of a decrease in sucking negative pressure, the sucking cap 41 is separated from the nozzle face and the sucking negative pressure is suddenly returned to 0. In a change in sucking negative pressure in the second rotation, as ink is sucked, the sucking negative pressure decreases and gradually reaches 0. By the sudden change of the sucking negative pressure in the first rotation, dust, air bubbles, etc., in a passage are separated from parts to which they are sticking, and made easily movable. An amount of the suction of ink by the sucking negative pressure in the second rotation following it is large, and the dust and air bubbles in the passage made easily movable by the previous operation are surely sucked and removed. By omitting or increasing the first rotation, the form of the suction of ink can be altered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ejecting apparatus for ejecting ink onto a recording medium to perform recording, and more particularly to a recovery apparatus for restoring the ejection performance of a recording head.

[0002]

2. Description of the Related Art Conventionally, as a recovery device for recovering the ejection performance of a recording head, a suction cap that comes into contact with the nozzle surface of the recording head so as to be able to come and go, and a suction pump that sucks ink from the recording head through the suction cap. And a driving means such as a motor for moving the suction cap to and away from the nozzle surface and driving the suction pump means.

In such a recovery device, a suction pump is driven to perform a suction operation. In general, the suction operation generates one suction negative pressure, and the ink in the recording head is blown at a stroke through a suction cap. It is performed by suction.

[0004]

In the use of such an ink ejecting apparatus, the ink which is drying out is removed from the nozzle at the time of automatic recovery automatically performed according to the length of the non-use period by the built-in timer means. It is only necessary to suction a relatively small amount of ink.However, when the nozzle hole of the recording head becomes defective due to drying of ink, clogging of dust, mixing of bubbles into the nozzle, etc. It is desirable to suck a certain amount of ink.

[0005] Further, depending on the state of ejection failure, it may not be possible to completely recover the ink by suctioning the ink, and it is necessary to repeat the suction operation, and it may take extra time to recover the ejection performance. . Further, simply repeating the suction operation may cause a case where the injection does not return to normal. The present invention has been made in order to solve the above-described problems, and has as its object to provide a highly reliable recovery device with high recovery performance.

Another object of the present invention is to provide a recovery device capable of changing the manner of ink suction according to the state of nozzle holes and ink flow paths of a recording head.

[0007]

Means for Solving the Problems and Effects of the Invention In order to achieve this object, the invention according to claim 1 is directed to an ink jetting apparatus including a recording head having a nozzle surface having an opened nozzle hole for jetting ink. A suction cap that comes into contact with the nozzle surface of the recording head so as to be able to come and go, a suction pump means that suctions ink of the recording head through the suction cap,
Driving means for driving the suction pump means while bringing the suction cap into and out of contact with the nozzle surface, and control means for controlling the driving means, wherein the control means makes the suction cap contact the nozzle surface and A series of suction operations for sucking ink from the recording head by a suction pump unit and separating at least a part of the suction cap from the nozzle surface are performed a plurality of times at different speeds.

As described above, a series of suction operations in which the suction cap is brought into close contact with the nozzle surface to suck ink from the recording head by the suction pump means and at least a part of the suction cap is separated from the nozzle surface are performed at different speeds. By performing the above steps a plurality of times, a change is caused in the ink flow, and dust, bubbles, and the like can be easily moved from the flow path in the recording head and can be easily removed.

In the recovery device for an ink ejecting apparatus according to claim 1, preferably, the last suction operation of the plurality of suction operations is performed at the slowest speed, so that dust, bubbles, and the like are generated by the first suction operation. It is easy to move away from the flow path. In addition, the last suction operation has the largest amount of ink suction, and on the other hand, there is little change in the suction negative pressure, so that no new dust and bubbles are generated in the flow path, and the suction performed in advance is performed. Dust, air bubbles, etc., which have become easy to move due to the operation, can be reliably removed by suction.

In the recovery device for an ink ejecting apparatus according to the first aspect, by selecting and executing the number of times of the suction operation, it is possible to change the ink suction mode according to the state of the nozzle hole and the flow path. it can. In addition, since it can be realized only by changing the control with one pump, it can be provided at low cost.

According to a fourth aspect of the present invention, there is provided an ink ejecting apparatus including a recording head having a nozzle surface having an opened nozzle hole for ejecting ink. Suction pump means for sucking ink of the recording head through the suction cap, driving means for moving the suction cap to and away from the nozzle surface and driving the suction pump means, and control means for controlling the driving means, The suction pump has a cylinder and a piston movable in the cylinder, and the controller reciprocates the piston a plurality of times at different speeds.

As described above, by causing the piston to reciprocate a plurality of times at different speeds, a change is caused in the ink flow, and dust and air bubbles are easily moved from the flow path in the recording head and are easily removed. Can be.

The piston is reciprocated a plurality of times at different speeds, wherein the driving means has a cam for reciprocating the piston at least once in one revolution, and the control means controls the plurality of cams at different speeds. It can be easily realized by rotating it.

Preferably, in the recovery device of the ink ejecting apparatus according to claim 4, the cam is also linked to the suction cap so that the suction cap comes into contact with or separates from the nozzle surface of the recording head. A series of suction operations in which the suction cap is brought into close contact with the nozzle surface to suction the ink from the recording head by the suction pump means, and at least a part of the suction cap is separated from the nozzle surface, accurately realizes a change in the ink flow. , And dust, air bubbles, and the like can be easily moved from the flow path in the recording head.

According to a seventh aspect of the present invention, there is provided an ink ejecting apparatus including a recording head having a nozzle surface having an opened nozzle hole for ejecting ink, wherein a suction cap which comes into contact with and separates from the nozzle surface of the recording head; Suction pump means for sucking ink of the recording head through the suction cap, driving means for moving the suction cap to and away from the nozzle surface and driving the suction pump means, and control means for controlling the driving means, The control means performs the operation of bringing the suction cap into contact with the nozzle surface and sucking ink from the recording head by the suction pump means at a high speed and then at a low speed.

By the above-described high-speed suction operation, dust, bubbles, and the like can be easily moved away from the flow path. In addition, while the amount of ink suctioned in the subsequent suction operation is large, the sudden change in the suction negative pressure is small, so that no new dust and bubbles are generated in the flow path, and the suction operation performed in advance Dust, air bubbles, and the like that have become easy to move can be reliably removed by suction.

The above operation includes a series of suction operations in which the suction cap is brought into contact with the nozzle surface to suck ink from the recording head by the suction pump means, and at least a part of the suction cap is separated from the nozzle surface. Performing at a high speed and then at a low speed ensures the realization.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view showing the entire configuration of the ink ejecting apparatus. Referring to FIG.
Is for mounting a recording head 5 on a carriage 6 and performing a recording operation while moving in parallel along a recording medium (printing paper) 4. The recording medium 4 is moved by the transport roller 3 at right angles to the moving direction of the carriage 6. The carriage 6 is slidably supported by guide shafts 8 and 9, and is driven by a belt 11 wrapped around pulleys 12 and 13. The pulley 12 is driven by a motor 10.

The recording heads 5 are provided independently for the four colors of yellow, black, cyan and magenta, and the ink cartridge 7 is detachably connected to each of them. As shown in FIG. 2, each recording head 5 includes a plurality of ink flow paths 5b attached to an actuator 5a such as a piezoelectric material.
And a nozzle plate 5c having a nozzle hole opened on the front surface thereof in communication with the flow path 5b. A manifold 5d that distributes ink to the ink flow path 5b is connected to a rear surface of the actuator 5a. The ink cartridge 7 is connected to the rear end of the manifold 5d.

As shown in FIG. 1, a recovery mechanism RM for recovering from non-ejection or defective ejection of the recording head 5 is provided on the side of the conveyance path of the recording medium 4.
The recovery mechanism RM includes a suction cap 41 that can be brought into contact with and separated from a nozzle hole opening surface (hereinafter, referred to as a nozzle surface) of the recording head 5, a suction pump 42 that suctions and removes ink in the recording head 5 through the suction cap 41, It has a suction cap 41 and a cam 43 for driving a suction pump 42. A wiper member 32 for wiping the nozzle surface of the recording head 5 is disposed adjacent to the recording medium side of the suction cap 41. On the opposite side, the wiper member 32 covers the nozzle surface of the recording head 5 when recording is not performed. A storage cap device 33 is provided to avoid drying.

The storage cap device 33 has a storage cap 71 corresponding to the plurality of recording heads 5, and a casing 72 supporting the storage cap 71 is provided on a guide rod member 73 extending parallel to the moving direction of the carriage 6. It is supported so that it can slide and rotate. In addition, the casing 72 has an engaging projection 72a that projects forward to engage with the carriage 6 when the carriage 6 moves and to slide integrally with the carriage 6. When the carriage 6 moves from the position facing the recording medium toward the storage cap 71, the storage cap 71 slides following the movement of the carriage 6 and moves around the guide rod 73 by the action of the not-shown inclined cam means. It rotates and comes into close contact with the nozzle surface of the recording head 5 to prevent drying of the ink. Thereafter, when the carriage 6 moves in the direction of the recording medium again, the storage cap 71 moves away from the recording head 5 while sliding and returns to the initial state.

As shown in FIG. 3, the suction pump 42 has two pistons 58 and 59 in a cylinder 57, and a suction port 63 provided on a side surface of the cylinder 57 is connected to a tube 5.
5 and connected to the opening 44 communicating with the suction cap 41, and the discharge port 64 is opened to the waste ink tank 58 (FIG. 1). The drive shafts 61 and 62 of the pistons 58 and 59 are
They are engaged with the cam grooves 43c and 43d of the cam 43, respectively. The rear ends of the suction cap 41 and the suction pump 42 are also engaged with the cam grooves 43a and 43b of the cam 43.

FIG. 4 is a view showing the relationship between the cam grooves 43a to 43d.
Suction cap 41, suction pump 42, pistons 58, 5
9 shows the operation of FIG. With one rotation of the cam 43, the suction cap 4
1 is brought into contact with the nozzle surface of the recording head, the two pistons 58 and 59 are reciprocated to suck ink from the recording head, the suction cap 41 is separated from the nozzle surface, and the wiper member 32 is moved by the recording head 5. A series of operations of projecting toward the path and retreating can be performed.

That is, as shown in FIG. 7, in the initial state, the two pistons 58 and 59 approach each other and approach the discharge port 64 between both pistons. Cam 43
When the is driven, the suction cap 41 is advanced to come into contact with the nozzle surface of the recording head 5 (rotation angle A of the cam), and both pistons 58 and 59 are kept close to each other, as shown in FIG. Correspond to the suction port 63 (angle B). From this state, by retracting the piston 58 while one piston 59 is stopped as shown in FIG. 9, the pump chamber 76 between both pistons is enlarged, and a suction pressure is generated (angle C). The pump chamber 76 is connected to the inside of the suction cap 41 via the suction port 63, and sucks ink from the recording head 5 by the generated negative pressure. Thereafter, the suction cap 41 is retracted from the recording head 5 at an angle D, and during the retraction, only the piston 58 is further retracted at an angle E to suck the ink remaining in the suction cap 41 and the tube 55 (FIG. 10). Immediately before the completion of the retraction of the piston 58, the piston 59 also starts retreating at the angle F. As shown in FIG. 11, when the suction port 63 is closed and the discharge port 64 is opened, only the piston 59 continues to retreat, compressing the pump chamber 76 and discharging the ink in the pump chamber 76 from the discharge port 64 to the waste ink tank. Discharge to 58.

When the suction cap 41 separates from the recording head 5, the wiper member 32 is moved forward, and the carriage 6 is moved to the wiper member 32, so that the nozzle surface of the recording head 5 that has suctioned ink as described above is moved. Then, the excess ink adhering to the nozzle surface is wiped by rubbing with the wiper member 32. This operation is repeated for each recording head.

FIG. 5 shows a control system of the ink ejecting apparatus. The control apparatus 100 includes a well-known CPU, ROM, RA
M for driving the recording head 5, the motor 10 for driving the carriage, the motor 102 for driving the transport roller 3, and the cam 43 for the recovery device based on data received via the interface 101, command signals, and the like. Of the motor 103 is controlled. Further, the ink ejecting apparatus has various operation switches 104, and can instruct a recovery operation or the like artificially. FIG. 6 shows a flow of the operation related to the recovery operation in the control device 100.

The recovery operation is repeated once or plural times depending on the situation. Here, one time means that the suction cap 41, the piston 53,
This is a series of operations of the wiper member and the wiper member. For example, the elapsed time from the previous recovery operation is measured by a timer means in the control measure 100, and the control device detects the recovery time when the power is turned on, when recording data is input, and when one day has passed since the previous recovery operation. The apparatus motor 103 is controlled to rotate the cam 43 at a low speed one rotation. When three days or more have elapsed, control is performed such that one revolution of the cam is driven at a high speed and the next one revolution is driven at a low speed. When the user presses the operation switch 103 to instruct a recovery operation, control is performed to drive one rotation at a high speed and the next one rotation at a low speed, as described above. When the ink cartridge 7 is replaced to guide new ink to the recording head, control is performed such that two rotations are driven at a high speed and the next two rotations are driven at a low speed. Such a program is stored in the ROM of the control device 100.

When a recovery command is input, it is determined how many times the recovery operation according to the recovery command is performed (step S1 in FIG. 6). When the recovery command is one recovery operation (S
1: Yes), the control device 100 controls the motor 103 for the recovery device to rotate the cam 43 one rotation at a low speed (S2). When the recovery command is a recovery operation for a plurality of times (S1: No), the control device 100 controls the motor 103 for the recovery device to rotate the cam 43 at a high speed first and a required number of times (S3). To perform the required number of rotations at low speed (S4). Here, the required number differs as described above when the user commands the recovery operation or when the ink cartridge 7 is replaced.

By changing the rotation speed of the cam 43 in this manner, the manner of change of the ink suction amount and the suction negative pressure is changed.

More specifically, if the rotation speed of the cam 43 is low and there is a sufficient time until the suction cap 41 is separated from the nozzle surface after the suction negative pressure is generated, FIG.
As shown in FIG. 2A, the change in the suction negative pressure due to one rotation of the cam 43 decreases to zero as the suction negative pressure decreases with the suction of the ink. On the other hand, as described above, the cam 4
When the rotation is performed a plurality of times by changing the rotation speed of FIG.
(B), the suction negative pressure generated at the first rotation,
Although the suction negative pressure generated in the second rotation is the same, the time required for the suction cap 41 to separate from the nozzle surface becomes shorter in the first rotation. , And the suction negative pressure is rapidly returned to zero. At this time, although the ink suction amount is reduced as compared with the second rotation, a sudden change in the suction negative pressure makes it easy to move away from the place where dust, bubbles and the like are attached. The subsequent suction negative pressure of the second rotation of the cam 43 is the same as that in FIG.
While the amount of ink suction increases, the sudden change in suction negative pressure is small, so that no new dust and bubbles are generated in the flow channel, and the dust in the flow channel that has been easily moved by the previous suction.
Remove any air bubbles by suction.

A comparison was made of the recovery performance when an abnormal injection occurred. Only one rotation of the cam 43 (FIG. 12A)
When the suction is performed in step, the probability of recovery to the normal state is 7
It was 0%. Also, while keeping the rotation speed of the cam 43 the same,
In the case of two rotations, the ink suction amount and the suction time were both doubled, but the probability of recovery to the normal state was 75%, which was not a significant effect.

On the other hand, in the case where the rotation speed of the cam 43 in the first rotation is increased and the rotation in the second rotation is set to the above rotation speed (FIG. 12B), the probability of recovery to the normal state is obtained. Rose to 98%. Accordingly, it can be seen that the recovery rate of the ejection failure was greatly improved while saving both the ink suction amount and the suction time.

In the above description, a series of suction operations are performed once at a high speed and a low speed, but may be performed twice at a high speed and once at a low speed as shown in FIG. When a relatively large amount of ink suction is required, such as when replacing a cartridge, the suction operation may be performed twice at high speed, twice at low speed, or more times. Also,
As shown in FIG. 12D, in order to shorten the recovery time,
The rotation speed of the cam 43 may be further increased from the time when the suction cap 41 is separated from the nozzle surface and the suction negative pressure becomes 0 to the initial state (360 ° from the rotation angle D of the cam 43). Further, the piston may be reciprocated a plurality of times by one rotation of the cam 43.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of an ink ejecting apparatus according to the present invention.

FIG. 2 is a sectional view of a connection portion between a recording head and an ink cartridge according to the present invention.

FIG. 3 is a cross-sectional view showing a relationship among a wiper member, a suction cap, a suction pump, and a cam according to the present invention.

FIG. 4 is a diagram illustrating the rotation angle of a cam and the operation of a suction cap, a wiper member, and a suction pump.

FIG. 5 is a block diagram of a control system of the ink ejecting apparatus.

FIG. 6 is a flowchart illustrating a flow of a purge operation.

FIG. 7 is an explanatory diagram of the operation of the suction pump.

FIG. 8 is a diagram illustrating the operation of the suction pump.

FIG. 9 is a diagram illustrating the operation of the suction pump.

FIG. 10 is a diagram illustrating the operation of the suction pump.

FIG. 11 is a diagram illustrating the operation of the suction pump.

FIG. 12 is an explanatory diagram of a mode of a change in suction negative pressure by a suction pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink ejection device 5 Recording head 32 Wiper member 41 Suction cap 42 Suction pump 43 Cam 100 Control device

Claims (8)

[Claims] 1. An ink ejecting apparatus comprising a recording head having a nozzle surface with an opened nozzle hole for ejecting ink, a suction cap which comes into contact with the nozzle surface of the recording head so as to be able to come in contact with and separate from the recording head, and a recording head through the suction cap. Suction pump means for sucking the ink, drive means for driving the suction pump means while bringing the suction cap into and out of the nozzle surface, and control means for controlling the drive means, the control means comprising: A series of suction operations in which a suction cap is brought into contact with a nozzle surface to suck ink from the recording head by the suction pump unit and at least a part of the suction cap is separated from the nozzle surface are performed a plurality of times at different speeds. A recovery device for an ink ejecting device. 2. The ink jetting apparatus recovery device according to claim 1, wherein said control means performs the last suction operation of the plurality of suction operations at the slowest speed. 3. The apparatus according to claim 1, wherein the control unit selects and executes the number of times of the suction operation. 4. An ink ejecting apparatus comprising a recording head having a nozzle surface with an opened nozzle hole for ejecting ink, a suction cap which comes into contact with the nozzle surface of the recording head so as to be able to come and go, and a recording head through the suction cap. Suction pump means for sucking the ink, driving means for driving the suction pump means while bringing the suction cap into and out of the nozzle surface, and control means for controlling the driving means, the suction pump means comprising: A recovery device for an ink ejecting apparatus, comprising: a cylinder; and a piston movable in the cylinder, wherein the control means reciprocates the piston a plurality of times at different speeds. 5. The apparatus according to claim 4, wherein said driving means has a cam for reciprocating said piston at least once per rotation, and said control means rotates said cam a plurality of times at different speeds. The recovery device of the ink ejecting apparatus according to any one of the preceding claims. 6. The recovery of the ink ejecting apparatus according to claim 5, wherein the cam is linked to the suction cap so that the suction cap contacts and separates from a nozzle surface of the recording head. apparatus. 7. An ink ejecting apparatus including a recording head having a nozzle surface having an opened nozzle hole for ejecting ink, a suction cap which comes into contact with the nozzle surface of the recording head so as to be able to come into contact with the recording head, and the recording head through the suction cap. Suction pump means for sucking the ink, drive means for driving the suction pump means while bringing the suction cap into and out of the nozzle surface, and control means for controlling the drive means, the control means comprising: An operation for recovering an ink ejecting apparatus, wherein an operation of bringing a suction cap into contact with a nozzle surface and sucking ink from the recording head by the suction pump means is performed at a high speed and then at a low speed. 8. A series of suctions that bring the suction cap into contact with a nozzle surface, suction the ink from the recording head by the suction pump means, and separate at least a part of the suction cap from the nozzle surface. 8. The ink jetting apparatus recovery device according to claim 7, wherein the operation is performed at a high speed and then at a low speed.