JP2001347689A - Ink jet recorder and method of cleaning print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder wherein a cleaning mechanism is simplified and a print head can be restored to an ejectable condition in a short time. SOLUTION: This ink jet recorder comprises a pump 9 coupled to a cap 10 with a pipe 11. The ink jet recorder further comprises a negative pressure generating section 13 that sucks ink from the print head 2 by generating a negative pressure in the cap 10 by driving the pump 9 and a negative pressure supply switching section 12 that switches supply of the negative pressure to the print head 2 by selectively closing or opening the pipe 11.

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 for forming an image by discharging ink onto printing paper and a method for cleaning a print head.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus generally includes an ink tank of four colors of black, yellow, magenta, and cyan and a print head. In addition, a cap is provided to cover the print head during non-printing, and a cleaning mechanism is provided to clean the print head and restore the ink dischargeable state when the ink tank is replaced or when the discharge failure of the print head is recovered. Have been.

[0003] The cleaning mechanism of the print head includes one vacuum that sucks ink from the print head by negative pressure.
A cap is provided.

[0004] As a method of cleaning the print head,
In general, suctioning ink from the print head, wiping the head surface of the print head, and performing preliminary ejection (spitz) are performed in combination in plural times.

[0005]

In the conventional ink jet recording apparatus, when the ink tank is replaced or when the ink discharge failure of the print head is recovered, the print head is cleaned to recover the ink discharge state. A vacuum cap is required in addition to the cap to cover the print head, and the cleaning mechanism is complicated.

Also, since there is only one vacuum cap,
When replacing the ink tank or recovering from the ink discharge failure of the print head, it is necessary to suck ink from each print head in order to clean the print head and restore the ink dischargeable state. There is also a problem that it takes time to restore the print head to a state where ink can be ejected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording apparatus which simplifies a cleaning mechanism and restores a print head to a state capable of discharging in a short time.

[0008]

In order to achieve the above object, in an ink jet recording apparatus according to the present invention, a negative pressure generating section for generating a negative pressure by driving a pump and a predetermined cap among a plurality of caps are provided. A second pipe having one end divided into a manifold and having one end connected to the remaining cap except for a predetermined cap, and the other end connected to the pump; And a negative pressure supply switching unit that switches the negative pressure supply to the remaining caps by blocking / conducting the other end of the tube.

In order to achieve the above object, an ink jet recording apparatus according to the present invention has a pump connected to a cap by a tube, and drives the pump to generate a negative pressure in the cap so that the print head can generate a negative pressure. A negative pressure generating unit that sucks ink and a negative pressure supply switching unit that selectively shuts off and conducts the pipe to switch the negative pressure supply to the print head are provided.

According to another aspect of the present invention, there is provided a method of cleaning a print head, comprising: a first ink suction means for generating a negative pressure on a predetermined cap to suction ink; A second ink suction means for generating a negative pressure in all the caps including the ink suction means for sucking ink by suctioning ink from the print head in which the ink tank has been replaced by the first ink suction means, The ink is sucked by the second ink suction means.

[0011]

Embodiments of the present invention will be described with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals.

FIG. 2 is a perspective view showing a printer mechanism according to the first embodiment . The carriage 1 has black A, black B, yellow, magenta, and cyan ink tanks. Print heads 2a to 2e (hereinafter collectively referred to as print head 2) are mounted, and are slidably provided on a carriage shaft 4 having both ends supported by a frame 3.

The frame 3 is provided with a spacing motor 5 and a pulley 6, which are wound around a motor gear 5a fixed to a shaft of the spacing motor 5 and the pulley 6. The carriage unit 1 is connected to the belt 7. At one end of the moving range of the carriage unit 1, a cleaning unit 8 for sucking ink from each print head and wiping the head surface of the print head is provided.

FIG. 1 is a schematic view of a cleaning unit according to the present invention, FIG. 3 is a perspective view showing the structure of the cleaning unit shown in FIG. 2, FIG. 4 is a detailed view of a cap, and FIG. It is a perspective view of a switching part.

As shown in FIG. 1, the cleaning unit 8 has a pump 9 connected to caps 10a to 10e (hereinafter, referred to as a cap 10 in a generic manner) by a pipe 11, and the pump 9 is The pump 9 generates a negative pressure in the cap 10 by driving and sucks ink from the print head 2, a cap moving unit 14 for bringing the cap 10 into close contact with the print head 2, and a pump 9. A negative pressure supply switching unit for supplying a negative pressure to the print head by switching a pipe connected to the cap;

The tube 11 is formed of an elastic material such as silicon rubber, and has a first tube 11a connecting the pump 9 and the cap 10a, and a cap 10b having one end divided in various ways.
To a second tube 11b connected to the pump 9 at the other end.

As shown in FIG. 3, the cap moving section 14 has a cap stage 19 rotatably supported on a frame 18 by a shaft 17, and an arrangement interval of the print heads 2a to 2e on the upper surface of the cap stage 19. And the caps 10a to 10e set in the above.

As shown in FIG. 4, the cap 10a has a high porosity, a first absorber 20a having good ink permeability and absorptivity, and a low porosity as compared with the first absorber 20a. Second absorber 20b with poor ink permeability and absorbency
And a cap 20c are stored in a layered manner in a frame 20d, and a rubber tube for discharging ink is provided below the frame 20d.
The bus 11a is attached. Caps 10b-10
e is a rubber tube 11b having the same structure as the cap 10a.
Is attached.

The second absorber 20b is a first absorber 20b.
Since the porosity is low and the permeability and absorption of the ink are inferior to those of the rubber tube 11a, when the negative pressure is applied to the cap 10a, only the periphery of the mounting portion of the rubber tube 11 is not easily sucked. Negative pressure is applied to the whole.

As shown in FIG. 5, the negative pressure supply switching section 12 is provided with a second cam 24 and a torsion spring 2 for turning a lever 25 to shut off and conduct the rubber tube 11b.
6 mag.

The pump 9 is provided with a pair of pump rollers 28a, 28a so as to form a pair at 180 ° with the shaft 27a of the pump gear 27 interposed therebetween.
8b, the pump rollers 28a and 28b rotate integrally with the rotation of the pump gear 27, and the rubber tube 11a
To generate a negative pressure in the rubber tubes 11a and 11b.

The driving unit 16 is provided with a cleaning mode, which will be described later.
Motor, idle gears 30 to 33, two-stage gears 34 and 35, and a planetary gear 36, and drive the pump 9, the cap moving unit 14, and the cam mechanism 15 as shown in FIG.

The cam mechanism 15 includes a cam shaft 21, a cam gear 22, a first cam 23, a second cam 24, and the like. The camshaft 21 includes a first cam 23, a second cam 2
The cam gear 22 is fixed to an end formed integrally with the frame 4 and rotatably supported by the frame 18.

The first cam 23 has a cam groove 23a,
A shaft, which will be described later, provided on the lower surface of the cap stage 19 is fitted in the cam groove 23a.
Is rotated.

The second cam 24 is in contact with the lever 25 of the negative pressure supply switching section 12. The lever 25 has a substantially L-shape. As shown in FIG. 3, a central portion is rotatably supported by the frame 18 and a torsion spring 26 provided on a support shaft.
And one arm is brought into contact with the cam surface of the second cam 24 and the other arm is brought into contact with the rubber tube 11b.

FIG. 7 is an explanatory diagram (1) of the operation of the cleaning unit, and shows a state in which the print head 2 and the cap 10 are in close contact with each other. FIG. 8 is an explanatory diagram (2) of the operation of the cleaning unit, showing a state in which the print head 2 and the cap 10 are separated. 9A and 9B are explanatory diagrams of the operation of the negative pressure supply switching unit. FIG. 9A shows a state in which the second rubber tube 11b is crushed, and FIG. 9B shows a state in which the second rubber tube 11b is crushed. Is open.

Next, the operation of the cleaning unit will be described. As shown in FIG. 7, the cleaning motor 38 is
When the tag gear 29 is rotated in the direction of arrow A, the idle gear 3
The planetary gear 36 is connected to the two-stage gear 35 via the
And the cam gear 2 through the idle gear 31.
2 is rotated in the direction of arrow C.

When the cam gear 22 rotates in the direction of arrow C,
The first cam 23 and the second cam 24 integrated with the camshaft 21 also rotate in the direction of arrow C. The first cam 23 has an arrow C
When rotated in the direction, the cap stage 19 on which the cap 10 is mounted rotates in the direction of the arrow EF, and the cap 10 comes into close contact with and separates from the print head 2.

When the second cam 24 rotates in the direction of arrow C, the lever 25 of the negative pressure supply switching section 12 rotates in the direction of HI as shown in FIG. The urging force of the second rubber tube 11b causes the second rubber tube 11b to be opened and crushed by the urging force of the torsion spring 26. Since the second rubber tube 11b is an elastic body, the second rubber tube 11b is restored and becomes a conductive state in the open state.

As shown in FIG. 7, when the cleaning motor 38 moves the motor gear 29 in the direction of arrow B, the planetary gear 36 meshes with the idle gear 32 via the idle gear 30, the second gear 34. The drive is transmitted to the pump gear 27 via the idle gear 33, and the pump gear 27
Rotates in the direction of arrow G.

When the pump gear 27 rotates in the direction of arrow G, the pump rollers 28a and 28b rotate while crushing the first rubber tube 11a, and the first rubber tube 1a is rotated.
A negative pressure is generated in 1a.

FIGS. 6A and 6B are cam diagrams showing the operation of the cam mechanism. FIGS. 6A and 6B show the first cam 2 respectively.
3, a cam diagram of the second cam 24 is shown.

At time t0, the first cam 23 and the second cam 2
Numerals 4 denote a cap standby position and a blocking position, respectively. The cap 10 is separated from the print head 2 as shown in FIG. 8, and the lever 25 of the negative pressure supply switching unit 12 is shown in FIG. 9A. Thus, the second rubber tube 11b is in a crushed state.

At time t1, the first cam 23 rotates the cap stage 19 in the direction of arrow E as shown in FIG. At this time, the second cam 24 is in the shut-off position, and the lever 25 of the negative pressure supply switching section 12 is set to the second rubber tube 11.
b is in a crushed state.

At time t2, the first cam 23 is at the head cap position, and the cap 10 and the print head 2 are
As shown in (2), the second cam 24 is in the blocking position and the second rubber tube 11b is in a crushed state.

At time t3, the first cam 23 is at the head cap position and the second cam 24 is at the conduction position. As shown in FIG. 9B, the lever 25 of the negative pressure supply switching section 12 rotates in the direction of the arrow I against the urging force of the torsion spring 26, and moves the second rubber tube 11b. Open.

At time t4, the first cam 23 rotates the cap stage 19 in the direction of arrow F as shown in FIG. At this time, the second cam 24 is at the conduction position.

At time t5, the cap stage 19 is at the head cap retreat position, and the lever 25 of the negative pressure supply switching unit 12 is at the shut-off position where the second rubber tube 11b is crushed.

From time t2 to time t3, as shown in FIG. 7, when the cleaning motor 38 moves the motor gear 29 in the direction of arrow B, the pump gear 27 rotates, and the first rubber tube 11a is rotated. Generate negative pressure. At this time, the lever 25 of the negative pressure supply switching unit 12 is connected to the second rubber tube 11b.
Is crushed, the negative pressure acts only on the print head that is in close contact with the cap 14a, and a strong suction force acts.

Similarly, when the cleaning motor 38 moves the motor gear 29 in the direction of the arrow B from the time t3 to the time t4, the second rubber tube 11b is in the restored conductive state. The negative pressure generated in the nozzle 11a sucks ink from the print head 2 which is in close contact with the caps 14a to 14e.

FIGS. 10 to 20 are diagrams showing the state in which ink is being sucked. The ink tanks for black A, black B, yellow, magenta and cyan and the print heads 2a to 2e mounted on the carriage unit 1 are shown. This shows a state in which ink is being sucked from.

FIG. 16 is a control block diagram of the ink jet recording apparatus according to the first embodiment, in which a microprocessor 40a (hereinafter referred to as an MPU 40a) and a memory 40 are shown.
b and LF respectively.
An LF motor 45, an SP motor 5, a print head 2, an LF motor 45 via a motor driver 41, an SP motor driver 42, a print head driver 43, and a cleaning motor driver 44.
The cleaning motor 38 is connected.

The printer control unit 40 includes an operation panel 4
6, access cover sensor 47, ink end sensor 4
8. Input I / F 50 for inputting print data from the host device
Is connected.

The access cover sensor 47 and the ink end sensor 48 are respectively arranged at predetermined positions in the apparatus. The operation panel 46 has LED lamps 46a to 4 corresponding to the respective ink tanks and indicating that the ink is empty.
6e, an ink tank replacement key 46f for notifying the MPU 40a of the ink tank replacement is provided.

FIG. 17 is a flowchart showing the operation of replacing the ink tank according to the first embodiment.

Next, the operation at the time of replacing the ink tank will be described with reference to the flowchart of FIG. MPU in step S1
40a interrupts periodically during printing, and checks via the ink end sensor 48 whether or not each ink tank is in the ink end state. As a result, for example, when it is detected that the yellow-ink tank is in the ink-end state, the LED lamp 46c corresponding to the yellow-ink tank on the operation panel 46 is blinked to stop printing. Ends the processing.

In step S2, the MPU 40a operates the operation panel 46.
It is checked whether or not the ink tank replacement key 46f is pressed. When the ink tank replacement key 46f is pressed, the SP motor 5 is driven to move the carriage unit 1 to the center of the printing apparatus. .

In step S3, the MPU 40a checks whether or not the access cover (not shown) has been opened / closed via the access cover sensor 47. If the access cover has been opened / closed, the flow branches to step S4. Normally, the ink tank is replaced with a new one when the access cover is opened and closed.

In step S4, the MPU 40a drives the SP motor 5 to move the carriage 1 to the home position.

In step S5, the MPU 40a detects the amount of ink in the yellow ink tank via the ink end sensor 48, checks whether the yellow ink tank has been replaced, and if so, branches to step S6. If not, the process branches to step S11.

In step S6, the MPU 40a drives the SP motor 5, and moves the carriage unit 1 as shown in FIG.
The cap 10a is moved to a position facing the print head 2c.

In step S7, as shown in FIG. 7, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow A by a predetermined amount, and rotates the cap stage 19 in the direction of arrow E. At this time, the cap 10a is attached to the print head 2c.
The rubber tube 10b is in a state of being crushed by the lever 25.

In step S8, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow B, and
A negative pressure is generated in the nozzle 10a to suck the yellow ink from the yellow head 2c. At this time, rubber tube 1
Since the rubber tube 10b is in a state where the rubber tube 10b is crushed by the lever 25, a negative pressure is applied to only the print head 2c and the yellow ink is sucked with a large suction force.

In step S9, the MPU 40a rotates the cleaning motor 38 in the direction of arrow A by a predetermined amount, rotates the cap stage 19 in the direction of arrow F, and separates the cap 10 from the print head 2, as shown in FIG. Let it.

In step S10, the MPU 40a drives the SP motor 5, and as shown in FIG.
The carriage unit 1 is moved to a position facing the print heads 2a to 2e.

In step S11, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow A by a predetermined amount, rotates the cap stage 19 in the direction of arrow E, and moves the caps 10a to 10e to the print head 2a, as shown in FIG. ~
2e so that the rubber tube 10b is released from the lever 25.

In step S12, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow B to generate a negative pressure in the rubber tubes 10a and 10b, thereby causing the print head 2 to rotate.
The ink is sucked from a to 2e. After the suction of the ink, the process is terminated in a capping state in which the caps 10a to 10e are brought into close contact with the print heads 2a to 2e.

Here, the state when a negative pressure is applied to all the caps will be described. The ink coming out of each print head is absorbed by the first absorber 20a shown in FIG. 4, diffuses and permeates quickly throughout the first absorber 20a, and soaks into the second absorber 20b thereunder. Go out.

At this time, even if one of the caps discharges the ink earlier than the other cap, the porosity of the second absorber 20b, which is inferior to the first absorber 20a, in the permeability and absorbency of the ink. Is small and the resistance
A pressure difference occurs between the upper and lower absorbers 20b, and the first and second absorbers 20a and 20b
Since the ink impregnated in b is discharged, defective ink discharge can be prevented.

If the process branches from step S5 to step S11, in step S11 the MPU 40a drives the SP motor 5 to move the carriage 10 to the position where the caps 10a to 10e face the print heads 2a to 2e.

In step S12, the MPU 40a cuts off the print head surface from the atmosphere as shown in FIG.
The cleaning motor 38 is driven to rotate in the direction of arrow A, the cap stage 19 is rotated in the direction of arrow E, and the process is terminated in the capping state in which the caps 10a to 10e are in close contact with the print heads 2a to 2e.

According to the first embodiment, a negative pressure can be generated in all the caps and ink can be simultaneously sucked from a plurality of print heads. Sometimes the suction time can be reduced.

Also, by switching between a case where a negative pressure is generated only in a predetermined cap and a case where a negative pressure is generated in all caps including the predetermined cap,
Negative pressure can be adjusted with a small pump.

Further, a strong negative pressure is applied to the print head whose ink tank has been replaced to suck ink, and then a weak negative pressure is applied to all the print heads to suck ink at the same time. At this time, even if the nozzles of the print head, which are not related to the ink tank replacement, are left in the atmosphere for a long time, even if the ink changes over time, the occurrence of ejection failure does not occur.

Further, since the ink is simultaneously sucked from all the print heads and the process is completed, the degree of change over time when the ink at the nozzle tip of the print head is left in the atmosphere can be substantially the same.

The ink is sucked by applying a strong negative pressure to the print head whose ink tank has been replaced, and then suctioning the ink simultaneously by applying a weak negative pressure to all the print heads. Thus, the print head can be restored to a state in which discharge can be performed in a short time.

Second Embodiment FIG. 18 is a control block diagram of an ink jet recording apparatus according to a second embodiment . The difference from the first embodiment is that a timer 49 is provided.

FIG. 19 is a flowchart (1) showing the operation of replacing the ink tank according to the second embodiment, and FIG. 20 is a flowchart showing the operation of replacing the ink tank according to the second embodiment. (2).

In step S 1, the MPU 40 a periodically interrupts during printing, and checks via the ink end sensor 48 whether or not each ink tank is in the ink end state. As a result, for example, when it is detected that the yellow ink tank is in the ink end state, the operation panel 46 is detected.
LED lamp 46 corresponding to the yellow ink tank above
c is blinked, printing is stopped, and if not, the process is terminated.

In step S2, the MPU 40a operates the operation panel 46.
It is checked whether or not the ink tank replacement key 46f is pressed. When the ink tank replacement key 46f is pressed, the SP motor 5 is driven to move the carriage unit 1 to the center of the printing apparatus. .

At step S3, the MPU 40a sets the timer 49
Is started. In step S4, the MPU 40a checks whether or not the access cover (not shown) has been opened and closed via the access cover sensor 47. If the access cover has been opened and closed, the process branches to step S5. Normally, the ink tank is replaced with a new one when the access cover is opened and closed.

In step S5, the MPU 40a drives the SP motor 5 to move the carriage 1 to the home position.

In step S6, the MPU 40a detects the amount of ink in the yellow ink tank via the ink end sensor 48, checks whether the yellow ink tank has been replaced, and if so, branches to step S7. If not, the process branches to step S15.

At step S7, the MPU 40a
It is checked whether or not 9 has reached the timeout. If the timeout has been reached, the flow branches to step S8, and if not, the flow branches to step S17.

In step S9, the MPU 40a drives the SP motor 5, and moves the carriage unit 1 as shown in FIG.
The cap 10a is moved to a position facing the print head 2c.

In step S9, as shown in FIG. 7, the MPU 40a drives the cleaning motor 38 to rotate by a predetermined amount in the direction of arrow A, and rotates the cap stage 19 in the direction of arrow E. At this time, the cap 10a is attached to the print head 2c.
The rubber tube 10b is in a state of being crushed by the lever 25.

In step S10, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow B to generate a negative pressure in the rubber tube 10a to suck the yellow ink from the print head 2c. At this time, the rubber tube 10
Since the rubber tube 10b is in a state where the rubber tube 10b is crushed by the lever 25, a negative pressure is applied to only the print head 2c and the yellow ink is sucked with a large suction force.

In step S11, as shown in FIG. 8, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow A by a predetermined amount, rotates the cap stage 19 in the direction of arrow F, and separates the cap from the print head.

In step S12, the MPU 40a drives the SP motor 5, and puts the caps 10a to 10e on the print head 2.
The carriage unit 1 is moved to a position facing a to 2e.

In step S13, as shown in FIG. 7, the MPU 40a drives the cleaning motor 38 to rotate by a predetermined amount in the direction of arrow A, rotates the cap stage 19 in the direction of arrow E, and moves the caps 10a to 10e to the print head 2a. ~
2e so that the rubber tube 10b is released from the lever 25.

In step S10, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow B to generate a negative pressure in the rubber tubes 11a and 11b, thereby causing the print head 2 to rotate.
The ink is sucked from a to 2e. After the suction of the ink, the process is terminated in a capping state in which the caps 10a to 10e are brought into close contact with the print heads 2a to 2e.

If the process branches from step S6 to step S15, the MPU 40a drives the SP motor 5 to move the carriage 1 to a position facing the print heads 2a to 2e in step S15.

In step S16, the MPU 40a, as shown in FIG.
The cleaning motor 38 is driven to rotate in the direction of arrow A, the cap stage 19 is rotated in the direction of arrow E, and the process is terminated in the capping state in which the caps 10a to 10e are in close contact with the print heads 2a to 2e.

In step S17, the MPU 40a drives the SP motor 5 to move the cap 10a to a position facing the print head 2c, as shown in FIG.

In step S18, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow A by a predetermined amount, and rotates the cap stage 19 in the direction of arrow E, as shown in FIG. At this time, the cap 10a is in close contact with the yellow head 2c, and the rubber tube 10b is crushed by the lever 25.

In step S19, the MPU 40a drives the cleaning motor 38 to rotate in the direction of arrow B to generate a negative pressure in the rubber tube 10a to suck yellow ink from the yellow head 2c. At this time, the negative pressure in the rubber tube 10a is applied to only the yellow head 2c because the rubber tube 10b is crushed by the lever 25, and the yellow ink is sucked with a large suction force. Then, after sucking the yellow ink, the process returns to step S15.

According to the second embodiment, by providing a timer which starts when the ink exchange key is pressed and measures an elapsed time until the ink tank is exchanged, the nozzles of all print heads are exchanged for the ink tank exchange. Even if the ink at the tip is left in the air, if the ink tank is replaced within a time period that does not cause a change over time, the ink is not sucked from all the print heads. The amount of ink to be discarded can be saved as compared with the case of.

In the first and second embodiments, FIG.
As shown in FIG. 21B, when the lever 25 is rotated in the direction I by the cam 24, the rubber tube 11b is caused to return by its own restoring force. However, as shown in FIG. The U-shaped leaf spring 50 sandwiching 11b is inserted into lever-2.
22, the leaf spring 50 is also expanded by the rubber tube 11b being crushed by the lever 25 as shown in FIG. 22 (A), and as shown in FIG. When the cam 25 rotates the cam 25 in the direction I, the rubber tube 11b may return with its own restoring force and the restoring force of the leaf spring 50.

In this case, if the rubber tube 11b is left in a crushed state for a long time, the rubber tube 11b
Even if the ink sandwiched between them becomes viscous due to a change with time and sticks to the rubber tube 11b, and the elasticity of the rubber tube 11b cannot return to the original circular open state, the restoring force of the leaf spring 50 can be obtained. Rubber tube
The block 11b can be shut off and opened.

Third Embodiment FIG. 23 is a perspective view of a cleaning unit according to a third embodiment, and FIG. 24 is a cross-sectional view of the cleaning unit shown in FIG. The cleaning unit 60 according to the third embodiment is significantly different from the cleaning unit 6 according to the first embodiment in FIG.
As shown in FIG.
10e are integrally moved in the direction of arrow JK to print head 2
And the cam mechanism 62 has a cap 10
The point is that cams 68 to 72 for crushing the rubber tubes 63 to 67 connected to a to 10e are provided.

The cap moving section 61 includes a U-shaped holder 74 fixed to a frame 73 and caps 10a to 10e.
And a drive section 76 for driving the cap stage 75.

The side walls 74a and 74b of the holder 74 have
Pins 77 respectively provided on the side walls of the cap stage 75
Is provided with a groove 78 for slidably fitting. FIG.
As shown in FIG. 4, a rack 80 is provided on the side wall of the cap stage 75 so as to mesh with the shaft gear 79 of the drive unit 76.

The shaft gear 79 is provided on the side wall 7 of the holder 74.
A gear 81 rotatably supported by the motors 4a and 74b and driven by a motor (not shown) is provided at one end. Shaft gear 79
Is rotated in the direction of arrow L, the cap stage 75 moves in the direction of arrow J to bring the caps 10a to 10e into close contact with the print heads 2a to 2e shown in FIG. When the shaft gear 79 rotates in the direction of arrow M, the cap stage 7
5 moves in the direction of arrow K, and separates the caps 10a to 10e from the print heads 2a to 2e.

Caps 10a to 10e and cap stay
A spring 82 is provided between the jig 75 and the jig 75 as a buffer member.

The driving section 102 includes a motor 91 and a motor gear 92, an idle gear 93 meshing with the motor gear 92,
It comprises a planetary gear 95 that rotates around the idle gear 93 and meshes with the gear 94 and a cam mechanism 62.

The cam mechanism 62 includes a U-shaped base 83 fixed to a frame 73, and a cam shaft 85 provided with cams 68 to 72 and a gear 84.

The negative pressure supply switching unit 101 is provided with a rubber tube 63.
The lever 86 has a T-shape as shown in FIGS. 25 and 26. The lever 86 is rotatable about a base 83. It is supported and urged against the cam surface of the cam 68 by a spring (not shown).

One end of the horizontal bar abuts against the cam surface of the cam 68, and the other end crushes the rubber tube 63 to put it in a cutoff state. When one end falls into the concave portion 68a, the other end separates from the rubber tube 63 and makes the rubber tube 63 conductive. The levers 87 to 90 also have the same relationship as the cams 69 to 72 and the rubber tubes 64 to 67.

FIG. 27 is a detailed view of a rubber tube. Rubber tubes 63 to 67 are connected to a rubber tube 99 via a rubber tube collecting pipe 98. Rubber tube 9
9 is connected to a pump unit (not shown).

The pump unit according to the first embodiment has the
When the motor 91 is rotated in the direction of arrow R in the same manner as in the case of the steering unit, the planetary gear 95 meshes with a pump gear (not shown) to rotate the pump gear, and the pump gear rotates with the rotation of the pump gear into the rubber tube 99. Generates negative pressure.

FIGS. 28A to 28E are cam diagrams showing the operation of the cam mechanism according to the third embodiment. FIGS.
8 shows the blocking / conducting operation of the rubber tubes 63 to 67 corresponding to 8 to 72. The concave portions of the cams 68 to 72 sequentially increase by 60 ° with respect to the cam 68. Also, as shown in FIG. 26, when the lever 86 is in a recessed state in the recess of the cam 68, the rotation angle of the cam shaft 85 is defined as 0 °.

At time t1, when the rotation angle of the camshaft 85 is 0 °, the lever 86 falls into the concave portion of the cam 68 to open the rubber tube 63, thereby making the cap 10a and the rubber tube 99 conductive. Also, levers 87 to 90
Crushes the rubber tubes 64 to 67, respectively, so that the space between the caps 10b to 10e and the rubber tube 99 is shut off.

The motor 91 rotates in the direction of arrow R to engage the planetary gear 95 with a pump gear (not shown).
A negative pressure is generated in a.

At time t2, when the rotation angle of the camshaft 85 is 60 °, the lever 87 falls into the concave portion of the cam 69 to open the rubber tube 64, thereby making the cap 10b and the rubber tube 99 conductive. Also, levers 86, 8
8 to 90 crush the rubber tubes 63 and 65 to 67, respectively, so that the caps 10a, 10c to 10e and the rubber tube 99 are shut off.

The motor 91 rotates in the reverse direction of the arrow R to mesh the planetary gear 95 with a pump gear (not shown).
A negative pressure is generated in b.

Similarly, at times t3, t4, and t5, negative pressure is generated in the caps 10c, 10d, and 10e, respectively.

The operation at the time of ink tank replacement is described in the first section.
The operation of the ink tank replacement according to the embodiment is the same as that of the first embodiment, except that when the ink is suctioned from all the print heads after the predetermined ink tank replacement, the ink is not suctioned all at once, but is sucked sequentially. This is to restore the ink dischargeable state.

In this embodiment, the levers 87 to 90
Of the levers 87-90 directly contact the cam surface.
A roller may be provided at one end of each of them so that they come into contact with the cam surface. In this case, the load on the motor is reduced.

According to the third embodiment, the cap 10
Ink can be sequentially sucked in a state in which the print heads a to 10e are once brought into close contact with the print heads 2a to 2e, so that the print head cleaning time can be reduced.

Fourth Embodiment FIG. 29 is a perspective view of a cam mechanism according to a fourth embodiment, and FIG. 30 is a cam diagram showing the operation of the cam mechanism shown in FIG. The difference between the fourth embodiment and the third embodiment is that, as shown in FIG. 30, when the rotation angle of the cam shaft 85 is 300 °, the rubber tubes 63 to 67 connected to the caps 10a to 10e. Are made conductive.

For this purpose, as shown in FIG.
01 to 105 each have two concave portions.

Therefore, according to the fourth embodiment, the ink is sucked while the caps 10a to 10e are once brought into close contact with the print heads 2a to 2e. As a result, the ink can be ejected, so that the print head cleaning time can be reduced as compared with the third embodiment.

Fifth Embodiment FIG. 31 is a structural view of a pipe connecting a pump portion and a cap of a cleaning unit according to a fifth embodiment. Fifth
This embodiment is different from the third embodiment in that an ink absorber 201 housed in a sealed container 200 is provided between the cap 2 and the pump 9.

That is, the rubber tube 99 is divided, and the container 200 is placed between the rubber tube 99a and the rubber tube 99b.
And the pump 9 is provided between the rubber tube 99b and the rubber tube 99c. A waste ink absorber 203 for storing waste ink is provided at an end of the rubber tube 99c.

Next, the operation will be described. When the ink tank is replaced or when the ink discharge failure of the print head is recovered, the cap 10 is brought into close contact with the print head 2 by the pump 9 to clean the print head and restore the ink discharge state. When the ink is absorbed, the ink permeates the ink absorber 202 in the cap 10 and then permeates the ink absorber 201 in the container 200. The ink that has passed through the ink absorber 201 is the discharged ink absorber 2
03.

Next, when the pump 9 is operated in a state where the cap 10 and the print head 2 are separated from each other, the atmosphere is taken in through the ink absorber 202 in the cap 10.
At this time, the ink in the ink absorber 202
The ink that has penetrated into the ink absorber 201 inside and has passed through the ink absorber 201 is stored in the waste ink absorber 203.

In the non-printing state, a cap is put on to prevent drying of the ink. However, if the sealed state between the cap 10 and the print head 2 is continued for a long time, first, the ink absorbing member 202 in the cap 10 is removed. Although the ink evaporates, the amount of ink remaining in the ink absorber 201 in the container 200 is larger than the amount of ink remaining in the ink absorber 202, and the ink evaporates from the ink absorber 202 and disappears. Even if it goes wrong, rubber tube 99
a, so that cap 2 is supplied to cap 2.
The inside can be maintained in a high humidity state. Therefore, the fifth
According to the embodiment, even if the sealed state of the cap and the print head in the non-printing state continues for a long time, the inside of the cap can be maintained in a high humidity state, so the non-printing state continues for a long time. Also, clogging due to solidification of the ink in the print head can be prevented.

In the first to fifth embodiments, FIG.
As shown in FIG. 21B, the rubber tube crushed by the lever is returned by its own restoring force.
As shown in FIG. 22, U-shaped leaf springs 50 sandwiching a rubber tube are provided on both sides of the lever, and the rubber tube is crushed by the lever as shown in FIG. The spring 50 is also expanded, and as shown in FIG. 22 (B), when the lever opens the rubber tube, the rubber tube may return with its own restoring force and the restoring force of the leaf spring 50. Good.

In this case, when the rubber tube is left in a state where the rubber tube is crushed for a long time, the ink sandwiched between the rubber tubes becomes viscous and sticks to the rubber tube due to aging, and the elasticity of the rubber tube is increased. Even if it is not possible to return to the original circular open state by only the above, the rubber tube can be reliably shut off and opened by the restoring force of the leaf spring 50.

[0120]

The present invention is configured as described above and has the following effects.

A negative pressure generating section for generating a negative pressure by driving a pump, a first pipe connecting a predetermined cap and a pump among a plurality of caps, and a predetermined pipe having one end divided into a manifold. A second pipe connected to the remaining caps excluding the cap, and the other end connected to the pump, and the other end of the second pipe cut off / conductive to switch the negative pressure supply to the remaining caps. With the provision of the negative pressure supply switching unit, the cap can be used also as a vacuum cap, so that the cleaning mechanism can be simplified.

Similarly, a negative pressure generating unit having a pump connected to the cap by a tube, driving the pump to generate a negative pressure in the cap, and sucking ink from the print head,
By providing a negative pressure supply switching unit that selectively shuts off and conducts the tube to switch the negative pressure supply to the print head, the cap can also be used as a vacuum cap, thus simplifying the cleaning mechanism. Can be

Further, since a negative pressure is generated in all the caps and ink can be simultaneously sucked from a plurality of print heads, it is possible to recover to a state where ink can be ejected in a short time.

Further, by switching between a case where a negative pressure is generated only in a predetermined cap and a case where a negative pressure is generated in all the caps including the predetermined cap,
Negative pressure can be adjusted with a small pump.

Further, a first ink suction means for generating a negative pressure in a predetermined cap to suction ink, and a second ink suction means for generating a negative pressure in all caps including the predetermined cap to suction ink. Means, when the ink tank is replaced, after the ink is sucked by the first ink suction means from the print head in which the ink tank has been replaced,
Since a negative pressure can be generated in a predetermined cap by a negative pressure generating unit that suctions ink from the entire print head by the second ink suction means, the ink can be sucked. Even if the ink is left in the air for a long time and the ink changes with time, it is possible to prevent a discharge failure.

Further, since the second ink suction means sucks ink from all the print heads at the same time and finishes, the degree of change over time when the ink at the nozzle tip of the print head is left in the atmosphere is almost the same. it can.

Further, the cap has a high porosity, a first absorbent having good ink permeability and absorbency, and a low porosity and low ink permeability and absorbability as compared with the first absorbent. By providing the inferior second absorber, when negative pressure is applied to the cap, only the periphery of the rubber tube mounting portion is not easily sucked by ink, and negative pressure is applied to the whole, so that ink is discharged. Failure can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cleaning unit according to the present invention.

FIG. 2 is a perspective view showing a printer mechanism according to the first embodiment.

FIG. 3 is a perspective view showing a configuration of a cleaning unit shown in FIG.

FIG. 4 is a detailed view of a cap.

FIG. 5 is a perspective view of a negative pressure supply switching unit.

FIG. 6 is a cam diagram showing the operation of the cam mechanism.

FIG. 7 is an explanatory diagram (1) of the operation of the cleaning unit.

FIG. 8 is an explanatory diagram (2) of the operation of the cleaning unit.

FIG. 9 is a diagram illustrating the operation of a negative pressure supply switching unit.

FIG. 10 is a drawing of a cyan ink suction state.

FIG. 11 is a drawing showing a magenta ink suction state.

FIG. 12 is a diagram showing a state of suction of yellow ink.

FIG. 13 is a drawing (1) of a black ink suction state.

FIG. 14 is a drawing (2) of a black ink suction state.

FIG. 15 is a diagram illustrating a state of suction of all inks.

FIG. 16 is a control block diagram of the inkjet recording apparatus according to the first embodiment.

FIG. 17 is a flowchart when the ink tank is replaced according to the first embodiment.

FIG. 18 is a control block diagram of an ink jet recording apparatus according to a second embodiment.

FIG. 19 is a flowchart (1) for replacing an ink tank according to the second embodiment.

FIG. 20 is a flowchart (2) for replacing an ink tank according to the second embodiment.

FIG. 21 is a perspective view showing a modified example of the negative pressure supply switching unit.

FIG. 22 is a state diagram of a modification.

FIG. 23 is a perspective view of a cleaning unit according to a third embodiment.

24 is a sectional view taken along the line AA of FIG.

FIG. 25 is an explanatory diagram showing a cutoff state.

FIG. 26 is an explanatory diagram showing a conductive state.

FIG. 27 is a detailed view of a tube.

FIG. 28 is a cam diagram showing the operation of the cam mechanism according to the third embodiment.

FIG. 29 is a perspective view of a cam mechanism according to a fourth embodiment.

30 is a cam diagram showing the operation of the cam mechanism shown in FIG. 29.

FIG. 31 is a configuration diagram of a pipe connecting a pump unit and a cap of a cleaning unit according to a fifth embodiment.

[Explanation of symbols]

 6, 60 Cleaning unit 9 Pump unit 14, 61 Cap moving unit 15, 62 Cam mechanism 12, 101 Negative pressure supply switching unit 16, 102 Drive unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Koyama 4-11-21 Shibaura, Minato-ku, Tokyo F-term in the Oki Data Corporation (reference) 2C056 EA14 EB20 EB38 EB50 EC11 EC22 EC24 EC26 EC41 EC57 FA10 JA05 JA14 JA18 JA25 JC08 JC20

Claims (11)

[Claims] 1. A non-printing apparatus comprising: a plurality of caps each of which covers a plurality of print heads during non-printing; a negative pressure generating unit that generates a negative pressure by driving a pump; A first pipe connecting a predetermined cap and the pump; a second pipe having one end divided into a manifold and connected to the remaining caps excluding the predetermined cap, and the other end connected to the pump; And a negative pressure supply switching unit that switches the negative pressure supply to the remaining caps by blocking and conducting the other end of the second tube. 2. The ink jet recording apparatus according to claim 1, wherein the other end of the second tube is connected to the first tube instead of the pump. 3. An ink jet recording apparatus provided with a plurality of caps which respectively cover a plurality of print heads during non-printing, comprising a pump connected to said cap by a plurality of pipes, and driving said pump into said cap. A negative pressure generating unit that generates a negative pressure and sucks ink from the print head; and a negative pressure supply switching unit that selectively shuts off and conducts the plurality of tubes to switch the negative pressure supply to the print head. An ink jet recording apparatus comprising: 4. The ink jet recording according to claim 1, wherein the tube is an elastic body which is crushed when a force is applied from the outside, and is brought into a cutoff / conductive state by being restored when the force is removed. apparatus. 5. The ink jet recording apparatus according to claim 4, wherein the negative pressure supply switching unit includes a cam mechanism for rotating a lever to crush and shut off the tube. 6. The ink jet recording apparatus according to claim 4, wherein said tube further comprises an auxiliary elastic member for assisting an elastic force other than its own elasticity. 7. The ink jet recording apparatus according to claim 6, wherein the auxiliary elastic member is a U-shaped leaf spring sandwiching a pipe that can be cut off and connected. 8. A first absorber having a high porosity and good ink permeability and absorbency, and a cap having a low porosity and ink permeability and absorbency as compared with the first absorber. 4. The ink jet recording apparatus according to claim 1, further comprising: a second absorbent member having a lower resistance. 9. The ink jet recording apparatus according to claim 1, wherein the cap has a member that penetrates the ink between the cap and the negative pressure generating section. 10. A method for cleaning a print head, in which all print heads are restored to a state in which ink can be ejected after replacing an ink tank, wherein a first ink for suctioning ink by generating a negative pressure in a predetermined cap. A second ink suction means for suctioning ink by generating a negative pressure in all caps including a predetermined cap, wherein the first ink suction means sucks ink from the print head whose ink tank has been replaced; And a second ink sucking means for sucking ink from all the print heads. 11. A printing apparatus, further comprising: a timer which starts when the ink exchange key is pressed and measures an elapsed time until the ink tank is exchanged. After the ink is sucked by the ink suction means, the ink is sucked from all the print heads by the second ink suction means. If the time-out has not been reached, the first ink is transferred from the print head whose ink tank has been replaced. The cleaning method for a print head according to claim 10, wherein the ink is sucked by the suction means.