JP2002248797A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder capable of maintaining high quality recording by preventing mixture of colors due to reverse flowing from a nozzle during recovery operation and suppressing unnecessary discharging of ink in a low cost structure. SOLUTION: This ink jet recorder comprises a cap 52 having a plurality of covering sections for capping one ejection nozzle or integrally plural ejection nozzles of a recording head 3, a tube pump 59 for sucking ink from the ejection nozzles under a condition that the cap 52 is brought into intimate contact with a nozzle face (ejection face) 3a and the right side of the cap 52 is separated from the nozzle face 3a, a coupling section for coupling the covering sections of the cap 52 with the tube pump 59, a cam 65 for allowing the inner sections of the covering sections to communicate with the open air at a desired timing, an air communication arm 74, and a selecting cam 101 for selecting the cam 65 and the air communication arm 74. The cap 52 and the selecting cam 101 are selected to be operated.

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 having head recovery means.

[0002]

2. Description of the Related Art Among recording methods of printers and the like, an ink jet recording method of discharging ink from a discharge port (nozzle) to perform recording on recording paper is a low-noise non-impact recording method and a high-density and high-speed recording operation. Is widely adopted in recent years.

[0003] A general ink jet recording apparatus is provided with means for driving a carrier on which an ink jet head is mounted, conveying means for conveying recording paper, and control means for controlling these.

In addition, in order to generate energy for discharging ink from a nozzle portion of an ink jet head, an ink is applied to the ink using an electromechanical transducer such as a piezo element, or an electromagnetic wave such as a laser is irradiated to generate heat. There is a method in which the liquid is foamed by heat generation or a method in which the liquid is heated and foamed by an electrothermal transducer element having a heat generating resistor.

[0005] Among them, an ink jet recording apparatus of the type in which ink droplets are ejected using thermal energy can perform high-resolution recording because nozzles can be arranged at a high density. In particular, ink jet heads using electrothermal transducer elements as energy generating elements can be easily miniaturized, and by applying IC technology and micromachining technology, which have recently made remarkable progress in technology and improved reliability in the semiconductor manufacturing field. By making full use of its advantages, high-density mounting can be easily achieved and manufacturing costs can be reduced.

In such an ink jet recording apparatus, in order to prevent a printing failure due to nozzle clogging,
Head recovery means is provided. One of the head recovery means is covered with a cap, and by opening a solenoid valve communicating with the cap while sucking ink from a nozzle by a suction pump through the cap, the ink jet head and the ink supply flow path are opened. High-viscosity ink, fine dust and bubbles in the ink are sucked out from the nozzle tip together with the ink.

The other is to wipe off the head surface with a flexible wiper blade to remove fine dust and residual ink adhering to the head surface and keep the head surface in a clean state. The other is to discharge a small amount of ink immediately before the ink jet head performs recording to maintain stable discharge.

In recent years, in a color ink jet recording apparatus, full-color recording has become possible by using multi-color ink and discharging ink from nozzles corresponding to each color.

In such a color ink jet recording apparatus, the distance between the nozzles corresponding to each color is reduced in order to reduce the size of the apparatus, improve the landing accuracy of the ink on the recording paper, or shorten the recording time by shortening the moving distance of the carriage. The nozzles of a plurality of colors are capped as much as possible, the caps of the plurality of colors are capped with the same cap cover, and suction recovery is performed with a single cap having a plurality of cover covers.

In the recovery operation of the ink jet head having the above-described configuration, it is general to perform a suction operation only on the cover portion that covers the nozzles having deteriorated print quality. This is because if all the cover portions in the cap are sucked, the ink is unnecessarily sucked out even from a head maintaining a quality that does not require a recovery operation.

As a mechanism for selecting a cover to perform such a suction operation, a solenoid valve is provided at a portion where each cover and the outside air communicate with each other as described above, and by controlling the solenoid valves, the suction operation is required. By opening only the solenoid valve of the cover portion that is not open and communicating with the atmosphere, ink is not sucked.

In some cases, the air release valve and its selection mechanism may be constituted by an inexpensive mechanical mechanism alone without using an electromagnetic valve for the air communication portion. In this case, a configuration is adopted in which a valve mechanism mainly opened and closed by a cam and an arm driven by the cam is selected, and another arm interferes with the above-mentioned arm at a necessary timing, and only a valve that needs to be opened to the atmosphere is opened. Take a configuration that keeps In addition, in the case of such a configuration, a position detecting mechanism such as a sensor is required for both of the cam constituting the atmospheric valve and the position of the arm to be selected accurately.

[0013]

However, the nozzles of a plurality of colors including the nozzles of low print quality are capped by the same cap cover, and the air release valve of the cover which does not require suction is opened to perform suction. Opening the solenoid valve between the inside of the cap cover and the atmosphere communication part of the outside air while performing the operation to perform the suction recovery operation, and then separating the cap from the print head, the ink mixed in the cap will be mixed with the nozzle surface of the print head. , And flows into the print head from the nozzle due to the minute negative pressure for preventing the ink from dropping, causing color mixing, thereby significantly lowering print quality.

Further, in the case of the ink jet printer as in the above conventional example, a plurality of solenoid valves for communicating with the atmosphere must be provided. Similarly, if the atmosphere communication portion has a mechanical configuration, a plurality of position detection mechanisms such as sensors are required, which increases costs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and prevents color mixing due to backflow from a nozzle during a recovery operation, maintains high-quality recording, and at the same time, requires an inexpensive configuration. It is an object of the present invention to provide an ink jet recording apparatus capable of suppressing the discharge of an ink.

[0016]

The ink jet recording apparatus of the present invention has the following construction.

(1) In an ink jet recording apparatus,
A plurality of ink ejection units for ejecting different types of ink, a plurality of cover units for capping the plurality of ink ejection units, respectively, and the ink in a state where the cover unit is capping the ink ejection unit. Suction means for performing suction from the discharge unit, a plurality of communication means for communicating the inside of the plurality of cover parts with the outside air, and a communication selection means for selectively opening and closing the communication state of the plurality of communication means. And a common drive source for performing selection by the communication selecting means and moving the plurality of cover portions with respect to the plurality of ink ejection portions.

(2) In the ink jet recording apparatus according to the above (1), by switching the drive of the drive source, it is possible to selectively switch the movement of the plurality of cover parts and the selection by the communication selection means.

(3) In the ink jet recording apparatus according to the above (1) or (2), the communication selecting means is provided until the end of one cycle of the plurality of cover parts which perform a cyclic operation in the suction operation by the suction means. The communication state selected by is returned to the initial state.

(4) In the ink jet recording apparatus according to the above (2) or (3), the movement of the plurality of lids and the selection by the communication selecting means are performed by using a planetary gear linked to the driving source. It can be selectively switched according to the driving direction of the source.

(5) In the ink-jet recording apparatus according to any one of the above (2) to (4), the communication means includes a control cam integrally having a plurality of cam plates connected from the driving source, and a control cam driven by the cam plate. And a plurality of air communication arms centered on a shaft having a contact that contacts each other, and one end of the air communication arm forms an on-off valve in the communication means.

(6) In the ink jet recording apparatus according to the above (5), the communication selecting means includes a selection cam integrally provided with the same number of the parallel arms as the air communication arms and having different angles at different angles. The communication arm is engaged with a contact different from the contact with the control cam to forcibly detach the air communication arm from the control cam.

(7) In the ink jet recording apparatus of the above (6), the selection cam is provided with a biasing means for biasing in a direction opposite to a direction driven by the drive source.

(8) In the ink jet recording apparatus according to the above (7), the selection cam, which is engaged with the selection cam contact of the atmosphere communication arm, includes a control cam contact of the atmosphere communication arm and the control cam contact. And that the engagement with the atmosphere communication arm is released when the engagement is performed again.

(9) The ink jet recording apparatus according to any one of the above (1) to (8), further comprising an electrothermal converter for generating thermal energy used for discharging ink. The ink is ejected from the ink ejection section by utilizing the film boiling generated in the ink by the heat energy generated.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same or corresponding parts.

FIG. 1 is a perspective view showing the overall schematic structure of an ink jet apparatus according to one embodiment.

In FIG. 1, reference numeral 1 denotes a main body of an ink jet recording apparatus.
A plurality of nozzle rows are provided on the surface facing 1 in a direction substantially orthogonal to the main scanning, and different inks are ejected for each nozzle row. The recording head 3 is supplied with ink of each color from the ink tank 4 to the nozzle row of each color via each supply tube 5. Note that the recording head 3 includes an electrothermal converter that generates thermal energy used to discharge ink, and the recording head 3 utilizes film boiling generated in the ink by the thermal energy generated by the electrothermal converter. Ink is ejected from the nozzle.

The recording head 3 is mounted on a carrier 2, and the carrier 2 is slidably supported along a guide shaft 7 and a frame 8, both ends of which are fixed to a guide rail 6 and arranged in parallel with each other. Have been. The carrier 2 is reciprocated by a belt driving device (not shown) and a motor.

In the vicinity of the moving range of the carrier 2, a transport roller 9 and a pinch roller (not shown) that comes in contact with the transport roller 9 are provided. At the front of the ink jet recording apparatus main body 1, a cassette 10 which is detachable from a frame is attached. The recording paper 11 is supplied from the cassette 10, reaches a recording position facing the recording head 3, and is moved in the moving direction of the carrier 2 by the rotation of the transport roller 9 and the pinch roller while being sandwiched between the transport roller 9 and the pinch roller. Are conveyed substantially at right angles to each other, and are discharged to the paper discharge stacker 13 after recording is completed.

At a home position provided near one end of the moving range of the carrier 2, a head recovery means 50 is provided at a position which can face the recording head 3. The head recovery unit 50 operates during standby, before or after the recording operation, or between recordings for each line, and performs operations such as capping, suction, and wiping to maintain performance such as preventing clogging of the recording head 3. .

Next, the head recovery means 50 will be described in detail with reference to FIGS.

FIG. 2 is a schematic sectional view showing the structure and operation of the head recovery means 50 and the periphery of the cam of FIG. 1, and shows only those parts necessary for explaining the present invention.

The recording head 3 has a nozzle surface 3a for discharging ink, and is scanned in a direction (main scanning direction) orthogonal to the paper surface together with the movement of the carriage. The head recovery means 50 is provided with a cap 52 at a position facing the nozzle surface 3a of the recording head 3 when the carrier 2 moves to the home position. The configuration of the recording head 3 and the cap 52 will be described with reference to FIG.

FIG. 3 is a sectional view showing the configuration of the recording head 3 and the cap 52 of FIG. 2, and is a sectional view taken along line AA in FIG. The inside of the recording head 3 is divided into black (Bk), cyan (C), magenta (M), and yellow (Y) ink chambers as a typical configuration of a color ink jet recording apparatus.

Each ink chamber is provided with a filter 3b for preventing foreign matter from entering so as not to clog the nozzles. An ink layer and an air layer are formed in the upper and lower spaces of the filter 3b.

The nozzle arrays of cyan (C), magenta (M), and yellow (Y) are used to reduce the size of the apparatus, improve the impact accuracy of ink on recording paper, or shorten the recording distance by shortening the moving distance of the carriage. The distance between the nozzles is reduced as much as possible, and the nozzle row of black (Bk) is slightly apart from other colors.

The cap 52 is formed with a Bk cap (cover lid) 52a and a collar (C, M, Y) cap (cover lid) 52b, and separates nozzle rows having different use frequencies by suction selection described later. By performing suction recovery, the amount of discharged ink can be reduced. Cap 52
Are integrally formed on the upper surface of the cap base 60, and the absorber 14 is provided inside each cap. The cap base 60 is provided with a claw 60 a having a mounting hole. The cap base 60 is swingably mounted by fitting into a boss 61 a provided on the cap holder 61, and is urged upward by the cap spring 15. .

As shown in FIG. 2, each ink chamber of the recording head 3 has an ink supply port 3c, and a supply tube 5 and an ink tank 4 of each color are connected to each color.

The ink tank 4 is constructed and arranged so that the recording head 3 has a predetermined head difference H so that the recording ink does not drop except during printing operation. Then, the ink is automatically supplied from the supply tube 5 by the negative pressure in the recording head 3. A valve 12 is provided in the supply path including the supply tube 5 so that the supply path can be opened and closed.

The recovery base 51 supports and fixes the components of the head recovery means 50 for the recording head 3, the valve 12, and the like, and will be described below.

Each of the Bk cap 52a and the collar (C, M, Y) cap 52b of the cap 52 has an air communication tube 71 to the right of the center in the longitudinal direction of the nozzle row.
Is attached, and one end thereof is connected to each atmosphere communication valve 72. A suction tube 53 into which ink or the like can flow is attached to the left side of the center in the longitudinal direction of the nozzle row, and this tube 53 is passed between a tube frame 54 and a pump frame 55 (FIG. 2). , The configurations around the Bk cap and the collar cap are both shown in the same sectional view.)

A pump roller holder 56 is rotatably supported on the pump frame 55. Two pump rollers 57 projecting outward are provided on the pump roller holder 56 for Bk and for the collar. Similarly, two symmetrical positions are provided at the center. Pump spring 58
Urges the pump roller 57 in the direction of pressing against the tube frame 54 side. The tube 53, the tube frame 54, the pump frame 55, the pump roller holder 56,
A tube pump 59 is constituted by the pump roller 57.

A cam 65 is rotatably supported on one side of the recovery base 51. Cam (control cam) 6
5 includes cam plates 65 necessary for the operation of the head recovery means 50.
a to 65e are integrally formed. The configuration of each recovery unit will be described below.

The shaft 73 fixed to the recovery base 51 has
Two atmosphere communication arms 74 are used for Bk and for the collar, and the cap arm 62 and the one-sided arm 111 are pivotally supported.

Reference numeral 75 denotes an atmosphere communication spring, which is provided two so as to urge the two atmosphere communication arms 74 in the counterclockwise direction, and keeps the Bk and color atmosphere communication valves 72 in a sealed state. When the cam plate 65a rotates, the cam plate 65
The two air communication arms 74 that follow the protrusion 65aa of FIG.
Rotate simultaneously. Then, by the operation of the valve arm 74b formed at the other end of the atmosphere communication arm, the two atmosphere communication valves 72 are simultaneously opened and closed.

The guide portion 61a is engaged with the slide rib 51a of the recovery base 51, and the guide hole 61b is engaged with the slide shaft 51b, and the cap holder 61 is supported so as to be slidable in the vertical direction. The cap arm 62 has a shaft 73
It is rotatably supported above. The cam followers 62a, 62b of the cap arm 62 are connected to the cam plates 65b, 65b.
It swings following the rotation of c. At the other end of the cap arm 62, a cap driving roller portion 62c is formed, which engages with the groove 61c of the cap holder 61, and
2 slides up and down with the swing.

Numeral 81 denotes a wiper blade, which is made of a light-emitting material such as urethane and fixed and supported by a wiper holder 82. The wiper holder 82 is supported at a portion (not shown) with respect to the recovery base 51 so as to be slidable in the left-right direction. The wiper cleaner 83 cleans the wiper blade 81 by coming into contact with the tip portion 81a thereof as the wiper blade 81 moves.

Reference numeral 66 denotes a valve shaft,
The valve 12 is slidably supported in a left-right direction at a portion (not shown), and the valve 12 is opened and closed by a cam plate 65e (not shown).

Reference numeral 101 denotes a selection cam (communication selection means).
Cam portions 101a and 101b are provided. The selection cam 101 is rotated around a shaft 102 and urged by a spring at a portion (not shown) so as to rotate counterclockwise, and the cam portion 101a comes into contact with a stopper 51c provided on the recovery base 51. It has been stopped by. By selectively swinging the two air communication arms 74 by a selection operation described later, the air communication valve 72 for Bk and the color is provided.
Can be selected.

FIG. 4 is a view showing a driving section of the head recovery means 50 of FIG. 1, and is a view seen from the near side with respect to FIG. As shown in FIG. 4, a stepping motor 91 as a driving source is attached to the head recovery means 50, and a pinion gear 91a of the stepping motor 91 is provided.
Is connected to a pendulum gear transmission mechanism 93 via a reduction gear 92. The pendulum gear transmission mechanism 93 is attached to a base gear 93a connected to the reduction gear 92, a pendulum arm 93b swingably attached to the base gear 93a, and attached to the tip of the pendulum arm 93b. Planetary gear 93c.

The planetary gear 93c is engaged with the cam gear 94 when it is located on the right side of the drawing as shown in FIG. The cam gear 94 and the above-described cam 65 rotate integrally. A cam gear flag 95 is provided on the outer periphery of the cam gear 94. The cam gear flag 95 is a light-shielding plate that shields light from the optical sensor 96. The optical sensor can know the phase of the cam gear 94 by detecting whether or not the light is shielded.

When the stepping motor 91 rotates forward (counterclockwise in FIG. 4), the reduction gear 92 and the base gear 93a of the pendulum gear transmission mechanism 93 rotate in conjunction with each other, and the pendulum arm 93b moves as shown in FIG. The planetary gear 93c meshes with the cam gear 94. As a result, the cam gear 94 rotates counterclockwise. At this time, the cam 65
The cam plates 65a to 65e integral with the cam gear 94 also rotate counterclockwise integrally with the cam gear 94.

When the stepping motor 91 reversely rotates (clockwise in the figure), the reduction gear 92 and the base gear 93a rotate in conjunction with each other, the pendulum arm 93b tilts to the left in FIG. The selection cam 101 integrally connected is rotated.

The pendulum transmission mechanism 93 drives the cam gear 94 counterclockwise when the stepping motor 91 is rotating forward, and selects the cam 10 when the stepping motor 91 is rotating backward.
1 is a one-way drive transmission unit that drives the first clockwise.

A stepping motor 97, which is another driving source, is attached to the head recovery means 50, and a pinion gear 97a of the stepping motor 97 is provided.
Is connected to a pump gear 99 via a reduction gear 98. The tube pump 59 described above rotates integrally with the pump gear.

When the stepping motor 97 rotates forward (counterclockwise in the figure), the reduction gear 98 and the pump gear 99 rotate in conjunction with each other. As a result, when the pump frame 55 rotates counterclockwise, the pump roller 57 moves while squeezing the suction tube 53 between the suction tube 53 and the tube frame 54. By this operation, the pressure in the cap 52 becomes lower than the atmospheric pressure, and at the same time, high-viscosity ink, fine dust, and bubbles in the ink liquid are also sucked out. Printing performance can be restored.

FIG. 2 shows the state of the head recovery means 50 during the recording operation. The cap 52 stands by at a position away from the ejection port surface 3a by a predetermined amount, and the recording head 3 can freely move on the cap 52. In order to maintain stable ejection, the recording head 3 applies a small amount of ink immediately before recording. The liquid is discharged into the cap 52. When a predetermined amount of ink accumulates in the cap 52, the pump is operated to discharge the ink in the cap 52 and prevent the ink from overflowing.

When ink is ejected from the nozzles of the recording head 3, the amount of ink in the recording head 3 decreases. The reduced ink is replenished from the ink tank 4 via the supply tube 5 by the negative pressure in the recording head 3, and maintains the required liquid level before printing.

In the head recovery means 50 of the present embodiment having the above-described schematic configuration, the operation of recovering the ink liquid level in the recording head 3 and the color mixing of ink which is the object of the present invention will be described with reference to FIGS. The prevention will be described below.

FIG. 5 is an operation diagram showing a state in which the inside of the recording head 3 of the embodiment is set at a predetermined negative pressure. In order to recover the lowered ink liquid level in the recording head 3, the stepping motor 91 is rotated forward by a predetermined amount, and the cam 65 is rotated. According to the rotation of the cam plates 65b and 65c, the cam follower 62
When a moves from the inclined surface 65ca of the cam plate 65c to the outer peripheral surface 65cb and the cap arm 62 swings, the cap base 61 slides upward.

Then, the cap 52 comes into contact with the head 3, and the nozzle surface 3a of the recording head is sealed. A cam plate 65e (not shown) pushes the valve shaft 66 to the left to close the valve 12. By operating the tube pump 59 in this state, ink is sucked out from the nozzles of the recording head 3, and the air remaining in the recording head 3 is sucked out from the nozzles to make the inside of the recording head 3 a predetermined negative pressure.

FIG. 6 is an operation diagram showing a state where the ink level in the recording head 3 of the embodiment has recovered. In FIG. 5, after a predetermined negative pressure is generated in the recording head 3, when the cam 65 is rotated by a predetermined amount, the valve shaft 66 is pulled back by the cam plate 65e (not shown), the valve 12 is opened, and the negative pressure in the recording head 3 is reduced. The ink is filled from the ink tank 4 through the supply tube 5 and the ink level is restored.

When the valve 12 is opened, the tube pump 5
The suction amount is reduced by lowering the rotation speed of 9 or rotating it intermittently. Accordingly, it is possible to prevent a negative pressure from being generated in the cap 52 and backflow of the ink from the nozzles, and to suppress the amount of discharged ink.

FIG. 7 shows one-sided opening of the cap of one embodiment.
It is an operation | movement figure which shows the state which opened the atmosphere communication valve 72 after that. In FIG. 6, the cap 52 is filled with the sucked ink. In particular, when the atmosphere communication valve 72 is opened in this state, the air flows into the cap 52 through the atmosphere communication tube 71, so that the ink is discharged into the cap 52b. Therefore, the ink flows backward from the nozzles and mixes.

As a countermeasure, one side of the cap 52 is opened. When the cam 65 is rotated by a predetermined amount, the cam plate 65d
, The cam follower portion 1 of the one-sided arm 111
11a is from the inclined surface 65da of the cam plate 65d to the outer peripheral surface 65d.
b, the one-sided opening arm 111 swings around the shaft 73,
Since the push-down portion 111b abuts against the abutting portion 60a of the cap base 60, the cap base 60 rotates the counter-clockwise substantially by bending the cap spring 15.

By this operation, the right side of the cap 52 is separated from the head surface 3a. Since the cap opening mechanism uses a cap angle correction mechanism for bringing the cap 52 into close contact with the discharge port surface 3a, it is not necessary to provide a special mechanism around the cap, and the cost increase can be suppressed.

At approximately the same time as the one-side opening of the cap 52, the suction speed is increased by increasing the rotation speed of the tube pump 59 or the like. The ink filled in the cap 52 is sucked from the right side in the figure together with the ink adhered to the discharge port surface 3a without blowing to the discharge port surface 3a by air flowing in the direction of arrow B.

When the cam 65 is further rotated after the cap is opened, the cam plate 65a is rotated, and follows the slope 65ab of the projection 65aa of the cam plate 65a, and the atmosphere communication arm 74 is moved.
Rotates. When the cam 65 rotates to a phase where the cam follower 74a contacts the outer peripheral surface 65ac of the cam plate, the valve arm 74b formed at the other end of the atmosphere communication arm separates from the atmosphere communication valve 72, and the atmosphere communication valve 72 is opened. (See FIG. 8).

FIG. 8 is an operation diagram showing an idle suction state according to one embodiment. When the cam 65 is rotated by a predetermined amount, the atmosphere communication valve 7 is rotated.
In the open state 2, the one-sided arm 111 rotates clockwise, and the cap 52 comes into close contact with the discharge port surface 3a by the urging force of the cap spring 15. During this time, since the tube pump 59 continues to be driven, the air flows from the atmosphere communication valve 72 through the atmosphere communication tube 71 into the cap 52, so that a small amount of ink flowing into the atmosphere communication tube at the time of suction and the ink in the cap are cleaned. Can be aspirated.

Since the gap between the discharge port surface 3a and the absorber 14 is very small, ink adhering to the discharge port surface 3a that could not be completely suctioned by opening the cap can also be sucked. In addition, the ink suction and air inflow by the above-mentioned one-side opening of the cap and the idle suction form an ink flow in the longitudinal direction of the nozzle row, so that the ink of each color hardly flows to other nozzle rows.

FIG. 9 is an operation diagram showing wiping of the recording head 3 according to one embodiment. As the cam plates 65b and 65c rotate, the cam follower portion 62b moves on the slope 6 of the cam plate 65c.
When the cap arm 62 swings from 5ba to the outer peripheral surface 65bb, the cap base 61 slides downward. Next, in this state, the wiper blade 81 is moved leftward by a driving unit (not shown).

In accordance with this operation, the leading end portion 81a traces the ejection port surface 3a to clean the recording head 3. At this time, since the amount of ink adhering to the ejection port surface 3a due to the opening of the cap shown in FIG. 7 and the empty suction shown in FIG. 8 is small, it is possible to suppress color mixing by wiping.

After the wiping is completed, the cam 65 is rotated,
It returns to the state of FIG. The above is one cycle of the cam 65. After that, the ink mixed in a small amount in the nozzle is preliminarily ejected into the cap 52 to prevent the color mixing. Thus, the ink liquid level recovery operation in the recording head 3 ends.

When the normal suction recovery of the recording head 3 is performed, the cam 65 is rotated to the state shown in FIG. 6 and the tube pump 59 is driven from the state in which the valve 12 is opened, and then the operation shown in FIGS. I do. As a result, color mixing can be prevented even during normal suction recovery.

FIGS. 10 and 11 show the opening selection operation of the atmosphere communication valve 72. FIG. When the head recovery unit 50 is in the recordable state (the state shown in FIG. 2) and the stepping motor 91 is rotated in the reverse direction as described with reference to FIG.
Rotates clockwise.

FIG. 10 shows a color air communication valve 7 according to an embodiment.
FIG. 4 is a diagram illustrating an open-to-atmosphere state of FIG. When the cam portion 101a rotates by a predetermined amount, the air communication arm 74 (for the color) is positioned at the front.
Pushes up the cam follower portion 74c and gets over the claw portion of the 74c. Thereafter, when the stepping motor 91 is rotated forward to perform the ink liquid level recovery operation or the normal recovery operation, the planetary gear 93c rotates clockwise, and the selection gear 103 integrated with the selection cam 101 moves counterclockwise. Rotate in the direction.

When the cam portion 101a engages with the claw portion of the cam follower portion 74c, the selection gear 103 stops rotating, so that the planetary gear 93c is disengaged from the selection gear 103 and engages with the cam gear 95 to perform a recovery operation. At this time, since the valve arm 74b of the front air communication arm 74 (for color) is separated from the front air communication valve 72 (for color) and is in the air communication state, the collar cap 52b is in the idle suction state during the suction operation. , Bk only the cap 52a can be sucked.

FIG. 11 shows an air communication valve 74 for Bk according to one embodiment.
It is a figure which shows the atmosphere open state. Similarly, the selection cam 101
Is rotated further than that in FIG.
1a is separated from the color cam follower 74c, and the color air communication arm 74 is rotated counterclockwise by the air communication spring 75, and the color valve arm 74b closes the color air communication valve 72. When the cam portion 101b further rotates, the cam portion 101b is moved to the cam follower portion 74 of the back atmosphere communication arm 74 (for Bk).
Get over the claw part of c. Thereafter, when the recovery operation is performed similarly, only the color cap 52b can be sucked.

As described above, even if the cam portions 101a and 101b are slightly rotated by the rotation of the selection cam 101 more than the claw engagement portion of the cam follower 74c, the selection gear 103 is urged counterclockwise by the spring. Therefore, when shifting to the recovery operation, the planetary gear 93c is turned on the selection gear 10 until the cam portions 101a and 101b engage with the claws of the cam follower 74c.
3, the opening of the air communication valve can be reliably selected without detecting the position with a sensor or the like.

After the suction operation is completed, as shown in FIGS. 7 and 8, the cam followers 74a are pushed up by the cam followers 74a by the cam plate 65a so that the cam portions 101a, 101a are communicated.
As for b, the engagement with the claw portion of the cam follower 74c is released, and the cam portion 101a abuts against the stopper 51c by the urging force of the spring. That is, even if the opening of the atmosphere communication valve is selected, it can be returned to the initial state every time the recovery operation is completed.

According to this configuration, the cap cover for covering the nozzle row that does not require suction recovery can be selected independently of the cap operation, and can be communicated with the atmosphere so that suction recovery is not performed. The color mixture of the ink in the cap cover due to the suction of the ink in the cover and the inflow of the outside air can be suppressed. At the same time, a mechanism can be provided at low cost without providing a special sensor for detecting the position in the atmosphere communication selecting means.

Although this embodiment has been described as a single recording head having a plurality of ink ejection sections capable of ejecting different types of inks by type, a plurality of recording heads having a plurality of ink ejection sections for each head are described. It can also be implemented.

[0084]

As described above, according to the present invention,
While the selection by the communication selection means and the movement of the plurality of cover parts are performed by a common drive source, the communication state of the plurality of communication means can be selectively opened and closed by the communication selection means. This has the effect of suppressing unnecessary waste ink discharge.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall schematic configuration of an inkjet apparatus according to an embodiment.

FIG. 2 is a schematic sectional view showing a configuration around a head recovery unit and a cam in FIG. 1;

FIG. 3 is a sectional view showing a configuration of a recording head and a cap of FIG. 2;

FIG. 4 is a diagram showing a configuration of a driving unit of a head recovery unit in FIG. 1;

FIG. 5 is an operation diagram showing a state where a predetermined negative pressure is applied to the inside of the recording head according to the embodiment;

FIG. 6 is an operation diagram showing a state in which the ink level in the recording head of the embodiment has recovered.

FIG. 7 is an operation diagram showing a state in which the cap of the embodiment is opened one-sided and then the atmosphere communication valve is opened.

FIG. 8 is an operation diagram showing an idle suction state according to one embodiment;

FIG. 9 is an operation diagram showing wiping of the recording head of one embodiment.

FIG. 10 is a diagram showing an atmosphere open state of a color atmosphere communication valve according to an embodiment;

FIG. 11 is a diagram showing an atmosphere open state of a Bk atmosphere communication valve according to one embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet recording apparatus 2 Carrier 3 Recording head 4 Ink tank 5 Supply tube 6 Guide rail 7 Guide shaft 8 Frame 9 Conveyance roller 10 Cassette 11 Recording paper 12 Valve 13 Discharge stacker 14 Absorber 15 Cap spring 50 Head recovery means 51 Recovery base 52 Cap 53 Tube 54 Tube frame 55 Pump frame 56 Pump roller holder 57 Pump roller 58 Pump spring 59 Tube pump 60 Cap base 61 Cap holder 62 Cap arm 65 Cam 66 Valve shaft 71 Atmospheric communication tube 72 Atmospheric communication valve 73 Shaft 74 Atmospheric communication arm 81 Wiper blade 82 Blade holder 83 Wiper cleaner 91 Stepping motor 92 Reduction gear 93 Pendulum gear transmission mechanism 94 Arm open arm gear 95 cam gear flag 96 optical sensor 97 the stepper motor 98 reduction gear 99 the pump gear 101 selection cam 102 Axis 103 selected gear 111 pieces

Claims (9)

[Claims] A plurality of ink ejecting units for ejecting different types of ink, a plurality of cover units respectively capping the plurality of ink ejecting units, and the cover unit capping the ink ejecting units. Suction means for performing suction from the ink ejection unit in a state where the plurality of lids are in communication with each other, a plurality of communication means for communicating the inside of the plurality of cover parts with the outside air, and a communication state of the plurality of communication means can be selectively opened and closed. An ink jet recording apparatus comprising: a communication selection unit that performs the selection by the communication selection unit; and a common drive source that performs the selection by the communication selection unit and the movement of the plurality of cover units with respect to the plurality of ink ejection units. 2. The ink-jet recording apparatus according to claim 1, wherein the switching of the driving of the driving source can selectively switch between the movement of the plurality of cover parts and the selection by the communication selecting means. . 3. The communication state selected by the communication selection means returns to an initial state before the end of one cycle of the plurality of cover parts that perform a cyclic operation in the suction operation by the suction means. 3. The ink jet recording apparatus according to claim 1, wherein 4. The method according to claim 1, wherein the movement of the plurality of cover portions and the selection by the communication selection means can be selectively switched by a driving direction of the driving source using a planetary gear interlocked with the driving source. The ink jet recording apparatus according to claim 2 or 3, wherein 5. The communication means includes: a control cam integrally having a plurality of cam plates connected from the drive source; and a plurality of atmosphere communication arms around a shaft having a contact that is driven by the cam plate. 5. An ink jet recording apparatus according to claim 2, wherein one end of said air communication arm constitutes an on-off valve in said communication means. 6. The communication selecting means may include a selection cam integrally having the same number of parallel selection cam plates as the air communication arm and having different angles, and a contact member of the air communication arm with the control cam. 6. The ink-jet recording apparatus according to claim 5, wherein said second arm engages with another contact to forcibly release said air communication arm from said control cam. 7. The ink jet recording apparatus according to claim 6, wherein said selection cam includes an urging means for urging in a direction opposite to a direction driven by said driving source. 8. The air communication arm when the selection cam is engaged with the selection cam contact of the air communication arm again by the control cam contact of the air communication arm with the control cam contact. 8. The ink jet recording apparatus according to claim 6, wherein the engagement with the arm is released. 9. An ink discharge unit, comprising: an electrothermal converter that generates thermal energy used for discharging ink, and utilizing film boiling generated in the ink by the thermal energy generated by the electrothermal converter. 9. The ink jet recording apparatus according to claim 1, wherein the ink is ejected more.