JPH0361593B2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to ink suction performed by bringing a cap into close contact with the recording head of an inkjet recording device.
In particular, it relates to a method for removing the ink suction cap from the recording head.

<Prior Art> The present inventors have already made proposals for solving various problems caused by clogging of conventional inkjet recording devices in Japanese Patent Application No. 57-141297 and Japanese Patent Application No. 58-2422, etc. came.

However, in pursuing this problem further, it was found that it would be better to further improve the above proposal.

First, the inkjet recording device of Japanese Patent Application No. 57-141297 has a permanent magnet 33 and a magnetic detector 371 installed on a detection plate 30 attached to a shaft 27 for driving a pump 21, as shown in FIG. By stopping the motor 20 during the piston machining process and releasing the suction cap 10 after a few seconds, ink scattering to the outside is prevented. and,
This uses a pump having a structure in which one-way valves 34 and 35 are provided below a pressure chamber 32 as shown in FIG. However, in this case, if the suction cap 10 is pulled away immediately after suction, atmospheric pressure is instantaneously applied within the suction cap where negative pressure remains. The meniscus inside the nozzle is destroyed by the sudden pressure fluctuation at this time and the mechanical shock when the nozzle is pulled apart, causing air to enter deep inside the nozzle and making it impossible to eject ink.

Further, in the inkjet recording device of Japanese Patent Application No. 58-2422, as shown in FIG.
This is to discharge ink and cleaning fluid. The flow of ink flowing from the ink tank 6 to the head 1 through the piping 5 is switched by the switching valve 4, so that the cleaning liquid in the cleaning liquid tank 2 flows to the head 1 through the piping 3, and the waste liquid passes through the suction pump 13. The water is discharged into the tank 15. In such an inkjet recording apparatus, a similar problem occurs when the suction cap 11 is pulled apart.

On the other hand, Japanese Patent Laid-Open No. 119238/1983 discloses a clogging prevention device for an inkjet printing device,
It is described that when the lip packing that is in close contact with the nozzle is separated, the inside of this clogging prevention device is communicated with the atmosphere to prevent sudden negative pressure from being generated and to prevent ink from dripping from the nozzle.

However, since this anti-clogging device is not connected to a suction device, it merely prevents ink from dripping from the nozzle due to negative pressure when the lip packing is pulled away from the nozzle.

The above-mentioned patent application No. 141297/1982 and patent application No. 2422/1983
In this method, a suction cap connected to a suction pump is placed in close contact with the nozzle part to perform suction, so the suction cap is filled with ink vapor. Therefore, when the suction cap is separated from the recording head, dripping and scattering of ink from the suction cap also becomes a problem.

<Purpose> The purpose of the present invention is to solve these problems and prevent air from entering the nozzle or leaking from the suction cap when the suction cap is brought into close contact with the recording head and the suction cap is pulled away after sucking ink from the nozzle. To provide a method for removing an ink suction cap of an inkjet recording device without causing ink to scatter.

The ink suction cap detachment method of the inkjet recording apparatus of the present invention involves bringing the cap into close contact with the ink ejection nozzle portion of the inkjet recording head, creating a negative pressure inside the cap, and sucking ink inside the recording head through the nozzle. The method is characterized by comprising the steps of: a step of communicating the inside of the cap with the atmosphere to suck out ink remaining in the cap; and a step of separating the cap from the recording head.

<Structure> The method for removing the ink suction cap of the inkjet recording apparatus of the present invention will be described in detail below, including its peripheral parts.

4 to 6 show an embodiment of an inkjet recording device according to the present invention, in which a recording head 141
The suction cap 102 has a flexible outer edge 101 that easily comes into close contact with the periphery of the nozzle 142 of the head in a standby position (described later).
Further, the cap support 104 is held between a shaft 105 crimped to a frame 106 and a frame 107. Further, from the motor 108 to a gear train, a belt drive wheel 109 and a belt 11
A housing 113 having a nozzle cleaner 111 and an adjacent space 112, which is rotated by a rotor, is aligned with the cap support 104 and held on the shaft 105.
The cap support 104 and the housing 113 are selectively attached to the recording head 141 by the plunger 114.
come into contact with. The suction cap 102 has an opening 11
5, 116 are provided, and the opening 115 is connected by a tube to the inlet portion 120-1 of a suction pump 119 driven by a motor 108, a gear train, a pin 117, and a pin follower 118. The opening 116 is also connected by a tube to an air intake valve 122 that is selectively opened and closed by a solenoid 121. Reference numeral 123 designates a switching valve that selectively switches between an ink tank and a cleaning liquid tank, which will be described in detail later.The switch valve 123 is configured to switch via a switching lever 126 depending on the direction of rotation of the cam 125 of the gear 124 caused by the forward and reverse rotation of the motor 108. There is. Note that 127 is a filter provided between the ink tank 149 and the recording head 141. FIG. 5 is a perspective view of the ink cartridge periphery connected to the configuration shown in FIG.
The ink cartridge 128 in which the ink waste liquid absorbing member 148 is housed is the cartridge holder 1.
It is held at 29. Ink is ink tank 149
The needle 130 inserted into the tube enters the switching valve 123 via the tube connector 133, is supplied to the recording head 141 through the filter 127, and is supplied from the recording head nozzle section to the inlet section 120- of the suction pump 119 by the suction cap 102.
1, and is fed into the waste liquid absorbing member 148 inside the cartridge 128 through the needle 132 via the tube connector 134 from the outlet portion 120-2. On the other hand, the cleaning liquid tank 145 in the cartridge 128 passes through the needle 131 to the filter 135 and one of the T-shaped tube connectors.
The cleaning liquid is led to the switching valve 123 via the switching valve 36-1, passes through the recording head along the same path as the ink, and is sent from the needle 132 to the waste liquid absorbing member 148. An air intake valve 137 is selectively opened by a plunger 138, and is connected to one side of the T-shaped connector 136-2. Nao 139
140 is a spring contact for detecting the remaining amount of ink in the ink tank, and 140 is a micro switch that determines whether the ink cartridge 128 is set in the cartridge holder 129. The operation of the above configuration will be explained with reference to the structural diagram shown in FIG. 6 and the operation sequence shown in FIG. 7 and subsequent figures. Figures 6 and 7
In the figure, when the recording device is switched off, the suction cap 1 is energized by energizing the solenoid 114.
02 is pulled, and the recording head 141 is moved in front of the cap 102 by a carriage device (not shown). Here, by turning off the power to the solenoid 114, the flexible outer edge 101 comes into close contact with the periphery of the nozzle 142, completing the capping operation and cutting off all power to the recording apparatus. Incidentally, even after the power is turned on, dust adhesion to the nozzle 142 can be prevented by performing a similar capping operation while there is no recording command. Now, when the recording apparatus is stopped for a short period of time (when it is used every day), this cap 102 alone can prevent the nozzle from drying and there will be no problem in the next recording. However, when the nozzle is stopped for a long time, during transportation, when stored at high temperatures, etc., the ink inside the nozzle dries, resulting in a so-called clogged state.
Therefore, if such a situation is expected, the following operation is performed when the power of the recording apparatus is turned off.
6 and 8, when the motor 108 is reversed after performing the cap operation, the cam 125 formed integrally with the gear 124 rotates counterclockwise, actuating the switching lever 126, and causing the switching piston 143 of the switching valve 123 to rotate. A recess 144 is provided to communicate the head 141 with a cleaning liquid tank 145 inside the ink cartridge 128. At the same time pump 11
9 is driven, but the pump structure is a bellows elastic body 14
6 is a combination of a pressure chamber and two one-way valves 147, and the internal volume of the bellows elastic body 146 is changed by the rotation of the pin 117 by the rotation of the motor 108 and the pin follower 118.
One-way valve 147 is installed above the pressure chamber.
This pump 119 can always suck liquid from the pump inlet part 120-1 and discharge it from the outlet part 120-2 regardless of whether the motor 108 rotates forward or backward. Now, when this pump is driven, head 1
The ink in the ink cartridge 128 is extracted from the nozzle 142 and transferred to the waste liquid absorbing member 14 inside the ink cartridge 128.
Sent to 8. At this time, the valve 122 connected to the cap 102 is closed, and if the valve 137 branched from the cleaning liquid tank 145 to the switching valve 123 is closed, the head 141
After the ink inside is removed, the cleaning liquid is poured into the head 14.
Get inside 1. Solenoid 1 after an appropriate period of time
When the valve 137 is energized and the valve 137 is opened, air is taken in, and all of the cleaning liquid that has cleaned the inside of the head is also sent to the waste liquid absorbing member 148, making it possible to completely remove ink from the inside of the head, especially from the fine nozzles 142. In this state, the nozzle 142 cannot become clogged no matter what conditions it is stored under. Next, regarding the operation when the recording device is turned on, in FIGS. 6 and 9, if it is left for a short period of time, that is, if the ink in the head is not drained, the pump 108 rotates in the normal direction (in this case, the switching piston 143 The ink in the head (which remains moved downward from the beginning and the recess 144 communicates the ink tank 149 in the ink cartridge 128 with the head 141) is refreshed. This is to solve the slight increase in viscosity at the tip of the nozzle 142, and the pump operation only takes a short time. Thereafter, the solenoid 121 is energized and the valve 122 is opened to draw air into the cap. As a result, the negative pressure inside the cap is eliminated, and at the same time, the small amount of ink remaining inside the cap and the ink on the front side of the nozzle 142 are removed by the absorbing material 15.
5 to the waste liquid absorbing member 148. After this operation is completed, the solenoid 114 is energized to move the cap 102 back from the head 141, and the head 141 moves to a position facing the recording paper. As described above, according to this embodiment, the cap 102 is brought into close contact with the nozzle portion of the recording head 141, and the inside of the cap is made to have a negative pressure, and the recording head 102 is injected through the nozzle 142.
The ink in the nozzle 41 is sucked out, and then, while this suction action continues, the valve 122 is opened to communicate the inside of the cap with the atmosphere, and the ink remaining in the cap and the ink attached to the nozzle surface is sucked out. 102 from the recording head 141. Therefore, when the cap 102 is separated, it is possible to prevent the problem that the ink meniscus in the nozzle 142 is destroyed due to sudden pressure fluctuations and mechanical shocks, causing air to enter deep into the nozzle and causing ink to be unable to be ejected. At the same time, the ink remaining in the cap 102 and the ink adhering to the nozzle surface can be sucked out and discharged, eliminating problems such as ink dripping or scattering from the cap when the cap is pulled apart, and problems such as ink dripping from the nozzle surface. can.

Next, if the ink in the head has been removed by the above operation, the following operation is performed when the power is turned on. (For example, the switching piston 143
This can be easily determined by detecting the position. ) First, the motor 108 is rotated forward for a short time (the switching piston 143 is switched to communicate with the ink tank 149 side), and the switching valve 123 is moved from the ink tank 149 to the switching valve 123.
Refresh the ink. In the above-mentioned ink extraction operation, the ink is drawn from the switching valve 123 to the head 14.
1 has been completely drained, but ink remains between the ink tank 149 and the switching valve 123, so it is preferable to refresh the ink in this area. Next, the motor 108 is reversed to open the valve 137, and after the ink pushed forward of the switching valve 123 is discharged through the head 141, the valve 137 is closed and the pump 119 is further operated. This allows the cleaning liquid to be transferred from the cleaning liquid tank 145 to the switching valve 123, filter 127, and head 14.
1 (nozzle 142). Since it is preferable to use a liquid with a high cleaning effect (low surface tension) as the cleaning liquid, it is preferable to use a liquid that has a high cleaning effect (low surface tension). This is convenient for filling the container without bubbles, and in the present invention, a mixed liquid mainly containing ethyl alcohol is used. After all the channels are filled with the cleaning liquid, when the motor 108 is rotated forward after a stabilization time, the switching piston 143 is switched to the ink tank 149 side, and the ink is replaced with the cleaning liquid, filling the inside of the head 141. After this, the valve 122 is opened and the cap 10 is opened while the suction action continues.
The inside of the cap 102 is communicated with the atmosphere to suck out the ink remaining in the cap and the ink attached to the nozzle surface, and then a series of cap detachment operations are performed to separate the cap 102 from the recording head 141, and the head moves to the recording paper position. do. The cleaner 111 provided in the housing 113 is driven by the rotation of the motor 108 and cleans the nozzle 142 surface of the head 141. When necessary, the recording head 141 can be moved to the position indicated by the dashed-dotted line in FIG. 6 to perform the recording as appropriate. In addition, a space 112 provided next to the cleaner 111 in the housing 113 is used to keep all nozzles in a constant state by moving the head to this position at regular intervals during recording and ejecting several drops from all nozzles. The ejected ink is guided to an absorbing member (not shown) through the opening 150.

<Effects> As described above, the method for removing an ink suction cap of an inkjet recording apparatus according to the present invention includes the steps of bringing the cap into close contact with the nozzle portion of the recording head, creating a negative pressure inside the cap, and sucking ink inside the recording head through the nozzles. There are two steps: a step of communicating the inside of the cap with the atmosphere to suck out any ink remaining inside the cap, and a step of separating the cap from the recording head. This can prevent the problem of the ink meniscus inside the nozzle being destroyed and air entering deep inside the nozzle, causing ink to be unable to be ejected. At the same time, since the ink remaining in the cap and the ink attached to the nozzle surface can be blown out, problems such as ink dripping or scattering from the cap and ink dripping from the nozzle surface are avoided when the cap is separated from the recording head. It can be resolved.

[Brief explanation of drawings]

FIG. 1 is a perspective exploded view of a conventional recording device, FIG. 2 is a sectional view of the pump device shown in FIG. 1, FIG. 3 is a schematic configuration diagram of the conventional device, and FIGS. 4 and 5 are according to the present invention. FIG. 6 is an exploded perspective view of the recording apparatus, FIG. 6 is a schematic configuration diagram of the apparatus according to the present invention, and FIGS. 7 to 9 are operation sequence diagrams of the embodiment of the present invention. 101... Flexible outer edge, 102... Suction cap, 108... Motor, 111... Nozzle cleaner, 112... Opening, 113... Housing, 1
14... Solenoid, 119... Suction pump, 1
21,138...Solenoid, 122,137...
...Air intake valve, 123...Switching valve, 127,
135... Filter, 128... Ink cartridge, 141... Recording head, 142... Nozzle, 143... Switching piston, 145... Cleaning liquid tank, 146... Bellows-shaped elastic body, 147... One-way valve, 148... Waste liquid absorbing member, 149... Ink tank.

Claims (1)

[Scope of Claims] 1. A step of bringing a cap into close contact with an ink discharge nozzle portion of an inkjet recording head, applying negative pressure in the cap to sucking ink in the recording head through the nozzle, and sucking ink in the recording head through the nozzle. 1. A method for removing an ink suction cap of an inkjet recording apparatus, comprising the steps of: sucking out ink remaining in the cap by communicating with the atmosphere; and separating the cap from the recording head.