JP3671997B2 - Cleaning method for ink jet recording apparatus - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to a method for cleaning an ink jet recording apparatus .
[0002]
[Prior art]
An ink jet recording apparatus that records printing data by ejecting ink pressurized in a pressure chamber as ink droplets from a nozzle onto a recording paper is used to increase the ink viscosity due to evaporation of the ink solvent from the nozzle opening, There is a problem that defective printing occurs due to solidification of the ink, adhesion of dust to the nozzle opening, and mixing of bubbles into the pressure generating chamber. For this reason, the ink jet recording apparatus is a capping device that seals the nozzle openings during non-printing to prevent ink evaporation and forcibly discharges ink from the nozzle openings by applying a negative pressure to the nozzle openings. And a pump unit for supplying negative pressure thereto.
[0003]
On the other hand, in order to improve the printing quality during color printing, an ink jet recording apparatus using at least six inks of dark magenta, light magenta, dark cyan, light cyan, yellow, and black has been proposed.
[0004]
Such multi-color inks require at least six nozzle openings, so that two recordings are usually used in order to simplify the production process yield and sealing with a capping device. The head is mounted on one carriage, and the capping device is provided with a cap member for individually sealing each recording head, and further provided with two pumps for supplying negative pressure to each cap member.
[0005]
These two pumps are connected to a paper feed motor via a coupling mechanism that contacts and separates from the paper feed mechanism depending on the position of the carriage, and can be driven individually depending on the rotation direction of the motor.
[0006]
[Problems to be solved by the invention]
According to such a configuration, it is possible to reduce the load on the motor when the pump is driven, but it takes a long time to maintain the recording head, and a mechanism for switching between two pumps depending on the rotation direction is used as a pump. In addition, there is a problem that the structure of the pump is complicated and the size thereof is increased.
The present invention has been made in view of such problems, and an object of the present invention is to propose a cleaning method suitable for an ink jet recording apparatus having two recording heads.
[0008]
[Means for Solving the Problems]
In order to solve such a problem, in the present invention, in the cleaning method of an ink jet recording apparatus provided with a cleaning mechanism in which a plurality of recording heads are mounted on a carriage and the ink on the nozzle surface is wiped off by a wiping blade, When the blade is positioned between the plurality of recording heads, the carriage is stopped for the time required for the wiping blade to return to its original state due to elasticity, and then the next recording head is moved to the area of the wiping blade. Let
[0009]
[Action]
Since the second recording head is wiped after the wiping blade which has been elastically deformed after the cleaning of the first recording head is restored to the original state, the ink of the first recording head is transferred to the first recording head. The ink of the second recording head can be reliably scraped off without adhering to the ink.
[0010]
【Example】
Therefore, details of the present invention will be described below based on the illustrated embodiment.
FIG. 1 shows an embodiment of the present invention. A carriage 1 is connected to a motor 3 by a timing belt 2 and is guided by a guide member 4 so as to move in parallel with a platen 5. Yes. A first recording head 7 and a second recording head 8 are mounted side by side in the movement direction of the carriage 1 on the surface of the carriage 1 facing the recording sheet.
[0011]
Further, a damper function for supplying ink to the first and second recording heads 7 and 8 is provided on the upper surface of the carriage 1 by connecting ink cartridges (not shown) through ink supply tubes 9, 9, 9,. Sub tank units 10 and 11 are mounted.
[0012]
A capping device 12 that seals the nozzle plates of the recording heads 7 and 8 is provided in a non-printing area of the movement path of the recording heads 7 and 8.
[0013]
As shown in FIG. 2, when the carriage 1 moves to the non-printing area, the capping device 12 follows the movement of the carriage 1 and moves the guide surface 14 of the base 13 while moving the slider 15 that moves up and down. The cap members 16 and 17 for sealing the recording heads 7 and 8 are provided.
[0014]
The cap members 16 and 17 are communicated with ink suction ports 18 and 19 connected to ends 32a and 33a of tubes 32 and 33 of the pump unit 30, which will be described later, and air communication ports 21 and 22 of the valve seat member 20, respectively. . In a region where the valve seat member 20 is located when the cap members 16 and 17 are moved to a position where the recording heads 7 and 8 can be sealed, the spring member 23 is constantly urged toward the valve seat member side to elastically move the valve seat member 22. A valve member 24 in contact therewith is disposed.
[0015]
The discharge port sides of the tubes 32 and 33 constituting the pump unit 30 are communicated with waste ink tanks 61 and 63 containing ink absorbing materials 60 and 62, respectively.
[0016]
Further, a cleaning unit 65 including a wiping blade 66 that elastically contacts the nozzle surface and eliminates clogging of the nozzle opening is disposed on the printing area side of the capping device 12.
[0017]
FIG. 3 shows an embodiment of the pump unit. In this embodiment, the pump frame 31 which also serves as a base body has two tube pumps in view of supplying negative pressure to the two cap members 16 and 17 simultaneously. The tube support surfaces 34 and 35 which support so that the center part of the tubes 32 and 33 may be formed in a substantially semicircle shape so that it may comprise are comprised back to back.
[0018]
Pulleys 36, 37, 38, 39 constituting the handling pump integrated with the tubes 32, 33 are rotated at both ends by pump wheels 40, 41 configured as cylindrical external gears meshing with a train wheel connected to the paper feed motor. It is supported movably.
[0019]
Engaging portions 46 and 47 to be joined in the pump frame are formed on opposite sides of the pump wheels 40 and 41 as shown in FIG. 4, and each pump wheel is shown in FIGS. The pulleys 36, 37 and 38, 39 of 40, 41 are coupled so as to have a predetermined phase difference, in this embodiment, a phase difference of approximately 90 degrees, and are rotatably supported by the end plates 48, 49 on both sides. Yes. The frame 31 and the end plates 48 and 49 are integrally fixed by screws (not shown) to constitute a pump unit.
[0020]
In this embodiment, when the power supply to the recording apparatus is turned on, or when an ink cartridge (not shown) is replaced, it is necessary to forcibly discharge ink from the recording heads 7 and 8 or to fill the ink. A control device (not shown) moves the carriage 1 to a position where the recording heads 7 and 8 can be sealed by the capping device 12. As a result, the cap members 16 and 17 move up the base 13 while being accompanied by the recording heads 10 and 11, and seal the recording heads 10 and 11. Further, the air communication ports 21 and 22 of the cap members 16 and 17 move together with the valve seat member 20 and are elastically contacted with the valve member 24 to be sealed.
[0021]
When the paper feed motor is driven in reverse in this state, at least one of the pump wheels 40 and 41 of the pump unit 30 is rotated by receiving a driving force from the paper feed motor. As a result, the pulleys 36, 37, and 38, 39 engaged with the pump wheels 40, 41 handle the tubes 32, 33 while maintaining the phase difference of 90 degrees, and the two cap members 16, 17 are simultaneously negatively charged. Supply pressure.
[0022]
Each of the recording heads 7 and 8 discharges ink from the nozzle openings to the cap members 16 and 17 under the action of negative pressure. At the stage where a predetermined amount of suction is completed, the carriage 1 is moved slightly toward the recording area, and the air communication holes 21 and 22 are formed while maintaining the state where the recording heads 7 and 8 are sealed with the cap members 16 and 17. The cap members 16 and 17 are opened to the atmosphere by moving away from the valve member 24. When the pump unit 30 is operated again in this state, only the ink discharged to the cap members 16 and 17 is sucked into the tubes 32 and 33 without causing the ink to flow out from the recording heads 7 and 8, respectively. The waste ink tanks 61 and 63 are discharged.
[0023]
In this way, the ink from the pump tubes 32 and 33 is discharged to the independent waste ink tanks 61 and 63, so that the ink absorption capability of the ink absorbing materials 60 and 62 of the waste ink tanks 61 and 63 is maximized. Not only can the storage capacity be improved, but also the water head can be kept small even when the box is tilted to prevent ink leakage.
[0024]
Thus, since the rollers 36, 37, and 38, 39 that handle the two tubes 32, 33 have a phase difference of 90 degrees, the load is averaged and a drive source with a high output rating is required. In addition, the suction time can be shortened by simultaneously performing suction.
[0025]
By the way, when the recording heads 7 and 8 are clogged, the paper feed motor is reversed to move the wiping blade 66 into the traveling area of the recording heads 7 and 8 so that the recording heads 7 and 8 are moved in one direction. When moved (FIG. 6 (I)), the wiping blade 66 is elastically contacted with the first recording head 7 to scrape ink residue and paper dust on the nozzle surface together with the ink K (FIG. 6 (II)).
[0026]
When the cleaning of the first recording head 7 is completed and the wiping blade 66 is positioned between the first and second recording heads 7 and 8, the motor 3 is stopped (FIG. 6 (III)). Thereby, the elastically deformed wiping blade 66 returns to the original state (FIG. 6 (IV)). When the carriage 1 is moved again after a time required for returning due to its own elasticity, for example, about 0.5 seconds has passed, the ink K in the tip region of the wiping blade 66 is transferred to the second recording head 8. The second recording head 8 is wiped after coming into contact with the side surface and scraping the ink here (FIG. 6 (V)). Thus, the ink K ′ of the second recording head 8 can be surely scraped without causing the ink of the first recording head 7 to adhere to the second recording head 8 (FIG. 6 (VI)).
[0027]
On the other hand, when the second recording heads 7 and 8 are continuously cleaned without stopping the carriage 1 halfway, the ink K of the wiping blade 66 that has been elastically deformed by the first recording head 7 and the second recording head 7. The contact area with the side surface of the recording head 8 is small, and a large amount of ink remains on the wiping blade 66, not only the cleaning effect on the second recording head 8 is reduced, but also the repulsive force of the wiping blade 66 causes the recording head 8 to It will give a big shock.
[Brief description of the drawings]
FIG. 1 is a top view showing an embodiment of an ink jet recording apparatus of the present invention.
FIG. 2 is a perspective view showing an embodiment of the capping device of the present invention.
FIG. 3 is an assembled perspective view showing an embodiment of the pump unit of the present invention.
FIG. 4 is a view showing a cross-sectional structure of the same pump unit with the end plate and the tube removed.
FIGS. 5 (a) and 5 (b) are cross-sectional views showing an engaged state between a tube and a pulley of two pumps, respectively.
6 (I) to (VI) are diagrams showing the cleaning method of the present invention. FIG.
[Explanation of symbols]
1 Carriage 7, 8 Recording head 10, 11 Buffer tank unit 12 Capping device 16, 17 Cap member 30 Pump unit 31 Pump frame 32, 33 Tubes 36 to 39 Pulley 40, 41 Pump wheel 61, 63 Waste ink tank 66 Wiping blade

Claims (1)

In a cleaning method for an ink jet recording apparatus having a plurality of recording heads mounted on a carriage and having a cleaning mechanism for wiping off ink on a nozzle surface with a wiping blade,
When the wiping blade is positioned between the plurality of recording heads, the carriage is stopped for a time required for the wiping blade to return to its original state due to elasticity, and then the next recording head is moved to the area of the wiping blade. Cleaning method to move to.

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