JPH1178041A - Ink jet recorder and cleaning method suitable therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge ink forcibly from two recording heads in a short time while reducing the size and simplifying the structure of a pump unit. SOLUTION: The ink jet recorder comprises two recording heads 7, 8 carried on a carriage 1 and reciprocated in the breadthwise direction of a recording sheet, a capping unit 12 disposed in the nonprinting region of the recording heads 7, 8 and having two cap members 16, 17 for sealing two recording heads 7, 8 individually in response to movement of the carriage 1, and a pump unit 30 coupled with the cap members 16, 17 and driven simultaneously by receiving power supply from the same drive source.

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 a recording head which moves in the width direction of a recording sheet, and ejecting ink droplets onto the recording sheet in accordance with print data to form an image. Related to the device.

[0002]

2. Description of the Related Art An ink jet recording apparatus for recording print data by discharging ink pressurized in a pressure chamber from a nozzle as ink droplets onto a recording sheet is known as an ink viscosity caused by evaporation of an ink solvent from a nozzle opening. This causes a problem that printing failure occurs due to rise of ink, solidification of ink, adhesion of dust to nozzle openings, and mixing of air bubbles into a pressure generating chamber or the like. For this reason, an ink jet recording apparatus is a capping device for sealing a nozzle opening during non-printing to prevent ink from evaporating, and for applying a negative pressure to the nozzle opening to forcibly discharge ink from the nozzle opening. And a pump unit for supplying a negative pressure thereto.

On the other hand, in order to improve the print quality in color printing, at least dark magenta, light magenta, dark cyan,
2. Description of the Related Art An ink jet recording apparatus using six colors of light cyan, yellow, and black inks has been proposed.

[0004] As described above, in the case of using multi-color inks, at least six rows of nozzle openings are required, so that the production process yield and the simplification of sealing by a capping device are usually required. The two recording heads are mounted on one carriage, the capping device is provided with cap members for individually sealing the recording heads, and two pumps for supplying a negative pressure to each cap member are provided. ing.

[0005] These two pumps are connected to a paper feed motor via a coupling mechanism that comes into contact with and separates from the paper feed mechanism depending on the position of the carriage, and are configured to be individually driven in the rotation direction of the motor.

[0006]

According to such a structure, the load on the motor at the time of driving the pump can be reduced, but on the other hand, a long time is required for maintenance of the recording head, and two pumps are required. Since it is necessary to incorporate a mechanism for switching in accordance with the rotation direction into the pump, there is a problem that the structure of the pump is complicated and large. The present invention has been made in view of such a problem,
An object of the present invention is to provide an ink jet recording apparatus capable of shortening a suction time for maintenance of a recording head and filling of ink, and simplifying and miniaturizing a pump unit.

Another object of the present invention is to propose a cleaning method suitable for an ink jet recording apparatus having two recording heads.

[0008]

According to the present invention, in order to solve such a problem, the present invention is mounted on a carriage,
A first recording head reciprocally driven in the width direction of the recording paper,
A second printhead, a first printhead and a second printhead, which are arranged in a non-printing area of the printhead and are responsive to the movement of the carriage.
Capping means having a first cap member and a second cap member for individually sealing the recording heads, and being connected to the first and second cap members, receiving power from the same drive source. And a first pump and a second pump driven simultaneously.

[0009]

By adjusting the phase difference between the two pumps and averaging the loads, the suction is executed at the same time without requiring a drive source having a large output rating and the suction time is reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows an embodiment of the present invention, in which a carriage 1 is connected to a motor 3 by a timing belt 2, is guided by a guide member 4, and moves parallel to a platen 5. I have. On the surface of the carriage 1 facing the recording paper, a first recording head 7 and a second recording head 8 are mounted side by side in the moving direction of the carriage 1.

On the upper surface of the carriage 1, ink supply tubes 9, 9, 9,
‥‥, the first and second recording heads 7,
Sub tank units 10 and 11 having a damper function of supplying ink to the ink tank 8 are mounted.

A capping device 12 for sealing the nozzle plates of the recording heads 7 and 8 is provided in a non-printing area on the movement path of the recording heads 7 and 8.

As shown in FIG. 2, when the carriage 1 moves to the non-printing area, the capping device 12 moves up and down while moving on the guide surface 14 of the base 13 following the movement of the carriage 1. The slider 15 is provided with cap members 16 and 17 for sealing the recording heads 7 and 8.

The cap members 16 and 17 are connected to one ends 3 of tubes 32 and 33 of a pump unit 30 described later, respectively.
The ink suction ports 18 and 19 connected to 2a and 33a are connected to the air communication ports 21 and 22 of the valve seat member 20, respectively.
When the cap members 16 and 17 move to the positions where the recording heads 7 and 8 can be sealed, the area where the valve seat member 20 is located is constantly urged toward the valve seat member side by the spring 23 and the valve seat member 22 A contacting valve member 24 is arranged.

Tube 3 constituting pump unit 30
The ejection port sides 2 and 33 are ink absorbing materials 60 and 6 respectively.
2 are communicated with waste ink tanks 61 and 63 containing the ink.

Further, on the printing area side of the capping device 12, a cleaning unit 65 provided with a wiping blade 66 that resiliently contacts the nozzle surface and eliminates clogging of the nozzle opening is disposed.

FIG. 3 shows an embodiment of the pump unit. In this embodiment, a pump frame 31 serving also as a base is provided with two pump members 16 and 17 because two pump members are simultaneously supplied with a negative pressure. Tube supporting surfaces 34 and 35 for supporting the central portions of the tubes 32 and 33 so as to form a substantially semicircular shape so as to constitute a tube pump are formed back to back.

The pulleys 36, 37, 38, and 39, which constitute a pump integrated with the tubes 32, 33, are connected to pump wheels 40, 41 configured as cylindrical external gears that mesh with a train connected to a paper feed motor. Both ends are rotatably supported.

On opposite sides of the pump wheels 40 and 41, engaging portions 46 and 47 are formed to be joined in the pump frame as shown in FIG. 4, and as shown in FIGS. Pulleys 36, 3 of each pump wheel 40, 41
7, 38 and 39 are coupled so as to have a predetermined phase difference, approximately 90 degrees in this embodiment.
It is rotatably supported by 8, 49. The frame 31 and the end plates 48 and 49 are integrally fixed by screws (not shown) to constitute a pump unit.

In this embodiment, when the power supply to the recording apparatus is turned on, or the ink cartridge (not shown) is replaced, the ink must be forcibly discharged from the recording heads 7 and 8, and the ink must be filled. In this case, 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 by moving the base 13 together with the recording heads 10 and 11 and move up.
0 and 11 are sealed. In addition, each cap member 16, 17
The air communication ports 21 and 22 move together with the valve seat member 20 and elastically contact the valve member 24 to be sealed.

When the paper feed motor is driven in reverse rotation in this state, at least one of the pump wheels 40 and 41 of the pump unit 30 rotates by receiving the driving force from the paper feed motor. This allows the pulleys 36, 37, and 38, 39 engaging the respective pump wheels 40, 41 to handle the tubes 32, 33 while maintaining a 90 degree phase difference, and simultaneously apply a negative force to the two cap members 16, 17. Supply pressure.

The recording heads 7 and 8 discharge ink from the nozzle openings to the cap members 16 and 17 under the action of the negative pressure. When a predetermined amount of suction is completed, the carriage 1
Is slightly moved to the recording area side, while maintaining the state where the recording heads 7 and 8 are sealed with the cap members 16 and 17,
The air communication holes 21 and 22 are separated from the valve member 24, and the cap members 16 and 17 are opened to the atmosphere. When the pump unit 30 is operated again in this state, the recording heads 7, 8
Without causing ink to flow out of the cap member 1
Only the ink discharged into tubes 6 and 17 is
2, 33, and the individual waste ink tanks 61, 63
Is discharged.

In order to discharge the ink from the pump tubes 32 and 33 to the independent waste ink tanks 61 and 63 in this manner, the ink absorbing material 6 of the waste ink tanks 61 and 63 is used.
In addition to improving the storage capacity by maximizing the ink absorption capacity of 0, 62, it is possible to prevent the leakage of ink by keeping the head small even when the box is tilted. Can be.

As described above, since the rollers 36 and 37 and the rollers 38 and 39 that handle the two tubes 32 and 33 have a phase difference of 90 degrees, the load is averaged and the driving source has a large output rating. The suction time can be shortened by performing the suction at the same time without requiring anything.

When the recording heads 7 and 8 are clogged, the paper feed motor is rotated in the reverse direction 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 to one side. (Fig. 6
(I)) First, the wiping blade 66 elastically contacts the first recording head 7 to scrape off ink residue and paper dust on the nozzle surface together with the ink K (FIG. 6 (II)).

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) )). As a result, the wiping blade 66 that has been elastically deformed returns to the original state (see FIG. 6 (I
V)). When the carriage 1 is moved again after the time required for the return due to its own elasticity, for example, about 0.5 seconds has elapsed, the ink K in the tip region of the wiping blade 66 is discharged from the second recording head 8. After contacting the side surface and the ink is scraped here (Fig. 6 (V)), the second
Is wiped. Thus, the ink K ′ of the second recording head 8 can be reliably scraped off without causing the ink of the first recording head 7 to adhere to the second recording head 8 (FIG. 6 (VI)).

On the other hand, when the two recording heads 7 and 8 are continuously cleaned without stopping the carriage 1 halfway, the ink K of the wiping blade 66 elastically deformed by the first recording head 7 is removed. The contact area with the side surface of the second recording head 8 is small, a large amount of ink remains on the wiping blade 66, and not only the cleaning effect on the second recording head 8 is reduced, but also the recording is performed by the repulsive force of the wiping blade 66. A large impact is applied to the head 8.

[0028]

As described above, according to the present invention, the first recording head and the second recording head mounted on the carriage and driven back and forth in the width direction of the recording paper, and the non-printing of the recording head. Capping means disposed in a region, the capping means having a first cap member and a second cap member for individually sealing the first and second recording heads in response to the movement of the carriage; The first pump and the second pump are connected to the cap member and driven simultaneously by receiving power supply from the same driving source. Therefore, the phase difference between the two pumps is adjusted to balance the load. Thus, the suction time can be shortened by performing the suction at the same time without requiring a drive source having a large output rating.

[Brief description of the drawings]

FIG. 1 is a top view showing one 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 one embodiment of the pump unit of the present invention.

FIG. 4 is a diagram showing a cross-sectional structure of the pump unit, with a head plate and a tube removed.

FIGS. 5A and 5B are cross-sectional views showing engagement states of tubes and pulleys of two pumps, respectively.

FIGS. 6 (I) to (VI) are views showing a cleaning method of the present invention.

[Explanation of symbols]

 DESCRIPTION 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 Tube 36-39 Pulley 40, 41 Pump wheel 61, 63 Waste ink tank 66 Wiping blade

Continuation of the front page (72) Inventor Masahiro Isono 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Seiji Mochizuki 3-3-5, Yamato, Suwa-shi, Nagano Seiko Epson Corporation

Claims (4)

[Claims] A first recording head and a second recording head mounted on a carriage and driven reciprocally in the width direction of recording paper; and a first recording head and a second recording head disposed in a non-printing area of the recording head. Capping means having a first cap member and a second cap member for individually sealing the first and second recording heads in response thereto, and the capping means connected to the first and second cap members, and An ink jet recording apparatus comprising: a first pump and a second pump that are simultaneously driven by receiving power from a driving source. 2. The pump according to claim 1, wherein the first and second pumps are rotated by power from a driving unit and a pump frame formed so that a tube supporting surface for regulating the outer shape of the tube to be substantially semicircular is back to back. 2. The pump wheel according to claim 1, wherein the pump wheels are rotatably provided in grooves of the pump wheels. The pump wheels handle the tubes in the frame symmetrically with respect to the center of rotation of the pump wheels, and have a phase difference of about 90 degrees. 3. The ink jet recording apparatus according to claim 1. 3. The ink jet recording apparatus according to claim 1, wherein the discharge sides of the tubes constituting the first and second pumps are respectively connected to different waste ink tanks. 4. A cleaning method for an ink jet recording apparatus, comprising: a first recording head and a second recording head mounted on a carriage; and a cleaning mechanism for wiping ink on a nozzle surface by a wiping blade. At a stage positioned between the first recording head and the second recording head, the carriage is stopped for a time required for the wiping blade to return to its original state due to elasticity, and then the wiping of the second recording head is performed. A cleaning method that moves to the area of the blade.