JPH1044471A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a unit for recovering an ink jet head clogged with ink which is applicable to oil ink without requiring any check valve or one way clutch. SOLUTION: Driving force is transmitted from a drive source 1 such that an ink suction pump is engaged with a pump drive gear 6 to perform suction in response to the rotation of a paper feed roller (drive source) 1 in the first direction. Planetary gear mechanisms 2, 3 are disengaged from the pump drive gear 6 in response to the rotation of the drive source 1 in the second direction. The passage between an ink reservoir 11 and an ink discharge tank 15 is interrupted to enclose the ink sump 11 while being interlocked with the engagement of the planetary gear mechanisms 2, 3 and the pump drive gear 6. The passage between the ink reservoir 11 and the ink discharge tank 15 is then opened while being interlocked with the disengagement of the planetary gear mechanism and the pump drive gear 6 and the ink is fed from the ink sump to the discharge ink tank.

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, and more particularly to a recovery mechanism (international patent classification B41J2 / 165) for realizing normal ink ejection of an ink jet head.

[0002]

2. Description of the Related Art Conventionally, in an ink jet recording apparatus, air is sucked into an ink jet head due to long standing or impact vibration, and when ejection failure occurs or defective ink in the head is removed to recover normal ejection. A recovery mechanism has been needed.

For example, as shown in FIG. 3, when a carriage 16 approaches a cap 13 which can be separated from and connected to an ink jet head, the recovery mechanism disclosed in Japanese Patent Application Laid-Open No. 2-78569 moves the cap 13 by a mechanism (not shown). Then, the cap 13 is brought into close contact with the inkjet head. Next, when the paper feed roller 1 is rotated in the direction of arrow b opposite to the paper feed direction, the gears 20 and 21 are driven via the one-way clutch 19 that transmits the driving force only in the direction of arrow b. A gear 21, a pump cam 23 and a position detection cam 26 are fixed to the shaft 22. When the pump cam 23 is driven, the pin 25 provided at one end of the piston 9 of the suction pump 29 engages with the cam groove 24 of the pump cam 23 to drive the piston 9 to make the inside of the cap 13 a negative pressure, thereby causing ink jet. The ink is discharged from the discharge port of the head and stored in the tank 29.

Further, when the paper feed roller 1 is rotated in the direction of arrow b, the ink in the tank 29 is discharged to the discharge ink tank 15 by engaging the cam groove 24 and driving the piston 9. Further, at this time, the position detection cam 26 turns on the detection switch 27 to stop the rotation of the paper feed roller, and one suction operation is completed to return to the initial state.

[0005]

In the above-described conventional configuration, the initial state of the recovery operation based on the position of the one-way clutch and the pump cam that transmits only the driving force in the direction opposite to the paper feed direction from the paper feed drive source. A means for detecting and confirming is required, which is disadvantageous in terms of cost and miniaturization. In addition, when oil-based ink or the like is used for storing ink in the pump, an expensive oil-resistant sealing material such as a fluorine-based rubber must be used, which is disadvantageous in cost.

In addition, after the ink is stored in the pump, a check valve is required to discharge the ink to the discharge ink tank without flowing back in the direction of the cap. In addition, it causes airtightness to be impaired.

[0007]

In order to solve the above-mentioned problems, a jet head recording apparatus according to the present invention is arranged such that a cap is brought into close contact with the front surface of an ink jet head from which normal ejection is to be restored, and the ink is stored in the ink reservoir by a suction pump. When the ink in the ink jet head is discharged by making the inside of the cap a negative pressure, the driving force of the driving source is transmitted by engaging with the suction pump according to the rotation of the driving source in the first direction. A planetary gear mechanism for releasing the engagement with the suction pump in response to rotation in a second direction; and the ink reservoir and the discharge ink tank in conjunction with the engagement of the planetary gear mechanism with the suction pump. And closing the ink reservoir to close the ink reservoir, and opening the passage in conjunction with the release of the engagement relationship with the rotation in the second direction. It is.

According to the present invention, no ink is stored in the pump, and even when handling oil-based ink, it is not necessary to use an expensive oil-resistant sealing material, which is advantageous in terms of cost. By opening and closing the tank passage, a check valve is not required inside the pump, so that the structure is simplified.

[0009]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a cap is brought into close contact with the front surface of an ink jet head from which normal ejection is to be recovered, and a negative pressure is applied to the inside of the cap via a reservoir using a suction pump. In the ink jet head recording apparatus that discharges ink in the ink jet head, the suction pump engages with the suction pump according to the rotation of the drive source in the first direction, and the suction pump drives the driving force of the drive source. A planetary gear mechanism that transmits to perform a suction operation and releases the engagement with the suction pump according to rotation in a second direction; and the planetary gear mechanism according to rotation of the drive source in a first direction. In conjunction with the engagement of the gear mechanism with the suction pump, the passage between the ink reservoir and the drain ink tank is shut off to seal the ink reservoir, and the rotation is caused by the rotation in the second direction. In conjunction with the release of the engagement relationship is obtained by further comprising a means for opening said passage,
There is no need to store ink inside the pump, and even when handling oil-based ink, there is no need to use an expensive oil-resistant seal material, which is advantageous in terms of cost.By opening and closing the passage between the ink reservoir and the waste ink tank, Since a check valve is not required inside the pump, ink can be discharged from the head by a pump having a simple structure.

According to a second aspect of the present invention, the piston of the suction pump is configured to be driven according to the rotation of a first gear, and the rotation of the drive source in the first direction is performed. The planetary gear mechanism engages with the first gear and rotates so that the piston of the suction pump is driven in the suction direction, and the planetary gear mechanism rotates with the rotation of the drive source in the second direction. Disengaging the first gear, and engaging the first gear with the further rotation of the drive source in the second direction, causing the piston of the suction pump to move in the opposite direction to the suction direction. The suction pump can be driven only by switching the rotation direction of the drive source.

According to a third aspect of the present invention, the first gear has a notched portion having no teeth for disengaging substantially with the planetary gear mechanism. The transmission of the driving force of the driving source to the first gear is configured to be interrupted by the cutout portion after performing a predetermined suction operation of the suction pump, and further transmitting the driving force of the driving source. The transmission of the driving force of the drive source to the first gear through the planetary gear mechanism when the planetary gear mechanism and the first gear are engaged with the second rotation is the suction. After the pump is returned to the original non-suction state, the pump is interrupted by the notch, and the recovery mechanism can be initialized only by switching the rotation direction of the drive source. Gear with a notch that engages with the planetary gear mechanism. The drive to the recovery mechanism is transmitted only by the first rotation of the drive source, and the one-way clutch is not required, and the transmission from the drive source is interrupted by the notch of the gear having the notch. A means for detecting and confirming the initial state (the piston is at the bottom dead center) becomes unnecessary, which is advantageous in terms of cost and size.

(Embodiment 1) An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing a main part of an ink jet recording apparatus according to the present invention. Reference numeral 1 denotes a drive motor (not shown) coupled to one end, which is reversibly rotated in a paper feed direction a or a paper feed reverse direction b. The other end is fixed with a sun gear 2 constituting a planetary gear mechanism. Reference numeral 3 denotes a planetary gear, which engages with the sun gear 2 by a rotating arm 4 which is independently rotatably supported coaxially with the sun gear 2, and the planetary gear 3 and the rotating arm 4 generate friction at a contact surface thereof. .

Further, a cam 5 eccentric to the rotation center of the sun gear 2 is formed on the rotating arm 4. Reference numeral 6 denotes a pump driving gear having a notch A at a part of the outer periphery. The pump includes a piston 7 and a cylinder 8. One end of the piston 7 is rotatably connected to the pump driving gear 6, and the cylinder 8 has a base 9. It is fixed to. 10 is an air flow path,
The upper part of the ink reservoir 11 and the cylinder 8 are connected. An ink flow path 12 connects the cap 13 and the upper part of the ink reservoir 11. Numeral 14 denotes a drain ink tube made of an elastic member, which is provided at a position lower than the ink reservoir 11 through the gap between the base indicated by a two-dot chain line from the lower portion of the ink reservoir 11 and the cam 5 provided on the rotary arm 4, and has one end connected to the atmosphere. It is configured to communicate with the waste ink tank 15 that is opened to the outside. 16
Denotes a carriage, on which an inkjet head (not shown) is mounted on the lower surface of the carriage 16, supported by a carriage rail 17, and driven left and right by a carriage drive motor (not shown).

Next, the recovery operation of the present invention will be described with reference to the schematic diagram of FIG. However, since one end of the drain ink tank was open to the atmosphere, one end of the drain ink tube was omitted from the atmosphere. FIG. 2A shows a state in which the carriage 16 in FIG. 1 is moved above the cap 13 and the ejection surface of the inkjet head 18 is in close contact with the cap 13. At this time, the planetary gear 3 is at the position c where it meshes with the notch of the pump drive gear 6 or at the position d directly below the sun gear 2 due to its own weight. The piston is located at the top dead center, and the ink reservoir 11 is opened to the atmosphere through a drain tube 14.

FIG. 2B shows a state in which the paper feed roller 1 and the sun gear 2 have started to rotate in the paper feed reverse direction b from the state shown in FIG. The rotating arm 4 rotates the planetary gear 3 to the position e by friction between the rotating arm 4 and the planetary gear 3. At this time, the planetary gear 3 meshes with the pump driving gear 6 and starts transmitting the driving force. With the rotation of the rotary arm 4, the cam 5 presses the ink discharge tube 14 against the substrate to deform the ink tube 11 so that the inside of the ink reservoir 11 is sealed, and the piston 7 moves from the top dead center to the bottom dead center, and the ink reservoir 11 is moved. Start to create a negative pressure inside.

FIG. 2C shows a state in which the paper feed roller 1 and the sun gear 2 continue to rotate in the paper feed reverse direction b.
When the planetary gear 3 continues to rotate, the meshing position with the pump drive gear 6 reaches the notch A. At this time, the driving of the planetary gear 3 is not transmitted to the pump driving gear 6, the pump driving gear 6 stops, the piston 7 reaches the bottom dead center, and the ink from the ink jet head 18 accumulates in the ink reservoir 11.

FIG. 2D shows a state in which the paper feed roller 1 and the sun gear 2 have started to rotate in the paper feed direction a from the state of FIG. 2C. The rotating arm 4 rotates the planetary gear 3 to the position c by friction between the rotating arm 4 and the planetary gear 3. At this time, the planetary gear 3 meshes with the pump drive gear 6 and starts transmitting the drive. Further, the cam 5 releases the deformation of the ink discharge tube 14 with the rotation of the rotary arm 4, and the inside of the ink reservoir 11 is opened to the atmosphere. At this time, the ink in the ink reservoir 11 is discharged from the ink reservoir 11 via the discharge ink tube 14.

FIG. 2E shows a paper feed roller 1 and a sun gear 2.
Indicates a state in which it continues to rotate in the paper feed direction a. Planetary gear 3
Continues to rotate, the meshing position with the pump drive gear 6 reaches the notch A. At this time, the driving of the planetary gear 3 is not transmitted to the pump driving gear 6, the pump driving gear 6 stops, the piston 7 reaches the top dead center, and returns to the initial state. In the first embodiment, the drive source of the recovery mechanism is a paper feed motor, but may be an original motor.

[0019]

According to the ink jet recording apparatus of the present invention, there is no need to use an expensive oil-resistant sealing material even when handling oil-based ink or the like, because the ink does not accumulate in the pump. Since a check valve is not required inside the pump by opening and closing the passage between the ink reservoir and the waste ink tank, it is possible to provide an ink jet head recovery device having a simple structure and high airtightness. In addition, if a gear having a notch engaged with the planetary gear mechanism is used, the drive to the recovery mechanism is started only by the first rotation of the drive source, and a complicated clutch is not required, and the drive from the drive source is not required. Since the transmission is interrupted by the notch of the gear having the notch, means for detecting and confirming the initial state (the piston is at the bottom dead center) becomes unnecessary, which is advantageous in terms of cost and size.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an ink jet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing different operation states according to the embodiment of the present invention.

FIG. 3 is a perspective view of a main part of a conventional ink jet recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed roller 2 Sun gear 3 Planetary gear 4 Rotating arm 5 Cam 6 Pump gear 7 Piston 8 Cylinder 11 Ink pool 13 Cap 14 Drain ink tube 15 Drain ink tank

Claims (3)

[Claims] 1. An ink jet device in which a cap is brought into close contact with a front surface of an ink jet head from which normal ejection is to be recovered, and a negative pressure is applied to the inside of the cap via an ink reservoir by a suction pump to discharge ink in the ink jet head. In the head recording device, the suction source is engaged with the suction pump in accordance with the rotation of the drive source in the first direction, and the driving force of the drive source is transmitted so that the suction pump performs a suction operation. A planetary gear mechanism for releasing the engagement relationship with the suction pump in accordance with the rotation, and interlocking with engagement of the suction pump of the planetary gear mechanism with rotation of the drive source in a first direction. The passage between the ink reservoir and the drain ink tank is shut off to keep the ink reservoir in a sealed state, and the passage is opened in conjunction with the release of the engagement relationship with the rotation in the second direction. An ink jet recording apparatus having means. 2. A piston of the suction pump is configured to perform a suction operation in accordance with rotation of a first gear in a first direction, and the piston is driven by rotation of the drive source in a first direction. The planetary gear mechanism is engaged with the first gear to rotate the first gear in a first direction, and with the rotation of the drive source in a second direction, the planetary gear mechanism Disengage the engagement with the first gear and re-engage the first gear with the further rotation of the drive source in the second direction, causing the piston of the suction pump to move in the opposite direction to the suction direction. 2. The ink jet recording apparatus according to claim 1, wherein the first gear is rotated in the second direction so as to be driven in the second direction. 3. The first gear has a toothless notch that substantially disengages with the planetary gear mechanism, and the first gear is connected to the first gear through the planetary gear mechanism. The transmission of the driving force of the driving source is configured to be interrupted by the notch after performing a predetermined suction operation of the suction pump, and the driving force is further interrupted by a second rotation of the driving source. At the time of engagement between the planetary gear mechanism and the first gear, transmission of the driving force of the drive source to the first gear via the planetary gear mechanism causes the suction pump to return to the original non-suction state. 3. The ink jet recording apparatus according to claim 2, wherein the ink jet recording apparatus is configured to be interrupted by the cutout after the operation.