JP2003205634A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus in which a pump means can be prevented from being rendered undrivable due to sticking of ink and power consumption and noise can be reduced at the time of driving the pump means. <P>SOLUTION: The imaging apparatus comprises a print head ejecting ink to a material being recorded, a cap member covering the nozzle part, and a pump means connected with the cap member and sucking ink in order to restore the print head. The pump means comprises a cylinder having an ink suction opening and an ink discharge opening, and a piston reciprocating in the inner space of the cylinder. The imaging apparatus further comprises means for detecting whether the pump means was driven or not, and a pump drive means for redriving the pump means with a larger driving power if driving of the pump means was not detected by the detecting means although a pump drive signal has been delivered from the imaging apparatus body. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an ink jet printer, and more particularly to a driving means for a print head recovery mechanism therein.

[0002]

2. Description of the Related Art Conventionally, in a print head recovery mechanism of an image forming apparatus, particularly in a pump means for sucking and discharging ink by using a cylinder and a piston, a piston that reciprocates in the cylinder and an inner wall of the cylinder. The contact surfaces of are closely sealed.

[0003]

However, in the print head recovery mechanism of the above-mentioned conventional image forming apparatus, in particular, the pump means for sucking and discharging the ink by using the cylinder and the piston is left for a long time. In some cases, the residual ink in the cylinder causes the piston and the inner wall of the cylinder to stick to each other, which makes it impossible to drive the pump means.

When a motor is used to drive the pump means and a driving force based on the fixed state is applied to the pump means, excessive torque is generated in the normal state, resulting in large power consumption. However, there is a problem that the noise when driving the pump means becomes large.

The present invention has been made in view of the above problems, and an object thereof is to avoid inability to drive the pump means due to ink sticking and to reduce power consumption and noise when the pump means is driven. An object is to provide an image forming apparatus capable of achieving the above.

[0006]

To achieve the above object, the present invention provides a print head for ejecting ink to a recording material, a cap member for covering a nozzle portion, and the print head connected to the cap member. In the image forming apparatus having a pump unit that sucks ink to recover the ink, the pump unit includes a cylinder having an ink suction port and an ink discharge port, and a piston that reciprocates in the internal space of the cylinder. And a detection unit that detects whether or not the pump unit is driven, and the detection unit drives the pump unit in spite of the pump drive signal from the image forming apparatus main body being issued. When is not detected, it is characterized by having pump driving means for re-driving the pump means with a larger driving force.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a perspective view of an ink jet printer according to the present invention, and FIG. 2 is a schematic plan view of a sheet feeding mechanism.

The sheet sent out by the paper feeding roller 102 of the paper feeding means 101 is sent to the carrying roller 302, further sent to the platen 301 by the carrying roller 302, and printed by the print head mounted on the carriage 201. To go. Here, the pulse motor 30
The drive from 5 is performed via the reduction gear 306 to the transport roller 30.
It is transmitted to the transport gear 303 fixed to one end of the second roller 2, and the transport roller 302 is rotated. Further, the LF output gear 304 fixed to the other end of the conveying roller 302 can transmit the drive to the sheet feeding unit 101 and the recovery unit 500.

The drive switching means 600 includes a gear train for drive transmission and switching, and a recovery means 500. The recovery means 500 is for recovering clogging of the print head and maintaining a good print state, and is a pump means 503, a cap means 501 and a wiping means 5.
Have 02.

The recovery means 500 will be described in detail below.

FIG. 3 is a perspective view of the drive switching means 600, FIG. 4 is a plan view of the drive switching means 600, and FIG. 5 is a right side view of the drive switching means. The recovery means 500 includes a pump means 503, a cap means 501, and a wiping means 502. The driving force output from the LF output gear 304 is transmitted to the LF transmission gear 602, the transmission shaft 605,
It is transmitted to the P clutch gear 630 via the P transmission gear 606.

Reference numeral 604 denotes a P, which is rotatably provided on a P output gear shaft 509 whose both ends are pivotally supported by the drive base 601.
It is an output gear. The driving force is transmitted to the P output gear 604 by meshing with the P clutch gear 630 or the P clutch trigger gear 632. Also, the P output gear 604 is P
The clutch gear has a toothless portion, and the P-clutch gear 6 is provided when the pump means is not driven, such as when feeding / discharging or printing.
It does not mesh with 30. When the pump means 503 is driven or the cap means 502 is started to drive, the P-clutch trigger gear 632 is slid by the carriage 201 so that the ratchet portion of the P-clutch trigger gear 632 meshes with the ratchet portion of the P-clutch gear 630. , The driving force of the P transmission gear 606 is the P output gear 604.
Is transmitted to the piston gear 510, and the piston gear 510 is rotated by being transmitted to the piston gear 510.

The P output gear 604 is provided with a cam portion 604b for regulating the vertical movement of the carriage lock 511 biased in the direction of the carriage 201 by the spring means 543 and for regulating the phase of the toothless portion. It has a first cap 513 and a cam portion 604c for restricting the vertical movement of the second cap 514.

FIG. 6 is a sectional view of the pump means 503.
The rotation transmitted to the piston gear 510 is transmitted to the screw portion 513a of the piston shaft 513 from the guide portion 510a provided in the inner diameter portion of the piston gear 510, and the piston shaft 513 reciprocates left and right. The cylinder portion is formed by a first cylinder 516 and a second cylinder 517, and has ink suction ports 516a and 517a and ink discharge ports 516b and 517b, respectively.

A seal material A 523 and a washer 52 are provided between the first cylinder 516 and the second cylinder 517.
2, 523 are sandwiched. Second cylinder 51
7 and the cylinder cap 515 between the sealing material B5
26 and a washer 525 are sandwiched. A first piston 518 is arranged in the first cylinder 516, and a second piston 519 is arranged in the second cylinder 517, respectively.
A piston stopper 520 and a stopper rubber 521 are provided at the position 13, and the first piston 518 is restricted.

Reference numeral 514 denotes a recess 513b of the piston shaft 513.
Is press-fitted to the guide portion 51 of the cylinder cap 515.
By reciprocating along 5a, the piston shaft 51
3 is a guide pin for preventing itself from rotating. Further, the cylinder cap 515 has its convex portion 515b engaged with the concave portion of the second cylinder 517, and its rotation is restricted.

FIG. 7 is a process diagram for sucking and discharging ink on the side of the first cylinder. The movement start position of the piston 518 is shown in (a).

When the piston moves and passes through the suction port 516a, ink 59 is transferred to the suction side in the first cylinder 516.
1 is sucked and stops at the position (b) where a predetermined suction amount is sucked. Further, when the piston 518 returns to the movement limit position (c) in the suction start position direction, the first cylinder 516
The ink 591 inside is the piston 518 and the piston shaft 51.
The ink 591 moves to the discharge side in the first cylinder through the ink flow path between the first and second cylinders. Further, the piston 518
Moves to the ink discharge port 516b side, the piston 51
8 and the seal material 523 sandwiched by the washers 524 and 525, the ink 591 is forcibly discharged from the discharge port 51.
It is discharged from 6b. After that, the ink 519 is completely removed by the first suction process by reciprocating the piston 518.
Is discharged to the outside of the cylinder 516.

FIG. 8 is a process drawing when the ink is sucked and discharged on the second cylinder side, and the ink is sucked and discharged by the same process as the above process. FIG. 9 shows pump means 5
It is the figure which connected the cap part to 03, and FIG. 10 shows the sectional view of the 2nd cap 529 part.

The first cap 528 and the second cap 5
29 is fixed to the cap holder 527, and the two bosses provided on the cap holder 527 cause the first
Arm 516 formed integrally with the cylinder 516 of
It is rotatably supported between the hole of c and the hole of the first arm 517c formed integrally with the second cylinder 517. 527c is a positioning hole provided on the cap holder, and is engaged with a boss provided on the drive base 601.

Further, the pump means 503 has one end, in which the shaft portion 510b of the piston gear 510 is in the hole portion of the drive base 601,
On the other hand, the shaft portion 516d of the second cylinder 516 is engaged with the hole portion of the bearing member 532 installed on the drive base 601, and is rotatably supported.

Further, from the back side of the cap holder 527, it is urged by a spring member 544 installed on the drive base 601, and a rotational force is applied to the pump means 503. The tube portion 529 is integrally formed with the second cap 529.
a is formed and is press-fitted into the convex portion that is the suction port of the second cylinder 517. The same applies to the first cap 528.

Reference numeral 531 denotes an in-cap absorber B for absorbing and holding ink in the second cap 529, and similarly in the first cap 528, in-cap absorber A5.
30 are provided. Both 527a and 527b are positioning bosses provided on the cap holder 527, and engage with U-shaped grooves provided on the drive base 601. Numeral 517d is a second arm portion integrally formed with the second cylinder 517, and the P output gear 6
The cam portion 604c on 04 restricts the rotation of the pump means 503.

In the state where the print head is sucking ink, the first cap 528 or the second cap 529 abuts the print head, and the second cylinder 51
The second arm portion 517d on the No. 7 is separated from the cam portion 604c on the P output gear 510, and the pressure contact force of the first cap 528 or the second cap 529 with respect to the print head becomes a predetermined value.

FIG. 11 is a front view of the drive switching means 600, and FIG. 12 is a left side view of the drive switching means 600. FIG. 11 shows a state in which the wiping means 502 is set to the wiping position for wiping.

A procedure for setting the wiping means 502 will be described.

When the B trigger lever 532 is moved in the direction of arrow B by a predetermined amount by the carriage 201, the cam portion (not shown) of the B trigger lever 532 engages with the boss 534b on the B lever 534, and the drive base 601 is driven. The B lever 534 having the rotating shaft 534a sandwiched between it and the base cover 640 rotates in the arrow E direction. Reference numeral 536 is a B lock rotatably supported by the B lever 534, and when the B lever 534 rotates a predetermined amount, it rides on a convex portion of the drive base 601 and is locked.

Reference numeral 538 denotes a B lock release lever for releasing the above lock state. After the wiping operation is completed, the carriage 201 moves in the direction of arrow C, so that the carriage 201 releases the B lock release lever 538.
And the B lock release lever 538 is rotated in the arrow F direction, the B lock 536 rotates in the unlocking direction, and the spring means 535 provided between the drive base 601 and the B lever 534 causes B lever 534
Is set to the non-wiping position.

The wiping means 502 has the following configuration.

The first blade 540 is attached to the B holder 539.
The second blade 541 is attached by sandwiching a spacer (not shown), and is held by the B retainer 542.
Further, the B holder 539 is biased in the direction of arrow G by the spring means 540 provided between the B holder 539 and the B lever 534, and the abutting surface 539a of the B holder 539 is placed on the bottom surface of the carriage 201 during the wiping operation. By contacting each other, the amount of overlap between the face surface of the print head mounted on the carriage 201 and the first blade 540 and the second blade 541 is managed, and proper wiping is possible.

FIG. 13 is a schematic diagram at the time of initial operation. (A) shows a standby state when the ink jet printer is not used, and the nozzle portion of the print head is cap 5
It is covered with 29.

Reference numeral 604d denotes a cam portion on the P output gear 604, which is engaged with a P sensor lever 545 for detecting the rotation angle of each cam portion and the rotation angle of the P output gear 604.
A cam for restricting the sensor transmission lever 512. At the time of initialization, the drive from the pulse motor 305 is transmitted to the P output gear 604 and rotated in the arrow A1 direction.
By this rotation, the cap 529 is pushed down in the direction of arrow A2 and separated from the print head. The P sensor transmission lever 512 slides in the arrow A2 direction by the cam portion 604d, the P sensor lever 545 rotates in the arrow A4 direction,
The light blocking portion of the P sensor lever 545 enters the detection sensor. The piston 519 moves in the arrow A5 direction via the piston gear 510 and the piston shaft 513.

FIG. 3B is a diagram showing a state after the initial. At the initial time, the pulse motor 305 is driven at 60% of the maximum current value because it is sufficient if a torque sufficient for sliding the piston 519 and the like can be obtained. As a result, it is possible to reduce the noise caused by the motor operating noise,
It consumes less power. However, after this initial operation, when it is determined that the light shielding portion of the P sensor lever 545 has not entered the detection sensor, it is determined that the initial operation has failed due to the step out of the pulse motor 305, and the pulse motor 305 is not detected. Drive current to 100%,
Perform the initial operation again. The cause of step-out of the pulse motor 305 is due to the ink remaining in the cylinder when the ink jet printer body is left for a long time.
This is because the piston and the inner wall of the cylinder are fixed to each other, and a larger driving force is required to enable the operation.

FIG. 14 shows the operation of the cap means 501 and the pump means 503 with respect to the rotation angle of the P output gear 604.
FIG. 7 is a diagram showing an example of a suction operation by

The P output gear 604 has a home position when the rotation angle is 0 and serves as a reference position for the cap operation and the suction operation. The P output gear 604 can be rotated in the forward and reverse directions within a range of 0 to 330 °, and when the first cap 528 sucks ink, when the suction 1 is taken as an example, it is 299 ° to 82 °.
Rotate in the reverse direction until. Further, when the second cap 529 sucks the ink, the suction 1 is taken as an example, and it is 35 ° to
Rotate in the forward direction up to 250 °.

The start position and end position of the P output gear associated with suction or idle suction determine the amount of suction or the negative pressure applied to the print head during suction, including the number of repetitions of suction and idle suction. , Has a plurality of steps and can be selected. The standby position when the inkjet printer is not used is the first cap 528.
270 when the print head corresponding to is installed
And 110 ° when the print head corresponding to the second cap 529 is mounted.

FIG. 15 shows a print head mounted on an ink jet printer.

(A) is a black head suitable for high-speed monochrome printing, (b) is a color head suitable for graphic printing, and (c) is a photo head suitable for photographic printing. Select the optimum head according to your needs.

[0040]

As is apparent from the above description, according to the present invention, the print head for ejecting ink to the recording material, the cap member for covering the nozzle portion, and the print head connected to the cap member are provided. In the image forming apparatus having a pump unit that sucks ink to recover the ink, the pump unit includes a cylinder having an ink suction port and an ink discharge port, and a piston that reciprocates in the internal space of the cylinder. And a detection unit that detects whether or not the pump unit is driven, and the detection unit drives the pump unit in spite of the pump drive signal from the image forming apparatus main body being issued. When is not detected, because it has a pump drive means for re-driving the pump means with a larger driving force,
It is possible to avoid the inability to drive the pump means due to the adhered ink, and it is possible to reduce the power consumption and noise when the pump means is driven.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet printer according to the present invention.

FIG. 2 is a schematic plan view of a sheet feeding mechanism of the inkjet printer according to the present invention.

FIG. 3 is a perspective view of drive switching means of the inkjet printer according to the present invention.

FIG. 4 is a plan view of drive switching means of the inkjet printer according to the present invention.

FIG. 5 is a right side view of drive switching means of the inkjet printer according to the present invention.

FIG. 6 is a cross-sectional view of pump means of the inkjet printer according to the present invention.

FIG. 7 is a process drawing of ink suction / discharge of the first cylinder of the inkjet printer according to the present invention.

FIG. 8 is a process drawing of ink suction / discharge of the second cylinder of the inkjet printer according to the present invention.

FIG. 9 is a close-up view of the pump means and the cap means of the inkjet printer according to the present invention.

FIG. 10 is a second part of the inkjet printer according to the present invention.
3 is a cross-sectional view of the cap of FIG.

FIG. 11 is a front view of drive switching means of the inkjet printer according to the present invention.

FIG. 12 is a left side view of drive switching means of the inkjet printer according to the present invention.

FIG. 13 is a schematic view of the inkjet printer according to the present invention during an initial operation.

FIG. 14 is an explanatory diagram of a rotation angle of a P output gear, a cap, and a piston of the inkjet printer according to the present invention.

FIG. 15 is a perspective view of a print head of the inkjet printer according to the present invention.

[Explanation of symbols]

201a detection sensor 503 pumping means 513 Piston shaft 516 First cylinder 517 second cylinder 518 first piston 519 Second piston 545 P sensor lever

Claims (8)

[Claims] 1. An image having a print head for ejecting ink to a recording material, a cap member for covering a nozzle portion, and a pump means connected to the cap member and sucking ink to recover the print head. In the forming apparatus, the pump unit includes a cylinder having an ink suction port and an ink discharge port, and a piston that reciprocates in the internal space of the cylinder, and detects whether the pump unit is driven. Detecting means, despite the fact that the pump drive signal is issued from the image forming apparatus main body,
It is characterized by further comprising pump driving means for re-driving the pump means with a larger driving force when the detection means does not detect the driving of the pump means. 2. The image forming apparatus according to claim 1, wherein the pump driving unit includes a motor. 3. The image forming apparatus according to claim 2, wherein the driving force for re-driving the pump means is increased by changing the driving current for driving the motor. 4. The image forming apparatus according to claim 2, wherein the driving force for re-driving the pump means is increased by changing the driving voltage for driving the motor. 5. The image forming apparatus according to claim 2, wherein the motor is a pulse motor. 6. The image forming apparatus according to claim 5, wherein the driving force at the time of re-driving the pump means is increased by changing the driving frequency for driving the motor. 7. The image forming apparatus according to claim 1, wherein the detection unit is provided on a carriage that carries the recording head and reciprocates. 8. The image forming apparatus according to claim 7, wherein the detection unit also serves as a positioning unit when the carriage reciprocates.