JP2012250383A - Apparatus for maintenance and recovery of ink ejection head, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a suction amount in which ink is sucked from an ink ejection head, with a simple configuration.SOLUTION: An apparatus for maintenance and recovery of the ink ejection head includes: a capping device 50 that drives a cap member 31 while the cap being stuck to and spaced from the ink ejection head 25; and a tubing pump 40 that sucks out the ink from the ink ejection head 25. After the tubing pump 40 is rotated and driven at a predetermined angle while the cap member 31 is spaced from the ink ejection head, the cap member 31 is stuck to the ink ejection head 25, and afterward, the tubing pump 40 is further driven to suck in the ink from the ink ejection head 25.

Description

  The present invention relates to an ink discharge head maintenance / recovery device and an image forming apparatus, and more particularly to an ink discharge head capping device, an ink discharge head maintenance / recovery device including a tubing pump for sucking ink from the ink discharge head, and an image. The present invention relates to a forming apparatus.

  As an image forming apparatus, an ink jet recording apparatus that forms an image on a recording medium by discharging ink droplets from an ink discharge head is widely used. The ink jet recording apparatus is advantageous in that it can be easily made compact and can record a high-definition image at a high speed. In addition, since recording can be performed on plain paper without requiring special processing, there is an advantage that the running cost is low. In addition, the non-impact recording method has advantages such as low noise and easy compatibility with color image recording using multi-color inks.

  In such an ink jet recording apparatus, when the nozzle of the ink discharge head is clogged, a cleaning operation for sucking ink from the ink discharge head is performed. In this cleaning operation, a tubing pump may be used as a suction pump for sucking ink from the ink discharge head. This tubing pump is provided with a structure for transferring a liquid by pressing a tube disposed around it with a roller moving along a circumference. The tubing pump has an advantage that it is easy to switch between a suction state and a non-suction state by forward rotation and reverse rotation.

  In Patent Document 1, in order to stabilize the suction amount, a DC motor driven by PWM control is used as a pump drive source, and the generated pressure and discharge amount of the pump are detected by detecting the phase of the roller with respect to the tube by the current PWM value. An image forming apparatus for controlling the image is described.

  However, the tubing pump does not stabilize the operating angle of the pump until the roller crushes the tube, and the suction amount varies, so if the suction amount is set based on the lower limit of variation, the variation becomes the upper limit. Had the problem of wasting ink.

  In the invention described in Patent Document 1, the current value changes according to the phase of the roller during one rotation of the pump, and control is performed based on this change amount. However, since the change amount of the current value is minute, the current value depends on the current value. Further, there is a problem that the phase detection accuracy of the roller is low, it is difficult to accurately detect the roller phase, and the detected suction amount becomes unstable.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of stabilizing the amount of suction of ink from an ink ejection head with a simple configuration.

  An ink discharge head maintenance / recovery device according to the present invention includes an ink discharge head that discharges ink from a nozzle to form an image on a recording medium, a cap member that is driven in close contact with and driven away from the ink discharge head, and the cap A cap member driving device comprising: a cap member driving device for driving a member; a tubing pump for sucking ink from the ink discharging head; and a pump driving device for driving the tubing pump. And the pump driving device, the tubing pump is rotated by a predetermined angle in a state where the cap member is separated from the ink discharge head, and then the cap member is brought into close contact with the ink discharge head. Then, the ink is discharged by driving the tubing pump. Characterized in that it comprises a control means for sucking ink from the head.

  According to the present invention, since the cap member can be separated from the ink discharge head, the tubing pump can be driven to rotate by a predetermined angle, and the ink suction can be started from the state where the cap member is in close contact with the ink discharge head. The amount of ink that is wasted at the start of the cleaning operation of the apparatus can be reduced.

1 is a schematic diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment. The operation state of the tubing pump used for the maintenance / recovery device of the ink discharge head is shown. (A) is a plan view showing a non-suction state, and (b) is a plan view showing the state during suction. . The position of the roller at the time of the suction start of the tubing pump is shown, (a) is a plan view showing a state of a large angle, and (b) is a plan view showing a state of a small angle. It is a perspective view which shows the capping apparatus used for the maintenance recovery apparatus of the ink discharge head. 3 is a block diagram showing a control system of the ink ejection head maintenance / recovery device. FIG. 3 is a flowchart showing the operation of the ink discharge head. FIG. 2 shows an ink ejection head maintenance and recovery device according to Embodiment 2, wherein (a) is a perspective view showing the whole, (b) is a perspective view showing a connected state of a pump gear and a drive gear, and (c) is a pump gear. It is a top view which shows the connection state of a drive gear. 6 is a plan view illustrating a configuration of an ink ejection head according to Embodiment 3. FIG.

  An image forming apparatus according to a mode for carrying out the present invention (hereinafter simply referred to as an embodiment) will be described.

  FIG. 1 is a schematic diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment. The image forming apparatus according to the embodiment is an ink jet recording apparatus. In the image forming apparatus according to the embodiment, before the cap member comes into close contact with the head and sucks ink from the head, the tubing pump is driven so that the roller crushes the tube, and the cap member is held against the head in this state. And suck the ink from the head.

<Embodiment 1>
The image forming apparatus 10 according to the first embodiment includes a recording apparatus engine 20 for forming an image, a paper feeding unit 12, and a scanner 13 inside the recording apparatus main body 11. Further, the recording apparatus main body 11 includes a waste liquid tank 14 that stores waste ink.

  The recording apparatus engine 20 includes a carriage 22 that is driven in the main scanning direction along the rod 21. The carriage 22 holds four ink ejection heads 25Y, 25M, 25C, and 25K (corresponding to yellow (Y), magenta (M), cyan (C), and black (K)). The ink discharge heads 25Y, 25M, 25C, and 25K discharge ink droplets of each color. The recording apparatus engine 20 has an ink cartridge 24 that holds ink of each color. In addition, when the ink discharge head is described regardless of the color, it is referred to as “ink discharge head 25”.

  Further, the recording apparatus engine 20 is provided with an ink discharge head maintenance apparatus 30. The maintenance device 30 includes cap members 31Y, 31M, 31C, and 31K for capping the ink discharge heads 25Y, 25M, 25C, and 25K, a blade member 32 for wiping the nozzle surfaces of the ink discharge heads 25Y, 25M, 25C, and 25K, And a tubing pump 40 which is a suction pump. Waste ink sucked by the tubing pump 40 is guided to the waste liquid tank 14 through the discharge tube 34 and the waste liquid introduction duct 35. The cap members 31Y, 31M, 31C, and 31K correspond to the ink discharge heads 25Y, 25M, 25C, and 25K for the respective colors. When the cap member is described regardless of the color, it is simply referred to as “cap member 31”. These cap members 31Y, 31M, 31C, 31K are driven by a cap member driving device.

  At the time of image formation, a recording medium conveyance device (not shown) conveys the recording medium from the paper supply unit 12 provided at the bottom of the recording apparatus main body 11 to the recording apparatus engine 20. Then, while conveying the recording medium by a sub-scanning conveying means (not shown), the carriage 22 on which the ink ejection heads 25Y, 25M, 25C, and 25K are mounted is driven in the main scanning direction to eject ink onto the recording medium. To form an image.

  When the ink in the ink discharge heads 25Y, 25M, 25C, and 25K that discharge ink cannot be discharged normally due to drying or the like, the ink discharge heads 25Y and 25M are provided by the tubing pump 40 provided in the maintenance device 30. The dry ink in 25C is forcibly sucked.

  The sucked ink is stored in the waste liquid tank 14 from the tubing pump 40 through the waste liquid introduction duct 35. When ink is sucked from the ink discharge heads 25Y and 25M, the ink adheres to the head nozzle surface, and is thus wiped with the blade member 32 (wiping operation). The wiped ink is recovered from the ink recovery port 33 to the waste liquid tank 14. As a result, new ink is conveyed to the ink ejection heads 25Y, 25M, 25C, and 25K, and normal printing can be performed.

  Next, the tubing pump will be described. 2A and 2B show an operating state of a tubing pump used in the ink ejection head maintenance / recovery device according to the first embodiment. FIG. 2A is a plan view showing a non-suction state, and FIG. It is a top view which shows a state. As shown in FIG. 2, the tubing pump 40 includes a tube 41 arranged in an arc shape, and a roller 42 that is arranged inside the tube 41 and revolves while rotating along the tube. Ink is sucked by moving while rotating while crushing. Here, the roller 42 is rotationally driven by the shaft 42 a being guided by a rotationally driven plate 43.

  The plate 43 is formed with a guide portion 44 for guiding the shaft 42a. At both ends of the guide portion 44, a suction end surface 44a that contacts the shaft 42a when rotating in the forward direction of the pump (at the time of suction), and a shaft 42a when rotating in the reverse direction of the pump (when the pump is not suctioned) The non-suction end surface 44b is formed.

  Here, when rotating in the forward direction, the roller 42 is guided by the guide portion 44 and moves to the suction end face 44a. In a state where the roller 42 is moved to the suction end face 44a, as shown in FIG. 2A, the dimension between the shaft 42a of the roller 42 and the rotation center O of the plate 43 becomes large (the arrow A in FIG. 2A). ), The roller 42 can crush the tube 41.

  On the other hand, at the time of reverse rotation, the roller 42 is guided by the guide portion 44 and moves to the non-suction end surface 44b. In a state where the roller 42 is positioned on the non-suction end surface 44b, the distance between the shaft 42a of the roller 42 and the rotation center O of the plate 43 becomes small (arrow B in FIG. 2B), and the roller 42 makes contact with the tube 41. The tubing pump 40 does not perform suction.

  Accordingly, when the tubing pump 40 is used, suction is performed by rotating the tubing pump 40 in the forward direction, and suction is not performed when the tubing pump 40 is reversed. Therefore, there is a region where suction cannot be performed until the roller crushes the tube even if the roller is rotated in the forward direction from the state where the roller escapes from the tube and suction is performed. This region is difficult to adjust because it varies depending on the phase of the rollers.

  3A and 3B show the position of the roller at the start of suction of the tubing pump according to the first embodiment. FIG. 3A is a plan view showing a large angle state, and FIG. 3B is a plan view showing a small angle state. is there. When the suction starts, when the roller is in the position of D1 in FIG. 3A, the pump rotation angle E1 until the roller crushes the tube (suction start position C) is C shown in FIG. 3B. To an angle E2 from D2 to D2.

  When the rollers 42 are in these angles, ink cannot be sucked even though the plate 43 of the tubing pump 40 is rotating. In addition, since this angle has a different value every time the initial position of the roller performs suction, the suction amount varies.

  In the image forming apparatus according to the embodiment, suction is started from a state in which the tube 41 crushes the roller 42 so as to obtain a stable suction amount. For this reason, the tubing pump 40 is controlled as follows.

  First, in a state where the cap member 31 is not in close contact with the ink discharge head 25, the tubing pump 40 is rotated in the forward direction so that the roller 42 crushes the tube 41. After that, capping is performed in a state where the roller 42 does not escape from the tube 41 even if it is reversed, and the tubing pump 40 is again rotated in the forward direction and sucked. By such an operation, in the tubing pump 40, suction can be performed from the state where the roller 42 has crushed the tube 41, and the amount of suction can be stabilized.

  FIG. 4 is a perspective view showing the capping device according to the first embodiment. The capping device 50 drives the cap member 31 to be in close contact with and separated from the ink discharge head 25. The cap member 31 is formed by raising and lowering a cap holder 54 on which the cap member 31 is set by a cam 51 rotated by a drive shaft 52 concentric with the drive shaft.

  FIG. 5 is a block diagram showing a control system of the ink discharge head maintenance / recovery device according to the first embodiment. In the first embodiment, a pump motor 45 as a pump driving device for driving the tubing pump 40 and a capping device 50 are shown. A capping motor 55 serving as a cap member driving device for driving the motor 45 is provided separately, and the motors 45 and 50 are driven and controlled by the control device 60 as control means as follows.

  FIG. 6 is a flowchart showing the operation of the ink jet head maintenance / recovery device according to the first embodiment. In the first embodiment, the tubing pump is rotationally driven with the cap member removed before the ink discharge head 25 is sucked by the tubing pump (step S1). As a result, the tube 41 can be crushed by the roller 42. From this state, the cap member 31 is driven up (step S2), and then the tubing pump is driven to perform suction (step S3). Thereby, the area | region which does not attract | suck to the suction start position C shown in FIG. 3 can be eliminated, and the amount of suction can be stabilized.

  After completion of the suction, the cap member 31 is lowered (step S4), and the nozzle surface of the ink discharge head 25 is wiped by the blade member 32 (step S5), and the maintenance is completed.

  At this time, when the cap member 31 shifts from the close contact state to the ink discharge head 25 to the separated state, it is desirable that the shaft rotation angle of the tubing pump 40 is 1 degree or less. Thereby, capping can be performed in a state where the roller 42 of the tubing pump 40 is not separated, and the ink suction amount is stabilized.

<Embodiment 2>
Next, an ink ejection head maintenance / recovery device according to Embodiment 2 will be described. 7A and 7B show the configuration of an ink ejection head maintenance / recovery device according to Embodiment 2, wherein FIG. 7A is a perspective view showing the whole, and FIG. (C) is a top view which shows the connection state of a pump gear and a drive gear.

  In the ink ejection head maintenance and recovery device according to the second embodiment, the tubing pump 40 and the capping device 50 are driven by a motor 61 which is a common drive source. A pinion 62 is disposed on the motor 61, and a drive gear 63 that is a drive member is engaged with the pinion 62, and a pump gear 64 is connected to the drive gear 63 via a pin 67. In the second embodiment, these mechanisms constitute the control means.

  The pump gear 64 has an arcuate groove portion 66 into which a pin 67 is inserted, and the pin 67 contacts both ends of the groove portion 66 with a play of a predetermined angle θ. For this reason, the pump gear 64 is driven with an angle θ delayed from the rotation of the drive gear 63. In the second embodiment, the delay means is realized by these mechanisms.

  The capping device 50 is connected to the drive gear 63 via a one-way clutch 65.

  In this ink discharge head maintenance / recovery device, when the motor 61 is rotated in the forward direction, the tubing pump 40 is driven to be sucked (see FIG. 2A), while the one-way clutch 65 is idled to the capping device 50. The driving force is not transmitted.

  On the other hand, when the motor 61 is reversed, the roller 42 of the tubing pump 40 is separated from the tube 41 and does not perform suction (see (b)), while the capping device 50 is powered by the one-way clutch 65. The cap member 31 is raised and lowered.

  When the rotation direction of the motor 61 is reversed, the contact between the pin 67 and the end of the groove 66 is delayed by a predetermined angle θ, and the driving force of the driving gear 63 is not transmitted to the pump gear 64 during that time. . Without this predetermined delay, the motor 61 rotates in the forward direction so that the roller 42 crushes the tube 41, and then the driving force is transmitted to the tubing pump 40 when the motor 61 is reversed to raise the cap member 31. As a result, the roller 42 is separated from the tube 41 and the suction amount becomes unstable.

  For this reason, the predetermined delay angle θ needs to be larger than the driving amount of the motor necessary for raising the cap member 31. Since this value can be calculated as a design value of the drive system, a predetermined suction amount can be obtained by adding this value to the rotation amount of the motor 61.

<Embodiment 3>
Next, Embodiment 3 will be described. FIG. 8 is a plan view showing the configuration of the ink ejection head according to the third embodiment. As described in the second embodiment, when the motor 61 is rotated in the forward direction, the roller 42 of the tubing pump 40 crushes the tube 41, and then the motor 61 is reversed to raise the cap member. If the roller is separated from the tube, the suction amount of the tubing pump 40 becomes unstable.

  Therefore, in the third embodiment, the speed reduction mechanism 70 is disposed between the pinion 62 of the motor 61 and the pump gear 64. The speed reduction mechanism 70 includes a belt transmission device 71, an idle gear 72, and a relay gear 73. The pinion 62 is engaged with the idle gear 72 and the relay gear 73 is engaged with the pump gear 64. Other configurations are the same as those of the second embodiment. In addition to the belt electric mechanism, a gear train and other mechanisms can be adopted as the speed reduction mechanism.

  According to the third embodiment, the reduction ratio of the driving force from the motor 61 can be made sufficiently high by the reduction mechanism. Therefore, even if the motor 61 is rotated in the direction and the roller 42 of the tubing pump 40 crushes the tube 41 and then the motor 61 is reversed and the cap member 31 is raised, the rotation of the motor 61 is decelerated, and the tubing pump 40 is hardly transmitted to the tube 40, so that the roller 42 is not separated from the tube 41 and the suction amount of the tubing pump 40 can be stabilized.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Recording apparatus main body 12 Paper feed part 13 Scanner 14 Waste liquid tank 20 Recording apparatus engine 21 Rod 22 Carriage 24 Ink cartridge 25 Ink discharge head 25Y, 25M, 25C, 25K Ink discharge head 30 Maintenance apparatus 31 Cap member 31Y, 31M, 31C, 31K Cap member 32 Blade member 34 Discharge tube 35 Waste liquid introduction duct 40 Tubing pump 41 Tube 42 Roller 42a Shaft 43 Plate 44 Guide portion 44a Suction end surface 44b Non-suction end surface 45 Pump motor (pump drive device)
50 Capping Device 51 Cam 52 Drive Shaft 54 Cap Holder 55 Capping Motor (Cap Member Drive Device)
60 Control device (control means)

JP 2007-145006 A Japanese Patent No. 4347669

Claims (4)

An ink ejection head that ejects ink from nozzles to form an image on a recording medium;
A cap member that is driven in close contact with and separated from the ink discharge head;
A cap member driving device for driving the cap member;
A tubing pump for sucking ink from the ink discharge head;
A pump drive for driving the tubing pump;
In the maintenance and recovery device for the ink discharge head comprising
The cap member driving device and the pump driving device are driven and controlled, and the tubing pump is rotated by a predetermined angle in a state where the cap member is separated from the ink discharge head, and then the cap member is moved to the ink. A maintenance / recovery device for an ink discharge head, comprising: a control unit that closely contacts the discharge head and then drives the tubing pump to suck ink from the ink discharge head. The control means includes
A pump gear for driving the tubing pump;
A driving member for driving the cap member driving device;
With
The delay mechanism for transmitting a driving force to the pump gear when the driving member rotates by a predetermined angle or more is provided between the pump gear and the driving member. Ink discharge head maintenance and recovery device.   2. The apparatus for maintaining and recovering an ink discharge head according to claim 1, wherein when the cap member shifts from a close contact state to the ink discharge head to a separated state, an axial rotation angle of the tubing pump is set to 1 degree or less. .   An image comprising: the ink ejection head maintenance / recovery device according to any one of claims 1 to 3; and a recording medium conveyance device that conveys the recording medium to an arrangement position of the ink ejection head. Forming equipment.