JP4993584B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a head for ejecting liquid droplets.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a combination of these, an ink jet recording apparatus or the like is known as an image forming apparatus of a liquid discharge recording method using a recording head for discharging a recording liquid droplet, for example. . In this liquid discharge recording type image forming apparatus, a recording liquid, for example, ink droplets, is transported from a recording head (not limited to paper, including OHP, and ink droplets, other liquids can be attached) This is also used as a synonym for image formation (recording, printing, printing, printing) by discharging onto a recording medium or recording medium, recording paper, recording paper, etc.). And a serial type image forming apparatus that forms an image by ejecting droplets while the recording head moves in the main scanning direction, and forms an image by ejecting droplets without moving the recording head There is a line type image forming apparatus using a line type head.

As a line-type image forming apparatus, for example, Patent Document 1 discloses a recording apparatus maintenance kit in which a head unit having an inkjet head is formed so as to be freely drawn out of the apparatus main body, and the function of the head unit is maintained and recovered by the drawn head unit. Is described as being freely attachable.
JP 2004-142365 A

Further, as a serial type image forming apparatus, for example, in Patent Document 2, when a recording head is mounted on a carriage on the apparatus main body side, a head cap unit is placed on the recovery apparatus side while the ejection hole surface of the nozzle is in contact with the recovery apparatus side. By providing a fitting mechanism for fixing the recording head to the recording head, the recording head can be replaced while the head cap unit is still attached, preventing damage to the nozzles and contamination of the hands, and a recovery device. It is described that the head cap unit corresponding to the capping member on the side can be replaced simultaneously with the replacement of the recording head so that the good recovery action of the recovery device can be stably maintained.
JP 2002-321377 A

Other references include the following:
Japanese Patent Laid-Open No. 2002-200748 JP 2003-285446 A JP 2005-225041 A Japanese Patent Laid-Open No. 10-044449

  By the way, the line-type head has a larger number of nozzles per head than the short head, and the ejection failure such as the ejection bend in which the ejected droplet bends and the droplet cannot be ejected is relatively unfavorable. It tends to occur. For this reason, a maintenance / recovery mechanism (means or apparatus) for maintaining and recovering the nozzle performance is provided, but it is difficult to always maintain a state where there is no defective nozzle even by the maintenance / recovery operation, and the head can be replaced. I need it.

  However, when a line-type head having a large number of nozzles is replaced, since the recording liquid (hereinafter referred to as “ink”) is built in the head, the ink in the head leaks from the nozzle and the apparatus There is a problem that the inside will be polluted.

  Therefore, it is conceivable to replace the head while the nozzle surface of the head is sealed with a cap member as described in Patent Document 2, but as described above, in the case of a line-type head, the ink incorporated in the head The amount is not the ratio of the short head, but there is a problem that it is difficult to hold only the cap member when ink leaks from the nozzle when the head is removed.

The present invention has been made in view of the above problems, and an object thereof to be able to easily perform the replacement operation of the F head.

To solve the above problems, an image forming apparatus according to the present invention,
A head portion composed of a line-type head for discharging droplets;
A head support portion, wherein the head portion is removably mounted,
And sustain times Fukute stage including a cap member for sealing the liquid ejection surface of the head portion,
With
The head unit is arranged to be movable in the horizontal direction between an image forming position for forming an image and a retracted position retracted from the image forming position.
Engaging means for engaging and integrating the head part and the maintenance / recovery means in a state where the head part is in the retracted position is connected to the liquid supply path in the head part and the liquid supply path in the head support part And severable,
The head portion is provided with an on-off valve that closes the inlet side of the liquid supply path when removed from the head support portion,
The head support member is provided with an atmosphere opening path branched from a liquid supply path connected to the liquid storage means for storing the liquid, and an atmosphere opening / closing valve for opening and closing the atmosphere opening path is provided.
Before the head part is removed from the head support member, the liquid in the head part is discharged and eliminated in a state where the air release valve is opened.

An image forming apparatus according to the present invention includes:
A head portion for discharging droplets;
A head support part to which the head part is detachably mounted;
Maintenance and recovery mechanism means including a cap member for sealing the liquid discharge surface of the head portion;
With
The liquid supply path in the head part and the liquid supply path in the head support part are provided to be connectable and disconnectable,
The head portion is provided with an on-off valve that closes the inlet side of the liquid supply path when removed from the head support portion,
The head support member is provided with an atmosphere opening path branched from a liquid supply path connected to the liquid storage means for storing the liquid, and an atmosphere opening / closing valve for opening and closing the atmosphere opening path is provided.
Before removing the head part from the head support member, the liquid in the head part is discharged and eliminated in a state where the air release valve is opened,
Removably attached to the head support portion with the head portion covered with the cap member,
The cap member is attached to the head portion by magnetic force, and includes an electromagnet that separates the cap member from the head portion .

By the present invention lever, also reduces the risk of leakage by sealing holding the nozzle surface of the cap member only Dehe head portion facilitates replacement.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. An example of an image forming apparatus to which the present invention is applied will be described with reference to FIGS. 1 is a schematic configuration diagram showing the overall configuration of the image forming apparatus, FIG. 2 is a right side view of FIG. 1 in a state in which the head structure is in the image forming position, and FIG. 3 is a diagram in which the head structure is in the retracted position. It is a right view of FIG. 1 in a certain state.

  The image forming apparatus is a copying apparatus. The apparatus main body 1 includes an image reading unit 2 such as a scanner for reading an original image, and a recording unit 3 for forming an image on a recording medium (hereinafter referred to as “recording paper”) P. It is configured.

  Then, the recording paper P stored in the recording paper cassette 4 is separated and fed one by one by the paper feeding roller 5 and the separation pad, and is conveyed to the printing unit 10 through the conveyance path 7. A head structure 11 including a head unit composed of a line-type head that records ink by ejecting ink droplets onto the recording paper P, and the recording paper P are adsorbed and conveyed to the printing unit 10 by electrostatic adsorption or the like. A driving belt 17 and a driven roller 18 that are circulated around the driving roller 17 and the like, and the head structure 11 with respect to the recording paper P that is attracted to the conveying belt 12 and conveyed at a predetermined speed. Ink droplets are ejected from a line-type head mounted on the printer to form an image. Next, the recording paper P on which the image is formed passes through the paper discharge path 13 and is discharged and stacked on the paper discharge stack unit 14.

  Ink is supplied to the head portion of the head structure 11 of the printing unit 10 from an ink cartridge 15 that is detachably attached to the apparatus main body 1 via an ink tube (not shown). Further, the head structure 11 is supported by the rotary shaft 16 so as to be rotatable in the horizontal direction. At the time of image formation, as shown in FIG. It can be moved to a retracted position facing the maintenance / recovery mechanism (maintenance / recovery means) 20. Further, on the front side of the apparatus main body 1, a maintenance / recovery mechanism that performs maintenance / recovery of the head portion of the head structure 11 corresponding to the retracted position of the head structure 11 outside the conveyance area of the recording paper P by the conveyance belt 12. A portion 20 is disposed, and a waste liquid tank 21 is disposed for containing waste liquid of ink that does not contribute to image formation generated in the maintenance and recovery mechanism portion 20.

  Further, an operation unit 24 operated by an operator is provided on the front side of the apparatus main body 1. The lower protruding portion of the operation unit 24 is opened when the head structure 11 is attached to and detached from the recording unit 3 of the apparatus main body 1 integrally with the maintenance / recovery mechanism unit 20 or its cap member or the waste liquid tank 21. A cover 26 for opening and closing is provided.

  Further, as will be described later, the head structure 11 is detachably attached to the recording unit 3 together with the entire maintenance / recovery mechanism unit 20 or the cap member 28 of the maintenance / recovery mechanism unit 20. As shown in FIG. 3, the attachment / detachment position of the head structure 11 is a position where the head structure 11 and the maintenance / recovery mechanism unit 20 face each other, that is, the front surface side of the apparatus main body 1. By allowing the head structure 11 to be attached and detached on the front side of the apparatus main body 1, the head replacement operation is facilitated.

  Next, details of the head structure 11 will be described with reference to FIGS. 4 is a perspective explanatory view of the head structure, FIG. 5 is a perspective explanatory view of a head support portion of the head structure, and FIG. 6 is a perspective explanatory view of the head portion of the head structure.

  The head structure 11 is configured by detachably mounting the head portion 31 to the head support portion 32. As shown in FIG. 6, the head unit 31 is a nozzle in which a plurality of nozzles 33n for discharging droplets of each color, for example, each color of yellow (Y), magenta (M), cyan (C), and black (K) are arranged. Rows 33y, 33m, 33c, and 33k (hereinafter simply referred to as “nozzle row 33” when colors are not distinguished from each other) are also included.

  In this example, the nozzle rows 33y and 33m are formed on one nozzle plate 34a, and the nozzle rows 33c and 33k are formed on one nozzle plate 34b. What formed the nozzle row may be used. Further, here, one nozzle row 33 is configured to have a length corresponding to the width of the recording medium (recording paper P), but a configuration in which a plurality of liquid ejection heads are arranged in the nozzle row direction, or It can also be set as the structure which has arrange | positioned several head blocks (head array).

  An ink tube 35 connected to the ink cartridge 15 is connected to the head support portion 32, and an energy generating means for generating energy for discharging droplets in the head portion 31 from a control portion (not shown) is driven. A signal transmission means for transmitting a signal is connected.

  As shown in FIGS. 5 and 6, the head support portion 32 and the head portion 31 are connected to the flow path connector portions 41 and 42 for connecting and disconnecting the ink path, which is the liquid supply path, respectively, and the signal transmission path. In addition, electrical connector portions 43 and 44 to be cut are provided. Thereby, when the head part 31 is mounted on the head support part 32, the flow path connector parts 41 and 42 are connected and the ink path is connected, so that ink is supplied from the ink cartridge 15 to the head part 31. In addition, the electrical connector portions 43 and 44 are connected and the signal transmission path is connected, so that the head portion 31 can be driven by a control unit (not shown).

  Further, a handle 36 is provided on the upper surface of the head portion 31, and the head portion 31 can be easily detached from the head support portion 32 by lifting the handle 36. Further, the head portion 31 and the head support portion 32 form a wedge-shaped convex portion 46 and a concave portion 47 (which may be reversed) that are detachably fitted to each other.

Here, an example of the flow path connector portions 41 and 42 will be described with reference to FIG. FIG. 7 is an enlarged cross-sectional explanatory view of a main part of the flow path connector part.
The head support portion 32 includes a tube 51, a joint portion 52, and a ring-shaped seal member 53 such as an O-ring. On the other hand, the head portion 31 includes a check valve configured by a lid member 55 that also serves as a valve seat and a valve body 56 that opens and closes an opening 55a on the distal end side of a joint portion 54 that is detachably fitted to the joint portion 52. 57.

  As a result, as shown in FIG. 7A, when the ink is about to flow from the tube 51 side of the head support portion 32 in the direction indicated by the arrow, pressure is applied to the valve body 56 of the check valve 57 and the valve body. 56 moves in a direction away from the opening 55 a of the lid member 55 to create a gap (opens), so that the ink flows toward the joint portion 54 of the head portion 31 and is supplied to the head portion 31. On the other hand, since the valve body 56 of the check valve 57 is in close contact with the lid member 55 and closes against the ink flow from the head portion 31 toward the head support portion 32, ink does not flow. Therefore, as shown in FIG. 7B, even when the head portion 31 is detached from the head support portion 32, ink can be prevented from leaking from the head portion 32 side.

Another example of the flow path connector portions 41 and 42 will be described with reference to FIG. FIG. 8 is an enlarged cross-sectional explanatory view of a main part of the flow path connector part.
The head support portion 32 includes a tube 51, a joint portion 52, and a ring-shaped seal member 53 such as an O-ring, and a protrusion 58 is provided at the center of the joint portion 52. On the other hand, the head portion 31 is provided with a lid member 61 in which a hole (opening) 60 in which the protruding portion 58 can advance and retreat is formed on the distal end side of the joint portion 54, and the protruding portion 58 on the head support portion 32 side. A ball 62 as a valve body capable of closing the hole 60 is disposed between the inner surface of the lid member 61 and biased toward the protruding portion 58 by a spring 63. Further, a flow path 64 is formed in the lid member 61.

  As a result, as shown in FIG. 8A, when the head portion 31 is mounted on the head support portion 32, the protruding portion 58 of the head support portion 32 pushes the ball 62 against the urging force of the spring 63. Since the hole 60 is opened, the ink flows toward the joint portion 54 of the head portion 31 and the ink is supplied to the head portion 31. On the other hand, as shown in FIG. 8B, when the head portion 31 is removed from the head support portion 32, the ball 62 is pressed against the hole 60 by the urging force of the spring 63, thereby closing the hole 60. Therefore, even if the head unit 31 is detached from the head support unit 32, ink can be prevented from leaking from the head unit 31 side.

Next, the drive mechanism and positioning mechanism of the head structure 11 will be described with reference to FIGS. 9 is an explanatory perspective view of the main part of the recording unit, FIG. 10 is an explanatory plan view of the same, FIG. 11 is an explanatory diagram of the left side of FIG. 10, and FIG.
First, the head support portion 31 of the head structure 11, the side plate 70 constituting the belt structure that holds the conveyor belt 12 so as to be able to move around, and the frame 22 of the maintenance / recovery mechanism portion 20 are positioned through the rotary shaft 16. Yes. Thereby, each positional relationship of the head structure 11, the conveyance belt 12, and the maintenance recovery mechanism part 20 can be maintained with high precision.

  Here, the head structure 11 is provided with a head support portion 32 fixed to the tip of the rotating shaft 16, and the side plate 70 that is the structure of the conveyor belt 12 and the frame 22 of the maintenance / recovery mechanism portion 20 have the rotating shaft 16. It is provided for relative rotation. A head rotation drive mechanism 75 that rotates the head structure 11 is provided. The head rotation drive mechanism 75 includes a gear 76 that is fixed to the central portion of the rotary shaft 16 and a motor 77 that includes a gear 78 that meshes with the gear 76. By driving the motor 77, the rotary shaft 16 rotates. Thus, the head structure 11 rotates in the horizontal direction. The rotary shaft 16 may be configured such that the head structure 11 itself rotates as a fixed support shaft.

  In addition, an encoder 80 is provided as means for detecting the amount of rotation of the head structure 11. The encoder 80 includes an encoder wheel 81 fixed to the lower end of the rotary shaft 16 and an encoder sensor 82 that detects a slit of the encoder wheel 81.

  In addition, a height adjustment mechanism 83 that is a means for adjusting the vertical height position of the head structure 11 is provided. The height adjustment mechanism 83 includes a gear 84 that is integrally provided in the axial direction of the rotary shaft 16 and a motor 85 that includes a gear 86 that meshes with the gear 84, and the rotary shaft 16 is driven by driving the motor 85. When the head structure 11 is moved up and down, the relative height position of the head structure 11 changes, and the height can be adjusted (changed) during a maintenance and recovery operation or when the head structure 11 is rotated.

  Further, in order to maintain the gap between the head structure 11 and the conveyor belt 12, the rollers 90 are rotatably held on the front end portion and the rotation base side of the head structure 11, respectively, so that the head structure 11 is set to the image forming position. In this state, the rollers 90 are in contact with the side plates 70 and 71 constituting the belt structure that holds the transport belt 12. As a result, the distance X (see FIG. 12) between the head structure 11 and the conveyor belt 12 during image formation can be kept constant.

  Further, the side plate 71 constituting the belt structure is provided with a stopper 92 that restricts the rotation of the head structure 11. Accordingly, when the head structure 11 is rotated to the image forming position, the rotation of the encoder wheel 81 is stopped by engaging with the stopper 92 and stopping, so that the head structure 11 is stopped from the output of the encoder 80. Can be detected. On the other hand, the maintenance / recovery mechanism 20 is also provided with a stopper 93 that restricts the rotation of the head structure 11.

  Thereby, when the head structure 11 is rotated to the retracted position, the rotation of the encoder wheel 81 is stopped by engaging and stopping the stopper 93, so that the head structure 11 is stopped from the output of the encoder 80. Can be detected. Then, the rotation drive of the motor 77 that drives the rotary shaft 16 is stopped by detecting the stop of the head structure 11 by these encoders 80. In this way, the head structure 11 can be rotated to the image forming position during printing, to the standby position, or to the retracted position for the maintenance and recovery operation. Thus, by physically restricting the position of the head structure 11, the head structure 11 can be accurately positioned at the image forming position, and the image quality is improved. In addition, the head structure 11 can be accurately positioned on the maintenance / recovery mechanism 20, and the capping by the cap member 28 can be performed reliably.

  In addition, a sensor 95 for detecting that the head structure 11 is in the image forming position (printing position) and a sensor 96 for detecting that the head structure 11 is in the retracted position for the standby or maintenance / recovery operation are disposed. The drive of the motor 77 is controlled according to the detection signals of the sensors 95 and 96.

  The conveyor belt 12 is an endless belt that is wound around the driving roller 17 and the driven roller 18 as described above, and moves around when the driving roller 17 is rotationally driven by a motor (not shown). In addition, detection sensors 98 and 99 for detecting the recording medium (recording paper P) are arranged on the upstream side and the downstream side of the conveyor belt 12, respectively, and jam detection is performed by the output signals of these detection sensors 98 and 99. ing.

  The maintenance / recovery mechanism unit 20 includes a wiper 27 for wiping the surfaces of the nozzle plates 34a and 34b of the head unit 31 (hereinafter referred to as "nozzle surfaces") to form a clean and nozzle meniscus, and a nozzle for moisturizing. And a cap member 28 for sealing the surface. The wiper 27 rises at the time of wiping (wiping), and the head surface 11 rotates to wipe the nozzle surface by moving the nozzle surface relative to the wiper 27. Further, the cap member 28 rises during standby, and moisturizes by capping the nozzle surface so that the nozzle does not dry.

  Here, another example of the maintenance / recovery mechanism unit 20 will be described with reference to FIG. The maintenance / recovery mechanism unit 20 is configured such that the wiper 101 fixed to the holder 102 is moved and scanned in the longitudinal direction by the belt 104 to wipe the nozzle surfaces (surfaces of the nozzle plates 34a and 34b) of the head unit 31. It is.

Next, the rotation operation of the head structure in the image forming apparatus configured as described above will be described with reference to the flowchart shown in FIG. 14 and the plan explanatory view shown in FIG.
First, referring to FIG. 14, when a print command is given, the motor 77 of the head rotation drive mechanism 75 is rotationally driven to move the head structure 11 from the retracted position (standby position) to the image forming position (print position). Rotate. Then, it is checked whether or not the sensor 95 has detected the head structure 11 within a predetermined time to determine whether or not the head structure 11 has moved to the printing position.

  At this time, if the head structure 11 has moved to the printing position within a predetermined time (the state of FIG. 15A), the feeding operation of the recording paper P from the recording paper cassette 4 is started. Then, after the start of paper feeding, the inlet sensor 98 is turned on within a predetermined time, and thereafter, the outlet sensor 99 is turned on by a predetermined time. Further, the inlet sensor 98 is turned off by a predetermined time, and then until the predetermined time. When the exit sensor 99 is turned off, the printing operation has been normally performed, and thus this processing is terminated.

  On the other hand, if it is not possible to detect that the head structure 11 has moved to the printing position within a predetermined time, the head structure 11 cannot rotate normally due to a foreign object such as jammed paper, or the head structure 11 cannot be rotated normally. Since some trouble has occurred, for example, the drive motor 77 of the rotation drive mechanism 75 does not operate, “error” is displayed on the operation unit 24 and the operation is stopped as it is.

  Further, as described above, after the start of paper feeding, time-out occurs in any one of the sequences of the inlet sensor 98, the outlet sensor 99 being turned on, the inlet sensor 98 being turned off, and the outlet sensor 99 being turned off within a predetermined time (predetermined). When the predetermined state is not reached in time, an error has occurred. Therefore, a “paper jam” is displayed on the operation unit 24, and the motor 77 of the head rotation drive mechanism 75 is driven to rotate in the reverse direction. 11 is rotated in the direction from the print position side to the standby position. Then, it is checked whether the sensor 96 that detects that the head structure 11 is in the standby position has detected the head structure 11 after a predetermined time has elapsed, and the head structure 11 has returned to the standby position normally ( 15B), the operation is stopped when the head structure 11 returns to the standby position normally, and the operation is performed when the head structure 11 does not return to the standby position normally. After “error” is displayed on the unit 24, the operation is stopped.

Next, a configuration for discharging and removing ink in the head portion 31 when the head structure 11 is removed will be described with reference to a schematic explanatory diagram of FIG.
As described above, the ink supply tube 35 is connected to the head support portion 32 and ink is supplied from the ink cartridge 15. The ink supply path 36 is formed in the head support portion 32, and the inside of the head portion 31 is formed. The ink supply path 40 and the flow path connector portions 41 and 42 are connected so as to be connectable and disconnectable. Further, the flow path connector portion 42 of the head portion 31 is provided with the on-off valve 50 as described in FIG. 7 or FIG. 8 (not limited to this), and the head portion 31 is connected to the head support portion 32. The on-off valve 50 is closed when removed from the supply passage 40 to prevent liquid leakage from the supply path 40.

  Further, an air release path 37 that is branched from the supply path 36 and opened to the atmosphere is formed in the head support portion 32, and an air release valve 38 that opens and closes the atmosphere release port of the atmosphere release path 37 is provided. . The air release valve 38 may itself be an electromagnetic solenoid valve, or may be a valve mechanism as shown in FIG. In the atmosphere release valve 38 shown in FIG. 17, a spring 204 and a ball 205 as a valve body are housed in a holder 201 provided in the head support portion 32, and a cap member 205 is interposed via a packing member 202 as a valve seat member. The pressure member 206 is held by the cap member 205 so as to be movable, and the valve is opened by pushing the pressure member 206 with the plunger of the solenoid 211 on the apparatus main body side.

  With this configuration, when the head unit 31 is removed, the head unit 31 is driven to discharge droplets while the head structure atmosphere release valve 38 is opened and the supply path 36 of the head support unit 32 is opened to the atmosphere. By doing so, air can be introduced through the atmosphere release path 37 and the liquid in the head part 31 can be discharged and removed.

Next, a configuration in which the head portion 31 and the maintenance / recovery mechanism portion 20 of the head structure 11 are integrally attached and detached will be described with reference to FIGS. 18 and 19 as well. Note that FIG. 18 is a perspective view of a main part, and FIG. 18 is a front view.
Fitting portions 20 </ b> A and 20 </ b> B are provided on both sides in the longitudinal direction of the maintenance / recovery mechanism portion 20. On the other hand, on both sides of the head portion 31 of the head structure 11 in the longitudinal direction, fitting portions 31A and 31B that fit into the fitting portions 20A and 20B of the maintenance and recovery mechanism portion 20 are provided. Thereby, when the head structure 11 is rotated to the upper part of the maintenance / recovery mechanism 10, the fitting parts 31A and 31B of the head part 31 and the fitting parts 20A and 20B of the maintenance / recovery mechanism part 20 are respectively provided. Fit (engage). Further, the maintenance / recovery mechanism unit 20 is provided with a contact surface 20D with which the roller 90 of the head structure 11 abuts, and the height direction of the head portion 31 is the contact surface of the maintenance / recovery mechanism unit 20 with the roller 90 of the head portion 31. It is determined by contacting with 20D.

  The frame 22 of the maintenance / recovery mechanism unit 20 is detachably attached to the support unit 25, and the support unit 25 is positioned and supported by the rotating shaft 16. Thereby, the positional relationship between the head unit 31 and the maintenance / recovery mechanism unit 20 is maintained. Further, ink generated by wiping, idle discharge, or the like is stored in a waste liquid tank 21 provided below the maintenance / recovery mechanism unit 20.

  Since it comprised in this way, in the state which made the head structure 11 the standby position, it will be in the state with which the head part 31 and the maintenance recovery mechanism part 20 were connected integrally. Therefore, as described above, the atmosphere release valve 38 is opened, and the ink in the head unit 31 is discharged to the maintenance / recovery mechanism unit 20 and removed. Thereafter, by gripping the handle 36 of the head portion 31 and pulling it upward, the head portion 31 is separated from the head support portion 32 and the maintenance / recovery mechanism portion 20 is separated from the support portion 25. And the maintenance / recovery mechanism 20 can be taken out in an integrated state.

  In this way, the nozzle surface of the head portion 31 can be taken out while being sealed with the cap member 28 of the maintenance / recovery mechanism portion 20, so that the ink remaining inside leaks from the nozzles of the head portion 31. In addition, since the ink in the head unit 31 is discharged and removed in advance as described above, the ink is removed from the nozzles 33n of the head unit 31 when the head unit 31 and the maintenance / recovery mechanism unit 20 are separated after the removal. Leakage can also be prevented. When the head unit 31 is mounted, the reverse procedure is performed.

  Further, since the maintenance / recovery mechanism unit 20 and the waste liquid tank 21 can be integrally attached and detached, the waste liquid tank 21 can be taken out and replaced when the head is replaced, and a waste liquid discharge path between the maintenance / recovery mechanism unit 20 and the waste liquid tank 21 is provided. It is possible to prevent the waste liquid from dripping from the maintenance / recovery mechanism unit 20 without being divided or exposed.

Next, a first example of a configuration in which only the cap member 28 is integrally attached to and detached from the head portion 31 will be described with reference to a schematic explanatory diagram of FIG. In addition, the line direction in each figure is a direction along the nozzle row (in the image forming position, the direction is orthogonal to the recording medium conveyance direction).
In this example, the cap member 28 that seals the nozzle surface of the head portion 31 has a contact member 301 such as a rubber member that contacts the nozzle surface and covers the nozzle surface on the cap base member 302 made of a magnetic material such as iron. It is provided and configured. The cap base member 302 includes a magnet 303 made of a permanent magnet. A part of the head portion 31 includes a magnetic member 304 that holds the cap member 28. Further, below the cap member 28, an electromagnet 305 serving as a separating unit that separates the cap member 28 from the head portion 31 is held by a holding member 306. The magnetic force that attracts the cap base member 302 when the electromagnet 305 is turned on is set to be stronger than the magnetic force that the magnet 303 attracts the magnetic member 304 of the head portion 31.

  Thus, the electromagnet 305 is turned off in a state where the head portion 31 is opposed to the maintenance / recovery mechanism portion 20 and the head portion 31 is relatively lowered and brought into contact with the cap member 28 and is capped by the cap member 28. Accordingly, as shown in FIG. 20A, the head portion 31 and the cap member 28 are coupled by magnetic force, and the cap member 28 is also integrated with the head portion 31 when the head portion 31 is removed. Can be removed.

  Then, after mounting the head member 31 in a state of being coupled with the cap member 28, the electromagnet 305 is turned on, whereby the cap member 28 is attracted to the electromagnet 305 as shown in FIG. Since 31 is separated, the head unit 31 can be rotated to the image forming position.

  Thus, when only the cap member 28 is configured to be attached to and detached from the apparatus main body integrally with the head portion 31, when the head portion 31 is removed as described above, the ink in the head portion 31 is discharged and removed. Therefore, the sealed state of the head portion 31 can be maintained by the cap member 28, and ink leakage is prevented.

Next, a second example of a configuration in which only the cap member 28 is integrally attached to and detached from the head portion 31 will be described with reference to the schematic explanatory view of FIG.
Here, engagement concave portions 311 are provided on both end surfaces in the line direction of the head portion 31 (or both end surfaces in a direction orthogonal to the line direction), and the head portion 31 is provided on the flexible peripheral portion 28 a of the cap member 28. An engaging convex portion 312 that is detachably engaged with the engaging concave portion 311 is provided. An engaging portion 313 is provided on the lower surface of the cap member 28, and an engaging member 314 having an engaging portion 314 a that can be engaged with the engaging portion 313 by swinging in the direction of the arrow below the cap member 28. Are pivotally supported by a shaft 316 so as to be swingable. The swinging mechanism of the locking member 314 can be performed by an electromagnetic solenoid or the like.

  As a result, the head portion 31 is opposed to the maintenance / recovery mechanism portion 20 and the head portion 31 is relatively lowered, whereby the engaging convex portion 312 of the cap member 28 is moved to the head portion 31 as shown in FIG. The cap member 28 is connected to the head portion 31 and is capped, and the cap member 28 is also removed integrally with the head portion 31 when the head portion 31 is removed. Can do.

  Then, after being attached to the head portion 31 in a state of being coupled to the cap member 28, the locking member 314 is swung in the direction indicated by an arrow by an electromagnetic solenoid (not shown), so that the locking member 314 is Since the locking portion 314a engages with the engaging portion 313 of the cap member 28, the cap member 28 is separated from the head portion 31 by raising the head portion 31 relatively as shown in FIG. Therefore, the head unit 31 can be rotated to the image forming position.

  Thus, when only the cap member 28 is configured to be attached to and detached from the apparatus main body integrally with the head portion 31, when the head portion 31 is removed as described above, the ink in the head portion 31 is discharged and removed. Therefore, the sealed state of the head portion 31 can be maintained by the cap member 28, and ink leakage is prevented.

Next, another example of the head positioning mechanism will be described with reference to the schematic explanatory views of FIGS.
In the example shown in FIG. 22, a substantially L-shaped swing arm 151 having a pressing member 152 is disposed so as to be swingable by a shaft 153. As shown in FIG. When moving to the image forming position in the direction of the arrow, the swing arm 151 is pushed by the head structure 11 and swung as shown in FIG. The head structure 11 is positioned and held at the image forming position.

  In the example shown in FIG. 23, a substantially L-shaped swing arm 161 having an engaging portion 162 is disposed so as to be swingable about a shaft 163. As shown in FIG. Moves to the image forming position in the direction of the arrow, the swinging arm 161 is pushed by the head structure 11 and swings as shown in FIG. The head structure 11 is pressed from above by engaging with an engagement recess 165 provided on the upper surface of the head, and the head structure 11 is positioned and held at the image forming position.

Next, a second embodiment of the present invention will be described with reference to a schematic plan view of FIG.
In this embodiment, the two head structures 111A and 111B are disposed so as to be rotatable in the horizontal direction above the conveyor belt 12, and the two head structures 111A and 111B are stepped as shown in FIG. By arranging in a direction orthogonal to the recording medium conveyance direction, a line type head is configured as a whole. And with respect to the two head structures 111A and 111B, maintenance / recovery mechanisms 120A and 120B are arranged outside the area of the conveyor belt 12, respectively, and during standby or maintenance / recovery operation, as shown in FIG. The two head structures 111A and 111B are rotated to positions (retreat positions) facing the maintenance / recovery mechanisms 120A and 120B.

  Also in this configuration, by adopting the configuration of the above embodiment, the head structure 111A and the maintenance / recovery mechanism 120A, and the head structure 111B and the maintenance / recovery mechanism 120B can be integrally attached to and detached from the apparatus main body.

Next, a third embodiment of the present invention will be described with reference to a schematic perspective explanatory view of FIG.
This embodiment is applied to a serial type image forming apparatus, and the head portion 531 is provided with recording heads 533Y, 533M, 533C, and 533K including four liquid discharge heads. A carriage 532 serving as a head support member is slidably attached to the guide rod 530. The head portion 531 and the carriage 532 can be attached and detached by an engaging convex portion (similar to FIG. 6) provided on the head portion 531 and an engaging concave portion 47 provided on the carriage 532, as in the above-described embodiment. ing. Note that the head portion 531 and the carriage 532 are connected to a liquid supply path and an electric signal transmission path by a flow path connector section, an electrical connector section and the flow path connector section 41, and an electrical connector section 43 (not shown) as in the above-described embodiment. And cutting.

  In the above-described embodiment, the example in which the conveyance unit that conveys the recording medium is a conveyance belt has been described. However, a rotating body such as a roller may be used.

1 is a schematic configuration diagram illustrating an overall configuration of an image forming apparatus to which the present invention is applied. FIG. 2 is a right side view of FIG. 1 in a state where the head structure of the apparatus is in an image forming position. FIG. 2 is a right side view of FIG. 1 in a state where the head structure is in the retracted position. It is a perspective explanatory view of a head structure similarly. It is a perspective explanatory view of the head support part of the head structure. It is a principal part perspective view of the head part of the head structure. It is a section explanatory view showing an example of composition of a channel connector part of the head structure. It is a section explanatory view showing other examples of composition of a channel connector part of the head structure. It is a perspective explanatory drawing with which it uses for description of a head rotation drive mechanism and a positioning mechanism. It is a plane explanatory drawing similarly. It is front explanatory drawing of FIG. It is left side explanatory drawing of FIG. It is principal part perspective explanatory drawing which shows the other example of the maintenance recovery mechanism part of the apparatus. It is a flowchart with which it uses for description of the rotational drive control of the head structure. It is a plane explanatory view explaining a different state of a head structure similarly. FIG. 5 is a schematic explanatory diagram for explaining a liquid supply path and an air release mechanism for a head portion of a head structure. It is typical cross-sectional explanatory drawing which shows an example of the air | atmosphere release valve of FIG. FIG. 5 is a perspective explanatory view for explaining a connection configuration of a head structure and a maintenance / recovery mechanism. It is a front typical explanatory drawing similarly. It is typical explanatory drawing with which it uses for description of an example of the connection structure of the cap member of the head part of a head structure, and a maintenance recovery mechanism part. It is typical explanatory drawing with which it uses for description of the connection structure of the cap part of the head part of a head structure, and a maintenance recovery mechanism part. It is typical explanatory drawing with which it uses for description of the other example of the positioning structure of the head structure. FIG. 10 is a schematic explanatory diagram for explaining still another example of the positioning structure of the head structure. It is typical plane explanatory drawing with which it uses for description of 2nd Embodiment of this invention. It is a typical perspective explanatory view with which it uses for description of 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus main body 2 ... Image reading part 3 ... Recording part 4 ... Recording paper feed cassette P ... Paper (recording medium)
DESCRIPTION OF SYMBOLS 10 ... Printing part 11 ... Head structure 12 ... Conveying belt 14 ... Paper discharge stack part 20 ... Maintenance recovery mechanism part 21 ... Waste liquid tank 28 ... Cap member 31 ... Head part 32 ... Head support part 36 ... Liquid supply path 37 ... Air | atmosphere Open path 38 ... Air release valve 40 ... Liquid supply path 41, 42 ... Flow path connector section 43, 44 ... Electric connector section 50 ... Open / close valve

Claims (12)

A head portion composed of a line-type head for discharging droplets;
A head support portion, wherein the head portion is removably mounted,
And sustain times Fukute stage including a cap member for sealing the liquid ejection surface of the head portion,
With
The head unit is arranged to be movable in the horizontal direction between an image forming position for forming an image and a retracted position retracted from the image forming position.
Engaging means for engaging and integrating the head part and the maintenance / recovery means in a state where the head part is in the retracted position is connected to the liquid supply path in the head part and the liquid supply path in the head support part And severable,
The head portion is provided with an on-off valve that closes the inlet side of the liquid supply path when removed from the head support portion,
The head support member is provided with an atmosphere opening path branched from a liquid supply path connected to the liquid storage means for storing the liquid, and an atmosphere opening / closing valve for opening and closing the atmosphere opening path is provided.
An image forming apparatus, wherein the liquid in the head portion is discharged and removed in a state where the air release valve is opened before the head portion is removed from the head support member.   2. The image forming apparatus according to claim 1, wherein the head portion is detachably attached to the head support portion in a state where the head portion is covered with the cap member.   2. The image forming apparatus according to claim 1, wherein the head unit is detachably attached to the head support unit in a state where the head unit is connected to the maintenance and recovery unit.   4. The image forming apparatus according to claim 3, wherein a waste liquid tank that contains liquid waste liquid that does not contribute to image formation is connected to the maintenance and recovery means. 5. The image forming apparatus according to claim 1 , wherein the head unit is a head structure in which a head that discharges a plurality of color droplets is integrally formed. 6. The image forming apparatus according to claim 1 , wherein the head portion is provided with a handle. 7. The image forming apparatus according to claim 1 , wherein the head portion is detachable on the front side of the apparatus main body. 8. The image forming apparatus according to claim 1 , further comprising a height adjusting unit that adjusts a height position of the head unit. 9. The image forming apparatus according to claim 1 , further comprising means for determining an interval between the head unit and a transport unit that transports the recording medium. 10. The image forming apparatus according to claim 1 , further comprising means for positioning the head unit at a right angle to the transport direction of the recording medium. A head portion for discharging droplets;
A head support part to which the head part is detachably mounted;
Maintenance and recovery mechanism means including a cap member for sealing the liquid discharge surface of the head portion;
With
The liquid supply path in the head part and the liquid supply path in the head support part are provided to be connectable and disconnectable,
The head portion is provided with an on-off valve that closes the inlet side of the liquid supply path when removed from the head support portion,
The head support member is provided with an atmosphere opening path branched from a liquid supply path connected to the liquid storage means for storing the liquid, and an atmosphere opening / closing valve for opening and closing the atmosphere opening path is provided.
Before removing the head part from the head support member, the liquid in the head part is discharged and eliminated in a state where the air release valve is opened,
Removably attached to the head support portion with the head portion covered with the cap member,
An image forming apparatus comprising: an electromagnet that attaches the cap member to the head portion by a magnetic force and separates the cap member from the head portion.   The image forming apparatus according to claim 2, further comprising an engaging portion that detachably engages with the cap member and the head portion, and a lock that engages the cap member and separates the cap member from the head. An image forming apparatus comprising: means.

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