JP2011136468A - Ink jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recorder in a line head system in which the consumption of ink used for the recovery in the discharging state of a recording head can be suppressed, and further, deterioration in image quality can be suppressed. <P>SOLUTION: A control part 131 controls a roller movement mechanism 61 upon monochrome recording, arranges a part of a conveyance face 47 at a close position close to the nozzle face 22a of a recording head 22K, further arranges the other one part of the conveyance face 47 at a separation position separated from the close position to the nozzle faces 22a of the recording heads 22C, 22M, 22Y other than the recording head 22K to control a cap movement mechanism 91, and a cap member 83 is oppositely arranged to each nozzle face 22a of the other recording heads so as to cover each nozzle face 22a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs recording on a recording medium such as paper by ejecting ink from nozzles of a recording head.

  2. Description of the Related Art Conventionally, a line head type inkjet recording apparatus that includes a plurality of recording heads and can perform color recording is known. Each recording head of the ink jet recording apparatus has a nozzle surface on which a plurality of nozzles capable of ejecting ink are formed over the entire area in the width direction of the paper.

  In this ink jet recording apparatus, for example, recording heads of other colors are not used in monochrome recording only of black, but these unused recording heads have a nozzle surface opened even during the monochrome recording. As a result, the nozzle is in a situation where it is easy to dry. When the ink in the nozzles is dried and thickened, it affects the subsequent recording quality, so a large amount of ink is forcibly discharged from the nozzles to restore the discharged state in order to discharge the thickened ink from the nozzles. Is executed. In such a recovery operation, there is a problem in that a large amount of ink from an unused recording head is consumed.

  In Patent Document 1, each color recording head is composed of a plurality of divided heads, and only necessary ones of the divided heads remain in the printing position according to the size of the paper, and unnecessary ones are in the capping position. An ink jet recording apparatus in which the nozzle surface is capped by receding has been proposed.

  Patent Document 2 proposes an ink jet recording apparatus that includes a carriage type recording head and retracts a recording head that is not used for recording to a retracted position.

JP 7-314701 A JP-A-4-275155

  However, since the recording apparatuses described in Patent Document 1 and Patent Document 2 have a structure in which a recording head that requires high positional accuracy is moved, image quality may be degraded. Also, in the carriage type recording apparatus described in Patent Document 2, the structure for moving the recording head tends to be complicated.

  Accordingly, the present invention has been made in view of such a point, and an object of the present invention is a line that can suppress consumption of ink used for recovery of the ejection state of the recording head and can suppress deterioration in image quality. It is an object of the present invention to provide a head type ink jet recording apparatus.

  The present invention relates to a line head type ink jet recording apparatus. The recording apparatus includes a plurality of rollers, a conveyance belt that is spanned by the plurality of rollers and on which the recording medium is placed, and that can convey the recording medium in the conveyance direction by the rotation of the rollers. A plurality of recording heads having a nozzle surface facing the conveyance surface of the conveyance belt and arranged along the conveyance direction, and moving the conveyance surface by moving at least one of the plurality of rollers. Roller moving means that can move in a direction to move away from and contact the nozzle surface, a plurality of cap members that are arranged to face the nozzle surface of each recording head and cover each nozzle surface, respectively, and separated from the nozzle surface Cap moving means capable of moving each cap member in the direction of contact, and roller control means and control means for controlling the cap moving means are provided.

  The control means distinguishes the plurality of recording heads into recording heads that are used and recording heads that are not used. The control means arranges the transport surface at a close position close to the nozzle surface of the recording head to be used, and from the proximity position to the nozzle surface of the recording head not to be used. The roller moving unit is controlled so as to be arranged at a separated position, and the cap moving unit is controlled so that the nozzle surface of the unused recording head arranged at the separated position is covered with the cap member.

  In this configuration, the conveying surface is arranged at the separation position with respect to the nozzle surface of the recording head that is not used. Thereby, a space is formed between the nozzle surface and the transport surface of the recording head that is not used, and the cap member can be moved to this space to cover each nozzle surface. Therefore, even when there are recording heads that are not used at the time of image formation, it is possible to suppress drying of the nozzle surfaces of the recording heads that are not used. This can reduce the amount of ink consumed. In addition, in this configuration, since the rollers that support the conveyor belt are moved to move the conveyor surface of the conveyor belt relative to the nozzle surface, it is necessary to move the recording head that requires high positional accuracy. Absent. Thereby, it is possible to suppress the deterioration of the image quality caused by moving the recording head as in the conventional case.

  Specifically, for example, the recording head to be used is one of the plurality of recording heads. During monochromatic recording as in this case, the nozzle surfaces of other recording heads that are not used are covered with a cap member, and drying is suppressed.

  The plurality of rollers preferably include a tension roller capable of adjusting the tension of the conveyor belt.

  In this configuration, even when the tension of the conveyor belt changes as the moving roller moves, the tension can be adjusted by the tension roller.

  Further, the recording apparatus of the present invention is disposed adjacent to the transport belt on the downstream side in the transport direction with respect to the transport belt, and a receiving mechanism that receives the recording medium transported by the transport belt from the transport belt. A receiving mechanism moving means for moving the receiving mechanism, and the control means adjusts the receiving mechanism moving means to adjust the position of the receiving mechanism in accordance with the movement of the conveying surface of the conveying belt. It is preferable to control.

  In this configuration, since the position of the receiving mechanism is adjusted according to the movement of the conveying surface of the conveying belt, the recording medium can be smoothly transferred from the conveying belt to the receiving mechanism even if the combination of the recording head used and the recording head not used is changed. Can be handed over to.

  As described above, according to the present invention, it is possible to suppress the consumption of ink used for recovery of the ejection state of the recording head, and it is possible to suppress deterioration in image quality.

1 is a configuration diagram illustrating an outline of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 3 is a plan view illustrating a conveyance belt, a recording head, and a cap moving mechanism of the ink jet recording apparatus according to the first embodiment. It is a perspective view which shows the said cap drive mechanism. (A)-(c) is a perspective view which shows operation | movement of the said cap drive mechanism. It is a perspective view which shows the roller moving mechanism which moves the moving roller of the inkjet recording device of 1st Embodiment. In the ink jet recording apparatus of the first embodiment, it is a configuration diagram showing a state at the time of monochromatic recording. FIG. 2 is a configuration diagram illustrating a state of a head cap mode (when not in use) in the ink jet recording apparatus according to the first embodiment. (A) is a top view which shows the modification of the said cap moving mechanism, (b) is a side view of the said cap unit. (A) is a block diagram which shows the outline of the conveyance unit 30, the recording head 22, and the cap member 83 in the inkjet recording device concerning 2nd Embodiment of this invention, (b) is the monochrome recording of this inkjet recording device. It is a block diagram which shows the state of time.

  Hereinafter, an ink jet recording apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
An ink jet recording apparatus 1 shown in FIG. 1 is a line head type ink jet printer capable of forming an image on a sheet P as an example of a recording medium based on image information received from an external computer. The recording apparatus 1 includes a recording unit 20, a sheet storage unit 101, a sheet conveyance path 5, a conveyance unit 30, a discharge unit 103, an elevating mechanism 40, a cap unit 50 (FIG. 3) and a control for controlling them in the casing 2. Part 131 is provided. In the following description, a transport direction when the paper P is transported on the transport unit 30 is a direction D1, and a direction perpendicular to the direction (the width direction of the paper P) is a direction D2.

  As shown in FIGS. 1 and 2, the recording unit 20 includes four recording heads 22 (22K, 22C, 22M, and 22Y) corresponding to black, cyan, magenta, and yellow in order from the upstream side in the direction D1, And a support frame (not shown) for supporting them. Corresponding to the recording heads 22 for each color, four ink tanks (not shown) are provided. Each color ink is supplied to each recording head 22 from this ink tank. In the following description, the identification symbols “K”, “C”, “M”, and “Y” are omitted unless particularly limited.

  The four recording heads 22 are arranged side by side above a conveyance belt 31 of a conveyance unit 30 described later. Each recording head 22 has the nozzle surface 22a on its lower surface. A plurality of nozzles that eject ink are provided on the nozzle surface 22a. The nozzle surface 22a is formed in a rectangular shape that is long in the direction D2. Each recording head 22 forms an image by ejecting ink in a direction substantially perpendicular to the paper surface of the paper P from the nozzle surface 22a.

  As the ink ejection method of the recording head 22, for example, various methods such as a piezo method for ejecting ink using a piezo element and a thermal ink jet method in which bubbles are generated by a heating element and ink is ejected by applying pressure are applied. be able to.

  The paper storage unit 101 can store the paper P and is disposed below the recording unit 20. The paper storage unit 101 includes a paper feed cassette 3 that stores paper and a paper supply roller 4 for supplying paper to the paper transport path 5.

  The sheet conveyance path 5 includes a roller 102 disposed on the upstream side of the sheet conveyance path 5 and a registration roller 6 that temporarily stops the sheet to perform oblique correction and then sends the sheet to the conveyance unit 30. Yes.

  The transport unit 30 is disposed below the recording unit 20. The transport unit 30 supplies the paper P to the recording unit 20, and transports the paper P with an image formed on the surface thereof by the recording unit 20 to the discharge unit 103. The transport unit 30 includes a frame 36, a group of rollers (rollers 71 to 77), a transport belt 31, and a paper holding mechanism (not shown).

  The conveyor belt 31 is an endless belt and is stretched around rollers 71 to 77. The upper surface of the conveyance belt 31, that is, the upper surface of the portion located between the rollers 72 and 73 functions as a conveyance surface 47 that conveys the paper P and passes the recording unit 20. The transport surface 47 faces the nozzle surfaces 22 a of the plurality of recording heads 22.

  The rollers 71 to 77 of the roller group are rotatably supported by the frame 36 with a predetermined interval. In the present embodiment, the roller 71, the roller 72, the roller 74, the roller 76, and the roller 77 are fixed rollers that are rotatably fixed to the frame 36. Among these rollers, for example, the roller 71 is connected to a motor (not shown) and functions as a driving roller.

  The roller 72 (upstream roller) supports the conveyor belt 31 on the upstream side of the recording head 22K (first recording head) disposed at the uppermost stream in the direction D1. The roller 77 (downstream roller) supports the conveyance belt 31 between the recording head 22K and the recording head 22C (second recording head).

  The roller 73 functions as a moving roller that can be moved in the vertical direction by a roller moving mechanism 61 (FIG. 5) as roller moving means, and the roller 75 adjusts the tension of the transport belt 31 that changes as the roller 73 moves. Functions as a possible tension roller.

  As shown in FIG. 5, the roller moving mechanism 61 includes a bearing 62 that supports both ends of the shaft 73a of the roller 73, a cam 63 that contacts the lower surface of the bearing 62, and a shaft 64 that supports the cam 63. And a motor (not shown) connected to the shaft 64. The bearing 62 is supported by the casing 2, for example. When the motor is driven, the cam 63 rotates about the shaft 64 and the roller 73 moves in the vertical direction. The roller moving mechanism 61 is controlled by the control unit 131.

  The sheet holding mechanism is disposed at a position facing the recording unit 20 along the conveyance surface 47 below the conveyance surface 47 of the conveyance belt 31. The sheet holding mechanism has a large number of air suction holes (not shown) on the upper surface of the case, and external air can be sucked into the case through these holes. The conveyor belt 31 is also provided with a number of air suction holes (not shown). Accordingly, when the air is sucked by the paper holding mechanism, the paper P is adsorbed on the upper surface of the transport belt 31, so that the paper P can be transported stably.

  The elevating mechanism 40 has a pair of eccentric cams 41 and 42 disposed below the transport unit 30. The eccentric cams 41 and 42 have shaft portions 41b and 42b supported by a support member (not shown), respectively, and are rotated by drive motors (not shown) around the shaft portions 41b and 42b. The eccentric cams 41 and 42 have a plurality of bearings 41 a and 42 a, respectively, and support the transport unit 30 in a state where these bearings 41 a and 42 a are in contact with the frame 36 of the transport unit 30. The transport unit 30 moves in the vertical direction as the eccentric cams 41 and 42 rotate about the shaft portions 41b and 42b.

  FIG. 1 shows a state in which the eccentric cams 41 and 42 are erected substantially vertically and the transport unit 30 is lifted. When the eccentric cams 41 and 42 rotate inward from each other in this state, the transport unit 30 is lowered as shown in FIG.

  In the image forming mode in which an image is formed on the paper P by the recording unit 20, the transport unit 30 is lifted by the lifting mechanism 40 and disposed at a position close to the nozzle surface 22a of the recording head 22 as shown in FIG. Is done. This position is adjusted so that the gap between the nozzle surface 22a and the paper P is suitable for printing.

  On the other hand, in the head cap mode, which will be described later, the transport unit 30 is lowered by the elevating mechanism 40 and moved to a position separated from the recording head 22 as shown in FIG. The height of the transport unit 30 can be adjusted as appropriate by adjusting the rotation angle of the eccentric cams 41 and 42.

  As shown in FIGS. 2 and 3, the cap unit 50 includes four cap members 83 (83K, 83C, 83M, and 83Y) that cover the nozzle surfaces 22a of the recording heads 22, and cap movement that moves the cap members 83. It has four cap moving mechanisms 91 as means.

  Each cap member 83 has a shape capable of sealing the nozzle surface 22 a of the corresponding recording head 22. Each cap member 83 has a rectangular upper surface that is long in the direction D2, and an elastic member 83a made of synthetic rubber or the like is disposed along the periphery of the upper surface (FIG. 3). Since the elastic member 83a is interposed between the nozzle surface 22a and the cap member 83 in this manner, each cap member 83 is disposed so as to face the nozzle surface 22a of the recording head 22 and covers the nozzle surface 22a. Sealability can be improved.

  Each cap drive mechanism 91 includes a support member 94 that supports each cap member 83, a lateral movement mechanism that moves the cap member 83 in the direction D <b> 1 together with the support member 94, and a cap member together with the support member 94. And a vertical movement mechanism for moving 83 in the vertical direction. Each cap moving mechanism 91 can move each cap member 83 independently of the other cap members 83.

  Each support member 94 is disposed below the corresponding cap member 83 and extends upward from both ends in the direction D2 of the plate-like portion 94a and a rectangular plate-like portion 94a extending along the longitudinal direction thereof. And a pair of upright portions 94b, 94b. Each cap member 83 is placed on the plate-like portion 94a.

  As shown in FIG. 3, each vertical movement mechanism includes a wire 98 attached to each of the pair of standing portions 94 b and 94 b, a motor 95 that winds or feeds each wire 98, and a rotating shaft 95 a of the motor 95. A winding portion 96 that is attached and winds the wire 98 and a pulley 97 that determines a hanging position of the support member 94 are included. In FIG. 3, only one of the two wires 98 is shown, and the other wire 98 is not shown. Each support member 94 is supported in a state of being suspended by two wires 98.

  As shown in FIGS. 2 and 3, each lateral movement mechanism includes pinions 93 and 93 attached to the outer surfaces of the pair of standing portions 94 b, and racks 92 and 92 that mesh with the pinions 93, respectively. including. Each rack 92 is a member cut into a flat bar. Each rack 92 is fixed to front and rear side plates 81, 81 supported by the casing 2. Each pinion 93 is a small-diameter circular gear that meshes with the teeth of the rack 92. Each pinion 93 can move in the horizontal direction while rotating with the drive of a motor (not shown) and meshing with the rack 92. When the pinion 93 moves in the horizontal direction, the vertical movement mechanism such as the motor 95 moves in the same direction as the pinion 93 along a guide rail (not shown).

  In the image forming mode shown in FIG. 1, each cap member 83 is retracted to the corresponding horizontal position of the recording head 22, that is, the retracted position opposite to the direction D <b> 1 so as not to interfere with image formation. (Position shown in FIG. 3). Further, in the cap mode shown in FIG. 7, each cap member 83 is disposed at a position that covers the nozzle surface 22a of the corresponding recording head 22 from below (position shown in FIG. 4C described later).

  The discharge unit 103 includes a receiving mechanism 7, a discharge roller 8, a discharge port 9, and a discharge tray 10. The receiving mechanism 7 is disposed adjacent to the conveyance belt 31 on the downstream side in the direction D1 from the conveyance belt 31. The receiving mechanism 7 receives the paper P transported by the transport belt 31 from the transport belt 31 and guides it to the carry-out roller 8. The paper P guided to the carry-out roller 8 is sent to the discharge port 9 and is discharged from the side surface of the casing 2 to a discharge tray 10 that extends outward.

  The receiving mechanism 7 is movable in the vertical direction by a receiving mechanism moving means including a cam 7a disposed on the lower surface of the receiving mechanism 7 and a motor (not shown) that rotates the cam 7a. This receiving mechanism moving means is controlled by the control unit 131.

  The control unit 131 includes a central processing unit (CPU), a memory (ROM) that stores data such as a program, and a memory (RAM) that temporarily stores data when the program is executed. The controller 131 controls operations of the roller moving mechanism 61, the lifting mechanism 40, the cap moving mechanism 91, the receiving mechanism moving means, and the like.

  Hereinafter, operations of the image forming mode and the cap mode of the recording apparatus 1 will be described.

  First, the operation during color recording in the image forming mode of the recording apparatus 1 will be described. During this color recording, four recording heads 22 are used.

  At the time of color recording, when a command for forming a color image is issued from a computer connected to the outside, the control unit 131 controls the roller moving mechanism 61 so that the conveyance surface 47 of the conveyance belt 31 is moved to each nozzle. It arrange | positions in the proximity position close | similar to the surface 22a (arrangement | positioning of FIG. 1). At the time of this color recording, each cap member 83 is retracted to a retracted position adjacent to the corresponding recording head 22.

  Specifically, the control unit 131 drives the motor of the roller moving mechanism 61 to rotate the cam 63 so that the cam 63 stands up in the vertical direction. As a result, the roller 73 is lifted upward. The lifted position is adjusted so that the conveyance surface 47 of the conveyance belt 31 is disposed at a position close to each nozzle surface 22a.

  Next, the paper P is sent out from the paper storage unit 101 to the transport unit 30. Then, when the paper P is being transported by the transport belt 31 of the transport unit 30, ink is ejected from the recording head 22 and an image is formed on the paper P. Then, the paper P on which the image is formed is conveyed by the roller 8 of the discharge unit 103 and is discharged from the discharge port 9 to the discharge tray 10.

  When the image forming command is not issued for a predetermined time after the image forming operation is completed, or when a power switch (not shown) is turned off, the recording apparatus 1 forms an image, for example. Transition from the possible state to the head cap mode described later.

  Next, the operation at the time of monochrome recording in the image forming mode will be described. In the present embodiment, a case where monochrome recording is performed using only the black recording head 22K will be described as an example.

  At the time of monochrome recording using the recording head 22K, when a command for forming a monochrome image is issued from an externally connected computer, the control unit 131 distinguishes between the recording head 22 to be used and the recording head 22 not to be used. To do. In this embodiment, since monochrome monochrome recording is performed, the control unit 131 selects the black recording head 22K as the recording head 22 to be used, and cyan, magenta, and yellow recording heads 22C and 22M as the unused recording heads 22. , 22Y is selected. Such distinction of the recording heads, that is, the combination of the recording heads to be used and the recording heads not to be used may be stored in the memory in advance.

  Next, the control unit 131 controls the roller moving mechanism 61 to place a part of the transport surface 47 at a position close to the nozzle surface 22a of the recording head 22K and to record another part of the transport surface 47. The nozzle surfaces 22a of the recording heads 22C, 22M, and 22Y other than the head 22K are arranged at spaced positions that are separated from the proximity positions.

  Specifically, the control unit 131 drives the motor of the roller moving mechanism 61 to rotate the cam 63 to make the cam 63 bend in the horizontal direction. As a result, as the roller 73 moves downward, the downstream portion of the conveyor belt 31 (the portion between the roller 77 and the roller 73) is lowered. The lowered position is adjusted so that a space is formed between the transport surface 47 and the nozzle surfaces 22a of the recording heads 22C, 22M, and 22Y so that the cap members 83 can be disposed.

  On the other hand, since the positions of the rollers 72 and 77 are fixed, the conveyance surface 47 of the conveyance belt 31 supported between the rollers 72 and 77 is close to the nozzle surface 22a of the recording head 22K. Placed in position.

  Next, the control unit 131 controls the cap moving mechanism 91 to move the cap members 83C, 83M, and 83Y corresponding to the three recording heads 22C, 22M, and 22Y in the vertical direction and the horizontal direction, so that the recording head 22C, The nozzle surfaces 22a and 22Y are arranged opposite to each other to cover the nozzle surfaces (FIG. 6). At this time, the cap member 83K corresponding to the recording head 22K remains in the retracted position at the retracted position adjacent to the recording head 22K.

  The operation of the cap members 83C, 83M, 83Y will be described in detail as follows. Each cap member 83 (83C, 83M, 83Y) moves downward from the retracted position shown in FIG. 3 toward the position shown in FIG. 4A by the vertical movement mechanism. That is, when the motor 95 is driven and the wire 98 is fed out, the cap member 83 is moved downward together with the support member 94. When the pinion 93 meshes with the rack 92, the driving of the motor 95 is stopped and the cap member 83 is disposed at the position shown in FIG.

  Next, when the motor (not shown) for rotating the pinion 93 is driven, the pinion 93 rotates and moves in the direction D <b> 1 while meshing with the rack 92. As a result, the cap member 83 moves in the direction D1 together with the support member 94. At this time, as shown in FIG. 4B, the longitudinal movement mechanism such as the motor 95 also moves in the direction D1 along the guide rail (not shown). When the cap member 83 reaches below the recording head 22, the motor (not shown) is stopped, and the cap member 83 is disposed opposite to the nozzle surface 22a (FIG. 4B).

  Next, when the motor 95 is driven and the wire 98 is wound up, the cap member 83 is moved upward together with the support member 94. When the upper surface of the cap member 83 comes into contact with the nozzle surface 22a, the driving of the motor 95 is stopped and the cap member 83 is disposed at the position shown in FIG. Thereby, the capping operation of each nozzle surface 22a by the cap members 83C, 83M, 83Y is completed.

  Next, the paper P is sent out from the paper storage unit 101 to the transport unit 30. Then, when the paper P is being transported by the transport belt 31 of the transport unit 30, ink is ejected from the recording head 22 </ b> K, and a monochromatic image is formed on the paper P. Then, the paper P on which the image is formed is conveyed by the roller 8 of the discharge unit 103 and is discharged from the discharge port 9 to the discharge tray 10.

  After the monochrome image forming operation is completed, if an image forming command is not issued for a predetermined time or a power switch (not shown) is turned off, the recording apparatus 1 is, for example, The state shifts from a state in which an image can be formed to a head cap mode to be described later.

  Next, the operation in the head cap mode will be described.

  First, from the state of the image forming mode shown in FIG. 1, the eccentric cams 41 and 42 are rotated in the direction in which the tips of the eccentric cams 41 and 42 are lowered, and the transport unit 30 is lowered. The rotation of the eccentric cams 41 and 42 is stopped when the transport unit 30 moves downward to the extent that the cap member 83 can move between the transport belt 31 and the nozzle surface 22a of the recording head 22.

  Next, a motor (not shown) in the lateral movement mechanism of the cap movement mechanism 91 of the cap unit 50 is driven to rotate each pinion 93 and slide each cap member 83 in the direction D1. When each cap member 83 reaches a predetermined position below the corresponding recording head 22, the driving of the motor is stopped.

  Next, the motor 95 of each vertical movement mechanism is driven to wind the wire 98, whereby each cap member 83 is moved upward together with the support member 94. When the upper surface of each cap member 83 comes into contact with the corresponding nozzle surface 22a of the recording head 22, the driving of the motor 95 is stopped. Thereby, the nozzle surface 22a of each recording head 22 is sealed by the cap member 83 (FIG. 7).

  The cap moving mechanism 91 may have the following configuration. FIG. 8A is a plan view showing a modified example of the cap moving mechanism 91, and FIG. 8B is a side view thereof.

  Each cap moving mechanism 91 in this modification can move each cap member 83 independently of the other cap members 83. As shown in FIGS. 8A and 8B, each cap moving mechanism 91 includes a frame body 181 in which an L-shaped long hole 195 is formed, a rack 192 cut into a flat bar, and this rack. It includes a pinion 193 that is a small-diameter circular gear that meshes with the teeth of 192, a shaft member 194 that is inserted through a hole provided in the center of the pinion 193, a wire that is not shown, a motor that is not shown.

  The frame body 181 has a bottom plate 181a at a position along one side plate (the lower side plate in FIG. 8A). Four racks 192 are arranged along the direction D1 on the upper surface of the bottom plate 181a. Each pinion 193 meshes with each rack 192.

  Four long holes 195 are formed at positions facing each other on the side plate on one side and the side plate on the other side in the direction D2 of the frame 181. Both ends of the shaft member 194 are inserted into these long holes 195. The shaft member 194 is rotatably supported by a bearing (not shown) provided on the bottom surface of each cap member 83. In other words, the shaft member 194 supports each cap member 83 via the bearing.

  The shaft member 194 is configured to be rotatable by a motor (not shown). When this motor is driven, the shaft member 194 rotates and the pinion 193 rotates while meshing with the rack 192. Thereby, each cap member 83 supported by the shaft member 194 slides in the horizontal direction along the long hole 195.

  Each shaft member 194 has unillustrated wires fixed to both ends, and the other end of each wire is connected to an unillustrated motor. That is, each shaft member 194 is suspended by a pair of wires at both ends. When the motor is driven, the wire is wound or sent out, so that each cap member 83 supported by the shaft member 194 slides up and down along the long hole 195.

  Further, the frame body 181 is fixed to the upper part of the frame 36 of the transport unit 30. Therefore, as the transport unit 30 moves in the vertical direction by the lifting mechanism 40, the frame 181 and other members such as the rack 192 supported by the frame 181 also move in the vertical direction.

  Next, the operation at the time of monochrome printing of the cap moving mechanism 91 of this modification will be described.

  At the time of monochromatic printing, the control unit 131 controls the roller moving mechanism 61 to place a part of the transport surface 47 at a position close to the nozzle surface 22a of the recording head 22K and The nozzles 22a, 22M, and 22Y other than the recording head 22K are arranged at spaced apart positions with respect to the nozzle surfaces 22a of the recording heads 22C, 22M, and 22Y.

  Next, the control unit 131 controls the cap moving mechanism 91 to move the cap members 83C, 83M, and 83Y corresponding to the three recording heads 22C, 22M, and 22Y along the L-shaped long hole 195 in the vertical direction and the horizontal direction. To the nozzle surfaces 22a of the recording heads 22C, 22M, and 22Y. At this time, the upper surfaces of the cap members 83C, 83M, and 83Y are separated from the nozzle surface 22a.

  Next, the transport unit 30 is moved upward by the elevating mechanism 40, and the frame body 181 fixed to the transport unit 30 is moved upward. The shaft member 194 that supports the cap members 83C, 83M, and 83Y is near the end on the direction D1 side of the portion (lateral hole portion) extending in the horizontal direction of the L-shaped long hole 195, that is, in FIG. It is located near the left end of the long hole 195. On the other hand, the shaft member 194 that supports the cap member 83K is positioned in a portion (vertical hole portion) extending in the vertical direction of the L-shaped long hole 195. Therefore, when the frame body 181 is moved upward by the lifting mechanism 40, the cap members 83C, 83M, and 83Y are also moved upward. Then, the elevating mechanism 40 is stopped when the upper surfaces of the cap members 83C, 83M, 83Y come into contact with the nozzle surface 22a. Thereby, the capping operation of each nozzle surface 22a by the cap members 83C, 83M, 83Y is completed. Thereafter, the paper P is conveyed in the above-described flow, and image formation is performed.

  As described above, in the first embodiment, at the time of color recording, the plurality of recording heads 22 are used for recording on a recording medium, and the conveyance surface 47 is disposed at the close position close to each nozzle surface 22a. On the other hand, at the time of monochromatic recording, a part of the conveyance surface 47 is arranged at the close position close to the nozzle surface 22a of the recording head 22K, and another part of the conveyance surface 47 is a recording head other than the recording head 22K. The nozzle surfaces 22a of 22C, 22M, and 22Y are arranged at the separated positions that are separated from the proximity positions. As a result, a space is formed between the nozzle surface 22a and the transport surface 47 of the other recording heads 22C, 22M, and 22Y, and the cap member 83 is moved to this space to face each nozzle surface 22a. It can arrange | position and can cover each nozzle surface 22a. Accordingly, during the monochrome recording, it is possible to suppress the drying of the nozzle surfaces 22a of the other unused recording heads 22C, 22M, and 22Y, and thus the ejection state of these recording heads 22C, 22M, and 22Y is recovered. The frequency of executing the operation can be reduced to suppress the ink consumption. In addition, in this configuration, the roller that supports the conveyance belt 31 is moved to move the conveyance surface of the conveyance belt with respect to the nozzle surface. Therefore, it is necessary to move the recording head that requires high positional accuracy. There is no. Thereby, it is possible to suppress the deterioration of the image quality caused by moving the recording head as in the conventional case.

  In the first embodiment, since the position of the receiving mechanism 7 is adjusted in accordance with the movement of the conveyance surface 47 of the conveyance belt 31, the recording medium after recording is conveyed to the conveyance belt in both monochrome recording and color recording. 31 can be smoothly transferred to the receiving mechanism 7.

Second Embodiment
FIG. 9A is a configuration diagram showing the transport unit 30, the recording head 22, and the cap member 83 of the inkjet recording apparatus 1 according to the second embodiment of the present invention, and FIG. 9B is a diagram for monochrome recording. It is a block diagram which shows a state.

  As shown in FIG. 9A, the recording apparatus 1 of the second embodiment further includes a roller 78 and a roller 79, and the rollers 72, 73, 77, 78, and 79 are vertically moved by a roller moving mechanism. This is different from the first embodiment in that the movable roller is movable. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment here, and the detailed description is abbreviate | omitted.

  The moving rollers 72, 73, 77, 78, 79 can be independently moved by a roller moving mechanism as shown in FIG. Therefore, monochromatic recording using only the recording head 22 of any one of black, cyan, magenta, and yellow is possible. Color recording using only two or three of these four recording heads 22 is also possible.

  For example, at the time of monochrome recording using only the black recording head 22K, the control unit 131 controls the corresponding roller moving mechanism 61 so that the rollers 73, 78, and 79 are moved from the state at the time of color recording shown in FIG. While moving downward, the rollers 72 and 77 are not moved. Thereby, the conveyance surface 47 of the conveyance belt 31 is maintained at a close position with respect to the nozzle surface 22a of the recording head 22K, and is disposed at a separate position with respect to the nozzle surfaces 22a of the other recording heads 22C, 22M, and 22Y. Is done. The nozzle surfaces 22a of the recording heads 22C, 22M, and 22Y are sealed with corresponding cap members 83. In this state, black monochrome recording is executed.

  Further, at the time of monochrome recording using only the cyan recording head 22C, as shown in FIG. 9B, the control unit 131 controls the corresponding roller moving mechanism 61 to perform the color recording shown in FIG. 9A. While the rollers 72, 79, 73 are moved downward from the state, the rollers 77, 78 are not moved. As a result, the conveyance surface 47 of the conveyance belt 31 is maintained at a close position with respect to the nozzle surface 22a of the recording head 22C, and is disposed at a separate position with respect to the nozzle surfaces 22a of the other recording heads 22K, 22M, and 22Y. Is done. The nozzle surfaces 22a of the recording heads 22K, 22M, and 22Y are sealed with corresponding cap members 83. In this state, cyan monochrome recording is executed.

  Similarly, during single color recording using only the magenta recording head 22M, the rollers 72, 73, 77 are moved downward from the state of color recording shown in FIG. 9A, and the rollers 78, 79 are not moved. During monochrome recording using only the yellow recording head 22Y, the rollers 72, 77, 78 are moved downward from the state of color recording shown in FIG. 9A, and the rollers 73, 79 are not moved. Monochromatic recording is performed at the same time.

  Further, color recording using only two or three of the four recording heads 22 is performed as follows. For example, during color recording using the black recording head 22K and the cyan recording head 22C, the rollers 73 and 79 are moved downward, and the rollers 72, 77, and 78 are not moved, and color recording is executed. When performing color recording using the cyan recording head 22C, the magenta recording head 22M, and the yellow recording head Y, the roller 72 is moved downward, and the rollers 73, 77, 78, and 79 are not moved, and color recording is performed. Is done.

  As described above, in the second embodiment, in addition to obtaining the same operational effects as those in the first embodiment, it is possible to perform monochrome recording for each color.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention. For example, in the above embodiment, a four-color full-color ink jet recording apparatus has been described as an example. However, the present invention can also be applied to an ink jet recording apparatus using five or more colors of ink.

DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus 2 Casing 5 Paper conveyance path 7 Receipt mechanism 7a Cam 20 Recording part 22 Recording head 22a Nozzle surface 30 Conveyance unit 31 Conveyance belt 35 Paper holding mechanism 40 Lifting mechanism 61 Roller moving mechanism 71-79 Roller 83 Cap member 91 Cap Moving mechanism 131 Control unit

Claims (4)

A line head type inkjet recording apparatus,
Multiple rollers,
A conveyance belt that is stretched over the plurality of rollers and has a conveyance surface on which a recording medium is placed, and is capable of conveying the recording medium in a conveyance direction by rotation of the roller;
A plurality of recording heads having a nozzle surface facing the transport surface of the transport belt and arranged along the transport direction;
Roller moving means capable of moving the conveying surface in a direction to be in contact with and away from the nozzle surface by moving at least one of the plurality of rollers;
A plurality of cap members arranged to face the nozzle surfaces of the recording heads and respectively covering the nozzle surfaces;
A cap moving means capable of moving each cap member in a direction of separating from and contacting the nozzle surface;
Control means for controlling the roller moving means and the cap moving means,
The control means includes
Distinguishing the plurality of recording heads into recording heads that are used and recording heads that are not used;
The transport surface is disposed at a close position close to the nozzle surface of the recording head to be used, and is disposed at a separate position away from the proximity position with respect to the nozzle surface of the recording head not to be used. Controlling the roller moving means to
An ink jet recording apparatus that controls the cap moving means to cover the nozzle surface of the recording head not used disposed at the separated position with the cap member.   The inkjet recording apparatus according to claim 1, wherein the recording head to be used is one of the plurality of recording heads.   The inkjet recording apparatus according to claim 1, wherein the plurality of rollers include a tension roller capable of adjusting a tension of the conveyance belt. A receiving mechanism that is arranged adjacent to the conveyor belt on the downstream side in the transport direction with respect to the transport belt and receives the recording medium transported by the transport belt from the transport belt;
Receiving mechanism moving means for moving the receiving mechanism;
The inkjet recording apparatus according to claim 1, wherein the control unit controls the receiving mechanism moving unit so as to adjust a position of the receiving mechanism in accordance with the movement of the conveying surface of the conveying belt. .

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