JP2019089293A - Ink jet printer - Google Patents

Abstract

To make it possible to eliminate slack in a recording medium when a rolled medium is rotated in a normal direction and in a reverse direction, and hence improve image quality.SOLUTION: An ink jet printer has: a carrying member disposed so as to freely rotate; a carrying drive unit that carries a recording medium P by rotating the carrying member; a sheet feed device 51 with a rolled medium; a platen 25; and a paper feed processing unit that drives the carrying drive unit in a normal direction, draws the recording medium P from the rolled medium, and supplies it to the platen 25; a print processing unit that drives a recording head Hdi; and a re-winding unit that when image formation on the recording medium P is finished, drives the carrying drive unit in a reverse direction to carry the recording medium P toward the sheet feed device 51. Tension is applied to the recording medium P on the sheet feed device 51 side by the carrying member. Slack occurring in the recording medium P can thus be eliminated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inkjet printer.

  Conventionally, in an image forming apparatus such as a printer, a copier, a facsimile, and a multifunction machine, for example, an inkjet printer, a carriage is moved along a rail, and ink droplets are ejected from a recording head mounted on the carriage. By being attached to the image, an image such as a character, an image, etc. is formed, and printing is performed.

  In the ink jet printer, a roll sheet as a roll-like medium is formed by winding a recording medium around a paper tube, and the roll sheet is set in a sheet feeding device as a sheet side roll sheet. . Then, at the time of printing, the recording medium is fed out from the paper feed side roll paper by rotating the paper feed side roll paper as the conveyance motor is driven, and disposed in the housing of the ink jet printer. The sheet is conveyed toward the platen, and after an image is formed by the recording head on the platen, the sheet is sent to a winding device and wound around a paper tube to be a winding side roll sheet.

  By the way, when the paper feed side roll paper is set in the paper feeding device, the tension applied to the recording medium is changed by switching the gears in the gear mechanism which is disposed in the paper feeding device and connected to the torque limiter. There is provided an ink jet printer adapted to be used (see, for example, Patent Document 1).

JP 2007-290866 A

  However, in the above-mentioned conventional ink jet printer, when the paper feed side roll paper is rotated in the forward direction and the reverse direction, it is not possible to eliminate the slack which occurs on the recording medium, and the image quality is deteriorated.

  The present invention solves the problems of the above-mentioned conventional ink jet printer, and can eliminate the slack generated in the recording medium when the roll-shaped medium is rotated in the forward direction and the reverse direction, thereby improving the image quality. It is an object of the present invention to provide an ink jet printer capable of

  Therefore, in the ink jet printer according to the present invention, a transport member rotatably disposed in the transport path, a drive unit for transporting the recording medium by rotating the transport member, and a roll shape on the paper feed side A sheet feeding device provided with a medium, a platen, and the drive unit for conveying are driven in the forward direction to rotate the conveying member, thereby feeding the recording medium from the roll-shaped medium on the sheet feeding side and supplying the sheet to the platen A paper processing unit, a print processing unit that drives a recording head arranged to face the platen, and forms an image on a recording medium, and the transfer unit when the image formation on the recording medium is completed. And a rewind processing unit that drives the drive unit in the reverse direction and transports the recording medium to the sheet feeding device.

  Then, a tension is applied to the recording medium on the side of the sheet feeding device from the conveyance member in the conveyance path.

  According to the present invention, in the ink jet printer, the transport member rotatably disposed in the transport path, the transport driving unit for transporting the recording medium by rotating the transport member, and the roll shape on the paper feed side A sheet feeding device provided with a medium, a platen, and the drive unit for conveying are driven in the forward direction to rotate the conveying member, thereby feeding the recording medium from the roll-shaped medium on the sheet feeding side and supplying the sheet to the platen A paper processing unit, a print processing unit that drives a recording head arranged to face the platen, and forms an image on a recording medium, and the transfer unit when the image formation on the recording medium is completed. And a rewind processing unit that drives the drive unit in the reverse direction and transports the recording medium to the sheet feeding device.

  Then, a tension is applied to the recording medium on the side of the sheet feeding device from the conveyance member in the conveyance path.

  In this case, when the formation of the image on the recording medium is completed, the rewinding processing unit drives the driving unit for conveyance in the reverse direction, and the recording medium is conveyed to the paper feeding device side, and supplied from the conveyance member in the conveyance path. Since tension is applied to the recording medium on the paper device side, it is possible to eliminate slack in the recording medium when the roll-like medium is rotated in the forward and reverse directions.

  Therefore, since the recording medium can be stably conveyed, the image quality can be improved.

It is a figure for demonstrating the operation | movement of the inkjet printer in the 1st Embodiment of this invention. FIG. 1 is a perspective view of an ink jet printer according to a first embodiment of the present invention. FIG. 1 is a perspective view of an essential part of an ink jet printer according to a first embodiment of the present invention. FIG. 3 is a perspective view of a medium transport unit according to the first embodiment of the present invention. It is a control block diagram of the ink jet printer in a 1st embodiment of the present invention. It is a flowchart which shows operation | movement of the inkjet printer in the 1st Embodiment of this invention. It is a conceptual diagram of the paper feed side drive part in the 1st Embodiment of this invention. It is a figure for demonstrating the operation | movement of the inkjet printer in the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, an inkjet printer as an image forming apparatus will be described.

  FIG. 2 is a perspective view of the ink jet printer according to the first embodiment of the present invention, and FIG. 3 is a perspective view of the main part of the ink jet printer according to the first embodiment of the present invention.

  In the figure, reference numeral 10 denotes an ink jet printer, Cs denotes a main body of the ink jet printer 10, that is, a casing for enclosing the apparatus main body, and Fr denotes a frame of the ink jet printer 10. The frame Fr includes an upper frame Fr1 and a lower frame Fr2. Become.

  The upper frame Fr1 is formed by rising from the left end of the receiving plate PB which is disposed extending from the left end to the right end when the ink jet printer 10 is viewed from the front side (the front side in the drawing) Side plate PL1, side plate PR1 formed by raising from the right end of the receiving plate PB, frame PL2 formed by raising from the receiving plate PB by a predetermined distance to the right from the side plate PL1, the side A frame PR2 is formed by raising from the receiving plate PB by a predetermined distance from the plate PR1 to the left, and an upper plate PT connecting the upper ends of the side plates PL1 and PR1 and the frames PL2 and PR2.

  The lower frame Fr2 is disposed in parallel with a predetermined distance between the vicinity of the left end and the vicinity of the right end of the ink jet printer 10, and the pedestals 35 and 36 for supporting the upper frame Fr1, and the pedestals The columns 37, 38 are formed by rising from the centers of the columns 35, 36.

  The casing Cs is an exterior body that encloses the upper frame Fr1, and a first casing portion Cs1 that encloses between the frame PL2 and PR2, and a second that encloses between the side plate PL1 and the frame PL2. And a third casing Cs3 surrounding the space between the side plate PR1 and the frame PR2. Further, the housing Cs has a top wall Wt, a front wall Wf extending obliquely downward from a front end of the top wall Wt, and a back wall extending hanging from a rear end of the top wall Wt. Wr and side walls Ws1 and Ws2 extending from the left and right ends of the top wall Wt along the side plates PL1 and PR1. A plate-like cover is formed of a light transmitting material (transparent or translucent material) between the frames PL2 and PR2 on the front wall Wf as a transmission window for observing the state in the housing Cs. 28 is disposed openably and closably by a hinge hg disposed at the upper end.

  In the casing Cs, a rail 15 is disposed between the side plates PL1 and PR1, and along the rail 15, the carriage 17 is disposed movably in the left-right direction, that is, in the main scanning direction. For this purpose, the drive-side pulley 18 is disposed on the side plate PR1, and the driven-side pulley 19 is rotatably disposed on the side plate PL1, and the endless belt 21 travels by the drive-side pulley 18 and the driven-side pulley 19. The carriage 17 is attached to a predetermined portion of the endless belt 21 so as to be freely stretched. Further, a carriage motor 24 as a drive unit for carriage travel is disposed in proximity to the drive-side pulley 18.

  A plurality of recording heads Hdi (i = 1, 2,...) Described later so that the carriage 17 can form one or more, in this embodiment, color images. 1) is mounted with the nozzle face downward.

  The linear scale 23 is disposed extending along and parallel to the rail 15, and the scale of the linear scale 23 is read by an encoder (not shown) disposed on the carriage 17 and the encoder The position of the carriage 17 is detected based on the sensor output of Further, the moving speed of the carriage 17 is calculated based on the change in the position of the carriage 17 and the time.

  Therefore, when driving the carriage motor 24 to rotate the drive-side pulley 18 and causing the endless belt 21 to travel, the carriage 17 is moved in the main scanning direction and each recording head Hdi is moved in the main scanning direction. be able to. At this time, ink droplets of each color are ejected from the recording heads Hdi toward the recording medium P as the carriage 17 moves, and are attached to the recording medium P, whereby an image such as a character or an image is formed on the recording medium P. It is formed. In this way, recording is performed by the recording head Hdi and printing is performed. In the present embodiment, a film made of resin such as vinyl chloride or PET can be used as the recording medium P in addition to paper.

  Further, a platen 25 having a plate-like shape is disposed so as to extend along the rail 15 and in parallel with the rail 15, that is, in the main scanning direction. The platen 25 is disposed to extend between the frames PL2 and PR2 on the receiving plate PB in the first casing Cs1, and supports the recording medium P conveyed on the platen 25.

  Then, a rear paper guide 29 (FIG. 1) as a first medium guide unit (described later) is disposed behind the platen 25 in the first housing unit Cs1. The rear paper guide 29 The medium P is guided toward the platen 25. A transport roller pair 30 as a transport member for transporting the recording medium P is rotatably disposed between the rear paper guide 29 and the platen 25.

  The conveying roller pair 30 is adjacent to the platen 25 and extends in the main scanning direction, the conveying roller 31 as a first roller rotatably disposed, and a predetermined roller above the conveying roller 31. The pinch roller 32 is a second roller which is disposed rotatably at a plurality of positions at a pitch and presses the recording medium P against the transport roller 31. When the conveyance roller 82 is rotated by driving the conveyance motor 82 (FIG. 5) as a conveyance drive unit and a first drive unit to be described later, the pinch roller 32 is rotated in unison.

  As a result, the recording medium P is fed out from a paper feed side roll paper Rs (FIG. 1) as a paper roll side roll-like medium which will be described later while being nipped by the conveyance roller 31 and the pinch roller 32. The guide 29 is conveyed toward the platen 25. Then, while being transported on the platen 25, the recording medium P and the nozzle surface of the recording head Hdi are made to face each other, ink droplets are ejected from the recording head Hdi, and the ink droplets are adhered to the recording medium P.

  In the present embodiment, printing is performed by the multi-pass method, and after the conveyance motor 82 is driven to convey the recording medium P by a predetermined distance, the conveyance motor 82 is stopped, In this state, the carriage 17 is moved, an ink droplet is ejected from the recording head Hdi, and one scan is performed. Then, each time the recording medium P is conveyed by a predetermined distance by driving the conveyance motor 82, one scan is repeatedly performed, and an image of one line is formed by a plurality of scans. By repeating this operation, an image is formed on the recording medium P and printing is performed.

  When printing is performed by the single pass method, the distance by which the recording medium P is conveyed is equal to the size of the nozzle array of the recording head Hdi, and an image of one line is formed each time one scanning is performed. .

  A front paper guide 33 as a second medium guiding unit is disposed in front of the platen 25 in the first casing Cs1, and the recording medium P on which an image is formed is formed by the front paper guide 33. It is guided out of the housing Cs and discharged. The front paper guide 33 has a curved shape in order to guide the recording medium P discharged horizontally from the platen 25 downward.

  Further, between the frame PR2 and the side plate PR1 in the third casing Cs3, the nozzle surface of each recording head Hdi is wiped in order to hold the not-shown nozzles of the recording head Hdi in a good state. Wipe unit 41 as a first maintenance device is disposed to prevent drying of the nozzle between the side plate PL1 and the frame PL2 in the second housing Cs2, and viscosity within the nozzle is maintained. A cap unit (purge unit) 42 as a second maintenance device including a suction mechanism or the like for suctioning the raised ink is disposed.

  Then, in a predetermined portion of the third housing portion Cs3, in the present embodiment, on the side plate PR1 side, a display portion including an operation portion including operation elements such as operation buttons and a display element such as a display lamp The operation panel 43 provided is disposed.

  Further, in the lower frame Fr2, the recording medium P is fed out between the columns 37, 38 formed by raising from the centers of the pedestals 35, 36 and supplied to the platen 25 through the rear paper guide 29 as described later. A medium conveyance unit u1 including a paper feeding device 51 (FIG. 1) as a medium conveyance device and a winding device 52 for winding the recording medium P conveyed from the platen 25 via the front paper guide 33 is disposed.

  Next, the medium transport unit u1 will be described.

  FIG. 4 is a perspective view of the medium transport unit according to the first embodiment of the present invention.

  In the figure, u1 is a medium transport unit, 51 is a sheet feeding device, 52 is a winding device, and 26 is a tension bar.

  By winding the recording medium P (FIG. 3) around a paper tube (not shown), roll paper as a roll medium is formed, and the roll paper is set in the paper feeding device 51 as paper feed side roll paper Rs. . Further, the recording medium P on which an image is formed by the recording head Hdi is taken up by a take-up device 52 in a paper tube, and a take-up side roll paper Re as a take-up side roll-like medium is formed.

  The sheet feeding device 51 is disposed adjacent to a sheet feeding drive unit 55 and the sheet feeding drive unit 55, and a drive side supporting unit 56 rotatably supporting one end of the sheet roll paper Rs. The paper feed side drive unit 55 is provided with a driven side support unit 57 and the like disposed opposite to the drive side support unit 56 and rotatably supporting the other end of the paper feed side roll paper Rs. A paper feed motor 84 (FIG. 5) as a drive unit on the paper feed side described later for rotating the side roll paper Rs and as a second drive unit is disposed.

  The drive-side support portion 56 and the driven-side support portion 57 each have a “U” shape, a lower arm Am1, a raised portion Am2 formed by being raised from one end of the lower arm Am1, and A presser base Am3 is provided which extends parallel to the lower arm Am1 from the upper end of the upright portion Am2.

  The paper feed side flanges fs are disposed at both ends of the paper feed side roll paper Rs, and each paper feed side flange fs is placed on a pair of rollers 61 disposed on the lower arm Am1. It is rotatably supported by 61.

  Each of the sheet feeding side flanges fs is rotatably supported at the upper part by a pressing roller 62 disposed rotatably with respect to the pressing base Am3. The presser base Am3 is connected to the presser lock 64 via the link 63. When the presser base Am3 is moved with respect to the feed side flange fs to press the press roller 62 against the feed side flange fs and the presser lock 64 is operated to fix the presser base Am3, each feed side flange fs It can be rotatably supported by the roller 61 and the pressing roller 62.

  The paper feed side flange fs on the drive side support portion 56 and the paper feed side motor 84 are connected, and the paper feed side roll paper Rs can be rotated by driving the paper feed side motor 84.

  The take-up device 52 is disposed adjacent to the take-up side drive unit 65 and the take-up side drive unit 65, and supports the one end of the take-up side roll paper Re rotatably. 66, and provided with a driven side supporting portion 67 and the like disposed opposite to the driving side supporting portion 66 and rotatably supporting the other end of the winding side roll paper Re, and the winding side driving portion 65, A take-up side motor 85 (FIG. 5) as a take-up side drive unit described later for rotating the take-up side roll paper Re and as a third drive unit is provided.

  The drive side support portion 66 and the driven side support portion 67 each have a “U” shape, a lower arm Am1, a raised portion Am2 formed by being raised from one end of the lower arm Am1, and A presser base Am3 is provided which extends parallel to the lower arm Am1 from the upper end of the upright portion Am2.

  The take-up side flanges fe are disposed at both ends of the take-up side roll paper Re, and the take-up side flanges fe are placed on a pair of rollers 71 disposed on the lower arm Am1. It is rotatably supported by

  Further, each take-up side flange fe is rotatably supported at its upper part by a press roller 72 disposed rotatably with respect to the press base Am3. The presser base Am3 is connected to the presser lock 74 via the link 73. The presser base Am3 is moved with respect to the take-up side flange fe to press the press roller 72 against the take-up side flange fe, and the presser lock 74 is operated to fix the presser base Am3. It can be rotatably supported by the pressing roller 71 and the pressing roller 72.

  The take-up side flange fe on the drive-side support 66 side and the take-up side motor 85 are connected, and the take-up side roll paper Re can be rotated by driving the take-up side motor 85.

  The tension bar 26 is vertically movably guided along a roller guide gd disposed adjacent to the drive side support portion 66 and the driven side support portion 67 of the winding device 52.

  An operation switch SW as an operation element is disposed in the winding-side drive unit 65, and the operator operates the operation switch SW as needed to instruct the driving direction of the winding-side motor 85. , On / off etc. can be performed manually.

  Next, a control device of the inkjet printer 10 will be described.

  FIG. 5 is a control block diagram of the ink jet printer according to the first embodiment of the present invention.

  In the figure, 81 is a control unit that controls the entire ink jet printer 10, 75 is a ROM, 76 is a RAM, 77 is a timer as a clock unit that measures time in response to an instruction from the control unit 81, 78 is An input unit Hdi is a recording head.

  The control unit 81 includes a CPU (not shown) that operates according to a control program recorded in the ROM 75, and the paper feeding device 51 feeds out and feeds the recording medium P (FIG. 3) from the paper feed side roll paper Rs. A paper feed processing unit Pr1 that conveys the recording medium P from the paper feeding device 51 side to the winding device 52 side by the roller pair 30, that is, a printing processing unit Pr2 that forms an image by the recording head Hdi In 52, the recording medium P is taken up by the winding processing unit Pr3 for taking up the recording medium P on which the image is formed on the take-up side roll paper Re, and the conveyance roller pair 30, from the winding device 52 side to the paper feeding device 51 side. That is, it has a rewinding processing unit Pr4 that conveys in the reverse direction and rewinds the paper to the paper feed side roll paper Rs. Further, a program for control, various setting values and the like are recorded in the ROM 75.

  The RAM 76 is used as a work area when control is performed by the control unit 81 or as a buffer for temporarily recording data.

  The input unit 78 is connected to a host computer (not shown) as a higher-level device, the operation panel 43 (FIG. 2), the operation switch SW, etc., and transmits print data transmitted from the host computer. Information when the switch SW or the like is operated is input to the control unit 81.

  Then, the recording head Hdi is driven by receiving the image data generated by the control unit 81 based on the print data, and discharges an ink droplet toward the recording medium P.

  Also, Sn is a rotation amount detection unit that detects the rotation amount of the transport roller 31, Sed is a roll end sensor as a rising detection unit disposed opposite the paper feed side roll paper Rs in the paper feeding device 51, Sd is a lower position sensor for detecting that the tension bar 26 has reached the lower setting position, Su is an upper position sensor for detecting that the tension bar 25 has reached the upper setting position, and Hr is for the rear paper guide 29 Rear heater as a first heating member disposed, Sr a temperature sensor for detecting the temperature of the rear paper guide 29, Hp a platen heater as a second heating member disposed on the platen 25, Sp a platen 25. A temperature sensor for detecting the temperature of 25. Hf is a front heater as a third heating member disposed on the front paper guide 33. Sf is a heater. A temperature sensor for detecting the temperature of the cement paper guide 33.

  The roll end sensor Sed sends to the control unit 81 a sensor output according to the presence or absence of the paper feed side roll paper Rs in the paper feeding device 51. In the paper feed side roll paper Rs, since the end of the recording medium P is fixed to the paper pipe, when all the recording media P are fed out from the paper feed side roll paper Rs, the paper pipe is pulled up and floats up. Based on the sensor output of the roll end sensor Sed at this time, the control unit 81 determines that the recording medium P in the sheet feeding device 51 is exhausted.

  Further, 24 is a carriage motor, 82 is a conveyance motor, 84 is a paper feed motor, 85 is a take-up motor, 86 is disposed in the paper feed driver 55 (FIG. 4) and switches the rotation transmission system. Reference numeral 87 denotes a heater drive circuit.

  The transport motor 82 is driven in the forward or reverse direction, and when driven in the forward direction, rotates the transport roller pair 30 in the forward direction, transports the recording medium P in the forward direction, and is driven in the reverse direction. The transport roller pair 30 is rotated in the reverse direction to transport the recording medium P in the reverse direction.

  The sheet feeding motor 84 is disposed in the sheet feeding drive unit 55 of the sheet feeding device 51, is driven only in the forward direction, and rotates the sheet feeding side roll sheet Rs in the reverse direction. The take-up motor 85 is disposed in the take-up drive unit 65 of the take-up device 52, driven in the forward or reverse direction, and driven in the forward direction. When rotated in the forward direction, the recording medium P is wound on the take-up side roll paper Re, and driven in the reverse direction, the take-up side roll paper Re is rotated in the reverse direction, and the recording medium P is taken up as the take-up side roll paper Unroll from Re.

  Then, the heater drive circuit 87 drives (turns on / off) the rear heater Hr, the platen heater Hp, and the front heater Hf in response to an instruction from the control unit 81.

  Next, the operation of the ink jet printer 10 will be described.

  FIG. 1 is a diagram for explaining the operation of the ink jet printer according to the first embodiment of the present invention.

  In the figure, Rt1 is a conveyance path of the recording medium P, 25 is a platen, Hdi is a recording head, 26 is a tension bar, 29 is a rear paper guide, 30 is a conveyance roller pair, 31 is a conveyance roller, 32 is a pinch roller, and 33 is A front paper guide, 51 is a sheet feeding device, 52 is a winding device, Rs is a sheet feeding side roll sheet, and Re is a winding side roll sheet.

  The conveyance roller pair 30 is disposed between the rear paper guide 29 and the platen 25 in the conveyance path Rt1 of the recording medium P. When the transport motor 82 (FIG. 5) is driven in the forward direction, the transport roller pair 30 is rotated in the forward direction, and the recording medium P is transported in the forward direction while being nipped by the transport roller 31 and the pinch roller 32. . When the transport motor 82 is driven in the reverse direction, the transport roller pair 30 is rotated in the reverse direction, and the recording medium P is transported in the reverse direction while being nipped by the transport roller 31 and the pinch roller 32.

  Then, in the sheet feeding device 51, when the sheet feeding motor 84 is driven in the forward direction, the sheet feeding side flange fs and the paper tube attached to the sheet feeding side flange fs are in the reverse direction (rewinding direction) The paper feed side roll paper Rs is rotated in the reverse direction, and the recording medium P is rewound. Further, in the winding device 52, when the winding side motor 85 is driven in the forward direction, the winding side flange fe and the paper tube attached to the winding side flange fe are rotated in the forward direction. The take-up side roll paper Re is rotated in the forward direction, and the recording medium P is taken up.

  In the inkjet printer 10, when printing is performed, the paper feed processing unit Pr1 of the control unit 81 (FIG. 5) drives the conveyance motor 82 in the forward direction and rotates the conveyance roller pair 30 in the forward direction. As a result, the paper feed side roll paper Rs is rotated in the forward direction, and the recording medium P is fed out from the paper feeding device 51, and the housing Cs is formed from the medium introduction port (not shown) formed in the back wall Wr (FIG. 3). The sheet is supplied to the inside, conveyed in the forward direction in the housing Cs, guided by the rear paper guide 29, and sent to the platen 25.

  Subsequently, the print processing unit Pr2 of the control unit 81 drives the carriage motor 24 to move the carriage 17 (FIG. 3) in the main scanning direction and drives each recording head Hdi to record the recording medium on the platen 25. The ink droplets are discharged to P, and an image is formed on the recording medium P.

  During this time, as described above, in the present embodiment, printing is performed by the multipass method, and an image of one line is formed by a plurality of scans.

  That is, each time the sheet feed processing unit Pr1 transports the recording medium P by a predetermined distance, the print processing unit Pr2 performs one scan. The distance by which the recording medium P is transported each time one scan is performed, that is, the unit transport amount Δk, which is the transport amount transported in one pass, is the number of passes for forming an image of one line. It is set according to

  In the present embodiment, the unit transport amount Δk transported in one pass is extremely shorter than the distance Lk by which the recording medium P is transported along the front paper guide 33, and the distance Lk is the unit transport amount Δk. 5 to 100 times of.

  In this manner, while the recording medium P is conveyed in the forward direction and printing is performed, in order to prevent the recording medium P from being slackened between the conveyance roller pair 30 and the winding device 52, The take-up processing unit Pr3 of the control unit 81 drives the take-up motor 85 of the take-up drive unit 65 in the forward direction, rotates the take-up side roll paper Re in the forward direction, and takes up the recording medium P. Take up on the side roll paper Re. The take-up side drive unit 65 is provided with a take-up side torque limiter (not shown) that limits the torque by a value smaller than the load caused by the recording medium P being pinched by the conveyance roller 31 and the pinch roller 32. A tension is applied to the recording medium P.

  The conveyance of the recording medium P is not affected even if the torque is limited by the take-up torque limiter while an image is formed.

  Furthermore, a tension bar 26 is disposed between the front paper guide 33 and the winding device 52. The tension bar 26 is vertically movably guided along the roller guide gd (FIG. 4) disposed adjacent to the driving side support portion 66 and the driven side support portion 67 of the winding device 52, A tension is applied to the recording medium P.

  That is, the tension bar 26 is moved between the lower setting position and the upper setting position, and when it reaches the lower setting position, it is detected by the lower position sensor Sd, and the winding side motor 85 is driven in the forward direction. When it reaches the upper set position, it is detected by the upper position sensor Su, and the take-up motor 85 is driven in the reverse direction to be moved downward.

  Therefore, the occurrence of slack in the recording medium P wound up by the winding device 52 can be further prevented.

  In the present embodiment, the tension bar 26 is disposed between the front paper guide 33 and the winding device 52, but the front paper guide is not provided without the tension bar 26. The recording medium P guided by 33 can be sent directly to the winding device 52, as represented by the two-dot chain line L1 in the figure.

  By the way, in the rear paper guide 29, the rear heater Hr heats the recording medium P conveyed on the first heating area Ar1. Since the recording medium P before the ink droplets are attached is uniformly heated, when the ink droplets adhere to the recording medium P on the platen 25, the ink can be well fixed to the recording medium P.

  Further, in the platen 25, the platen heater Hp heats the recording medium P conveyed in the second heating area Ar2. Since the recording medium P on the platen 25 is brought to a predetermined temperature, the ink droplet can be stabilized and adhered to the recording medium P. If the temperature of the recording medium P is too low or too high, the spread of the deposited ink becomes unstable and the image quality is degraded.

  A suction mechanism (not shown) is disposed below the platen 25. The suction mechanism sucks air from a plurality of suction holes (not shown) formed in the platen 25 to press the recording medium P onto the platen 22. Close contact and flatten.

  Then, in the front paper guide 33, the front heater Hf heats the recording medium P conveyed in the third heating area Ar3. Since the recording medium P after the image is formed is uniformly heated, the ink adhering to the recording medium P can be fixed well.

  In this case, in order to heat the recording medium P sufficiently, it is necessary to transport the recording medium P in a state of being in close contact with the surfaces of the rear paper guide 29, the platen 25 and the front paper guide 33.

  For example, in order to form an image by the recording head Hdi, when the conveyance roller pair 30 is rotated in the forward direction and the recording medium P is conveyed in the forward direction toward the platen 25, the conveyance roller pair 30 and the sheet feeding When slack occurs in the recording medium P with the device 51 or when the recording medium P floats up from the rear paper guide 29 as represented by a one-dot chain line L2 in the figure, the slack, floating and the like are eliminated The recording medium P can not be stably conveyed by the conveyance roller pair 30, and the image quality of the image formed by the recording head Hdi is degraded.

  Therefore, while the recording medium P is conveyed in the forward direction and printing is performed, the above-described rewinding is performed to prevent the recording medium P from being slackened between the sheet feeding device 51 and the conveyance roller pair 30. In the sheet feeding device 51, the processing unit Pr4 drives the sheet feeding motor 84 in the forward direction, rotates the sheet feeding side roll sheet Rs in the reverse direction, and rewinds the recording medium P.

  Therefore, while printing is being performed, an appropriate tension is applied to the recording medium P between the conveyance roller pair 30 and the paper feed side roll paper Rs, and the occurrence of slack is prevented, so the recording medium P is used. The image can be stably conveyed and the image quality can be improved.

  When the formation of the image of one page by the recording head Hdi is completed and the printing is completed, the recording medium P is guided out of the housing Cs by the front paper guide 33, discharged, and sent to the winding device 52, The take-up side roll paper Re is taken up.

  At this time, if the heating condition per unit transport amount of the recording medium P transported in the third heating area Ar3 is different between the end of the image and the other portion, the image quality is degraded.

  Therefore, until the end of the image passes through the third heating area Ar3, the unit carry amount Δk carried in one pass is made equal to the carry amount of the recording medium P when the image is formed. .

  Next, the operation of the inkjet printer 10 when printing is completed will be described.

  FIG. 6 is a flowchart showing the operation of the ink jet printer according to the first embodiment of the present invention.

  First, the sheet feed processing unit Pr1 drives the conveyance motor 82 in the forward direction, conveys the recording medium P by a unit conveyance amount Δk equal to that when an image is formed, and starts timekeeping by the timer 77.

  Subsequently, the sheet feed processing unit Pr1 stands by for a predetermined time, and when the clocking by the timer 77 ends, the printing range of the image of one page is determined depending on whether the end of the image passes the third heating area Ar3. It is determined whether everything has been heated by the front heater Hf, and the recording medium P is transported by the unit transport amount Δk until all of the printing range of the image of one page is heated by the front heater Hf.

  During this time, the carriage 17 (FIG. 3) is not moved in the main scanning direction, the recording head Hdi is not driven, and the recording medium P is conveyed. The predetermined time is set to be equal to the time for driving the recording head Hdi by moving the carriage 17 in the main scanning direction in one pass. Therefore, the recording medium P can be transported under the same transport conditions as during the formation of the image, and can be heated under the same heating conditions as during the printing.

  When the end of the image passes the third heating area Ar3 and the entire printing range of the image of one page is heated by the front heater Hf, the sheet feeding processing unit Pr1 ends the conveyance of the recording medium P.

  In this case, the heating condition of the recording medium P can be matched between the end of the image and the other portion, so that the image quality can be improved.

  By the way, when the formation of the image of the next page is continuously started by the recording head Hdi in a state where the end of the image has passed through the third heating area Ar3, it corresponds to the length of the third heating area Ar3. This causes a margin corresponding to the length of the recording medium P, and the consumption of the recording medium P increases.

  Therefore, before the formation of the image of the next page is started, the rewinding processing unit Pr4 drives the transport motor 82 in the reverse direction, rotates the transport roller pair 30 in the reverse direction, and reverses the recording medium P. A predetermined transport amount Q is transported in the direction.

  The transport amount Q is set so that the ink droplet fixed on the recording medium P does not contact the pinch roller 32 and is crushed. The rewind processing unit Pr4 transports the recording medium P in the reverse direction at a constant speed, and when the end of the image reaches a predetermined stop position near the transport roller pair 30, the transport motor 82 is driven. Stop it. The stop position of the end of the image is set between the end on the conveyance roller pair 30 side and the conveyance roller pair 30 in the second heating area Ar2.

In this case, the conveyance distance of the recording medium P from the end of the formation of the image of one page to the end of the image passing through the third heating area Ar3 is D1, and the recording medium P has a unit conveyance amount Δk Assuming that the number of times of conveyance is N, the conveyance distance D1 is
D1 = Δk · N
become. Then, assuming that the distance between the end on the conveyance roller pair 30 side and the stop position of the end of the image in the second heating area Ar2 is D2, the conveyance amount Q is
Q = D1 + D2
become.

  Therefore, the rewind processing unit Pr4 reads the rotation amount per unit time of the transport roller 31 detected by the rotation amount detection unit Sn, and is necessary to transport the recording medium P by the transport amount Q based on the rotation amount. The time .tau.1 is calculated, and when the time .tau.1 elapses after the conveyance of the recording medium P in the reverse direction is started, the conveyance motor 82 is stopped.

  As described above, since the recording medium P is conveyed by the conveyance amount Q in the reverse direction each time an image of one page is formed, it is possible to shorten the margin generated between each page of the image, and consumption of the recording medium P The amount can be reduced.

  As the transport roller pair 30 is rotated in the reverse direction, the take-up side roll paper Re is rotated in the reverse direction in the take-up device 52 to resist the torque of the take-up side torque limiter. The recording medium P is fed out.

  By the way, when the recording medium P is conveyed in the reverse direction by the rewinding processing unit Pr4, if the recording medium P is slackened between the conveying roller pair 30 and the paper feeding device 51, the paper feeding processing unit Pr1 Therefore, when the recording medium P is conveyed in the forward direction again, tension can not be applied to the recording medium P, and the conveyance amount of the recording medium P increases, and when the slack is eliminated thereafter, the tension is applied to the recording medium P. As a result, the transport amount of the recording medium P is reduced.

  Therefore, when the recording medium P is slackened or the slackness is eliminated and the transport amount of the recording medium P fluctuates, the image quality is degraded when printing is performed by the print processing unit Pr2.

  In addition, when the recording medium P is conveyed in the reverse direction by the rewinding processing unit Pr4, the recording medium P may be lifted from the rear paper guide 29 as represented by a dashed dotted line L2 in FIG. In this state, the recording medium P can not be uniformly heated by the rear heater Hr, and temperature unevenness occurs in the recording medium P. In that case, when the recording medium P is conveyed again in the forward direction by the paper feed processing unit Pr1, the recording medium P can not be brought to a predetermined temperature by the platen heater Hp on the platen 25, and the image quality is degraded. Resulting in.

  Furthermore, the recording medium P can not be stably conveyed, and skew (slanting), conveyance wrinkles and the like occur on the recording medium P, and the recording medium P contacts the carriage 17 and a jam occurs. Sometimes.

  Therefore, in the present embodiment, in order to prevent the recording medium P from rising from the rear paper guide 29, the conveyance motor 82 is driven in the reverse direction, and the recording medium P is conveyed in the reverse conveyance amount Q. Meanwhile, the paper feed side motor 84 is driven in the forward direction by the rewinding processing unit Pr4, the paper feed side roll paper Rs is rotated in the reverse direction, and the recording medium P is clocked by the timer 77 for a predetermined time. The paper is rewound on the paper feed side roll paper Rs at a constant speed of τ2. The predetermined time τ2 is set in advance according to the amount of slack, surfacing, etc. assumed to occur in the recording medium P.

  In this case, the conveyance amount per unit time of the recording medium P rewound by driving the feed side motor 84 in the normal direction is the unit of the recording medium P conveyed by driving the conveyance motor 82 in the reverse direction. It is more than the transport amount per hour.

  In the present embodiment, after the drive of the conveyance motor 82 in the reverse direction is started, the drive of the paper feed side motor 84 in the forward direction is started, but the reverse direction of the conveyance motor 82 is After the drive of the feed motor 84 is started at the same time the drive of the feed motor 84 is started, or after the drive of the feed motor 84 is started in the normal direction, the reverse direction of the transport motor 82 is started. The drive of can be started.

  The predetermined time τ2 in which the recording medium P is rewound on the paper feed side roll sheet Rs is set longer than the time τ1 in which the recording medium P is transported in the reverse direction. That is, the driving of the sheet feeding motor 84 is stopped after the driving of the transport motor 82 in the reverse direction is stopped. By doing this, when the recording medium P is conveyed in the normal direction and formation of an image of the next page is started, tension can be appropriately applied to the recording medium P.

  In this manner, when the recording medium P is conveyed in the reverse direction by the rewind processing unit Pr4 and is rewound on the paper feed side roll sheet Rs, the paper feed processing unit Pr1 forms an image of the next page. For this purpose, the conveyance motor 82 is driven in the forward direction, the pair of conveyance rollers 30 is rotated in the forward direction, the recording medium P is conveyed in the forward direction, and is fed to the platen 25. Then, the formation of the image by the recording head Hdi is started from the portion of the recording medium P uniformly heated in the first heating area Ar1. That is, the formation of the image of the next page is started after the recording medium P is conveyed from the first heating area Ar1 by the conveyance amount set in advance.

  By the way, in the sheet feeding device 51, the roll end sensor Sed is disposed so as to face the sheet feed side roll sheet Rs. As described above, when all the recording media P are fed out from the paper feed side roll paper Rs, the paper tube is pulled up and floats up, and the control unit 81 controls based on the sensor output of the roll end sensor Sed at this time. It is determined that the recording medium P has run out in the sheet feeding device 51.

  However, while the recording medium P is being conveyed in the reverse direction by the rewinding processing unit Pr4, when the paper feed side roll paper Rs is pressed by the recording medium P being rewound, the paper feed side roll paper Rs is fed In some cases, the control unit 81 erroneously determines that the recording medium P has run out.

  Therefore, the sheet feed processing unit Pr1 reads the sensor output of the roll end sensor Sed, and determines whether or not the feed side roll sheet Rs is lifted from the feed side flange fs. When the paper feed side roll paper Rs is lifted from the paper feed side flange fs, the paper feed processing unit Pr1 drives the conveyance motor 82 in the forward direction until the rising of the paper feed side roll paper Rs is resolved, and the paper is fed. The recording medium P is fed out of the side roll paper Rs.

  Then, when the sensor output of the roll end sensor Sed is read and it is determined that the rising of the paper feed side roll paper Rs has been eliminated, the paper feed processing unit Pr1 drives the conveyance motor 82 in the forward direction, and the recording medium P is read. The sheet is unwound and sent to the platen 25.

  As described above, since the recording medium P is rewound on the paper feed side roll sheet Rs while the transport motor 82 is driven in the reverse direction by the rewinding processing unit Pr4, a tension is applied to the recording medium P, Sag can be prevented from occurring. Therefore, the recording medium P can be brought into close contact with the rear paper guide 33, and can be uniformly heated by the rear heater Hr, so that the temperature unevenness of the recording medium P does not occur. Then, since the recording medium P can be brought to a predetermined temperature by the platen heater Hp on the platen 25, the image quality can be improved.

  Further, since the recording medium P can be stably conveyed, a skew, a conveyance wrinkle or the like does not occur in the recording medium P, and the recording medium P does not contact the carriage 17 and a jam does not occur.

  By the way, the recording medium P is nipped by the conveyance roller 31 and the pinch roller 32 with a large nipping force in the conveyance roller pair 30. 85 is driven in the forward direction to rotate the take-up side roll paper Re in the forward direction, or the rewind processing unit Pr4 drives the paper feed side motor 84 in the paper feeding device 51 in the forward direction to If the position of the recording medium P nipped by the conveyance roller 31 and the pinch roller 32 changes when the roll paper Rs is rotated in the reverse direction, an image can not be formed on the recording medium P with high accuracy. .

  Therefore, as described above, a value smaller than a load generated by the recording roller P being pinched by the conveyance roller 31 and the pinch roller 32 by the winding-side torque limiter disposed in the winding-side drive unit 65 Torque is limited. Further, in order to apply a tension to the recording medium P to be conveyed, a first torque limiter 90 (FIG. 7) as a tension applying member, which will be described later, is disposed in the sheet feeding drive unit 55. The torque limiter 90 limits the torque to a value smaller than the load generated when the recording medium P is nipped by the conveyance roller 31 and the pinch roller 32.

  Therefore, the take-up side motor 85 is driven in the forward direction to rotate the take-up side roll sheet Re in the forward direction, or the feed side motor 84 is driven in the forward direction to reverse the feed side roll sheet Rs. When the recording medium P is rotated, the position nipped by the conveyance roller 31 and the pinch roller 32 in the recording medium P does not change, so that the image can be formed on the recording medium P with high accuracy.

  The conveyance amount when the conveyance motor 82 is driven and the conveyance roller pair 30 is rotated to convey the recording medium P is calculated based on the number of revolutions of the conveyance roller 31 detected. If the recording medium P is slipped or the like at a position nipped by the conveyance roller 31 and the pinch roller 32, the conveyance amount of the recording medium P can not be accurately calculated. Therefore, it is necessary to accurately adjust the set value of the torque limited by the torque limiter on the winding side and the first torque limiter 90 so that no slip or the like occurs in the recording medium P.

Next, the flowchart will be described.
Step S1 The paper feed processor Pr1 transports the recording medium P by a unit transport amount Δk.
Step S2 The sheet feed processing unit Pr1 stands by for a predetermined time.
Step S3 The paper feed processing unit Pr1 determines whether all of the print range has been heated. If all of the print area is heated, the process proceeds to step S4, and if all of the print area is not heated, the process returns to step S1.
Step S4 The rewind processing unit Pr4 transports the recording medium P in the reverse direction by a predetermined transport amount Q.
Step S5: The rewind processing unit Pr4 rewinds the recording medium P onto the paper feed side roll paper Rs for a predetermined time τ2.
Step S6 The paper feed processing unit Pr1 determines whether the paper feed side roll paper Rs has lifted from the paper feed side flange fs. When the paper feed side roll paper Rs is lifted from the paper feed side flange fs, the process proceeds to step S7, and when the paper feed side roll paper Rs is not lifted, the process is ended.
Step S7 The paper feed processing unit Pr1 feeds the recording medium P until the rising of the paper feed side roll paper Rs is cancelled, and the process ends.

  Next, the paper feed side drive unit 55 will be described.

  FIG. 7 is a conceptual view of the sheet feed side drive unit according to the first embodiment of the present invention.

  In the figure, 55 is a paper feed side drive unit, Rs is a paper feed side roll sheet, Bs is a base as a base for mounting each element of the paper feed side drive unit 55, 84 is a paper feed attached to the base Bs. A paper side motor sh1 is attached to the paper feed side flange fs (FIG. 1), supports the paper feed side roll paper Rs, and serves as a first shaft for transmitting the rotation of the paper feed side motor 84, and A roll paper support shaft 90 as a medium support shaft is attached to the base Bs, limits the torque of the roll paper support shaft sh1, and applies a tension to the roll paper support shaft sh1, sh2 is a second torque limiter The output shaft of the feed side motor 84 as a shaft of the motor, gr1 is a first gear attached to the output shaft sh2, sh3 is a rotation transmission shaft as a third shaft rotatably supported by the base Bs, gr2 Is said A second gear wheel 86 rotatably supported by the base Bs via the rotation transmission shaft sh3 and engaged with the first gear gr1, 86 selectively selects between the second gear gr2 and the rotation transmission shaft sh3. A second torque limiter 91 attached to the rotation transmission shaft sh3 limits the torque output from the paper feed motor 84 and transmits it to the roll paper support shaft sh1. A third gear connected to the rotation transmission shaft sh3 via a torque limiter 91, and a fourth gear gr4 attached to the roll paper support shaft sh1. The first to fourth gears gr1 to gr4 constitute a rotational transmission member.

  The sheet feed motor 84 is connected to the roll sheet support shaft sh1 via the first to fourth gears gr1 to gr4 and driven to feed the recording sheet P from the sheet roll paper Rs. It is rotated in the forward direction and in the reverse direction when the recording medium P is unwound.

  Further, the electromagnetic clutch 86 intermittently transmits the rotation from the paper feed motor 84 to the roll paper support shaft sh1, and when the transport motor 82 is driven in the forward direction, the paper feed motor 84 and the roll paper support are supported. When the conveyance motor 82 is driven in the reverse direction, the paper feed motor 84 and the roll paper support shaft sh1 are connected.

  The value of the torque limited by the second torque limiter 91 is set larger than the value of the torque limited by the first torque limiter 90. The fourth gear gr4 has a diameter larger than that of the third gear gr3 and has a large number of teeth, and the third and fourth gears gr3 and gr4 constitute a reduction gear.

  When the sheet feed processing unit Pr1 drives the conveyance motor 82 in the forward direction, the conveyance roller pair 30 is rotated in the forward direction, and the recording medium P is fed out from the sheet feed side roll sheet Rs. At this time, as the recording medium P is fed from the paper feed side roll paper Rs, the paper side roll paper Rs is rotated, but the rotation of the paper side roll paper Rs is suppressed by the first torque limiter 90. Tension is applied to the recording medium P. When a load of a predetermined value is applied to the roll paper support shaft sh1, the first torque limiter 90 is idled, and thus no load of a predetermined value or more is applied to the roll paper support shaft sh1.

  While the sheet feed processing unit Pr1 drives the transport motor 82 in the forward direction, the rewind processing unit Pr4 turns off the electromagnetic clutch 86 to shut off the second gear gr2 from the rotation transmission shaft sh3 to supply the sheet. The paper side motor 84 and the roll paper support shaft sh1 are shut off. Therefore, the second torque limiter 91 does not limit the torque, and the third and fourth gears gr3 and gr4 are idled as the paper feed side roll sheet Rs is rotated.

  Further, when the rewinding processing unit Pr3 drives the transport motor 82 in the reverse direction, the transport roller pair 30 is rotated in the reverse direction, and the recording medium P is transported in the reverse direction. At this time, the rewinding processing unit Pr3 drives the sheet feeding motor 84, turns on the electromagnetic clutch 86, connects the second gear gr2 to the rotation transmission shaft sh3, and supports the sheet feeding motor 84 and the roll sheet When the shaft sh1 is connected, the torque output to the output shaft sh2 of the paper feed motor 84 is transmitted to the roll paper support shaft sh1 against the torque limited by the first torque limiter 90. That is, the rotation of the paper feed motor 84 is performed by the first and second gears gr1 and gr2, the electromagnetic clutch 86, the rotation transmission shaft sh3, the second torque limiter 91, the third and fourth gears gr3 and gr4, and the roll. The sheet is transmitted to the paper feed side roll paper Rs via the paper support shaft sh1, and the paper feed side roll paper Rs is rotated. As a result, the recording medium P is rewound on the paper feed side roll paper Rs, and the slack of the recording medium P between the conveyance roller pair 30 and the paper feed side roll paper Rs is eliminated.

  At this time, the torque limited by the second torque limiter 91 is transmitted to the paper feed side roll paper Rs. When driving the sheet feeding motor 84, if a torque larger than the torque limited by the second torque limiter 91 is generated, the second torque limiter 91 is idled.

  When the electromagnetic clutch 86 is turned off, the rotation of the paper feed motor 84 is not transmitted to the paper feed roll paper Rs, and the rotation transmission shaft sh3 is idled, so the second torque limiter 91 does not function. It will be in the state.

  By the way, when the recording medium P is rewound on the paper feed side roll sheet Rs, the conveyance amount of the recording medium P which is rewound by driving the paper feed side motor 84 in the forward direction is reverse to the conveyance motor 82. The amount of conveyance of the recording medium P conveyed by driving is larger than the conveyance amount of the recording medium P. Therefore, when the slack of the recording medium P is eliminated, the recording conveyed by the conveyance roller pair 30 even if the paper feeding motor 84 is driven. It can not rewind more than the transport amount of the medium P. Therefore, a large load is applied to the second torque limiter 91, and the second torque limiter 91 is caused to slip.

  The first torque limiter 90 is idled while a large load is applied while the recording medium P is rewound on the paper feed side roll sheet Rs.

  As described above, since the second torque limiter 91 is disposed in the paper feed drive unit 55, it is possible to prevent the excessive load from being applied to the paper feed drive unit 55 when the slack of the recording medium P is eliminated. can do. Further, in the state where the slack of the recording medium P is eliminated, the recording medium P can be rewound in the state where the optimum tension is applied.

  When the second torque limiter 91 is idled, the torque of the paper feed motor 84 is not transmitted to the paper feed side roll paper Rs, so there is no need to control the drive of the paper feed motor 84. That is, when the slack is eliminated, it is not necessary to detect that the slack is eliminated and to stop or lock the drive of the sheet feeding motor 84.

  Furthermore, since the value of the torque limited by the second torque limiter 91 is large, for example, even when a heavy paper feed side roll paper Rs exceeding 50 kg is set in the paper feeding device 51, the paper feed is performed. By driving the side motor 84, the paper feed side roll paper Rs can be easily rotated.

  Further, when printing is performed by driving the conveyance roller pair 30 in the forward direction, the torque necessary for applying a tension to the recording medium P and the paper feed side motor 84 in the forward direction to drive the recording medium P The value is different from the torque required to rewind the paper on the paper feed side roll paper Rs. Therefore, in the present embodiment, the first and second torque limiters 90 and 91 having different values of the limited torque are disposed.

  When the paper feed motor 84 is driven to rewind the recording medium P onto the paper feed side roll paper Rs, the paper feed side roll paper Rs is resisted against the torque limited by the first torque limiter 90. Since torque is to be transmitted, a torque that is larger than the torque limited by the first torque limiter 90 and smaller than the torque limited by the second torque limiter 91 is transmitted to the paper feed side roll sheet Rs. Ru. The torque limited by the first and second torque limiters 90 and 91 is set based on the evaluation of the previously performed experiment or the like.

  As described above, in the present embodiment, when the formation of the image on the recording medium P is completed, the conveyance motor 82 is driven in the reverse direction by the rewind processing unit Pr4, and the recording medium P is moved to the sheet feeding device 51 side. The recording medium P is conveyed, and tension is applied to the recording medium P on the side of the paper feeding device 51 from the pair of conveyance rollers 30 in the conveyance path Rt1. Therefore, when the paper feed side roll paper Rs is rotated in the forward direction and the reverse direction It is possible to eliminate the slack that occurs in P.

  Accordingly, the recording medium P can be stably conveyed and the image quality can be improved.

  Next, a second embodiment of the present invention will be described. The same reference numerals are given to those having the same structure as in the first embodiment, and the effects of the same embodiment are incorporated for the effects of the invention by having the same structure.

  FIG. 8 is a diagram for explaining the operation of the ink jet printer according to the second embodiment of the present invention.

  In the figure, Rt1 is a conveyance path of the recording medium P, 25 is a platen, Hdi is a recording head, 26 is a tension bar, 29 is a rear paper guide as a first medium guiding portion, and 30 is a conveyance roller pair as a conveyance member. 31 is a conveying roller as a first roller, 32 is a pinch roller as a second roller, 33 is a front paper guide as a second medium guiding portion, 51 is a sheet feeding device as a medium conveying device, 52 is a roll Take-up device, Rs: paper feed side roll paper as roll medium on the paper feed side, fr: paper feed side flange, Re: wind side roll paper as roll medium on take-up side, fe: wind side flange It is.

  In the present embodiment, first and second bars 95 and 96 as tension applying members are disposed between the sheet feeding device 51 and the rear paper guide 29 in the conveyance path Rt1 of the recording medium P. The first bar 95 is disposed between the feed side support portion 56 (FIG. 4) of the sheet feeding device 51 and the driven side support portion 57, and the second bar 96 is a tension bar. It is guided so as to be vertically movable along a roller guide (not shown) disposed adjacent to the side support portion 56 and the driven side support portion 57.

  The recording medium P is fed from the paper feed side roll paper Rs, is sent to the rear paper guide 29 via the first and second bars 95 and 96, and meanwhile is meandered downward by the second bar 96. , The tension produced by the weight of the second bar 96 is applied.

  Thus, when the recording medium P is being conveyed in the forward direction by the paper feed processing unit Pr1 (FIG. 5) and when the recording medium P is being conveyed in the reverse direction by the rewinding processing unit Pr4, It is possible not only to prevent the occurrence of slack in the sheet, but also to prevent the recording medium P from coming up from the rear paper guide 29.

  In the present embodiment, the recording medium P is fed by driving the paper feed motor 84 (FIG. 5) as the paper feed side drive unit and as the second drive unit in the forward direction. Since the load on the feed motor 84 is applied by the weight of the second bar 96 when rewinding to the paper Rs, the torque limited by the second torque limiter 91 disposed in the feed drive unit 55 is Be changed.

  The movable range of the second bar 96 is longer than 1⁄2 of the transport amount of the recording medium P when rewinding to the paper feed side roll paper Rs by driving the paper feed side motor 84 in the forward direction. By doing this, it is possible to eliminate the need to rewind the recording medium P by driving the sheet feeding motor 84 in the forward direction.

  In each of the above-described embodiments, the recording medium P is rewound on the paper feed side roll paper Rs in order to reduce the consumption of the recording medium P. After all the paper side roll paper Rs is drawn out, an image is formed on the recording medium P, and the paper is rolled up on the winding side roll paper Re of the winding device 52, all the recording medium P is fed to the paper feed side roll paper Rs. Can be rewound.

  Although the inkjet printer 10 has been described in each of the above embodiments, the present invention can be applied to an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine.

  The present invention is not limited to the above-described embodiments, and can be variously modified based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 inkjet printer 25 platen 30 conveyance roller pair 51 sheet feeding device 82 conveyance motor Hdi recording head P recording medium Pr1 sheet feeding processing part Pr2 printing processing part Pr4 rewinding processing part Rs sheet feeding side roll sheet Rt1 conveyance path

Claims (9)

(A) a transport member rotatably disposed in the transport path;
(B) a drive unit for transport which transports the recording medium by rotating the transport member;
(C) a sheet feeding device provided with a roll-shaped medium on the sheet feeding side;
(D) Platen,
(E) A feed processing unit which drives the transport driving unit in the forward direction, rotates the transport member, feeds a recording medium from a roll-shaped medium on the paper feed side, and supplies the recording medium to the platen;
(F) a print processing unit which drives a recording head disposed facing the platen to form an image on a recording medium;
(G) When the formation of the image on the recording medium is completed, the driving unit for conveyance is driven in the reverse direction, and a rewind processing unit for conveying the recording medium to the paper feeding device side;
(H) An ink jet printer characterized in that a tension is applied to the recording medium on the side of the sheet feeding device from the transport member in the transport path. (A) The sheet feeding apparatus includes a driving unit on the sheet feeding side,
(B) The rewinding processing unit drives the drive unit on the paper feed side in the forward direction when driving the transport drive unit in the reverse direction to transport the recording medium to the paper feeding device side. The ink jet printer according to claim 1, wherein the recording medium is tensioned.   3. The ink jet printer according to claim 2, wherein the rewinding unit drives the drive unit on the sheet feeding side to rewind the recording medium onto a roll-shaped medium on the sheet feeding side. (A) The sheet feeding device includes a first torque limiter,
4. The ink jet printer according to claim 2, wherein the first torque limiter applies a tension to the recording medium fed from the roll-shaped medium on the paper feed side. (A) The sheet feeding device includes a second torque limiter,
(B) The second torque limiter according to any one of claims 2 to 4, wherein the second torque limiter limits the torque output from the drive unit on the feed side and transmits the torque to the roll-like medium on the feed side. Inkjet printer.   During the time when the drive unit on the feed side is driven in the forward direction and the recording medium is rewound onto the roll-like medium on the feed side, the drive unit for conveyance is driven in the reverse direction, and the print medium is reversed. The ink jet printer according to any one of claims 2 to 5, wherein the time for conveyance is made longer. (A) The sheet feeding apparatus includes a rising detection unit that detects rising of the roll-shaped medium on the sheet feeding side,
(B) The paper feed processing unit reads the sensor output of the floating detection unit, and when the roll-like medium on the paper feed side rises, drives the drive unit for conveyance in the forward direction, and the roll on the paper feed side The ink jet printer according to any one of claims 1 to 6, wherein the recording medium is fed from the recording medium.   The rewind processing unit transports the recording medium to the sheet feeding device side until the end of the image when the formation of the image is completed reaches a stop position preset between the recording head and the transport member. The ink jet printer according to any one of Items 1 to 7.   9. The tension bar according to any one of claims 1 to 8, further comprising a tension bar for applying a tension to the recording medium fed from the roll-like medium on the paper feed side between the paper feeding device and the conveyance member in the conveyance path. An ink jet printer according to claim 1.

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