JP2011173265A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus decreasing floating of mist of ink ejected to the outside of the end edge of a recording medium, and preventing deterioration in image quality at the end of the recording medium, in recording with a margin. <P>SOLUTION: The image forming apparatus is equipped with: a recording head 51 for ejecting the ink to perform recording; a scanning unit 50 which moves in the state where the recording head is mounted; and a platen which supports the recording medium. The apparatus is equipped with: an ink collecting port 25 for collecting the ink ejected to the outside of the end edge of the recording medium; a suction means 27 for generating suction force in the ink collecting port; an opening/closing means 99 opening/closing the ink collecting port; and a controller 95 for controlling the opening/closing means. When performing the recording with margin, the ink collecting port is closed when the scanning unit moves to the position where it covers the ink collecting port located at the end edge of the recording medium. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that performs recording by ejecting ink from a recording head onto a recording medium.

  Image forming apparatuses such as printers, facsimiles, word processors, and copying machines are configured to record an image on a recording medium based on image information. As an embodiment of an image forming apparatus, an apparatus using a recording head that performs recording by discharging ink onto a recording medium based on image information is used. As an example, an ink jet recording apparatus using an ink jet recording head that performs recording by discharging ink from a plurality of discharge ports formed on a face surface facing a recording medium is used. For the scanning method of the image forming apparatus, a scanning unit having a recording head mounted on a carriage is used, recording for one line for recording while moving the scanning unit along the recording medium, and recording by a conveying means such as a conveying roller. There is a serial method in which recording is performed by alternately repeating conveyance of a medium at a predetermined pitch.

  In an image forming apparatus that ejects ink, ink mist composed of minute ink particles may be generated when ink is ejected. After the ink mist is generated from the ejection port, the ink mist flows in the moving direction behind the scanning unit as the scanning unit moves. The scanning unit reverses the moving direction for each scanning of one line. For this reason, the ink mist is largely wound up by the reversal of the scanning unit, and as a result, most of the ink mist stays at the reversal position of the scanning unit. If the accumulated ink mist stains the recording medium or the inside of the apparatus, and the ink mist accumulates on the recording operation mechanism unit or its control means, it may cause a malfunction. As means for preventing such a problem, Patent Document 1 discloses a method in which a suction port is provided in the vicinity of the recording head over the entire moving range of the carriage, and ink mist generated immediately after ink ejection is collected by the suction means. It is disclosed.

  On the other hand, in an image forming apparatus, for example, Patent Document 2 discloses a configuration for performing “marginless recording” in which continuous paper (roll paper) wound in a roll shape is used to perform recording without blank spaces on the entire surface of a recording medium. Yes. This image forming apparatus is configured to record in a wide area including the edge of the recording medium in the width direction and to cut the front and rear end portions of the recording area with a cutter in the transport direction. In this case, as a means for receiving ink ejected outside the edge of the recording medium, an ink receiver that opens on the recording medium support surface of the platen is provided. The ink receiver is configured by a concave portion that opens on the conveying surface of the platen from the viewpoint of preventing ink stains on the back surface of the recording medium. Further, a discharge hole is formed inside the ink receiver, and the received ink is discharged to the waste ink storage unit. In the case where recording media having different width sizes are used, ink receivers are provided at a plurality of locations corresponding to the respective width sizes.

  Incidentally, the ink ejected from the recording medium for marginless recording may be misted and floated before landing in the ink receiver. For this reason, in the configuration of the ink receiver disclosed in Patent Document 2, the floating ink mist may adhere to the vicinity of the ejection port of the recording head, and ink ejection may become unstable. In addition, the floating ink mist may stain the back surface of the recording medium and reduce the image quality. As a method for coping with this, Patent Document 3 discloses that an ink suction port for performing marginless recording on a recording medium is provided on the platen, and ink ejected outside the edge of the recording medium is sucked by a suction fan. A method is disclosed.

JP 2004-330638 A Japanese Patent Laid-Open No. 11-321016 JP 2005-205650 A

  Incidentally, in recent image forming apparatuses that perform recording by ejecting ink, the ink droplets of the ejected ink have been miniaturized in order to improve the image quality. For this reason, in a conventional method (for example, Patent Document 3) in which ink protruding from the recording medium is collected by suction, ink droplets for forming an image on the end of the recording medium may be sucked together with the ink mist. When such a suction action occurs, the landing position of the ink droplet on the recording medium tends to be shifted, which may affect the image quality at the edge of the image. Such a shift in the landing position is not noticeable in the image flow at the end portion because there is no margin portion in the case of recording without a margin, but in the case of recording with a margin, the deterioration in image quality at the end portion becomes conspicuous. .

  The present invention has been made in view of such technical problems. An object of the present invention is to reduce floating of ink mist of ink ejected outside the edge of a recording medium and to prevent deterioration of image quality at the edge of the recording medium in recording with margins. A forming apparatus is provided.

  An image forming apparatus according to the present invention includes a recording head that performs recording by discharging ink to a recording medium based on image information, a scanning unit that mounts the recording head and moves along the recording medium, and the recording head A platen that supports the recording medium at a position opposed to the recording medium, an ink collecting port that collects ink discharged to the outside of the edge of the recording medium, and a suction force that is generated at the ink collecting port. A suction unit; an opening / closing unit that opens and closes the ink collection port; and a control unit that controls the opening / closing unit. When performing recording with a margin, the scanning unit is positioned at the edge of the recording medium. The ink collection port is closed when the ink collection port is moved to a position covering the ink collection port.

  According to the present invention, in recording with a margin, an image that can reduce the floating of the ink mist of the ink discharged to the outside of the edge of the recording medium and can prevent the deterioration of the image quality at the edge of the recording medium. A forming apparatus is provided.

FIG. 2 is a longitudinal sectional view of the image forming apparatus according to the embodiment as viewed from line AA in FIG. 1 is a perspective view of an image forming apparatus according to an embodiment. Front sectional view showing a state when the ink collecting port is closed by the opening / closing means Front sectional view showing a state when the ink collection port is opened by the opening / closing means The block diagram which shows the structure of the control part of an image forming apparatus Table of control table related to ink collection port open / close control Flow chart of control operation of ink collection port opening / closing means

  Embodiments of the present invention will be specifically described below with reference to the drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings. FIG. 1 is a vertical cross-sectional view showing a main configuration of an image forming apparatus according to an embodiment. FIG. 2 is a perspective view of the image forming apparatus according to the embodiment. The image forming apparatus according to the present embodiment is an ink jet image forming apparatus that uses a recording head that performs recording by discharging ink onto a recording medium based on image information. The carriage 52 on which the recording head 51 is mounted is guided and supported so as to be able to reciprocate in the direction of the arrow X along a main rail 57 installed in the apparatus main body. The recording head 51 is detachably attached to a head holder 53 provided on the carriage 52. The recording head 51 is supplied with ink from an ink tank (not shown) through an ink tube (not shown). In the case of color recording, inks of a plurality of colors such as black, cyan, magenta, and yellow are supplied.

  In the apparatus main body, a carriage motor 114 for reciprocating the recording head 51 in a direction (main scanning direction X) intersecting the conveyance direction and a conveyance motor 110 for driving a conveyance roller 12 for conveying the recording medium. And. A timing belt 211 is stretched between a drive pulley 210 on the output shaft of the carriage motor 114 and an idler pulley arranged on the opposite side, and the carriage 52 is connected to the timing belt 211. By forward and reverse rotation of the carriage motor 114, the carriage 52 is guided by the main rail 57 and moves parallel to the left and right over the platen 21. A linear encoder 59 is stretched on the apparatus main body in parallel with the moving direction of the carriage 52. The linear encoder 59 is read by the encoder sensor 58 mounted on the carriage 52, and the control unit 95 (FIG. 5) detects the position and scanning speed of the carriage 52 and the recording head 51 based on the output signal. The carriage 52 is equipped with a paper width sensor 93 (for example, a photo interrupter) that detects the presence or absence of a recording medium as the carriage moves. Based on the detection signal from the paper width sensor 93, the control unit 95 detects the edge position and the width dimension of the recording medium.

  The transport motor 110 is a motor for transporting the recording medium in the transport direction (sub-scanning direction) Y. The image forming apparatus according to the present embodiment can use roll paper 82, which is continuous paper wound in a roll shape, as a recording medium. The conveyance motor 110 rotationally drives the conveyance roller 12 via a timing belt (not shown). A pinch roller 11 that is a driven rotating body for applying a conveying force is pressed against the conveying roller 12. By reading the rotary encoder 212 fixed to one end of the transport roller 12 with an encoder sensor (not shown), the rotation amount of the transport roller 12 and the transport amount of the recording medium 82 can be feedback-controlled.

  As described above, the image forming apparatus according to the present embodiment uses the scanning unit 50 in which the recording head 51 is mounted on the carriage 52. Then, recording for one line (or one pass) for forming an image while moving the scanning unit 50 along the recording medium, and conveying the recording medium at a predetermined pitch by the conveying means using the conveying roller 12 or the like (paper feeding) ) Is repeated, image recording on the recording medium is performed. That is, the operation of the scanning unit 50 that reciprocates in the main scanning direction X and the operation of the conveying roller 12 that conveys the roll paper 82 that is a recording medium in the sub-scanning direction Y while pulling out a predetermined amount are appropriately (or alternately). ) Repeat to form the desired image. The image forming apparatus according to the present embodiment is capable of recording both on a predetermined size of cut paper and roll paper 82 that is continuous paper.

  The image forming apparatus is provided with a control unit 95 including a controller having a CPU, a memory, an I / O circuit, and the like. The control unit 95 controls the operation of the drive motor and various devices according to a control program stored in advance in the internal memory. As a result, the conveyance / recording operation of the recording medium (continuous paper and cut paper) is controlled, and the drive of the recording head 51 is controlled based on the image information, thereby recording an image on the recording medium. Further, the control unit 95 controls the opening and closing of the ink collection port 25 by an opening / closing means 99 described later, and controls the operation of the entire image forming apparatus and their timing.

  Here, the conveyance unit (conveyance means) for the roll paper 82 supplied from the recording medium insertion port 41 on the back side of the apparatus main body will be described. The roll paper 82 is loaded on the spool 81 in a wound state, and is attached to the back of the apparatus main body so that it can be pulled out. The user inserts the leading end of the roll paper 82 into the insertion port 41 from the back of the apparatus main body. The control unit 95 detects the presence / absence of a recording medium based on detection information from an upstream sensor (upstream recording medium detection sensor) 91 arranged on the conveyance downstream side of the paper feed guide 32. As the upstream sensor 91, for example, a photo interrupter is used to detect the presence or absence of a recording medium by irradiating a light to be detected from a light emitting element, receiving the reflected light by a light receiving element and outputting a signal. . When the upstream sensor 91 detects that the roll paper (recording medium) 82 has been inserted, the roll paper is sandwiched between the transport roller 12 and the pinch roller 11 while being guided by the paper feed guide 32, and the recording head on the platen 21. 51 is conveyed directly below (image forming area).

  A number of suction holes 22 are formed in a predetermined arrangement in the platen 21 that supports the recording medium at a position facing the recording head 51. Each suction hole 22 of the platen 21 is connected to a suction means (suction fan) 27 through a duct 26, and a negative pressure suction force can be applied to each suction hole 22 by the suction means 27. When the recording medium is conveyed directly under the recording head 51, the suction fan 27 is operated to suck the recording medium on the platen 21 through the suction hole 22. As a result, the recording medium can be adsorbed on the upper surface of the platen 21 and can be transported without any paper floating. The recording medium (roll paper) is sandwiched between the transport roller 12 and the pitch roller 11 and further transported, and an image is recorded on the recording medium sucked and transported on the platen 21. A cutting device 72 is mounted on the scanning unit 50 (its carriage 52). When the image recording is completed, the cutting device 72 cuts the recording medium upstream of the image forming area. The image recording part cut off by cutting is discharged from a paper discharge port 42 on the front side of the apparatus main body and stored in a basket 37 disposed below. An internal guide 33 for guiding the recording medium to be discharged is provided between the platen 21 and the paper discharge outlet 42, and an external guide for guiding the recording medium outward and downward is provided outside the paper discharge outlet 42. 34 is provided.

  Between the platen 21 and the internal guide 33, a fixed blade 73 is provided that extends in a direction intersecting the transport direction. The round blade 71 of the cutting device 72 mounted on the carriage 52 protrudes and moves along the fixed blade 73, thereby cutting between pages of the recorded recording medium (roll paper). When not cutting, the round blade 71 is stored in the cutting device 72 in a locked state against a spring biasing force (not shown). When cutting, the locking is released, the round blade 71 protrudes on the conveyance path, and the circular blade 71 moves while rotating with the movement of the scanning unit 50 in a state where the round blade 71 is in pressure contact with the fixed blade 73. The recording medium (roll paper) is cut. The scanning unit 50 is an assembly that moves on the platen 21 together with the recording head 51 in a direction (scanning direction) intersecting the transport direction. The scanning unit 50 of this embodiment includes a cutting device 72, an encoder sensor 58, a paper width sensor 93, and the like mounted on the carriage in addition to the carriage 52 and the recording head 51.

  In the apparatus main body, an ink mist suction device 43 for sucking and collecting ink mist generated when ink is ejected is disposed along the movement direction of the carriage 52. The ink mist suction device 43 includes suction means (not shown) such as a suction fan, and a duct 45 having an ink mist suction port 44. The duct 45 extends in the direction intersecting the transport direction in the vicinity of the scanning unit 50, and a large number of ink mist suction ports 44 are formed in a predetermined arrangement on the side surface of the duct 45 on the carriage 52 side. Most of the ink mist stays in the vicinity of the reverse position of the scanning unit 50. However, since the width of the recording medium is wide, the ink mist suction port 44 is arranged in the vicinity of the scanning position of the recording head 51 over almost the entire movement range of the scanning unit 50.

  The transport surface (recording medium support surface) of the platen 21 is provided with an ink collection port 25 for collecting ink ejected to the outside of the edge of the recording medium during marginless recording. The platen 21 is provided with an opening / closing means 99 for opening and closing the ink collecting port 25. FIG. 3 is a front sectional view showing a state when the ink collecting port 25 is closed by the opening / closing means 99. FIG. 4 is a front cross-sectional view showing a state when the ink collecting port 25 is opened by the opening / closing means 99. Next, the ink collection port opening / closing means 99 will be described.

  Each ink collection port 25 provided on the platen 21 is connected to a suction fan 27 as a suction means via a duct 26 formed on the back side of the conveying surface of the platen 21, and the ink is collected by the suction fan 27. The ink ejected outside the edge of the recording medium is collected by the suction force generated at the collection port 25. The ink collected by the ink collection port 25 is guided to a waste ink storage unit (not shown). The ink collection ports 25 on the platen 21 are provided at a plurality of positions corresponding to the edges in the width direction according to various sizes of recording media used for marginless recording. The opening / closing means 99 is a means for opening and closing each ink collecting port 25, and includes a solenoid 98, a connecting rod 78, a connecting plate 77, a rotating shaft 76, and a closing plate 74. The opening / closing operation of each ink collecting port 25 by the opening / closing means 99 is controlled by the control unit 95.

  When closing the ink collection port 25, the solenoid 98 is energized and moved in the direction in which the connecting rod 78 is drawn. As a result, the closing plate 74 rotates clockwise around the rotation shaft 76 via the connecting plate 77 and is pressed against the sealing material 79 mounted around the ink collecting port 25, whereby the ink collecting port 25. Close the mouth. The connecting rod 78 is disposed below the plurality of ink collecting ports 25 and is connected to each connecting plate 77 of the plurality of ink collecting ports. Thereby, the plurality of ink collecting ports 25 can be opened and closed by one solenoid 98. As another example, for example, a plurality of solenoids 98 may be provided for each ink collecting port 25, and the opening and closing of each ink collecting port may be controlled individually. Each closing plate 74 is urged counterclockwise about the rotation shaft 76 by a spring (not shown). Therefore, when each ink collecting port 25 is opened, the energization of the solenoid 98 is stopped to free the connecting rod 78, and the closing plate 74 is rotated in the counterclockwise direction around the rotation shaft 76 by the biasing force of the spring. Rotate. Thereby, each ink collection port 25 can be opened.

  FIG. 5 is a block diagram illustrating a configuration of the control unit 95 of the image forming apparatus. The CPU 100 controls the operation of the entire apparatus including a recording operation according to a control program stored in the ROM 102. The CPU 100 inputs recording data, recording mode setting information, and the like from the host computer 104 via the input interface 106. Further, the CPU 100 writes recording data or the like into the RAM 108 or reads out from the RAM 108. Specifically, the CPU 100 determines a determination signal from an upstream sensor (upstream recording medium detection sensor) 91, a CR (carriage) position detection sensor (encoder sensor) 58, a paper width sensor (paper width detection sensor) 93, etc., and a host. Based on recording data from the computer 104, recording mode information, and the like, the conveyance motor 110, fan motor 112, carriage motor 114, recording head 51, opening / closing means (ink collecting port opening / closing mechanism) 99, and the like are controlled.

  Next, the operation of the image forming apparatus will be described. First, recording data, recording mode setting information, and the like are transferred from the host computer to the image forming apparatus by a user operation. Based on the transferred print data, print mode setting information, the position information of the scanning unit 50 detected by the carriage position detection sensor (encoder sensor) 58, the control unit 95 opens / closes the ink collection port open / close mechanism. ) 99 controls the opening and closing operation of the ink collection port 25. In this case, the recording data includes, for example, data such as image density and image width, and the recording mode setting information includes, for example, setting information for recording without margins and recording with margins.

  FIG. 6 is a table of a control table related to opening / closing control of each ink collecting port 25 on the platen 21. The opening / closing control of the opening / closing means 99 is performed based on a control table illustrated in FIG. When the recording mode setting information transferred by the user operation is recording without margins, the ink collecting port 25 is opened, and the ink ejected from the edge of the recording medium is collected using a suction force. As a result, it is possible to reduce the floating of the ink mist due to the ink that is discarded outside the edge of the recording medium, and to reduce the adhesion of ink to the ejection port of the recording head 51 and the back surface of the recording medium. When the recording mode setting information transferred by the user operation is a recording with a margin, when the scanning unit 50 is located at the end of the recording medium, the opening / closing means 99 is closed so as to close the ink collecting port 25. Control.

  Here, when the scanning unit 50 is positioned at the end of the recording medium, the scanning unit 50 covers almost the entire area of the ink collection port 25 positioned at the edge of the recording medium. When the scanning unit 50 covers the ink collecting port 25, a space is formed between the recording medium and the scanning unit 50, and ink ejected from the end of the recording medium acts on the ink collecting port 25. It is easy to be sucked by the negative suction pressure, and the landing position of the ink droplet on the recording medium is likely to shift. Therefore, when performing recording with a margin, when the scanning unit 50 is at a position covering the ink collecting port 25 at the edge of the recording medium, the ink collecting port is controlled to be closed, thereby controlling the ink. The suction action of the collection port 25 is eliminated. Accordingly, it is possible to eliminate or reduce the landing deviation of the ejected ink at the end of the recording medium when recording with a margin. Further, when the recording head 51 is not ejecting ink, control is performed so that the ink collecting port 25 is opened even when the scanning unit 50 completely covers the ink collecting port 25 at the end of the recording medium. To do. Thereby, the ink mist staying at the reverse position of the scanning unit 50 can be sucked and collected. On the other hand, when the scanning unit 50 is not located at the edge of the recording medium, the ink collecting port 25 is controlled to be opened so as to collect ink mist staying at or near the reverse position of the scanning unit 50. To do.

  FIG. 7 is a flowchart of a control operation for opening / closing the ink collecting port 25 by the opening / closing means 99 when printing with margins. Next, a series of opening / closing control operations of the ink collection port 25 when performing the above-described recording with a margin will be described. When recording with margins is started, the control unit 95 that has received setting information such as image information (recording data, printing data) and recording mode (printing mode such as recording with margins or recording without margins) opens and closes ( The control method of the ink collection port opening / closing mechanism 99 is determined (steps S01 and S02). As a control method in that case, a method of controlling opening / closing of each ink collecting port 25 according to image information or a method of controlling opening / closing of each ink collecting port 25 according to the position of the scanning unit 50 is adopted. Further, when performing recording without margins, a method of controlling the ink collecting port 25 to be opened is employed. When recording with margins is performed, the following opening / closing means 99 is used to open the edge of the recording medium. Opening / closing control for closing the ink collecting port 25 is performed. That is, when printing without margins is performed, each ink collecting port 25 may remain open regardless of the following control when printing with margins.

  Hereinafter, this will be specifically described with reference to FIG. After determining the control method, the scanning unit 50 is moved, and the width of the recording medium is detected by the paper width sensor 93 mounted on the scanning unit (step S03). Then, driving of the carriage motor 114 and the carry motor 110 is started to start a recording operation (printing operation) (step S04). First, the scanning unit 50 is moved to the edge of the recording medium on the HP (home position) side (the right side in FIG. 2) (step S10). Next, in step S <b> 11, it is determined from the detection result of the carriage detection position sensor (encoder sensor) 58 whether or not the scanning unit 50 has moved to a position that covers the ink collecting port 25 at the edge on the HP side.

  When it is detected that the scanning unit 50 has moved to a position that covers the ink collecting port 25 at the edge on the HP side, the ink collecting port 25 is closed by energizing the solenoid 98 and driving the opening / closing means 99 ( Step S12). At that time, while the scanning unit 50 covers the ink collecting port 25 at the edge, the solenoid 98 is always energized to close the ink collecting port 25. That is, when performing recording with a margin, control is performed so that the ink collection port is closed when the scanning unit 50 moves to a position that covers the ink collection port 25. At that time, when the scanning unit 50 passes through another ink collecting port 25 during recording (image formation), the scanning unit 50 moves to a position covering the ink collecting port located at the edge of the recording medium. In this case, only the ink collecting port may be closed and the other ink collecting ports may be left open.

  Next, the moving direction of the scanning unit 50 is reversed to start moving toward the image forming area (in the BP direction). In step S13, the scanning unit 50 reaches a position where it does not cover the HP-side ink collecting port 25. It is determined from the detection result of the carriage detection position sensor 58 whether or not it has moved. When it is detected that the scanning unit 50 has moved to a position where the ink collecting port 25 is not covered, the energization of the solenoid 98 is stopped and the ink collecting port 25 is opened (step S14). Thereafter, an image is formed on the recording medium by the recording head 51 while moving the scanning unit 50 in the BP direction (left direction in FIG. 2) (step S15).

  Next, in step S <b> 16, it is determined from the detection result of the position sensor 58 whether or not the scanning unit 50 has moved to the edge of the recording medium on the BP side and has reached a position that covers the ink collection port 25 of the edge. To do. When it is detected that the scanning unit 50 has moved to a position that covers the ink collecting port 25 at the edge, the solenoid 98 is energized again to close the ink collecting port 25 (step S17). Also in this case, when the scanning unit 50 moves through the other ink collecting port 25 while moving to the BP side, only the ink collecting port located at the end portion on the BP side is closed, and the other. The ink collection port may be left open. FIG. 3 shows a state in which the recording unit 51 performs recording with a margin at the end of the recording medium with the scanning unit 50 covering the entire upper surface of the ink collecting port 25 at the edge of the recording medium. The scanning unit 50 reverses on the BP side and moves toward the HP side again. However, as long as the scanning unit covers the entire upper surface of the ink collection port 25 at the edge portion on the BP side, the scanning unit 50 is always connected to the solenoid 98. The ink collecting port 25 is closed by energizing. Next, in step S30, it is determined whether or not recording with margins (printing with margins, etc.) has been completed for the entire recording medium. If completed, a series of operations is terminated. If not finished, the opening / closing operation by the opening / closing means 99 is further continued.

  That is, when the recording is not completed, the scanning unit 50 is reversed on the BP side (step S18), and the movement of the scanning unit to the HP side is started (step S19). In step S <b> 20, it is determined from the detection result of the carriage detection position sensor 58 whether or not the scanning unit 50 has moved to a position that does not cover the upper surface of the BP side ink collection port 25. When it is detected that the scanning unit 50 has moved to a position where the ink collecting port 25 is not covered, the energization of the solenoid 98 is stopped and the ink collecting port 25 is opened (step S21). Thereafter, the scanning unit 50 moves in the right direction (HP direction) in FIG. 2 while forming an image on the recording medium by the recording head 51 (step S22). FIG. 4 shows a state in which the image is formed by the recording head 51 in a state where the scanning unit 50 does not cover the ink collecting port 25 at the edge of the recording medium.

  Next, in step S <b> 23, it is determined from the detection result of the position sensor 58 whether or not the scanning unit 50 has moved to a position that covers the ink collecting port 25 at the HP side edge of the recording medium. When it is detected that the scanning unit 50 has moved to a position that covers the ink collecting port 25 at the edge, the ink collecting port 25 is closed by energizing the solenoid 98 and driving the opening / closing means 99 (step). S24). At that time, while the scanning unit 50 covers the ink collecting port 25, the solenoid 98 is always energized to close the ink collecting port 25. That is, when performing recording with a margin, control is performed so that the ink collection port is closed when the scanning unit 50 moves to a position that covers the ink collection port 25. Again, when the scanning unit 50 moves to the HP side while performing recording, when passing through another ink collecting port, only the ink collecting port located at the edge on the HP side is closed, and the other ink collecting ports are closed. The ink collection port may remain open.

  Next, the movement direction of the scanning unit 50 is reversed (step S25), and the movement of the scanning unit 50 in the BP direction is started again (step S26). In step S27, it is determined from the detection result of the carriage detection position sensor 58 whether or not the scanning unit 50 has moved to a position that does not cover the upper surface of the HP-side ink collection port 25. When it is detected that the scanning unit 50 has moved to a position where the ink collecting port 25 is not covered, the energization of the solenoid 98 is stopped and the ink collecting port 25 is opened (step S28). Thereafter, the process returns to step S15, and an image is formed on the recording medium by the recording head 51 while moving the scanning unit 50 in the BP direction (the left direction in FIG. 2).

  In the above, the case where recording is performed while the scanning unit 50 is moved (ink is ejected from the recording head 51) has been described. However, even when there is a margin, when the recording head 51 is not ejecting ink, the ink collecting ports 25 are controlled to be opened. In addition, when performing recording without margins, the ink collection port may remain open because the displacement of the ink droplet landing position due to suction at the end of the recording medium and the image flow are not noticeable.

  As described above, the scanning unit 50 repeats scanning (reciprocating movement) to form an image. When the image is formed, the opening / closing means (ink collecting port opening / closing mechanism) 99 described above is always opened / closed. Take control. When recording with margins, only when the scanning unit 50 moves to the edge of the recording medium, the ink collecting port 25 at the edge is closed, and suction from the ink collecting port 25 works. Control to not. Thereby, it is possible to prevent the suction action with respect to the ink ejected to form an image on the edge of the recording medium. Therefore, it is possible to prevent or reduce the landing position deviation of the ink droplets at the edge of the recording medium due to suction, and it is possible to prevent the image quality from being lowered due to the sharpness reduction at the image edge. Further, when the scanning unit 50 is not located at the edge of the recording medium, the ink collecting port 25 is opened, whereby the ink mist staying at the reverse position of the scanning unit 50 (end of the recording medium). Can be collected by suction. As a result, the vicinity of the reversal position of the scanning unit 50 in which ink mist tends to stay can be intensively sucked, and efficient ink mist collection can be performed. In this way, in recording with a margin, an image forming apparatus capable of reducing the floating of the ink mist of the ink ejected outside the edge of the recording medium and preventing the deterioration of the image quality at the edge of the recording medium is provided. Is done.

  In the above embodiment, the inkjet recording apparatus has been described as an example. However, the present invention can be similarly applied to any image forming apparatus that performs recording with ink ejection and margins, regardless of the recording method. is there. Furthermore, the present invention can be similarly applied regardless of the form of the recording medium, such as continuous paper such as roll paper or cut paper of a predetermined size. The present invention can be similarly applied regardless of the number of recording heads, the type of ink used, the number of properties, and the like. The present invention is also applicable to the case where various different materials such as paper, plastic film, photographic paper, and non-woven fabric are used as the recording medium.

21 Platen 22 Suction hole 25 Ink collection port 26 Duct 27 Suction means (suction fan)
50 Scanning Unit 51 Recording Head 52 Carriage 58 Carriage Position Detection Sensor 74 Closing Plate 82 Recording Medium (Roll Paper)
95 Control unit 98 Solenoid 99 Opening / closing means (ink collecting port opening / closing mechanism)
100 CPU

Claims (6)

A recording head that performs recording by discharging ink to the recording medium based on image information, a scanning unit that mounts the recording head and moves along the recording medium, and supports the recording medium at a position facing the recording head A platen, an ink collecting port for collecting ink ejected outside the edge of the recording medium, suction means connected to the ink collecting port so as to generate a suction force, and the ink collecting unit An opening and closing means for opening and closing the mouth, and a control unit for controlling the opening and closing means,
An image forming apparatus that closes an ink collecting port when the scanning unit moves to a position that covers the ink collecting port located at an edge of a recording medium when performing recording with a margin. .   The image forming apparatus according to claim 1, wherein when performing recording with a margin, the ink collecting port is closed when the scanning unit moves to a position covering the ink collecting port.   The image forming apparatus according to claim 1, wherein the ink collection port is opened when the recording head is not discharging ink.   4. The image forming apparatus according to claim 1, wherein opening and closing of the ink collecting port is controlled according to image information.   4. The image forming apparatus according to claim 1, wherein opening and closing of the ink collection port is controlled according to a position of the scanning unit. 5.   The image forming apparatus according to claim 1, wherein the ink collecting port is opened when printing without margins.

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