JP6079428B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus that records images on the front and back surfaces of a sheet.

  Conventionally, an ink jet recording apparatus capable of recording an image on both sides of a sheet is known. Such an ink jet recording apparatus includes, for example, a transport unit that transports paper in a transport direction, a recording unit that records an image by ejecting ink onto the paper transported by the transport unit, and an image formed by the recording unit. And a reversing unit that reverses the recorded paper to reach the transport unit.

  Patent Document 1 describes an image recording apparatus in which a media sensor that detects the presence or absence of paper is mounted in a recording unit. This media sensor includes a light emitting unit that emits light and a light receiving unit that receives reflected light of the light emitted from the light emitting unit. Then, it is determined that there is a sheet when the amount of reflected light received by the light receiving unit is equal to or greater than the threshold, and it is determined that there is no sheet when the amount is less than the threshold.

JP 2006-273507 A

  In the ink jet recording apparatus configured as described above, since the paper that has absorbed the ink tends to float, there is a possibility that the paper transported by the transport unit to record an image on the back surface may come into contact with the recording unit. When the paper comes into contact with the nozzles provided in the recording unit, the paper is soiled. In particular, if the paper continues to be conveyed in contact with the nozzles, the stain becomes large.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ink jet recording apparatus that prevents the paper from being soiled due to contact with the recording unit when image recording is performed on both sides of the paper. There is.

  (1) An ink jet recording apparatus according to the present invention includes a transport unit that transports paper in a transport direction, a recording head that ejects ink onto the paper transported by the transport unit, and a sensor that outputs a signal corresponding to the presence or absence of the paper A recording unit having a carriage mounted with the recording head and the sensor and reciprocatingly moved in a main scanning direction orthogonal to the conveyance direction, a reversing unit for reversing the front and back of the sheet to reach the conveying unit, and a sheet A first recording process, which is a recording process for recording an image on the surface of the paper, a reversing process for inverting the front and back of the paper on which the first recording process has been performed and reaching the transport unit, and a paper reversed by the reversing process And a control unit that executes a second recording process, which is a recording process for recording an image on the back surface of the recording medium. The recording process is based on a cueing process in which a sheet is conveyed to the conveying unit until an area where an image is first recorded reaches a position where the recording head can face, and a signal output from the sensor. A detection process for detecting the presence or absence of a sheet at the position of the recording unit, and the recording head for conveying the sheet to the conveyance unit by a predetermined line feed width in the conveyance direction and conveying the sheet by a predetermined line feed width And at least a discharge process for discharging ink. In the first recording process, the control unit executes the cueing process in a state where the carriage is arranged at a position where the passage area of the sheet conveyed by the conveyance unit and the sensor face each other. In the second recording process, the control unit executes the cueing process in a state where the carriage is arranged at a position outside the passage area, and the sheet conveyed by the cueing process and the sensor Further, a sheet facing process for moving the carriage to a position where the two face each other is further executed.

  According to the above configuration, since the cueing process is executed in the second recording process with the carriage being out of the paper passage area, it is possible to prevent the paper from contacting the recording head during the cueing process.

  (2) Preferably, in the first recording process, the control unit executes a passing area facing process for moving the carriage to a position where the passing area and the sensor face each other prior to the cueing process. Further, the control unit executes a carriage retracting process for retracting the carriage to a position outside the passing area in the second recording process prior to the cueing process.

  According to the above configuration, the passage area and the sensor can be reliably faced at the start of execution of the cueing process included in the first recording process. Similarly, the carriage can be reliably arranged at a position outside the passage area at the start of execution of the cueing process included in the second recording process.

  (3) Preferably, in the detection process, the control unit detects both end positions of the paper in the main scanning direction based on a signal output from the sensor. Then, in the carriage retracting process included in the second recording process, the control unit retracts the carriage to a position deviating from between both end positions of the paper detected in the detection process included in the first recording process. .

  According to the above configuration, in the second recording process, the carriage retraction position is determined based on the both end positions of the paper detected in the detection process, and therefore the carriage moving distance in the carriage retraction process and the paper facing process is shortened. Can do. As a result, the throughput of the recording process is further improved.

  (4) Preferably, in the detection process included in the second recording process, the control unit includes a predetermined range including both end positions of the paper detected in the detection process included in the first recording process. Is scanned by the sensor to detect the positions of both ends of the paper.

  According to the above configuration, in the detection process included in the second recording process, it is only necessary to cause the sensor to scan a predetermined range including the both end positions of the paper, so that the throughput of the recording process is further improved.

  (5) Preferably, the control unit further executes an acquisition process for acquiring a recording instruction including information specifying a size of a sheet on which an image is recorded in the recording process. The control unit moves the carriage to a position where the passage area and the sensor face each other based on the size of the paper acquired in the acquisition process in the passage area facing process included in the first recording process. Let

  (6) Specifically, in the passing area facing process included in the first recording process, the control unit sets the passing area in the passing area among a plurality of stop positions provided apart in the main scanning direction. The carriage is moved to a stop position that is included and is closest to the end of the passing area. Then, the control unit notifies that the sheet conveyed by the conveying unit is different from the size of the sheet included in the recording instruction on condition that the sheet cannot be detected in the detection process included in the first recording process. The notification process is performed.

  According to the above configuration, the notification process is executed when the size of the sheet actually transported by the transport unit is smaller than the size of the sheet specified by the recording instruction. As a result, it is possible to suppress contamination due to ink landing on the outside of the paper.

  (7) Preferably, the ink jet recording apparatus further includes an ink receiving portion that is provided in a position within the moving range of the carriage and out of the passage region, and that receives ink discharged from the recording head. The control unit retracts the carriage to a position facing the ink receiving unit in the carriage retracting process included in the second recording process.

  According to the above configuration, the process of calculating the retracted position of the carriage according to the paper size can be omitted.

  (8) Preferably, the control unit performs the passing area facing process on the condition that the upper carriage is disposed at a position deviating from the passing area at the start of the first recording process. Run prior to.

  According to the above configuration, the passing area facing process is executed only when the carriage is arranged at a position outside the passing area at the start of the first recording process. In other words, when the above condition is not satisfied, the passing area facing process is not executed. As a result, the throughput of the recording process is improved.

  (9) Preferably, the control unit changes the carriage retracting process to the cueing process on the condition that the carriage is disposed at a position facing the passing area at the start of the second recording process. Run in advance.

  According to the above configuration, the carriage retracting process is executed only when the carriage is arranged at a position facing the passing area at the start of the second recording process. In other words, the carriage retracting process is not executed when the above conditions are not satisfied. As a result, the throughput of the recording process is improved.

  (10) As an example, the control unit performs the second recording on the sheet on the condition that there is no image to be recorded on the back surface of one of the plurality of sheets on which images are sequentially recorded. In the process, the cueing process is executed in a state where the carriage is arranged at a position outside the passage area, and the sheet facing process, the detection process, and the ejection process are omitted.

  (11) Preferably, the carriage has an inclined surface inclined upward from a side near the recording head to a side far from the recording head at a position adjacent to the recording head in the main scanning direction and facing the sheet. .

  According to the above configuration, in the sheet facing process included in the second recording process, the lifted sheet can be pressed downward while being brought into contact with the inclined surface. As a result, it is possible to more effectively prevent the sheet from coming into contact with the recording head.

  (12) As an example, the ink jet recording apparatus includes a first transport path extending in the first transport direction that is the transport direction, a branch position that branches from the first transport path, and the first transport direction from the branch position. And a main body formed with a second transport path that extends in the second transport direction from the branch position toward the merge position. The transport unit is provided in the first transport path downstream of the merging position in the first transport direction, and a first transport roller pair that transports the paper on the first transport path in the first transport direction. And a sheet on the first conveyance path that is provided downstream of the first conveyance roller pair in the first conveyance direction and upstream from the branch position in the first conveyance direction. And a second transport roller pair for transporting the ink in the first transport direction. The reversing unit is provided in the first conveyance path on the downstream side in the first conveyance direction from the branch position, and the sheet on which the image is recorded by the recording unit is disposed on the upstream side in the first conveyance direction. A reversing roller pair that conveys the end portion as a leading end to the second conveying path and a sheet that is provided in the second conveying path and is conveyed to the second conveying path by the reversing roller pair in the second conveying direction. And a pair of re-conveying rollers for conveying the sheet. The recording unit is provided in the first conveyance path on the downstream side in the first conveyance direction from the first conveyance roller pair and on the upstream side in the first conveyance direction from the second roller pair.

  (13) Preferably, the first transport path includes a curved portion that curves along the first transport direction. The first conveying roller pair is provided at an end of the curved portion on the downstream side in the first conveying direction.

  The present invention can be expected to have a particularly advantageous effect when a sheet is conveyed on a conveyance path that is curved on the upstream side of the recording unit as in the above configuration.

  According to the present invention, in the second recording process, the cueing process is executed in a state where the carriage is out of the passage area of the paper, so that the paper can be prevented from coming into contact with the recording head during the cueing process.

FIG. 1 is a perspective view of the multifunction machine 10. FIG. 2 is a longitudinal sectional view schematically showing the internal structure of the printer unit 11. FIG. 3 is a plan view of the carriage 40 and the guide rails 53 and 54. 4A and 4B are views showing the carriage 40, where FIG. 4A is a rear view, FIG. 4B is a bottom view, and FIG. 4C is a right side view. FIG. 5 is a block diagram illustrating a configuration of the control unit 130. FIG. 6 is a flowchart showing the procedure of the image recording process. FIG. 7 is a flowchart showing the procedure of the recording process, where (A) shows the first recording process and (B) shows the second recording process. FIG. 8 is a diagram showing the relationship between the passage area of the paper 12 and the stop position of the carriage 40.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. The embodiment described below is merely an example of the present invention, and it is needless to say that the embodiment of the present invention can be changed as appropriate without departing from the gist of the present invention. The multifunction machine 10 is installed and used in the state shown in FIG. In the present embodiment, the vertical direction 7 is defined with reference to a state in which the multifunction machine 10 is installed (the state shown in FIG. 1), and the front-rear direction 8 is defined as the front side (front side) where the opening 13 is formed. The left-right direction 9 is defined when the multifunction machine 10 is viewed from the front side. The three directions shown in FIG. 1 are similarly displayed in other drawings.

[Overall structure of MFP 10]
The multifunction machine 10 (an example of the ink jet recording apparatus of the present invention) has various functions such as a facsimile function and a print function. As shown in FIG. 1, the multifunction machine 10 according to this embodiment includes a printer unit 11 (an example of a main body of the present invention) having a double-sided image recording function for recording images on both sides of a sheet 12 (see FIG. 2). ing. An opening 13 is formed in the front of the printer unit 11. A paper feed tray 20 (see FIG. 2) and a discharge tray 21 (see FIG. 2) capable of supporting the paper 12 can be inserted and removed in the front-rear direction 8 through the opening 13.

  A first transport path 65 extends from the rear end of the paper feed tray 20 inside the printer unit 11. The first transport path 65 includes a curved portion that curves along the first transport direction 15 and a straight portion that extends in the front-rear direction 8. The first transport path 65 is partitioned by an outer guide member 18 and an inner guide member 19 that face each other with a predetermined interval. The paper 12 supported on the paper feed tray 20 is conveyed so as to make a U-turn from the lower side to the upper side of the curved portion, and then conveyed along the straight portion toward the recording unit 24. The paper 12 on which image recording has been performed by the recording unit 24 is transported through the linear portion and discharged to the discharge tray 21. In other words, the sheet 12 is conveyed in the first conveyance direction 15 indicated by the one-dot chain line arrow in FIG.

  A second transport path 67 is provided inside the printer unit 11. The second conveyance path 67 branches from the first conveyance path 65 at the branch position 36 and extends so as to merge with the first conveyance path 65 at the merge position 37 upstream of the first conveyance direction 15 from the branch position 36. It is. That is, the second transport path 67 is connected to the first transport path 65 at the branch position 36 and the merge position 37. The second transport path 67 is partitioned by guide members 31 and 32 that face each other in the vertical direction 7. The sheet 12 switched back at the branch position 36 is transported along the second transport path 67 in the second transport direction 16 (direction indicated by a two-dot chain line arrow in FIG. 2) from the branch position 36 to the merge position 37. It is again guided to the first conveyance path 65.

  As shown in FIG. 2, a paper feed roller 25 is provided on the upper side of the paper feed tray 20. The paper feed roller 25 is rotatably provided on the front end side of the paper feed arm 26. The paper feed arm 26 is rotatably provided on a shaft 27 supported by the frame of the printer unit 11. The paper feed arm 26 is urged to rotate toward the paper feed tray 20 by its own weight or an elastic force by a spring or the like. As a result, the paper feed roller 25 contacts the upper surface of the paper 12 supported by the paper feed tray 20. The paper feed roller 25 rotates in the forward direction with the reverse driving force of the conveying motor 102 (see FIG. 5). The forward rotation of the paper feed roller 25 is a rotation in a direction in which the paper 12 is sent to the first transport path 65 and transported on the first transport path 65 in the first transport direction 15. That is, the forward rotation of the paper feed roller 25 when the printer unit 11 is viewed from the direction of FIG. 2 is a clockwise rotation.

[Conveying roller pair, discharge roller pair, reverse roller pair, re-conveying roller pair]
As shown in FIG. 2, in the first conveyance path 65, a conveyance roller pair (an example of the first conveyance roller pair of the present invention) including a first conveyance roller 60 and a pinch roller 61, a second conveyance roller 62, and A pair of discharge rollers provided with a spur 63 (an example of a second transport roller pair of the present invention) and a pair of reverse rollers provided with a third transport roller 45 and a spur 46 are provided. The second transport path 67 is provided with a re-transport roller pair including a fourth transport roller 68 and a driven roller 69. Each roller pair conveys the paper 12 by rotating in a state where the paper 12 is sandwiched. The transport roller pair and the discharge roller pair constitute an example of a transport unit according to the present invention that transports the paper 12 in the first transport direction 15. The reversing roller pair and the re-conveying roller pair constitute an example of the reversing unit of the present invention that reverses the front and back of the paper 12 to reach the conveying unit.

  The pair of transport rollers is provided on the downstream side from the joining position 37 and on the upstream side from the recording unit 24 in the first transport direction 15. More specifically, the transport roller pair is provided in the vicinity of the end of the curved portion of the first transport path 65 (that is, the downstream end of the first transport direction 15). The first transport roller 60 is externally fitted to a rotating shaft 34 to which a driving force is applied from a transport motor 102 capable of normal rotation and reverse rotation, and rotates integrally with the shaft 34. On the other hand, the pinch roller 61 is disposed to face the first transport roller 60 and is rotated along with the rotation of the first transport roller 60. The first transport roller 60 and the pinch roller 61 sandwich the paper 12 and transport it in the first transport direction 15.

  The first transport roller 60 is rotated forward by receiving a normal driving force from the transport motor 102. Here, the forward rotation of the first transport roller 60 is a rotation in a direction in which the paper 12 is transported in the first transport direction 15. That is, when the printer unit 11 is viewed from the direction of FIG. 2, the forward rotation of the first conveying roller 60 is a counterclockwise rotation, and the forward rotation of the pinch roller 61 is a clockwise rotation. Hereinafter, the expression “forward rotation of the conveyance roller pair” means that the first conveyance roller 60 shown in FIG. 2 rotates counterclockwise and the pinch roller 61 rotates clockwise.

  On the other hand, the first transport roller 60 is reversely rotated by applying a reverse driving force from the transport motor 102. The reverse rotation of the first conveyance roller 60 is a rotation in a direction in which the paper 12 is conveyed in a direction opposite to the first conveyance direction 15. That is, the reverse rotation of the first conveying roller 60 viewed from the direction of FIG. 2 is a clockwise rotation, and the reverse rotation of the pinch roller 61 is a counterclockwise rotation. Hereinafter, the expression “reverse rotation of the conveying roller pair” means that the first conveying roller 60 shown in FIG. 2 rotates clockwise and the pinch roller 61 rotates counterclockwise.

  The discharge roller pair is provided downstream of the recording unit 24 and upstream of the branch position 36 in the first transport direction 15. The second transport roller 62 is fitted around a shaft 64 that is rotated by a driving force applied from the transport motor 102, and rotates integrally with the shaft 64. On the other hand, the spur 63 is disposed to face the second transport roller 62 and is rotated along with the rotation of the second transport roller 62. The second transport roller 62 and the spur 63 sandwich the paper 12 and transport it in the first transport direction 15.

  The second transport roller 62 is rotated forward by receiving a normal driving force from the transport motor 102. Here, the forward rotation of the second transport roller 62 is a rotation in a direction in which the paper 12 is transported in the first transport direction 15. That is, the forward rotation of the second transport roller 62 viewed from the direction of FIG. 2 is a clockwise rotation, and the forward rotation of the spur 63 is a counterclockwise rotation. Hereinafter, the expression “forward rotation of the discharge roller pair” means that the second transport roller 62 shown in FIG. 2 rotates clockwise and the spur 63 rotates counterclockwise.

  On the other hand, the second conveyance roller 62 is reversely rotated by applying a reverse driving force from the conveyance motor 102. The reverse rotation of the second transport roller 62 is a rotation in a direction in which the paper 12 is transported in the direction opposite to the first transport direction 15. That is, the reverse rotation of the second transport roller 62 viewed from the direction of FIG. 2 is a counterclockwise rotation, and the reverse rotation of the spur 63 is a clockwise rotation. Hereinafter, the expression “reverse rotation of the discharge roller pair” means that the second transport roller 62 shown in FIG. 2 rotates counterclockwise and the spur 63 rotates clockwise.

  The reverse roller pair is provided downstream of the branch position 36 in the first transport direction 15. The third transport roller 45 is fitted on a shaft 44 that is rotated by a driving force applied from the transport motor 102, and rotates integrally with the shaft 44. On the other hand, the spur 46 is disposed so as to face the third transport roller 45 and is rotated along with the rotation of the third transport roller 45. The third transport roller 45 and the spur 46 sandwich the paper 12 and transport it in the first transport direction 15 or the second transport direction 16.

  The third transport roller 45 is forwardly rotated by being supplied with a normal driving force from the transport motor 102. Here, the forward rotation of the third transport roller 45 is a rotation in a direction in which the paper 12 is transported in the first transport direction 15. That is, the forward rotation of the third conveying roller 45 viewed from the direction of FIG. 2 is a clockwise rotation, and the forward rotation of the spur 46 is a counterclockwise rotation. Hereinafter, the expression “forward rotation of the pair of reverse rollers” indicates that the third transport roller 45 shown in FIG. 2 rotates clockwise and the spur 46 rotates counterclockwise.

  On the other hand, the third conveyance roller 45 is reversely rotated by applying a reverse driving force from the conveyance motor 102. The reverse rotation of the third transport roller 45 is a rotation in the direction in which the paper 12 is transported in the direction opposite to the first transport direction 15. That is, the reverse rotation of the third transport roller 45 viewed from the direction of FIG. 2 is a counterclockwise rotation, and the reverse rotation of the spur 46 is a clockwise rotation. Hereinafter, the expression “reverse rotation of the reverse roller pair” means that the third transport roller 45 shown in FIG. 2 rotates counterclockwise and the spur 46 rotates clockwise.

  The re-transport roller pair is provided in the second transport path 67. The fourth transport roller 68 is rotated by a driving force applied from a transport motor 102 capable of forward drive and reverse drive. On the other hand, the driven roller 69 is disposed so as to face the fourth transport roller 68, and rotates with the rotation of the fourth transport roller 68. The fourth transport roller 68 and the driven roller 69 cooperate to sandwich the paper 12 and transport it in the second transport direction 16.

  The 4th conveyance roller 68 is supported by the arm 70, as FIG. 2 shows. The arm 70 rotatably supports the fourth transport roller 68 on one end side, and the other end side is rotatably supported on the printer unit 11. Further, the end portion on the side supported by the printer unit 11 is disposed upstream of the second conveyance direction 16 with respect to the end portion on the side supporting the fourth conveyance roller 68. As a result, the arm 70 can bring the fourth transport roller 68 into and out of contact with the driven roller 69. More specifically, the arm 70 presses the fourth transport roller 68 against the driven roller 69 when a force opposite to the second transport direction 16 is applied to the sheet 12 sandwiched between the pair of re-transport rollers. Operate.

  The fourth transport roller 68 rotates forward regardless of the rotation direction (forward rotation drive and reverse rotation drive) of the transport motor 102. Here, the forward rotation of the fourth transport roller 68 is a rotation in a direction in which the paper 12 is transported in the second transport direction 16. That is, the forward rotation of the fourth transport roller 68 viewed from the direction of FIG. 2 is a counterclockwise rotation, and the forward rotation of the driven roller 69 is a clockwise rotation. Hereinafter, the expression “forward rotation of the re-conveying roller pair” means that the fourth conveying roller 68 shown in FIG. 2 rotates counterclockwise and the driven roller 69 rotates clockwise.

[Recording unit 24]
As shown in FIG. 2, in the first transport path 65, the recording unit 24 is downstream of the first transport roller 60 in the first transport direction 15 and upstream of the second transport roller 62 in the first transport direction 15. Is provided. A platen 42 is provided below the recording unit 24 and at a position facing the recording unit 24 with the first conveyance path 65 interposed therebetween. The platen 42 supports the paper 12 that is transported through the first transport path 65. The recording unit 24 records an image on the paper 12 supported by the platen 42 by a known inkjet method. The recording unit 24 includes a recording head 38 in which a plurality of nozzles that eject ink droplets are formed on the paper 12, a media sensor 76 (see FIG. 4 as an example of the sensor of the present invention), an encoder sensor 78 A, and the recording head 38. , A media sensor 76, and a carriage 40 on which an encoder sensor 78A is mounted.

  As shown in FIG. 3, the carriage 40 is supported by guide rails 53 and 54 that extend in the left-right direction 9 at positions separated in the front-rear direction 8. The guide rails 53 and 54 are supported by the printer unit 11. The carriage 40 is connected to a known belt mechanism provided on the guide rail 54. The belt mechanism includes a drive pulley 57 provided at one end of the guide rail 54 in the left-right direction 9, a driven pulley 58 provided at the other end, and an endless annular belt 59 wound around the drive pulley 57 and the driven pulley 58. And have. The driving pulley 57 is driven by a carriage driving motor 103 (see FIG. 5). The carriage 40 is connected to a belt 59 on the bottom side. The driving pulley 57 is rotated by the carriage driving motor 103, and the belt 59 moves in the circumferential direction by the rotation of the driving pulley 57, whereby the carriage 40 connected to the belt 59 reciprocates in the left-right direction 9.

  The recording head 38 is mounted on the carriage 40 as shown in FIG. A plurality of nozzles are formed on the lower surface of the recording head 38 as shown in FIG. Ink is supplied to the recording head 38 from an ink cartridge through an ink tube. The recording head 38 ejects ink as fine ink droplets from the nozzles. In the process of moving the carriage 40, an image is recorded on the paper 12 by ejecting ink droplets from the recording head 38 onto the paper 12 supported by the platen 42.

[Inclined surface 40A]
The carriage 40 has an inclined surface 40 </ b> A that is inclined upward from the side close to the recording head 38 to the side far from the recording head 38 at a position adjacent to the recording head 38 and facing the paper 12 in the left-right direction 9. The inclined surface 40A is provided to abut against the sheet 12 that has floated and push the sheet 12 downward when the carriage 40 moves to the right. In the present embodiment, an example in which the inclined surface 40A is provided only on the right side of the recording head 38 is shown, but the present invention is not limited to this, and an inclined surface may be provided on the left side of the recording head 38.

[Media sensor 76]
As shown in FIG. 4, the media sensor 76 is mounted on the carriage 40 at a position adjacent to the recording head 38 in the left-right direction 9 on the lower surface of the carriage 40 (the surface facing the platen 42). The media sensor 76 is used to detect the paper 12 conveyed through the first conveyance path 65. The media sensor 76 includes a light emitting unit composed of a light emitting diode and the like, and a light receiving unit composed of an optical sensor or the like. The light emitting unit emits light toward the platen 42 with the amount of light instructed by the control unit 130. The light applied to the platen 42 is reflected by the platen 42 or the paper 12 supported by the platen 42, and the reflected light is received by the light receiving unit. The media sensor 76 outputs a signal corresponding to the amount of reflected light received by the light receiving unit to the control unit 130. For example, the media sensor 76 outputs a higher level signal to the control unit 130 as the amount of received light is larger.

  The encoder sensor 78A is mounted on the lower surface of the carriage 40 as shown in FIG. Further, as shown in FIG. 3, the guide rail 54 is provided with a belt-like encoder strip 78 </ b> B extending in the left-right direction 9. The encoder sensor 78A and the encoder strip 78B are disposed at positions facing each other in the up-down direction 7. In the process of moving the carriage 40, the encoder sensor 78A reads the encoder strip 78B to generate a pulse signal, and outputs the generated pulse signal to the control unit 130. The encoder sensor 78A and the encoder strip 78B constitute the carriage sensor 78 shown in FIG.

[Abutment lever 80]
Further, a contact lever 80 is provided on the right end side of the guide rail 53 as shown in FIG. The contact lever 80 is disposed at a position where it can contact the carriage 40. The abutment lever 80 abuts on the carriage 40 that moves from left to right and moves to the right, moves away from the carriage 40 that moves from right to left, and returns to the left. A driving force transmission mechanism 104 described later switches whether to transmit the driving force of the conveyance motor 102 to the paper feed roller 25 according to the position of the contact lever 80. Hereinafter, the position of the contact lever 80 shown in FIG. 3 is referred to as a first position, and the position of the contact lever 80 that has been contacted with the carriage 40 and moved rightward is referred to as a second position.

[First sensor 160 and second sensor 170]
As shown in FIG. 2, in the first transport path 65, the first sensor is located upstream of the first transport roller 60 in the first transport direction 15 and downstream of the merge position 37 in the first transport direction 15. 160 is provided. The first sensor 160 includes a shaft 161, a detector 162 that can rotate around the shaft 161, and an optical sensor 163 that includes a light emitting element and a light receiving element that receives light emitted from the light emitting element. Yes.

  One end of the detector 162 protrudes into the first conveyance path 65. When an external force is not applied to one end of the detector 162, the other end of the detector 162 enters an optical path from the light emitting element to the light receiving element of the optical sensor 163, and blocks light passing through the optical path. At this time, the optical sensor 163 outputs a low level signal (refers to a “signal whose signal level is less than the threshold”) to the control unit 130 described later. On the other hand, when one end of the detector 162 is pushed and rotated by the downstream end of the first conveying direction 15 of the paper 12, the other end of the detector 162 is removed from the optical path, and light passes through the optical path. At this time, the optical sensor 163 outputs a high level signal (refers to “a signal having a signal level equal to or higher than a threshold”) to the control unit 130. That is, the first sensor 160 outputs a detection signal according to the presence or absence of the paper 12 at the position where the first sensor 160 is installed to the control unit 130.

  In the first conveyance path 65, a second sensor 170 is provided on the downstream side in the first conveyance direction 15 from the recording unit 24 and the second conveyance roller 62 and on the upstream side in the first conveyance direction 15 from the branch position 36. Yes. Similar to the first sensor 160, the second sensor 170 includes a shaft 171, a detector 172, and an optical sensor 173. Similar to the first sensor 160, the second sensor 170 outputs a detection signal according to the presence or absence of the paper 12 at the position where the second sensor 170 is installed to the control unit 130.

[Rotary encoder 73]
As shown in FIG. 2, the first transport roller 60 is provided with a rotary encoder 73 that generates a pulse signal by the rotation of the first transport roller 60. The rotary encoder 73 is provided on the shaft 34 of the first transport roller 60 and rotates with the first transport roller 60, and the encoder disk 74 is sandwiched from the thickness direction (a direction perpendicular to the paper surface of FIG. 2). The optical sensor 72 is provided. In the encoder disk 74, transmissive portions through which light is transmitted and non-transmissive portions through which light is not transmitted are alternately arranged at equal pitches in the circumferential direction. The optical sensor 72 emits light from a light emitting unit (not shown) toward the encoder disk 74, and the light passing through the encoder disk 74 is received by a light receiving unit (not shown).

  When the light emitting part of the optical sensor 72 and the transmission part of the encoder disk 74 face each other, the light output from the light emitting part is received by the light receiving part. At this time, the optical sensor 72 outputs a high level signal to the control unit 130. On the other hand, when the light emitting part of the optical sensor 72 and the non-transmissive part of the encoder disk 74 face each other, the light output from the light emitting part is not received by the light receiving part. At this time, the optical sensor 72 outputs a low level signal to the control unit 130. As a result, the encoder disk 74 is rotated (in other words, the conveying motor 102 or the first conveying roller 60 is rotated), whereby a pulse signal is output from the optical sensor 72 to the control unit 130.

[Route switching member 41]
As shown in FIG. 2, in the first conveyance path 65, the second conveyance roller 62 is downstream in the first conveyance direction 15 and the third conveyance roller 45 is upstream in the first conveyance direction 15 (that is, the branch position). 36), a path switching member 41 is provided. The path switching member 41 includes auxiliary rollers 47 and 48, a flap 49, and a shaft 87. The flap 49 extends substantially from the shaft 87 in the first conveying direction 15 and is pivotally supported by the shaft 87 so as to be rotatable. The spur-shaped auxiliary rollers 47 and 48 are rotatably supported by the flap 49. The flap 49 pivots about the shaft 87, so that the discharge posture (the posture indicated by the broken line in FIG. 2) positioned above the branch position 36 relative to the inner guide member 19 and the extended end portion 49A branch. The posture can be changed to a reverse posture (posture indicated by a solid line in FIG. 2) located below the position 36.

  The flap 49 in the normal state is in an inverted posture due to its own weight. Then, the flap 49 is rotated around the shaft 87 by being lifted by the paper 12 conveyed through the first conveyance path 65, and changes its posture from the reverse posture to the discharge posture. Thereafter, the flaps 49 (specifically, the auxiliary rollers 47 and 48) contact the paper 12 and guide the paper 12. When the upstream end (that is, the rear end) of the sheet 12 in the first conveyance direction 15 passes through the auxiliary roller 47, the flap 49 changes its posture from the discharge posture to the reverse posture due to its own weight. Thereby, the rear end of the first conveyance direction 15 of the paper 12 faces downward (that is, the entrance of the second conveyance path 67). When the third transport roller 45 continues to rotate forward in this state, the paper 12 is transported in the first transport direction 15 and discharged to the discharge tray 21. On the other hand, when the rotation of the third conveyance roller 45 is switched from the forward rotation to the reverse rotation, the sheet 12 is guided to the second conveyance path 67 with the end on the upstream side in the first conveyance direction 15 as the leading end.

[Discharged ink tray 50]
As shown in FIG. 3, the waste ink tray 50 (an example of the ink receiving portion of the present invention) is disposed at the right end in the left-right direction 9 (that is, the position deviated from the passage region of the paper 12) within the movement range of the carriage 40. Is provided. The upper surface of the waste ink tray 50 facing the lower surface of the recording head 38 is opened, and can receive ink droplets discharged from the recording head 38 by the flushing process. The flushing process is a process in which the recording head 38 discharges ink from the nozzle hole of each nozzle toward the waste ink tray 50. The ink having increased viscosity due to drying or the like is discharged from each nozzle by the flushing process and landed on the discharged ink tray 50.

[Driving force transmission mechanism 104]
The driving force transmission mechanism 104 shown in FIG. 5 uses the driving force of the conveying motor 102 as a feed roller 25, a first conveying roller 60, a second conveying roller 62, a third conveying roller 45, and a fourth conveying roller 68. To communicate. The driving force transmission mechanism 104 is configured by combining all or part of a gear, a pulley, an endless annular belt, a planetary gear mechanism (pendulum gear mechanism), a one-way clutch, and the like.

  Specifically, the driving force transmission mechanism 104 does not transmit the normal driving force of the conveying motor 102 to the paper feed roller 25 in the state where the contact lever 80 is in the first position, and reversely rotates the conveying motor 102. The paper feeding roller 25 is rotated forward by the driving force. On the other hand, the drive force transmission mechanism 104 does not transmit the forward drive force and the reverse drive force of the transport motor 102 to the paper feed roller 25 in a state where the contact lever 80 is in the second position.

  In addition, the driving force transmission mechanism 104 has the first conveyance roller 60, the second conveyance roller 62, the third conveyance roller 45, and the fourth conveyance force by the normal rotation driving force of the conveyance motor 102 regardless of the position of the contact lever 80. The transport roller 68 is rotated forward, the fourth transport roller is rotated forward by the reverse driving force of the transport motor 102, and the first transport roller 60, the second transport roller 62, and the third transport roller 45 are rotated in reverse.

[Control unit 130]
The control unit 130 controls the overall operation of the multifunction machine 10. As shown in FIG. 5, the control unit 130 includes a CPU 131, a ROM 132, a RAM 133, an EEPROM 134, an ASIC 135, and an internal bus 137 that interconnects these components.

  The ROM 132 stores a program for the CPU 131 to control various operations. The RAM 133 is used as a storage area for temporarily recording data, signals, and the like used when the CPU 131 executes the program. The EEPROM 134 stores settings, flags, and the like that should be retained even after the power is turned off.

  The ASIC 135 is electrically connected to a transport motor 102 and a carriage drive motor 103. The ASIC 135 acquires a drive signal for rotating each motor from the CPU 131, and outputs a drive current corresponding to the drive signal to the corresponding motor. Each motor is driven to rotate forward or reversely at a predetermined rotational speed by the drive current output from the ASIC 135.

  Further, the rotary encoder 73, the media sensor 76, the carriage sensor 78, the first sensor 160, and the second sensor 170 are electrically connected to the ASIC 135. The control unit 130 detects the amount of rotation of each roller 25, 60, 62, 45, 68 based on the pulse signal acquired from the rotary encoder 73. Further, the control unit 130 detects the presence or absence of the sheet 12 at the position facing the carriage 40 or the end position of the sheet 12 in the width direction based on the signal acquired from the media sensor 76. The control unit 130 detects the position of the carriage 40 in the left-right direction 9 based on the pulse signal output from the carriage sensor 78. Further, the control unit 130 detects the position of the paper 12 based on the detection signals acquired from the first sensor 160 and the second sensor 170.

[Image recording processing]
With reference to FIGS. 6-8, the image recording process by the multifunction machine 10 is demonstrated. The image recording process is executed by the CPU 131 of the control unit 130. The following processes may be executed by the CPU 131 reading out and executing a program stored in the ROM 132, or may be realized by a hardware circuit mounted on the control unit 130.

  As shown in FIG. 6, the control unit 130 supplies the paper 12 supported by the paper feed tray 20 to the first conveyance path 65 on the condition that an image recording instruction has been acquired from the user (S11: Yes). A paper feed process for paper is executed (S12). The acquisition destination of the image recording instruction is not particularly limited. For example, the image recording instruction may be acquired through an operation panel provided in the multifunction machine 10 or may be acquired from an external device through a communication network. The image recording instruction includes, for example, the number of pages on which image recording is performed, the size of the paper 12 on which image recording is performed, and image data recorded on each page.

  In the paper feeding process (S12), the control unit 130 rotates the transport motor 102 in the reverse direction with the contact lever 80 being in the first position, thereby rotating the paper feed roller 25 in the forward direction and the first transport roller. 60, the 2nd conveyance roller 62, the 3rd conveyance roller 45, and the 4th conveyance roller 68 are reversely rotated. Accordingly, the paper feed roller 25 sends the uppermost paper 12 out of the plurality of papers 12 supported by the paper feed tray 20 to the first transport path 65. In addition, the control unit 130 counts pulse signals output from the rotary encoder 73.

  The controller 130 continues the paper feed process (S12) until the number of pulse signals from the time when the low level signal is acquired from the first sensor 160 reaches a predetermined threshold value. The predetermined threshold value is used when the leading edge of the sheet 12 that has reached the position of the first sensor 160 (refers to the “end on the downstream side in the first conveying direction 15”, hereinafter the same) reaches the first conveying roller 60. This is the number of pulse signals corresponding to the necessary transport distance. In other words, the predetermined threshold is the number of pulse signals corresponding to the rotation amount of the paper feed roller 25 (in other words, the rotation amount of the conveyance motor 102) necessary for conveying the paper 12 by the above-described conveyance distance. . As a result, the leading edge of the paper 12 reaches the first transport roller 60. Further, the skew of the paper 12 is corrected by the front end of the paper 12 coming into contact with the first conveying roller 60 that is rotating in the reverse direction.

  Next, when the leading edge of the paper 12 reaches the pair of conveyance rollers, the control unit 130 executes a first recording process (S13). The first recording process is a process of recording an image on the surface of the paper 12. Details of the first recording process will be described with reference to FIG.

  First, as shown in FIG. 7A, the control unit 130 specifies the position of the carriage 40 in the left-right direction 9 based on the pulse signal output from the carriage sensor 78 (S21). When the carriage 40 is disposed at a position outside the passage area of the paper 12 (S21: No), the control unit 130 executes a passage area facing process (S22). On the other hand, when the carriage 40 is arranged at a position where the passing area and the media sensor 76 face each other (S21: Yes), the execution of the passing area facing process (S22) is omitted. The passage area of the paper 12 may be specified based on the size of the paper 12 included in the image recording instruction, or may be specified based on the maximum paper size that can pass through the first conveyance path 65, for example. Also good.

  The passing area facing process (S22) is a process of moving the carriage 40 to a position where the passing area and the media sensor 76 face each other. More specifically, in the passing area facing process, the control unit 130, for example, as shown in FIG. 8, among the plurality of stop positions 55A, 55B, and 55C provided in advance in the left-right direction 9, the paper The carriage 40 is moved to a stop position 55B that is included in the 12 passing areas and is closest to the end of the passing area. Note that the stop position selected in the passing area facing process does not have to be the entire carriage 40 facing the passing area, and may be a position where at least the passing area and the media sensor 76 face each other.

  The stop positions 55A, 55B, and 55C are determined in advance at the design stage corresponding to a plurality of paper sizes. For example, the stop position 55 </ b> A is set at a position that is out of the maximum passage area of the paper 12 that can pass through the first transport path 65. The stop position 55B is set at a position that is included in the passage area of the first size paper 12 and that is out of the passage area of the second size paper 12 that is smaller than the first size. Further, the stop position 55C is set to a position that is included in the passage area of the second size paper 12 and is out of the passage area of the third size paper 12 that is smaller than the second size.

  Next, the control unit 130 causes the pair of conveyance rollers to convey the sheet 12 until the area where the image is first recorded reaches a position where the area can face the recording head 38 (hereinafter referred to as “indexing position”). A cueing process is executed (S23). Specifically, the control unit 130 drives the first conveyance roller 60 until the paper 12 reaches the cueing position by driving the conveyance motor 102 in the normal rotation state with the contact lever 80 being in the first position. Rotate forward. The position of the paper 12 can be specified by a pulse signal output from the rotary encoder 73.

  Next, based on the signal output from the media sensor 76, the control unit 130 executes detection processing for detecting the presence or absence of the paper 12 at a position facing the recording unit 24 (more specifically, the carriage 40). (S24). Specifically, the control unit 130 causes the light emitting unit of the media sensor 76 to output light. Then, when the signal level of the signal output from the media sensor 76 exceeds a predetermined threshold value, the control unit 130 determines that the paper 12 is present at a position facing the recording unit 24 (S25: Yes). On the other hand, when the signal level of the signal output from the media sensor 76 is equal to or less than the above threshold, the control unit 130 determines that the sheet 12 does not exist at the position facing the recording unit 24 (S25: No).

  When the sheet 12 is present at a position facing the recording unit 24 (S25: Yes), the control unit 130 executes an ejection process for recording an image on the surface of the sheet 12 (S26). In the ejection process, a process for transporting the paper 12 by a predetermined line feed width in the first transport direction 15 and a process for ejecting ink to the area of the paper 12 facing the recording head 38, and recording an image on the surface of the paper 12 are performed. It is a process that repeats until it finishes. Note that the controller 130 causes the paper 12 to be conveyed to at least one of the conveyance roller pair and the discharge roller pair by driving the conveyance motor 102 in the normal rotation state with the contact lever 80 being in the first position. Further, the control unit 130 drives the carriage driving motor 103 to move the carriage 40 in the left-right direction 9 and causes the recording head 38 to eject ink at a predetermined timing to record an image on the surface of the paper 12. .

  On the other hand, when the sheet 12 does not exist at the position facing the recording unit 24 (S25: No), the control unit 130 performs the discharge process (S26) included in the first recording process and steps S14 to S16 shown in FIG. Execution is omitted and notification processing is executed (S17). The case where the sheet 12 does not exist at the position facing the recording unit 24 is, for example, a case where the size of the sheet 12 actually conveyed is smaller than the size of the sheet 12 included in the image recording instruction.

  Therefore, in the notification process (S17) shown in FIG. 6, the control unit 130 notifies the user that the size of the paper 12 conveyed by the cueing process (S24) is different from the paper size included in the image recording instruction. . The notification method is not particularly limited. For example, a message (or error code) is displayed on the liquid crystal panel, an LED lamp is turned on (or flashes), and a voice message (or beep sound) is output from a speaker. And so on.

  Next, the control unit 130 determines whether image recording on the back surface of the paper 12 is necessary (S14). The necessity of image recording on the back surface of the paper 12 is determined based on information included in the image recording instruction. When image recording on the back surface of the paper 12 is necessary (S14: Yes), the control unit 130 executes a reversal process (S15). On the other hand, when it is not necessary to record an image on the back surface of the paper 12 (S14: No), the control unit 130 omits steps S15 and S16 and executes a discharge process (S18).

  The reversing process (S15) is a process of inverting the front and back of the paper 12 on which the first recording process (S13) has been performed and reaching the pair of conveying rollers. Specifically, the control unit 130 drives the carriage driving motor 103 to move the carriage 40 to the right, thereby moving the contact lever 80 to the second position. Next, the control unit 130 drives the conveyance motor 102 in the normal rotation state with the abutment lever 80 being in the second position, whereby the sheet 12 is fed to the conveyance roller pair, the discharge roller pair, and the reverse roller pair for the first time. Transport in the transport direction 15. Next, the control unit 130 passes the path switching member 41 at the rear end of the sheet 12 (refers to the “upstream end of the first transport direction 15”, hereinafter the same) (that is, the flap 49 is moved from the discharge posture). On the condition that the posture is changed to the reverse posture), the conveyance motor 102 is driven in the reverse direction with the contact lever 80 in the second position. Thus, the sheet 12 is conveyed to the second conveyance path 67 with the upstream end in the first conveyance direction 15 as the head by the reverse roller pair rotating in the reverse direction, and the second conveyance path by the re-conveying roller pair rotating in the forward direction. 67 is conveyed in the second conveyance direction 16. The above reversal process is continued until the paper 12 reaches the pair of conveyance rollers through the merge position 37.

  Next, the control unit 130 executes a second recording process (S16). The second recording process is a process for recording an image on the back surface of the paper 12. Details of the second recording process will be described with reference to FIG. A detailed description of the processes common to the respective processes included in the first recording process will be omitted, and the differences will be mainly described.

  First, as shown in FIG. 7B, the control unit 130 specifies the position of the carriage 40 in the left-right direction 9 based on the pulse signal output from the carriage sensor 78 (S31). This process is common to step S21 shown in FIG. When the carriage 40 is disposed at a position facing the passage area (S21: Yes), the control unit 130 executes a carriage retracting process (S32). On the other hand, when the carriage 40 is disposed at a position outside the passage area of the paper 12 (S21: No), the execution of the carriage retreat process (S32) is omitted.

  The carriage retracting process (S32) is a process of retracting the carriage 40 to a position outside the passing area by driving the carriage driving motor 103. More specifically, the controller 130 may move the carriage 40 to a position facing the waste ink tray 50 regardless of the size of the paper 12 in the carriage retracting process, or may perform a plurality of stops shown in FIG. Of the positions 55A, 55B, and 55C, the carriage 40 may be moved to a stop position 55A that is out of the passage area of the paper 12 and closest to the passage area.

  Next, the control unit 130 performs a cueing process (S33). Since the cueing process (S33) included in the second recording process is common to the cueing process (S23) included in the first recording process, the description thereof will be omitted. However, the cueing process (S23) included in the first recording process is executed in a state where the carriage 40 is arranged at a position facing the passing area. On the other hand, the cueing process (S33) included in the second recording process is executed in a state where the carriage 40 is arranged at a position out of the passage area.

  Next, the control unit 130 executes a sheet facing process (S34). The sheet facing process is a process of moving the carriage 40 to a position facing the sheet 12 conveyed by the cueing process (S33). Since the processing content of the control unit 130 in the sheet facing process (S34) is the same as the passing area facing process (S22) included in the first recording process, the description thereof is omitted. However, the passing area facing process (S22) included in the first recording process is executed prior to the cueing process (S23). On the other hand, the sheet facing process (S34) included in the second recording process is executed after the cueing process (S33) is completed.

  Next, the control part 130 performs a detection process (S35). Since the detection process (S35) included in the second recording process is the same as the detection process (S24) included in the first recording process, the description thereof will be omitted. When the sheet 12 is present at a position facing the recording unit 24 (S36: Yes), the control unit 130 executes an ejection process for recording an image on the back surface of the sheet 12 (S37). Since the discharge process (S37) included in the second recording process is common to the discharge process (S26) included in the first recording process, the description thereof will be omitted. On the other hand, when the sheet 12 does not exist at the position facing the recording unit 24 (S36: No), the control unit 130 omits the ejection process (S37) included in the second recording process and executes the notification process. (S17).

  Next, the control unit 130 executes the discharge process shown in FIG. 6 (S18). The discharge process is a process of discharging the paper 12 on which image recording has been completed to the discharge tray 21. More specifically, the control unit 130 discharges the paper 12 to the discharge tray 21 by driving the transfer motor 102 in the normal direction to rotate the transfer roller pair, the discharge roller pair, and the reverse roller pair in the forward direction. The control unit 130 can recognize that the paper 12 has been discharged to the discharge tray 21 based on signals output from the first sensor 160, the second sensor 170, the rotary encoder 73, and the like.

[Operational effects of this embodiment]
According to the present embodiment, since the cueing process (S33) is performed in the second recording process (S16) with the carriage 40 being out of the passage area of the paper 12, the paper 12 is loaded during the cueing process (S33). Contact with the recording head 38 can be prevented. On the other hand, in the first recording process (S13), the cueing process (S23) is executed in a state where the passing area and the media sensor 76 face each other, so there is no need to move the carriage 40 after the cueing process, and the recording process Throughput is improved.

  The passing area facing process (S22) in the present embodiment is executed only when the carriage 40 is arranged at a position outside the passing area at the start of the first recording process (S21: No). Thereby, the throughput of the first recording process is improved. However, the present invention is not limited to this. For example, when the carriage 40 is arranged at a position different from the stop position 55B in FIG. 8 at the start of the first recording process, the carriage 40 may be moved to the stop position 55B by the passing area facing process.

  Further, in the passing area facing process (S22) in the present embodiment, the stop position is determined according to the size of the paper 12 included in the image recording instruction, so the size of the actually conveyed paper 12 is specified by the image recording instruction. If it is smaller than the size of the paper sheet, the notification process (S17) is executed. As a result, it is possible to suppress contamination due to ink landing on the paper 12.

  However, the stop position of the carriage 40 in the passing area facing process is not limited to the above example. For example, the carriage 40 may be stopped at a position where all sheets that can pass through the first conveyance path 65 can face each other. Thereby, in the passing area facing process, the process of determining the stop position according to the size of the paper 12 can be omitted.

  In the detection processing (S24, S35) in the present embodiment, only the presence or absence of the paper 12 at the position facing the recording unit 24 is detected. However, the present invention is not limited to this, and both end positions of the paper 12 in the left-right direction 9 may be further detected. Specifically, the control unit 130 moves the carriage 40 in a state where light is emitted from the light emitting unit of the media sensor 76, and the position where the signal level of the signal output from the media sensor 76 greatly fluctuates is changed. What is necessary is just to judge an edge part position.

  Note that the movement range of the carriage 40 (hereinafter referred to as “scanning range”) in a state in which light is emitted from the light emitting unit is specified according to the size of the paper 12 included in the image recording instruction, for example. What is necessary is just to be in the predetermined range including 12 edge part positions. The scanning range in the detection process (S35) included in the second recording process is, for example, a predetermined range including the edge position of the paper 12 detected in the detection process (S35) included in the first recording process. It may be inside. If the end position of the paper 12 cannot be detected in the above-described processing, it may be notified that the paper size is different in the notification processing (S17). Alternatively, the detection of the end position of the paper 12 may be retried using the entire movable range of the carriage 40 as a scanning range.

  The carriage retracting process (S32) in the present embodiment is executed only when the carriage is disposed at a position facing the passing area at the start of the second recording process (S31: Yes). Thereby, the throughput of the second recording process is improved. However, the present invention is not limited to this. For example, when the carriage 40 is arranged at a position different from the stop position 55A in FIG. 8 at the start of the second recording process, the carriage may be moved to the stop position 55A by the carriage retracting process.

  In the carriage retracting process (S32) in the present embodiment, the stop position is determined in accordance with the size of the sheet 12 included in the image recording instruction, so the carriage 40 in the carriage retracting process (S32) and the sheet facing process (S34). Can be shortened. As a result, the throughput of the second recording process is further improved.

  However, the stop position of the carriage 40 in the carriage retracting process is not limited to the above example. For example, the carriage 40 may be retracted to a position (typically a position facing the waste ink tray 50) that is out of the passage area of all sheets that can pass through the first transport path 65. Thereby, in the carriage retracting process, the process of determining the stop position according to the size of the paper 12 can be omitted.

  Alternatively, the stop position of the carriage 40 in the carriage retracting process may be determined based on the edge position of the paper 12 detected by the detecting process (S24) included in the first recording process. That is, the control unit 130 causes the RAM 133 to store the edge position of the paper 12 detected in the detection process (S24). Then, in the carriage retracting process (S32), the control unit 130 may determine a position away from the sheet 12 by a predetermined distance (for example, 1 mm) from the end position stored in the RAM 133 as the stop position. Thereby, in the cueing process (S33) included in the second recording process, the carriage 40 can be surely arranged at a position outside the passage area of the conveyed paper 12. In the sheet facing process (S34), the movement time of the carriage 40 can be shortened.

  Alternatively, when the both end positions of the sheet 12 are detected in the detection process (S24) included in the first recording process, the carriage 40 may be retracted to a position that deviates from between the both end positions of the sheet 12 detected in the detection process. Good. That is, the control unit 130 is out of the stop positions 55A, 55B, and 55C from the positions of both ends of the paper 12 detected in the detection process (S24) and is at the stop position closest to the end position of the paper 12. The carriage 40 may be moved. As a result, the carriage 40 can be retreated to a position out of the passage area more reliably.

  Further, according to the present embodiment, by providing the inclined surface 40A on the carriage 40, it is possible to press down the raised paper 12 in the paper facing process (S34). As a result, the sheet 12 can be more effectively prevented from coming into contact with the recording head 38.

  Furthermore, in the image recording process according to the present embodiment, the reverse process (S15) and the second recording process (S16) are omitted when there is no image to be recorded on the back surface of the paper 12 (S14: No). This is not the case when images are continuously recorded on a plurality of sheets. That is, the control unit 130 executes the image recording process shown in FIG. 6 for each of a plurality of sheets on which images are continuously recorded. Then, in step S14 of the image recording process for one of the plurality of sheets, the control unit 130 performs the inversion process (S15) and FIG. 7B (B) on condition that there is no image to be recorded on the back surface of the sheet. ) Steps S31 to S33 may be executed, and Steps S34 to S37 of FIG. 7B may be omitted. As a result, the orientation of the plurality of sheets on which images are recorded can be aligned on the discharge tray 21.

DESCRIPTION OF SYMBOLS 10 ... Multifunction machine 11 ... Printer part 15 ... 1st conveyance direction 16 ... 2nd conveyance direction 24 ... Recording part 36 ... Branch position 37 ... Merge position 38 ... Recording head 40... Carriage 40 A. Inclined surface 50... Waste ink tray 55 A, 55 B, 55 C. Stop position 76.

Claims (13)

A transport unit for transporting paper in the transport direction;
A recording head that ejects ink onto the paper conveyed by the conveying unit, a sensor that outputs a signal corresponding to the presence or absence of the paper, and a reciprocation in the main scanning direction perpendicular to the conveying direction with the recording head and the sensor mounted A recording unit having a moving carriage;
A reversing unit that reverses the front and back of the paper to reach the transport unit;
Inverted by the first recording process, which is a recording process for recording an image on the surface of the paper, the reversing process for inverting the front and back of the paper on which the first recording process has been performed and reaching the transport unit, and the reversing process A control unit that executes a second recording process, which is a recording process for recording an image on the back surface of the paper,
The above recording process
A cueing process for transporting the paper to the transport unit until an area where an image is first recorded reaches a position where the recording head can face the recording head;
A detection process for detecting the presence or absence of paper at the position of the recording unit based on a signal output from the sensor;
At least a discharge process for transporting a sheet to the transport unit by a predetermined line feed width in the transport direction and ejecting ink to the recording head with respect to the sheet transported by a predetermined line feed width;
The control unit
In the first recording process, the cueing process is executed in a state where the carriage is arranged at a position where the passage area of the sheet conveyed by the conveying unit and the sensor face each other,
In the second recording process, the cueing process is executed in a state in which the carriage is arranged at a position outside the passage area, and the sheet conveyed by the cueing process and the sensor face each other. An ink jet recording apparatus that further executes a sheet facing process for moving the carriage. The control unit
In the first recording process, a passing area facing process for moving the carriage to a position where the passing area and the sensor face is executed prior to the cueing process,
The inkjet recording apparatus according to claim 1, wherein in the second recording process, a carriage retracting process for retracting the carriage to a position deviating from the passage area is executed prior to the cueing process. The control unit
In the detection process, based on a signal output from the sensor, the both end positions of the paper in the main scanning direction are detected,
3. The carriage according to claim 2, wherein in the carriage retracting process included in the second recording process, the carriage is retracted to a position deviating from between both end positions of the paper detected in the detection process included in the first recording process. Inkjet recording device.   In the detection process included in the second recording process, the control unit causes the sensor to scan a predetermined range including both end positions of the paper detected in the detection process included in the first recording process. The ink jet recording apparatus according to claim 3, wherein the positions of both ends of the paper are detected by this. The control unit
Further executing an acquisition process for acquiring a recording instruction including information for specifying the size of the paper on which an image is recorded in the recording process;
5. In the passing area facing process included in the first recording process, the carriage is moved to a position where the passing area and the sensor face each other based on the paper size acquired in the acquiring process. Any one of the inkjet recording apparatuses. The control unit
In the passing area facing process included in the first recording process, out of a plurality of stopping positions spaced apart in the main scanning direction, the stopping included in the passing area and closest to the end of the passing area Move the carriage to the position,
On the condition that the sheet cannot be detected in the detection process included in the first recording process, a notification process for notifying that the sheet conveyed by the conveyance unit is different from the size of the sheet included in the recording instruction is executed. The ink jet recording apparatus according to claim 5. An ink receiving portion that is provided in a position within the moving range of the carriage and out of the passage region, and that receives ink discharged from the recording head;
The inkjet recording apparatus according to claim 2, wherein the control unit retracts the carriage to a position facing the ink receiving unit in the carriage retracting process included in the second recording process.   The control unit executes the passing area facing process prior to the cueing process on the condition that an upper carriage is disposed at a position deviating from the passing area at the start of the first recording process. Item 8. The ink jet recording apparatus according to any one of Items 2 to 7.   The controller executes the carriage retracting process prior to the cueing process on the condition that the carriage is arranged at a position facing the passage area at the start of the second recording process. The ink jet recording apparatus according to any one of 2 to 8.   The control unit deviates from the passage area in the second recording process for the paper on condition that there is no image to be recorded on the back surface of one of the plurality of papers on which images are continuously recorded. The inkjet according to any one of claims 1 to 9, wherein the cueing process is performed in a state where the carriage is disposed at a predetermined position, and the sheet facing process, the detection process, and the ejection process are omitted. Recording device.   11. The carriage according to claim 1, wherein the carriage has an inclined surface that is inclined upward from a side close to the recording head to a side far from the recording head at a position adjacent to the recording head and facing a sheet in the main scanning direction. Inkjet recording device. A first conveyance path extending in the first conveyance direction, which is the conveyance direction, and the first conveyance path which branches from the first conveyance path at a branch position and is upstream of the branch position in the first conveyance direction. And a main body formed with a second transport path extending in the second transport direction from the branch position toward the merge position.
The transport unit is
A first conveying roller pair that is provided in the first conveying path downstream from the merging position in the first conveying direction, and that conveys the paper on the first conveying path in the first conveying direction;
Provided in the first conveyance path downstream from the first conveyance roller pair in the first conveyance direction and upstream from the branch position in the first conveyance direction, and the sheet on the first conveyance path is disposed on the first conveyance path. A second transport roller pair for transporting in the first transport direction;
The inversion part is
A sheet that is provided in the first conveyance path downstream from the branching position in the first conveyance direction and on which an image is recorded by the recording unit, has an upstream end in the first conveyance direction as a leading edge. A pair of reversing rollers transported to the second transport path;
A re-conveying roller pair that is provided in the second conveying path and conveys the sheet conveyed to the second conveying path by the reversing roller pair in the second conveying direction;
The recording section is provided in the first conveyance path on the downstream side in the first conveyance direction from the first conveyance roller pair and on the upstream side in the first conveyance direction from the second roller pair. To 11. The inkjet recording apparatus according to any one of 11 to 11. The first transport path includes a curved portion that curves along the first transport direction,
The inkjet recording apparatus according to claim 12, wherein the first transport roller pair is provided at an end portion of the curved portion on the downstream side in the first transport direction.

Images