JP6299123B2 - Medium processing apparatus and method for controlling medium processing apparatus - Google Patents

Description

The present invention relates to control how the media processing device and the media processing apparatus for performing processing such as printing the front and back surfaces of a sheet-like medium.

  A double-sided printing apparatus that forms images on the front and back sides of a printing paper is described in Japanese Patent Application Laid-Open No. 2004-133260. The double-sided printing apparatus disclosed in Patent Document 1 conveys a conveyance path from a paper feed cassette that supplies printing paper to a discharge port via an image forming position by a photosensitive drum, and reverses the front and back of the printing paper fed from the conveyance path. A reversing conveyance path that returns to the path is provided. The reversing conveyance path has a drawing path in which an upstream end is connected between the discharge port and the image forming position, a branch from the middle of the drawing path, and a downstream end is connected between the sheet feeding cassette and the image forming position. A delivery path is provided. The printing paper is first transported along the transport path in the direction toward the discharge port, and an image is formed on the surface when passing through the image forming position. Next, the printing paper is drawn into the drawing path from the conveyance path. Thereafter, the conveyance direction of the printing paper is reversed, and the printing paper drawn into the drawing path is sent out from the feeding path to the conveyance path. As a result, the printing paper is returned to the transport path with the front and back sides reversed. The printing paper returned to the conveyance path is conveyed again toward the discharge port, and an image is formed on the back surface when passing through the image forming position. Thereafter, the printing paper is discharged from the discharge port.

  If the power is accidentally turned off while the printing paper is being conveyed along the conveyance path or the reverse conveyance path, the printing paper remains in the apparatus. Since the remaining printing paper causes a paper jam, the double-sided printing apparatus disclosed in Patent Document 1 performs a discharging process for discharging the remaining printing paper when the power is newly turned on. The double-sided printing apparatus of Patent Document 1 includes a detector that detects a printing sheet on a conveyance path between a connection portion between the conveyance path and a delivery path and an image processing position, a detector that detects a printing sheet on a pull-in path, A detector that detects the printing paper on the feed path is installed, and if any of the printing paper is detected by the detector when the power is turned on, the conveyance direction of the printing paper is determined based on the detection position of the printing paper. It controls and discharges from the discharge port without causing damage such as wrinkles on the remaining printing paper.

JP 2001-337562 A

  In the medium processing apparatus, in order to perform processing on the medium conveyed on the conveyance path, it is necessary to grasp the position of the medium on the conveyance path before the medium passes through the processing position. Therefore, it is difficult to omit the detector that detects the medium at a position closer to the supply unit than the processing position on the conveyance path. However, it is desirable to omit the detector that detects the medium on the reversing conveyance path in order to reduce the manufacturing cost of the apparatus.

In view of these points, the present invention has been made in view of the above problems. A medium processing apparatus that can discharge a medium remaining in the apparatus without damaging it even when a detector that detects the medium on the reversing conveyance path is omitted. It is to provide. Another object is to propose a control method for such a medium processing apparatus .

  In order to solve the above-described problems, the present invention provides a transport path from a supply unit that supplies a sheet-shaped medium to a discharge port via a processing position for processing the medium, and the above-described transport path. A reversing conveyance path that reverses the front and back of the medium and returns it to the conveyance path, a conveyance mechanism that conveys the medium along the conveyance path, and a reversing conveyance roller that conveys the medium along the reversing conveyance path A drive motor for driving the transport mechanism, a reverse transport motor for driving the reverse transport roller, a detector for detecting the medium, and driving control of the transport motor and the reverse transport motor. In the medium control device having the control unit, the reversing conveyance path has a loop shape, and is connected between the supply unit of the conveyance path and the processing position. A conveyance roller configured to convey the medium between a connection portion of the conveyance path to which the diversion conveyance path is connected and the processing position; and the detector is disposed between the connection portion and the reversal conveyance roller. The medium is detected, and the conveyance roller is rotated in a first rotation direction to convey the medium in a direction approaching the discharge port by driving the conveyance motor in the forward direction, and the conveyance motor is driven in the reverse direction. The reversing conveyance roller is rotated in the same rotation direction as the second rotation direction by driving the reversing conveyance motor, and the control unit is rotated in the second rotation direction opposite to the first rotation direction. The transport motor is driven in the reverse direction to feed the medium transported closer to the discharge port than the connection portion into the reversing transport path, and the reversing transport motor is driven to drive the transport robot. The medium is transferred from the roller to the reversing conveyance roller, and then the medium is conveyed along the conveying path by the reversing conveying roller and sent to the conveying path, and the conveying motor is driven in the forward direction. A reversing controller that delivers the medium from the reversing transport roller to the transport roller, and driving the reversing transport motor when the medium is detected by the detector at power-on and initialization. And a discharge control unit that drives the transport motor in the forward direction.

  According to the present invention, the reversing conveyance path has a loop shape and is connected between the processing position in the conveyance path and the supply unit. When the medium is sent to the reversing conveyance path, the medium is transferred from the conveying roller to the reversing conveying roller, and when the medium is returned to the conveying path with its front and back reversed, The medium is transferred from the transport roller to the transport roller. And the detector which detects a medium detects a medium between the conveyance roller which conveys a medium between a processing position and a supply part, and the connection part of the conveyance path for inversion in a conveyance path. Therefore, if the detector detects a medium when the power is turned on or during initialization, the remaining medium is either entirely located on the conveyance path, or part of the medium is located on the conveyance path. Can be determined to be located on the reversing conveyance path.

  Here, when a part of the medium remaining in the apparatus is positioned on the transport path and the other part is positioned on the reversing transport path, the medium is sent from the transport path to the reversing transport path. In this state, the rear end portion in the transport direction is nipped by the transport roller, and the front end portion is nipped by the reverse transport roller. In such a case, the transport motor is driven in the forward direction to transport the medium on the transport path toward the discharge port, and the reverse transport motor is driven to return the medium on the reverse transport path to the transport path. If it does, the rotation direction of the conveyance roller which nips a medium mutually, and the conveyance roller for inversion may become reverse, and a medium may be torn. That is, the transport roller rotates in the first rotation direction by driving the transport motor in the forward direction, and the reverse transport roller is rotated in the direction opposite to the first rotation direction by driving the reverse transport motor (the same as the second rotation direction). Rotation in the direction of rotation) may cause damage to the medium. In response to such a problem, the present invention drives the transport motor in the forward direction without driving the reversing transport motor when a medium is detected when the power is turned on and during the initialization operation. As a result, the rotation direction of the conveyance roller and the rotation direction of the reversing conveyance roller are not reversed, so that even if the medium is nipped by both the conveyance roller and the reversing conveyance roller, the medium is not damaged. It can be moved toward the outlet. In addition, if the rotation direction of the transport roller that nips the medium and the reverse transport roller are reversed, an excessive load is applied to each of the transport motor, the transport roller, the reverse transport motor, and the reverse transport roller. Although there is a possibility of damage, since the transport motor is driven without driving the reversing transport motor, these damages can also be avoided. Further, since the transport motor is driven in the forward direction, the front end portion in the transport direction is nipped by the transport roller while the medium is returned from the transport path for reversal to the transport path, and the rear end portion is for reversal. Even when nipped by the transport roller, the medium can be transported toward the discharge port using the transport roller. Further, since the transport motor is driven in the forward direction, when the print paper is on the transport path, the print paper can be transported toward the discharge port by the transport mechanism.

  Next, when the medium is being sent from the conveyance path to the reverse conveyance path, the rear end portion in the conveyance direction is nipped by the conveyance roller, and the front end portion is nipped by the reverse conveyance roller, and The reversing transport motor when the front end in the transport direction is nipped by the transport roller and the rear end is nipped by the reversing transport roller with the medium being returned from the reversing transport path to the transport path. When the medium is conveyed using the conveyance roller by driving the conveyance motor in the forward direction without driving the reversal, the conveyance roller for reversal is accompanied with the conveyance of the medium. Therefore, a load that causes the reversing conveyance roller to rotate is applied to the conveyance roller and the conveyance motor. Further, when the reversing transport roller is rotated along with the transport of the medium, a counter electromotive force is generated by the reversing transport motor that drives the reversing transport roller, so that the counter electromotive force drives the reversing transport roller. It can damage the control circuit. For such a problem, a transport control unit that drives the transport motor in the forward direction to transport the medium supplied from the supply unit at a first speed to reach the processing position; and The medium that has been driven in the forward direction to reach the processing position is transported and passed through the processing position, and the medium is subjected to the processing at the processing position, and the medium is placed closer to the discharge port than the connection portion. It is preferable that the discharge control unit drives the transport motor at a speed capable of transporting the medium at a second speed slower than the first speed. In this way, since the rotation speed of the reversing transport roller that rotates with the medium can be suppressed as compared with the case of transporting the medium at the first speed, the counter electromotive force generated by the reversing transport motor can be suppressed. In addition, the present inventors set the medium transport speed when transporting the remaining medium by driving only the transport motor to a slower speed than the transport speed when the medium reaches the processing position. For example, it has been confirmed by experiments that the load applied to the transport roller and the transport motor can be reduced with the rotation of the reversing transport roller.

  In the present invention, the discharge control unit does not drive the reversing transport motor, and the transport roller along the transport path and the reversing transport path from the length of the medium along the transport path; Drive the transport motor in the forward direction for a transport time that can transport a difference distance obtained by subtracting the separation distance from the reversing transport roller, and then drive the reversing transport motor together with the transport motor to It is desirable to transport the medium at a speed higher than the second speed. In this way, the rear end portion in the transport direction is nipped by the transport roller while the remaining medium is sent from the transport path to the reversing transport path, and the front end portion is nipped by the reversing transport roller. In this case, the nip of the medium by the reverse conveying roller is released by driving the conveying time of the conveying motor. Therefore, even if the reverse conveyance motor is driven while the conveyance motor is driven in the forward direction after the conveyance time has elapsed, the medium is not damaged. Further, after the nip of the medium by the reverse conveying roller is released, the medium conveying speed is faster than the conveying speed (second speed) when only the conveying motor is driven to convey the remaining medium. If so, the discharge time for discharging the medium can be shortened.

  In the present invention, when the medium is no longer detected by the detector while the transport motor is driven for the transport time, the discharge control unit thereafter turns the reversal transport motor to the transport motor. It is preferable that the medium is transported at a speed faster than the second speed. That is, when the medium is no longer detected by the detector, the state where the remaining medium is nipped by both the transport roller and the reverse transport roller is eliminated. Therefore, after the medium is no longer detected, the reversing conveyance motor is driven while driving the conveyance motor in the forward direction, and the medium can be discharged at a speed higher than the second speed.

  In the present invention, it is preferable that the discharge control unit drives the transport motor in the forward direction together with the reversing transport motor when the medium is not detected by the detector at the time of power-on and initialization operation. In other words, if the remaining medium is not detected when the power is turned on or during the initialization operation, even if there is no remaining medium or the medium remains, the medium remains on both the transport roller and the reverse transport roller. There is no case where it is nipped. Therefore, the medium can be discharged from the discharge port by driving the reverse conveying motor while driving the conveying motor in the forward direction.

  In the present invention, a print head for printing on the medium at the processing position may be provided. That is, the medium processing apparatus can be a double-sided printing apparatus that performs printing on the front and back surfaces of a sheet-like medium.

  Next, the present invention reverses the transport path from the supply unit that supplies the sheet-shaped medium to the discharge port via the processing position for processing the medium, and the front and back of the medium fed from the transport path. A reversing conveying path that returns to the conveying path, and conveys the medium along the conveying path by a conveying mechanism using a conveying motor as a driving source, and by a reversing conveying roller driven by the reversing conveying motor. In the control method of the medium processing apparatus for transporting the medium along the reversing transport path, the reversing transport path is looped and connected between the supply unit of the transport path and the processing position, and The transport mechanism includes a transport roller that transports the medium between a connection portion of the transport path to which the reversal transport path is connected and the processing position, and the transport roller is connected to the transport motor. The medium is rotated in the first rotation direction for conveying the medium in the first conveyance direction toward the discharge port by driving in the forward direction, and the first rotation direction opposite to the first rotation direction is driven by the reverse driving of the conveyance motor. The reversing transport roller is rotated in the same rotational direction as the second rotational direction by driving the reversing transport motor, and the transport motor is driven in the reverse direction. The medium transported to the discharge port side from the connecting portion is sent to the reversing transport path, and the reversing transport motor is driven to transfer the medium from the transport roller to the reversing transport roller. The medium is conveyed along the reversing conveyance path by the reversing conveyance roller, and the medium is sent to the conveyance path; Driving in the direction to deliver the medium from the reversing conveying roller to the conveying roller, detecting the medium between the connecting portion on the conveying path and the conveying roller at the time of power-on and initialization operation, When a medium is detected, the transport motor is driven in the forward direction without driving the reversing transport motor.

  According to the present invention, the reversing conveyance path has a loop shape and is connected between the processing position in the conveyance path and the supply unit. When the medium is sent to the reversing conveyance path, the medium is transferred from the conveying roller to the reversing conveying roller, and when the medium is returned to the conveying path with its front and back reversed, The medium is transferred from the transport roller to the transport roller. When the power is turned on and the initialization operation is performed, the medium is detected between the conveyance roller that conveys the medium between the processing position and the supply unit and the connection portion of the conveyance path for reversal in the conveyance path. Therefore, when a medium is detected at the time of power-on or the like, the remaining medium is either entirely located on the conveyance path, or one end portion is located on the conveyance path and the other end. It can be determined that the portion is located on the reversing conveyance path.

  Here, when a part of the medium remaining in the apparatus is positioned on the transport path and the other part is positioned on the reversing transport path, the medium is sent from the transport path to the reversing transport path. In this state, the rear end portion in the transport direction is nipped by the transport roller, and the front end portion is nipped by the reverse transport roller. In such a case, the transport motor is driven in the forward direction to transport the medium on the transport path toward the discharge port, and the reverse transport motor is driven to return the medium on the reverse transport path to the transport path. If it does, the rotation direction of the conveyance roller which nips a medium mutually, and the conveyance roller for inversion may become reverse, and a medium may be torn. In response to such a problem, the present invention drives the transport motor in the forward direction without driving the reversing transport motor when a medium is detected when the power is turned on and during the initialization operation. As a result, the rotation direction of the conveyance roller and the rotation direction of the reversing conveyance roller are not reversed, so that even if the medium is nipped by both the conveyance roller and the reversing conveyance roller, the medium is not damaged. Can be discharged from the outlet. In addition, if the rotation direction of the transport roller that nips the medium and the reverse transport roller are reversed, an excessive load is applied to each of the transport motor, the transport roller, the reverse transport motor, and the reverse transport roller. Although there is a possibility of damage, if the transport motor is driven without driving the reversing transport motor, the damage can be avoided. Further, since the transport motor is driven in the forward direction, the front end portion in the transport direction is nipped by the transport roller while the medium is returned from the transport path for reversal to the transport path, and the rear end portion is for reversal. Even when nipped by the transport roller, the medium can be transported toward the discharge port using the transport roller. Further, since the transport motor is driven in the forward direction, when the print paper is on the transport path, the print paper can be transported toward the discharge port by the transport mechanism.

  Next, when the medium is being sent from the conveyance path to the reverse conveyance path, the rear end portion in the conveyance direction is nipped by the conveyance roller, and the front end portion is nipped by the reverse conveyance roller, and The reversing transport motor when the front end in the transport direction is nipped by the transport roller and the rear end is nipped by the reversing transport roller with the medium being returned from the reversing transport path to the transport path. When the medium is conveyed using the conveyance roller by driving the conveyance motor in the forward direction without driving the reversal, the conveyance roller for reversal is accompanied with the conveyance of the medium. Therefore, a load that causes the reversing conveyance roller to rotate is applied to the conveyance roller and the conveyance motor. Further, when the reversing transport roller is rotated along with the transport of the medium, a counter electromotive force is generated by the reversing transport motor that drives the reversing transport roller, so that the counter electromotive force drives the reversing transport roller. It can damage the control circuit. To solve this problem, the transport motor is driven in the forward direction, the medium supplied from the supply unit is transported at a first speed to reach the processing position, and the transport motor is moved in the forward direction. The medium that has been driven to reach the processing position is transported and passed through the processing position, and the medium is subjected to the processing at the processing position so that the medium is positioned closer to the discharge port than the connection portion. When the medium is detected, it is preferable that the transport motor is driven at a speed at which the medium can be transported at a second speed slower than the first speed. In this way, since the rotation speed of the reversing transport roller that rotates with the medium can be suppressed as compared with the case of transporting the medium at the first speed, the counter electromotive force generated by the reversing transport motor can be suppressed. In addition, if the conveyance speed of the medium when only the conveyance motor is driven to convey the remaining medium is set slower than the conveyance speed when the medium reaches the processing position, the reverse conveyance roller As a result, the load on the transport roller and the transport motor can be reduced.

  In the present invention, when the medium is detected, the reversing transport motor is driven along the transport path and the reversing transport path from the length dimension of the medium along the transport path without driving the reversing transport motor. The transport motor is driven in the forward direction for a transport time that can transport a differential distance obtained by subtracting a separation distance between the transport roller and the reversing transport roller, and then the reversing transport motor is moved together with the transport motor. It is desirable to drive and transport the medium at a speed faster than the second speed. In this way, the rear end portion in the transport direction is nipped by the transport roller while the remaining medium is sent from the transport path to the reversing transport path, and the front end portion is nipped by the reversing transport roller. In this case, the nip of the medium by the reverse conveying roller is released by driving the conveying motor for longer than the conveying time. Therefore, even if the reverse conveyance motor is driven while the conveyance motor is driven in the forward direction after the conveyance time has elapsed, the medium is not damaged. Further, after the nip of the medium by the reversing transport roller is released, the transport speed of the medium is faster than the transport speed (second speed) when transporting the remaining medium by driving only the transport motor. Since the speed is set, the discharge time for discharging the medium can be shortened.

  In the present invention, when the medium is not detected while the transport motor is driven for the transport time, the reversing transport motor is driven together with the transport motor so that the medium is faster than the second speed. It is desirable to transport at a speed. That is, when the medium is no longer detected by the detector, the state where the remaining medium is nipped by both the transport roller and the reverse transport roller is eliminated. Accordingly, after the medium is no longer detected, the medium can be discharged at a speed higher than the second speed by driving the reversing transport motor while driving the transport motor in the forward direction.

  In the present invention, when the medium is not detected, it is desirable to drive the transport motor in the forward direction together with the reversing transport motor. In other words, if the remaining medium is not detected when the power is turned on or during the initialization operation, even if there is no remaining medium or the medium remains, the medium remains on both the transport roller and the reverse transport roller. There is no case where it is nipped. Therefore, the medium can be discharged from the discharge port by driving the reverse conveying motor while driving the conveying motor in the forward direction.

  In the present invention, the medium may be printed at the processing position. That is, the medium processing apparatus can be a double-sided printing apparatus that performs printing on the front and back surfaces of a sheet-like medium.

  According to the present invention, it is possible to discharge a medium remaining in the apparatus without damaging it without mounting a detector for detecting the medium on the reverse conveyance path.

1 is a front perspective view of a printer to which the present invention is applied. FIG. 2 is a schematic longitudinal sectional view and a partial sectional view of the printer of FIG. 1. FIG. 2 is a block diagram of a control system of the printer in FIG. 1. It is explanatory drawing of a double-sided printing operation. It is explanatory drawing of a double-sided printing operation. It is explanatory drawing of a double-sided printing operation. It is explanatory drawing of a double-sided printing operation. It is explanatory drawing of paper discharge operation | movement. It is a graph of the load of a conveyance motor at the time of paper discharge operation | movement, and a counter electromotive current.

  A printer as an embodiment of a medium processing apparatus to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
FIG. 1 is an external perspective view of the printer according to the present embodiment as viewed from the front. As shown in FIG. 1, the printer 1 is an ink jet printer that performs printing on the front and back surfaces of a printing paper. The printer 1 includes a printer main body 2 and a reversing unit 3. The printer main body 2 has a rectangular parallelepiped shape that is long in the printer width direction X as a whole. A concave portion 4 is formed in the central portion of the back surface of the printer main body 2, and the reversing unit 3 is attached thereto. The reversing unit 3 is a unit for inverting the front and back of the printing paper P (see FIG. 2), which is a sheet-like medium, and returning it to the printer body 2.

  A paper cassette mounting portion 5 is provided on the front surface of the printer main body portion 2. The paper feed cassette mounting unit 5 is open to the front of the printer 1 (front of the printer 1 front-rear direction Y) in the lower part of the printer vertical direction Z on the front surface of the printer main body unit 2. A paper feed cassette (supply unit) 6 is detachably attached to the paper feed cassette mounting unit 5 from the front of the printer 1. A paper discharge tray 7 is attached to the upper side of the paper cassette mounting unit 5. A front end portion of the paper discharge tray 7 protrudes from the printer main body 2 to the front Y1 of the printer (front of the front-rear direction Y of the printer). A rectangular paper discharge port (discharge port) 8 is formed on the upper side of the paper discharge tray 7 so as to extend rearward of the printer Y2 (backward in the printer front-rear direction Y).

  The front surface of the printer above the paper discharge port 8 is an operation surface 9. On the operation surface 9, a power switch 9a, a plurality of operation buttons 9b, and the like are arranged. Rectangular opening / closing doors 10 a and 10 b are attached to the front portion of the printer on both sides of the discharge tray 7 and the discharge outlet 8. When these open / close doors 10a and 10b are opened, an ink cartridge mounting portion (not shown) is opened, and the ink cartridge (not shown) can be replaced. An open / close lid 11 for maintenance is attached to the central portion of the upper surface of the printer 1.

(Internal structure)
FIG. 2A is a schematic longitudinal sectional view showing the internal configuration of the printer 1, and FIG. 2B is a partial longitudinal sectional view of the printer 1. As shown in FIG. 2, inside the printer 1, there are a conveyance path 13 from the paper feed cassette 6 to the paper discharge outlet 8 via a printing position (processing position) A by the print head 12, and a reverse conveyance path 14. Is formed. The transport path 13 is formed inside the printer main body 2, and the reversing transport path 14 is formed inside the reversing unit 3. Further, inside the printer 1, a paper feed roller 15 that supplies the printing paper P stored in the paper feeding cassette 6 in a stacked state to the conveyance path 13, and a conveyance that conveys the printing paper P along the conveyance path 13. A mechanism 16 and a first reversing transport roller pair 17 and a second reversing transport roller pair 18 that transport the printing paper P along the reversing transport path 14 are provided.

  The paper feed roller 15 is disposed above the rear end portion of the paper feed cassette 6 in the front-rear direction Y of the printer. The paper feed roller 15 is rotated by driving a paper feed motor 19 (see FIG. 3), and sends the printing paper P to the transport path 13.

  The conveyance path 13 is curved from the rear end of the paper feed cassette 6 to the printer front Y1 continuously upward from the rear end of the inclined conveyance path portion 13a and the inclined conveyance path portion 13a extending obliquely upward toward the rear Y2 of the printer. And a horizontal conveyance path portion 13c extending substantially horizontally from the upper front end of the curved conveyance path portion 13b toward the front Y1 of the printer and reaching the paper discharge port 8.

  The transport mechanism 16 includes a first transport roller pair 20, a second transport roller pair 21, a first discharge roller pair 22, and a second discharge roller pair 23 arranged along the transport path 13. The first transport roller pair 20, the second transport roller pair 21, the first discharge roller pair 22, and the second discharge roller pair 23 are downstream from the upstream side in the first transport direction M1 from the paper feed cassette 6 toward the paper discharge port 8. It is arranged in this order toward the side. The first transport roller pair 20 is disposed in the curved transport path portion 13b, and the second transport roller pair 21, the first discharge roller pair 22, and the second discharge roller pair 23 are disposed in the horizontal transport path portion 13c.

  The first transport roller pair 20 includes a first transport roller 20a and a driven roller 20b. A retard roller 20c is pressed against the first transport roller 20a. The second transport roller pair 21 includes a second transport roller (transport roller) 21a and a driven roller 21b. The first discharge roller pair 22 includes a first discharge roller 22a and a driven roller 22b. The second discharge roller pair 23 includes a second discharge roller 23a and a driven roller 23b. The 2nd conveyance roller 21a is provided with the friction layer by which the inorganic particle was disperse | distributed on the surface.

  A driving source of the transport mechanism 16 is a transport motor 24 that is driven in the forward direction and the reverse direction. The driving force of the transport motor 24 is transmitted to the first transport roller 20a, the second transport roller 21a, the first discharge roller 22a, and the second discharge roller 23a via a drive force transmission mechanism (not shown). The transport motor 24 is a DC motor and is disposed on the side of the paper feed cassette 6 in the printer width direction X.

  The transport mechanism 16 transports the printing paper P in the first transport direction M1 by driving the transport motor 24 in the forward direction. Further, the transport mechanism 16 transports the printing paper P in the second transport direction M2 opposite to the first transport direction M1 by driving the transport motor 24 in the reverse direction. That is, each of the first transport roller 20a, the second transport roller 21a, the first discharge roller 22a, and the second discharge roller 23a brings the printing paper P close to the discharge port 8 by driving the transport motor 24 in the forward direction. Rotate in the first rotation direction R1 transported in the direction (see FIG. 4), and rotate in the second rotation direction R2 opposite to the first rotation direction R1 by driving the transport motor 24 in the reverse direction (see FIG. 5).

  The print head 12 is an inkjet head. The print head 12 performs printing on the printing paper P conveyed in the first conveyance direction M1 at the printing position A set between the second conveyance roller pair 21 and the first discharge roller pair 22 in the horizontal conveyance path portion 13c. . A platen 25 is arranged at a position facing the nozzle surface of the print head 12 with a certain gap. The platen 25 defines the printing position A.

  The reversing conveyance path 14 has a loop shape and is connected in the middle of the conveyance path 13. The reversing conveyance path 14 is continuous with the rear end of the horizontal conveyance path portion 13c, and extends upwardly in the horizontal direction to the rear side Y2 of the printer. A path 27, a lower path 28 that extends in a curved manner toward the printer front Y 1 continuously to the downward path 27, and an upward path 29 that curves upward from the lower path 28 are provided. The upward path 29 has its upper part bent obliquely to the front Y1 of the printer and joined to the curved conveyance path part 13b. A portion of the upward path 29 and the curved conveyance path portion 13 b on the downstream side of the conveyance path 13 is a common path 30.

  The first reversing conveyance roller pair 17 and the second reversing conveyance roller pair 18 convey the printing paper P sent from the conveyance path to the upper path 26 by the conveyance mechanism 16 in one direction along the reversal conveyance path 14. Return from the upward path 29 to the transport path. The first reversing transport roller pair 17 includes a first reversing transport roller 17 a and a driven roller 17 b, and is disposed between the upper path 26 and the downward path 27. The second reversing conveyance roller pair 18 includes a second reversing conveyance roller 18 a and a driven roller 18 b, and is disposed between the lower path 28 and the upward path 29.

  The driving force of the reversing transport motor 31 is transmitted to the first reversing transport roller 17a and the second reversing transport roller 18a via a train wheel (not shown). The reversing transport motor 31 is a motor different from the transport motor 24 and is mounted on the reversing unit 3. When the reversing transport motor 31 is driven, the first reversing transport roller 17a and the second reversing transport roller 18a rotate in the same rotational direction as the second rotational direction R2. That is, the first reversing transport roller 17a and the second reversing transport roller 18a cooperate with the second transport roller 21a when the second transport roller 21a rotates in the second rotation direction R2. It rotates in the direction of rotation that can be transported. Note that the conveyance force of the printing paper P by the first reverse conveyance roller pair 17 and the second reverse conveyance roller pair 18 is weaker than the conveyance force of the printing paper P by the second conveyance roller pair 21. The conveyance force is the product of the nip force and the friction coefficient.

  A path switching flap 36 is disposed at the connection portion 35 of the reversing conveyance path 14 in the conveyance path 13. The path switching flap 36 is disposed so as to be rotatable in the up-down direction Z of the printer with the rear end as the center. The path switching flap 36 has a space between the first switching position 36A where the front portion is placed on the outer peripheral surface of the first conveying roller 20a and the second switching position 36B where the front portion is spaced upward from the outer peripheral surface of the conveying roller 18a. Moving. The path switching flap 36 is maintained at the first switching position 36A by its own weight in a normal state.

  In a state in which the path switching flap 36 is located at the first switching position 36A, the printing paper P that is transported in the second transport direction M2 by the transport mechanism 16 in the second transport direction M2 toward the printer rear Y2 is used for reversal. Guided to the upper path 26 side of the transport path 14. The printing paper P that has entered the reversing transport path 14 is transported in one direction by the first reversing transport roller 17a and the second reversing transport roller 18a, and returned from the common path 30 to the horizontal transport path portion 13c again. Here, the path switching flap 36 is moved up from the first switching position 36A to the second switching position 36B by being pushed up by the printing paper P returning from the common path 30 to the horizontal conveyance path portion 13c. Accordingly, the printing paper P returned from the reversing conveyance path 14 to the conveyance path 13 enters the horizontal conveyance path portion 13 c while pushing up the path switching flap 36. Thereafter, when the printing paper P passes through the connection portion 35, the path switching flap 36 returns to the first switching position 36A again by its own weight.

  Even when the printing paper P supplied from the paper feed cassette 6 is transported along the transporting path 13, the printing paper P enters the horizontal transporting path portion 13 c while pushing up the path switching flap 36. Then, when the printing paper P passes through the connection portion 35, the path switching flap 36 returns to the first switching position 36A again by its own weight.

  Here, above the rear end portion of the horizontal conveyance path portion 13c, the printing paper is detected at a detection position B set between the second conveyance roller pair 21 and the connection portion 35 (path switching flap 36) in the conveyance path 13. A paper detector (detector) 37 for detecting P is disposed.

  The paper detector 37 includes a detection lever 37a that can contact the printing paper P conveyed at the detection position B. The detection lever 37a is supported so as to be swingable about a swing center axis extending in the printer width direction X, and when the printing paper P is not present at the detection position B, a predetermined midpoint is set. Placed in position. When the printing paper P is present at the detection position B, the detection lever 37a is moved from the middle position to the paper detection position by contact with the printing paper P, whereby the paper detector 37 detects the printing paper P.

  The printing paper P sent out from the paper feed cassette 6 to the transport path 13 by the paper feed roller 15 is transported in the first transport direction M1 by the transport mechanism 16 and reaches the printing position A. The printing paper P that has reached the printing position A is further transported in the first transport direction M1 by the transport mechanism 16 and passes through the printing position A. At the printing position A, printing is performed on the surface of the printing paper P by the printing head 12.

  When printing on the surface of the printing paper P is completed, the printing paper P is transported to the discharge port 8 side from the connection portion 35. Here, the transport mechanism 16 transports the printing paper P in the second transport direction M2 and sends it to the reversal transport path 14.

  The printing paper P sent to the reversing transport path 14 is transported along the reversing transport path 14 by the first reversing transport roller 17a and the second reversing transport roller 18a. Returned to The printing paper P returned to the transport path 13 is further transported in the first transport direction M1 by the transport mechanism 16 and passes through the processing position again. At the printing position A, printing is performed on the back surface of the printing paper P by the printing head 12. When printing on the front and back surfaces of the printing paper P is completed, the printing paper P is further transported in the first transport direction M1 and discharged from the paper discharge port.

(Control system)
As shown in FIG. 3, the control system of the printer 1 is mainly configured by a control unit 41 including a CPU. On the input side of the control unit 41, a communication unit 42 that connects an external device such as a computer and the printer 1 so as to communicate with each other, and a paper detector 37 are connected. The print head 12, the paper feed motor 19, the transport motor 24, and the reverse transport motor 31 are connected to the output side of the control unit 41. The communication unit 42 sequentially inputs print data supplied from an external device to the control unit 41.

  The control unit 41 includes a paper feed control unit 43, a position acquisition unit 44, a conveyance control unit 45, a print control unit 46, a reverse control unit 47, and a discharge control unit 48.

  The paper feed control unit 43 drives the paper feed motor 19 to rotate the paper feed roller 15, and sends the printing paper P stored in the paper feed cassette 6 to the transport path 13.

  The position acquisition unit 44 calculates the cumulative transport amount of the print paper P in the first transport direction M1 from the time when the paper detector 37 detects the print paper P, and the cumulative transport amount and the transport direction of the print paper P are calculated. The position of the front end of the printing paper P in the first transport direction M1 is acquired based on the length dimension. Here, the cumulative transport amount can be calculated based on the application time of the drive current to the transport motor 24 and the like. Further, the length dimension of the printing paper P can be acquired based on the paper size information included in the print data or the like or the paper size information of the printing paper P set for the printer 1.

  The transport controller 45 drives the transport motor 24 in the forward direction to transport the printing paper P sent from the paper feed cassette 6 to the transport path 13 at the first speed in the first transport direction M1 and to the printing position A. To reach. That is, the conveyance control unit 45 conveys the printing paper P sent out from the paper feed cassette 6 and passes the detection position B, and after the printing paper P passes the detection position B, the position acquisition unit 44 acquires it. Based on the position of the printing paper P being printed, the printing start scheduled position on the surface of the printing paper P is positioned at the printing position A. Further, when the printing paper P returned from the reversing transport path 14 to the transport path 13 by the first reversing transport roller 17a and the second reversing transport roller 18a passes the detection position B, the transport control unit 45 passes the detection position B. The printing paper P is transported based on the position of the printing paper P acquired by the printer 44, and the scheduled printing start position on the back surface of the printing paper P is positioned at the printing position A.

  The print control unit 46 drives the transport motor 24 in the forward direction to transport the print paper P positioned at the print position A, and passes the print position A. Further, the printing head 12 is driven to print on the printing paper P passing through the printing position A. When printing on the front surface or back surface of the printing paper P is completed, the printing paper P is positioned on the paper discharge port 8 side of the connection portion 35 and the detection position B on the transport path 13.

  When the printing on the printing paper P is completed, the reversal control unit 47 drives the transport motor 24 in the reverse direction, so that the first transport roller 20a, the second transport roller 21a, the first discharge roller 22a, and the second discharge roller 23a are driven. Each is rotated in the second rotation direction R <b> 2, and the printing paper P is sent from the conveyance path 13 to the reversal conveyance path 14. Further, the reversal control unit 47 drives the reversing transport motor 31 to rotate the first reversing transport roller 17a and the second reversing transport roller 18a, so that the second transport roller 21a changes to the first reversing transport roller 17a. Deliver the printing paper P. The timing at which the reversal control unit 47 starts driving the reversing transport motor 31 is when the printing paper P fed into the reversing transport path 14 is detected by the paper detector 37.

  Further, the reversal control unit 47 drives the reversing transport motor 31 to reverse the printing paper P delivered from the second transport roller 21a by the first reversing transport roller 17a and the second reversing transport roller 18a. It is transported along the transport path 14 and returned to the transport path 13.

  Here, when the reversal control unit 47 returns the printing paper P to the transport path 13, the transport motor 24 is driven in the forward direction to drive the first transport roller 20 a, the second transport roller 21 a, the first discharge roller 22 a and the first transport roller 24. Each of the two discharge rollers 23a is rotated in the first rotation direction R1, and the printing paper P is delivered from the second reverse conveying roller 18a to the second conveying roller 21a. The timing at which the reversal control unit 47 changes the driving of the transport motor 24 from the reverse direction to the forward direction is that the printing paper P transported by the first reverse transport roller 17a and the second reverse transport roller 18a is the paper detector 37. This is the point when it is no longer detected. When the printing paper P is detected by the paper detector 37 when the printing paper P is delivered from the second reversing conveyance roller 18a to the second conveyance roller 21a, the conveyance control of the printing paper P is performed by the reversal control unit. The process shifts from 47 to the conveyance control unit 45.

  The discharge control unit 48 performs a paper discharge operation for discharging the printing paper P remaining on the transport path 13 and the reverse transport path 14 when the power is turned on and the initialization operation. The initialization operation is performed by operating the operation button 9b or opening / closing the reversing unit 3.

  The discharge controller 48 drives the transport motor 24 in the forward direction without driving the reversing transport motor 31 when the paper detector 37 detects the print paper P when the power is turned on and during the initialization operation. At this time, the discharge controller 48 drives the transport motor 24 at a speed at which the transport mechanism 16 can transport the printing paper P at a second speed that is slower than the first speed. Further, the discharge control unit 48 can transport a difference distance obtained by subtracting the separation distance between the transport roller along the transport path 13 and the reverse transport path 14 and the reverse transport roller from the length dimension of the printing paper P. The transport motor 24 is driven for the drive time. Then, after the drive time has elapsed, the discharge control unit 48 drives the reversing transport motor 31 together with the transport motor 24 to transport the printing paper P at a first speed that is faster than the second speed.

  Further, when the printing paper P is no longer detected by the paper detector 37 while the transport motor 24 is driven for the transport time, the discharge control unit 48 sets the reverse transport motor 31 together with the transport motor 24 thereafter. Driven, the printing paper P is conveyed at a first speed higher than the second speed, and discharged from the paper discharge port 8.

  On the other hand, when the medium is not detected by the paper detector 37 when the power is turned on and during the initialization operation, the discharge control unit 48 uses the transport motor 24 and the reverse transport motor at a speed at which the print paper P can be transported at the first speed. 31 is driven for a preset time. At this time, the transport motor 24 is driven in the forward direction.

(Double-sided printing operation)
4 to 7 are explanatory diagrams of the double-sided printing operation. The double-sided printing operation of the printer 1 will be described with reference to FIGS. When print data for double-sided printing is supplied from an external device to the printer 1, the paper feed control unit 43 drives the supply motor 19 to rotate the paper feed roller 15 as shown in FIG. Further, the conveyance control unit 45 drives the conveyance motor 24 in the forward direction to rotate the first conveyance roller 20a, the second conveyance roller 21a, the first paper discharge roller 22a, and the second paper discharge roller 23a in the first rotation direction R1. Let As a result, the printing paper P stored in the paper feed cassette 6 is sent out to the transport path 13 by the paper feed roller 15. Further, the printing paper P sent out to the transport path 13 is transported along the transport path 13 in the first transport direction M1 at the first speed. Here, when a plurality of print sheets P are sent out to the transport path 13 by the paper feed roller 15, one sheet of the print sheets P passes through the nip portion between the first transport roller 20 a and the retard roller. Printing paper P is separated, and only the separated printing paper P enters the conveyance path 13. When the paper feed roller 15 rotates once and the print paper P enters the transport path 13, the paper feed control unit 43 stops the paper feed motor 19.

  The printing paper P transported along the transport path 13 by the transport mechanism 16 enters the horizontal transport path portion 13 c while pushing up the path switching flap 36. 4B, when the front end of the printing paper P in the first transport direction M1 passes the detection position B, the printing paper P is detected by the paper detector 37. When the printing paper P is detected, the position acquisition unit 44 thereafter obtains the position of the printing paper P on the transport path 13. Accordingly, the transport control unit 45 positions the scheduled print start position on the surface of the print paper P at the print position A based on the information acquired by the position acquisition unit 44. FIG. 4C shows a state in which the printing paper P is positioned at the printing position A. Until the printing paper P is positioned at the printing position A, the printing paper P is conveyed at the first speed.

  When the printing paper P is positioned at the printing position A, the printing control unit 46 prints on the surface of the printing paper P passing through the printing position A by repeating the printing operation by the printing head 12 and the paper feeding operation by the transport mechanism 16 alternately. Apply. During the printing process shown in FIG. 4D, the printing paper P is conveyed (paper fed) at a speed corresponding to the printing resolution. When the printing process is finished, as shown in FIG. 5A, the printing paper P is positioned on the discharge port 8 side with respect to the printing position A, that is, on the discharge port 8 side with respect to the connection portion 35. Become.

  When the printing is completed, as shown in FIG. 5B, the reversal control unit 47 drives the drive motor in the reverse direction to drive the first transport roller 20a, the second transport roller 21a, the first paper discharge roller 22a, and the second transport roller. The paper discharge roller 23a is rotated in the second rotation direction R2. Thereby, the printing paper P is conveyed in the second conveying direction M2. Here, since the path switching flap 36 is located at the first switching position 36 </ b> A, the printing paper P is fed into the reversing conveyance path 14.

  Further, when the driving motor is driven in the reverse direction, the reversing control unit 47 drives the reversing transport motor 31 to move the first reversing transport roller 17a and the second reversing transport roller 18a to the second rotation direction R2. Rotate in the same direction. As a result, the printing paper P fed into the reversing conveyance path 14 is transferred from the second conveying roller 21a to the first reversing conveying roller 17a and the second reversing conveying roller 18a. That is, as shown in FIG. 5C, the printing paper P is in a state of being conveyed while the second conveying roller 21a and the first reversing conveying roller 17a are nipped. Then, as shown in FIG. 5D, the printing paper P is conveyed while being nipped by the second conveying roller 21a, the first reversing conveying roller 17a, and the second reversing conveying roller 18a. As shown to Fig.6 (a), it will be in the state conveyed along the conveyance path 14 for reversal by the conveyance roller 17a for 1st inversion and the conveyance roller 18a for 2nd inversion. Thereafter, the printing paper P is returned from the reversing transport path 14 to the transport path 13 by the first reversing transport roller 17a and the second reversing transport roller 18a.

  Here, as shown in FIG. 6B, when the printing paper P is not detected by the paper detector 37, the reversal control unit 47 drives the transport motor 24 in the forward direction so that the first transport roller 20 a, The second transport roller 21a, the first paper discharge roller 22a, and the second paper discharge roller 23a are rotated in the first rotation direction R1. As a result, the printing paper P returned from the reversing conveyance path 14 to the conveyance path 13 is delivered to the conveyance mechanism 16. That is, as shown in FIGS. 6 (d) and 7 (a), the printing paper P is conveyed through a state in which the second reversing conveyance roller 18a and the second conveyance roller 21a are conveyed while being nipped by both. As shown in FIG. 7B, the transport mechanism 16 is transported along the transport path 13.

  As shown in FIG. 6C, when the leading edge of the printing paper P in the first transport direction M1 passes the detection position B, the printing paper P is detected by the paper detector 37. When the printing paper P is detected, since the position acquisition unit 44 acquires the position of the printing paper P on the conveyance path 13 thereafter, the conveyance control unit 45 acquires the position of the printing paper P. The printing start scheduled position on the back surface of the printing paper P is positioned at the printing position A based on the stored information. FIG. 7A shows a state in which the printing paper P is positioned at the printing position A.

  When the printing paper P is positioned at the printing position A, the printing control unit 46 alternately repeats the printing operation by the printing head 12 and the paper feeding operation by the transport mechanism 16, so that the printing paper P passing through the printing position A is printed. Print on the back side. During the printing process shown in FIGS. 7B and 7C, the printing paper P is conveyed at a speed corresponding to the printing resolution.

  When the printing process is finished, the printing paper P is conveyed from the printing position A toward the paper discharge port 8 as shown in FIG. In other words, the paper is transported in the first transport direction M1 by the first paper discharge roller 22a and the second paper discharge roller 23a, and is discharged from the paper discharge port 8. As shown in FIG. 7C, when the printing paper P is no longer detected by the paper detector 37, the reversing control unit 47 stops driving the reversing transport motor 31.

(Discharge operation at power-on and initialization)
Here, if the power is accidentally turned off while the printing paper P is being transported through the transport path 13 or the reversing transport path 14, the printing paper P remains in the transport path 13 or the reversing transport path 14. . Further, if the initialization operation is performed while the printing paper P is being transported through the transporting path 13 and the reversing transporting path 14, the printing paper P remains in the transporting path 13 and the reversing transporting path 14. . Since the remaining printing paper P causes a paper jam, the printer 1 performs a paper discharge operation when a new power supply is turned on and an initialization operation is performed. The paper discharge operation is performed based on whether or not the print paper P is detected by the paper detector 37.

  If the printing paper P is not detected by the paper detector 37 when the power is turned on and during the initialization operation, the discharge controller 48 drives the transport motor 24 in the forward direction and the reverse transport motor 31. At this time, the discharge controller 48 drives the transport motor 24 and the reverse transport motor 31 at a speed at which the printing paper P can be transported at the first speed. The first speed is a conveyance speed until the printing paper P reaches the printing position A from the paper cassette.

  That is, when the printing paper P is not detected by the paper detector 37, the printing paper P is in the state shown in FIGS. 4 (a), 5 (a), 7 (c), and 7 (d). The case where it remains in the conveyance path 13 is assumed. In these cases, the printing paper P remains on the transport path 13. Accordingly, by driving the transport motor 24, the printing paper P is transported at the first speed along the transport path 13 by the transport mechanism 16 and discharged from the paper discharge port 8.

  Further, when the printing paper P is not detected by the paper detector 37, it is assumed that the printing paper P remains in the reversing conveyance path 14 in the state shown in FIG. 6B. In this case, the printing paper P is sent from the reversing conveyance path 14 to the conveyance path 13 by the first reversing conveyance roller 17a and the second reversing conveyance roller 18a by the driving of the reversing conveyance motor 31. Further, the printing paper P sent out to the transport path 13 is transported at a first speed along the transport path 13 by the transport mechanism 16 by driving of the transport motor 24 and discharged from the paper discharge port 8.

  It should be noted that when the printing paper P is not detected by the paper detector 37 when the power is turned on and during the initialization operation, the case where the printing paper P does not remain in the conveyance path 13 or the reverse conveyance path 14 is included. However, the discharge control unit 48 drives the transport motor 24 and the reverse transport motor 31 for a predetermined time on the assumption that the printing paper P remains.

  Next, when the printing paper P is detected by the paper detector 37 when the power is turned on and during the initialization operation, the discharge control unit 48 transports the printing paper P at a speed at which the printing paper P can be transported at the second speed. Are driven in the positive direction for a predetermined driving time. In addition, the discharge control unit 48 drives the reversing conveyance motor 31 together with the conveyance motor 24 for a set time after the drive time has elapsed, and conveys the remaining printing paper P at the first speed. Further, if the printing paper P is no longer detected by the paper detector 37 while the transport motor 24 is driven for a predetermined drive time, the discharge control unit 48 thereafter turns the reverse transport motor 31 into the transport motor. 24, the printing paper P is transported at a first speed.

  That is, when the paper detector 37 detects the printing paper P when the power is turned on and during the initialization operation, the detected printing paper P is as shown in FIGS. 4 (b) to 4 (d). The entirety is located on the conveyance path 13, or FIG. 5 (b) to FIG. 5 (d), FIG. 6 (a), FIG. 6 (c), FIG. 6 (d), FIG. As shown in FIG. 7B, it can be determined that a part is located on the conveyance path 13 and the other part is located on the reversal conveyance path 14.

  Here, when a part of the remaining printing paper P is located on the conveyance path 13 and the other part is located on the reversal conveyance path 14, FIGS. 5 (c) and 5 (d). As shown in FIG. 4, the rear end portion in the transport direction is nipped by the second transport roller 21a while the printing paper P is being fed from the transport path 13 to the upper path 26 of the reversing transport path 14, and the front end portion is The case where it is nipped by the first reverse conveying roller 17a is included. In such a case, the transport motor 24 is driven in the forward direction to transport the print paper P on the transport path 13 toward the paper discharge port 8, and the print paper P on the reverse transport path 14 is transported. When the reversing conveyance motor 31 is driven to return to the path 13, the rotation directions of the second conveying roller 21a that nips the printing paper P and the reversing conveyance roller are reversed, and the printing paper P is torn. There is. More specifically, the second transport roller 21a is rotated in the first rotation direction R1 by driving the transport motor 24 in the forward direction, and the reverse transport roller is the first rotation direction R1 by driving the reverse transport motor 31. Since it rotates in the reverse rotation direction (the same rotation direction as the second rotation direction R2), the printing paper P may be damaged.

  Therefore, in this example, when the printing paper P is detected when the power is turned on and during the initialization operation, it is assumed that the remaining printing paper P is in the state shown in FIG. As shown in FIG. 8A, the conveyance motor 24 is driven in the forward direction without driving the reverse conveyance motor 31 and without rotating the first reverse conveyance roller 17a and the second reverse conveyance roller 18a. .

  Thus, the rotation direction of the second conveyance roller 21a and the rotation direction of the first reversal conveyance roller 17a and the second reversal conveyance roller 18a are not reversed. When nipped by the first reversing transport roller 17a and the second reversing transport roller 18a, the printing paper P is transported in the direction toward the paper discharge port 8 by the second transporting roller 21a, and the printing paper P is damaged. There is nothing. When the rotation direction of the second conveyance roller 21a that nips the printing paper P from each other and the rotation direction of the first reversal conveyance roller 17a and the second reversal conveyance roller 18a are reversed, the conveyance motor 24, the second An excessive load is applied to each of the transport roller 21a, the reverse transport motor 31 and the first reverse transport roller 17a. As a result, these may be damaged, but since the transport motor 24 is driven without driving the reversing transport motor 31, these damages can also be avoided.

  Further, since the transport motor 24 is driven in the forward direction, the printing paper P is returned from the reverse transport path 14 to the transport path 13 as shown in FIGS. 6 (d) and 7 (a). Even when the front end portion in the transport direction is nipped by the second transport roller 21a and the rear end portion is nipped by the second reversing transport roller 18a, the printing paper P is removed by the rotation of the second transport roller 21a. It can be conveyed toward the paper discharge port 8. Since the transport motor 24 is driven in the forward direction, printing is performed by the transport mechanism 16 even when the printing paper P is on the transport path 13 as shown in FIGS. 4B to 4D. The paper P can be conveyed toward the paper discharge port 8.

  Here, the transport motor 24 is moved in the forward direction by a transport time that can transport the difference distance obtained by subtracting the separation distance L between the second transport roller 21a and the first reversing transport roller 17a from the length dimension of the printing paper P. When driven, the medium is not nipped by the first and second reversing transport rollers 17a and 18a. That is, as shown in FIG. 5D, the rear end portion in the transport direction is nipped by the second transport roller 21a while the remaining medium is being sent from the transport path 13 to the reversal transport path 14. Even when the front end portion is nipped by both the first reversing transport roller 17a and the second reversing transport roller 18a, the nip of the medium by the first and second reversing transport rollers 17a and 18a is released. The state shown in FIG. Therefore, even if the reversing conveyance motor 31 is driven while the conveyance motor 24 is driven in the forward direction after the conveyance time has elapsed, the printing paper P is not damaged. Further, since the conveyance motor 24 and the reversal conveyance motor 31 are driven after the nip of the medium by the reversing conveyance roller is released and the printing paper P is conveyed at the first speed, the discharge time for discharging the printing paper P is shortened. it can.

  If the printing paper P is not detected by the paper detector 37 while the carry motor 24 is driven for the carrying time, as shown in FIG. 8C, the printing paper P is fed to the second carrying roller 21a. And the state of being nipped by both of the first reversing transport rollers 17a are eliminated. Accordingly, after the printing paper P is no longer detected, the reversing conveyance motor 31 is driven while the conveyance motor 24 is driven in the forward direction to convey the printing paper P at the first speed in the first conveyance direction M1. . Thereby, the discharge time for discharging the printing paper P can be shortened.

  Here, as shown in FIGS. 5C and 5D, the rear end portion in the transport direction is the second transport roller 21a in a state where the printing paper P is being fed from the transport path 13 to the reversal transport path 14. When the front end side portion is nipped by the first reversing transport roller 17a, the second transport roller 21a is driven by driving the transport motor 24 in the forward direction without driving the reversing transport motor 31. When the printing paper P is transported using the first and second reversing transporting rollers 17a and 18a, the printing paper P is transported. Further, as shown in FIGS. 6D and 7A, the front end portion in the transport direction nips the second transport roller 21a with the printing paper P being returned from the reverse transport path 14 to the transport path 13. When the rear end portion is nipped by the second reversing transport roller 18a, the second transport roller 21a is used by driving the transport motor 24 in the forward direction without driving the reversing transport motor 31. When the printing paper P is conveyed, the first reversing conveying roller 17a and the second reversing conveying roller 18a are rotated along with the conveying of the printing paper P. Therefore, in these cases, the second transport roller 21a and the transport motor 24 are subjected to a load that rotates the first reverse transport roller 17a and the second reverse transport roller 18a. Further, when the first reversing transport roller 17a and the second reversing transport roller 18a are rotated along with the transport of the printing paper P, the reversal that drives the first reversing transport roller 17a and the second reversing transport roller 18a. Since the counter electromotive force is generated in the transfer motor 31, the counter electromotive force may damage the drive control circuit of the reverse transfer motor 31.

  In response to such a problem, the discharge controller 48 drives the transport motor 24 in the forward direction at a speed at which the printing paper P can be transported at a second speed that is slower than the first speed, which is a normal transport speed. As a result, the rotation speed of the first reversing transport roller 17a and the second reversing transport roller 18a that rotate with the printing paper P can be suppressed as compared with the case of transporting the printing paper P at the first speed. Back electromotive force generated by the transport motor 31 can be suppressed. Further, the transport speed of the printing paper P when the discharge control unit 48 drives only the transport motor 24 to transport the remaining printing paper P is set to a slower speed (second speed) than the first speed. Therefore, the load applied to the second transport roller 21a and the transport motor 24 can be reduced by the accompanying rotation of the first reverse transport roller 17a and the second reverse transport roller 18a.

  FIG. 9 is a graph showing the load applied to the transport motor 24 and the counter electromotive force generated by the reverse transport motor 31. Graph α shows the printing paper when the printing paper P is conveyed toward the paper discharge port 8 by driving the conveyance motor 24 in the forward direction without driving the reversing conveyance motor 31 from the state shown in FIG. The relationship between the conveyance speed of P and the load of the conveyance motor 24 is shown. The load of the transport motor 24 is calculated from the current value of the transport motor 24. The graph β shows the relationship between the conveyance speed of the printing paper P and the counter electromotive force generated by the reversing conveyance motor 31 as the printing paper P is conveyed in this case. The graph γ is a comparative example, and the reversing transport motor 31 is driven in the opposite direction from the normal state from the state shown in FIG. 5D, and the first reversing transport motor 31 and the second reversing transport motor 31 are driven. While rotating in the same rotational direction as the first rotational direction R1 and driving the transport motor 24 in the forward direction to transport the print paper P toward the paper discharge port 8, the transport speed of the print paper P and the transport motor 24 It shows the relationship of load.

  The graph α indicates that the load on the transport motor 24 is reduced when the transport speed of the print paper P is suppressed when transporting the print paper P only by driving the transport motor 24. In addition, the graph β indicates that the generation of the counter electromotive force in the reversing transport motor 31 can be suppressed by suppressing the transport speed of the print paper P when transporting the print paper P only by driving the transport motor 24. Yes. That is, the second speed at which the printing paper P is conveyed by driving the conveyance motor 24 in the forward direction without driving the reversing conveyance motor 31 is the first speed (20 ips: inch / second) at which the printing paper P is normally conveyed. , That is, 5 ips, the load of the transport motor 24 is reduced to about 3/4. When the second speed for transporting the printing paper P is set to 5 ips, the counter electromotive force generated by the reversing transport motor 31 is suppressed to a value close to 0 mA. Here, the same applies to the case where the printing paper P is conveyed toward the paper discharge port 8 by driving the conveyance motor 24 in the forward direction without driving the reverse conveyance motor 31 from the state shown in FIG. Result is obtained.

  If the printing paper P detected by the paper detector 37 is in the state shown in FIGS. 4B to 4D, 5B, and 7B, the printing paper is printed. P is transported toward the paper discharge port 8 by the transport mechanism 16 when the transport motor 24 is driven in the forward direction, and is discharged from the paper discharge port 8. When the printing paper P detected by the paper detector 37 is in the state shown in FIG. 6A and FIG. 6C, the printing paper P is moved by the reversing conveyance motor 31 together with the conveyance motor 24. By being driven, the sheet moves from the reversing conveyance path 14 to the conveyance path 13, and then is conveyed by the conveyance mechanism 16 toward the sheet discharge port 8 and is discharged from the sheet discharge port 8.

(Other embodiments)
In the above example, the reversing unit 3 includes the first reversing transport roller 17a and the second reversing transport roller 18a as the reversing transport rollers that transport the printing paper P along the reversing transport path 14. There may be one reversing conveyance roller, or three or more.

  In the above example, the present invention is applied to the printer 1 capable of double-sided printing. However, the present invention is applicable to a medium processing apparatus other than the printer 1 such as a scanner and a facsimile including the reversing unit 3. The same applies.

1. Printer (medium processing device) 2. Printer body 3. Reversing unit 4. Recess 5. Recess 5. Paper feed cassette mounting 6. Paper feed cassette (supply unit) 7. Paper discharge tray 8. Discharge port (discharge port), 9 / operation surface, 9a / power switch, 9b / operating button, 10a / 10b / opening / closing door, 11 / opening / closing lid, 12 / printing head, 13 / conveying path, 13a / inclined conveying path Part, 13b / curved conveying path part, 13c / horizontal conveying path part, 14 / reversing conveying path, 15 / feed roller, 16 / conveying mechanism, 17 / reversing conveying roller pair, 17a / reversing conveying roller, 17b · Followed roller, 18 · Reversing conveying roller pair, 18a · Reversing conveying roller, 18b · Followed roller, 19 · Paper feed motor, 20 · First conveying roller pair, 20a · First conveying roller, 20b · Followed roller 20c · retard roller, 21 · second transport roller pair, 21a · second transport roller (transport roller), 21b · driven roller, 22 · first discharge roller pair, 22a · first discharge roller, 22b · driven roller, 23, second discharge roller pair, 23a, second discharge roller, 23b, driven roller, 24, transport motor, 25, platen, 26, upper path, 27, downward path, 28, lower path, 29, upward path, 30 · Common path, 31 · Reverse transfer motor, 35 · Connection part, 36 · Path switching flap, 36A · 1st switching position, 36B · 2nd switching position, 37 · Paper detector (detector), 37a · Detection lever, 41 / control unit, 42 / communication unit, 43 / feed control unit, 44 / position acquisition unit, 45 / conveyance control unit, 46 / print control unit, 47 / reverse control unit, 4 -Discharge control unit, A-Printing position (processing position), B-Detection position, M1-Transport direction, M2-Transport direction, P-Printing paper, R1-First rotation direction, R2-Second rotation direction, X- Printer width direction, Y / printer front / rear direction, Y1 / printer front, Y2 / printer rear, Z / printer up / down direction

Claims (8)

A conveyance path from a supply unit that supplies a sheet-like medium to a discharge port via a processing position where the medium is processed, and an inversion that reverses the front and back of the medium fed from the conveyance path and returns to the conveyance path A transporting path, a transporting mechanism that transports the medium along the transporting path, a reversing transporting roller that transports the medium along the reversing transporting path, and a transporting motor that is a drive source of the transporting mechanism. In the medium control device having a reversing conveyance motor that drives the reversing conveyance roller, a detector that detects the medium, and a control unit that drives and controls the conveyance motor and the reversing conveyance motor.
The reversing conveyance path has a loop shape, and is connected between the supply unit of the conveyance path and the processing position.
The transport mechanism includes a transport roller that transports the medium between a connection portion of the transport path to which the reversing transport path is connected and the processing position.
The detector detects the medium between the connection and the transport roller;
The transport roller rotates in a first rotation direction for transporting the medium in a direction approaching the discharge port by driving the transport motor in the forward direction, and the first rotation by driving in the reverse direction of the transport motor. Rotate in the second direction of rotation opposite to the direction,
The reversing transport roller rotates in the same rotational direction as the second rotational direction by driving the reversing transport motor,
The controller is
The transport motor is driven in the reverse direction to feed the medium transported closer to the discharge port than the connection portion into the reversing transport path, and the reversing transport motor is driven to The medium is delivered to the reversing transport roller, and then the medium is transported along the transport path by the reversing transport roller and sent to the transport path, and the transport motor is driven in the forward direction to A reversing control unit that delivers the medium from the reversing conveying roller to the conveying roller;
A discharge controller that drives the transport motor in the forward direction without driving the reversing transport motor when the medium is detected by the detector at power-on and initialization operation;
A transport control unit that drives the transport motor in the forward direction to transport the medium supplied from the supply unit at a first speed to reach the processing position;
The transport motor is driven in the forward direction to transport the medium that has reached the processing position to pass through the processing position, and the medium is subjected to the processing at the processing position, and the medium is moved more than the connection portion. A printing control unit positioned on the discharge port side,
The discharge control unit
Driving the transport motor at a speed capable of transporting the medium at a second speed slower than the first speed;
Separation between the transport roller and the reverse transport roller along the transport path and the reverse transport path from the length dimension of the medium along the transport path without driving the reverse transport motor. The transport motor is driven in the forward direction for a transport time that can transport the difference distance minus the distance, and then the reversing transport motor is driven together with the transport motor to drive the medium at a speed higher than the second speed. Transport by
A medium processing apparatus. In claim 1,
When the medium is no longer detected by the detector while the transport motor is driven for the transport time, the discharge control unit drives the reverse transport motor together with the transport motor thereafter. A medium processing apparatus for conveying the medium at a speed higher than the second speed. In claim 1 or 2,
The discharge control unit drives the transport motor in the forward direction together with the transport motor for reversal when the medium is not detected by the detector when the power is turned on and during an initialization operation. In any one of claims 1 to 3,
A medium processing apparatus comprising: a print head that performs printing on the medium at the processing position. A conveyance path from a supply unit that supplies a sheet-like medium to a discharge port via a processing position where the medium is processed, and an inversion that reverses the front and back of the medium fed from the conveyance path and returns to the conveyance path The medium is transported along the transport path by a transport mechanism using a transport motor as a drive source, and the medium is transported by the reversing transport roller driven by the reversing transport motor. In a control method of a medium processing apparatus transported along a path,
The reversing transport path is looped and connected between the supply section of the transport path and the processing position, and the transport mechanism is connected to the transport path connecting section to which the reversing transport path is connected. A transport roller that transports the medium to and from a processing position, and the transport roller transports the medium in a first transport direction toward the discharge port by driving the transport motor in a positive direction; It rotates in the rotation direction, and rotates in the second rotation direction opposite to the first rotation direction by driving the reverse direction of the transport motor, and the reverse transport roller is driven by the reverse transport motor. Rotate in the same rotation direction as the second rotation direction,
The transport motor is driven in the reverse direction, and the medium transported to the discharge port side from the connection portion is sent to the reverse transport path, and the reverse transport motor is driven to drive the transport roller. From the medium to the reversing transport roller,
The reversing conveyance roller conveys the medium along the reversing conveyance path and sends the medium to the conveyance path, and the conveyance motor is driven in the forward direction to transfer the medium from the reversing conveyance roller to the conveyance roller. Deliver the media,
When the power is turned on and the initialization operation, the medium is detected between the connection portion on the conveyance path and the conveyance roller,
When the medium is detected, the transport motor is driven in the forward direction without driving the reversing transport motor,
Driving the transport motor in the forward direction to transport the medium supplied from the supply unit at a first speed to reach the processing position;
The transport motor is driven in the forward direction to transport the medium that has reached the processing position to pass through the processing position, and the medium is subjected to the processing at the processing position, and the medium is moved more than the connection portion. Located on the side of the outlet,
When the medium is detected, the transport motor is driven at a speed at which the medium can be transported at a second speed slower than the first speed;
When the medium is detected, the transport roller along the transport path and the reverse transport path from the length dimension of the medium along the transport path without driving the reverse transport motor; Drive the transport motor in the forward direction for a transport time that can transport a difference distance obtained by subtracting the separation distance from the reversing transport roller, and then drive the reversing transport motor together with the transport motor to Conveying the medium at a speed faster than the second speed;
A control method for a medium processing apparatus. A conveyance path from a supply unit that supplies a sheet-like medium to a discharge port via a processing position where the medium is processed, and an inversion that reverses the front and back of the medium fed from the conveyance path and returns to the conveyance path The medium is transported along the transport path by a transport mechanism using a transport motor as a drive source, and the medium is transported by the reversing transport roller driven by the reversing transport motor. In a control method of a medium processing apparatus transported along a path,
The reversing transport path is looped and connected between the supply section of the transport path and the processing position, and the transport mechanism is connected to the transport path connecting section to which the reversing transport path is connected. A transport roller that transports the medium to and from a processing position, and the transport roller transports the medium in a first transport direction toward the discharge port by driving the transport motor in a positive direction; It rotates in the rotation direction, and rotates in the second rotation direction opposite to the first rotation direction by driving the reverse direction of the transport motor, and the reverse transport roller is driven by the reverse transport motor. Rotate in the same rotation direction as the second rotation direction,
The transport motor is driven in the reverse direction, and the medium transported to the discharge port side from the connection portion is sent to the reverse transport path, and the reverse transport motor is driven to drive the transport roller. From the medium to the reversing transport roller,
The reversing conveyance roller conveys the medium along the reversing conveyance path and sends the medium to the conveyance path, and the conveyance motor is driven in the forward direction to transfer the medium from the reversing conveyance roller to the conveyance roller. Deliver the media,
When the power is turned on and the initialization operation, the medium is detected between the connection portion on the conveyance path and the conveyance roller,
When the medium is detected, the transport motor is driven in the forward direction without driving the reversing transport motor,
Driving the transport motor in the forward direction to transport the medium supplied from the supply unit at a first speed to reach the processing position;
The transport motor is driven in the forward direction to transport the medium that has reached the processing position to pass through the processing position, and the medium is subjected to the processing at the processing position, and the medium is moved more than the connection portion. Located on the side of the outlet,
When the medium is detected, the transport motor is driven at a speed at which the medium can be transported at a second speed slower than the first speed;
When the medium is not detected while the transport motor is driven for the transport time, the reverse transport motor is driven together with the transport motor to transport the medium at a speed higher than the second speed. ,
A control method for a medium processing apparatus. In claim 5 or 6,
When the medium is not detected, the medium processing apparatus is controlled by driving the conveyance motor in the forward direction together with the reversing conveyance motor. In any one of claims 5 to 7,
A method of controlling a medium processing apparatus, wherein printing is performed on the medium at the processing position.

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