JP2013237496A - Printing device - Google Patents

Abstract

There is provided a printing apparatus capable of preventing an unintended print medium from being sent to a registration roller at the time of releasing a jam even if a decrease in conveyance accuracy of the print medium to the registration roller is suppressed.
An external drive force transmission unit of a common drive unit transmits only a rotational drive force in a normal rotation direction from an output shaft of a common motor to a pickup roller and a scraper roller of an external paper feed unit. The side driving force transmission unit always connects the output shaft of the common motor and the intermediate conveyance roller 36 of the internal paper feeding unit 12 so as to be able to transmit the rotational driving force in the normal rotation direction and the reverse rotation direction. The controller 7 separates the uppermost sheet P on the external sheet feed tray 21 and the scraper roller 22 when feeding from the internal sheet feeder 12.
[Selection] Figure 1

Description

  The present invention relates to a printing apparatus that performs printing on a printing medium.

  2. Description of the Related Art Conventionally, in a printing apparatus, a mechanism is known in which paper taken out from a paper feed tray is sent out to a printing unit having an inkjet head or the like by a registration roller. In such a mechanism, the sheet is abutted against the registration roller and temporarily stopped to form a slack in the sheet, thereby correcting the skew of the sheet. Thereafter, the registration roller is driven to feed the paper to the printing unit.

  In addition, there is known a printing apparatus provided with a plurality of paper feeding units that convey paper to registration rollers in order to use paper of various sizes and types for printing.

  For example, the printing apparatus described in Patent Document 1 includes an external paper feed unit that feeds a part from a side paper feed tray that is partially exposed from the apparatus housing, and an internal paper feed that feeds from a paper feed tray provided at the lower part of the apparatus. And a paper section. When paper is fed from the external paper feed unit, the primary paper feed roller picks up the paper from the side paper feed tray and conveys it to the registration roller. On the other hand, when the paper is fed from the internal paper feeding unit, the intermediate transport roller receives the paper that has been taken out from the paper feed tray by the rollers and transported to the registration rollers.

  In the configuration of such a printing apparatus, there is one in which the primary sheet feeding roller of the external sheet feeding unit and the intermediate conveyance roller of the internal sheet feeding unit are driven by a single motor in order to reduce the size of the apparatus. In this case, in order to adopt an exclusive configuration in which the primary paper feed roller and the intermediate transport roller are switched and driven, the drive force transmission system from the motor to the primary paper feed roller, and the drive force transmission system from the motor to the intermediate transport roller, Each is provided with a driving force cutting means such as a one-way clutch or an electromagnetic clutch. Thereby, for example, it is possible to realize an exclusive configuration in which the primary sheet feeding roller is driven by the forward rotation driving of the motor and the intermediate conveyance roller is driven by the reverse driving of the motor.

JP 2010-215389 A

  In order to perform stable slack formation and skew correction even when the paper size and type change, the primary paper feed roller for transporting paper to the registration rollers and the intermediate transport roller for the internal paper feed unit Therefore, stable conveyance performance is required.

  However, when the one-way clutch is provided in the driving force transmission system as described above, the conveyance accuracy of the primary paper feed roller and the intermediate conveyance roller may be lowered due to the backlash or overrun of the one-way clutch. In addition, when an electromagnetic clutch is provided in the driving force transmission system, transmission of the driving force is delayed due to the time required for the operation of the electromagnetic clutch, and as a result, the conveyance accuracy of the primary paper feed roller and the intermediate conveyance roller may be reduced. is there. Due to such a decrease in the conveyance accuracy to the registration roller, the amount of slack of the paper at the registration roller becomes unstable, or the speed of the paper at the time of collision with the registration roller becomes faster than expected, and the collision sound becomes louder. There was an inconvenience.

  If the driving force cutting means such as the one-way clutch of the driving force transmission system is deleted, it is possible to suppress the decrease in the conveyance accuracy to the registration roller as described above.

  Here, when driving force cutting means such as a one-way clutch of a driving force transmission system from the motor to the primary paper feed roller of the external paper feed unit is deleted, even when driving the intermediate conveyance roller in paper feed from the internal paper feed unit, The primary paper feed roller of the external paper feed unit is driven. As described above, the primary paper feed roller picks up and conveys the paper on the side paper feed tray, and is in contact with the paper. For this reason, it is not preferable that the primary paper feed roller is driven when paper is fed from the internal paper feed unit. For this reason, it is not preferable to delete the driving force cutting means such as a one-way clutch in the driving force transmission system from the motor to the primary paper feed roller.

  On the other hand, if the driving force cutting means of the driving force transmission system from the motor to the intermediate conveyance roller is deleted, the intermediate conveyance roller of the internal paper feeding unit is driven even when the primary paper feeding roller is driven in paper feeding from the external paper feeding unit Is done. As described above, the intermediate conveyance roller receives the sheet taken out from the sheet feeding tray by the roller and conveyed to the registration roller when feeding from the internal sheet feeding unit. When paper is fed from the external paper feed unit, the paper is not transported from the paper feed tray of the internal paper feed unit to the intermediate transport roller. For this reason, even if the intermediate conveyance roller of the internal paper feeding unit is driven during paper feeding from the external paper feeding unit, it merely idles and there is no inconvenience due to this.

  By the way, in a printing apparatus, a paper jam (jam) may occur, and the operation may be stopped during execution of a print job. When the operation of the printing apparatus is stopped in this way, the user performs a jam clearing operation of removing paper remaining in the apparatus.

  Here, in the configuration in which the driving force cutting unit of the driving force transmission system from the motor to the intermediate conveyance roller is deleted, the intermediate conveyance roller is moved to the paper due to the occurrence of a jam during the execution of the print job fed from the internal paper feeding unit. Assume that the operation of the printing apparatus is stopped in a state where the nip is held. When the user pulls the paper to remove the paper nipped by the intermediate transport roller, the intermediate transport roller rotates. This rotation is transmitted to the output shaft of the motor by the driving force transmission system. As a result, the output shaft of the motor rotates.

  When the user pulls the sheet in the sheet conveyance direction (downstream side) by the intermediate conveyance roller, the output shaft of the motor rotates in the reverse direction by the rotation of the intermediate conveyance roller. Here, the rotational direction in which the motor drives the primary paper feed roller in the paper transport direction is the forward rotation direction, and the rotational direction in which the motor drives the intermediate transport roller in the paper transport direction is the reverse rotation direction. Even if the output shaft of the motor rotates in the reverse direction, the rotation is not transmitted to the primary paper feed roller by a one-way clutch of a driving force transmission system from the motor to the primary paper feed roller of the external paper feed unit.

  However, when the user pulls the sheet to the opposite side (upstream side) of the sheet conveyance direction by the intermediate conveyance roller, the output shaft of the motor rotates in the forward direction by the rotation of the intermediate conveyance roller. As a result, the primary paper feed roller of the external paper feed unit rotates. As a result, unintended paper is sent from the side paper feed tray to the registration rollers by the primary paper feed roller.

  The present invention has been made in view of the above, and a printing apparatus capable of preventing an unintended print medium from being sent out to a registration roller even when a jam is released, even if a decrease in conveyance accuracy of the print medium to the registration roller is suppressed. The purpose is to provide.

  In order to achieve the above object, a first feature of a printing apparatus according to the present invention is that the registration roller that conveys the print medium to the printing unit and the print medium loaded on the first paper feed stand are separated from each other. A first paper feed unit having a first roller transported to the registration rollers, a second paper feed unit having a second roller for receiving a print medium taken out from the second paper feed table and transporting the print media to the registration rollers, A drive source having an output shaft for outputting a rotational drive force in one rotational direction and a second rotational direction; and a first power source for transmitting only the rotational drive force in the first rotational direction from the output shaft of the drive source to the first roller. A first transmission unit, a second transmission unit that constantly connects the output shaft of the drive source and the second roller so as to be able to transmit the rotational driving force in the first rotational direction and the second rotational direction, and the first Topmost print medium on the paper feed tray and the first roller When the paper feed from the first paper feed unit and the contact / separation drive unit that contacts and separates the output shaft, the output shaft of the drive source is driven to rotate in the first rotation direction, and the second paper feed unit A control unit that rotationally drives the output shaft of the drive source in the second rotation direction when feeding paper, and the control unit performs the contact and separation when feeding from the second paper feed unit. The drive unit separates the uppermost print medium on the first paper feed table from the first roller.

  A second feature of the printing apparatus according to the present invention is that the control unit determines that the paper source in the next print job to be executed is the first during the execution of the print job in which the paper source is the second paper source. When it is determined that the sheet feeding unit is the first sheet feeding unit, the contact / separation driving unit matches the uppermost printing medium on the first sheet feeding table with the first roller before the end of the print job being executed. It is to start relative movement for contact.

  A third feature of the printing apparatus according to the present invention is that, when the control unit stops the operation of the printing apparatus and the print medium is sandwiched between the second rollers, the output shaft of the drive source. Is rotated in the second rotation direction, and the second roller is driven until the print medium is released.

  According to the first feature of the printing apparatus according to the present invention, the second transmission unit always connects the output shaft of the driving source and the second roller so as to be able to transmit the driving force, so that the registration by the second roller is performed. A reduction in the accuracy of transporting the print medium to the roller is suppressed. The control unit separates the uppermost print medium on the first paper feed table from the first roller when feeding paper from the second paper feed unit. As a result, the second roller is rotated by pulling the printing medium nipped by the second roller when the jam is released, and this rotation is transmitted by the second transmission unit, the output shaft of the drive source, and the first transmission unit. Even if the first roller rotates, an unintended print medium is not sent from the first paper feed table to the registration roller. Therefore, according to the first feature, it is possible to prevent an unintended print medium from being sent to the registration roller at the time of jam release even if the decrease in the accuracy of conveyance of the print medium to the registration roller is suppressed.

  According to the second feature of the printing apparatus according to the present invention, the control unit determines that the first paper source in the next print job to be executed is the first during the execution of the print job in which the paper source is the second paper source. When it is determined that the paper feed unit is in use, the relative movement for bringing the uppermost print medium on the first paper feed table into contact with the first roller is started before the end of the print job being executed. As a result, the printing apparatus can quickly start feeding the next print job, and can suppress a decrease in productivity.

  According to the third feature of the printing apparatus according to the present invention, when the operation of the printing apparatus is stopped, when the printing medium is held between the second rollers, the control unit performs the second operation until the printing medium is released. Drive the roller. Accordingly, it is possible to more reliably prevent an unintended print medium from being sent out from the first paper feed table to the registration roller by preventing the second roller from holding the print medium when the jam is released.

1 is a schematic configuration diagram of a printing apparatus according to an embodiment. FIG. 2 is a block diagram illustrating a configuration of a control system of the printing apparatus illustrated in FIG. 1. It is a front view of a common drive part. It is a side view of a common drive part. 6 is a flowchart for explaining the operation of the printing apparatus. 6 is a flowchart for explaining the operation of the printing apparatus. FIG. 10 is an explanatory diagram of an operation of a common drive unit when a sheet feeding source is an external sheet feeding unit. FIG. 10 is an explanatory diagram of an operation of a common drive unit when a sheet feeding source is an internal sheet feeding unit. FIG. 10 is an explanatory diagram of an operation of a common drive unit when a sheet nipped by an intermediate conveyance roller is pulled downstream. FIG. 10 is an explanatory diagram of an operation of a common drive unit when a sheet nipped by an intermediate conveyance roller is pulled upstream.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus or the like for embodying the technical idea of the present invention, and the technical idea of the present invention is to arrange the components and the like as follows. It is not something specific. The technical idea of the present invention can be variously modified within the scope of the claims.

  1 is a schematic configuration diagram of a printing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram illustrating a configuration of a control system of the printing apparatus illustrated in FIG. 1, and FIG. 3 is a diagram of the printing apparatus illustrated in FIG. FIG. 4 is a front view of the common drive unit, and FIG. 4 is a side view of the common drive unit. In the following description, the paper surface direction of FIG. Moreover, as shown in FIG. 1, when viewed from the user, the top, bottom, left, and right are defined as the top, bottom, left, and right directions.

  In FIG. 1, a path indicated by a thick line is a transport path through which the paper P that is a print medium is transported. Among the transport routes, a route indicated by a solid line is a normal route RC, a route indicated by a one-dot chain line is a reverse route RR, a route indicated by a broken line is a paper discharge route RD, and a route indicated by a two-dot chain line is a paper feed route RS. In the following description, upstream and downstream mean upstream and downstream in the transport path.

  As shown in FIGS. 1 and 2, the printing apparatus 1 according to the present embodiment includes a paper feeding unit 2, a printing unit 3, an upper surface transport unit 4, a paper discharge unit 5, a reversing unit 6, and a control. A portion 7 and a housing 8 that stores or holds each portion are provided.

  The paper feeding unit 2 feeds the paper P. The paper feed unit 2 includes an external paper feed unit 11, an internal paper feed unit 12, a registration roller 13, an elevating motor 14, an internal paper feed motor 15, a common drive unit 16, and a registration motor 17.

  The external paper feeding unit 11 conveys the paper P to the registration roller 13. The external paper feed unit 11 corresponds to a first paper feed unit in the claims. The external paper feed unit 11 includes an external paper feed stand 21, an external paper feed scraper roller 22 (hereinafter referred to as a scraper roller 22 as appropriate), an external paper feed pickup roller 23 (hereinafter referred to as a pickup roller 23 as appropriate), And a plate 24.

  The external paper feed tray 21 is used for loading paper P used for printing. The external paper feed tray 21 is partly exposed outside the housing 8. The external paper feed table 21 corresponds to the first paper feed table in the claims.

  The scraper roller 22 is in contact with the uppermost (uppermost) paper P among the papers P stacked on the external paper feed table 21 and rotates to remove the uppermost paper P from the stacked paper P. Separate and send to the registration roller 13 side (right side). The scraper roller 22 is disposed above the right end portion of the external paper feed tray 21. The scraper roller 22 corresponds to a first roller in the claims.

  The pick-up roller 23 holds the paper P between the lower plate 24 arranged below and conveys it to the right side. The pickup roller 23 is arranged adjacent to the right side of the scraper roller 22.

  The separator plate 24 is for separating the paper P so that the paper P is conveyed one by one by the pickup roller 23. The sucker plate 24 contacts the pickup roller 23 from below.

  The internal paper feeding unit 12 conveys the paper P to the registration roller 13. The internal paper feeding unit 12 corresponds to a second paper feeding unit in the claims. The internal paper feed unit 12 includes a plurality of internal paper feed trays 31, a plurality of internal paper feed scraper rollers 32 (hereinafter referred to as scraper rollers 32 as appropriate), and an internal paper feed pickup roller 33 (hereinafter referred to as pickup roller 33 as appropriate). A plurality of vertical plates 34, a plurality of pairs of vertical conveying rollers 35, and an intermediate conveying roller 36.

  The internal paper feed tray 31 is used for stacking paper P used for printing. The internal paper feed tray 31 is arranged at the lower part in the housing 8. A movable plate 37 is provided on the internal paper feed tray 31. The movable plate 37 is made of a plate-like member provided on the bottom surface of the internal paper feed tray 31. Sheets P are stacked on the movable plate 37. The movable plate 37 is configured such that the left end side can be moved up and down by a movable plate motor (not shown). As a result, the uppermost sheet P stacked on the movable plate 37 can be brought into contact with the scraper roller 32. The internal paper feed table 31 corresponds to a second paper feed table in the claims.

  The scraper roller 32 abuts on the uppermost sheet P among the sheets P stacked on the movable plate 37 of the internal sheet feed table 31 and rotates to remove the uppermost sheet P from the stacked sheets P. Separate and send to the left. The scraper roller 32 is disposed above the left end portion of the internal paper feed tray 31.

  The pickup roller 33 holds the paper P between the lower plate 34 arranged below and feeds it to the left side. The pickup roller 33 is disposed adjacent to the left side of the scraper roller 32.

  The separator plate 34 is for separating the paper P so that the paper P is conveyed one by one by the pickup roller 33. The sucker plate 34 contacts the pickup roller 33 from below.

  The vertical conveyance roller 35 conveys the paper P taken out from the internal paper feed tray 31 by the scraper roller 32 and the pickup roller 33 to the intermediate conveyance roller 36. The vertical conveyance roller 35 is disposed along the paper feed path RS.

  The intermediate transport roller 36 receives the paper P taken out from the internal paper feed tray 31 and transported along the paper feed path RS, and transports it to the registration rollers 13. The intermediate conveyance roller 36 includes a pair of a driving roller 36a and a driven roller 36b. The driving roller 36 a is rotationally driven by the common driving unit 16. The driven roller 36b is disposed so as to be in contact with the driving roller 36a, and rotates following the rotation of the driving roller 36a. The intermediate conveyance roller 36 is disposed in the downstream portion of the sheet feeding path RS. The intermediate conveyance roller 36 corresponds to a second roller in the claims.

  The registration roller 13 temporarily stops the paper P transported from the external paper feeding unit 11, the internal paper feeding unit 12, and the reversing unit 6, and after the slack is formed on the paper P, transports it toward the printing unit 3. The registration roller 13 is disposed on the normal route RC in the vicinity of the junction point between the paper feed route RS and the reverse route RR.

  The raising / lowering motor 14 raises / lowers the external sheet feeding table 21. As a result, the lifting / lowering motor 14 brings the uppermost sheet P on the external sheet feed table 21 into contact with the scraper roller 22. The raising / lowering motor 14 is equivalent to the contacting / separating drive part of a claim.

  The internal paper feed motor 15 drives a plurality of pickup rollers 33 and a plurality of pairs of vertical conveyance rollers 35. When the pickup roller 33 rotates, the scraper roller 32 also rotates in the same direction in synchronization with the pickup roller 33 via a belt pulley mechanism (not shown). The internal paper feed motor 15 can be connected / released to / from each pickup roller 33 and each vertical transport roller 35 by a clutch (not shown). The pickup pickup roller 33, the scraper roller 32, and the vertical conveyance roller 35 to be driven are switched by the clutch.

  The common drive unit 16 drives the scraper roller 22 and the pickup roller 23 of the external paper feed unit 11 and the intermediate conveyance roller 36 of the internal paper feed unit 12. As shown in FIGS. 3 and 4, the common drive unit 16 includes a common motor 41, an external drive force transmission unit 42, and an internal drive force transmission unit 43.

  The common motor 41 generates a rotational driving force in the forward rotation direction (first rotation direction) and the reverse rotation direction (second rotation direction). The common motor 41 has an output shaft 41a that outputs rotational driving force in the forward direction and the reverse direction. The common motor 41 corresponds to a drive source in claims.

  The external driving force transmission unit 42 transmits only the rotational driving force in the normal rotation direction from the output shaft 41 a of the common motor 41 to the pickup roller 23 and the scraper roller 22. The external driving force transmission unit 42 corresponds to a first transmission unit in claims. The external driving force transmission unit 42 includes a one-way clutch 46, an output gear 47, and a driven gear 48.

  The one-way clutch 46 is provided on the output shaft 41 a of the common motor 41. The one-way clutch 46 transmits only the rotational driving force in the forward direction to the output gear 47 among the rotational driving force in the forward direction (clockwise) and the rotational direction in the reverse direction (counterclockwise) of the common motor 41. .

  The output gear 47 is engaged with the driven gear 48 and transmits a rotational driving force to the driven gear 48. The output gear 47 is provided on the output shaft 41 a of the common motor 41 via the one-way clutch 46. Due to the function of the one-way clutch 46, when the output shaft 41a of the common motor 41 rotates in the forward direction, the output gear 47 rotates in the same direction. However, even if the output shaft 41a rotates in the reverse direction, the output gear 47 rotates. do not do.

  The driven gear 48 is provided on the rotation shaft 49. The driven gear 48 is meshed with the output gear 47. As a result, the driven gear 48 rotates according to the rotation of the output gear 47 and rotates the rotating shaft 49. The rotation shaft 49 is a shaft on which the pickup roller 23 is provided. When the rotation shaft 49 rotates, the pickup roller 23 rotates in the same direction as the rotation shaft 49. The pickup roller 23 is connected to the scraper roller 22 by a belt pulley mechanism (not shown). When the pickup roller 23 rotates, the scraper roller 32 also rotates in the same direction in synchronization with the pickup roller 23 via the belt pulley mechanism.

  The internal driving force transmission unit 43 always connects the output shaft 41a of the common motor 41 and the intermediate conveyance roller 36 so as to be able to transmit the rotational driving force in the normal rotation direction and the reverse rotation direction. Here, “always connected so that the rotational driving force in the forward direction and the reverse direction can be transmitted” means that the internal driving force transmission unit 43 can cut off the transmission of the rotational driving force such as a one-way clutch or an electromagnetic clutch. This means that it does not have a driving force cutting means. The internal driving force transmission unit 43 corresponds to a second transmission unit in claims. The internal drive force transmission unit 43 includes an output pulley 51, a belt 52, and a driven pulley 53.

  The output pulley 51 transmits the rotational driving force of the common motor 41 to the belt 52. The output pulley 51 is provided on the output shaft 41 a of the common motor 41.

  The belt 52 transmits the rotational driving force of the common motor 41 transmitted by the output pulley 51 to the driven pulley 53. The belt 52 is stretched between the output pulley 51 and the driven pulley 53.

  The driven pulley 53 is provided on the rotating shaft 54. The driven pulley 53 is rotated by the rotational driving force transmitted by the belt 52. As a result, the driven pulley 53 rotates according to the rotation of the output pulley 51 and rotates the rotating shaft 54. The rotation shaft 54 is a shaft on which the drive side roller 36 a of the intermediate transport roller 36 is provided. When the rotation shaft 54 rotates, the drive side roller 36 a rotates in the same direction as the rotation shaft 54. Further, the driven roller 36b rotates following the rotation of the driving roller 36a.

  The registration motor 17 rotates the registration roller 13.

  The printing unit 3 performs printing on the paper P while conveying the fed paper P. The printing unit 3 is disposed on the downstream side of the registration roller 13. The printing unit 3 includes a belt conveyance unit 56 and an inkjet head unit 57.

  The belt conveyance unit 56 conveys the sheet P conveyed from the registration roller 13 by sucking and holding the sheet P on the belt. The roller on which the belt of the belt conveyance unit 56 is wound is driven by a motor (not shown), whereby the belt rotates and the paper P on the belt is conveyed.

  The inkjet head unit 57 has a plurality of line-type inkjet heads (not shown) in which a plurality of nozzles are arranged in a direction (front-rear direction) substantially orthogonal to the transport direction of the paper P. The inkjet head unit 57 is disposed above the belt conveyance unit 56. The inkjet head unit 57 prints an image by ejecting ink from the inkjet head onto the paper P conveyed by the belt conveyance unit 56.

  The upper surface transport unit 4 transports the paper P transported by the belt transport unit 56 so as to make a U-turn from the right direction to the left direction. The upper surface transport unit 4 includes a plurality of pairs of upper surface transport rollers 59.

  The upper surface conveyance roller 59 nips and conveys the paper P. The pair of upper surface transport rollers 59 is disposed upstream of the reversing path RR. The other upper surface transport rollers 59 are arranged along the normal path RC between the printing unit 3 and the paper discharge unit 5. The plurality of pairs of upper surface transport rollers 59 are rotationally driven by a plurality of motors (not shown).

  The paper discharge unit 5 discharges and stacks the printed paper P. The paper discharge unit 5 includes a switching unit 61, a paper discharge roller 62, and a paper discharge stand 63.

  The switching unit 61 switches the transport path of the paper P between the paper discharge path RD and the reverse path RR. The switching unit 61 is driven by a solenoid (not shown). The switching unit 61 is disposed at a branch point between the paper discharge route RD and the reversal route RR. The paper discharge path RD is a path extending from the downstream end of the normal path RC toward the paper discharge tray 63.

  The paper discharge roller 62 conveys the paper P conveyed by the upper surface conveyance unit 4 and discharges it to the paper discharge tray 63. The paper discharge roller 62 is disposed between the switching unit 61 and the paper discharge tray 63 along the paper discharge path RD.

  The paper discharge tray 63 stacks the paper P discharged by the paper discharge roller 62.

  The reversing unit 6 reverses the single-side printed paper P and conveys it to the registration roller 13 during duplex printing. The reversing unit 6 includes a reversing roller 66, a switchback unit 67, a refeed roller 68, and a switching gate 69.

  The reversing roller 66 temporarily transports the paper P transported by the upper surface transport unit 4 to the switchback unit 67 and then transports it to the refeed roller 68. The reverse roller 66 is disposed on a reverse path RR between the uppermost transport roller 59 on the most downstream side and the carry-in port of the switchback unit 67. The reverse roller 66 is driven to rotate by a motor (not shown).

  The switchback portion 67 is a space for the reversing roller 66 to temporarily carry in the paper P. The switchback portion 67 is formed at the lower part of the paper discharge tray 63. The switchback portion 67 is opened near the reversing roller 66 for carrying the paper P therein.

  The refeed roller 68 conveys the paper P conveyed by the reversing roller 66 to the registration roller 26. The refeed roller 68 is disposed on a reverse path RR between the reverse roller 66 and the registration roller 26. The refeed roller 68 is rotationally driven by a motor (not shown).

  The switching gate 69 guides the sheet P conveyed by the upper surface conveying roller 59 to the reverse roller 66. Further, the switching gate 69 guides the paper P carried out from the switchback portion 67 by the reverse roller 66 to the refeed roller 68. The switching gate 69 is disposed in the vicinity of the center of gravity at the three locations of the uppermost transport roller 59, the reverse roller 66, and the refeed roller 68 on the most downstream side.

  The control unit 7 controls the operation of each unit of the printing apparatus 1. The control unit 7 includes a CPU, a RAM, a ROM, a hard disk, and the like.

  Next, the operation of the printing apparatus 1 will be described.

  5 and 6 are flowcharts for explaining the operation of the printing apparatus 1. The processing of the flowcharts of FIGS. 5 and 6 is started, for example, when a print job is input to the printing apparatus 1 from an external PC (personal computer).

  Here, the printing apparatus 1 is in a state in which the scraper roller 22 is in contact with the uppermost sheet P on the external sheet feed table 21 during standby. Further, the left end side of the movable plate 37 of the internal paper feed tray 31 is lifted, and the uppermost sheet P on the movable plate 37 is in contact with the scraper roller 32.

  When the print job is received, in step S10 of FIG. 5, the control unit 7 determines whether or not the paper supply source at the time of execution of the print job is the internal paper supply unit 12. Here, the control unit 7 can determine whether the paper feed source is the external paper feed unit 11 or the internal paper feed unit 12 based on the paper information included in the print job.

  If it is determined that the paper supply source is the internal paper supply unit 12 (step S10: YES), in step S20, the control unit 7 controls the elevating motor 14 to lower the external paper supply table 21 by a specified amount. Specifically, the control unit 7 drives the elevating motor 14 for a predetermined time so as to lower the external sheet feed table 21. As a result, the control unit 7 separates the uppermost sheet P on the external sheet feed table 21 from the scraper roller 22.

  Next, in step S <b> 30, the control unit 7 starts paper feeding from the internal paper feeding unit 12 and printing.

  On the other hand, when it is determined that the paper feed source is the external paper feed unit 11 (step S10: NO), the control unit 7 does not perform the process of step S20, but in step S30, the paper feed from the external paper feed unit 11 is performed. , And start printing.

  Here, regarding paper feeding and printing, a case where the paper feeding source is the external paper feeding unit 11 and a case where the paper feeding source is the internal paper feeding unit 12 will be described.

  When the paper supply source is the external paper supply unit 11, first, the control unit 7 starts normal rotation driving of the common motor 41. Thereby, as shown in FIG. 7, the output shaft 41a of the common motor 41 rotates clockwise. At the same time, the output gear 47 rotates clockwise via the one-way clutch 46. Thereby, the driven gear 48 and the rotating shaft 49 rotate counterclockwise, so that the pickup roller 23 and the scraper roller 22 rotate counterclockwise. As a result, the uppermost sheet P is separated from the sheet P stacked on the external sheet feed table 21 by the scraper roller 22 and conveyed toward the registration roller 13 by the scraper roller 22 and the pickup roller 23.

  At this time, when the common motor 41 is driven forward, the driven pulley 53 and the rotating shaft 54 are rotated clockwise by the rotational driving force transmitted by the belt 52. As a result, as shown in FIG. 7, the driving roller 36a of the intermediate conveyance roller 36 rotates clockwise, and the driven roller 36b rotates counterclockwise following the rotation of the driving roller 36a. Here, when the paper is fed from the external paper feeding unit 11, the sheet P is not conveyed to the intermediate conveyance roller 36, so the intermediate conveyance roller 36 rotates idly.

  As described above, the control unit 7 stops the common motor 41 at the timing when the sheet P transported from the external sheet feeding table 21 to the registration roller 13 hits the registration roller 13 and a predetermined amount of slack is formed. . Thereafter, the control unit 7 controls the registration motor 17 to drive the registration roller 13. As a result, the paper P is conveyed from the registration roller 13 to the printing unit 3.

  In the printing unit 3, the paper P is printed by the inkjet head unit 57 while being conveyed by the belt conveyance unit 56.

  In the case of single-sided printing, the paper P printed on one side is transported along the normal route RC by the upper surface transport unit 4 and is guided from the normal route RC to the paper discharge route RD by the switching unit 61. Then, the paper P is discharged to a paper discharge tray 63 by a paper discharge roller 62.

  In the case of duplex printing, the paper P printed on one side is conveyed along the normal route RC by the upper surface conveyance unit 4 and is guided from the normal route RC to the reverse route RR by the switching unit 61. Thereafter, the paper P is guided to the reversing roller 66 by the switching gate 69 in the reversing unit 6, and is carried into the switchback unit 67 by the reversing roller 66. Next, the paper P is unloaded from the switchback portion 67 by the reversing roller 66, guided to the refeed roller 68 by the switching gate 69, and conveyed to the registration roller 13 by the refeed roller 68. The paper P is sent out from the registration roller 13 to the belt conveyance unit 56. Here, since the paper P is reversed by the reversing unit 6, the unprinted surface (the other surface) is directed upward, and is printed on the other surface by the inkjet head unit 57. Then, the double-side printed paper P is transported from the upper surface transport unit 4 to the paper discharge unit 5 and is discharged onto the paper discharge tray 63 by the paper discharge roller 62.

  On the other hand, when the paper supply source is the internal paper supply unit 12, first, the control unit 7 clutches the pickup roller 33 and the vertical conveyance roller 35 corresponding to the internal paper supply table 31 on which the paper P used for printing is loaded. To the internal paper feed motor 15. Thereafter, the control unit 7 drives the internal paper feed motor 15. As a result, the paper P is taken out from the internal paper feed tray 31 by the scraper roller 32 and the pickup roller 33, and the vertical transport roller 35 transports the paper P toward the intermediate transport roller 36.

  Before the paper P taken out from the internal paper feed tray 31 reaches the intermediate conveyance roller 36, the control unit 7 starts the reverse drive of the common motor 41. Thereby, as shown in FIG. 8, the output shaft 41a and the output pulley 51 of the common motor 41 rotate counterclockwise. The rotational driving force of the output pulley 51 is transmitted to the driven pulley 53 by the belt 52, and the driven pulley 53 and the rotating shaft 54 rotate counterclockwise. As a result, the driving roller 36a of the intermediate conveyance roller 36 rotates counterclockwise, and the driven roller 36b rotates clockwise following the rotation of the driving roller 36a.

  When the paper P reaches the intermediate transport roller 36, the paper P is transported toward the registration roller 13 while being nipped between the driving roller 36a and the driven roller 36b.

  Even if the common motor 41 is driven in reverse, the counterclockwise rotational driving force of the output shaft 41 a is not transmitted to the output gear 47 due to the function of the one-way clutch 46. For this reason, the pickup roller 23 and the scraper roller 22 do not rotate.

  As described above, the control unit 7 stops the common motor 41 at the timing when the sheet P conveyed from the intermediate conveyance roller 36 toward the registration roller 13 hits the registration roller 13 and a predetermined amount of slack is formed. Thereafter, the control unit 7 controls the registration motor 17 to drive the registration roller 13. As a result, the paper P is conveyed from the registration roller 13 to the printing unit 3.

  The paper P transported to the printing unit 3 is ejected after one-sided printing or double-sided printing as in the case where the paper feeding source is the external paper feeding unit 11 described above.

  In the printing apparatus 1, the sheets P are sequentially fed according to the number of prints designated by the print job, and a plurality of sheets P are simultaneously conveyed on the conveyance path. In the case of duplex printing, the paper P fed from the external paper feed unit 11 or the internal paper feed unit 12 and the single-side printed paper P re-feeded from the reversing unit 6 are alternately fed from the registration rollers 13. It is conveyed to the printing unit 3.

  Returning to FIG. 5, after feeding and printing are started in step S <b> 30, in step S <b> 40, the control unit 7 determines whether or not there is a next received print job.

  If it is determined that there is a next print job (step S40: YES), in step S50, the control unit 7 determines whether or not the paper feed source at the time of execution of the next print job is the external paper feed unit 11. to decide.

  If it is determined that the paper feed source at the time of execution of the next print job is the external paper feed unit 11 (step S50: YES), in step S60, the control unit 7 prints currently being fed and printed. It is determined whether the job paper source is the internal paper feeder 12.

  If it is determined that the paper feed source of the print job being executed is the internal paper feed unit 12 (step S60: YES), the control unit 7 determines the rise start timing of the external paper feed tray 21 in step S70. Specifically, the control unit 7 only requires the time required to raise the external paper feed tray 21 by the specified amount lowered in step S20 from the predicted discharge end timing for the number of printed sheets by the print job being executed. The previous timing is set as the rising start timing of the external paper feed tray 21.

  Next, in step S <b> 80, the control unit 7 determines whether or not it is time to start raising the external paper feed tray 21. When it is determined that it is not time to start raising the external paper feed tray 21 (step S80: NO), the control unit 7 repeats step S80.

  When it is determined that it is time to start raising the external sheet feed table 21 (step S80: YES), in step S90, the control unit 7 controls the lift motor 14 to raise the external sheet feed table 21. Specifically, the control unit 7 starts driving the elevating motor 14 at the rising start timing, and when the uppermost sheet P on the external paper feed tray 21 is detected by an upper limit sensor (not shown), the elevating motor 14 is moved. Stop. As a result, the external paper feed tray 21 is raised by a specified amount, and the scraper roller 22 comes into contact with the uppermost paper P.

  Next, in step S <b> 100, the control unit 7 determines whether or not the discharge of the number of printed sheets by the print job being executed has been completed. Here, when the control unit 7 detects that the trailing edge of the last sheet P for the number of printed sheets has passed by a sheet sensor (not shown) provided in the vicinity of the downstream side of the paper discharge roller 62, the controller 7 prints the number of printed sheets. Is determined to be finished. If it is determined that the number of printed sheets has not been discharged (step S100: NO), the control unit 7 repeats step S100.

  If it is determined that the number of printed sheets has been discharged (step S100: YES), the control unit 7 proceeds to step S30 and starts paper feeding and printing in the next print job. Note that since the rising start timing of the external paper feed tray 21 is determined as described in step S70, the rise end of the external paper feed tray 21 and the completion of the discharge of the number of printed sheets by the print job being executed are as follows. , Almost at the same time.

  On the other hand, when it is determined in step S60 that the paper source of the print job being executed is the external paper source 11 (step S60: NO), the control unit 7 determines that the external paper source 21 does not need to be raised. The process proceeds to step S100, and the subsequent processing is performed.

  If it is determined in step S50 that the paper supply source at the time of execution of the next print job is the internal paper supply unit 12 (step S50: NO), in step S110, the control unit 7 performs the print job being executed. It is determined whether the paper source is the external paper feeder 11.

  When it is determined that the paper feed source of the print job being executed is the external paper feed unit 11 (step S110: YES), in step S120, the control unit 7 feeds the number of prints in the print job being executed. It is determined whether or not it has been completed. When the control unit 7 detects that the trailing edge of the last sheet P corresponding to the number of printed sheets has passed by a sheet sensor (not shown) provided in the vicinity of the upstream side of the registration roller 13, the controller 7 corresponds to the number of printed sheets. It is determined that paper feeding has been completed. When it is determined that the sheet feeding for the number of printed sheets has not been completed (step S120: NO), the control unit 7 repeats step S120.

  When it is determined that the feeding for the number of printed sheets has been completed (step S120: YES), in step S130, the control unit 7 controls the lift motor 14 to set the external sheet feeding table 21 to a specified amount, similarly to step S20. Only descend. Thereafter, the control unit 7 proceeds to step S100 and performs the subsequent processing.

  On the other hand, when it is determined in step S110 that the paper feed source of the print job being executed is the internal paper feed unit 12 (step S110: NO), the lowering of the external paper feed tray 21 is unnecessary (already lowered). The control unit 7 proceeds to step S100 and performs the subsequent processing.

  If it is determined in step S40 that there is no next print job (step S40: NO), in step S140 in FIG. 6, the control unit 7 finishes discharging the number of printed sheets by the print job being executed. Determine whether or not. If it is determined that the number of printed sheets has not been discharged (step S140: NO), the control unit 7 returns to step S40 in FIG.

  If it is determined that the discharge of the number of printed sheets has been completed (step S140: YES), in step S150, the control unit 7 determines whether or not the paper supply source of the discharged print job is the internal paper supply unit 12. Judging.

  If it is determined that the paper feed source of the print job that has been discharged is the internal paper feed unit 12 (step S150: YES), in step S160, the control unit 7 controls the lift motor 14 to control the external paper feed base 21. To raise. Here, the control unit 7 raises the external sheet feed table 21 until the uppermost sheet P on the external sheet feed table 21 is detected by the upper limit sensor. As a result, the scraper roller 22 comes into contact with the uppermost sheet P on the external sheet feed table 21. As described above, the control unit 7 ends the series of operations.

  On the other hand, when it is determined that the paper feed source of the print job that has been discharged is the external paper feed unit 11 (step S150: NO), the control unit 7 does not need to raise the external paper feed stand 21, and the control unit 7 continues the series. End the operation.

  Incidentally, the paper P may be jammed during execution of the print job. The control unit 7 can determine whether or not a jam of the paper P has occurred based on whether or not the detection timing of the paper P in a plurality of paper sensors (not shown) arranged on the transport path is normal. . If it is determined that a jam has occurred, the control unit 7 stops the operation of the printing apparatus 1. Accordingly, the conveyance of the paper P is stopped, and the paper P being conveyed on the conveyance path remains in the printing apparatus 1. The paper P remaining in the printing apparatus 1 is removed by a jam clearing operation performed by the user.

  Here, it is assumed that the operation of the printing apparatus 1 is stopped in a state where the intermediate conveyance roller 36 nips (pinch) the paper P due to the occurrence of a jam while the paper source is executing the print job of the internal paper feeding unit 12. . In this case, in the jam clearing operation, the user may pull the paper P nipped by the intermediate conveyance roller 36 to the downstream side or the upstream side.

  When the user pulls the paper P downstream, as shown in FIG. 9, the paper P is pulled downstream (upward), so that the rotation shaft 54 and the driven pulley 53 are moved together with the driving roller 36 a of the intermediate transport roller 36. Rotate counterclockwise. The driven roller 36b rotates clockwise. When the driven pulley 53 rotates counterclockwise, the rotational driving force is transmitted to the output pulley 51 by the belt 52, and the output pulley 51 and the output shaft 41a of the common motor 41 rotate counterclockwise (reverse direction).

  Even if the output shaft 41 a of the common motor 41 rotates in the reverse direction, the output gear 47 does not rotate due to the function of the one-way clutch 46. For this reason, the pickup roller 23 and the scraper roller 22 do not rotate.

  On the other hand, when the user pulls the paper P upstream, as shown in FIG. 10, the paper P is pulled upstream (downward), so that the rotation shaft 54 and the driven shaft are driven together with the driving roller 36 a of the intermediate transport roller 36. The pulley 53 rotates clockwise. The driven roller 36b rotates counterclockwise. When the driven pulley 53 rotates clockwise, the rotational driving force is transmitted to the output pulley 51 by the belt 52, and the output pulley 51 and the output shaft 41a of the common motor 41 rotate clockwise (forward rotation direction).

  When the output shaft 41 a of the common motor 41 rotates clockwise, the output gear 47 rotates clockwise via the one-way clutch 46. Thereby, the driven gear 48 and the rotating shaft 49 rotate counterclockwise, so that the pickup roller 23 and the scraper roller 22 rotate counterclockwise.

  For this reason, if the scraper roller 22 is in contact with the uppermost sheet P on the external sheet feed table 21, the unintended sheet P is sent out to the registration roller 13. In the printing apparatus 1, as described above, when the paper supply source executes a print job of the internal paper feed unit 12, the external paper feed base 21 is lowered to connect the uppermost paper P on the external paper feed base 21. The scraper roller 22 is spaced apart. As a result, when the user releases the jam, even if the sheet P nipped by the intermediate conveyance roller 36 is pulled upstream, the sheet P on the external sheet feed table 21 is transferred to the registration roller 13 by the pickup roller 23 and the scraper roller 22. Will not be sent out.

  As described above, in the printing apparatus 1, the internal driving force transmission unit 43 does not have a driving force cutting unit such as a one-way clutch, and the output shaft of the common motor 41 can always transmit the rotational driving force. 41a and the intermediate conveyance roller 36 are connected. Thereby, in the printing apparatus 1, a decrease in the conveyance accuracy of the paper P by the intermediate conveyance roller 36 is suppressed. The control unit 7 lowers the external paper feed table 21 when feeding from the internal paper feed unit 12, and separates the uppermost paper P on the external paper feed table 21 from the scraper roller 22. . As a result, when the paper P nipped by the intermediate conveyance roller 36 is pulled upstream when the jam is released, the intermediate conveyance roller 36 rotates, and this rotation causes the output shaft of the internal driving force transmission unit 43 and the common motor 41 to rotate. 41a, even if the pickup roller 23 and the scraper roller 22 are rotated by being transmitted by the external driving force transmission unit 42, unintended paper P can be prevented from being sent out from the external paper feed tray 21 to the registration roller 13.

  In addition, when the control unit 7 determines that the paper feed source in the next print job is the external paper feed unit 11 during execution of the print job in which the paper feed source is the internal paper feed unit 12, the printing being executed is performed. The rising of the external sheet feeding base 21 is started at the rising start timing before the end of the job (the discharge of the number of printed sheets). As a result, the printing apparatus 1 can promptly start feeding the next print job, and can suppress a reduction in productivity.

  When the control unit 7 stops the operation of the printing apparatus 1 due to the occurrence of a jam, and the paper P is nipped by the intermediate conveyance roller 36, the controller 7 reversely drives the common motor 41 until the paper P is released. The intermediate conveyance roller 36 may be driven. In this case, for example, when the operation is stopped, when the paper P is detected by a paper sensor (not shown) disposed in the vicinity of the downstream side of the intermediate transport roller 36, the control unit 7 nips the paper P on the intermediate transport roller 36. Judge that it has been. Then, when it is detected by the paper sensor in the vicinity of the downstream side of the intermediate conveyance roller 36 that the trailing edge of the paper P has passed, the control unit 7 determines that the intermediate conveyance roller 36 has released the paper P. Thereby, the intermediate transport roller 36 does not nip the paper P when the jam is released, and the unintended paper P can be more reliably prevented from being sent out from the external paper feed table 21 to the registration roller 13. .

  Moreover, the external drive force transmission part 42 and the internal drive force transmission part 43 are not restricted to the structure shown in this Embodiment. For example, you may comprise the internal side driving force transmission part 43 using a gear.

  In the present embodiment, the uppermost sheet P on the external sheet feed table 21 and the scraper roller 22 are brought into contact with and separated from each other by raising and lowering the external sheet feed table 21. However, the present invention is not limited to this, and any configuration may be used as long as the uppermost sheet P on the external paper feed table 21 and the scraper roller 22 can be brought into contact with and separated from each other by relative movement between the external paper feed table 21 and the scraper roller 22.

  It goes without saying that the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Paper feed part 3 Printing part 4 Upper surface conveyance part 5 Paper discharge part 6 Inversion part 7 Control part 11 External paper feed part 12 Internal paper feed part 13 Registration roller 14 Lifting motor 16 Common drive part 21 External paper feed stand 22 External paper feed scraper roller 23 External paper feed pickup roller 31 Internal paper feed stand 36 Intermediate transport roller 41 Common motor 41a Output shaft 42 External drive force transmission unit 43 Internal drive force transmission unit

Claims (3)

A registration roller that conveys the print medium to the printing unit;
A first paper feed unit having a first roller that separates a print medium loaded on the first paper feed table and conveys the print medium to the registration roller;
A second paper feed unit having a second roller that receives the print medium taken out from the second paper feed tray and conveys it to the registration roller;
A drive source having an output shaft for outputting a rotational drive force in the first rotational direction and the second rotational direction;
A first transmission unit for transmitting only the rotational driving force in the first rotational direction from the output shaft of the drive source to the first roller;
A second transmission unit that connects the output shaft of the drive source and the second roller so that the rotational driving force in the first rotation direction and the second rotation direction can be transmitted at all times;
A contact / separation driving unit for contacting and separating the uppermost print medium on the first sheet feeding table and the first roller;
When feeding paper from the first paper feed unit, the output shaft of the drive source is driven to rotate in the first rotation direction, and when feeding from the second paper feed unit, A controller that rotates the output shaft in the second rotation direction;
The control unit causes the first printing medium on the first sheet feeding table to be separated from the first roller by the contact / separation driving unit when feeding from the second sheet feeding unit. Printing device to do.   When the control unit determines that the paper supply source in the next print job to be executed is the first paper supply unit during execution of a print job in which the paper supply source is the second paper supply unit, Before the end of the middle print job, the contact / separation driving unit starts relative movement for bringing the uppermost print medium on the first paper feed table into contact with the first roller. The printing apparatus according to claim 1.   When the printing unit stops the operation of the printing apparatus and the print medium is sandwiched between the second rollers, the control unit rotates the output shaft of the driving source in the second rotation direction to perform printing. The printing apparatus according to claim 1, wherein the second roller is driven until the medium is released.