JP2012229126A - Duplex printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a duplex printing apparatus that can smoothly deliver a sheet from a paper ejection tray to a paper refeed tray.SOLUTION: In the duplex printing apparatus 10, the sheet on a paper feed tray 21 is conveyed to a print unit 4 where the sheet undergoes a first printing processing, is conveyed to the paper ejection tray 32, is then conveyed from the paper ejection tray to the paper refeed tray 51, is turned over, is conveyed from the refeed tray to the printing unit where the sheet undergoes a second printing processing, and is conveyed to the paper ejection tray. The paper ejection tray includes an end plate 322 receiving a front end of the conveyed sheet. The end plate is arranged to be movable toward the paper refeed tray along with the received sheet. The paper refeed tray includes a refed-paper conveying means 512 for conveying the sheet on the paper refeed tray to a downstream end part in the conveying direction of the sheet on the refeed tray. The sheet on the paper ejection tray is delivered to the refed-paper conveying means by the end plate moving toward the paper refeed tray.

Description

  The present invention relates to a duplex printing apparatus capable of printing on both sides of a sheet.

  Conventionally, in order to reduce paper consumption, a double-sided printing apparatus that performs printing on both sides of a paper is used. Then, as shown in Patent Document 1, in order to reduce the size of the double-sided printing apparatus, the printing apparatus uses a single plate cylinder, transports the surface-printed paper toward the surface-printed plate cylinder again, and performs reverse printing. Is disclosed.

JP 2000-318934 A

  In the double-sided printing apparatus of Patent Document 1, the paper stacked on the paper discharge tray is transferred to the paper refeed tray as the end plate on the paper discharge tray moves toward the paper refeed tray. It has become. Here, when the paper is transferred from the paper discharge tray to the paper refeed tray, the paper loaded on the paper discharge tray is moved at a time, so the number of paper is large and the overall weight of the stacked paper is heavy. The frictional resistance between the lower surface of the stacked paper and the upper surface of the paper discharge tray and the frictional resistance between the lower surface of the stacked paper and the upper surface of the paper refeed tray are increased, so that the stacked paper cannot be smoothly transferred from the paper discharge tray to the paper refeed tray. There is a possibility that damage such as wrinkles may occur in the lower sheet of the loaded sheet. In addition, a motor for moving the end plate needs to have a large driving force, which may increase the cost.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a double-sided printing apparatus capable of smoothly delivering a sheet from a paper discharge tray to a refeed tray.

  In the present invention, the paper on the paper feed tray is transported to the printing unit, the first printing process is performed by the printing unit, the paper is transported to the paper discharge tray, and the paper is transported from the paper discharge tray to the paper refeed tray. In the double-sided printing apparatus, the paper tray is turned over from the paper feed tray and transported to the printing unit, and the second printing process is performed by the printing unit to transport the paper to the paper discharge tray. An end plate is provided, and the end plate is provided so as to be movable toward the refeed tray along with the received paper, and the refeed tray is placed on the refeed tray. Refeeding transport means for transporting the sheet to the downstream end of the sheet feeding direction of the sheet feeding tray is provided, and the sheet on the sheet discharge tray moves the end plate toward the sheet feeding tray. And by, wherein the adapted to be passed to the refeeding means.

  According to the above configuration, since the paper on the paper discharge tray is transferred to the paper refeeding means of the paper refeed tray by the movement of the end plate, the paper can be smoothly transferred from the paper discharge tray to the paper refeed tray. Can be done.

The present invention preferably further comprises the following configuration.
(1) On the upper surface of the paper discharge tray, a plurality of rollers are provided for smooth conveyance of the paper.
(2) The transport speed at which the refeed transport means transports the paper is set to be higher than the moving speed at which the end plate moves toward the refeed tray.
(3) The re-feed conveyance unit is configured to be inclined downward in the sheet conveyance direction.
(4) In the configuration (3), the inclination angle of the refeed conveyance means is within 10 degrees with respect to the horizontal plane.
(5) The refeed tray includes a pair of refeed side plates that regulate both side edges of the paper on the refeed tray, and the refeed side plates have a length in the paper width direction of the paper. The position in the paper width direction is adjusted accordingly.
(6) In the configuration (5), the refeeding side plate is movable between a restriction position that restricts both side edges of the paper and a standby position that is not restricted. Is positioned at the standby position when being transported from the paper discharge tray to the refeed tray, and is positioned at the regulation position after the paper is transported to the refeed tray. Yes.
(7) The paper discharge tray includes a U-shaped forming member that lifts both side edges of the paper on the paper discharge tray and supports the paper in a U-shape. It can be moved up and down between a protruding position where it protrudes from the upper surface of the paper tray and lifts the paper and a retracted position that does not protrude from the upper surface of the paper discharge tray.
(8) In the configuration (7), the U-shaped forming member is configured by a pair of fin members disposed symmetrically with respect to the intermediate line of the sheet width, and the pair of fin members is a sheet A plurality of fin members are provided at intervals in the transport direction, the fin member extends in the paper width direction, one end in the paper width direction is supported by the paper discharge tray, and the other end in the paper width direction Is rotatable around the one end.
(9) In the configuration (7) or (8), the protruding amount of the U-shaped member from the upper surface of the paper discharge tray varies according to the type of paper on the paper discharge tray. Yes.
(10) In any one of the configurations (7) to (9), the paper discharge tray includes a pair of paper discharge side plates that regulate both side edges of the paper on the paper discharge tray. When transported from the printing unit to the paper discharge tray, the U-shaped forming member is positioned at the protruding position, and the distance between the paper discharge side plates of the paper discharge side plate is smaller than the paper width of the paper. When the paper is transported from the paper discharge tray to the refeed tray, the U-shaped member is located at the retracted position, and the paper discharge side plate is It is located at a restricting position that restricts both side edges.
(11) In any one of the configurations (7) to (9), the paper discharge tray includes a pair of paper discharge side plates that regulate both side edges of the paper on the paper discharge tray. When transported from the printing unit to the paper discharge tray, the U-shaped forming member is positioned at the protruding position, and the distance between the paper discharge side plates of the paper discharge side plate is smaller than the paper width of the paper. When the paper is transported from the paper discharge tray to the refeed tray, the U-shaped member is located at the retracted position, and the paper discharge side plate is It is located laterally outward from the restricting position that restricts both side edges.
(12) In the configuration (10) or (11), after the predetermined time has elapsed after the U-shaped forming member is changed from the protruding position to the retracted position, the sheet is transferred from the discharge tray to the refeed tray. It is designed to be conveyed.
(13) In the configuration (12), the predetermined time can be arbitrarily changed.

  According to the configuration (1), the paper on the paper discharge tray can be smoothly conveyed by the plurality of rollers on the upper surface of the paper discharge tray.

  According to the configuration (2), in delivering the paper from the paper discharge tray to the refeed tray, the load on the end plate is reduced, and wrinkles and the like are generated on the lowest paper on the paper discharge tray. Therefore, the paper can be smoothly transferred from the paper discharge tray to the refeed tray.

  According to the configurations (3) and (4), since the paper placed on the refeed tray is easily transported in the paper transport direction of the refeed tray, the paper from the discharge tray to the refeed tray Can be delivered more smoothly. Further, since the paper refeeding means is inclined downward in the paper conveying direction, a space can be formed above the paper refeeding means, and a part of the paper is disposed in the space. The space around the paper conveying means can be minimized, and the double-sided printing apparatus can be miniaturized. In addition, since the inclination angle of the refeeding conveyance means is within 10 degrees with respect to the horizontal plane, it is possible to prevent the sheet from collapsing on the refeeding tray.

According to the configurations (5) and (6), when the paper is conveyed to the refeed tray, the refeed side plate is located at a standby position where the paper is not regulated. And the sheet can be prevented from skewing in the refeed tray.
After the paper is transported to the refeed tray, the refeed side plate is positioned at a restriction position for restricting the paper and aligns the paper. When the sheet is fed again, skew of the sheet can be prevented.

  According to the configuration (7), since the paper discharge tray includes the U-shaped forming member, the paper on the paper discharge tray is held in a U-shape, and as a result, the paper on the paper discharge tray is well aligned. can do. Further, since the U-shaped member can be moved up and down between the protruding position and the retracted position, when the paper is placed on the paper discharge tray, the U-shaped forming member is set to the protruding position. By holding the paper in a U-shape and improving the alignment of the paper, when the paper is transferred from the paper discharge tray to the re-feed tray, the U-shaped forming member is moved to the retracted position, thereby The U-shaped state can be eliminated, and the paper can be smoothly transferred from the paper discharge tray to the refeed tray.

  According to the configuration (8), it is possible to easily configure the U-shaped member that can move the sheet up and down between the protruding position and the retracted position while holding the sheet on the discharge tray in a U-shape.

  According to the configuration (9), the U-shaped forming member can have a protruding amount corresponding to the type of paper, and as a result, the paper is well aligned regardless of the type of paper on the paper discharge tray. be able to.

According to the configuration (10), when the paper is transported from the printing unit to the paper discharge tray, the U-shaped forming member is positioned at the protruding position, and the paper discharge side plate is positioned at the guide position. Therefore, the paper on the paper discharge tray can be easily held in a U-shape.
Further, when the paper is transported from the paper discharge tray to the paper refeed tray, the U-shaped forming member is positioned at the retracted position, and the paper discharge side plate is positioned at the restricting position. As a result, it is possible to prevent the sheet from jamming and smoothly transfer the sheet from the discharge tray to the refeed tray.

According to the configuration (11), when the paper is transported from the printing unit to the paper discharge tray, the U-shaped forming member is positioned at the protruding position, and the paper discharge side plate is positioned at the guide position. Therefore, the paper on the paper discharge tray can be easily held in a U-shape.
When the paper is transported from the paper discharge tray to the paper refeed tray, the U-shaped member is positioned at the retracted position, and the paper discharge side plate is positioned laterally outward from the regulation position. Therefore, it is possible to prevent the skew of the sheet, and as a result, it is possible to prevent the sheet from being jammed and to smoothly transfer the sheet from the discharge tray to the refeed tray. In particular, when the paper discharge side plate is positioned laterally outward from the regulation position, the U-shaped forming member is positioned at the retracted position, so that the paper held in the U-shape on the paper discharge tray is changed to a flat state. In this case, air existing between the sheets can be easily diffused to the outside through a gap between the both side edges of the sheet and the sheet on the sheet discharge side. Further, since the air existing between the sheets is removed, it is possible to prevent the alignment of the sheets from being lost when the sheets are conveyed from the discharge tray to the refeed tray.

  According to the configuration (12), when the paper held in the U-shape on the paper discharge tray is changed to the flat state, the air existing between the paper is between the paper side edges and the paper discharge side plate. Time to dissipate to the outside through the gap can be secured. Further, since the air existing between the sheets is removed, it is possible to prevent the alignment of the sheets from being lost when the sheets are conveyed from the discharge tray to the refeed tray.

  According to the configuration (13), after the U-shaped forming member is changed from the protruding position to the retracted position, the time until the paper is transported from the paper discharge tray to the refeed tray can be changed. The waiting time can be set according to the type (size, thickness, etc.).

  In short, according to the present invention, it is possible to provide a duplex printing apparatus capable of smoothly delivering a sheet from a paper discharge tray to a refeed tray.

It is the schematic of the double-sided printing apparatus which concerns on this invention. It is a figure explaining the action | operation of a duplex printing apparatus. It is a figure explaining the action | operation of a duplex printing apparatus. It is a figure explaining the action | operation of a duplex printing apparatus. 3 is a time chart showing the relationship between image reading by an image reading unit, plate making by a plate making unit, and printing by a printing unit. 6 is a time chart different from FIG. 5 showing the relationship between image reading by the image reading unit, plate making by the plate making unit, and printing by the printing unit. 7 is a time chart different from FIG. 5 and FIG. 6 showing the relationship among image reading of the image reading unit, plate making of the plate making unit, and printing of the printing unit. It is a perspective view of a paper feed tray. FIG. 6 is a perspective plan view of a paper feed tray. FIG. 10 is a perspective plan view of the paper feed tray, and shows the main body portion further transparently than in the case of FIG. 9. It is a see-through | perspective back surface perspective view of a paper feed tray. It is a front perspective view of a paper discharge tray. FIG. 4 is a rear perspective view of a paper discharge tray. FIG. 6 is a bottom view of a paper discharge tray. It is a perspective view of a paper discharge side plate. It is a perspective view of an end plate. It is an upper perspective view of a U-shaped member. It is a lower perspective view of a U-shaped member. It is a perspective view which shows the base guide in a closed position. It is a perspective view which shows the base guide in an open position. It is a perspective view from another direction which shows the base guide of FIG. It is a perspective view from another direction which shows the base guide of FIG. It is an upper perspective view of a re-feed tray. It is a side perspective view of a re-feed tray. It is a bottom view of a refeed tray. It is a lower perspective view of the re-feed tray with the holding member removed. FIG. 5 is a side view of the refeed tray, showing a state where the refeed tray is positioned below. FIG. 6 is a side view of the refeed tray, showing a state where the refeed tray is positioned above. FIG. 5 is a schematic diagram illustrating operations of a paper feed tray, a paper discharge tray, and a refeed tray. FIG. 5 is a schematic diagram illustrating operations of a paper feed tray, a paper discharge tray, and a refeed tray. FIG. 5 is a schematic diagram illustrating operations of a paper feed tray, a paper discharge tray, and a refeed tray. FIG. 5 is a schematic diagram illustrating operations of a paper feed tray, a paper discharge tray, and a refeed tray. FIG. 5 is a schematic diagram illustrating operations of a paper feed tray, a paper discharge tray, and a refeed tray. FIG. 5 is a schematic diagram illustrating operations of a paper feed tray, a paper discharge tray, and a refeed tray. FIG. 10 is a diagram for explaining the operation of the refeed tray when the refeed tray moves and the intermediate line between the paper discharge side plates matches the intermediate line between the refeed side plates. FIG. 10 is a diagram for explaining the operation of the sheet refeed tray when the sheet refeeding side plate moves and the intermediate line between the sheet discharge side plates and the intermediate line between the sheet refeeding side plates coincide with each other.

  FIG. 1 is a schematic view of a duplex printing apparatus 10 according to the present invention. For convenience of explanation, the upstream side of the paper feeding direction and the transport direction M1 will be described as “front side”, and the downstream side of the paper feed direction and the transport direction M1 will be described as “rear side”.

  As shown in FIG. 1, a paper feeding unit 2 is arranged at the front lower part of the printing machine main body 1, and a paper discharge unit 3 is arranged at the rear lower part of the printing machine main body 1. A printing unit 4 is disposed between the paper feeding unit 2 and the paper discharging unit 3 in the front-rear direction. A re-feeding unit 5 is disposed in front of the paper discharging unit 3 and below the printing unit 4. Has been placed. Further, a plate making unit 6 is disposed at the front upper portion of the printing press main body 1, and a plate discharging unit 7 is disposed at the rear upper portion of the printing press main body 1. An image reading unit 8 is disposed on the upper side of the printer main body 1. In addition, a control unit (not shown) that controls the operation of the double-sided printing apparatus is disposed in the printer main body 1.

  The sheet feeding unit 2 includes a sheet feeding tray 21, a sheet feeding roller 22 and a suction member 23 disposed at the rear end of the sheet feeding tray 21, and a pair of timing rollers 24 disposed behind the sheet feeding roller 22. It is equipped with. The paper feed roller 22 and the separating member 23 are configured to take out the sheets stacked on the paper feed tray 21 one by one from the top. The timing roller 24 is operated at an appropriate timing in synchronism with the rotation of the plate cylinder 41 of the printing unit 4 so that printing can be performed at a predetermined position on the sheet, and the sheet taken out by the sheet feeding roller 22 and the sheet member 23 is printed. The unit 4 is sent to the printing section.

  The paper discharge unit 3 includes an air suction type transport belt mechanism 31, a paper discharge tray 32, and a base guide 33. The paper discharge unit 3 conveys the paper printed by the printing unit 4 backward while sucking air by the transport belt mechanism 31 and discharges the paper onto the paper discharge tray 32. The base guide 33 is movable in the vertical direction. When the paper is conveyed to the paper discharge tray 32 by the transport belt mechanism 31, the base guide 33 is located at the lower closed position, and the paper is removed from the paper discharge tray 32. When transported to the re-feed unit 5, it is positioned at the upper open position.

  The printing unit 4 includes a cylindrical plate cylinder 41 on which an stencil sheet that has been subjected to pre-making is mounted on an outer peripheral surface, and a pressing roller 42 that is opposed to the plate cylinder 41 so as to come into contact with and separate from below. The printing unit 4 sandwiches the paper between the rotating plate cylinder 41 and the pressing roller 42 and conveys the paper in the M1 direction, while using the ink supplied from the plate cylinder 41 to print the image of the stencil sheet on the paper. Transfer (first printing, second printing) is performed on the upper surface.

  The paper re-feed unit 5 receives the first printed paper stacked on the paper discharge tray 32 from the paper discharge unit 3 and the paper on the paper re-feed tray 51 from the top. A sheet refeed roller 52 and a separating member 54 for picking up and conveying the sheets one by one, and one or more pairs of intermediate conveyance rollers 53 for conveying the sheet conveyed from the sheet refeed roller 52 toward the printing unit 4 again. ing. The refeed unit 5 transports the sheets on the refeed tray 51 one by one from the top to the timing roller 24 of the sheet feed unit 2 by the sheet refeed roller 52, the intermediate transport roller 53, and the buckling member 54. It is supposed to be.

  The plate making unit 6 includes a stencil sheet roll 61, a thermal head 62, and a platen roller 63 that contacts the thermal head 62. Based on the image data read by the image reading unit 8, the plate making unit 6 makes a stencil sheet roll 61 with a thermal head 62 and attaches the stencil sheet after plate making to the outer peripheral surface of the plate cylinder 41 of the printing unit 4. It is like that.

  The plate discharging unit 7 is inserted into the printing press main body 1, a plate discharging housing 71, a pair of upper and lower drawing rollers 72 attached to the front upper end of the housing 71, and slidably inserted into the housing 71 from the rear. And a base paper storage roll 73 having an open top surface. The drawing roller 72 is located at a position corresponding to the rear upper end portion of the plate cylinder 41, and rotates by sandwiching the leading end portion of the stencil sheet after printing mounted on the outer peripheral surface of the plate cylinder 41. The stencil sheet after use of printing is wound around the base paper storage roll 73 of the housing 71.

  2 to 4 are diagrams for explaining the operation of the double-sided printing apparatus 10. Hereinafter, the outline of the operation of the duplex printing apparatus 10 will be described with reference to FIGS.

  As shown in FIG. 1, the plate making unit 6 makes a stencil sheet roll 61 with a thermal head 62 based on image (surface image) data read by the image reading unit 8, and prints the stencil sheet N1 after the plate making. Mounted on the outer peripheral surface of the plate cylinder 41 of the unit 4.

  Next, the paper feed roller 22 and the separator member 23 take out the paper P1 (not printed on the front and back surfaces) stacked on the paper feed tray 21 one by one from the top. The timing roller 24 operates at an appropriate timing in synchronism with the rotation of the plate cylinder 41 of the printing unit 4 so that printing can be performed at a predetermined position of the paper P1, and feeds the taken paper P1 to the printing unit of the printing unit 4.

  Then, the printing unit 4 sandwiches the paper P1 between the rotating plate cylinder 41 and the pressing roller 42, and conveys the paper P1 in the M1 direction, while using the ink supplied from the plate cylinder 41, the stencil base paper N1. Is transferred to the upper surface (front surface) of the sheet P1 (first printing process, hereinafter referred to as “surface printing process”).

  As shown in FIG. 2, the paper discharge unit 3 conveys the paper P <b> 2 that has undergone surface printing processing by the printing unit 4 to the rear while sucking air by the conveyance belt mechanism 31, and discharges it onto the paper discharge tray 32. . At this time, the base guide 33 is positioned at the lower closing position, and aligns the leading ends of the sheets P2 stacked on the sheet discharge tray 32.

  In the plate discharge unit 7, the drawing roller 72 rotates while pinching the front end portion of the stencil sheet N <b> 1 after the surface printing is used, which is mounted on the outer peripheral surface of the plate cylinder 41. Wrapping the stencil sheet N1 after the surface printing is used.

  After the stencil sheet N1 after using the front surface printing is removed from the plate cylinder 41, the stencil printing unit 6 uses the thermal head 62 to move the stencil sheet roll 61 with the thermal head 62 based on the data of the image (back image) read by the image reading unit 8. Plate making is performed, and the stencil sheet N2 after plate making is mounted on the outer peripheral surface of the plate cylinder 41 of the printing unit 4.

  Then, as shown in FIG. 3, the paper discharge unit 3 directs the paper P2 that has been subjected to the front surface printing processing stacked on the paper discharge tray 32 in the paper refeed direction (M2 direction). Pass to. At this time, the base guide 33 is located at the upper open position. Then, as shown in FIG. 4, the base guide 33 is located at the lower closed position, and the refeed roller 52 and the separator member 54 take out the paper P2 received from the paper discharge unit 3 one by one from the top. The refeed roller 52 and the intermediate transport roller 53 turn over the taken paper P2 so that the printed surface is the lower surface and the unprinted back surface is the upper surface, and the timing roller 24 of the paper feeding unit 2 Transport to. Here, the sheet P <b> 2 is bent between the intermediate conveyance roller 53 and the timing roller 24 so that a P <b> 2 a is formed.

  The timing roller 24 operates at an appropriate timing in synchronization with the rotation of the plate cylinder 41 of the printing unit 4, and feeds the paper P <b> 2 to the printing unit of the printing unit 4 with the unprinted back surface as the upper surface. Here, the intermediate conveyance roller 53 and the timing roller 24 rotate at substantially the same linear velocity so as to maintain the bending P2a of the paper P2 formed between the intermediate conveyance roller 53 and the timing roller 24. This linear velocity coincides with the linear velocity of the plate cylinder 41. The printing unit 4 sandwiches the paper P2 between the rotating plate cylinder 41 and the pressing roller 42 and conveys the back image of the stencil sheet N2 with ink supplied from the inside of the plate cylinder 41 while conveying the paper P2 in the conveying direction M1. Transfer is performed on the upper surface (back surface) of the paper P2 (second printing process, hereinafter referred to as “back surface printing process”).

  The sheet P3 that has been subjected to the back surface printing process by the printing unit 4 is conveyed rearward while being sucked by the conveying belt mechanism 31 and discharged onto the sheet discharge tray 32.

  The plate discharge unit 7 uses the drawing roller 72 for printing on the base paper storage roll 73 of the housing 71 by sandwiching and rotating the front end portion of the stencil paper N2 after printing mounted on the outer peripheral surface of the plate cylinder 41. The subsequent stencil sheet N2 is wound.

  FIG. 5 is a time chart showing the relationship between image reading by the image reading unit 8, plate making by the plate making unit 6, and printing by the printing unit 4, and the horizontal axis shows time. Hereinafter, the flow of image reading, plate making, and printing in the duplex printing apparatus 10 will be described with reference to FIG.

(In the case of “original fixed reading” in which the image reading unit 8 reads the front side and the back side of the original respectively)
The user selects a duplex printing mode displayed on an operation panel (not shown) of the duplex printing apparatus 10 and sets a document on the image reading unit 8. When the user presses the plate-making key on the operation panel, the image reading unit 8 reads the surface of the document (see A1 in FIG. 5). When the image reading unit 8 starts reading the surface of the original, the plate making unit 6 starts making the surface of the original on the stencil sheet (see A2 in FIG. 5). When the image reading unit 8 finishes reading the document surface, the operation panel displays “Place the next document”, and the user turns the document over and sets it in the image reading unit 8, and makes the plate on the operation panel. Press the key again. Then, the image reading unit 8 reads the back side of the document (see A3 in FIG. 5). When the plate-making on the surface of the document is completed, the plate-making unit 6 winds the stencil sheet that has been pre-made around the plate cylinder 41, and the printing unit 4 prints the surface image on the surface of the paper (see A4 in FIG. 5). As described above, the sheet subjected to the front surface printing process is once discharged to the discharge tray 32, stacked, and sent to the refeed tray 51 in a stacked state.

  When the front surface printing process is completed, the plate discharge unit 7 removes the stencil sheet that has been made from the plate cylinder 41 and collects it. The plate making unit 8 starts making the back side of the original on the stencil sheet from the back side data of the original read by the image reading unit 8 (see A5 in FIG. 5). When the plate making of the back side of the document is completed, the plate making unit 6 winds the stencil stencil sheet that has been made to the plate cylinder 41, and the printing unit 4 prints the back side image on the back side of the paper fed from the refeed tray 51 (FIG. 5 A6). As described above, the paper subjected to the back surface printing process is discharged to the paper discharge tray 32 and stacked.

(In the case of “ADF reading”, an ADF (automatic document feeder) is used to continuously read the front and back sides of a document with the image reading unit 8)
The difference between “ADF reading” and “original fixed reading” is that, in the time chart shown in FIG. 5, at time T1 between the end of image reading on the front surface and the start of image reading on the back surface, However, in the fixed document reading, the user simply turns the document over from the front side to the back side. The operation of the double-sided printing apparatus 10 in the case of ADF reading is as follows.

  The user selects the duplex printing mode displayed on the operation panel of the duplex printing apparatus 10 and sets the document on the ADF. When the user presses the plate-making key on the operation panel, the image reading unit 8 reads the surface of the document (see A1 in FIG. 5), then turns the document over and reads the back surface of the document (see A3 in FIG. 5). When the image reading unit 8 starts reading the surface of the original, the plate making unit 6 starts making the surface of the original on the stencil sheet (see A2 in FIG. 5). When the plate-making on the surface of the document is completed, the plate-making unit 6 winds the stencil sheet that has been pre-made around the plate cylinder 41, and the printing unit 4 prints the surface image on the surface of the paper (see A4 in FIG. 5). As described above, the sheet subjected to the front surface printing process is once discharged to the discharge tray 32, stacked, and sent to the refeed tray 51 in a stacked state.

  When the front surface printing process is completed, the plate discharge unit 7 removes the stencil sheet that has been made from the plate cylinder 41 and collects it. The plate making unit 8 starts making the back side of the original on the stencil sheet from the back side data of the original read by the image reading unit 8 (see A5 in FIG. 5). When the plate making of the back side of the document is completed, the plate making unit 6 winds the stencil stencil sheet that has been made to the plate cylinder 41, and the printing unit 4 prints the back side image on the back side of the paper fed from the refeed tray 51 (FIG. 5 A6). As described above, the paper subjected to the back surface printing process is discharged to the paper discharge tray 32 and stacked.

  FIG. 6 is a time chart different from FIG. 5 showing the relationship between image reading of the image reading unit 8, plate making of the plate making unit 6, and printing of the printing unit 4, and the horizontal axis shows time. . The flow of image reading, plate making and printing in the duplex printing apparatus 10 shown in FIG. 6 is as follows.

(Original scanning)
The user selects a duplex printing mode displayed on an operation panel (not shown) of the duplex printing apparatus 10 and sets a document on the image reading unit 8. When the user presses the plate-making key on the operation panel, the image reading unit 8 reads the surface of the document (see B1 in FIG. 6). When the image reading unit 8 finishes reading the document surface, the operation panel displays “Place the next document”, and the user turns the document over and sets it in the image reading unit 8, and makes the plate on the operation panel. Press the key again. Then, the image reading unit 8 reads the back side of the document (see B2 in FIG. 6). When the image reading unit 8 finishes reading the back side of the document, the plate making unit 6 starts plate-making on the surface of the document on the stencil sheet (see B3 in FIG. 6). When the plate-making on the surface of the document is completed, the plate-making unit 6 winds the stencil stencil sheet that has been made on the plate cylinder 41, and the printing unit 4 prints the surface image on the surface of the paper (see B4 in FIG. 6). As described above, the sheet subjected to the front surface printing process is once discharged to the discharge tray 32, stacked, and sent to the refeed tray 51 in a stacked state.

  When the front surface printing process is completed, the plate discharge unit 7 removes the stencil sheet that has been made from the plate cylinder 41 and collects it. The plate making unit 8 starts making the back side of the original on the stencil sheet from the back side data of the original read by the image reading unit 8 (see B5 in FIG. 6). When the plate making of the back side of the document is completed, the plate making unit 6 winds the stencil stencil sheet that has been made to the plate cylinder 41, and the printing unit 4 prints the back side image on the back side of the paper fed from the refeed tray 51 (FIG. 6 B6). As described above, the paper subjected to the back surface printing process is discharged to the paper discharge tray 32 and stacked.

(ADF reading)
As described with reference to the time chart of FIG. 5, the difference between “ADF reading” and “original fixed reading” is that, in the time chart shown in FIG. At time T1, the ADF automatically turns over the document from the front side to the back side in ADF reading, whereas in the fixed document reading, the user simply turns the document over from the front side to the back side. Therefore, description of the operation of the duplex printing apparatus 10 in the case of ADF reading is omitted.

  FIG. 7 is a time chart different from FIGS. 5 and 6 showing the relationship between the image reading of the image reading unit 8, the plate making of the plate making unit 6, and the printing of the printing unit 4. The horizontal axis represents time. Show. The flow of image reading, plate making and printing in the duplex printing apparatus 10 shown in FIG. 7 is as follows.

(Original scanning)
The user selects a duplex printing mode displayed on an operation panel (not shown) of the duplex printing apparatus 10 and sets a document on the image reading unit 8. When the user presses the plate-making key on the operation panel, the image reading unit 8 reads the surface of the document (see D1 in FIG. 7). When the image reading unit 8 finishes reading the document surface, the operation panel displays “Place the next document”, and the user turns the document over and sets it in the image reading unit 8, and makes the plate on the operation panel. Press the key again. Then, the image reading unit 8 reads the back side of the document (see D2 in FIG. 7). When the image reading unit 8 starts reading the back side of the original, the plate making unit 6 starts making the back side of the original on the stencil sheet (see D3 in FIG. 7). When the plate making on the back side of the original is completed, the plate making unit 6 winds the stencil sheet that has been made on the plate cylinder 41, and the printing unit 4 prints the back image on the back side of the paper (see D4 in FIG. 7). As described above, the paper subjected to the back surface printing process is once discharged to the discharge tray 32, stacked, and sent to the refeed tray 51 in a stacked state.

  When the back side printing process is finished, the plate discharge unit 7 removes the stencil sheet that has been made from the plate cylinder 41 and collects it. The plate-making unit 8 starts plate-making of the surface of the document on the stencil sheet from the surface data of the document read by the image reading unit 8 (see D5 in FIG. 7). When the plate-making on the surface of the original is completed, the plate-making unit 6 winds the stencil stencil sheet made around the plate cylinder 41, and the printing unit 4 prints the surface image on the surface of the paper fed from the refeed tray 51 (FIG. 7 D6). As described above, the paper subjected to the front surface printing process is discharged to the paper discharge tray 32 and stacked.

(ADF reading)
As described with reference to the time chart of FIG. 5, the difference between “ADF reading” and “original fixed reading” is that when the front side image reading ends and the back side image reading starts in the time chart shown in FIG. At time T1, the ADF automatically turns over the document from the front side to the back side in ADF reading, whereas in the fixed document reading, the user simply turns the document over from the front side to the back side. Therefore, description of the operation of the duplex printing apparatus 10 in the case of ADF reading is omitted.

(Test print)
A test print key is provided on the operation panel of the duplex printing apparatus 10. The test print key is for performing a test print, and the test print is a mode for performing only the front surface printing process regardless of the number of printed sheets. When the print image such as the print density and the print position is confirmed in advance, the front side print process is performed by pressing the test print key. By pressing the test print key a plurality of times, a plurality of front surface printing processes are performed.

  Here, in the double-sided printing process, a test print (front surface printing process) is performed in order to confirm the print image, and the test-printed paper is not removed from the paper discharge tray 32, and a desired set number of sheets are printed. Consider the case of processing.

  In the above case, before the reverse side printing process, the total number of sheets of test printed sheets (test number) and the number of front side printed sheets (front set number) are re-released from the discharge tray 32. It is conveyed to the paper feed tray 51. Then, in the back side printing process, the back side printing process is performed for the set number of front side sheets, and therefore, after the back side printing process, the paper for which the front side printing process is performed for the test number of sheets remains in the refeed tray 51. Become.

  As a countermeasure for the above problem, the control unit of the double-sided printing apparatus 10 stores the number of test sheets when a test print is performed. During the back side printing process, the control unit performs the back side printing process for the total number of set sheets (front set number) input by the user to the operation panel and the stored test number. As a result, even when a test print is performed, the problem that paper remains in the refeed tray 51 after the back side printing process can be solved. Further, the control unit may perform the back surface printing process on all the sheets stacked on the refeed tray 51 regardless of the set number of front surfaces. Note that even when pre-printing (a mode in which an initial print processing number of sheets is set separately from a desired set number of sheets and performing front side printing after plate making) is performed, the same control as the above-described test print can be performed. .

  Hereinafter, the configuration of the paper feed tray 21, the paper discharge tray 32, and the refeed tray 51 will be described more specifically.

(Paper tray)
FIG. 8 is a perspective view of the paper feed tray 21. The paper feed tray 21 includes a paper feed table 211 on which paper is placed, and a pair of paper feed side plates 212 that regulate both side edges of the paper at an interval substantially equal to the paper width. The paper feed table 211 includes a main body portion 2111 and a protruding portion 2112 that protrudes forward from the main body portion 2111. The sheet feeding side plate 212 is erected on the main body 2111.

  FIG. 9 is a perspective plan view of the paper feed tray 21, and shows the main body portion 2111 in a transparent manner. The sheet feeding side plate 212 is movable in a direction orthogonal to the M1 direction (paper width direction, Y direction). As shown in FIG. 9, the sheet feeding side plate moving mechanism that moves the sheet feeding side plate 212 in the Y direction includes a rail 2121, a rack 2122, a pinion 2123, and a lever 2124. The sheet feeding side plate 212 is fixed to a rack 2122 that can slide along a rail 2121 that extends and is fixed to the main body 2111 in the Y direction. The rack 2122 is opposed to the pinion 2123. As a result, when the one sheet feeding side plate 212 is slid inward along the rail 2121 by the lever 2124, the other sheet feeding side plate 212 is also slid inward along the rail 2121 by the same distance. When one sheet feeding side plate 212 is slid outward along the rail 2121, the other sheet feeding side plate 212 is also slid outward along the rail 2121 by the same distance. Therefore, the distance between the pair of paper feed side plates 212 can be freely changed.

  FIG. 10 is also a perspective plan view of the paper feed tray 21, but shows the main body portion 2111 further transparently than in the case of FIG. 9. FIG. 11 is a perspective rear perspective view of the paper feed tray 21. The paper feed tray 21 is movable in the Y direction with respect to the printing machine main body 1. As shown in FIGS. 10 and 11, the paper feed tray moving mechanism for moving the paper feed tray 21 in the Y direction includes a drive screw shaft 213, a motor 214, a screwing portion 215, two slide shafts 216, 217. In addition, the paper feed tray 21 includes a movement amount detection sensor 218 that detects a movement amount of the paper feed tray 21 in the Y direction.

  One end of the drive screw shaft 213 is rotatably fixed to the printing press main body 1 and extends in the Y direction. The motor 214 is provided at the other end of the drive screw shaft 213 so as to rotate the drive screw shaft 213. The screwing portion 215 is fixed to the side wall 2111 a of the main body portion 2111 of the paper feed table 211. The drive screw shaft 213 is screwed into the screwing portion 215 and passes through the screwing portion 215. The slide shafts 216 and 217 are provided on both sides of the drive screw shaft 213 in parallel with the drive screw shaft 213. Accordingly, when the motor 214 is operated to rotate the drive screw shaft 213, the screwing portion 215 moves on the drive screw shaft 213 while rotating relative to the drive screw shaft 213, that is, the paper feed tray 21 is moved. It moves along the slide axes 216, 217.

  The movement amount detection sensor 218 includes a disk 2181 that rotates with the rotation of the drive screw shaft 213, and a slit counter 2182. The disk 2181 has a large number of slits at the periphery thereof at equal intervals, and the slit counter 2182 obtains the number of slits passing through the counter unit. Thereby, the amount of rotation of the drive screw shaft 213, that is, the amount of movement of the screwing portion 215, that is, the amount of movement of the paper feed tray 21 in the Y direction is detected.

  As described above, the paper feed side plate 212 is moved in the Y direction as a pair so that the paper feed side plate 212 is symmetrical with respect to the intermediate line in the Y direction of the paper feed stand 211 by the paper feed side plate moving mechanism. It is supposed to be. As a result, the sheet feeding side plate 212 can move in the Y direction with respect to the printing machine main body 1 in a state where the middle line in the Y direction of the sheet feeding table 211 and the middle line between the sheet feeding side plates 212 coincide. ing. The first side plate detection means (not shown) detects the amount of movement in the Y direction of the paper feed side plate 212 based on the amount of movement of the lever 2124, and the amount of movement of the paper feed tray 21 in the Y direction by the movement amount detection sensor 218. Is detected. As a result, the first side plate detection unit detects the position of the paper supply side plate 212 in the Y direction with respect to the printing press main body 1. The control unit controls the paper feed tray moving mechanism and / or the paper feed side plate moving mechanism to move the paper feed side plate 212 based on the detection result of the first side plate detecting means.

(Output tray)
12 is a front perspective view of the paper discharge tray 32, FIG. 13 is a rear perspective view of the paper discharge tray 32, and FIG. The paper discharge tray 32 includes a pair of paper discharge trays 321 on which paper is stacked, an end plate 322 that receives the leading edge of the paper printed by the printing unit 4, and a pair of paper that regulate both side edges of the paper at an interval substantially equal to the paper width A paper discharge side plate 323. Further, the paper discharge tray 32 includes a U-shaped forming member 324 that maintains the paper stacked on the paper discharge tray 321 in a U-shape. The paper discharge side plate 323 is erected in a substantially vertical posture with respect to the upper surface of the paper discharge table 321. The paper discharge side plate 323 has a protruding portion 323a that protrudes inward in the Y direction. The protrusions 323a are continuous in the vertical direction, and a plurality of protrusions 323a are formed at intervals in a direction parallel to the M1 and M2 directions (hereinafter referred to as the M direction). Similarly, the end plate 322 also has a protruding portion 322a that protrudes in the M2 direction. The protrusions 322a are continuous in the vertical direction, and a plurality of protrusions 322a are formed at intervals in the Y direction. The paper contact surface of the protrusion 323a and the paper contact surface of the protrusion 322a are made of a high friction member having a high coefficient of friction with the paper, such as rubber. A plurality of rollers 325 are arranged on the paper discharge table 321 so that the paper stacked on the paper discharge table 321 can be smoothly conveyed. The rollers 325 are evenly arranged on the paper discharge table 321 so as to uniformly hold the sheets of all specifications used.

  FIG. 15 is a perspective view of the paper discharge side plate 323. As shown in FIG. 15, the paper discharge side plate moving mechanism for moving the paper discharge side plate 323 in the Y direction includes a rack 3231, a belt type transmission mechanism 3232, and a motor 3233. As shown in FIG. 14, the rack 3231 is a frame body having upper and lower openings, and one end portion in the Y direction is fixed to the side portion 32 a of the paper discharge tray 32. A lower end portion 323 b of the paper discharge side plate 323 passes through the opening of the rack 3231 and is fixed to the belt 3232 a of the belt type transmission mechanism 3232. The motor 3233 is connected to the belt type transmission mechanism 3232. When the motor 3233 operates, the belt-type transmission mechanism 3232 operates and the belt 3223a rotates. As a result, the paper discharge side plate 323 fixed to the belt 3232a moves in the rack 3231 in the Y direction. Therefore, the paper discharge side plate 323 can be moved in the Y direction by the paper discharge side plate moving mechanism. As shown in FIG. 15, each paper discharge side plate 323 is provided with a paper discharge side plate moving mechanism, so that it can be individually moved in the Y direction.

  The paper discharge tray 32 can be moved in the Y direction with respect to the printer main body 1 by a paper discharge tray moving mechanism (not shown). The paper discharge tray moving mechanism includes a mechanism similar to the paper feed tray moving mechanism.

  The paper discharge tray 32 includes second side plate detection means (not shown) that detects the position of the paper discharge side plate 323 in the paper width direction. As described above, the sheet discharge side plate 323 is moved in the Y direction in the rack 3231 by the rotation of the belt 3232a. Therefore, the second side plate detection means is discharged based on the rotation distance of the belt 3232a. The position of the paper side plate 323 in the Y direction is detected. The control unit controls the paper discharge tray moving mechanism and / or the paper discharge side plate moving mechanism based on the detection result of the second side plate detecting means to move the paper discharge side plate 323.

  The paper discharge side plates 323 are usually located at a guide position where the distance between the paper discharge side plates 323 is smaller than the paper width, and thus the printed paper is maintained in a U shape between the side plates, while the U shape is maintained. A drop guide is formed on the forming member 324.

  FIG. 16 is a perspective view of the end plate 322. As shown in FIG. 16, the end plate moving mechanism that moves the end plate 322 in the M direction includes slide shafts 3221 and 3222, a belt-type transmission mechanism 3223, and a motor 3224. The slide shafts 3221 and 3222 are provided in parallel with the M direction and penetrate the lower portion of the end plate 322. The end portions in the M1 direction of the slide shafts 3221 and 3222 are positioned at the receiving position for receiving the leading end portion of the paper discharged to the discharge tray 32, and the end portions in the M2 direction of the slide shafts 3221 and 3222 are in the discharge tray. It is located at a delivery position where 32 sheets are delivered to the refeed tray 51. The lower end 322 a of the end plate 322 is fixed to the belt 3223 a of the belt type transmission mechanism 3223. The end portion in the M1 direction of the orbit of the belt 3223a is positioned below the end portion in the M1 direction of the slide shafts 3221 and 3222, and the end of the orbit in the M2 direction of the belt 3223a is the slide shafts 3221 and 3222. It is located below the M1 direction end. The motor 3224 is connected to the belt type transmission mechanism 3223. When the motor 3224 is activated, the belt-type transmission mechanism 3223 is activated, and the belt 3223a rotates. As a result, the end plate 322 fixed to the belt 3223a is movable in the M direction along the slide shafts 3221 and 3222. As a result, the end plate 322 can move between the receiving position and the delivery position.

  FIG. 17 is an upper perspective view of the U-shaped member 324, and FIG. 18 is a lower perspective view of the U-shaped member 324. As shown in FIGS. 17 and 18, the U-shaped forming member 324 is arranged on the paper discharge tray 321 symmetrically with respect to the intermediate line O1 of the paper width, and is configured by a plurality of fin members provided in the M direction. ing. Each fin member is formed so as to become higher in the Y direction outward from the intermediate line O1, and its upper edge is formed to be substantially parallel to the paper discharge table 321 at the outer end in the Y direction.

  The U-shaped member rotation mechanism that rotates the U-shaped member 324 includes rotational shafts 3241 and 3242, a transmission mechanism 3243, and a motor 3244. The rotation shafts 3241 and 3242 are provided below the paper discharge tray 321 in parallel with the M direction. The U-shaped forming member 324 is configured such that two fin members 324a and 324b are connected in the M direction by a connecting member 3245, and a plurality of U members are provided in the M direction. The fin members 324a and 324b connected to each other have Y-direction inner ends fixed to rotating shafts 3241 and 3242, respectively. The pair of fin members 324a in the forefront portion in the M2 direction are supported by support members 3243b connected to the rotation shaft 3243a of the conduction mechanism 3243 at the Y direction outer ends. The rotation shaft 3243a is connected to the motor 3244 through a gear or the like. When the motor 3244 rotates, the rotation shaft 3243a rotates, and as a result, the support member 3243b connected to the rotation shaft 3243a moves up and down. As the support member 3243b moves up and down, the pair of fin members 324a at the forefront of the M2 direction rotate with respect to the paper discharge table 321 about the rotation shafts 3241 and 3242. Since the other fin members are fixed to the rotation shafts 3241 and 3242, if the fin member 324a at the forefront portion in the M2 direction rotates, the rotation shafts 3241 and 3242 rotate, and as a result, the other fin members 324b The M2 direction frontmost fin member 324a is rotated with respect to the paper discharge table 321 by the same angle. Accordingly, the U-shaped member 324 moves up and down between a protruding position that protrudes from the upper surface of the paper discharge table 321 and a retracted position that does not protrude from the upper surface of the paper discharge table 321. Then, the U-shaped member rotation mechanism is controlled in accordance with the type (size, thickness, etc.) of the paper loaded on the paper discharge tray 32, and the amount of rotation of the rotary shafts 3241 and 3242 is changed to form the U-shape. The amount of protrusion of the member 324 from the upper surface of the paper discharge tray 321 varies. For example, when the thickness per sheet is thick, the protruding amount of the U-shaped forming member 324 from the upper surface of the paper discharge table 321 is small, and when the thickness per sheet is thin, The protruding amount of the U-shaped member 324 from the upper surface of the paper discharge table 321 is increased.

(Base guide)
FIG. 19 is a perspective view showing the base guide 33 in the closed position, and FIG. 20 is a perspective view showing the base guide 33 in the open position. 21 is a perspective view from another direction showing the base guide 33 in FIG. 19, and FIG. 22 is a perspective view from another direction showing the base guide 33 in FIG. 21 and 22, the transport belt mechanism 31 is omitted. As shown in FIGS. 19 to 22, the base guide moving mechanism for moving the base guide 33 in the vertical direction is formed as a pair in the Y direction, a rail 331, a rack 332, a gear 333, and one motor. 334 and a connecting rod 335 that connects the pair of gears 333. Each of the rails 331 is attached to the printing press main body 1, and a long groove 331a is formed in the vertical direction. And the side protrusion part 33a of the base guide 33 is inserted in the long groove 331a. A side portion 33 b of the base guide 33 is fixed to the rack 332. A plurality of teeth 332 a are formed at one end of the rack 332 at the top and bottom, and the teeth 332 a mesh with the gear 333. The drive shaft of the motor 334 is connected to one gear 333. When the motor 334 is activated, one gear 333 is rotated, and the other gear 333 is also rotated via the connecting rod 335. When the gear 333 rotates, the rack 332 meshed with the gear 333 moves up and down. As a result, the base guide 33 fixed to the rack 332 moves in the vertical direction as the side protrusion 33a moves in the vertical direction in the long groove 331a of the rail 331. The motor 334 and one gear 333 are connected via a one-way clutch (not shown), and the one-way clutch transmits a driving force in a direction in which the base guide 33 moves upward. The drive force in the direction in which the base guide 33 moves downward cannot be transmitted.

(Refeed tray)
FIG. 23 is an upper perspective view of the refeed tray 51, and FIG. 24 is a side perspective view of the refeed tray 51. The re-feed tray 51 includes a re-feed tray 511 on which the stacked sheets are placed, a re-feed transport unit 512 that transports the stacked sheets on the re-feed tray 511 to the sheet downstream end of the re-feed tray 511, A pair of refeeding side plates 513 that regulate both side edges of the stacked sheets at an interval substantially equal to the sheet width.

  The refeed side plate 513 can be moved in the Y direction by a refeed side plate moving mechanism (not shown) including a motor. The sheet refeeding side plate moving mechanism includes a mechanism similar to the sheet feeding side plate moving mechanism. Here, in the paper refeeding side plate moving mechanism, the one corresponding to the lever 2124 of the paper feeding side plate moving mechanism is driven by the motor. Therefore, the refeeding side plate 513 can be moved between a restriction position that restricts both side edges of the paper and a standby position that is not restricted by the refeeding side plate moving mechanism.

  The re-feed transport unit 512 includes a roller 5121 positioned at the end of the re-feed base 511 in the M1 direction, a roller 5122 positioned in the M2 direction with respect to the roller 5121, and a transport wound around the roller 5121 and the roller 5122. Belt 5123. The rollers 5121 and 5122 are rotated by a drive motor (not shown), and the conveyor belt 5123 is rotated by the rotation of the rollers 5121 and 5122. The re-feed conveying means 512 is preferably configured to be inclined horizontally or downward in the M2 direction (front side), and in the present embodiment, downward in the M2 direction (front side). It is comprised so that it may incline. In addition, it is preferable that the inclination angle of the re-feed conveyance unit 512 is within 10 degrees with respect to the horizontal plane. The stacked sheets on the transport belt 5123 are transported to the end portion in the M2 direction of the refeed table 511 by the rotation of the transport belt 5123. In addition, the conveyance speed of the refeed conveyance means 512 is faster than the movement speed of the end plate 322.

  FIG. 25 is a bottom view of the refeed tray 51. A holding member 514 that holds the refeed tray moving mechanism is fixed to the printing press main body 1. FIG. 26 is a lower perspective view of the refeed tray 51 with the holding member 514 removed. As shown in FIG. 26, the refeed tray moving mechanism that moves the refeed tray 51 in the Y direction includes a drive screw shaft 5151, a motor 5152, a slide member 5153, and a connecting member 5154. . Further, the refeed tray 51 includes a movement amount detection sensor 5155 that detects the movement amount of the refeed tray 51 in the Y direction.

  The motor 5152 is held by the holding member 514. One end of the drive screw shaft 5151 is connected to the motor 5152 and extends in the Y direction. The drive screw shaft 5151 is rotated by a motor 5152. The slide member 5153 is attached to the drive screw shaft 5151 so as to be movable in the Y direction along the drive screw shaft 5151 when the drive screw shaft 5151 rotates. The connecting member 5154 connects the slide member 5153 and the outer frame 51 a of the refeed tray 51. Accordingly, when the motor 5152 is operated to rotate the drive screw shaft 5151, the slide member 5153 moves in the Y direction along the drive screw shaft 5151. When the slide member 5153 moves in the Y direction, the refeed tray 51 connected to the slide member 5153 by the connecting member 5154 moves in the Y direction.

  The movement amount detection sensor 5155 includes a disk 5155a that rotates with the rotation of the drive screw shaft 5151, and a slit counter 5155b. The disc 5155a has a large number of slits on the periphery thereof at equal intervals, and the slit counter 5155b obtains the number of slits passing through the counter portion. Thereby, the amount of rotation of the drive screw shaft 213, that is, the amount of movement of the slide member 5153, that is, the amount of movement of the refeed tray 51 in the Y direction is detected.

  As described above, the refeeding side plate 513 is paired by the refeeding side plate moving mechanism so that the refeeding plate 511 is symmetrical with respect to the intermediate line in the Y direction of the refeeding plate 511. It moves in the Y direction. As a result, the refeeding side plate 513 moves in the Y direction with respect to the printing machine main body 1 in a state where the intermediate line in the Y direction of the refeeding table 511 matches the intermediate line between the refeeding side plates 513. It is possible. Then, a third side plate detection means (not shown) detects the amount of movement of the refeed side plate 513 in the Y direction based on the amount of rotation of the motor, and the amount of movement detection sensor 5155 moves the refeed tray 51 in the Y direction. Detect the amount. As a result, the third side plate detecting means detects the position of the refeed side plate 513 in the Y direction with respect to the printing press main body 1. The control unit controls the refeed tray moving mechanism and / or the refeeding side plate moving mechanism based on the detection result of the third side plate detecting means, and moves the refeeding side plate 513.

  27 and 28 are side views of the refeed tray 51. FIG. 27 shows a state where the refeed tray 511 is positioned below. FIG. 28 shows the refeed tray 511. The state located in the upper part is shown. As shown in FIGS. 27 and 28, the refeeding table up / down mechanism for moving the refeeding table 511 in the vertical direction includes a rotating member 5161, a connecting member 5162, a swinging member 5163, a push-up member 5164, It has.

  The rotating member 5161 is connected to a motor (not shown) and is rotated in the R1 direction by the motor. One end of the connecting member 5162 is attached to the eccentric position 5161a of the rotating member 5161, and the other end is attached to the center position 5161b of the swinging member 5163 extending in the vertical direction. The swing member 5163 is attached to a spring member 5165 attached to the frame of the refeed tray 51 so as to be rotatable about the swing shaft 5163a. The push-up member 5164 is attached to the swing member 5163 so as to be rotatable about the swing shaft 5163b. Accordingly, when the rotating member 5161 is rotated by operating the motor, the connecting member 5162 swings in the M direction. When the connecting member 5162 swings in the M direction, the swinging member 5163 rotates in the R2 direction about the swinging shaft 5163a while expanding and contracting the spring member 5165 connected to the lower end thereof. When the swing member 5163 rotates about the swing shaft 5163a, the push-up member 5164 rotates about the swing shaft 5163a in the R3 direction. Here, the re-feeding table 511 is attached to the frame of the re-feeding conveying means 512 at the end portion 511a in the M1 direction, and can be rotated in the vertical direction around the end portion 511a. Therefore, when the push-up member 5164 is rotated in the R3 direction, the re-feeding base 511 is rotated by the push-up member 5164 in the vertical direction around the end portion 511a.

  FIG. 27 shows a state in which the push-up member 5164 is rotated and the push-up member 5164 and the paper re-feeding base 511 are not in contact with each other. Is transported. FIG. 28 shows a state in which the push-up member 5164 is rotated and the push-up member 5164 pushes up the re-feeding table 511 to the maximum. When transporting paper from the refeed tray 51 to the timing roller 24 of the paper feed unit 2, the push-up member 5164 is arranged so that the uppermost paper on the refeed stand 511 contacts the refeed roller 52. The re-feeding table up / down mechanism operates so as to gradually push up the re-feeding table 511.

(Re-feed roller, etc.)
As shown in FIG. 23, the refeed roller 52 includes a roller body 521 that extends in the Y direction and covers the entire width of the sheet. The roller body 521 is formed by kneading ceramic particles into a rubber material. The surface of the roller main body 521 is made uneven with ceramic granular material or the like. The diameter of the ceramic granular material or the like is 10 to 30 μm. The roller body 521 may be formed by adhering a ceramic granular material, a urethane granular material, glass beads, or the like to the surface of a rubber material. However, it is preferable to knead the ceramic particles in the rubber material because the paper conveying force of the roller main body 521 is larger than when the ceramic particles are bonded to the surface of the rubber material.

  As shown in FIG. 24, the buckling member 54 includes a facing portion 541 that protrudes toward the roller body 521 of the refeed roller 52. The facing portion 541 is located at a substantially central portion in the Y direction, is located at one variable protruding portion 541a that can change the protruding amount toward the roller main body 521, and outside the variable protruding portion 541a in the Y direction. And a plurality of fixed protrusions 541b protruding toward the surface. The variable projecting portion 541a and the fixed projecting portion 541b are provided in the vicinity of the central portion in the Y direction of the upper inclined portion 11a of the front side plate 11 positioned in front of the refeed tray 51. The variable protrusion 541a and the fixed protrusion 541b are provided at positions separated from the roller body 521 so as not to press the sheet against the roller body 521 of the refeed roller 52. The roller main body 521 of the refeed roller 52 and the facing portion 541 of the buckling member 54 take out and transport the sheets on the refeed tray 51 one by one from the top.

  As shown in FIGS. 1 to 4, at least one of the pair of intermediate transport rollers 53, specifically, the roller body of the roller 53 a (rear roller) on the side where the surface of the surface-printed paper comes into contact is It is formed by adhering ceramic particles or glass beads to the surface of the ABS material. The surface of the roller body of the roller 53a is made uneven with ceramic particles or the like. The diameter of the ceramic granular material or the like is 10 to 30 μm. Of course, irregularities may be formed on the surfaces of the roller bodies of both of the pair of intermediate conveyance rollers 53 with ceramic granular materials or the like.

  The refeed tray 51 may be unitized and attached to the printing press main body 1 so that it can be pulled out from the printing press main body 1. Further, the re-feed tray 51, the re-feed roller 52, the intermediate conveyance roller 53, and the suction member 54 may be unitized (re-feed unit 5) so that it can be pulled out from the printing press main body 1. In this case, by pulling out the refeed unit 5, it is possible to efficiently process the paper jammed in the refeed unit 5.

(Operation mode of the paper feed tray, paper discharge tray, and re-feed tray during duplex printing)
FIGS. 29 to 34 are schematic views showing the operation of the paper feed tray 21, the paper discharge tray 32, and the refeed tray 51 during double-sided printing. Hereinafter, the operation relationship will be described with reference to FIGS. 29 to 34.

  FIG. 29 shows a state of the paper feed tray 21, the paper discharge tray 32, and the re-feed tray 51 before the use of the duplex printing apparatus 10 is started. The intermediate line C1 between the paper supply side plates 212, the intermediate line C2 between the paper discharge side plates 323, and the intermediate line C3 between the refeed side plates 513 coincide.

  When sheets are stacked on the sheet feed table 211 and the user inputs the Y-direction position of the front print image on the operation panel, the control unit controls and inputs the sheet feed tray moving mechanism as shown in FIG. The paper feed tray 21 is moved in the Y direction (Y6) so that the paper is positioned at the selected position. As a result, the intermediate line C1 between the paper supply side plates 212 also moves in the Y direction.

  When the paper feed tray 21 moves in the Y direction, based on the detection result of the intermediate line C1 between the paper supply side plates 212 by the first side plate detection means and the detection result of the intermediate line C2 between the paper discharge side plates 323 by the second side plate detection means. As shown in FIG. 31, the control unit controls the discharge tray moving mechanism so that the intermediate line C1 between the paper supply side plates 212 and the intermediate line C2 between the discharge side plates 323 coincide with each other. 32 is moved in the Y direction (Y7).

  When the intermediate line C1 between the paper supply side plates 212 and the intermediate line C2 between the paper discharge side plates 323 coincide with each other, the sheets on the paper supply table 211 are subjected to surface printing processing one by one by the printing unit 4 and discharged to the paper discharge tray 32. Is done. When the paper is discharged to the paper discharge tray 32, the U-shaped forming member 324 is located at a protruding position protruding from the upper surface of the paper discharge table 321, and the paper discharge side plate 323 is a distance between the paper discharge side plates 323. Is positioned at a guide position smaller than the paper width. As a result, the paper subjected to the front surface printing process is guided to drop onto the U-shaped forming member 324 while being maintained in a U-shape between the paper discharge side plates 323 on the paper discharge tray 32.

  When the discharge tray 32 moves in the Y direction, the detection result of the intermediate line C2 between the discharge side plates 323 by the second side plate detection means and the detection result of the intermediate line C3 between the refeeding side plates 513 by the third side plate detection means. As shown in FIG. 32, the control unit controls the refeed tray moving mechanism so that the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 match. The refeed tray 51 is moved in the Y direction (Y8).

  When the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the paper refeed side plates 513 coincide, the paper on the paper discharge tray 321 is transferred to the paper refeed tray 51 in a stacked state. When the paper is delivered to the refeed tray 51, the U-shaped member 324 is positioned at a retracted position so as not to protrude from the upper surface of the paper discharge tray 321, and the paper discharge side plate 323 is a distance between the paper discharge side plates 323. Is located at the same position as the paper width (YJ). Here, the paper discharge side plate 323 may be positioned laterally outward from the YJ position. In this case, the gap between the YJ position and the paper discharge side plate 323 is preferably about 2 mm on both sides. When the paper discharge side plate 323 is positioned at the YJ position or laterally outward from the YJ position, the U-shaped state of the paper is canceled and transferred to the refeed tray 51.

  Then, after a predetermined time elapses after the U-shaped member 324 is changed from the protruding position to the retracted position, the end plate 322 moves from the receiving position toward the delivery position, whereby the sheet is re-applied. It moves toward the paper feed tray 51. After the predetermined time has elapsed after the U-shaped forming member 324 is changed from the protruding position to the retracted position, the operation of conveying the sheet toward the refeed tray 51 is performed by “automatic mode” and “manual start” of the duplex printing apparatus 10. Applicable to both modes. Here, the “automatic mode” refers to a mode in which the paper on the paper discharge tray 32 is automatically conveyed to the refeed tray 51 after the front surface printing process is completed. This means a mode in which the paper on the paper discharge tray 32 is conveyed to the refeed tray 51 by pressing the plate making key or the print key (manual start key) on the operation panel after the front surface printing process is completed. The predetermined time can be arbitrarily changed according to the type (size, thickness, etc.) of the paper, and is, for example, about 1 to 5 seconds. When using thick paper as the paper, the U-shaped member 324 is always positioned at the retracted position without protruding (referred to as “thick paper mode”). In such a thick paper mode, Since the sheets are always stacked on the discharge tray 32 in a flat state, the predetermined time is set to 0 seconds.

  When the leading edge of the sheet is placed on the refeed conveyance unit 512 of the refeed tray 51, the sheet is conveyed to the front end of the refeed tray 51 by the refeed conveyance unit 512 and the end plate 322. When paper is received in the paper refeed tray 51, the paper refeed side plate 513 is positioned at a standby position where the paper is not restricted and the distance between the paper refeed side plates 513 is larger than the paper width. Then, after receiving the paper in the refeed tray 51, the refeed side plate 513 regulates the paper width direction of the paper by the refeed side plate moving mechanism, and the distance between the refeed side plates 513 is the same as the paper width. Align the paper at the regulation position.

  When the user inputs the Y-direction position of the back printed image on the operation panel, as shown in FIG. 33, the control unit controls the refeed tray moving mechanism so that the sheet is positioned at the input position. Then, the refeed tray 51 is moved in the Y direction (Y9). As a result, the intermediate line C3 between the refeed side plates 513 is also moved in the Y direction.

  When the refeed tray 51 moves in the Y direction, the detection result of the intermediate line C2 between the paper discharge side plates 323 by the second side plate detection unit and the detection result of the intermediate line C3 between the refeed side plates 513 by the third side plate detection unit. As shown in FIG. 34, the control unit controls the discharge tray moving mechanism so that the intermediate line C2 between the discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 coincide. The paper discharge tray 32 is moved in the Y direction (Y10).

  When the intermediate line C3 between the paper refeeding side plates 513 and the intermediate line C2 between the paper discharge side plates 323 coincide with each other, the refeeding base vertical mechanism moves the refeeding base 511 upward, Each sheet of paper is printed on the back side by the printing unit 4 via the paper refeed roller 52, the separating member 54, and the intermediate transport roller 53, and is discharged to the paper discharge tray 32. When the paper is discharged to the paper discharge tray 32, the U-shaped forming member 324 is located at a protruding position protruding from the upper surface of the paper discharge table 321, and the paper discharge side plate 323 is a distance between the paper discharge side plates 323. Is positioned at a guide position smaller than the paper width. As a result, the paper subjected to the reverse side printing process is guided to drop onto the U-shaped forming member 324 while being maintained in a U-shape between the discharge-side plates 323 on the discharge tray 32.

  In the above operation mode, when receiving paper in the refeed tray 51, the refeed side plate 513 is positioned at a standby position where the paper is not restricted and the distance between the refeed side plates 513 is larger than the paper width. Yes. Then, after receiving the paper in the refeed tray 51, the refeed side plate 513 regulates the paper width direction of the paper by the refeed side plate moving mechanism, and the distance between the refeed side plates 513 is the same as the paper width. The paper is aligned at the restriction position. However, when the paper is received in the refeed tray 51, the refeed side plate 513 is positioned at the restriction position where the distance between the refeed side plates 513 is the same as the paper width by the refeed side plate moving mechanism. Anyway. In this case, it is preferable that the end portion on the paper receiving side of the refeeding side plate 513, that is, the rear end portion, has a square shape in a top view that extends rearward in the paper width direction. Since the refeed side plate 513 has the above-described shape, it is possible to prevent jamming of the paper when the paper is received in the refeed tray 51.

  According to the double-sided printing apparatus having the above configuration, the following effects can be exhibited.

(1) As the end plate 322 moves, the paper in the paper discharge tray 32 is transferred to the paper refeeding conveyance means 512 of the paper refeed tray 51. Therefore, the paper is transferred from the paper discharge tray 32 to the paper refeed tray 51. Can be carried out easily, and the paper can be conveyed smoothly.

(2) Since the plurality of rollers 325 are arranged on the paper discharge tray 321 of the paper discharge tray 32, the sheets stacked on the paper discharge tray 321 can be smoothly conveyed.

(3) Since the transport speed of the re-feed transport means 512 is faster than the moving speed of the end plate 322, the load on the end plate 322 during the delivery of paper from the paper discharge tray 32 to the re-feed tray 51 Is reduced, and it is possible to prevent wrinkles and the like from being generated on the lowermost sheet of the sheets stacked on the discharge tray 32, and to smoothly transfer the sheet from the discharge tray 32 to the refeed tray 51. it can.

(4) Since the paper refeeding means 512 is configured to incline downward in the M2 direction, that is, the paper transporting direction, the paper placed on the paper refeeding tray 51 is transported in the paper refeeding tray 51. It is easy to be conveyed in the direction. As a result, the delivery of paper from the paper discharge tray 32 to the refeed tray 51 can be performed more smoothly. In addition, since the refeed conveyance unit 512 is inclined downward in the sheet conveyance direction, a space can be formed above the refeed conveyance unit 512, and a part of the sheet is disposed in the space. The space around the paper refeeding means can be minimized, and the duplex printing apparatus can be miniaturized. In addition, the inclination angle of the refeeding conveyance unit 512 is within 10 degrees with respect to the horizontal plane, so that it is possible to prevent the sheet from collapsing on the refeeding tray 51.

(5) When the paper is received in the refeed tray 51, the refeed side plate 513 is positioned at a standby position where the paper is not restricted and the distance between the refeed side plates 513 is larger than the paper width. In addition, it is possible to prevent interference between the sheet re-feed side plate 513 and the sheet, and to prevent skew of the sheet in the sheet re-feed tray 51.
Then, after receiving the paper in the refeed tray 51, the refeed side plate 513 regulates the paper width direction of the paper by the refeed side plate moving mechanism, and the distance between the refeed side plates 513 is the same as the paper width. Therefore, when the paper is re-feeded from the re-feed tray 51 to the printing unit 4, skewing of the paper can be prevented.

(6) Since the U-shaped forming member 324 is disposed on the paper discharge table 321, the paper on the paper discharge table 321 is held in a U-shape, and as a result, the paper on the paper discharge table 321 is well aligned. can do. Further, since the U-shaped member 324 can move up and down between the protruding position and the retracted position, the U-shaped forming member 324 is positioned at the protruding position when a sheet is placed on the paper discharge table 321. Thus, the U-shaped forming member 324 is moved to the retracted position when the paper is transferred from the paper discharge tray 32 to the refeed tray 51 while keeping the paper in a U-shape and improving the alignment of the paper. Thus, the U-shaped state of the paper can be eliminated, and the paper can be smoothly transferred from the paper discharge tray 32 to the refeed tray 51.

(7) When the paper is conveyed from the printing unit 4 to the paper discharge tray 32, the U-shaped forming member 324 is positioned at the protruding position, and the paper discharge side plate 323 is positioned at the guide position. The paper on the paper discharge tray 32 can be easily held in a U-shape. Further, when the sheet is conveyed from the discharge tray 32 to the refeed tray 51, the U-shaped member 324 is positioned at the retracted position, and the discharge side plate 323 is positioned at the restricting position. Further, the skew of the sheet can be prevented, and as a result, the sheet can be prevented from jamming, and the sheet can be smoothly transferred from the sheet discharge tray 32 to the sheet refeed tray 51. In particular, when the paper discharge side plate 323 is positioned laterally outward from the restriction position, the U-shaped forming member 324 is positioned at the retracted position, so that the paper held in the U-shape on the paper discharge tray 32 is in a flat state. In this case, the air existing between the sheets can be easily diffused to the outside through the gap between the both side edges of the sheet and the sheet discharge side plate 323. That is, by forming a gap between the both side edges of the sheet and the sheet discharge side plate 323, the sheet alignment on the sheet discharge tray 32 is slightly shifted or the sheet width dimension is slightly larger than the specified value. However, it is possible to reliably change the sheet to a flat state. Note that the air existing between the sheets can escape from between the sheets by changing the sheets from the U-shaped state to the planar state. Then, when the air existing between the sheets is released, it is possible to prevent the alignment of the sheets from being lost when the sheets are conveyed from the discharge tray 32 to the refeed tray 51.

(8) After the predetermined time has elapsed after the U-shaped forming member 324 is changed from the protruding position to the retracted position, the sheet is conveyed from the sheet discharge tray 32 to the refeed tray 51. When a sheet held in a U-shape on the tray 32 is changed to a flat state, air existing between the sheets is diffused to the outside through a gap between both side edges of the sheet and the sheet discharge side plate 323. Time can be secured. Then, when the air existing between the sheets is released, it is possible to prevent the alignment of the sheets from being lost when the sheets are conveyed from the discharge tray 32 to the refeed tray 51.

(9) The time required for air to escape between sheets varies depending on the type (size, thickness, etc.) of the sheet. Here, after the U-shaped forming member 324 is changed from the protruding position to the retracted position, the time until the paper is conveyed from the paper discharge tray 32 to the refeed tray 51 can be changed. The waiting time can be set accordingly.

(10) The U-shaped forming member 324 is configured by a plurality of fin members that are arranged symmetrically with respect to the intermediate line O1 of the paper width on the paper discharge table 321 and are provided in the M direction. It can be turned up and down around the inner end in the paper width direction as a rotation axis. By configuring the U-shaped member 324 in this way, the U-shaped member 324 that can hold the sheet on the paper discharge tray 321 in a U-shaped state and can move up and down between the protruding position and the retracted position is easy. Can be configured.

(11) The U-shaped member 324 has a U-shaped member rotating mechanism controlled according to the type of paper stacked on the paper discharge tray 32, and the U-shaped member 324 is moved from the upper surface of the paper discharge tray 321. Since the amount of protrusion of the sheet fluctuates, it is possible to make the sheet alignment good regardless of the sheet type.

(12) Since the upper edge of the U-shaped forming member 324 is substantially parallel to the paper discharge table 321 at the outer end in the paper width direction, the U-shaped forming member 324 has a U-shaped state. It is possible to prevent the outer end portion in the paper width direction from warping upward, and to improve the alignment of the paper.

(13) When the paper is transferred from the paper discharge tray 32 to the refeed tray 51, the paper discharge side plate 323 is located at a position where the interval between the paper discharge side plates 323 is the same as the paper width length. Further, the skew of the sheet can be prevented, and as a result, the sheet can be prevented from jamming, and the sheet can be smoothly transferred from the sheet discharge tray 32 to the sheet refeed tray 51.

(14) The paper discharge side plate 323 is formed with a plurality of protrusions 323a having a paper contact surface made of a high friction member, and the end plate 322 also has a plurality of protrusions having a paper contact surface made of a high friction member. A portion 322a is formed. As a result, by aligning the sheets of paper discharged to the paper discharge tray 32 toward the paper discharge tray 321 with the protrusions 323a and 322a, the paper dropping posture is stabilized, and the paper is discharged with the papers aligned. It can be loaded on the paper table 321. In addition, although the protrusion part 323a is spaced apart in the M direction and continuously formed in the up and down direction, it is continuously or intermittently in the M direction and continuously in the up and down direction. It may be formed intermittently. Further, the protrusions 322a are formed in the Y direction with an interval and continuously in the vertical direction, but continuously or intermittently in the Y direction and continuously in the vertical direction or It may be formed intermittently.

(15) The one-way clutch transmits the driving force in the direction in which the base guide 33 moves upward, and cannot transmit the driving force in the direction in which the base guide 33 moves downward. As the base guide 33 is lowered by its own weight toward the paper discharge table 321 with the rotation of the gear 333 and the gear 333, there is no action of pressing the base guide 33 downward, and between the paper discharge table 321 and the base guide 33. It is possible to prevent an object or the like from being caught forcibly.

(16) The intermediate conveying roller 53 and the timing roller 24 have the same linear velocity, that is, the line of the plate cylinder 41 so as to maintain the bending P2a of the paper P2 formed between the intermediate conveying roller 53 and the timing roller 24. It is designed to rotate at speed. As a result, load fluctuations applied to the timing roller 24 can be prevented, and the conveyance performance of the timing roller 24 can be stabilized.

(17) The refeed roller 52 starts transporting the paper that is placed on the refeed tray 51 and is not transported. Therefore, the refeed roller 52 is more suitable for paper than the intermediate transport roller 53 and the timing roller 24. It gives great power. Therefore, the surface-printed ink is likely to adhere to the roller body 521 of the refeed roller 52. In the present embodiment, the roller main body 521 of the paper refeed roller 52 is uneven, so that the contact area between the paper and the paper refeed roller 52 can be reduced, and as a result, surface printing is performed on the paper. Ink can be prevented from adhering to the refeed roller 52.

(18) The re-feed roller 52 conveys the paper subjected to the front surface printing process. In the case of the paper subjected to the front surface printing process, the paper sheet may wave. Even in such a case, the roller main body 521 of the refeed roller 52 extends over the entire paper width, so that the roller main body 521 contacts the paper over the entire paper width. As a result, the undulation of the sheet is suppressed in the conveyance by the re-feed roller 52, and the generation of wrinkles and the jam of the sheet can be prevented. Further, when the roller body 521 is in contact with the paper over the entire width of the paper, for example, the paper such as a renewed paper that is originally weak and has a weakness due to the surface printing process has been reduced. Even when the paper is fed, only the central portion in the paper width direction is not transported first, and the paper can be transported at a uniform speed throughout the paper width direction. Further, since the roller body 521 contacts the paper over the entire width of the paper, the ink is transferred to the entire surface of the paper. Here, when the re-feed roller 52 contacts only a part of the paper, for example, the central part of the paper width of the paper, a stripe-like or striped ink pattern having a predetermined width from the front end of the paper including the margin to the rear end of the paper. However, the ink is transferred only to the central portion of the paper in the paper width direction, and such an ink transfer state is easily noticeable. Therefore, the ink transfer can be made inconspicuous when the ink is transferred to the entire surface of the paper, as compared with the case where the ink is transferred only to a part of the paper.

(19) Since the roller body 521 is formed by kneading ceramic particles into a rubber material, it is possible to easily form irregularities on the surface of the roller body 521. Further, by kneading the ceramic granular material into the rubber material, the paper conveying force of the roller main body 521 can be increased as compared with other methods for forming irregularities.

(20) Since the facing portion 541 of the surface member 54 is provided at a position spaced from the roller body 521, the surface member 54 is prevented from pressing the paper against the paper re-feed roller 52. It is possible to further prevent the attached surface printing ink from being transferred to the refeed roller 52. Further, since the surface member 54 does not contact the refeed roller 52, it is possible to prevent the ceramic granular body of the roller body 521 of the refeed roller 52 from being peeled off. Further, when the sucker member 54 is brought into contact with the refeed roller 52, it is conceivable that the plasticizers respectively added to both resins move to each other. In such a case, as time passes, one or both of the buckling member 54 and the rubber material of the refeed roller 52 become brittle or swell, and the refeed performance deteriorates. Can be prevented. Depending on the specifications of the paper, it may be preferable to bring the buckling member 54 into contact with the re-feed roller 52 in the conveyance of the paper. In this case, the opposing portion including the variable protrusion 541a and the fixed protrusion 541b. 541 may be provided on the roller body 521 so as to be able to contact and separate.

(21) Since the facing portions 541 are provided at intervals in the paper width direction, a guide portion that guides the conveyance of the paper can be formed between the facing portions 541, and the guide portion allows the paper to be conveyed. Skew can be prevented.

(22) Since the surface of the roller body of one roller 53a of the pair of intermediate transport rollers 53 is uneven, the contact area between the roller body of the roller 53a and the sheet is reduced, and the roller of the roller 53a is changed from the sheet. Ink adhesion to the main body can be suppressed.

(23) During the front surface printing process of the paper, the intermediate line C1 between the paper supply side plates 212 and the intermediate line C2 between the paper discharge side plates 323 coincide with each other. Can be better. Further, when the paper is transferred from the paper discharge tray 32 to the paper refeed tray 51, the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the paper refeed side plates 513 coincide with each other. Therefore, it is possible to prevent the skew of the sheet, and as a result, it is possible to prevent the sheet from jamming and to smoothly transfer the sheet from the discharge tray 32 to the refeed tray 51. Furthermore, since the paper width direction position in the refeed tray 51 is aligned, the paper width direction position of the back side printed image can be aligned.

In particular, in the above operation mode, the following effects can be exhibited.
(24-1) The control unit controls the discharge tray moving mechanism to move the discharge tray 32 so that the intermediate line C1 between the paper supply side plates 212 and the intermediate line C2 between the discharge side plates 323 coincide. Therefore, it is not necessary to move the paper feed tray 21 and / or the paper feed side plate 212 in order to match the intermediate line C1 between the paper feed side plates 212 and the intermediate line C2 between the paper discharge side plates 323. As a result, since the paper feed tray 21 and the paper feed side plate 212 do not move during the front surface printing process, the Y-direction position of the print image can be stabilized.

(24-2) The control unit controls the re-feed tray moving mechanism to move the re-feed side plate 513, and the intermediate line C2 between the paper discharge side plate 323 and the intermediate line C3 between the re-feed side plate 513. To match. Here, as compared with the case where only the refeeding side plate 513 is moved and the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeeding side plates 513 are matched, the refeeding tray 51 is moved. Thus, when the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 are matched, the amount of movement of the refeed tray 51 with respect to the reference position can be reduced.

  FIG. 35 and FIG. 36 are schematic diagrams for explaining the reason why the movement amount of the above-described refeed tray 51 can be reduced. FIG. 35 is a diagram for explaining the operation of the refeed tray 51 when the refeed tray 51 moves and the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 coincide. It is. FIG. 35A shows the refeed tray 51 and the refeed side plate 513 at the reference position. In FIG. 35B, the refeed tray 51 moves by L1 in the YA direction so that the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 coincide. Thereafter, as shown in FIG. 35C, when the Y-direction position of the back printed image is moved by L2 from the reference position in the YB direction, the refeed tray 51 is moved in the YB direction from the position in FIG. Move by L1 + L2. Thus, the refeed tray 51 is displaced by L1 in the YA direction and by L2 in the YB direction with respect to the reference position in FIG.

  On the other hand, FIG. 36 illustrates the operation of the refeed tray 51 when the refeed side plate 513 moves and the intermediate line C2 between the discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 coincide. It is a figure to do. FIG. 36A shows the refeed tray 51 and the refeed side plate 513 at the reference position. In FIG. 36B, the refeeding side plate 513 moves by L1 in the YA direction so that the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeeding side plates 513 coincide. Thereafter, as shown in FIG. 36C, when the Y-direction position of the back printed image is moved by L2 from the reference position in the YB direction, the refeed tray 51 is moved in the YB direction from the position in FIG. Move by L1 + L2. Thus, the refeed tray 51 is displaced by L1 + L2 in the YB direction with respect to the reference position in FIG. Here, the movement of the sheet re-feeding side plate 513 shown in FIG. 36B and the movement of the sheet re-feeding tray 51 shown in FIG. 36C can be performed in the reverse direction as described above. The paper feed tray 51 is displaced by L1 + L2 with respect to the reference position in FIG.

  That is, when the refeed tray 51 moves and the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 coincide with each other, the refeed tray 51 is set to L1 with respect to the reference position. The movement is L2. On the other hand, when the refeeding side plate 513 moves and the intermediate line C2 between the paper discharge side plates 323 and the intermediate line C3 between the refeeding side plates 513 coincide with each other, the refeeding tray 51 is L1 + L2 with respect to the reference position. Move. Therefore, moving the refeed tray 51 can reduce the amount of movement of the refeed tray 51 relative to the reference position than moving the refeed side plate 513. As a result, it is possible to reduce the size of the printing press main body 1 in which the refeed tray 51 is disposed.

(24-3) The control unit controls the discharge tray moving mechanism to move the discharge tray 32, and generates an intermediate line C2 between the discharge side plates 323 and an intermediate line C3 between the refeed side plates 513. Since they match, the paper alignment in the paper discharge tray 32 can be improved. Further, it is not necessary to move the refeed tray 51 and / or the refeed side plate 513 in order to make the intermediate line C2 between the discharge side plates 323 and the intermediate line C3 between the refeed side plates 513 coincide. As a result, since the refeed tray 51 and the refeed side plate 513 do not move during the back surface printing process, the Y-direction position of the print image can be stabilized.

  In the above embodiment, the paper feed side plates 212 are paired so as to be symmetric with respect to the intermediate line in the paper width direction of the paper feed table 211 on the paper feed table 211 by the paper feed side plate moving mechanism. It is designed to move in the direction. The paper discharge side plate 323 can be individually moved in the paper width direction by a paper discharge side plate moving mechanism. The refeed side plate 513 moves in the paper width direction as a pair on the refeed base 511 so as to be symmetrical with respect to the intermediate line of the refeed base 511 in the paper width direction. ing. However, the paper feed side plate 212 may be individually movable in the paper width direction like the paper discharge side plate 323.

  In the above embodiment, the paper feed tray 21 and the paper feed side plate 212 are automatically moved in the paper width direction based on information input to the operation panel. However, the user manually moves the paper feed tray 21 and the paper feed side plate 212. It may be moved in the paper width direction. Even in this case, the paper discharge tray 32, the paper discharge side plate 323, the refeed tray 51, and the refeed side plate 513 are automatically set for the paper feed tray 21 and the paper feed side plate 212 that are manually moved in the paper width direction. To move in the paper width direction.

  Here, when the loaded paper is moved in the paper width direction, the side plates (the paper feed side plate 212, the paper discharge side plate 323, and the refeed side plate 513) are not moved, but the tray on which the paper is loaded (paper feed). The tray 21, the paper discharge tray 32, and the refeed tray 51) are preferably moved in the paper width direction. This is because when the loaded paper is moved by the side plate, the friction acting between the upper surface of the tray and the lowest paper of the loaded paper is large, and the motor for moving the side plate needs to generate a high torque, This is because the motor cost increases. When the side plates can be individually moved by the motor, the tray moving mechanism is not provided. When the tray is movable, the left and right side plates are moved by one motor. Thus, the cost of the motor can be reduced. Even if the side plates can be individually moved, a tray moving mechanism may be provided in the case of a manual moving mechanism without a motor.

  The present invention is not limited to the configuration described in the above embodiment, and can include various modifications that can be considered by those skilled in the art without departing from the content described in the claims.

  In the present invention, a duplex printing apparatus capable of smoothly delivering a sheet from a sheet discharge tray to a sheet refeed tray can be provided, which is of great industrial utility value.

DESCRIPTION OF SYMBOLS 1 Printer body 2 Paper feed unit 21 Paper feed tray 22 Paper feed roller 23 Sakiki member 24 Timing roller 211 Paper feed stand 212 Paper feed side plate 213 First side plate detection means 3 Paper discharge unit 31 Conveying belt mechanism 32 Paper discharge tray 321 Ejection Paper base 322 End plate 323 Discharge side plate 324 U-shaped forming member 325 Roll 4 Printing unit 41 Plate cylinder 42 Press roller 5 Refeed unit 51 Refeed tray 52 Refeed roller 53 Intermediate transport roller 54 Sabaki member 511 Refeed Paper base 512 Refeeding conveyance means 513 Refeeding side plate 521 Roller body 541 Opposing part 6 Plate making unit 61 Stencil paper roll 62 Thermal head 63 Platen roller 7 Ejecting unit 71 Housing 72 Pull-in roller 73 Base paper storage roll 10 Double-sided printing device P1 Paper (Both sides and Has not been printed)
P2 Paper with front side printing P3 Paper with back side printing after front side printing

Claims (14)

The paper on the paper feed tray is transported to the printing unit, is subjected to the first printing process by the printing unit, transported to the paper discharge tray, transported from the paper discharge tray to the paper refeed tray, and from the paper refeed tray. In a double-sided printing apparatus that is turned over and transported to the printing unit, second printed by the printing unit and transported to the paper discharge tray,
The paper discharge tray includes an end plate that receives the leading edge of the conveyed paper,
The end plate is provided so as to be movable toward the refeed tray with the received paper.
The re-feed tray includes re-feed transport means for transporting the paper placed on the re-feed tray to the downstream end in the paper transport direction of the re-feed tray.
The double-sided printing apparatus is characterized in that the paper on the paper discharge tray is delivered to the paper re-feeding conveying means by moving the end plate toward the paper re-feeding tray.
The double-sided printing apparatus according to claim 1, wherein a plurality of rollers are provided on the upper surface of the paper discharge tray to facilitate paper conveyance.
3. The duplex printing apparatus according to claim 1, wherein a conveyance speed at which the refeed conveyance unit conveys the sheet is set to be higher than a moving speed at which the end plate moves toward the refeed tray.
The double-sided printing apparatus according to any one of claims 1 to 3, wherein the re-feed conveyance unit is configured to be inclined downward in a sheet conveyance direction.
The double-sided printing apparatus according to claim 4, wherein an inclination angle of the re-feed conveyance unit is within 10 degrees with respect to a horizontal plane.
The refeed tray includes a pair of refeed side plates that regulate both side edges of the paper on the refeed tray;
6. The double-sided printing apparatus according to claim 1, wherein the re-feeding side plate is configured such that a position in the paper width direction is adjusted according to a length of the paper in the paper width direction.
The re-feeding side plate is movable between a regulation position that regulates both side edges of the paper and a standby position that is not regulated,
The re-feeding side plate is positioned at the standby position when the paper is transported from the paper discharge tray to the re-feeding tray, and after the paper is transported to the re-feeding tray, The double-sided printing apparatus according to claim 6, wherein the double-sided printing apparatus is located at a position.
The paper discharge tray includes a U-shaped forming member that lifts both side edges of the paper on the paper discharge tray and supports the paper in a U shape.
The U-shaped forming member protrudes from the upper surface of the paper discharge tray and can move up and down between a protruding position for lifting the paper and a retracted position that does not protrude from the upper surface of the paper discharge tray. The double-sided printing apparatus as described in any one of -7.
The U-shaped member is composed of a pair of fin members arranged symmetrically with respect to the intermediate line of the paper width,
A plurality of the pair of fin members are provided at intervals in the paper conveyance direction,
The fin member extends in the paper width direction, one end portion in the paper width direction is supported by the paper discharge tray, and the other end portion in the paper width direction is rotatable about the one end portion. The double-sided printing apparatus according to claim 8.
10. The double-sided printing apparatus according to claim 8, wherein the U-shaped forming member is configured such that a protruding amount from the upper surface of the paper discharge tray varies according to the type of paper on the paper discharge tray.
The paper discharge tray includes a pair of paper discharge side plates that regulate both side edges of the paper on the paper discharge tray,
When the paper is conveyed from the printing unit to the paper discharge tray, the U-shaped forming member is located at the protruding position, and the distance between the paper discharge side plates of the paper discharge side plates is smaller than the paper width of the paper. Is located at the guide position,
When the paper is transported from the paper discharge tray to the refeed tray, the U-shaped forming member is located at the retracted position, and the paper discharge side plate is located at a restriction position that restricts both side edges of the paper. The double-sided printing apparatus according to claim 8, which is configured as described above.
The paper discharge tray includes a pair of paper discharge side plates that regulate both side edges of the paper on the paper discharge tray,
When the paper is conveyed from the printing unit to the paper discharge tray, the U-shaped forming member is located at the protruding position, and the distance between the paper discharge side plates of the paper discharge side plates is smaller than the paper width of the paper. Is located at the guide position,
When the paper is transported from the paper discharge tray to the refeed tray, the U-shaped forming member is located at the retracted position, and the paper discharge side plate is located on the side of the restriction position that restricts both side edges of the paper. The double-sided printing device according to any one of claims 8 to 10, wherein the duplex printing device is located outward.
The sheet is transported from the paper discharge tray to the refeed tray after a predetermined time has elapsed after the U-shaped member is changed from the protruding position to the retracted position. The double-sided printing apparatus according to 12.
  The double-sided printing apparatus according to claim 13, wherein the predetermined time can be arbitrarily changed.

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