JP5544203B2 - Feeding method and feeding mechanism of printing apparatus - Google Patents

Description

  The present invention relates to a paper feeding method and a paper feeding mechanism of a printing apparatus that feeds a printing paper forward by rotating a pickup roller placed on the uppermost surface of the stacked printing paper.

  2. Description of the Related Art Conventionally, there is known a paper feeding mechanism of a printing apparatus in which a pickup roller is placed on the uppermost surface of a stacked printing paper, and at the time of paper feeding, the printing paper is fed forward by rotating at least the pickup roller by a rotation driving mechanism. For example, Patent Document 1 discloses a pickup roller that feeds a sheet while contacting and separating the uppermost sheet stored in a sheet feed tray, a sheet feed roller that feeds the sheet to be fed, and a sheet feed roller. A sheet feeding unit composed of a retard roller that is elastically biased in the pressing direction, a transport roller device disposed downstream of the sheet feeding unit, and a sheet at a predetermined height in the sheet feeding tray In order to raise, a paper feeding device of an image forming apparatus provided with a paper raising means is disclosed.

JP 7-215497 A

  However, the conventional paper feeding device (paper feeding mechanism) described above has the following problems.

  First, for example, when printing a cover used for case binding, various materials such as cardboard and coated paper are used as the cover material. Therefore, in the paper feed mechanism (paper feed method) that feeds by rotating the pickup roller, However, there are cases in which it is not always possible to cope with it sufficiently. Specifically, as shown in FIG. 12A, when the stacked printing sheets Pt are thick and have cut cuts Ptc ..., burrs or the like are generated at the cuts Ptc ... Even if it is set in the paper feed cassette (paper feed tray) as it is and the pickup roller is placed and rotated, the thick paper Pt is not easily separated from each other, and misfeed (feeding failure) and double feed are likely to occur. Therefore, in practice, pre-processing such as performing a manual work (separation work) in advance is necessary.

  Second, since the pickup roller is placed on the uppermost surface of the stacked printing paper, it is supported by one end of a roller support member, and the other end of the roller support member is supported by a paper feed roller (feed roller). The shaft is supported so as to be able to rotate and displace. For this reason, when the pickup roller is rotated by the start of paper feeding, a downward moment is generated by the pickup roller, and an unnecessary load by the pickup roller is applied to the uppermost surface of the printing paper. In particular, the load W generated at this time becomes unstable as shown in FIG. 12B, and an excessive load Wp is also added. Eventually, it is difficult to secure stable paper feeding, which becomes a factor of further double feeding, and is insufficient from the viewpoint of protecting the paper surface, which may adversely affect printing quality.

  An object of the present invention is to provide a paper feeding method and a paper feeding mechanism of a printing apparatus that solve the problems existing in the background art.

  In order to solve the above-described problem, the paper feeding method of the printing apparatus M according to the present invention places the pickup roller 3 on the top surface Ptu of the printing paper Pt... A feed method in which a feed roller 9 and a retard roller 10 arranged in the upper and lower directions are provided in the front, and at the time of paper feeding, at least the pickup roller 3 is rotated by the rotation drive mechanism 4 to feed the printing paper Pt forward. The roller 3 is disposed at a home position Xh that is located a predetermined distance behind the front end position of the printing paper Pt. At the time of paper feeding, the pickup roller 3 is locked in a non-rotating state and placed on the surface of the printing paper Pt. On the other hand, while moving forward by a predetermined stroke Ls in the parallel direction, during this movement or after the end of the movement The lock is released and the pickup roller 3 is rotated to feed paper. After the printing paper Pt is sent out by the pickup roller 3, a constant load torque is applied to the rotation of the pickup roller 3 by the torque limiter 5. The pickup roller 3 is returned to the home position Xh by moving backward in the direction parallel to the paper surface of the printing paper Pt.

  In this case, according to a preferred aspect of the invention, the printing paper Pt can include printing paper other than plain paper and plain paper including at least thick paper.

  On the other hand, the paper feeding mechanism 1 of the printing apparatus M according to the present invention is placed on the uppermost surface Ptu of the printing paper Pt... Set on the tray 2 and is rotated by the rotation driving mechanism 4 in order to solve the above-described problem. And a feed mechanism including at least a pickup roller 3 for feeding the printing paper Pt forward, and a feed roller 9 and a retard roller 10 disposed in front of the pickup roller 3, and a front end of the printing paper Pt. A pickup roller 3 disposed at a home position Xh positioned a predetermined distance behind the position, a roller moving mechanism 6 for moving the pickup roller 3 forward or backward in the direction parallel to the paper surface of the printing paper Pt, and a pickup roller Lock mechanism 7 capable of locking or unlocking 3 in a non-rotating state, and at least rotationally driven A controller 8 capable of controlling the structure 4, the roller moving mechanism 6 and the lock mechanism 7, and a torque limiter 5 which can apply or release a constant load torque to the pickup roller 3 and can be controlled by the controller 8. It is characterized by providing.

  In this case, according to a preferred aspect of the invention, the controller 8 can be provided with a non-normal paper feeding mode for feeding printing paper Pt other than plain paper including at least thick paper. Further, the controller 8 can be provided with a normal paper feeding mode for feeding plain paper, and the paper feeding mode selection unit 11 can select the normal paper feeding mode or the non-normal paper feeding mode. Further, the non-normal paper feeding mode can be provided with at least a thick paper feeding mode for feeding thick paper and a recycled paper feeding mode for feeding recycled paper. In the thick paper feed mode, during feeding, the pickup roller 3 is moved forward by a predetermined stroke Ls in a direction parallel to the paper surface of the printing paper Pt while being locked in a non-rotating state. After the movement, a control function for releasing the lock and rotating the pickup roller 3 can be provided, and the recycled paper feed mode includes a feed start time and a next feed time in any paper feed mode. Can be provided with a control function for changing the position of the peripheral surface of the pickup roller 3 in contact with the uppermost surface Ptu of the printing paper Pt.

  According to the sheet feeding method and the sheet feeding mechanism 1 of the printing apparatus M according to the present invention, the following remarkable effects can be obtained.

  (1) The pickup roller 3 is disposed at a home position Xh that is located a predetermined distance behind the front end position of the printing paper Pt, and the pickup roller 3 is locked in a non-rotating state during feeding, and the printing paper Since the sheet is moved forward by a predetermined stroke Ls in the direction parallel to the paper surface of Pt, the forward movement gives a forward squeeze to the stacked printing paper Pt... Between each printing paper Pt. Effective separation (separation) can be performed. Thereby, misfeeds (feeding failure) and double feeds of the printing papers Pt can be avoided, and in particular, preprocessing such as performing a manual work (separation work) in advance can be eliminated.

  (2) At the time of paper feeding, the pickup roller 2 is locked in a non-rotating state and moved forward by a predetermined stroke Ls in the direction parallel to the paper surface of the printing paper Pt, and during or after the movement, Since the pickup roller 3 is rotated by releasing the lock, it is possible to avoid a problem that an unnecessary load is applied by the pickup roller 3 to the uppermost surface Ptu of the printing paper Pt. As a result, it is possible to secure a stable paper feeding operation, eliminate the double feed factor, protect the paper surface, and eliminate adverse effects on the print quality.

  (3) After the printing paper Pt is sent out by the pickup roller 3, a constant load torque is applied to the rotation of the pickup roller 3 by the torque limiter 5, and the printing paper Pt moves backward in the direction parallel to the paper surface of the printing paper Pt. As a result, the pickup roller 3 is returned to the home position Xh, so that the rearward movement gives a squeeze to the stacked printing paper Pt... Separation (separation) can be performed, and misfeeding (feeding failure) and double feeding of the printing paper Pt at the time of the next paper feeding can be further avoided.

  (4) Since the feed roller 9 and the retard roller 10 disposed above and below are provided in front of the pickup roller 3, the functions of the feed roller 9 and the retard roller 10 in a general paper feeding mechanism can be used as they are, and the printing paper Pt It is possible to more effectively and surely prevent double feeding.

  (5) According to a preferred embodiment, if the controller 8 is provided with a non-normal paper feeding mode for feeding printing paper Pt other than plain paper including at least thick paper, thick paper other than plain paper, coated paper, recycled paper, It is possible to smoothly and accurately feed various printing papers Pt... Such as racing paper and plastic film.

  (6) According to a preferred embodiment, if the controller 8 is provided with a normal paper feed mode for feeding plain paper, and the paper feed mode selection unit 11 can select the normal paper feed mode or the non-normal paper feed mode. Further, since it can be used (shared) for plain paper and various printing papers other than plain paper, convenience and versatility can be improved.

  (7) According to a preferred embodiment, a recycled paper feed mode is provided in the non-normal paper feed mode, and the recycled paper feed mode is used to start feeding at the time of arbitrary feeding and feeding at the next feeding. When a control function is provided to change the peripheral surface position of the pickup roller 3 that contacts the uppermost surface Ptu of the printing paper Pt at the start, a large amount of paper dust adheres like recycled paper and paper is fed. Even when paper dust adheres to the pickup roller 3, the peripheral surface other than the adhered portion can be brought into contact with the uppermost surface Ptu of the printing paper Pt ... Problems such as slippage of the pickup roller 3 due to paper dust can be avoided, and even recycled paper with much paper dust can be reliably fed.

FIG. 2 is a partial cross-sectional side view showing a main part of a paper feed mechanism of a printing apparatus according to a preferred embodiment of the present invention; Functional explanatory diagram of the paper feed mechanism, Partial cross-sectional plan view of the paper feed mechanism, An external perspective view showing the entire paper feeding unit of a printing apparatus provided with the paper feeding mechanism, Block system diagram showing the control system of the paper feed mechanism, A flow chart for explaining the operation of the thick paper feed mode of the paper feed mechanism; Operation explanatory diagram of the thick paper feed mode of the paper feed mechanism, Timing chart showing the operation of the thick paper feed mode of the paper feed mechanism, Operation explanatory diagram of plain paper feed mode of the paper feed mechanism, Timing chart showing operation of plain paper feed mode of the paper feed mechanism, Operation explanatory diagram of recycled paper feed mode of the paper feed mechanism, Timing chart showing the operation of the recycled paper feed mode, An illustration of problems in the background art,

  Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.

  First, the configuration of the paper feed mechanism 1 of the printing apparatus M according to the present embodiment will be described with reference to FIGS.

  FIG. 4 shows an appearance of a paper feeding unit U having a manual feed type paper feeding mechanism 1 provided in the printing apparatus M. The paper feed unit U includes a manual paper feed tray (tray) 2, and this paper feed tray 2 protrudes outward from an opening Mo provided in the exterior portion of the printing apparatus M. Can set a large number of stacked printing sheets Pt. A paper feed mechanism 1 according to the present embodiment is disposed at the front of the paper feed tray 2. The paper feed mechanism 1 includes a frame-shaped base frame 20 that is integrally provided at the front portion of the paper feed tray 2. The main part of the paper feed mechanism 1 is disposed on the upper surface 20 u of the base frame 20, and the base frame 20 is configured such that a part of the front portion can be loaded inside the printing paper Pt.

  As shown in FIG. 1, the paper feed mechanism 1 includes, as rollers, a pickup roller 3 placed on the uppermost surface Ptu of the printing paper Pt... In addition, a feed roller 9 and a retard roller 10 arranged in the vertical direction and a pair of conveying rollers 21 and 22 arranged in the vertical direction are provided in front of the feed roller 9 and the retard roller 10. As described above, in the paper feed mechanism 1 according to the present embodiment, the feed roller 9 and the retard roller 10 arranged vertically are provided in front of the pickup roller 3 as a basic configuration. The functions of the feed roller 9 and the retard roller 10 can be used as they are, and the multi-feed of the printing paper Pt can be more effectively and reliably prevented.

  On the other hand, as shown in FIG. 4, a substantially U-shape is formed in the center in the left-right direction on the upper surface of the base frame 20, and a subframe 23 having an intermediate portion as an upper surface portion is fixed. A main shaft 24 penetrating between the left and right side portions of the sub frame 23 is provided. The main shaft 24 is rotatably supported by a bearing (not shown) attached to the left and right side portions. Therefore, the position is fixed. A first link member 25 whose one end side is rotatably supported by the main shaft 24 is disposed inside the subframe 23, and the other end side (front end side) of the first link member 25 has left and right sides. A second link member 28 whose one end side is rotatably supported by the pair of shaft portions 26 and 27 is disposed, and the other end side (tip side) of the second link member 28 is rotatable by a roller shaft 29. A pickup roller 3 to be supported is arranged. At this time, the pickup roller 3 is considered to be positioned a predetermined distance behind the front end position of the printing paper Pt, and this rear position is set as the home position Xh.

  One end side of the main shaft 24 is coupled to the output shaft of the feed clutch 31 using an electromagnetic clutch, and the input shaft of the feed clutch 31 is fed to the side surface 20p of the base frame 20 via the rotation transmission portion 32. The motor (servo motor) 33 is coupled to the rotating shaft. 1 is schematically (in principle) drawn by the transmission belt system as the rotation transmission unit 32, but the transmission system such as a direct system or a gear system is not limited. Further, the first transmission gear 34 is fixed to the feed clutch 31 side of the main shaft 24, the second transmission gear 35 is fixed to the shaft portion 26, and the third transmission gear 36 is fixed to one end side of the roller shaft 29. The gear 34 and the second transmission gear 35, and the second transmission gear 35 and the third transmission gear 36 are meshed so as to be able to transmit rotation. Thereby, the rotation drive mechanism that can transmit the rotation of the feed motor 33 to the pickup roller 3 via the rotation transmission unit 32, the feed clutch 31, the first transmission gear 34, the second transmission gear 35, and the third transmission gear 36. 4 is configured. In this case, if the feed clutch 31 is turned on, the rotation can be transmitted, and if the feed clutch 31 is turned off, the rotation can be released.

  On the other hand, a fourth transmission gear 37 is fixed to the other end side of the main shaft 24, and a load clutch 38 using an electromagnetic clutch is disposed in the vicinity of the fourth transmission gear 37. Then, the fifth transmission gear 39 is fixed to the input shaft of the load clutch 38, the fifth transmission gear 39 and the fourth transmission gear 37 are meshed so as to be capable of rotational transmission, and a constant load is applied to the output shaft of the load clutch 38. A torque limiter 5 capable of applying torque is coupled. Thus, when the load clutch 38 is turned on, a constant load torque is applied from the torque limiter 5 to the pickup roller 3, and when the load clutch 38 is turned off, the application of the load torque can be released. it can.

  Further, one end side of the transmission link member 41 is rotatably connected to the other end side of the roller shaft 29, and the other end side of the transmission link member 41 is forward in the direction parallel to the surface of the printing paper Pt. While being extended, the other end of the transmission link member 41 is integrally provided with a driven portion 41s. The upper and lower positions of the transmission link member 41 are restricted by the guide portion 42. The driven portion 41s has a pair of opposing vertical surfaces 41f and 41r, and the disk cam 43 is engaged between the vertical surfaces 41f and 41r. The disk cam 43 is formed in a circular shape, and a support shaft 44 is fixed to an eccentric position spaced from the center position, and an eighth transmission gear 49 is fixed to the support shaft 44. In addition, a slide motor (servo motor) 45 is disposed in the vicinity of the disk cam 43, and the sixth transmission gear 46 is fixed to the rotating shaft of the slide motor 45. Further, a seventh transmission gear 48 is disposed between the sixth transmission gear 46 and the eighth transmission gear 49 so as to be rotatably supported by a support shaft whose position is fixed. The transmission gear 46, the seventh transmission gear 48, and the eighth transmission gear 49 are meshed so as to be able to transmit rotation. Thereby, the rotation of the slide motor 45 is transmitted to the disc cam 43 via the sixth transmission gear 46, the seventh transmission gear 48, and the eighth transmission gear 49, and the driven portion 41s, that is, the driven portion 41s, that is, depending on the rotation angle of the disc cam 43. The transmission link member 41 is displaced in the front-rear direction. As a result, as shown in FIG. 2, a roller moving mechanism 6 is configured in which the pickup roller 3 moves forward or backward in the direction parallel to the paper surface of the printing paper Pt.

  In addition, a branch transmission unit 51 is interposed in the rotation transmission unit 32 between the feed motor 33 and the feed clutch 31, and the rotation of the feed motor 33 is transmitted to the rotation driving mechanism that rotates the feed roller 9 and the retard roller 10. . Further, the feed clutch 31 and the feed motor 33 constitute the lock mechanism 7, and when the feed clutch 31 is turned on, the pickup roller 3 is locked in the non-rotation state by the detent torque of the feed motor 33, and the feed clutch 31 is turned off. Then, the lock can be released.

  On the other hand, as shown in FIG. 5, the controller 8 that controls the rotation drive mechanism 4, the roller moving mechanism 6, and the lock mechanism 7 described above is provided. The controller 8 has a function of controlling the entire printing apparatus M, and has a controller main body 61 having a computer function including a CPU, a memory, a power supply unit, and the like. The above-described feed motor 33 is connected to the controller main body 61 via the servo circuit 62, the above-described slide motor 45 is connected via the servo circuit 63, and the above-described feed clutch 31 and load clutch 38 are further connected. To do. On the other hand, a first paper sensor 64 that detects the front and rear ends of the print paper Pt to be sent out is disposed in front of the feed roller 9 in the transport direction, and the transported print is transported in front of the transport roller 21 in the transport direction. A second paper sensor 65 for detecting the front edge and the rear edge of the paper Pt is provided, and the first paper sensor 64 and the second paper sensor 65 are connected to the controller main body 61.

  The controller main body 61 is connected with a display 66 for performing various displays and an operation unit (input unit) 67 for performing input operations such as various settings and selections. In particular, the operation unit 67 is accompanied by a paper feed mode selection unit 11 related to the paper feed method according to the present embodiment. The paper feed method according to the present embodiment is applied to a print paper other than plain paper including at least thick paper as a print paper Pt, and includes a non-normal paper feed mode for feeding the print paper Pt. This non-normal paper feed mode includes a thick paper feed mode for feeding thick paper, which will be described later, and a recycled paper feed mode for feeding recycled paper, as well as a normal paper feed mode for feeding plain paper. The paper feed mode selection unit 11 can select a normal paper feed mode, a thick paper feed mode, and a recycled paper feed mode. As described above, the normal paper feed mode for feeding plain paper is provided, and the normal paper feed mode or the non-normal paper feed mode can be selected by the paper feed mode selection unit 11. There is an advantage that it can be used (shared) for printing paper, and convenience and versatility can be improved.

  Further, a program memory 68, a data memory 69, and a database 70 are attached to the controller main body 61. In particular, the program memory 68 includes a sequence program for executing the above-described normal paper feed mode and non-normal paper feed mode (thick paper feed mode, recycled paper feed mode) including the paper feed method according to the present embodiment. Control program). In FIG. 5, reference numeral 52 denotes a paper stopper mechanism attached to the rear end of the paper feed tray 2. The sheet stopper mechanism 52 includes an elastic stopper wall 55 supported by an elastic hinge portion 54 urged by a spring or the like at the upper end of the fixed wall 53, and when the upper end printing paper Pt is displaced rearward. The displacement can be allowed.

  Next, the operation of the paper feed mechanism 1 including the paper feed method according to the present embodiment, in particular, the operation in the thick paper feed mode will be described with reference to the flowchart shown in FIG. 6, FIG. 7 and FIG.

  In the thick paper feeding mode, during feeding, the pickup roller 3 is locked in a non-rotating state and moved forward by a predetermined stroke Ls in the direction parallel to the paper surface of the printing paper Pt. After that, a basic control function for releasing the lock and rotating the pickup roller 3 is provided.

  A specific operation will be described below. First, the power switch of the printing apparatus M is turned on (step S1). Then, the paper feed mode selection unit 11 attached to the operation unit 67 selects a paper feed mode, and further sets necessary printing conditions such as the number of prints and print density (step S2). The printing apparatus M according to the present embodiment includes a normal paper feed mode suitable for plain paper printing, a thick paper feed mode suitable for thick paper feed, and a recycled paper feed mode suitable for recycled paper feed. Then, the paper feed mode selection unit 11 selects the thick paper feed mode. At this time, as shown in FIG. 5, the pickup roller 3 is placed on the uppermost surface Ptu of the printing paper (thick paper) Pt, and is positioned at the home position Xh.

  When the necessary printing conditions have been set, the start key is turned on (steps S3 and S4). Thereby, the pickup roller 3 moves forward from the home position Xh (step S5). In FIG. 8, the time point t1 indicates the forward start time. In this case, the feed clutch 31 is turned on at time t1, and the slide motor 45 is turned on in the forward rotation side. When the feed clutch 31 is turned on, the pickup roller 3 is connected to the feed motor 33, but the feed motor 33 is turned off. Thereby, the pickup roller 3 is locked in a non-rotating state by the detent torque of the feed motor 33. Further, when the slide motor 45 is turned ON on the positive rotation side, the rotation of the slide motor 45 is transmitted to the disk cam 43, whereby the transmission link member 41 moves forward and the pickup roller 3 is locked in rotation. Move forward (arrow Ff direction). At this time, since the pickup roller 3 moves forward in the direction parallel to the paper surface of the printing paper Pt, the printing paper Pt... Does not receive a vertical load from the pickup roller 3 due to a moment generated during rotation. Further, since the rotation of the pickup roller 3 is locked, the uppermost printing paper Pt is pulled forward by the friction between the peripheral surface of the pickup roller 3 and the uppermost surface Ptu of the printing paper Pt. As a result, a forward (separation) process is performed on the stacked printing sheets Pt... And the uppermost printing sheet Pt is sent forward (step S6).

  According to such a thick paper feed mode (the paper feed method according to the present embodiment), the pickup roller 3 is disposed at the home position Xh that is located a predetermined distance behind the front end position of the print paper Pt, and is also fed. Since the pickup roller 3 is locked in a non-rotating state and is moved forward by a predetermined stroke Ls in parallel with the paper surface of the printing paper Pt during paper feeding, the printing paper loaded by the forward movement is loaded. It is possible to give a forward squeeze to Pt... And perform effective separation (separation) between the printing papers Pt. Thereby, misfeeds (feeding failure) and double feeds of the printing papers Pt can be avoided, and in particular, preprocessing such as performing a manual work (separation work) in advance can be eliminated.

  Then, when reaching a time point t2 shown in FIG. 8 where a preset movement time Tm has elapsed from the time point t1, the feed motor 33 is turned on, and as shown in FIG. 7B, the pickup roller 3 and the feed roller 9, Further, the transport rollers 21 and 22 are rotated in the direction of the arrow Rf, so that the transport is possible (steps S7 and S8). The retard roller 10 rotates in the reverse direction of the arrow Rr to prevent double feeding. As a result, the pickup roller 3 starts rotating in the middle of the forward movement, and the printing paper Pt is fed forward by the rotation of the pickup roller 3 and the forward movement. Therefore, almost no moment is generated when the pickup roller 3 rotates. Thereafter, the pickup roller 3 moves from the home position Xh by a predetermined stroke Ls. When the pickup roller 3 reaches the most advanced position Xf, the slide motor 45 is turned off (time t3 in FIG. 8).

  In this way, at the time of paper feeding, the pickup roller 2 is locked in a non-rotating state and moved forward by a predetermined stroke Ls in the direction parallel to the paper surface of the printing paper Pt, and during this movement or after the movement ends, Since the pickup roller 3 is rotated by releasing the lock, it is possible to avoid a problem that an unnecessary load is applied to the uppermost surface Ptu of the printing paper Pt. As a result, it is possible to secure a stable paper feeding operation, eliminate the double feed factor, protect the paper surface, and eliminate adverse effects on the print quality.

  On the other hand, when the printing paper Pt is sent out, the leading edge of the printing paper Pt is detected by the first paper sensor 64 at time t4, and thereafter, the leading edge of the printing paper Pt is detected by the second paper sensor 65 at time t5. For this reason, if the leading edge of the printing paper Pt is detected by the second paper sensor 65, the feed clutch 31 is turned off at time t6 when a preset delay time Tr has elapsed. As a result, the rotation of the pickup roller 3 is stopped (steps S9 and S10).

  Thereafter, when the trailing edge of the printing paper Pt is detected by the first paper sensor 64 at time t7, the load clutch 38 is turned on and the slide motor 45 is turned on in the reverse rotation side. Thereby, the pickup roller 3 moves backward (step S11). At this time, as shown in FIG. 7C, the pickup roller 3 moves rearward (in the direction of the arrow Fr) from the most advanced position Xf, and the load clutch 38 is ON, so that the torque limiter with respect to the pickup roller 3 is turned on. 5 is connected, and a constant load torque is applied in the direction of the arrow Rc with respect to the rotation of the pickup roller 3. Therefore, the uppermost printing paper Pt is pulled rearward due to friction between the peripheral surface of the pickup roller 3 and the uppermost surface Ptu of the printing paper Pt, and is rolled backward (separated) with respect to the stacked printing paper Pt. Processing is performed (step S12). At this time, as shown in FIG. 7C, the printing paper Pt... On the upper end side is displaced backward, so that this displacement is allowed by elastic displacement of the elastic stopper wall 55.

  In this way, after the printing paper Pt is sent out by the pickup roller 3, a constant load torque is applied to the rotation of the pickup roller 3 by the torque limiter 5 and the rearward direction is parallel to the paper surface of the printing paper Pt. If the pickup roller 3 is returned to the home position Xh by being moved, the rearward movement gives a squeeze to the rear side of the stacked printing paper Pt, so that the spare between the printing papers Pt. Therefore, it is possible to further avoid misfeeding (feeding failure) and double feeding of the printing paper Pt...

  If the trailing edge of the printing paper Pt is detected by the second paper sensor 65 at time t8, the feed motor 33 is stopped at time t9 when a preset delay time Tt has elapsed. Further, after this, when the pickup roller 3 reaches the home position Xh at time t10, the slide motor 45 is stopped and the load clutch 38 is turned off (steps S13 and S14). Thereafter, when the printing process is continued, the same paper feeding process is repeated (steps S15, S5...).

  Next, other paper feed modes other than the thick paper feed mode will be described with reference to FIGS.

  9 and 10 show operations when the normal paper feed mode is selected. The normal paper feed mode is suitable for feeding plain paper, which is a conventional general paper feed method. Therefore, the printing paper (plain paper) Pt is fed out only by the rotation of the pickup roller 3, and the pickup roller 3 is not moved forward and backward.

  With the start of paper feeding, the feed clutch 31 is turned on at time t1 shown in FIG. 10, and the feed motor 33 is turned on at time t2. This state is shown in FIG. As a result, the pickup roller 3 rotates and feeds the printing paper Pt, and the feed roller 9 and the transport rollers 21 and 22 rotate to be in a transportable state. The retard roller 10 rotates in the reverse direction to prevent double feeding. If the first paper sensor 64 detects the trailing edge of the printing paper Pt at time t5, the feed clutch 31 is turned OFF, and if the second paper sensor 65 detects the trailing edge of the printing paper Pt at time t6. Then, the rotation of the feed motor 33 is stopped. In the normal sheet feeding mode, such a general sheet feeding operation is repeated.

  On the other hand, FIGS. 11 and 12 show the operation when the recycled paper feed mode is selected. In the recycled paper feed mode, the peripheral surface position of the pickup roller 3 that is in contact with the uppermost surface Ptu of the printing paper Pt... It has basic control functions that make it different. In the case of recycled paper, a large amount of paper dust adheres, and it is often the case that paper dust adheres to the pickup roller 3 when feeding paper. Therefore, the recycled paper feed mode is suitable for feeding such recycled paper.

  If both the feed clutch 31 and the feed motor 33 are turned on at the time t1 shown in FIG. 12 due to the start of paper feeding, the pickup roller 3 rotates at the home position Xh, and the printing paper (recycled paper) Pt is fed. Is called. After that, if the trailing edge of the printing paper Pt is detected by the first paper sensor 64 at time t4, the feed clutch 31 is turned off to stop the rotation of the pickup roller 3, and printing is performed by the second paper sensor 65 at time t5. When the trailing edge of the paper Pt is detected, the rotation of the feed motor 33 is stopped. As a result, the same paper feeding operation as that of the plain paper (normal paper feeding mode) described above is performed. FIG. 11 shows the state of the pickup roller 3 indicated by a virtual line at this time. As shown in the figure, when the recycled paper to which the paper dust adheres is fed, the paper dust Dp adheres to the peripheral surface of the pickup roller 3 facing the uppermost surface Ptu of the printing paper Pt.

  For this reason, in the recycled paper feed mode, the trailing edge of the printing paper Pt is detected by the first paper sensor 64 at time t4 shown in FIG. 12, that is, the printing paper Pt has been detected to have passed the pickup roller 3. Then, the slide motor 45 is turned on in the positive rotation side for a preset operating time Ts. In this case, the load clutch 38 remains OFF. As a result, the pickup roller 3 moves from the home position Xh to the change position Xe, but the pickup roller 3 idles (passive rotation) as it moves. As a result, the paper dust Dp adhering to the peripheral surface of the pickup roller 3 also moves, and in the illustrated example, rotates about 90 °.

  Therefore, at the time of the next paper feeding, both the feed clutch 31 and the feed motor 33 are turned on at time t7, and the same paper feeding process is performed. At this time, the pickup roller 3 abutting on the uppermost surface Ptu of the printing paper Pt. The circumferential surface position of this is different from that at the time of the previous sheet feeding. When the time point t10 corresponding to the time point t4 described above is reached, the slide motor 45 is turned on in the reverse rotation side for a preset operation time Ts, and the pickup roller 3 is returned from the change position Xe to the home position Xh. By repeating the above sheet feeding operation every time, the peripheral surface position of the pickup roller 3 to which the paper dust Dp adheres can be made different from at least the immediately preceding sheet feeding. In particular, if the operation time Ts is selected and the length of the operation time Ts is set to be different for each paper feed, the adhesion position of the paper dust Dp can be randomly distributed for each paper feed.

  Therefore, if such a recycled paper feed mode is used, a pickup roller that abuts on the uppermost surface Ptu of the print paper Pt at the start of feed at an arbitrary feed and at the start of the next feed. 3 can be made different, so that the peripheral surface other than the adhering part can be brought into contact with the uppermost surface Ptu of the printing paper Pt at the time of the next paper feeding, so that it is picked up by the paper dust Dp. Problems such as the roller 3 slipping can be avoided, and even recycled paper with a large amount of paper dust Dp can be reliably fed.

  The preferred embodiment has been described in detail above. However, the present invention is not limited to such an embodiment, and the present invention is not limited to the detailed configuration, shape, material, quantity, numerical value, method (method), and the like. Any change, addition, or deletion can be made without departing from the scope of the above.

  For example, in the embodiment, the manual feed type paper feed tray 2 is illustrated, but a cassette type may be used. In addition, the detailed configuration of the sheet feeding structure 1 according to the embodiment is an exemplification, and can be replaced by another component or configuration having the same function. Therefore, for example, a linear motor may be used instead of the illustrated feed motor 45, and the roller shaft 29 or the like may be directly moved by the linear motor. On the other hand, as the non-normal paper feeding mode, the cardboard paper feeding mode and the recycled paper paper feeding mode are illustrated, but they are suitable for other printing papers such as coated paper, tracing paper, and plastic film, respectively. A mode can be set, and by providing such a non-normal sheet feeding mode, various printing sheets Pt... Can be fed smoothly and accurately. Note that the thick paper feed mode (the same applies to the recycled paper feed mode) does not mean the purpose of using thick paper but the mode suitable for thick paper. Accordingly, various kinds of printing papers that need to be spun as in the case of thick paper can be fed in the thick paper feed mode.

  The sheet feeding method and the sheet feeding mechanism according to the present invention can be used for various apparatuses including a printing function (printing apparatus) such as a ticket issuing machine and a financial terminal, as well as various printing apparatuses such as a printing machine and a copying machine. it can.

  DESCRIPTION OF SYMBOLS 1: Paper feed mechanism, 2: Tray, 3: Pickup roller, 4: Rotation drive mechanism, 5: Torque limiter, 6: Roller moving mechanism, 7: Lock mechanism, 8: Controller, 9: Feed roller, 10: Retard roller , 11: Paper feed mode selection unit, M: Printing device, Pt...: Printing paper, Ptu: Top surface, Xh: Home position, Ls: Predetermined stroke

Claims (8)

  A pickup roller is placed on the uppermost surface of the printing paper set in the tray, and a feed roller and a retard roller arranged vertically are provided in front of the pickup roller, and at least the pickup roller is driven to rotate during paper feeding. In the paper feeding method of the printing apparatus that feeds the printing paper forward by rotating the printing paper, the pickup roller is disposed at a home position that is located a predetermined distance behind the front end position of the printing paper, and at the time of paper feeding The pickup roller is locked in a non-rotating state and moved forward by a predetermined stroke in a direction parallel to the paper surface of the printing paper, and the lock is released during or after the movement. Rotate the roller to feed the paper After being fed out by the pickup roller, a constant load torque is applied to the rotation of the pickup roller by a torque limiter, and the pickup roller is moved backward in the direction parallel to the paper surface of the printing paper. A paper feeding method for a printing apparatus, characterized by returning to a home position.   The paper feeding method for a printing apparatus according to claim 1, wherein the printing paper includes printing paper other than plain paper and plain paper including at least thick paper.   At least a pickup roller that is placed on the uppermost surface of the printing paper set in the tray and that feeds the printing paper forward by rotating by a rotation driving mechanism is provided, and a feed roller disposed above and below the pickup roller. And a pick-up roller disposed at a home position positioned a predetermined distance behind the front end position of the printing paper, and the pick-up roller with respect to the paper surface of the printing paper. A roller moving mechanism that moves forward or backward in the parallel direction, a lock mechanism that can lock or unlock the pickup roller in a non-rotating state, and at least the rotation drive mechanism, the roller moving mechanism, and the lock mechanism can be controlled. Controller and the pickup low Constant load torque can be imparted or a possible grant release the sheet feeding mechanism of the printing apparatus, characterized in that it comprises a controllable torque limiter by the controller with respect to.   The paper feeding mechanism of the printing apparatus according to claim 3, wherein the controller includes a non-normal paper feeding mode for feeding printing paper other than plain paper including at least thick paper.   5. The controller according to claim 4, further comprising a normal paper feed mode for feeding plain paper and a paper feed mode selection unit capable of selecting the normal paper feed mode or the non-normal paper feed mode. The paper feeding mechanism of the printing apparatus described.   6. The printing apparatus according to claim 4, wherein the non-normal paper feed mode includes at least a thick paper feed mode for feeding thick paper and a recycled paper feed mode for feeding recycled paper. Paper feeding mechanism.   In the thick paper feeding mode, during feeding, the pickup roller is moved forward by a predetermined stroke in a parallel direction with respect to the paper surface of the printing paper while being locked in a non-rotating state. The paper feeding mechanism of the printing apparatus according to claim 6, further comprising a control function for releasing the lock and rotating the pickup roller.   In the recycled paper feeding mode, the peripheral surface position of the pickup roller that contacts the top surface of the printing paper is different at the time of starting feeding at an arbitrary feeding time and at the time of starting feeding at the next feeding time. The sheet feeding mechanism of the printing apparatus according to claim 6, further comprising a control function.

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