JP6583215B2 - Punching device and image forming apparatus - Google Patents

Description

  The present invention relates to a punching device for punching paper and an image forming apparatus including the punching device.

  A post-processing device (also referred to as a finisher) that performs post-processing of printed paper may be attached to the image forming apparatus. Some post-processing apparatuses perform a punching process. An example of an apparatus for performing a perforation process is described in Patent Document 1.

  Specifically, in Patent Document 1, a paper that has been carried in is punched, a motor for punching operation and a driving amount of the motor are detected, time measurement is performed for a predetermined time while the motor is driven, and punching operation is performed. There is described a paper punching device that measures a motor driving amount for a predetermined time during motor driving that is sometimes measured, and changes a motor stop operation start position according to the measured motor driving amount. In the technique described in Patent Document 1, pulses generated by the encoder are counted from a time immediately after the start of rotation of the drilling motor to a specified time. Then, the brake start position in the drilling operation counting the pulses is determined based on the count value. With this configuration, an attempt is made to provide a paper punching device that is low in cost and has good motor stop accuracy (see Patent Document 1: Claim 1, paragraphs [0011], [0048], and [0049]).

JP 2004-345834 A

  The punching device includes a punching blade for punching paper. The drilling blade protrudes. The protruding punching blade hits the paper. As a result, the paper is punched. The punching blade is returned to the retracted position (home position) so as not to disturb the next sheet. Here, a perforation process (punch process) may be performed using a motor. A piercing device using a motor may be provided with a rotating member. The rotating member is rotated by driving of the motor. The rotating member moves the drilling blade. The drilling blade reciprocates by the action of the rotating member. After drilling, the rotating member is rotated to return the drilling blade to the home position.

  A drilling motor may require a relatively large torque. Further, the punching operation may be performed in about several tens of milliseconds. That is, a motor that can cope with large load fluctuations is used. For example, a DC motor may be used. And the motor has inertia. The motor does not stop simultaneously with braking. Due to inertia, the drilling motor rotates to some extent after braking.

  The amount of rotation of the rotating member and motor from the start of braking to the stop of the motor (hereinafter referred to as “the amount of rotation after braking”) varies. One factor of variation is the motor temperature. The value of winding resistance varies depending on the motor temperature. In other words, the easiness of the motor current changes according to the temperature. Here, applying the brake means changing the motor current to zero. Therefore, the ease of braking (deceleration performance) may change depending on the motor temperature. In other words, the motor brake is temperature dependent. Due to variations in the amount of rotation after braking, the position of the drilling blade when the motor is stopped may deviate from the home position. Other factors of variation include motor component characteristics.

  In some cases, the rotating member (motor) stops before reaching the home position. In some cases, the rotating member stops after passing the home position. When the deviation is accumulated, the drilling blade may protrude before the drilling starts. In order to correct the deviation, in the conventional post-processing apparatus, adjustment processing is always performed after the motor is stopped. In order to set the drilling blade to the home position, the rotating member is rotated at a low speed in the adjustment process. In addition, adjustment processing takes time, so that the deviation | shift amount of a punching blade is large. Sufficient adjustment processing time is required for each drilling. Immediately after one drilling, it is not possible to proceed to the next drilling process. Therefore, there is a problem that the variation in the rotation amount after braking is a factor that decreases the processing speed (productivity) of the punching device.

  In the technique described in Patent Document 1, the amount of rotation from the start of rotation of the motor to a certain point is measured. However, the motor deceleration process is not measured. In other words, it does not take into account that the amount of rotation after braking varies depending on the environment. Therefore, in the technique described in Patent Document 1, the stop angle of the rotating member varies. Therefore, the technique described in Patent Document 1 cannot solve the above problem.

  The present invention reduces variations in the amount of rotation during the braking period. The rotating member is stopped at a constant or substantially constant angle to reduce variations in the stop position of the drilling blade.

  In order to solve the above-described problem, the drilling device according to claim 1 includes a shaft, a punch motor, a cam, a drilling unit, a speed sensor, an angle sensor, and a control unit. The punch motor rotates the shaft. The cam is attached to the shaft. The piercing portion includes a piercing blade. The perforated part is in contact with the cam. The perforating part reciprocates the perforating blade according to the rotation of the cam, and perforates the paper when protruding. The speed sensor detects the rotational speed of the shaft. The angle sensor detects that the rotation angle of the shaft has reached a predetermined reference angle. The controller recognizes the rotational speed of the shaft based on the output of the speed sensor. The control unit brakes and stops the punch motor. The control unit recognizes an absolute value of the deceleration of the shaft within a predetermined measurement period based on the output of the speed sensor. The measurement period is a period that is provided between the start of braking and the stop of the punch motor. A reference waiting time that is a reference for the waiting time from the start of rotation of the punch motor to the start of braking is determined in advance. When the absolute value is smaller than a predetermined deceleration reference value, the control unit starts braking before the reference waiting time elapses from the start of rotation of the punch motor in the next drilling. When the absolute value is larger than the deceleration reference value, the control unit starts braking after the reference waiting time has elapsed from the start of rotation of the punch motor in the next drilling.

  According to the present invention, it is possible to reduce variation in the rotation amount during the brake period. Therefore, the rotating member can be stopped at a constant or substantially constant angle. Further, the drilling blade can be stopped at the target position.

1 is a diagram illustrating an example of a multifunction machine according to an embodiment. It is a figure which shows an example of the multifunctional machine with which the post-processing apparatus concerning embodiment was attached. It is a figure which shows an example of the punching apparatus which concerns on embodiment. It is a perspective view which shows an example of the punching apparatus which concerns on embodiment. It is a perspective view which shows an example of the punching apparatus which concerns on embodiment. It is the figure which expanded the cam which concerns on embodiment. It is the figure which expanded the punch motor which concerns on embodiment. It is the figure which expanded the angle sensor and speed sensor which concern on embodiment. It is a figure which shows an example of punch motor control of the post-processing control part which concerns on embodiment. It is a flowchart which shows an example of the flow of the process at the time of the punching of the punching apparatus which concerns on embodiment. It is a figure which shows an example of the timing chart of the punching apparatus which concerns on embodiment. It is a figure which shows an example of the timing chart of the punching apparatus which concerns on embodiment.

  Hereinafter, the post-processing device 2 including the punching device 1, the punching device 1, and the image forming apparatus according to the present invention will be described with reference to FIGS. 1 to 12. The image forming apparatus will be described using the multifunction peripheral 100 as an example. However, each element such as configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example.

(Outline of image forming apparatus)
First, a multifunction peripheral 100 according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a multifunction peripheral 100 according to the embodiment.

  The multi-function device 100 includes a main control unit 3 and a storage unit 3a. The main control unit 3 controls the overall operation of the apparatus and controls each unit of the multifunction peripheral 100. The main control unit 3 includes a CPU 31 and an image processing unit 32. The CPU 31 performs calculation and control related to control. The image processing unit 32 performs image processing necessary for the job on the image data. The storage unit 3a includes a storage device such as a ROM, a RAM, and an HDD. The storage unit 3a stores a control program and data.

  The main control unit 3 is communicably connected to the document conveying unit 4a and the image reading unit 4b. The document transport unit 4a transports the set document toward the reading position. The image reading unit 4b can read a document conveyed by the document conveying unit 4a and a document set on a document table (contact glass, not shown). The image reading unit 4b generates image data. The main control unit 3 controls the operations of the document conveying unit 4a and the image reading unit 4b. The main control unit 3 is connected to the operation panel 5 in a communicable manner. The operation panel 5 includes a display panel 51, a touch panel 52, and hard keys 53. The operation panel 5 receives user operations.

  The multifunction device 100 includes a printing unit 6. The printing unit 6 includes an engine control unit 60, a paper feeding unit 6a, a conveyance unit 6b, an image forming unit 6c, and a fixing unit 6d. The engine control unit 60 is communicably connected to the main control unit 3. The main control unit 3 gives the engine control unit 60 a print instruction, the contents of the print job, and image data used for printing. Based on an instruction from the main control unit 3, the engine control unit 60 controls operations of the paper feeding unit 6a, the transport unit 6b, the image forming unit 6c, and the fixing unit 6d. Specifically, the engine control unit 60 supplies sheets one by one to the sheet feeding unit 6a. The engine control unit 60 conveys the supplied paper to the conveyance unit 6b. The engine control unit 60 causes the image forming unit 6c to form a toner image. The image forming unit 6c transfers the toner image onto a sheet. The engine control unit 60 fixes the toner image transferred on the paper to the fixing unit 6d.

  The main control unit 3 includes a communication unit 33. The communication unit 33 is an interface for communicating with a computer 200 such as a PC or a server. The communication unit 33 receives data (print data) indicating print contents such as image data. The main control unit 3 causes the printing unit 6 to perform printing based on the printing data.

(Post-processing device 2)
Next, the outline | summary of the post-processing apparatus 2 which concerns on embodiment is demonstrated using FIG. 1, FIG. FIG. 2 is a diagram illustrating an example of the multifunction peripheral 100 to which the post-processing device 2 according to the embodiment is attached.

  The post-processing device 2 performs various post-processings on the printed paper. The post-processing device 2 is attached to the main body of the multifunction peripheral 100. As shown in FIG. 2, the post-processing device 2 is attached (fitted) to the in-body discharge unit 101 of the multifunction peripheral 100. There is also a type of image forming apparatus in which the post-processing device 2 is attached to the side of the apparatus.

  The printed paper that has passed through the fixing unit 6d is sent to the post-processing device 2 from the carry-in port 102. The post-processing device 2 includes a punch unit 10, a paper transport unit 21, a staple unit 22, a processing tray unit 23, and a discharge tray 24. Further, as shown in FIG. 1, the post-processing device 2 includes a post-processing control unit 20 (corresponding to a control unit). The post-processing control unit 20 is a substrate including a processing circuit 2a such as a CPU, a memory 2b, and a timing circuit 2c. The post-processing control unit 20 controls the operation of each unit. Note that the main processing unit 3 or the engine control unit 60 may control the operation of the post-processing device 2 without providing the post-processing control unit 20 in the post-processing device 2.

  The multifunction peripheral 100 (post-processing apparatus 2) includes a punching apparatus 1. As shown in FIG. 1, the punching device 1 includes a post-processing control unit 20 and a punch unit 10. When the operation panel 5 is set to perform punching processing, the post-processing control unit 20 causes the punching unit 10 to perform punching processing on paper. When the setting for punching processing is not performed on the operation panel 5, the post-processing control unit 20 does not cause the punching unit 10 to perform punching processing on paper.

  The paper transport unit 21 transports the paper that has passed through the punch unit 10. The paper transport unit 21 transports the paper to the processing tray unit 23. The paper transport unit 21 includes a first transport roller pair 21a, a second transport roller pair 21b, and a paper transport guide 21c. The processing tray unit 23 includes a processing tray 23a, a first discharge roller 23b, a second discharge roller 23c, a stopper 23d, and a width regulating plate 23e. The post-processing control unit 20 causes the processing tray unit 23 to align and discharge the sheet bundle. When stapling is set on the operation panel 5, the post-processing control unit 20 causes the stapling unit 22 to perform stapling on the sheet bundle before ejection.

(Punching device 1)
Next, an example of the perforation apparatus 1 according to the embodiment will be described with reference to FIGS. FIG. 3 is a diagram illustrating an example of the punching device 1 according to the embodiment. 4 and 5 are perspective views showing an example of the punching device 1 according to the embodiment. FIG. 6 is an enlarged view of the cam 14 according to the embodiment. FIG. 7 is an enlarged view of the punch motor 11 according to the embodiment. FIG. 8 is an enlarged view of the angle sensor 7 and the speed sensor 8 according to the embodiment. In FIGS. 4 to 8, arrows indicating directions are attached. The directions indicated by the arrows correspond to the front and rear, the top and bottom, and the left and right of the punching device 1 (the multifunction device 100 and the post-processing device 2). 3 and 4 are perspective views of the punching device 1 as viewed from the upstream side in the paper conveyance direction. 3 and 4, the broken line indicates the paper entry direction.

  As shown in FIG. 3, the punching device 1 includes a post-processing control unit 20 and a punching unit 10. The punch unit 10 includes a punch motor 11, a shaft 12, a motor drive unit 13 (motor driver), a cam 14, a punching unit 15, an angle sensor 7, and a speed sensor 8. The piercing portion 15 includes a piercing blade 9. The white arrow in FIG. 3 is a force transmission path of the punch motor 11.

  The punch motor 11 reciprocates the punching blade 9. For example, a DC brush motor can be used as the punch motor 11. The motor drive unit 13 includes a plurality of switching elements 131. The switching element 131 turns on / off the supply of current to the punch motor 11. The post-processing device 2 controls each switching element 131. The post-processing device 2 can control the motor driving unit 13 to apply the brake of the punch motor 11. Details of the brake will be described later.

  As shown in FIGS. 4 and 5, the punching device 1 includes an upper guide portion 16 and a lower guide portion 17. The upper guide portion 16 and the lower guide portion 17 guide the sheet. The paper enters between the upper guide portion 16 and the lower guide portion 17 and passes therethrough. A perforated portion 15 is provided above the upper guide portion 16. A shaft 12 and a cam 14 are provided above the perforated portion 15. The punch motor 11 rotates the shaft 12. The cam 14 is attached to the shaft 12.

  The piercing portion 15 includes a piercing blade 9, a contact member 18, and an elastic member 19. A plurality of perforations 15 are provided. The punching blade 9 makes a hole in the paper. A contact member 18 is provided above the drilling blade 9. The upper end of the punching blade 9 is in contact with the lower surface of the contact member 18. The drilling blade 9 is, for example, a metal pipe. A blade is provided at the lower tip. The upper guide portion 16 and the lower guide portion 17 have holes (not shown) at positions corresponding to the drilling blades 9. The punching blade 9 moves downward, and the lower end of the punching blade 9 hits the paper. Further, the punching blade 9 moves downward to make a hole in the paper. The punching blade 9 is retracted after punching so as not to interfere with the next sheet of paper.

  The shaft 12 is provided above each perforated portion 15. The shaft 12 is attached to the rotating shaft of the punch motor 11. By rotating the punch motor 11, the shaft 12 rotates. For example, when the punch motor 11 is rotated once, the shaft 12 is rotated once. The shaft 12 is supported by the support shaft member 12a. A cam 14 is attached to the shaft 12 at a position corresponding to the perforated portion 15. 4 and 5 show an example in which four cams 14 are attached to the shaft 12. The mounting angle of each cam 14 is the same. FIG. 4 shows a state in which the cam cover 14a is attached. FIG. 5 shows a state in which the cam cover 14a is removed.

  A contact member 18 is provided below the shaft 12 (cam 14). The cam 14 has an oval (egg) shape when viewed from the axial direction of the shaft 12. The upper surface of the cam 14 and the contact member 18 is in contact. According to the rotation angle of the shaft 12, the thickness of the cam 14 at the portion in contact with the contact member 18 changes. That is, the amount by which the cam 14 pushes the contact member 18 downward (in the direction of the drilling blade 9) changes according to the rotation angle of the shaft 12. Thereby, according to rotation of the cam 14, the perforation blade 9 reciprocates. The shaft 12 and the cam 14 move the drilling blade 9 up and down using the driving force of the punch motor 11.

  4 and 5 show an example in which four perforated portions 15 are provided (corresponding to a four-hole method). Here, the drilling device 1 includes a mechanism that shifts the shaft 12 in the front-rear direction so that the two-hole drilling and the four-hole drilling can be switched. As shown in FIG. 5, the cams 14 corresponding to the inner two of the four perforated portions 15 are arranged in two rows (two). Since the two cams 14 are provided, the inner two cams 14 are in contact with the corresponding contact members 18 regardless of whether the shaft 12 is shifted forward or backward. That is, in any case of two holes or four holes, the inner two perforated portions 15 perforate. As shown in FIG. 5, the cams 14 corresponding to the outer two of the four perforated portions 15 are arranged in one row (one sheet). By shifting the shaft 12, it is possible to select contact or non-contact between the two outer cams 14 and the corresponding contact member 18. In the non-contact state, the cam 14 is swung. Therefore, the punching blade 9 does not move up and down. FIG. 6 shows an example of a non-contact state.

  As shown in FIGS. 4, 5, 7, and 8, the piercing device 1 includes an angle sensor 7. The angle sensor 7 detects that the rotation angle of the shaft 12 (punch motor 11) has reached a predetermined reference angle. The angle sensor 7 includes a first pulse plate 71 and a first optical sensor 72. The first photosensor 72 is a transmissive photosensor. The first optical sensor 72 includes a light emitting unit 73 and a light receiving unit 74. A first pulse plate 71 is attached to the shaft 12. The light emitting unit 73 and the light receiving unit 74 sandwich the first pulse plate 71. The first pulse plate 71 rotates between the light emitting unit 73 and the light receiving unit 74. The first optical sensor 72 reads the first pulse plate 71. A cutout is provided in the first pulse plate 71 so that the output of the first optical sensor 72 (light receiving unit 74) changes when the angle of the shaft 12 becomes the reference angle. The output of the light receiving unit 74 is the output of the angle sensor 7. The output of the light receiving unit 74 is input to the post-processing control unit 20. The post-processing control unit 20 recognizes that the angle of the shaft 12 has become the reference angle based on the output of the angle sensor 7.

  Further, as shown in FIGS. 4, 5, 7, and 8, the perforation apparatus 1 includes a speed sensor 8. The speed sensor 8 is a sensor for detecting the rotational speed of the shaft 12 (punch motor 11). The speed sensor 8 includes a second pulse plate 81 and a second optical sensor 82 (corresponding to a sensor unit). The second optical sensor 82 is a transmissive optical sensor. The second optical sensor 82 includes a light emitting unit 83 and a light receiving unit 84. A second pulse plate 81 is attached to the shaft 12. The light emitting unit 83 and the light receiving unit 84 sandwich the second pulse plate 81. The second pulse plate 81 rotates between the light emitting unit 83 and the light receiving unit 84.

  The second pulse plate 81 is provided with a plurality of grooves 81a (slits). For example, the number of slits can be several tens to several hundreds (for example, 40 to 50). The slit is provided at a position between the light emitting unit 83 and the light receiving unit 84. A slit is dug at every certain angle. Therefore, every time the shaft 12 rotates by a certain angle, the output 2 of the second optical sensor 82 (light receiving unit 84) changes. The output of the light receiving unit 84 is the output of the speed sensor 8. That is, the light receiving unit 84 outputs a pulse signal that rises or falls every time the shaft 12 (punch motor 11) rotates by a certain angle.

  The output of the light receiving unit 84 is input to the post-processing control unit 20. The post-processing control unit 20 can recognize that the shaft 12 has rotated by a certain angle based on the output of the second optical sensor 82. Further, the post-processing control unit 20 can recognize the rotation speed of the shaft 12 (punch motor 11) based on the pulse period of the pulse signal. In other words, the post-processing control unit 20 can recognize the rotational speed of the shaft 12 based on the time interval of the rising edge or the falling edge of the pulse signal. Therefore, the post-processing control unit 20 measures the period (edge interval) of each pulse signal. For example, the timing circuit 2c in the post-processing control unit 20 measures the cycle.

  A case where the rotational speed (rps) of the shaft 12 per second is obtained will be described. In this case, the post-processing control unit 20 divides 1 (second) by one pulse period. Thereby, the pulse number A per second in the current cycle is obtained. Then, the post-processing control unit 20 divides the pulse number A by the pulse number B (the number of slits of the second pulse plate 81) generated when the shaft 12 makes one turn. Thereby, rps of the shaft 12 can be obtained. Multiply by 60 to determine rpm. For example, when the period of one pulse is 10 milliseconds, the number of pulses A = 100. When the pulse number B is 50, the number of rotations per second = 100/50 = 2 [rps].

  Here, one of the positions where the sheet to be conveyed and the punching blade 9 do not contact is set as the home position range of the punching blade 9. In other words, when the punching blade 9 is within the home position range, the punching blade 9 is in a position retracted from the paper. In the punching device 1, the position when the punching blade 9 is lifted up most is within the home position range.

  Specifically, in the home position range, after the angle sensor 7 detects that the shaft 12 has become the reference angle, the output of the speed sensor 8 changes the shaft 12 in the forward direction only by a predetermined number of alignment pulses. This is the range of positions that can be taken by the drilling blade 9 when rotated to the center. In the perforating apparatus 1, the number of alignment pulses is 2 (may be other than 2). Therefore, the reference angle is an angle of the shaft 12 when the punching blade 9 is rotated backward by two pulses of the speed sensor 8 from the position where the punching blade 9 is in the home position range. For example, one pulse and three pulses are out of range. After punching, the post-processing control unit 20 stops the punch motor 11 at a position where the punching blade 9 is within the home position range.

  Note that when the main power of the multifunction peripheral 100 or the post-processing apparatus 2 is turned on, the post-processing control unit 20 performs a startup process. The process for bringing the punching blade 9 into the home position range is included in the activation process. In this case, the post-processing control unit 20 rotates the punch motor 11 forward at a low speed. After the angle sensor 7 detects that the shaft 12 has reached the reference angle, the post-processing control unit 20 stops the punch motor 11 when the output of the speed sensor 8 changes the number of alignment pulses.

  When drilling, the post-processing control unit 20 starts the rotation of the shaft 12 from the state where the drilling blade 9 is within the home position range. As the shaft 12 rotates, the cam 14 rotates. The cam 14 pushes down the contact member 18 by the rotation of the cam 14. As a result, each punching blade 9 moves downward. The post-processing control unit 20 further rotates the shaft 12 (punch motor 11). Eventually, the drilling blade 9 descends to the lower limit position. In this process, the paper is perforated. The post-processing control unit 20 further rotates the shaft 12. Eventually, the amount by which the cam 14 pushes down each contact member 18 decreases.

  Thereby, the punching blade 9 moves upward. An elastic member 19 (spring) is provided outside each punching blade 9. The upper end of the elastic member 19 is in contact with the lower surface of the contact member 18. The elastic member 19 urges the contact member 18 and the punching blade 9 upward. When the rotation of the shaft 12 continues, the lower end of each drilling blade 9 is lifted above the upper guide portion 16. As a result, each punching blade 9 is retracted to a position that does not block paper conveyance. The post-processing control unit 20 drives the punch motor 11 to lower the punching unit 15 to a position where the sheet is pushed out (to the lower side of the lower guide unit 17). After punching, the post-processing control unit 20 raises the punching unit 15 and then stops the punch motor 11.

(Brake of punch motor 11)
Next, an example of the brake of the punch motor 11 according to the embodiment will be described with reference to FIG. FIG. 9 is a diagram illustrating an example of punch motor 11 control of the post-processing control unit 20 according to the embodiment.

  The motor drive unit 13 turns on / off the current supply of the punch motor 11. Here, the punch motor 11 may be rotated in reverse. Therefore, the motor driving unit 13 includes four switching elements 131. Each switching element 131 is, for example, a transistor. An H bridge circuit is formed using the four switching elements 131. The motor drive unit 13 includes an H bridge circuit.

  The post-processing control unit 20 controls ON / OFF of each switch. For convenience, the upper left switch in the H bridge circuit shown in FIG. 9 is referred to as a first switch 13a. The upper right switch is referred to as a second switch 13b. The lower left switch is referred to as a third switch 13c. The lower right switch is referred to as a fourth switch 13d. When the punch motor 11 is rotated forward, the post-processing control unit 20 turns on the first switch 13a and the fourth switch 13d, and turns off the second switch 13b and the third switch 13c. When the punch motor 11 is rotated in the reverse direction, the post-processing control unit 20 turns off the first switch 13a and the fourth switch 13d, and turns on the second switch 13b and the third switch 13c.

  When the brake is applied, the post-processing control unit 20 turns off the first switch 13a and the second switch 13b, and turns on the third switch 13c and the fourth switch 13d. As a result, both terminals of the punch motor 11 are short-circuited. A current tends to flow in the direction opposite to that during rotation. As a result, the punch motor 11 is braked. That is, the post-processing control unit 20 reduces the rotational speed of the punch motor 11 by the short brake.

(Flow of setting at the start of braking)
Next, an example of the flow of setting the brake start time of the punching device 1 according to the embodiment will be described with reference to FIGS. FIG. 10 is a flowchart illustrating an example of a flow of processing during drilling of the drilling device 1 according to the embodiment. 11 and 12 are diagrams illustrating an example of a timing chart of the perforating apparatus 1 according to the embodiment.

  The start of FIG. 10 is a point in time when the punching process is started. First, the post-processing control unit 20 starts the rotation of the punch motor 11 (step # 1). As a result, the shaft 12 and the cam 14 rotate. The punching blade 9 protrudes and the paper is punched. The post-processing control unit 20 (timer circuit 2c) measures the time elapsed from the start of the rotation of the punch motor 11 (step # 2). Further, the post-processing control unit 20 confirms whether or not it is the first drilling after the main power supply of the multifunction peripheral 100 or the post-processing device 2 is turned on (step # 3).

  At the time of the first drilling (Yes in Step # 3), the post-processing control unit 20 starts the brake of the punch motor 11 when the reference waiting time D1 has elapsed after the rotation of the punch motor 11 is started (Step # 4). . In the second and subsequent drilling, the post-processing control unit 20 starts braking the punch motor 11 at a timing determined based on the measurement in the immediately preceding drilling process (step # 5). The reference waiting time D1 is a reference of time from the start of rotation of the punch motor 11 to the start of braking. The reference waiting time D1 is stored in the memory 2b (see FIG. 3). Details of the reference waiting time D1 will be described later.

  After step # 4 and step # 5, post-processing control unit 20 (timer circuit 2c) measures the period of each pulse of the pulse signal within the measurement period (step # 6). The measurement period is predetermined. The measurement period can be determined as appropriate. The measurement period is a period provided between the start of the brake and the stop of the punch motor 11. In the punching device 1, the measurement period is a time corresponding to a predetermined number of pulses of the pulse signal (output signal of the speed sensor 8) from the brake start time. The predetermined number of pulses can be determined as appropriate. For example, the predetermined number of pulses can be 5 to 10 pulses. In the case of 10 pulses, the post-processing control unit 20 measures each period of 10 pulses output from the speed sensor 8 after the start of braking.

  Further, the post-processing control unit 20 monitors the outputs of the angle sensor 7 and the speed sensor 8 until the brake period T5 (see FIGS. 11 and 12) elapses from the start of braking (step # 7). Is predetermined. The brake period T5 is a period from the start of braking to the time point when the punch motor 11 is predicted to have stopped reliably. Note that the post-processing control unit 20 may detect the magnitude of the current flowing through the punch motor 11. When the current of the punch motor 11 becomes zero, the post-processing control unit 20 may recognize that the brake period T5 has ended.

  Then, the post-processing control unit 20 obtains a reduction in the rotational speed of the shaft 12 based on the period of each pulse (step # 8). For example, the post-processing control unit 20 (processing circuit 2a) obtains the sum of the periods of each pulse (total period). Further, the post-processing control unit 20 obtains the rotation speed (first rotation speed) of the shaft 12 based on the cycle of the first pulse in the measurement period. Further, the post-processing control unit 20 obtains the rotational speed (second rotational speed) of the shaft 12 based on the cycle of the last pulse in the measurement period. Further, the post-processing control unit 20 obtains the absolute value of the difference between the first rotation speed and the second rotation speed. The post-processing control unit 20 divides the absolute value of the difference by the total period. The value obtained by dividing is the absolute value of deceleration. That is, the post-processing control unit 20 differentiates the speed with respect to time. Deceleration indicates the rate of change of speed per unit time. The post-processing control unit 20 recognizes the absolute value of the deceleration of the shaft 12 within the measurement period. Note that the post-processing control unit 20 may obtain the rotation speed corresponding to each cycle based on the cycle of each pulse. Then, the post-processing control unit 20 may divide the average value of the calculated rotation speeds by the total period. The value obtained by dividing may be used as the deceleration.

  Subsequently, the post-processing control unit 20 checks whether or not the difference between the obtained deceleration and the deceleration reference value D2 is within the allowable range D3 (step # 9). The deceleration reference value D2 and the allowable range D3 are determined in advance. The deceleration reference value D2 and the allowable range D3 are stored in the memory 2b. The allowable range D3 can be determined as appropriate. The allowable range D3 may be zero.

  The deceleration reference value D2 may be determined based on experiments. Further, the deceleration reference value D2 may be an absolute value of deceleration on the specification of the punch motor 11. Further, the ease with which the punch motor 11 is braked is also related to the temperature. For example, the absolute value of the average deceleration when the punch motor 11 is at room temperature may be used as the deceleration reference value D2. Further, when the temperature of the punch motor 11 is about room temperature (about 25 degrees), when braking is started based on the reference waiting time D1, the absolute value of the deceleration at which the punching blade 9 stops in the home position range is set as the deceleration reference value D2. It is good.

  The reference waiting time D1 is a reference time of the waiting time from the start of rotation of the punch motor 11 to the start of braking. The reference waiting time D1 may be determined in consideration of the balance with the deceleration reference value D2. The reference waiting time D1 may be a waiting time such that the drilling blade 9 stops in the home position range when the absolute value of the deceleration within the measurement period is the deceleration reference value D2. Further, the ease with which the punch motor 11 is braked is also related to the temperature. Therefore, the reference waiting time D1 may be determined in consideration of the temperature of the punch motor 11. For example, the reference waiting time D1 is a waiting time such that the punching blade 9 stops in the home position range when the temperature of the punch motor 11 is about room temperature and the absolute value of the deceleration within the measurement period is the deceleration reference value D2. It is good.

  When the difference is within the allowable range D3 (Yes in Step # 9), the post-processing control unit 20 sets the next drilling to start braking when the reference waiting time D1 has elapsed from the start of rotation of the punch motor 11. (Step # 10). In other words, the post-processing control unit 20 sets the waiting time for the next drilling to the reference waiting time D1.

  When the difference is outside the allowable range D3 (No in Step # 9), the post-processing control unit 20 checks whether or not the absolute value of the deceleration is smaller than the deceleration reference value D2 (Step # 11). In other words, the post-processing control unit 20 checks whether or not the brake is difficult to work.

  If the absolute value of the deceleration is outside the allowable range D3 and smaller than the deceleration reference value D2 (Yes in step # 11), it can be said that the brake is difficult to work. Therefore, the post-processing control unit 20 sets the next drilling to be set to start braking before the reference waiting time D1 has elapsed from the start of rotation of the punch motor 11 (step # 12). In other words, the post-processing control unit 20 makes the waiting time for the next drilling shorter than the reference waiting time D1.

  If the absolute value of deceleration is outside the allowable range D3 and greater than the deceleration reference value D2 (No in step # 11), it can be said that the brake is likely to be effective. Therefore, the post-processing control unit 20 sets the next perforation setting to start braking after the reference waiting time D1 has elapsed from the start of rotation of the punch motor 11 (step # 13). In other words, the post-processing control unit 20 makes the waiting time for the next drilling longer than the reference waiting time D1.

  The post-processing control unit 20 makes the brake start point at the time of the next drilling earlier as the absolute value of the deceleration is smaller. Further, the post-processing control unit 20 delays the brake start time at the next drilling as the absolute value of the deceleration is larger. For example, the shift amount data D4 is stored in the memory 2b (see FIG. 3). In the shift amount data D4, an amount to be shifted from the reference waiting time D1 is determined according to the deceleration. The shift amount data D4 is defined such that the smaller the absolute value of the deceleration, the earlier the brake start time at the next drilling. Further, the shift amount data D4 is defined such that the greater the absolute value of the deceleration, the later the brake start time at the time of the next drilling.

  After the brake is started, the punch motor 11 (the shaft 12, the cam 14, and the drilling blade 9) is eventually stopped. Therefore, the post-processing control unit 20 checks whether or not the drilling blade 9 has stopped within the home position range (step # 14). In other words, the post-processing control unit 20 checks whether or not the shaft 12 has stopped in an angle range where the drilling blade 9 is within the home position range. The post-processing control unit 20 confirms based on the monitoring result at step # 7. After the end of the brake period T5 (after steps # 10, 12, 13), the post-processing control unit 20 performs step # 14.

  Specifically, the post-processing control unit 20 recognizes that the shaft 12 has reached the reference angle based on the output of the angle sensor 7. After recognizing the reference angle, the post-processing control unit 20 checks whether the output of the sensor unit has changed by the number of alignment pulses (2 pulses). After recognizing the reference angle, when the output of the sensor unit changes by the number of alignment pulses, the post-processing control unit 20 determines that the drilling blade 9 is within the home position range. When the punching blade 9 stops within the home position range (Yes in step # 14), this flow ends (end).

  On the other hand, when the punching blade 9 stops outside the home position range (No in step # 14), the post-processing control unit 20 adjusts the position of the punching blade 9 (step # 15). After the adjustment, this flow ends (end). That is, when the position of the punching blade 9 when the punch motor 11 is stopped is shifted from the home position, the post-processing control unit 20 adjusts the position of the punching blade 9. The post-processing control unit 20 rotates the punch motor 11 forward or backward so that the punching blade 9 is within the home position range.

  The top charts in FIGS. 11 and 12 show an example of the current flowing through the punch motor 11. The second chart shows changes in the rotational speed of the punch motor 11. The rotation speed is obtained based on the pulse period of the speed sensor 8. The third chart shows an example of the pulse signal of the speed sensor 8. The bottom chart shows an example of the output of the angle sensor 7. 11 and 12 show an example in which the output of the angle sensor 7 falls when it is detected that the shaft 12 has reached the reference angle.

  Further, a time point T1 in FIGS. 11 and 12 is a time point when the rotation of the punch motor 11 is started. Time T2 is the time when braking is started. Time T3 is the end time of the brake period T5. The time from time T1 to time T2 is the waiting time T4 from the start of rotation to the start of braking. A period from time T2 to time T3 is a brake period T5.

  FIG. 11 is an example of a timing chart when the drilling blade 9 is in the home position range at the end of the brake period T5. That is, it is an example of a timing chart when Step # 14 is Yes. In FIG. 11, the time when the output of the angle sensor 7 falls is indicated by T6. In the example of FIG. 11, the pulse signal of the speed sensor 8 has changed twice from the time T6. In other words, the pulse signal of the speed sensor 8 rises twice from time T6. In this case, the post-processing control unit 20 determines that the drilling blade 9 has stopped in the home position range. The post-processing control unit 20 accurately sets the brake start timing at the next drilling. Therefore, the drilling blade 9 can be almost stopped within the home position range regardless of the degree of braking.

  On the other hand, FIG. 12 is an example of a timing chart when the drilling blade 9 is out of the home position range at the end of the brake period T5. The degree of braking is affected by the temperature of the punch motor 11. When drilling continuously, the temperature of the punch motor 11 gradually increases. If punching is not performed, the temperature of the punch motor 11 is lowered to about room temperature. Depending on the degree of temperature change of the punch motor 11, the punching blade 9 may stop outside the home position range. For example, the case where time has passed since the last drilling can be considered. When stopped outside the home position range, the post-processing control unit 20 adjusts the position of the punching blade 9.

  Specifically, when the punch motor 11 stops before the punching blade 9 reaches the home position range due to the brake, the post-processing control unit 20 rotates the punch motor 11 in the forward direction. The post-processing control unit 20 stops the punch motor 11 when the output of the speed sensor 8 is changed by the number of alignment pulses after the angle sensor 7 detects the reference angle of the shaft 12 is reached. When the punch motor 11 stops after the punching blade 9 reaches the home position range by the brake, the post-processing control unit 20 rotates the punch motor 11 in the reverse direction. The post-processing control unit 20 reversely rotates the punch motor 11 by the number of changed pulses after the output of the speed sensor 8 changes by the number of alignment pulses.

  FIG. 12 shows an example in which the punch motor 11 is stopped before the punching blade 9 reaches the home position range. In FIG. 12, the time when the output of the angle sensor 7 falls is indicated by T7. In the example of FIG. 12, the pulse signal does not rise even once between time T7 and time T3. In this case, the post-processing control unit 20 determines that the punching blade 9 has stopped outside the home position range. The example of FIG. 12 shows an example in which the punch motor 11 is rotated at a low speed by the number of alignment pulses (2 pulses).

  Thus, the punching device 1 according to the embodiment includes the shaft 12, the punch motor 11, the cam 14, the punching unit 15, the speed sensor 8, the angle sensor 7, and the control unit (post-processing control unit 20). The punch motor 11 rotates the shaft 12. The cam 14 is attached to the shaft 12. The piercing portion 15 includes a piercing blade 9. The perforated part 15 contacts the cam 14. The punching unit 15 reciprocates the punching blade 9 according to the rotation of the cam 14, and punches the paper when protruding. The speed sensor 8 detects the rotational speed of the shaft 12. The angle sensor 7 detects that the rotation angle of the shaft 12 has reached a predetermined reference angle. The control unit recognizes the rotational speed of the shaft 12 based on the output of the speed sensor 8. The control unit brakes the punch motor 11 and stops it. The control unit recognizes the absolute value of the deceleration of the shaft 12 within a predetermined measurement period based on the output of the speed sensor 8. The measurement period is a period provided after the brake is started until the punch motor 11 stops. A reference waiting time D1, which is a reference for the waiting time from the start of rotation of the punch motor 11 to the start of braking, is determined in advance. When the absolute value is smaller than the predetermined deceleration reference value D2, the control unit starts to apply the brake before the reference waiting time D1 elapses from the start of the rotation of the punch motor 11 in the next drilling. When the absolute value is larger than the deceleration reference value D2, the control unit starts braking after the reference waiting time D1 has elapsed from the start of rotation of the punch motor 11 in the next drilling.

  By comparing the absolute value of the deceleration of the shaft 12 (motor) in the brake period T5 with the deceleration reference value D2, the state of the brake can be confirmed. When it is difficult to apply the brake, the brake start time can be advanced. Further, when the brake is often applied, the brake start time can be delayed. Thus, the brake start time can be adjusted according to the current degree of braking. As a result, the variation in the rotation amount during the brake period T5 is reduced. Therefore, the shaft 12 (cam 14) can be stopped at a constant or substantially constant angle. Further, the drilling blade 9 can be stopped at a constant or almost constant position. Since the variation in the rotation amount during the brake period T5 is small, it is not necessary to adjust the position of the drilling blade 9 after the motor (shaft 12) is stopped. Even if the position of the punching blade 9 is shifted, the shift amount is small. Therefore, the time required for adjusting the position of the punching blade 9 can be made shorter than before. Therefore, the processing speed (productivity) of the punching device 1 can be increased.

  Further, the reference waiting time D1 is determined such that when the absolute value is the deceleration reference value D2, the punch motor 11 stops at a position where the punching blade 9 is within a predetermined home position range. The punching blade 9 within the home position range is in a state of being retracted from the paper. Thereby, the drilling blade 9 can be stopped within the home position range. In other words, the shaft 12 (cam 14, punch motor 11) can be stopped at an angle where the drilling blade 9 is within the home position range.

  Further, when the absolute value is smaller than the deceleration reference value D2, the control unit makes the brake start time at the next drilling earlier as the absolute value is smaller. When the absolute value is greater than the deceleration reference value D2, the control unit delays the brake start time at the next drilling as the absolute value increases. Thereby, the brake start time can be further advanced as the brake is less likely to be applied. Moreover, the brake start time can be delayed more easily as the brake is applied. Therefore, the variation in the rotation amount during the brake period T5 can be reduced. As a result, the stop angle of the shaft 12 (cam 14) can be made constant or substantially constant. Further, the stop position of the punching blade 9 can be made constant or almost constant.

  Further, when the difference between the absolute value and the deceleration reference value D2 is within the predetermined allowable range D3, the control unit applies the brake after the reference waiting time D1 has elapsed from the start of the rotation of the punch motor 11 in the next drilling. Start. Thereby, when the brake should be started at the reference waiting time D1, the braking start time can be set as the reference waiting time D1.

  The speed sensor 8 includes a pulse plate and a sensor unit. The pulse plate is attached to the shaft 12 and has a plurality of grooves 81a provided at fixed angles. The sensor unit reads the groove 81a and outputs a pulse signal that rises or falls every time the shaft 12 rotates by a certain angle. The measurement period is a time corresponding to a predetermined number of pulses of the pulse signal from the brake start time. The control unit obtains an absolute value based on the pulse period of the pulse signal. Thereby, a pulse encoder can be used for the speed sensor 8. Based on the pulse, the absolute value of the deceleration can be obtained. In addition, the measurement time can be determined based on the pulse. The speed change during the rotation period of the shaft 12 for a predetermined pulse from the start of the brake can be captured.

  Further, when the position of the punching blade 9 when the punch motor 11 is stopped is deviated from the home position range, the control unit rotates the punch motor 11 forward or backward so that the punching blade 9 is in the home position range. Let Thereby, when the stop position of the perforation blade 9 shifts, the alignment of the perforation blade 9 can be performed. That is, the position of the punching blade 9 can be corrected. In other words, the angle of the shaft 12 (cam 14) can be corrected to an angle at which the drilling blade 9 is in the home position range. Therefore, the position of the punching blade 9 before drilling can be always kept within the home position range. Further, the shaft 12 can always be rotated from the same angle. Further, the shaft 12 can be stopped at an angle at which the drilling blade 9 is in the home position range.

  The speed sensor 8 includes a pulse plate and a sensor unit (second optical sensor 82). The pulse plate is attached to the shaft 12 and has a plurality of grooves 81a provided at fixed angles. The sensor unit reads the groove 81a and outputs a pulse signal that rises or falls every time the shaft 12 rotates by a certain angle. The home position range is when the angle sensor 7 detects that the shaft 12 is at the reference angle, and then the shaft 12 is rotated in the positive direction as much as the output of the sensor unit changes by a predetermined number of alignment pulses. This is the position range of the drilling blade 9. When the punch motor 11 is stopped before the punching blade 9 reaches the home position range due to the brake, the control unit rotates the punch motor 11 in the forward direction, and the output of the sensor unit is output after the shaft 12 reaches the reference angle. The punch motor 11 is stopped when the number of alignment pulses has changed. When the punch motor 11 is stopped after the punching blade 9 has passed the home position range due to the brake, the control unit controls the punch motor 11 by the number of pulses further changed after the output of the sensor unit has changed by the number of alignment pulses. Reverse. Thereby, the position of the punching blade 9 shifted from the home position range can be corrected. When the punching blade 9 stops before reaching the home position range, the punch motor 11 can be rotated forward. When the punching blade 9 stops past the home position range, the punch motor 11 can be reversed. Regardless of the position of the drilling blade 9 at the time of stopping (the angle of the shaft 12), the position of the drilling blade 9 can be within the home position range. Therefore, the drilling blade 9 can always be rotated from the home position range. Further, the drilling blade 9 can always be stopped in the home position range.

  Further, the control unit reduces the rotational speed of the punch motor 11 by a short brake. Thereby, after a brake start, a motor can be stopped quickly. The image forming apparatus (multifunction machine 100) includes the above-described punching device 1. Thereby, the brake start time can be adjusted in accordance with the current degree of brake application. As a result, the variation in the rotation amount during the brake period T5 is reduced. Therefore, the variation in the stop position of the punching blade 9 is reduced. There is no need to correct the position of the punching blade 9. Accordingly, it is possible to provide an image forming apparatus with high processing speed (productivity).

  The scope of the present invention is not limited to the description of the embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention is applicable to a punching device and an image forming apparatus including the punching device.

DESCRIPTION OF SYMBOLS 100 Compound machine (image forming apparatus) 1 Punching device 11 Punch motor 12 Shaft 14 Cam 15 Punching unit 20 Post-processing control unit (control unit) 7 Angle sensor 8 Speed sensor 81 Second pulse plate 82 Second optical sensor (sensor unit) 81a Groove 9 Drilling blade D1 Reference waiting time D2 Deceleration reference value D3 Allowable range

Claims (9)

A shaft,
A punch motor for rotating the shaft;
A cam attached to the shaft;
A perforating portion that includes a perforating blade, contacts the cam, reciprocates the perforating blade according to rotation of the cam, and perforates the paper when protruding;
A speed sensor for detecting the rotational speed of the shaft;
An angle sensor for detecting that the rotation angle of the shaft has become a predetermined reference angle;
The rotational speed of the shaft is recognized based on the output of the speed sensor, the punch motor is braked and stopped, and the absolute value of the deceleration of the shaft within a predetermined measurement period based on the output of the speed sensor And a control unit for recognizing
The measurement period is a period provided between the start of braking and the stop of the punch motor,
A reference waiting time that is a reference for the waiting time from the start of rotation of the punch motor to the start of braking is predetermined,
The controller is
When the absolute value is smaller than a predetermined deceleration reference value, the next drilling starts to apply the brake before the reference waiting time elapses from the start of rotation of the punch motor,
When the absolute value is larger than the deceleration reference value, in the next drilling, a brake is started after the reference waiting time has elapsed from the start of rotation of the punch motor. The reference waiting time is determined such that when the absolute value is the deceleration reference value, the punch motor stops at a position where the drilling blade is within a predetermined home position range,
The punching device according to claim 1, wherein the punching blade within the home position range is in a state of being retracted from the paper. The controller is
When the absolute value is smaller than the deceleration reference value, the smaller the absolute value, the earlier the brake start time at the next drilling,
3. The drilling device according to claim 1, wherein when the absolute value is larger than the deceleration reference value, the brake start time at the next drilling is delayed as the absolute value increases. When the difference between the absolute value and the deceleration reference value is within a predetermined allowable range,
The said control part starts a brake from the time of the said reference waiting time having passed since the rotation start of the said punch motor in the next drilling, The punching apparatus in any one of Claim 1 thru | or 3 characterized by the above-mentioned. . The speed sensor includes a pulse plate and a sensor unit,
The pulse plate is attached to the shaft and has a plurality of grooves provided at certain angles,
The sensor unit reads a groove and outputs a pulse signal that rises or falls every time the shaft rotates by the predetermined angle,
The measurement period is a time corresponding to a predetermined number of pulses of the pulse signal from the brake start time,
The perforating apparatus according to claim 1, wherein the control unit obtains the absolute value based on a pulse period of the pulse signal. When the position of the drilling blade when the punch motor is stopped is deviated from the home position range,
The punching apparatus according to claim 2, wherein the control unit rotates the punch motor forward or reversely so that the punching blade is in the home position range. The speed sensor includes a pulse plate and a sensor unit,
The pulse plate is attached to the shaft and has a plurality of grooves provided at certain angles,
The sensor unit reads a groove and outputs a pulse signal that rises or falls every time the shaft rotates by the predetermined angle,
In the home position range, after the angle sensor detects that the shaft has reached the reference angle, the output of the sensor unit rotates the shaft in the positive direction only by a predetermined number of alignment pulses. The position range of the drilling blade when
When the punch motor is stopped before the drilling blade reaches the home position range by a brake,
The control unit rotates the punch motor forward, and stops the punch motor when the output of the sensor unit changes by the number of alignment pulses after the shaft reaches the reference angle.
When the punch motor stops by the brake after the drilling blade has passed the home position range,
The punching apparatus according to claim 2, wherein the control unit reversely rotates the punch motor by the number of pulses further changed after the output of the sensor unit has changed by the number of alignment pulses.   The punching device according to any one of claims 1 to 7, wherein the control unit reduces the rotational speed of the punch motor by a short brake.   An image forming apparatus comprising the punching device according to claim 1.