JP4054627B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet processing apparatus capable of nipping and conveying a sheet or releasing nipping, and an image forming apparatus including the sheet processing apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image forming apparatus such as a printer is provided with a sheet post-processing device that performs post-processing such as stapling (needle striking) and ejects a plurality of sheets on which images have been formed (printed) with alignment. There is something that is.
[0003]
As such a sheet post-processing device, sheets provided on the side of the sheet discharge port side of the image forming apparatus main body, and printed on the image forming apparatus main body side are sequentially supplied from the discharge port, and each end is aligned. And the thing of the type which performs a post-process and discharges | emits is known.
[0004]
In some of these discharge devices, the roller pair can be separated to form an intermediate sheet stacking unit. In the post-processing mode, the roller pair urged by the roller pair urging means abuts on an arm member that rotatably supports one of the roller pairs, and the cam that determines the interval between the roller pairs rotates to rotate the roller pair. The pair of rollers is separated by winning the biasing means.
[0005]
After aligning the sheets in the intermediate stacking section that is configured to be separated, after the post-processing by post-processing means such as stapling, the cam rotates the post-processed sheet bundle, and the arm member is rotated by the force of the roller urging means. By moving in the same direction as the direction, the roller pair nips and discharges to the sheet stacking unit.
[0006]
In the stack mode in which no post-processing is performed, the sheets are stacked on the sheet stacking unit by conveying the sheets without separating the roller pairs.
[0007]
[Problems to be solved by the invention]
However, in such a conventional sheet post-processing apparatus, when the cam that is in contact with an arm that rotatably supports one side of the roller pair rotates to nip the roller pair, that is, the roller pair When a roller separated in the same direction as the urging direction of the urging means is moved and stopped, an impact sound is generated, which may cause discomfort to the user.
[0008]
Further, the cam rotates too much in the direction urged by the urging means, and the arm that pivotally supports the roller at a predetermined position does not stop and the interval between the rollers may not be stable. In this case, the pair of rollers does not nip, the conveyance force for discharging the sheet is insufficient, and jamming occurs. In the case of a pair of rollers having a comb-tooth configuration, the sheet cannot be stiff and the sheet stacking property is deteriorated. was there.
[0009]
Further, when a stepping motor having a small torque is used, the cam rotates out faster than the stepping motor and the stepping motor is forcibly turned out of time.
[0010]
As a means for solving this problem, it is known to provide an oil damper in which silicone oil or the like is sealed in the rotating shaft or gear train of the cam to apply a load to the cam drive system.
[0011]
FIG. 13 is a graph showing the relationship between the magnitude of torque received by the cam due to the force received from the biased arm and the rotation angle of the cam. Here, as shown in FIG. 12, the sign of torque is defined as positive torque acting on the cam in the counterclockwise direction and minus torque acting in the clockwise direction, and the phase angle on the horizontal axis is 0. The roller pair is in the nip state at a degree, the separation state is at 180 degrees, and the vertical axis represents the torque.
[0012]
The solid line indicates the torque when the oil damper is not provided, and the alternate long and short dash line indicates the torque when the oil damper is provided to reduce the negative torque between the cam phase of 180 degrees and 360 degrees. Show.
[0013]
If the oil damper is provided, the negative torque between the cam phase of 180 degrees and 360 degrees But When the operation of nipping the roller pair is performed, that is, when the roller separated in the same direction as the direction in which the roller pair urging means is urged is moved and stopped, the impact sound is reduced.
[0014]
However, when an oil damper is provided, the roller pair is separated In Since it is necessary to rotate the cam against the damper, the torque at the phase of 0 to 180 is increased, and a motor as a drive source with a higher torque is required than before the oil damper is provided, which is expensive.
[0015]
In general, a high-torque motor requires a larger amount of electric power and is large in size, and requires a space for providing a large motor for the apparatus.
[0016]
SUMMARY An advantage of some aspects of the invention is that it provides a sheet processing apparatus that is low in noise, space-saving, low-cost, and power-saving, and an image forming apparatus including the sheet processing apparatus.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, a typical configuration according to the present invention is a sheet processing apparatus having a pair of rollers that can hold and convey a sheet, and supports any one of the rollers. And an abuttable arm, a biasing means for biasing the arm in a direction in which a roller supported by the arm approaches the other roller, and the arm biased by the biasing means , The radius of the working surface that contacts the arm is rotation Change with A cam capable of swinging the arm, When the roller supported by the arm approaches the other roller, it contacts the working surface of the cam, Brake means for applying a braking force to the rotation of the cam. Then, the brake means starts contact with the working surface where the radius of the cam increases. It is characterized by doing.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. In each of the following embodiments, an example of a sheet post-processing apparatus mounted on a printer apparatus typified by a laser beam printer will be described.
[0019]
[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS.
[0020]
FIG. 1 is a schematic cross-sectional explanatory view showing the overall configuration of a sheet post-processing apparatus and an image forming apparatus (printer) according to the first embodiment.
[0021]
{Image forming device}
In FIG. 1, reference numeral 100 denotes a printer main body as an image forming apparatus, which is connected to a computer alone or connected to a network such as a LAN, and based on image information and print signals sent from these computers and networks. This is an apparatus that forms (prints) an image on a sheet and discharges it by a predetermined image forming process.
[0022]
On the other hand, the sheet post-processing apparatus (sheet processing apparatus) 300 is the first in a face-down state in which the sheet discharged from the printer main body 100 to the outside of the apparatus passes through a conveyance unit in the sheet post-processing apparatus and the image surface is face down. The sheet is placed on one sheet stacking unit, aligned by an aligning unit, bundled for each predetermined job, stapled at one or more positions of the sheet, and discharged and stacked on the stacking unit 325 of the sheet post-processing apparatus. Or a device for discharging and stacking on the stacking unit 325 of the sheet post-processing apparatus simply by face-down.
[0023]
Here, the sheet post-processing apparatus 300 and the printer main body 100 are electrically connected by a cable connector (not shown). The sheet post-processing apparatus 300 has a casing part 300A for storing each part, and is detachable from the apparatus main body 100A of the printer main body 100 described later.
[0024]
{Printer body}
Next, the configuration of each unit of the printer main body 100 will be described along the conveyance path of the conveyed sheet S.
[0025]
In the printer main body 100, a plurality of sheets S are stacked in a feeding cassette 200 loaded in the lower part of the apparatus main body, and the uppermost sheet among them is sequentially separated one by one by a feeding roller 101 and a separation roller pair 102. It is designed to be fed. The fed sheet is conveyed to the image forming unit by the conveyance roller pair 103 and the registration roller pair 104.
[0026]
In this embodiment, an electrophotographic system is used as the image forming unit, the photosensitive drum 105 is charged, and selective exposure is performed from the exposure unit 106 by a predetermined print signal supplied from a computer or a network. This is developed with toner by the developing means 107 to form a visible image. Then, the toner image is transferred to the conveyed sheet by applying a transfer bias to the transfer roller 108, and then the toner image is permanently fixed by applying heat and pressure in the downstream fixing device 109.
[0027]
As shown in FIG. 1, the sheet S on which the image is fixed is folded back in a substantially U-shaped sheet conveyance path to the discharge roller 130, so that the image surface is reversed and the image surface is on the lower side. In this state, the paper is discharged face down from the printer main body 100 by the discharge roller 130.
[0028]
Here, the position of the flapper 150 of the printer main body 100 is determined based on a control signal from a control unit (not shown), so that the sheet S is transferred to the face-down discharge unit 125 provided on the upper portion of the printer main body 100. Whether to be discharged or to be discharged to the stacking unit 325 of the sheet post-processing apparatus 300 is selected.
[0029]
{Sheet post-processing device}
Next, the configuration of the sheet post-processing apparatus 300 and the movement of each part when the sheet S conveyed by the discharge roller 130 goes to the sheet post-processing apparatus 300 will be described with reference to FIGS. Here, FIG. 2 is a cross-sectional explanatory view of the discharge roller 130 and the sheet post-processing apparatus 300, and FIG. 3 is a cross-sectional view illustrating the operation of the slide guide, and is an explanatory view showing a state in which the slide guide is in the standby position. is there.
[0030]
In FIG. 2, 330a is a discharge upper roller, 330b is a discharge lower roller, M is a jogger motor as a drive source, 322 is a paddle, and 323 is a reference wall for abutting the rear end of the sheet.
[0031]
As shown in FIG. 2, the discharge roller pair 330 including the discharge upper roller 330a and the discharge lower roller 330b is disposed on the downstream side in the sheet conveying direction of the flapper 150, and is rotated by a drive motor (not shown). Is done.
[0032]
Further, the discharge upper roller 330a is pivotally supported by an arm 331 which can rotate by swinging around a paddle shaft 350.
[0033]
The jogger motor M is a motor for driving slide guides 301 and 302 described later, and a stepping motor is used in this embodiment.
[0034]
The paddles 322 are made of a flexible material such as rubber, and a plurality of paddles 322 are fixed to the paddle shaft 350 in a direction orthogonal to the sheet conveying direction. When the paddle shaft is driven and rotated in the clockwise direction in FIG. 2, the sheet S is moved in the direction opposite to the sheet conveying direction, and the end surface of the sheet S is brought into contact with the reference wall 323 for alignment.
[0035]
As shown in FIG. 3, in the sheet post-processing apparatus 300 according to the present embodiment, slide guides 301 and 302 are provided as guide members that perform alignment in the sheet width direction.
[0036]
In the sheet post-processing apparatus 300, when stapling is performed based on a command output in advance from a computer or the like, a sheet S to be stapled is discharged by a solenoid (not shown) before being discharged by the discharge roller 130. The flapper 150 is rotated counterclockwise in FIG. 2 through the link, and is brought into a stopped state by contacting the stopper at the position of FIG. Can be switched.
[0037]
As a result, the sheet S is carried into the inlet 390 of the sheet post-processing apparatus 300 by the roller pair 120 provided in the printer main body 100.
[0038]
The sheet S carried into the sheet post-processing apparatus 300 is detected by rotating the flag 361 of the entrance sensor clockwise and causing the photosensor 362 to transmit light. Thereafter, the sheet is conveyed upward by the inlet roller pair 363.
[0039]
The sheet post-processing apparatus 300 can be stapled and discharged and stacked on the stacking unit 325 of the sheet post-processing apparatus, or can be discharged and stacked on the stacking unit 325 of the sheet post-processing apparatus simply face down.
[0040]
Here, an operation of discharging and stacking on the stacking unit 325 of the sheet post-processing apparatus in a face-down manner will be described with reference to FIG.
[0041]
At this time, as shown in FIG. 5A, in the sheet post-processing apparatus 300, the bottom surfaces of the right slide guide 301 and the left slide guide 302 with respect to the sheet carry-in direction are in contact with the sheet S that is carried in. The sheet S is retreated to a position where the sheet S is not moved, that is, a position outside the sheet S by a predetermined amount, and the sheet S is directly conveyed to the stacking unit of the sheet post-processing apparatus.
[0042]
The sheet conveyed by the entrance roller pair 363 passes through the staple roller pair 320, then passes through the gap between the staples H, is conveyed by the discharge roller pair 330, and is stacked on the sheet discharge unit 325 of the sheet post-processing apparatus.
[0043]
{Post-processing operation}
Next, an operation when stapling and discharging and stacking on the stacking unit 325 of the sheet post-processing apparatus will be described with reference to FIG.
[0044]
At this time, as shown in FIG. 3A, in the sheet post-processing apparatus 300, the reference pins 303 and 304 provided on the wall surfaces of the right slide guide 301 and the left slide guide 302 with respect to the sheet carry-in direction are The sheet S is retracted to a position outside the sheet S by a predetermined amount so as not to interfere with the loaded sheet S. Spacing between bottom surfaces of slide guides 301 and 302 Is It is at a position smaller than the width of the sheet S and waits for the sheet S to enter. This position is set as a standby position.
[0045]
The sheet conveyed by the inlet roller pair 363 passes through the staple roller pair 320 and then passes through the gap between the staples H, and then is conveyed by the discharge roller pair 330 and is configured by the slide guides 301 and 302. The sheet is conveyed onto the guide surface of the sheet stacking unit 300B.
[0046]
Here, as shown in FIG. 6A, the guide surface of the first sheet stacking unit 300B is inclined at a predetermined angle with respect to the horizontal direction, and is mutually on the upstream side and the downstream side in the sheet loading direction. The inclination angles are different, and specifically, a bent portion 300C that is bent at an inclination angle α is formed between a predetermined section on the upstream side and a predetermined section on the downstream side. The guide surface of the first sheet stacking unit 300 </ b> B has such a bent portion 300 </ b> C, thereby preventing the bending of the central portion of the sheet S that is not guided by the slide guides 301 and 302.
[0047]
Immediately after the first sheet is conveyed onto the surface formed by the slide guides 301 and 302, the arm 331 rotates counterclockwise so that the discharge upper roller 330a supported by the arm 331 is moved upward. Retreating in the direction, the discharge roller pair 330 is separated, and at the same time, the drive connected to the discharge roller pair 330 is cut to stop the rotation of the discharge upper roller 330a and the discharge lower roller 330b.
[0048]
When the trailing edge of the sheet S completely passes through the staple roller pair 320, the sheet returns to the direction opposite to the conveyance direction by its own weight and moves toward the reference wall 323.
[0049]
Next, only the left slide guide 302 is operated, and the alignment operation in the width direction of each sheet stacked on the first sheet stacking unit 300B is started. Specifically, when the slide guide 302 is driven by the motor M and moves to the right side in FIG. 3A, the reference pin 304 provided on the left slide guide 302 abuts on the left side surface of the sheet S and moves to the right side. The sheet S is pushed into the slide guide 301 side. Then, when the right side surface of the sheet S abuts on a reference pin 303 provided on the slide guide 301, alignment of the sheets in the width direction is performed. The sheet S is set to move to a staple position set at a position where the sheet S is in contact with the reference pin 303 and aligned.
[0050]
After the sheet aligning operation, the left slide guide 302 moves in a direction wider than the width of the sheet S so that the next sheet can be conveyed again at the standby position.
[0051]
(Slide guide)
Here, the configuration of the slide guide will be described with reference to FIGS. Each of the slide guides 301 and 302 is guided by a total of four guide pins 313a provided on the mold frame and guide pins 313b provided on the sheet metal frame, so that the left and right directions in FIG. A reciprocating movement is possible in a direction (sheet width direction) orthogonal to the direction, and is moved by transmission of a driving force from the jogger motor M.
[0052]
When viewed from the downstream side in the sheet conveyance direction, the slide guides 301 and 302 are each a wall portion that guides both sides of the sheet S and a support portion that supports the upper and lower surfaces of the sheet S, as shown in FIG. Therefore, each sheet discharged onto the first sheet stacking portion 300B is supported by the lower surface of the U-shape, and the central portion in the width direction of the sheet S is not guided. It has a configuration.
[0053]
The left slide guide 302 is provided with a slide rack 310 having a flat gear that meshes with the step gear 317. On the other hand, a slide rack 312 having a flat gear that meshes with the step gear 317 is also attached to the right slide guide 301. Here, the right slide rack 312 is provided so as to be movable relative to the right slide guide 301 via a coiled spring 314. Here, one end of the spring 314 contacts the right slide guide 301, the other end contacts the right slide rack 312, and urges the right slide guide 301 and the right slide rack 312 to expand. The right slide rack 312 has an embossed portion 312a for moving the square hole portion 301a on the right slide guide 301 side.
Two reference pins 303 made of metal having excellent wear resistance are provided on the side wall of the right slide guide 301, and two reference pins 304 are provided on the side wall of the left slide guide 302, respectively. When aligning, the left slide guide 302 moves as will be described later, and the reference pins 303 and 304 come into contact with the sheet side end faces 305 and 306.
[0054]
The right slide guide 301 and the left slide guide 302 are supported in the height direction by a step gear 317 and a jog sheet metal frame.
[0055]
The stapler H is fixedly arranged on the right slide guide 301 side in order to staple each sheet at the upper left corner of the image surface of the image-formed sheet and bind the sheets.
[0056]
Next, the operation of each slide guide 301, 302 will be described. When the sheet post-processing apparatus 300 is turned on, the staple roller pair 320 driven by the drive motor starts rotating, and then the jogger motor M rotates and the step gear 317 rotates, whereby the left slide guide 301 is rotated. The rack 310 is driven and retracts to the outside. In the right slide guide 301, when the jogger motor M rotates and the step gear 317 rotates, the slide rack 312 first moves relative to each other, and the embossed portion 312a of the slide rack 312 is changed to the square hole portion 301a of the right slide guide 301 in FIG. After coming into contact with the right end surface shown, it is retracted to the outside by being pressed by the embossed portion 312a.
[0057]
The right slide guide 301 is provided with a slit portion 301S, and when the slit portion 301S moves to a predetermined retreat distance, as shown in FIG. M stops. This position is the home position.
[0058]
When a signal that the sheet S enters the sheet post-processing apparatus 300 is input from the printer main body 100 to the sheet post-processing apparatus 300, the jogger motor M rotates, and the right slide guide 301 and the left slide guide 302 move inward. 3A and 3B, the vehicle stops at a position wider by a predetermined amount d than the width of the entering sheet S. In this position, the right slide guide 301 is in a state where the stopper 301b abuts against the end surface 313c of the guide pin 313a and cannot move further inward. The position shown in FIG. 3 is set as a standby position, and at this standby position, the side surface of the right slide guide 301 becomes a reference position during the alignment operation.
[0059]
In the present embodiment, when the size (width) of the sheet S is the maximum size that can be conveyed, the standby positions of the right slide guide 301 and the left slide guide 302 so that the gaps on both sides become predetermined amounts d and d, respectively. Is set.
[0060]
When aligning a narrower sheet in the sheet post-processing apparatus 300, the left slide guide 301 is moved to the right by an amount corresponding to this, so that the gap on the left side in FIG. The predetermined amount is d. On the other hand, in this case, the gap between the sheet and the left slide guide 302 is wider than the predetermined amount d by half of the narrowed amount.
[0061]
As shown in FIG. 4, after the lateral alignment is performed by the slide guides 301 and 302, both slide guides are retracted a little outside, the regulation of the lateral alignment direction of the sheet S is set to a rough state, and the sheet S is conveyed by the sheet. Make it movable in the direction. Thereafter, as shown in FIG. 6B, the paddle 322 rotates clockwise about the paddle shaft 350 so that the paddle 322 comes into contact with the upper surface of the sheet S and abuts the sheet S against the reference wall 323. Align.
[0062]
By these operations, alignment in the direction perpendicular to the sheet conveying direction and the sheet conveying direction is possible. In order to maintain this aligned state, as shown in FIG. 3A, a lever provided with a friction member is arranged in the vertical direction in the vicinity of the right end surface of the aligned sheet as shown in the arrow A. It has stamp means 400 that moves and presses the aligned sheet, and the lever presses the upper surface of the sheet after the alignment operation is finished and before the next entering sheet comes into contact with the aligned sheet, The next sheet is prevented from moving the aligned sheet. This stamp means 400 moves the stamp member 400 up and down via a link by a solenoid 400a.
[0063]
When the second and subsequent sheets are conveyed, the discharge roller pair 330 is separated, so when the trailing edge of the sheet S completely passes through the staple roller pair 320, the sheet returns to the direction opposite to the conveyance direction by its own weight, and the reference wall Move in direction 323. Before starting the alignment operation, the stamp unit 400 moves upward to end the hold operation. Since the alignment operation from here is exactly the same as that of the first sheet, the description thereof is omitted.
[0064]
By repeating such an operation, the operation of aligning the last (nth) sheet (Sn) of one job is performed, and each reference pin 304 provided on the left slide guide 302 moves the left side surface of the sheet to the right slide guide 301. 4 in a state where the movement of the left slide guide 302 is stopped and the position of the right side of the rear end is stapled by a small stapler H positioned on the right side of the rear end of the sheet bundle.
[0065]
According to this configuration and operation, during the alignment operation of each sheet, the right slide guide 301 does not stop and move at the reference position, only the left slide guide 302 moves, and the left end of each sheet moves to the reference position. Thus, the binding process by the stapler H fixedly arranged on the right slide guide 301 side is performed accurately and reliably. Furthermore, the position of the left edge of each sheet is constant even when the width of each sheet carried in one job varies or when the sheet size changes, for example, from letter size to A4 size within one job. Therefore, the finish of the binding process by the stapler H becomes accurate and beautiful, and an excellent effect is obtained.
[0066]
In the present embodiment, when the stapling operation is completed as described above, the discharge upper roller 330a pivotally supported on the arm 331 is rotated by the arm 331 rotating clockwise as shown in FIG. 6C. Moving downward, the discharge roller pair 330 is formed, and at the same time, the drive is connected to both rollers of the discharge roller pair 330 to start the rotation of the discharge upper roller 330a and the discharge lower roller 330b.
[0067]
By this operation, the sheet bundle S is nipped by the discharge upper roller 330 a and the discharge lower roller 330 b and conveyed onto the surface formed by the right slide guide 301 and the left slide guide 302.
[0068]
When the sheet bundle S is completely discharged from the discharge roller pair 330, the jogger motor M is rotationally driven to move the left slide guide 302 from the state shown in FIG. When the left slide guide 302 starts to move, the slide rack 312 moves to the right in FIG. 4 on the right slide guide 301 side, and the right slide guide 301 itself does not move immediately.
[0069]
When the position of the left slide guide 302 passes the standby position shown in FIG. 3, the embossed portion 312a of the slide rack 312 comes into contact with the end surface of the square hole portion 310a of the right slide guide 301, and the right slide guide 301 is in FIG. The slide guides 301 and 302 are moved to the right side.
[0070]
Further, when the interval between the supported slide guides 301 and 302 becomes close to the width of the sheet or wider than that, the stapled sheet bundle moves downward as shown in FIGS. 5 and 6C. Fall into. As a result, the sheet bundle falls to the stacking unit 325 of the sheet post-processing apparatus and is stacked.
[0071]
(Paddle drive configuration)
Here, a means for rotating the paddle shaft 350 will be described.
[0072]
The configuration of the drive system will be described with reference to FIG. FIG. 7A shows a gear series, gears 504a and 504b, which transmits driving to the discharge upper roller 330a. The gear 504a is fixed to the shaft of the discharge upper roller 330a. FIG. 7B is a diagram in which the gear 504b and the swing plate 560 are deleted from the diagram of FIG. 7A, and FIG. 7B shows a gear series and a gear 506 that transmits driving to the lower discharge roller 330b. The gear 506 is fixed to the lower discharge roller 330b.
[0073]
This drive series is divided into two series. The conveyance drive system receives rotation from the H motor gear 501 fixed to the shaft of the drive motor, and the sheet is provided with three roller pairs including a discharge roller pair 330, a gear 513, and a conveyance roller pair (not shown) to which the belt pulley 521 is fixed. It is conveyed in the direction of the arrow (from the bottom to the top in the figure).
[0074]
The paddle and roller separation drive system outputs a driving force from the P motor gear 401. The swing holder 450 is swingable about a rotation center 450 a and has a configuration in which a switching gear 403 that is pivotally supported can be selectively connected to the cam gear L 404 and the idler gear 406.
[0075]
Next, the operation of the paddle 322 will be described with reference to FIG. When the P motor gear 401 fixed to the P motor rotates counterclockwise (in the direction of the arrow in the figure), the step gear 402 rotates counterclockwise together with the swing holder 450, and swings when the switching gear 403 is connected to the idler gear 406. The moving holder 450 does not rotate counterclockwise any further. At this time, the switching gear 403 is not connected to the cam gear L404.
[0076]
The idler gear 406 is connected to a paddle gear 407 fixed to the paddle shaft 350. By rotating the paddle shaft 350 in the clockwise direction, the paddle 322 is rotated, and the sheet is moved to the opposite side to the sheet conveyance direction to move the reference wall. The end surface of the sheet S can be brought into contact with the H.323 and can be aligned.
[0077]
{Separation configuration of discharge roller pair}
Next, a configuration in which the discharge upper roller 330a pivotally supported by the arm 331 is retracted upward and the discharge roller pair 330 is separated will be described.
[0078]
As shown in FIG. 8A, the swing holder 450 is configured to hold the switching gear 403 and the step gear 402 so as to be rotatable, and to be swingable left and right around the rotation center 450a. It is held between the step gear 402 and the swing holder 450 with a constant frictional force. No The
[0079]
When the swing holder 450 swings to the right, the switching gear 403 connects to the cam gear L404, and when the swing holder 450 swings to the left, the switch gear 403 connects to the idler gear 406 to transmit the drive.
[0080]
When the P motor gear 401 fixed to the P motor rotates counterclockwise (in the direction of the arrow in the figure), the step gear 402 Is When the switch gear 403 is rotated together with the swing holder 450 and the switching gear 403 is connected to the cam gear L404, the swing holder 450 does not rotate further clockwise. At this time, the switching gear 403 is not connected to the idler gear 406.
[0081]
When the switching gear 403 is connected to the cam gear L404, the cam gear L404 rotates 180 degrees clockwise and the cam gear R405 rotates 180 degrees counterclockwise.
[0082]
The drive release plate 550 supports the drive release gear 502 and can swing around the rotation center 550a. In addition, as shown in FIG. 7, the drive release plate 550 is biased counterclockwise by a spring 555. The cam gear L404 rotates 180 degrees clockwise so that the cam surface is driven by the drive release plate 550. The The connection between the drive release gear 502 and the idler gear 503 is released by rotating about 10 degrees clockwise.
[0083]
The arm 331 is pressed downward by a pressure spring P as an urging means in a nip state, and ensures a nip pressure necessary for sheet conveyance.
[0084]
When the cam gear R405 rotates clockwise and the cam surface 405a indicated by the dotted line moves in a direction to push up the arm 331, the arm 331 is compressed counterclockwise around the paddle shaft 350 while being compressed by the pressure spring P. By rotating, the discharge upper roller 330a pivotally supported by the arm 331 is moved upward to separate the discharge roller pair 330 from each other.
[0085]
With this series of operations, the separation of the discharge roller 330 and the release of the drive to the discharge roller pair 330 are realized.
[0086]
With the above configuration, the separation operation of the discharge roller pair 330 and the sheet alignment operation by the paddle 322 are selectively performed by one motor.
[0087]
{Nip configuration of discharge roller pair}
Next, with reference to FIG. 9 to FIG. 13, the operation of the discharge upper roller 330a moving downward and nipping will be described.
[0088]
When the sheet alignment and post-processing are completed, when the P motor gear 401 fixed to the P motor rotates again counterclockwise (in the direction of the arrow in FIG. 8A), the step gear 402 is moved together with the swing holder 450. Rotates and the switching gear 403 is connected to the cam gear L404. When the switching gear 403 is connected to the cam gear L404, the cam gear L404 starts rotating clockwise and the cam gear R405 starts rotating counterclockwise. Since the pressure spring P is compressed, when the cam gear R405 starts to rotate at a predetermined angle, the cam gear R405 receives a force from the pressure spring P via the arm 331 and generates a counterclockwise torque. Due to the torque, the gear R405 receives the rotating force without receiving the driving force from the P motor.
[0089]
9 shows a perspective view of the driving means for moving the discharge upper roller 330a as seen from the same direction as FIG. 8, and FIG. 10 shows a perspective view of the opposite side.
[0090]
(Brake configuration)
A cam 505 having the same cam shape is provided on the opposite side of the cam gear R405, and the distance of the discharge upper roller 330a is determined by contacting the opposite surface of the arm 331. Further, as with the opposite surface, the pressure spring P biases the arm 331 downward.
[0091]
As shown in FIG. 11, the brake plate 500 serving as a brake means includes a leaf spring portion 500 a and a friction member 500 b made of a material having a high friction coefficient such as rubber, and an end portion 500 c is fixed to the frame. . The cam 505 is long in the width direction (a direction perpendicular to the axis), and the cam action surface is provided with a region in contact with the brake plate 500 in addition to a portion in contact with the arm 331.
[0092]
FIG. 12 shows the positional relationship between the phase angle of the cam 505 and the brake plate 500 and the position of the sensor 590 that detects the position of the cam provided on the opposite side and the flag portion 404a provided on the cam gear L404. The angle of the cam 505 when the pair 330 is nipped is 0 degree, and the angle of the cam 505 when the pair 330 is separated is 180 degrees.
[0093]
As shown in FIG. 12, the brake plate 500 hardly comes into contact with the cam when the arm 331 is raised, that is, when the cam 505 has a phase of 0 to 180 degrees.
[0094]
On the other hand, during the process of lowering the arm 331, when the cam gear R405 starts to rotate by a predetermined angle, the cam gear R405 receives a force from the pressure spring P via the arm 331 and generates a clockwise torque in FIG. To do. Due to the torque, the friction member 500b of the brake plate 500 abuts the cam 505 and brakes the torque received from the pressure spring P in a phase in which the cam gear R405 receives the rotating force without receiving the driving force from the P motor. Generating power. The torque is indicated by a one-dot chain line in FIG.
[0095]
The torque curve is set so that the pressure spring P cancels the torque curve (curve shown by the solid line in FIG. 13) generated on the cam shaft via the arm 331, the cam 505, and the cam gear R405. The maximum value of the torque (clockwise torque in 12) is drastically reduced.
[0096]
The flag portion 404a provided on the cam gear L404 turns off the sensor 590 just before a predetermined angle at which the phase of the cam 505 and the cam gear 405 is 360 degrees. When the predetermined pulse P motor is driven from this timing, the P motor is stopped, and the pair of discharge upper rollers 330 are in the nip position (phase 360 degrees). Since the negative torque is reduced, the cam gear 405 and the cam 505 do not overrun.
[0097]
Therefore, by adopting this configuration, it is possible to eliminate an impact when the arm 331 is lowered, and to determine the position of the discharge upper roller pair with high accuracy. Moreover, the impact sound accompanying the lowering of the arm 331 is also suppressed.
[0098]
Further, even if the P motor is a stepping motor, it will not be stepped out by being rotated by the torque urged from the arm, so that no jamming occurs.
[0099]
[Second Embodiment]
Next, a brake configuration of the arm 331 according to the second embodiment of the present invention will be described with reference to FIG.
[0100]
In the first embodiment described above, the brake plate 500 includes the leaf spring portion 500a and the friction member 500b. However, in the brake plate 600 of this embodiment, the friction member 601 is fixed to the support member 602, and the support member 602 is attached to the brake plate 500. Is provided with a cylindrical guide portion 602a, which is slidably attached to the guide portion 650a of the frame. Further, a compression spring 660 is inserted into the cylindrical guide portion 602 a of the support member 602, and is urged in a direction extending between the support member 602 and the frame 650.
[0101]
The support member 602 has a pin-shaped stopper 670, and the position of the support member 602 is regulated by abutting the end surface of the guide portion 650a of the frame with the stopper. The difference from the first embodiment is only the portion of the brake plate 500, and the other portions have exactly the same configuration, and thus the description thereof is omitted.
[0102]
FIG. 14 shows the positional relationship between the phase angle of the cam 505 and the brake plate 600. The angle of the cam 505 when the discharge roller pair 330 is nipped is 0 degree, and the angle of the cam 505 when it is separated. It is 180 degrees.
[0103]
As shown in FIG. 14, the brake plate 600 hardly comes into contact with the cam 505 in the process in which the arm 331 moves up, that is, in the phase where the cam 505 is 0 to 180 degrees.
[0104]
On the other hand, in the process of lowering the arm 331, when the cam gear R405 starts to rotate by a predetermined angle, the cam gear R405 receives a force from the pressure spring P via the arm 331 and generates a clockwise torque in FIG. . Even if the driving force from the P motor is not received by the torque, the friction member 601 of the brake plate 600 abuts the cam 505 and brakes the torque received from the pressure spring P in the phase in which the gear R405 receives the rotating force. The power to generate is generated.
[0105]
The torque curve is set so that the pressure spring P cancels the torque curve generated on the cam shaft via the arm 331, the cam 505, and the cam gear 405. The maximum value of the negative torque is the same as that of the first embodiment. Similarly, it is drastically reduced.
[0106]
According to this embodiment, when there is no space for providing the leaf spring as in the first embodiment described above, a space-saving cam braking means can be provided by using a compression spring.
[0107]
[0108]
[0109]
[0110]
[0111]
[0112]
[0113]
【The invention's effect】
As described above, according to the configuration of the present invention, a pair of rollers that can be separated by a cam can be reliably operated. For example, even if the pair of rollers are arranged alternately, The interval can be stabilized. Accordingly, a predetermined conveying force can be applied to the conveyed sheet and the sheet can be applied with a firmness, so that a pair of separable rollers with good sheet stackability can be realized.
[0114]
In addition, the maximum torque applied to the cam that separates the rollers can be reduced compared to a configuration in which an oil damper with silicon oil or the like sealed in the cam rotation shaft or gear train is applied to the cam drive system. A small motor can be employed, and the separation roller pair can be reduced in size, power consumption, and cost.
[0115]
Furthermore, it is possible to provide a small, low-cost and power-saving sheet processing apparatus and an image forming apparatus including the same.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a printer equipped with a sheet post-processing apparatus according to a first embodiment of the present invention.
FIG. 2 is an operation explanatory diagram of the sheet post-processing apparatus according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view for explaining the operation of the slide guide in the first embodiment, showing a state in which the slide guide is in a standby position.
FIG. 4 is a cross-sectional view for explaining the operation of the slide guide in the first embodiment, showing a state in which the sheets are aligned by the slide guide.
FIG. 5 is a cross-sectional view for explaining the operation of the slide guide in the first embodiment, showing a state in which the slide guide is located at the home position and the sheet bundle is dropped.
FIG. 6 is a cross-sectional view according to the first embodiment of the present invention and an operation explanatory diagram.
FIG. 7 is a cross-sectional view of a drive unit according to the first embodiment of the present invention.
FIG. 8 is a cross-sectional view of a drive unit according to the first embodiment of the present invention.
FIG. 9 is a perspective view of a drive unit according to a second embodiment of the present invention.
FIG. 10 is a perspective view of the vicinity of a brake plate according to a second embodiment of the present invention.
FIG. 11 is an enlarged view of a brake plate according to the second embodiment of the present invention.
FIG. 12 is a cross-sectional view of a brake means in the second embodiment of the present invention.
FIG. 13 is a graph showing a torque curve of a cam
FIG. 14 is a cross-sectional view of the brake means in the second embodiment of the present invention.
[Explanation of symbols]
H ... Staple
M: Jogger motor
P… Pressure spring
S ... Sheet
100 ... Printer body
100A ... Main body
101 ... Feed roller
102 ... Separation roller pair
103 ... Conveying roller pair
104 ... Registration roller pair
105 ... Photoconductor drum
106 ... exposure means
107. Developing means
108 ... transfer roller
109 ... Fixer
120 ... Roller pair
125 ... Face-down discharge section
130 ... discharge roller
150 ... Flapper
200 ... Feed cassette
300 ... Sheet post-processing device
300A ... casing part
300B ... Sheet stacking section
300C ... Bent part
301, 302 ... slide guide
301S ... slit part
301a: Embossed part
301b ... stopper
303, 304 ... reference pin
305, 306 ... Both end faces of the sheet
310 ... slide rack
312 ... slide rack
312a ... Square hole
313a ... guide pin
313b Guide pin
313c ... end face
314: Spring
316 ... Photosensor
317 ... Step gear
320: Staple roller pair
322 ... Paddle
323 ... Reference wall
325 ... Loading section
330 ... discharge roller pair
330a ... discharge upper roller
330b ... discharge lower roller
331 ... arm
350 ... Paddle shaft
361 ... flag
362 ... Photosensor
363: Rear entrance roller pair
400… Stamp means
400a ... Solenoid
401 ... motor gear
402 ... Step gear
403 ... switching gear
404 ... Cam gear L
404a ... Flag part
405: Cam gear R
405a ... cam surface
406 ... idler gear
407 ... paddle gear
450… Oscillating holder
450a ... rotation center
500… Brake plate
500a ... leaf spring
500b ... friction member
501: Motor gear
502 ... Drive release gear
503 ... idler gear
504a, 504b ... Gear
505 ... Cam
513: Gear
521 ... Belt pulley
550 ... Drive release plate
550a ... rotation center
555 ... Spring
560 ... Oscillating plate
590 Sensor
600… Brake plate
601 ... Friction member
602 ... Support member
602a ... guide part
650a ... guide part
660 ... compression spring
670 Stopper

Claims (7)

In a sheet processing apparatus having a pair of rollers that can be sandwiched and conveyed and can be separated,
An arm that supports one of the rollers and swings;
A biasing means for biasing the arm in a direction in which the roller supported by the arm approaches the other roller;
A cam capable of swinging the arm by abutting on the arm biased by the biasing means, and a radius of the working surface contacting the arm changing with rotation;
Brake means for contacting a working surface of the cam when the roller supported by the arm approaches the other roller and applying a braking force to the rotation of the cam;
I have a,
The sheet processing apparatus according to claim 1, wherein the brake means starts contact with a working surface where a radius of the cam increases .   The sheet processing apparatus according to claim 1, wherein the roller pairs are arranged alternately.   The sheet processing apparatus according to claim 1, wherein the brake means is configured to bias a friction member toward the cam.   4. A sheet processing apparatus according to claim 3, wherein the means for urging the friction member toward the cam comprises a leaf spring or a compression spring. The sheet processing apparatus according to any one of claims 1 to 4 , wherein the cam is rotated by a stepping motor. The sheet processing apparatus according to any one of claims 1 to 5, further comprising a detection means for detecting a rotational position of the cam. Image processing means for forming an image on a sheet;
The sheet processing apparatus according to any one of claims 1 to 6 , which processes the image-processed sheet;
An image forming apparatus comprising:

Images