JP2006256731A - Sheet handling device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet handling device B increased in the number of sheets to be loaded on an upper stage stack tray 18a and improved in space efficiency without increasing manufacturing costs. <P>SOLUTION: This sheet handling device is provided with the upper stag stack tray 18a to be loaded with sheets under a pair of downstream discharge rollers 17 and, thereafter, to be moved over the pair of downstream discharge rollers 17 for waiting, and an escape tray 31 hung over the upper stage stack tray 18a. The escape tray 31 is assembled by connecting a rear end tray 31c, which is integrally formed with a top cover of the sheet handling device B by resin-molding, to a light tip tray 31a freely to turn around a support shaft 31b. When the upper stage stack tray 18a loaded with the sheets rises, the tip tray 31a is pushed by the sheets to retreat upward. With this structure, a large quantity of the sheets can be loaded on the upper stage stack tray 18a without worrying about interference with the tip tray 31a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet processing apparatus and a sheet processing apparatus for receiving a sheet discharged from an image forming apparatus such as a copying machine, a printer, a facsimile machine, a multi-function machine, and other office machines and stacking the sheet on a sheet stacking member that can be moved up and down. The present invention relates to a built-in / connected image forming apparatus, and more particularly, to a technique for increasing a sheet stackable height of a sheet stacking member.

  Accepts sheets carried out from image forming apparatuses such as copiers, printers, facsimiles, etc., and aligns, sorts, stacks, staples, folds, stuffs envelopes, packs, binds, sorts, punches, inspects, processes, etc. Sheet processing apparatuses that perform simple processing have been put into practical use. Also, in an image forming apparatus such as a copying machine, such a sheet processing apparatus is built in or connected as a purchase option (so-called option).

  Some models of the sheet processing apparatus include a discharge member disposed at a predetermined height and a sheet stacking member supported so as to be movable up and down with respect to the housing structure, and the sheet is transferred from the discharge member to the sheet stacking member. Is discharged and loaded. In addition, the sheet stacking member is gradually lowered as the sheet stacking progresses to maintain the sheet stacking surface height substantially constant.

  Patent Document 1 shows a sheet processing apparatus connected to an image forming apparatus. Here, a sheet stacking member (saddle tray) fixed to the housing structure is disposed below the sheet stacking member that can be raised and lowered.

  Patent Document 2 discloses a sheet processing apparatus including a sheet stacking member that can be moved up and down in two stages. Here, prior to the start of stacking on the lower sheet stacking member by the common discharge member, the disturbing upper sheet stacking member is moved to a position higher than the discharge member.

  Also, a drawer aligning wall attached so as to be capable of being pulled out upward is provided, and a locking portion formed at the upper end of the drawer aligning wall is pushed up by the uppermost surface of the sheets stacked on the upper sheet stacking member. The drawer aligning wall supports the rear end of the sheet so that the sheet stacked on the lower sheet stacking member inclined downward toward the discharge member side does not slide down to the housing structure side.

JP 11-322180 A JP 2002-226118 A

  Due to the recent progress in downsizing and cost reduction of image forming apparatuses and restrictions on installation area, sheet processing apparatuses are required to reduce apparatus height and installation area in addition to downsizing the appearance. On the other hand, it is also required to increase the number of sheets that can be stacked (height) of the sheet processing apparatus, to reduce the frequency of taking out stacked sheets, and to be able to cope with large-lot printing. In some sheet processing apparatuses, it is proposed that an emergency discharge tray is provided to stack sheets for interrupt printing or FAX reception printing.

  However, as shown in Patent Document 1, if a fixed tray is provided below the sheet stacking member that can be moved up and down and assigned to the emergency discharge tray, it is possible to miss the emergency discharge because the sheets discharged to the fixed tray are inconspicuous Increases nature.

  However, if the upper sheet stacking member in the sheet processing apparatus disclosed in Patent Document 2 is assigned to the emergency discharge tray, normal sheet stacking cannot be performed on the upper sheet stacking member. Will decrease. Therefore, it has been proposed to provide three stages of sheet stacking members that can be moved up and down independently and assign the uppermost stage to the emergency discharge tray. However, adding one stage of expensive sheet stacking members including a motor and a speed reduction mechanism reduces the manufacturing cost. However, there is a problem that emergency discharge cannot be performed in a state where it is retracted upward from the normal discharge position.

  Naturally, if a fixed emergency discharge tray is provided above the ascending / descending sheet stacking member, the room for ascending the sheet stacking member and the number of sheets that can be stacked are reduced.

  It is also possible to arrange an emergency discharge tray on the upper surface of the sheet processing apparatus casing avoiding the upper side of the sheet stacking member. However, the length of the casing increases to increase the size of the sheet processing apparatus, or the emergency discharge tray. However, large-size sheets cannot be stacked, and the conveyance path for discharging the sheets to the emergency discharge tray and the arrangement of the discharge members become tight.

  The present invention provides an emergency discharge tray at the top without increasing the length of the casing, without reducing the ascending / descending space of the sheet stacking member that can be moved up and down, and without providing an expensive driving device or the like. It is an object of the present invention to provide a sheet processing apparatus capable of providing an additional sheet stacking unit.

  The sheet processing apparatus according to the present invention includes a first sheet stacking member that is supported so as to be movable up and down along the housing structure and stacks sheets, and a first sheet stacking member disposed above the first sheet stacking member and capable of stacking sheets. In a sheet processing apparatus including a two-sheet stacking member, at least a part of the second sheet stacking member is configured to be retractable upward, and in contact with a sheet stacked on the first sheet stacking member It is pushed up to evacuate.

  In the sheet processing apparatus of the present invention, the second sheet stacking member (additional stacking unit such as an emergency discharge tray) is disposed at the top of the housing structure. Further, at least part of the second sheet stacking member is positioned above the first sheet stacking member, and when the first sheet stacking member on which the sheets are stacked rises, the second sheet stacking member is placed on the stacked sheet. The lower surface of the battery collides. However, since at least a part of the second sheet stacking member is pushed up by the collided sheet as it is and retreats to a position or state that does not hinder the rise of the first sheet stacking member, the second sheet stacking member is caused by the second sheet stacking member. There is no decrease in the room for raising one sheet stacking member or the number of sheets that can be stacked.

  Further, since the second sheet stacking member is retracted by being driven by the rising of the first sheet stacking member, a drive motor and a drive mechanism for retracting the second sheet stacking member are unnecessary, and the second sheet stacking member Thinning and weight reduction are easy, and the addition of parts on the housing structure side is also minimal.

  Therefore, an easy-to-use sheet processing apparatus in which the second sheet stacking member is disposed above the first sheet stacking member can be provided at a low cost while being reduced in size and weight.

  Hereinafter, a sheet processing apparatus of this embodiment and an image forming apparatus equipped with the sheet processing apparatus will be described with reference to the drawings.

  The image forming apparatus includes a copying machine, a facsimile machine, a printer, and a complex machine of these. The image forming apparatus provided with the sheet processing apparatus according to the present embodiment is not limited to the copying machine. In addition, the sheet processing apparatus of the present embodiment can be mounted on office machines and inspection apparatuses other than the image forming apparatus.

  In addition, unless otherwise specified, the dimensions, numerical values, materials, shapes, relative arrangements, and specific numerical values of the number of stacked sheets described in the following description are within the scope of the present invention. It is not intended to limit only to those.

  In the description of the present exemplary embodiment, an example is described in which the sheet processing apparatus is an independent apparatus that is configured to be detachable from the apparatus main body of the image forming apparatus as an independent apparatus. It goes without saying that the sheet processing apparatus of the present embodiment is also applied to a sheet processing apparatus that is incorporated in a housing such as an image forming apparatus and provided integrally therewith. However, since there is no particular functional difference from the case of the sheet processing apparatus described below, description thereof is omitted.

(Image forming device)
FIG. 1 is an explanatory diagram of a configuration of an image forming apparatus including a sheet processing apparatus according to the present embodiment.

  The image forming apparatus A of the present embodiment includes, for example, an image forming unit 3 that is an image forming unit, and is configured by combining, for example, a sheet processing apparatus B that is a processing unit. The sheet processing apparatus B includes a finisher unit C that can discharge the sheets formed by the image forming apparatus A to the upper stacking tray 18a (or the lower stacking tray 18b) by sort processing for each number of copies, and interrupt printing and FAX reception. In this case, there is provided an escape unit D that discharges and stacks sheets to the escape tray 31 in an urgent manner.

  As shown in FIG. 1, the document supply device 1 mounted on the upper part of the image forming apparatus A separates documents one by one from the stacked document bundle for reading and automatically feeds them to the reading unit 2. The reading unit 2 performs so-called continuous scanning, in which line images are continuously extracted from an automatically fed document and converted into electrical signals.

  The image forming unit 3 scans the laser beam modulated using the electrical signal or image data formed by the reading unit 2 with the scanning unit 3a and irradiates the photosensitive drum 3b with electrostatic force on the surface of the photosensitive drum 3a. A latent image is formed. The electrostatic latent image on the photosensitive drum 3a is supplied with toner and developed into a toner image. Thereafter, the toner image is transferred to the sheet P taken out one by one from the sheet cassette 4 in which the sheets P of various sizes are accommodated and conveyed by the conveying roller 5 or the like. The toner image is fixed on the surface thereof by being conveyed to 6 and subjected to heat and pressure.

  In the case of single-sided printing, the sheet P that has been fixed is discharged as it is to the sheet processing apparatus B. However, in the case of double-sided printing, the sheet P is switched back and sent to the retransmission pass 7, and the image forming unit 3 is again turned upside down. To form an image on the back surface. The sheet P for duplex printing is also fixed by the fixing unit 6 and then discharged to the sheet processing apparatus B.

(Sheet processing equipment)
2 is an explanatory diagram of the configuration of the sheet processing apparatus of the present embodiment, FIG. 3 is an explanatory diagram of sheet conveyance in the finisher unit, FIG. 4 is a block diagram of a control system of the sheet processing apparatus, and FIG. 5 is a flowchart of random mode control. is there. The sheet processing apparatus B according to the present embodiment includes, for example, an upper stack tray 18a that is a first sheet stacking member, an escape tray 31 that is a second sheet stacking member, a rear tray 31c that is a fixed tray section, a rotating tray section, and the like. A front end tray 31a, a sorting member such as an inlet flapper 26, a first discharge member such as a downstream discharge roller pair 17 and a second discharge member such as a discharge port roller pair 29.

  As shown in FIG. 2, the entrance flapper 26 disposed on the downstream side of the first transport roller pair 10 is driven by a solenoid (not shown) and has a transport path toward the finisher unit C and a transport path toward the escape unit D. The sheet received by the first conveying roller pair 10 from the image forming apparatus A in FIG. 1 is distributed to the finisher unit C and the scoop unit D. Then, the sheets distributed to the finisher unit C are transferred from the second conveying roller pair 15 to the upstream discharge roller pair 16, and the upper stack tray 18 a (or the lower stack) by the downstream discharge roller pair 17 (see FIG. 3). It is discharged to the tray 18b).

  The upper stacking tray 18a disposed on the side of the finisher unit C is fixed to the upper support frame 19a so that the inclination angle of the sheet stacking surface is 30 °. The upper support frame 19a is disposed opposite to both side surfaces (perpendicular to the paper surface) of the upper stack tray 18a, and support rollers 21 are rotatably supported at upper and lower ends thereof.

  The lower stacking tray 18b disposed immediately below the upper stacking tray 18a is fixed to the lower support frame 19b so that the inclination angle of the sheet stacking surface is 30 °. The lower support frame 19b is disposed opposite to both side surfaces of the lower stack tray 18b, and support rollers 21 are rotatably supported at upper and lower ends thereof.

  Corresponding to the support frames 19a and 19b, the guide rails 22 for guiding the support rollers 21 are disposed opposite to the support columns 37 of the sheet processing apparatus B. The guide rails 22 are U-shaped in cross section, and are arranged in parallel and facing each other with their openings facing each other at a predetermined interval corresponding to the width of the upper stacking tray 18a (lower stacking tray 18b). It extends in the vertical direction of the device B. Then, as the support roller 21 rolls in the opening of the guide rail 22, the upper support frame 19 a and the lower support frame 19 b, and thus the upper stack tray 18 a and the lower stack tray 18 b are guided along the guide rail 22 in the up-and-down direction. Is done.

  A stacker motor 209a for driving up and down and a speed reduction mechanism are built in the upper stacking tray 18a, and a pinion gear (not shown) driven by the stacker motor 209a through the speed reduction mechanism is attached to the support frame 19a. A stacker motor 209b for driving up and down is built in the lower stacking tray 18b, and a pinion gear (not shown) driven by the stacker motor 209b via a speed reduction mechanism is attached to the support frame 19b.

  A rack 37a that meshes with the pinion gear of the upper support frame 19a (and the lower support frame 19b) and converts the rotational motion into a translational motion is provided on the support 37 of the sheet processing apparatus B so as to extend in the vertical direction. Accordingly, the upper stacking tray 18a can be moved to an arbitrary height position along the guide rail 22 by operating the stacker motor 209a, and the lower stacking tray 18b is guided by operating the stacker motor 209b. It can be moved to any height along the rail 22.

  As shown in FIG. 2, the finisher unit C has a staple tray 12 for stacking a predetermined number of sheets to form a sheet bundle in the staple mode, a staple unit 42 for binding the formed sheet bundle, and stapled. A paper discharge port 36 for discharging the sheet bundle and a swing guide 20 that pivotally supports one roller 17b of the downstream discharge roller pair 17 (see FIG. 3) to selectively open and close the paper discharge port 36 are provided. .

  In the staple mode, the swing guide 20 is rotated upward to widen the distance between the rollers 17a and 17b of the downstream discharge roller pair 17 so that the sheet discharged from the upstream discharge roller pair 16 can flow backward to the staple tray 12. . Further, at the time of normal sheet discharge described above, the swing guide 20 is rotated downward to bring the rollers 17a and 17b of the downstream discharge roller pair 17 into contact, and the sheets are nipped to nip the upper stack tray 18a (lower stack tray 18b). ) Can be discharged.

  In the staple mode, the sheet received from the image forming apparatus A by the first conveying roller pair 10 is stacked and aligned on the staple tray 12 from the second conveying roller pair 15 via the upstream discharge roller pair 16, and the staple unit 42 sets the predetermined position. In a state of a sheet bundle that is stapled and stapled every predetermined number of sheets, the sheet is discharged to the upper stacking tray 18a (lower stacking tray 18b) by the downstream discharge roller pair 17.

  The swing guide 20 is provided with a distance measuring sensor 54 that detects the uppermost surface (sheet stacking surface) of the sheets stacked on the upper stacking tray 18a (lower stacking tray 18b). The distance measuring sensor 54 includes an infrared irradiation unit and a light receiving unit that receives reflected light from the sheet surface, and is loaded on the upper stacking tray 18a (lower stacking tray 18b) by measuring the angle of the reflected light. A signal corresponding to the distance to the uppermost surface (sheet stacking surface) of the sheet is output.

  As shown in FIG. 3, the sheet processing apparatus B includes a buffer path 14 that waits for the preceding sheet when two consecutive sheets are stacked and discharged simultaneously, and a buffer roller that conveys the sheet P <b> 2 in the buffer path 14. 23, a buffer flapper 25 that selectively distributes the sheet P3 to the buffer path 14 is provided.

  In the normal discharge mode, the sheet conveyed from the copying machine main body A is transferred from the first conveyance roller pair 10 to the upstream discharge roller pair 16 via the second conveyance roller pair 15 and to the downstream discharge roller pair 17. Nipped and discharged to the upper stacking tray 18a (lower stacking tray 18B) shown in FIG.

  However, when two-sheet simultaneous discharge control for discharging the succeeding sheet P3 on the preceding sheet P2 is performed, the flapper 25 is rotated downward to feed the sheets P2 and P3 into the buffer path 14 and rotate. The sheet P2 and P3 are fed to the upstream discharge roller pair 16 by rotating the buffer roller 23 by rotating the flapper 28 inward and then rotating the flapper 28 inward. In a stacked state, two sheets are discharged simultaneously from the downstream discharge roller pair 17 to the upper stacking tray 18a (lower stacking tray 18b).

  More specifically, the buffer roller 23 starts to rotate at a predetermined timing after the entry sensor 27 detects the leading edge of the sheet P2, and winds up the sheet P2 that has entered the buffer path 14. The buffer roller 23 stops rotating at the timing when the buffer sensor 126 detects the leading edge of the sheet P2, and causes the sheet P2 to stay in the buffer path 14.

  Subsequently, when the leading edge of the sheet P3 passes through the entry sensor 27, the buffer roller 23 starts to rotate again at a predetermined timing and winds up the sheet P3 that has entered the buffer path 14. The predetermined timing is a timing at which the leading edge of the preceding sheet P2 that has circulated around the buffer path 14 and the leading edge of the sheet P3 that has entered the buffer path 14 overlap each other with a predetermined shift amount.

  In the staple mode, the conveyance speed of the preceding sheet received from the image forming apparatus A by the first conveyance roller pair 10 is increased so as not to decrease the processing speed of the image forming apparatus A, and the conveyance interval with the subsequent sheet. You may gain time to spread and stapling. In this case, if the drive motor of the first conveying roller 10 is shared with the other rollers, the succeeding sheet reaches the first conveying roller 10 before the conveying speed of the preceding sheet is sufficiently increased. The paper interval cannot be secured.

  Therefore, the buffer roller 23 and the first transport roller pair 10 are individually driven by the motor 205 and the motor 211 so that they can be driven independently. Further, the downstream discharge roller pair 17 that repeatedly starts / stops and reverses is driven by a drive motor 208.

  As shown in FIG. 4, on the input side of the MPU 200 that performs overall control of the sheet processing apparatus B of the present embodiment, an operation unit 201, an entry sensor 27, a buffer sensor 126, a discharge sensor 29, a distance measuring sensor 54, a stack A sensor 55, a staple slide home position sensor 213, a stacker motor encoder 226, and the like are connected. The operation unit 201 is an image display device provided with an input touch sensor for operating the sheet processing apparatus B.

  Further, on the output side of the MPU 200, a conveyance motor 211, a first flapper solenoid 202, a second flapper solenoid 203, a staple slide motor 212, a discharge motor 205, a paddle solenoid 206, and a side guide motor 207 are provided via drivers D1 to D11. A drive motor 208, stacker motors 209a and 209b, and a stapler motor 210 are connected. The MPU 200 also controls a motor, an actuator, etc. (not shown) used for conveyance and the like.

  Further, the MPU 200 stores therein a control program corresponding to, for example, the operation procedure shown in FIG. 5 and various programs corresponding to various processing modes (not shown).

  The MPU 200 detects the operation content through the operation unit 201 and the input signal of the sensor, performs a predetermined calculation, operates the motor and actuator, and executes an operation sequence corresponding to various processing modes.

  For example, when the distance measuring sensor 54 detects the position of the upper stacking tray 18a, a position detection signal is input to the MPU 200, and the MPU 200 outputs a drive signal of the stacker motor 209a (209b) to the driver D9 (D10) based on the position detection signal. ). Based on this drive signal, the driver D9 (D10) rotates the stacker motor 209a (209b) forward and backward to raise and lower the upper stacking tray 18a (lower stacking tray 18b). As a result, the upper stacking tray 18a (lower stacking tray 18b) moves to a position where the sheet discharge port 36 is not blocked regardless of the sheet stacking amount.

(Cascade mode and random mode)
As a method of stacking sheets on the upper stacking tray 18a and the lower stacking tray 18b, there are a cascade mode in which the maximum number of sheets can be secured and a random mode in which one of the upper stacking tray 18a or the lower stacking tray 18b is designated in advance. is there.

  In the cascade mode, first, up to 1300 sheets that can be stacked on the upper stacking tray 18a are stacked, and then the upper stacking tray 18a is moved to a predetermined position above the paper discharge port 36 and waited. At this time, as will be described later, the leading end tray 31a of the escape tray 31 is pushed up by the upper surface of the sheets stacked on the upper stacking tray 18a, and is rotated and retracted. Thereafter, up to 2450 sheets that can be loaded on the lower stacking tray 18b are loaded (see FIG. 10). Therefore, it is possible to increase the number of stacked sheets as a whole sheet processing apparatus with a single operation.

  In the random mode, when one of the upper stacking tray 18a and the lower stacking tray 18b is designated, the designated upper stacking tray 18a (lower stacking tray 18b) moves below the paper discharge port 36 to transfer the sheet. To load. When loading on the lower stacking tray 18b (upper stacking tray 18a) is notified during loading, the designated lower stacking tray 18b (upper stacking tray 18a) moves below the paper discharge port 36, and is not designated. The upper stacking tray 18a (lower stacking tray 18b) moves to a predetermined standby position. By such an operation, in the random mode, the upper stack tray 18a and the lower stack tray 18b can be stacked until the maximum stack number reaches 1300 sheets and 1700 sheets, respectively.

  The total maximum stack number of 3000 sheets in the random mode is 1700 sheets stacked on the lower stack tray 18b and retracted to the lower limit position, and the upper surface of the sheets stacked on the upper stack tray 18a is below the discharge port 36. Is the maximum number of sheets that can be located Therefore, the maximum stackable number of sheets in the random mode is determined by the lower limit position of the lower stacking tray 18b.

  Stack control of 3000 sheets in the random mode of the sheet processing apparatus A of the present embodiment, in other words, stacking control for discharging the sheets divided into 1300 full sheets of the upper stack tray 18a and 1700 full sheets of the lower stack tray 18b. Will be described with reference to the flowchart of FIG.

  As shown in FIG. 5, when the sheet processing apparatus starts a stacking operation (S1), the image forming apparatus A notifies which of the upper stacking tray 18a and the lower stacking tray 18b is stacked (S2). . Here, if the upper stacking tray 18a is notified, the lower stacking tray 18b is lowered to the lower limit position which is a predetermined standby position (S3), and then the upper stacking tray 18a is moved to a predetermined sheet below the discharge port 36. Move to the loading position (S4).

  Then, the sheet discharge to the upper stack tray 18a is started and the sheets are stacked (S5). In the process of stacking the sheets on the upper stacking tray 18a, the distance measuring sensor 54 monitors the height of the uppermost sheet on the upper stacking tray 18a, and the uppermost sheet of the sheets stacked on the upper stacking tray 18a is the discharge port. Based on the output signal of the distance measuring sensor 54, the upper stacking tray 18a is controlled so as to descend appropriately (S6) so as to be kept at a predetermined height position below 36.

  Here, assuming that the sheet height h1 at the stacking number α of the upper stacking tray 18a and the sheet height H1 at the stacking number of 1300 sheets, the stacking is continued during (h1 <H1) (S10). However, when (h1> H1) is satisfied, stack over is determined (S9), further stacking of sheets is prohibited, and the stacking operation on the upper stacking tray 18a is completed.

  However, even if the stacking operation on the upper stacking tray 18a is completed, the stacking operation is resumed if there is a stacking notification specifying the lower stacking tray 18b. That is, when there is a notification of stacking on the lower stacking tray 18b (S2), the upper stacking tray 18a is moved to a predetermined position above the discharge port 36 to be in a standby state (S11), and then the lower stacking tray 18b is moved to the standby state. The sheet is moved to a predetermined sheet stacking position below the sheet discharge port 36 (S12), and sheets are stacked on the lower stacking tray 18b (S13). While the sheets are being stacked on the lower stacking tray, the distance measuring sensor 54 monitors the height of the uppermost sheet on the lower stacking tray 18b, and the lower stacking is performed in the same manner as when the sheets are stacked on the upper stacking tray (S6). Based on the detection signal detected by the distance measuring sensor 54, the lower stacking tray 18b is appropriately lowered so that the uppermost surface of the sheets stacked on the tray 18b is maintained at a predetermined sheet stacking position below the discharge port 36. (S14).

  Here, assuming that the sheet height h2 at the stacking number β of the lower stacking tray 18b and the sheet height H2 at the stacking number of 1700 sheets, the stacking is continued during (h2 <H2) (S17). However, when (h2> H2) is satisfied, stack over is determined (S16), and further sheet stacking is prohibited, and the stacking operation on the lower stacking tray 18b ends.

  However, even if the stacking operation on the lower stacking tray 18b is completed, if the upper stacking tray 18a is not stacked over and there is a stacking notification specifying the upper stacking tray 18a, the stacking operation on the upper stacking tray 18a is resumed. (S3 to S10).

  By performing the above-described operation control, sheets can be continuously stacked on the upper and lower stacking trays until the stacking number α of the upper stacking tray 18a reaches 1300 and the stacking sheet β of the lower stacking tray 18a reaches 1700.

  Although the above description has been given by taking an example of a sheet processing apparatus that performs sheet binding processing, it is needless to say that the present invention is not limited to this and can be applied to a sheet processing apparatus that performs punching processing.

(Escape unit)
6 is a perspective view of the escape tray, FIG. 7 is a plan view of the front end tray, FIG. 8 is an explanatory view of the rotation range of the front end tray, FIG. 9 is a schematic view of the front end tray in contact with the sheet, and FIG. It is explanatory drawing of the state at the time of stacking the number of sheets. The sheet processing apparatus B of the present embodiment includes, for example, an escape tray 31 that is a second sheet stacking member, a front tray 31a that is a rotating tray portion, a rear tray 31c that is a fixed tray portion, and a second discharge member. For example, a discharge port roller 29 is provided.

  As shown in FIG. 2, an escape tray 31 on which sheets discharged from the escape unit D are stacked is disposed on the upper portion of the sheet processing apparatus B. The escape tray 31 is assigned to an interrupt print job instructed during normal processing using the upper stack tray 18a or the lower stack tray 18b or a printout upon FAX reception, and is assigned to the upper stack tray 18a or the lower stack tray 18b. Without being mixed with the stacked sheets, the stacked sheets are held in a conspicuous position at the top and easy to take out.

  The escape tray 31 is formed by connecting a rear end tray 31c integrally molded with the upper cover of the sheet processing apparatus B and a front end tray 31a resin-molded as one component by a fulcrum shaft 31b. 31a is rotatable within a rotation range (from 8 degrees to 90 degrees) limited by horizontal and vertical abutting surfaces formed on the rear end tray 31c side.

  The sheet taken into the sheet processing apparatus B by the first conveying roller pair 10 is fed into the escape unit D by rotating the entrance flapper 26 downward. The sheet that has entered the escape unit D is transferred to the discharge roller pair 29 via the conveying roller pairs 27 and 28, nipped by the discharge roller pair 29, and discharged toward the landing point Δ of the escape tray 31.

  The leading edge of the sheet that has collided with the landing point Δ of the escape tray 31 is stopped by being rubbed against the inclined surface of the escape tray (or the uppermost surface of the stacked sheets) and stopped by sliding down the inclined surface with its own weight. It is stacked with the rear end aligned by the loading wall 32.

  As shown in FIG. 6, the escape tray 31 is arranged in a positional relationship overlapping with the upper stacking tray 18a in the transport direction in order to make the apparatus compact in the transport direction. In other words, the rotatable front end tray 31a is disposed above the upper stacking tray 18a, and when the upper stacking tray 18a on which the sheets P are stacked rises, the upper portion of the stacked sheets P collides with the upper stacking tray 18a. However, since the front end tray 31a is light and freely rotatable, the front end tray 31a is pushed up as the upper stacking tray 18a is raised, and is rotated from the upper side to the upstream side to be retracted.

  As shown in FIG. 7, the escape tray 31 has a fulcrum shaft 31b protruding from both ends of the base, and is assembled by inserting the fulcrum shaft 31b into the support hole on the fixed tray (31c) side.

  As shown in FIG. 8, the fulcrum shaft 31b is located in the vicinity of the rear end of the sheets stacked on the upper stacking tray 18a and upstream in the sheet discharging direction, and the front end tray 31a receives external force F from below. And pivots upward about the fulcrum shaft 31b. Further, the escape tray 31a can be rotated from a normal position where the sheets are stacked and held to a substantially vertical position, and returns to a normal position where the sheets are held by its own weight unless an external force F is applied. (Fall).

  Here, since the fulcrum shaft 31b is positioned upstream of the rear end of the sheet bundle stacked on the upper stacking tray 18a in the sheet discharge direction, the radial force received by the fulcrum shaft 31b is not excessive. The support hole formed in the upper cover of the sheet processing apparatus B does not become larger than necessary due to the rotation of the escape tray 31a.

  Further, when a full sheet is taken out to the upper stacking tray 18a, if the sheet is lifted and the front end tray 31a is further pushed up, the front end tray 31a rotates to a vertical position. A wall extending further upward from 40 prevents the lifted sheet from falling to the upstream side in the conveyance direction.

  In the present embodiment, as will be described later, the rotation amount of the front end tray 31a during retraction is designed to be 25 degrees, and the uppermost surface of the sheet does not reach the front end tray 31a even when it is fully loaded. There is no opportunity for the applied sheet to hit the back side of the front end tray 31a.

  However, an embodiment in which the rotation amount is designed to be 90 degrees so that sheets can be stacked on the upper stacking tray 18a even higher is possible. At this time, as the upper stacking tray 18a rises, the back surface side of the front end tray 31a hits the rear end of the sheets stacked on the inclined upper stacking tray 18a to align the sheets.

  In any embodiment, the upper stacking tray 18a protects the sheets stacked unstablely on the upper stacking tray 18a, and prevents the alignment state from being disturbed or collapsed. .

  In this embodiment, the front end tray 31a returns to the normal position where the sheet is held by its own weight. For example, the front end tray 31a is always attached downward by a torsion coil spring disposed around the fulcrum shaft 31b. By energizing, it may be configured to return to the normal position as the upper stacking tray 18a is lowered.

  Incidentally, as shown in FIG. 6, the escape tray 31 can be stacked up to a specified height corresponding to 250 sheets detected by the full load detection lever 30. The escape tray 31 has a bottom surface 31d that is approximately 35 mm downward from the nip position of the discharge roller 29, and an inclined surface (31a, 31c) that is bent from approximately 20 degrees to 8 degrees in the middle. Consists of.

  The discharged sheet falls along the inclination of the tray due to its own weight, and the trailing edge comes into contact with the stacking wall 32 and is aligned in the conveying direction. The inclination angle that becomes shallow toward the leading edge is the large-sized sheet that is discharged. Large size sheet that has an effect of reducing the speed at which the sheet returns along the inclination angle due to its own weight, and when the sheet rear end abuts against the stacking wall 32, more force is applied in the conveying direction than the vicinity of the rear end of the small size sheet. Is prevented from buckling upward due to its own weight.

  The buckling of the trailing edge of the sheet is likely to occur particularly in the second original drawing sheet where the sheet is not waisted or in a high-temperature and high-humidity environment, and becomes prominent when the angle of the tray exceeds 30 degrees. In the present embodiment, in order to enable more stable loading, the tilt angle is used. Further, when the sheet falls along the inclined surface due to its own weight, the horizontal bottom surface 31d reduces the speed immediately before the rear end of the sheet comes into contact with the stacking wall 32, and the rear end of the sheet substantially approaches the stacking wall 32. The rear end of the sheet curled downward is prevented from entering between the stacking wall 32 and the rear end of the already stacked sheet so that the sheet does not bulge upward. This prevents a decrease in the number of stacked sheets due to the stacking height exceeding the sheet thickness.

  Further, if the inclined surface of the escape tray 31 is steep, the leading edge of the sheet discharged from the discharge port roller 29 curls downward when it collides with the inclined surface (or the uppermost surface of the stacked sheets). The sheets on the tray 31 are wound in a roll shape, and the possibility of the stacked sheets falling or jamming at the discharge port roller 29 increases. However, in the present embodiment, the inclination of the upper stacking tray 18a is designed to be 25 degrees even in a state where the front end tray 31a is lifted upward by a sheet full of the upper stacking tray 18a (see FIG. 10). Therefore, it is possible to secure a stable loadability that is not wound in a roll shape.

  Further, as shown in FIG. 2, the fulcrum shaft 31b is disposed downstream of the landing point Δ where the leading edge of the sheet discharged from the discharge roller pair 29 collides, so that the leading end tray 31a is loaded. Even when the sheet is pushed upward by the sheet bundle, the leading edge of the sheet collides with the escape tray 31 at a constant shallow entry angle irrespective of the pushing up, and curling downward or roll winding caused by this curl cannot occur. Accordingly, the sheets are stacked on the escape tray 31 without increasing the roundness of the lower end of the sheet.

  Further, as shown in FIG. 9, the front end portion 31f of the front end tray 31a has a tapered shape inclined downward, so that when the front end tray 31a is pushed upward by the stacked sheet bundle, the front end of the sheet is the front end tray 31a. I don't get drowned.

  In the sheet processing apparatus of the present embodiment, the front end tray 31a is lifted upward by the sheets fully loaded on the upper stacking tray 18a, and the tip tray 31a is rotated and retracted by 56 mm, for example, in A4 size. Accordingly, as compared with the case where the revolving is not retracted, about 400 sheets can be stacked on the upper stacking tray 18a. Accordingly, the leading tray 31a rotates and retracts upward, whereby the number of sheets that can be stacked on the upper stacking tray 18a can be increased, and even when a foreign object is placed on the top surface of the stacked sheets, the escape tray 31 is placed. Further, it is possible to avoid damage to the upper stacking tray 18a and the like.

  Further, when the height of the sheets stacked on the upper stack tray 18a does not reach the height that interferes with the escape tray 31, the leading end tray 31a can maintain the original tray angle without rotating and retracting. is there. Here, when the entire escape tray 31 is fixed, for example, the upward movement of the discharge port roller 29 accompanying the upward movement of the escape tray 31 or the number of stacked sheets on the upper stacking tray 18a is reduced. In addition, since it is necessary to prevent the escape tray 31 and the upper stacking tray 18a from being damaged by adding a proximity sensor to the back surface of the escape tray 31, this leads to an increase in the size of the apparatus, component costs, and assembly costs.

  As shown in FIG. 10, when the upper stack tray 18 a is lifted above the downstream discharge roller pair 17 after stacking up to 1300 full sheets on the upper stack tray 18 a by the cascade mode, the leading end side of the 1300 sheets is The front end tray 31a is pushed up and rotated upward to about 25 degrees to be retracted. Thereafter, the lower stacking tray 18b is moved below the downstream discharge roller pair 17 to start sheet stacking, and the stacking of up to 2450 full sheets is completed.

  As described above, according to the sheet processing apparatus of the present embodiment, the number of sheets stacked on the upper stacking tray 18a and the space efficiency can be increased without increasing the manufacturing cost and without enlarging the apparatus. realizable. Then, by increasing the number of stacked sheets, the sheet take-out frequency is reduced and the operation rate of the image forming apparatus is increased. Further, if the built-in sheet processing apparatus is reduced in size and the manufacturing cost thereof is reduced, it is possible to provide an inexpensive image forming apparatus that is reduced in size without impairing the processing capability.

  In other words, in the sheet processing apparatus B of the present embodiment, since the escape tray 31 is arranged at a position higher than the normal upper stacking tray 18a, the sheet discharged to the escape tray 31 is conspicuous, forgetting to take out, There is no worry of being mixed with other large numbers of seats or losing whereabouts. Since the front end tray 31a is located above the upper stacking tray 18a, the sheet processing apparatus B having a relatively small housing structure can be stacked with a large size sheet on the escape tray. When the upper stacking tray 18a is lifted, it is pushed up by the stacked sheet bundle, and the front end tray 31a is retracted upward. Therefore, a special drive mechanism for retracting the front end tray 31a is unnecessary, and interference is avoided. There is no need for sensors or control to do this. Since sheets can be stacked on the upper stacking tray 18a without worrying about interference, the number of sheets that can be stacked on the upper stacking tray 18a is remarkably increased as compared with the case where attention is paid.

  Therefore, the user-friendly sheet processing apparatus B in which the escape tray 31 is arranged above the upper stacking tray 18a can achieve a large capacity while reducing the size and weight, and the performance price ratio can be increased.

1 is an explanatory diagram of a configuration of an image forming apparatus including a sheet processing apparatus according to an embodiment. It is explanatory drawing of a structure of the sheet processing apparatus of this embodiment. FIG. 10 is an explanatory diagram of sheet conveyance in the finisher unit. It is a block diagram of a control system of the sheet processing apparatus. It is a flowchart of random mode control. It is a perspective view of an escape tray. It is a top view of a front end tray. It is explanatory drawing of the rotation range of a front-end | tip tray. It is a schematic diagram of the state which the front-end | tip tray contacted the sheet | seat. It is explanatory drawing of the state at the time of stacking the maximum number of sheets.

Explanation of symbols

A Image forming apparatus (image forming means)
B sheet processing device (processing means)
C Finisher unit D Escape unit 3 Image forming unit 17 Downstream discharge roller pair (first discharge means)
18a Upper stacking tray (first sheet stacking member)
18b Lower stacking tray 26 Entrance flapper (sorting member)
29 Discharge roller pair (second discharge means)
31 Escape tray (second sheet stacking member)
31a Tip tray (rotating tray)
31b fulcrum shaft 31c rear end tray (fixed tray)
31d Bottom

Claims (9)

A first sheet stacking member on which sheets are stacked so as to be movable up and down along the housing structure;
A sheet processing apparatus comprising: a second sheet stacking member disposed above the first sheet stacking member and capable of stacking sheets;
At least a part of the second sheet stacking member is configured to be retractable upward, and the sheet is pushed up and retracted by contacting the sheet stacked on the first sheet stacking member. Processing equipment. The second sheet stacking member includes a fixed tray portion fixed to the housing structure, and a rotating tray portion that is pivotally supported on the distal end side of the fixed tray portion and is rotatable upward.
The sheet processing apparatus according to claim 1, wherein the rotating tray unit is located above the first sheet stacking member.   The sheet processing apparatus according to claim 2, wherein the fixed tray portion is resin-molded integrally with an upper surface cover of the housing structure. The rotating tray portion is rotatable between a normal inclination angle in which the stacking surface is inclined low toward the sheet discharge side and a maximum inclination angle that holds the back side surface of the stacking surface almost vertically. There,
4. The sheet processing apparatus according to claim 2, wherein the back side surface held vertically can protect or align the sheets stacked on the first sheet stacking member. 5. The first sheet stacking member is inclined low toward the discharge side of the stacked sheets,
The sheet processing apparatus according to claim 2, wherein the normal inclination angle is set smaller than an inclination angle of the first sheet stacking member. A sorting member arranged at a branch point of the sheet conveyance path to sort the received sheet;
A first discharge member that discharges the sheet distributed by the distribution member downward to the first sheet stacking member;
6. The sheet processing apparatus according to claim 2, further comprising: a second discharge member that discharges the sheet that is distributed upward by the distribution member to the fixed tray unit.   The sheet processing apparatus according to claim 6, wherein the second discharge member has a height position and a discharge angle at which a leading end of the discharged sheet hits the fixed tray portion at a shallow angle. . Image forming means for forming an image on a sheet;
A processing unit that processes the sheet on which the image is formed by the image forming unit;
8. An image forming apparatus according to claim 1, wherein the processing unit is the sheet processing apparatus according to claim 1. 9. The image forming apparatus according to claim 8, wherein the processing means are commonly controlled by a control means for controlling the image forming means.

Images