JP2007091352A - Sheet processing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet processing device reducing frequency of alarm processing attendant on determination of full-loading without causing increase of the number of parts and enlargement of the whole device and capable of increasing the number of sheets capable of being continuously delivered and continuously loaded. <P>SOLUTION: When the loaded number of sheets of a lower tray 104 exceeds 1,700 regardless of the loaded number of sheets of an upper tray 103, delivery to the upper tray 103 is forbidden, thereby, the upper tray 103 does not come to a sheet receiving position below a pair of delivery rollers. Further, loading up to 2,450 sheets causing interference if the upper tray 103 comes to the sheet receiving position below the pair of delivery rollers 102, namely, additional loading of 750 sheets exceeding usual full-loading is allowed for the lower tray 104. Thereby, the lower tray 104 can be continuously operated and continuously loaded without causing the alarm processing attendant on determination of full-loading if the loading is up to 2,450 sheets. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention incorporates / connects a sheet processing apparatus that accepts a sheet discharged from an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine, or another office machine, and stacks it on a sheet stacking unit, and a sheet processing apparatus. More specifically, the present invention relates to a technique for delaying full load judgment and increasing the number of sheets that can be continuously stacked by sheet stacking means.

  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 some models of image forming apparatuses, such a sheet processing apparatus is built in or connected as a purchase option (so-called option).

  Some models of sheet processing equipment have multiple stackable trays that can be raised and lowered. The stacking tray is positioned below the pair of discharge rollers arranged at a predetermined height, and the sheets are discharged from the pair of discharge rollers. Are loaded on the loading tray. As the stacking progresses, the stacking tray is gradually lowered so that the height of the top surface of the stacked sheets is maintained substantially constant, whereby a large number of sheets exceeding 1000 sheets can be stacked continuously.

  In the sheet processing apparatus disclosed in Patent Document 1, a shutter mechanism is provided on the front surface of the discharge member, and the stacking tray on which sheets are stacked can be moved to a position higher than the discharge roller pair. Then, with the upper stack tray retracted to a position higher than the discharge roller pair, sheets are stacked on the lower stack tray by the discharge roller pair. This apparatus includes three stacking trays, and can stack up to 300 sheets of tray 1, 1000 sheets of tray 2, and 200 sheets of tray 3.

  The sheet processing apparatus shown in Patent Document 2 includes two stages of self-propelled stacking trays with a built-in motor, and with the lower stacking tray lowered to the lower limit position regardless of whether or not the stacking has been performed, The upper stacking tray is moved below the pair of discharge rollers to start stacking sheets on the upper stacking tray. A movable shutter mechanism that can be pulled out downward is provided to lower the lower limit position of the lower stacking tray, thereby increasing the number of sheets that can be stacked on the lower stacking tray.

JP 09-048559 A JP 2004-269163 A

  In the sheet processing apparatus disclosed in Patent Document 2, when a sheet is stacked on the upper stacking tray, the upper stacking tray descends as the stacking progresses and collides with a sheet stacked on the lower stacking tray. When an overload of the stacking tray is detected, an emergency stop occurs, and image formation and sheet discharge are stopped retroactively to the image forming apparatus.

  When such a collision accident occurs, the alignment state of the sheets loaded on the lower stacking tray may be disturbed or the sheets may be torn. Repeating such a collision accident may impair the mechanical life of the stacking tray. There is sex. Therefore, in a normal sheet processing apparatus, when a sheet is stacked on the lower stacking tray, stacking exceeding a predetermined height is prohibited, and even if the upper stacking tray becomes a predetermined full load, such a collision occurs. To prevent it from happening.

  In other words, the stacking height that does not contact the lower surface of the upper stacking tray even if it is determined that the upper stacking tray is full is determined as the full load amount in the lower stacking tray. When the number of sheets corresponding to the stacking height is reached, a full load determination is made and further stacking of sheets on the lower stacking tray is prohibited. Then, image formation and sheet discharge in the image forming apparatus are stopped, and alarm processing is performed. After that, when the operator in charge called by the alarm processing takes out the sheet from the lower stacking tray and performs a reset operation on the image forming apparatus, the interrupted image forming, sheet discharging, and the lower stacking tray in the sheet processing apparatus are performed. The sheet stacking on is resumed.

  Therefore, if it is possible to delay the determination of the full load of the lower stacking tray, the frequency of alarm processing will be reduced, and the number of image forming jobs that can be continuously discharged and stacked without intervening alarm processing will increase. As a result, the burden on the operator is reduced. In addition, the combination and order of the sheet bundle taken out in the middle by the alarm processing and the subsequent sheet bundle will not cause a trouble.

  However, in order to delay the full load judgment, as shown in Patent Document 2, it is necessary to increase the room for raising and lowering the stacking tray physically and mechanically, resulting in an increase in the number of parts of the sheet processing apparatus and an increase in size. Cost will be increased.

  The present invention provides a sheet processing apparatus capable of increasing the number of sheets that can be continuously discharged and continuously stacked by reducing the frequency of alarm processing accompanying full load determination without causing an increase in the number of parts or an increase in the size of the entire apparatus. The purpose is that.

  The sheet processing apparatus of the present invention is arranged above and below, the sheets are stacked, and upper and lower sheet stacking means that can be moved up and down independently, and the upper and lower sheet stacking units disposed at a predetermined height. Upon receiving the designation of the discharge member capable of discharging the sheet and the upper sheet stacking means, the upper sheet stacking means is positioned below the discharge member and the sheets are stacked by the discharge member. When the lower sheet stacking means is designated, the lower sheet stacking means is positioned below the discharge member in a state where the upper sheet stacking means is retracted to a position higher than the discharge member. And a control unit for stacking sheets by the discharge member, and detecting a sheet stacking amount in the lower sheet stacking unit And when the sheet stacking amount detected by the detecting unit reaches a predetermined amount, prohibiting the subsequent stacking in the upper sheet stacking unit and continuing the stacking in the lower sheet stacking unit Means.

  In the sheet processing apparatus of the present invention, until the sheet stacking amount of the lower sheet stacking unit reaches a predetermined amount, the upper sheet stacking unit is moved below the discharge member and the sheets are stacked on the upper sheet stacking unit. However, when the sheet stacking amount of the lower sheet stacking unit reaches a predetermined amount, it is prohibited to move the upper sheet stacking unit below the discharge member itself, and the upper sheet stacking unit is discharged. If the sheet is moved below the member, the lower sheet stacking unit is allowed to stack a sheet having an “additional stacking height” that will surely collide with the lower surface of the upper sheet stacking unit.

  In other words, by eliminating the opportunity for the sheets stacked on the lower sheet stacking means to collide with the lower surface of the upper sheet stacking means, allowing the lower sheet stacking means to continue to stack the sheets, Increases the number of sheets that can be stacked continuously using the lower sheet stacking means without causing the sheets stacked on the means to collide with the lower surface of the upper sheet stacking means and without increasing the space for raising and lowering the lower sheet stacking means. I am letting.

  Hereinafter, a sheet processing apparatus according to an embodiment of the present invention and a copier as an embodiment of an image forming apparatus including the sheet processing apparatus will be described with reference to the drawings. However, the sheet processing apparatus of the present invention is not limited to a configuration in which sheets are simply stacked on the sheet stacking unit as in the present embodiment, and is accompanied by stapling processing and sorting processing as shown in Patent Document 2. A configuration for stacking sheet bundles may be used, a configuration for performing other processing such as punching processing may be added, or a configuration for performing only other processing or another configuration for performing the same processing may be performed. . The image forming apparatus of the present invention is not limited to the copying machine of the present embodiment, and may be implemented by a facsimile, a printer, a complex machine of these, or the like.

  The finisher 101 according to the present embodiment may be connected to a copying machine, a multifunction peripheral, a printing apparatus, or the like other than the apparatus main body 105 of the copier 100. The finisher 101 according to the present embodiment is separable from the apparatus main body 105. It may be configured by a separate casing, or may be incorporated in the casing of the apparatus main body 105 so as not to be separated.

<Image forming apparatus>
FIG. 1 is a front view of a copying machine provided with a finisher according to an embodiment of the present invention, and FIG. 2 is an explanatory view of sheet stacking on an upper tray and a lower tray in the finisher. The copier 100, which is an image forming apparatus of the present invention, includes an apparatus body 105, which is an image forming unit, and a finisher 101, which is a sheet processing apparatus, for example.

  As shown in FIG. 1, the apparatus main body 105 of the copying machine 100 discharges the sheet on which the image has been formed by the image forming unit 110 to the finisher 101 through the discharge roller pair 109. The finisher 101 discharges and stacks the sheet received from the apparatus main body 105 onto the upper tray 103 or the lower tray 104 through the discharge roller pair 102.

  The apparatus main body 105 of the copying machine 100 reads an image of a document using a reading unit (not shown), and the image forming unit 110 copies the read image onto a sheet supplied from a sheet supply unit (not shown). The operation unit 112 is formed of a liquid crystal screen using a touch panel. The person in charge of operation can set various specifications and conditions related to image formation, sheet processing, and the like through the operation unit 112. In addition to the device status such as full load, the operation unit 112 displays error messages such as upper tray collision and overload.

  The image formation control unit 111 reads the setting content through the operation unit 112 according to a predetermined processing program, controls the image formation unit 110 and the like to form an image on the sheet, and communicates with the finisher control unit 201 of the finisher 101. , Processing data and instructions are transmitted to the finisher 101, and information such as full load is received.

<Sheet processing device>
The finisher 101, which is a sheet processing apparatus of the present invention, includes, for example, an upper tray 103 and a lower tray 104 that are sheet stacking units, a discharge roller pair 102 that is a discharge member, a finisher control unit 201 that is a control unit, and the like. For example, a finisher control unit 201, an encoder 230, and area sensors 203, 204, and 205, which are detection units, and a finisher control unit 201, which is a prohibition unit, are provided. The detection unit includes, for example, an encoder 230 that is a measurement index, and area sensors 203, 204, and 205 that are reading units.

  The finisher 101 receives the image-formed sheet by the entrance roller pair 122, transports the transport path 106 by the transport roller pair 121, and passes it to the discharge roller pair 102, from the discharge roller pair 102 to the upper tray 103 or the lower tray 104. Eject and load. A conveyance sensor 209 disposed downstream of the entrance roller 122 detects the received sheet, and a conveyance sensor 210 disposed upstream of the discharge roller pair 102 detects the discharged sheet.

  The upper tray 103 is a self-propelled type incorporating an upper tray motor 211 and a pinion gear 221, and can be moved up and down by a pinion gear 221 meshed with a rack gear 223 provided in the finisher 101, and can be positioned and stopped at an arbitrary height position. It is. The lower tray 104 is also a self-propelled type incorporating a lower tray motor 212 and a pinion gear 222, and can be moved up and down by the pinion gear 222 meshed with the rack gear 223, and can be positioned and stopped at an arbitrary height position.

  The upper tray 103 and the lower tray 104 are controlled by the finisher control unit 201 to move up and down independently, and are positioned below the discharge roller pair 102 to stack sheets. When the upper tray 103 moves up and down over the discharge roller pair 102, the shutter 108 moves to the front surface of the discharge roller pair 102, closes the opening of the discharge roller pair 102, and is stacked on the upper tray 103. The sheet is not slid down to the opening of the discharge roller pair 102.

  An upper tray paper presence / absence sensor 207 and a lower tray paper presence / absence sensor 208 provided on the upper tray 103 and the lower tray 104 detect the presence / absence of sheets stacked on the upper tray 103 and the lower tray 104, respectively. The paper surface detection sensor 206 detects the uppermost surface of the sheets stacked on the upper tray 103 (or the lower tray 104) positioned below the discharge roller pair 102.

  When the sheets are stacked on the upper tray 103 (lower tray 104), the finisher control unit 201 gradually lowers the upper tray 103 (lower tray 104) based on the output of the paper surface detection sensor 206, and stacks the stacked sheets. The height of the uppermost surface, that is, the loading surface is maintained substantially constant.

  As shown in FIG. 2A, the finisher control unit 201, when stacking sheets on the upper tray 103, lowers the lower tray 104 to the lower limit position and waits for the upper tray 103. 2 is moved to a sheet receiving position defined below the discharge roller pair 102. When the sheets are stacked on the lower tray 104, the upper tray 103 is moved from the discharge roller pair 102 as shown in FIG. The lower tray 104 is moved to the same sheet receiving position while being retracted to a higher position.

  As shown in FIG. 2A, the finisher control unit 201 detects the encoder 230 fixed to the finisher 101 with area sensors 203, 204, and 205 provided on the upper tray 103 and the lower tray 104, respectively. The height positions of the upper tray 103 and the lower tray 104 are determined. The encoder 230 is a sticker on which a light reflection / absorption pattern corresponding to a three-digit binary number is printed. The area sensors 203, 204, and 205 are reflected light detection elements each having a light source and a light receiving element. Seven area codes of 000 = A0, 001 = A1, 010 = A2,..., 111 = A7 are identified, assuming that the reflection of the area sensors 203, 204, and 205 is 0 and the absorption is 1.

  FIG. 9 shows the relationship between the output value of the area sensor, the area code, and the number of stacked sheets. In the figure, area sensor 1 is area sensor 203, area sensor 2 is area sensor 204, and area sensor 3 is area sensor 205. As described above, the values of the area sensors 1, 2, and 3 can be used to know how many stacks the upper tray 103 (lower tray 104) currently corresponds to.

<Control of sheet processing apparatus>
3 is a block diagram showing the configuration of the finisher control system, FIG. 4 is a flowchart of job print request processing in the image formation control unit, FIG. 5 is a flowchart of page print request processing in the image formation processing unit, and FIG. 6 is stacking in the finisher. FIG. 7 is a flowchart of the paper surface detection process in the upper tray and the lower tray of the finisher, FIG. 8 is a flowchart of the full load determination process in the upper tray and the lower tray, and FIG. 9 is an explanatory diagram of the full load determination using the area sensor. It is.

  As shown in FIG. 3 with reference to FIGS. 1 and 2, the finisher control unit 100 includes a ROM 215, a RAM 216, a communication interface unit 202, and the like. The ROM 215 stores processing programs and various data corresponding to the flowcharts shown in FIGS. The RAM 216 holds a processing program read from the ROM 215, and working data, input data, communication data, calculation results, and the like that are sequentially generated in the control process are written / erased each time. The communication interface unit 202 exchanges control data with the image formation control unit 111 of the apparatus main body 105 of the copying machine 100.

  The input port of the finisher control unit 201 includes transport sensors 209 and 210, an upper tray paper presence / absence sensor 207, a lower tray paper presence / absence sensor 208, a paper surface detection sensor 206, area sensors 203, 204 and 205, and other sensors and devices (not shown). Etc. are connected. The output ports of the finisher control unit 201 are connected to conveyance motors 213 and 214, an upper tray motor 211, a lower tray motor 212, other motors (not shown), actuators, and the like. The conveyance motor 213 drives the entrance roller pair 122 and the conveyance roller pair 121 to convey the sheet. The conveyance motor 214 drives the discharge roller pair 102 to discharge the sheet.

  The finisher control unit 201 reads out a processing program from the ROM 215 and stores it in the RAM 216, refers to the output of these sensors in accordance with the processing program, and sends control from the image formation control unit 111 (FIG. 1) of the apparatus main body 105. Necessary arithmetic processing is performed based on the data, and various parts of the finisher 101 are controlled by controlling these various motors and actuators.

  As shown in FIG. 4 with reference to FIG. 1, the image formation control unit 111 of the apparatus main body 105 communicates with the finisher control unit 201 when the processing content is designated through the operation unit 112 and the start of the processing is instructed. To determine whether the upper tray 103 (or lower tray 104) of the stacking destination is full (S101). If not, the page print request process shown in the flowchart of FIG. 5 is performed (S102).

  Next, it is determined whether or not the job of the page print request process is finished (S103). If there is a page to be printed, the process returns to step S101.

  When it is determined whether or not the upper tray 103 (or lower tray 104) is full (S101), if the upper tray 103 (or lower tray 104) is full, a full load display and an alarm are transmitted through the operation unit 112 or the like. (S104), and then the stacked sheets are taken out from the upper tray 103 (or the lower tray 104) of the stacking destination, and the full load display and alarm transmission are continued until a predetermined reset operation is performed on the operation unit 112.

  As shown in FIG. 5 with reference to FIG. 1, the image formation control unit 111 of the apparatus main body 105 receives an image from a sheet supply unit (cassette) (not shown) when a page print request (S102 in FIG. 4) is instructed. A sheet is fed to the forming unit 110 (S111), an image is formed on the fed sheet by the image forming unit 110 (S112), and a stacking request for the image-formed sheet is transmitted to the finisher control unit 201 of the finisher 101. (S113). Thereafter, the finisher 101 is discharged through the discharge roller pair 109 (S114), the page print request process is terminated, and the process continues to step S103 in FIG.

  As shown in FIG. 6 with reference to FIG. 1, when the finisher control unit 201 of the finisher 101 receives a stacking request from the image formation control unit 111, the finisher control unit 201 activates the transport motors 213 and 214 to discharge from the discharge roller pair 109. Then, the sheet discharged from the apparatus main body 105 is conveyed to the upper tray 103 (or the lower tray 104) (S121). When the conveyance sensor 210 detects the trailing edge of the sheet and a predetermined time elapses, it is regarded that the discharge is completed, and the finisher control unit 201 performs a paper surface detection process of the upper tray 103 (or the lower tray 104) shown in FIG. 7 (S122). ) When the paper surface detection process is completed, the full tray determination of the upper tray 103 (or the lower tray 104) shown in FIG. 8 is performed to confirm the stacking status (S123).

  As shown in FIG. 7 with reference to FIG. 1, when the finisher 105 stacks sheets on the upper tray 103, the upper tray paper surface detection process shown in FIG. When sheets are stacked on the tray 104, a lower tray paper surface detection process shown in FIG. 7B is performed.

  When the sheet discharge to the upper tray 103 is completed, the finisher control unit 201 lowers the upper tray 103 (S131) and waits until the paper surface detection sensor 206 is turned off (S132). The finisher control unit 201 reverses the upper tray motor 211 immediately after the paper surface detection sensor 206 is turned off, raises the upper tray 103 (S133), waits until the paper surface detection sensor 206 is turned on, and turns the upper tray motor 211 on. Stop (S134). As a result, the uppermost surface of the stacked sheets is positioned at a predetermined sheet receiving position.

  Finally, the finisher control unit 201 creates area codes A0 to A7 (see FIG. 9) from the outputs of the area sensors 203, 204, and 205, and stores them in the RAM 216 as the stack number data of the upper tray 103 (S135).

  On the other hand, when the finisher 101 is stacking sheets on the lower tray 104, the finisher control unit 201 lowers the lower tray 104 when the sheet discharge to the lower tray 104 is completed, as shown in FIG. (S141). When the paper surface detection sensor 206 is turned off (S142), the finisher control unit 201 raises the lower tray 104 to a position where the paper surface detection sensor 206 is turned on (S143), and the sheets stacked on the lower tray 104 are moved. The uppermost surface is positioned at a height convenient for discharging by the discharge roller pair 102 (S144). The finisher control unit 201 reads the outputs of the area sensors 203, 204, and 205, creates area codes A0 to A7 (see FIG. 9), and stores them in the RAM 216 as the stacking number data (S145).

<Full load judgment>
In the full load determination (S123) in the flowchart of FIG. 6, the finisher control unit 201 determines whether or not the area code of the lower tray 104 is A5 = 101 or more shown in FIG. 9, as shown in FIG. It is determined whether or not the lower tray 104 positioned at the stacking height has been lowered to a position corresponding to the number of stacked sheets 1700, that is, whether or not the lower tray 104 has stacked more than 1700 sheets (S151).

  If the finisher control unit 201 exceeds 1700 sheets, the finisher control unit 201 notifies the image forming processing unit 111 that the upper tray 103 is full even if it is not full (S152). And the upper tray 103 is not brought to the sheet discharge position below the discharge roller 102. At this time, if there is an image forming job specifying the upper tray 103, the image forming processing unit 111 performs alarm processing, but if there is no image forming job, the alarm processing is not performed and the lower tray 104 is specified (or the tray is not specified). For the forming job, sheet discharge is designated in the lower tray 104 and the job is continued as it is.

  Then, the finisher control unit 201 continues to permit the stacking of sheets for the lower tray 104 even if it exceeds 1700, which is the conventional full sheet count, and determines whether or not the stack number of the lower tray 104 exceeds 2450 sheets. Determination is made (S153). Then, as shown in FIG. 2B, when the area code of the lower tray 104 reaches A6 = 110, it is determined that the stacking of more than 2450 sheets is made, and the full load of the lower tray 104 is notified to the image forming processing unit 111. (S154). At this time, the image formation processing unit 111 stops image formation and sheet discharge and performs alarm processing. If the area code of the lower tray 104 is A5 = 101, the stacking on the lower tray 104 is continued. As a result, 750 sheets can be additionally stacked on the conventional 1700 sheets without causing contact with the bottom of the upper tray 103. That is, the image forming processing unit 111 of the apparatus main body 105 regards the stacking of the lower tray 104 as being forbidden, and does not discharge the finisher 101 any more.

  Thereafter, the finisher control unit 201 determines whether the number of stacked upper trays 103 exceeds 1300 sheets (S155). That is, as shown in FIG. 2A, it is determined whether or not the area code of the upper tray 103 is A4 = 100, the area codes are A2 and A3, and the above-described full load determination (S152) is also made. If not, stacking on the upper tray 103 is permitted, but if the area code reaches A4 = 100 and it is determined that stacking exceeds 1300 sheets, the image forming control unit 111 is notified of the full loading of the upper tray 103 (S156).

  The full load judgment will be explained in detail. When the number of stacked lower trays 104 exceeds 1,700, conventionally, the lower tray 104 is usually controlled so that the lower tray 104 is full and the upper tray 104 is not full. However, in this embodiment, the lower tray 104 is not full, and the upper tray 103 is full.

  This has the effect of increasing the loading capacity by not filling the lower tray 104, and by making the upper tray 103 full, the upper tray 103 is prevented from being selected as a loading destination. Collision between the sheets stacked on 104 and the lower surface of the upper tray 103 can be avoided.

  In addition, when the upper tray 103 is fully loaded, it becomes impossible to load the upper tray 103 thereafter. For example, in the case of an image forming job in which no tray is specified, the maximum loading capacity of 1300 sheets is first loaded on the upper tray 103. By stacking up to the maximum, the total stackable capacity of the upper tray 103 and the lower tray 104 can be maximized.

  As described above, according to the sheet processing apparatus of the present embodiment, the stacking amount of the lower tray 104 immediately before it cannot be physically stacked on the upper tray 103 due to an increase in the stacking amount of the lower tray 104 is set to the first threshold (for example, 1700). Sheet)), and when the loading amount of the lower tray 104 exceeds the first threshold during loading on the lower tray 104, the upper tray 103 is fully loaded, thereby ensuring the safety of loading.

  In addition, the notification of full loading of the lower tray 104 is performed when the loading amount of the lower tray 104 exceeds a second threshold (for example, 2450 sheets) exceeding the first threshold (for example, 1700 sheets), thereby reducing the stacking space of the lower tray 104. It can be used effectively.

  A full load determination can be made with only a slight change in the processing program executed by the finisher control unit 201 without expanding the lifting range of the upper tray 103 or the lower tray 104, or with any mechanical change or addition of parts. Can be delayed to increase the number of continuous stacks by 750, reducing the stop time of the copier 100 due to full load judgment and alarm processing, increasing the operating rate of the copier 100, and reducing the operator's work can do. In addition, the opportunity for dividing processed sheets by continuous discharge and continuous stacking is reduced, and the integration of divided sheets is less likely to occur.

Note that in this embodiment, the encoder 230 provided in the finisher 101 is detected by the area sensors 203, 204, and 205 to determine whether the upper tray 103 and the lower tray 104 are full. The full load determination may be performed by detecting other parameters that change in response to the change. For example, the load of the upper tray motor 211 (lower tray motor 212) may be detected, or a weight detection sensor may be provided on the upper tray 103 (lower tray 104) to detect the sheet stacking weight. The number of stacked sheets may be detected by counting ON / OFF of the conveyance sensor 210.
<Another embodiment>

  FIG. 10 is a front view of a copying machine equipped with a finisher according to another embodiment, FIG. 11 is an explanatory diagram of the configuration of the finisher, and FIG. 12 is a flowchart of finisher stacking control.

  The copying machine 300 includes an apparatus main body 301 that performs image formation, and a finisher 319 that performs post-processing on the image-formed sheet. A document feeder 302 is mounted on the upper portion of the apparatus main body 301, and a document D to be copied is placed on a document placing unit 303 by a user, and is sequentially separated one by one by a feeding unit 304 to be a registration roller. Supplied to pair 305. The document D is temporarily stopped by the registration roller pair 305 to form a loop to correct skewing. Thereafter, when the document D passes through the introduction path 306 and passes through the reading position 308, the image on the surface of the document is read. The document D that has passed the reading position 308 is conveyed through the discharge path 307 and discharged to the discharge tray 309.

  When reading both the front and back sides of a document, first, the document D passes through the reading position 308 as described above, whereby an image on one side of the document is read. Thereafter, the document D is transported back by the reverse roller pair 310 immediately before completion of discharge to the discharge tray 309 after being transported through the discharge path 307, and is sent again to the registration roller pair 305 in a state where the front and back are reversed.

  Then, the document D is corrected in skew by the registration roller pair 305 and passes through the reading position 308 through the introduction path 306 in the same manner as when the image on one side is read, and at this time, the document D on the other side is read. The image is read. Thereafter, the document D is conveyed through the discharge path 307 and discharged / stacked from the reverse roller pair 310 to the discharge tray 309.

  On the other hand, the image of the document D passing through the reading position 308 is irradiated with light from the illumination system 311. The reflected light reflected from the document D is guided by a mirror 312 to an optical element 313 (CCD or other element) and converted into an electrical signal to form image data. Then, a laser beam based on the image data is irradiated to form a latent image on the photosensitive drum 314.

  The latent image formed on the photosensitive drum 314 is further developed with toner supplied from a toner supply device (not shown) to form a toner image. Sheets P are stacked on the cassette 315.

  The sheet P is fed from the cassette 315 to the registration roller pair 349 and enters between the photosensitive drum 314 and the transfer unit 316 at a timing synchronized with the rotational phase of the photosensitive drum 314. Then, the toner image on the photosensitive drum 314 is transferred onto the sheet P by the transfer device 316. The sheet P on which the toner image has been transferred is heated and pressurized while passing through the fixing device 317, and the toner image is fixed.

  When images are formed on both sides of the sheet P, the sheet P on which the image is fixed on one side by the fixing unit 317 passes through a double-sided path 318 provided on the downstream side of the fixing device 317, and is switched back and transported halfway. Is inverted. Thereafter, the sheet P is again fed between the photosensitive drum 314 and the transfer device 316 by the registration roller pair 349, and the toner image is also transferred to the back surface. Then, the toner image is fixed by the fixing device 317 and discharged to the finisher 319.

  As shown in FIG. 11, the finisher 319 performs processing designated by the user on the sheets, and discharges / stacks the sheets P on the upper tray 328 a, the lower tray 128 b, and the saddle tray 350.

  The upper tray 328a and the lower tray 328b are supported by a guide groove (not shown) provided in the casing of the finisher 319 so as to be able to move up and down, and each is configured to be self-propelled with a built-in motor, and each moves to an arbitrary height position / Can be stopped.

  The paper surface detection lever 333 pivotally supported by the housing structure of the finisher 319 rotates in contact with the stacking surface of the sheets P, and turns the paper surface detection sensor 424 ON / OFF. The stacking surface is the upper tray 328a (or lower tray 128b) surface in the unstacked state of sheets, and the uppermost sheet surface in the stacked state of sheets P.

  The finisher 319 includes a processing tray 329 that temporarily stacks sheets P to form a sheet bundle, an alignment mechanism (not shown) that aligns the width direction of the sheet bundle on the processing tray 329, and a stapler that binds near the edge of the sheet bundle. A unit 332 and the like, and when discharging the sheet to the upper tray 328a (or the lower tray 128b), in addition to the normal mode in which the image-formed sheet P is simply discharged and stacked, the staple mode, the bookbinding mode The sheet processing according to each mode can be executed.

  In the normal mode, the sheet P discharged from the apparatus main body 301 to the finisher 319 shown in FIG. 10 is sequentially conveyed from the receiving roller pair 337 to the inlet roller pair 321, the first paper discharge roller pair 326, and the bundle roller pair 327. Then, the bundled roller pair 327 is discharged to the upper tray 328a (or the lower tray 328b). At this time, the bundling roller pair 327 is set in a contact state in which the swing guide 352 is rotated downward, and the buffer roller 324 is set in a separated state that does not contact the sheet P.

  In the staple mode, the sheet P is stacked on the processing tray 329 to form a sheet bundle, the width direction alignment is performed, and the rear end side of the sheet bundle is stapled by the stapler 366 of the staple unit 332, and then the sheet bundle is formed. The paper is discharged to the upper tray 328a (or the lower tray 328b). When the sheets P are stacked on the processing tray 329, the bundle roller pair 327 is set in a separated state in which the swing guide 352 is rotated upward.

  After staple binding, the swing guide 352 is rotated downward, and the bundling roller pair 327 pinches the sheet bundle. The bundling roller pair 327 conveys the sheet bundle and discharges it to the upper tray 328a (or the lower tray 328b). The finisher 319 includes a buffer unit 340 that accumulates a plurality of sheets P in a staple mode or the like. The buffer roller 324 is rotated downward as necessary for the buffer operation and comes into contact with the sheet P.

  In the bookbinding mode, the flapper 322 disposed on the entrance side of the finisher 319 is rotated upward to guide the sheet P to the lower bookbinding portion 339. The bookbinding unit 339 stacks a predetermined number of sheets P, staples the center fold line by the stapler 338, protrudes the push plate 339b onto the fold line, and nips the sheet bundle in a folded state on the rotating folding roller pair 339a. Let The pair of folding rollers 339a pressurizes and conveys the sheet bundle in a folded state, finishes it in a booklet shape with a crease. The sheet bundle in the form of a booklet is discharged to the saddle tray 350.

  As shown in FIG. 12, a finisher control unit (not shown), which is a calculation control device provided in the finisher 319, counts the number of ejected sheets and determines the loading state of the upper tray 328a (or the lower tray 328b). When the sheet discharge is notified from the control unit (not shown) of the apparatus main body 301, the finisher control unit (not shown) determines whether the upper tray 328a or the lower tray 328b is designated (S211), and the tray Is not specified (YES in S211), the upper tray 328a is positioned at the sheet discharge position below the bundle roller pair 327 with the lower tray 328b lowered to the lower limit position, and stacked on the upper tray 328a ( S212).

  When up to 1300 sheets are stacked on the upper tray 328a (YES in S213), the upper tray 328a is put on standby at a position higher than the bundle roller pair 327, and sheets are stacked on the lower tray 328b (S214). When the total number of stacked sheets on the lower tray 328b reaches 2450 sheets (S215), the control unit of the apparatus main body 301 is notified of the full load, prohibits sheet discharge, and performs alarm processing.

  On the other hand, if the upper tray 328a or the lower tray 328b is designated, it is determined whether or not stacking on the upper tray 328a is prohibited (S216). If loading on the upper tray 328a is not prohibited (NO in S216), Stacking is performed on the designated upper tray 328a or lower tray 328b (S221). If the total number of stacked sheets on the upper tray 328a reaches 1300 sheets (YES in S222) or the total number of stacked sheets on the lower tray 328b reaches 1700 sheets (S223), The full discharge to the control unit is not notified, and the sheet discharge to the upper tray 328a is prohibited for the time being. As a result, the upper tray 328a remains on standby at a position higher than the bundle roller pair 327, and does not move below the bundle roller pair 327 and collide with the sheets stacked on the lower tray 328b.

  Then, the stacking of sheets on the lower tray 328b is continued until the total number of sheets stacked on the lower tray 328b reaches 2450 sheets (S221), and when the total number of stacked sheets on the lower tray 328b reaches 2450 sheets, or the upper tray In the case where stacking on the 328a is prohibited (S224), when the sheet discharge specifying the upper tray 328a is notified (S217), the control unit of the apparatus main body 301 is notified of the full load and the sheet discharge is prohibited. Perform alarm processing.

1 is a front view of a copying machine including a finisher according to an embodiment of the present invention. FIG. 4 is an explanatory diagram of sheet stacking on an upper tray and a lower tray in a finisher. It is a block diagram which shows the structure of the control system of a finisher. 6 is a flowchart of job print request processing in an image formation control unit. 6 is a flowchart of page print request processing in an image forming processing unit. It is a flowchart of the stacking request process in the finisher. It is a flowchart of a paper surface detection process in the upper tray and the lower tray of the finisher. It is a flowchart of the full load determination process in an upper tray and a lower tray. It is explanatory drawing of full load judgment using an area sensor. It is a front view of a copying machine provided with the finisher of another embodiment. It is explanatory drawing of a structure of a finisher. 6 is a flowchart of finisher stacking control.

Explanation of symbols

100, 300 copier 101 sheet processing apparatus (finisher)
102 Paper surface detection sensors 103, 104 Sheet stacking means (upper tray, lower tray)
105 Image forming means (apparatus body)
110 Image forming unit 111 Image forming control unit 112 Operation unit 201 Control means (finisher control unit)
203, 204, 205 Area sensor 206 Paper surface detection sensor 211 Upper tray motor 212 Lower tray motor

Claims (8)

Upper and lower sheet stacking means that are arranged one above the other and on which sheets are stacked and can be moved up and down independently;
A discharge member disposed at a predetermined height and capable of discharging sheets to the upper and lower sheet stacking means;
When receiving the designation of the upper sheet stacking means, the upper sheet stacking means is positioned below the discharge member and the sheets are stacked by the discharge member, while receiving the designation of the lower sheet stacking means. Control means for positioning the lower sheet stacking means below the discharge member and stacking sheets by the discharge member in a state where the upper sheet stacking means is retracted to a position higher than the discharge member. In a sheet processing apparatus comprising:
Detecting means for detecting a sheet stacking amount in the lower sheet stacking means;
And a prohibiting unit that prohibits subsequent stacking in the upper sheet stacking unit and continues stacking in the lower sheet stacking unit when the sheet stacking amount detected by the detecting unit reaches a predetermined amount. A sheet processing apparatus.   The predetermined amount is a sheet stacking amount corresponding to a maximum stacking height that the lower sheet stacking unit can perform when the upper sheet stacking unit is positioned below the discharge member to be fully loaded. The sheet processing apparatus according to claim 1.   When the upper sheet stacking means is positioned below the discharge member to be fully loaded, the prohibiting means has a predetermined full load reference amount that exceeds the maximum stacking height that the lower sheet stacking means is capable of. 3. The sheet processing apparatus according to claim 1, wherein when the sheet stacking amount reaches, sheet stacking is notified by prohibiting subsequent stacking in the lower sheet stacking unit.   The detection means includes a measurement index provided along a lifting path of the sheet stacking means, and a reading means provided in the sheet stacking means for reading the measurement index, and the height of the sheet stacking means in the lower stage The sheet processing apparatus according to claim 1, wherein a position is measured to detect the sheet stacking amount.   The detecting means includes a counting means for counting the cumulative number of sheets discharged to the sheet stacking means, and detects the sheet stacking amount by counting the cumulative number of sheets stacked on the lower sheet stacking means. The sheet processing apparatus according to any one of claims 1 to 3.   4. The detection unit includes a load measuring unit that detects a lifting load of the sheet stacking unit, and measures the lifting load of the lower sheet stacking unit to obtain the sheet stacking amount. The sheet processing apparatus according to claim 1. Image forming means for forming an image on a sheet;
An image forming apparatus comprising: the sheet processing apparatus according to claim 1, which processes a sheet on which an image is formed by the image forming unit. Image forming means for forming an image on a sheet;
The upper and lower sheet stacking units that are arranged vertically and on which the sheets on which images are formed by the image forming unit are stacked and can be moved up and down independently,
A discharge member disposed at a predetermined height and capable of discharging sheets to the upper and lower sheet stacking means;
When receiving the designation of the upper sheet stacking means, the upper sheet stacking means is positioned below the discharge member and the sheets are stacked by the discharge member, while receiving the designation of the lower sheet stacking means. Control means for positioning the lower sheet stacking means below the discharge member and stacking sheets by the discharge member in a state where the upper sheet stacking means is retracted to a position higher than the discharge member. In an image forming apparatus comprising:
Detecting means for detecting a sheet stacking amount in the lower sheet stacking means;
And a prohibiting unit that prohibits subsequent stacking in the upper sheet stacking unit and continues stacking in the lower sheet stacking unit when the sheet stacking amount detected by the detecting unit reaches a predetermined amount. An image forming apparatus.

Images