JP2008120533A - Sheet processing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a structure by using a detachable detection sensor for a sheet loading tray also as an another sensor. <P>SOLUTION: This sheet processing device 119 is provided with an optional tray 18c and a stack tray 18a which are liftably and detachably provided to a device body 119A and on which sheets delivered from the device body are loaded, a sheet sensor 3 detecting the vertical positions of the trays 18c and 18a, and a CPU 900 vertically moving the trays 18c and 18a to a position detected by the sheet sensor. The CPU determines that the trays 18c and 18a are not mounted on the device body 119A when the sheet sensor 3 is inoperative although the stack tray is vertically moved to the position detected by the sheet sensor 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet processing apparatus capable of detecting attachment / detachment of a sheet stacking tray on which sheets discharged from the apparatus main body are stacked, and an image forming apparatus including the sheet processing apparatus.

  An image forming apparatus for forming an image on a sheet is a sheet processing apparatus having a stack tray on which sheets on which an image is formed are stacked as they are, or sorted, perforated, or bound in a bundle Some types have

  In such a sheet processing apparatus, there is one in which the stack tray can be attached and detached in order to save space when packing the sheet processing apparatus and to add a stack tray as an optional tray (patent) Reference 1).

  Such a sheet processing apparatus includes an attachment / detachment detection sensor that detects attachment / detachment of the stack tray in order to prevent malfunction during operation.

JP 2004-269158 A

  In recent years, however, sheet processing apparatuses have been required to reduce the number of parts in accordance with cost competition and simplification of device configuration. For this reason, since the conventional sheet processing apparatus was equipped with the attachment / detachment detection sensor, it was expensive. Moreover, the equipment configuration was complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet processing apparatus having a simplified structure by using a sheet stacking tray attachment / detachment detection sensor also as another sensor.

  It is an object of the present invention to provide an image forming apparatus that includes a sheet processing apparatus having a simplified structure and that has a simplified structure.

  The sheet processing apparatus of the present invention is provided with an apparatus main body, a sheet stacking tray that is detachably mounted on the apparatus main body, on which sheets discharged from the apparatus main body are stacked, and an elevation position of the sheet stacking tray. Position detecting means for detecting, and control means for raising and lowering the sheet stacking tray to a position detected by the position detecting means, wherein the control means detects the sheet stacking tray by the position detecting means. When the position detecting means does not detect the sheet stacking tray even if it is moved up and down, it is determined that the sheet stacking tray is not attached to the apparatus main body.

  An image forming apparatus according to the present invention includes: an image forming unit that forms an image on a sheet; and a sheet processing device that discharges and stacks a sheet on which an image has been formed by the image forming unit. This is a sheet processing apparatus.

  In the sheet processing apparatus according to the present invention, the position detecting means for detecting the raising / lowering position of the sheet stacking tray can also be used for detecting the loading / unloading of the sheet stacking tray, thereby reducing the cost, simplifying the mechanism, and reducing the number of parts. It can be carried out.

  The image forming apparatus according to the present invention includes a sheet processing apparatus that reduces cost, simplifies the mechanism, and reduces the number of parts. Therefore, the cost can be reduced, the mechanism can be simplified, and the number of parts can be reduced.

  The present invention relates to a sheet processing apparatus according to an embodiment of the present invention and an image forming apparatus including the sheet processing apparatus.

(Image forming device)
Examples of the image forming apparatus include a copying machine, a printer, a facsimile, and a complex machine of these. The image forming apparatus according to the embodiment of the present invention will be described by taking an electrophotographic copying machine as an example, but is not limited thereto.

  FIG. 1 is a cross-sectional view of, for example, a copying machine which is an image forming apparatus of the present invention along the sheet conveying direction.

  The copying machine 100 includes an apparatus main body 101 and a finisher 119 that is a sheet post-processing apparatus. A document feeder 102 is provided on the upper part of the apparatus main body 101. The document feeder 102 is not necessarily provided.

  The document D is placed on the document placing unit 103 by the user, sequentially separated one by one by the feeding unit 104, and supplied to the registration roller pair 105. Subsequently, the document D is temporarily stopped by the registration roller pair 105, a loop is formed, and skew is corrected. Thereafter, the document D passes through the introduction path 106 and passes through the reading position 108, whereby the image formed on the surface of the document is read. The document D that has passed the reading position 108 passes through the discharge path 107 and is discharged onto the discharge tray 109.

  When reading both the front and back sides of a document, first, the document D passes through the reading position 108 as described above, whereby one image surface of the document is read. Thereafter, the document D passes through the discharge path 107, is switched back by the reverse roller pair 110, and is sent again to the registration roller pair 105 in a state where the front and back are reversed. Then, in the same manner as when the image of one side is read, the skew of the original D is corrected by the registration roller pair 105, passes through the introduction path 106, and the other image side is read at the reading position 108. Thereafter, the document D passes through the discharge path 107 and is discharged to the discharge tray 109.

  The document passing through the reading position 108 is irradiated with light from the illumination system 111. The reflected light reflected from the original is guided to the optical element 113 (CCD or other element) by the mirror 112 and converted into image data. Then, by irradiating the photosensitive drum 114 with laser light based on the image data, a latent image is formed on, for example, the photosensitive drum 114 as image forming means. The latent image formed on the photosensitive drum 114 is developed with toner supplied from a toner supply device (not shown) to become a toner image.

  In addition, a sheet P such as paper or plastic film stacked on the cassette 115 in accordance with the toner image forming operation is sent out from the cassette 115 according to a recording signal, and between the photosensitive drum 114 and the transfer device 116. enter in. Then, the toner image on the photosensitive drum 114 is transferred to the sheet by the transfer device 116. The sheet on which the toner image has been transferred is heated and pressed while passing through the fixing device 117, and the toner image is fixed.

  When images are formed on both sides of the sheet, the sheet on which the toner image is fixed on one side by the fixing device 117 passes through the double-sided path 118 provided on the downstream side of the fixing device 117 and is transferred to the photosensitive drum 114. And the toner image is transferred to the back surface. While the document D is passing through the double-sided path 118, the document D is switched back and turned upside down, and a toner image is transferred to the back side. Then, the toner image on the back surface is fixed by the fixing device 117 and is discharged to the external finisher 119 side.

  The finisher 119 sequentially takes sheets discharged from the apparatus main body 101 and performs various processes. Processing includes aligning multiple sheets that have been fetched into a single bundle, stapling to bind the bundle of bundled sheets with staples, punching to punch holes near the trailing edge of the imported sheets, sorting, non-sorting Processing and bookbinding processing. The finisher 119 performs at least one of these processes. As shown in FIG. 2, the finisher 119 of the present embodiment is provided with, for example, a folding device 400, a processing unit 500, and the like.

  The processing unit 500 includes an inlet roller pair 502 (see FIG. 2), a flapper 551, and the like. The entrance roller pair 502 guides the sheet conveyed from the apparatus main body 101 (see FIG. 1) of the image forming apparatus. The flapper 551 is provided downstream of the entrance roller pair 502, and guides the sheet to the sort path 552 in the non-sort and sort modes and to the bookbinding path 553 in the folding mode.

  In the case of non-sorting, the sheet guided to the sorting path 552 by the flapper 551 is selectively discharged to the upper stack tray 18a, the lower stack tray 18b, and the option tray 18c by the normal rotation of the discharge conveyance roller pair 560 that can be rotated forward and backward. Is done. A punch unit (not shown) for punching near the rear end of the conveyed sheet can be attached between the apparatus main body 101 and the finisher 119.

  Further, in the sort mode, the sheet guided to the sort path 552 by the flapper 551 is loaded on the processing tray (intermediate tray) 630 by reverse rotation after a predetermined amount of normal rotation is performed by the discharge conveyance roller pair 560. Note that the sheets stacked in a bundle on the processing tray 630 are subjected to alignment processing, stapling processing by the stapler 601 and the like as necessary. Thereafter, the sheet bundle is selectively discharged onto stack trays 18a and 18b configured to be movable (self-propelled) in the vertical direction by a pair of paper discharge conveyance rollers 560.

  On the other hand, the folding device 400 includes two pairs of staplers 818 as binding means and a folding roller pair 826 as folding means for folding a sheet bundle. Then, the sheet from the bookbinding path 553 is stored in the storage guide 820 and then conveyed until the leading end contacts the positioning member 823 that can move in the vertical direction.

  On the storage guide 820 side of the pair of folding rollers 826, a protruding member 825 which is a protrusion means is provided with the storage guide 820 interposed therebetween. The protruding member 825 provided opposite to the folding roller pair 826 is protruded toward the sheet bundle stored in the storage guide 820, whereby the sheet bundle is pushed out to a nip that is a folding portion of the folding roller pair 826. It is. The sheet bundle is folded by the pair of folding rollers 826 and then discharged to the saddle discharge tray 832.

  The two upper and lower stack trays 18a and 18b are attached to, for example, a finisher main body 119A (see FIG. 2) that is an apparatus main body so as to be movable in the vertical direction. The stack trays 18a and 18b are driven up and down (up and down) by transmitting the forward / reverse driving of the stacker motors 209a and 209b inside the stack trays 18a and 18b to a rack portion (not shown) formed in a part of the column 37 by the pinion gear 225. It can be done. The option tray 18c is connected to the upper stack tray 18a by a connecting member 19 (see FIG. 3), and the operation is interlocked with the upper stack tray 18a. The option tray 18c is detachably attached to the connecting member 19.

  In the present embodiment, as shown in FIG. 3, the upper stack tray 18 a that is the first tray and the option tray 18 c that is the third tray are the sheet stacking for stacking the sheets discharged from the discharge port (discharge port) 36. The position can be moved to a retracted position above the paper discharge port 36. The trays 18a, 18b, and 18c are moved down to the sheet stacking position and then lowered as the stacked sheets increase.

  Further, the lower stack tray 18b, which is the second tray, is movable between the initial position HP and the sheet stacking position. When stacking sheets, the lower stack tray 18b moves to the sheet stacking position after the upper stack tray 18a has moved to the retracted position.

  The lower stack tray 18b moves to the sheet stacking position and then descends as the number of stacked sheets increases. Further, when the sheets are stacked on the upper stack tray 18a or the option tray 18c at the retracted position, the lower stack tray 18b is lowered so as not to prevent the both 18a and 18c from being lowered to the sheet stacking position. ing.

  The stack detection sensors 7, 9, and 8 are sensors that detect the presence or absence of sheets stacked on the respective trays 18a, 18b, and 18c.

  On the other hand, as shown in FIG. 3, a sheet sensor 3 is provided at a discharge port 36 for discharging sheets or stapled sheet bundles to the stack trays 18a and 18b and the optional tray 18c, which are sheet stacking trays. ing. The sheet sensor 3 detects the uppermost surface of the sheets (bundles) stacked on the trays 18a, 18b, and 18c or the sheet stacking surfaces of the trays 18a and 18c when the sheets (bundles) are not stacked. It has become. By the detection operation of the sheet sensor 3, the trays 18 a, 18 b, and 18 c are moved up and down to positions where the stacked sheets (bundles) do not block the paper discharge outlet 36.

  The sheet sensor 3 detects a sheet (bundle) or each of the trays 18a, 18b, and 18c with a flag that performs a mechanical operation. However, the sheet sensor 3 is not limited to this. The sheet sensor 3 reflects, for example, a sheet (bundle) stacked on each tray 18a, 18b, 18c or a light emitting unit that irradiates the upper surface of each tray 18a, 18b, 18c and a sheet (bundle). And a light receiving portion for receiving the received light. The sheet sensor 3 may detect the position of the sheet upper surface on each tray 18a, 18b, 18c by measuring the angle of the reflected light.

  The position detection signal detected by the sheet sensor 3 is input to the CPU 900 provided in the finisher main body 119A. The position detection signal may be input to the control unit 910 (see FIG. 1) of the apparatus main body 101. Further, the CPU 900 and the control unit 910 may be integrated by incorporating either one into the other.

  In the present embodiment, the trays 18a, 18b, and 18c are moved downward and then moved up to a position where the sheet sensor 3 is turned on. This is to keep the distance between the uppermost position of the sheets (bundles) stacked on the trays 18a, 18b, and 18c and the paper discharge port 36 constant. Furthermore, this is also for preventing sheets (bundles) stacked on the trays 18a, 18b, and 18c from leaning against the slats 25.

  In FIG. 3, a first lower limit sensor 1 is a sensor that detects a lower limit position of the stack tray 18a that gradually descends as the number of stacked sheets increases. The second lower limit sensor 29 is a sensor that detects the lower limit position of the lower stack tray 18b.

  The upper surface detection sensor 5 is a sensor that detects the sheet stacking surface of the lower stack tray 18b or the upper surface of the stacked sheets. This detected position is called an upper standby position. The upper surface detection sensor 5 is disposed below the first lower limit sensor 1.

  Since the upper surface detection sensor 5 is located below the first lower limit sensor 1, the lower stack tray 18b detected by the first lower limit sensor 1, the lower stack tray 18b detected by the upper surface detection sensor 5 and located at the upper standby position, and the like A gap is generated between the sheets on the tray.

  By this gap, when sheets are stacked on both trays 18a and 18c, it is possible to prevent the upper stack tray 18a from colliding with the lower stack tray 18b at the upper standby position and the sheets on the tray 18b.

  Further, both the first lower limit sensor 31 and the second lower limit sensor 30 are located above the second lower limit sensor 29. As the stacked amount of sheets increases, the sheet surface height is kept constant by the sheet sensor 3, and the trays 18a, 18b, and 18c are gradually lowered. When sheets having a sheet size of 216 mm or less stacked in the transport direction are stacked on the trays 18a, 18b, and 18c, the full sheet is detected by the lower limit sensors 1 and 29, respectively. When sheets having a sheet size exceeding 216 mm in the conveyance direction are stacked, the full sheet is detected by the sensors 31 and 30 before the lower limit.

  Next, the electrical hardware configuration of the sheet post-processing apparatus of this embodiment will be described with reference to the block diagram of FIG.

  In FIG. 4, for example, the CPU 900 as a control unit reads out data from the stored ROM 901 and performs control and calculation while temporarily storing it in the RAM 902. Driving of each motor, solenoid, and clutch is controlled based on input information from each sensor, main body communication unit, saddle communication unit, puncher communication unit, and the like.

  The sensors that input signals to the CPU 900 include an entrance path sensor, a conveyance path sensor, a first lower limit sensor 1, a first lower limit sensor 31, a sheet sensor 3, an upper surface detection sensor 5, a stack detection sensor 7, 8, 9 and an upper limit sensor 32. There are various HP (home position) detection sensors. Further, there are a staple interference sensor, a second lower limit sensor 29, an upper cover sensor, a front cover sensor, a second lower limit front sensor 30, an upper limit sensor 32, and the like.

  The seat sensor 3, the first lower limit sensor 31, the first lower limit sensor 1, the upper surface detection sensor 5, the second lower limit sensor 30, and the second lower limit sensor 29 are examples of position detection means.

  In addition, as a drive unit to which a control signal is output from the CPU 900, an entrance conveyance motor, a bundling motor, a swing motor, a front alignment motor, a back alignment motor, a rear end assist motor, an upper tray motor 33, a lower tray motor 34, There are gear change motors and stapler motors. Further, there are a stapler shift motor, an entrance roller separation SL, a buffer roller separation SL, a first discharge roller separation SL, a buffer paper presser SL, a bundle lowering clutch, a shutter clutch, and the like.

  The CPU 900 causes the upper surface of one stacking tray or the upper surface of a sheet or sheet bundle stacked on the stacking tray to be positioned below the discharge port 36, and moves the other stacking tray so as not to contact the stacking tray. Drive control means is configured. Further, the CPU 900 constitutes a calculation means for calculating a time for moving each stacking tray by the drive control means from a result of predicting the stacking amount of each stacking tray based on the sheet information from the image forming apparatus. Then, the timing at which the sheet from the image forming apparatus can be received from the timing at which the CPU 900 can discharge the sheet from the discharge port based on the calculation result of the calculation unit is set to be less from the image forming apparatus than the timing at which the sheet can be received. The timing control means is configured to control so that the discharge timing is simultaneous or delayed.

  In addition to the above configuration, a combination of the sheet sensor 3, the first lower limit sensor 1, and the first lower limit sensor 31 constitutes a determination unit that determines the presence or absence of a tray.

  Next, as operation of the present embodiment, the attachment detection processing control of the option tray 18c and the upper stack tray 18a of the finisher 119 is illustrated in the structural diagram shown in FIGS. 1 to 3, the control block diagram shown in FIG. , Based on the flowchart shown in FIG. The control processing shown in the flowcharts of FIGS. 5 and 6 is executed by the CPU 900 in accordance with the program stored in the ROM 901 in FIG. 4 in advance.

  The attachment detection process control of the option tray 18c and the upper stack tray 18a is performed by NO / OFF operations of the sheet sensor 3 that detects the uppermost surface of the sheet, the upper limit sensor 32, and the like.

  The sheet sensor 3 itself detects the sheets stacked on the option tray 18c, the upper stack tray 18a, and the trays 18c, 18a, and 18b. However, it cannot be distinguished which tray is being detected, whether the tray is being detected, or whether a sheet is being detected. Even though the sheet sensor 3 can detect the sheets stacked on the lower stack tray 18b, it cannot detect the lower stack tray 18b.

  The upper limit sensor 32 detects the sheets stacked on the option tray 18c, the options tray 18c, the sheets stacked on the upper stack tray 18b, and the upper stack tray 18b.

  First, when receiving an initial request (S1) from the apparatus main body 101, the CPU 900 controls the lower tray motor 34 to detect the lower stack tray 18b attached to the apparatus main body 119A by the second lower limit sensor 29. The position is lowered (S2). Similarly, the CPU 900 assumes that the upper stack tray 18a and the option tray 18c are connected to the apparatus main body 119A, and controls the upper tray motor 33 to detect the virtual upper stack tray 18a by the first lower limit sensor 1. (S3).

  Then, the CPU 900 raises the virtual option tray 18c, the upper stack tray 18a, and the actually mounted lower stack tray 18b until it is detected by the sheet sensor 3 (S4).

  However, the sheet sensor 3 does not perform the detection operation (No in S5), and the upper limit sensor 32 may not perform the detection operation even after a time period during which it can be considered that the virtual upper stack tray 18a has reached the upper limit position (S6). YES). In this case, since the sheet sensor 3 and the upper limit sensor 32 do not perform the detection operation, the virtual upper stack tray 18a is not actually mounted. The option tray 18 c is connected to the upper stack tray 18 c by the connecting member 19. For this reason, the fact that the upper stack tray 18a is not attached means that the option tray 18c is also not connected. That is, the virtual upper stack tray 18a and the option tray 18c are not actually mounted (S7).

  In the circulation process of processes S4, S5, and S6, when the sheet sensor 3 performs a detection operation (Yes in S5), the sheet sensor 3 detects the option tray 18c, the upper stack tray 18a, and the trays 18c and 18a. , 18b, one of the sheets stacked.

  The CPU 900 controls the upper and lower tray motors 33 and 34 to continue raising the virtual upper stack tray 18a and the actually mounted lower stack tray 18b (S8).

  There is a case where the upper limit sensor 32 does not perform the detection operation (YES in S9) even when it is time for the option tray 18c to reach the upper limit position while the sheet sensor 3 remains ON (NO in S8 to S11). In this case, the sheet sensor 3 detects in step S5 the virtual upper stack tray 18a, the sheets stacked on the virtual upper stack tray 18a, and the sheets stacked on the actually mounted lower stack tray 18b. That would have been either.

  Therefore, the CPU 900 determines that the virtual option tray 18c is not actually connected (S10).

  When the sheet sensor 3 is turned off in the circulation process of the processes S8, S9, and S11 (YES in S11), the sheet sensor 3 is located between the virtual trays 18c and 18a (or virtual sheets on the tray 18a). Or the space between the virtual upper stack tray 18a and the sheet on the lower stack tray 18b that is actually installed is detected.

  Then, even if the sheet sensor 3 is turned off (YES in S11), the CPU 900 continues to control the upper and lower tray motors 33 and 34 to raise the upper and lower stack trays 18a and 18b (S12).

  If the upper limit sensor 32 does not detect the virtual option tray 18c when the virtual option tray 18c reaches the upper limit position (S12, S13), the virtual option tray 18c is not actually mounted. Therefore, the CPU 900 determines that the option tray 18c is not actually mounted (S14).

  Conversely, when the sheet sensor 3 remains off (YES in S11) and is turned on again (S12, S13, S15), the virtual option tray 18c is actually mounted (S16). ). When the option tray 18c is mounted, the upper stack tray 18a supporting the option tray 18c is also mounted.

  The determination of the processing S14 and the processing S16 is described from another angle as follows.

  In process S5, suppose that the sheet sensor 3 detects the option tray 18c. In this case, in the process S11, the sheet sensor 3 has detected between the option tray 18c and the upper stack tray 18a, and the process reaches the process S15 through the processes S12 and S13. In the process S15, the sheet sensor 3 has detected the upper stack tray 18a. Therefore, in this case, the virtual option tray 18c and the virtual upper stack tray 18a are actually mounted.

  In process S4, it is assumed that the sheet sensor 3 detects the upper stack tray 18a without detecting the option tray 18c. In this case, in the process S11, the sheet sensor 3 has detected between the sheets on the upper stack tray 18a and the lower stack tray 18b. For this reason, the process reaches the process S14 without detecting the option tray 18c in the process S13. Therefore, in this case, the virtual option tray 18c is not connected. However, since the option tray 18c is not detected in the process S4, it is natural that the option tray 18c is not connected in the process S14.

Next, a combination of the sheet sensor 3 that detects the uppermost surface of the sheet, the first lower limit sensor 31 that detects the position of the tray, the first and second lower limit sensors 1 and 29, and the stack detection sensors 8 and 9. Thus, the detection operation of whether or not the tray is mounted on the apparatus main body 119A will be described.
The description will be made based on the structure shown in FIGS. 1 to 3, the control block diagram shown in FIG. 4, and the flowchart shown in FIG.

  The CPU 900 that has received the initial request (S20) checks whether or not sheets are stacked on the option tray 18c by the stack detection sensor 8 on the option tray 18c (S21). If the stack of sheets is detected, the CPU 900 recognizes that the option tray 18c is connected (S36).

  Next, the CPU 900 assumes that the lower stack tray 18b is attached, and lowers the lower stack tray 18b to the position of the second lower limit sensor 29 (S22).

  Similarly, the CPU 900 assumes that the upper stack tray 18a is attached and lowers the upper stack tray 18a to the position of the first lower limit sensor 1 (S23).

  Next, the CPU 900 checks the stack detection sensor 7 on the upper stack tray 18a, the stack detection sensor 8 on the option tray 18c cannot detect the sheet, and the stack detection sensor 7 on the upper stack tray 18a detects the sheet. If detected, the process proceeds to the next step (Yes in S24).

  Next, the CPU 900 raises the upper stack tray 18a until the sheet sensor 3 detects the tray (option tray 18c) (S25).

  In the CPU 900, the sheet sensor 3 detects the tray (option tray 18c) (S26), further raises the upper stack tray 18a, and once detects the space (S27). After that, the CPU 900 checks the first lower limit sensor 31 again (S28). At this time, when the first lower limit sensor 31 detects the tray again (Yes in S28), the detected tray is the lower stack tray 18b, and the tray detected in the process S26 becomes the option tray 18c. Therefore, the CPU 900 recognizes that the option tray 18c is connected (S35). The space in the process S27 is a space between the option tray 18c and the upper stack tray 18a.

  When the sensor before the first lower limit 31 once detects the space between the trays and reaches the upper limit position again without detecting the tray, the tray detected in the process S26 is the upper stack tray 18a, and the option tray 18c is It will not be installed. Therefore, the CPU 900 recognizes that the option tray 18c is not attached (S34). The space detected by the first pre-lower limit sensor 31 is a space between the upper stack tray 18a and the lower stack tray 18b.

  If the stack detection sensor 8 on the option tray 18c cannot detect a sheet (No in S21) and the stack detection sensor 9 on the upper stack tray 18a also cannot detect a sheet (No in S24), the CPU 900 performs processing ( S29) is performed.

  The CPU 900 performs ascent control of the upper stack tray 18a assuming that the upper stack tray 18a is attached (S29). The CPU 900 controls the raising of the upper stack tray 18a until the sheet sensor 3 detects the tray (S30) or until the tray reaches the upper limit position (S31).

  When the tray reaches the upper limit position without being detected by the sheet sensor 3, the upper stack tray 18a and the optional tray 18c are not attached to the apparatus main body 119A. Therefore, the CPU 900 recognizes that the upper stack tray 18a is not attached to the apparatus main body 119A (S33).

  When the sheet sensor 3 detects the tray (Yes in S30), the CPU 900 checks the first lower limit sensor 31 (S32).

  When the upper stack tray 18a is detected at this position (Yes in S32), the upper stack tray 18a and the option tray 18c are mounted on the apparatus main body 119A. Therefore, the CPU 900 recognizes that the option tray 18c is connected (S35).

  If the upper stack tray 18a is not detected at this position, the tray detected in step S30 is the upper stack tray 18a, and the option tray 18c is not attached to the apparatus main body 119A. Therefore, the CPU 900 recognizes that the option tray 18c is not connected (S35).

  In the above operation, when the CPU 900 recognizes that the tray is mounted, the CPU 910 of the apparatus main body 101 of the copying machine 100 is notified of the mounting information by communication. The CPU 910 that has received the mounting information displays the tray mounted on the finisher 119 on the display unit 35 provided in the apparatus main body 101. Further, the CPU 900 controls the sheet processing apparatus to discharge the sheet to the connected tray, and performs accurate sheet discharge control and the like so as not to accidentally discharge the sheet to the unconnected tray. .

  As described above, the finisher 119 detects the mounting of the trays 18c and 18a by the combination of the sheet sensor 3, the first lower limit sensor 31, the first and second lower limit sensors 1 and 29, and the stack detection sensors 8 and 9. It can be done. Therefore, the finisher 119 does not need to be provided with a dedicated sensor for mounting detection, and the structure can be simplified and the cost can be reduced.

  In the above description, the stack detection sensors 8 and 9 are not necessarily required for tray attachment / detachment detection.

  Further, only the mounting of the option tray 18c and the upper stack tray 18a has been described by way of example, but the present invention can also be applied to the lower stack tray 18b.

1 is a cross-sectional view of an image forming apparatus according to the present invention, for example, a copying machine along a sheet conveying direction. It is sectional drawing along the sheet conveyance direction of the sheet processing apparatus in embodiment of this invention. In FIG. 2, it is the figure which showed the position of the sensor. FIG. 3 is a control block diagram of the sheet processing apparatus in FIG. 2. 3 is a flowchart for explaining an operation of a sheet processing measure in FIG. 2. 3 is a flowchart for explaining an operation of a sheet processing measure in FIG. 2.

Explanation of symbols

D Document P Sheet 1 First lower limit sensor (position detection means)
3 Sheet sensor (position detection means)
5 Upper surface detection sensor (position detection means)
7, 8, 9 Stack detection sensor 18a Upper stack tray (sheet stack tray)
18b Lower stack tray (sheet stacking tray)
18c Option tray (sheet stacking tray)
29 Second lower limit sensor (position detection means)
30 Second lower limit front sensor (position detection means)
31 First lower limit sensor (position detection means)
35 Display 36 Paper discharge port 37 Post 100 Copier (image forming apparatus)
DESCRIPTION OF SYMBOLS 101 Apparatus main body 102 Document feeding apparatus 114 Photosensitive drum (Image formation means)
119 Finisher (sheet processing device)
119A Finisher body (device body)
630 Processing tray (intermediate tray)
900 CPU (control means)

Claims (4)

The device body;
A sheet stacking tray that is detachably mounted on the apparatus main body and on which sheets discharged from the apparatus main body are stacked; and
Position detecting means for detecting the elevation position of the sheet stacking tray;
Control means for raising and lowering the sheet stacking tray to a position detected by the position detection means,
Even if the control means raises and lowers the sheet stacking tray to a position detected by the position detecting means, when the position detecting means does not detect the sheet stacking tray, the sheet stacking tray is mounted on the apparatus main body. Judge that it is not,
A sheet processing apparatus. The position detection means is an upper surface detection sensor that is installed at a position where a sheet is discharged from the apparatus main body and detects the upper surface of the sheet stacking tray.
The sheet processing apparatus according to claim 1. The position detection means is a lowering detection sensor for detecting a lowering limit position of the sheet stacking tray;
The sheet processing apparatus according to claim 1. An image forming means for forming an image on a sheet;
A sheet processing apparatus for discharging and stacking sheets on which images have been formed by the image forming means,
The sheet processing apparatus is the sheet processing apparatus according to any one of claims 1 to 3.
An image forming apparatus.

Images