JP2021165190A - Image forming system, sheet loader and method for controlling the same - Google Patents

Abstract

To provide a sheet loader that if an elevation abnormality occurs on a loading tray, can specify a failure point to shorten the downtime in early stages.SOLUTION: A sheet loader comprises a loading tray 700, a tray elevation motor M10 that raises and lowers the loading tray, an area detection unit 600 that detects an elevation position of the loading tray, and determination means 952 that if the loading tray stops due to an impossibility to lower during descent processing of the loading tray, makes reference to position information of the loading tray, and determines that the loading tray stops due to a failure if a position the loading tray stops is within a movement range of ascent processing of the loading tray performed within a past predetermined time and determines that the loading tray possibly becomes impossible to lower due to a foreign matter put below the same if the position the loading tray stops is not within a movement range of ascent processing of the loading tray performed within the past predetermined time.SELECTED DRAWING: Figure 13

Description

The present invention relates to an image forming system, a seat loading device, and a control method thereof.

An image forming system is known in which a sheet on which an image is formed is subjected to predetermined post-processing and discharged to the outside of the machine. Such an image forming system includes a loading tray for loading sheets to be ejected after post-processing, and moves the loading tray up and down according to the height of the loaded sheets to allow the sheet ejection port and the loading tray to move up and down. There is one that matches the loading position (Patent Document 1).

The image forming system described in Patent Document 1 stops the lowering of the loading tray when foreign matter such as luggage is placed under the loading tray and the loading tray cannot be lowered, and the height at which the loading tray is stopped. A signal is output to notify that the foreign matter is removed accordingly. Then, after the user removes the foreign matter based on the signal, the loading tray is raised, and if it can be raised, it is determined that the foreign matter could not be lowered because the foreign matter was placed under the loading tray. On the other hand, if the loading tray cannot be raised even if the foreign matter below the loading tray is removed, it is determined that the loading tray could not be lowered due to a failure of the motor for raising and lowering the loading tray.

By the way, in recent years, as a technique for reducing downtime when an abnormality occurs in an image forming system, a method of performing a failure diagnosis for identifying a failed portion by the device itself has been devised. In such an image forming system, it is possible to eliminate an abnormality at an early stage by notifying a service person of a failed component such as a motor or a sensor identified by a failure diagnosis. That is, in the image forming system, when an abnormality occurs in the device, it is possible to diagnose the faulty part causing the abnormality earlier and notify the serviceman, which is the downtime until the device returns to the usable state. It leads to shortening.

Japanese Unexamined Patent Publication No. 2015-221698

However, in the technique described in Patent Document 1, when an abnormality occurs when the loading tray is lowered, a signal for removing foreign matter is always output when the position where the loading tray is stopped is equal to or lower than a predetermined height. There is. Therefore, the device is stopped until the user removes the foreign matter, and it is not even possible to determine whether or not a failure has occurred. Therefore, even if an abnormality occurs when lowering the loading tray, there is a problem that the faulty part cannot be identified immediately, and as a result, the downtime until the device returns to the usable state becomes long. rice field.

An object of the present invention is an image forming system, a sheet loading device, and a control method thereof capable of diagnosing a faulty part at an early stage and shortening downtime when an abnormality occurs in a loading means for loading a sheet and the sheet is stopped. Is to provide.

In order to achieve the above object, the sheet loading device according to claim 1 includes a loading means for loading a sheet, a driving means for raising and lowering the loading means, and an elevating detecting means for detecting an elevating position of the loading means. When the loading means cannot be lowered and is stopped during the lowering process of the loading means, the position information of the loading means detected by the elevating detection means is referred to, and the position where the loading means is stopped is within a predetermined time in the past. When it is within the moving range in the ascending process of the loading means performed in the above, it is determined that the loading means has stopped due to a failure, and the position where the loading means has stopped is the position where the loading means was stopped within the predetermined time in the past. When the loading means is not within the moving range in the ascending process of the loading means, the loading means is provided with a determination means for determining that there is a possibility that the loading means cannot be lowered due to a foreign matter placed below the loading means. ..

According to the present invention, it is possible to diagnose a faulty part at an abnormal time without requiring a user's operation, identify the faulty part at an early stage, and shorten downtime.

It is a vertical cross-sectional view which shows the schematic structure of the image formation system which concerns on 1st Embodiment. It is a block diagram which shows the control structure of the image formation system of FIG. It is a figure which shows the operation display part of the image forming apparatus in FIG. It is a figure which shows the schematic structure of the finisher. It is a partially enlarged view which shows the area detection part mounted on the loading tray. It is a figure for demonstrating the flag used for the position detection of a loading tray. It is a top view which shows the arrangement state of a flag. It is a figure which shows the correspondence between the divided area and the position along the height direction of a finisher. It is a block diagram which shows the control structure of a finisher. It is a figure for demonstrating the tray drive sensor. It is a flowchart which shows the procedure of the loading tray elevating process. It is a flowchart which shows the procedure of the loading tray ascending process executed in step S101 of FIG. It is a flowchart which shows the procedure of the loading tray lowering process executed in step S102 of FIG. It is a figure which shows the loading tray management information. It is a figure which shows the mode in which a loading tray and a foreign matter interfere with each other. It is a flowchart which shows the procedure of the 2nd loading tray lowering process.

Hereinafter, embodiments will be described in detail with reference to the drawings.

(First Embodiment)
FIG. 1 is a vertical cross-sectional view showing a schematic configuration of an image forming system according to the first embodiment.

In FIG. 1, the image forming system 800 is mainly composed of an image forming apparatus 450 and a post-processing apparatus (hereinafter, referred to as “finisher”) 500. The image forming apparatus 450 includes a document feeding unit 100, an image reader 200 that reads an image of the fed document, a printer 300 that forms the read image on paper (sheet), and an operation display unit 400.

The document feeding unit 100 feeds the documents set upward on the document tray 101 one by one from the first page to the left in FIG. 1, and passes through a curved path from left to right on the platen glass 102. It is conveyed to the glass through a predetermined reading position. Then, after that, the document feeding unit 100 ejects the document from which the image has been read toward the output tray 112. The predetermined reading position is a reading position provided on the platen glass 102 included in the image reader 200, and is a position where the scanner unit 104 is fixed.

When the document passes through the scanning position on the platen glass 102 from left to right, the document image is scanned by the scanner unit 104 fixed at the position corresponding to the scanning position. When the document passes through the scanning position, light is emitted from the lamp 103 of the scanner unit 104 toward the document, and the reflected light from the document is guided to the lens 108 via the mirrors 105, 106, and 107. The light that has passed through the lens 108 is imaged on the imaging surface of the image sensor 109.

By transporting the document so as to pass through the scanning position from left to right in this way, the direction orthogonal to the transport direction of the document is the main scanning direction, and the transport direction is the sub-scanning direction. A read scan is performed. That is, when the document passes through the scanning position, the entire document image is scanned by transporting the document in the sub-scanning direction while scanning the document image line by line in the main scanning direction with the image sensor 109. The optically read image is converted into image data by the image sensor 109 and output to the printer 300. The image data output to the printer 300 is input as a video signal to the exposure unit 110 of the printer 300.

When reading a document without using the document feeding section 100, first, the user lifts the document feeding section 100, places the document on the platen glass 102, and displays the scanner unit 104 from the left in FIG. The document is read by scanning to the right. Such a method of reading a document image without using the document feeding unit 100 is called a document fixed reading.

Next, the printer 300 will be described. The exposure unit 110 of the printer 300 modulates and outputs the laser beam based on the video signal input from the image reader 200. The output laser light is irradiated onto the photosensitive drum 111 while being scanned by the polygon mirror 119. As a result, an electrostatic latent image corresponding to the laser beam is formed on the surface of the photosensitive drum 111. At this time, the exposure unit 110 outputs the laser beam so that an upright image (an image that is not a mirror image) is formed on the photosensitive drum 111 at the time of fixed reading of the document. The electrostatic latent image formed on the photosensitive drum 111 is visualized as a developer image by the developer supplied from the developer 113.

On the other hand, the sheet S fed by the pickup roller 127 or 128 from the upper cassette 114 or the lower cassette 115 mounted on the lower part of the printer 300 is conveyed to the registration roller 126 stopped by the paper feed roller 129 or 130. .. The skew of the sheet S is corrected by abutting the tip of the sheet S against the registration roller (resist roller) 126. After that, the sheet S is supplied between the photosensitive drum 111 and the transfer unit 116 by driving the resist roller 126 at the timing when the developer image formed on the photosensitive drum 111 reaches the transfer unit 116. The developer image formed on the photosensitive drum 111 is transferred by the transfer unit 116 onto the supplied sheet S. The sheet S to which the developer image is transferred is conveyed to the fixing portion 117. The fixing unit 117 fixes the transferred developer image on the sheet S by heating and pressurizing the sheet S. The sheet S on which the developer image is fixed is discharged from the printer 300 to the outside of the image forming apparatus 450, that is, to the finisher 500 via the flapper 121 and the discharge roller 118.

When the sheet S is discharged with the image forming surface facing downward (face down), the sheet S that has passed through the fixing portion 117 is once guided into the inversion path 122 by the switching operation of the flapper 121. Then, after the rear end of the sheet S passes through the flapper 121, the sheet S is switched back and discharged from the printer 300 via the discharge roller 118. Such a paper ejection form is called reverse paper ejection. The reverse paper ejection is preferably applied when forming an image in order from the first page, such as when forming an image read by using the document feeding unit 100 or forming an image output from a computer. In reverse paper ejection, the sheet order after paper ejection is the correct page order.

On the other hand, when a sheet having high rigidity such as thick paper is fed from the manual paper feed unit 125 and an image is formed on the sheet S, the sheet S is not guided by the inversion path 122 and the image forming surface is turned upward. It is discharged to the outside of the machine in the state (face up).

Further, when double-sided recording in which an image is formed on both sides of the sheet S is set, the sheet S in which the image is formed on one surface is guided to the inversion path 122 by the switching operation of the flapper 121 and then transported on both sides. It is transported to the path 124. The sheet S transported to the double-sided transport path 124 is resupplied between the photosensitive drum 111 and the transfer unit 116 at the same timing as described above, and an image is formed on the other surface. The sheet S discharged from the printer 300 of the image forming apparatus 450 is sent to the finisher 500 and subjected to predetermined post-processing. The configuration of the finisher 500 will be described later.

Next, the control configuration of the image forming system 800 will be described. FIG. 2 is a block diagram showing a control configuration of the image forming system 800 of FIG.

In FIG. 2, the image forming system 800 includes a CPU circuit unit 900 as a control configuration. The CPU circuit unit 900 incorporates a CPU 901, a ROM 902, and a RAM 903. The CPU 901 is connected to the ROM 902 and the RAM 903 by an address bus or a data bus.

The CPU circuit unit 900 is connected to the document feed control unit 911, the image reader control unit 921, the image signal control unit 922, the printer control unit 931, the operation display control unit 941 and the finisher control unit 951, respectively, by an address bus or a data bus, respectively. Has been done. Further, the CPU circuit unit 900 is connected to the external I / F 904 via the image signal control unit 922, and is also connected to the computer 905 via the image signal control unit 922 and the external I / F 904.

The CPU 901 is a CPU that performs basic control of the entire image forming system 800. That is, the CPU 901 comprehensively controls each control unit 911, 921, 922, 904, 931, 941 and 951 by the control program stored in the ROM 902. The ROM 902 stores the control program. The RAM 903 temporarily holds the control data and is used as a work area for arithmetic processing associated with the control.

The document feeding control unit 911 drives and controls the document feeding unit 100 based on an instruction from the CPU circuit unit 900. The image reader control unit 921 performs drive control on the scanner unit 104, the image sensor 109, and the like, and transfers the image signal output from the image sensor 109 to the image signal control unit 922.

The image signal control unit 922 converts the analog image signal from the image sensor 109 into a digital signal, performs various processes, and outputs the analog image signal to the printer control unit 931. Further, the image signal control unit 922 performs various processes on the digital image signal input from the computer 905 via the external I / F 904 and outputs the digital image signal to the printer control unit 931. The processing operation by the image signal control unit 922 is controlled by the CPU circuit unit 900. The printer control unit 931 controls the exposure unit 110 and the printer 300 based on the input image signal, and performs image formation and paper transfer.

The operation display control unit 941 exchanges information between the operation display unit 400 and the CPU circuit unit 900. The operation display unit 400 includes a plurality of keys for setting various functions related to image formation, a display unit for displaying information indicating a setting state, and the like. The operation display control unit 941 outputs a key signal corresponding to the operation of each key to the CPU circuit unit 900, and displays the corresponding information on the operation display unit 400 based on the signal from the CPU circuit unit 900.

The finisher control unit 951 is mounted on the finisher 500, which will be described later, and controls the drive of the entire finisher 500 by exchanging information with the CPU circuit unit 900. The control content of the finisher control unit 951 will be described later.

Next, the operation display unit 400 of the image forming apparatus 450 will be described.

FIG. 3 is a diagram showing an operation display unit 400 of the image forming apparatus 450 in FIG. 1.

3A is a diagram showing a display screen of the operation display unit 400, and FIGS. 3B and 3C are diagrams showing display examples displayed on the display screen, respectively.

In FIG. 3, the operation display unit 400 includes a start key 402 for starting the image forming operation and a stop key 403 for interrupting the image forming operation. Further, the operation display unit 400 includes ten keys 404 to 412 and 414 for setting the number of positions, an ID key 413, a clear key 415, a reset key 416, and the like. A display unit 420 made of a touch panel is arranged above the numeric keys 404 to 412 and 414, and various keys are displayed as soft keys on the display screen of the display unit 420.

The operation display unit 400 is used for setting the operation mode of the finisher 500, which will be described later. That is, in the image forming system 800, each post-processing mode such as non-sort, sort, staple sort (binding mode), and bookbinding mode is executed as the post-processing mode. Such a post-processing mode is set by an input operation from the operation display unit 400 by the user.

When the post-processing mode is set, for example, when the "finishing" key is selected by the user on the initial screen shown in FIG. 3A, the display screen of the display unit 420 is shown in FIG. 3B. Menu selection screen is displayed. The user sets the post-processing mode in the finisher 500 using the displayed menu selection screen.

That is, in FIG. 3B, when the user finishes the finishing selection operation with the "sort" key selected, for example, the sort mode is set. On the other hand, when the user presses, for example, the "staple" key in FIG. 3B, the staple setting screen shown in FIG. 3C is displayed on the display screen of the display unit 420. Then, the user selects a binding method such as corner binding and two-place binding (double) on the displayed staple setting screen.

Next, a schematic configuration of the finisher 500 as an aftertreatment device will be described.

FIG. 4 is a diagram showing a schematic configuration of the finisher 500. 4A is a vertical cross-sectional view of the finisher 500 as viewed from the front side (front side of FIG. 1), and FIG. 4B is a vertical sectional view of the finisher 500 from above (upper side of FIG. 1). It is a plan view as seen.

In FIG. 4, the finisher 500 sequentially captures the sheets S discharged from the image forming apparatus 450, and performs post-processing on the captured plurality of sheets S according to the post-processing mode set by using the operation display unit 400. Examples of the post-treatment include a bundling process in which a plurality of sheets are aligned and bundled into one bundle, a stapling process in which the rear end of the bundled sheet bundle is bound with a staple, and the like.

That is, the finisher 500 takes the sheet S discharged from the image forming apparatus 450 into the internal transport path 520 by the transport roller pair 511. The taken-in sheet S is conveyed by the transfer roller pairs 512 and 513. The transport path 520 is provided with transport sensors 570, 571, and 572, each of which detects the presence or absence of the sheet S.

The transfer roller pair 512 is arranged on the shift unit 580 together with the transfer sensor 571. The shift unit 580 is configured to be movable in the sheet width direction (the front and back directions of the paper surface in FIG. 4, that is, the front side and the back side) orthogonal to the transport direction by the shift motor M4 described later. The shift unit 580 is offset in the width direction while transporting the seat S by driving the shift motor M4 in a state where the transport roller pair 512 sandwiches the seat S.

In the sort mode set by the user by selecting the "shift" key on the display screen of FIG. 3B, the shift unit 580 shifts the front shift sheet S to the front side by 15 [mm] and the back shift, for example. Sheet S is offset to the back side by 15 [mm]. When it is detected that the seat S has passed through the shift unit 580 by the input of the signal from the transport sensor 571, the finisher control unit 951 drives the shift motor M4 to return the shift unit 580 to the center position. On the other hand, when the user has not selected the "shift" key on the display screen of FIG. 3B, the shift unit 580 passes the seat S as it is without offsetting.

A flapper 540 is arranged between the transfer roller pair 513 and the transfer roller pair 514. The flapper 540 guides the sheet inverted and conveyed by the transfer roller pair 514 to the buffer path 524 which functions as a buffer unit. In the buffer path 524, a transfer roller pair 518 that sends the waiting sheet S back to the main transfer path is arranged. The transfer roller pair 514, the flapper 540, and the buffer path 524 are provided in the middle of the transfer path, make one or more sheets S stand by, and send the sheet S to the transfer path again. As a result, the waiting sheet S and the subsequent sheet S are superposed to form a sheet bundle.

A switching flapper 541 for transporting the sheet S to either the upper paper ejection path 522 or the lower paper ejection pass 523 is arranged between the transport roller pair 514 and the transport roller pair 515. When the switching flapper 541 is switched to the upper paper discharge path 522 side, the sheet S is guided to the upper paper discharge path 522 by the transport roller pair 514 driven by the buffer motor M2 described later. Then, after that, the sheet S is discharged onto the loading tray 701 by the transfer roller pair 515 driven by the paper discharge motor M3 described later. A transport sensor 574 is provided on the upper paper ejection path 522 to detect the passage of the sheet S.

When the switching flapper 541 is switched to the lower paper discharge path 523 side, the sheet S is guided to the lower paper discharge path 523 by the transport roller pair 514 driven by the buffer motor M2. Then, the sheet S is guided to the processing tray 630 by the transport roller pairs 516, 517, 518 driven by the paper ejection motor M3. A transport sensor 575, 576 is provided in the lower paper ejection path 523 to detect the passage of the sheet S.

The sheet S guided to the lower paper ejection path 523 is ejected to the processing tray 630 and is conveyed by the knurled belt 661 driven in synchronization with the transfer roller pair 518 and the paddle 660 driven by the paddle motor M6 described later. It is pulled back to the rear end side of the direction. The pulled back sheet S hits the stopper 631 and stops.

The matching members 641 provided on the front side and the back side on the processing tray 630 are moved in a direction orthogonal to the transport direction of the sheet S by the matching motor M7 described later. The sheet S loaded on the processing tray 630 is subjected to a matching process by the matching member 641, and a stapler process is performed by the stapler 601 as needed. The processed sheet S or the sheet bundle is discharged onto the loading tray 700 by the bundle discharge roller pair 680.

A paper surface sensor 720 and a full load sensor 730 corresponding to the loading tray 700 are provided. The paper surface sensor 720 detects the sheet S or the sheet bundle (hereinafter, referred to as “loading paper”) loaded on the loading tray 700. When the paper surface sensor 720 as the paper surface detecting means detects the loaded paper, the loading tray 700 is lowered by driving the tray elevating motor M10, which will be described later. By lowering the loading tray 700 to a position where the loading paper is not detected by the paper surface sensor 720, the heights of the output port of the finisher 500 and the loading position of the loading tray 700 are kept constant. Like the loading tray 700, the loading tray 701 is controlled by the paper surface sensor 721 to move up and down so as to keep the height of the paper ejection port and the loading position constant. When the loading tray 700 is lowered to the position of the loading sensor 730, the image forming apparatus 450 is notified of the loading information. When the loading information is notified, the image forming process is temporarily suspended until the loading paper on the loading tray 700 is removed.

The loading tray 700 and the loading tray 701 are attached to the finisher 500 as shown in FIG. 4 (b). The loading tray 700 has a tray elevating motor M10 described later, and the loading tray 701 has a tray elevating motor M11 described later. On the other hand, a rack gear (not shown) is built in the rear column 610b of the finisher 500. The rack gear is fitted with a pinion gear connected to the tray elevating motors M10 and M11 to support the loading trays 700 and 701. As a result, the loading trays 700 and 701 are configured to be able to move up and down with respect to the paper ejection port of the finisher 500.

The loading trays 700 and 701 as the sheet loading device include elevating area detection units 600 and 601 for detecting the elevating position along the elevating direction, respectively.

FIG. 5 is a partially enlarged view showing the elevating area detection unit 600 (601) mounted on the loading tray 700 (701). In FIG. 5, the elevating area detection unit 600 (601) as the elevating detection means includes four area sensors PI1, PI2, PI3, and PI4. The area sensors PI1, PI2, PI3, and PI4 are photo interrupters, and in the example of FIG. 5, they have a U shape when viewed from above. The position of the loading tray 700 (701) along the moving direction is detected based on the combination of the detection results when the four area sensors PI1, PI2, PI3, and PI4 as the flag detecting means detect the corresponding flags. NS.

FIG. 6 is a diagram for explaining a flag used for detecting the position of the loading tray. In FIG. 6, FIG. 6A is a diagram showing an arrangement example of four types of flags arranged along the height direction of the rear support column 610b, and FIG. 6B is a combination of four types of flags. It is a figure which shows the area where the loading tray detected by is present. In FIG. 6A, four types of flags F1, F2, F3, and F4 are arranged in the rear column 610b along the moving direction of the loading tray. The flags F1 and F2 are divided into two regions.

FIG. 7 is a plan view showing the arrangement state of the flags F1, F2, F3, and F4. 7A is a plan view of each flag viewed from above, and FIG. 7B is a plan view showing the positional relationship between the flag and the area sensor. In FIG. 7A, the flags F1, F2, F3, and F4 are arranged at predetermined intervals along the lateral direction (sheet ejection direction). In FIG. 7B, the flags F1, F2, F3, and F4 are arranged so that their respective tip portions are located in the central gaps of the area sensors PI1, PI2, PI3, and PI4.

As the loading tray 700 (701) moves up and down, the detection results of the area sensors PI1, PI2, PI3, and PI4 change. As shown in FIG. 6B, the elevating area detection unit 600 (601) moves the position of the loading tray 700 (701) in the moving direction by combining the four detection results of the area sensors PI1, PI2, PI3, and PI4. It is detected by dividing it into 9 areas.

FIG. 8 is a diagram showing the correspondence between the divided areas 1 to 9 and the positions of the finishers 500 along the height direction. In FIG. 8, the nine areas 1 to 9 are areas along the height direction of the finisher 500 and indicate the positions where the loading trays are present.

Next, the control configuration of the finisher 500 provided with the loading tray 700 that can be raised and lowered along the areas 1 to 9 will be described.

FIG. 9 is a block diagram showing a control configuration of the finisher 500.

In FIG. 9, the finisher 500 includes a finisher control unit 951 as a control configuration. The finisher control unit 951 includes a CPU 952, a ROM 953, and a RAM 954. The CPU 952 is connected to the ROM 953 and the RAM 954 by a data bus or an address bus, respectively.

The finisher control unit 951 is connected to the CPU circuit unit 900 by a data bus or an address bus. The CPU 952 of the finisher control unit 951 is connected to an inlet motor M1, a buffer motor M2, a paper ejection motor M3, a transport sensor 570-576, a solenoid SL1, SL2, a shift motor M4, a bundle ejection motor M5, and a paddle motor M6, respectively. ing. Further, the CPU 952 is connected to a matching motor M7, a staple motor M8, a staple moving motor M9, a tray elevating motor M10, M11, a paper surface sensor 720, 721, a full load sensor 730, 731, and a tray paper presence / absence sensor 740, 741, respectively. There is. Further, the CPU 952 is connected to the tray drive sensors 750 and 751 and the area sensors PI1, PI2, PI3, and PI4, respectively.

The CPU 952 communicates with the CPU circuit unit 900 provided on the main body side of the image forming apparatus 450, executes various programs stored in the ROM 953 based on the instruction from the CPU circuit unit 900, and controls the drive of the finisher 500. do. The ROM 953 stores various programs. The RAM 954 functions as a work area during program execution.

The finisher control unit 951 receives detection results input from various sensors provided in the finisher 500, and controls the drive of various motors, solenoids, and the like provided in the finisher 500. The inlet motor M1 drives the transport roller pairs 511, 512, and 513. The buffer motor M2 drives the transport roller pairs 514 and 589. The paper ejection motor M3 drives the transport roller pairs 515, 516, 517, 518. The shift motor M4 drives the shift unit 580.

The bundling / discharging motor M5 drives a bundling / discharging roller pair 680. The paddle motor M6 drives the paddle 660. The matching motor M7 drives the matching member 641. The stapler motor M8 executes a stapler 601 binding operation for binding a bundle of sheets. The stapler moving motor M9 moves the stapler 601 along the outer circumference of the processing tray 630 in a direction orthogonal to the transport direction. The staple binding position is changed by the staple moving motor M9. The CPU 952 receives the detection result as an input signal from the transport sensors 570 to 576 and the like that detect the passage of the sheet S. The tray elevating motors M10 and M11 elevate and elevate the loading trays 700 and 701.

The tray drive sensors 750 and 751 are designed to switch the output on / off each time the loading trays 700 and 701 move up and down by a predetermined amount, and detect the raising and lowering of the loading trays 700 and 701. Therefore, the tray drive sensors 750 and 751 also function as drive detection means for the tray elevating motors M10 and M11 for driving the loading trays 700 and 701, respectively.

FIG. 10 is a diagram for explaining the tray drive sensor 750. In FIG. 10, an encoder 760 and a tray drive sensor 750 that detects the rotation of the encoder 760 are shown. When the tray elevating motor M10 is driven, the encoder 760 rotates clockwise or counterclockwise via a pulley (not shown). The tray drive sensor 750 is composed of a photo interrupter, and the rotation of the encoder 760 repeats shading and non-shading. FIG. 10A shows a state in which the tray drive sensor 750 is shielded from light by the encoder 760. On the other hand, FIG. 10B shows a state in which the tray drive sensor 750 is not shielded from light by the encoder 760 (non-light shielding). If the tray elevating motor M10 is rotating, the tray drive sensor 750 outputs a pulse signal that repeats low level and high level. This pulse signal is called a rotation pulse. The output of the tray drive sensor 750 is input to the CPU 952, and the CPU 952 detects whether or not the tray elevating motor M10 is rotating based on the presence or absence of a change in the rotation pulse. The tray drive sensor 751 has the same configuration as the tray drive sensor 750 and functions in the same manner.

Returning to FIG. 9, the solenoid SL1 drives the switching flapper 540. The solenoid SL2 drives the switching flapper 541. The area sensors PI1, PI2, PI3, and PI4 detect the flags F1, F2, F3, and F4, respectively, and detect the positions of the loading trays 700 and 701 according to the combination of the detection results.

Next, elevating control for raising and lowering the loading trays 700 and 701 of the finisher 500 will be described.

The loading tray 700 moves up and down according to a change in the amount of loaded paper loaded on the loading tray 700, and adjusts the height of the output port of the finisher 500 and the loading position (top surface when loading sheets) of the loading tray 700. It is controlled to keep it constant. At that time, if an abnormality occurs in the ascending / descending operation of the loading tray 700, the cause is diagnosed. Specifically, foreign matter such as luggage is placed under the loading tray 700, and the foreign matter interferes with the loading tray 700 to interfere with the lowering operation, or is used for driving control of the loading tray 700. It is detected whether the motor, sensor, etc.

FIG. 11 is a flowchart showing a procedure for raising and lowering the loading tray. The loading tray elevating process is executed by the CPU 952 of the finisher control unit 951 according to the loading tray elevating process program stored in the ROM 953. The loading tray elevating process is started when the power is turned on to the finisher 500.

In FIG. 11, when the power is turned on to the finisher 500, the loading tray 700 is initialized. That is, the CPU 952 starts the raising process for raising the loading tray 700, and raises the loading tray 700 to a position where the loading tray 700 or the loading paper is detected by the paper surface sensor 720 (step S101). After raising the loading tray 700 (step S101), the CPU 952 proceeds to the process in step S102. That is, the CPU 952 starts the lowering process for lowering the loading tray 700, and lowers the loading tray 700 until the loading tray 700 or the loading paper is no longer detected by the paper surface sensor 720 (step S102). Details of the raising process and the lowering process of the loading tray 700 will be described later.

After lowering the loading tray 700 to a position where the loading tray 700 or the loading paper is not detected by the paper surface sensor 720 (step S102), the CPU 952 determines whether or not the image forming apparatus 450 is printing (step S103). As a result of the determination in step S103, when the image forming apparatus 450 is printing (“YES” in step S103), the CPU 952 lowers the loading tray 700 so that the sheet S is not detected according to the amount of loaded paper. (Step S104).

After lowering the loading tray 700 to a position where the loading tray 700 or the loading paper is not detected by the paper surface sensor 720 by the loading tray lowering process (step S104), the CPU 952 proceeds to the process in step S106. That is, the CPU 952 determines whether or not the loading paper loaded on the loading tray 700 has been removed by the user (step S106). If the loaded paper is removed as a result of the determination in step S106 (“YES” in step S106), the CPU 952 proceeds to step S107 in order to keep the height of the paper ejection port and the loading position of the finisher 500 constant. .. That is, the CPU 952 raises the loading tray 700 until the paper surface sensor 720 detects the loading tray 700 (step S107).

After executing the ascending process of the loading tray 700 (step S107), the CPU 952 lowers the loading tray 700 to a position where the loading tray 700 is not detected by the paper surface sensor 720 (step S108). As a result, the heights of the output port of the finisher 500 and the loading position of the loading tray 700 are kept constant. After lowering the loading tray 700 (step S108), the CPU 952 returns the process to step S103 and repeats the processes from steps S103 to S108. The processing of steps S103 to S108 is continued until the power of the finisher 500 is turned off.

On the other hand, if the image forming apparatus 450 is not printing as a result of the determination in step S103 (“NO” in step S103), the CPU 952 determines whether or not there is loaded paper on the loading tray 700 (step S105). .. If there is a load paper as a result of the determination in step S105 (“YES” in step S105), the CPU 952 proceeds to the process in step S106. That is, the CPU 952 determines whether or not the loading paper on the loading tray 700 has been removed (step S106). On the other hand, if there is no loaded paper as a result of the determination in step S105 (“NO” in step S105), the CPU 952 returns the process to step S103.

If the loaded paper is not removed as a result of the determination in step S106 (“NO” in step S106), the CPU 952 returns the process to step S103 and repeats the processes from steps S103 to S108.

According to the process of FIG. 11, when the image forming apparatus 450 is printing (“YES” in step S103), the loading tray 700 is lowered to a position where the loading paper is not detected by the paper surface sensor 720 (step S104). When the loaded paper is taken out (“YES” in step S106), the loading tray 700 is raised so that the height of the paper ejection port and the loading position of the loading tray 700 are aligned (step S107). As a result, the loading tray 700 can be lifted and lowered, and the sheet S can be ejected and loaded on the loading tray 700 while keeping the height of the output port of the finisher 500 and the loading position of the loading tray 700 constant. ..

Next, the loading tray raising process executed in step S101 of FIG. 11 will be described.

FIG. 12 is a flowchart showing a procedure of the loading tray raising process executed in step S101 of FIG. The loading tray raising process is executed by the CPU 952 of the finisher control unit 951 according to the loading tray raising processing program stored in the ROM 953.

In FIG. 12, when the loading tray raising process is started, the CPU 952 first stores the position of the loading tray 700 at that time (step S201). After storing the position of the loading tray 700 (step S201), the CPU 952 proceeds to the process in step S202. That is, whether or not the paper surface sensor 720 has detected the loading tray 700 or the loaded paper, in other words, whether or not the detection signal of the paper surface sensor 720 is off (not detecting the loading tray 700 and the loaded paper). Determine (step S202). If the detection signal of the paper surface sensor 720 is off as a result of the determination in step S202 (“YES” in step S202), the CPU 952 drives the tray elevating motor M10 so as to raise the loading tray 700 (step S203).

After driving the tray elevating motor M10, the CPU 952 determines whether or not the tray elevating motor M10 has operated a predetermined amount (step S204). The predetermined amount is an amount sufficient to raise the loading tray 700 until the detection signal of the paper surface sensor 720 changes from off to on (detecting the loading tray 700 or the loading paper).

As a result of the determination in step S204, when the tray elevating motor M10 is operating by a predetermined amount (“YES” in step S204), the CPU 952 determines whether or not the rotation pulse has changed based on the output of the tray drive sensor 750. (Step S205).

As a result of the determination in step S205, if the rotation pulse has not changed (“NO” in step S205), the tray elevating motor M10 is not rotating, so that the CPU 952 stops driving the tray elevating motor M10. (Step S206). After stopping the tray elevating motor M10 (step S206), the CPU 952 does not need to consider the abnormality arranged below the loading tray 700 in this process of raising the loading tray 700, so that the elevating mechanism fails. Is determined to have occurred (step S207). Then, the CPU 952 ends this process after that.

On the other hand, as a result of the determination in step S202, when the detection signal of the paper surface sensor 720 is changed from off to on by driving the tray elevating motor M10 (“NO” in step S202), the CPU 952 advances the process to step S208. That is, the CPU 952 stops driving the tray elevating motor M10 because the loading tray 700 has risen to a predetermined height (step S208). After stopping the tray elevating motor M10 (step S208), the CPU 952 updates the tray operation information (step S209), and then ends this process. At this time, the CPU 952 updates the tray management information, that is, the position information of the loading tray 700, based on the movement range from the position where the loading tray 700 stored in step S201 starts moving to the position where the movement ends.

Further, as a result of the determination in step S204, if the tray elevating motor M10 is not operating by a predetermined amount (“NO” in step S204), the CPU 952 returns the process to step S202 and continues the loading tray ascending process. Further, if the rotation pulse is changed as a result of the determination in step S205 (“YES” in step S205), the tray elevating motor M10 is rotating. Then, the CPU 952 repeats the processes of steps S202 to S205 until the detection signal of the paper surface sensor 720 is turned on.

According to the process of FIG. 12, when the detection signal of the paper surface sensor 720 is off (“YES” in step S202), the loading tray 700 is raised to the paper ejection port by driving the tray elevating motor M10 (step S203). .. At this time, if the rotation pulse does not change even if the tray elevating motor M10 is controlled to be driven (“NO” in step S205), it is determined that a failure of the elevating function has occurred (step S207). In the loading tray raising process of FIG. 12, it is not necessary to consider the malfunction caused by the foreign matter placed below the loading tray 700, so that the rotation pulse does not change even if the tray elevating motor M10 is driven (step S205). "NO") is determined to be a failure of the elevating mechanism. This makes it possible to determine the failure without waiting for the user's processing.

Next, the loading tray lowering process executed in step S102 of FIG. 11 will be described.

FIG. 13 is a flowchart showing a procedure of the loading tray lowering process executed in step S102 of FIG. The loading tray lowering process is executed by the CPU 952 of the finisher control unit 951 according to the loading tray lowering processing program stored in the ROM 953.

In FIG. 13, when the loading tray lowering process is started, the CPU 952 first determines whether or not the paper surface sensor 720 detects the loading tray 700 or the loaded paper, that is, whether or not the detection signal of the paper surface sensor 720 is ON. Determine (step S301). When the detection signal of the paper surface sensor 720 is turned on as a result of the determination in step S301 (“YES” in step S301), the CPU 952 drives the tray elevating motor M10 to lower the loading tray 700 (step S302). This is because the loading tray 700 is lowered to match the height of the loading position on the loading tray 700 with the output port position. After driving the tray elevating motor M10 (step S302), the CPU 952 determines whether or not the tray elevating motor M10 has operated by a predetermined amount (step S303). The predetermined amount is an amount sufficient to lower the loading tray 700 until the detection signal of the paper surface sensor 720 changes from on to off.

As a result of the determination in step S303, when the tray elevating motor M10 is operating by a predetermined amount (“YES” in step S303), the CPU 952 determines whether or not the rotation pulse has changed based on the output of the tray drive sensor 750. (Step S304). If the rotation pulse changes as a result of the determination in step S304 (“YES” in step S304), the tray elevating motor M10 is able to rotate. The CPU 952 determines whether or not the loading tray 700 has been lowered to a predetermined position, that is, whether or not the mounting paper loaded on the loading tray 700 is full (step S305).

As a result of the determination in step S305, when the loading paper on the loading tray 700 is full (“YES” in step S305), the CPU 952 stops the tray elevating motor M10 (step S306). Then, after that, the CPU 952 notifies the user of the information that the full load has been detected (step S307), causes the user to remove the full load paper, and ends the main load tray lowering process.

On the other hand, if the rotation pulse has not changed as a result of the determination in step S304 (“NO” in step S304), the CPU 952 stops the tray elevating motor M10 (step S308). In this process of lowering the loading tray 700, if the rotation pulse does not change even if the motor is controlled to operate by a predetermined amount, it is possible that the loading tray 700 cannot be lowered due to an obstacle such as a foreign substance. Is.

After stopping the tray elevating motor M10 (step S308), the CPU 952 determines whether or not the stop position of the loading tray 700 that has stopped moving is within the moving range in which the loading tray 700 has risen within a predetermined time in the past. (Step S309). At this time, the CPU 952 determines whether or not the stop position of the loading tray 700 is within the moved range raised within a predetermined time based on the management information of the loading tray.

FIG. 14 is a diagram showing loading tray management information. The loading tray management information is information based on the elevating position of the loading tray detected by the elevating area detection unit 600.

In FIG. 14, as the management information of the loading tray, the time when the loading tray 700 enters and exits each area 1 to 9 when ascending is shown. For example, when the loading tray 700 rises from area 7 to area 4 at 10:25, the time when the loading tray 700 leaves the area is 10:25 in area 7, area 6, and area 5, respectively, and the area 4 is in the area. The time of entry, 10:25, is memorized. After that, when the loading tray 700 descends to area 5 and then rises from area 5 to area 4 again at 10:45, the area 5 has the time of leaving the area at 10:45, and the area 4 has the area. 10:45, which is the time of entry, is memorized. As described above, as the management information of the loading tray in each area, the latest time when the loading tray 700 enters and exits each area when the loading tray 700 is raised is stored in the RAM 954. When the management information of the loading tray stored in the RAM 954 exceeds the useful period in which the management information is used, the management information is erased by the CPU 952 and becomes invalid. Further, the time as management information may be stored in seconds.

Returning to FIG. 13, the CPU 952 refers to the loading tray management information of FIG. 14, and whether the elapsed time from the time registered in the area where the loading tray 700 has stopped to the current time is within the set predetermined time. Judge whether or not. For example, if the predetermined time is set to 1 hour and the loading tray 700 stops descending in the area 5 at 11:30, the determination is as follows.

Since the lowering of the loading tray 700 stopped in the area 5 at 11:30, the elapsed time from the ascending to the descending in the area 5 is 45 minutes. Therefore, in step S309, it is determined that the position where the loading tray 700 has stopped is within the moving range that has risen within one hour, which is a predetermined time. On the other hand, when the loading tray 700 stops descending in area 6 at 11:30, the elapsed time from ascending to descending in area 6 is 1 hour and 5 minutes. Therefore, in step S309, it is determined that the position where the loading tray 700 is stopped is not within the moved range that has risen within one hour, which is a predetermined time.

As a result of the determination in step S309, when the stop position of the loading tray 700 is within the moving range in which the loading tray 700 has risen within the predetermined time in the past (“YES” in step S309), the CPU 952 processes the process in step S310. Proceed to. That is, since the CPU 952 performed the ascending operation immediately before without any problem, it is determined that the reason for stopping the loading tray 700 is not a foreign substance but a mechanical failure (step S310).

On the other hand, as a result of the determination in step S309, if the stop position of the loading tray 700 is not within the moving range in which the loading tray 700 has risen within the predetermined time in the past (“NO” in step S309), the CPU 952 processes. Proceed to step S311. That is, since the CPU 952 has passed a predetermined time or more since the loading tray 700 was previously lifted, there is a possibility that a foreign object is placed under the loading tray 700 by a third party during that time, for example. (Step S311).

FIG. 15 is a diagram showing a mode in which the loading tray 700 and the foreign matter interfere with each other. In FIG. 15, the foreign matter 710 is placed within the movable range of the loading tray 700, and the loading tray 700 and the foreign matter 710 interfere with each other.

Returning to FIG. 13, as a result of the determination in step S301, when the paper surface sensor 720 has not detected the loading tray 700 or the loaded paper and the detection signal of the paper surface sensor 720 is not turned on (“NO” in step S301, CPU952. Proceeds to step S312. That is, the CPU 952 determines that it is not necessary to lower the loading tray 700 and stops the tray elevating motor M10 (step S312). At this time, driving the tray elevating motor M10 (step). According to S302), it is determined that the loading tray 700 is lowered and the heights of the output port of the finisher 500 and the loading position of the loading tray 700 are kept constant. After that, the CPU 952 performs the main loading tray lowering process. finish.

On the other hand, as a result of the determination in step S303, when the tray elevating motor M10 is not operating by a predetermined amount (“NO” in step S303), the CPU 952 returns the process to step S301 and the tray elevating motor M10 operates by a predetermined amount. Continue the loading tray lowering process until.

If, as a result of the determination in step S305, the sheets loaded on the loading tray 700 are not fully loaded (“NO” in step S305), the CPU 952 returns the process to step S301. Then, after that, the CPU 952 repeats the processes of steps S301 to S305 for sequentially lowering the loading tray 700 so that the paper surface sensor 720 is turned off according to the amount of loaded paper on the loading tray 700.

According to the process of FIG. 13, if the rotation signal does not change even if the tray elevating motor M10 is driven so as to lower the loading tray 700, the driving of the tray elevating motor M10 is stopped (step S308). Then, it is determined whether or not the tray stop position is within the ascending range of the loading tray 700 within the predetermined time in the past (step S309). As a result of the determination, if it is within the ascending range (“YES” in step S309), the tray immediately before was able to be ascended without any problem, so the reason why the loading tray 700 stopped was not a foreign substance but a mechanical failure. Determine (step S310).

On the other hand, if the tray stop position is not within the tray rising range within the predetermined predetermined time in the past (“NO” in step S309), it cannot be denied that the foreign matter may have been placed before the predetermined time. Therefore, it is determined that there may be foreign matter below the loading tray 700 (step S311).

As described above, according to the present embodiment, it is possible to determine the occurrence of a failure without waiting for the operation of removing the foreign matter by the user. That is, if an operation abnormality occurs when the loading tray 700 is lowered, it is determined whether the cause is a foreign substance or a mechanical failure. Therefore, if the cause is a failure, it can be recovered at an early stage. Downtime can be shortened. Although the loading tray 700 has been described in the present embodiment, the loading tray 701 can be similarly applied and determined.

In the present embodiment, as the tray management information in FIG. 14, the time when the loading tray 700 enters and exits each area when ascending is used, but the present invention is not limited to this. Further, the above-mentioned predetermined time is not limited to one hour, and may be a shorter time. In addition to the time of entering and exiting each area when ascending, it is also possible to manage the movement amount of the tray elevating motor M10, that is, the encoder count information detected by the tray drive sensor 750 by the encoder 760 as the position management information of the loading tray 700. Is.

(Second Embodiment)
Next, the image forming system according to the second embodiment will be described. The apparatus configuration and the procedure for raising the loading tray in the second embodiment are the same as in the case of the image forming system according to the first embodiment. Therefore, the description thereof will be omitted.

In the present embodiment, the loading tray 700 is controlled so as to move up and down according to a change in the remaining amount of the loaded paper loaded on the tray, and to keep the height of the paper ejection port and the loading position of the finisher 500 constant. NS. If an abnormality occurs in the lifting operation of the loading tray 700, the cause is detected.

That is, foreign matter placed below the loading tray 700 interferes with the loading tray 700 and interferes with the ascending / descending operation, or is caused by a failure of the motor or sensor used for driving control of the loading tray 700. It is detected whether the ascending / descending operation is hindered. Then, in the case of a motor or sensor failure, it is detected which motor or sensor has failed.

FIG. 16 is a flowchart showing a procedure of the second loading tray lowering process in the second embodiment. The second loading tray lowering process is executed by the CPU 952 of the finisher control unit 951 according to the second loading tray lowering processing program stored in the ROM 953.

In FIG. 16, when the second loading tray lowering process is started, the CPU 952 first initializes the lowering process number n, which is a variable for counting the number of lowering operations to be performed (step S401). After initializing the lowering process number n (step S401), the CPU 952 determines whether or not the paper surface sensor 720 has detected the loading tray 700 or the loading paper, that is, whether or not the detection signal of the paper surface sensor 720 is ON. (Step S402).

When the detection signal of the paper surface sensor 720 is turned on as a result of the determination in step S402 (“YES” in step S402), the CPU 952 first counts up (increments) the number of descent processes n in order to perform the descent operation from now on. (Step S403). After counting up the number of descending processes n (step S403), the CPU 952 determines whether or not the number of descending processes n exceeds the predetermined number of descending processes N (step S404). For example, in the case of a setting in which the descending operation is performed up to the third time and the descending operation is not performed after the fourth time, N = 3 is set and it is determined whether or not n exceeds N = 3. The predetermined number of descents N is predetermined based on an empirical rule.

As a result of the determination in step S404, when the number of lowering processes n does not exceed the predetermined number of lowering processes N (“NO” in step S404), the CPU 952 drives the tray elevating motor M10 to lower the loading tray 700. (Step S405). After driving the tray elevating motor M10 (step S405), the CPU 952 determines whether or not the tray elevating motor M10 is operated by a specified amount from turning on to off the detection signal of the paper surface sensor 720 (step S406).

As a result of the determination in step S406, when the tray elevating motor M10 is operating by a specified amount that the detection signal of the paper surface sensor 720 is turned from on to off (“YES” in step S406), the CPU 952 stops the tray elevating motor M10. (Step S407). After stopping the tray elevating motor M10 (step S407), the CPU 952 determines whether or not the rotation signal has changed based on the output of the tray drive sensor 750 (step S408).

As a result of the determination in step S408, if the rotation signal has changed (“YES” in step S408), it means that the tray elevating motor M10 has rotated, so the CPU 952 returns the process to step S402.

On the other hand, if the rotation signal has not changed as a result of the determination in step S408 (“NO” in step S408), the CPU 952 determines that some abnormality has occurred and proceeds to the process in step S409. That is, the CPU 952 determines whether or not the position of the loading tray 700 has changed from the position before the start of descent (step S409). At this time, the CPU 952 determines the position of the loading tray 700 based on the management information of the loading trays in the areas 1 to 9 described with reference to FIG.

If the position of the loading tray 700 has changed as a result of the determination in step S409 (“YES” in step S409), the CPU 952 advances the process to step S410. That is, since the rotation signal has not changed even though the position of the loading tray 700 has changed, the CPU 952 determines that the tray drive sensor 750 has failed (step S410), and then performs the main loading tray lowering process. To finish.

On the other hand, if the position of the loading tray 700 has not changed as a result of the determination in step S409 (“NO” in step S409), the CPU 952 advances the process to step S411. That is, the CPU 952 determines whether or not the position of the loading tray 700 that has stopped moving is within the moving range in which the loading tray 700 has risen within a predetermined time in the past (step S411). At this time, the CPU 952 refers to the management information of FIG. 14 and determines whether or not the elapsed time from the time registered in the stopped area to the current time is within the predetermined time.

As a result of the determination in step S411, if the position of the stopped loading tray 700 is within the moving range in which the loading tray 700 has risen within the predetermined time in the past (“YES” in step S411), the CPU 952 processes the process in step S412. Proceed to. That is, the reason why the loading tray 700 cannot be lowered is not the foreign matter but the tray elevating motor because the CPU 952 has no problem in the ascending operation immediately before the loading tray 700 and the possibility that foreign matter is placed within the predetermined time is low. It is determined that the M10 has failed (step S412). Further, at this time, since the drive signal has not been detected and the position of the loading tray has not changed, it is determined that the tray elevating motor M10 has failed. Then, after that, the CPU 952 ends the main loading tray lowering process.

On the other hand, as a result of the determination in step S411, if the stop position of the loading tray 700 is not within the moving range in which the loading tray 700 has risen within the predetermined time in the past (“NO” in step S411), the CPU 952 processes. Proceed to step S413. That is, since the CPU 952 has passed a predetermined time or more from the immediately preceding ascending process, it determines that foreign matter may have been placed under the loading tray 700 during that time (step S413). The state in which the foreign matter is placed is, for example, a mode in which the loading tray 700 and the foreign matter 710 below the loading tray 700 interfere with each other, as shown in FIG.

Further, as a result of the determination in step S406, if the tray elevating motor M10 is not operating by a specified amount that turns off the detection signal of the paper surface sensor 720 (“NO” in step S406), the CPU 952 processes the process in step S414. Proceed. That is, the CPU 952 determines whether or not the loading tray 700 has been lowered to a predetermined position due to full load (step S414). If the loading tray 700 is not full as a result of the determination in step S414 (“NO” in step S414), the CPU 952 returns the process to step S406. That is, the CPU 952 repeats the determination in step S406 until a specified amount of operation is performed until the detection signal of the paper surface sensor 720 is turned off.

On the other hand, if the result of the determination in step S414 is that the sheets on the loading tray 700 are full (“YES” in step S414), the CPU 952 proceeds to the process in step S415. That is, the CPU 952 stops driving the tray elevating motor M10 (step S415), notifies the user of the information on which the tray elevating motor M10 is detected by, for example, an alarm or a display on the display screen (step S416), and the user loads the tray. Let the processing of time be carried out. Then, after that, the CPU 952 ends the main loading tray lowering process.

If n exceeds N as a result of the determination in step S404 (“YES” in step S404), the CPU 952 advances the process to step S417. That is, the CPU 952 determines whether or not the position of the loading tray 700 has changed from the position before the start of descent (step S417). Since the detection signal of the paper surface sensor 720 remains on even though the detection signal of the paper surface sensor 720 is lowered by a specified amount enough to be turned off by the lowering process of n times, it is abnormal. This is because there is a possibility that At this time, the CPU 952 determines the position of the loading tray 700 based on the management information of the loading trays in areas 1 to 9.

If the position of the loading tray 700 has changed as a result of the determination in step S417 (“YES” in step S417), the CPU 952 determines that the paper surface sensor 720 is out of order (step S418), and lowers the loading tray. End the process. The reason for determining that the paper surface sensor 720 is out of order is that the paper surface sensor 720 cannot detect the position change even though the position of the loading tray 700 has changed (“YES” in step S417). be.

On the other hand, if the position of the loading tray 700 has not changed as a result of the determination in step S417 (“NO” in step S417), the CPU 952 proceeds to the process in step S419. That is, the CPU 952 determines that the mechanical transmission member (mechanical member) such as a gear for transmitting the driving force of the tray elevating motor M10 to the loading tray 700 is broken (S419), and ends the main loading tray lowering process. do. It is determined that the mechanical members such as gears are broken because the drive signal is detected by the descending operation up to n times, and the tray elevating motor M10 is operating normally, but the loading tray 700 This is because the position of is not changed.

On the other hand, as a result of the determination in step S402, when the detection signal of the paper surface sensor 720 is not on but off (“NO” in step S402), the CPU 952 does not need to lower the loading tray, so that the loading tray is lowered. End the process.

According to the process of FIG. 16, if the rotation signal does not change even if the detection signal of the paper surface sensor 720 is turned off by the specified amount of lowering operation, the tray drive sensor 750 fails on condition that the tray position has changed. (Step S410).

In addition, when the rotation signal did not change even when the specified amount of lowering operation was performed and the tray position did not change, the tray stop position was within the range of the tray raising process within the predetermined time. (Step S412), it is determined that the tray elevating motor M10 has failed. On the other hand, if the rotation signal does not change even if the specified amount of lowering operation is performed and the tray position does not change, it is a condition that the tray stop position is not within the range of the tray raising process within the predetermined time. In addition, it is determined that there may be a foreign substance under the tray (step S413).

Further, when the detection signal of the paper surface sensor 720 remains ON, the number of lowering processes n exceeds a preset predetermined number of lowering times N, and the position of the loading tray 700 has changed, the paper surface sensor It is determined that the failure of 720 is performed (step S418). On the other hand, when the detection signal of the paper surface sensor 720 remains ON, the number of lowering processes n exceeds the preset predetermined number of lowering N, and the position of the loading tray 700 has not changed, the gear It is determined that there is a failure in the mechanical member such as (step S419).

By making such a determination, if an abnormality is detected during the lowering process of the loading tray, it is possible to determine whether or not there is a possibility that a foreign object is placed under the loading tray 700 and where the failure location is. It can be specified concretely. Therefore, downtime can be shortened by recovering the faulty part at an early stage.

In the present embodiment, when it is determined as a result of the determination in step S411 that a foreign matter may be placed below the loading tray 700, it is preferable to display that fact on the display screen of the operation display unit 400. As a result, the user can grasp the presence of the foreign matter at an early stage, remove the foreign matter, and restore the normal state.

100 Automatic document feeder 200 Image reader 300 Printer 400 Operation display 450 Image forming device 500 Post-processing device (finisher)
600, 601 Elevating area detection unit 700, 701 Loading tray 720, 721 Paper surface sensor 750, 751 Tray drive sensor 800 Image formation system 900 CPU circuit unit 951 Finisher control unit 952 CPU
M10, M11 Tray lifting motor

Claims (11)

Loading means for loading sheets and
A driving means for raising and lowering the loading means and
An elevating detection means for detecting the elevating position of the loading means and
When the loading means cannot be lowered and stops during the lowering process of the loading means, the position information of the loading means detected by the raising / lowering detecting means is referred to.
When the position where the loading means is stopped is within the moving range in the ascending process of the loading means performed within the predetermined time in the past, it is determined that the loading means has stopped due to a failure.
If the position where the loading means is stopped is not within the movement range in the ascending process of the loading means performed within the predetermined time in the past, the loading means can be lowered by a foreign object placed below the loading means. Judgment means for determining that there is a possibility that it has disappeared,
A seat loading device characterized by being provided with. A paper surface detecting means for detecting the uppermost surface of the loaded paper loaded on the loading means and a drive detecting means for detecting that the driving means are being driven are provided.
When it is not possible to detect that the driving means is being driven by the driving detecting means even if the loading means is subjected to a predetermined amount of lowering processing for changing the detection signal of the paper surface detecting means from on to off, the determination is made. The sheet loading device according to claim 1, wherein the means is determined to be a failure of the drive detecting means on condition that the loading means is lowered. When it is not possible to detect that the drive detecting means is being driven by the driving means even if the loading means is subjected to a predetermined amount of lowering processing for changing the detection signal of the paper surface detecting means from on to off. When the position of the loading means has not changed, the determining means requires that the position where the loading means is stopped is within the movement range in the ascending process of the loading means within a predetermined time in the past. The sheet loading device according to claim 2, further comprising determining that the drive means is out of order. When it is not possible to detect that the drive means is being driven by the drive detection means even if the loading means is subjected to a predetermined amount of lowering processing for changing the detection signal of the paper surface detection means from on to off. When the position of the loading means has not changed, the determining means is provided on the condition that the position where the loading means is stopped is not within the movement range in the ascending process of the loading means within the predetermined time in the past. The sheet loading device according to claim 2, wherein it is determined that a foreign object may be placed below the loading means. The detection signal of the paper surface detecting means is on, the number of lowering processes n performed to lower the loading means exceeds a preset predetermined number of lowering processes N, and the position of the loading means is The sheet loading device according to any one of claims 2 to 4, wherein when the change is made, the determination means determines that the paper surface detection means has failed. The detection signal of the paper surface detecting means is on, the number of lowering processes n performed to lower the loading means exceeds a preset predetermined number of lowering processes N, and the position of the loading means is 2. Seat loading device. The elevating detection means includes a plurality of flags arranged along the elevating direction of the loading means and a plurality of flag detecting means for detecting each of the plurality of flags, and the detection results of the plurality of flag detecting means. The sheet loading device according to any one of claims 1 to 6, wherein the elevating position of the loading means is detected based on the combination of the above. A storage means for storing the detection result of the elevating detection means is provided.
The sheet loading device according to any one of claims 1 to 7, wherein the determination means makes the determination with reference to the position information of the loading means stored in the storage means. The determination means
The sheet loading device according to claim 8, wherein when a predetermined time elapses after the detection result of the elevating detection means is stored in the storage means, the stored detection result is invalidated. An image forming device that forms an image on a sheet,
An image forming system comprising the sheet loading device according to any one of claims 1 to 9, which loads a sheet on which an image is formed by the image forming device. It is a control method of a sheet loading device including a loading means for loading a sheet, a driving means for raising and lowering the loading means, and an elevating detection means for detecting an elevating position of the loading means.
When the loading means cannot be lowered and stops during the lowering process of the loading means, a step of referring to the position information of the loading means detected by the raising / lowering detecting means and a step of referring to the position information of the loading means.
When it is determined whether or not the position where the loading means is stopped during the lowering process is within the moving range in the ascending process of the loading means performed within the predetermined time in the past, and if it is within the moving range, The step of determining that the loading means has stopped due to a failure, and
When it is determined whether or not the position where the loading means is stopped during the lowering process is within the moving range in the ascending process of the loading means performed within the predetermined time in the past, and the position is not within the moving range. , A step of determining that the loading means may not be able to descend due to a foreign object placed under the loading means.
A method for controlling a seat loading device, which comprises.

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