Image forming device

Abstract

To suppress the deterioration of usability when the opening / closing operation of an FU tray is carried out.SOLUTION: An image forming device is equipped with an image forming portion 180 that forms an image on a recording material, a discharge tray 115 to which the recording material on which the image is formed is discharged, a discharge tray 412 that is disposed on the downstream side of the discharge tray 115 and to which the recording material on which the image is formed is discharged, an FU tray 116 that is provided between the image forming portion 180 and the discharge tray 115, forms a part of a carrying path carrying the recording material to the discharge tray 115 in a close state, and becomes a discharge tray to which the recording material is discharged in an open state, and an FU tray opening / closing sensor 117 that detects an open / close state of the FU tray 116. At the time of forming an image on the plurality of recording materials, when the FU tray 116 discharges the recording materials to the discharge tray 115 in the close state, if the FU tray 116 is switched to the open state, the recording materials are discharged to the discharge tray 116, and if the FU tray 116 is switched to the close state again, the recording materials are discharged to the discharge tray 412.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus using an electrophotographic method. [Background technology]

[0002] Conventionally, image forming apparatuses have been provided that include a tray (hereinafter, referred to as an FU tray) that forms part of a transport path along which a recording material is transported when closed, and functions as an output tray to which the recording material is output when open. For example, in the image forming apparatus described in Patent Document 1, when the FU tray is open (open state), it is used as an output tray for recording material on which an image has been formed. On the other hand, when the FU tray is closed, it forms part of a transport path along which a recording material is transported, and the recording material on which an image has been formed can be output to an output tray provided further downstream of the transport path. The opening and closing operation of the FU tray, which switches between being used as part of the transport path and being used as an output tray, is left to the user. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-110455 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the user closes the FU tray and opens it during continuous printing in which the recording material is discharged to a discharge tray further downstream in the transport path, the transport path to the downstream discharge tray is cut off. As a result, the recording material being transported is discharged to the open FU tray. After that, when the user closes the FU tray and the transport path to the downstream side is formed again, the recording material on which the image has been formed can again be discharged to the downstream discharge tray.

[0005] In particular, in continuous printing, it is important that the order of the printed (image-formed) recording materials, that is, the recording materials are discharged onto the discharge tray in the order in which they were printed. However, due to the opening and closing operation of the FU tray during continuous printing, the printed recording materials are discharged onto the FU tray while the FU tray is open. When the FU tray is then closed, the printed recording materials are initially discharged onto the original discharge tray to which the printed recording materials were discharged. As a result, after the continuous printing is completed, the stack formed of the recording materials discharged onto the original discharge tray does not include the recording materials discharged onto the FU tray. In addition, when attempting to merge the recording materials discharged onto the FU tray with the recording materials discharged onto the original discharge tray, there is a problem in that it is difficult to know at which page position of the recording materials discharged onto the FU tray should the recording materials discharged onto the original discharge tray be inserted.

[0006] The present invention has been made under such circumstances, and has an object to suppress a decrease in usability when an opening and closing operation of a FU tray is performed. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention has the following configuration.

[0008] (1) An image forming apparatus comprising: an image forming section which forms an image on a recording material; a first discharge tray onto which the recording material having the image formed thereon is discharged; a second discharge tray which is disposed downstream of the first discharge tray onto which the recording material having the image formed thereon is discharged; an opening / closing member which is provided between the image forming section and the first discharge tray and which forms part of a transport path for transporting the recording material to the first discharge tray when closed and which serves as a third discharge tray onto which the recording material is discharged when open; and an opening / closing detection means which detects the open / close state of the opening / closing member; wherein, when forming an image on a plurality of sheets of recording material, if the opening / closing member is in a closed state and discharging the recording material to the first discharge tray, when the opening / closing member is switched to an open state, the recording material is discharged to the third discharge tray, and when the opening / closing member is switched to the closed state again, the recording material is discharged to the second discharge tray. Effect of the Invention

[0009] According to the present invention, it is possible to suppress a decrease in usability when the FU tray is opened or closed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus according to first and second embodiments. [Diagram 2] Control block diagram of a control unit of an image forming apparatus according to first and second embodiments [Diagram 3] Hardware configuration diagram of the image forming apparatus main body of the first and second embodiments [Figure 4] Flowchart showing a control sequence for sorting destination selection in the first embodiment [Diagram 5] Flowchart showing a control sequence for detecting a paper jam in the second embodiment [Figure 6] Flowchart showing a control sequence for selecting a sorting destination in the second embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0012] [Configuration of image forming device] FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus including an image forming apparatus main body 100, a sorting device 400, and optional paper feed cassettes 200 and 300 according to the first embodiment. In FIG. 1, a photosensitive drum 122 is made of an organic photosensitive material or an amorphous silicon photosensitive material, and is rotated in the direction of the arrow in the figure (clockwise direction) at a predetermined peripheral speed (process speed). The peripheral surface of the photosensitive drum 122 is uniformly charged to a predetermined polarity and potential by a charging roller 123. A laser optical box 109 emits a laser beam modulated (on / off converted) in response to a pixel signal into which image information input from an image signal generating device (not shown) such as an image reading device or a computer is converted. The laser beam emitted from the laser optical box 109 is deflected by a reflecting mirror 108 rotated by a scanner motor 158 (see FIG. 3) and irradiated onto the surface of the photosensitive drum 122. As a result, the photosensitive drum 122 is exposed to light, and an electrostatic latent image corresponding to the image information is formed on the photosensitive drum 122. The electrostatic latent image formed on the photosensitive drum 122 is developed by the developer 121 attaching toner to form a toner image. The photosensitive drum 122, charging roller 123, and developer 121 are integrated as a detachable process cartridge 120.

[0013] On the other hand, a recording material S is fed one by one from a paper feed cassette of the image forming apparatus main body 100 by a paper feed roller 102 and a separation roller 103, and is conveyed to a transfer roller 107 by a paper feed cassette conveying roller 104 and a conveying roller 105. Then, the transfer roller 107 transfers a toner image formed on a photosensitive drum 122 onto the conveyed recording material S. The formation of an electrostatic latent image on the photosensitive drum 122 is started according to the timing when a conveying sensor 106, which detects the recording material S conveyed on the conveying path, detects the leading edge of the recording material S. By applying a voltage of the opposite polarity to the toner to the transfer roller 107, the toner image is transferred from the photosensitive drum 122 to the recording material S. The recording material S to which the toner image has been transferred is separated from the photosensitive drum 122 and conveyed to a fixing device 130.

[0014] The fixing device 130 has a fixing sleeve 133 heated by a heater 132, and a pressure roller 134 that contacts the fixing sleeve 133 to form a nip portion and pressurizes the recording material S passing through the nip portion. The toner image on the recording material S transported to the fixing device 130 is heated and pressurized as it passes through the nip portion, and is fixed to the recording material S. The recording material S with the fixed toner image is then transported by the FU roller 111 driven by a DC brushless motor 622 (see FIG. 3) and the FD roller 112 driven by a stepping motor 623 (see FIG. 3), and discharged to the discharge tray 115.

[0015] When double-sided printing is performed, the rotation direction of the stepping motor 623 is reversed after a predetermined time has elapsed since the rear end of the recording material S, on whose front surface a toner image has been fixed by the fixing device 130, passes the sensor 110, which is a recording material detection means. As a result, the recording material S is conveyed to the double-sided conveying path L1 by the FD roller 112. The recording material S conveyed to the double-sided conveying path L1 passes the double-sided conveying sensor 113, and is conveyed again to the transfer roller 107 by the double-sided conveying roller 114. Then, the toner image is transferred to the back surface of the recording material S conveyed to the transfer roller 107, and the toner image transferred to the recording material S is fixed to the recording material S by the fixing device 130, and the recording material S is discharged to the discharge tray 115.

[0016] The FU (face-up) tray 116, which is an opening / closing member, is a tray having two functions: it forms part of a conveying path in the downstream direction from the FU roller 111, and it also serves as a discharge tray (third discharge tray) to which the recording material S conveyed by the FU roller 111 is discharged. When the FU tray 116 is closed (shown by a solid line in the figure) (also called a closed state), it forms part of a conveying path that conveys the recording material S conveyed by the FU roller 111 to the discharge tray 115 or the like. On the other hand, when the FU tray 116 is opened (shown by a dashed line in the figure) (also called an open state), it serves as a discharge tray to which the recording material S conveyed by the FU roller 111 is discharged with the printed surface on which the toner image is fixed facing upward (face-up (FU)). An FU tray opening / closing sensor 117, which is an opening / closing detection means, detects the opening / closing state of the FU tray 116. When the FU tray open / close sensor 117 detects that the FU tray 116 is open (as indicated by the dashed line in the drawing), a predetermined switching operation is performed, and the recording material S that has passed through the fixing device 130 is discharged onto the FU tray 116.

[0017] When the recording material S is fed from the MP tray 140, the recording material S stacked on the MP tray 140 is fed to the MP separation roller 143 by the MP paper feed roller 142. Then, the MP separation roller 143 separates the fed recording material S into one sheet and conveys it to the conveying roller 105. The recording material S conveyed to the conveying roller 105 is further conveyed and conveyed to the transfer roller 107. The toner image on the photosensitive drum 122 is transferred onto the recording material S conveyed to the transfer roller 107 in the same manner as the recording material S fed from the paper feed cassette. The transferred toner image is fixed onto the recording material S by the fixing device 130, and then the recording material S is discharged to the outside of the image forming apparatus main body 100 (for example, to the discharge tray 115).

[0018] The optional paper feed cassettes 200 and 300 are paper feed cassettes that can be added to the image forming apparatus main body 100. When the recording material S is fed from the optional paper feed cassettes 200 and 300, the optional paper feed rollers 202 and 302 feed the recording material S to the optional separation rollers 203 and 303, similar to the feeding from the paper feed cassettes. The optional separation rollers 203 and 303 then separate the supplied recording material S into one sheet and feed it to the optional conveying rollers 204 and 304. The recording material S conveyed to the optional conveying rollers 204 and 304 is further conveyed to the image forming apparatus main body 100. After being conveyed to the image forming apparatus main body 100, the recording material S is subjected to image formation in the same manner as the recording material S fed from the paper feed cassette or the MP tray 140.

[0019] The image forming apparatus main body 100 includes a switching member 118, a conveying guide 127, an FD roller 112, a discharge tray 115, and a full-load sensor 126 (see FIG. 3) on the downstream side of the conveying path formed by the FU tray 116. The discharge tray 115 is provided on the upper part of the image forming apparatus main body 100. The full-load sensor 126 has a full-load sensor flag 125 shown in the figure that comes into contact with the uppermost recording material S discharged to the discharge tray 115. The full-load sensor 126, which is a full-load detection means, detects the stacking state by the position of the full-load sensor flag 125 moving upward in the figure as the stacking amount of the discharged recording materials S increases. When the full-load sensor 126 detects the full-load state of the discharge tray 115, the image forming apparatus main body 100 stops image formation until the recording materials S fully loaded on the discharge tray 115 are removed. The switching member 118 can be switched by a flapper solenoid 618 (see FIG. 3) between a position where the recording material S that has passed through the fixing device 130 is conveyed to the sorting device 400 (shown by a solid line in the figure) and a position where the recording material S is discharged to the discharge tray 115 (shown by a dashed line in the figure). The display unit 499 is a display unit for notifying the user of the state of the image forming apparatus, etc.

[0020] [Configuration of sorting device] Next, a sorting device 400 that can be installed on the image forming apparatus main body 100 will be described. A conveying guide 401 receives the recording material S that is guided and conveyed by a switching member 118 and a conveying guide 127 in the image forming apparatus main body 100, and conveys it through the sorting device 400. The conveying guide 401 has a plurality of branching sections, and removable discharge trays 410 (fourth discharge tray), 411, and 412 (second discharge trays) are disposed at each branching section. The switching members 402 and 403 are configured to be switchable to a position indicated by a solid line or a position indicated by a broken line in FIG. 1 by flapper solenoids 489 and 491 (see FIG. 3), which are actuators and will be described later. 1, the recording material S is conveyed by a conveying roller pair 442 and a discharge roller pair 443, and the recording material S is discharged to the discharge tray 410. When the recording material S is discharged to the discharge tray 411, the switching member 402 is switched to the position indicated by the dashed line in the figure, the switching member 403 is switched to the position indicated by the solid line in the figure, the recording material S is conveyed by the conveying roller pair 442 and the discharge roller pair 444, and is discharged to the discharge tray 411. When the recording material S is discharged to the discharge tray 412, the switching member 403 is switched to the position indicated by the dashed line in the figure, and the recording material S is discharged to the discharge tray 412 by a discharge roller pair 445.

[0021] The discharge tray presence / absence sensors 420, 421, 422 detect whether the discharge trays 410, 411, 412 are attached, respectively. Further, the full-load sensors 433, 434, 435 (see FIG. 3) detect that the amount of recording material S stacked on the corresponding discharge trays 410, 411, 412 has reached a predetermined amount or more based on the state of the full-load sensor flags 430, 431, 432 that come into contact with the recording material S. The full-load sensors 433, 434, 435 are full-load detection means. Further, the full-load sensor flag 431 is integrated with the discharge tray 410, and the full-load sensor flag 432 is integrated with the discharge tray 411.

[0022] [Control function block] 2 is a block diagram for explaining the functional configuration of the control unit of the image forming apparatus of this embodiment. The image forming apparatus includes, as control units, a printer control unit 502 that controls the image forming apparatus main body 100, and a sorting device control unit 503 that controls the sorting device 400. The image forming apparatus further includes a controller 501 that is an interface unit between the external device 500 and the printer control unit 502 and the sorting device control unit 503.

[0023] The controller 501 communicates with an external device 500 such as a host computer, and receives a print request. Then, the controller 501 that has received the print request transmits a print instruction specifying print conditions created from data included in the print request to a printer control unit 502 via a serial I / F (interface). In addition, the display unit 499 displays the status of the image forming apparatus based on the display data transmitted from the controller 501.

[0024] The printer control unit 502 controls each image forming mechanism based on the print instruction received from the controller 501. Specifically, the printer control unit 502 controls a recording material conveying mechanism 511 including the feed roller 102, the FU roller 111, the switching member 118, etc., to convey and discharge the recording material S. The printer control unit 502 also controls an image forming unit 180 including the laser optical box 109, the developing device 121, the photosensitive drum 122, the transfer roller 107, etc., to form an image on the recording material S, and controls a fixing device 130 to fix the toner image on the recording material S.

[0025] The open / close detection unit 516 detects whether the FU tray 116 constituting the open / close mechanism 515 is open (as shown by the broken line in FIG. 1) or closed (as shown by the solid line in FIG. 1) based on the detection result of the FU tray open / close sensor 117 that detects the state of the open / close mechanism 515. The full load detection unit 521 detects the arrival of the recording material S at the discharge tray 115 and the full load state of the discharge tray 115 by controlling the full load detection mechanism 522 having the full load sensor 126 (see FIG. 3). The sorting destination selection unit 518 determines the discharge destination of the recording material S based on the sorting destination information notified from the controller 501 via the serial I / F and the detection result of the open / close detection unit 516. Specifically, the sorting destination selection unit 518 selects and determines one of the discharge tray 115, the FU tray 116, and the discharge trays 410, 411, and 412 of the sorting device 400 as a sorting destination to which the recording material S can be transported and discharged. When the sorting destination determined by the sorting destination selection unit 518 is any one of the discharge trays 410, 411, 412 of the sorting device 400, the conveying direction switch control unit 517 switches the switch member 118 to the position indicated by the solid line in FIG.

[0026] Further, the controller 501 acquires the sorting destination information determined by the sorting destination selection unit 518 of the printer control unit 502 via the serial I / F. When the sorting destination acquired from the printer control unit 502 is one of the discharge trays 410, 411, and 412 of the sorting device 400, the controller 501 transmits designation information of the discharge tray of the sorting destination to the sorting device control unit 503 via the serial I / F. The sorting device control unit 503 controls each control mechanism based on the sorting destination designation information received from the controller 501. Specifically, the sorting device control unit 503 transmits control instructions from the recording material conveyance control unit 504 having the sorting control unit 505 and the discharge tray control unit 506 to the conveyance motor control unit 507 and the conveyance direction switching control unit 508 based on the sorting destination designation information received from the controller 501. The recording material conveyance mechanism 512 drives the conveyance roller pair 442, the discharge roller pairs 443, 444, and 445, and the switching members 402 and 403. The conveying motor control unit 507 and the conveying direction switching control unit 508 control the recording material conveying mechanism 512 to convey the recording material S conveyed from the image forming apparatus main body 100 into the sorting device 400. The discharge tray presence / absence detection mechanism 513 has discharge tray presence / absence sensors 420, 421, and 422. The recording material conveying control unit 504 controls the discharge tray presence / absence detection mechanism 513 by the discharge tray presence / absence detection unit 509 to detect the presence or absence of the discharge trays 410, 411, and 412. The full-load detection mechanism 514 has full-load sensors 433, 434, and 435 (see FIG. 3). The recording material conveying control unit 504 controls the full-load detection mechanism 514 by the full-load detection unit 510 to detect the arrival of the recording material S at the discharge trays 410, 411, and 412 and the full-load state of the discharge trays 410, 411, and 412.

[0027] User notification request units 519 and 520 notify the controller 501 of information when the printer control unit 502 and the sorting device control unit 503, respectively, encounter a situation that should be notified to the user, such as a paper jam in the image forming device or an actuator failure. Specifically, the user notification request units 519 and 520 transmit a display request for displaying notification information for the user on the display unit 499 to the controller 501 via the serial I / F.

[0028] [Hardware configuration of the control unit] FIG. 3 is a block diagram showing a hardware configuration related to the image forming apparatus main body 100 and the control unit of the sorting apparatus 400 in this embodiment.

[0029] (Image forming device body) The image forming apparatus main body 100 has a CPU 601 that controls the image forming apparatus main body 100, a timer 602 that generates control timing, a ROM 603 that stores a control program for the CPU 601, a RAM 604 that stores data and the like, and an I / O port 606. The CPU 601, timer 602, ROM 603, RAM 604, and I / O port 606 are connected via a bus 605. In this embodiment, the CPU 601, timer 602, ROM 603, RAM 604, bus 605, and I / O port 606 are assumed to be provided in the printer control unit 502.

[0030] The I / O port 606 is connected to a heater driving circuit 611 that drives the heater 132 of the fixing device 130, and a DC brushless motor driving circuit 612 that drives a DC brushless motor 622. Also connected to the I / O port 606 are a stepping motor driving circuit 613 that drives a stepping motor 623, and a scanner motor driving circuit 615 that drives the scanner motor 158. Furthermore, connected to the I / O port 606 are an FU tray open / close sensor input circuit 614 that inputs the output of the FU tray open / close sensor 117 to the I / O port 606, and a solenoid driving circuit 617 that drives a flapper solenoid 618 that switches the switching member 118. Also connected to the I / O port 606 is a full-load sensor input circuit 616 that inputs the output of the full-load sensor 126 to the I / O port 606.

[0031] The CPU 601 drives the heater 132, the DC brushless motor 622, the stepping motor 623, the scanner motor 158, and the flapper solenoid 618 by controlling drive circuits connected to the I / O port 606 via the bus 605. In addition, the CPU 601 can detect the state of the FU tray open / close sensor 117 and the state of the fully loaded sensor 126 by acquiring signals input from input circuits connected to the I / O port 606 via the bus 605.

[0032] (Sorting device) The sorting device 400 has a CPU 450 that controls the entire sorting device 400, a timer 451 that generates control timing, a ROM 452 that stores a control program that controls the operation of the CPU 450, a RAM 453 that stores data and the like, and an I / O port 455. The CPU 450, timer 451, ROM 452, RAM 453, and I / O port 455 are connected via a bus 454. In this embodiment, the CPU 450, timer 451, ROM 452, RAM 453, bus 454, and I / O port 455 are assumed to be provided in the sorting device control unit 503.

[0033] The following circuits are connected to the I / O port 455. That is, a conveyor motor driver 470 that drives a conveyor motor 471 in the sorting device 400, and discharge tray presence / absence sensor input circuits 484, 485, 486 that input the outputs of the discharge tray presence / absence sensors 420, 421, 422 to the I / O port 455 are connected. Also, solenoid drive circuits 487, 490 that drive flapper solenoids 489, 491 that are actuators that switch the switching members 402, 403 are connected to the I / O port 455. Furthermore, full-load sensor input circuits 481, 482, 483 that input the outputs of the full-load sensors 433, 434, 435 to the I / O port 455 are connected to the I / O port 455.

[0034] The CPU 450 drives a conveying motor 471 by controlling a conveying motor driver 470 connected to an I / O port 455 via a bus 454. When the conveying motor 471 is driven, a conveying roller pair 442 and discharge roller pairs 443, 444, and 445 are driven, and the recording material S conveyed from the image forming apparatus main body 100 is conveyed to a designated discharge tray 410, 411, or 412.

[0035] The CPU 450 also drives a flapper solenoid 489 by controlling a solenoid driving circuit 487 connected to an I / O port 455 via a bus 454. A switching member 402 is connected to the flapper solenoid 489. When the signal output from the CPU 450 to the solenoid driving circuit 487 is in an ON state, the flapper solenoid 489 switches the switching member 402 to the position shown by the broken line in FIG. 1, and the recording material S is conveyed to the discharge tray 411. On the other hand, when the signal output from the CPU 450 to the solenoid driving circuit 487 is in an OFF state, the flapper solenoid 489 switches the switching member 402 to the position shown by the solid line in FIG. 1, and the recording material S is conveyed to the discharge tray 410. The CPU 450 also drives a flapper solenoid 491 by controlling a solenoid driving circuit 490 connected to an I / O port 455 via a bus 454. A switching member 403 is connected to the flapper solenoid 491. When the signal output from the CPU 450 to the solenoid drive circuit 490 is in the ON state, the flapper solenoid 491 switches the switching member 403 to the position indicated by the dashed line in Fig. 1, and the recording material S is transported to the discharge tray 412. On the other hand, when the signal output from the CPU 450 to the solenoid drive circuit 490 is in the OFF state, the flapper solenoid 491 switches the switching member 403 to the position indicated by the solid line in Fig. 1, and the recording material S is transported toward the discharge trays 410, 411.

[0036] The CPU 450 acquires signals input from discharge tray presence sensor input circuits 484, 485, 486 connected to the I / O port 455 via the bus 454. The CPU 450 can check the presence or absence of the discharge trays 410, 411, 412 using the discharge tray presence sensors 420, 421, 422 based on the acquired input signals. The CPU 450 also acquires signals input from full-load sensor input circuits 481, 482, 483 connected to the I / O port 455 via the bus 454. The CPU 450 can check the full-load state of the discharge trays 410, 411, 412 using the full-load sensors 433, 434, 435 based on the acquired input signals.

[0037] (controller) The image forming apparatus main body 100 has a CPU 550 that controls the entire controller 501, a timer 551 that generates control timing, a ROM 552 that stores a control program that controls the CPU 550, a RAM 553 that stores data and the like, and an I / O port 555. The CPU 550, timer 551, ROM 552, RAM 553, and I / O port 555 are connected via a bus 554.

[0038] Further, an I / O port 555 of the controller 501 and an I / O port 606 of the image forming apparatus main body 100 are connected via serial communication drivers 556 and 620 which perform bidirectional serial communication, respectively. Similarly, an I / O port 555 of the controller 501 and an I / O port 455 of the sorting device 400 are connected via serial communication drivers 557 and 492 which perform bidirectional serial communication, respectively. A serial communication unit 467 controls the bidirectional serial communication between the image forming apparatus main body 100 and the controller 501, and the bidirectional serial communication between the sorting device 400 and the controller 501. The bidirectional communication between the image forming apparatus main body 100 and the sorting device 400 is relayed by the controller 501.

[0039] When the controller 501 receives a print request from the external device 500 (FIG. 2) connected via the serial communication unit 467, the controller 501 performs the following process. That is, the controller 501 notifies the CPU 601 (also the CPU 601 of the printer control unit 502) of the image forming apparatus main body 100 of the image forming apparatus main body 100 as print information, such as image data and a sorting destination of the recording material S, and instructs the start of printing via the serial communication unit 467. The controller 501 also notifies the CPU 450 (also the CPU 450 of the sorting apparatus control unit 503) of a conveyance notice of the recording material S and information on a discharge destination of the conveyed recording material S. The CPU 601 of the image forming apparatus main body 100 and the CPU 450 of the sorting apparatus 400 perform a print operation (image forming operation) based on the control instruction and notification information received from the controller 501. Furthermore, information such as paper jams occurring in the image forming apparatus main body 100 and the sorting apparatus 400, the full state of the discharge tray, and the detection status of the presence or absence of the discharge tray is notified to the controller 501 via the serial communication unit 467. If a situation occurs in which printing cannot be continued, the controller 501 instructs the CPU 601 of the image forming apparatus main body 100 and the CPU 450 of the sorting apparatus 400 to suspend printing. Based on the information notified from the CPU 601 of the image forming apparatus main body 100 and the CPU 450 of the sorting apparatus 400, the controller 501 displays information that needs to be notified to the user on the display unit 499 of the image forming apparatus main body 100.

[0040] [Sorting destination selection control when opening and closing the FU tray] As described in FIG. 2, the sorting destination selection unit 518 of the printer control unit 502 determines the discharge destination of the recording material S based on the sorting destination information notified from the controller 501 and the detection result of the open / closed state of the FU tray 116 by the open / close detection unit 516. That is, the sorting destination selection unit 518 selects and determines one of the discharge tray 115, the FU tray 116, and the discharge trays 410, 411, and 412 of the sorting device 400 as a sorting destination to which the recording material S can be transported and discharged. FIG. 4 is a flowchart showing a control sequence of the sorting destination selection unit 518 of this embodiment for selecting a sorting destination to which the recording material S is discharged. The process shown in FIG. 4 is started when a print job for printing the recording material S is executed, and is executed by the CPU 601 (also the CPU 601 of the printer control unit 502), which is a control means of the image forming apparatus main body 100.

[0041] The sorting destination selection unit 518 changes the sorting destination one by one to the discharge tray on the downstream side of the conveying path based on the sorting destination of the recording material S notified / requested by the controller 501 every time the FU tray 116 is opened / closed during continuous printing of the recording material S. In this way, the stack of multiple recording materials S to be discharged is divided, and the user is notified that the stack of recording materials S has been divided into multiple discharge trays. For this purpose, an "FU tray open / close history flag" is provided in the RAM 604 in order to detect that the FU tray 116 has been closed again from an open state during execution of a print job. The "FU tray open / close history flag" is set to ON when a change in state of the FU tray 116 from a closed state to an open state is detected, and is set to OFF when a change in state of the FU tray 116 from an open state to a closed state is detected. In addition, an "FU tray open / close history counter" is provided in the RAM 604 in order to measure the number of times that the FU tray 116 has been closed again from an open state during execution of a print job. Further, the RAM 604 stores "destination tray information" which indicates the discharge tray to which the recording material S is discharged.

[0042] In step (hereinafter, S) 700, the CPU 601 clears the FU tray open / close history counter to 0, and sets the FU tray open / close history flag to off. In S701, the CPU 601 sets the discharge tray that is the sorting destination notified / requested by the controller 501 ("requested sorting destination from controller") in the sorting destination tray information.

[0043] In S702, the CPU 601 controls the open / close detection unit 516 to obtain the detection result of the open / close state of the FU tray 116 by the FU tray open / close sensor 117, and determines whether the FU tray 116 is closed. If the CPU 601 determines that the FU tray 116 is closed, the process proceeds to S705, and if the CPU 601 determines that the FU tray 116 is not closed (is open), the process proceeds to S703.

[0044] In S703, the CPU 601 sets the sorting destination tray information to the FU tray 116 because the FU tray 116 is open and the recording material S is discharged to the FU tray 116. In S704, the CPU 601 sets the FU tray open / close history flag to ON, and the process proceeds to S770.

[0045] In S705, the CPU 601 acquires information about the FU tray opening and closing history flag and determines whether the FU tray opening and closing history flag is off. If the CPU 601 determines that the FU tray opening and closing history flag is off, the process proceeds to S720. On the other hand, if the CPU 601 determines that the FU tray opening and closing history flag is not off (it is on), the CPU 601 determines that the FU tray 116 has changed from an open state to a closed state, and the process proceeds to S706. In S706, the CPU 601 adds 1 to the counter value of the FU tray opening and closing history counter (FU tray opening and closing history counter + 1), sets the FU tray opening and closing history flag to off, and the process proceeds to S720.

[0046] In S720, the CPU 601 branches to a process according to the destination to which the recording material S set in the destination tray information is discharged. That is, if the destination tray information is set to "discharge tray 115" which is the most upstream discharge tray on the conveying path, the CPU 601 proceeds to S730, and if the destination tray information is set to "discharge tray 412", the CPU 601 proceeds to S740. If the destination tray information is set to "discharge tray 411", the CPU 601 proceeds to S750, and if the destination tray information is set to "discharge tray 410" which is the most downstream discharge tray on the conveying path, the CPU 601 proceeds to S760. If the destination tray information is set to "FU tray 116", the CPU 601 proceeds to S768.

[0047] In S730, the CPU 601 acquires the counter value of the FU tray opening / closing history counter, and proceeds to processing according to the counter value. If the counter value of the FU tray opening / closing history counter is 0 (when the FU tray 116 has never been opened or closed), or is 4 or more (when the FU tray 116 has been opened or closed four or more times), the CPU 601 advances the processing to S770. On the other hand, if the counter value of the FU tray opening / closing history counter is 1, 2, or 3, the CPU 601 advances the processing to S732, S733, or S734, respectively. In S732, the CPU 601 sets the sorting destination tray information to the discharge tray 412 provided one tray downstream of the discharge tray 115 on the transport path, and proceeds to processing to S770. In S733, the CPU 601 sets the sorting destination tray information to the discharge tray 411 provided two trays downstream of the discharge tray 115 on the transport path, and proceeds to processing to S770. In S734, the CPU 601 sets the sorting destination tray information to the discharge tray 410, which is provided three trays downstream of the discharge tray 115 on the transport path, and advances the process to S770.

[0048] In S740, the CPU 601 acquires the counter value of the FU tray opening / closing history counter, and proceeds to processing according to the counter value. If the counter value of the FU tray opening / closing history counter is 0 (when the FU tray 116 has never been opened or closed), or 4 or more (when the FU tray 116 has been opened or closed four or more times), the CPU 601 advances the processing to S770. On the other hand, if the counter value of the FU tray opening / closing history counter is 1, 2, or 3, the CPU 601 advances the processing to S742, S743, or S744, respectively. In S742, the CPU 601 sets the sorting destination tray information to the discharge tray 411 provided one tray downstream of the discharge tray 412 on the transport path, and proceeds to processing to S770. In S743, the CPU 601 sets the sorting destination tray information to the discharge tray 410 provided two trays downstream of the discharge tray 412 on the transport path, and proceeds to processing to S770. In S744, the CPU 601 sets the sorting destination tray information to the discharge tray 115, which is provided one tray upstream of the discharge tray 412 on the transport path, and advances the process to S770.

[0049] In S750, the CPU 601 acquires the counter value of the FU tray opening / closing history counter, and proceeds to processing according to the counter value. If the counter value of the FU tray opening / closing history counter is 0 (when the FU tray 116 has never been opened or closed), or 4 or more (when the FU tray 116 has been opened or closed four or more times), the CPU 601 advances the processing to S770. On the other hand, if the counter value of the FU tray opening / closing history counter is 1, 2, or 3, the CPU 601 advances the processing to S752, S753, or S754, respectively. In S752, the CPU 601 sets the sorting destination tray information to the discharge tray 410 provided one tray downstream of the discharge tray 411 on the transport path, and proceeds to processing to S770. In S753, the CPU 601 sets the sorting destination tray information to the discharge tray 115 provided two trays upstream of the discharge tray 411 on the transport path, and proceeds to processing to S770. In S754, the CPU 601 sets the sorting destination tray information to the discharge tray 410 that is provided one tray upstream of the discharge tray 411 on the transport path, and proceeds to S770.

[0050] In S760, the CPU 601 acquires the counter value of the FU tray opening / closing history counter, and proceeds to processing according to the counter value. If the counter value of the FU tray opening / closing history counter is 0 (when the FU tray 116 has never been opened or closed), or 4 or more (when the FU tray 116 has been opened or closed four or more times), the CPU 601 advances the processing to S770. On the other hand, if the counter value of the FU tray opening / closing history counter is 1, 2, or 3, the CPU 601 advances the processing to S762, S763, or S764, respectively. In S762, the CPU 601 sets the sorting destination tray information to the discharge tray 115, which is provided three trays upstream of the discharge tray 410 on the transport path, and proceeds to processing to S770. In S763, the CPU 601 sets the sorting destination tray information to the discharge tray 412, which is provided two trays upstream of the discharge tray 410 on the transport path, and proceeds to processing to S770. In S764, the CPU 601 sets the sorting destination tray information to the discharge tray 411 provided one tray upstream of the discharge tray 410 on the transport path, and proceeds to S770.

[0051] Here, in the processes of S730, S740, S750, and S760, if the counter value of the FU tray opening / closing history counter is 0, the FU tray 116 has never been opened or closed, and the CPU 601 has not updated the sorting destination tray information. If the counter value of the FU tray opening / closing history counter is 4 or more, the FU tray 116 has been opened or closed a number of times equal to or more than the number of discharge trays (four) that the image forming apparatus has, and the CPU 601 has not updated the sorting destination tray information.

[0052] In S768, the CPU 601 sets the sorting destination tray information to the discharge tray 115 because the FU tray 116 is set in the sorting destination tray information but the FU tray 116 is closed and cannot discharge the recording material S. In S769, the CPU 601 stops the image forming operation so that the recording material S is not continuously discharged to a discharge tray other than the FU tray 116. Furthermore, the CPU 601 controls the user notification request unit 519 to notify the controller 501 to interrupt printing and to notify the user of the printing interruption on the display unit 499. Then, the CPU 601 advances the process to S770.

[0053] In S770, the CPU 601 determines the sorting destination tray information to which the recording material S is discharged, and when an inquiry about the sorting destination tray information is received from the controller 501, the sorting destination tray information stored in the RAM 604 is returned. Here, the sorting destination tray information is set to the sorting destination information that is the optimum discharge destination of the recording material S determined by the CPU 601 based on the sorting destination notified / requested by the controller 501 and the current open / closed state of the FU tray 116.

[0054] In S772, the CPU 601 determines whether the print job has ended. If the CPU 601 determines that the print job has ended, the process proceeds to S773. If the CPU 601 determines that the print job has not ended, the process returns to S701. Here, the CPU 601 determines whether the print job has ended based on the print reservation status in the print job, the occurrence status of paper jams on the conveying path, and the counter value of the FU tray opening and closing history counter. In particular, in this embodiment, the image forming apparatus has four discharge trays that can be switched as sorting destinations: the discharge tray 115 provided in the image forming apparatus main body 100, and the discharge trays 410, 411, and 412 provided in the sorting device 400. In this embodiment, when the counter value of the FU tray opening and closing history counter exceeds 3 and becomes 4 or more, the number of stacks of recording materials to be divided into each discharge tray exceeds the number of discharge trays, so the CPU 601 ends the print job.

[0055] In S773, the CPU 601 acquires the counter value of the FU tray opening / closing history counter, and determines whether the counter value is greater than 0. If the CPU 601 determines that the counter value is greater than 0, it determines that the FU tray 116 was opened or closed during execution of a print job, and proceeds to the process in S774, but if the CPU 601 determines that the counter value is 0 or less, it ends the process.

[0056] In S774, the CPU 601 controls the user notification request unit 519 to request the controller 501 to notify the user of information, and ends the process. Here, the content of the information notification to the user from the controller 501 is the following information. That is, the notified information is information indicating that the sorting destinations of the recording materials S have been distributed to a plurality of discharge trays due to the opening and closing operation of the FU tray 116, and that the stack of the recording materials S discharged to the original discharge tray may not include the necessary pages. In addition, the recording materials S discharged to the FU tray 116 are stacked with the printed surface facing up (face up), but the recording materials S discharged to the discharge tray downstream of the FU tray 116 are stacked with the printed surface facing down (face down). As a result, the stacking order of the recording materials S is reversed depending on the discharge tray. Therefore, the notified information includes information indicating the need to reverse the order of the stacks of recording materials S discharged to the FU tray 116 if there are recording materials S discharged to the FU tray 116, and information indicating the overlapping order for bundling multiple stacks of recording materials S in printing order. Further notified information includes information indicating the reason why the print job was terminated due to a shortage of switchable discharge trays because the number of opening and closing operations of the FU tray 116 described above is four or more.

[0057] As described above, in this embodiment, during continuous printing by a print job, each time the FU tray 116 is opened or closed, the sorting destination to which the recording materials S are discharged is changed to the next discharge tray downstream on the transport path, and the stack of discharged recording materials S is divided. Furthermore, in conjunction with the opening and closing of the FU tray 116, the user is notified that the recording materials S are being divided and discharged to multiple discharge trays. This makes it clear where the recording materials S that have been discharged to the FU tray 116 should be inserted in the stack of recording materials discharged to the other discharge trays.

[0058] The above-mentioned various parameters and the method of acquiring the parameters are not limited to the contents of the description of this embodiment. For example, the FU tray opening / closing history counter, which is incremented by one each time the opening / closing operation of the FU tray 116 is detected, may have an upper limit depending on the total number of discharge trays provided in the image forming apparatus. Also, the selection of the discharge tray after the opening / closing operation of the FU tray 116 described in S730 to 764 of FIG. 4 is not limited to the discharge tray one downstream on the conveyance path of the discharge tray before the opening / closing operation of the FU tray 116. For example, the discharge tray to be selected may be the discharge tray two downstream or three downstream depending on the presence or absence of a destination discharge tray, the detection result of the full-load detection mechanism 522, etc.

[0059] As described above, according to this embodiment, it is possible to suppress a decrease in usability when the FU tray is opened or closed. EXAMPLES

[0060] In the first embodiment, a configuration has been described in which the sorting destination is changed to the discharge tray one downstream on the conveying path every time the FU tray 116 is opened or closed during continuous printing, and the stack of recording materials S is divided, thereby clarifying the insertion position of the recording materials S discharged to the FU tray 116. However, even if the FU tray 116 is opened or closed during continuous printing, depending on the position on the conveying path of the recording materials S being conveyed, the recording materials S may be discharged to the discharge tray, which is the original sorting destination, instead of the FU tray 116. For example, if the leading edge of the recording material S has reached any of the FD roller 112, the conveying roller pair 442, and the discharge roller pair 445, even if the FU tray 116 is opened at that point, the recording material S can be discharged to the discharge tray, which is the original sorting destination. Furthermore, if the FU tray 116 is closed before the leading edge of the succeeding recording material S reaches the FU tray 116, even if the opening or closing operation of the FU tray 116 is detected, the recording material S is not discharged to the FU tray 116, and the recording material S is normally discharged to the discharge tray, which is the original sorting destination. However, in the control sequence shown in FIG. 4 described in the first embodiment, when the opening / closing operation of the FU tray 116 is detected, even though the recording material S is discharged to the original discharge tray, the discharge tray is changed, and the stack of recording material S is unnecessarily divided.

[0061] Therefore, in this embodiment, the FU tray 116 is operated from a closed state to an open state, and the discharge tray is changed depending on the result of detecting whether the recording material S being conveyed has been discharged to the discharge tray that is the original sorting destination. A method for solving the problem that the recording material S is unnecessarily divided into multiple discharge trays will be described below. Note that the configurations of the image forming apparatus main body 100 and the sorting device 400 in this embodiment are the same as those in the first embodiment, and the same devices and members are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted here.

[0062] [Detection of recording material discharged to the discharge tray using a full-load detection mechanism] Normally, an image forming apparatus performs continuous printing while checking that the recording material S being conveyed has been correctly discharged to the discharge tray, and is configured to notify a paper jam in which the recording material S is stuck on the conveying path if the recording material S does not reach the discharge tray to which it is sorted. Even in the image forming apparatus of this embodiment, the full load detection mechanism 522 provided in each discharge tray can detect the arrival of the recording material S at each discharge tray.

[0063] The full-load detection mechanism 522 has a full-load sensor flag and a full-load sensor on each discharge tray. The full-load sensor flag is discharged to the discharge tray and contacts the topmost recording material S stacked, and the full-load sensor detects whether the height of the stack of recording materials S is equal to or greater than a predetermined height based on the state of the full-load sensor flag. The full-load detection unit 521 then judges the full-load state of each discharge tray based on the detection result of the full-load sensor. Specifically, the discharge tray 115 of the image forming apparatus main body 100 of this embodiment is provided with a full-load sensor flag 125, and a full-load sensor 126 detects the state of the full-load sensor flag 125. The sorting device 400 also has discharge trays 410, 411, and 412, and the discharge trays 410, 411, and 412 are provided with full-load sensor flags 430, 431, and 432, respectively. The full-load sensors 433, 434, and 435 detect the states of the full-load sensor flags 430, 431, and 432, respectively.

[0064] When the leading edge of the recording material S reaches the full-load sensor flag, the full-load sensor flag is pushed up by the stiffness of the recording material S while the recording material S is conveyed a certain distance while in contact with the full-load sensor flag. Therefore, the full-load sensor detects that the corresponding discharge tray is in a full-load state. Then, when the recording material S is further conveyed downstream of the discharge tray, the stiffness of the recording material S overcomes the weight of the full-load sensor flag, and the recording material S is pressed in the direction of gravity (downward), so that the full-load sensor flag falls in the direction of gravity. As a result, if the height of the stack of recording materials S loaded on the discharge tray is less than a predetermined height, the full-load sensor does not detect the full-load state of the corresponding discharge tray. On the other hand, if the stack of recording materials S loaded on the discharge tray is at a height equal to or greater than the predetermined height, the full-load sensor flag remains pushed up by the stack of recording materials S, and the full-load sensor continues to detect that the corresponding discharge tray is in a full-load state. In this way, the full-load detection mechanism 522 can detect that the recording material S has reached the discharge tray by using a mechanism in which the full-load sensor temporarily detects the full-load state while the recording material S is being discharged (transported) to the discharge tray until the stack of recording material S in the discharge tray becomes full.

[0065] [Sequence for detecting discharge of recording material to the discharge tray] 5 is a flowchart showing a control sequence in which the CPU 601 of the printer control unit 502 detects the arrival of the recording material S at the destination discharge tray, the full-load state of the destination discharge tray, and detects a paper jam of the recording material S. The process shown in FIG. 5 is started for each recording material S in order to monitor the state of the recording material S when conveyance of the recording material S is started in order to print the recording material S, and is executed by the CPU 601 of the image forming apparatus main body 100 (which is also the CPU 601 of the printer control unit 502).

[0066] In this embodiment, the discharge trays onto which the recording material S is discharged are the discharge tray 115 and FU tray 116 of the image forming apparatus main body 100, and the discharge trays 410, 411, and 412 of the sorting device 400. The arrival of the recording material S at the discharge tray 115 and FU tray 116 of the image forming apparatus main body 100 and the fully loaded state of the discharge tray 115 are detected by the fully loaded detection unit 521 of the printer control unit 502 described above. On the other hand, the arrival of the recording material S at the discharge trays 410, 411, and 412 of the sorting device 400 and the fully loaded state of the discharge tray 115 are detected by the fully loaded detection unit 510 of the sorting device control unit 503 described above. Therefore, when the sorting destination of the recording material S is the discharge tray 410, 411, or 412 of the sorting device 400, the CPU 601 instructs the recording material transport control unit 504 of the sorting device control unit 503 via the controller 501 to monitor the discharge tray 410, 411, or 412. As a result, the recording material transport control unit 504 (also the CPU 450) detects the arrival of the recording material S at the discharge tray 410, 411, or 412 and the full-load state of the discharge tray 410, 411, or 412 by the full-load detection unit 510 controlling the full-load detection mechanism 514. Then, the recording material transport control unit 504 notifies the CPU 601 via the controller 501 of the arrival of the recording material S at the discharge tray 410, 411, or 412 and the detection result of the full-load state of the discharge tray 410, 411, or 412 by the full-load detection mechanism 514.

[0067] Furthermore, the RAM 604 of the image forming apparatus main body 100 is provided with a "recording material leading edge arrival history" for managing whether or not the full-load sensor installed in the discharge tray of the sorting destination detects the arrival of the recording material S being printed within a predetermined time. The "recording material leading edge arrival history" is set to ON when the arrival of the recording material S is detected, and is set to OFF when the arrival of the recording material S is not detected. Furthermore, the RAM 604 of the image forming apparatus main body 100 is provided with an "FU tray discharge history" for managing the discharge of the recording material S being printed to the FU tray 116. The "FU tray discharge history" is set to ON when it is detected that the recording material S has been discharged to the FU tray 116, and is set to OFF when it is not detected.

[0068] Furthermore, when the recording material conveyance control unit 504 (which is also the CPU 450) receives an instruction to monitor the state of the corresponding discharge tray from the CPU 601, it performs the following process. That is, the CPU 450 sets the "recording material leading edge arrival history" provided in the RAM 453 and the "discharge tray full state" that indicates the full state of the corresponding discharge tray to off.

[0069] In S801, the CPU 601 sets "recording material leading edge arrival history" and "FU tray discharge history" provided in the RAM 604 to OFF. In S802, the CPU 601 acquires the detection result of the sensor 110 installed on the downstream side of the conveyance path of the fixing device 130, and determines whether the sensor 110 has detected the leading edge of the recording material S. If the CPU 601 determines that the sensor 110 has detected the leading edge of the recording material S, it resets and starts the timer 602 and proceeds to the process in S803, and if it determines that the sensor 110 has not detected the leading edge, it returns the process to S802.

[0070] In S803, the CPU 601 determines whether or not a predetermined time has elapsed by referring to the timer 602. If the CPU 601 determines that the predetermined time has elapsed, the process proceeds to S810, and if the CPU 601 determines that the predetermined time has not elapsed, the process returns to S803.

[0071] In S810, the CPU 601 branches to a process according to the sorting destination of the recording material S notified / requested by the controller 501 ("sorting destination from the controller"). That is, if the "sorting destination from the controller" is the discharge tray 115, the CPU 601 resets and starts the timer 602 and proceeds to S830. If the "sorting destination from the controller" is the FU tray 116, the CPU 601 ends the process because the FU tray 116 is not provided with a mechanism for detecting that the recording material S has been discharged to the FU tray 116, such as a full-load sensor. Furthermore, if the "sorting destination from the controller" is the discharge tray 410, 411, or 412, the CPU 601 proceeds to S840, S850, or S860, respectively. When the "sorting destination from the controller" is the discharge tray 410, 411, or 412 of the sorting device 400, the CPU 601 instructs the recording material transport control unit 504 of the sorting device control unit 503 via the controller 501 to monitor the state of the corresponding discharge tray. As a result, the recording material transport control unit 504 (also the CPU 450) resets and starts the timer 451, controls the full load detection unit 510, and detects the arrival of the recording material S at the corresponding discharge tray and the full load state via the full load detection mechanism 514.

[0072] In S830, the CPU 601 controls the full-load detection unit 521 to obtain the detection result of the full-load sensor 126, and determines whether the state of the full-load sensor 126 has changed from the off state (the discharge tray 115 is not in the full-load state) to the on state (the discharge tray 115 is in the full-load state). If the CPU 601 determines that the state of the full-load sensor 126 has changed from the off state to the on state, the process proceeds to S831, and if the CPU 601 determines that the state of the full-load sensor 126 has not changed from the off state to the on state, the process proceeds to S832. In S831, the CPU 601 sets the "recording material leading edge arrival history" provided in the RAM 604 to on. In S832, the CPU 601 refers to the timer 602 to determine whether a predetermined time has elapsed. If the CPU 601 determines that the predetermined time has elapsed, the process proceeds to S833, and if the CPU 601 determines that the predetermined time has not elapsed, the process returns to S830.

[0073] In S833, the CPU 601 controls the full-load detection unit 521 to obtain the detection result of the full-load sensor 126 and determines whether the state of the full-load sensor 126 is on (the discharge tray 115 is in a full-load state). If the CPU 601 determines that the full-load sensor 126 is on, the process proceeds to S834, and if the CPU 601 determines that the full-load sensor 126 is not on (off), the process proceeds to S870. In S834, the CPU 601 determines that the height of the stack of recording materials S loaded on the discharge tray 115 has reached a predetermined height or more, and therefore sets the "discharge tray 115 full-load status" indicating the full-load state of the discharge tray 115 to on, and the process proceeds to S870.

[0074] In S840, the CPU 450 of the sorting device control unit 503 controls the full-load detection unit 510 to obtain the detection result of the full-load sensor 433. Then, the CPU 450 judges whether the state of the full-load sensor 433 has changed from the off state (the discharge tray 410 is not in the full-load state) to the on state (the discharge tray 410 is in the full-load state). If the CPU 450 judges that the state of the full-load sensor 433 has changed from the off state to the on state, the process proceeds to S841, and if the CPU 450 judges that the state of the full-load sensor 433 has not changed from the off state to the on state, the process proceeds to S842. In S841, the CPU 450 sets the "recording material leading edge arrival history" provided in the RAM 453 to on. In S842, the CPU 450 judges whether a predetermined time has elapsed by referring to the timer 451. If the CPU 450 judges that the predetermined time has elapsed, the process proceeds to S843, and if the CPU 450 judges that the predetermined time has not elapsed, the process returns to S840.

[0075] In S843, the CPU 450 controls the full-load detection unit 510 to obtain the detection result of the full-load sensor 433 and judges whether the state of the full-load sensor 433 is on (the discharge tray 410 is in a full-load state). If the CPU 450 judges that the state of the full-load sensor 433 is on, the process proceeds to S844. On the other hand, if the CPU 450 judges that the state of the full-load sensor 433 is not on (is off), the CPU 450 notifies the CPU 601 via the controller 501 of the "recording material leading edge arrival history" and the "discharge tray 410 full-load state", and the process proceeds to S870. In S844, the CPU 450 can judge that the height of the stack of recording materials S stacked on the discharge tray 410 has reached a predetermined height or more, and therefore sets the "discharge tray 410 full-load state", which indicates the full-load state of the discharge tray 410, to on. Then, the CPU 450 notifies the CPU 601 of the "recording material leading edge arrival history" and the "full-load status of the discharge tray 410" via the controller 501, and advances the process to S870.

[0076] In S850, the CPU 450 of the sorting device control unit 503 controls the full-load detection unit 510 to obtain the detection result of the full-load sensor 434. Then, the CPU 450 judges whether the full-load sensor 434 has changed from an off state (the discharge tray 411 is not in a full-load state) to an on state (the discharge tray 411 is in a full-load state). If the CPU 450 judges that the state of the full-load sensor 434 has changed from an off state to an on state, the process proceeds to S851, and if the CPU 450 judges that the state of the full-load sensor 434 has not changed from an off state to an on state, the process proceeds to S852. In S851, the CPU 450 sets the "recording material leading edge arrival history" provided in the RAM 453 to on. In S852, the CPU 450 judges whether a predetermined time has elapsed by referring to the timer 451. If the CPU 450 judges that the predetermined time has elapsed, the process proceeds to S853, and if the CPU 450 judges that the predetermined time has not elapsed, the process returns to S850.

[0077] In S853, the CPU 450 controls the full-load detection unit 510 to obtain the detection result of the full-load sensor 434 and judges whether the state of the full-load sensor 434 is on (the discharge tray 411 is in a full-load state). If the CPU 450 judges that the state of the full-load sensor 434 is on, the process proceeds to S854. On the other hand, if the CPU 450 judges that the state of the full-load sensor 434 is not on (it is off), the CPU 450 notifies the CPU 601 via the controller 501 of the "recording material leading edge arrival history" and the "discharge tray 411 full-load state", and the process proceeds to S870. In S854, the CPU 450 can judge that the height of the stack of recording materials S stacked on the discharge tray 411 has reached a predetermined height or more, and therefore sets the "discharge tray 411 full-load state", which indicates the full-load state of the discharge tray 411, to on. Then, the CPU 450 notifies the CPU 601 of the "recording material leading edge arrival history" and the "full-load state of the discharge tray 411" via the controller 501, and advances the process to S870.

[0078] In S860, the CPU 450 of the sorting device control unit 503 controls the full-load detection unit 510 to obtain the detection result of the full-load sensor 435. Then, the CPU 450 judges whether the full-load sensor 435 has changed from an off state (a non-full state in which the discharge tray 412 is not fully loaded) to an on state (the discharge tray 412 is fully loaded). If the CPU 450 judges that the state of the full-load sensor 435 has changed from an off state to an on state, the process proceeds to S861, and if the CPU 450 judges that the state of the full-load sensor 435 has not changed from an off state to an on state, the process proceeds to S862. In S861, the CPU 450 sets the "recording material leading edge arrival history" provided in the RAM 453 to on. In S862, the CPU 450 judges whether a predetermined time has elapsed by referring to the timer 451. If the CPU 450 judges that the predetermined time has elapsed, the process proceeds to S863, and if the CPU 450 judges that the predetermined time has not elapsed, the process returns to S860.

[0079] In S863, the CPU 450 controls the full-load detection unit 510 to obtain the detection result of the full-load sensor 435 and judges whether the state of the full-load sensor 435 is on (the discharge tray 412 is in a full-load state). If the CPU 450 judges that the state of the full-load sensor 435 is on, the process proceeds to S864. On the other hand, if the CPU 450 judges that the state of the full-load sensor 435 is not on (off), the CPU 450 notifies the CPU 601 via the controller 501 of the "recording material leading edge arrival history" and the "discharge tray 412 full-load state", and the process proceeds to S870. In S864, the CPU 450 can judge that the height of the stack of recording materials S stacked on the discharge tray 412 has reached a predetermined height or more, and therefore sets the "discharge tray 412 full-load state", which indicates the full-load state of the discharge tray 412, to on. Then, the CPU 450 notifies the CPU 601 of the "recording material leading edge arrival history" and the "full-load status of the discharge tray 412" via the controller 501, and advances the process to S870.

[0080] In S870, the CPU 601 judges the full-load state of the discharge tray of the sorting destination to which the recording material S is discharged based on the "discharge tray full-load state" of the corresponding discharge tray, and notifies the controller 501 of the full-load state if the corresponding discharge tray is in a full-load state. When the controller 501 is notified of the full-load state of the discharge tray from the CPU 601, it suspends the execution of the print job in which the recording material is discharged to the corresponding discharge tray while the notified "discharge tray full-load state" is in an ON state. Then, the CPU 601 of the image forming apparatus main body 100 and the CPU 450 of the sorting device control unit 503 of the sorting device 400 acquire the detection result of the full-load sensor of each discharge tray by a monitoring process not shown. Then, when the CPU 601 and the CPU 450 of the sorting device 400 detect that the full-load sensor is in an OFF state (a state in which the discharge tray is not in a full-load state) for a predetermined time or more, they notify the controller 501 that the full-load state of the discharge tray has been released. When the controller 501 receives a notification from the CPU 601 and the CPU 450 of the sorting device 400 that the full-load state of the discharge tray has been released, it instructs the image forming apparatus main body 100 to resume the print job.

[0081] In S880, the CPU 601 determines whether or not the "recording material leading edge reaching history" is in an ON state. If the CPU 601 determines that the "recording material leading edge reaching history" is in an ON state, the process ends. If the CPU 601 determines that the "recording material leading edge reaching history" is not in an ON state (is in an OFF state), the process proceeds to S881. In S881, the CPU 601 controls the open / close detection unit 516 to acquire the detection result of the FU tray open / close sensor 117, and determines whether or not the FU tray 116 is in an open state (open state). If the CPU 601 determines that the FU tray 116 is in an open state, the process proceeds to S882, and if the CPU 601 determines that the FU tray 116 is not in an open state (is in a closed state), the process proceeds to S883. In S882, the CPU 601 determines that the recording material S has been discharged to the FU tray 116, sets the "FU tray discharge history" provided in the RAM 604 to ON, and ends the process. In S883, the CPU 601 determines that the recording material S is stuck on the transport path to the corresponding discharge tray because the recording material S has not been discharged to the FU tray 116, notifies the controller 501 of a paper jam, and ends the process.

[0082] 5 is executed for each sheet of recording material S transported through the image forming apparatus. Therefore, if the transport of a subsequent recording material S starts before the monitoring process for a certain recording material S is completed, the monitoring processes for the two recording materials S are executed in parallel. In order to correctly detect a paper jam for each recording material S, the "recording material leading edge arrival history" and "FU tray discharge history" stored in RAM 604 are individually prepared in numbers equal to the maximum number of recording materials S transported simultaneously through the image forming apparatus.

[0083] [Sorting destination selection control when opening and closing the FU tray] Next, a control sequence for selecting a sorting destination to which the recording material S is discharged by the sorting destination selection unit 518 of the printer control unit 502 in this embodiment will be described. FIG. 6 is a flowchart showing a control sequence for selecting a sorting destination to which the recording material S is discharged by the sorting destination selection unit 518 in this embodiment. In the control sequence shown in FIG. 6, the opening and closing operation of the FU tray 116 during continuous printing is monitored, as in the control sequence shown in FIG. 4 of the first embodiment. Then, in the control sequence shown in FIG. 6, the presence or absence of the recording material S discharged to the FU tray 116 is determined by referring to the "FU tray discharge history" set in the control sequence shown in FIG. 5 described above. Then, when the recording material S is discharged to the FU tray 116 and it is determined that the necessary pages are not included in the bundle of recording materials S discharged to the original discharge tray, the sorting destination after the opening and closing operation of the FU tray 116 is changed to the downstream discharge tray. This prevents the discharge tray from being changed and the bundle of recording materials S from being divided even though the recording material S is not discharged to the FU tray 116.

[0084] In the flowchart shown in Fig. 6, the same processes as those in the flowchart of Fig. 4 described in the embodiment 1 are denoted by the same step numbers. Therefore, in the following, only the processes in the flowchart of Fig. 6 that are different from those in the flowchart of Fig. 4 will be described.

[0085] In S705, the CPU 601 acquires information on the FU tray opening / closing history flag and determines whether the FU tray opening / closing history flag is off. If the CPU 601 determines that the FU tray opening / closing history flag is off, the CPU 601 advances the process to S720. On the other hand, if the CPU 601 determines that the FU tray opening / closing history flag is not off (is on), the CPU 601 advances the process to S900. In S900, the CPU 601 determines whether the "FU tray discharge history" that is set to on or off by the process in FIG. 5 described above is on. If the CPU 601 determines that the "FU tray discharge history" is on, the CPU 601 advances the process to S901, and if the CPU 601 determines that the "FU tray discharge history" is not on (is off), the CPU 601 advances the process to S902. In S901, since the "FU tray discharge history" is set to on, the CPU 601 determines that the recording material S has been discharged to the FU tray 116, and increments the counter value of the "FU tray opening / closing history counter" by 1 (FU tray opening / closing history counter + 1). In S902, the CPU 601 sets the "FU tray open / close history flag" to OFF, and the process proceeds to S720.

[0086] In Fig. 6, the processes of S900 to S902 are added based on the "FU tray discharge history" due to paper jam detection in Fig. 5. This makes it possible to change the discharge tray after closing the FU tray 116 to the discharge tray downstream of the discharge tray that was used immediately before, only if the recording material S is discharged to the FU tray 116 while the FU tray 116 is open during continuous printing. As a result, it is possible to prevent the recording material S from being divided and distributed to multiple discharge trays even though the recording material S has not been discharged to the FU tray 116.

[0087] In this embodiment, a paper jam detection monitoring process is added to check whether the paper being transported has been correctly discharged to the discharge tray, as shown in Fig. 5. In the process of Fig. 5, if the paper cannot be discharged to the discharge tray because the FU tray 116 is in an open state, a history is kept that the recording material S has been discharged to the FU tray 116. The image forming apparatus executes the monitoring process of the recording material S shown in Fig. 5 every time the transport of one sheet of recording material S begins, and ends the process after a sufficient amount of time has passed until the paper is discharged outside the image forming apparatus.

[0088] In addition, in the control sequence for selecting the sorting destination of the recording material S shown in Fig. 6, the sorting destination of the recording material S after the opening and closing operation of the FU tray 116 is changed only when it is detected by the paper jam detection monitoring process shown in Fig. 5 that a discharge history of the recording material S to the FU tray 116 remains. The image forming apparatus executes the control sequence shown in Fig. 6 upon the start of a print job, and continues until the print job is completed. Thus, in this embodiment, the image forming apparatus executes the paper jam detection monitoring process and the sorting destination selection control sequence in parallel, thereby determining whether or not to change the sorting destination when the opening and closing operation of the FU tray 116 during continuous printing is detected.

[0089] Note that the various parameters and parameter acquisition methods of the present embodiment described above are not limited to the contents of the description of the present embodiment, as in the case of embodiment 1. Also, in the present embodiment, the arrival of the recording material S at the discharge trays 410, 411, and 412 of the sorting device 400 and the detection of the full-load state of the discharge tray 115 are configured to be performed by the sorting device 400, but may be configured to be performed by the CPU 601 of the image forming apparatus main body 100, for example.

[0090] As described above, according to this embodiment, it is possible to suppress a decrease in usability when the FU tray is opened or closed. [Explanation of symbols]

[0091] 115 Output Tray 116 FU Tray 117 FU tray open / close sensor 180 Image forming section 412 Output Tray

Claims

1. an image forming section for forming an image on a recording material; a first discharge tray onto which the recording material on which the image is formed is discharged; a second discharge tray disposed downstream of the first discharge tray and into which the recording material having an image formed thereon is discharged; an opening / closing member that is provided between the image forming unit and the first discharge tray, and that forms a part of a conveying path for conveying the recording material to the first discharge tray when it is closed, and that serves as a third discharge tray to which the recording material is discharged when it is open; and an opening / closing detection means for detecting an opening / closing state of the opening / closing member, An image forming apparatus characterized in that, when forming images on multiple sheets of recording material, if the opening / closing member is in a closed state and the recording material is being discharged to the first discharge tray, when the opening / closing member is switched to an open state, the recording material is discharged to the third discharge tray, and when the opening / closing member is switched to the closed state again, the recording material is discharged to the second discharge tray.

2. a fourth discharge tray disposed downstream of the second discharge tray and at the most downstream position, to which the recording material having an image formed thereon is discharged; The image forming apparatus according to claim 1, characterized in that when forming images on multiple sheets of recording material, if the opening / closing member is in a closed state and the recording material is being discharged to the fourth discharge tray, when the opening / closing member is switched to an open state, the recording material is discharged to the third discharge tray, and when the opening / closing member is switched to the closed state again, the recording material is discharged to the first discharge tray.

3. The image forming apparatus according to claim 2, characterized in that when forming images on multiple sheets of recording material, if the opening / closing member is in an open state and recording material is being discharged to the third discharge tray, when the opening / closing member is switched to a closed state, the image forming operation by the image forming unit is stopped.

4. The image forming apparatus according to claim 3, characterized in that the opening / closing detection means measures the number of times it detects a change in the opening / closing state of the opening / closing member, and if the number of times is greater than 0 when a print job is completed, notifies the user that recording material has been discharged to multiple output trays.

5. The image forming apparatus according to claim 4, characterized in that when the number of times that the measured change in the open / close state of the opening / closing member is detected is equal to or greater than the number of the discharge trays, the image forming operation by the image forming unit is stopped.

6. 6. The image forming apparatus according to claim 3, further comprising a notification that the image forming unit has stopped forming an image.

7. a full-load detection unit provided on each of the discharge trays except the third discharge tray, the full-load detection unit contacting the topmost recording material stacked on the discharge tray to detect a full-load state of the discharge tray; a recording material detection unit that is provided in a conveying path between the image forming unit and the opening / closing member and detects a conveyed recording material; Equipped with 7. An image forming apparatus according to claim 4, wherein if the full-load detection means provided on the discharge tray to which the recording material is discharged detects a change in state of the discharge tray from a non-full state to a full-load state within a predetermined time after the recording material detection means detects the recording material, it is determined that the recording material has been discharged to the discharge tray.

8. a full-load detection unit provided on each of the discharge trays except the third discharge tray, the full-load detection unit contacting the topmost recording material stacked on the discharge tray to detect a full-load state of the discharge tray; a recording material detection unit that is provided in a conveying path between the image forming unit and the opening / closing member and detects a conveyed recording material; Equipped with 7. An image forming apparatus according to claim 4, wherein, within a predetermined time after the recording material detection means detects the recording material, if the full-load detection means provided on the discharge tray to which the recording material is discharged does not detect a change in state of the discharge tray from a non-full state to a full-load state, and if the open / close detection means detects the open state of the open / close member, it is determined that the recording material has been discharged to the third discharge tray.

9. a full-load detection unit provided on each of the discharge trays except the third discharge tray, the full-load detection unit contacting the topmost recording material stacked on the discharge tray to detect a full-load state of the discharge tray; a recording material detection unit that is provided in a conveying path between the image forming unit and the opening / closing member and detects a conveyed recording material; Equipped with 7. An image forming apparatus as claimed in claim 4, wherein if, within a predetermined time after the recording material detection means detects the recording material, the full-load detection means provided on the discharge tray to which the recording material is discharged does not detect a change in the state of the discharge tray from a non-full state to a full-load state, and the open / close detection means detects the open / close member in a closed state, it determines that a paper jam of the recording material has occurred, stops the image forming operation by the image forming unit, and notifies the user of the stop of the image forming operation and the occurrence of a paper jam.

10. 10. The image forming apparatus according to claim 7, wherein when the full load detection means detects that the discharge tray is fully loaded, the image forming operation by the image forming unit is stopped, and the stop of the image forming operation and the full load state of the discharge tray are notified.

11. The image forming apparatus according to claim 10, characterized in that when the opening / closing detection means determines that the recording material has been discharged to the discharge tray based on the detection result of the full-load detection means provided in the discharge tray to which the recording material is discharged, between the time when the opening / closing detection means detects a change in the state of the opening / closing member from a closed state to an open state and the time when the opening / closing detection means detects a change in the state of the opening / closing member from an open state to a closed state, the opening / closing detection means does not update the number of times that it has detected a change in the opening / closing state of the opening / closing member.

Images