Sheet stacking device, sheet stacking method, and program

Abstract

To provide a sheet stacking device, a sheet stacking method and a program which can suppress a decrease in production efficiency due to stopping of job execution when there is an obstruction to reciprocating movement by foreign objects or the like during reciprocating movement of a stacking tray.SOLUTION: A sheet stacking device includes: a stacking tray 7 for stacking sheets on which images are formed; a moving mechanism 11 for reciprocating the stacking tray 7 within a preset range; determination means 21 for determining whether there is an obstruction to the movement of the stacking tray 7 by the moving mechanism 11; and control means 23 for continuing the reciprocating movement of the stacking tray 7 with a limited movable range when the determination means 21 determines that there is the obstruction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sheet stacking device provided in an image forming device such as a multifunction digital multifunction peripheral (MFP) that forms images on sheets such as paper, and a post-processing device that performs post-processing such as binding and punching on sheets transported from the image forming device, and further to a sheet stacking method and program. [Background technology]

[0002] As a sheet stacking device provided in the above-mentioned image forming device, post-processing device, etc., there has been known a device equipped with a sorting function (sorting function) that discharges multiple copies one by one when multiple sheets, which are recording media such as paper on which an image has been formed or post-processed, are discharged to a discharge tray, which is one of the accumulation trays.

[0003] In addition, some printers have a function that, when discharging sheets using the sorting function, moves the accumulation tray back and forth horizontally each time a set of sheets is discharged, discharging the sheets in a shifted position one set at a time.

[0004] In addition, there are also post-processing devices that perform post-processing by moving the sheets horizontally while they are accumulated on a processing tray that serves as an accumulation tray during post-processing, and then moving them in the opposite direction back to their original position after post-processing, i.e., by moving them back and forth to perform post-processing.

[0005] Such accumulation trays, such as output trays and processing trays, are located outside the main body of the image forming device or post-processing device and can be touched by the user, so that due to user carelessness or other reasons, an obstacle may be placed within the range of movement of the accumulation tray, causing a malfunction in which the back-and-forth movement of the accumulation tray is obstructed by this obstacle.

[0006] Generally, the accumulation tray moving mechanism is equipped with a ratchet mechanism for safety, and if an external force is applied to the moving mechanism by an obstacle, the drive shaft of the drive motor will spin freely. However, in the past, if the accumulation tray's reciprocating movement was obstructed by an obstacle, the operation of the sheet accumulation device would stop and a warning would be issued by display on the operation panel and audio.

[0007] However, the operation of the sheet stacking device is stopped until the obstruction caused by the obstacle or the like is removed, and therefore, job execution is stopped during that time, resulting in a decrease in production efficiency.

[0008] In addition, Patent Document 1 discloses a post-processing device that can reduce declines in paper alignment quality and perform post-processing without reducing productivity by being able to quickly detect the misalignment even if the alignment member becomes misaligned due to user contact or other reasons.The post-processing device has a paper output tray for collecting discharged paper and a paper alignment member for aligning the paper on the output tray, and is characterized by having a position detection means for detecting the position of the paper alignment member and a control means for determining that the paper alignment member has moved out of its specified operating range based on position detection information from the position detection means. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 5050955 Summary of the Invention [Problem to be solved by the invention]

[0010] However, although the above-mentioned Patent Document 1 discloses that the alignment member is returned to its original position when it becomes misaligned, the operation is stopped and the operation of the sheet accumulation device continues. Therefore, when an obstacle blocks the reciprocating movement of the accumulation tray, the operation of the sheet accumulation device stops, and the execution of the job also stops, resulting in a decrease in production efficiency.

[0011] This invention has been made in consideration of this technical background, and aims to provide a sheet accumulation device, a sheet accumulation method, and a program that can prevent job execution from being stopped and production efficiency from decreasing when the reciprocating movement of the accumulation tray is obstructed by an obstacle or the like during the reciprocating movement of the accumulation tray. [Means for solving the problem]

[0012] The above object can be achieved by the following means: (1) a stacking tray for stacking sheets on which images are formed; During execution of a job that requires the accumulation tray to be moved back and forth, The accumulation tray is set within a preset range. Horizontally a movement mechanism for reciprocating movement; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; After an instruction to execute a job requiring the reciprocating movement of the accumulation tray is given, If the determination means determines that there is an obstruction, Until the end of the job a control means for continuing the reciprocating movement of the accumulation tray within a limited movable range; A sheet accumulation device comprising: (2) A motor for driving the moving mechanism and a current detection means for detecting a current of the motor are provided, The sheet stacking device described in the preceding paragraph 1, wherein the judgment means judges that obstruction has occurred if the motor current detected by the current detection means changes beyond a predetermined threshold while the moving mechanism is being driven. (3) a collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth within a preset range; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; a control means for continuing the reciprocating movement of the accumulation tray while limiting the movement range when the determination means determines that there is an obstruction; and a variable resistance element provided so that its resistance value changes in accordance with the amount of movement of the stacking tray; and a voltage detection means for detecting a voltage applied to the variable resistance element. and, Equipped with When the change in the applied voltage of the variable resistance element detected by the voltage detection means deviates from a preset transition, the determination means determines that an obstruction has occurred. Rusi Cart stacking device. (4) A distance measuring sensor is provided in the direction of reciprocating movement of the stacking tray to detect the distance to the stacking tray; 2. The sheet stacking device according to claim 1, wherein the determining unit determines whether or not there is an obstruction based on the detection result of the distance measuring sensor. (5) The sheet accumulation device according to any one of the above paragraphs 1 to 4, which is capable of informing the user that the reciprocating movement range is limited when a job is completed. (6) The sheet stacking device according to the preceding paragraph 5, wherein the notification that the reciprocating movement range is limited is made by a display on the operation panel. (7) The sheet stacking device according to the preceding paragraph 5, wherein the notification that the reciprocating movement range is limited is made by voice. (8) a collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth within a preset range; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; a control means for continuing the reciprocating movement of the accumulation tray while limiting the movement range when the determination means determines that there is an obstruction; and Equipped with When the judgment means judges that there is an obstruction, the control means causes the accumulation tray to retry operation within the normal movement range after a preset time has elapsed, and also causes the judgment means to make a judgment; when the judgment means judges again that there is an obstruction, the control means continues the reciprocating movement of the accumulation tray within the possible range, and when it judges that there is no obstruction, returns the accumulation tray to the normal range and causes the reciprocating movement to be performed. Rusi Cart stacking device. (9) A sheet accumulation device as described in any one of paragraphs 1 to 8, wherein, if the judgment means determines that an obstruction exists, the control means requests the user to remove the obstruction after the job is completed, and if the obstruction is not resolved within a specified time, requests the user to contact a service technician. (10) a collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth within a preset range; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; a control means for continuing the reciprocating movement of the accumulation tray while limiting the movement range when the determination means determines that there is an obstruction; and Equipped with If the reciprocating movement range after the restriction is smaller than the predetermined range, the user is allowed to select whether to continue the job without reciprocating the accumulation tray. Rusi Cart stacking device. (11) The sheet stacking device according to any one of the above paragraphs 1 to 10, wherein the stacking tray is a paper discharge tray. (12) The sheet stacking device according to any one of the above paragraphs 1 to 10, wherein the stacking tray is a processing tray for performing post-processing on the sheets. (13) The sheet stacking device according to the preceding paragraph 12, wherein the stacking tray includes an alignment member for aligning the stacked sheets, and the movement of the stacking tray is the movement of the alignment member. (14) When the state in which the determining means determines that an obstruction has occurred continues for a predetermined time, the control means stops the operation of the motor. 2 to The sheet accumulation device described above. (15) a stacking tray for stacking sheets on which images are formed; During execution of a job that requires the accumulation tray to be moved back and forth, The accumulation tray is set within a preset range. Horizontally a movement mechanism for reciprocating movement; A sheet accumulation device comprising: a determining step of determining whether or not there is an obstruction to the movement of the accumulation tray; After an instruction to execute a job requiring the reciprocating movement of the accumulation tray is given, If it is determined that there is an obstruction in the determination step, Move to the end of the job a control step of continuing the reciprocating movement of the accumulation tray within a possible range; A sheet accumulation method comprising: (16) a stacking tray for stacking sheets on which images are formed; During execution of a job that requires the accumulation tray to be moved back and forth, The accumulation tray is set within a preset range. Horizontally a movement mechanism for reciprocating movement; A computer of a sheet accumulation device including: a determining step of determining whether or not there is an obstruction to the movement of the accumulation tray; After an instruction to execute a job requiring the reciprocating movement of the accumulation tray is given, If it is determined that there is an obstruction in the determination step, Move to the end of the job a control step of continuing the reciprocating movement of the accumulation tray within a possible range; Run To program. [Effects of the Invention]

[0013] According to the invention described in the preceding paragraph (1), whether or not there is an obstruction to the reciprocating movement of the stacking tray on which sheets are stacked is determined, and if it is determined that there is an obstruction, the reciprocating movement operation is continued within the possible range, so the reciprocating movement operation does not stop. Therefore, the operation of discharging sheets while shifting their position one copy at a time continues, or post-processing operations that require reciprocating movement continue. As a result, even if reciprocating movement is obstructed by an obstacle or the like, it is possible to avoid stopping job execution and suppress a decrease in production efficiency.

[0014] According to the invention described in the preceding paragraph (2), if the motor current changes beyond a predetermined threshold while the moving mechanism is being driven by the motor, it is determined that there is an obstruction, so that the presence or absence of an obstruction can be determined with high accuracy.

[0015] According to the invention described in the preceding paragraph (3), if the change in the applied voltage of the variable resistance element, which is configured so that its resistance value changes according to the amount of movement of the stacking tray, deviates from a preset trend, it is determined that there is an obstruction to the movement, so that the presence or absence of obstruction can be determined with high accuracy.

[0016] According to the invention described in the preceding paragraph (4), the presence or absence of obstruction to movement is determined based on the detection results of a distance measuring sensor that is arranged in the direction of reciprocating movement of the accumulation tray and detects the distance from the accumulation tray, so that the presence or absence of obstruction can be determined with high accuracy.

[0017] According to the invention described in the preceding paragraph (5), it is possible to notify the user that the reciprocating movement range is restricted at the end of a job, so that the user can recognize that the reciprocating movement range is restricted and can take measures such as removing any obstructions.

[0018] According to the invention described in the preceding paragraph (6), the user can recognize that the reciprocating movement range is limited by the display on the operation panel.

[0019] According to the invention described in the preceding paragraph (7), the user can recognize that the reciprocating movement range is restricted by the audio notification.

[0020] According to the invention described in the preceding paragraph (8), if it is determined that there is an obstruction, after a preset time has elapsed, the accumulation tray is retried within the normal movement range to determine whether or not there is a fault, and if it is again determined that there is an obstruction, the reciprocating movement of the movement mechanism is continued within the possible range, and if it is determined that there is no obstruction, the reciprocating movement is returned to the normal range and can be performed.

[0021] According to the invention described in the preceding paragraph (9), if it is determined that an obstruction exists, the user is requested to remove the obstruction after the job is completed, and if the obstruction is not resolved within a specified time, the user is requested to contact a service technician. Therefore, if it is difficult for the user to remove the obstruction, the obstruction can be reliably removed by contacting a service technician.

[0022] According to the invention described in the preceding paragraph (10), if the reciprocating movement range after the restriction is smaller than the predetermined range, the original effect of the reciprocating movement operation cannot be enjoyed, so the user's wishes can be respected by allowing the user to choose whether or not to continue the job without reciprocating movement.

[0023] According to the invention described in the preceding paragraph (11), even if the reciprocating movement of the sheet discharge tray is hindered, the sheet discharge operation can be continued while shifting the position one copy at a time.

[0024] According to the invention described in the preceding paragraph (12), even if the reciprocating movement of the processing tray that performs post-processing on the sheets is obstructed, the processing tray can be reciprocated within a limited range to continue the post-processing operation.

[0025] According to the invention described in the preceding paragraph (13), it is determined whether or not there is any obstruction to the reciprocating movement of the aligning member that aligns the stacked sheets.

[0026] According to the invention described in the preceding paragraph (14), if the state in which the judgment means judges that there is an obstruction continues for a predetermined period of time, the operation of the motor is stopped since it is possible that the motor or the moving mechanism has malfunctioned.

[0027] According to the invention described in the preceding paragraph (15), the operation of discharging sheets continues while shifting the position of each copy, or the post-processing operation that requires back-and-forth movement continues, so that even if an obstacle impedes the back-and-forth movement of the accumulation tray, the job execution can be prevented from being stopped and a decrease in production efficiency can be suppressed.

[0028] According to the invention described in the preceding paragraph (16), it is possible to determine whether or not there is any obstruction to the reciprocating movement of the accumulation tray that accumulates sheets, and if it is determined that there is obstruction, it is possible to cause the computer of the sheet accumulation device to execute a process of continuing the reciprocating movement of the accumulation tray within the possible range. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic front view of an image forming apparatus equipped with a sheet stacking device according to an embodiment of the present invention; [Figure 2] FIG. [Figure 3] 1 is a block diagram showing a sheet stacking device according to an embodiment of the present invention; [Figure 4] FIG. 10 is a block diagram showing a sheet stacking device according to another embodiment of the present invention. [Figure 5] FIG. 10 is a block diagram showing a sheet stacking device according to still another embodiment of the present invention. [Figure 6] 10 is a flowchart showing the operation of the control unit when an instruction to execute a job requiring a shift operation is given. [Figure 7] FIG. 10 is a perspective view showing another example of the configuration of the accumulation tray. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0031] 1 is a schematic front view of an image forming apparatus 1 equipped with a sheet stacking device according to an embodiment of the present invention. The image forming apparatus 1 is equipped with an image forming unit 2 that forms images on sheets, which are recording media such as paper, a paper feed unit 3 that stores sheets, which are recording media such as paper, and feeds the sheets to the image forming unit 2, a reading unit 4 that reads documents, an operation panel 5 that allows user operations and displays various information, and a post-processing apparatus 6 equipped with a sheet stacking device according to an embodiment of the present invention. The sheet stacking device of the image forming apparatus 1 and the sheet stacking device of the post-processing apparatus 6 are both used as one unit.

[0032] The post-processing device 6 performs post-processing such as binding, punching, and saddle-stitching on sheets on which images have been formed by the image forming device 1, and is provided with an accumulation tray 7 at the rear. This accumulation tray 7 functions as a paper output tray for discharging post-processed sheets, and also functions as a processing tray for accumulating sheets in the middle of processing in order to perform the post-processing, depending on the type of post-processing. In addition, when post-processing by the post-processing device 6 is not performed, the accumulation tray also functions as a paper output tray for discharging sheets on which images have been formed by the image forming device 1.

[0033] FIG. 2 is a perspective view of the accumulation tray 7. In this embodiment, the accumulation tray 7 is provided on a rectangular base plate 8 via a movement mechanism so as to be able to move back and forth in the horizontal direction indicated by arrow A in FIG. 2 (the front-to-rear direction in FIG. 1). In FIG. 2, the solid line portion of the accumulation tray 7 indicates a normal position where the accumulation tray 7 does not move, and the dashed line portion indicates a state where the accumulation tray 7 has moved in the horizontal direction. The movement mechanism for moving the accumulation tray 7 back and forth in the horizontal direction is well known, so a detailed description will be omitted. Also, in FIG. 2, the symbol P indicates sheets that have been transported and accumulated on the accumulation tray 7 from the direction of arrow B.

[0034] The stacking tray 7 is discharged with image-formed sheets P that have not been set for post-processing and are discharged from the image forming apparatus 1, or with image-formed sheets P that have been post-processed. At this time, if a sorting mode (sorting mode) for multiple copies has been set by the user, the stacking tray repeats a horizontal movement and a return to its original position, that is, a reciprocating movement operation (hereinafter, the horizontal reciprocating movement operation is also referred to as a shift operation), each time some of the sheets P are discharged.

[0035] Alternatively, depending on the type of post-processing, the first half of the sheets P in the transport direction may move horizontally while being transported onto the accumulation tray 7 during post-processing, and then the sheets may be drawn into the post-processing device 6 as needed to undergo post-processing, and the accumulation tray 7 may return to its original position, and this process may be repeated for each post-processing. In this case as well, the accumulation tray 7 may repeat the shift operation.

[0036] However, there are cases where an obstacle is placed in the shifting operation range of the accumulation tray 7 due to carelessness of the user, etc., and the shifting operation is hindered.

[0037] Therefore, in this embodiment, it is determined whether the shifting operation of the accumulation tray 7 is obstructed or not. If it is obstructed, a range in which the shifting operation is possible is set based on the obstructed position, and the shifting operation is continued within that range.

[0038] Fig. 3 is a block diagram showing a sheet stacking device according to an embodiment of the present invention. In the example shown in Fig. 3, a drive current of a motor 12 that drives a moving mechanism 11 that reciprocates the stacking tray 7 is detected, and when the drive current of the motor 12 falls below a preset threshold, it is determined that an obstruction has occurred to the shifting operation of the stacking tray 7.

[0039] 3 includes the above-described accumulation tray 7, movement mechanism 11, and motor 12, as well as a motor drive unit 13 for driving the motor 12, a current detection unit 14 for detecting the motor current determined by the motor drive unit 13, and a control unit 20. The control unit 20 also includes an obstruction determination unit 21, a shift range determination unit 22, and a motor control unit 23. The current detection unit 14 and the motor drive unit 13 are connected to a DC voltage power supply 15a of, for example, 24 volts.

[0040] The current detection unit 14 detects the drive current of the motor 12 driven by the motor drive unit 13 .

[0041] The obstruction determination unit 21 determines whether the shifting operation of the accumulation tray 7 has been obstructed, for example, by a user inadvertently placing an obstructing object within the shifting operation range of the accumulation tray 7, based on the detection result of the motor current by the current detection unit 14. In this embodiment, it is determined that obstruction has occurred when the current of the motor 12 falls below a preset threshold. In other words, if the shifting operation is obstructed, the ratchet of the movement mechanism 11 rotates freely, reducing the load on the motor. As a result, the current of the motor 12 falls below the preset threshold, and when the current detection unit 14 detects this, the obstruction determination unit 21 determines that the shifting operation has been obstructed.

[0042] When the obstruction determination unit 21 determines that obstruction exists, the shift range determination unit 22 determines the range within which shifting is possible based on the obstructed position. The obstructed position can be identified, for example, as follows. That is, the shift range determination unit 22 measures the time from when the motor drive unit 13 starts driving the motor 12, and can identify the time from when the motor 12 starts driving to when the obstruction determination unit determines that obstruction exists. In addition, since the movement speed (motor speed) of the accumulation tray 7 during shifting is also set in advance, the shift range determination unit 22 can identify the movement distance of the accumulation tray, i.e., the obstructed position, from the time from when the motor 12 starts driving to when obstruction occurs and the movement speed of the accumulation tray 7. Alternatively, if the motor 12 is a pulse motor or the like, the movement distance of the accumulation tray, i.e., the obstructed position, may be identified based on the number of drive pulses, etc.

[0043] The shift range determination unit 22 sets the range between the position before the start of movement of the accumulation tray 7 and the position where the movement is obstructed as a limited shift operable range, and notifies the motor control unit 23 of this.

[0044] The motor control unit 23 controls the rotation direction, speed, etc. of the motor 12 so that the accumulation tray 7 shifts within a range where the shifting is possible.

[0045] In this way, if an obstacle or the like occurs that interferes with the shifting operation of the accumulation tray 7, the shifting operation of the accumulation tray 7 is continued while avoiding the obstacle and limiting the range within which the shifting operation is possible, so the shifting operation does not stop. Therefore, the operation of discharging sheets while shifting their position one copy at a time continues, or the post-processing operation that requires reciprocating movement continues. As a result, even if the shifting operation is interfered with by an obstacle, it is possible to avoid stopping the execution of the job and suppress a decrease in production efficiency.

[0046] The control unit 20 in Fig. 3 is configured by a computer equipped with a CPU, RAM, and ROM, and the operations of the inhibition determination unit 21, the shift range determination unit 22, and the motor control unit 23 are executed by the CPU operating in accordance with an operation program stored in the ROM, etc. The same applies to the configuration examples shown in Figs. 4 and 5.

[0047] Also, the case has been described in which the inhibition determination unit 21 determines that a shift operation has been inhibited when the current detection unit 14 detects that the current of the motor 12 has fallen below a preset threshold. However, if a ratchet is not provided to avoid an increase in the load on the motor 12 when an obstacle is present, the load on the motor 12 increases due to the presence of an obstacle. Therefore, the inhibition determination unit 21 may determine that a shift operation has been inhibited when the current detection unit 14 detects that the current of the motor 12 has exceeded a preset threshold.

[0048] FIG. 4 is a block diagram showing a sheet stacking device according to another embodiment of the present invention.

[0049] In the example shown in Figure 4, a variable resistance element 30 is used to detect whether or not the shift operation of the accumulation tray 7 is obstructed, and the variable resistance element 30 is provided so that its resistance value changes depending on the amount of movement of the accumulation tray 7.

[0050] The sheet stacking device also includes a stacking tray 7, a moving mechanism 11, a motor 12, a variable resistance element 30, a motor drive unit 13, a voltage detection unit 16, and a control unit 20. The configurations of the stacking tray 7, the moving mechanism 11, the motor 12, the motor drive unit 13, and the control unit 20 are the same as those of the sheet stacking device shown in Fig. 3, so the same reference numerals are used and detailed description will be omitted. The motor drive unit 13 is connected to a DC voltage power supply 15a of, for example, 24 volts, and the variable resistance element 30 is connected to a DC voltage power supply 15b of, for example, 3.3 volts.

[0051] The voltage detection unit 16 detects the voltage applied to the variable resistance element 30. The voltage applied to the variable resistance element 30 varies depending on the resistance value of the variable resistance element 30, and the resistance value varies regularly depending on the amount of movement of the accumulation tray 7. Therefore, the obstruction determination unit 21 determines whether the transition of the voltage change detected by the voltage detection unit 16 is a preset transition, and if the voltage change deviates from the preset transition, determines that the shift operation has been obstructed.

[0052] When the obstruction determination unit 21 determines that obstruction has occurred, the shift range determination unit 22 determines the range in which reciprocating movement is possible based on the obstructed position. That is, the shift range determination unit 22 sets the range between the position before the accumulation tray 7 starts moving and the obstructed position as a limited range in which shifting is possible, and notifies the motor control unit 23. The motor control unit 23 controls the rotation direction, speed, etc. of the motor 12 so that the accumulation tray 7 shifts within the range in which shifting is possible.

[0053] 4, even if an obstacle or the like occurs to hinder the shift operation of the accumulation tray 7, the accumulation tray 7 continues to move back and forth while avoiding the obstacle and limiting the shift operation to a range where it is possible, so the shift operation does not stop. Therefore, the operation of discharging sheets P while shifting their position one copy at a time continues, or the post-processing operation requiring back and forth movement continues. As a result, even if the shift operation is hindered by an obstacle, it is possible to avoid stopping the execution of the job and suppress a decrease in production efficiency.

[0054] FIG. 5 is a block diagram showing an example of a sheet stacking device according to still another embodiment of the present invention.

[0055] In the example shown in FIG. 5, a distance measuring sensor 40 that is arranged in the moving direction of the accumulation tray 7 and can measure the distance to the accumulation tray 7 is used to detect whether or not the shift operation of the accumulation tray 7 is obstructed.

[0056] The sheet stacking device also includes a stacking tray 7, a moving mechanism 11, a motor 12, a distance measurement sensor 40, a motor drive unit 13, a voltage detection unit 16, and a control unit 20. The configurations of the stacking tray 7, the moving mechanism 11, the motor 12, the motor drive unit 13, and the control unit 20 are the same as those of the sheet stacking device shown in Figures 3 and 4, so the same reference numerals are used and detailed description will be omitted.

[0057] The distance measurement sensor 40 measures the distance to the accumulation tray 7, and the distance to the accumulation tray 7 changes regularly depending on the amount of movement of the accumulation tray 7. For this reason, the obstruction determination unit 21 determines whether the change in the distance to the accumulation tray 7 detected by the distance measurement sensor 40 is a preset transition, and if it is outside the preset transition, determines that the shift operation has been obstructed.

[0058] When the obstruction determination unit 21 determines that obstruction has occurred, the shift range determination unit 22 determines the range in which reciprocating movement is possible based on the obstructed position. That is, the shift range determination unit 22 sets the range between the position before the accumulation tray started to move and the obstructed position as a limited range in which shifting is possible, and notifies the motor control unit 23. The motor control unit 23 controls the rotation direction, speed, etc. of the motor 12 so that the accumulation tray 7 shifts within the range in which shifting is possible.

[0059] 5, even if an obstacle or the like occurs to hinder the shift operation of the accumulation tray 7, the accumulation tray 7 continues to move back and forth while avoiding the obstacle and limiting the shift operation to a range where it is possible, so the shift operation does not stop. Therefore, the operation of discharging sheets P while shifting their position one copy at a time continues, or the post-processing operation requiring back and forth movement continues. As a result, even if the shift operation is hindered by an obstacle, it is possible to avoid stopping the execution of the job and suppress a decrease in production efficiency.

[0060] 6 is a flowchart showing the operation of the control unit 20 when an instruction to execute a job requiring a shift operation is given. This operation is executed by the CPU of the control unit 20 operating in accordance with an operation program stored in the ROM or the like.

[0061] After starting the shift operation in step S01, it is determined in step S02 whether there is an obstruction to the shift operation, using the method described above with reference to Figures 3 to 5. If there is no obstruction (NO in step S02), it is determined in step S15 whether the job has ended. If the job has not ended (NO in step S15), the process returns to step S02. When the job has ended (YES in step S15), the shift operation also ends.

[0062] If there is an obstruction to the shift operation in step S02 (YES in step S02), the shift operation range is determined in step S03, and then it is determined in step S04 whether the determined range is shorter than a preset range. If it is not shorter (NO in step S04), the shift operation is retried after a certain period of time has elapsed in step S05, and then it is determined again in step S06 whether there is an obstruction. If there is no obstruction (NO in step S06), the shift operation is resumed in step S07, and then the process returns to step S02. If there is an obstruction in step S06 (YES in step S06), then in step S08, an instruction is issued to resume the shift operation within the determined range, i.e., the limited range, and then the process proceeds to step S09.

[0063] In step S09, it is checked whether the shift operation has resumed. If the shift operation has resumed (YES in step S09), the process proceeds to step S10 to determine whether the job has ended. If the job has not ended (NO in step S10), the process remains in step S10 and waits for the job to end. Once the job has ended (YES in step S10), the process leaves the user informed in step S11 by a sound from the operation panel, speaker, etc. that an obstacle is present and the shift operation is being obstructed. If the obstruction is not resolved after a predetermined time has elapsed, the user may be asked to contact a service technician. In step S12, the fact that the shift operation has been obstructed is notified to the management server so that it can be recorded in the management server.

[0064] If the shift operation is not resumed in step S09 (NO in step S09), it is determined in step S13 whether a certain time has elapsed, and if not (NO in step S13), the process returns to step S09. If the certain time has elapsed (YES in step S13), there is a possibility that some abnormality such as a breakdown has occurred, so the motor 12 is stopped in step S14, and then the occurrence of the abnormality is notified in step S11, and a request is made to contact a service technician.

[0065] If the determined range is short in step S04 (YES in step S04), the intended effect of the shift operation cannot be obtained, so in step S16 the user is asked by a message or the like whether or not to execute the job without the shift operation, and the user is allowed to make a selection. In step S17, it is determined whether or not the user has selected to execute the job without the shift operation, and if execution without the shift operation has been selected (YES in step S17), the job is executed without the shift operation in step S18, and then the process proceeds to step S10, where it is determined whether or not the job has been completed.

[0066] In step S17, if the user does not select execution without shifting (NO in step S17), the process proceeds to step S08, where shifting is resumed within the determined range.

[0067] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, while the case where the entire accumulation tray 7 shifts horizontally has been described, as shown in FIG. 7, the accumulation tray 7 may also be configured with a pair of alignment plates 71, 71 arranged facing each other and spaced apart in the horizontal direction. A guide member 72 extending downward from the bottom end is connected to each alignment plate 71, 71, and each guide member 72 is inserted into a long slot 73 that is long in the horizontal direction. The guide members 72 are driven by a motor (not shown) to move one alignment plate 71 along the long slot 73 independently of the other alignment plate 71, or to move toward or away from each other, thereby forming a movement mechanism that enables the accumulation tray 7 to be shifted.

[0068] In the accumulation tray 7 of FIG. 7, particularly when used as a processing tray for post-processing the sheets P, the alignment plates 71, 71 can be shifted to move the stacked sheets P in the horizontal direction.

[0069] In addition, although the image forming apparatus 1 is equipped with a post-processing device 6 and the accumulation tray 7 serves as both the paper output tray of the image forming apparatus 1 and the paper output tray and processing tray of the post-processing device 6, it may also be the paper output tray of an image forming apparatus 1 that does not have a post-processing device 6 installed. [Explanation of symbols]

[0070] 1. Image forming device 2 Image forming unit 3 Paper feed section 5 Operation panel 6 Aftertreatment device 7. Accumulation tray 11 Moving mechanism 12 motors 13 Motor drive unit 14 Current detection section 20 Control Unit 21 Inhibition judgment section 22 Shift range determination unit 23 Motor control unit 30 Variable resistance element 40 Distance sensor P paper

Claims

1. a collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth in a horizontal direction within a preset range during execution of a job that requires the accumulation tray to be moved back and forth; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; a control means for continuing the reciprocating movement of the accumulation tray by limiting the movement range to an allowable range until the end of the job when the determination means determines that an obstruction has occurred after an instruction to execute a job requiring the reciprocating movement of the accumulation tray has been given; A sheet accumulation device comprising:

2. a motor that drives the moving mechanism and a current detection means that detects a current of the motor; 2. The sheet stacking device according to claim 1, wherein the determining means determines that an obstruction has occurred when the motor current detected by the current detecting means changes beyond a predetermined threshold value while the moving mechanism is being driven.

3. A stacking tray for stacking sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth within a preset range; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; a control means for continuing the reciprocating movement of the accumulation tray while limiting the movement range when the determination means determines that there is an obstruction; and a variable resistance element provided so that its resistance value changes in accordance with the amount of movement of the stacking tray; and a voltage detection means for detecting a voltage applied to the variable resistance element; Equipped with In a sheet stacking device, when the change in the applied voltage of the variable resistance element detected by the voltage detection means deviates from a preset transition, the determination means determines that an obstruction has occurred.

4. a distance measuring sensor disposed in the reciprocating movement direction of the accumulation tray and detecting the distance to the accumulation tray; 2. The sheet stacking device according to claim 1, wherein the determining means determines whether or not there is obstruction based on the detection result of the distance measuring sensor.

5. 5. The sheet stacking device according to claim 1, wherein the device is capable of informing the user that the reciprocating movement range is limited when a job is completed.

6. 6. The sheet stacking device according to claim 5, wherein the notification that the reciprocating movement range is limited is made by a display on the operation panel.

7. 6. The sheet stacking device according to claim 5, wherein the notification that the reciprocating movement range is limited is made by voice.

8. A collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth within a preset range; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; a control means for continuing the reciprocating movement of the accumulation tray while limiting the movement range when the determination means determines that there is an obstruction; and Equipped with When the judgment means determines that there is an obstruction, the control means causes the accumulation tray to retry operation within the normal movement range after a preset time has elapsed and causes the judgment means to make a judgment, and when the judgment means again determines that there is an obstruction, the control means continues the reciprocating movement of the accumulation tray within the possible range, and when it determines that there is no obstruction, returns the accumulation tray to the normal range and causes the reciprocating movement to occur.

9. A sheet accumulation device as described in any one of claims 1 to 8, wherein if the judgment means determines that there is an obstruction, the control means requests the user to remove the obstruction after the job is completed, and if the obstruction is not resolved within a specified time, requests the user to contact a service technician.

10. A collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth within a preset range; a determining means for determining whether or not the movement of the stacking tray by the moving mechanism is obstructed; a control means for continuing the reciprocating movement of the accumulation tray while limiting the movement range when the determination means determines that there is an obstruction; and Equipped with A sheet accumulation device that allows a user to select whether or not to continue a job without reciprocating movement of an accumulation tray when the reciprocating movement range after the restriction is smaller than a predetermined range.

11. 11. The sheet stacking device according to claim 1, wherein the stacking tray is a sheet discharge tray.

12. 11. The sheet stacking device according to claim 1, wherein the stacking tray is a processing tray for performing post-processing on the sheets.

13. 13. The sheet stacking device according to claim 12, wherein the stacking tray includes an alignment member for aligning the stacked sheets, and the movement of the stacking tray is the movement of the alignment member.

14. 3. The sheet stacking device according to claim 2, wherein the control means stops the operation of the motor when the state in which the determination means determines that an obstruction has occurred continues for a preset time period.

15. a collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth in a horizontal direction within a preset range during execution of a job that requires the accumulation tray to be moved back and forth; A sheet accumulation device comprising: a determining step of determining whether or not there is an obstruction to the movement of the accumulation tray; a control step of continuing the reciprocating movement of the accumulation tray while limiting the movement range until the end of the job when it is determined in the determination step that there is an obstruction after an instruction to execute a job requiring the reciprocating movement of the accumulation tray is given; A sheet accumulation method comprising:

16. a collection tray for collecting sheets on which images are formed; a moving mechanism for moving the accumulation tray back and forth in a horizontal direction within a preset range during execution of a job that requires the accumulation tray to be moved back and forth; A computer of a sheet accumulation device including: a determining step of determining whether or not there is an obstruction to the movement of the accumulation tray; a control step of continuing the reciprocating movement of the accumulation tray while limiting the movement range until the end of the job when it is determined in the determination step that there is an obstruction after an instruction to execute a job requiring the reciprocating movement of the accumulation tray is given; A program to execute.

Images