JP2020063115A - Image forming apparatus, control method thereof and control program thereof - Google Patents

Abstract

To reliably detect failure of paper feed trays 60 and 70 while reducing a manufacturing cost.SOLUTION: A printer 10 includes: a plurality of paper feed trays 60 and 70; a failure confirmation unit (control unit 100, upper limit sensors 64 and 74, lift-up motors 65 and 75, motor drivers IC 101, signal lines 104A to 104K) that confirms a failure of the plurality of paper feed trays 60 and 70; and a control unit 100 that controls the plurality of paper feed trays 60 and 70. At least a part of the failure confirmation unit (output port 102A, signal line 104A, input port 103C, signal line 104F) is shared by the plurality of paper feed trays 60 and 70. The failure confirmation unit confirms a failure when the control section 100 operates one of the plurality of paper feed trays 60 and 70.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to an image forming apparatus, an image forming apparatus control method, and an image forming apparatus control program, and particularly to an image forming apparatus suitable for detecting a failure, an image forming apparatus control method, and an image forming apparatus control method. Regarding control programs.

  As a paper feed tray of the image forming apparatus, a push-up plate is arranged on the bottom surface, and the paper stacked on the push-up plate is pushed upward by the push-up plate so that the uppermost paper is brought into contact with the paper feed roller. Things are generally known. In the paper feeding tray having such a structure, the push-up plate is pushed up by the lift-up drive, and the upper limit sensor installed in the paper feeding tray detects that the uppermost paper comes into contact with the paper feeding roller.

  On the other hand, when a lift-up abnormality occurs in the push-up plate of the paper feed tray, the faulty component causing the abnormality, such as the lift-up motor, the coupling gear between the push-up plate and the lift-up motor, and the upper limit sensor, are specified. Is important for reducing the maintenance time of service personnel and preventing unnecessary replacement of parts.

  Japanese Unexamined Patent Application Publication No. 2004-242242 discloses an image forming apparatus that controls the elevation of a plurality of paper feed trays by using one lift-up motor and an electromagnetic clutch provided for each paper feed tray. In this image forming apparatus, in order to reduce the torque of the lift-up motor, the elevation control of each paper feed tray is performed at exclusive timing.

  Further, Patent Document 2 discloses an image forming apparatus that detects a lift-up abnormality by using a failure detection sensor of a paper feed tray. In this image forming apparatus, the failure state is recorded, and when the failure state continues in the standby state after the power is turned on, the insertion / removal display of the paper feed tray is performed.

JP, 2008-127117, A JP, 2008-110861, A

  In the image forming apparatus of Patent Document 2, each paper feed tray is provided with a sensor for detecting a failure. Further, although Patent Document 1 describes that the drive means is shared by the respective paper feed trays, no particular consideration is given to detection of a failure. In order to reliably detect the failure of the plurality of paper feed trays, when the configuration for detecting the failure of each of the plurality of paper feed trays is provided, the manufacturing cost cannot be reduced.

  This disclosure has been made to solve the above-mentioned problems, and one of the purposes of this disclosure is to reduce the manufacturing cost and to reliably detect the failure of the sheet feeding device, the image forming apparatus, and the image forming apparatus. A method of controlling a forming apparatus and a control program of an image forming apparatus are provided.

  In order to achieve the above object, according to an aspect of the present disclosure, an image forming apparatus includes a plurality of sheet feeding devices, a failure confirmation unit that confirms a failure of the plurality of sheet feeding devices, and a plurality of sheet feeding devices. And a control unit for controlling. At least a part of the failure confirmation unit is shared by the plurality of sheet feeding devices. The failure confirmation unit confirms a failure when the control unit operates one of the plurality of sheet feeding devices.

  Preferably, the paper feeding device includes a drive unit for moving the paper stored in the paper feeding device to a position where the paper can be fed. The failure confirmation unit includes a drive failure confirmation unit that confirms a failure of the drive unit. At least a part of the drive failure confirmation unit is shared by the plurality of sheet feeding devices.

  More preferably, the paper feeding device includes a paper detection unit that detects whether the paper stored in the paper feeding device has been moved to a position where paper can be fed. The failure confirmation unit includes a detection failure confirmation unit that confirms a failure of the paper detection unit. At least a part of the detection failure confirmation unit is shared by a plurality of sheet feeding devices. More preferably, the failure confirmation unit confirms the failure of the paper detection unit before the failure of the drive unit.

  Preferably, the failure confirmation unit confirms the failure at a timing when the operations of the plurality of sheet feeding devices do not overlap. Preferably, the control unit prohibits the operation of another sheet feeding device when the failure confirmation unit confirms the failure of the sheet feeding device.

  Preferably, when confirming the failure of at least two or more of the plurality of sheet feeding devices, the control unit sequentially operates the two or more sheet feeding devices of which the failure is confirmed. The failure confirmation unit sequentially confirms a failure of the sheet feeding device operated by the control unit.

  Preferably, the control unit is capable of executing control for feeding a sheet from one of the sheet feeding devices. The failure confirmation unit prohibits the confirmation of the failure of the paper feeding device when the control unit controls the paper feeding.

  Preferably, when the paper is replenished in the paper feeding device, the control unit moves the paper to a position where the paper can be fed even if the failure confirmation unit confirms that the other paper feeding device has failed. The drive unit is controlled to do so.

  According to another aspect of the present disclosure, a control method includes an image including a plurality of paper feeding devices, a failure confirmation unit that confirms a failure of the plurality of paper feeding devices, and a control unit that controls the plurality of paper feeding devices. It is a method of controlling the forming apparatus. At least a part of the failure confirmation unit is shared by the plurality of sheet feeding devices. The control method includes a step in which the control unit operates one of the plurality of paper feeding devices, and a failure check unit causes a failure when the control unit operates one of the plurality of paper feeding devices. And controlling to confirm.

  According to still another aspect of the present disclosure, the control program includes a plurality of paper feeding devices, a failure confirmation unit that confirms a failure of the plurality of paper feeding devices, and a control unit that controls the plurality of paper feeding devices. It is a control program executed by a control unit in the image forming apparatus. At least a part of the failure confirmation unit is shared by the plurality of sheet feeding devices. The control program causes the control unit to perform a step of operating one of the plurality of sheet feeding devices and a step of controlling to confirm a failure while operating one of the plurality of sheet feeding devices. Let it run.

  According to this disclosure, it is possible to provide an image forming apparatus, a control method for an image forming apparatus, and a control program for an image forming apparatus that can reliably detect a failure of a sheet feeding device while reducing manufacturing costs. it can.

It is a diagram showing a schematic configuration of a printer according to the present embodiment. It is a figure which shows schematic structure of the mechanism of a paper feed tray. It is a control block diagram of the printer of the present embodiment. It is a control block diagram of the paper feed tray of the present embodiment. It is a flow chart which shows a flow of processing of a 1st embodiment. It is a flow chart which shows a flow of lift-up control processing of a 1st embodiment. It is a flow chart which shows a flow of failure part specific control processing of a 1st embodiment. It is a flow chart which shows a flow of lift-up control processing of a modification of a 1st embodiment. It is a flow chart which shows a flow of processing of a 2nd embodiment. It is a flow chart which shows a flow of failure part specific control processing of a 2nd embodiment.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  In the present embodiment, a case where the image forming apparatus according to the present disclosure is a tandem type digital color printer (hereinafter referred to as a printer) will be described.

  FIG. 1 is a diagram showing a schematic configuration of a printer 10 according to the present embodiment. Referring to FIG. 1, the printer 10 includes a transfer belt 12 as an intermediate transfer member, imaging units 20Y, 20M, 20C, 20K, temporary transfer rollers 30Y, 30M, 30C, 30K, and a secondary transfer roller 34. The cleaner blade 38, the paper feed trays 60 and 70, the timing roller pair 48, the fixing unit 50, and the paper discharge tray 11.

  The transfer belt 12 is an endless belt, is supported by the rollers 14 and 16 so as not to slacken, and the roller 16 is rotated counterclockwise in FIG. 1 to be rotationally driven in the direction of arrow A at a predetermined speed. .

  The imaging units 20Y, 20M, 20C, and 20K (hereinafter, these are representatively referred to as the imaging unit 20) are toners of the respective basic colors of yellow (Y), magenta (M), cyan (C), and black (K). The transfer belt 12 is disposed below the lower horizontal portion. The imaging unit 20 includes a photosensitive drum 22, a charging device 24, a print head 26, a developing device 28, a primary transfer roller 30, and a cleaner 32. The charger 24, the print head 26, the developing device 28, the primary transfer roller 30, and the cleaner 32 are provided around the photoconductor drum 22. The imaging unit 20 is configured to be movable between a position (pressing position) where the photoconductor drum 22 comes into contact with the transfer belt 12 and a non-contacting position (separation position) by a press contacting and separating motor (not shown). .

  The charger 24 uniformly charges the surface of the photoconductor drum 22. The print head 26 outputs a laser beam to the photoconductor drum 22 based on each color data that constitutes the image data, and exposes the surface of the photoconductor drum 22 that is uniformly charged according to the image data to perform static exposure. Form a latent image. The developing unit 28 develops the electrostatic latent image formed on the surface of the photosensitive drum 22 with toner of each color to form a toner image. The primary transfer roller 30 faces the photoconductor drum 22 with the transfer belt 12 interposed therebetween, and electrostatically attracts the toner image formed on the surface of the photoconductor drum 22 to primarily transfer the toner image onto the transfer belt 12. The cleaner 32 collects and cleans the toner remaining on the surface of the photosensitive drum 22 after the primary transfer.

  The secondary transfer roller 34 faces the roller 14 with the transfer belt 12 sandwiched therebetween, and a position (contact position) where the secondary transfer roller 34 comes into contact with the transfer belt 12 and a position where the secondary transfer roller 34 does not come into contact with each other by a press contact separation motor (not shown). It is configured to be movable to and from the (separated position). The secondary transfer roller 34 is moved to the pressure contact position and is applied with a high-voltage positive transfer voltage, so that the toner image formed on the transfer belt 12 is electrostatically applied to the sheet conveyed to the transfer area 36. Secondary transfer.

  The cleaner blade 38 is pressed against the portion of the transfer belt 12 supported by the roller 16, scrapes off the toner remaining on the transfer belt 12 after the secondary transfer, and collects it in the waste toner box 40.

  The paper feed trays 60 and 70 are arranged in a two-stage configuration (the paper feed tray 60 is an upper stage and the paper feed tray 70 is a lower stage) below the printer 10 and are detachably arranged, and the paper S as a recording medium is stacked and stored. To do. Details of the paper feed trays 60 and 70 will be described later. The sheets S stored in the sheet feeding trays 60 and 70 are sent to the conveying path 46 one by one from the uppermost sheet by the rotation of the sheet feeding rollers 62 and 72. The transport path 46 extends from the paper feed trays 60 and 70 to the paper discharge tray 11 through the nip portion of the timing roller pair 48, the transfer area 36, and the fixing unit 50. The paper S sent from the paper feed trays 60 and 70 is fed to the transfer area 36 by the timing roller pair 48 in synchronization with the toner image on the transfer belt 12, and the toner image is secondarily transferred in the transfer area 36. To be done. After that, the secondary-transferred toner image is fixed on the paper S by heat melting by the fixing unit 50, and the paper S on which the toner image is fixed is discharged to the paper discharge tray 11.

  FIG. 2 is a diagram showing a schematic configuration of the mechanism of the paper feed tray 60. In FIG. 2, the paper feed tray 60 is described as an example, but the paper feed tray 70 has the same configuration. With reference to FIGS. 1 and 2, the paper feed tray 60 includes a push-up plate 61, a paper feed roller 62, restriction plates 63A and 63B, a lift-up motor (not shown), and an upper limit sensor 64. The regulation plate 63A regulates the position of the sheets S stacked on the push-up plate 61 in the width direction, and is movable in the width direction of the paper feed tray 60. The regulation plate 63B regulates the position of the rear end of the paper S and is movable in the paper feed direction of the paper feed tray 60.

  When the sheets S are stacked on the push-up plate 61 and the paper feed tray 60 is inserted into the printer 10, the lift-up motor is rotationally driven, and the push-up plate 61 is raised and held with the support shaft 61A as a fulcrum. The upper limit position is detected by the sheet S coming into contact with the upper limit sensor 64 and the light blocking plate blocking the light of the photo interrupter. When the upper limit position of the sheet S is detected, the lift-up motor is stopped and the lifting of the push-up plate 61 is stopped. The position of the push-up plate 61 is the paper feed position. On the other hand, when the paper feed tray 60 is pulled out of the printer 10, the holding of the push-up plate 61 is released, and the push-up plate 61 is lowered to the bottom surface portion of the paper feed tray 60. The position of the push-up plate 61 becomes the standby position. The failure of the lift-up motor can be detected by monitoring the motor driver overcurrent signal during rotational driving. Further, the upper limit sensor failure can be detected by monitoring the sensor logic when the LED (light emitting diode) of the photo interrupter is turned on / off.

  FIG. 3 is a control block diagram of the printer 10 of the present embodiment. With reference to FIG. 3, the printer 10 includes a control unit 100, an image forming unit 110, an operation panel unit 130, an upper sheet feed tray 60, a lower sheet feed tray 70, a transport unit 140, and a discharge unit 140. And a paper unit 150.

  The control unit 100 includes a CPU (Central Processing Unit) for controlling the entire printer 10, a ROM (Read Only Memory) for storing a program to be executed by the control unit 100, and a program for the control unit 100. A RAM (Random Access Memory) used as a work area necessary for execution is included. A hard disk drive or a memory card may be used as an auxiliary storage device for supplementing the storage area of the RAM. The control unit 100 also sends and receives data to and from an external device such as a PC via a communication network.

  The operation panel unit 130 includes a display, a plurality of operation buttons for causing the printer 10 to execute a predetermined function, and a touch pad superimposed on the display. The display is composed of a liquid crystal display device (hereinafter, referred to as “LCD” (Liquid Crystal Display)) or the like, and displays an image received from the control unit 100, the image showing the state of the printer 10 and the operation buttons of the touch pad. . An operation signal indicating the operation content input to the printer 10 by operating the operation button and the touch pad is transferred to the control unit 100.

  The image forming unit 110 includes the components shown in FIG. As shown in FIG. 1, the image forming unit 110 primarily and secondarily transfers the toner image formed on the photosensitive drum 22. The transport unit 140 transports the sheet from the transport path 46 to the fixing unit 50 through the timing roller pair 48. The paper discharge unit 150 discharges the paper that has passed through the fixing unit 50 to the paper discharge tray 11.

  As shown in FIGS. 1 and 2, the paper feed tray 60 includes a push-up plate 61, a paper feed roller 62, restriction plates 63A and 63B, an upper limit sensor 64, and a lift-up motor 65. The paper feed tray 70 also includes the same configuration as the paper feed tray 60.

  FIG. 4 is a control block diagram of the paper feed trays 60 and 70 of the present embodiment. With reference to FIG. 4, the upper limit sensor 64 is composed of a photo interrupter, and specifically includes an infrared LED 64A that emits infrared light and a phototransistor 64B that detects light from the infrared LED 64A. Similarly to the upper limit sensor 64 in the upper stage, the upper limit sensor 74 in the lower stage also includes an infrared LED 74A and a phototransistor 74B.

  The infrared LED 64A and the infrared LED 74A are connected to the output port 102A of the control unit 100 by the signal line 104A and share the signal line 104A. The infrared LED 64A and the infrared LED 74A emit infrared light and light up in accordance with the ON state upper limit sensor (upper / lower) LED output signal output from the control unit 100, and the OFF state upper limit sensor (upper / lower stage) LED. Turns off according to the output signal. The ON-state signal is, for example, a high-level (for example, 5V) signal. The off-state signal is, for example, a low-level (for example, 0 V) signal.

  The phototransistor 64B is connected to the input port 103A of the control unit 100 by the signal line 104B. The phototransistor 74B is connected to the input port 103B of the control unit 100 by the signal line 104C. The light blocking plate is configured to be movable between a position that blocks light incident from the infrared LED 64A and the phototransistor 64B and a position that does not block light. The light blocking plate is moved to a position where light is blocked by the paper S when the upper limit is reached by the paper S being lifted by the push-up plate 61, and returns to a position where light is not blocked when the paper S is not moved. The phototransistor 64B outputs an ON-state upper limit sensor (upper stage) detection signal indicating that the paper S has reached the upper limit when the light blocking plate blocks the light from the infrared LED 64A, but does not block the light. At this time, an off-state upper limit sensor (upper stage) detection signal indicating that the paper S has not reached the upper limit is output. Similarly to the phototransistor 64B, the phototransistor 74B also outputs an upper limit sensor (lower stage) detection signal in the ON state or the OFF state.

  In this way, the fact that the paper S has reached the upper limit can be detected separately by the paper feed trays 60 and 70. However, when the upper limit sensor (upper / lower) LED output signal is turned off in order to detect the failure of either upper limit sensor 64 or 74, both the upper and lower infrared LEDs 64A and 74A are turned off. Since the infrared LED that does not detect a failure is also turned off, even when the paper S does not reach the upper limit, the upper limit sensor detection signal in the ON state indicating that the upper limit is reached is output. This state is called a fixed upper limit state.

  The upper lift-up motor 65 is connected to the channel 1 of the motor driver IC 101 by signal lines 104G and 104H. The lower lift-up motor 75 is connected to the channel 2 of the motor driver IC 101 by the signal lines 104J and 104K. The motor driver IC 101 is connected to the output port 102B of the control unit 100 via a signal line 104D, connected to the output port 102C via a signal line 104F, and connected to the input port 103C via a signal line 104E.

  The control unit 100 outputs a lift-up motor (upper stage) drive signal for driving the lift-up motor 65 from the output port 102B to the motor driver IC 101 via the signal line 104D. In accordance with the lift-up motor (upper stage) drive signal from the control unit 100, the motor driver IC 101 outputs a motor drive signal for driving the upper stage lift-up motor 65 from the channel 1 via the signal line 104G to the lift-up motor 65. Output to. The lift-up motor 65 is driven according to this motor drive signal. When detecting the overcurrent, the lift-up motor 65 outputs an overcurrent signal to the channel 1 of the motor driver IC 101 via the signal line 104H. The motor driver IC 101 outputs a lift-up motor (upper / lower stage) overcurrent signal to the input port 103C of the control unit 100 via the signal line 104E in accordance with the overcurrent signal from the lift-up motor 65.

  As described above, the motor driver IC 101 is controlled by the control unit 100, uses the channel 1 to drive the lift-up motor 65, detects an abnormality in the lift-up motor 65, and transmits it to the control unit 100. Similarly, the motor driver IC 101 is controlled by the control unit 100, uses the channel 2 to drive the lift-up motor 75 in the lower stage, detects an abnormality in the lift-up motor 75, and transmits it to the control unit 100.

  As a result, the lift-up motors 65 and 75 are independently controlled. However, a signal indicating an abnormality of the plurality of lift-up motors 65 and 75 (here, an overcurrent signal) is input to the control unit 100 via one signal line 104E. Therefore, when a plurality of lift-up motors 65 and 75 are driven at the same time, it is not possible to determine which lift-up motor 65 or 75 the overcurrent signal is caused by.

  As shown in FIG. 4, by sharing at least a part of the configuration for confirming the failure of the printer 10 with the plurality of paper feed trays 60 and 70, the number of input ports and output ports of the control unit 100 used. Can be reduced and the number of parts can be reduced, so that the manufacturing cost can be reduced. However, in detecting a failure, a problem occurs as described above.

  Therefore, the printer 10 in this disclosure includes a plurality of paper feed trays 60 and 70 and a failure confirmation unit (control unit 100, upper limit sensors 64 and 74, lift-up motor 65) that confirms a failure of the plurality of paper feed trays 60 and 70. , 75, a motor driver IC 101, signal lines 104A to 104K), and a control unit 100 for controlling a plurality of paper feed trays. At least a part of the failure confirmation unit is shared by the plurality of paper feed trays 60 and 70. The failure confirmation unit confirms a failure when the control unit 100 operates one of the plurality of paper feed trays 60 and 70. As a result, it is possible to reliably detect the failure of the paper feed trays 60 and 70 while reducing the manufacturing cost.

[First Embodiment]
FIG. 5 is a flowchart showing the flow of processing of the first embodiment. Referring to FIG. 5, the process shown in FIG. 5 is periodically executed. The control unit 100 initializes the failed component identification flag to the off state (step S1). The faulty component identification flag is a flag that indicates that the faulty component identification control process will be executed if it is on.

  The control unit 100 determines whether any of the plurality of paper feed trays 60 and 70 has been inserted into the printer 10 (step S2). When it is determined that one of the plurality of paper feed trays 60 and 70 has been inserted (YES in step S2), the control unit 100 confirms whether or not another paper feed tray is in the process of specifying the defective component (step S2). S3). When it is determined that the defective component is being identified (YES in step S3), the control unit 100 waits until the identification of the defective component is completed. As a result, erroneous detection of an overcurrent signal due to simultaneous drive of the lift-up motors 65 and 75 can be prevented. Further, erroneous detection of the upper limit sensor detection signal due to the turning off of the infrared LEDs 64A, 74A of the upper limit sensors 64, 74 can be prevented.

  When determining that the identification of the failed component is completed (YES in step S3), the control unit 100 determines whether or not the identification of the failed component is necessary by determining whether or not the failed component identification flag is in the ON state. Yes (step S4). When the failure component identification flag is in the OFF state and it is determined that the identification of the failure component is not necessary (NO in step S4), the control unit 100 performs normal lift-up control of the inserted paper feed tray ( Step S5).

  Next, the control unit 100 determines whether a lift-up abnormality has occurred during the lift-up control (step S6). When it is determined that the lift-up abnormality has occurred (YES in step S6), the control unit 100 sets the failed component identification flag to the on state (step S7), removes the paper feed tray, and sets the paper S incorrectly. A message prompting the user to confirm whether there is any is displayed on the operation panel unit 130 (step S8). The control unit 100 determines whether the paper feed tray has been pulled out (step S9). When it is determined that it has been pulled out (YES in step S9), the control unit 100 again determines whether or not the paper feed tray has been inserted (step S2).

  If it is determined that the paper feed tray has been inserted (YES in step S2), and it is determined that another paper feed tray is not in the process of identifying the faulty component (NO in step S3), the faulty component identification flag is in the on state ( When it is determined to be YES in step S4, the control unit 100 determines whether or not printing is being performed from another paper feed tray (step S10). When it is determined that printing is being performed from another paper feed tray (YES in step S10), the control unit 100 waits until printing is completed. During printing, it is necessary to lift up so that the uppermost part of the paper S is always placed at the paper feeding position for each paper feeding tray, and therefore, waiting for the start of the identification of the defective component is completed until the printing is completed. When it is determined that the printing is completed (NO in step S10), the defective part identification control process is executed (step S11).

  FIG. 6 is a flowchart showing the flow of the lift-up control process of the first embodiment. This lift-up control process is called and executed in step S5 of FIG. Referring to FIG. 6, control unit 100 first initializes the lift-up abnormal state (step S5-1). Next, the control unit 100 drives the lift-up motor (step S5-2).

  The control unit 100 determines whether or not a predetermined lift-up abnormal time has elapsed (step S5-3). When it is determined that the lift-up abnormal time has not elapsed (NO in step S5-3), the control unit 100 receives from the upper limit sensor an upper limit sensor detection signal in the ON state indicating that the paper S has reached the upper limit. It is determined whether or not (step S5-4). When determining that the upper limit sensor signal indicating that the upper limit has been reached has not been received (NO in step S5-4), the control unit 100 repeats steps S5-3 and S5-4.

  When determining that the upper limit sensor signal indicating that the upper limit has been reached is received (YES in step S5-4), the control unit 100 determines that the sheet S has reached the sheet feeding position, and stops the lift-up motor. Yes (step S5-5).

  When it is determined that the lift-up abnormal time has elapsed (YES in step S5-3) before the upper-limit sensor signal indicating that the upper limit has been reached is received, the control unit 100 indicates that the lift-up abnormal state is present. The flag is set (step S5-6) and the lift-up motor is stopped (step S5-5). After step S5-5, the control unit 100 returns the process to be executed to the process of the caller of the lift-up control process.

  FIG. 7 is a flowchart showing the flow of the failed part identification control process of the first embodiment. This faulty component identification control process is called and executed in step S11 of FIG. Referring to FIG. 7, control unit 100 first turns off the infrared LED of the upper limit sensor to detect a failure of the upper limit sensor (step S11-1). As described above, when the infrared LED is turned off, the upper limit sensor is in a fixed upper limit state. The control unit 100 monitors the upper limit sensor in the fixed upper limit state, and determines whether or not the ON state upper limit sensor detection signal indicating that the paper S has reached the upper limit is output from the phototransistor (step). S11-2). When it is determined that the upper limit sensor detection signal in the ON state is not output (NO in step S11-2), it is determined that the upper limit sensor is out of order (step S11-5), and this faulty part identification control process is executed. When it is finished, the process to be executed is returned to the caller.

  When determining that the upper limit sensor detection signal in the ON state is output (YES in step S11-2), the control unit 100 turns on the infrared LED of the upper limit sensor (step S11-3). The control unit 100 determines whether or not the off-state upper limit sensor detection signal indicating that the sheet S has not reached the upper limit is output from the phototransistor (step S11-4). Immediately before the user confirms the setting error of the paper S, the paper feed tray is inserted and removed, the holding of the push-up plate is released, and the push-up plate is lowered to the bottom portion of the paper feed tray. Therefore, the paper S should not reach the upper limit. When it is determined that the upper limit sensor detection signal in the off state is not output (NO in step S11-4), the control unit 100 determines that the upper limit sensor is out of order (step S11-5), and this failure occurs. The component specifying control process is terminated, and the process to be executed is returned to the calling source.

  Next, in order to detect the failure of the lift-up motor, the control unit 100 drives the lift-up motor (step S11-6). The control unit 100 monitors the overcurrent signal of the lift-up motor and determines whether the lift-up motor has an abnormality (step S11-7).

  When it is determined that the lift-up motor has no abnormality (NO in step S11-7), the control unit 100 determines whether a predetermined lift-up abnormality time has elapsed (step S11-9). When it is determined that the lift-up abnormal time has not elapsed (NO in step S11-9), the control unit 100 receives from the upper limit sensor an upper limit sensor detection signal in the ON state indicating that the paper S has reached the upper limit. It is determined whether or not (step S11-11). When determining that the upper limit sensor signal indicating that the upper limit has been reached is not received (NO in step S11-11), the control unit 100 repeats steps S11-7, S11-9, and step S11-11.

  When determining that the upper limit sensor signal indicating that the upper limit has been reached is received (YES in step S11-11), the control unit 100 determines that the sheet S has reached the sheet feeding position, and stops the lift-up motor. Yes (step S11-12).

  When it is determined that an abnormality is detected (YES in step S11-7) before the upper limit sensor signal indicating that the upper limit is reached is received (YES in step S11-7), the control unit 100 determines that the lift-up motor is out of order ( In step S11-8), the lift-up motor is stopped (step S11-12), and the process to be executed is returned to the calling source of this process.

  When it is determined that the lift-up abnormal time has elapsed (YES in step S11-9) before the upper-limit sensor signal indicating that the upper limit is reached is received, the control unit 100 causes the lift-up mechanism (for example, a push-up plate and a lift-up plate). It is determined that there is an abnormality in the lift-up motor coupling gear (step S11-10), and the lift-up motor is stopped (step S11-12). The processing to be executed is returned to the calling processing of this processing.

[Modification of First Embodiment]
FIG. 8 is a flowchart showing the flow of lift-up control processing of the modified example of the first embodiment. Referring to FIG. 8, the description of the portions common to those of FIG. 6 will not be repeated. Steps S5-21 and S5-22 are the same as steps S5-1 and S5-2 of FIG.

  After step S5-2, it is determined whether or not the lift-up motor is being driven by another paper feed tray (step S5-23). When it is determined that the lift-up motors of other paper feed trays are not driven (NO in step S5-23), the control unit 100 monitors the over-current signal of the lift-up motors, and the lift-up motor has an abnormality. It is determined whether or not (step S5-24). When it is determined that the lift-up motor has no abnormality (NO in step S5-24), the control unit 100 executes the processing of step S5-26 and subsequent steps. The processing after step S5-26 is the same as the processing after step S5-3 in FIG.

  When it is determined that the abnormality is detected (YES in step S5-24) before the upper limit sensor signal indicating that the upper limit is reached is received, the control unit 100 determines that the lift-up motor is out of order ( Step S5-25), the lift-up motor is stopped (step S5-29), and the process to be executed is returned to the calling source of this process.

  When it is determined that the lift-up motors of other paper feed trays are being driven (YES in step S5-23), it is determined which lift-up motor has an abnormality, as shown in FIG. Since it is not possible, the control unit 100 skips the process of step S5-24 and executes the process of step S5-26.

[Second Embodiment]
In the first embodiment, as shown in FIG. 5, the lift-up control process is not executed when another paper feed tray is in the process of identifying a defective component. In the second embodiment, since it is rare that a plurality of components fail at the same time, the lift-up control process is allowed to be executed at the timing when a plurality of paper feed trays overlap each other.

  FIG. 9 is a flowchart showing the flow of processing of the second embodiment. Referring to FIG. 9, when it is determined that one of the plurality of paper feed trays 60 and 70 has been inserted into the printer 10 (step S22), the control unit 100 identifies the other paper feed tray as a defective part. The lift-up control process is executed regardless of whether it is in progress (step S5). Further, the defective part identification control process is executed regardless of whether or not printing is being performed from another paper feed tray (step S28). Except for these processes, the process is the same as that shown in FIG.

  FIG. 10 is a flowchart showing the flow of the failed component identification control process of the second embodiment. The control unit 100 first confirms whether or not another paper feed tray is in the process of identifying a defective component (step S28-1). When it is determined that the defective component is being identified (YES in step S28-1), the control unit 100 waits for the end of the identification of the defective component. When it is determined that the identification of the failed component is completed (NO in step S28-1), the lift-up motor is driven (step S28-2).

  The control unit 100 determines whether or not the lift-up motor is driven by the lift-up control in another paper feed tray (step S28-3). When it is determined that the lift-up motors of the other paper feed trays are being driven (YES in step S28-3), the control unit 100 determines in step S528-4 whether the lift-up motor is abnormal. Instead, the process to be executed proceeds to step S28-6. The processing after step S28-6 is the same as the processing after step S11-9 in FIG. Although it is determined in step S11-10 in FIG. 7 that the lift-up mechanism is abnormal, it is determined in step S28-8 that corresponds to FIG. 10 that the lift-up mechanism is abnormal or the upper limit sensor is defective.

[Modification]
(1) In the above-described embodiments, the image forming apparatus is described as the printer 10 which is a tandem type digital color printer. However, the image forming apparatus is not limited to the printer 10, and may be a tandem type facsimile apparatus or an MFP (Multi Function Peripherals). The printing method is not limited to the tandem method or the digital method, and a monochrome printer may be used instead of the color printer.

  (2) In the above-described embodiment, what is shared by the plurality of paper feed trays 60 and 70 is the signal line 104E for transmitting the lift-up motor overcurrent signal from the motor driver IC 101 to the control unit 100 and the control unit 100. Input port 103C. However, the present invention is not limited to this, and a plurality of paper feed trays 60 and 70 may have another configuration, for example, a signal of a control signal from the control unit 100 to the lift-up motors 65 and 75. It may be a line and an output port of the control unit 100.

  (3) In the above-described embodiment, what is shared by the plurality of paper feed trays 60 and 70 is the signal line 104A and the control of the output signal from the control unit 100 to the infrared LEDs 64A and 74A of the upper limit sensors 64 and 74. It is assumed that the output port is 102A. However, the present invention is not limited to this, and a plurality of paper feed trays 60 and 70 may be shared by other configurations, for example, from the phototransistors 64B and 74B of the upper limit sensors 64 and 74 to the control unit 100. It may be a signal line for the input signal and the input port of the control unit 100.

  (4) In the above-described embodiment, the software as shown in each flowchart is executed by the control unit 100 of the printer 10 so that the control unit 100 realizes a plurality of predetermined functions. However, the present invention is not limited to this, and at least a part of these predetermined functions may be realized by a hardware circuit inside the control unit 100.

  (5) In the above-described embodiments, the disclosure has been described as an image forming apparatus such as the printer 10. However, the present invention is not limited to this, and the disclosure may be regarded as a control method executed by an image forming apparatus such as the printer 10 as shown in each of the above-described flowcharts. The disclosure may be regarded as a control program for executing the processing shown in each of the flowcharts.

  Further, the disclosure can be regarded as a computer-readable recording medium in which the control program is recorded. This recording medium includes magnetic tapes, flexible disks, magnetic disks such as hard disks, CD-ROMs, CD-Rs, CD-RWs, DVD-ROMs, DVD-Rs, DVD-RWs, DVD-RAMs, DVD + Rs, DVD + RWs, and the like. It may be an optical disk, a magneto-optical disk such as MO, a memory card, or a medium such as a USB memory in which the program is fixedly held, or the program may be transferred from a server such as an ASP (Application Service Provider) via a communication network. It may be a medium that fluidly carries the program for downloading.

  (6) The techniques described in the embodiments and the modifications are intended to be implemented singly or in combination as much as possible.

[effect]
(1) As shown in FIGS. 1 to 4, the printer 10 includes a plurality of paper feed trays 60, 70 and a failure confirmation unit (control unit 100, upper limit) for confirming a failure of the plurality of paper feed trays 60, 70. The sensors 64 and 74, the lift-up motors 65 and 75, the motor driver IC 101, the signal lines 104A to 104K), and the control unit 100 that controls the plurality of paper feed trays 60 and 70 are provided. As shown in FIG. 4, at least a part of the failure confirmation unit (output port 102A, signal line 104A, input port 103C, signal line 104F) is shared by the plurality of paper feed trays 60 and 70. As shown in step S11-6 and subsequent steps in FIG. 7 and step S28-2 and subsequent steps in FIG. 10, the failure confirmation section causes the control section 100 to operate one of the plurality of paper feed trays 60 and 70. Check for malfunctions.

  As a result, at least a part of the failure confirmation unit is shared by the plurality of paper feed trays 60 and 70, so that the manufacturing cost can be prevented from increasing. Further, even when at least a part of the failure confirmation unit is shared by the plurality of paper feed trays 60 and 70, the control unit 100 operates one of the plurality of paper feed trays 60 and 70. Since the failure is confirmed when the paper trays 60 and 70 are present, the failure can be detected. As a result, it is possible to reliably detect the failure of the paper feed trays 60 and 70 while reducing the manufacturing cost.

  (2) As shown in FIGS. 3 and 4, the paper feed trays 60, 70 are lift-up motors 65 for moving the paper S stored in the paper feed trays 60, 70 to a position where paper can be fed. Including 75. As illustrated in FIG. 4, the failure confirmation unit is a drive failure confirmation unit that confirms a failure of the lift-up motors 65 and 75 (control unit 100, lift-up motors 65 and 75, motor driver IC 101, signal lines 104D to 104K). including. As shown in FIG. 4, at least a part of the drive failure confirmation unit (input port 103C, signal line 104F) is shared by the plurality of paper feed trays 60 and 70.

  As a result, it is possible to reliably detect the failure of the paper feed trays 60 and 70 while reducing the manufacturing cost.

  (3) As shown in FIGS. 3 and 4, the upper limit of the paper feed trays 60 and 70 is to detect whether the paper S stored in the paper feed trays 60 and 70 has been moved to a position where paper can be fed. Includes sensors 64,74. The failure confirmation unit includes a detection failure confirmation unit (control unit 100, upper limit sensors 64 and 74, signal lines 104A to 104C) that confirms a failure of the upper limit sensors 64 and 74. At least a part of the detection failure confirmation unit (output port 102A, signal line 104A) is shared by the plurality of paper feed trays 60 and 70.

  As a result, it is possible to reliably detect the failure of the paper feed trays 60 and 70 while reducing the manufacturing cost.

  (4) As shown in FIG. 7, the failure confirmation unit confirms the failure of the upper limit sensors 64, 74 before the failure of the lift-up motors 65, 75.

  As a result, first, it is confirmed that there is no abnormality in the upper limit sensors 64, 74 and then the abnormality of the lift-up motors 65, 75 is confirmed, so that the failure can be detected efficiently and surely.

  (5) As shown in step S3 of FIG. 5, the failure confirmation unit confirms the failure at a timing when the operations of the plurality of paper feed trays 60 and 70 do not overlap.

  This makes it possible to reliably detect the failure of the paper feed tray without being affected by the confirmation of the failure of the other paper feed tray.

  (6) As shown in steps S3 and S5 of FIG. 5, when the failure confirmation unit confirms the failure of the paper feed trays 60 and 70, the control unit 100 determines the other paper feed trays 60 and 70. Operation is prohibited.

  As a result, it is possible to prevent the operation of the paper feed trays 60 and 70 from affecting the confirmation of a failure in another paper feed tray.

  (7) As shown in step S3 and step S11 in FIG. 5 and in FIG. 7, the control unit 100 confirms a failure in at least two or more of the plurality of paper feed trays 60 and 70. The two or more paper feed trays 60 and 70 to be checked are operated in sequence (specifically, after the operation during the identification of the defective component of the other paper feed tray is completed in step S3, the paper feed tray is operated in step S11). The operation for identifying the defective part of the tray is started). As shown in steps S3 and S11 of FIG. 5 and FIG. 7, the failure confirmation unit sequentially confirms the failure of the paper feed trays 60 and 70 operated by the control unit.

  As a result, it is possible to prevent the operation of the paper feed trays 60 and 70 from affecting the confirmation of a failure in another paper feed tray.

  (8) As shown in FIGS. 1 and 3, the control unit 100 can execute control to feed the paper S from one of the paper feed trays 60 and 70. As shown in steps S10 and S11 of FIG. 5, the failure confirmation unit prohibits the confirmation of the failure of the paper feed trays 60 and 70 when the control unit 100 is controlling the paper S to be fed. To do.

  As a result, it is possible to prevent the operation of the paper feed trays 60 and 70 from affecting the confirmation of a failure in another paper feed tray. Further, since the control for feeding the paper S to check the failure of the paper feed trays 60 and 70 is not interrupted, downtime of printing using the paper S can be suppressed.

  (9) As shown in steps S22 and S5 of FIG. 9, when the paper S is replenished in the paper feed trays 60 and 70, the controller 100 causes the failure checker to check the other paper feed trays 60 and 70. Even if it is confirmed that the failure of No. 2 is detected, the lift-up motors 65 and 75 are controlled so as to move the paper S to the position where the paper can be fed.

  Accordingly, when the paper S is supplied to the paper feed trays 60 and 70, the paper S can be efficiently moved to a position where the paper can be fed.

  The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present disclosure is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

  10 Printer, 11 Paper Output Tray, 12 Transfer Belt, 14, 16 Roller, 20, 20C, 20K, 20M, 20Y Imaging Unit, 22 Photosensitive Drum, 24 Charging Device, 26 Printhead, 28 Developing Device, 30 Primary Transfer Roller , 30C, 30K, 30M, 30Y Temporary transfer roller, 32 cleaner, 34 secondary transfer roller, 36 transfer area, 38 cleaner blade, 40 waste toner box, 46 transport path, 48 timing roller pair, 50 fixing unit, 60, 70 Paper feed tray, 61 push-up plate, 61A support shaft, 62,72 paper feed roller, 63A, 63B regulation plate, 64,74 upper limit sensor, 64A, 74A infrared LED, 64B, 74B phototransistor, 65,75 lift-up motor, 100 control unit, 101 motor Driver IC, 102A, 102B, 102C output port, 103A, 103B, 103C input port, 104A, 104B, 104C, 104D, 104E, 104F, 104G, 104H, 104J, 104K signal line, 110 image forming unit, 130 operation panel unit , 140 conveyance section, 150 paper ejection section.

Claims (11)

Multiple paper feeders,
A failure confirmation section for confirming a failure of the plurality of paper feeding devices,
A control unit for controlling the plurality of paper feeding devices,
At least a part of the failure confirmation unit is shared by the plurality of paper feeding devices,
The image forming apparatus, wherein the failure confirmation unit confirms a failure when the control unit operates one of the plurality of sheet feeding devices. The paper feeding device is
A drive unit for moving the paper stored in the paper feeding device to a position where paper can be fed;
The failure confirmation unit includes a drive failure confirmation unit that confirms a failure of the drive unit,
The image forming apparatus according to claim 1, wherein at least a part of the drive failure confirmation unit is shared by a plurality of the sheet feeding devices. The paper feeding device is
A sheet detection unit for detecting whether or not the sheets stored in the sheet feeding device have been moved to a position where sheets can be fed,
The failure confirmation unit includes a detection failure confirmation unit that confirms a failure of the paper detection unit,
The image forming apparatus according to claim 1, wherein at least a part of the detection failure confirmation unit is shared by a plurality of the sheet feeding devices.   The image forming apparatus according to claim 3, wherein the failure confirmation unit confirms a failure of the sheet detection unit before a failure of the drive unit.   The image forming apparatus according to claim 1, wherein the failure confirmation unit confirms a failure at a timing at which operations of the plurality of sheet feeding devices do not overlap.   The image forming apparatus according to claim 1, wherein the control unit prohibits an operation of another sheet feeding device when the failure confirmation unit confirms a failure of the sheet feeding device. When confirming the failure of at least two or more of the plurality of sheet feeding devices, the control unit sequentially operates the two or more sheet feeding devices for confirming the failure,
The image forming apparatus according to claim 1, wherein the failure confirmation unit sequentially confirms a failure of the sheet feeding device operated by the control unit. The control unit is capable of executing control of feeding a sheet from one of the sheet feeding devices,
The image forming apparatus according to claim 1, wherein the failure confirmation unit prohibits confirmation of a failure of the paper feeding device when the control unit controls the paper feeding.   When the paper is replenished in the paper feeding device, the control unit reaches the position where the paper can be fed even if the failure checking unit has confirmed that the other paper feeding device has failed. The image forming apparatus according to claim 2, wherein the drive unit is controlled to move. A method for controlling an image forming apparatus, comprising: a plurality of sheet feeding devices; a failure confirmation unit that confirms a failure of the plurality of sheet feeding devices; and a control unit that controls the plurality of sheet feeding devices,
At least a part of the failure confirmation unit is shared by the plurality of paper feeding devices,
The control method is
The control unit operating one of the plurality of paper feeding devices;
The failure confirmation unit controls the one of a plurality of sheet feeding devices to confirm a failure when the control unit is operating, and a method for controlling an image forming apparatus. A control program executed by the control unit in an image forming apparatus including a plurality of paper feeding devices, a failure confirmation unit that confirms a failure of the plurality of paper feeding devices, and a control unit that controls the plurality of paper feeding devices And
At least a part of the failure confirmation unit is shared by the plurality of paper feeding devices,
The control program is
Operating one of the plurality of paper feeders;
A control program for the image forming apparatus, which causes the control unit to execute a step of controlling to confirm a failure while operating one of the plurality of sheet feeding devices.

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