JP2020066511A - Paper feeding device, image formation system and control method - Google Patents

Abstract

To provide a paper feeding device for appropriately detecting abnormality in operation of a loading part.SOLUTION: When a loading part capable of loading a sheet is lowered via a lifting mechanism, a behavior of the lifting mechanism caused by the operation of the lowering is detected. Based on a result of the detection, abnormality of the operation of the loading part is informed.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a sheet feeding device that feeds an image forming apparatus, an image forming system, and a control method.

  As a sheet feeding device of an image forming apparatus, one provided with a sheet feeding device for continuously feeding a large number of sheets is known. The sheet feeding device is detachably attached to the main body of the image forming apparatus, and includes a stacking unit on which, for example, about 3000 sheets can be placed.

  The loading section is suspended by a wire, and the wire is wound around a winding pulley that is rotated in both forward and reverse directions by a lifting motor. That is, the loading section descends by reversing the lifter motor and releasing the wire wound on the take-up pulley from the take-up pulley, and rotating the elevating motor forward to take up the wire by the take-up pulley. To rise. Alternatively, the wire is wound around the take-up pulley by rotating the lifter motor forward to release the wire, and the wire is lowered by rotating the lift motor in the reverse direction to wind up the wire by the take-up pulley.

  Further, the sheet feeding device includes a lower limit sensor that is detected when the stacking unit moves to the lowermost sheet feeding position and an upper limit sensor that is detected when the stacking unit moves to the uppermost sheet feeding position. I have it. When the lower limit sensor is turned on, it is detected that the stacking unit has moved to the paper supply position. After that, when a predetermined number of sheets are replenished on the stacking section by the operator, the stacking section starts rising and the upper limit sensor is turned on to detect that the stacking section has moved to the sheet feeding position, The sheets on the stacking unit are fed one by one.

  The stacking unit of the sheet feeding device configured as described above is lowered to the sheet replenishment position when the image forming apparatus is powered on or when the image forming apparatus requests to replenish sheets. After the sheets are replenished as necessary, the sheet is raised to the sheet feeding position. In other words, the elevating motor reverses to lower the stacking unit, the lower limit sensor is turned on, and then the elevating motor rotates forward to raise the stacking unit and the upper limit sensor is turned on, so that the image forming operation by the image forming apparatus is performed. It will be possible.

  However, if the elevating motor continues to reverse when the stacking unit is not descending for some reason while it is descending, the wire is released from the pulley, causing slack, and when the reverse rotation continues, it is released. The reverse winding condition occurs when the wire begins to be rewound around the counter rotating pulley. When the wire is reversely wound in this way, the loading section rises even though the lifting motor is reversed to open the wire (the loading section is moved down), and the reverse rotation is continued. If continued, there was a problem that the upper part of the paper feeding device is contacted and the device is damaged.

  In order to avoid such a reverse winding state, in the paper feeding device, the time from the start of the lowering of the lifter plate to the turning on of the lower limit switch is counted, and the time is compared with a preset reference time. If the lower limit switch is not turned on even after the reference time is exceeded, it is determined that the wire is in the reverse winding state, and the lifter motor is stopped. Further, as a configuration for detecting the reverse winding of the wire for raising and lowering the sheet stacking plate, a configuration for detecting a change in the trajectory of the wire is known (Patent Document 1).

JP, 10-17158, A

  However, when the lower limit switch is not turned on even after the reference time is exceeded, it is determined that the reverse winding state of the wire has occurred, and the lifter motor is stopped, or as in Patent Document 1, a change in the trajectory of the wire is detected. In the case of the configuration, the wire is completely released from the winding pulley since the reverse winding is actually detected after the detection. When the take-up pulley is rotated in the winding direction with the wire completely opened in this way (recovery operation), the take-up wire crosses over the take-up pulley and overlaps. It may be taken. In that case, the lifting / lowering operation of the lifter plate is different from the normal lifting / lowering operation (tilt of the lifter plate, etc.), which may affect the sheet feeding performance.

  In view of such conventional problems, it is an object of the present invention to provide a sheet feeding device, an image forming system, and a control method that appropriately detect an abnormality in the operation of the stacking unit.

  In order to solve the above-mentioned problems, a sheet feeding device according to the present invention, when a stacking unit capable of stacking sheets is moved up and down through an elevating mechanism, and when the stacking unit is lowered by the control unit, It is characterized by further comprising: detection means for detecting a behavior of the elevating mechanism caused by the descending operation; and informing means for informing the user based on a result of the detection by the detection means.

  According to the present invention, it is possible to appropriately detect an abnormality in the operation of the stacking unit.

FIG. 3 is a diagram showing configurations of an image forming apparatus and a sheet feeding apparatus. It is a figure which shows the structure of a paper feeder. It is a figure which shows the structure of a sheet storage part. It is a figure which shows the structure of the raising / lowering mechanism of a sheet storage part. It is a figure which shows the structure of an encoder and an encoder rotation detection sensor. It is a figure for demonstrating the normal raising / lowering operation of a loading part. It is a figure for demonstrating a raising / lowering operation when a foreign substance exists in the lower part of a loading part. It is a figure for explaining generation of reverse winding. It is a figure which shows the output signal of an encoder rotation detection sensor. It is a flow chart which shows processing of lifting control. It is a flow chart which shows processing of lifting control. FIG. 3 is a diagram showing a block configuration around a control system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the present invention according to the claims, and all combinations of features described in the present embodiments are not necessarily essential to the solving means of the present invention. . In addition, the same reference numerals are given to the same components, and the description thereof will be omitted.

  FIG. 1 is a diagram showing a schematic configuration of an image forming system 100 including an image forming apparatus 1 and a sheet feeding device 2 in this embodiment. FIG. 1A shows a state in which the sheet feeding device 2 is attached to the image forming apparatus 1, and FIG. 1B shows a state in which the sheet feeding device 2 is separated from the image forming apparatus 1.

  As shown in FIG. 1, a laser scanner 11 and a mirror 12 for exposing the photosensitive drum 10 to write an electrostatic latent image are provided above the image forming apparatus 1. The image forming apparatus 1 converts the received image data into write image data and sends it to the laser scanner 11 to form an electrostatic latent image on the photosensitive drum 10 according to the write image data.

  The image forming unit includes an optical system having a photosensitive drum 10, a laser scanner 11 and a mirror 12, a charging device 13, a developing device 14, a transfer roller 15 and a cleaner 16. The charger 13 uniformly charges the surface of the photosensitive drum 10. The laser scanner 11 forms an electrostatic latent image on the surface of the photosensitive drum 10 charged by the charger 13. Then, the developing device 14 develops the electrostatic latent image formed by the laser scanner 11 into a toner image so as to be transferred to the sheet S. The transfer roller 15 transfers the toner image developed on the surface of the photosensitive drum 10 to the sheet S. The cleaner 16 removes the toner remaining on the photosensitive drum 10 after transferring the toner image.

  A transport unit 17 for transporting the sheet S having the toner image transferred thereon, and a fixing device for fixing the toner image on the sheet S transported by the transport unit 17 as a permanent image on the downstream side of the image forming unit. And 18 are provided. Further, a discharge roller 19 for discharging the sheet S having the toner image fixed by the fixing device 18 from the image forming apparatus 1 is provided on the downstream side of the fixing device 18. A discharge sheet stack tray (hereinafter referred to as a discharge tray) 20 for receiving the sheets S discharged by the discharge rollers 19 is provided outside the upper portion of the image forming apparatus 1. Further, the cassette feeding trays 30a to 30d are provided so as to be positioned at the uppermost stream in sheet conveyance, and can store a predetermined number of sheets S. Further, a manual feeding section 30e is provided on the side surface of the image forming apparatus 1.

  In the lower portion of the image forming apparatus 1, from four cassette feeding roller pairs 31a to 31d for feeding from the cassette feeding trays 30a to 30d, and a manual feeding section 30e provided on the side surface of the image forming apparatus 1. A manual feeding roller pair 31e for feeding is provided, and the paper feeding device 2 is detachably attached to the lower portion of the manual feeding portion 30e.

  The paper feeding device 2 is configured to be able to stack a relatively large capacity (thousands) of sheets. The sheet feeding device 2 feeds the sheets S stacked and stored in a stacking unit 36 (described later) that can be moved up and down by the feeding roller 31f one by one. The sheet S picked up by the cassette feeding roller pairs 31a to 31d, the manual feeding roller pair 31e, and the feeding deck roller 31f is conveyed to the downstream side through the vertical conveying path 33 by the pulling roller pairs 32a to 32d. At the most downstream position of the vertical conveyance path 33, there is a registration roller pair 34, which performs final sheet skew correction, image writing in the image forming unit, and sheet conveyance timing adjustment. Further, as shown in FIG. 1B, when the sheet feeding device 2 is separated from the image forming apparatus 1 for jamming or the like, it is stored inside the sheet feeding device 2 in FIG. 1A. The sheet feeding device 2 is separated from the image forming apparatus 1 along the attachment / detachment rail 35.

  Next, the configuration of the sheet feeding device 2 will be described with reference to FIG. FIG. 2 shows a state in which the sheet storage unit 3 is pulled out from the sheet feeding device 2.

  The sheet feeding device 2 includes a sheet storage unit 3 including a stacking unit 36 that stacks the sheets S illustrated in FIG. 1 and can be moved up and down, and a pair of frames 37. The sheet storage unit 3 is slidably supported along opening / closing rails 38 provided on the left and right sides of the sheet storage unit 3 inside the sheet feeding device 2 with respect to the moving direction of the sheet storage unit 3. Further, the sheet feeding device 2 is provided with a storage box opening / closing switch 39, and when the user presses the storage box opening / closing switch 39, the lock of the lock portion (not shown) is released, and the sheet storage section 3 is opened / closed by the open / close rail 38. The sheet storage unit 3 is pushed out by a biasing member (not shown) to a pull-out position where the sheet storage unit 3 can be pulled out to the front side. As a result, the user can easily pull out the sheet storage portion 3 and move it to the sheet replenishable position, and it becomes easy to replenish the sheet S.

  FIG. 12 is a diagram showing a block configuration around the control system in the sheet feeding device 2. The CPU 64 controls the entire sheet feeding device 2 and can communicate with the image forming apparatus controller 1102 of the image forming apparatus 1 via the communication circuit 1101. The memory 53 is used as a working memory of the CPU 64. The storage device 1103 is, for example, a ROM, and stores necessary data, parameters, and the like such as error information such as an operation abnormality of the stacking unit 36 described later. The operation of the sheet feeding device 2 in the present embodiment is realized by, for example, the CPU 64 loading a program stored in the storage unit 1103 into the memory 53 and executing the program. The timer 62 is used when measuring a predetermined time. The CPU 64 controls the motor drive circuit 60, and according to the drive of the motor drive circuit 60, various motors in the sheet feeding device 2, for example, a lift motor 100 for moving up and down the stacking unit 36 operates. The winding pulley 42 is rotated by the drive of the lifting motor 100, and winds / releases the wire 40. In accordance with the winding / discharging of the wire 40, the sheet stacking unit 36 moves up and down, and the relay roller 41 rotates. Operations of the winding pulley 42, the wire 40, and the relay roller 41 will be described later.

  Output signals from various sensors in the paper feeding device 2 are transmitted to the CPU 64 via the sensor input circuit 63. Here, the various sensors are, for example, the lower limit sensor 44, the paper surface detection sensor 43, the sheet presence sensor 66, the storage opening / closing sensor 65, and the encoder rotation detection sensor 51. The storage opening / closing sensor 65 is a sensor for detecting the open / closed state of the sheet storage unit 3. The lower limit sensor 44, the paper surface detection sensor 43, the encoder rotation detection sensor 51, and the encoder 50 will be described later. Further, the CPU 64 detects the depression of the storage opening / closing switch 39 to control a solenoid (not shown) to release the locked state of the sheet storage unit 3.

  Next, the detailed configuration of the sheet storage unit 3 will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic configuration diagram of the sheet storage unit 3 in the present embodiment as seen from the moving direction along the opening / closing rail 38. FIG. 4 is a perspective view of the elevating mechanism of the stacking unit 36 as seen obliquely from above.

  The stacking unit 36 is configured such that the stacking unit 36 moves up and down between a pair of frames 37. In the stacking unit 36, one end of the wire 40 is fixed to the connection points A, B, C, and D near the four corners of the stacking unit 36, and the other end is rotatably provided above the sheet storage unit 3 to guide the wire 40. Via the relay roller 41, the take-up pulleys 42 provided at the front and rear of the sheet storage section 3 are connected. Further, the relay roller 41 is provided with a circular encoder 50 that rotates in conjunction with the rotation of the relay roller 41, and an encoder rotation detection sensor 51 is provided near the encoder 50. The take-up pulley 42 is rotated by the lifting motor 100. The winding pulleys 42 are connected to each other by a shaft 45.

  FIG. 5 is a cross-sectional view of the relationship between the relay roller 41, the encoder 50, and the encoder rotation detection sensor 51 described above, as viewed from above. The encoder 50 and the relay roller 41 are configured so that their side surfaces are in contact with each other. With such a configuration, it is possible to detect the behavior (rotational motion) of the relay roller 41 by interlocking the rotation amount of the encoder with the relay roller 41. As shown in FIG. 5, the encoder 50 has a convex portion and can pass through the concave portion of the encoder rotation detection sensor 51. The encoder rotation detecting sensor 51 has a light source and a light receiving unit (not shown), and the light source and the light receiving unit are blocked each time the convex portion of the encoder 50 passes through the concave portion of the encoder rotation detecting sensor 51. As a result, the encoder rotation detection sensor 51 outputs a pulse signal. The CPU 64 detects an abnormality in the lifting operation of the stacking unit 36 based on a change in the pulse signal output from the encoder rotation detection sensor 51, for example, a stop of the output signal or a change in the number of pulses.

  The loading portion 36 moves up by winding the wire 40 by the winding pulley 42, and moves down by discharging the wire 40. Further, as shown in FIG. 3, a paper surface detection sensor 43 for detecting the paper surface (uppermost portion) stacked on the stacking portion 36 that is lifted on one side of the frame 37, and the presence or absence of a sheet on the stacking portion 36 are detected. A sheet presence / absence sensor 66 is provided. When the paper surface (uppermost portion) loaded on the lifted stacking portion 36 is detected by the paper surface detection sensor 43, the drive of the winding pulley 42 is controlled so as to stop the lifting of the stacking portion 36. Similarly, a lower limit sensor 44 for detecting that the stacking unit 36 has descended to the lowermost end is provided at the lower part of one side of the frame 37, and when the lowered stacking unit 36 is detected, the lowering of the stacking unit 36 is stopped. Thus, the drive of the take-up pulley 42 is controlled.

  As shown in FIG. 4, the take-up pulley 42 is fixed to the shaft 45, and the shaft 45 is connected so as to interlock with the drive of the lifting motor 100. When the take-up pulley 42 is rotated in the take-up direction by the drive of the lifting motor 100, the wire 40 is taken up by the take-up pulley 42 and is connected to the wire 40 at the connection points A, B, C, D. The part 36 rises. When the drive of the lifting motor 100 is reversed and the winding pulley 42 is rotated in the discharging direction, the wire 40 is discharged from the winding pulley 42 and is lowered by the weight of the loading unit 36.

  FIG. 6 is a view showing a state in which the wire 40 is discharged by the winding pulley 42 and the stacking unit 36 normally descends. The wire 40 wound by the winding pulley 42 is always loaded by the weight of the stacking unit 36 and the stacked sheets S, and the load exists in the discharging direction of the wire 40 when the stacking unit 36 is raised or lowered. To do.

  However, as shown in FIG. 7, when a foreign substance G or the like exists in the lower portion of the stacking unit 36, the lowering of the stacking unit 36 is hindered, and the stacking unit 36 does not descend midway (abnormal operation). In that case, the winding pulley 42 continues to discharge the wire 40 until the lower limit sensor 44 provided at the lower portion of the sheet storage unit 3 detects the stacking unit 36. Further, since the lower portion of the loading portion 36 is supported by foreign matter and the load applied to the wire 40 is lost, the wire 40 begins to loosen. Further, if the state continues, the wire 40 wound around the take-up pulley 42 is all discharged, and the wire 40 is reversed to the normal state on the take-up pulley 42 even though the wire 40 is being discharged. The winding starts in the direction of, and it becomes a reverse winding state. FIG. 8 is a diagram showing a state in which the wire 40 is further discharged from the state of FIG. 7 during the abnormal operation to cause reverse winding.

  Even after the foreign matter is removed and the return operation of the wire 40 is performed after the reverse winding occurs, the winding wire 40 is wound in a state where the winding wire 40 crosses and overlaps with the winding pulley 42. Sometimes. In this case, the stacking unit 36 may be tilted, which may affect the paper feeding performance. Therefore, in this embodiment, an abnormality in the lifting operation of the stacking unit 36 is detected early before reverse winding occurs.

  Hereinafter, the detection mechanism of the lifting / lowering operation abnormality of the stacking unit 36 in the present embodiment will be described. When the stacking unit 36 is normally moved up and down, as shown in FIG. 6, the relay rollers 41 are inserted from the four corners of the stacking unit 36 depending on the weight of the stacking unit 36 and the weight of the sheets S stacked on the stacking unit 36. A tension is applied to the wire 40 stretched between the winding pulleys 42 via the. In such a state, the relay roller 41 rotates in the direction of the arrow in accordance with the movement of the wire 40 being released from or wound up by the winding pulley 42, for example, when the winding pulley 42 is in the normal direction. .

  On the other hand, when a foreign substance is mixed under the stacking unit 36, the lower limit sensor 44 provided at the lower portion of the sheet storage unit 3 detects the stacking unit 36 as illustrated in FIG. Even if 42 continues to release the wire 40, the relay roller 41 does not rotate as in the above-described normal operation because the wire 40 is loosened. As a result, the signal of the encoder rotation detection sensor 51 shows an output different from that during the normal lifting operation. In the present embodiment, it is determined whether the relay roller 41 is rotating or not by detecting an output of the encoder rotation detection sensor 51 which is different from the normal output operation. With such a configuration, it is possible to determine an abnormality in the lifting operation at the time when the wire 40 is bent, and it is possible to prevent the occurrence of reverse winding.

  A method for determining an abnormality of the stacking unit 36 in this embodiment will be described with reference to FIG. FIG. 9 is a diagram showing an output signal (time-voltage) of the encoder rotation detection sensor 51. In particular, FIG. 9A shows an output signal of the encoder rotation detection sensor 51 when the stacking unit 36 is normally moved up and down, and FIG. 9B is an encoder rotation detection sensor 51 when the stacking unit 36 is vertically moved. The output signal of is shown.

  When the loading section 36 is normally moving up and down, as shown in FIG. 9A, an output signal (pulse signal) corresponding to the rotation speed of the take-up pulley 42 driven by the lifting motor 100 is output at a predetermined cycle. Is output. On the other hand, in FIG. 9B, as in FIG. 9A, an output signal corresponding to the rotation speed of the take-up pulley 42 driven by the lifting motor 100 is output in a predetermined cycle until a certain time. However, from the time when the foreign matter is present immediately below the loading section 36, the wire 40 is bent and the output signal is not output. FIG. 9B shows a state in which the output signal is not output, but the output signal may be irregular depending on the bending state of the wire.

  Therefore, in this embodiment, when the number of pulses in the output signal from the encoder rotation detection sensor 51 is not more than the specified number within the predetermined time when the winding pulley 42 is rotated by the drive of the lifting motor 100, the loading unit When it is determined that an abnormality has occurred in the lifting operation of the 36, the driving of the lifting motor 100 is stopped, and the lowering operation of the stacking unit 36 is stopped. Note that the above-mentioned predetermined time is appropriately set based on, for example, the pulse width of the encoder detection sensor 51, the moving speed of the stacking unit 36, and the like.

  10 and 11 are flowcharts showing the control processing of the lifting operation of the stacking unit 36 in the present embodiment. The processing of FIGS. 10 and 11 is started when the power of the sheet feeding device 2 is turned on, or when the image forming apparatus 1 requests the sheet replenishment. First, the case 1 in which the sheet feeding device 2 is powered on and the initial operation is normally performed will be described.

  In S1001, the CPU 64 determines whether the initial operation has been performed when the power was turned on. If it is determined that the initial operation has not been performed yet, the process proceeds to S1005, and if it is determined that the initial operation has already been performed, the process proceeds to S1002. In this case, since the initial operation has not been performed yet, the process proceeds to S1005.

  The initial operation is performed in the processing after S1005. In S1005, the CPU 64 controls the motor drive circuit 60 to drive the lifting motor 100 and lower the stacking unit 36. In S1006, the CPU 64 determines whether an abnormality in the output signal from the encoder rotation detection sensor 511 is detected. In S1006, the output signal from the encoder rotation detection sensor 51, for example, the rising edge of the pulse is monitored while the stacking unit 36 is being lowered, and it is determined whether or not a predetermined number or more of pulses cannot be detected within a predetermined time. Here, if it is determined that the specified number of pulses can be detected or more, the process proceeds to step S1007, and if it is determined that the number of pulses or more cannot be detected, the process proceeds to step S1016. In this case, the process proceeds to S1007.

  In S1007, the CPU 64 monitors the output signal of the lower limit sensor 44 and determines whether it is ON. If it is determined not to be ON, the process of S1006 is repeated, and if it is determined to be ON, the process proceeds to S1008.

  In S1008, the CPU 64 controls the motor drive circuit 60 to stop the drive of the lift motor 100. Then, in S1009, it is determined whether or not this operation is an initial operation. In this case, it is determined that the operation is the initial operation, and the process proceeds to S1011. In S <b> 1011, the CPU 64 controls the motor drive circuit 60 to drive the lift motor 100 and raise the stacking unit 36. When the CPU 64 detects that the paper surface detection sensor 43 is turned on in S1012, the motor drive circuit 60 is controlled in S1013 to stop the drive of the lifting motor 100. Then, in S1014, the CPU 64 resets the area of the storage unit 1103 that stores the error information. This is because it was found in this initial operation that there is no foreign matter or the like. In S1015, the CPU 64 completes the initial operation, and thereafter ends the processing of FIGS. 10 and 11.

  Next, Case 2 will be described in which the sheet feeding device 2 is powered on and an error occurs during the lowering operation of the stacking unit 36 in the initial operation.

  Since S1001, S1005, and S1006 are the same as those in Case 1, the description thereof will be omitted. In this case, it is determined in S1006 that the specified number of pulses cannot be detected, and the process proceeds to S1016. In S1016, the CPU 64 controls the motor drive circuit 60 to stop the drive of the lift motor 100. In S1017, the CPU 64 refers to the area of the storage unit 1103 that stores error information and determines whether or not this error has occurred for the first time. Here, when it is determined that it is the first time, the CPU 64 issues a warning notice in S1018. Here, the warning notification is, for example, a message such as "Open the storage and check if there is any foreign matter under the loading section. After confirmation, close the storage". This is to display on the display unit on the device 1 side to notify the user.

  When the CPU 64 detects that the storage case opening / closing switch 39 is pressed in S1019, the CPU 64 unlocks and opens the sheet storage unit 3 in S1020. Then, in step S <b> 1021, the CPU 64 stores, in the memory 53, an error information of the operation error of the stacking unit 36 as error information. At that time, the number of times of determination of an operation error, that is, the number of times of occurrence of error information is also stored. In S1022, the CPU 64 monitors that the storage opening / closing sensor 65 is turned off, and if it is turned off, in S1023, the motor drive circuit 60 is controlled to drive the lifting motor 100 to raise the stacking unit 36.

  When the CPU 64 detects in S1024 that the paper surface detection sensor 43 is ON, in S1025, the CPU 64 controls the motor drive circuit 60 to stop the drive of the lift motor 100. Then, the processing from S1001 is repeated. If the foreign matter is removed when the processing from S1001 is repeated, the initial operation after S1007 is performed.

  If the number of error occurrences is not the first time in S1017, the cause of the operation abnormality error of the stacking unit 36 is not that caused by the inclusion of foreign matter under the stacking unit 36, but a sensor failure or harness related to the operation of the stacking unit 36. There is a high possibility that it is the cause of self-recovery such as disconnection. Therefore, in S1026, the CPU 64 notifies that a serviceman call is to be made, and in S1027, the paper feeding device 2 is degenerated and its use is restricted so that the user cannot perform normal operation. Then, the processing of FIGS. 10 and 11 is ended. The notification of the above serviceman call is, for example, displaying a message such as “Needs maintenance by a serviceman” on the display unit of the image forming apparatus 1 to notify the user.

  As described above, in the present embodiment, whether to notify the foreign matter confirmation message or retract the paper feeding device 2 is switched according to the number of times the operation abnormality error is determined. With such a configuration, it is possible to distinguish between cases in which the user can easily perform recovery and cases in which the recovery is not possible, and to perform appropriate notification according to each case.

  Next, Case 3 in which there is a request to replenish the sheet and the sheet replenishing operation is normally performed will be described.

  In this case, since it is determined in S1001 that the initial operation has already been performed, the process proceeds to S1002. In S1002, the CPU 64 determines whether or not the condition that the sheet presence sensor 66 is ON and the sheet surface detection sensor 43 is OFF is satisfied. If it is determined that the condition is satisfied, in S1004, the CPU 64 unlocks the sheet storage unit 3 and opens it. On the other hand, when it is determined that the condition is not satisfied, for example, when there is a sheet on the stacking unit 36, the depression of the storage opening / closing switch 39 is waited. When it is determined that the storage opening / closing switch 39 has been pressed, in S1004, the CPU 64 unlocks the sheet storage unit 3 and opens it. The pressing of the storage opening / closing switch 39 is awaited in S1003 because the sheet supply instruction may be canceled. When the sheet replenishment instruction is canceled, it is not necessary to replenish the sheet, and thus the processing of FIGS. 10 and 11 may be ended.

  Since S1005 to S1009 are the same as the description in Case 1, the description thereof will be omitted. In this case, it is determined in S1009 that the operation is not the initial operation, so the process proceeds to S1010. When the CPU 64 detects in S1010 that the storage opening / closing sensor 65 is OFF, that is, when the sheets are replenished and the sheet storage unit 3 is closed, the process proceeds to S1011. Since S1011 to S1015 are the same as those in Case 1, the description thereof will be omitted.

  Next, Case 4 will be described in which there is a request to replenish the sheets and an error occurs during the lowering operation of the stacking unit 36 in the sheet replenishing operation.

  Since S1001 to S1006 are the same as those in Case 3, the description thereof will be omitted. In this case, it is determined in S1006 that the specified number of pulses cannot be detected, and the process proceeds to S1016. Since steps S1016 to S1027 are the same as the case 2, the description thereof will be omitted.

  As described above, according to the present embodiment, it is possible to separate reverse winding, which occurs due to the presence of foreign matter in the lower portion of the stacking unit 36, from wire jamming of the harness and failure of the sensor switch. Further, the early detection of the lifting / lowering operation abnormality of the stacking unit 36 prevents the occurrence of reverse winding and enables recovery of the lifting / lowering operation of the stacking unit 36. Further, when the wire is caught in the harness or the sensor switch fails, the paper feeding device 2 is retracted so as not to accept the normal operation, so that the paper feeding device 2 can be prevented from further damage.

  1 Image forming apparatus: 2 Paper feeding apparatus: 36 Stacking section: 41 Relay roller: 50 Encoder: 51 Encoder rotation detection sensor: 53 Memory: 64 CPU: 100 Lifting motor: 1103 Storage section

Claims (10)

Control means for moving up and down a stacking part capable of stacking sheets through an elevating mechanism,
When lowering the stacking unit by the control unit, a detection unit that detects a behavior of the elevating mechanism that accompanies the lowering operation,
An informing means for informing the user based on the result of the detection by the detecting means,
A paper feeding device comprising: The elevating mechanism includes a wire connected to the loading unit, and a roller that guides the wire,
The detection means outputs a signal according to the rotation of the roller,
The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device. The detection means outputs a pulse signal according to the rotation of the roller,
The notifying means performs notification based on a change in the number of pulses of the pulse signal,
The sheet feeding device according to claim 2, wherein the sheet feeding device is a sheet feeding device.   The sheet feeding device according to claim 3, wherein the notification unit notifies the user when the pulse signal is no longer output.   5. The control unit limits the operation of the elevating mechanism when the user is notified by the notification unit based on the detection result of the detection unit. The paper feeding device according to the item.   The sheet feeding device according to claim 5, wherein the control unit limits the operation of the elevating mechanism according to the number of times the notification unit notifies the user. An input means for receiving a sheet supply instruction from the user,
The control means lowers the stacking portion via the elevating mechanism when the input means receives an instruction to supply sheets.
The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.   7. The sheet feeding device according to claim 1, wherein the control unit lowers the stacking unit via the elevating mechanism when the power supply of the sheet feeding device is turned on. apparatus. A sheet feeding device according to any one of claims 1 to 8,
An image forming system, comprising: an image forming apparatus that forms an image on a sheet fed from the sheet feeding apparatus. A method for controlling a sheet feeding device having a stacking unit capable of stacking sheets, comprising:
A lowering step of lowering the stacking section by control means for moving the stacking section up and down through an elevating mechanism;
A detection step of detecting the behavior of the elevating mechanism that occurs along with the lowering in the lowering step;
An informing step of informing the user based on the result of the detection in the detecting step,
A control method comprising:

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