JP2008050139A - Method of detecting removal of fixing member, paper feeder, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent a mobile body from being damaged and a power supply circuit from being failed by preventing the mobile body from being continuously driven before a fixing member is removed without performing complicated operations. <P>SOLUTION: A loading plate 21 is liftable in the range L1 between a fixed position 211 and a terminal position 213 on both sides of the initial position 212. The loading plate 21 receives the supply of a drive force for the lifting operation from a drive device 51 through cables 53, 54. When a paper feeder 1 is shipped from the plant, the loading plate 21 is secured to the fixed position 211 with a fixing screw 25. When a power is supplied to the paper feeder 1, the drive device 51 gradually raises the loading plate 21 to the position above the initial position 212. A lower limit detection sensor 32 outputs an on signal when the loading plate 21 is positioned in the range below the initial position 212. The fixing screw 25 is determined to be unremoved when the lower limit detection sensor 32 outputs the on signal even when the loading plate 21 exceeds the initial position 212. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fixing member removal detection method for detecting whether or not a fixing member that restricts movement of a moving body inside the apparatus has been removed from the apparatus, a paper feeding device to which the detection method is applied, and the paper feeding The present invention relates to an image forming apparatus provided with the apparatus.

  A device such as a paper feeding device or an image forming device includes a moving body such as a scanning plate that scans an image surface of a document placed on a platen or a document table that rises as the amount of paper loaded decreases. Some are provided so as to be movable within a predetermined range. At the time of transportation from when the device is shipped from the factory until it is installed at the place of use, the posture of the device is not stable. If the moving body moves in the apparatus due to a change in the attitude of the apparatus during a period when the apparatus is unstable during transportation or the like, the moving body collides with a part of the apparatus and is damaged. In addition, the positional accuracy of the moving body is lowered by the action of vibration.

  Therefore, in an apparatus provided with a moving body, the moving body is fixed to the apparatus via a fixing member such as a fixing screw or a lock pin at the time of factory shipment. The fixed member is removed from the device after the device is installed at the place of use, and the movable member is movable within the device, making the device ready for use.

  However, when the use of the device is started without removing the fixing member after the device is installed, the driving force is supplied to the moving body whose movement is restricted by the fixing member, and the moving body is damaged or the power supply circuit Cause failure.

For this reason, some conventional devices cannot be used without the fixing member being removed. For example, there is an image forming apparatus in which a seal member is bridged on a pressure plate that covers a platen and each lock pin (fixing member) of two scanning units is connected by a seal member (see, for example, Patent Document 1). When the lock pin is not removed from the image forming apparatus, the platen cannot be opened by lifting the pressure plate, and the document cannot be placed on the platen. For this reason, it is said that an image of a document cannot be read unless the lock pin is removed, and failure due to not releasing the fixing of the scanning unit before using the image forming apparatus can be prevented.
JP-A-11-64999

  In general, when the image forming apparatus is powered on, a process of continuously driving the scanning unit to move it to the home position is performed. For this reason, Patent Document 1 discloses a configuration in which a power plug or a power switch is covered with a tag provided on a seal member.

  However, in the configuration of Patent Document 1, there is a problem that complicated operations such as an operation of connecting the fixing member with the seal member and an operation of covering the power plug and the power switch with the tag are required.

  In addition, the configuration disclosed in Patent Document 1 connects a plurality of first fixing members exposed to the outside of the apparatus by a second fixing member that fixes another moving body. It cannot be applied to a moving body in which the fixing member is not exposed to the outside of the apparatus, such as a plate.

  The object of the present invention is to prevent the moving body from being continuously driven before the fixing member is removed without complicated work, and reliably prevent the damage to the moving body and the failure of the power supply circuit. Another object of the present invention is to provide a fixing member removal detection method, a sheet feeding device, and an image forming apparatus.

  The fixing member removal detection method of the present invention includes a reading step and a discrimination step. The reading process and the determination process are performed while the moving body is driven for the first time after the power is turned on to the apparatus having the moving body movable between the fixed position and the terminal position sandwiching the initial position. In the reading step, the detection result of the sensor that detects the position of the moving body is read. In the determination step, it is determined whether or not the fixing member that fixes the movable body to the fixed position is removed based on the detection result of the sensor read in the reading step.

  The reading process is executed at least two times before and after the reference time after a predetermined time has elapsed since the start of driving of the moving body. In the determination step, it is determined that the fixing member is not removed when there is no change in the detection signal of the sensor.

  The moving body is driven intermittently until the determination process is completed. The driving force does not continuously act on the moving body, and even when the fixing member is not removed, the fixing member is not damaged or the driving unit is not damaged.

  By making the cumulative drive amount of the intermittent drive longer than the moving distance from the fixed position of the moving body to the initial position, it is accurately determined whether or not the fixed member has been removed.

  The user recognizes the necessity for the removal work of the fixing member by performing a warning process for prompting the removal of the fixing member according to the determination result in the determination process.

  The sheet feeding device according to the present invention includes a stacking plate, a driving unit, a fixing member, a sensor, and a control unit. The stacking plate is placed on a sheet, and can be raised and lowered between a lower fixed position and an upper terminal position across the initial position. The drive unit drives the stacking plate. The fixing member fixes the stacking plate at a fixed position. The sensor detects the loading plate within a range equal to or less than the initial position. The control unit is configured to determine whether or not the fixing member is removed based on the detection result of the sensor while the driving unit drives the stacking plate from the fixed position toward the initial position. .

  When the sensor detects the vicinity of the fixed portion of the stacking plate by the fixing member, the state in which the fixing member is not removed can be reliably determined.

  Note that the state in which the fixing member is removed includes not only the state in which the fixing member is physically removed from the apparatus, but also the fixing member does not engage with the moving body or the loading plate, Including the state that can not be fixed in the fixed position.

  According to this invention, it can be determined based on the detection result of the sensor that detects the moving body at the initial position whether or not the fixing member that fixes the moving body to the fixing position of the apparatus is removed. When it is determined that the fixed member has not been removed, the moving body is stopped from moving continuously before the fixed member is removed by stopping the movement of the moving body, requiring complicated work at the time of factory shipment. Therefore, it is possible to reliably prevent the damage of the moving body and the failure of the power supply circuit. In addition, it is possible to use an existing sensor in the apparatus for determining whether or not the fixing member is removed, and it is not necessary to add a new part, and the cost is not increased.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 100 that receives paper fed from a paper feeding device 1 according to an embodiment of the present invention. The sheet feeding device 1 is disposed on the side of the image forming apparatus 100. In this embodiment, only one sheet feeding device 1 is disposed on the side of the image forming apparatus 100, but a plurality of sheet feeding devices 1 may be disposed. In this embodiment, the sheet feeding device 1 supplies the sheet P to the image forming apparatus 100. However, the sheet feeding device 1 can also supply other sheet bodies such as an OHP film.

  The image forming apparatus 100 forms an image on the paper P by an electrophotographic image forming process. The image forming apparatus 100 includes paper feed cassettes 101, 102, 103, and 104 at the bottom and a paper discharge tray 105 at the top. A paper transport path F <b> 1 is provided between the paper feed cassettes 101, 102, 103 and the paper discharge tray 105. A photosensitive drum 106 is disposed in the vicinity of the paper transport path F1. Around the photosensitive drum 106, a charger 107, an optical scanning unit 108, a developing unit 109, a transfer unit 110, a cleaning unit 111, and the like are disposed.

  The paper P is supplied to the transfer position between the photosensitive drum 106 and the transfer unit 110 in synchronization with the rotation of the photosensitive drum 106 on the upstream side of the photosensitive drum 106 in the conveyance direction in the paper conveyance path F1. A registration roller 112 is disposed. A fixing unit 113 is disposed on the downstream side of the photosensitive drum 106 in the transport direction in the paper transport path F1.

  The charger 107 charges the outer peripheral surface of the photosensitive drum 106 to a predetermined potential. The optical scanning unit 108 forms an electrostatic latent image on the surface of the photosensitive drum 106 based on image data input from the outside. The developing unit 109 supplies toner to the surface of the photosensitive drum 106 to visualize the electrostatic latent image, and forms a toner image. The transfer unit 110 transfers the toner image formed on the surface of the photosensitive drum 106 onto the paper P. The fixing unit 113 fixes the toner image on the paper P. The paper P on which the toner image is fixed is discharged to the paper discharge tray 105. The cleaning unit 111 collects the toner remaining on the surface of the photosensitive drum 106 that has passed the transfer position.

  In addition, the image forming apparatus 100 includes a reverse conveyance path F2. When forming an image on both sides of the paper P, the reverse conveyance path F2 reverses the front and back of the paper P on which the image is formed on one side and conveys it to the transfer unit. Further, the image forming apparatus 100 includes a paper transport path F3. The paper transport path F3 connects the paper feed cassette 104 and the upstream side of the registration roller 112 in the transport direction in the paper transport path F1. The paper transport path F3 is provided substantially horizontally. The paper transport path F3 also leads to a manual feed tray 114 that is provided on the side surface of the image forming apparatus 100 and supplies paper of an irregular size, and a paper receiving unit 115 that receives the paper P supplied from the paper supply device 1. . The paper transport path F3 transports the paper P supplied from the manual feed tray 114 or the paper receiving unit 115 to the transfer unit.

  FIG. 2 is a front cross-sectional view illustrating the configuration of the paper feeding device 1. The sheet feeding device 1 includes a mounting table 2, a pickup roller 3, a feed roller 4, a reverse roller 5, a transport roller 6 and the like inside a housing 9. The mounting table 2 includes a stacking plate 21, a front reference plate 22, side reference plates 23 and 24 (the side reference plate 24 is not shown), a rear end reference plate not shown, and the like. The loading plate 21 is a moving body according to the present invention, is disposed horizontally, and can be raised and lowered within a predetermined lifting range within the mounting table 2. A plurality of sheets are positioned by the front reference plate 22, the side reference plates 23 and 24, and the rear end reference plate and stacked and stored on the stacking plate 21.

  The pickup roller 3 is swingable within a predetermined range D in the vertical direction with the rotation axis of the feed roller 4 as the central axis. Within the predetermined range D, the pickup roller 3 rotates in contact with the vicinity of the downstream end in the sheet feeding direction on the upper surface of the uppermost sheet among the plurality of sheets placed on the stacking plate 21, The sheet is guided between the feed roller 4 and the reverse roller 5.

  The sheet passes between the feed roller 4 and the reverse roller 5. Both the feed roller 4 and the reverse roller 5 rotate in the clockwise direction in FIG. When the pickup roller 3 simultaneously guides a plurality of sheets between the feed roller 4 and the reverse roller 5, only the uppermost sheet contacts the feed roller 4 and is guided to the transport roller 6. Paper other than the uppermost paper is returned to the stacking plate 21 by the reverse roller 5.

  By repeating the sheet feeding operation, the number of sheets stored in the stacking plate 21 is decreased, and the position of the upper surface of the uppermost sheet is decreased. When the position of the upper surface of the uppermost sheet becomes lower than the lower limit position of the predetermined range D, the pickup roller 3 does not come into contact with the upper surface of the uppermost sheet, and the sheet cannot be fed. Therefore, when it is detected that the position of the upper surface of the uppermost sheet has approached the lower limit position of the predetermined range D, the stacking plate 21 is raised by a predetermined amount via a driving device described later. As the number of sheets stored in the stacking plate 21 decreases due to the repeated feeding operation, the stacking plate 21 is repeatedly raised.

  The sheet feeding device 1 can store, for example, about 5000 sheets on the stacking plate 21. In addition, the paper feeding device 1 can selectively store a plurality of types of paper such as A3 size, B4 size, A4 size, and B5 size.

  Therefore, the side reference plates 23 and 24 are movable within a predetermined range in a direction orthogonal to the paper feeding direction on the stacking plate 21. One movement of the side reference plates 23 and 24 is transmitted to the other in the opposite direction. As a result, the paper placed on the stacking plate 21 is fed with reference to the center position in the direction orthogonal to the paper feeding direction.

  When the sheet feeder 1 is shipped from the factory, the stacking plate 21 is fixed to the bottom surface of the mounting table 2 with fixing screws 25. In order to prevent the stacking plate 21 from moving in the mounting table 2 due to vibration during transport of the paper feeding device 1 and colliding with the front reference plate 22, the side reference plates 23 and 24, the rear end reference plate, and the like. It is. The fixing screw 25 corresponds to the fixing member of the present invention. The fixing screw 25 is attached to the downstream side of the sheet feeding direction on the upper surface of the stacking plate 21.

  A drive device 51 (see FIG. 4) including a lifting motor 52 is provided on the back surface of the paper placing table 2. The rotation of the lifting motor 52 is transmitted through the wires 53 and 54 (see FIG. 4), so that the sheet stacking plate 21 is moved up and down along a guide shaft (not shown) while maintaining a horizontal state. To do.

  Slide rails 7 and 8 are provided on portions of the inner wall surface of the sheet feeding device 1 and the outer wall surface of the sheet placing table 2 that face each other. The sheet placing table 2 is guided by slide rails 7 and 8 so as to be freely inserted into and removed from the front side of the sheet feeding device 1. The sheet mounting table 2 moves in a horizontal direction between a storage position stored inside the sheet feeding device 1 and an exposed position where the entire surface of the sheet stacking plate 21 is exposed on the front side of the sheet feeding device 1.

  FIG. 3 is a diagram illustrating a paper supply operation in the paper supply device 1. The mounting table 2 is provided with a side detection sensor 31 and a lower limit detection sensor 32, and the stacking plate 21 is provided with an empty detection sensor 33. The side surface detection sensor 31 detects the paper P stored in the stacking plate 21 or the stacking plate 21 in which the paper P is not stored at the reference position set below the lower limit position of the predetermined range D.

  The lower limit detection sensor 32 is a sensor of the present invention, and detects the stacking plate 21 in the range of the initial position 212 or less as will be described later. The empty detection sensor 33 detects a state in which the paper P is not stored on the stacking plate 21.

  When the sheet feeding operation is repeated and the number of sheets P stored on the stacking plate 21 is reduced, and the sheet P is replenished on the stacking plate 21, the side detection sensor 31 is moved as shown in FIG. The stacking plate 21 is lowered to a position where the sheet P is no longer detected. From this state, when the paper P is replenished as shown in FIG. 3C and the side surface detection sensor 31 detects the paper, the side detection sensor 31 does not detect the paper P as shown in FIG. The loading plate 21 is lowered.

  When the empty detection sensor 33 detects that the paper P is not stored on the stacking plate 21, the stacking plate 21 is lowered to a position where the side detection sensor 31 does not detect the stacking plate 21. Thereafter, when sheets are replenished on the stacking plate 21, the stacking plate 21 is lowered to a position where the side detection sensor 31 does not detect the sheet P.

  The operation of lowering the stacking plate 21 when paper is replenished on the stacking plate 21 is repeatedly performed until the lower limit detection sensor 32 detects the stacking plate 21 as indicated by a two-dot chain line in FIG. Can do.

  FIG. 4 is a diagram illustrating the position of the stacking plate 21 in the paper feeding device 1. The stacking plate 21 is movable up and down in a range L1 between a lower fixed position 211 and an upper end position 213 with the initial position 212 interposed therebetween. The loading plate 21 is supplied with a driving force for the raising / lowering operation from the driving device 51 via the wires 53 and 54. The drive device 51 corresponds to the drive unit of the present invention. The driving device 51 includes a lifting motor 52 and a plurality of gears, and winds or feeds the wires 53 and 54 at the same speed.

  During conveyance from the time when the paper feeding device 1 is shipped to the use position, the stacking plate 21 is fixed to the fixing position 211 by the fixing screw 25. When the power supply is turned on after the paper feeding device 1 is installed at the use position and the fixing screw 25 is removed from the paper feeding device 1, the driving device 51 raises the stacking plate 21 to the initial position 212. Let

  The lower limit detection sensor 32 corresponds to the sensor of the present invention. As an example, the lower limit detection sensor 32 is a limit switch provided with an actuator 321 so as to be swingable. The actuator 321 abuts in the vicinity of a portion of the stacking plate 21 to which the fixing screw 25 is attached. The lower limit detection sensor 32 outputs an ON signal when the stacking plate 21 is located in the range of the initial position 212 or less. Therefore, even when the stacking plate 21 is located at the fixed position 211, the lower limit detection sensor 32 outputs an ON signal.

  When the stacking plate 21 reaches the initial position 212 during the paper supply operation, the lower limit detection sensor 32 is turned on, and the lowering of the stacking plate 21 is stopped. The stacking plate 21 moves up and down in a range L2 between the initial position 212 and the terminal position 213 according to the paper loading state. The end position 213 is the upper limit position of the predetermined range D shown in FIG. Further, when a paper feed abnormality such as a jam occurs, the stacking plate 21 is lowered to the initial position 212.

  FIG. 5 is a block diagram illustrating a configuration of the control unit 30 of the sheet feeding device 1. In the sheet feeding device 1, a side surface detection sensor 31, a lower limit detection sensor 32, an empty detection sensor 33, a timer 35, a display 36, a motor driver 37, and the like are connected to the control unit 30. The control unit 30 controls these input / output devices according to a program written in the storage unit 40.

  The timer 35 measures a predetermined time. The display device 36 displays a message to the user based on the display data supplied from the control unit 30. The motor driver 37 is included in the drive device 51 and drives the lifting motor 52 based on drive data supplied from the control unit 30.

  FIG. 6 is a flowchart showing a part of the processing procedure of the control unit 30. At the start of use of the sheet feeding device 1, the control unit 30 continuously operates the elevating motor 52 for the convenience of stacking sheets on the stacking plate 21, and the stacking plate 21 is moved by the side detection sensor 31. Raise to the position where it is detected.

  As described above, the stacking plate 21 is fixed to the fixing position 211 by the fixing screw 25 when the paper feeding device 1 is shipped from the factory. If the driving force in the upward direction is continuously transmitted from the lifting motor 52 to the stacking plate 21 in this state, the stacking plate 21 is deformed, the wires 53 and 54 are broken, and the driving device 51 is damaged. Therefore, the fixing screw 25 needs to be removed from the paper feeding device 1 before the power is supplied to the paper feeding device 1.

  However, the user may neglect the work of removing the fixing screw 25 before turning on the power to the sheet feeding device 1.

  Therefore, when the power is supplied to the sheet feeding device 1, the control unit 30 determines whether or not the lower limit detection sensor 31 detects the stacking plate 21 (S1). When the lower limit detection sensor 31 detects the stacking plate 21 and outputs an ON signal, the control unit 30 activates the timer 35 and drives the lifting motor 52 for a predetermined time, so that the stacking plate 21 is placed. The timer 35 is stopped by increasing the fixed amount (S2 to S4).

  The predetermined amount when raising the stacking plate 21 in S3 is a distance shorter than the distance between the fixed position 211 and the initial position 212. The raising / lowering motor 52 is driven for a predetermined time during which the loading plate 21 is raised by a predetermined amount. By raising the loading plate 21 little by little, it is possible to prevent the lifting motor 52 from being damaged due to an excessive load acting when the fixing screw 25 is not removed.

  Thereafter, the detection state of the lower limit detection sensor 31 is determined (S5), and the processes of S2 to S4 are continued until the lower limit detection sensor 31 stops detecting the stacking plate 21 or the timer 35 times out (S6). ). The timer 35 is set to a time longer than the reference time of the present invention, which is the drive time of the elevating motor 52 required for the stacking plate 21 to rise from the fixed position 211 to a position exceeding the initial position 212.

  After the power is turned on, the processes of S3 to S6 are repeated until the accumulated drive time from the start of the rise of the stacking plate 21 at the fixed position 211 passes the reference time. Therefore, the detection state of the lower limit detection sensor 31 is determined twice or more before and after the reference time. When the fixing screw 25 is removed, the detection state of the lower limit detection sensor 31 is determined at both the timing when the stacking plate 21 is at a position below the initial position 212 and the timing at the position above it.

  If the lower limit detection sensor 31 does not detect the stacking plate 21 and does not output an ON signal before the timer 35 expires, the control unit 30 determines that the fixing screw 25 has been removed. The control unit 30 resets the timer 35 (S7) and lowers the stacking plate 21 until the lower limit detection sensor 31 outputs an ON signal (S8 to S10). The control unit 30 waits for a paper stacking operation on the stacking plate 21 in a state where the stacking plate 21 is stopped at the initial position 212 (S11).

  If the timer 35 expires before the lower limit detection sensor 31 stops outputting the ON signal, the control unit 30 determines that the fixing screw 25 has not been removed. The control unit 30 lowers the stacking plate 21 until the timer 35 expires, returns the stacking plate 21 to the fixed position 211 (S12 to S14), and displays a message for instructing the removal of the fixing screw 25 on the display 36. (S15). Thereafter, when the power is turned on again or cleared, the control unit 30 performs the process of S1 again. The clear operation is an operation of a clear button on an operation panel (not shown).

  When the lower limit detection sensor 31 does not output an ON signal in the process of S1, the control 30 determines that the fixing screw 25 has already been removed, and executes the standby mode (S11). At this time, the control unit 30 can also perform the processes of S8 to S10 to place the stacking plate 21 at the initial position 212.

  Based on the detection result of the existing lower limit detection sensor 31 in the sheet feeding device 1 in order to detect the stacking plate 21 within the range of the initial position 212 or less, it is accurately determined whether or not the fixing screw 25 has been removed. Can be determined.

  The fixing screw 25 is rotatably supported on the bottom surface of the mounting table 2, does not come into contact with the stacking plate 21 due to the rotation, and releases the fixing of the stacking plate 21 without being removed from the paper feeding device 1. Also good. Further, the fixing member is not limited to a fixing screw.

  Means for measuring the amount of rotation of the lifting motor 52 may be provided, and a counter for integrating and counting the cumulative amount of rotation of the lifting motor 52 may be provided instead of the timer 35.

  The present invention is not limited to the above-described embodiment, and can be similarly applied to other apparatuses including a moving body to be fixed during transportation, such as an image reading apparatus including a mirror base.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus 100 that receives paper fed from a paper feeding device 1 according to an embodiment of the present invention. 2 is a front cross-sectional view illustrating a configuration of the paper feeding device 1. FIG. FIG. 4 is a diagram illustrating a paper supply operation in the paper feeding device 1. 5 is a diagram illustrating the position of a stacking plate 21 in the paper feeding device 1. FIG. 3 is a block diagram illustrating a configuration of a control unit 30 of the sheet feeding device 1. FIG. 4 is a flowchart illustrating a part of a processing procedure of a control unit 30.

Explanation of symbols

1 Paper feeder 21 Loading plate (moving body)
25 Fixing screw (fixing member)
32 Lower limit detection sensor (sensor)
51 Drive unit (drive unit)
52 Elevating motor 53, 54 Wire 100 Image forming apparatus 211 Fixed position 212 Initial position 213 End position

Claims (12)

  A sensor that detects the position of the moving body while driving the moving body for the first time after turning on the power to the device having the moving body movable between the fixed position and the terminal position across the initial position. A reading step for reading a detection result, and a determination step for determining whether or not a fixing member for fixing the movable body to the fixed position is removed based on the detection result of the sensor read in the reading step. A fixing member removal detection method.   The reading step is performed at least twice before and after the reference time after a predetermined time has elapsed since the start of driving of the moving body, and the determination step changes the detection signal of the sensor at the time of the two detections. The fixing member removal detection method according to claim 1, wherein it is determined that the fixing member is not removed when there is not.   The method according to claim 1 or 2, wherein the moving body is intermittently driven until the determination step is completed.   The fixed member removal detection method according to claim 3, wherein an integrated drive amount of the intermittent drive is longer than a moving distance of the moving body from the fixed position to the initial position.   5. The fixing member removal detection method according to claim 1, further comprising a warning process that prompts removal of the fixing member according to a determination result in the determination step. A stacking plate on which paper is placed, the stacking plate being raised and lowered between a lower fixed position and an upper end position across the initial position;
A drive unit for driving the loading plate;
A fixing member for fixing the stacking plate at the fixing position;
A sensor for detecting the loading plate in a range below the initial position;
While the drive unit drives the stacking plate from the fixed position toward the initial position, it is configured to determine whether or not the fixed member is removed based on the detection result of the sensor. And a control unit.   The sheet feeding device according to claim 6, wherein the sensor detects a vicinity of a fixed portion of the stacking plate by the fixing member.   The control unit determines that the fixing member is not removed when there is no change in the detection signal of the sensor at the time of two detections before and after the reference time after a predetermined time has elapsed after the driving of the driving unit is started. The sheet feeding device according to claim 6 or 7 configured to do so.   The sheet feeding device according to claim 8, wherein the driving unit intermittently drives the stacking plate from a fixed position toward an initial position.   The sheet feeding device according to claim 9, wherein the intermittent driving amount of the intermittent driving is a time longer than a moving distance of the moving body from the fixed position to the initial position.   The sheet feeding device according to any one of claims 6 to 10, wherein the control unit is configured to issue a warning prompting removal of the fixing member in accordance with the determination result.   An image forming apparatus comprising the paper feeding device according to claim 6, wherein an image is formed on a paper fed from the paper feeding device.

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