JP2013063845A - Paper feeder and image forming device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost by reducing the number of sensors, and to ensure design flexibility.SOLUTION: This paper feeder includes a first paper storage part, a bottom plate arranged in the first paper storage part and movably supported in the vertical direction, a first driving part for vertically moving the bottom plate, a second paper storage part adjacent to the first paper storage part and stacking and storing paper, a moving member arranged in the second paper storage part and movably supported in the horizontal direction, a second driving part for horizontally moving the moving member for moving the paper stacked in the second paper storage part to the first paper storage part from the second paper storage part, a detecting member rotatably arranged around the axis orthogonal to both directions for moving the bottom plate and the moving member and changing an angle when in contact with the moving bottom plate and the moving member, a sensor for detecting a rotation angle of the detecting member, and a control part for controlling the first and second driving parts by detecting a position of the bottom plate and the moving member on the basis of output of the sensor that indicates the rotation angle of the detecting member.

Description

  The present invention relates to a paper feeding device used for, for example, a copying machine, a printer, a facsimile, and the like, and an image forming apparatus having the paper feeding device.

  Conventionally, in an image forming apparatus, as a paper feeding device capable of accommodating a large capacity, sheets are stacked on a movable bottom plate, and the bottom plate is moved up and down according to the amount of paper, and an image forming unit is formed one by one from the top sheet. A paper feeding device for feeding paper to a paper is known. In addition, a first sheet storage unit on the downstream side and a second sheet storage unit on the upstream side with respect to the sheet conveyance direction are provided, and sheets are fed from the first sheet storage unit to the image forming unit one by one. There is also provided a paper feeding device having means for collectively transferring the paper in the second paper storage unit to the first paper storage unit when the paper in the paper storage unit is consumed.

  For example, in Patent Document 1, when the paper in the first paper storage unit is consumed, the bottom plate of the first paper storage unit is lowered, and when the bottom plate is lowered to a predetermined position, the guide of the second paper storage unit is changed. A paper feeding device is described in which a bundle of paper is collectively transferred from the second paper storage unit to the first paper storage unit by moving in the direction of one paper storage unit.

JP 2004-262606 A

  However, the paper feeder disclosed in Patent Document 1 detects a paper end sensor 27 that detects that the paper in the first paper storage unit has been consumed, and detects that the bottom plate of the first paper storage unit has been lowered to a predetermined position. There are many sensors such as the descent detection sensor 20 and the home sensor 39 and the push-in sensor 40 of the second paper storage unit for detecting the position of the guide for moving the sheet bundle from the second paper storage unit to the first paper storage unit. It is installed. If a large number of sensors are required in the paper feeder, the number of parts increases, which not only increases costs, but also requires space for sensor installation. It will also be.

  Therefore, the present invention provides a sheet feeding apparatus capable of accommodating a large capacity capable of reducing cost by minimizing the number of sensors and ensuring a degree of design freedom, and an image forming apparatus using the same. The purpose is to do.

  In order to solve the above-described problem, a paper feeding device according to the present invention feeds a stacked paper sheet one by one from the upper surface while raising the stacked paper sheet, and stacks and stores the paper sheets, and the first paper storage section. A bottom plate that is supported so as to be movable in the vertical direction, a first drive unit that moves the bottom plate up and down, and a second paper storage unit that is provided adjacent to the first paper storage unit and that stacks and stores paper. A moving member that is provided in the second paper storage unit and supported so as to be movable in the horizontal direction, and that the paper loaded in the second paper storage unit is moved from the second paper storage unit to the first paper storage unit. A second drive unit that horizontally moves the moving member, and is provided so as to be rotatable about an axis perpendicular to both the vertical direction in which the bottom plate moves and the horizontal direction in which the moving member moves, and contacts the moving bottom plate or moving member. Detection unit whose angle is changed by doing And a sensor that detects the rotation angle of the detection member, and a control unit that detects the positions of the bottom plate and the moving member based on the output of the sensor indicating the rotation angle of the detection member, and controls the first and second drive units. Is provided.

  Further, the rotation angle of the detection member is changed by contacting the bottom plate, and the control unit detects that the bottom plate is at the lower limit position based on the output of the sensor indicating the rotation angle of the changed detection member. May be.

  Further, the rotation angle of the detection member is changed by contacting the movement member, and the control unit is configured such that the movement member is moved from the second sheet storage unit to the first based on the output of the sensor indicating the changed rotation angle of the detection member. It may be possible to detect that the sheet is in a transfer completion position where the transfer of the sheet to the storage unit is completed.

  According to the present invention, since the number of sensors can be reduced as compared with the conventional sheet feeding device capable of accommodating a large capacity, the cost can be reduced and the degree of design freedom can be secured.

The figure which shows the whole structure of an image forming apparatus Top view of the paper feeder Cutaway view of the paper feeder Explanatory diagram showing operations relating to detection of the lower limit position of the bottom plate and the paper transfer completion position Explanatory drawing showing the paper transfer operation of the paper supply device Control flowchart of paper feeder

<Overall configuration>
Hereinafter, an embodiment of a paper feeding device according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows the internal structure of an electrophotographic copying machine equipped with a paper feeder according to the present invention. The image forming apparatus includes a main body 1 including a control unit 90 that controls the whole, an image forming unit 10, a reading unit 20, and a paper feeding unit 50 that is a paper feeding device according to the present invention.

  The control unit 90 includes a CPU (Central Processing Unit), and controls the sheet feeding unit 50 as a sheet feeding apparatus and the entire image forming apparatus.

  The image forming unit 10 includes a charging charger 12, a laser exposure unit 21, a developing device 13, a transfer roller 14, a residual toner cleaner 15, and the like around a photosensitive drum 11 that rotates in the direction of arrow a. The image forming process in the image forming unit 10 is well known, and details thereof are omitted.

  The sheets are fed one by one from the sheet feeding unit 50 described in detail below based on the rotation of the sheet feeding roller 51. The fed paper is immediately separated into one sheet by the rolling roller 32 and conveyed to the timing roller 35 through the vertical conveyance path 33, where it is synchronized with the photosensitive drum 11 and sent to the transfer unit. After the transfer, the sheet is fed into the fixing device 37, where the toner image is fixed, and is discharged from the discharge roller 38 onto the tray 16.

<Paper feeder>
Next, the paper feeding unit 50 will be described with reference to FIGS. 2 is a plan view of the paper feed unit 50 as viewed from above, and FIG. 3 is a cross-sectional view of the paper feed unit 50 of FIG. 2 as viewed from a cross section taken along the chain line XX.

  As shown in FIG. 3, rails 4, 4 are provided on both outer sides of the housing 55 of the paper feed unit 50, and the rails 4, 4 provide a front side of the main body 1, that is, in a direction orthogonal to the paper transport direction P. It can be pulled out. The replenishment of the paper into the housing 55 is performed with the paper feeding unit 50 pulled out from the main body 1.

  The sheet feeding unit 50 generally includes a lift 52 which is a bottom plate of the first sheet storage unit juxtaposed in the sheet conveyance direction P in the housing 55, a sheet placement table 53 as a second sheet storage unit, and the sheet placement table 53. And a shifter 60 as a transfer member that slides the sheet bundle onto the lift 52. In the state where the lift 52 is lowered, the upper surface of the sheet placing table 53 and the upper surface of the lift 52 are flush with each other.

  A sheet bundle S1 is loaded on the lift 52 (see FIG. 1), and the lift 52 rises as the number of sheets decreases, and presses the uppermost surface of the sheet bundle S1 against the sheet feeding roller 51. A sheet bundle S <b> 2 is stacked on the sheet mounting table 53. When all the sheets on the lift 52 are fed, the lift 52 is lowered to the lower limit position. When the lift 52 is lowered to the lower limit position and is flush with the paper stacking base 53, the shifter 60 moves in the paper transport direction P and slides the paper bundle S2 on the paper stacking base 53 onto the lift 52. ing.

  First, the lift 52 will be described. The lift 52 is a plate-like table that can be moved up and down by a lifting mechanism including a pulley and a wire (not shown), and has an opening 56 at the most downstream position in the paper transport direction P. The lift 52 rises when the motor M1, which is the first drive unit, rotates in the forward direction, and descends due to the reverse rotation. Above the lift 52 at the upper end of the housing, a lift upper limit sensor 71 composed of an optical sensor is installed. A swingable shading plate (not shown) is pushed up by the sheet bundle S1 on the lift 52 to shield the optical axis of the lift upper limit sensor 71, and an ON signal is output from the lift upper limit sensor 71 to detect the upper limit of the lift. . If the upper limit of the lift is detected, the forward rotation of the motor M1 is turned off and the lift is stopped. As a result, the uppermost part of the sheet bundle is pressed against the sheet feed roller 51, and the sheet can be fed. In addition, an empty sensor 72 composed of an optical sensor is provided in the vicinity of the lift upper limit sensor 71. The empty sensor 72 detects whether or not the sheet is on the lift at the lift upper limit position. When the sheet runs out, a filler (not shown) of the empty sensor 72 falls into the opening 56 of the lift 52, thereby blocking the optical axis of the empty sensor and outputting an ON signal. While the sheet is on the lift 52, the empty sensor 72 is off because the filler is lifted by the sheet. On the other hand, a lift empty sensor 73, which is a reflective optical sensor, is provided below the lift 52 and on the bottom surface of the housing. The lift empty sensor 73 detects whether or not the sheet is on the lift other than the lift upper limit position. The lift empty sensor 73 projects light toward the opening 56 of the lift 52 and receives the reflected light to detect the presence or absence of paper. When the paper is stacked on the lift 52, the light reflected on the paper enters the lift empty sensor 73 and is turned off. When the paper is not stacked, the light is turned on without receiving the reflected light. A signal is output. Further, a lift lower limit / transfer completion sensor 76 is provided below the lift 52 and in the vicinity of the paper placing table 53, and detects that the lift 52 is at the lower limit position. The lift lower limit / transfer completion sensor 76 also detects the transfer completion position of the shifter 60. The lift lower limit / transfer completion sensor 76 will be described in detail later.

  The paper placement table 53 is formed by a part of the bottom surface of the housing 55, and the inside of the paper placement table 53 is hollow so that the shifter 60 can move, and two slits 57 and 57 are formed along the paper conveyance direction P. Has been. A paper empty sensor 75 is provided on the upper surface of the paper placing table 53. The sheet empty sensor 75 is turned on when the actuator is pushed in by placing a sheet bundle on top. Thereby, it is detected whether or not a sheet is placed on the sheet placing table 53.

  Next, the shifter 60 will be described. The shifter 60 is generally composed of two rods 63 and 63 for moving the paper and a base plate 61 to which the rods 63 and 63 are fixed. The position of the shifter 60 is determined by the home sensor 74 and the lift lower limit / shift. It is detected by the loading completion sensor 76.

  In the shifter 60, two rods 63, 63 project from a base plate 61 extending in a direction orthogonal to the paper transport direction P, and the two rods 63, 63 are parallel to the base plate 61. The rod connector 64 is connected to the inside of the sheet placing table 53 by an extending rod connector 64. The base plate 61 can be moved in the paper transport direction P and in the opposite direction by a moving mechanism including a pulley and a wire (not shown). The moving mechanism moves the base plate 61 by driving the motor M2, which is the second driving unit, to rotate forward / reversely. The two rods 63, 63 are provided on the inner surface of the housing 55 with a home sensor 74 that detects whether or not the position on the most upstream side in the paper transport direction P is the home position, that is, the initial position. . The home sensor 74 is turned on when an actuator protruding from the housing 55 is pushed on the back surface of one rod 63, and it is detected that the shifter 60 is in the home position. The two slits 57, 57 of the paper mounting table 53 are formed at positions corresponding to the rods 63, and the rods 63, 63 are conveyed along with the base plate 61 along the slits 57, 57 by the forward rotation of the motor M2. The direction P moves from the upstream side to the downstream side. An interlocking member 67 slidably attached in the paper transport direction P is provided near the lower limit of lift / transfer completion sensor 76 and below the paper placement table 53. The interlocking member 67 plays a role of turning on and off a lift lower limit / transfer center 76 described later.

<Lift lower limit / transfer completion sensor and actuator>
Next, referring to FIG. 4, a lift lower limit / transfer completion sensor 76 and an actuator 80 for operating the lift lower limit / transfer completion sensor shared to detect the lower limit position of the lift 52 and the transfer completion position of the sheet by the shifter 60 are used. Will be described.

  The actuator 80 has a light shielding plate 81 that is rotatable about a support shaft 82 provided in the housing 55, and the light shielding plate 81 is attached in a clockwise direction (in the direction of arrow A in the figure) about the support shaft 82. It is energized. The light shielding plate 81 has a protruding portion 81a. When the lift 52 is raised, the light shielding plate 81 is locked with the protruding portion 81a of the light shielding plate 81 protruding upward. The lift lower limit / transfer completion sensor 76 is configured to be turned on when the light transmission of the light emitting diode is blocked. When the lift 52 is raised, the lift lower limit / transfer completion sensor 76 is turned off in the light transmission state (see FIG. 4 (1)).

  When the lift 52 is lowered, the bottom back surface 52 a pushes down the protruding portion 81 a of the light shielding plate 81 against the urging force of the light shielding plate 81. The light shielding plate 81 rotates counterclockwise (arrow B in the figure), and blocks light transmission of the light emitting diode of the lift lower limit / transfer completion sensor 76. Thereby, the lift lower limit / transfer completion sensor 76 is turned on, and it is detected that the lift 52 is at the lower limit position, and the lift 52 stops (FIG. 4 (2)). When the lift 52 is lowered to the lower limit position, the upper surface 52b of the lift 52 and the upper surface of the paper mounting table 53 are aligned at substantially the same height, so that the sheet bundle S2 is batched from the paper mounting table 53 to the upper surface 52b of the lift 52. Thus, the slide can be transferred.

  An interlocking member 67 is provided in the vicinity of the lift lower limit / transfer center 76 and at the lower part of the paper placement table 53. The interlocking member 67 is slidably attached in the paper transport direction P. When the shifter 60 moves toward the downstream side in the paper transport direction P and transports the paper bundle S2 to the lift 52, the two shifters 60 are moved. The rod 63 is pushed into the lower bottom surface of the lift 52 by a rod connector 64 that couples the rod 63. When the interlocking member 67 is pushed toward the downstream side in the paper transport direction P, the tip of the interlocking member 67 abuts against the light shielding plate 81 of the actuator 80 and further rotates the light shielding plate 81 counterclockwise (arrow B in the figure). Move. Then, the light emitting diode of the lift lower limit / transfer completion sensor 76 becomes translucent again and turns off, and it is detected that the shifter is at the transfer completion position. Then, the shifter 60 stops (FIG. 5 (3)).

  Thus, in the present embodiment, the lower limit position of the lift 52 and the completion position of the sheet bundle transfer operation by the shifter 60 are shared by one sensor.

<Transfer action>
A transfer operation from the paper stacking base 53 to the lift 52 in the paper supply unit 50 will be described with reference to FIG.

  In the paper feeding unit 50, a sheet bundle S1 is placed on a lift 52, and a sheet bundle S2 is placed on a sheet placing base 53. The uppermost sheet of the sheet bundle S1 is picked up by the sheet feeding roller 51 and conveyed one by one by the separating roller 32. When the lift upper limit sensor 71 is turned off along with the decrease in the sheet bundle S1, the lift 52 rises when the motor M1 rotates forward and stops when it is turned on, so that the uppermost surface of the sheet bundle S1 is fed to the paper feed roller 51. Press contact. (FIG. 5 (1)).

  When the empty sensor 72 detects that all the sheet bundles S1 on the lift 52 have disappeared, the motor M1 reverses and the lift 52 descends. When the protrusion 81a of the actuator 80 is pushed and rotated by the bottom rear surface of the lift 52 and the lift lower limit / transfer completion sensor 76 is turned on, it is determined as the lower limit position, and the lift 52 stops. (FIG. 5 (2)).

  Next, when the lift lower limit / transfer completion sensor 76 is turned on, the motor M2 rotates forward and the shifter 60 moves in the paper transport direction P. As a result, the sheet bundle S2 is collectively transferred onto the lift 52 while being pushed out by the two rods 63 and 63. (FIG. 5 (3)).

  The rod connector 64 (FIG. 2) that couples the rods 63, 63 of the shifter 60 pushes the interlocking member 67 in the paper transport direction P, whereby the actuator 80 of the lift lower limit / transfer completion sensor 76 is turned off. Then, it is determined that the transfer is completed, the motor M2 is stopped, and the shifter 60 is stopped (FIG. 5 (4)).

  When the lift lower limit / transfer completion sensor 76 is turned off, the motor M1 rotates forward and the lift 52 starts to rise (FIG. 5 (5)), and the upper limit is detected when the lift upper limit sensor 71 is turned on. The motor M1 stops and the lift 52 stops. At the same time, when the motor M2 rotates in the reverse direction, the shifter 60 moves from the upstream side to the downstream side in the paper transport direction P, that is, toward the initial position (FIG. 5 (6)), and the home sensor 74 is turned on. Stop (FIG. 5 (7)).

<Transfer control>
By the way, when the power source of the main body 1 is turned on or when the paper feeding unit 50 is once pulled out of the main body 1 for paper feeding and set again in the main body 1, the positions of the lift 52 and the shifter 60 may not be specified. is there. For example, when the home sensor 74 is off and the lift lower limit / transfer completion sensor 76 is off, it is unclear which of the following cases is.
When the lift 52 is at the lower limit position and the shifter 60 is at the transfer completion position (see FIG. 5 (4)).
The lift 52 is not in the lower limit position, and the shifter 60 is in the transfer completion position (see FIG. 5 (5)).
The lift 52 is not in the lower limit position, and the shifter 60 is not in the transfer completion position (see FIG. 5 (6)).
Therefore, in order to detect which case, in the present embodiment, when the power source of the main body 1 is turned on, and the paper feeding unit 50 is once pulled out of the main body 1 for paper feeding or the like, and again the main body 1 When set to 1, control is performed to drive the motor M2 for a predetermined time in order to move the shifter 60 by a predetermined amount from the downstream side in the paper transport direction P to the upstream side. The predetermined amount is an amount by which the interlocking member 67 can return to the initial position by moving the shifter 60 from the downstream side to the upstream side in the paper transport direction P if the shifter 60 is at the transfer completion position. It is. If the interlocking member 67 returns to the initial position, if the lift 52 is not at the lower limit position, the light shielding plate 81 rotates to the position shown in FIG. 4 (1), and the lift lower limit / transfer completion sensor 76 is turned off. When the lift 52 is at the lower limit position, the light shielding plate 81 is rotated to the position shown in FIG. 4B, and the lift lower limit / transfer completion sensor 76 is turned on. Accordingly, it can be determined whether or not the lift 52 is at the lower limit position.

  Hereinafter, processing executed by the control unit when the power is turned on or when the paper feeding unit 50 is pulled out from the main body 1 for paper feeding or the like and set to the main body 1 again will be described with reference to FIG. explain. FIG. 6 is a flowchart of processing executed by the control unit 90.

  When the power is turned on or the paper feeding unit 50 is set in the main body 1, it is determined in step S1 whether or not the home sensor 74 is turned on, that is, whether or not the shifter 60 is in the initial position. .

  If the home sensor 74 is not turned on (No in step S1), the process proceeds to step S2, and the motor M2 is reversely rotated by a predetermined count, so that the shifter 60 approaches the initial position from the downstream side in the paper transport direction P to the upstream side. Move to a predetermined amount. Then, the process proceeds to step S3.

  If the home sensor 74 is turned on (Yes in step S1), the process proceeds to step S3 as it is.

  In step S3, it is determined whether or not the lift lower limit / transfer completion sensor is turned on. If it is on (Yes in step S3), it is determined that the lift 52 is at the lower limit position, and the process proceeds to step S4.

In step S4, it is determined whether or not the lift empty sensor 73 is turned on.
If it is on (Yes in step S4), it can be determined that the lift 52 is empty and has no paper. Next, the process proceeds to step S5.

  In step S5, the motor M2 is driven to move the shifter 60 toward the downstream side in the paper transport direction P, and the process proceeds to step S6.

  In step S6, it is determined whether or not the lift lower limit / transfer completion sensor 76 is turned on. If it is turned on (Yes in step S6), the sensor 76 is in a light-shielded state and the shifter 60 has not yet reached the transfer completion position, so the process returns to step S5. If it is not turned on (No in step S6), it can be seen that the sensor 76 is in a light-transmitting state, that is, the shifter 60 has reached the transfer completion position, so that the process proceeds to step S7, the motor M2 is stopped, Let Next, go to step 8.

  In step S8, it is determined whether or not the lift upper limit sensor 71 is turned on. If the lift upper limit sensor is not turned on (NO in step S8), the process proceeds to step S9, the motor M1 is rotated forward to raise the lift 53, and the process returns to step S8.

  If the lift upper limit sensor 71 is turned on in step S8 (Yes in step S8), the process proceeds to step S10, where the motor M1 is stopped and the lift 52 is stopped. Next, the process proceeds to step 11.

  In step S11, it is determined whether or not the home sensor 74 is turned on. If it is not turned on (No in step S11), the shifter 60 is not in the initial position, so the motor M2 is driven to move toward the upstream side in the paper transport direction P. If the home sensor 74 is turned on in step S11 (Yes in step S11), it is known that the shifter 60 is in the initial position, so the motor M2 is stopped, the shifter 60 is stopped, and the process ends.

  If it is determined in step S3 that the lift lower limit / transfer completion sensor is not on (No in step S3), the process proceeds to step S15. In this case, the lift 52 is not in the lower limit position and is in a floating state.

  In step S15, it is determined whether or not the lift empty sensor 73 is turned on. If it is off, it can be seen that there is paper in the lift 52. Next, the process proceeds as described above with steps S8 to S13, and the process ends.

  If the lift empty sensor 73 is turned on in step S15 (Yes in step S15), it is found that there is no paper in the lift 53, so the process proceeds to step S16, the motor M1 is reversed and the lift 53 is lowered. Then, the process proceeds to step S17.

  In step S17, it is determined whether or not the lift lower limit / transfer completion sensor 76 is turned on. If it is not turned on (No in step S17), the lift 53 is not yet in the lower limit position, and the process returns to step S16. If it is turned on (Yes in step S17), it is determined that the lift 53 is at the lower limit position, the motor M1 is stopped, and the lift 53 is stopped. Then, the process returns to step S5.

  As described above, in the present invention, since the transfer completion position of the shifter 60 and the lower limit position of the lift 53 can be detected by one sensor, the number of sensors can be reduced, and the cost can be reduced. , Can increase the degree of design freedom.

  As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to this structure.

  The image forming apparatus may be a copying machine, a facsimile machine, a scanner, or a multifunction machine having these functions comprehensively. Instead of pushing the actuator 80 by the interlocking member 67, the actuator 80 may be pushed directly by one of the rods 63. Further, the determination based on on / off of the sensor may be reversed.

52: Lift 53: Paper placement table 60: Shifter 63: Rod 64: Rod connector 67: Interlocking member 74: Home sensor 76: Lift lower limit / transfer completion sensor 80: Actuator 90: Control unit

Claims (6)

A paper feeding device that feeds the stacked paper one by one from the top while raising the loaded paper,
A first sheet storage unit for storing and storing sheets;
A bottom plate provided in the first sheet storage unit and supported so as to be movable in the vertical direction;
A first drive unit for moving the bottom plate up and down;
A second paper storage section provided adjacent to the first paper storage section for stacking and storing paper;
A moving member provided in the second sheet storage unit and supported so as to be movable in the horizontal direction;
A second drive unit that horizontally moves the moving member to move the paper stacked in the second paper storage unit from the second paper storage unit to the first paper storage unit;
It is provided so as to be rotatable about an axis orthogonal to both the vertical direction in which the bottom plate moves and the horizontal direction in which the moving member moves, and the angle is changed by contacting the moving bottom plate or the moving member. A detection member;
A sensor for detecting a rotation angle of the detection member;
And a control unit that detects the positions of the bottom plate and the moving member based on the output of the sensor indicating the rotation angle of the detection member and controls the first and second driving units. Paper device. The rotation angle of the detection member is changed by contacting the bottom plate,
2. The sheet feeding device according to claim 1, wherein the control unit detects that the bottom plate is in a lower limit position based on an output of the sensor indicating the changed rotation angle of the detection member. The rotation angle of the detection member is changed by contacting the moving member,
The control unit is a transfer completion position at which the moving member completes transfer of the sheet from the second sheet storage unit to the first storage unit based on the output of the sensor indicating the changed rotation angle of the detection member. The sheet feeding device according to claim 1, wherein the sheet feeding device is detected. An initial position detecting unit for detecting whether or not the transfer member is in an initial position before starting the sheet transfer from the second sheet storage unit to the first sheet storage unit;
When the initial position detection unit detects that the transfer member is not in the initial position, the control means drives the second drive unit to move the transfer member by a predetermined amount in a direction approaching the initial position, Determining whether the bottom plate is in a lower limit position based on whether the output from the sensor changes;
The sheet feeding device according to claim 3. When the control means detects that the bottom plate is at the lower limit position, the control means drives the second drive unit to move the transfer member toward the transfer completion position, and then the transfer member moves to the transfer completion position. 5. The sheet feeding device according to claim 4, wherein when it is detected, the second driving unit is stopped to stop the transfer member. 6.   An image forming apparatus comprising the paper feeding device according to claim 1.

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