JP2019069848A - Sheet feeding apparatus, image reading apparatus, and image forming apparatus - Google Patents

Abstract

To provide a sheet feeding apparatus that suppresses noise generated at the time of sheet feeding and maintains accuracy of a standby position at the time of standby.SOLUTION: A sheet feeding apparatus includes: a first cam 200 capable of rotating and displacing a pickup roller 101 to a first phase of a feeding position and a second phase of a separating position; a second cam 300 rotating integrally with the first cam; drive transmission means having a one-way clutch that causes the first cam to transmit a drive force in a first direction, and does not transmit a rotational drive force in a second direction opposite to the first direction; and energization means for energizing the second cam so that the drive transmission from the motor causes the first cam to rotate in the first direction, and so that a rotational torque for rotating the first cam in the first direction is reduced, the rotational torque being generated by a pressing of a release link 109 when the first cam is displaced from the second phase to the first phase, energizing the second cam when a rotational torque is applied in the second direction to displace the second cam from the first phase to the second phase, applying a rotational torque in the first direction until the second cam reaches a predetermined phase, and applying a rotational torque in the second direction when the second cam rotates from the predetermined phase in the first direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet feeding apparatus for feeding a sheet, and an image reading apparatus and an image forming apparatus provided with the sheet feeding apparatus.

  As a sheet feeding apparatus mounted on the image forming apparatus, in addition to a structure for feeding a sheet from a sheet storage unit provided inside the image forming apparatus main body, a tray is provided on the side surface of the image forming apparatus main body. There is a configuration of a so-called manual feed tray system for feeding

  In the manual sheet feeding type sheet feeding apparatus, at the time of sheet feeding, the pickup roller abuts on the sheet on the tray, and the sheet is fed to the conveyance path by rotation of the pickup roller. There are various methods for the pickup roller and the sheet to abut, depending on the application and specifications. For example, there is a method in which a tray on which sheets are stacked moves to a pickup roller side and abuts, or a method in which a pickup roller supported by a lift plate moves to a sheet side and abuts a sheet along with the movement of the lift plate. Further, in recent years, in view of space saving, cost reduction, etc., a one-way clutch that allows rotation in only one direction is often used as a drive configuration adopted for the sheet feeding apparatus.

  Here, when the sheet feeding apparatus performs the feeding operation, a collision noise is generated as the pickup roller abuts on the sheet. On the other hand, in recent years, noise reduction at the time of operation of the image forming apparatus has been required. Therefore, particularly in the case of a manual sheet feeding type sheet feeding apparatus often provided on the side surface of the apparatus main body, it is essential to take measures to suppress the collision noise when the pickup roller collides with the sheet. In particular, in the configuration using a one-way clutch for the drive transmission system, the shaft may rotate faster than the rotation of the gear due to the characteristics of the one-way clutch, so it is necessary to take measures to suppress the collision noise between the pickup roller and the sheet. Become.

  On the other hand, Patent Document 1 describes a configuration for suppressing collision noise between a pickup roller and a sheet in a sheet feeding apparatus having a one-way clutch in a drive transmission system. Specifically, the rotational drive force of the drive source is transmitted to the first cam via the drive transmission system having a one-way clutch, and the lift plate supporting the pickup roller is rotated by the first cam to move the pickup roller from the sheet Move from the separated position to the abutting position. Also, the second cam integrally formed with the first cam is biased by the biasing means to apply a rotational torque in the direction opposite to the rotational direction of the first cam, whereby the pickup roller moves to a position where it abuts the sheet. Reduce energy at the time of Such a configuration reduces the collision noise when the pickup roller and the sheet abut.

  Further, in Patent Document 1, when moving the pickup roller to a position separated from the position where the pickup roller abuts against the sheet by the rotation of the first cam, the second cam is biased by the biasing unit, and the rotation direction of the first cam Apply rotational torque in the same direction. There is also described a configuration in which the biasing force of the biasing means acts as a force for assisting the rotation of the first cam.

JP, 2016-222457, A

  However, in the configuration of Patent Document 1, for example, when the first cam rotates while the load on the first cam of the lift plate is weaker than usual, such as when the tray is closed or when the pickup roller is lifted by the user. Problems can arise.

  That is, as described above, in the configuration of Patent Document 1, the biasing means biases the second cam when moving to a position separated from the position where the pickup roller contacts the sheet by the rotation of the first cam. Assists the rotation of the first cam. For this reason, when such an operation is performed in a state in which the load of the lift plate on the first cam is weaker than usual, the speed of the first cam is excessively increased by the biasing force of the biasing unit that biases the second cam. In this case, the first cam may stop at a position beyond the original position, and the gap between the pickup roller and the tray on which the sheet is stacked may be reduced, which may make it difficult to place the sheet on the tray.

  Therefore, it is an object of the present invention to suppress the noise generated at the time of sheet feeding and maintain the accuracy of the standby position at the time of standby even when using a one-way clutch as the drive transmission means for transmitting the drive from the drive source. It is an object of the present invention to provide a sheet feeding device that can do the same.

  In order to achieve this object, the sheet feeding apparatus according to the present invention rotates a feeding rotating body for feeding a sheet in contact with a stacked sheet, and a support member for supporting the feeding rotation body. A first cam member for moving the feeding rotary body to a feeding position for feeding the sheet by contacting the stacked sheet, and a separating position separated from the sheet, A first cam member which is rotatable and displaceable to a first phase for positioning the rotating body at the feeding position and a second phase for positioning the rotating body at the separated position; Drive transmission means for transmitting to the cam member, wherein the driving force for rotating the first cam member in the first direction is transmitted, and the driving force for rotating the first cam member in the second direction opposite to the first direction is transmitted Drive transmission means having a one-way clutch, and a first cam member The link member that presses and rotates the support member based on the rotation, the second cam member that rotates integrally with the first cam member, and the drive transmission from the drive source via the drive transmission means When the first cam member is rotated in the first direction and the first cam member is displaced from the second phase to the first phase, the first cam member is pressed by the link member. To urge the second cam member to apply a rotational torque in the second direction so as to reduce the rotational torque for rotating the first cam member in the first direction. When displacing from the second phase to the second phase, the second cam member is biased to apply rotational torque in the first direction until the second cam member reaches the predetermined phase, When rotating in the first direction from a predetermined phase, And biasing means for imparting a rotational torque of the second direction, and having a.

  According to the present invention, in the sheet feeding apparatus, even when the one-way clutch is used as the drive transmission means for transmitting the drive from the drive source, the noise generated at the time of sheet feeding is suppressed and the standby state at the standby time Position accuracy can be maintained.

FIG. 1 is a schematic cross-sectional view of an image forming apparatus. It is a schematic diagram of a tray feeding part. It is a figure explaining the composition of the gear which transmits drive to a tray feeding part. It is operation | movement explanatory drawing of a tray feeding part. It is operation | movement explanatory drawing of the 1st cam which a tray feeding part has. It is operation | movement explanatory drawing of the 2nd cam which a tray feeding part has. It is operation | movement explanatory drawing of the 1st cam which a tray feeding part has. It is operation | movement explanatory drawing of the 2nd cam which a tray feeding part has. It is operation | movement explanatory drawing of a tray feeding part. It is operation | movement explanatory drawing of a tray feeding part. It is operation | movement explanatory drawing of the 2nd cam which a tray feeding part has. FIG. 10 is an operation explanatory view of the tray feeding portion at the time of feeding operation. FIG. 14 is an operation explanatory view when moving to the separation position of the tray feeding unit. It is operation | movement explanatory drawing of the 2nd cam which a tray feeding part has. It is a graph which shows transition of the torque which acts on the multi cam which a tray feeding part has. FIG. 7 is a schematic view showing a configuration of a tray feeding portion when the tray is closed in a state where the pickup roller is at the feeding position. It is a schematic diagram for demonstrating the operation | movement of the tray feeding part in the state which the tray closed. It is a schematic diagram for demonstrating the operation | movement of the tray feeding part in the state which the tray closed. It is a schematic diagram for demonstrating the operation | movement of the tray feeding part in the state which the tray closed. It is a graph which shows the relationship between the phase of multicam, and a rotational speed.

  The configuration and image forming operation of the image forming apparatus A equipped with the sheet feeding apparatus according to the first embodiment of the present invention will be described below with reference to the drawings, and then the sheet feeding apparatus will be described.

First Embodiment
<Image forming apparatus>
As shown in FIG. 1, the image forming apparatus A supplies a sheet S that is a recording medium, an image forming unit that transfers a toner image to the sheet S, and a sheet supply unit that supplies the sheet S to the image forming unit. And a fixing unit configured to fix the toner image on the sheet S.

  The sheet stacking unit has a sheet storage unit 2 that stores the sheet S inside the image forming apparatus A main body. The sheet feeding apparatus further includes a tray feeding unit 1 (manual feeding tray) as a sheet feeding apparatus provided outside the apparatus main body at the time of image formation and allowing the user to load the sheet S on the tray 100 and feed the sheet S.

  The image forming unit includes a process cartridge 4, an intermediate transfer unit, and a laser scanner unit 9 which are attachable to and detachable from the main body of the image forming apparatus A. In the process cartridge 4, process cartridges 4y, 4m, 4c and 4k corresponding to yellow, magenta, cyan and black colors are arranged in a line. Further, each process cartridge 4 includes a photosensitive drum 5 (5y, 5m, 5c, 5k) as an image carrier, a charging roller 6 (6y, 6m, 6c, 6k), and a developing roller 7 (7y, 7m, 7c, 7k). Etc.).

  The intermediate transfer unit includes a primary transfer roller 17 (17y, 17m, 17c, 17k), an intermediate transfer belt 11, a drive roller 12, a tension roller 13, a secondary transfer opposing roller 14a, and a cleaning device 18. The intermediate transfer belt 11 is an endless cylindrical belt and is stretched by a drive roller 12, a tension roller 13, and a secondary transfer opposite roller 14a.

  In the image formation, when the control unit (not shown) issues a print signal, the sheet S stacked and stored on the sheet stacking unit by the feeding roller 3 or the pickup roller 101 is sent out to the sheet conveyance path. Thereafter, the sheet S is sent to the registration roller 10 via the conveyance roller 8. Here, when the sheet S rushes into the nip portion formed by the pair of registration rollers 10, the registration roller 10 is stopped. Then, the conveyance roller 8 pushes the sheet S into the nip portion, so that the sheet S is bent between the conveyance roller 8 and the registration roller 10, and the leading edge of the sheet S is corrected so as to be aligned at the same time. Then, after the leading edge of the sheet S is aligned, the registration roller 10 rotates and the sheet S is delivered to the image forming unit.

  On the other hand, in the image forming portion, first, the surface of the photosensitive drum 5 is charged by the charging roller 6. Then, the laser scanner unit 9 emits a laser beam from a light source (not shown) provided inside, and irradiates the laser beam onto the photosensitive drum 5. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 5. The electrostatic latent image is developed by the developing roller 7 to form a toner image on the photosensitive drum 5. The toner image formed on the photosensitive drum 5 is primarily transferred onto the intermediate transfer belt 11 by applying a transfer bias to the primary transfer roller 17. The intermediate transfer belt 11 is rotated by the driving roller 12 receiving a driving force from a driving source such as a motor (not shown). The primary transferred toner image reaches the secondary transfer portion formed by the secondary transfer opposite roller 14a and the secondary transfer roller 14b located downstream in the rotational direction by the rotation of the intermediate transfer belt 11, where the toner image is formed. The sheet S is transferred.

  The sheet S on which the toner image has been transferred is sent to the fixing device 15, and is heated and pressurized to fix the toner image on the sheet S. Then, the sheet S is conveyed by the discharge roller 16 and discharged to the discharge unit.

<Sheet feeding device>
Next, the overall configuration and operation of the tray feeding unit 1 as a sheet feeding apparatus will be described.

  As shown in FIG. 2, the tray feeding unit 1 has a pickup roller 101 (feeding rotary member) that takes in the sheet S stacked on the tray 100. Further, the sheet feeding roller 102 feeds the sheet S taken in by the pickup roller 101 to the sheet conveyance path. In addition, in order to avoid double feeding of the sheet S, a separation roller 103 is provided which rotates in a direction opposite to the sheet conveying direction to separate the overlapped sheet S.

  The tray 100 is configured to be able to open and close with respect to the main body of the image forming apparatus A. The user places the sheet S on the tray 100 with the tray 100 opened. When the tray 100 is closed, the pickup roller 101 and the like are also accommodated inside the main body of the image forming apparatus A. The configuration in a state where the tray 100 is closed will be described later.

  The feed roller 102 is rotatably provided on a feed roller shaft 102 a supported by a multi frame (not shown). Further, an elevating plate 106 as a supporting member for supporting the pickup roller 101 is also rotatably provided on the feeding roller shaft 102a. As a result, with the rotation of the lift plate 106, the pickup roller 101 moves to the feeding position at which the pickup roller 101 abuts the sheet S or to the separating position separated from the feeding position. The pickup roller 101 is rotatably provided on a pickup roller shaft 101a supported by the lift plate 106.

  The lift plate 106 is controlled to rotate by the first cam 200 of the multi cam 108 via the release link 109 (link member). The multi cam 108 is rotatably provided on the multi cam shaft 108 a, and the first cam 200 (first cam member) and the second cam 300 (second cam member) are integrally formed. Therefore, the first cam 200 and the second cam 300 rotate integrally. Although it is desirable that the first cam 200 and the second cam 300 be integrally formed from the viewpoint of cost reduction, they may be separately formed as long as they are interlocked to rotate.

  The feed roller shaft 102a and the feed roller 102 are synchronized in rotation by a coupling member (not shown). Also, the rotation of the pickup roller 101 shaft is synchronized with that of the pickup roller 101 as well. In addition, the rotation of the multi cam 108 and the multi cam shaft 108 a is similarly synchronized.

  Further, the separation roller 103 is rotatably provided on the separation roller shaft 103 a supported by the separation roller holder 107. The separation roller holder 107 is rotatably provided on a multi frame (not shown), and is pressurized by a pressure spring 112 provided between the multi frame and the separation roller holder 107. The rotation of the separation roller shaft 103 a is restricted by the rotation of the separation roller holder 107. Further, on the separation roller shaft 103a, a torque limiter 104 that is rotationally synchronized by a coupling member is provided.

<Drive part>
Next, the configuration of the drive unit of the tray feeding unit 1 will be described. The drive unit of the tray feeding unit 1 has a feeding gear 111, a cam gear 110, a motor (not shown), etc. as shown in FIG.

  The feed gear 111 (first gear) is provided on the end side of the feed roller shaft 102a (first shaft), and transmits the driving force of a motor (not shown) as a drive source. When the driving force of the motor is transmitted to the feeding roller shaft 102 a via the feeding gear 111, the driving force is also transmitted to the pickup roller shaft 101 a via the drive train 117. Therefore, the pickup roller 101 can rotate in synchronization with the rotation of the feed roller 102.

  Further, below the feed roller shaft 102a, there is a multi cam shaft 108a (second shaft) which is a rotational shaft of the multi cam 108, and at an end portion side of the multi cam shaft 108a, a cam gear 110 is engaged with the feed gear 111. (2nd gear) is attached. Therefore, when the feed gear 111 is driven by the motor to rotate, the drive is also transmitted to the cam gear 110 to rotate.

  Further, as shown in FIG. 3, a one-way clutch 111 OW is press-fitted at the center of the feed gear 111 so as to synchronize its rotation with the feed gear 111. Further, a one-way clutch 110 OW is press-fitted at the center of the cam gear 110 meshing with the feed gear 111 so as to synchronize the rotation with the cam gear 110.

  As shown in Table 1 below, the one-way clutch 111 OW and the one-way clutch 110 OW have a rotational driving force when the feeding gear 111 rotates in the WCC direction (first direction) shown in FIG. To communicate. On the other hand, when it rotates in the WC direction (the second direction), it spins without transmitting the rotational driving force. Similarly, when the cam gear 110 rotates in the VCC direction (first direction), the rotational drive force is transmitted to the multi cam shaft 108a, and when the cam gear 110 rotates in the VC direction (second direction), the rotational drive force is transmitted. I'm going to idle without you.

  The feed roller shaft 102a can rotate in the WCC direction faster than the feed gear 111 due to the characteristics of the one-way clutch. Similarly, the multi cam shaft 108a moves in the VCC direction faster than the cam gear 110. It can rotate.

<Spaced position>
Next, the configuration before the sheet feeding operation is performed and the relationship between the forces acting on the respective members in the state before the sheet feeding job is input will be described. At this time, the pickup roller 101 is at the separated position separated from the sheet S. In addition, since the motor is not driven and a moment for rotating the multi cam 108 is not generated as described later, the multi cam 108 does not rotate.

  First, the first cam 200, the release link 109, and the like that control the rotation of the lift plate 106 will be described. FIG. 4 is a cross-sectional view of the Y cross section shown in FIG. As shown in FIG. 4, a roller pressure spring 113 is attached between a wall surface 150 fixed to a multi frame (not shown) and the elevating plate 106, and the roller pressure spring 113 arrows the elevating plate 106. Energize in the P direction. As a result, a moment MG is generated which causes the lift plate 106 to rotate in the direction of the arrow G about the feed roller shaft 102a.

  FIG. 5 is an enlarged view of a DT3 area of FIG. As shown in FIG. 5, when a moment MG in the direction of arrow G is generated, the convex portion 106x provided on the lift plate 106 is moved toward the plate contact portion 109x provided on the release link 109 by the action of the moment MG. Force FH in the arrow H direction is generated. Then, when the convex portion 106x presses the plate contact portion 109x by the action of the force FH, a moment MI in the arrow I direction around the release link shaft 109a which is the axis of the release link 109 is generated. Then, due to the action of the moment MI, a pressing force FJ is generated in which the release link 109 presses the first cam 200 in the direction of the arrow J with the point M as a force point.

  Here, when the pickup roller 101 is at the separated position, this pressing force FJ is directed in the axial center direction of the multi cam shaft 108 a. Therefore, a moment for rotating the first cam 200 is not generated, and the first cam 200 is in the stop state.

  Next, the relationship between the brake lever 114 and the second cam 300 will be described. 6 is a cross-sectional view of the X cross section of FIG. As shown in FIG. 6, a tension spring 116 (spring member) attached to a multi-frame (not shown) is attached to the groove portion 115 on the brake lever 114 (contact member). The brake lever 114 is supported rotatably (movable) about the brake lever shaft 114a. Then, due to the tension FT in the direction of the arrow T of the tension spring 116, a moment MK which rotates in the direction of the arrow K around the brake lever shaft 114a is generated in the brake lever 114. Then, due to the action of the moment MK, the brake lever 114 generates a pressing force FL that presses the second cam 300 in the arrow L direction with the point N as a force point. The pressing force FL can also be considered as a biasing force that biases the second cam 300 via the brake lever 114 based on the elastic force of the tension spring 116.

  Here, when the pickup roller 101 is in the separated position, the pressing force FL is directed in the axial center direction of the multi cam shaft 108 a. Therefore, a moment for rotating the second cam 300 is not generated, and the second cam 200 is in the stop state.

  The above is the relationship between the configuration when the pickup roller 101 is in the retracted position and the force acting on each member. That is, the pressing force FJ that the release link 109 presses the first cam 200 and the pressing force FL that the brake lever 114 presses the second cam 300 are both in the axial direction. Also, the motor is not driven and the gears are not rotating. Therefore, the first cam 200 and the second cam 300 are in the stop state.

<Movement from separation position to feeding position>
Next, an operation when the feed job is input and the pickup roller 101 moves from the separation position to the feed position will be described. Here, the feeding position is a position where the pickup roller 101 abuts on the sheet S to perform the feeding operation. In the tray feeding unit 1, it is confirmed by the sheet sensor (not shown) that the sheet S is present on the tray 100, and the pickup roller 101 moves from the separation position to the feeding position when receiving a feeding job instruction. It is set to

  First, when a feed job command is input, a drive is transmitted from a motor (not shown) to the feed gear 111, and the feed gear 111 rotates in the direction of the arrow WC shown in FIG. Here, as described above, when the feed gear 111 rotates in the direction of the arrow WC, no drive is transmitted to the feed roller shaft 102a, so the feed roller shaft 102a does not rotate.

  On the other hand, due to the rotation of the feed gear 111 in the arrow WC direction, the cam gear 110 meshing with the feed gear 111 rotates in the arrow VCC direction. Then, as described above, when the cam gear 110 rotates in the arrow VCC direction, the drive is transmitted to the multi cam shaft 108 a, so the multi cam shaft 108 a also rotates in the arrow VCC direction. Then, the multi cam 108 rotates with the rotation of the multi cam shaft 108 a, and thereby the first cam 200 and the second cam 300 also rotate in the arrow VCC direction.

  Then, as shown in FIG. 7, when the first cam 200 rotates in the arrow VCC direction, the release link 109 rotates in the arrow I direction due to the shape of the cam. Then, with the rotation of the release link 109, the plate contact portion 109x moves in the direction away from the convex portion 106x. When the plate contact portion 109x moves in a direction away from the protrusion 106x, the protrusion 106x follows the movement of the plate contact portion 109x by the action of the moment MG. As a result, the lift plate 106 pivots in the direction of arrow G about the feed roller shaft 102 a, and the pickup roller 101 descends in the tray 100 direction.

  Here, when the first cam 200 rotates in the arrow VCC direction, the contact point between the plate contact portion 109x and the convex portion 106x gradually moves from the position of the contact point M to the position of the contact point M '. Along with this, the direction in which the release link 109 presses the first cam 200 changes from the arrow J direction (the axial center direction of the first cam 200) to the arrow J 'direction.

  As described above, when the release link 109 presses the first cam 200 in the direction of the arrow J ′, a rotational torque TVCC for rotating the first cam in the VCC direction (first direction) is generated. Therefore, the release link 109 is generated by pressing the first cam 200 in addition to the driving force transmitted from the motor via the feed gear 111 and the cam gear 110 as drive transmission means to the first cam 200. Both rotational torque TVcc in the direction of VCC will work.

  As described above, when the rotational torque TVCC other than the driving force transmitted from the motor acts on the first cam 200, the rotational speed at which the first cam 200 rotates based on the driving force of the motor due to the features of the one-way clutch described above. It rotates in the direction of VCC faster than it does. Therefore, the lift plate 106 is lowered at high speed, and the pickup roller 101 collides with the sheet S to generate a loud collision sound.

  Therefore, it is necessary to prevent the lifting plate 106 from falling at high speed due to the rotational torque TVCC. Therefore, in the tray feeding unit 1 according to the present embodiment, the brake lever 114 presses the second cam 300 to apply rotational torque in the VC direction (second direction), thereby reducing the rotational torque TVcc. The rotational speed of one cam 200 is reduced. This will be described in detail below.

  First, as shown in FIG. 8, when the driving force of the motor is transmitted and the multi cam shaft 108a rotates in the arrow VCC direction, the second cam 300 which rotates in synchronization with the multi cam shaft 108 a rotates in the arrow VCC direction. With the rotation of the second cam 300, the contact point between the second cam 300 and the brake lever 114 gradually moves from the contact point N to the position of the contact point N '. Along with this, the direction in which the brake lever 114 presses the second cam 300 changes from the arrow L direction (the axial center direction of the second cam 300) to the arrow L ′ direction.

  As described above, when the brake lever 114 presses the second cam 300 in the direction of the arrow L ', a rotational torque TMR in the direction of the arrow R centering on the multi cam shaft 108a is generated. The rotational torque TMR is a rotational torque in the opposite direction to the rotational torque TVCC generated by the release link 109 pressing the first cam 200. Therefore, by generating rotational torque TMR in this manner, rotational torque TVcc is reduced. Therefore, the rotational speed of the first cam 200 is reduced, the lowering speed of the lift plate 106 is reduced, and the collision noise when the pickup roller 101 and the tray or the sheet S collide can be suppressed.

  When the pickup roller 101 is moved from the feeding position to the retracted position, the brake lever 114 does not have to constantly press the second cam 300 in the direction of the arrow L ', and the above effect can be obtained if it is temporarily pressed. be able to. In addition, as the timing at which the brake lever 114 presses the second cam 300 in the direction of the arrow L ′, the second cam is positioned after the timing at which the first cam 200 is pressed by the release link 109 and the rotational torque TVCC is applied. It is preferred to form 300.

  Also, by pressing the second cam 300 in the direction of the arrow L 'by the brake lever 114, the rotational torque TVcc is reduced so that the rotational speed of the first cam 200 does not become faster than the rotational speed based on the driving force of the motor. Preferred.

  Next, an operation after the pickup roller 101 abuts on the sheet S on the tray 100 will be described. Even after the pickup roller 101 and the sheet S on the tray 100 abut, the motor is driven until the multi-position sensor (not shown) detects that the multi-cam 108 has reached a predetermined position. For this reason, the multi cam 108 rotates in the arrow VCC direction until the multi cam 108 comes to a predetermined position.

  Here, when the first cam 200 is further rotated in the VCC direction with the rotation of the multi cam 108, the plate contact portion 109x is further moved in the direction away from the convex portion 106x. On the other hand, since the pickup roller 101 is in contact with the sheet S, the lift plate 106 does not rotate, and the convex portion 106 x does not move in the direction of the plate contact portion 109 x. Therefore, as shown in FIG. 9, the convex portion 106x and the plate contact portion 109x completely separate from each other.

  Note that, as shown in FIG. 10, even when the sheet S is not stacked on the sheet stacking portion, the lift roller 106 does not rotate because the pickup roller 101 abuts on the tray 100, and the convex portion 106x is a plate. It can not move in the contact portion 109 x direction. Therefore, the convex portion 106x and the plate contact portion 109x completely separate at a predetermined timing.

  When the convex portion 106x and the plate contact portion 109x are completely separated as described above, the pressing force FJ with which the release link 109 presses the first cam 200 is a force by the action of the moment based on the weight of the release link 109. The pressing force FJ is directed in the axial direction of the first cam 200 when the multi-position sensor detects that the multi-cam 108 comes to a predetermined position and the pickup roller 101 is at the feeding position. Therefore, when the pickup roller 101 is at the feeding position, a moment for rotating the first cam 200 is not generated.

  On the other hand, with regard to the brake lever 114, when the second cam 300 further rotates in the VCC direction with the rotation of the multi cam 108, the brake lever 114 is pushed upward with this rotation. Along with this, the direction of the pressing force FL at which the brake lever 114 presses the second cam 300 gradually changes. When the multi-position sensor detects that the multi-cam 108 comes to a predetermined position and the pickup roller 101 is at the feeding position, the pressing force FL is directed in the axial direction, as shown in FIG. Therefore, when the pickup roller 101 is at the feeding position, a moment for rotating the second cam 300 by the pressing force of the brake lever 114 pressing the second cam 300 is not generated.

  A multi-position sensor (not shown) detects that the multi-cam 108 has reached a predetermined position, and when the pickup roller 101 comes to the feed position, the driving of the motor is stopped. Accordingly, the rotation of the multi cam shaft 108 a in the NCC direction also stops.

<Feeding operation>
Next, the sheet S feeding operation performed by the tray feeding unit 1 will be described.

  First, when the multi-position sensor detects that the multi-cam 108 has reached a predetermined position and detects that the pick-up roller 101 has come to the feed position, the motor is stopped once and then driven in the opposite direction to the previous one. start. Thus, the driving force in the direction of the arrow WCC shown in FIG. 12 is transmitted to the feeding roller shaft 102a through the feeding gear 111, and the feeding roller shaft 102a starts to rotate in the WCC direction. Further, the rotational driving of the feed roller shaft 102a is transmitted to the pickup roller 101 via the drive train 117 and the pickup roller shaft 101a, and the pickup roller 101 rotates in the arrow WCC direction. As a result, the sheet S at the top of the tray 100 is taken into the pickup roller 101, and is fed to the sheet conveyance path via the feeding roller 102.

  When the feed gear 111 rotates in the arrow WCC direction, the cam gear 110 rotates in the opposite direction VC. As described above, when the cam gear 110 is in the VC direction, the drive is not transmitted to the multi cam shaft 108 a by the action of the one-way clutch. Therefore, the lift plate 106 does not move up and down without the multicam 108 rotating during the feeding operation.

  During the feeding operation, the biasing force in the direction of arrow P by the roller pressure spring 113 acts as a force for pressing the sheet S.

<Movement from the feeding position to the separated position>
Next, an operation when the pickup roller 101 moves from the feeding position to the separating position will be described. When the feeding operation is completed, the motor starts driving in the opposite direction to the feeding operation, and the rotational force in the direction of the arrow WC shown in FIG. 3 is transmitted to the feeding gear 111. As a result, the drive is transmitted to the multi cam shaft 108 a through the cam gear 110 as described above, and the multi cam shaft 108 a rotates in the VCC direction shown in FIG. 3. On the other hand, as described above, since the feed gear 111 is idled, the drive from the motor is not transmitted to the feed roller shaft 102a.

  Next, as the multi cam shaft 108 a rotates in the VCC direction, the first cam 200 rotates in the VCC direction in synchronization with this rotation. When the first cam 200 rotates in the VCC direction, as shown in FIG. 13, the release link 109 starts to rotate in the arrow O direction while being pushed up. As a result, the plate contact portion 109x and the convex portion 106x which are separated during the feeding operation gradually come close to contact again.

  When the first cam 200 further rotates, the plate contact portion 109x presses the convex portion 106x, and the lift plate 106 rotates in the arrow V direction shown in FIG. As a result, the lift plate 106 is raised and the pickup roller 101 is moved to the separated position.

  On the other hand, with regard to the second cam 300, when the multi cam shaft 108a rotates in the arrow VCC direction, the second cam 300 rotates in the arrow VCC direction in synchronization with this rotation. When the second cam 300 rotates in the direction of the arrow VCC, as shown in FIG. 14, the contact point between the second cam 300 and the brake lever 114 changes based on the shape of the cam. Along with this, the brake lever 114 that has pressed the second cam 300 in the axial direction starts pressing the second cam 300 in the arrow L ′ ′ direction.

  As described above, when the brake lever 114 presses the second cam 300 in the arrow L ′ ′ direction, the rotational torque TW in the arrow W direction is applied to the second cam 300. The rotational torque TW is torque in the same direction as the VCC direction in which the multi cam 108 rotates due to the drive transmission from the motor. Therefore, the driving force necessary for the pickup roller 101 to return from the feeding position to the separating position is assisted, and the driving force from the motor necessary to raise the lift plate 106 can be reduced.

  When the pickup roller 101 moves to the feeding position, the brake lever 114 is pushed up by the second cam 300 as described above. Therefore, the tension FT of the tension spring 116 is larger when the pickup roller 101 is at the feeding position than at the separating position. For this reason, the force with which the brake lever 114 presses the second cam 300 in the direction of the arrow L ′ also becomes large, and the rotational torque TW becomes large. Therefore, the effect of reducing the driving force from the motor necessary to lift the lift plate 106 is improved.

  In addition, when the pickup roller 101 moves from the separated position to the feeding position, the brake lever 114 does not have to constantly press the second cam 300 in the direction of the arrow L ′ ′. You can get it. It is more preferable that the timing at which the brake lever 114 starts pressing the second cam 300 in the direction of the arrow L ′ be after the timing at which the lift plate 106 starts pivoting. Thus, when the brake lever 114 presses the second cam 300, the convex portion 106x and the plate contact portion 109x can be prevented from strongly colliding with each other, and noise can be suppressed.

  FIG. 15 is a graph showing the transition of torque in the direction of arrow VCC (see FIG. 7) acting on the multi cam 108 when the pickup roller 101 moves between the feeding position and the separating position. In this graph, the horizontal axis represents time, and the vertical axis represents the amount of torque. The solid line in the graph indicates the transition of the torque of the image forming apparatus A according to the present embodiment provided with the brake lever 114, and the broken line indicates the transition of the torque of the image forming apparatus according to the comparative example not having the brake lever 114. .

  First, time A of the graph is a transition of torque when the pickup roller 101 moves from the retracted position to the feeding position. At this time, in the image forming apparatus A according to the present embodiment, the rotational torque TVCC generated by the release link 109 pressing the first cam 200 and the torque MR generated by the brake lever 114 pressing the second cam 300. It is reduced by the action. Therefore, the torque acting on the multi cam 108 is suppressed to a relatively small value even when the torque transmitted from the motor is applied. On the other hand, since the image forming apparatus according to the comparative example does not have the brake lever 114, the rotational torque TVcc generated when the release link 109 presses the first cam 200 is not reduced but becomes a large value.

  Next, time B of the graph is a transition of torque when the pickup roller 101 moves from the feeding position to the retracted position. At this time, since the image forming apparatus A according to this embodiment has the brake lever 114, the rotational torque TW is applied in the same direction as the rotational direction VCC based on the driving force transmitted from the motor. Therefore, the torque acting on the multicam 108 is increased. On the other hand, since the image forming apparatus according to the comparative example does not have the brake lever 114, no torque is applied in the same direction as the rotational direction VCC based on the driving force transmitted from the motor. Therefore, the torque acting on the multicam 108 is reduced.

  Also from the above transition of torque, in the image forming apparatus A according to the present embodiment, when the pickup roller 101 moves from the separated position to the feeding position, the rotation of the lift plate 106 is decelerated, and the pickup roller 101 and the sheet S Collision noise was found to be suppressed. Further, it was found that the driving force required when the pickup roller 101 moves from the feeding position to the separating position can reduce the driving force transmitted from the motor.

<Operation of Tray Feeding Unit with Tray Closed>
The operation of the tray feeding unit 1 such as the movement of the pickup roller 101 described above is premised on a state in which the tray 100 is opened. However, when the tray 100 is closed, the first cam 200 may be rotated to shift the phase.

  The phase of the first cam 200 is displaced while the tray 100 is closed as described above, for example, in the following case. That is, in the state where the tray 100 is closed, when the phase of the first cam 200 is the phase for positioning the pickup roller 101 at the feeding position, the convex portion 106 x of the lift plate 106 and the plate contact portion 109 x of the release link 109 Are separated. When the user opens the tray 100 in this state, the lift plate 106 is rotated in the WCC direction about the feed roller shaft 102 a by the biasing force of the pressure spring 113. Then, the convex portion 106x of the lift plate 106 approaches the plate contact portion 109x, and the pickup roller 101 moves to the feeding position. In this case, the pickup roller 101 is in the way and the user can not set the sheet S on the tray 100. Therefore, in a state in which the tray 100 is closed, the phase of the first cam 200 is displaced from the phase where the pickup roller 101 is positioned at the feeding position to the phase where the pickup roller 101 is positioned at the separating position.

  Hereinafter, an operation of the tray feeding unit 1 when the multi cam 108 rotates with the tray 100 closed will be described. In the following description, the phase in which the first cam 200 positions the pickup roller 101 at the feeding position is referred to as a first phase, and the phase in which the first cam 200 is positioned at the separation position is referred to as a second phase. The first cam 200 is a member that can be rotated and displaced into a first phase and a second phase.

  First, the configuration of the tray feeding unit 1 when the tray 100 is closed with the pickup roller 101 in the feeding position will be described.

  FIG. 16 is a schematic view showing the configuration of the tray feeding portion 1 when the tray 100 is closed with the pickup roller 101 in the feeding position. As shown in FIG. 16, when the tray 100 is closed with the pickup roller 101 in the feeding position, the tray 100 abuts the pickup roller 101 or the lift plate 106, and the lift plate 106 is centered on the feed roller shaft 102a. Rotate in the WC direction. As a result, the pickup roller 101 moves upward.

  In the state where the tray 100 is closed, the movement trajectory of the plate contact portion 109x of the release link 109 is at a position where it does not interfere with the convex portion 106x of the lift plate 106. This is to allow the first cam 200 to be rotated and displaced to the second phase regardless of the phase of the first cam 200 when the tray 100 is closed. When the tray 100 is closed, the pickup roller 101 is restricted from moving by the tray 100.

  Next, the operation of the tray feeding unit 1 when the first cam 200 is rotated and displaced from the first phase to the second phase in a state where the tray 100 is closed will be described.

  First, the operation of the first cam 200 will be described. The first cam 200 is rotated in the direction of the arrow VCC by the transmission of rotational driving force of a motor (not shown), and is displaced from the first phase to the second phase. At this time, as described above, since the convex portion 106x of the lift plate 106 and the plate contact portion 109x of the release link 109 are separated, the load applied to the first cam 200 is sliding due to the rotation of the first cam 200. It is only a load. That is, when the first cam 200 is displaced from the first phase to the second phase with the tray 100 closed, the load on the first cam 200 by the lift plate 106 is weaker than in the normal state where the tray 100 is opened. The first cam 200 rotates.

  Next, the operation of the second cam 300 will be described. Since the first cam 200 and the second cam 300 are integrally formed as the multi cam 108, the second cam 300 rotates integrally with the first cam 200.

  FIG. 17 is a schematic view showing the relationship between the second cam 300 and the brake lever 114 when the first cam 200 is rotated and displaced from the first phase to the second phase with the tray 100 closed. is there. As shown in FIG. 17, when the second cam 300 rotates, the point at which the brake lever 114 abuts on the second cam 300 moves from point Z1 to point Z2. Thereby, a pressing force in the direction of the arrow Z2 'by the brake lever 114 is applied to the second cam 300. The pressing force in the direction of the arrow Z2 'is a rotational torque that causes the second cam 300 to rotate in the direction of the arrow VCC.

  As a result, rotational torque in the direction of arrow VCC based on the rotational driving force of a motor (not shown) and rotational torque in the direction of arrow VCC based on the pressing force in the direction of arrow Z2 'of the brake lever 114 are applied to the multicam 108. Here, by the action of the one-way clutch 110OX, the multi cam shaft 108a can rotate in the arrow VCC direction faster than the rotation of the cam gear 110. Therefore, when the rotational torque in the direction of arrow VCC is applied based on the pressing force of the brake lever 114, the multi cam 108 rotates faster than the rotational speed based on the rotational driving force of the motor.

  FIG. 18 is a schematic view showing the relationship between the second cam 300 and the brake lever 114 when the second cam 300 is further rotated from the state of FIG. As shown in FIG. 18, when the second cam 300 further rotates, the protrusion formed on the second cam 300 in a state where the second cam 300 rotates faster than the rotational speed based on the rotational driving force of the motor (not shown). The portion 300 a abuts on the brake lever 114.

  FIG. 19 is an enlarged view of a contact portion between the protrusion 300 a of the second cam 300 and the brake lever 114. As shown in FIG. 19, when the brake lever 114 abuts on the protrusion 300a at the point Z4, the pressing force with which the brake lever 114 presses the second cam 300 is in the direction of the arrow Z4 '. The pressing force in the direction of the arrow Z4 'is a rotational torque that causes the second cam 300 to rotate in the direction of the arrow VC. As described above, in a state where the brake lever 114 is in contact with the area from the point Z3 to the point Z5 of the protrusion 300a of the second cam 300, the pressing force with which the brake lever 114 presses the second cam 300 is the second cam 300. The rotation torque in the direction of the arrow VC.

  Thus, when the rotational torque for rotating the second cam 300 in the arrow VC direction is applied, the rotational torque in the VCC direction of the multicam 108 is reduced. As a result, the rotational speed of the multi cam 108 is reduced, and the rotational speeds of the first cam 200 and the second cam 300 are reduced. In this manner, after the brake lever 114 passes the projection 300 a of the second cam 300, the multi cam 108 returns to the rotational speed based on the rotational driving force of the motor (not shown).

  Thereafter, when the multi-position sensor (not shown) detects that the multi-cam 108 has come to the predetermined position, the driving of the motor is stopped and the rotation of the multi-cam 108 is also stopped. Specifically, when the multi-position sensor detects that the phase when the pickup roller 101 is positioned at the position farthest from the feeding position out of the second phase of the first cam 200, the driving source The driving is stopped and the rotation of the multi cam 108 is also stopped. That is, the phase when the protrusion 300a of the second cam 300 abuts on the brake lever 114 is the first phase of the first cam 300 and the position of the second phase that is most separated from the feeding position of the pickup roller 101. It is the phase between it and the phase when it is placed. The multi-position sensor is phase detection means for detecting the phase of the first cam 200, and a control unit (control means) (not shown) stops driving of the motor based on the detection result of the phase by the multi-position sensor.

  By thus decelerating the multicam 108, it is possible to stop the multicam 108 at its original position by suppressing excessive rotation of the multicam 108 when stopping the multicam 108. Therefore, it is possible to maintain the positional accuracy in the standby state in which the tray feeding unit 1 stands by for feeding the sheet S.

  The pressing force by which the brake lever 114 presses the second cam 300 can also be considered as a biasing force by which the tension spring 116 biases the second cam 300 via the brake lever 114 based on its elastic force. That is, the brake lever 114 and the tension spring 116 are biasing means for biasing the second cam 300.

  In addition, both members, which are biasing means, have a second phase until the brake lever 114 and the projection 300a of the second cam 300 abut each other when the first cam 200 is displaced from the first phase to the second phase. The cam 300 is energized to apply rotational torque in the direction of arrow VCC. Further, from the phase where the brake lever 114 and the projection 300a of the second cam 300 contact, when the first cam 200 further rotates in the arrow VCC direction, rotational torque in the arrow VC direction is applied to the second cam 300. In other words, when the first cam 200 is displaced from the first phase to the second phase, the second cam 300 is in a phase where the brake lever 114 and the projection 300 a of the second cam 300 come into contact with each other. The biasing force is a rotational torque in the direction of arrow VCC. Further, when the first cam 200 is further rotated in the arrow VCC direction from the phase in which the projection 300a of the second cam 300 contacts the brake lever 114, the biasing force is set to a rotational torque in the arrow VC direction. . When the first cam 200 is displaced from the first phase to the second phase, the biasing force applied to the second cam 300 is such that the first cam 200 has a second phase to a first phase. The elastic force stored in the tension spring 116 is included along with the movement of the brake lever 114 when it is displaced.

  FIG. 20 is a graph showing the relationship between the phase of the multicam 108 and the rotational speed. In the graph, the solid line shows the configuration of the present embodiment having the protrusion 300 a on the second cam 300, and the broken line shows the configuration of a comparative example having no protrusion 300 a on the second cam 300.

  As shown in FIG. 20, when the first cam 200 is displaced from the first phase to the second phase with the tray 100 closed, in the configuration of the comparative example, the second cam 300 has no protrusion 300a. The rotational torque in the direction of the arrow VC is not applied to the multi cam 108. Therefore, the multi cam 108 rotates faster than the rotational speed based on the rotational driving force of the motor.

  In this case, even when the drive of the drive source is stopped by detecting the first phase of the first cam 200 by a multi-position sensor (not shown), the multi-cam 108 rotates too much and exceeds the original position. It will stop. In this case, the gap between the pickup roller 101 and the tray 100 is smaller than originally required, and it becomes difficult to place the sheet S on the tray 100.

  On the other hand, in the configuration of the present embodiment, the pressing force of the brake lever 114 is made to be a rotational torque in the direction to reduce the rotational speed of the multi cam 108 by the projection 300 a of the second cam 300. For this reason, the rotational speed of the multi cam 108 returns to the rotational speed based on the driving force of the drive source. Therefore, the multi cam 108 can be stopped at the original position, and the positional accuracy in the standby state in which the tray feeding unit 1 stands by for feeding can be maintained.

  For example, an open / close sensor that detects the open / close of the tray 100 is provided, and the rotation operation of the multi cam 108 is performed only when the tray 100 is open. Thereby, when the first cam 200 is displaced from the first phase to the second phase in a state where the tray 100 is closed, the phenomenon that the rotational speed of the multi cam 108 becomes excessively fast due to the biasing force of the brake lever 114 is suppressed be able to. However, according to the configuration of the present embodiment, it is possible to suppress the phenomenon in which the rotational speed of the multicam 108 is excessively increased by the brake lever 114 with an inexpensive configuration without providing a new sensor.

  In addition, when the first cam 200 is displaced from the first phase to the second phase, the phenomenon that the rotational speed of the multi cam 108 becomes excessively fast due to the pressing force of the brake lever 114 corresponds to the multi cam 108 with the tray 100 closed. It can happen other than when it rotates. That is, for example, when the first cam 200 rotates with the load on the first cam 200 of the lift plate 106 being weaker than usual, such as when the pickup roller 101 is lifted manually by the user, such a phenomenon occurs. obtain. Therefore, even if the above configuration is applied not only to the manual sheet feeding type sheet feeding apparatus but also to the sheet feeding type of sheet feeding cassette type in which sheets are stacked inside the image forming apparatus A, the same effect as described above can be obtained. Can.

  Further, although the image forming apparatus A is illustrated as an apparatus for mounting the sheet feeding apparatus in the present embodiment, the present invention is not limited to this. That is, even if the image reading apparatus includes an image reading unit (image reading unit) that reads image information of a fed sheet as an electric signal and includes the sheet feeding apparatus according to the present invention, the effects of the present invention can be obtained. You can get it.

1 ... Tray feeding unit (sheet feeding device)
100 ... tray (bypass tray)
101: Pick-up roller (feed roller)
106: Lifting plate (supporting member)
109 ... Release link (link member)
110 OW: One-way clutch 111 OW: One-way clutch 114: Brake lever (abutment member, biasing means)
116 ... tension spring (spring member, biasing means)
First cam ... 200 (first cam member)
Second cam ... 300 (second cam member)
A: Image forming apparatus S: Sheet

Claims (11)

A feeding rotary member that feeds a sheet in contact with a stacked sheet;
A feeding position for feeding the sheet by bringing the feeding rotary body into contact with the stacked sheet by rotating a supporting member for supporting the feeding rotary body, and a separated position separated from the sheet A first cam member to be moved to the first position, wherein the first rotating member is rotatable and displaceable to a first phase for positioning the feeding rotary body at the feeding position and a second phase for positioning the feeding rotation body at the separated position. A cam member,
Drive transmission means for transmitting a drive force from a drive source to the first cam member, wherein the drive force for rotating the first cam member in a first direction is transmitted, and the first drive member is opposite to the first direction Drive transmission means having a one-way clutch that does not transmit the driving force to rotate in the two directions;
A link member that presses and rotates the support member based on the rotation of the first cam member;
A second cam member that rotates integrally with the first cam member;
When the first cam member is rotated in the first direction by drive transmission from the drive source through the drive transmission means, and the first cam member is displaced from the second phase to the first phase The second cam member is biased to reduce a rotational torque that causes the first cam member to rotate in the first direction, which is generated when the first cam member is pressed by the link member. When applying rotational torque in the direction 2 and displacing from the first phase to the second phase, the second cam member is biased to bring the second cam member into a predetermined phase. Biasing means for applying rotational torque in the first direction, and applying rotational torque in the second direction when rotating from the predetermined phase in the first direction;
A sheet feeding apparatus comprising: A feeding rotary member that feeds a sheet in contact with a stacked sheet;
A feeding position for feeding the sheet by bringing the feeding rotary body into contact with the stacked sheet by rotating a supporting member for supporting the feeding rotary body, and a separated position separated from the sheet A first cam member to be moved to the first position, wherein the first rotating member is rotatable and displaceable to a first phase for positioning the feeding rotary body at the feeding position and a second phase for positioning the feeding rotation body at the separated position. A cam member,
Drive transmission means for transmitting a drive force from a drive source to the first cam member, wherein the drive force for rotating the first cam member in a first direction is transmitted, and the first drive member is opposite to the first direction Drive transmission means having a one-way clutch that does not transmit the driving force to rotate in the two directions;
A link member that presses and rotates the support member based on the rotation of the first cam member;
A second cam member that rotates integrally with the first cam member;
Biasing means for biasing the second cam member to apply a biasing force;
Equipped with
The second cam member is rotated in the first direction by the drive transmission from the drive source through the drive transmission means, and the first cam member is rotated from the second phase to the second phase. The biasing force is set to reduce the rotational torque that causes the first cam member to rotate in the first direction, which is generated when the first cam member is pressed by the link member when displaced to the phase of 1. When the rotational torque is in the second direction, and the displacement from the first phase to the second phase, the biasing force is rotated in the first direction until the second cam member reaches a predetermined phase. A sheet feeding device having a shape in which the biasing force is a rotational torque in the second direction when rotating in the first direction from the predetermined phase as a torque.   The predetermined phase includes the first phase of the first cam member, and the phase of the second phase when the feeding rotary member is positioned at a position most distant from the feeding position. The sheet feeding device according to claim 1 or 2, wherein the sheet feeding device is in a phase between them.   When the first cam member is rotated and displaced from the first phase to the second phase, the biasing means adds the second cam member after the timing when the support member starts pivoting. The sheet feeding device according to any one of claims 1 to 3, wherein a rotational torque in the first direction is biased to be applied. The biasing means includes a movable contact member that contacts the second cam member, and a spring member that biases the contact member.
The biasing force for biasing the second cam member is an elastic force of the spring member applied to the second cam member via the contact member. The sheet feeding device according to item 1.   When the first cam member is displaced from the first phase to the second phase, the elastic force of the spring member applied to the second cam member via the contact member may The elastic force stored in the spring member is included according to the movement of the contact member when the cam member is displaced from the second phase to the first phase. Sheet feeding device.   The sheet feeding device according to any one of claims 1 to 6, wherein the first cam member and the second cam member are integrally formed. Phase detection means for detecting the phase of the first cam member;
Control means for controlling the drive of the drive source based on the detection result of the phase detection means;
The sheet feeding apparatus according to any one of claims 1 to 7, further comprising: A sheet feeding apparatus according to any one of claims 1 to 8.
Image reading means for reading sheet image information as an electrical signal;
Image reading apparatus characterized by having A sheet feeding apparatus according to any one of claims 1 to 8.
An image forming unit that transfers a toner image carried on an image carrier to a sheet to form an image;
An image forming apparatus comprising:   11. The image forming apparatus according to claim 10, wherein the sheet feeding apparatus feeds a sheet stacked on a tray configured to be openable and closable with respect to an apparatus main body of the image forming apparatus.

Images