JP2020040802A - Sheet feeding apparatus and image forming apparatus - Google Patents

Abstract

To quickly feed a sheet while enabling stable feeding of the sheet.SOLUTION: First feeding means (107) is disposed at a confluence of a conveying path of sheets fed from a placement unit (102) provided in a sheet storage unit (101) and a conveying path of sheets fed by second feeding means (121). First detecting means (1) detects that the first feeding means is at a feeding position between a lower position and an upper position. When the sheet storage unit is inserted into a device body, a lift-up operation is performed to raise the placement unit from a state in which the first feeding means is at the lower position to a state in which the first detecting means is in a detecting state. When feeding sheets from the placement unit after the lift-up operation, the first feeding means does not move from the feeding position, and when feeding sheets by the second feeding means, the first feeding means moves to the upper position.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a sheet feeding apparatus for feeding a sheet and an image forming apparatus for forming an image on a sheet.

  2. Description of the Related Art In an image forming apparatus, a sheet feeding apparatus that feeds a sheet used as a recording material can set a sheet at a plurality of positions, and a sheet conveyance path merges inside the sheet feeding apparatus. There is. In Japanese Patent Application Laid-Open No. H11-163, the conveying path of a sheet fed from a feeding cassette and the conveying path of a sheet fed from a manual feeding port are located near a feeding roller for feeding a sheet from the feeding cassette. Are described. In this device, when the feeding cassette is inserted into the main body, the loading plate supporting the sheets in the cassette is raised in a state where the feeding roller is retracted upward, and the position where the uppermost sheet is detected by the sensor is detected. , An initial operation is stopped. Thereafter, the feed roller descends and comes into contact with the sheet on the stacking plate, so that the feed roller sends out the sheet from the feed cassette.

Japanese Patent Application Laid-Open No. 2006-2222447

  By the way, in the case where the sheet is curved due to, for example, absorbing the moisture in the atmosphere, the initial operation may end in the configuration of Patent Literature 1 while the sheet remains curved. In this case, even if the feed roller is lowered, the sheet is deformed so as to be crushed by the feed roller, and there is a possibility that the pressing force of the feed roller against the uppermost sheet is insufficient. If the pressing force of the feeding roller is insufficient, even if the feeding roller rotates, a sufficient frictional force is not applied to the sheet, so that feeding failure may occur.

  For the feeding failure, the device described in Patent Document 1 uses a sensor for detecting the position of the feeding roller, and when the feeding roller is at a position lower than a predetermined position after the start of the feeding operation, the loading plate is moved. We deal with raising it. However, in the first feeding operation after the insertion of the feeding cassette, there is a possibility that a feeding failure occurs, so that the FPOT may be delayed. However, FPOT is an abbreviation for First Print Output Time and means the time required from the input of an image forming command to the image forming apparatus to the discharge of the first product.

  Therefore, an object of the present invention is to provide a sheet feeding device capable of feeding a sheet promptly while enabling stable feeding of the sheet.

  One embodiment of the present invention has a placement portion on which a sheet is placed, and a sheet storage portion inserted removably into the apparatus main body, and a sheet storage portion disposed above the placement portion and placed on the placement portion. A first feeding unit that feeds the placed sheet; and a second feeding unit that feeds the sheet from a position different from the placing unit. What is claimed is: 1. A sheet feeding apparatus in which a first feeding unit is arranged at a junction of a feeding path and a feeding path of a sheet fed by a second feeding unit, wherein the lifting unit moves the placement unit up and down. Moving means for moving the first feeding means between a lower position and an upper position above the lower position in the vertical direction; and wherein the first feeding means has the lower position in the vertical direction and A first detecting means capable of detecting that the feeding position is between the upper positions, Control means for controlling the elevating means and the moving means, wherein the control means is configured such that when the sheet storage unit in the pulled-out state is inserted into the apparatus main body, the first feeding means Lifting up the placing section in the state of being at the lower position, and stopping the placing section when the first detecting section detects that the first feeding means has moved to the feeding position. After performing the operation and performing the lift-up operation, when feeding a sheet from the placement unit, the first feeding unit is moved from the feeding position to the first feeding unit without moving the first feeding unit. When the sheet is fed by the second feeding unit after the sheet is fed and the lift-up operation is performed, before the leading edge of the sheet in the sheet conveying direction reaches the position of the first feeding unit. The first feeding means Serial is moved to the upper position, characterized in that.

  ADVANTAGE OF THE INVENTION According to this invention, a sheet can be fed promptly, enabling stable sheet feeding.

1 is a schematic diagram of an image forming apparatus according to a first embodiment. FIGS. 2A to 2C are schematic diagrams illustrating a configuration of a sheet feeding apparatus according to the first embodiment. FIG. 2 is a block diagram illustrating a control configuration of the sheet feeding apparatus according to the first embodiment. FIG. 2 is a perspective view of the feeding unit according to the first embodiment (a, b). FIG. 3A is a side view illustrating a cam shape of the feeding gear according to the first embodiment (a, b). 4A to 4C are schematic diagrams illustrating a relationship between a rotation angle of a feeding gear and an operation of a feeding unit according to the first embodiment. 4 is a flowchart illustrating the contents of stop state detection control according to the first embodiment. 5 is a flowchart illustrating the contents of an initial lift-up operation according to the first embodiment. 6 is a timing chart of an initial lift-up operation according to the first embodiment. 4A to 4C are schematic diagrams for explaining a sheet feeding operation from a sheet cassette according to the first embodiment. 4A to 4C are schematic diagrams for explaining a sheet feeding operation from a manual feed tray according to the first embodiment. FIG. 9 is a side view illustrating a feeding gear according to the second embodiment. 9 is a flowchart showing the contents of an initial lift-up operation according to the second embodiment. 9 is a timing chart of an initial lift-up operation according to the second embodiment.

  Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings.

  First, an image forming apparatus according to a first embodiment will be described. The image forming apparatus 10 of the present embodiment illustrated in FIG. 1 is an electrophotographic full-color laser beam printer. The image forming apparatus 10 includes an image forming unit 11 that forms an image on sheets P1 and P2 as recording materials, a sheet feeding device 100, and a fixing device 30. As recording materials, paper such as plain paper or cardboard, sheet material with surface treatment such as glossy paper or embossed paper, sheet material of special shape such as envelope, and sheet other than paper such as plastic film or cloth Wood can be used.

  The image forming unit 11 includes four process cartridges 11Y, 11M, 11C, and 11K that form toner images of four colors of yellow, magenta, cyan, and black, and a scanner unit 16. The process cartridge 11Y has a photosensitive drum 12, a charging roller 13, and a developing roller 14, and forms a toner image by an electrophotographic process. That is, after the surface of the photosensitive drum 12, which is a photosensitive member, is charged by the charging roller 13, the scanner unit 16 exposes the photosensitive drum 12 based on image information to write an electrostatic latent image on the drum surface. This electrostatic latent image is visualized by the toner supplied from the developing roller 14 to develop a yellow toner image.

  The above operation proceeds in parallel with the other process cartridges 11M, 11C, and 11K, and toner images of each color are formed on the photosensitive drum 12. These toner images are primarily transferred to an intermediate transfer belt 20 as an intermediate transfer body by a primary transfer roller 15. At this time, the toner images of each color are multiplex-transferred so as to overlap each other, and a full-color toner image is formed on the belt. The intermediate transfer belt 20 is stretched around a plurality of rollers including a driving roller 22 and a tension roller 21, and is rotated clockwise in the figure by the driving roller 22.

  In parallel with such a toner image forming process, the sheet feeding device 100 feeds the sheets P1 and P2 one by one from the feeding cassette 101 or the manual feed tray 120. The configuration of the sheet feeding device 100 will be described later in detail. After the skew of the sheets P1 and P2 is corrected by the registration roller 25, the sheets P1 and P2 are sent to a secondary transfer portion formed between the drive roller 22 and the secondary transfer roller 26, and the toner images are transferred from the intermediate transfer belt 20 to the secondary transfer portion. Transfer (secondary transfer) is performed. The fixing device 30 includes a fixing film 31 heated by a heater 33, and a pressure roller 32 pressed against the fixing film 31, and applies heat and pressure to a toner image on the sheet to form an image on the sheets P1 and P2. To fix. The sheets P1 and P2 sent from the fixing device 30 are discharged out of the apparatus main body 10A of the image forming apparatus 10 by the discharge rollers 35, and are stacked on a discharge tray 36 provided on the upper surface of the main body.

(Sheet feeding device)
The sheet feeding apparatus 100 according to the present embodiment is provided below the image forming apparatus 10 as shown in FIG. The sheet feeding apparatus 100 includes a feeding cassette 101, a feeding unit 104, a manual feed tray 120, a manual feeding roller 121, and a manual feeding path 130.

  The feeding cassette 101 is inserted into the apparatus main body 10 </ b> A of the image forming apparatus 10, which also serves as the apparatus main body of the sheet feeding apparatus 100, so as to be able to be pulled out. The sheet P1 stored in the feeding cassette 101 is supported by a middle plate 102 provided in the cassette. The middle plate 102 can be moved up and down by a lift plate 103. The feeding cassette 101 is a sheet storage unit of the present embodiment, and the middle plate 102 is a mounting unit of the present embodiment. The lift plate 103 is the elevating means of the present embodiment.

  The feeding unit 104 includes a pickup roller 107 located above the middle plate 102, and a feed roller 105 and a retard roller 106 that come into contact with each other. The pickup roller 107, which is the first feeding unit of the present embodiment, sends out the sheet P1 stacked on the middle plate 102 toward the feed roller 105. The feed roller 105 conveys the sheet P <b> 1 received from the pickup roller 107 toward the registration roller 25. The retard roller 106 receives, via a torque limiter, a driving force in a rotation direction that is opposite to the sheet P1 feeding direction. When a plurality of sheets enter the nip between the feed roller 105 and the retard roller 106, the retard roller 106 pushes back the sheets other than the uppermost sheet that is in contact with the feed roller 105 to the feed cassette 101. When only one sheet exists in the nip portion, the retard roller 106 follows the feed roller 105 by slipping of the torque limiter. Therefore, the feeding unit 104 feeds the uppermost sheet of the sheets P1 stacked on the middle plate 102 one by one. Note that the retard roller is an example of a separating member that separates a sheet, and may be replaced with a friction pad or a roller member that does not receive a driving force in a rotational direction that is opposed to the feeding direction.

  The manual feed tray 120 is supported on a side surface of the apparatus main body 10A. The sheet P2 placed on the manual feed tray 120 is drawn into a manual feed path 130 inside the apparatus by a manual feed roller 121, which is a second feeding unit of the present embodiment. In the manual feed path 130, a plurality of sets of transport rollers 122 and transport rollers 123 for transporting the sheet P2 are arranged. The manual feed path 130 joins the sheet conveyance path from the feed cassette 101 at a downstream portion in the sheet conveyance direction. That is, the sheet P2 fed from the manual feed tray 120 is conveyed to the registration roller 25 through below the pickup roller 107 of the feeding unit 104 and between the feed roller 105 and the retard roller 106.

  As shown in FIG. 2A, the pickup roller 107 is movable between an upper position (solid line position) and a lower position (broken line position) below the upper position. However, unless otherwise specified, "upper" and "lower" refer to the vertical direction when the sheet feeding device 100 is installed on a horizontal surface. When the sheet P1 is fed from the feeding cassette 101, as shown in FIG. 2B, the pickup roller 107 contacts the sheet P1 at a feeding position between the upper position and the lower position. The rotation and vertical movement of the pickup roller 107 are performed using the feed motor M2 as a drive source, and are controlled via a solenoid 111 as described later. Further, in the present embodiment, the retard roller 106 is also configured to be movable between a position in contact with the feed roller 105 and a position separated from the feed roller 105.

  In the sheet feeding apparatus 100, a first sensor 1, a second sensor 2, a sheet presence / absence sensor 3, and a cassette sensor 110 are provided as detection means for detecting the state of the apparatus. The first sensor is the first detecting means of the present embodiment, and the second sensor is the second detecting means of the present embodiment.

  The first sensor 1 is turned on when the pickup roller 107 is at the feeding position (FIGS. 2B and 2C), and when the pickup roller 107 is at the upper position or the lower position (FIG. 2A). ) Is in the OFF state. The first sensor 1 of this embodiment uses a photo interrupter that detects a flag 1f that moves up and down together with the pickup roller 107.

  The second sensor 2 is a sensor that detects whether or not an object (the sheet P1 or the intermediate plate 102) exists at a position where the object (the sheet P1 or the intermediate plate 102) is in contact with the pickup roller 107 in the feeding position regardless of the position of the pickup roller 107. is there. As the second sensor 2 of the present embodiment, a photo interrupter for detecting a flag 2f provided above the middle plate 102 is used. The second sensor 2 is turned off when the flag 2f is not in contact with the sheet P1 or the middle plate 102 (FIG. 2A). Further, the second sensor 2 swings the flag 2f when the sheet P1 or the intermediate plate 102 exists at a position where the sheet P1 or the intermediate plate 102 is in contact with the pickup roller 107 in the feeding position (FIGS. 2B and 2C). Is detected and turned on.

  The sheet presence / absence sensor 3 is a sensor capable of detecting whether or not the sheet P1 is stacked on the middle plate 102. As in the case of the second sensor 2, the photo-interrupter for detecting the swing of the flag 3f provided above the middle plate 102 is used for the sheet presence sensor 3 of this embodiment. However, a notch is provided in a portion of the middle plate 102 corresponding to the flag 3f, and when no sheet is placed on the middle plate 102, the flag 3f is swung even if the middle plate 102 is raised. It is configured not to move. Therefore, the sheet presence / absence sensor 3 detects the case where at least one sheet P1 is placed on the middle plate 102 and the uppermost sheet is in a position where it can be brought into contact with the pickup roller 107 at the feeding position (FIG. 2B). )), Only in the ON state.

  The cassette sensor 110 is a sensor that can detect whether or not the feeding cassette 101 is mounted on the apparatus main body. The cassette sensor 110 is turned on when the feeding cassette 101 is inserted into a predetermined mounting position of the apparatus main body, and turned off when the feeding cassette 101 is pulled out from the mounting position. The ON / OFF detection signal output by each of the sensors 1, 2, 3, and 110 is, for example, a voltage signal that switches between a high state (H level) and a low state (L level) of the output voltage from the sensor. Is transmitted to the controller 200 (FIG. 3) of the sheet feeding apparatus 100.

  FIG. 3 is a block diagram illustrating a control configuration of the sheet feeding apparatus 100. The controller 200, which is a control unit of the present embodiment, includes a central processing unit (CPU) 230 and a memory 240. The CPU 230 reads and executes a program stored in the memory 240, and controls the operation of the sheet feeding apparatus 100. The memory 240 includes a temporary storage medium and a non-transitory storage medium, serves as a storage location for programs and data, and serves as a work space when the CPU 230 executes the programs. Here, the description will be made assuming that the sheet feeding apparatus 100 is provided with the controller 200, but the controller 200 may also serve as a control unit for controlling the entire image forming apparatus 10.

  The controller 200 controls the operations of the lifter motor M1, the feed motor M2, the solenoid 111, and the manual solenoid 211 based on the detection signals of the above-described sensor groups (1, 2, 3, 110). That is, the controller 200 issues a drive command to the drive circuits 201, 202, 203, and 204 to control the energization of the motors M1 and M2 and the solenoids 111 and 211. The lifter motor M1 is a drive source that drives a lift plate 103 (FIG. 1) that moves the middle plate 102 up and down. The feed motor M2 is a drive source that drives the feed unit 104. The solenoid 111 is an actuator for controlling the position of the pickup roller 107. The manual feed solenoid 211 is an actuator for controlling the position of the manual feed roller 121 (FIG. 1) between a position where it comes into contact with the sheet P2 and a position where it is separated from the sheet P2.

(Feeding unit)
The feeding unit 104 will be described in detail with reference to FIGS. 4A and 4B are perspective views of the feeding unit 104. FIG. FIGS. 5A and 5B are side views of a cam provided on the feeding gear 116. FIG. FIGS. 6A to 6C are schematic diagrams for explaining the relationship between the rotation of the feed gear 116 and the operation of the feed unit 104.

  As shown in FIGS. 4A and 4B, the pickup roller 107 is rotatably supported by the roller holder 71. The roller holder 71 can swing up and down around a feed roller shaft 72 which is a rotation shaft of the feed roller 105, and is urged downward by a pressure spring 75. The pressing spring 75 as an example of the urging means is a coil spring contracted between the roller holder 71 and the apparatus main body. The spring force of the pressure spring 75 defines the pressing force (total load obtained by integrating the contact pressure) of the pickup roller 107 against the sheet when the pickup roller 107 is lifted to the feeding position.

  The driving force of the feeding motor M2 is transmitted to the feeding unit 104 via the driving mechanism 60 including the feeding gear 116. The drive mechanism 60 according to the present embodiment includes a drive transmission unit that transmits a driving force to the feeding unit 104 to rotate each roller, and a cam that swings the roller holder 71 up and down using the driving force of the feeding motor M2. The mechanism is unitized.

  The drive mechanism 60 includes a feed gear 116, a solenoid 111, and a gear train 69. The feed gear 116 includes a first toothless gear 61 locked by the solenoid 111, a cam disk 63 having a cam surface 63a, and a second toothless gear sandwiched between the first toothless gear 61 and the cam disk 63. 62. The cam disk 63 is a cam portion of the present embodiment, and the feed gear 116 is a rotating member of the present embodiment. The solenoid 111 is locking means of this embodiment that can lock the rotating member. Further, the first missing gear 61 and the second missing gear 62 are the gear portions of this embodiment that transmit the driving force from the driving source to the feeding means.

  The gear train 69 has a gear 69 a that meshes with the second missing gear 62, and transmits the rotation of the feed gear 116 to the feed roller shaft 72. The rotation of the feed roller shaft 72 is transmitted to the pickup roller 107 by a gear train 74 supported by the roller holder 71. Therefore, the pickup roller 107 and the feed roller 105 rotate with the rotation of the feed roller shaft 72. Further, the driving force of the feeding motor M2 is also input to the retard roller 106 via a torque limiter (not shown).

  As shown in FIGS. 5A and 5B, the cam disk 63 contacts the cam follower portion 71a of the roller holder 71 on the cam surface 63a. When the cam surface 63a lifts the cam follower portion 71a upward against the urging force of the pressure spring 75 (FIG. 5A), the pickup roller 107 moves to the upper position. When the cam surface 63a separates from the cam follower portion 71a (FIG. 5B), the roller holder 71 is lowered by the urging force of the pressing spring 75, and the pickup roller 107 moves toward the lower position.

  As shown in FIGS. 4A and 4B, the first toothless gear 61 includes a first engagement portion 116A and a second engagement portion 116B with which the flap 111b (engagement member) of the solenoid 111 can be engaged. have. When the solenoid body 111a is energized, the flap 111b, which is a metal plate, is sucked by the solenoid body 111a and retreats to a position where it does not engage with the first engagement portion 116A and the second engagement portion 116B. When the power supply to the solenoid main body 111a is interrupted, the flap 111b moves to a position where it can be engaged with the first engagement portion 116A or the second engagement portion 116B by the urging force of the return spring 111c. That is, the solenoid 111 is configured to maintain the locked state of the first engagement portion 116A or the second engagement portion 116B unless the solenoid is energized.

  The first missing gear 61 and the second missing gear 62 are gears that mesh with an input gear that is driven to rotate by the feed motor M2. In addition, the first missing gear 61 and the second missing gear 62 release the engagement with the input gear when the first engaging portion 116A or the second engaging portion 116B is locked by the solenoid 111. Have missing tooth portions 61a and 62a.

  The cam disk 63 rotates integrally with the second missing gear 62. On the other hand, the first missing gear 61 and the second missing gear 62 are relatively rotatable within a predetermined range, and a spring (not shown) is provided between the first missing gear 61 and the second missing gear 62. Is arranged. This spring has a function of rotating the first toothless gear 61 to a position where the engagement with the input gear starts when the engagement by the solenoid 111 is released. When the first toothless gear 61 starts rotating by meshing with the input gear, and reaches the limit of the range in which the second toothless gear 62 can rotate relative to the second toothless gear 62, the second toothless gear 62 is moved to the first toothless gear. It starts to rotate by being dragged by 61 and meshes with the input gear. On the other hand, when the first engagement portion 116A or the second engagement portion 116B is locked by the solenoid 111, the first toothless gear 61 first stops, and then the second toothless gear 62 meshes with the input gear. Is released, and the rotation of the second missing gear 62 stops.

  Since the feed gear 116 has such a configuration, rotation of the feed gear 116 is stopped in a state where the first engagement portion 116A or the second engagement portion 116B is locked by the solenoid 111. In this state, the drive transmission to the feed roller 105 and the pickup roller 107 is shut off as shown in FIGS. Since the cam disk 63 also stops, the vertical movement of the pickup roller 107 stops. When the first engagement portion 116A is locked (FIG. 6A), the pickup roller 107 stops at the upper position. Further, when the second engagement portion 116B is locked (FIG. 6B), the pickup roller 107 is in the feeding position in a state in which the pickup roller 107 is in contact with the sheet P1, or the lift of the middle plate 102 is increased. If not, it will stop at the lower position.

  When the engagement of the first engagement portion 116A or the second engagement portion 116B by the solenoid 111 is released, a driving force is input to the first toothless gear 61 and the second toothless gear 62, and the feeding gear 116 starts rotating (FIG. 6C). Thereafter, when the power supply to the solenoid 111 is cut off, the flap 111b is engaged with the first engagement portion 116A or the second engagement portion 116B, and the feed gear 116 is locked. Therefore, the feed gear 116 is configured to perform a short-time energization to the solenoid 111 while the feed motor M2 is rotating, so that the first engagement state of the first engagement portion 116A is stopped. It is possible to switch between the second stop state in which the engagement portion 116B is locked.

  As shown in FIG. 6C, the sheet P1 is fed by the pickup roller 107 until the feeding gear 116 switches from the second stop state to the first stop state. In other words, the shape of the cam surface 63a is set so that the pickup roller 107 stays at the feeding position at least until the leading end of the uppermost sheet P1 in the sheet feeding direction reaches the downstream conveying means. In the present embodiment, when the feeding gear 116 switches from the second stop state to the first stop state, the retard roller 106 also moves so as to be separated from the feed roller 105 (FIG. 6A). Accordingly, the shape of the cam surface 62a of the feeding gear 116 is such that, for example, after the leading end of the sheet P1 is nipped by the registration roller 25 (FIG. 1), the feeding unit 104 is moved from the state of FIG. The state is set to be switched to the state of a).

(Operation at power-on)
Hereinafter, an operation performed by the sheet feeding apparatus 100 will be described. First, stop state detection control performed when the power of the sheet feeding apparatus 100 changes from the off state to the on state will be described with reference to the flowchart of FIG. The case where the power is changed from the off state to the on state includes a case where the main power of the image forming apparatus 10 is turned on and the apparatus starts up, and a case where the power supply is restored after a power failure occurs.

  In the stop state detection control, it is determined whether the feed gear 116 is in the first stop state (FIG. 6A) or the second stop state (FIG. 6B). In this process, in the initial lift-up operation to be described later, the controller 200 lifts the intermediate plate 102 in a state where the pickup roller 107 is at the lower position (that is, the second stop state of the feed gear). This is done to keep track of the status.

  When the power of the sheet feeding apparatus 100 changes from the OFF state to the ON state as shown in FIG. 2, the controller 200 checks the detection signal of the cassette sensor 110 and checks whether the feeding cassette 101 is inserted into the apparatus main body 10A. Is determined (S101). If the cassette has not been inserted, the controller 200 waits until the insertion is detected. When detecting that the feeding cassette 101 has been inserted, the controller 200 checks a detection signal of the second sensor 2 (S102).

  When the second sensor 2 is ON, the sheet P1 (or the middle plate itself) stacked on the middle plate 102 is at a position where the sheet P1 can be brought into contact with the pickup roller 107 at the feeding position, and the middle plate 102 is lifted up. It turns out that it is in the state where it fell. When the second sensor 2 is OFF, the controller 200 determines that the lift of the middle plate 102 is not performed, and energizes the lifter motor M1 to start the lift of the middle plate 102 (S103). Thereafter, when the second sensor 2 changes from OFF to ON (S104), the lifting of the middle plate 102 is stopped (S105).

  When the second sensor 2 is ON in S102, or after the lift-up is stopped in S105, the controller 200 checks the detection state of the first sensor 1 (S106). Here, since the middle plate 102 has moved up to the position where the second sensor 1 is turned on, if the feeding gear 116 is in the second stop state, the pickup roller 107 is moved to the sheet P1 or the middle plate 102. Is held at the feeding position (FIGS. 2B and 2C). Therefore, when the first sensor 1 is ON, the controller 200 determines that the feeding gear 116 is in the second stopped state (the pickup roller 107 is at the feeding position) (S107). When the first sensor 1 is OFF, it is determined that the feeding gear 116 is in the first stopped state (the pickup roller 107 is at the upper position) (S108).

  When the feeding gear 116 is in the second stop state, the sheet feeding apparatus 100 is in a state where the sheet P1 can be fed from the feeding cassette 101. That is, as shown in FIG. 2B, the middle plate 102 is lifted up, and the pickup roller 107 is in contact with the uppermost sheet at the feeding position. However, it is assumed that the presence of the sheet P1 has been confirmed from the detection signal of the sheet presence / absence sensor 3. In this case, the controller 200 ends the stop state detection control without performing additional processing, and enters a standby state in which the controller 200 waits until sheet feeding is requested.

  On the other hand, when the feeding gear 116 is in the first stop state, the controller 200 performs the processing of S109 to S112 in order to enable the sheet P1 to be fed from the feeding cassette 101. First, while the feed motor M2 is rotating, the solenoid 111 is energized for a short time to release the first stop state (S109). Thereafter, the rotation of the feed motor M2 is continued until the feed gear 116 is locked again to the second stop state (S110).

  Next, the controller 200 checks again the detection state of the first sensor 1 (S111). Since it is confirmed that the sheet P1 or the intermediate plate 102 exists at the detection position of the second sensor 2 by the processing of S102 to S105, the first sensor 1 is normally ON. However, when a part of the sheet P1 is raised due to the curl of the sheet, the pickup roller 107 may move below the feeding position so as to crush the sheet P1. In this state, the pressing force of the pickup roller 107 against the sheet P1 is insufficient, so that even if the pickup roller 107 rotates, a sufficient frictional force is not applied to the uppermost sheet, and a feeding failure may occur. . Therefore, when the first sensor 1 is OFF in S111, the controller 200 additionally lifts the middle plate 102 (S112). Thereafter, upon confirming that the first sensor 1 has been switched from OFF to ON, the controller 200 stops the lift-up (S113), and ends the stop state detection control.

  By executing the above-described process, the controller 200 can recognize the stop state of the feeding gear 116 even when the power is turned on and off. Further, regardless of the stop state of the feeding gear 116 at the time when the power supply changes from the off state to the on state, it is possible to enter the standby state in a state where the sheet P1 can be fed from the feeding cassette 101.

  In the flowchart of FIG. 7, the description has been made on the assumption that the feed gear 116 is stationary in either the first stop state or the second stop state at the time when the power is turned on. On the other hand, the feed gear 116 stops at a rotation angle other than the first stop state and the second stop state, for example, when the power of the sheet feeding apparatus 100 is suddenly cut off due to a power failure or the like while the feed gear 116 is rotating. If there is a possibility that the feeding gear 116 may be locked, a process of locking the feed gear 116 when the power is restored is performed. For example, between S101 and S102, a process for rotating the feed motor M2 for a certain period of time while the solenoid 111 is kept in the non-energized state is inserted. As a result, even if the feed gear 116 is stopped at a position between the first stop state and the second stop state, the state shifts to one of the stop states, and the processing after S102 proceeds without delay. be able to.

(Initial lift-up operation)
Next, the initial lift-up operation of the sheet feeding device 100 will be described. FIG. 8 is a flowchart showing a control method of the initial lift-up operation. FIG. 9 is a timing chart when the initial lift-up operation is performed according to S201 to S207 in FIG.

  In FIG. 9, the "cassette sensor detection signal" indicates that the feed cassette 101 is inserted into the apparatus main body 10A when ON, and indicates that the feed cassette 101 is pulled out when OFF. "A" in the "stopped state of the feeding gear" indicates a first stopped state in which the first engaging portion 116A of the feeding gear 116 is locked, and "B" indicates that the second engaging portion 116B is locked. Represents a second stopped state. When the “feeding solenoid” is ON, it indicates that the solenoid 111 is being energized, and when it is OFF, it indicates that the energization of the solenoid 111 has been interrupted. “Lift-up operation” indicates a drive signal to the lifter motor drive circuit 201, ON indicates a lift-up signal for raising the middle plate 102, and OFF indicates a stop signal for stopping the middle plate 102. If the "first sensor detection signal" is ON, it indicates that the pickup roller 107 is at the feeding position, and if OFF, it indicates that the pickup roller 107 is at a position other than the feeding position.

  The initial lift-up operation is performed to raise the middle plate 102 so that the sheet P1 in the cassette can be fed when the feed cassette 101 in the pulled-out state is inserted into the apparatus main body 10A. Will be Here, it is assumed that the feeding cassette 101 is pulled out and inserted while the power of the sheet feeding apparatus 100 is turned on.

  When the feeding cassette 101 is pulled out from the apparatus main body 10A, the lift plate 103 (FIG. 1) is disconnected from the lifter motor M1, and the middle plate 102 descends to the lowest position. When it is confirmed that the cassette sensor 110 has detected the insertion of the feeding cassette 101 (S201, time T1 in FIG. 9), the controller 200 checks the stopped state of the feeding gear 116 (S202). Here, in the memory 240 (FIG. 3) of the controller 200, a storage area for a variable indicating the current stopped state of the feeding gear 116 is prepared, and the CPU 230 accesses the storage area of the memory 240 to perform feeding. The stop state of the gear 116 is determined. The above variables are updated when the stop state is acquired by the stop state detection control or when the feed gear 116 is driven to change the stop state.

  When the feeding gear 116 is in the first stop state (the pickup roller 107 is at the upper position), the controller 200 performs a process of moving the pickup roller 107 to the lower position. That is, while the feed motor M2 is rotating, the solenoid 111 is energized for a short time to release the first stop state (S203, time T2 in FIG. 9). Then, the rotation of the feed motor M2 is continued for a sufficient time for the second engagement portion 116B of the feed gear 116 to be locked, and the process stands by (S204). As a result, the feeding gear 116 transitions from the first stop state to the second stop state (time T3 in FIG. 9). In FIG. 9, the first sensor 1 is temporarily turned on because the pickup roller 107 passes through the feeding position while moving from the upper position to the lower position.

  After confirming that the feed gear 116 is in the second stop state in S202, or after shifting the feed gear to the second stop state by the processing of S203 and S204, the controller 200 lifts the middle plate 102 up. The process starts (S205, time T4 in FIG. 9). When it is confirmed that the first sensor 1 has changed from OFF to ON (S206), the controller 200 stops lifting (S207, time T5 in FIG. 9) and ends the initial lifting operation. As a result, the sheet feeding device 100 is in a state where the sheet P1 can be fed from the feeding cassette 101, and the controller 200 waits until a sheet feeding is requested.

(Sheet feeding operation)
Hereinafter, a sheet feeding operation when sheet feeding is requested after the controller 200 enters the standby state will be described. FIGS. 10A to 10C are schematic diagrams illustrating the operation of feeding the sheet P1 from the feeding cassette 101. FIGS. 11A to 11C illustrate feeding of the sheet P2 from the manual feed tray 120. FIG. 4 is a schematic diagram illustrating a state of an operation performed.

  As shown in FIG. 10A, in the standby state, the pickup roller 107 is in the feeding position and is in contact with the uppermost sheet of the sheets P1 stacked on the middle plate 102. Further, as a result of the above-described stop state detection control and the initial lift-up operation, the feed gear 116 is locked in the second stop state in the standby state.

  When the feeding of the sheet P1 is requested, the controller 200 rotates the feeding motor M2 and energizes the solenoid 111 for a short time. Then, the locking of the feeding gear 116 is released, the feeding gear 116 starts rotating, and the pickup roller 107 rotates. As a result, the uppermost sheet P1 is sent out from the feed cassette 101 as shown in FIG. The sheet P <b> 1 is conveyed toward the registration roller 25 while being separated from other sheets by the feed roller 105 and the retard roller 106 to which a driving force is input via the feeding gear 116.

  As shown in FIG. 10C, before the rear end of the uppermost sheet passes through the pickup roller 107, the roller holder 71 is lifted by the cam surface 63a of the feeding gear 116 (FIG. 5A). The pickup roller 107 moves to an upper position. The feeding gear 116 is locked in the first stop state. Thereafter, the controller 200 energizes the solenoid 111 at an appropriate timing before the next sheet feeding is requested (for example, at a timing such that the pickup roller 107 and the retard roller 106 do not contact the preceding sheet). As a result, the feeding gear 116 transitions from the first stop state to the second stop state, and becomes in a state where the next highest sheet can be fed from the feed cassette 101.

  As shown in FIG. 11A, even when the sheet P2 is fed from the manual feed tray 120, the pickup roller 107 is at the feeding position before the start of the feeding operation. When starting the feeding operation, the controller 200 issues a driving command to the manual solenoid driving circuit 203 (FIG. 3) to drive the manual solenoid 211. As a result, the manual feed roller 121 feeds out the sheet P2 placed on the manual feed tray 120. The sheet P2 is transported toward the position of the pickup roller 107 by the transport roller 122 and the transport roller 123.

  Further, in parallel with the feeding by the manual feed roller 121, the controller 200 performs a process for securing a transport path of the sheet P2. First, the intermediate plate 102 is lowered to a position where it does not contact the sheet P2 (FIG. 11B). Next, before the leading end of the sheet P2 reaches the position of the pickup roller 107 in the sheet conveyance direction (left direction in the figure), the pickup roller 107 is moved to an upper position (FIG. 11C). At this time, the retard roller 106 is also separated from the feed roller 105. In this embodiment, since the rotation of the pickup roller 107 and the vertical movement are linked by the feeding gear 116, the middle plate 102 is first lowered so as not to feed out the sheet P1 in the cassette.

  By the above processing, the sheet P2 conveyance path is opened at the position of the pickup roller 107 where the sheet conveyance path from the manual feed tray 120 and the sheet conveyance path from the feeding cassette 101 merge. Then, the sheet P2 passes below the pickup roller 107 located at the upper position and between the feed roller 105 and the retard roller 106 in a separated state, and is conveyed downstream (the registration roller 25 in this embodiment). Passed to.

  When the next sheet is subsequently fed from the manual feed tray 120 after the feeding of the sheet P2 is completed, the middle plate 102 and the pickup roller 107 are held at the positions shown in FIG. On the other hand, when the next sheet is not fed from the manual feed tray 120, control is performed to return the sheet P1 in the cassette to a standby state in which the sheet P1 in the cassette can be fed by a method similar to the above-described initial lift-up operation. That is, after the feeding gear 116 is set to the second stop state and the pickup roller 107 is positioned at the lower position (S202 to S204 in FIG. 8), the middle plate is kept until the first sensor 1 changes from OFF to ON. 102 is lifted up (S205 to S207).

(Effects of the present embodiment)
As described above, the pickup roller 107 of this embodiment is disposed at the junction where the sheet conveyance path from the manual feed tray 120 and the sheet conveyance path from the feeding cassette 101 join. That is, the pickup roller 107 is disposed at a position where the movement locus between the upper position and the lower position overlaps the sheet conveyance path from the manual feed tray 120. Then, when the feeding cassette 101 that has been pulled out is inserted, with the pickup roller 107 set at the lower position, the intermediate plate 102 is lifted up until the pickup roller 107 reaches the feeding position. A lift-up operation is performed. Thus, the pressing force of the pickup roller 107 on the sheet P1 becomes an appropriate magnitude.

  Here, as a comparative example, for example, in a configuration in which the pickup plate 107 is lowered after lifting up the middle plate 102 based only on the detection result of the second sensor 2, when the sheet P1 is curled, As a result, the amount of rise of the middle plate 102 is reduced. In this case, the pickup roller 107 moves below the feeding position so as to crush the sheet P1, and the pressing force of the pickup roller 107 on the sheet P1 is insufficient. As a result, even if the pickup roller 107 rotates, a sufficient frictional force is not applied to the uppermost sheet, and there is a possibility that a feeding failure occurs. Further, even when a sheet having no curl is fed, for example, when feeding a bulky sheet material such as an envelope, there is a possibility that a similar sinking of the pickup roller 107 occurs and a feeding failure occurs. is there. On the other hand, in the configuration of the present embodiment, the pressing force of the pickup roller 107 on the sheet P1 has an appropriate magnitude irrespective of the presence or absence of curl or the material of the sheet P1, so that the sheet P1 can be fed stably. It is.

  Further, the sheet feeding apparatus 100 according to the present embodiment waits in a state where the pickup roller 107 is in contact with the sheet P1 in the cassette by the initial lift-up operation, so that the feeding of the sheet P1 is started quickly to shorten the FPOT. Can contribute to.

  On the other hand, in the configuration of the present embodiment, when feeding the sheet P2 placed on the manual feed tray 120, it is necessary to retract the pickup roller 107 from the transport path of the sheet P2. However, if the movement of the pickup roller 107 to the upper position is started during the grace period from when the feeding of the sheet P2 is started to when the leading end of the sheet P2 reaches the pickup roller 107, the influence on the FPOT is minimized. Can be suppressed.

(Modification)
In the feeding operation of the sheet P2 set on the manual feed tray 120 shown in FIGS. 11A to 11C, in the present embodiment, it has been described that the pickup roller 107 does not contribute to the conveyance of the sheet P2. Instead, the pickup roller 107 may be lowered during the feeding operation of the sheet P2, and the pickup roller 107 may also contribute to the feeding of the sheet P2.

  In this case, for example, when the leading end of the sheet P2 reaches between the pickup roller 107 and the feed roller 105 (see FIG. 11C), the conveyance of the sheet P2 is temporarily stopped, and the feeding gear 116 is stopped in the first stopped state. To the second stop state. Further, the middle plate 102 is lifted up to a position where it comes into contact with the sheet P2, so that the pickup roller 107 and the sheet P1 on the middle plate hold the sheet P2 from the manual feed tray 120. In this state, when the feeding gear 116 is shifted from the second stop state to the first stop state, the sheet P2 is sent out by the pickup roller 107. Further, since the feed roller 105 and the retard roller 106 are in contact with each other, double feeding of the sheet P1 in the cassette is prevented.

  Further, in the present embodiment, a compact structure is realized by providing the feed gear 116 for interlocking the rotation of the pickup roller 107 and the vertical movement. However, a mechanism for moving the pickup roller 107 vertically and a mechanism for moving the pickup roller 107 up and down are provided. May be separately provided. For example, the cam disk 63 of the feeding gear 116 may be separated from the first and second missing gears 61 and 62 so as to be driven by a motor different from the feeding motor M2.

  Further, in the present embodiment, the pressing force of the pickup roller 107 at the feeding position has been described as being defined by the pressing spring 75. However, according to the present technology, the pickup roller 107 is applied to the sheet by its own weight and the weight of the roller holder 71 and the like. The present invention is also applicable to a configuration in which pressure is applied. Also in this case, if the amount of elevation of the middle plate in the initial lift-up operation is insufficient as in the above-described comparative example, the pickup roller 107 sinks below the feeding position, for example, the sheet feeding direction changes, and the sheet feeding direction changes. Inconveniences such as clogging are likely to occur. According to the present embodiment, such a disadvantage is avoided.

  Next, a sheet feeding apparatus according to a second embodiment will be described with reference to FIGS. This embodiment is different from the first embodiment in that the arrangement of the locking portion of the feed gear is different from that of the first embodiment, and the stop state of the feed gear can be controlled without using the second sensor 2. . Other components having the same configuration and operation as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  As shown in FIG. 12, the feed gear 216 of the present embodiment also has a first engagement portion 216C and a second engagement portion 216D to which the solenoid 111 can engage, similarly to the feed gear 116 of the first embodiment. It has. In the first stop state in which the first engagement portion 216C is locked, the pickup roller 107 is held at the upper position (see FIG. 6A). In the second stop state in which the second engagement portion 216D is locked, the pickup roller 107 is moved to the lower position (in a state where the pickup roller 107 can be moved to the feeding position by being pressed by the sheet P1 or the middle plate 102). It is held (see FIG. 6B).

  Unlike the first embodiment, the first rotation angle θ1 from the first engagement portion 216C to the second engagement portion 216D in the rotation direction R1 of the feeding gear 116, and the first rotation angle θ1 from the second engagement portion 216D to the first engagement portion. The second rotation angle θ2 up to 216C is different, and θ1 <θ2. That is, a transition time τ1, which is a time required for transitioning the feed gear 216 from the first stop state to the second stop state, and a transition time τ1 for transitioning the feed gear 216 from the second stop state to the first stop state. The difference is in the transition time τ2 which is the time. However, it is assumed that the rotation speed of the feeding motor M2 can be regarded as substantially constant.

  The arrangement of the first engagement portion 216C and the second engagement portion 216D is set so that, for example, the transition times τ1 and τ2 have a ratio of 1: 3 (τ2 / τ1 = 3). That is, when the feed motor M2 rotates at a predetermined speed at which the feed gear 116 rotates once at 400 msec, the transition time τ1 is 100 msec and the transition time τ2 is 300 msec. Therefore, if the process of energizing the solenoid 111 for a time longer than 100 msec and shorter than 300 msec is performed while the feed motor M2 is rotating at a predetermined speed, the feed gear 116 locks the first engagement portion 216C. The state is reproduced. That is, by the above-described processing, the feeding gear 116 can be set to the first stopped state regardless of the original stopped state.

  In the present embodiment, by performing an initial lift-up operation including an initialization process for initializing the stopped state of the feeding gear 116, stable feeding can be performed even when the sheet is curled. Hereinafter, the initial lift-up operation of the present embodiment will be described with reference to FIGS. FIG. 13 is a flowchart showing a control method of the initial lift-up operation. FIG. 14 is a timing chart when the initial lift-up operation is performed according to S301 to S311 in FIG.

  In FIG. 14, the “sheet presence / absence sensor detection signal” indicates that there is a sheet if ON, and indicates that the flag of the sheet presence sensor 3 is not in contact with the sheet if OFF. "Lift operation" represents a drive signal to the lifter motor drive circuit 201, H (+) represents a lift-up signal for raising the middle plate 102, H (-) represents a lift-down signal for lowering the middle plate 102, L represents a stop signal for stopping the middle plate 102. Further, “C” of the “stopped state of the feed gear” indicates a first stop state in which the first engagement portion 216C of the feed gear 216 is locked, and “D” indicates that the second engagement portion 216D is engaged. It represents the stopped second stopped state. Other items are common to FIG.

  When the initial lift-up operation is started, the controller 200 checks the detection signal of the cassette sensor 110 and determines whether or not the feeding cassette 101 is inserted into the apparatus main body 10A (S301). If the cassette has not been inserted, the controller 200 waits until the insertion is detected. When detecting that the feeding cassette 101 has been inserted, the controller 200 checks the detection signal of the first sensor 1 (S302, time T6 in FIG. 14).

  When the first sensor 1 is ON in S302, it is understood that the pickup roller 107 is already in the feeding position and is in contact with the upper surface of the sheet stacked on the middle plate 102 (or the middle plate itself). In this case, the controller 200 checks the detection signal of the sheet presence / absence sensor 3 and determines whether or not sheets can be fed from the feeding cassette 101 (S312). That is, if the sheet presence / absence sensor 3 is ON, it is determined that at least one sheet can be fed from the feed cassette 101 (S313), and the initial lift-up operation ends and the apparatus enters a standby state. If the sheet presence / absence sensor 3 is OFF, it is determined that there is no sheet that can be fed in the cassette (S314), and the initial lift-up operation ends.

  When the first sensor 1 is OFF in S302, it is understood that the pickup roller 107 is not at the feeding position. In this case, after initializing the position of the feeding gear 216, the controller 200 executes the processing of S303 to S311 for lifting up the middle plate 102.

  First, the controller 200 checks a detection signal of the sheet presence sensor 3 (S303). When the sheet presence sensor 3 is ON, there is a sheet near the pickup roller 107, and there is a possibility that the sheet is erroneously fed when the solenoid 111 is operated. Therefore, in this case, the controller 200 outputs a lift-down signal to lower the upper surface of the sheet to a position where the upper surface of the sheet does not contact the pickup roller 107 (S304, times T7 to T8). The time length Ta of the lift-down operation is such that the sheet at the upper limit of the range in which the upper surface of the sheet can exist (for example, the physical upper limit due to the sheet contacting a member above the middle plate 102) is It is the length to move below the lower position. If the sheet presence sensor 3 is OFF in S303, the process proceeds to S305 without performing the lift-down.

  After the lift-down operation, an initialization process of the feed gear 216 (S305 to S308) is performed. First, the controller 200 energizes the solenoid 111 for a predetermined time Tb while the feed motor M2 is rotating (S305, times T8 to T9 in FIG. 14). Then, the rotation of the feed motor M2 is continued for a sufficient time for the feed gear 216 to be locked again, and the process stands by (S306). Then, regardless of whether the feed gear 216 is in the first stop state or the second stop state, the feed gear 216 is in the first stop state in which the first engagement portion 216C is locked (time in FIG. 14). T10).

  The predetermined time Tb is set to be longer than the transition time τ1 from the first stop state to the second stop state and shorter than the transition time τ2 from the second stop state to the first stop state (τ1 <Tb <τ2). ). For example, when τ1 = 100 [msec] and τ2 = 300 [msec], Tb = 200 [msec] is set.

  Further, the controller 200 causes the feeding gear 216 determined to be in the first stop state to transition to the second stop state. That is, after releasing the first stop state by energizing the solenoid 111 for a short time Tc (S307), the controller 200 performs a sufficient time for the second engagement portion 216D of the feed gear 216 to be locked. The rotation of the feeding motor M2 is continued to wait (S308). As a result, the feeding gear 216 enters the second stop state, and the pickup roller 107 moves to the lower position. Note that the time Tc for energizing the solenoid 111 in S307 is set shorter than the transition time τ1 from the first stop state to the second stop state.

  After the initialization process, the controller 200 starts lifting the middle plate 102 (S309, time T11 in FIG. 14). When the controller 200 confirms that the first sensor 1 has changed from OFF to ON (S310), the controller 200 stops lifting (S311, time T12 in FIG. 14) and ends the initial lifting operation.

  After the above-described initial lift-up operation is performed, the operation of the sheet feeding apparatus when feeding a sheet is the same as that of the first embodiment. That is, when feeding the sheet P1 from the feeding cassette 101, the second stop state of the feeding gear 216 is released without moving the pickup roller 107 from the feeding position, and the pickup roller 107 is rotated (see FIG. 10). ). When the sheet P2 is fed from the manual feed tray 120, the operation of lowering the middle plate 102 and moving the pickup roller 107 to the upper position at least until the leading end of the sheet P2 reaches the position of the pickup roller 107 is performed. (See FIG. 11). Therefore, as in the first embodiment, it is possible to secure an appropriate pressing force of the pickup roller 107 by the initial lift-up operation, thereby enabling stable sheet feeding, and to contribute to shortening of FPOT.

  In addition, in the present embodiment, without using the second sensor 2 used for the stop state detection control in the first embodiment, an initialization process of setting the feed gear 216 to a predetermined stop state (S305 to S305). S308) is performed. Thereby, the second sensor 2 can be omitted, which is advantageous in terms of cost and miniaturization of the device.

  In the present embodiment, it has been described that the initialization process of the feed gear 216 is performed every time the initial lift-up operation is performed. However, when the controller 200 grasps the current stop state of the feed gear 216. , The initialization process may be omitted. In this case, a variable indicating the current stop state of the feed gear 216 is stored in the memory 240 so that the CPU 230 can access the memory 240 and determine the stop state of the feed gear 216 in the initial lift-up operation. . Further, when the initialization process is omitted, when the feed gear 216 is in the first stop state, the processing of S307 and S308 is executed, and when the feed gear 216 is in the second stop state, S307, The processing of S308 is omitted. Thus, similarly to the present embodiment, an appropriate pressing force of the pickup roller 107 can be secured by the lift-up operation in S309 to S311. Note that the case where the initialization process can be omitted is, for example, a case where the feeding cassette 101 is inserted or removed while the power of the sheet feeding apparatus 100 is turned on.

(Other embodiments)
In the first and second embodiments described above, the sheet feeding apparatus 100 assembled as a part of the image forming apparatus 10 has been described. However, the present technology is applied to a sheet feeding apparatus used while being connected to the image forming apparatus. Is also applicable. In addition, the manual feed tray 120 is an example of a second placement unit, and the present technology is also applicable to a configuration having another second placement unit. For example, in a configuration in which the image forming apparatus includes a plurality of feeding cassettes, a sheet from one feeding cassette (second mounting portion) is provided above the other feeding cassette (first mounting portion). The present invention is also applicable to a configuration in which the sheet is conveyed via a pickup roller. Further, the electrophotographic image forming unit 11 is an example of an image forming unit, and the present technology can be applied to an image forming apparatus including another image forming unit such as an ink jet system or a thermal transfer system.

  The present invention supplies a program for realizing one or more functions of the above-described embodiments to a system or an apparatus via a network or a storage medium, and one or more processors in a computer of the system or the apparatus read and execute the program. This processing can be realized. Further, it can also be realized by a circuit (for example, an ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 1 ... 1st detection means (1st sensor) / 2 ... 2nd detection means (2nd sensor) / 10 ... image forming apparatus / 10A ... apparatus main body / 11 ... image forming means (image forming part) / 25 ... conveyance means (Registration roller) / 60 moving means (drive mechanism) / 61, 62 ... gear part (first missing gear, second missing gear) / 63 ... cam part (cam disk) / 75 ... biasing means ( Pressing spring) / 100 Sheet feeding device / 101 Sheet storage unit (feeding cassette) / 102 Loading unit (middle plate) / 103 Lifting unit (lift plate) / 107 ... First feeding unit ( Pickup roller) / 111 Locking means (solenoid) / 111a Solenoid body / 111b Engaging member (flap) / 116, 216 Rotating member (feed gear) / 121 ... Second feeding means (manual feeding) Roller) / 200 ... Control means (C Controller) / S205~S207, S309~S311 ... lift-up operation / S305~S308 ... initialization process

Claims (12)

A sheet storage portion having a mounting portion on which a sheet is mounted, and a sheet storage portion inserted so as to be able to be pulled out into the apparatus main body,
A first feeding unit that is arranged above the placement unit and feeds a sheet placed on the placement unit;
And a second feeding means for feeding the sheet from a position different from the placing section,
A sheet feeding device in which the first feeding means is disposed at a junction of a sheet feeding path of a sheet fed from the placement section and a sheet feeding path of a sheet fed by the second feeding section. hand,
Lifting means for raising and lowering the placing section,
Moving means for moving the first feeding means between a lower position and an upper position above the lower position in the vertical direction;
A first detection unit that can detect that the first feeding unit is at a feeding position between the lower position and the upper position in a vertical direction;
Control means for controlling the elevating means and the moving means,
The control means includes:
When the sheet storage unit in the pulled-out state is inserted into the apparatus main body, the placing unit is raised in a state where the first feeding unit is at the lower position, and the first feeding unit is Performing a lift-up operation of stopping the placement unit when the first detection unit detects that the moving unit has moved to the feeding position;
In the case where the sheet is fed from the placement section after the lift-up operation is performed, the sheet is fed to the first feeding means without moving the first feeding means from the feeding position. ,
When the sheet is fed by the second feeding unit after performing the lift-up operation, the first feeding is performed before the leading edge of the sheet in the sheet conveying direction reaches the position of the first feeding unit. Moving the means to said upper position;
A sheet feeding device, characterized in that: Further comprising an urging means for urging the first feeding means downward,
In the lift-up operation, the first feeding unit is pressed by the sheet placed on the placement unit and moves from the lower position to the feeding position against the urging force of the urging unit. ,
The sheet feeding device according to claim 1, wherein: The moving means has a rotating member having a cam portion, and the first feeding means is configured to move between the lower position and the upper position with rotation of the cam portion,
Locking means that can lock the rotating member in a first stop state corresponding to the upper position or a second stop state corresponding to the lower position,
In the lift-up operation, in a state in which the rotating member is locked in the second stop state, the first feeding unit is pressed by a sheet placed on the placement unit, and the supply from the lower position is performed. Move to the sending position,
The sheet feeding device according to claim 1, wherein The rotating member has a gear unit that transmits a driving force from a driving source to the first feeding unit,
The cam portion and the gear portion may be configured such that, during a period in which the rotating member rotates from the second stop state to the first stop state, the first feeding unit causes the sheet to be fed from the placement unit at the feeding position. Configured to move the first feeding means to the upper position after feeding.
The sheet feeding device according to claim 3, wherein: The control unit executes the lift-up operation after performing an initialization process of setting the rotating member to the second stop state when the power of the sheet feeding apparatus changes from an off state to an on state. ,
The sheet feeding device according to claim 3 or 4, wherein In the rotation direction of the rotating member, a first rotation angle from the first stop state to the second stop state is smaller than a second rotation angle from the second stop state to the first stop state,
In the initialization processing, the control unit holds the locking unit at a position where the driving unit is not engaged with the rotating member for a predetermined time while a driving force is being input to the rotating member. Perform the process of locking the rotating member,
The predetermined time is set to be longer than a required time when the rotating member rotates at the first rotation angle and shorter than a required time when the rotating member rotates at the second rotation angle.
The sheet feeding device according to claim 5, wherein: Regardless of the position of the first feeding unit, it is possible to detect that the highest sheet of the sheets stacked on the placement unit is at a position where the top sheet can contact the first feeding unit at the feeding position. Further comprising a second detection means,
When the power of the sheet feeding device changes from an off state to an on state, the control unit controls the first feeding unit based on a detection result of the first detection unit and the second detection unit. Controlling the elevating means, the moving means, and the locking means so as to be in a state of contacting the sheet placed on the placing portion at the feeding position;
The sheet feeding device according to claim 3 or 4, wherein The control unit, when the power of the sheet feeding device changes from an off state to an on state, raises the placement unit until the second detection unit detects the top sheet,
Further, when the first detecting means does not detect that the first feeding means is at the feeding position in a state where the second detecting means detects the top sheet, the rotating member is moved to the first position. After changing from the stop state to the second stop state, the placing section is raised until the first detection means changes to the detection state,
The sheet feeding device according to claim 7, wherein: The locking means has a solenoid body whose energized state is controlled by the control means, and an engagement member which can be engaged with the rotating member and is driven by the solenoid body.
The sheet feeding device according to any one of claims 3 to 8, wherein: The control means, when executing the lift-up operation and then feeding the sheet by the second feeding means, holds the first feeding means at the upper position and the second feeding means. Passing the sheet fed from the position of the first feeding means,
The sheet feeding device according to any one of claims 1 to 9, wherein: The control means, when feeding the sheet by the second feeding means after executing the lift-up operation, after the leading end of the sheet reaches the position of the first feeding means, the first feeding means Is lowered, and the sheet fed from the second feeding means is sandwiched between the first feeding means and the sheet placed on the mounting portion, and then the first feeding means To be fed by
The sheet feeding device according to any one of claims 1 to 9, wherein: A sheet feeding device according to any one of claims 1 to 11,
Image forming means for forming an image on a sheet fed from the sheet feeding device,
An image forming apparatus comprising:

Images