JP2017061374A - Sheet feeding device and image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent multi feed and sheet feed disorder without complicating a configuration of the surrounding of a roller.SOLUTION: A sheet feeding device A comprises: transport path formation means for forming a transport path CP on which a sheet is transported; a tray 1 on which the sheet to be introduced to the transport path CP is mounted; a roller 3 for transporting the sheet on the tray 1 to the transport path CP; separation means 5 pressure contacting the roller 3 for separating a single sheet S from a sheet bundle; and drive means 4 for moving the roller 3 between a transport position where a peripheral face of the roller 3 is positioned in the transport path and a retreat position where the peripheral face of the roller retreats from the transport path.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a feeding device and an image reading device.

  An image forming apparatus such as a copying machine or a printer, or an image reading apparatus such as a scanner is provided with a feeding device that feeds a sheet such as a document into the apparatus. As such a feeding device, there is a feeding device including a tray on which sheets are stacked, a roller that conveys the sheet from the tray to a conveyance path, and a separation mechanism that is pressed against the roller and separates the sheets one by one. It is known (for example, Patent Documents 1 and 2).

  In the feeding device in which the tray and the conveyance path are inclined to the downstream side in the conveyance direction, the end portion of the sheet bundle loaded on the tray by the user contacts the roller. When the user stacks the sheet bundle on the tray without striking the sheet bundle, the middle layer portion at the end of the sheet bundle may come into contact with the nip portion between the roller and the separation mechanism and protrude beyond the lower layer portion. If feeding is started as it is, double feeding or feeding order may be out of order.

  As a countermeasure, for example, Patent Document 2 proposes an apparatus provided with a movable roller guide that lifts the front end of a sheet bundle that waits for the sheet bundle before feeding and prevents contact with the roller.

JP 2000-1233 A JP 2004-269231 A

  The roller and separation mechanism require regular maintenance in order to maintain the feeding performance. When a movable mechanism is added around the roller as in Patent Document 2, the configuration around the roller becomes complicated. This may reduce maintainability.

  An object of the present invention is to prevent double feed and feeding out of order without complicating the configuration around the roller.

According to the present invention, a conveyance path forming unit that forms a conveyance path through which a sheet is conveyed;
A tray on which sheets to be introduced into the conveyance path are stacked;
A roller for conveying the sheet on the tray to the conveyance path;
Separating means for pressing the roller and separating one sheet from the sheet bundle;
Drive means for moving the roller between a transport position where the peripheral surface of the roller is located in the transport path and a retracted position where the peripheral surface of the roller is retracted from the transport path;
A feeding device is provided.

  According to the present invention, it is possible to prevent double feed and feeding out of order without complicating the configuration around the roller.

1 is a schematic diagram of an image reading apparatus according to an embodiment of the present invention. (A) is a figure which shows the example of a drive transmission structure, (B) is the control with which the image reading apparatus of FIG. 1 is provided. (A) And (B) is operation | movement explanatory drawing of the feeding apparatus with which the image reading apparatus of FIG. 1 is provided. Block diagram of the device. The flowchart which shows the process example which the control apparatus of FIG.3 (B) performs. (A)-(C) are figures which show the other structural example of a feeder. (A) And (B) is a figure which shows the other structural example of a separation unit.

<First embodiment>
FIG. 1 is a schematic view of an image reading apparatus A according to an embodiment of the present invention. The image reading device A is a scanner that reads an image on a sheet and digitizes it, and is configured by applying a feeding device according to an embodiment of the present invention. The image reading apparatus A includes a main body unit U1 constituting the lower side thereof and an opening / closing unit U2 constituting the upper side thereof. The opening / closing unit U2 is connected to the main unit U1 so as to be openable and closable in the direction of arrow D1 by a connection mechanism (not shown).

  The main unit U1 includes a tray 1 on which sheets that are read originals are stacked, and a tray T on which read sheets are discharged. A conveyance path CP for conveying the sheet is formed between the main unit U1 and the opening / closing unit U2. The transport path CP is formed by the transport path forming member 2. The transport path forming member 2 includes a plate-like bottom wall forming member 21 formed in the housing of the main unit U1, and a plate-like top wall forming member 22 formed in the housing of the opening / closing unit U2.

  In the present embodiment, the tray 1 and the conveyance path CP are inclined downward with respect to the horizontal direction. More specifically, the tray 1 and the conveyance path CP are set so that the tray 1 side that is the upstream side in the sheet conveyance direction is relatively high and the tray T side that is the downstream side in the sheet conveyance direction is relatively low. Inclined. For this reason, the sheets stacked on the tray 1 are likely to enter the conveyance path CP by their own weight. The bottom wall forming member 21 is formed with openings 21a, 21b, and 21c that expose a configuration to be described later to the conveyance path CP. Similarly, the ceiling wall forming member 22 is formed with 22a, 22b, and 22c that expose a configuration to be described later to the conveyance path CP.

  The image reading apparatus A includes a feed roller 3 and a separation unit 5. The feed roller 3 and the separation unit 5 are disposed at a position facing the entrance of the transport path CP.

  The feed roller 3 is a drive roller provided in the main unit U1, and a plurality of the feed rollers 3 are provided on the same axis. A part of the peripheral surface of the feed roller 3 is exposed in the transport path CP through the opening 21a. The feed roller 3 is rotated around an axis orthogonal to the sheet conveyance direction by a drive mechanism (not shown). By rotating the feed roller 3, the sheet on the tray can be conveyed to the conveyance path CP. The drive mechanism includes, for example, a drive source such as a motor and a transmission mechanism that transmits the drive force of the drive source to the feed roller 3. The transmission mechanism is, for example, a gear mechanism or a belt transmission mechanism.

  The feed roller 3 is supported by the drive unit 4. The drive unit 4 is a unit that moves the feed roller 3 toward and away from the conveyance path CP. The drive unit 4 is a cam mechanism including a support member 41 and a cam 44. The support member 41 rotatably supports the feed roller 3. Further, the support member 41 is rotatably supported by the housing of the main unit U1 via the shaft 42. Accordingly, the support member 41 supports the feed roller 3 in a movable manner. The shaft 42 is an axis parallel to the rotation axis of the feed roller 3.

  Here, the cam 44 is a plate cam, and a drive shaft 43 is attached to the center of rotation. The drive shaft 43 is an axis parallel to the rotation axis of the feed roller 3 and is rotated by a drive mechanism (not shown). The drive mechanism includes a drive source such as an electromagnetic solenoid and a transmission member that transmits the drive force of the drive source to the drive shaft 43. The circumferential surface of the cam 44 includes a portion where the distance from the rotation center of the cam 44 is different. The peripheral surface of the cam 44 abuts on the support member 41. The cam 44 rotates the support member 41 around the drive shaft 43 by the rotation of the drive shaft 43. The feed roller 3 is moved by the rotation of the support member 41. In the present embodiment, the feed roller 3 is configured to rotate, but it may be configured to move in parallel.

  Any configuration may be used to rotationally drive the feed roller 3 while allowing the feed roller 3 to move. For example, the example shown in FIG. 2A can be employed. The example of the figure shows an example in which a universal joint 32 is provided between the feed roller 3 and its drive shaft 31. Since the universal joint 32 transmits the driving force while absorbing the deviation between the rotation center of the feed roller 3 and the rotation center of the drive shaft 31, the feed roller 3 can be moved.

  Returning to FIG. 1, the separation unit 5 is a unit that separates one sheet from the sheet bundle, and is provided in the opening / closing unit U2. The separation unit 5 includes a separation roller 51, a support member 52, and an elastic member 54.

The separation roller 51 is a rotating body that is disposed to face the feed roller 3 and is provided with an elastic body such as rubber on its peripheral surface. The same number of separation rollers 51 as the feed rollers 3 are provided on the same axis, and the circumferential surface of the separation rollers 51 is exposed to the conveyance path CP through the opening 22a. The separation rollers 51 are fed by the urging of the elastic member 54. A pressure contact portion (nip portion N) is formed by pressure contact with the roller 3. The separation roller 51 is provided with a torque limiter mechanism (not shown), and rotates with the sheet when a predetermined torque is applied. When double feeding occurs, a predetermined torque does not act due to slippage between sheets, and the sheet on the separation roller 51 side is not conveyed. Thereby, one sheet can be separated from the sheet bundle.

  Note that the separation roller 51 may be connected to a drive source (not shown) through a mechanism similar to the universal joint 32 described in FIG. In the case of this configuration, the separation roller 51 can be rotated in the direction opposite to the conveying direction when a predetermined torque is not applied, and thus one sheet can be separated from the sheet bundle.

  The support member 52 supports the separation roller 51 so as to be rotatable about an axis parallel to the feed roller 3. The support member 52 is rotatably supported by the casing of the opening / closing unit U2 via a shaft 53. The shaft 53 is an axis parallel to the rotation axis of the feed roller 3. The elastic member 54 is loaded between the support member 52 and the casing of the opening / closing unit U2, and here is a coil spring but may be rubber or the like. The elastic member 54 always gives the support member 52 a turning behavior in the direction in which the separation roller 51 is in pressure contact with the feed roller 3. In the present embodiment, the separation roller 51 is rotated, but a parallel movement may be employed.

  The image reading apparatus A includes a transport roller pair 6, a read unit 8, and a discharge roller pair 7 in the transport direction downstream from the feed roller 3 and the separation unit 5 in the transport direction. The conveyance roller pair 6 includes a conveyance roller 61 supported by the main unit U1 and a conveyance roller 62 supported by the opening / closing unit U2. The conveyance roller 61 is, for example, a driving roller, and its peripheral surface is exposed to the conveyance path CP through the opening 21b. The transport roller 62 is, for example, a driven roller that is pressed against the transport roller 61, and the peripheral surface thereof is exposed to the transport path CP through the opening 22b.

  In this embodiment, the reading unit 8 includes a reading sensor 81 supported by the main unit U1 and a reading sensor 82 supported by the opening / closing unit U2. The reading sensor 81 faces the conveyance path CP through the opening 21c. The reading sensor 82 faces the conveyance path CP through the opening 22c. The reading sensors 81 and 82 are, for example, contact image sensors. The reading sensor 81 reads the lower surface of the sheet, and the reading sensor 82 reads the upper surface of the sheet. As described above, in the present embodiment, the reading unit 8 is configured to be able to read both sides of the sheet, but may be configured to read only one side.

  The discharge roller pair 7 includes a discharge roller 71 supported by the main unit U1 and a discharge roller 72 supported by the opening / closing unit U2. The discharge roller 71 is, for example, a drive roller, and its peripheral surface is exposed to the transport path CP. The discharge roller 72 is, for example, a driven roller that is pressed against the transport roller 71, and its peripheral surface is exposed to the transport path CP.

  The sensor SR detects whether or not there is a sheet on the tray 1. In the case of the present embodiment, the sensor SR is disposed in the main unit U1 at the entrance of the transport path CP. The sensor SR is, for example, an optical sensor, and can be composed of a light emitting element that emits light and a light receiving element that receives reflected light from the sheet. The sensor SR may be a mechanical sensor. For example, a movable lever that moves according to the presence or absence of a sheet on the tray 1 and an optical sensor or a contact sensor that detects the movement of the movable lever can be used.

  Next, the configuration of the control system of the image reading apparatus A will be described with reference to FIG. FIG. 2B is a block diagram of the control device 10 of the image reading apparatus A.

  The control device 10 includes a CPU 11, a storage unit 12, an operation unit 13, a communication unit 14, and an interface unit 15. The CPU 11 controls the entire image reading apparatus A1 by executing a program stored in the storage unit 12. The storage unit 12 includes, for example, a RAM, a ROM, and the like. The operation unit 13 includes, for example, a switch, a touch panel, and the like, and accepts an operation from the operator.

  The communication unit 14 is an interface that performs information communication with an external device. When a PC (personal computer) is assumed as the external device, examples of the communication unit 14 include a USB interface and a SCSI interface. In addition to such a wired communication interface, the communication unit 14 may be a wireless communication interface, and may include both wired communication and wireless communication interfaces.

  The interface unit 15 is an I / O interface that inputs and outputs data with the actuator 16 and the sensor 17. The actuator 16 includes, for example, a motor for driving the feed roller 3, a motor for driving the pair of transport rollers 6, and a motor for driving the pair of discharge rollers 7. A part or all of these motors may be a single motor, and an actuator for switching drive transmission may be provided to enable independent driving. The actuator 16 also includes a drive source that drives the drive shaft 43, for example.

  The sensor 17 includes the sensor SR and the reading sensors 81 and 82 described above. The sensor 17 can include a sensor that detects the position of the sheet in the conveyance path CP. This sensor is, for example, a sensor that detects that a sheet has reached a predetermined position between the feed roller 3 and the conveyance roller pair 6, or a sheet that has reached a predetermined position between the conveyance roller pair 6 and the reading unit 8. This is a sensor for detecting the occurrence. In addition, the sensor 17 can include a sensor that detects the conveyance amount of the sheet from a predetermined position (for example, a sensor that detects the rotation amount of the roller).

<Operation of Image Reading Apparatus A>
A sheet reading operation by the image reading apparatus A will be described. When the user stacks one or more sheets on the tray 1 and instructs the start of reading, the reading operation is started. The sheets are stacked on the tray 1 with the surface facing downward, for example. Reading can be instructed from the operation unit 13 or an external device such as a PC, for example.

  The sheets on the tray 1 are introduced into the conveyance path CP by the feed roller 3 and the separation roller 8 and are separated and conveyed one by one. The sheet reaches the conveyance roller pair 6, and the conveyance of the sheet in the conveyance path CP is continued by the conveyance roller pair 6. Thereafter, the back side image of the sheet is read by the reading sensor 62, and then the front side image is read by the reading sensor 61. Thereafter, the sheet is discharged to the tray T by the discharge roller pair 7. The read image data is, for example, processed by the control device 10 and transmitted to the user's PC or the like.

<Movement of nip part>
As shown in FIG. 1, when the sheet is conveyed, the nip portion N between the feed roller 3 and the separation roller 51 is located in the conveyance path CP. This position of the feed roller 3 is called a conveyance position. When the nip portion N is in the transport position and the user stacks the sheet bundle on the tray 1 without throwing the sheet bundle, the bundle of sheets S (hereinafter referred to as the sheet bundle S is expressed as shown in FIG. 3A). May come into contact with the nip portion N.

  3A, the middle layer portion of the end portion of the sheet bundle S is in contact with the nip portion N, and the middle layer portion protrudes from the lower layer portion of the sheet bundle S. This is due to the fact that the peripheral surface of the feed roller 3 protrudes upward from the bottom wall forming member 21 and is located in the transport path CP at the transport position. If feeding is started as it is, double feeding may occur. In addition, feeding order may be out of order. In other words, there are cases where the sheet S should be conveyed in order from the lower layer side, but the middle layer sheet S is conveyed first.

  In the present embodiment, as described above, the feed roller 3 is configured to be movable. FIG. 3B shows a state in which the feed roller 3 has moved to the retracted position. At the retracted position, the peripheral surface of the feed roller 3 is retracted from the transport path CP. In the example of the figure, the peripheral surface of the feed roller 3 is located below the conveyance path CP.

  Movement of the feed roller 3 from the transport position to the retracted position is performed by rotating the cam 44 in the direction of the arrow D2. When the cam 44 is rotated in the direction of the arrow D2, the feed roller 3 is rotated to the retracted position in the direction of the arrow D3 due to the weight of the feed roller 3 and the urging of the elastic member 54 via the separation roller 51. The separation roller 51 is also lowered by the urging of the elastic member 54 so as to follow the movement of the feed roller 3.

  The feed roller 3 is moved from the retracted position to the transport position by rotating the cam 44 in the direction opposite to the arrow D2. When the cam 44 is rotated in the direction opposite to the direction of the arrow D2, the cam 44 pushes up the support member 41 and the feed roller 3 returns to the transport position. The separation roller 51 is also pushed up by the cam 44 through the feed roller 3 and rises.

  In this embodiment, the movement of the feed roller 3 from the transport position to the retracted position uses the weight of the feed roller 3 and the urging of the elastic member 54 via the separation roller 51. The feed roller 3 may be moved by the driving force of the unit 4.

  When the feed roller 3 is positioned at the retracted position, the nip portion N is positioned at the same height as the bottom surface of the transport path CP (the top surface of the bottom wall forming member 21). The nip N may be located below the bottom surface of the transport path CP.

  3B, even if the user stacks the sheet bundle on the tray 1 without striking the sheet bundle S, the middle layer at the end of the sheet bundle S as shown in FIG. The part does not protrude and the lower layer part at the end of the sheet bundle S protrudes. This is because the peripheral surface of the feed roller 3 is retracted from the conveyance path CP. Further, in the mode of FIG. 3B, since the separation roller 51 is located at a position where the conveyance path CP is blocked, the sheet bundle S does not flow into the apparatus.

  More specifically, when the user places the sheet bundle S on the tray 1, the end of the sheet bundle S hits the separation roller 51. The sheet bundle S is wound obliquely so that the lowermost sheet of the sheet bundle S protrudes most along the wedge-shaped space formed by the peripheral surface of the separation roller 51 and the bottom wall forming member 21. Get in. Due to the presence of the separation roller 51, the sheet bundle S does not travel further downstream. Further, when the sheet bundle S is set in this way, its presence is detected by the sensor SR, and the control device 10 can recognize that the sheet S exists on the tray 1.

  In this way, in the present embodiment, it is possible to prevent double feeding or feeding order error. By adopting a configuration in which the feed roller 3 is moved, the configuration around the feed roller 3 is not complicated, and it is possible to prevent deterioration of maintainability.

<Control example>
An example of control executed by the CPU 11 of the control device 10 will be described with reference to FIG. Here, a case where the sheet is read after the image reading apparatus A is turned on is illustrated.

  When the power source of the image reading apparatus A is turned on, the control apparatus 10 performs an initial operation, and rotates the cam 44 in S1 to move the feed roller 3 to the retracted position. Thereby, the nip portion N formed by the feed roller 3 and the separation roller 51 is retracted from the transport path CP to the feed roller 3 side.

  In S2, it waits for a reading start instruction from the user. If there is a start instruction, the process proceeds to S3. In S3, the detection result of the sensor SR is acquired, and it is determined whether or not the sheet S is stacked on the tray 1. If it is not loaded, the process proceeds to S4. If it is loaded, the process proceeds to S5. In S4, a warning is given to the user. As the warning, for example, an error message such as “there is no document” is notified by an image or sound. You may alert | report on a user's PC. Thereafter, the process returns to S2.

  When the sheet bundle S is stacked on the tray 1, the feeding roller 3 is in the retracted position, so that the shape of the end portion of the sheet bundle S is as shown in FIG. In S5, the cam 44 is rotated to move the feed roller 3 to the transport position. As a result, the nip portion N moves into the transport path CP. The lowermost sheet S of the sheet bundle S comes into contact with the nip portion N.

  In S6, a reading process is performed. Here, the feed roller 3, the conveyance roller pair 6 and the discharge roller pair 7 are driven to convey the sheet S to the tray T. In the process, the image of the sheet S is read by the reading unit 8.

  In S7, the detection result of the sensor SR is acquired and it is determined whether or not the sheet S is stacked on the tray 1. If it is not loaded, the process proceeds to S8. If it is loaded, the process returns to S6 and the reading process is continued. When the sheets S are not stacked on the tray 1, reading of all the sheets S is completed. Therefore, in S8, the feed roller 3 is moved to the retracted position in preparation for the next reading operation. Thus, one unit of processing is completed.

<Second embodiment>
In the first embodiment, when the feed roller 3 is located at the retracted position, the separation path 51 blocks the conveyance path CP. However, another configuration that restricts the entry of the sheet into the conveyance path CP may be provided. . FIGS. 5A to 5C are explanatory views showing an example thereof. 5A shows a case where the feed roller 3 is located at the transport position, FIG. 5B shows a case where the feed roller 3 is located at the retracted position, and FIG. FIG. 6 is an arrow D5 direction view of FIG.

  In the case of this embodiment, the restriction part 23 is provided. In the case of the present embodiment, the restricting portion 23 is formed integrally with the bottom wall forming member 21 and is a protrusion protruding from the upper surface of the bottom wall forming member 21 into the transport path CP.

  In the present embodiment, as shown in FIG. 5C, the three regulating portions 23 are provided in the same position as viewed in the sheet conveying direction in a direction orthogonal to the sheet conveying direction, and two feeding rollers are provided. 3 is provided between the two outermost two places and the two feed rollers 3. Therefore, the restricting portions 23 are located on both sides of each nip portion N. In addition, the regulation part 23 may be 1 or 2 or 4 or more. When providing the some control part 23, the some control part 23 can be arrange | positioned in the position symmetrical with respect to the center of a sheet | seat. When dealing with various sheet sizes, a plurality of restricting portions 23 can be arranged at positions symmetrical with respect to the center of the width of the conveyance path CP.

  By providing the restricting portion 23, the sheet comes into contact with the restricting portion 23 and the entry into the conveyance path CP is suppressed. Therefore, as shown in FIG. 5B, when the feed roller 3 is located at the retracted position, the restricting portion 23 can more reliably restrict the introduction of the sheet into the conveyance path. The restricting unit 23 is particularly configured to prevent the separation roller 51 from blocking the conveyance path CP due to a configuration in which the separation roller 51 does not block the conveyance path CP when the feed roller 3 is located at the retracted position. It is effective when not moving up to.

  The protrusion height h2 in the conveyance path CP of the restricting portion 23 is a height that does not reach the nip portion N when the feed roller 3 is located at the conveyance position. That is, when the height of the nip portion N from the upper surface of the bottom wall forming member 21 is h1, the relationship is h1> h2. Thereby, when the feed roller 3 is located at the conveyance position, it is possible to prevent the restricting unit 23 from interfering with the conveyance of the sheet.

  Further, the position of the restricting portion 23 is within the range of the length W of the nip portion N in the sheet conveying direction. Accordingly, it is possible to avoid a situation in which the leading edge of the sheet is sandwiched beyond the nip portion N when the feeding roller 3 is moved to the transport position in a state where a plurality of sheets are in contact with the regulating portion 23. The restricting portion 23 can be disposed in a plane in which the shaft of the feed roller 3 and the separation roller 51 include the shaft.

<Third embodiment>
In 1st and 2nd embodiment, although the separation unit 5 provided with the separation roller 51 was illustrated, the structure using a separation pad may be sufficient. FIG. 6A and FIG. 6B are explanatory diagrams showing an example thereof. FIG. 6A shows the case where the feed roller 3 is in the transport position, and FIG. 6B shows the case where the feed roller 3 is in the retracted position.

  A separation unit 5 ′ replacing the separation unit 5 includes a separation pad member 56. The separation pad member 56 is a plate-like member, and a nip portion N is formed by pressing the feed pad 3 at one end thereof. A portion of the separation pad member 56 that forms the nip portion N can include a material having a high friction coefficient such as rubber.

  The other end of the separation pad member 56 is supported by a support member 57. In the present embodiment, the support member 57 is a shaft that rotatably supports the separation pad 56. Hereinafter, the support member 57 may be referred to as a support shaft 57. The support shaft 57 is an axis parallel to the rotation axis of the feed roller 3 and is supported by the casing of the opening / closing unit U2. For this reason, the separation pad member 56 can be rotated about an axis parallel to the rotation axis of the feed roller 3, in other words, can be rotated in the sheet conveyance direction.

  The elastic member 58 is loaded between the separation pad member 56 and the casing of the opening / closing unit U2, and here is a coil spring but may be rubber or the like. The elastic member 58 always imparts a turning behavior in the direction in which the separation pad member 56 is in pressure contact with the feed roller 3.

  The rotation of the separation pad member 56 can be restricted by the lock mechanism 9 so as to be releasable. In the case of this embodiment, the lock mechanism 9 includes an arm member 92. A drive shaft 92 is attached to the center of rotation of the arm member 92. The drive shaft 92 is an axis parallel to the rotation axis of the feed roller 3 and is rotated by a drive mechanism (not shown). The drive mechanism includes a drive source such as an electromagnetic solenoid and a transmission member that transmits the drive force of the drive source to the drive shaft 92.

  As shown in FIG. 6A, when the feed roller 3 is at the transport position, the arm member 92 is separated from the separation pad member 56. The separation pad member 56 abuts on the circumferential surface of the feed roller 3 by the urging force of the elastic member 58 to form a nip portion N, but is in a state of being able to rotate to the downstream side in the conveyance direction, so that the sheet passes therethrough. Is acceptable.

  As shown in FIG. 6B, when the feed roller 3 is in the retracted position, the arm member 92 is rotated in the direction of the arrow D7 and abuts against the separation pad member 56 to restrict the rotation. This prevents the sheet from passing.

  In this way, the arm member 92 moves in conjunction with the position of the feed roller 3, and when the feed roller 3 is in the transport position, as shown in FIG. 6A, the arm member 92 is separated from the separation pad member 56. The separation pad member 56 is allowed to rotate. On the other hand, as shown in FIG. 6B, when the feed roller 3 is in the retracted position, the arm member 92 moves to a position in contact with the separation pad member 56 and prevents the separation pad member 56 from rotating.

  The principle of movement of the feed roller 3 is the same as in the first embodiment. When the feed roller 3 moves from the transport position to the retracted position, the feed roller 3 moves due to the weight of the feed roller 3 and the urging of the elastic member 58 via the separation pad member 56. When the feed roller 3 moves from the retracted position to the transport position, the roller 3 moves as the cam 44 is pushed up.

  As in the first embodiment, when the feeding roller 3 is in the retracted position, the sheet bundle is located in the lowermost layer of the sheet bundle along the wedge-shaped space formed by the arm member 92 and the bottom wall forming member 21. Enters the space while being slanted so as to protrude most. Accordingly, it is possible to prevent the middle layer portion of the end portion of the sheet bundle S from protruding.

<Other embodiments>
In the first to third embodiments, the image reading apparatus has been described as an embodiment of the present invention. However, the present invention is not limited to this, and the present invention can be applied to various apparatuses including a sheet feeding apparatus that feeds sheets. is there. For example, the present invention can be applied to an image forming apparatus such as a copying machine or a printer.

A image reading device, 1 tray, 2 transport path forming member, 3 feed roller, 4 drive unit, 5 separation unit

Claims (13)

A conveyance path forming means for forming a conveyance path through which the sheet is conveyed;
A tray on which sheets to be introduced into the conveyance path are stacked;
A roller for conveying the sheet on the tray to the conveyance path;
Separating means for pressing the roller and separating one sheet from the sheet bundle;
Drive means for moving the roller between a transport position where the peripheral surface of the roller is located in the transport path and a retracted position where the peripheral surface of the roller is retracted from the transport path;
A feeding device characterized by that. The feeding device according to claim 1,
When the roller is located at the retracted position, the separating means is located at a position closing the conveying path;
A feeding device characterized by that. The feeding device according to claim 1,
A regulation means for regulating the introduction of the sheet into the conveyance path when the roller protrudes into the conveyance path and the roller is located at the retracted position;
A feeding device characterized by that. The feeding device according to claim 3,
The protruding height of the restricting means in the transport path is a height that does not reach the pressure contact portion between the roller and the separating means when the roller is located at the transport position.
A feeding device characterized by that. The feeding device according to claim 3 or 4,
The regulating means is located within a range of the length of the pressure contact portion in the sheet conveying direction.
A feeding device characterized by that. The feeding device according to claim 1,
The separating means includes
A separation pad member in pressure contact with the roller;
A support means for supporting the separation pad member so as to be rotatable in a sheet conveying direction;
An elastic member for urging the separation pad member against the roller;
A lock mechanism for releasably restricting the rotation of the separation pad member to the downstream side in the sheet conveyance direction,
A feeding device characterized by that. The feeding device according to claim 1,
The driving means includes
Support means for movably supporting the roller between the transport position and the retracted position;
A cam mechanism that contacts the support means and moves the roller together with the support means,
A feeding device characterized by that. The feeding device according to claim 7, wherein
The support means supports the roller so as to be rotatable between the transport position and the retracted position.
A feeding device characterized by that. The feeding device according to claim 1,
The tray and the conveyance path are inclined downward with respect to the horizontal direction toward the downstream side in the conveyance direction,
The roller is located below the conveying path;
The separation means is located above the transport path;
A feeding device characterized by that. The feeding device according to claim 1,
The separating means includes
A separation roller in pressure contact with the roller;
A supporting means for supporting the separation roller so as to be rotatable in a sheet conveying direction;
An elastic member for biasing the separation roller to the roller,
A feeding device characterized by that. The feeding device according to claim 1,
Control means for controlling the drive means;
The control means moves the roller to the conveyance position when conveying a sheet on the tray, and moves the roller to the retracted position when not conveying the sheet.
A feeding device characterized by that. The feeding device according to claim 11,
Detecting means for detecting whether or not a sheet exists on the tray;
The control means includes
When the presence of the sheet is detected by the detection unit and a start instruction from the user is received, the roller is moved to the transport position,
When the presence of the sheet is not detected by the detection unit, the roller is moved to the retracted position.
A feeding device characterized by that. A feeding device according to any one of claims 1 to 12,
Reading means for reading an image of a sheet fed by the feeding device,
An image reading apparatus.

Images