JP5276705B2 - Sheet feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost and highly reliable sheet feeder by using a sheet abnormality detection unit for detecting the opened/closed state of a sheet stacking unit without adding any new detection unit when the sheet stacking unit is openable/closable. <P>SOLUTION: The sheet feeder includes a platen 301 having an open/close part (301b) on which a sheet is placed in the opened state of the open/close part (301b), a pickup roller (4) for feeding a document set on the platen (301), and a document abnormality detection sensor (SS1) for detecting abnormal conveying during separated sheet conveying. The platen (301) is disposed so that the closed state is detected by the document abnormality detection sensor (SS1) in the closed state of the open/close part (301b). The document abnormality detection sensor (SS1) detects the closed state in a state before the sheet is separated and conveyed. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a sheet feeding device, and more particularly to a sheet feeding device that feeds a sheet such as a document or printing paper.

  A sheet feeding apparatus 101 provided in the apparatus main body of the reading apparatus 200 shown in FIG. 1 sends out the sheets stacked on the sheet stacking table 1 from the sheet stacking table 1 by the pickup roller 4. At this time, the sheet stacking table 1 rises after stacking the sheets and presses the stacked sheets against the pickup roller 4.

  Further, when the sheets are sent out in a superimposed manner, the sheets overlapped by a feeding roller 6 provided adjacent to the pickup roller 4 on the downstream side of the pickup roller 4 and a separation roller 7 in pressure contact with the feeding roller 6. Are separated one by one and fed into the apparatus main body.

  The separation roller 7 constantly receives a rotational force for returning the sheet to the upstream side opposite to the downstream side in the sheet feeding direction from the separation motor 9 via a device that transmits a driving force such as a torque limiter (not shown). ing.

  When only one sheet exists between the feeding roller 6 and the separation roller 7, the force of feeding the sheet of the feeding roller 6 exceeds the upper limit value of the rotational driving force that can be transmitted by the torque limiter. The separation roller 7 rotates following the feeding roller 6 and feeds the sheet in the feeding direction.

  On the other hand, when there are a plurality of sheets between the feeding roller 6 and the separation roller 7, the separation roller 7 rotates in a direction to return the sheet to the upstream side, and returns the sheet other than the uppermost sheet to the upstream side. In this way, only one sheet can be fed.

  In the sheet feeding apparatus 101, sheets that are normally separated one by one are stacked and stacked on the sheet stacking table 1.

  However, a sheet bundle stopped by a staple or a clip or a sheet bundle bound by gluing or the like may be erroneously stacked on the sheet stacking table 1. The sheet feeding apparatus 101 attempts to separate and feed even a bundle of bound sheets like these one by one.

  In such a case, the uppermost sheet fed out by the pickup roller 4 in the sheet bundle is rotated so as to be rolled up around the bound portion and becomes a crease or tear, or the entire sheet bundle is rotated. It becomes a distorted shape.

  As described above, when the bound sheet bundle is mistakenly fed, the sheet is damaged as described above, and further, a sheet jam occurs in the sheet feeding apparatus 101.

  In order to cope with the above-described problems, there is a device that uses an optical sensor as a means for detecting abnormal conveyance of a sheet in a sheet feeding device (see Patent Document 1). In such a sheet feeding apparatus using an optical sensor that detects light crossing above a stacked sheet, the state of the sheet is detected from a change in the amount of light caused by the sheet blocking the optical path.

  Specifically, when the bound sheet bundle is rolled up during feeding, the amount of light received by the sheet bundle blocking the light falls below a certain set value, and from this change the sheet is bound by staples or the like. The feeding operation is stopped because it is determined that it is in a state of being stopped. This prevents damage to the sheet and occurrence of jam.

JP 2004-182449 A

  However, in Patent Document 1, when an operation such as a foreign object that cannot be transported is placed on the sheet stacking table, the operation starts with the sheet stacking table rising, and the sheet stacked between the sheet stacking table and the pickup roller or stacked sheets. There is a risk that an obstacle will be caught between the pickup roller and the pickup roller. Therefore, if the feeding operation is started as it is, there is a possibility that the obstacle is damaged or the inside of the transport path is damaged and the apparatus is damaged.

  In addition, when the sheet stacking table can be opened and closed and no opening / closing detection means is provided, if the sheet stacking table is accidentally moved up and down while the sheet stacking table is closed, the sheet stacking table can be operated with the sheet stacking table closed. Since the range is narrow, it is possible to operate beyond this and damage the device.

  In addition, if the sheet stacker is closed accidentally with the sheets loaded, the sheets will be bent significantly or the sheets may be caught in the opening / closing section, causing improper binding force on the sheets. Starting the process may damage the sheet.

  In order to prevent the damage of the apparatus and the sheet as described above, it is necessary to detect the open / close state of the sheet stacking table and control the operation.

  However, conventionally, in order to detect the open / closed state of the sheet stacking table, it is necessary to separately provide a new detecting means, which causes an increase in cost.

  Therefore, the present invention uses a sheet abnormality detecting means for detecting the open / closed state of the sheet stacking means when the sheet stacking means is openable and closable, so that it is reliable at low cost without adding a new detecting means. An object of the present invention is to provide a highly efficient sheet feeding apparatus.

To achieve the above object, the sheet feeding apparatus of the present invention, one and the sheet stacking means sheet is stacked, a sheet on said sheet stacking means has a closing portion in the open state of the closing part A sheet feeding unit that separates and feeds the sheet , and a sheet abnormality detecting unit that detects an abnormality of the sheet after starting the sheet separation and feeding. The sheet abnormality detection means is provided so that the closed state of the opening / closing portion is detected by the sheet abnormality detection means, and the sheet abnormality detection means is provided by the sheet stacking means in a standby state before the start of sheet separation and feeding. a means for detecting the closed state of the switching unit, wherein when the sheet abnormality detection unit detects the abnormality of the sheet after the start feeding sheet separated and fed, while the operation of the separation feeding means is stopped, the Sea Abnormality in the detection means while detecting the closed state of the closing part, characterized in that it is not performed feeding sheet separated and fed by said separating and feeding means.

  According to the present invention, when the sheet stacking means is configured to be openable and closable, the sheet abnormality detecting means is also used for detecting the open / closed state of the sheet stacking means, thereby reducing the cost without adding a new detecting means. Can improve the reliability.

1 is a schematic cross-sectional view for explaining an original reading apparatus according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram for explaining a main part of the document reading apparatus shown in FIG. 1. FIG. 2 is a side view schematically showing main parts of the document feeder in FIG. 1. FIG. 2 is a perspective view schematically showing a main part of the document feeder in FIG. 1. FIG. 5A is a perspective view showing a state in which corners of a bundle of documents are bound by staples, and FIG. 5B is a perspective view showing a state in which the document jumps up with the corners of the bundle of documents bound by staples. FIG. 6 is a perspective view showing a state where an obstacle is approaching the document feeder. 4A and 4B are diagrams for explaining a document reading apparatus including a document feeding apparatus according to a second embodiment of the present invention, where FIG. 5A is a plan view and FIG. FIG. 5 is a side view showing a state in which a document table movable portion is closed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a document reading apparatus provided with a document feeding apparatus according to the first embodiment of the present invention will be described.

  FIG. 1 is a schematic cross-sectional view for explaining an original reading apparatus according to a first embodiment of the present invention, and FIG. 2 is an explanatory view for explaining a main part of the original reading apparatus shown in FIG.

  1 and 2, the document reading device 200 includes a document feeding device (sheet feeding device) 101.

  A plurality of documents are stacked on the document table 1 as the sheet stacking means, and the document table 1 is configured to be movable up and down. The document table drive motor 2 is a moving means and moves the document table 1 up and down. The moving means may be a linear motor other than a stepping motor. The document detection sensor 3 detects a document stacked on the document table 1. The pick-up roller 4 (take-in means) sends out the originals stacked on the original table 1 from the original table 1. The pickup roller drive motor 5 rotates the pickup roller 4.

  The feed roller 6 is driven by a feed motor 8 so as to rotate in a direction in which a document is fed downstream. The separation roller 7 constantly receives a rotational force that rotates in a direction to push back the document upstream, from the separation motor 9 via a torque limiter (slip clutch) (not shown).

  When there is one document between the feeding roller 6 and the separation roller 7, the feeding roller determines the upper limit value of the rotational torque transmitted to the separation roller 7 by the torque limiter in the direction of pushing the document back to the upstream side. The rotational torque in the direction in which the document No. 6 is fed downstream is higher. As a result, the separation roller 7 rotates following the feeding roller 6.

  On the other hand, when there are a plurality of documents between the feeding roller 6 and the separation roller 7, the separation roller 7 rotates in a direction to push the document back to the upstream side and pushes back other than the uppermost document.

  In this way, the nip portion between the feeding roller 6 and the separation roller 7 is overlapped by the action of the feeding roller 6 feeding the document to the downstream side and the action of pushing back the document of the separation roller 7 to the upstream side. Only the uppermost document is fed downstream. The documents other than the uppermost document are pushed back to the upstream side, and the stacked documents are separated and fed. Therefore, the feeding roller 6 and the separation roller 7 constitute a pair of separation rollers 42 (separation feeding means).

  In the present embodiment, the separation roller pair 42 is employed as the separation feeding unit. However, instead of the separation roller pair 42, a separation belt roller pair in which either the separation roller or the feeding roller is a belt. May be adopted. Alternatively, a separation pad may be used in place of the separation roller 7.

  The transport motor 10 drives a roller for transporting the separated and fed document from the document reading position to the discharge position. Further, the transport motor 10 drives a roller so that the document transport speed can be changed according to the optimum speed for reading the document, the resolution of the document, and the like.

  The nip gap adjusting motor 11 adjusts a gap between the feeding roller 6 and the separation roller 7 or a pressure contact force with which the feeding roller 6 is pressed against the separation roller 7 via the document. As a result, the gap or pressure contact force suitable for the thickness of the document is adjusted, and the document can be separated and fed.

  The document reading unit 43 includes document reading sensors 14 and 15 that read a document, and is controlled to change a line scanning interval based on settings of a document reading speed and resolution. Using the document discharge sensor 16, it can be detected that the document passes through the document reading unit 43 and is being discharged to the discharge stacking unit 44.

  The registration clutch 19 is controlled to switch between a state where the rotational driving force of the transport motor 10 is transmitted to the registration roller 18 and a state where the transmission is interrupted. In a state where the rotation of the registration roller pairs 17 and 18 is stopped, the skew of the original can be corrected by causing the leading edge of the fed document to abut against the nip portion of the registration roller pair 17 and 18.

  The conveyance roller pair 20, 21, the conveyance roller pair 22, 23, and the downstream roller pair convey the document to the discharge stacking unit 44. The upper guide plate 40 and the lower guide plate 41 guide the document conveyed by the separation roller pair 42, the registration roller pair 17, 18, the conveyance roller pair 20, 21, the conveyance roller pair 22, 23, and the downstream roller pair. To do.

  When the separation / feed operation of all the originals is completed and the standby of the originals placed on the original platen 1, the original platen 1 performs the lowering operation and stops when it moves to the lowermost part of the driving range. . Then, the document is placed on the document table 1 and waits until an instruction to start the separation and feeding operation is given.

  The pre-feed sensor S1 detects the front end (downstream end) of the fed document. The post-feed sensor S2 detects the rear end (upstream end) of the fed document. The pre-registration sensor S3 is disposed on the upstream side of the registration roller pair 17 and 18, and detects the conveyed document. The post-registration sensor S4 is disposed on the downstream side of the registration roller pair 17 and 18, and detects the conveyed document.

  The control unit 45 controls the entire document reading apparatus 200 including the document feeding apparatus 101, and controls the motors based on output signals from the sensors to control the rotation of the rollers. .

  3 is a side view schematically showing the main part of the document feeder 101 in FIG. 1, and FIG. 4 is a perspective view schematically showing the main part of the document feeder 101. As shown in FIG. 3 and 4 show the positional relationship among the document abnormality detection sensor SS1, the pickup roller 4, the document table 1, and the document restriction plate 50. FIG.

  3 and 4, the document abnormality detection sensor SS1 includes a light emitting unit SS1-a and a light receiving unit SS1-b. The light emitting unit SS1-a is configured by a light emitting element such as an LED, and the light receiving unit SS1-b is configured by a light receiving element such as a phototransistor. Both the light emitting unit SS1-a and the light receiving unit SS1-b are connected to the control unit 45 (see FIGS. 1 and 2).

  The light emitting unit SS1-a is disposed at a predetermined position of the apparatus main body near one side of the document table 1, and the light receiving unit SS1-b is a predetermined of the apparatus main body near the other side of the document table 1. Arranged in position. Since it is desirable that the optical path passes through the vicinity of the pickup roller 4 in order to reliably detect abnormal conveyance of the sheet, the light emitting unit SS1-a emits light toward the vicinity of the side surface of the pickup roller 4. Further, in order to surely prevent the pickup roller 4 from being caught by a hand or the like, it is necessary to arrange an optical path for detection in the vicinity of the upstream side of the pickup roller 4.

  The light emitted from the light emitting unit SS1-a of the document abnormality detection sensor SS1 passes near the upstream side of the pickup roller 4 and proceeds to the light receiving unit SS1-b disposed on the opposite side. The optical paths of light emitted from the light emitting unit SS1-a of the document abnormality detection sensor SS1 are substantially parallel to the document stacking surface of the document table 1 and substantially orthogonal to the feeding direction of the document F1.

  Next, detection of abnormal conveyance of a document using the document abnormality detection sensor SS1 will be described.

  As shown in FIG. 5A, when the corners of the document F1 are fixed to the document bundle F by the staple SP1, the document F1 is separated from the feeding roller 6 and the separation roller 7 (see FIG. 1 and FIG. 1). As shown in FIG. 5B, a part starts to jump up. This jumping up is due to distortion that occurs because the pickup roller 4 and the feeding roller 6 feed the paper while the document F1 is fixed by the staple SP1.

  A part of the document F1 that has jumped up blocks the light emitted from the light emitting unit SS1-a of the document abnormality detection sensor SS1, thereby reducing the amount of light received by the light receiving unit SS1-b and causing the document F to jump up (abnormal) Transport) is detected. The control unit 45 stops the rotation of the document feeding motor 5, the feeding motor 8, and the separation motor 9 in accordance with a change in the received light signal output from the light receiving unit SS1-b of the document abnormality detection sensor SS1.

  As described above, when the document abnormality detection sensor SS1 is used, during separation and feeding, when the light path from the light emitted from the light emitting unit SS1-a to the light receiving unit SS1-b is blocked by the document, the document Can be detected. Then, the control unit 45 controls to stop feeding the document based on the detection result.

  Here, in this embodiment, the document abnormality detection sensor SS1 is used to detect an obstacle near the pickup roller 4 on the document table 1 as follows.

  Immediately before separation feeding is started, the control unit 45 drives the document table drive motor 2 until the document F1 on the uppermost surface of the document stack F stacked on the document table 1 is pressed against the pickup roller 4. Raise 1 The document detection sensor 3 detects that the document F1 is in pressure contact with the pickup roller 4.

  When the document table 1 is raised before separation feeding is started, the document abnormality detection sensor SS1 is used as an obstacle detection sensor, and the light emitted from the light emitting unit SS1-a is received by the light receiving unit SS1-b. When the optical path to reach is blocked by an obstacle, it is detected as an obstacle.

  For example, as shown in FIG. 6, when the hand A1 or the like enters the vicinity of the pickup roller 4 and blocks the optical path of the document abnormality detection sensor SS1, the hand is detected as an obstacle. Thereby, injury etc. can be prevented. In addition, a document with unevenness or warpage that is difficult to convey is also detected as an obstacle.

  Then, the control unit 45 controls the document table drive motor 2 so as to stop the elevation of the document table 1 based on the detection result. The control unit 15 controls the document table drive motor 2 so as to lower the document table 1 after stopping the driving of the document table 1 based on the detection result, or the document table based on the detection result. Control may be performed such as reducing the torque of the document table drive motor 2 that raises 1.

  When the torque of the document table drive motor 2 is reduced, the obstacle is caught between the pickup roller 4 and the document table 1 by reducing the document table 1 to a minimum torque that allows the document table 1 to continue to rise. However, since the pressing force due to the rising of the document table 1 is weak, it can be safely stopped.

  Further, other obstacles such as a writing instrument can be similarly detected by using the document abnormality detection sensor SS1, and the ascent of the document table 1 can be stopped, so that it is possible to prevent damage to the placed document or the apparatus. .

  Note that an abnormal conveyance or an obstacle can be detected by using an ultrasonic wave transmitting element / ultrasonic wave receiving element, which is an ultrasonic sensor, instead of a light emitting / light receiving element as a document abnormality detecting sensor.

  For example, when the disturbance light is strong at the place where the document feeder is installed, it may be difficult to detect abnormal conveyance or obstacles using the light emitting / receiving elements. In that case, the influence of disturbance light can be avoided by detecting abnormal conveyance using an ultrasonic sensor instead of the light emitting / receiving element.

  As described above, in the present embodiment, the document abnormality detection sensor SS1 for detecting the abnormal conveyance of the document is also used as an obstacle detection sensor when the document table 1 is raised, so that the vicinity of the pickup roller 4 is detected. Since the obstacle is detected and the ascent of the document table 1 is stopped or the ascending force is weakened, the safety in using the apparatus can be improved at low cost without adding a new detecting means.

  Next, with reference to FIG. 7 and FIG. 8, a document reading device provided with a document feeding device according to a second embodiment of the present invention will be described.

  FIG. 7 is a view for explaining an original reading apparatus provided with an original feeding apparatus according to the second embodiment of the present invention, and FIG. 8 is a view showing a state in which the original table is closed. In this embodiment, only different parts from those in the first embodiment will be described, and overlapping parts will be denoted by the same reference numerals in the drawings and description thereof will be omitted.

  As shown in FIGS. 7 and 8, in this embodiment, a document table 301 configured to be manually opened and closed is used instead of the document table 1. The document table 301 includes a document table fixing unit 301 a fixed to the document feeder, and a document table movable unit 301 b connected to the document table fixing unit 301 a through a hinge 302 so as to be opened and closed.

  The document table movable portion 301b is provided with a document regulating plate 351, and by pressing the document bundle F from both sides, the documents are prevented from being aligned and fed obliquely to assist stable feeding. FIG. 7A and FIG. 7B are diagrams in which the document is stacked on the document table 301 with the document table movable portion 301b of the document table 301 opened.

  As shown in FIG. 8, the document restricting plate 351 is used until the light emitted from the light emitting unit SS1-a of the document abnormality detection sensor SS1 reaches the light receiving unit SS1-b when the document table movable unit 301b is closed. It arrange | positions so that an optical path may be shielded.

  When the document table movable portion 301b is closed when no document is loaded on the document table 301, the document restriction plate 351 blocks the optical path of the document abnormality detection sensor SS1, and it is detected that the document table 3 is closed.

  Based on the detection result, the control unit 45 controls the document feed motor 5, the feed motor 8, and the separation motor 9 so as not to start the document separation / feed operation, and moves the document table 301 up and down. The document table drive motor 2 is controlled to stop the operation.

  Further, when the document is loaded on the document table 301 and the document table movable portion 301b is closed while the document table 1 is raised, the optical path of the document abnormality detection sensor SS1 is blocked by the document restriction plate 351 and the document bundle F. Then, it is detected that the document table 3 is closed.

  In this case, the control unit 45 controls the document feeding motor 5, the feeding motor 8, and the separation motor 9 so as not to start the separation feeding operation, and then the document table 301 is lowered to stop at the bottom of the driving range. Thus, the document table drive motor 2 is controlled.

  In this embodiment, the document restricting plate 351 is used as a part of the document table 301 that blocks the optical path of the document abnormality detection sensor SS1, but the opening / closing of the document table 301 is detected using the side surface of the document table movable unit 301b. You may do it.

  As described above, in the present embodiment, the document abnormality detection sensor SS1 for detecting the abnormal conveyance of the document is also used as the open / close state detection sensor of the document table 301 without adding new detection means. The reliability of the apparatus can be increased at low cost.

  That is, when the document table 301 is closed, it is possible to avoid the separation and feeding operation of the document and the raising / lowering operation of the document table 301, and the apparatus is damaged by operating beyond the movable range. Can be prevented.

  In addition, when the document table 301 is closed, the operation of starting the separation and feeding of the document is stopped. Therefore, when the document table 301 is closed, the document is greatly curved or is caught between the hinges 302 of the document table 301. Even if an inappropriate binding force is generated on the document, the document and the apparatus can be prevented from being damaged.

  Further, even when the document table is closed during the separation and feeding of the document, although it cannot be distinguished from the deformation of the document, the separation and feeding operation can be stopped immediately, so that the document can be prevented from being damaged.

  In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, in the above-described embodiment, the document feeding device has been exemplified. However, the present invention is not limited thereto. For example, the recording material feeding device for feeding a recording material for recording an image to the image forming unit of the image forming device. The present invention may be applied to.

  In the above-described embodiment, the case where the document feeding device is arranged in the device main body of the document reading device is illustrated. However, the present invention is not limited to this, and the document feeding device can be used, for example, for binding a document or punching a hole. The document may be arranged in the apparatus main body of the document post-processing apparatus to be fed to the document post-processing apparatus.

DESCRIPTION OF SYMBOLS 1 Document base 2 Document base drive motor 3 Document detection sensor 4 Pickup roller 5 Pickup roller drive motor 6 Feed roller 7 Separation roller 8 Feed motor 9 Separation motor 10 Conveyance motor 11 Nip gap adjustment motors 14 and 15 Document reading sensor 16 Document Discharge sensors 17 and 18 Registration roller 19 Registration clutch 20, 21, 22, and 23 Conveyance roller 40 Upper guide plate 41 Lower guide plate 42 Separating roller pair 43 Document reading unit 44 Discharge stacking unit 45 Control unit 50 Document restriction plate 101 Document feeding Device 200 Document reading device 301 Document table 301a Document table fixing unit 301b Document table movable unit 302 Hinge 351 Document restriction plate S1 Pre-feed sensor S2 Post-feed sensor S3 Pre-registration sensor S4 Post-registration sensor SS1 Document abnormality detection sensor SS1-a Light emitting part SS1-b Light receiving part F Bundles F1 manuscript SP1 stapling

Claims (11)

A sheet stacking means the sheets are stacked in the opened state of the closing part has an opening portion, and a separation feeding means for feeding by separating the sheets on said sheet stacking means one by one, the sheet separation A sheet abnormality detection means for detecting abnormality of the sheet after the start of feeding, and
The sheet stacking means is provided such that the closed state of the opening / closing part is detected by the sheet abnormality detecting means when the opening / closing part is in a closed state,
The sheet abnormality detection means is a means for detecting the closed state of the opening / closing unit by the sheet stacking means in a standby state before starting the separation and feeding of sheets .
When the sheet abnormality detection unit detects a sheet abnormality after the start of sheet separation and feeding, the operation of the separation feeding unit is stopped, while the sheet abnormality detection unit detects the closed state of the opening / closing unit. In this state, the sheet feeding apparatus is configured not to perform sheet separation and feeding by the separation feeding unit.   The sheet feeding apparatus according to claim 1, wherein the sheet abnormality detection unit detects the jumping of the sheet on the sheet stacking unit. The sheet abnormality detecting means detects a sheet abnormality in the vicinity of the upstream side of the sheet taking-in means , and is a sheet taking-in means for taking in the sheets stacked on the sheet stacking means in a state before separating and feeding sheets. The sheet feeding apparatus according to claim 1, wherein the sheet feeding device detects that the sheet stacking unit has approached an upstream side. A moving means for moving the sheet stacking means in the vertical direction; and a control means for controlling the moving means and the separation feeding means.
4. The control unit according to claim 1, wherein the control unit changes the control of the moving unit based on a detection result detected by the sheet abnormality detection unit. 5. Sheet feeding device.   5. The control unit according to claim 4, wherein the control unit controls the moving unit so that the sheet stacking unit is not raised when the sheet stacking unit is detected by the sheet abnormality detection unit. Sheet feeding device.   5. The control unit controls the moving unit to stop the lifting operation of the sheet stacking unit based on a detection result by the sheet abnormality detection unit before separating and feeding sheets. The sheet feeding apparatus described in 1.   The control means controls the moving means so as to stop the sheet stacking means at the lowest part of the driving range based on a detection result by the sheet abnormality detecting means at the time of separating and feeding sheets. The sheet feeding apparatus according to claim 4.   The said sheet | seat abnormality detection means has a light emission part which irradiates light, and a light-receiving part which light-receives the light irradiated by this light emission part, It is characterized by the above-mentioned. Sheet feeding device.   The sheet abnormality detecting means includes an ultrasonic wave transmitting unit that transmits ultrasonic waves and an ultrasonic wave receiving unit that receives ultrasonic waves transmitted from the ultrasonic wave transmitting unit. The sheet feeding apparatus according to any one of the above. An image reading apparatus comprising the sheet feeding device according to claim 1. An image forming apparatus comprising the sheet feeding device according to claim 1.

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