JP2017019606A - Feeding device, control method therefor, image reading device, image forming device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent causing damage to a manuscript by preventing conveyance abnormality of the manuscript generated because the manuscript is not set normally.SOLUTION: A feeding device includes a feeding part for feeding a sheet placed on a sheet placing part, a separation part for separating the sheet fed by the feeding part, and a conveyance part for conveying the sheet separated by the separation part. The feeding device stops conveyance of the sheet by the conveyance part, when a time from feeding start of the sheet by the feeding part until detection of the sheet by a detection part is shorter than a prescribed time.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a feeding technique for feeding and transporting a document inside an apparatus.

  2. Description of the Related Art Conventionally, there is an automatic document feeder (ADF) that automatically feeds and conveys a read document to and from a document reading device.

  Generally, the ADF is a document tray on which documents are stacked, a pickup roller that picks up and conveys documents from the document tray, and a separation that separates the documents conveyed from the pickup roller one by one and conveys them downstream. Department. The ADF also includes a shutter that regulates the leading edge of the document set on the document tray so that the separation operation at the separation unit is normally performed, and regulates the amount of the document inserted into the apparatus.

  When the document is fed and conveyed, the ADF allows the document to be fed into the apparatus by the pickup roller by opening the shutter. Further, when the discharge of the read original is completed, the shutter is closed to regulate the leading edge of the original set on the original tray as the ADF initialization operation. This shutter initialization timing may be performed when discharge of the read original is completed as described above, or when “ADF opening / closing” is performed as in Patent Document 1.

JP 2005-277533 A

  However, in a reading operation job by ADF, a document may be set on the stack tray of ADF before the shutter is initialized. In this case, since the shutter is in an open state, the document is set up to the separation unit located downstream of the shutter in the document conveyance direction, and there is a possibility that the separation operation during document feeding cannot be performed normally. If the conveyance of the document is continued in a state where the separation operation is not normally performed, a conveyance abnormality such as double feeding or jamming of the document may occur, and the document may be damaged.

  The present invention has been made in view of the above problems, and provides a technique capable of preventing an abnormality in the conveyance of a document due to a document not being set normally and preventing the document from being damaged. For the purpose.

In order to achieve the above object, a feeding device according to the present invention comprises the following arrangement. That is,
Separating means for separating sheets fed by the feeding means;
Conveying means for conveying the sheet separated by the separating means;
Detecting means for detecting that the sheet has reached the separating means;
Control means for stopping the conveyance of the sheet by the conveying means when the time from the start of the feeding of the sheet by the feeding means until the detection of the sheet by the detecting means is a predetermined time or less.

  According to the present invention, it is possible to prevent an abnormality in the conveyance of a document due to the document not being set normally and to prevent the document from being damaged.

2 is a cross-sectional view of an automatic document feeder. FIG. It is sectional drawing at the time of raising and lowering of a pickup roller. 3 is a block diagram illustrating a control configuration of an automatic document feeder. FIG. 6 is a flowchart illustrating an operation of the automatic document feeder.

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

  FIG. 1 is a sectional view of an automatic document feeder.

  As shown in FIG. 1, the automatic document feeder 1 includes a document placement tray (document placement portion) T1, a delivery path P1, and a discharge path along a conveyance direction (arrow K1 direction) of a document D that is a sheet. A paper tray T2 is provided. The automatic document feeder 1 also includes a transport path P2 that connects the vicinity of the downstream end and the vicinity of the upstream end of the transport path P1.

  The document placing tray T1 is gently inclined toward the side closer to the transport path P1 (downstream side in the document transport direction), and a plurality of documents D from which images can be read can be set in a stacked state. The set document D has its front end (end on the downstream side in the document transport direction) positioned by the shutter 12, and the side end in the direction orthogonal to the document transport direction is fed by a positioning member (not shown). Is positioned. The document D placed on the document placement tray T1 is placed with the surface having the image to be read facing upward. When both the front and back surfaces (one surface and two surfaces) are to be read, the first surface that is read first is placed facing upward.

  The conveyance path P1 guides the document D fed from the document placement tray T1 to a semi-circular U-turn and guides it to the flow reading glass (image reading position) G1, and further stops it below the flow reading glass G1. The document D after being read by the image reading unit 54 is conveyed so as to be raised obliquely and guided to the paper discharge tray T2. The transport path P2 branches at a branch point B1 in the vicinity of the paper discharge tray T2 in the transport path P1, and joins the transport path P1 at a junction B2 in front of the registration rollers 14 in the vicinity of the document placing tray T1 in the transport path P1. Yes. The conveyance path P <b> 2 guides the document D, which has been read from one side of the image and turned upside down, to the registration roller 14. Further, the image reading unit 54 can scan an image of a document placed on the document table glass G2 by scanning below the document table glass G2.

  The automatic document feeder 1 is provided with conveying members (feeding unit and conveying unit) such as a plurality of rollers for feeding and conveying the document D. A pickup roller 11 is disposed above the downstream end side of the document placing tray T1. In addition, a shutter 12, a separation roller 13a, a separation pad 13b, a registration roller 14, a lead roller 15, a pressing roller 16, a paper discharge roller 17, and a paper discharge reverse roller 18 that can be contacted and separated are disposed along the transport path P1. Has been.

  The separation roller 13 a separates the document D fed by the pickup roller 11 together with the separation pad 13 b and conveys it to the registration roller 14. The registration roller 14 performs registration of the document D by bringing the leading end of the document D conveyed to the nip portion into contact with the rotation of the registration roller 14 in a stopped state. The read roller 15 conveys the document D conveyed from the registration roller 14 to the flow reading glass G1. The pressing roller 16 regulates the floating of the conveyed document D on the flow reading glass G1. The paper discharge roller 17 conveys the document D after image reading by the image reading unit 54 described later toward the paper discharge reverse roller 18. The paper discharge reversing roller 18 rotates counterclockwise in the drawing, and discharges the document D for which image reading has been completed onto the paper discharge tray T2. When the image reading on the first side of the document D is completed and the image reading on the second side is performed, the paper discharge reverse roller 18 temporarily stops the rotation after conveying the document D1 halfway, and rotates clockwise in the figure. The document D is pulled into the transport path P2 by being reversed to the transport path P2 and transported toward the registration roller 14.

  FIG. 2 is an enlarged sectional view of the vicinity of the pickup roller 11 of the automatic document feeder 1. The operations of the pickup roller 11 and the shutter 12 during document feeding will be described with reference to FIG. 2A is a cross-sectional view when the pickup roller 11 is located at the standby position, and FIG. 2B is a cross-sectional view when the pickup roller 11 is located at the feeding position.

  The shutter 12 as a restricting unit is provided on the upstream side in the sheet conveying direction with respect to the separating unit (the separating roller 13a and the separating pad 13b), and the document D placed on the document placing tray T1 that is the sheet placing unit. It is possible to move to a regulation position that regulates the leading edge and an allowable position that allows the sheet to be conveyed to the separation unit. Since the shutter 12 is located at the restriction position, the front end of the document D abuts when the user sets the document D on the document placement tray T1 by the user. The amount of the original D inserted into is regulated. In this way, by restricting the leading edge of the document D by the shutter 12, the document D set by the user is prevented from being inserted to the positions of the separation roller 13a and the separation pad 13b. Further, it is possible to prevent abnormal conveyance such as double feeding or jamming that may occur when the document D is inserted to the position of the separation roller 13a and the separation pad 13b. The shutter 12 is configured to be interlocked with the operation of the pickup roller 11 by a shutter lock member 12a. Further, when the pickup roller 11 is positioned at the standby position shown in FIG. 2A before the conveyance of the document D is started, the shutter 12 is held at the regulation position by the shutter lock member 12a. When the pickup roller 11 moves to the feeding position where the document D is fed, the shutter lock member 12a releases the holding of the shutter 12 at the restriction position, thereby allowing the pickup roller 11 to convey the document D. To do.

  Since the shutter 12 is interlocked with the operation of the pickup roller 11, the shutter 12 is also initialized when the pickup roller 11 is initialized. The initialization operation at this time indicates a state in which the pickup roller 11 moves to the raised standby position and the shutter 12 is held by the shutter lock member 12a at the restriction position, as shown in FIG. . Initialization of the pickup roller 11 and the shutter 12 is performed before or after the start of the document feeding operation such as “when opening / closing the ADF”, “when setting the document”, “when the job is finished”, and the like. In the standby state after initialization, as shown in FIG. 2A, the pickup roller 11 stands by at the raised standby position, and the shutter 12 is held by the lock member 12a at the restricting position.

  When the feeding of the document D is started by the pickup roller 11, the pickup roller 11 is lowered to the feeding position as shown in FIG. At this time, as the pickup roller 11 is lowered, the shutter 12 is unlocked by the shutter lock member 12a, and the shutter 12 moves to the allowable position. Thereby, the conveyance of the document D is allowed, and the document D can be separated and conveyed by the separation roller 13a and the separation pad 13b. When the reading and discharging of the document D are completed, as the initialization operation of the automatic document feeder 1, the pickup roller 11 is raised to move the pickup roller 11 to the standby position and the shutter 12 to the restriction position.

  FIG. 3 is a block diagram showing the internal configuration of the automatic document feeder 1.

  The automatic document feeder 1 includes a CPU (control unit) 50 that controls the overall operation. The CPU 50 includes a RAM 51, a ROM 52, a communication I / F 53, a solenoid SL, an image reading unit 54, an image processing unit 55, a separation clutch C1, a registration clutch (registration clutch) C2, and an operation unit 57 via a system bus 56. It is connected. Further, a document size detection sensor S10, a document detection sensor S11, a final paper detection sensor S12, a separation motor M1, a read motor M2, and a registration sensor (registration sensor) S13 are connected to the CPU 50 via a system bus 56. Further, a read sensor S14, a timing sensor S15, a paper discharge sensor S16, and a timer counter T11 are connected to the CPU 50 via a system bus 56.

  The RAM 51 is a work area for the CPU 50 and a temporary storage area for data. The ROM 52 is written with a firmware program for driving the automatic document feeder 1 and a boot program for controlling the firmware program, and these are used by the CPU 50. The communication I / F 53 is connected to a system controller or an external device, through which an instruction for document conveyance, image data, and the like are transferred. The solenoid SL brings the paper discharge reversing roller 18 (FIG. 1) into contact / separation (contact / separation). The image reading unit 54 optically reads an image of the conveyed document D, performs image processing such as image determination and image correction by the image processing unit 55, and outputs the processed image to the system controller via the communication I / F 53. it can. The image processing unit 55 includes a printing rate calculation unit that calculates the printing rate of the image read by the image reading unit 54, and whether or not the printing rate calculated by the printing rate calculation unit is equal to or higher than a predetermined printing rate. A printing rate determination unit for determining This print rate can be calculated based on, for example, the number of prints present on the image and the white area.

  The separation clutch C1 connects and disconnects the drive of the separation motor M1 with respect to the separation roller 13a and the pickup roller 11. In other words, the separation roller 13a and the pickup roller 11 stop the document conveying operation for conveying the document (the document conveying operation can be stopped) by the separation clutch C1 being operated to cut the rotational force of the separation motor M1. ). The separation roller 13a and the pickup roller 11 are configured to be able to contact and separate from the document by a plunger (not shown), and the document conveying operation is stopped even when the plunger is actuated and separated from the document. It is configured as follows.

  The document size detection sensor S10 detects the size of the document D (for example, A4 size, B4 size, A3 size, etc.). The document detection sensor S11 detects whether or not the document D is set on the document placement tray T1. The final paper detection sensor S12 detects whether or not the original D fed by the pickup roller 11 is the final original. Here, the last paper detection sensor S12 is “ON” when the document D is set on the document placing tray T1, and the last sheet of the document D set on the document placing tray T1 is picked up. When the rear end of the document D (the end on the upstream side in the document transport direction) is transported by the roller 11 and is transported further downstream in the document transport direction than the final paper detection sensor S12, the “OFF” state is set. It is possible to detect paper.

  The read motor M2 rotationally drives the lead roller 15 and the paper discharge roller 17. The registration sensor S13 is disposed upstream of the registration roller 14 in the document conveyance direction, and detects the document D conveyed to the registration roller 14. The read sensor S14 is disposed upstream of the lead roller 15 in the document conveyance direction, and the read start timing of the image by the image reading unit 54 is controlled by the leading sensor S14 detecting the leading edge of the document D. The The timing sensor S15 is disposed in the vicinity of the separation roller 13a, and detects the end portion (front end / rear end) of the conveyed document D, so that the timing at which the document D is fed by the pickup roller 11 is detected. Be controlled. The paper discharge sensor S16 is disposed in the vicinity of the branch point B1, and detects that the original D on which an image has been read by the flow reading glass G1 is conveyed to the discharge position. The registration clutch C <b> 2 connects and disconnects the rotation of the separation motor M <b> 1 with respect to the registration roller 14. In any sensor, the time from when one sensor detects the leading edge of the document until the trailing edge of the document is detected, or from when the upstream sensor detects the leading edge of the document to when the downstream sensor detects the leading edge of the document. It is possible to detect the delay or stay of the document D during conveyance from the time, and it is possible to detect a jam in the conveyance paths P1 and P2. The timer counter T11 measures (measures) a time for detecting a delay jam or a stay jam of the document D at each sensor position and a time from the start of the document feeding / separating operation until the registration sensor S13 detects the document D. It is possible.

  As an example of the configuration, the conveyance drive necessary for conveying the document D is a configuration in which the conveyance drive is driven by two motors. Specifically, the pickup roller 11, the separation roller 13a, and the registration roller 14 are driven the same (driven by the separation motor M1), and the lead roller 15 and the paper discharge roller 17 are driven the same (driven by the lead motor M2).

  The CPU 50 can control operations of various components of the automatic document feeder 1 by reading a program stored in the ROM 52 and executing the program on the RAM 51. Various operations and settings for the automatic document feeder 1 or the image reading apparatus on which the automatic document feeder 1 is mounted are performed via the operation unit 57. The operation unit 57 includes, for example, a display unit (liquid crystal display, LED, etc.) for displaying the status of the apparatus, an instruction unit (button, touch panel), and the like. Various operations such as doubling can be performed.

  Next, as an operation of the automatic document feeder 1, an opening / closing (initialization) operation of the shutter 12 will be described. As shown in FIG. 2, the shutter 12 moves to the allowable position as the pickup roller 11 is lowered, and moves to the restriction position as the pickup roller 11 is raised.

  In such a configuration, in the present embodiment, the next document is set on the document placing tray T1 particularly when the shutter 12 is not moved to the restriction position, and the document is conveyed more than the restriction position of the shutter 12. A configuration for determining whether or not the device has been set up to the inside of the apparatus on the downstream side in the direction is realized.

  Specifically, it is determined whether or not the document D to be processed has been detected by the registration sensor S13 within a predetermined time after starting the feeding operation. Then, according to the determination result, when the document D to be processed is set on the document placing tray T1, it has been set inside the apparatus that is downstream of the restriction position of the shutter 12 in the document transport direction. Is detected. The specific operation will be described with reference to FIG.

  FIG. 4 is a flowchart showing the feeding operation of the automatic document feeder 1. Note that the flowchart shown in FIG. 4 is realized by the CPU 50 reading a program stored in the ROM 52 and executing it on the RAM 51.

  When the user presses a start key for starting scanning via the operation unit 57, the CPU 50 determines the presence or absence of the document D on the document tray T1 based on the detection result of the document detection sensor S11 (S201). ). As a result of the determination, if the document D is not placed on the document placement tray T1 (NO in S201), the image reading unit 54 is scanned below the document table glass G2 and placed on the document table glass G2. Fixed reading for reading the image of the document is performed (S209). Since this fixed reading is performed using a known technique, a detailed description thereof is omitted. On the other hand, as a result of the determination, when the document D is placed on the document placement tray T1 (YES in S201), the CPU 50 drives the separation motor M1 and drives the separation clutch C1 to lower the pickup roller 11. And move it to the feeding position. At this time, as the pickup roller 11 is lowered, the holding of the shutter lock member 12a is released, and the shutter 12 moves to a permissible position that allows conveyance of the document D. Thereafter, the CPU 50 rotates the separation roller 13a and the pickup roller 11 by driving the separation motor M1, and starts feeding / separating the document D (S202).

  After starting document feeding / separation, the CPU 50 starts measuring time (timer count Tn) by the timer counter T11 (S203). Then, the CPU 50 determines whether or not the registration sensor S13 is turned on (that is, the leading edge of the document D is conveyed to the registration roller 14) (S204). If the registration sensor S13 is not ON (NO in S204), the feeding and separation of the document D is continued until it is turned ON. On the other hand, when the registration sensor S13 is ON (YES in S204), the CPU 50 ends the time measurement (timer count Tn) by the timer counter T11 (S205).

  Then, the CPU 50 measures the document arrival time Tn measured by the timer counter T11 until the leading edge of the document D reaches the detection position of the registration sensor S13 after the document D starts feeding (when the registration sensor S13 is turned on from the start of feeding). It is determined whether or not (time until) is less than or equal to the predetermined time M (S206). At this time, the predetermined time M can determine whether or not the document D is inserted into the automatic document feeder 1 from the front end restriction position by the shutter 12 when the document D is placed on the document placement tray T1. Set to time. That is, when the document arrival time Tn is equal to or shorter than the predetermined time M, the time from when the document is fed until it reaches the registration sensor S13 is short, and the document placed on the document placement tray T1 is moved by the shutter 12. It can be determined that normal leading edge regulation is not performed and the leading edge of the document D is inserted to the downstream side in the document conveying direction from the shutter 12. When the document arrival time Tn is longer than the predetermined time M, the time from feeding the document D to reaching the registration sensor S13 is longer than the predetermined time, so the document placed on the document placement tray T1. It can be determined that the tip is normally regulated by the shutter 12 positioned at the regulation position.

  As a result of the determination, if the document arrival time Tn is longer than the predetermined time M (NO in S206), the CPU 50 determines that the document D has been correctly placed on the document placement tray T1, and continues to transport the document. Then, the image reading unit 54 performs a reading operation (S207).

  On the other hand, if the document arrival time Tn is equal to or shorter than the predetermined time M as a result of the determination (YES in S206), the document is not set correctly, that is, the document D is inserted to the downstream side in the document transport direction from the shutter 12 during document setting. Therefore, it is determined that there is a possibility that the separation operation of the document D is not performed correctly. In this case, the CPU 50 stops the feeding operation and outputs a separation alarm indicating a separation operation abnormality to the display unit of the operation unit 57 (S208). At this time, the user resets the document D that has not been correctly separated into the document placing tray T1, and presses a start key for starting scanning via the operation unit 57, thereby automatically feeding the document. The apparatus 1 can start the processing from S201 and start the document scanning operation again.

  The separation alarm in S208 is displayed until, for example, the original is set again on the original placement tray T1 and the original feeding is started. At this time, a message prompting the user to set the document again may be displayed on the display unit of the operation unit 57. Further, the document D is placed on the document placement tray T1 after the last sheet of the sheets placed on the document placement tray T1 is detected to have passed through the shutter 12 until the shutter 12 is closed. Predetermined information (warning information) such as a message indicating that it cannot be placed may be displayed on the display unit of the operation unit 57. Further, the warning information may be output not only by the display unit of the operation unit 57 but also by a lighting unit such as a lamp.

  In the present embodiment, the shutter 12 is configured to be interlocked with the operation of the pickup roller 11, but is not limited to this. For example, it may be configured to be provided with a stopper or the like that is driven separately from the pickup roller 11 and regulates the document at a predetermined position. Therefore, it is possible to prevent a document conveyance abnormality that may occur due to a set failure.

  As described above, according to the present embodiment, at the time of document feeding, the document arrival time from the start of feeding to a predetermined position is measured to detect a document setting position abnormality (separation operation abnormality). If an abnormality is detected, the document feeding and conveying operations are stopped. As a result, it is possible to prevent double feeding of documents, and to prevent jamming and reading errors due to document setting failure.

  Conventionally, the conveyance of the document is continued until various types of sensors detect a jam in the conveyance path. However, in this embodiment, the time from the start of document feeding until the leading edge of the document reaches the registration sensor S13. Therefore, it is possible to detect a set abnormality and to detect an abnormality during conveyance faster than in the past, and to stop conveyance. For this reason, it is possible to prevent document feeding due to the document not being set correctly, and conveyance errors such as jamming due to double feeding. Further, by preventing an abnormality in the conveyance of the original, it is possible to reduce the burden on the user when the original is damaged or the jam original is removed.

  In the above embodiment, the registration sensor S13 is used as a sensor for detecting a document setting failure. However, the present invention is not limited to this. For example, a document setting failure may be detected from the document arrival time from the start of document feeding until the leading edge of the document D is detected by the timing sensor S15, or upstream of the registration sensor S13 in the document conveyance direction. A new sensor may be provided on the side. At this time, by detecting a document setting failure using a sensor provided on the upstream side in the document conveyance direction in the conveyance path P1, it becomes possible to detect a document conveyance abnormality earlier, and before a jam occurs. Then, the conveyance of the document D can be stopped. For example, from the document arrival time until the leading edge of the document is detected by a new sensor that detects that the document has reached the position where the document is separated by the separation roller 13a and the separation pad 13b from the start of document feeding. By determining the setting failure, it is possible to detect the document setting failure earlier, and the conveyance of the document can be stopped before the jam occurs. As a result, damage to the document can be prevented, and the load on the user when removing the jammed document can be reduced.

  In addition, the normal value of the document arrival time for the document D to reach the detection position of various sensors arranged in the apparatus can be obtained empirically depending on the configuration of the conveyance path and the drive amount of the drive system. By using at least one of these various sensors, it is possible to detect a document setting failure or a jam in the conveyance path.

  Here, the document D reaches the detection positions of the various sensors at least when the leading edge / rear edge of the document D or an arbitrary position of the document D reaches the detection position (position where the sensor is turned on). Any one shall be included. Here, reaching the detection position means, for example, that the document D reaches a position where a line segment extending vertically downward toward the transport path and the transported document D intersect within the detection range of the sensor. means.

  In any case, here, at least one of various sensors arranged in the conveyance path of the automatic document feeder 1 is started after the feeding of the document D placed on the document placing tray T1 is started. The arrival time at which the sheet reaches the detection position of the sensor is measured. Then, based on the measurement result, the document reading state is determined on the upstream side in the transport direction of the document D with respect to the flow reading glass (image reading position) G1 by the image reading unit 54, and separation is performed according to the determination result. Control issuance of an alarm and the like, and stop of conveyance of the document D.

  With such a configuration, when a document set failure of the document D is detected, the fact is notified and the feeding and conveying operations are stopped. As a result, it is possible to prevent double feeding of the document D, and it is possible to prevent jamming and reading mistakes due to a defective set of the document D.

  The automatic document feeder 1 of the above embodiment can be used as a document feeder used in an image reading apparatus such as a copying machine or a facsimile. Further, the automatic document feeder 1 forms an image on a recording medium based on an image read by the image reading device, and supplies the original of a multifunction peripheral or a copier composed of the image forming device and the image reading device. It can also be used as a feeding device.

  In addition, the function of the above embodiment is realizable also with the following structures. That is, it is also achieved by supplying a program code for performing the processing of the present embodiment to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus executing the program code. In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code also realizes the function of the present embodiment.

  Further, the program code for realizing the function of the present embodiment may be executed by one computer (CPU, MPU), or may be executed by a plurality of computers cooperating. Also good. Further, the program code may be executed by a computer, or hardware such as a circuit for realizing the function of the program code may be provided. Alternatively, a part of the program code may be realized by hardware and the remaining part may be executed by a computer. Further, the CPU is not limited to the one that performs all the processing by one CPU, and a plurality of CPUs may perform the processing while appropriately cooperating.

  D: Document, G1: Flow reading glass, T1: Document placement tray, S10: Document size detection sensor: S10, S11: Document detection sensor, S12: Final paper document detection sensor, S13: Registration sensor, S14: Lead sensor, S15: Timing sensor, S16: Paper discharge sensor, 1: Automatic document feeder, 11: Pickup roller, 12: Shutter, 13a: Separation roller, 13b: Separation pad, 14: Registration roller, 50: Control unit, 55: Image processing unit

Claims (10)

A feeding means for feeding a sheet placed on the sheet placing portion;
Separating means for separating sheets fed by the feeding means;
Conveying means for conveying the sheet separated by the separating means;
Detecting means for detecting that the sheet has reached the separating means;
Control means for stopping the conveyance of the sheet by the conveying means when the time from the start of sheet feeding by the feeding means until the detection of the sheet by the detecting means is a predetermined time or less. Characteristic feeding device. The feeding device according to claim 1, wherein the detection unit detects that the sheet has reached the downstream side in the sheet conveyance direction with respect to the separation unit. The conveying means is a registration roller for performing registration of the sheet separated by the separating means;
The feeding device according to claim 1, wherein the detection unit detects that the sheet has reached the separation unit by detecting that the sheet has reached the registration roller. . It further comprises display means for displaying information to the user,
The said display means displays the information which shows that abnormality of separation operation | movement by the said separation means generate | occur | produced when the said time is below predetermined time. Feeding device. Provided upstream of the separating unit in the sheet conveying direction, and restricts the leading end of the sheet placed on the sheet placing unit, and allows the sheet to be conveyed to the separating unit. Further comprising a restricting means movable to an allowable position;
The predetermined time is a time during which it can be detected that the leading edge of the sheet placed on the sheet placing portion is placed on the downstream side in the sheet conveying direction from the restriction position. Item 5. The feeding device according to Item 4. The display means displays information indicating that a sheet cannot be placed on the sheet placing portion until the restricting means moves from the allowable position to the restricting position. Item 6. The feeding device according to Item 5. A feeding device according to any one of claims 1 to 6,
An image reading apparatus comprising: a reading unit that reads an image of a sheet conveyed by the conveying unit at a reading position. An image reading apparatus according to claim 7;
Image forming means for forming an image on a recording medium based on an image read by the image reading device;
An image forming apparatus comprising: A feeding unit that feeds the sheet placed on the sheet placing unit; a separating unit that separates the sheet fed by the feeding unit; and a conveying unit that conveys the sheet separated by the separating unit. A method of controlling a feeding device comprising:
A detection step of detecting that the sheet has reached the separating means;
And a control step of stopping the conveyance of the sheet by the conveyance unit when the time from the start of the sheet feeding by the feeding unit to the time when the sheet is detected in the detection step is a predetermined time or less. A method for controlling a feeding device. A feeding unit that feeds the sheet placed on the sheet placing unit; a separating unit that separates the sheet fed by the feeding unit; and a conveying unit that conveys the sheet separated by the separating unit. And a computer of a feeding device comprising:
A detection step of detecting that the sheet has reached the separating means;
And a control step of stopping the conveyance of the sheet by the conveying unit when the time from the start of the sheet feeding by the feeding unit to the detection of the sheet in the detection step being a predetermined time or less. Program.

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