JP2017186138A - Medium feeder, image reader, and recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medium feeder capable of more appropriately feeding out a medium.SOLUTION: A medium feeder comprises: a medium placement section on which a medium is placed; a feeding roller feeding out the medium from the medium placement section; and a control section controlling the feeding roller. The control section can execute a roller drive mode for alternately performing driving and stoppage of the feeding roller with a rotation amount less than a rotation amount at the time of medium feeding. In the roller drive mode, the control section switches a rotation speed of the feeding roller. In the roller drive mode, the control section alternately switches a rotation direction of the feeding roller between a normal rotation direction and a reverse rotation direction. The control section executes the roller drive mode before feeding of the medium.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a medium feeding apparatus for feeding a medium, and an image reading apparatus and a recording apparatus including the medium feeding apparatus.

  Hereinafter, a scanner which is an example of an image reading apparatus will be described as an example. The scanner is provided with a feeding device (also called ADF (Auto Document Feeder)) that automatically feeds a document that is an example of a medium, and may be configured to automatically feed and read a plurality of documents. is there.

As a configuration of such a feeding apparatus, as shown in Patent Document 1, a tray on which a document is placed (“Paper Plate 103” in Patent Document 1) and a surface of the document set in the tray are contacted. And a separation roller ("retard roller 114" in Patent Document 1) that feeds the original document and separates the original document in contact with the feeding roller. )).
Further, the paper transport device described in Patent Document 1 employs a configuration in which a feeding roller is in contact with the bottom paper among the set papers and is fed out from the bottom paper.

  Further, in the paper conveying apparatus described in Patent Document 1, an ultrasonic sensor (ultrasonic sensor 115 in Patent Document 1) is provided on the downstream side of the feeding roller and the separation roller. Arranged across the road, it is used to detect double feeding of documents.

  Furthermore, in the paper conveyance device described in Patent Document 1, a paper detection unit (“second paper detection unit 118” in Patent Document 1) that detects paper is provided on the downstream side of the ultrasonic sensor. Based on the detection signal of the paper detection unit, it is configured to monitor whether or not the front end of the paper has moved to the front of the imaging unit.

JP 2014-047050 A

  In some cases, the sheets set in the tray cannot be separated due to sticking between sheets, burrs at the front end, turning over, or the like. Such a problem can be suppressed if the user sufficiently rolls the paper bundle before setting the paper, but sufficient paper turning is not always performed.

  Some conventional feeding devices perform a retry operation (re-feed operation) when the paper detection sensor provided downstream of the feed roller does not detect the passage of the leading edge of the paper. However, in many cases, it is difficult to eliminate the state in which the sheets are stuck together as described above.

  Accordingly, the present invention has been made in view of such problems, and an object of the present invention is to provide a medium feeding device capable of feeding out a medium more appropriately.

  In order to solve the above problems, a medium feeding device according to a first aspect of the present invention includes a medium loading unit for loading a medium, a feeding roller for feeding the medium from the medium loading unit, and the feeding roller. A control unit that controls the feed roller, and the control unit is capable of executing a roller drive mode that alternately drives and stops the feed roller with a rotation amount smaller than the rotation amount at the time of feeding the medium. It is characterized by that.

  According to this aspect, the control unit that controls the feeding roller can execute a roller driving mode in which the feeding roller is alternately driven and stopped at a rotation amount smaller than the rotation amount at the time of feeding the medium. By executing the roller driving mode, it is possible to impart a rolling effect to the medium placed on the placement section, and thus it is possible to feed the medium appropriately.

According to a second aspect of the present invention, in the first aspect, the control unit switches a rotation speed of the feeding roller in the roller driving mode.
According to this aspect, the control unit switches the rotation speed of the feeding roller in the roller driving mode, that is, changes the whirling effect to be applied to the medium placed on the placement unit. The medium placed on the placement section can be effectively spread.

  According to a third aspect of the present invention, in the first or second aspect, the control unit alternately switches the rotation direction of the feeding roller between a normal rotation direction and a reverse rotation direction in the roller driving mode. Features.

  According to this aspect, the control unit alternately switches the rotation direction of the feeding roller between the normal rotation direction and the reverse rotation direction in the roller driving mode, that is, with respect to the medium placed on the placement unit. Since the imparting effect to be imparted is changed, the medium placed on the placement section can be more effectively spread.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the control unit executes the roller driving mode before feeding the medium.
According to this aspect, the control unit executes the roller driving mode before feeding the medium, that is, imparts a rolling effect to the medium before feeding the medium, and therefore feeds the medium appropriately. be able to.

  According to a fifth aspect of the present invention, in any one of the first and fourth aspects, a detection unit that detects passage of the medium is provided downstream of the feeding roller, and the control unit feeds the medium. The roller driving mode is executed when the detecting means does not detect the passage of the medium even when the feeding roller is rotated by a predetermined amount or more during operation.

  According to this aspect, the control unit executes the roller driving mode when the detection unit does not detect the passage of the medium even if the feeding roller is rotated by a predetermined amount or more during the medium feeding operation. The elimination of non-feed can be expected.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the control unit switches whether to execute the roller drive mode according to the type of the medium.
According to this aspect, the control unit switches whether to execute the roller driving mode according to the type of the medium, and therefore does not execute the roller driving mode when feeding a medium that does not need to be spun, for example. As a result, a decrease in throughput can be suppressed.

  According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the control unit changes the number of times of driving the feeding roller in the roller driving mode according to the type of the medium. And

  According to this aspect, the control unit changes the number of times of driving of the feeding roller in the roller driving mode according to the type of the medium. Therefore, for example, when feeding a medium with a slight degree of adhesion between the media, Decreasing the throughput can be suppressed by reducing the number of times of driving the feeding roller.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the feeding roller is in contact with a lowest-order medium among the media placed on the medium placement section. To do.
According to this aspect, since the feeding roller is in contact with the lowest medium among the media placed on the medium placement unit, the entire bundle of media is moved back and forth when the roller driving mode is executed. It is easy to move, and a medium-sparing effect can be obtained effectively.

  An image reading apparatus according to a ninth aspect of the present invention includes a reading unit that reads a medium, and a medium feeding device according to any one of the first to eighth aspects that feeds the medium toward the reading unit. , Provided.

  A recording apparatus according to a tenth aspect of the present invention is a medium feeding apparatus according to any one of the first to eighth aspects, wherein the recording means performs recording on a medium, and the medium is fed to the recording means side. And.

  According to the ninth aspect, in the image reading apparatus, and according to the tenth aspect, in the recording apparatus, it is possible to obtain the same operational effects as any of the first to eighth aspects described above. .

FIG. 3 is a perspective view of a medium in a non-feed state in the image reading apparatus according to the present invention. FIG. 3 is a perspective view showing a state in which the cover is opened and the paper discharge tray is unfolded in the image reading apparatus according to the present invention. FIG. 3 is a side view showing a medium feeding path in the image reading apparatus according to the present invention. The perspective view which shows the state which rotated the upper unit with respect to the lower unit in the image reading apparatus. The perspective view which shows the periphery of a feeding roller. The side view which shows the feed start state of the feed roller which concerns on a 1st Example. The side view which shows the roller drive mode execution state of the feeding roller which concerns on a 1st Example. The side view which shows the state after roller driving mode execution of the feeding roller which concerns on a 1st Example. The flowchart figure of the roller drive mode in the feed roller which concerns on a 1st Example. The flowchart figure of the roller drive mode in the feed roller which concerns on the example of a change of a 1st Example. The side view which shows the roller drive mode execution state of the feeding roller which concerns on a 2nd Example. The flowchart figure of the roller drive mode in the feed roller which concerns on a 2nd Example. The flowchart figure of the roller drive mode in the feed roller which concerns on the example of a change of a 2nd Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the same structure in each Example, the same code | symbol is attached | subjected and it demonstrates only in the first Example, The description of the structure is abbreviate | omitted in a subsequent Example.

  FIG. 1 is a perspective view of a non-feed state of a medium in an image reading apparatus according to the present invention, and FIG. 2 is a perspective view illustrating a state in which a cover is opened and a paper discharge tray is unfolded in the image reading apparatus according to the present invention. 3 is a side view showing a medium feeding path in the image reading apparatus according to the present invention, and FIG. 4 is a perspective view showing a state in which the upper unit is rotated with respect to the lower unit in the image reading apparatus. FIG. 5 is a perspective view showing the periphery of the feeding roller.

  6 is a side view showing a feeding start state of the feeding roller according to the first embodiment, and FIG. 7 is a side view showing a roller driving mode execution state of the feeding roller according to the first embodiment. FIG. 8 is a side view showing a state after the roller driving mode of the feeding roller according to the first embodiment is executed, and FIG. 9 is a flowchart of the roller driving mode in the feeding roller according to the first embodiment. is there.

  FIG. 10 is a flowchart of the roller driving mode in the feeding roller according to the modified example of the first embodiment, and FIG. 11 is a side view showing the roller driving mode execution state of the feeding roller according to the second embodiment. FIG. 12 is a flowchart of the roller driving mode in the feeding roller according to the second embodiment, and FIG. 13 is a flowchart of the roller driving mode in the feeding roller according to the modified example of the second embodiment. .

  In the XYZ coordinate system shown in each figure, the X direction is the apparatus width direction, the sheet width direction, the Y direction is the sheet conveyance direction in the image reading apparatus, and the Z direction is a direction orthogonal to the Y direction. A direction substantially perpendicular to the surface of the sheet to be conveyed is shown. In each figure, the −Y direction side is the front side of the apparatus, and the + Y direction side is the back side of the apparatus.

■■■ First Example ■■■■
<<< About Image Reading Apparatus >>>
1 and 2, a scanner 10 as an “image reading device” includes a lower unit 12, an upper unit 14, a cover unit 16, a paper discharge tray 18, and a paper feeding device 22 (described later). 3). In this embodiment, the upper unit 14 is attached to the lower unit 12 so as to be rotatable with respect to the lower unit 12 with the downstream side in the paper transport direction as a rotation fulcrum (see FIG. 4).

  Further, a cover portion 16 is attached to the upper portion on the back side of the lower unit 12 so as to be rotatable with respect to the lower unit 12. As shown in FIG. 1, the cover 16 covers the upper portion of the upper unit 14 and the feeding port 20 (see FIG. 2), and the rear surface of the apparatus as shown in FIG. It can turn to the side and can take the feedable state which opens the feed port 20. When the cover unit 16 is in a feedable state as shown in FIG. 2, the back surface of the cover unit 16 functions as a sheet placement surface 16 a of the sheet P as “medium”.

  Further, a discharge port 24 for discharging the paper P is provided on the front side of the lower unit 12. Further, the lower unit 12 includes a paper discharge tray 18 that can be pulled out from the discharge port 24 toward the front side of the apparatus. The paper discharge tray 18 can be in a state of being housed in the bottom of the lower unit 12 (see FIG. 1) and in a state of being pulled out to the front side of the apparatus (see FIG. 2). Further, in the present embodiment, the paper discharge tray 18 is configured by connecting a plurality of tray members, and the pull-out length from the discharge port 24 can be adjusted according to the length of the paper P to be discharged.

<About the paper transport path in the scanner>
Next, the paper transport path 26 in the scanner 10 will be described mainly with reference to FIG. In FIG. 3, the lower unit 12 and the upper unit 14 show only the outline of the casing by phantom lines. In FIG. 3, a thick solid line with a symbol P indicates a guide path for a sheet transported along the sheet transport path 26 in the scanner 10.

  In the present embodiment, the paper P set in the feeding port 20 is placed on the back surface of the cover portion 16 that takes a posture rotated toward the back side of the apparatus with respect to the lower unit 12, that is, the paper placement as a “medium placement portion”. It is supported and placed by the placement surface 16a. A plurality of sheets P can be set in the feeding port 20.

  As for the paper P placed on the paper placement surface 16a, the paper P placed at the bottom is fed by the feeding roller 28 to the downstream side in the feeding direction. The outer peripheral surface of the feeding roller 28 is made of a high friction material (for example, an elastomer such as rubber). In this embodiment, the feeding roller 28 is rotationally driven by a driving motor 27 (see FIG. 6) via a driving force transmission means (not shown).

  In FIG. 3, the symbol G indicates a bundle of sheets P placed (set) on the sheet placing surface 16a. The leading edge of the sheet bundle G is held at the feeding standby position (position shown in FIG. 3) by a stopper (not shown) before feeding is started, and the entry between the feeding roller 28 and a separation roller 30 described later is restricted. Has been.

  Further, a separation roller 30 is provided at a position facing the feeding roller 28. The separation roller 30 is provided in a state of being urged with respect to the feeding roller 28 by an urging means (not shown). In the present embodiment, the outer peripheral surface of the separation roller 30 is made of a high friction material (for example, an elastomer such as rubber) in the same manner as the feeding roller 28.

  Further, in this embodiment, the separation roller 30 is provided with a torque limiter 32. The separation roller 30 is connected to a rotation direction (clockwise direction in FIG. 3) opposite to the rotation direction (clockwise direction in FIG. 3) through a torque limiter 32 from a torque application means (not shown) or a drive source such as a motor. It is configured to receive a driving torque in the clockwise direction).

  That is, when the separation roller 30 is in direct contact with the feeding roller 28, the rotational torque received from the feeding roller 28 exceeds the limit torque of the torque limiter 32, so that the separation roller 30 rotates following the feeding roller 28 ( (Clockwise direction in FIG. 3).

  Then, when the feeding of the paper P is started and a plurality of papers P enter between the feeding roller 28 and the separation roller 30, the separation roller 30 does not receive the rotational torque from the feeding roller 28, and the feeding roller 28 The driven rotation stops. As a result, the upper paper P (paper P to be prevented from being double-fed) excluding the lowermost paper P to be fed cannot receive the transport force for proceeding to the downstream side, and the leading end thereof is directed to the separation roller 30. It is not possible to proceed downstream with the contacted state. Thereby, double feeding of the paper P is prevented. Since the lowest sheet P to be fed is in direct contact with the feeding roller 28, the lowermost sheet P advances downstream by the conveying force received from the feeding roller 28.

  In this embodiment, a plurality of feeding rollers 28 are provided at intervals in the apparatus width direction (X direction) as shown in FIGS. Specifically, two feeding rollers 28 are provided in the lower unit 12 at intervals in the apparatus width direction. In addition, two separation rollers 30 are also provided at intervals in the apparatus width direction corresponding to each feeding roller 28. In this embodiment, two sets of the feeding roller 28 and the separation roller 30 are provided in the apparatus width direction. However, one set may be provided, or three or more sets may be provided.

  Subsequently, on the downstream side of the feed roller 28 and the separation roller 30, a double feed detection sensor 34 as a “detection unit” that detects double feed of the paper P is disposed. In this embodiment, the double feed detection sensor 34 is configured as an ultrasonic sensor including a speaker unit and a microphone unit. The double feed detection sensor 34 is configured to oscillate an ultrasonic wave from the speaker unit toward the paper P passing through the paper transport path 26 and detect a reflected sound from the paper P with the microphone unit. In the present embodiment, the double feed detection sensor 34 is configured not only to detect double feed of the paper P based on the frequency of the reflected sound, but also to detect paper types such as thick paper.

  A pair of transport rollers 36 is provided on the downstream side of the double feed detection sensor 34 in the paper transport path 26. The transport roller pair 36 includes a transport drive roller 36a and a transport driven roller 36b that rotates following the transport drive roller 36a. In the present embodiment, the conveyance drive roller 36a is driven to rotate by a drive source (not shown).

  An image reading unit 38 as a “reading unit” is provided on the downstream side of the conveying roller pair 36. Here, the image reading unit 38 is transported along the paper transport path 26 and the upper reading unit 40 provided in the upper unit 14 so as to face the upper surface of the paper P transported along the paper transport path 26. And a lower reading unit 42 provided in the lower unit 12 so as to face the lower surface of the paper P. In this embodiment, the upper reading unit 40 and the lower reading unit 42 are configured as reading units, and as an example, configured as a contact image sensor module (CISM).

  After the image P is read by the image reading unit 38 at least one of the front and back surfaces of the paper P, the sheet P is nipped by a discharge roller pair 44 located downstream in the transport direction of the image reading unit 38 and discharged. 24 is discharged.

  In this embodiment, the discharge roller pair 44 includes a discharge drive roller 44a and a discharge driven roller 44b that rotates following the discharge drive roller 44a. In the present embodiment, the discharge drive roller 44a is driven to rotate by a drive source (not shown). In addition, the conveyance drive roller 36a and the discharge drive roller 44a may be rotationally driven by a common drive source, or may be separately rotated by separate drive sources.

  In this embodiment, a control unit 46 is provided in the lower unit 12. In the present embodiment, the control unit 46 is configured as an electric circuit including a plurality of electronic components. The control unit 46 controls a driving source that rotationally drives the upper reading unit 40, the lower reading unit 42, the transport driving roller 36a, and the discharge driving roller 44a. Further, the control unit 46 receives the detection signal from the double feed detection sensor 34 and controls the conveyance of the paper P in the scanner 10.

  In this embodiment, the control unit 46 is configured to control the conveyance of the paper P and the image reading operation in the scanner 10. Further, the control unit 46 may control an operation necessary for executing the document reading operation in the scanner 10 by an instruction from the outside (such as a PC).

<<< About the paper feeder >>>
Next, the configuration of the sheet feeding device 22 will be described with reference to FIG. In the present embodiment, the sheet feeding device 22 includes, as an example, a sheet placing surface 16a on which the sheet P is placed, a feeding roller 28, and a control unit 46. In the present embodiment, the feeding roller 28 is rotationally driven by a drive motor 27 controlled by the control unit 46.

  In the present embodiment, the feeding roller 28 is fed by the one-way clutch (not shown) as an example in the direction of feeding the paper P from the paper placement surface 16a to the downstream side in the feeding direction, that is, the forward rotation direction (reverse direction in FIG. 6). Only rotation in the clockwise direction) is allowed. That is, the feeding roller 28 is restricted from rotating in the direction in which the paper P is returned to the upstream side in the feeding direction, that is, the reverse direction (the clockwise direction in FIG. 6).

  In the present embodiment, the drive motor 27 is configured as a DC motor as an example. A rotary encoder 48 is attached to the drive motor 27. The rotary encoder 48 detects the amount of rotation of the drive motor 27, and consequently the feeding roller 28, and transmits the detected amount of rotation to the control unit 46. The control unit 46 controls the rotation drive of the drive motor 27 based on the received rotation amount. In the present embodiment, the control unit 46 is configured to be able to arbitrarily change the rotation speed of the feeding roller 28 by changing the drive frequency of the drive motor 27.

  In this embodiment, the drive motor 27 is configured as a DC motor. However, the drive motor 27 may be configured as a stepping motor. In this case, the control unit 46 does not include the rotary encoder 48, and the step number of the stepping motor is determined. It may be configured to detect and control the rotation of the stepping motor.

  In FIG. 6, the path length from the feeding standby position on the sheet placing surface 16 a to the double feed detection sensor 34 disposed between the feeding roller 28 and the conveying roller pair 36 in the sheet conveying path 26 is an example. L is set.

<<< Regarding the roller driving mode in the feeding roller >>>
In addition to FIG. 6, the roller driving mode of the feeding roller 28 according to the present embodiment will be described with reference to FIGS. 7 and 8.

  In FIG. 6, a plurality of sheets P are stacked and set on the sheet placing surface 16a. Then, when the control unit 46 drives the drive motor 27, the feeding roller 28 starts to rotate at a predetermined rotation speed in the forward rotation direction. Further, the rotary encoder 48 starts detecting the amount of rotation in the feeding roller 28 as the drive motor 27 starts to rotate.

  Then, the control unit 46 is set to rotate the feeding roller 28 by a rotation amount A at a predetermined rotation speed in the forward rotation direction. Here, the amount of rotation A of the feed roller 28 is the path length L from when the leading edge of the paper P is detected by the double feed detection sensor 34 from the feeding standby position (the leading edge position of the paper P in FIG. 6), and the paper. The rotation amount is set to the total amount of slip that causes the sheet P to slip with respect to the feeding roller 28 until the sheet P is drawn from the feeding standby position to the nip point between the feeding roller 28 and the separation roller 30.

  When the front end of the paper P is detected by the double feed detection sensor 34 when the control unit 46 rotates the feed roller 28 in the forward rotation direction by the amount of rotation A, the front end of the paper P is detected by the transport roller pair 36. The feed roller 28 is further rotated so as to reach the position. Then, the control unit 46 rotationally drives the conveyance driving roller 36a, nips the paper P by the conveyance roller pair 36, and feeds the paper P toward the image reading unit 38 located on the downstream side in the feeding direction. The paper P is read by the image reading unit 38 and discharged from the discharge port 24 by the discharge roller pair 44.

  On the other hand, when the control unit 46 rotates the feed roller 28 in the forward rotation direction by the amount of rotation A, if the leading end of the paper P is not detected by the double feed detection sensor 34, the control unit 46 is in the feed roller 28. Run the roller drive mode. Specifically, as shown in FIG. 7, the controller 46 rotates the feed roller 28 by a rotation amount B at a predetermined rotation speed in the forward rotation direction, and then stops the feed roller 28. Again, the feeding roller 28 is driven and stopped alternately so as to rotate in the forward direction by the amount of rotation B. That is, the roller driving mode of the feeding roller 28 in the present embodiment is a mode in which the rotation driving and stopping of the feeding roller 28 are alternately performed.

  Here, in this embodiment, the rotation amount B is set to be smaller than the rotation amount A in which the paper P is fed from the paper placement surface 16 a toward the double feed detection sensor 34. More specifically, the rotation amount B is set, for example, as a rotation amount corresponding to a feed amount that feeds the paper P about 2 mm to 3 mm downstream in the feed direction. That is, the rotation amount B is set to a rotation amount for feeding the feeding roller 28 minutely.

  In the present embodiment, when the roller driving mode is executed, the control unit 46 drives the feeding roller 28 in the forward rotation direction so that the feeding roller 28 is set for the set number of times, that is, N times of driving. Alternately with stop. In the present embodiment, the driving frequency N is set to about 10 as an example, but may be changed as appropriate. The rotation speed when rotating the feeding roller 28 by the rotation amount A and the rotation speed when rotating the rotation amount B by the rotation amount B may be the same rotation speed or different rotation speeds.

  Here, as shown in FIG. 7, the leading ends of the plurality of sheets P are located near the nip position between the feeding roller 28 and the separation roller 30 beyond the feeding standby position in FIG. 6. However, in the plurality of sheets P, for example, when the lowest sheet P1 and the next sheet P2 are attached, a force for peeling the attachment between the sheets P is required. When the feeding force at the feeding roller 28 is less than the peeling force, the sheet P1 is not fed downstream by the feeding roller 28 in the feeding direction, that is, a non-feed state.

  In the present embodiment, the feeding roller 28 is intermittently fed in the roller driving mode, so that vibration can be applied to the paper P1 that is in the non-feed state, and thus to the plurality of papers P. Specifically, the driving force transmission means (not shown) that transmits the driving force to the feeding roller 28 has a plurality of gears as an example, and the rotation of the feeding roller 28 is stopped by backlash of these gears and the like. At this time, the feeding roller 28 is returned by the amount corresponding to the backlash in the direction opposite to the rotation direction. Alternatively, in the paper P that is in a slip state with respect to the feeding roller 28, when the rotation of the feeding roller 28 stops, the feeding force of the feeding roller 28 that has acted on the paper P is lost, and the feeding that acts on the paper P The power fluctuates.

  As a result, vibration is applied to the plurality of sheets P set on the sheet placing surface 16a along the feeding direction. This vibration is applied as a curling effect on the plurality of sheets P. That is, by performing a series of operations of driving, stopping, and re-driving the feeding roller 28, vibration can be applied to the plurality of sheets P set on the sheet placing surface 16a. As a result, it is possible to reduce the sticking between the plurality of sheets P and to spread the plurality of sheets P by shifting the sheets P. As a result, the lowermost sheet P <b> 1 can be appropriately fed to the nip position between the feeding roller 28 and the separation roller 30.

  Next, as illustrated in FIG. 8, when the roller driving mode is finished, the control unit 46 drives the feeding roller 28 to rotate again with the rotation amount A once again. In the plurality of sheets P that are rolled in the roller driving mode, the lowermost sheet P1 is appropriately fed by the feeding roller 28 and sent to the detection position of the double feed detection sensor 34 in the sheet transport path 26. Then, when the paper P1 is detected by the double feed detection sensor 34, the control unit 46 sends the paper P1 to the image reading unit 38 to execute a reading operation.

  In the present embodiment, non-feed due to sticking of paper between the papers P can be reduced by executing the roller driving mode in the feed roller 28. In addition, by executing the roller driving mode in the feeding roller 28, it is possible to roll a plurality of sheets P, and it is possible to suppress the sheet P from continuing to idle while being slipped with respect to the feeding roller 28. As a result, the paper powder of the paper P adheres to the feed roller 28 and the friction coefficient on the outer peripheral surface of the feed roller 28 can be reduced, and the life reduction due to wear of the feed roller 28 can be suppressed.

<<<< Flow of Roller Drive Mode >>>>
Next, with reference to FIG. 9, the flow of control in the roller driving mode of the feeding roller 28 will be described. As step S1, when the control unit 46 receives an input signal of an image reading operation in the scanner 10, for example, an operation input of the scanner 10 by the user or an input signal from an external device, the control unit 46 rotates the feeding roller 28 in the forward direction (FIG. 6). In the counterclockwise direction) at a predetermined rotational speed by the amount of rotation A. In step S <b> 2, it is determined whether or not the double feed detection sensor 34 has detected the paper P sent by the feed roller 28.

  When the double feed detection sensor 34 detects the paper P, in step S3, the control unit 46 further rotates the feed roller 28 and sends the paper P so that the leading edge of the paper P reaches the transport roller pair 36. In step S 4, the control unit 46 rotates and drives the transport driving roller 36 a, nips the paper P to the transport roller pair 36, and sends the paper P toward the image reading unit 38.

  Then, the control unit 46 executes a reading operation in which the image reading unit 38 reads the image of the paper P sent as step S5. Thereafter, in step S6, the controller 46 rotates the discharge driving roller 44a to nip the paper P to the discharge roller pair 44 and discharge the paper P.

  When the double feed detection sensor 34 does not detect the paper P in step S2, the control unit 46 executes the roller driving mode in steps S7 to S9. Specifically, first, as step S7, the control unit 46 stops the feed roller 28 by rotating it in the forward rotation direction by a rotation amount B at a predetermined rotation speed. In step S8, the control unit 46 counts the number of times the feeding roller 28 has been rotationally driven in the roller driving mode. In step S9, the control unit 46 determines whether or not the counted number of rotations of the feeding roller 28 is equal to or greater than the set number N of feeding roller driving.

  When the counted number of times of rotating the feeding roller 28 is less than the set number N of feeding roller driving, the control unit 46 executes Step S7 again. That is, the control unit 46 alternately repeats the rotation driving and the stop of the feeding roller 28 until the feeding roller 28 is driven for the set number of times of driving N times.

  When the counted number of rotations of the feeding roller 28 is equal to or greater than the set number N of driving of the feeding roller, the process returns to step S1, and the operations from step S2 to step S6 are executed, or step S2. After that, the operations from step S7 to step S9 are repeated again.

<<< Modification of the first embodiment >>>
(1) In this embodiment, the rotation speed of the roller driving mode of the feeding roller 28 is a constant rotation speed, but the rotation speed may be changed during the rotation of the feeding roller 28, or the feeding roller The rotation speed may be changed each time the drive 28 is driven or every several times.

(2) As shown in FIG. 10, after receiving the input signal for executing the image reading operation, the control unit 46 executes the roller driving mode before rotating the feeding roller 28 by the rotation amount A in the forward rotation direction. May be. Specifically, before step S13 for rotating the feeding roller 28 in the forward rotation direction by the amount of rotation A, step S12 is executed through step S10 to step S11 as a roller driving mode. That is, the sheet P can be appropriately fed from the sheet placing surface 16a by previously executing the roller driving mode before feeding the sheet P set on the sheet placing surface 16a.
In FIG. 10, the operations in step S13, step S14, step S15, step S16, step S17, step S18, step S19, step S20, and step S21 are a series of steps from step S1 to step S9 in the first embodiment. Since it is the same as the operation, the description is omitted.

■■■ Second Example ■■■■
Next, a second embodiment of the roller driving mode in the feeding roller 28 will be described with reference to FIGS. 11 and 12. The roller driving mode in this embodiment is different from that in the first embodiment in that the feeding roller 28 is rotated not only in the normal rotation direction but also in the reverse rotation direction.

  Referring to FIG. 11, in the second embodiment, the driving motor 27 for rotating the feeding roller 28 is different from the first embodiment in that the feeding roller 28 is rotated in the forward direction (counterclockwise direction in FIG. 11). In addition to being configured to rotate not only in the reverse rotation direction (clockwise direction in FIG. 11), the rotation is also possible.

  In this embodiment, when the control unit 46 executes the roller driving mode in the feeding roller 28, the feeding roller 28 is rotated by a rotation amount B at a predetermined rotational speed in the normal rotation direction, and then the feeding roller 28 is stopped. After that, it is rotated by a rotation amount B at a predetermined rotation speed in the reverse rotation direction. In this embodiment, the series of operations are set to be repeated N times. Then, the sheet loading is performed by applying the conveying force of the feeding roller 28 toward the upstream side and the downstream side in the feeding direction in the sheet conveying path 26 with respect to the plurality of sheets P placed on the sheet placing surface 16a. Since vibration is applied to the plurality of sheets P set on the surface 16a, the effect on the plurality of sheets P can be changed, and the sheets P can be spread more effectively.

  Also in this embodiment, the rotation speed when rotating the feeding roller 28 by the rotation amount A and the rotation speed when rotating the rotation amount B by the rotation amount B may be the same rotation speed, or different rotation speeds. Also good.

  With reference to FIG. 12, the flow of control of the feeding roller 28 in the second embodiment will be described. In step S22, when the control unit 46 receives an input signal of an image reading operation in the scanner 10, for example, an operation input of the scanner 10 by the user or an input signal from an external device, the control unit 46 turns the feeding roller 28 in the forward direction (FIG. 6). In the counterclockwise direction) at a predetermined rotational speed by the amount of rotation A. In step S 23, it is determined whether or not the double feed detection sensor 34 has detected the paper P sent by the feed roller 28.

  When the double feed detection sensor 34 detects the paper P, in step S24, the control unit 46 further rotates the feed roller 28 and sends the paper P so that the leading edge of the paper P reaches the transport roller pair 36. In step S25, the control unit 46 rotates and drives the transport driving roller 36a, nips the paper P to the transport roller pair 36, and sends the paper P toward the image reading unit 38.

  Then, the control unit 46 executes a reading operation in which the image reading unit 38 reads the image of the paper P sent as step S26. Thereafter, in step S27, the control unit 46 rotates the discharge driving roller 44a to nip the paper P to the discharge roller pair 44 and discharge the paper P.

  When the double feed detection sensor 34 does not detect the paper P in step S23, the control unit 46 executes the roller driving mode from step S28 to step S31. Specifically, as step S28, the control unit 46 first stops the feed roller 28 by rotating it by a rotation amount B at a predetermined rotation speed in the forward rotation direction. In step S29, the control unit 46 rotates the feeding roller 28 in the reverse rotation direction at a predetermined rotation speed by the rotation amount B and stops it.

  In step S30, the control unit 46 counts the number of times that the feeding roller 28 is rotationally driven in the roller driving mode. In step S31, the control unit 46 determines whether the counted number of rotations of the feeding roller 28 is equal to or greater than the set number N of feeding roller driving.

  When the counted number of rotations of the feeding roller 28 is smaller than the set number N of feeding roller driving, the control unit 46 executes Step S28 again. That is, the control unit 46 alternately repeats the rotational driving and the stop in the feeding roller 28 until the feeding roller 28 is driven for the set number of times of driving N times.

  If the counted number of rotations of the feeding roller 28 is equal to or greater than the set number N of driving of the feeding roller, the process returns to step S22 to execute the operation from step S23 to step S27, or perform step S23. Then, the operations from step S28 to step S31 are repeated again.

<<< Modified Example of Second Embodiment >>>
(1) In this embodiment, the rotation speed in the forward rotation direction and the rotation speed in the reverse rotation direction are set to the same rotation speed in the roller drive mode, but different rotation speeds may be used instead of this configuration. Further, the rotation speed in the forward rotation direction and the rotation speed in the reverse rotation direction may be independently changed during the rotation of the feeding roller 28, or each time or every plural times when the feeding roller 28 is driven. The rotational speed in the forward direction and the rotational speed in the reverse direction may be changed.
(2) In the present embodiment, the feed roller 28 is driven to rotate alternately in the forward rotation direction and the reverse rotation direction in the roller drive mode. However, instead of this configuration, the feed roller 28 may be rotated only in the reverse rotation direction. .
(3) In this embodiment, in the roller drive mode, the rotation direction of the feeding roller 28 is alternately changed between the normal rotation direction and the reverse rotation direction. Instead of this configuration, for example, the rotation in the normal rotation direction is performed a plurality of times. After the execution, the rotation in the reverse rotation direction may be executed a plurality of times, or the ratio between the number of rotations in the forward rotation direction and the number of rotations in the reverse rotation direction may be set differently.

(4) As shown in FIG. 13, after receiving the input signal for executing the image reading operation, the control unit 46 executes the roller driving mode before rotating the feeding roller 28 by the rotation amount A in the forward rotation direction. May be. Specifically, step S35 is executed through step S32 to step S33 and step S34 as a roller driving mode before step S36 of rotating the feeding roller 28 in the forward rotation direction by the rotation amount A. That is, the sheet P can be appropriately fed from the sheet placing surface 16a by previously executing the roller driving mode before feeding the sheet P set on the sheet placing surface 16a.
In FIG. 13, the operations in step S36, step S37, step S38, step S39, step S40, step S41, step S42, step S43, step S44 and step S45 are the same as steps S22 to S31 in the second embodiment. Since this is the same as the series of operations, description thereof is omitted.

<<< Modified Example of First and Second Embodiments >>>
(1) If the control unit 46 includes detection means for detecting the driver information, the information on the paper P input from an external device, or the type of the paper P set on the paper placement surface 16a, Based on the detection information of the detection means, the presence or absence of execution of the roller driving mode in the feeding roller 28 may be switched. Accordingly, for example, when the paper P that does not need to be rolled is fed, the decrease in throughput can be suppressed by not executing the roller driving mode of the feeding roller 28.
(2) When the control unit 46 includes detection means for detecting the driver information or the type of the paper P input from the external device or the type of the paper P set on the paper placement surface 16a, Based on the detection information of the detection means, the number N of times of driving the roller in the feeding roller 28 may be changed. According to this configuration, for example, the decrease in throughput can be suppressed by reducing the driving frequency N of the feeding roller 28 when feeding the sheet P with a slight degree of adhesion between the sheets P.
(3) In the first and second embodiments, the paper feeding device 22 is applied to the scanner 10 as the image reading device. Instead of this configuration, ink is ejected toward the paper. You may apply to a recording apparatus provided with the recording head as a recording means, for example, an inkjet printer.

  In summary, the paper feeding device 22 controls the paper placement surface 16a on which the paper P is placed, the feed roller 28 that feeds the paper P from the paper placement surface 16a, and the control for controlling the feed roller 28. The controller 46 is capable of executing a roller drive mode in which the feeding roller 28 is alternately driven and stopped at a rotation amount B smaller than the rotation amount A at the time of paper feeding.

  According to the above configuration, the control unit 46 that controls the feeding roller 28 executes the roller driving mode in which the feeding roller 28 is alternately driven and stopped at the rotation amount B smaller than the rotation amount A at the time of paper feeding. Since it is possible, the roller driving mode can be executed to impart a rolling effect to the paper P placed on the paper placement surface 16a, and thus the paper P can be sent out appropriately.

  The controller 46 switches the rotation speed of the feeding roller 28 in the roller driving mode. According to this configuration, the paper P placed on the paper placement surface 16a can be spread more effectively.

  The controller 46 alternately switches the rotation direction of the feeding roller 28 between the normal rotation direction and the reverse rotation direction in the roller drive mode. According to this configuration, the paper P placed on the paper placement surface 16a can be spread more effectively.

  The control unit 46 executes the roller driving mode before feeding the paper P. According to this configuration, the paper P can be appropriately fed.

  The scanner 10 includes a double feed detection sensor 34 that detects the passage of the paper P on the downstream side of the feed roller 28, and the control unit 46 feeds a predetermined amount, that is, a rotation amount A or more during the paper P feeding operation. If the double feed detection sensor 34 does not detect the passage of the paper P even if the feed roller 28 is rotated, the roller drive mode is executed. According to this configuration, elimination of non-feed can be expected.

  The control unit 46 switches whether to execute the roller drive mode according to the type of the paper P. According to this configuration, for example, a decrease in throughput can be suppressed by not executing the roller driving mode when feeding the paper P that does not need to be rolled.

  The control unit 46 changes the number of driving times of the feeding roller 28 in the roller driving mode according to the type of the paper P. According to this configuration, for example, the decrease in throughput can be suppressed by reducing the driving frequency N of the feeding roller 28 when feeding the paper P with a slight degree of close contact between the papers.

  The feeding roller 28 is in contact with the lowermost sheet P1 among the sheets placed on the sheet placing surface 16a. According to this configuration, when the roller driving mode is executed, the entire sheet bundle G is easy to move back and forth, and the effect of spreading the sheets P can be obtained effectively.

  The scanner 10 includes an image reading unit 38 that reads the paper P, and a paper feeding device 22 that feeds the paper P to the image reading unit 38 side.

  The recording apparatus includes a recording head that records on the paper P, and a paper feeding device 22 that feeds the paper P toward the recording head.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

DESCRIPTION OF SYMBOLS 10 ... Scanner, 12 ... Lower unit, 14 ... Upper unit, 16 ... Cover part, 16a ... Paper loading surface, 18 ... Paper discharge tray, 20 ... Feeding port, 22 ... Paper feeding device, 24 ... Ejecting port, 26 ... paper conveyance path, 27 ... drive motor, 28 ... feed roller, 30 ... separation roller, 32 ... torque limiter, 34 ... double feed detection sensor, 36 ... conveyance roller pair, 36a ... conveyance drive roller, 36b ... conveyance driven Roller, 38 ... Image reading unit, 40 ... Upper reading unit, 42 ... Lower reading unit, 44 ... Discharge roller pair, 44a discharge driving roller, 44b discharge driven roller, 46 ... Control unit, 48 ... Rotary encoder, A, B ... Rotation amount, G ... paper bundle, L ... path length, N ... number of driving times, P, P1, P2 ... paper, S1, S2, S3, S4, S5, S6, S7, 8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38, S39, S40, S41, S42, S43, S44, S45 ... step

Claims (10)

A medium placement unit for placing a medium;
A feeding roller for feeding out the medium from the medium mounting section;
A control unit for controlling the feeding roller,
The control unit is capable of executing a roller driving mode in which driving and stopping of the feeding roller are alternately performed with a rotation amount smaller than a rotation amount at the time of medium feeding.
A medium feeding device. The medium feeding device according to claim 1, wherein the control unit switches a rotation speed of the feeding roller in the roller driving mode.
A medium feeding device. 3. The medium feeding device according to claim 1, wherein the control unit alternately switches a rotation direction of the feeding roller between a normal rotation direction and a reverse rotation direction in the roller driving mode.
A medium feeding device. The medium feeding device according to any one of claims 1 to 3, wherein the control unit executes the roller driving mode before feeding the medium.
A medium feeding device. The medium feeding device according to any one of claims 1 to 4, further comprising a detection unit that detects passage of the medium on a downstream side of the feeding roller,
The control unit executes the roller driving mode when the detection unit does not detect the passage of the medium even when the feeding roller is rotated by a predetermined amount or more during the medium feeding operation.
A medium feeding device. The medium feeding device according to any one of claims 1 to 5, wherein the control unit switches whether to execute the roller driving mode according to a type of the medium.
A medium feeding device. The medium feeding device according to any one of claims 1 to 6, wherein the control unit changes the number of times the feeding roller is driven in the roller driving mode according to a type of the medium.
A medium feeding device. The medium feeding device according to any one of claims 1 to 7, wherein the feeding roller is in contact with a lowest-order medium among the mediums placed on the medium placing unit.
A medium feeding device. Reading means for reading the medium;
The medium feeding device according to any one of claims 1 to 8, wherein the medium is fed to the side of the reading unit.
An image reading apparatus comprising: Recording means for recording on a medium;
The medium feeding device according to any one of claims 1 to 8, wherein the medium is transported toward the recording unit.
Recording device.

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