JP2020019607A - Medium feeding device and image reading device - Google Patents

Abstract

To provide a medium feeding device capable of solving the problem that, when it has a structure of pressing a bulged portion of a medium toward a resister roller by a swing guide member to correct skew, the pressing of the bulged portion on a side where conveyance is delayed due to skew is insufficient, which results in the skew being not properly corrected.SOLUTION: A medium feeding device comprises: a curved path as a medium feeding path which is formed between a first pair of feed rollers and a second pair of feed rollers and conveys a medium downward while curving the medium; and a receiving part which is formed outside of the curvature of the curved path and receives the bulged portion of the medium in the curved path. The first pair of feed rollers are disposed in a central region in a medium width direction which is a direction crossing the medium feeding direction. The receiving part has a pressing member for pressing the bulged portion of the medium in the upstream direction in the medium feeding direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a medium feeding device that feeds a medium and an image reading device including the same.

2. Description of the Related Art A medium feeding device that feeds a medium is provided in a scanner or a printer. This medium feeding device may be called an ADF, which is an abbreviation for Auto Document Feeder in a scanner, for example.
Further, some ADFs have a configuration in which the medium is curved and inverted downward after the medium is sent out. Patent Document 1 discloses an example of an ADF having such a configuration.

  In the ADF, there is a case where the skew correction is performed by causing the front end of the medium to follow the pair of registration rollers. At that time, a bulge is formed in a portion of the medium that is curved and inverted. In the ADF described in Patent Literature 1, a portion of the medium where the curve is reversed is called a loop, and the bulging portion is called a protrusion. It is pressed against the pair of registration rollers to imitate them.

JP 08-34544 A

When the front end of the medium reaches the registration roller pair in a state in which the medium is skewed, the bulge portion on the side that first reaches the registration roller pair due to skew in the medium width direction is the bulge on the side that reaches the registration roller pair with a delay. The degree of swelling is greater than at the site.
To explain in more detail below, the upper drawing of FIG. 9 shows an example of a state in which the medium D is conveyed in the downward direction in the drawing and before the leading end thereof reaches the registration roller pair 100, and is parallel to the conveyance direction. This shows a state inclined with respect to the straight line Lv, that is, a state skewed.

  When the leading end S1 on one side in the medium width direction reaches the registration roller pair 100 before the leading end S2 on the other side due to the skew, the bulging portion H1 on the leading end S1 becomes the bulging portion H2 on the leading end S2 due to subsequent conveyance. The degree of swelling becomes larger than that. Strictly speaking, the degree of swelling increases, in many cases, means that the swelling increases in the transport direction and also in the height direction.

  When the swing guide member described in Patent Document 1 is applied, the swing guide member has a swing shaft upstream in the transport direction, and in the example of FIG. 9, the bulging portions H1 and H2 are pressed toward the registration roller pair 100. Becomes However, with this configuration, the bulge portion H1 on the leading side is excessively pushed by the skew, and the bulge portion H2 on the side where the conveyance is delayed due to the skew, that is, the bulge portion H1 should be pushed strongly to correct the skew. The pressure on the side bulge H2 is insufficient, and the skew cannot be properly corrected.

  In order to solve the above problem, a medium feeding device of the present invention includes a first feed roller pair that feeds a medium downstream, a second feed roller pair provided downstream of the first feed roller pair, A medium feeding path formed between the first feed roller pair and the second feed roller pair, the medium feeding path being configured to convey a medium downward while curving the medium, and a curved path formed outside the curved path of the curved path. A receiving portion for receiving a bulge portion of the medium in the curved path, wherein the first feed roller pair is provided in a central region in a medium width direction that is a direction intersecting with a medium feeding direction, The receiving portion is provided with a pressing member that presses the bulging portion of the medium in the upstream direction in the medium feeding direction.

FIG. 2 is a perspective view of a medium feeding device and an image reading device according to the embodiment. FIG. 2 is a side sectional view of the medium feeding device and the image reading device according to the embodiment. FIG. 2 is a block diagram of a control system of the medium feeding device and the image reading device according to the embodiment. FIG. 4 is an enlarged side sectional view of a part of a medium feeding path of the medium feeding device according to the embodiment. FIG. 4 is an enlarged side sectional view of a part of a medium feeding path of the medium feeding device according to the embodiment. FIG. 2 is an enlarged plan view of a part of a medium feeding path of the medium feeding device according to the embodiment. FIG. 4 is an enlarged side sectional view of a part of a medium feeding path of the medium feeding device according to the embodiment. 9 is a flowchart showing the flow of control when feeding a medium. FIG. 4 is an enlarged plan view of a part of a medium feeding path of a medium feeding device according to a conventional technique. FIG. 4 is an enlarged side sectional view of a part of a medium feeding path having a configuration in which a pressing member is not provided.

Hereinafter, the present invention will be schematically described.
The medium feeding device according to the first aspect of the present invention includes: a first feed roller pair that feeds a medium downstream; a second feed roller pair provided downstream of the first feed roller pair; A medium feeding path formed between the 1 feed roller pair and the second feed roller pair, a curved path for conveying the medium downward while curving the medium, and a curved path formed outside the curved path; A receiving portion for receiving a bulge portion of the medium in the curved path, wherein the first feed roller pair is provided in a central region in a medium width direction that is a direction intersecting with a medium feeding direction, and The portion is provided with a pressing member that presses the bulging portion of the medium in the upstream direction in the medium feeding direction.

According to this aspect, the curved path is provided with the receiving portion that receives the bulging portion of the medium, and the first feed roller pair is provided in the central region in the medium width direction that is a direction intersecting with the medium feeding direction. Therefore, the bulging portion of the bulging portion can escape from the side of the first feed roller pair to the upstream in the transport direction, and the medium can be easily rotated around the contact portion with the first feed roller pair as a fulcrum. That is, the skew correction is facilitated.
The receiving portion is provided with a pressing member that presses the bulging portion of the medium in the upstream direction in the medium feeding direction, so that the medium is rotated around a contact portion with the first feed roller pair as a fulcrum. , Skew can be satisfactorily corrected.
Further, when the pressing member is not provided, the medium is easily attached to the outside of the curved path, and the medium is hardly rotated by the action of the attached, that is, it is difficult to correct the skew. By doing so, the pressing member functions to peel off the medium from the wall surface, and thus the skew can be satisfactorily corrected.

According to a second aspect of the present invention, in the first aspect, the pressing member is an elastic member whose downstream part in the medium feeding direction is fixed and whose upstream part in the medium feeding direction presses the bulging part of the medium. It is characterized by the following.
According to this aspect, the pressing member is a resilient member that fixes a downstream portion in the medium feeding direction and an upstream portion in the medium feeding direction presses the bulging portion of the medium. Appropriate pressing can be performed in the upstream direction in the feeding direction.

According to a third aspect of the present invention, in the first aspect, the pressing member has a swing shaft downstream of the medium feeding direction, and an upstream portion of the medium in the medium feeding direction from the swing axis is the medium. It is a swing member that presses a bulging portion.
According to this aspect, the pressing member has a swing shaft downstream in the medium feeding direction, and an upstream portion in the medium feeding direction from the swing shaft presses the bulging portion of the medium. Therefore, the bulging portion of the medium can be appropriately pressed toward the upstream in the medium feeding direction.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the pressing member is provided in a central region in the medium width direction.
According to this aspect, since the pressing member is provided in the central region in the medium width direction, a force pressing the medium by the pressing member is applied to both the one side and the other side in the medium width direction. The skew can be properly corrected even if the configuration is such that it is easy to act evenly, and in particular, it is not possible to determine which side is significantly expanded in the medium width direction.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the control means for controlling the first feed roller pair and the second feed roller pair includes the second feed roller pair according to a feed condition. The driving amount of the first feed roller pair when the first feed roller pair is driven while the feed roller pair is stopped is switched.

  According to this aspect, the control unit that controls the first feed roller pair and the second feed roller pair includes the first feed roller pair in a state where the second feed roller pair is stopped according to a feeding condition. Since the driving amount of the first feed roller pair when driving is changed, appropriate skew correction can be performed according to the feeding conditions.

An image reading device according to a sixth aspect of the present invention is the image reading device according to any one of the first to fifth aspects, wherein a reading unit that reads a medium, and the medium is fed toward a position where the reading unit reads the medium. And the medium feeding device.
According to this aspect, in the image reading apparatus, the same operation and effect as any of the above-described first to fifth aspects can be obtained.

Hereinafter, the present invention will be described specifically.
Hereinafter, a medium feeding device according to an embodiment of the present invention and an image reading device including the same will be described with reference to the drawings. As an example of the image reading device, a scanner 10 will be described as an example.
In the XYZ coordinate system shown in each drawing, the X direction is the width direction of the medium conveyed in the apparatus. The Z direction is the device height direction and the vertical direction. The Y direction is a direction orthogonal to the X direction and the Z direction. The −X direction is defined as the front side of the apparatus, and the + X direction side is defined as the back side of the apparatus.

As shown in FIG. 1, the scanner 10 is provided as an upper part of the recording unit 2 and is configured as a multifunction peripheral 1 having both a recording function and an image reading function.
As shown in FIG. 2, the scanner 10 includes a scanner body 11 having a reading unit 16 capable of reading a document set on a document table 14 and a document placed on a feed tray 20 facing the reading unit 16. And a medium feeding device 12 for feeding. Hereinafter, the original is referred to as a medium P.

  The medium feeding device 12 closes the scanner body 11 with respect to the platen 14 (FIG. 2) as shown by a solid line in FIG. 1, and opens the platen 14 as shown by a dotted line in FIG. It is configured to be able to switch between the posture. More specifically, the medium feeding device 12 is openably and closably connected to the scanner main body 11 using the −X side of the scanner main body 11 as a pivot point.

  An operation unit 6 is provided on the front side of the multifunction peripheral 1. The operation unit 6 is provided with display means such as a liquid crystal panel. In addition, by operating the operation unit 6, an instruction for a recording operation in the recording unit 2 and an image reading operation in the scanner 10 can be input to the MFP 1.

  The recording unit 2 of the multifunction device 1 includes a plurality of sheet storage cassettes 3 for storing recording sheets at a lower portion. A recording unit 4 that performs recording on the medium P to be conveyed is provided inside the recording unit 2, and performs recording on the sheet conveyed from the sheet storage cassette 3. The paper after recording is discharged from the discharge unit 7. In the multifunction device 1, the discharge unit 7 is provided between the scanner 10 and the sheet storage cassette 3 in the Z-axis direction, which is the height direction of the apparatus. The printed sheet discharged from the discharge unit 7 is supported by the discharge tray 5.

  In FIG. 2, an optical reading unit such as a CIS system or a CCD system is used as a reading unit 16 provided in the scanner main body 11. The reading unit 16 is provided below the document table 14 and is configured to be movable in the Y-axis direction, and can read a medium placed on the document table 14. The document table 14 is made of, for example, colorless and transparent glass.

On the lower surface of the medium feeding device 12 shown in FIG. 2, a pressing plate 15 for pressing the medium P placed on the document table 14 is provided. When the medium feeding device 12 is opened, the document table 14 is exposed. Reading the image of the medium P by placing the medium P on the platen 14, closing the medium feeding device 12 and pressing the medium P by the holding plate 15, and moving the reading unit 16 in the Y-axis direction. Can be.
The scanner 10 can read not only the medium P placed on the document table 14 but also the medium P conveyed by the medium feeding device 12.

  The medium feeding device 12 will be described with reference to FIG. In FIG. 2, an alternate long and short dash line indicated by a symbol T indicates a medium feeding path in the medium feeding device 12. The medium feeding path T is a path from a pickup position by a pick roller 21 to be described later to a discharge tray 39.

The medium P conveyed by the medium feeding device 12 is placed on the feeding tray 20 as shown in FIG. That is, the feed tray 20 is a medium placing portion on which the medium P before feeding is placed.
The medium P is sent out from the feed tray 20 by the pick roller 21.
The pick roller 21 is provided on the + Y side of the medium P placed on the feeding tray 20, that is, at a position facing the leading end side of the medium P in the feeding direction. A feed roller 22 is provided on the + Y side, which is downstream of the pick roller 21 in the feed direction. In other words, the pick roller 21 is located upstream of the feeding roller 22 in the feeding direction.

The pick roller 21 is configured to be displaceable between a contact state in contact with the medium P and a separated state in which the pick roller 21 is separated from the medium P, and rotates the medium in the contact state to direct the medium P toward the feeding roller 22. Pull out.
The pick roller 21 is attached to a holder 27 that swings coaxially with the feed roller 22. The pick roller 21 rotates by receiving power from the first motor 63 (FIG. 3).

  The feed roller 22 feeds the medium P picked up by the pick roller 21 further downstream. The feed roller 22 rotates by receiving power from the first motor 63 (FIG. 3).

A separation roller 23 is disposed below and opposite to the feeding roller 22. The rotation torque of the second motor 64 (FIG. 3) is transmitted to the separation roller 23, and a predetermined rotation resistance is given by a torque limiter (not shown).
At the time of document feeding, a rotation torque in a reverse rotation direction (clockwise direction in FIG. 2) for returning the medium P to the upstream is transmitted from the second motor 64 (FIG. 3) to the separation roller 23. When the medium P does not intervene with the feeding roller 22 or when only one medium P intervenes, the action of the torque limiter causes the medium P to move downstream in the forward rotation direction against the rotation torque. (In the counterclockwise direction in FIG. 2).

  On the other hand, when a plurality of stacked media P enters between the separation roller 23 and the feeding roller 22, the separation roller 23 rotates in the reverse rotation direction to return the medium P to the upstream by the rotation torque. This prevents double feeding of the medium P.

Next, an acceleration drive roller 24 that is rotated by the power of the second motor 64 (FIG. 3) downstream of the feed roller 22 and the separation roller 23 in the feed direction, and a driven rotation with respect to the acceleration drive roller 24. And an acceleration driven roller 25 as a first feed roller pair.
The medium P is sent further downstream by the acceleration roller pair 26.

  The medium feeding path T shown in FIG. 2 is curved downward at the downstream of the pair of acceleration rollers 26. The medium P is sent to the registration roller pair 35 as a second feed roller pair by the acceleration roller pair 26. The registration roller pair 35 includes a driving roller 35a and a driven roller 35b that is driven to rotate with respect to the driving roller 35a. The registration roller pair 35 and each feed roller disposed downstream from the registration roller pair 35 are driven by a third motor 65 (FIG. 3).

A transport roller pair 36 is provided downstream of the registration roller pair 35. The medium P is curved and inverted while being sent through the medium feeding path T by the registration roller pair 35 and the transport roller pair 36 further downstream thereof, and is sent to the reading area R1 in the medium feeding path T.
The reading area R1 of the medium feeding path T is formed of a colorless transparent member such as glass on the side facing the scanner main body 11, and the lower surface of the medium P in the reading area R1 when the medium P passes through the reading area R1. Is read by the reading unit 16 on the scanner body 11 side.
In FIG. 2, the reading unit 16 is located at a position shifted from the reading region R1 in the Y-axis direction. However, when reading the medium P conveyed by the medium feeding device 12, the reading unit 16 is positioned at a position corresponding to the reading region R1. Moved to

In the medium feeding path T, an upper reading section 18 is provided downstream of the reading area R1. The upper reading unit 18 is provided above the medium feeding path T. The medium P that has been read by the reading unit 16 is sent toward the upper reading unit 18 by the pair of transport rollers 37.
When the medium P passes through the reading region R2 by the upper reading unit 18, the upper surface of the medium P in the reading region R2 is read by the upper reading unit 18. The reading unit 16 and the upper reading unit 18 can read both sides of the medium P.

  The medium P that has been read by the upper reading unit 18 is discharged to a discharge tray 39 by a pair of discharge rollers 38. The discharge tray 39 is configured to receive the medium P discharged by the discharge roller pair 38 in an inclined posture.

■■■ Control system in the scanner ■■■
Hereinafter, a control system in the scanner 10 will be described with reference to FIG. FIG. 3 is a block diagram showing a control system of the scanner 10 according to the present invention.
In FIG. 3, a control unit 50 as a control unit performs various other controls of the scanner 10 including feed control and reading control of the document P. A signal from the operation unit 6 is input to the control unit 50, and a signal for realizing a display of the operation unit 6, particularly, a user interface (UI) is transmitted from the control unit 50 to the operation unit 6.
The control unit 50 controls the first motor 63, the second motor 64, and the third motor 65. As described above, the first motor 63 is a drive source for the pick roller 21 and the feed roller 22, the second motor 64 is a drive source for the separation roller 23 and the acceleration drive roller 24, and the third motor 65 is It is a driving source for the registration roller pair 35 and a feed roller downstream from the registration roller pair 35.
Read data from the reading unit 16 and the upper reading unit 18 is input to the control unit 50, and a signal for controlling each reading unit is transmitted from the control unit 50 to each reading unit.
The control unit 50 also receives detection signals from these detection means of a size detection unit 57, a first document detection unit 58, a double feed detection unit 59, a second document detection unit 60, and a temperature and humidity detection unit 61. Necessary control is performed based on the detection signal.

  The size detector 57 is provided on the feed tray 20 and detects the size of the medium P placed on the feed tray 20. The size detection unit 57 includes a plurality of sensors (not shown). Specifically, the size detection unit 57 includes a plurality of optical sensors arranged at intervals along the medium feeding direction and an interval along the medium width direction. And a plurality of optical sensors arranged apart from each other. When the optical sensor constituting the size detection unit 57 is covered by the placement of the medium P, the detection signal changes. The control unit 50 detects the size of the medium P placed on the feeding tray 20 based on a combination of the detection signals of the optical sensors.

The positions of these detection means of the first document detection unit 58, the double feed detection unit 59, and the second document detection unit 60 are shown in FIG. 4, for example. As shown in FIG. 4, the first document detection unit 58 is provided near the downstream of the feed roller 22 and the separation roller 23. The first document detection unit 58 is configured by an optical sensor, and the control unit 50 detects the passage of the leading edge and the rear edge of the document P based on a change in the detection signal of the first document detection unit 58.
The double feed detecting section 59 is provided immediately downstream of the first document detecting section 58. The double feed detecting section 59 includes an ultrasonic transmitting section and an ultrasonic receiving section (not shown) which are arranged to face each other with the original feeding path therebetween, and detects the ultrasonic wave detected by the ultrasonic receiving section with respect to the control section 50. Transmit an electrical signal indicating strength. When the double feeding of the medium P occurs or the thickness of the medium P changes, the electric signal indicating the intensity of the ultrasonic wave changes, whereby the control unit 50 determines whether or not the double feeding of the medium P is present and the thickness of the medium P. Can be detected.

The second document detection unit 60 is provided near the upstream of the registration roller pair 35. The second document detection unit 60 is constituted by an optical sensor, and the control unit 50 detects the passage of the leading edge and the trailing edge of the document P based on a change in the detection signal of the second document detection unit 60.
The temperature / humidity detector 61 is provided, for example, on the feed tray 20 and detects temperature and humidity.

  Referring back to FIG. 3, the control unit 50 includes a CPU 51, a ROM 53, and a memory 54. The CPU 51 performs various arithmetic processes according to the program 52 stored in the ROM 53, and controls the operation of the entire scanner 10. The memory 54, which is an example of a storage unit, is a readable and writable nonvolatile memory, and data necessary for various controls is stored in the memory 54. Further, the control unit 50 writes predetermined data into the memory 54 as needed.

  The scanner 10 is configured to be connectable to an external computer 70, and information is input to the control unit 50 from the external computer 70. The control unit 50 performs necessary control based on information transmitted from the external computer 70.

Subsequently, the skew correction of the medium P will be described with reference to FIG.
First, a basic skew correction method for the medium P will be described.
In FIG. 4, reference numeral Ta denotes a part of a path section in which the medium P is conveyed while curving downward in the medium feeding path T, and is a section between the acceleration roller pair 26 and the registration roller pair 35. Reference numerals 40 and 41 are medium guide members that form a curved path Ta. The medium guide member 41 has a concave portion 41a formed therein, and the concave portion 41a can receive a swelling portion when the medium P expands outward. Hereinafter, this part is referred to as a receiving part 42. Note that the bulging portion of the medium P may be referred to as a bending portion.

After detecting the leading end of the medium P by the first document detection unit 58, the control unit 50 rotates the acceleration roller pair 26 by a predetermined amount while the registration roller pair 35 is stopped. As a result, as shown in FIG. 5, a bulge portion H that enters the receiving portion 42 is formed in the medium P, and the tip Pf of the medium P is pressed against the pair of registration rollers 35 by the action of the bulge portion H to correct the skew. The bulging portion H is a portion that is locally formed only at the time of skew correction, separately from the curved shape when the medium P bends by traveling along the curved path Ta.
The above is the basic method of correcting the skew of the medium P.

Here, a technical problem in a configuration in which a pressing member described later is not provided will be described in detail with reference to FIG. The leading end of the medium P is directed toward the registration roller pair 35 along the outer guide member 41 as shown in the upper part of FIG. After the leading end of the medium P reaches the registration roller pair 35, the acceleration roller pair 26 is rotated by a predetermined amount while the registration roller pair 35 is stopped. Then, the medium P adheres to the guide member 41 outside the curved path Ta as shown in the lower diagram of FIG.
When the medium P adheres to the guide member 41 in this manner, it becomes difficult to rotate the medium P required for skew correction.

In order to cope with such a problem, in this embodiment, first, the acceleration roller pair 26 is provided in the central region in the medium width direction which is a direction intersecting with the medium feeding direction as shown in FIG.
Here, in FIG. 6, the swelling portion H is distinguished by reference numerals H1, H2, and H3 according to the position in the medium width direction. In the present embodiment, the bulging portion H3 is a region overlapping the pressing member 42 described later, the bulging portion H1 is a region on the left side of the bulging portion H3 in the drawing, and the bulging portion H2 is a region on the right side of the bulging portion H3 in the drawing. Hereinafter, the bulging portions H1, H2, and H3 are collectively referred to as a bulging portion H unless it is particularly necessary to distinguish them.

In FIG. 6, the bulge formed on the medium P at the time of skew correction is divided into a bulge H1 on one side and a bulge H2 on the other side in the width direction of the medium, and the medium reaches the registration roller pair 35 in advance. The bulge portion H1 on the side of the tip Pf1 bulges more remarkably than the bulge portion H2 on the other side. Accordingly, the sticking of the medium P to the guide member 41 is more remarkable at the bulging portion H1 in the medium width direction than at the bulging portion H2.
To cope with such a phenomenon, in the present embodiment, as described above, the acceleration roller pair 26 is provided in the central region in the medium width direction which is a direction intersecting with the medium feeding direction. Of the bulges, the bulge at the bulge portion H1, which has a particularly large bulge, can be released from the side of the acceleration roller pair 26 to the upstream in the feeding direction as indicated by the arrow Y1. If the bulge of the bulge portion H1 can be released from the side of the acceleration roller pair 26 to the upstream in the feeding direction, the sticking of the medium P to the guide member 41 can be eliminated or the degree of sticking can be reduced. can do.

  The pressing member 43 serves to release the bulge of the bulge portion H1 from the side of the acceleration roller pair 26 to the upstream side in the feeding direction. That is, in the present embodiment, the pressing portion 43 is provided in the receiving portion 42. The pressing member 43 has a downstream portion 43a fixed to the upper medium guide member 41, and is provided so that the upstream from the downstream portion 43a enters the receiving portion 42 and can be elastically deformed.

The pressing member 43 presses the central bulging portion H3 among the bulging portions of the medium P in the upstream direction in the medium feeding direction. The bulging portion H3 of the medium P is pushed in the direction of arrow E shown in FIG. The direction of the arrow E includes a direction in which the bulging portion H3 is separated from the medium guide member 41 and a direction in which the bulging portion H3 is pushed upstream in the feeding direction.
When the pressing member 42 pushes the bulging portion H3 away from the guide member 41 and in the upstream direction in the feeding direction, the bulging portion at the bulging portion H1 escapes in the direction of the arrow Y1 in FIG. Thereby, the sticking of the medium P to the guide member 41 near the bulging portion H1 is eliminated or its degree is reduced, and the medium P is rotated for skew correction, that is, rotated in the direction of arrow r in FIG. Easier to remove. Thereby, the medium leading end Pf2 on the side where the conveyance is delayed advances appropriately as shown by the arrow Y2 in FIG. 6 toward the registration roller pair 35, and the skew is satisfactorily corrected.

  Note that the direction in which the pressing member 43 presses the bulging portion H3 of the medium P results in the pressing of the medium P is divided into directions indicated by arrows E21, E22, and E23 in FIG. The direction of the arrow E21 acts to release the bulge of the bulge portion H1 in the upstream direction as described above. The directions of the arrows E22 and E23 are directions in which the leading end of the medium P abuts against the pair of registration rollers 35, and acts so as to stick the medium P to the guide member 41. As described above, the arrangement of the acceleration roller pair 26 and the pressing member The function of 43 prevents or reduces the degree of sticking to the guide member 41.

  In this embodiment, the acceleration roller pair 26 is provided at a position symmetrical with respect to the center position in the medium width direction. The fact that the acceleration roller pair 26 is provided in the center region in the medium width direction is not necessarily limited to the case where the acceleration roller pair 26 is located at the center position in the medium width direction, and is provided on both sides of the center position in the medium width direction. It is a meaning including the case where it is done.

In the present embodiment, the pressing member 42 is an elastic member whose downstream portion in the medium feeding direction is fixed, and whose upstream portion in the medium feeding direction presses the bulging portion H of the medium P. As the elastic member, any material may be used as long as it is an elastically deformable member. For example, a material such as a PET (polyethylene terephthalate) sheet having a low friction coefficient with the medium P and not hindering the rotation of the medium P It is preferred that
By configuring the pressing member 42 with an elastic member, the bulging portion H of the medium P can be appropriately pressed toward the upstream direction in the medium feeding direction.

Incidentally, the pressing member may be constituted by a swinging member as shown in FIG. The pressing member 44 shown in FIG. 7 has a swing shaft 44a downstream in the medium feeding direction, and an upstream portion in the medium feeding direction from the swing shaft 44a presses the bulging portion H of the medium P. Be composed. The upstream portion of the pressing member 44 is configured to be pressed by a spring 45.
Even with such a configuration, the bulging portion H of the medium P can be appropriately pressed toward the upstream in the medium feeding direction.

The pressing member is not a member that swings, but may be, for example, a piston-like member that moves forward and backward with respect to the bulging portion H. Such a piston-like member can be moved back and forth with respect to the bulging portion H by a solenoid capable of switching between an energized state and a non-energized state under the control of the control unit 50, for example.
At this time, the piston-like member is normally retracted from the curved path Ta, and advances to the curved path Ta at the same timing as the bulging portion H is formed or after the bulging portion H is formed, and presses the bulging portion H. Control may be performed.

Further, in this embodiment, the pressing member 42 is provided in the central region in the medium width direction as shown in FIG. Thus, the force for pressing the medium P by the pressing member 42 tends to act evenly on both the one side and the other side in the medium width direction, and it is not particularly determined which side is the side that expands significantly in the medium width direction. Even with the configuration, the skew can be properly corrected.
Note that that the pressing member 42 is provided in the center region in the medium width direction is not necessarily limited to the case where the pressing member 42 is located at the center position in the medium width direction, and is provided on both sides of the center position in the medium width direction. It is a meaning including the case where it is done.

  In the present embodiment, the pressing member is provided in the central region in the medium width direction. However, the pressing member may be formed to have a size covering the entire region in the medium width direction.

  The control unit 50 that controls the pair of acceleration rollers 26 and the pair of registration rollers 35 is configured to control the pair of acceleration rollers 26 when driving the pair of acceleration rollers 26 with the pair of registration rollers 35 stopped in accordance with the feeding conditions. May be switched. Note that the drive amount corresponds to an abutment amount when the leading end of the medium P abuts against the registration roller pair 35, and hence the drive amount is hereinafter referred to as an "abutment amount".

As an example of the feeding condition, the feeding speed of the medium P by the acceleration roller pair 26, the size of the medium P, the thickness of the medium P, the temperature and the humidity can be adopted. It can be set according to.
Table 1 shows an example of the added value of the abutting amount according to the feed speed. Table 2 shows an example of the added value of the abutting amount according to the size of the medium P. Table 3 shows an example of an added value of the abutting amount according to the temperature and the humidity and the thickness of the medium P.

For example, when the feed speed is "high speed", an additional value "6" can be obtained from Table 1, and when the size of the medium P is "A5 size width", an additional value "-2" can be obtained from Table 2. When the thickness of the medium P is “thick” under the condition of “temperature T1 ° C. or less and humidity S1% or more”, an additional value “1” can be obtained from Table 3. In this case, the abutment amount (mm) can be calculated as follows.
Abutment amount (mm) = "6" + "-2" + "1" = 5 (mm)
Note that the sizes of the medium P shown in Table 2 are the sheet sizes of the rows A and B defined by the international standard ISO 216.

  As described above, the control unit 50 that controls the pair of acceleration rollers 26 and the pair of registration rollers 35 operates when the pair of acceleration rollers 26 is driven in a state where the pair of registration rollers 35 is stopped according to the feeding condition. Since the drive amount 26, that is, the abutting amount, is switched, appropriate skew correction can be performed according to the feeding conditions.

Hereinafter, the flow of the feed control executed by the control unit 50 will be described with reference to FIG.
Upon receiving the medium feeding command (step S11), the control unit 50 obtains the medium size (step S12), obtains the temperature and humidity (step S13), and then starts feeding the medium P (step S13). S14).
When the feeding of the medium P is started and the leading end of the medium P reaches the double feed detecting unit 59, the medium thickness is obtained (Step S15), and the abutting amount is calculated according to the feeding condition (Step S16). Then, based on the obtained abutting amount, the skew correction is performed by abutting the leading end of the medium against the registration roller pair 35 (step S17), and further, the medium P is continuously fed to the reading position for reading. (Step S18).
In the above-described feeding control, the skew of the medium P is appropriately corrected by the operation of the pressing member 43 as described above.

DESCRIPTION OF SYMBOLS 1 ... Multifunction machine, 2 ... Recording unit, 3 ... Paper storage cassette, 4 ... Recording part, 5 ... Discharge tray, 6 ... Operation part, 7 ... Discharge part, 10 ... Scanner, 11 ... Scanner main body, 12 ... Medium feeding Apparatus, 14: platen, 16: reading section, 17: medium feeding mechanism, 18: upper reading section, 20: feeding tray (medium placement section), 21: pick roller, 22: feeding roller, 23: separation Roller, 24: Acceleration drive roller, 25: Acceleration driven roller, 26: Acceleration roller pair, 27: Holder, 35: Registration roller pair, 36: Conveyance roller pair, 37: Conveyance roller pair, 38: Discharge roller pair, 39 ... Discharge tray, 40, 41: medium guide member, 42: receiving portion, 43, 44: pressing member, 45: spring, 50: control portion, 51: CPU, 52: program, 53: ROM, 5 .., Memory 57, size detector 58, first document detector 59, double feed detector 60, second document detector 61, temperature and humidity detector 63, first motor 64, second motor , 65: third motor 70: external computer, P: medium (document)

Claims (6)

A first feed roller pair for feeding the medium downstream;
A second feed roller pair provided downstream of the first feed roller pair,
A medium feeding path formed between the first feed roller pair and the second feed roller pair, a curved path for conveying the medium downward while curving the medium,
A receiving portion formed outside the curve of the curved path and receiving a bulge portion of a medium in the curved path,
The first feed roller pair is provided in a central region in a medium width direction that is a direction intersecting with a medium feeding direction,
The receiving portion is provided with a pressing member that presses the bulging portion of the medium in the upstream direction in the medium feeding direction.
A medium feeding device characterized by the above-mentioned. 2. The medium feeding device according to claim 1, wherein the pressing member is an elastic member having a downstream portion fixed in the medium feeding direction and an upstream portion in the medium feeding direction pressing the bulging portion of the medium.
A medium feeding device characterized by the above-mentioned. 2. The medium feeding device according to claim 1, wherein the pressing member has a swing shaft downstream in the medium feeding direction, and an upstream portion in the medium feeding direction from the swing shaft moves the bulging portion of the medium. A swinging member to push,
A medium feeding device characterized by the above-mentioned. The medium feeding device according to any one of claims 1 to 3, wherein the pressing member is provided in a central region in the medium width direction.
A medium feeding device characterized by the above-mentioned. 5. The medium feeding device according to claim 1, wherein the control unit that controls the first feed roller pair and the second feed roller pair is configured to control the second feed roller pair according to a feed condition. 6. Switching the driving amount of the first feed roller pair when driving the first feed roller pair in a state where the feed roller pair is stopped;
A medium feeding device characterized by the above-mentioned. Reading means for reading a medium;
The medium feeding device according to any one of claims 1 to 5, wherein the medium is fed toward a position where the reading unit reads the medium.
An image reading device comprising:

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