JP2022011071A - Sheet feeder - Google Patents

Abstract

To provide a sheet feeder capable optimizing a separation load of a separation pad on a sheet, and separating thin paper and thick paper.SOLUTION: A sheet feeder comprises a feed roller 14 which feeds a plurality of sheets stacked at a loading part, and a separation pad 30 which is arranged opposite the feed roller 14 and separates the sheets sent by the feed roller 14 one by one. The separation pad 30 has a first separation part 31 which holds and separates a sheet with the feed roller 14, a second separation part 32 which comes into contact with the sheet and separates it at a position outside the feed roller in a width direction of the sheet, and an energization part 33 which is provided outside the second separation part 32 in the width direction and energizes the sheet toward the feed roller 14 in a thickness direction thereof.SELECTED DRAWING: Figure 4

Description

The present invention relates to a sheet feeding device that feeds sheets.

Conventionally, in a sheet feeding device that feeds sheets loaded on a loading platform one by one, a separating member for separating the sheets one by one is provided so that a plurality of sheets are not overlapped and sent to the transport path. There is. As an example, a separation pad in which the friction member is in the form of a sheet is used as the separation member, and the sheet is separated by pressing the separation pad against the sheet bundle.

A compression spring may be used as a means of pressing the separation pad against the sheet, but small sheet transfer devices use a sponge to reduce space. The compression spring can reduce the spring constant and adjust the force applied to the thin paper and the thick paper, but the sponge has a large spring constant and the difference in the force applied to the thin paper and the thick paper is large. Therefore, although a small sheet transport device can transport sheets of general thickness such as copy paper, there may be a problem that thick paper such as postcards cannot be fed. Therefore, Patent Document 1 proposes a technique for optimizing the separation load on the sheet.

Japanese Patent No. 5378085

However, in the sheet feeding device described in Patent Document 1, since the separation load differs depending on the thickness of the sheet, it may not be possible to sufficiently separate some papers.

In view of the above problems, the sheet feeding device according to the present invention is
A feeding roller that feeds multiple sheets loaded on the loading section,
It is provided with a separation pad which is arranged at a position facing the feeding roller and separates the sheets fed by the feeding roller one by one.
The separation pad has a first separation portion that sandwiches and separates the sheet from the feeding roller, and a second separation portion that contacts and separates the sheet at a position outside the feeding roller in the width direction of the sheet. It is characterized by having an urging portion provided on the outer side of the second separating portion in the width direction and urging the sheet to the feeding roller side in the thickness direction thereof.

It is possible to provide a sheet feeding device that separates from thin paper to thick paper by optimizing the separation load on the sheet in the separation pad.

Schematic cross-sectional view of the image reader according to this embodiment. The block diagram of the control unit of the image reading apparatus which concerns on this embodiment. The enlarged perspective view around the separation pad and the feed roller which concerns on this embodiment. The view which looked at the separation pad which concerns on this embodiment from the direction of arrow A of FIG. FIG. 3 is a cross-sectional view of the separated portion according to the present embodiment as viewed from the direction of arrow C in FIG. A cross-sectional view (when transporting thin paper) of the separated portion according to the present embodiment as viewed from the direction of arrow B in FIG. A cross-sectional view (during thick paper transport) of the separated portion according to the present embodiment as viewed from the direction of arrow B in FIG. The view which looked at the separation pad which concerns on 2nd Embodiment from the direction of arrow A of FIG.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are examples for realizing the present invention, and the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements, etc. of the components of the present embodiment should be appropriately modified or changed depending on the configuration of the apparatus to which the present invention is applied and various conditions without departing from the spirit of the present invention. be.
FIG. 1 is a schematic view of an image reading device 10 as an example of a sheet feeding device according to the present embodiment.

<Device configuration>
The image reading device 10 conveys one or more sheets S loaded on the loading platform 12 into the device one by one from the paper feed port, reads the image, and discharges the images to the outside of the device by the driving roller 20 and the driven roller 21. It is a device to do. The sheet S to be read is, for example, a sheet of OA paper, a check, a check, a business card, a card, or the like, and may be a thick sheet or a thin sheet.

<Paper>
A first transport unit 50 is provided as a paper feed mechanism for feeding the sheet S along the path RT. In the case of the present embodiment, the first transport unit 50 includes a feed roller 14 (feed roller) and a separation pad 30 arranged to face the feed roller 14, and feeds the sheet S on the loading platform 12 in the feed direction D. Transport one by one. A driving force is transmitted to the feed roller 14 from a drive unit 15 configured by a motor or the like via a transmission unit (not shown), and is rotationally driven in the direction of the arrow in the figure (direction in which the seat S is conveyed).

<Drive unit>
The transmission unit that connects the drive unit 15 and the feed roller 14 is, for example, in the present embodiment, in a state in which the drive force is transmitted in a normal state, and shuts off the drive force when the seat S is stopped. When the transmission of the driving force is cut off by the transmission unit, the feed roller 14 is in a state where it can freely rotate.

<Separation structure>
The separation pad 30 arranged to face the feed roller 14 is a member for separating the sheets S one by one, and is in pressure contact with the feed roller 14. In order to secure this pressure contact state, the separation pad 30 is provided with a compressible sponge member 35 (elastic member). The elastic force of the sponge member 35 is configured to urge the first friction member 31 and the second friction member, which will be described later, toward the feed roller 14.

<Transport structure>
The second transport unit 51 as a transport mechanism on the downstream side in the transport direction of the first transport unit 50 has a drive roller 16 and a driven roller 17 driven by the drive roller 16, and is transported from the first transport unit 50. The sheet S that has come is transported to the downstream side thereof. The driving force is transmitted from the driving unit 15 to the driving roller 16 and is rotationally driven. The driven roller 17 is in pressure contact with the drive roller 16 at a constant pressure and is brought around by the drive roller 16. The driven roller 17 may be configured to be urged to the drive roller 16 by an urging unit (not shown) such as a spring.

The third transport unit 52 located downstream of the second transport unit 51 in the transport direction includes a drive roller 20 and a driven roller 21 driven by the drive roller 20, and has been transported from the second transport unit 51. The sheet S is discharged to the outside of the device. That is, the third transport unit 52 functions as a discharge mechanism.

The driving force is transmitted from the driving unit 15 to the driving roller 20 and is rotationally driven. The driven roller 21 presses against the drive roller 20 at a constant pressure and is brought around to the drive roller 20. The driven roller 21 may be configured to be urged to the drive roller 31 by an urging unit (not shown) such as a spring.

<Image reading structure, control>
Here, in the image reading device 10 of the present embodiment, the image is read by the image reading units 18 and 19 arranged between the second transport unit 51 and the third transport unit 52, so that the second transport unit 51 is used. And the third transport unit 52 transports the sheet S at a constant speed. By always setting the transport speed at this time to be equal to or higher than the transport speed of the first transport unit 50, it is possible to reliably avoid a situation in which the succeeding sheet S catches up with the preceding sheet S. For example, in the present embodiment, the drive unit 15 to the first unit so that the transfer speed of the seat S by the second transfer unit 51 and the third transfer unit 52 is faster than the transfer speed of the sheet S by the first transfer unit 50. The reduction ratio of the transmission unit that is driven and transmitted to the transport unit 50 is made larger than the reduction ratio of the transmission unit that is driven and transmitted from the drive unit 15 to the second transport unit 51 and the third transport unit 52.

Even when the transport speed of the seat S by the second transport unit 51 and the third transport unit 52 and the transport speed of the sheet S by the first transport unit 50 are the same conditions, the drive unit 15 is controlled to perform the first. It is also possible to form a minimum space between the preceding sheet S and the succeeding sheet S by controlling only the drive on the transport unit 50 side and intermittently shifting the paper feed start timing of the succeeding sheet S.

<Resist sensor>
The medium detection sensors 41 and 42 arranged on the downstream side in the transport direction from the first transport unit 50 are on the upstream side of the image reading units 18 and 19 and on the upstream side of the transport path RT arranged on the downstream side of the first transport unit 50. This is an example of a detection sensor (sensor for detecting the behavior or state of the sheet), and the position of the sheet S conveyed by the first transfer unit 50, specifically, the sheet S at the detection position of the medium detection sensors 41 and 42. Detects whether the end of the has reached or passed. Various media detection sensors 41 and 42 can be used, but in the case of the present embodiment, it is an optical sensor, includes a light emitting portion and a light receiving portion thereof, and has a light receiving intensity when the sheet S reaches or passes through. The sheet S is detected on the principle that the (light receiving amount) changes. The medium detection sensors 41 and 42 are not limited to the above optical sensors, and for example, a sensor (image sensor or the like) capable of detecting the end of the sheet S may be used, or a lever protruding into the path RT. It may be a type sensor.

<Arrangement of CIS>
The image reading units 18 and 19 located on the downstream side of the medium detection sensors 41 and 42 are, for example, optically scanned, converted into an electric signal and read as image data, and have a light source such as an LED or an image inside. It is equipped with a sensor, lens array, etc. In the case of the present embodiment, the image reading units 18 and 19 are arranged one by one on both sides of the path RT, and read the front and back surfaces of the sheet S. However, one may be arranged only on one side of the path RT, and only one side of the sheet S may be read. Further, in the present embodiment, the image reading units 18 and 19 are arranged so as to face each other with the route RT interposed therebetween, but for example, they may be arranged at intervals in the transport direction of the route RT.

<Explanation of block diagram>
The control unit 80 will be described with reference to FIG. FIG. 2 is a block diagram of the control unit 80 of the image reading device 10.

The control unit 80 includes a CPU 81, a storage unit 82, an operation unit 83, a communication unit 84, and an interface unit 85. The CPU 81 controls the entire image reading device 10 by executing the program stored in the storage unit 82. The storage unit 82 is composed of, for example, a RAM, a ROM, or the like. The operation unit 83 is composed of, for example, a switch, a touch panel, or the like, and receives an operation from an operator.

The communication unit 84 is an interface for performing information communication with an external device. When a PC (personal computer) is assumed as the external device, the communication unit 84 may include, for example, a USB interface or a SCSI interface. Further, in addition to such a wired communication interface, the interface may be a wireless communication interface, and both wired communication and wireless communication interfaces may be provided.

The interface unit 85 is an I / O interface that inputs / outputs data to / from the actuator 86 and the sensor 87. The actuator 86 includes a drive unit 15, a transmission unit, and the like. The sensor 87 includes medium detection sensors 41, 42, image reading units 18, 19, and the like.

<Drive by receiving start instruction from PC>
The basic operation of the image reader 10 will be described. When the control unit 80 receives, for example, an image reading start instruction from an external personal computer to which the image reading device 10 is connected, the control unit 80 starts driving the third transport unit 52 from the first transport unit 50. The seats S loaded on the loading platform 12 are conveyed one by one from the seat S located at the bottom thereof.

Further, as will be described later, the image reading may be started by the start key provided on the operation unit 83 of the image reading device 10, and then the start of image reading may be notified to the external personal computer.

<Start reading according to the output of the resist sensor>
The control unit 80 starts reading the image of the sheet S by the image reading units 18 and 19 at the timing based on the detection result of the medium detection sensors 41 and 42, and the read image is temporarily stored and sequentially transmitted to the external personal computer. do. The sheet S from which the image has been read is discharged to the outside of the apparatus by the third transport unit 52, and the image reading process of the sheet S is completed.

<Details of separation pad>
FIG. 3 is a perspective view for explaining the arrangement of the separation pad 30 and the feed roller 14 according to the first embodiment of the present invention. FIG. 3A shows a state in which the separation pad 30 and the feed roller 14 are viewed from the upstream side, and FIG. 3B shows a state in which only the separation pad 30 is viewed from the downstream side. FIG. 4 is a view of the separation pad 30 as viewed from the direction of arrow A in FIG. FIG. 5 is a cross-sectional view of the separated portion as viewed from the direction of arrow C in FIG. FIG. 6 is a cross-sectional view of the state of the feed roller 14, the separation pad 30, and the sheet S when transporting thin paper from the direction of arrow B in FIG. 4, and FIG. 7 is a cross-sectional view of the feed roller 14 when transporting thick paper. FIG. 3 is a cross-sectional view of the state of the separation pad 30 and the sheet S when viewed from the direction of arrow B in FIG.

As shown in FIG. 3A, the feed roller 14 is provided with a plurality of (two in the figure) roller members 14a on the roller shaft 14b at intervals in the axial direction.

As shown in FIG. 4, the separation pad 30 includes a first friction member 31 and a second friction member 32 for separating the sheet S, and an urging portion 33 for urging the sheet S toward the feed roller 14. The first friction member 31 has two roller contact portions 31b that are in contact with the two roller members 14a of the feed roller 14, respectively. The second friction member 32 is arranged outside the roller shaft 14b in the axial direction with respect to the first friction member 31, and comes into contact with the sheet S together with the roller contact portion 31b.

Further, as shown in FIG. 3A, the second friction member 32 is axially distant from the roller member 14a on the outer side in the axial direction of the two roller members 14a with respect to the roller member 14a. It is arranged in two places so as to overlap (overlap).

As shown in FIGS. 3B and 4, the first friction member 31 and the second friction member 32 have four notches with respect to a single flat plate-shaped rectangular friction member (for example, rubber). Is formed by putting in. Further, similarly, a flat plate-shaped and rectangular low-friction member (for example, a film member formed of Mylar) is attached with four notches to the urging portion 33. ing. The axially outer portion of the roller member 14a in the urging portion 33, that is, the portion attached to the second friction member 32, is closer to the downstream side of the feeding direction D shown in FIG. 4 than the second friction member 32. The protrusion amount is short, and a step portion is provided so that the protrusion amount on the inside is smaller than that on the outside in the axial direction.

As shown in FIG. 3B, in the present embodiment, the first friction member 31 and the second friction member 32 are on the opposite side (back surface) of the feeding roller 14 in the thickness direction of the sheet S. The sponge member 35 is attached. The surface of the sponge member 35 opposite to the first friction member 31 and the second friction member 32 is attached by double-sided tape 38 so as to abut against the holder 36.

As described above, the restoring force (elastic force) of the sponge member 35 urges the first friction member 31 and the second friction member 32 toward the feeding roller 14, and feeds the first friction member 31 and the second friction member 32. A nip is formed between the roller 14 and the second friction member 32, and the second friction member 32 projects to a position where it overlaps with the roller member 14a of the feeding roller 14 in the axial direction.

Further, the urging portion 33, the first friction member 31, and the second friction member 32 on the upstream side in the feeding direction D are fixed to the holder 36 by the fixed sheet metal 37, the holder 36, the urging portion 33, and the first friction member. This is done by sandwiching the 31 and the second friction member 32. A double-sided tape 38 was used to attach the sponge member 35 to the holder 36, and a fixed sheet metal 37 was used to fix the urging portion 33, the first friction member 31, and the second friction member 32 to the holder 36 on the upstream side. However, it is not limited to this.

As shown in FIG. 4, the urging portion 33, the second friction member 32, and the first friction member 31 have a continuous comb-teeth shape. The urging portion 33 is composed of a member having a friction coefficient smaller than that of the first friction member 31 and the second friction member 32, and is attached to the feed roller 14 side in the thickness direction of the second friction member 32 as shown in FIG. Will be placed.

In the portion between the two first friction members 31 (central portion in the width direction), the urging portion 33 is about the same as the second friction member 32 with respect to the downward direction (direction of the feeding direction D) in FIG. It stands out.

In the width direction, in the portion where the second friction member 32 is provided, the urging portion 33 is provided so as to project toward the tip end side of the second friction member 32 halfway through the second friction member 32, and is provided as a feed roller. A step portion is provided so that the outer side of the 14 in the axial direction protrudes downward (downstream side of the feeding direction D) in FIG.

In this way, the urging portion 33 is arranged so as to come into contact with the sheet S when the sheet S is separated into the first friction member 31 and the second friction member 32 one by one.

Next, the separation operation of the sheet S by the feed roller 14 and the separation pad 30 will be described with reference to FIGS. 5, 6, 7, and 8.

As shown in FIGS. 4 and 5, the tip portions of the plurality of sheets S loaded on the loading platform 12 abut on the urging portion 33. When the feed roller 14 is rotationally driven in the feed direction by a drive means (not shown), a bundle of sheets S in the lower layer portion of the plurality of sheets S in contact with the urging portion 33 becomes a roller member 14a of the feed roller 14. The process proceeds to the nip portion of the first friction member 31 with the roller contact portion 31b. At that time, the base portion of the first friction member 31, the second friction member 32, or the urging portion 33 is in contact with the rollers of the roller member 14a and the first friction member 31 while handling so that the tip of the bundle of the sheets S is slanted. It guides to the nip portion with the portion 31b.

At the same time as the sheet S passes through the nip portion between the roller member 14a and the roller contact portion 31b, or thereafter, the sheet S comes into contact with the second friction member 32 and the tip end side (free end side) of the urging portion 33. At this time, the sheet S separated by the first friction member 31 comes into contact with the urging portion 33 and the second friction member 32, so that the lower sheet S is separated one by one and conveyed to the downstream side in the feeding direction. Will be done.

The contact pressure causes the second friction member 32 and the urging portion 33 to bend and deform. An elastically deformable member such as a sponge is installed behind the member in contact with the sheet S (opposite to the feed roller 14 in the thickness direction) to form a sheet separation portion, which is flexed and deformed by the contact pressure. ..

The separation operation of the sheet S by the feed roller 14 and the separation pad 30 at the time of conveying thin paper and thick paper will be described with reference to FIGS. 5, 6 and 7.

As shown in FIG. 6, the thin paper sheet S that has reached the nip portion of the first friction member 31 with the roller contact portion 31b has the second friction member 32, the roller contact portion 31b of the first friction member 31, and the urging portion. By the contact of 33, they are separated one by one. Since the thin sheet S is weak and bends and deforms in a wavy shape in the width direction, it sufficiently contacts the second friction member 32 and a large separation load acts on it. On the other hand, as shown in FIG. 7, the thick paper sheet S that has reached the nip portion with the roller contact portion 31b of the first friction member 31 is brought into contact with the roller contact portion 31b of the first friction member 31 and the urging portion 33. Separated one by one. Since the thick paper sheet S is strong and hard to bend, it is hard to come into contact with the second friction member 32, and the thick sheet S has a smaller separation load than the thin sheet S.

As a result, a large separation load acts on the thin paper sheet S because the contact area of the second friction member 32 is large, and a small separation is applied to the thick paper sheet S because the contact area of the second friction member 32 is small. The load works. Therefore, it is possible to avoid an excessive separation load acting even on the thick paper sheet S, so that the separation load is optimized according to the thickness of the sheet S.

The configuration of the present invention is not limited to that exemplified in the above embodiment, and the material, shape, dimensions, form, number, arrangement location, etc. can be appropriately changed as long as the gist of the present invention is not deviated. Is. For example, in the above embodiment, the root portion of the second friction member 32 in the urging portion 33 is projected outward from the inside in the axial direction toward the tip end side (free end side) of the second friction member 32. By doing so, the friction by the second friction member 32 is large for the thin paper with weak stiffness, and the friction by the second friction member 31 is small for the thick paper with strong stiffness, but the same effect can be obtained. It does not matter as long as it can be obtained. As an example, the number of linearly formed urging portions 33 may be larger on the outside than on the inside, or the shape may be like a wave protruding from the outside to the inside. Is also good.

Further, the shape of the root portion of the second friction member 32 in the urging portion 33 is such that it extends to the downstream side with the same width, but as shown in FIG. 8, the end portion on the downstream side is moved to the downstream side in the feeding direction. It is also possible to make the shape narrower as it goes. Specifically, the feed roller 14 is provided so as to project outward from the inside in the axial direction in the downward direction (downstream side of the feed direction D) in FIG. In other words, the inner end portion of the urging portion 33 in the width direction is provided so as to be located on the outer side toward the downstream side of the feeding direction D.

Although the present invention has been described above based on one embodiment, the present invention is not limited to the above-mentioned embodiment. In the above-described embodiment, the image reading device having the separation pad 30 has been described as an example, but the present invention is not limited to this, for example, a sheet feeding device (seat feeder or the like) for separating and feeding sheets. However, it can be widely applied to all office machines of image processing devices (printers, multifunction devices, fax machines, etc.) other than image reading equipped with such a sheet feeding device.

S Sheet D Feeding direction 10 Image reader 12 Loading platform 14 Feed roller 14a Roller shaft 14b Roller member 30 Separation pad 31 First separation part 31b Roller contact part 32 Second separation part 33 Erasing part

Claims (5)

A feeding roller that feeds multiple sheets loaded on the loading platform,
It is provided with a separation pad which is arranged at a position facing the feeding roller and separates the sheets fed by the feeding roller one by one.
The separation pad has a first separation portion that sandwiches and separates the sheet from the feeding roller, and a second separation portion that contacts and separates the sheet at a position outside the feeding roller in the width direction of the sheet. , A sheet feeding device provided outside the width direction of the second separating portion and having an urging portion for urging the sheet to the feeding roller side in the thickness direction thereof. The second separation portion has an elastic member having an elastic force toward the feeding roller side and a flat plate-shaped urging portion attached to the feeding roller side of the elastic member.
The sheet feeding device according to claim 1, wherein the area of the surface of the urging portion in contact with the sheet is larger on the outside than on the inside in the width direction. The sheet feeding device according to claim 2, wherein the friction coefficient of the surface in contact with the sheet in the urging portion is smaller than the friction coefficient of the surface in contact with the sheet in the elastic member. The sheet feeding device according to claim 2 or 3, wherein the urging portion is a film member attached to the surface of the elastic member. One of claims 1 to 4, wherein the urging portion is located on the outer side in the width direction as the inner end portion in the width direction moves toward the downstream side in the feeding direction of the sheet. The sheet feeding device described in.

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