JP2000103532A - Pick roller and paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid double feed and paper sheets jamming during the paper feed in an excellent manner by a simple and inexpensive constitution. SOLUTION: A paper feeder 1 is provided with a pick roller 3 which is closely attached to an outermost cut paper sheet K1 of a cut paper sheet group K and initially moves the cut paper sheet K1 by its rotation, a feed roller 5 which is rotated by the rotational force from a power source, rotates the pick roller 3 in the same direction in an interlocking manner with the rotation, and feeds the cut paper sheet K1 from the pick roller 3, carrying rollers 70, 71 to carry the cut paper sheet K1 from the feed roller 5, and a detecting means 8 to detect passing of the cut paper sheet K1 through the carrying rollers 70, 71, and stops the supply of the rotational force from the power source to the feed roller 5 when the passing of the cut paper sheet K1 is detected by the detecting means 8. A high friction surface 30A and a low friction surface 32A extended in the axial direction of the pick roller and different in coefficient of friction are formed on an outer circumferential surface of the pick roller 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder which feeds an outermost cut sheet from a cut paper group in which a plurality of cut sheets are stacked, and rotates the outermost cut paper by rotating the cut paper sheet. The present invention relates to a pick roller for initial movement and a sheet feeding device provided with the pick roller.

[0002]

2. Description of the Related Art In a copying machine, a printer, or the like, one cut sheet is taken out of a plurality of cut sheets (cut sheet group) stored in, for example, a cassette tray by a paper feeding device, and is taken out of a predetermined sheet. Printing is performed by transporting the paper to the printing device along the transport path. As the above-described paper feeding device, there is one having a configuration as shown in FIG. The feeding device 1 comprises a cassette tray 2 in which a plurality of cut sheets K are stacked accommodated, a pick roller 3 in close contact with the cut sheet K ₁ uppermost of said plurality of cut sheets K, from a power source (not shown) And a feed roller 5 arranged so as to be rotated by the rotational power and to be in close contact with the separator 4. Inside the cassette tray 2, a bottom plate 20 is arranged in a biased state by a spring 21 or the like, and a plurality of cut sheets K stacked on the bottom plate 20 are pressed by the pick roller 3. . The outer surfaces of the pick roller 3 and the feed roller 5 are covered with elastic bodies 30 and 50 such as rubber to have a relatively large friction coefficient. The pick roller 3 and the feed roller 5 are linked via a connecting gear 6. That is, when the feed roller 5 is rotated by the rotational power from the power source, the pick roller 3 is moved in conjunction with the rotation of the feed roller 5.
It is made to rotate in the same direction as. Generally, due to the design of the device, the peripheral speed of rotation of the pick roller 3 is set to be higher than the peripheral speed of rotation of the feed roller 5, for example, so as to rotate at twice the peripheral speed.

[0003] In the paper feeder 1 configured as described above, the pick roller 3 is driven by the uppermost cut sheet K of the plurality of cut sheets K.
Adheres to _1, since the surface of the pick roller 3 is a surface of large relatively friction coefficient, cut paper K ₁ rotated by the top in conjunction rotates pick roller 3 of the feed roller 5 is initial movement Let me do. Then, the cut sheet K ₁ reaching between the feed roller 5 and the separator 4 is
The paper is further fed by the rotation of the feed roller 5 and the rotation of the pick roller 3, and is transported by a pair of transport rollers 70 and 71. These transport rollers 70 and 71 are provided relatively close to the feed roller 5 in order to reliably receive the cut sheet K ₁ from the feed roller 5. In the vicinity of the conveying rollers 70 and 71, the sensor has 8 is disposed, whether cut sheet K ₁ is supplied to the conveying roller 70 and 71, i.e., the distal end portion of the cut sheet K ₁ has passed by the sensor 8 Is detected. The cut sheet K ₁ transport roller 70 in the sensor 8,
When it is detected that the power is supplied to the feed roller 71, the supply of the rotational power to the feed roller 5 is stopped, and the rotation of the feed roller 5 by the rotational power from the power source is stopped. At this time, since the transport rollers 70 and 71 are disposed relatively close to the feed roller 5, the transport rollers 7
Even when the cut sheet K ₁ is conveyed by 0,71, a period of time the rear end side of the cut sheet K ₁ is sandwiched between the feed roller 5 and the separator 4. Therefore, so as not to obstruct the conveyance of the cut sheet K ₁ by the conveying roller 70 and 71, the feed roller 5 even when the supply of rotational power is cut off and is capable of free rotation. Such a paper feeder 1 has a relatively simple configuration and can be provided at low cost.

[0004]

[SUMMARY OF THE INVENTION However, between the transport rollers is also in a state where the cut sheet K ₁ is conveyed by 70 and 71, a period of time the rear end side feed roller 5 and the separator 4 of the cut sheet K ₁ Is sandwiched between
In addition, the feed roller 5 to which the supply of the rotational power is cut off can freely rotate. Therefore, even when the cut sheet K ₁ is transported, as long as the cut sheet K ₁ is sandwiched between the feed roller 5 and the separator 4, so that the feed roller 5 rotates. Therefore, the pick roller 3 linked with the feed roller 5 also rotates. When the pick roller 3 rotates, the cut sheet K pressed by the pick roller 3 is sent out from the cassette tray 2 as described above. That is,
When the previous cut sheet K ₁ is separated from the pick roller 3 and the pick roller 3 is in close contact with the _second cut sheet K ₂ to be sent out next, it is sent out from the cassette tray 2. At this time, since the peripheral speed of the pick roller 3 is set to about twice the peripheral speed of the feed roller 5, the cut sheet K ₂ of the second sheet earlier than the cut sheet K ₁ fed previously Will also move faster. Then, as shown in FIG. 4, the second cut sheet K ₂ enters between the previous cut sheet K ₁ and the separator 4. In this case, usually, the previous cut sheet K ₁ and the second sheet of cut paper K ₂ are separated by a separator 4.

However, cut paper K_nAs standardized
Just plain paper that was
Thicker or smaller than paper, or recycled
Paper and the like are used. For this reason, the cut paper K_nAs ratio
When using a relatively small thickness, separate
Cut paper K by₁And the second cut paper K _Two
May not be able to be separated. In this case, as shown in FIG.
As the second cut paper K_TwoIs the cut paper K₁Nire
It will be conveyed. That is, the so-called double
Feed is generated. In particular, it can be displayed like recycled paper.
This phenomenon may occur on relatively rough surfaces.
I'm sorry.

On the other hand, when used as a relatively large thickness of the cut sheet K _n, even when had penetrated the second sheet of cut paper K ₂ between the cut preceding sheet K ₁ and the separator 4 , it may not be separated previously cut sheet K ₁ and the second sheet of cut paper K ₂ by the separator 4. In this case, since the cut paper K _n is a large thickness can not pass through between the simultaneously two feed rollers 5 and the separator 4, a paper jam occurs.

Therefore, it is conceivable to solve the above-mentioned problem by disconnecting the interlock between the feed roller 5 and the pick roller 3. For example, it is conceivable to employ an electromagnetic clutch or a torque limiter. However, the above-described paper feeder 1 has the advantage that it has a simple structure and is inexpensive, and adopting an electromagnetic clutch or a torque limiter that is disadvantageous in terms of cost is not in line with the actual situation.

The present invention has been conceived in view of the above-mentioned circumstances, and it is possible to satisfactorily avoid double feed and paper jam during a paper feeding operation by using a configuration which can be provided simply and inexpensively. Is an issue.

[0009]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

That is, the pick roller provided by the first aspect of the present invention is incorporated in a paper feeder that feeds the outermost cut sheet from a cut sheet group in which a plurality of cut sheets are stacked, and A pick roller for initially moving the outermost cut paper by its rotation, wherein a high friction surface and a low friction surface having different friction coefficients are formed on the outer peripheral surface while extending in the axial direction. And

In the above configuration, the outer surface of the pick roller has a high friction surface and a low friction surface. When the high friction surface is in close contact with the outermost cut paper, the cut paper is rotated by the rotation of the pick roller. In a state where the cut sheet is moved and the low friction surface is in close contact, the cut sheet is not moved or hardly moved. That is, in the pick roller, the cut sheet is exclusively moved by rotating the pick roller with the high friction surface in close contact. Therefore, compared with the case where the entire outer peripheral surface is made to have a high friction surface as in the case of the pick roller of the conventional paper feeding device, the area worn by moving the cut sheet is reduced in the present invention, This has the advantage of extending the life of the roller.

In a preferred embodiment, each of the high friction surface and the low friction surface is formed by a plurality of surfaces, and the high friction surface and the low friction surface are alternately formed in a circumferential direction. The friction surface and the low friction surface may be configured to have the same or substantially the same area.

In the above configuration, the high friction surface and the low friction surface are alternately formed in the circumferential direction. The state in which the cut sheet is not fed in close contact is repeated. For this reason, the cut sheet is fed intermittently by the pick roller having the above configuration. If the high friction surface and the low friction surface are configured to have the same or substantially the same area, the cut sheet will be intermittently fed at a constant rhythm.

The high friction surface is made of, for example, a rubber-like elastic material, and the low friction surface is made of, for example, a metal or a hard resin.

According to a second aspect of the present invention, there is provided a paper feeder which comes into close contact with the outermost cut paper of a cut paper group in which a plurality of cut papers are stacked, and rotates the outermost cut paper by rotating the cut paper. A pick roller for initially moving the cut sheet of paper, and rotating by the rotational power from a predetermined power source, rotating the pick roller in the same direction in conjunction with the rotation, and cutting the outermost layer from the pick roller A feed roller that feeds the paper, a feed roller that is arranged on the feed side of the feed roller, and that conveys the outermost cut paper from the feed roller; Detecting means for detecting that the cut sheet has passed through the transport roller, and the detecting means detects the cut of the outermost layer. A paper feeder configured to cut off the supply of rotational power from the power source to the feed roller when the passage of paper is detected, wherein the pick roller is the first roller of the present invention described above. The pick roller is one of the pick rollers described on the side.

In the above configuration, the pick roller described in the first aspect above is employed, and this pick roller is characterized by having a high friction surface and a low friction surface. When the cut sheet comes into close contact with the high friction surface, the cut sheet is moved by the rotation of the pick roller, and when the cut sheet comes into close contact with the low friction surface, it is not moved at all or hardly moved. For this reason, even if the pick roller rotates in conjunction with the rotation of the feed roller, the cut sheet is moved as long as the pick roller rotates, as in a conventional pick roller in which the entire outer peripheral surface is a high friction surface. There is no such thing.
That is, the distance over which the cut sheet is sent out during one rotation of the pick roller is reduced.

As described above, the peripheral speed of the pick roller is higher than that of the feed roller, for example, 2
If the second cut sheet is moved by the pick roller, the second cut sheet moves faster than the cut sheet sent earlier,
The cut sheet is sandwiched between the cut sheet and the separator, and double feed or paper jam occurs.

On the other hand, in the present invention, the outer peripheral surface of the pick roller has a high friction surface and a low friction surface, and the feeding operation by the pick roller is mainly performed on the high friction surface. For this reason, in the present invention, the feed speed of the cut sheet by the pick roller is substantially smaller than the feed speed of the cut sheet by the conventional pick roller, and double feed and paper jam are hardly generated. For example, if two high-friction surfaces and two low-friction surfaces are provided and these four surfaces have the same or substantially the same area, the pick roller can be one in comparison with the case where the entire surface is a high-friction surface.
Cut paper feed distance during rotation is halved. With this configuration, for example, even if the peripheral speed of the pick roller is set to twice the peripheral speed of the feed roller,
Since the feed distance of the cut sheet by the feed roller and the feed distance of the cut sheet by the pick roller are substantially the same, double feed and paper jam are less likely to occur.

If high friction surfaces and low friction surfaces are alternately provided in the circumferential direction on the outer peripheral surface of the pick roller, cut paper is intermittently supplied by the pick roller as described above. For example, if the second cut sheet enters between the separator and the previous cut sheet, the movement of the second cut sheet is restricted. Is added when contacting a low friction surface, and is hardly added when contacting a low friction surface. Therefore, the feed force is intermittently applied to the second cut sheet, and the second cut sheet is in a state as if vibration was applied.
Thus, the first cut sheet and the second cut sheet are separated by the separator, and it can be expected that double feed and paper jam are suppressed.

[0020] Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a side view showing an example of the sheet feeding device of the present invention, and FIG. 2 is an exploded side view of a pick roller of the sheet feeding device of FIG. In these drawings, members and elements equivalent to those shown in the drawings referred to for explaining the conventional example are denoted by the same reference numerals.

As shown in FIG. 1, the paper feeder 1 includes a cassette tray 2 in which a plurality of cut sheets K are stacked and stored.
If, the pick roller 3 in close contact with the cut sheet K ₁ at the top
A feed roller 5 that is rotated by rotational power from a power source (not shown) and is disposed in close contact with the separator 4, and a pair of transport rollers 70 and 71 disposed on the unloading side of the feed roller 5. It is configured.

As shown in FIG. 1, the cassette tray 2 has a bottom plate 20 disposed in a biased state by a spring 21 or the like, whereby a plurality of cut sheets K stacked on the bottom plate 20 are provided. Is pressed by the pick roller 3.

As shown in FIG. 2, the pick roller 3 has elastic members 30 made of rubber or the like fitted and fixed in two concave portions 32a formed in the roller body 32, respectively. Further, a gear portion 31 that rotates integrally with the roller body 32 is provided. Roller body 32
Are integrally formed by molding using a hard resin such as polyoxymethylene (POM), for example, and the recesses 32a, 32a are also formed at the same time. The recesses 32 a are formed to face each other so as to extend in the axial direction of the pick roller 2 in a quarter of the circumferential direction of the pick roller 2.
In the pick roller 2 having the above configuration, two side surfaces 32A of the roller body 32 and a surface 30A of the elastic body 30 alternately appear on the outer peripheral surface. Since the roller main body 32 is formed of a material having a relatively small friction coefficient such as a hard resin, and the elastic bodies 30 and 30 are formed of a material having a relatively large friction coefficient such as rubber, the pick roller 2 is formed. Has a high friction surface (the surface of the elastic body) 30
A and two low friction surfaces (side surfaces of the roller body) 32A are formed alternately. Thus, when the pick roller 3 is rotated, the pick roller 3 while the cut sheet K _n is in close contact with the high friction surface 30A in close contact with this
The moved cut sheet K _n by the rotational force, and while are made so as not to move little or do not at all move in close contact with the low friction surface 32A. For this reason, compared with the case where the entire outer peripheral surface is a high friction surface, in the pick roller 3 of the present embodiment, the cut paper K
_The distance for moving _n is approximately ２.

As shown in FIG. 1, the feed roller 5 has a peripheral surface of a roller body 52 made of resin or the like covered with an elastic body 50 such as rubber having a relatively large friction coefficient. I have. Further, a gear portion 51 that rotates integrally with the roller main body 52 is provided. The feed roller 5 is supplied with rotational power from a power source such as a motor (not shown) and rotates in the direction of arrow A in the figure. It should be noted that the feed roller 5 keeps rotating even when the rotational power is not supplied from the power source.
Free rotation in the direction. This is because, even cut sheet K _n is passed feeding the conveying rollers 70 and 71, a certain period is a state of being sandwiched between the rear end portion side feed roller 5 and the separator 4 of the cut sheet K _n , there is a free rotatable so as not to inhibit the conveyance of the cut sheet K _n by the transport rollers 70 and 71.

Between the pick roller 3 and the feed roller 5, the gears 31, 51 of these rollers 3, 5 are provided.
And a connecting gear 6 that meshes with. That is, when the feed roller 5 rotates, the pick roller 3 rotates in the same direction as the feed roller 5 in conjunction with the rotation. In general, the rotation peripheral speed of the pick roller 3 is set to be higher than the rotation peripheral speed of the feed roller 5 for the reason of the design of the apparatus. You.

The transport rollers 70 and 71 have an outer peripheral surface having a relatively large coefficient of friction and are arranged so as to be in close contact with each other. One transport roller 7
0 is rotatable in the direction of arrow B in FIG. 1 by power from an appropriate power source.
Free rotation is possible. That is, the rotation of one transport roller 70 also causes the other transport roller 71 to rotate. The transport rollers 70 and 71 configured as described above are provided with the cut sheet K _n from the feed roller 5.
Is disposed relatively close to the feed roller 5 in order to reliably receive the toner. As the power source for one transport roller 70, the same power source as the feed roller 5 may be used in consideration of cost. In the vicinity of the conveying rollers 70 and 71, the optical sensor 8 is arranged as the detecting means for detecting the passage of the cut sheet K _n. The optical sensor 8 may be a transmission type sensor or a reflection type sensor, and a unit other than the optical sensor 8 may be used as a detection unit.

[0028] In this sheet feeding device configured as 1, with the pick roller 3 comes into close contact with the uppermost cut sheet K ₁ of the stacked cut sheet K, the outer peripheral surface of the high friction surface 30A of the pick roller 3 and because it is a low friction surface 32A, when the pick roller 3 by the rotation of the feed roller 5 in conjunction rotated only while the cut sheet K ₁ high friction surface 30A and the top are in close contact with the cut sheet K ₁ is moved. The pick roller 3, from this which is formed alternately with the high friction surface 30A and a low friction surface 32A, the cut sheet K ₁ is moved intermittently by the rotation of the pick roller 3. As described above, when compared with the case where the entire outer peripheral surface is a high friction surface, the pick roller 3 in the present embodiment, this distance for moving the cut paper K ₁ during one rotation of approximately 1/2 It has been done. That is, pick the peripheral speed of the roller 3, when it is set to 2 times the peripheral speed of the feed roller 5, the speed and the feed roller 5 cut sheet K ₁ by moving the cut sheet K ₁ by the pick roller 3 Are almost the same as the speed at which the object is moved.

The cut sheet K ₁ reaching between the feed roller 5 and the separator 4 is further sent out by the rotation of the feed roller 5 and the rotation of the pick roller 3, and is transported by a pair of transport rollers 70 and 71. Since the optical sensor 8 is disposed near these transport rollers 70 and 71, the optical sensor 8 controls the cut sheet K.
₁ is whether or not supplied to the conveyance roller 70 and 71, i.e., the distal end portion of the cut sheet K ₁ whether passed is detected. When the cut sheet K ₁ in the optical sensor 8 is detected to have been fed to the conveying roller 70, 71, the supply of rotational power to the feed roller 5 is cut off, the feed roller by the power from the power source The rotation of 5 is stopped. Then, gradually conveyed cut sheet K ₁ by the rotation of the conveying rollers 70 and 71.

By the way, since the conveying rollers 70 and 71 are arranged relatively close to the feed roller 5, even when the cut sheet K ₁ is conveyed by the conveying rollers 70 and 71, a certain period of time the rear end side of the cut sheet K ₁ is sandwiched between the feed roller 5 and the separator 4. For this reason, the feed roller 5, which can be freely rotated, cuts the cut paper K between the feed roller 5 and the separator 4.
_{When 1} passes, it rotates freely, and in conjunction with this, the pick roller 3 also rotates. When the cut sheet K ₁ is separated from the pick roller 3, so that the pick roller 3 comes into close contact with the next cut sheet K _2. At this time, until separated from the cut sheet K ₁ is the feed roller 5, since the feed roller 5 and the pick roller 3 is rotated, the previous cut sheet K ₁ even though the following are fed by the feed roller 5 cut sheet K ₂ will be sent out.

In the conventional paper feeder, the feed roller 5
The peripheral speed of the pick roller 3 is higher than the peripheral speed,
The entire peripheral surface of the pick roller 3 was a high friction surface
Therefore, the next cut paper K_TwoThe moving speed of
Paper K₁Was faster than the moving speed. others
Therefore, as described with reference to FIG. ₁
Next cut paper K between the sheet and the separator 4_TwoPenetrated
I will. At this time, these brackets are
Toji K₁, K_TwoIf is not properly separated, cut paper K
_nIs relatively thin, double feed occurs and the ratio
If the thickness is relatively thick, paper jam has occurred.

[0032] In contrast, in the present invention, the high friction surface 30A and a low friction surface 32A are arranged alternately in cut sheet K _n feed rate feed roller on the outer circumferential surface of the pick roller 3 5
And the pick roller 3 are substantially the same. For this reason,
That may enter the next cut sheet K ₂ between the previous cut sheet K ₁ and the separator 4 are suitably avoided, double feed or paper jam can be avoided.

Further, in the paper feeder 1 of the present embodiment, the cut sheet K is intermittently fed by the pick roller 3. The next cut paper K ₂ is placed between the previous cut paper K ₁ and the separator 4.
If the entered is the next cut sheet K ₂ movement is limited, at this time is added when the force from the pick roller 3 is in contact with the high friction surface 30A, mostly in addition when in contact with the low friction surface 32A I can't. Therefore, the next cut K _2, feed force is applied intermittently, as if the next cut sheet K ₂ in a state as if a given vibration. As a result, the previous cut sheet K ₁ and the next cut sheet K _1
2 is separated by the separator 4, and it can be expected that the occurrence of double feed and paper jam is suppressed.

In this embodiment, the high friction surface 30A and the low friction surface 32 having substantially the same area are provided on the outer peripheral surface of the pick roller 3.
A were alternately provided on two surfaces each, but the high friction surface 30
A and the low friction surface 32A do not necessarily have to have substantially the same area, and it is not necessary to provide two surfaces.

In this embodiment, the cassette tray 2
The case where the uppermost cut sheet K1 is taken out _one by one from the plurality of cut sheets K stacked and accommodated in the above has been described.
One to be applied when taking out the cut paper K _n one by one from the stack of cut sheet group K without using a cassette tray, the cut paper K _n the bottom from the cut sheet group K as a so-called manual feed mode It can be applied to the case of taking out one by one.

[0036] Of course applicable not only cut sheet K _n as a subject to recording paper in the image formation in a copying machine or a printer, a document as an image reading target from a plurality stacked state, as an apparatus for taking out an original one by one It goes without saying that you can do it.

[0037]

According to the pick roller of the present invention, the cut sheet is exclusively moved by rotating the pick roller with the high friction surface in close contact. Therefore, compared with the case where the entire outer peripheral surface is a high friction surface as in the case of the pick roller of the conventional paper feeding device, the area worn by the initial movement of the cut sheet is reduced, and the pick roller An advantage such as a longer life is obtained.

In the paper feeder of the present invention, the outer peripheral surface of the pick roller has a high friction surface and a low friction surface, and the movement of the cut sheet by the pick roller is mainly performed on the high friction surface. For this reason, in the paper feeder, the feed speed of the cut sheet by the pick roller is substantially smaller than the feed speed of the cut sheet by the conventional pick roller, and the feed speed of the cut sheet by the feed roller and the pick roller The feeding speed can be made substantially the same as the feeding speed, and the occurrence of double feed and paper jam can be appropriately avoided.

[Brief description of the drawings]

FIG. 1 is a side view illustrating an example of a sheet feeding device of the present invention.

FIG. 2 is an exploded side view of a pick roller of the sheet feeding device of FIG.

FIG. 3 is a side view illustrating an example of a conventional sheet feeding device.

FIG. 4 is an enlarged view of a main part for explaining the operation of the sheet feeding device of FIG. 3;

FIG. 5 is a diagram illustrating a state of double feed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Paper feeder 2 Cassette tray 3 Pick roller 5 Feed roller 8 Sensor (as a detection means) 30A High friction surface 32A Low friction surface 70, 71 Transport roller K Plural cut paper (cut paper group) _Kn cut paper ( One)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toshiaki Kumagai 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa F-term in Fujitsu Limited (reference) 2C059 AA05 AA49 AA63 BB12 CC03 CC10 CC15 CC24 CC25 3F343 FA02 FB02 FB04 FC01 GA01 GB01 GC01 GD02 HD11 JA04 JA12 JD03 JD09 JD38 KB05 KB16 LA03 LC03 MA03 MA15 MA23 MC10

Claims (5)

[Claims] 1. A pick roller that is incorporated in a paper feeder that feeds an outermost cut sheet from a cut sheet group in which a plurality of cut sheets are stacked, and that initially rotates the outermost cut sheet by rotation of the pick roller. A pick roller, wherein a high friction surface and a low friction surface having different friction coefficients are formed on an outer peripheral surface thereof in the axial direction thereof. 2. The pick roller according to claim 1, wherein a plurality of said high friction surfaces and a plurality of low friction surfaces are formed, and said high friction surfaces and said low friction surfaces are formed alternately in a circumferential direction. . 3. The pick roller according to claim 2, wherein said high friction surface and said low friction surface have the same or substantially the same area. 4. The pick roller according to claim 1, wherein the high friction surface is formed of a rubber-like elastic material, and the low friction surface is formed of a metal or a hard resin. . 5. A pick roller which comes into close contact with the outermost layer cut sheet of a group of cut sheets in which a plurality of cut sheets are stacked, and initially rotates the outermost layer cut sheet by rotation thereof, and a predetermined power. A feed roller that rotates by the rotation power from the source and rotates the pick roller in the same direction in conjunction with the rotation, and feeds the outermost layer of cut paper from the pick roller, and a feed side of the feed roller. A transport roller that is disposed and transports the outermost cut paper from the feed roller, and is disposed near the transport roller and detects that the outermost cut paper has passed through the transport roller. Detecting means, when the passage of the outermost layer of cut paper is detected by the detecting means,
A sheet feeder configured to cut off the supply of rotational power from the power source to the feed roller, wherein the pick roller is the one described in any one of claims 1 to 4. To feed paper.