JP2006001656A - Roller, paper feeding device therewith, and image reading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve feeding separation performance in feeding of sheet material with high friction in a roller provided in a paper feeding device and an image reading device. <P>SOLUTION: The image reading device has a paper feed roller 3 for feeding the stacked sheet material 2, a separation roller 4 located in the carrying direction of the downstream side of the paper feed roller 3, for feeding the sheet material 2 to a carrying direction, and a retard roller 5 arranged to form a pair with the separation roller 4, for preventing carrying of the sheet material 2 which is not on the uppermost stage. The retard roller 5 has a cylindrical outer peripheral part 21 abutting on the separation roller 4, and an inner peripheral part 23 pivotally supported by a support shaft. The outer peripheral part 21 and inner peripheral part 23 of the retard roller 5 are connected with each other by a plurality of spoke parts 22. One end surface side of an axial direction of the retard roller 5 is constituted to be thinner compared with an end surface side on the opposite side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a roller such as an image scanner or a fax machine, a sheet feeding device including the roller, and an image reading device.

  In recent years, when a large amount of originals is digitized, an image reading apparatus equipped with a so-called ADF that separates the originals one by one and conveys them to a part that performs predetermined processing such as an image reading unit is used. In the manuscripts to perform, there are a lot of copy slips such as so-called carbonless paper coated with developer or color developer on the surface of the paper, depending on the surface properties, the friction between the paper is large, Documents with extremely poor separation are also included. In general, the image reading apparatus often discards the original document after digitizing the original image, and the double feeding of the original document may cause loss of original data as well as loss of image data. Higher performance is required for certainty.

  Hereinafter, a conventional paper feeding mechanism will be described.

  6A is an explanatory diagram of the separation principle when one sheet material is fed, FIG. 6B is an explanatory diagram of the separation principle when two sheet materials are fed, and FIG. FIG. 8 is an explanatory diagram of conditions, and FIG. 8 is an explanatory diagram of a roller provided in a conventional paper feeding mechanism.

  Conventionally, a porous sponge material has been used as a retard roller material for reliable separation between paper sheets.

  First, the principle of document separation will be described in detail with reference to FIG. 6B, taking as an example the case where two documents 2-1 and 2-2 enter the pressure contact portion between the separation roller 4 and the retard roller 5. .

  M1 is a friction coefficient between the separation roller 4 and the first document 2-1, M3 is a friction coefficient between the retard roller 5 and the document 2-2 contacting the retard roller, and M2 is a document 2-1 and a document 2-2. , T (illustrated in FIG. 7) is an idling load of the retard roller 5 by a torque limiter built in the retard roller 5, Rr is the radius of the retard roller 5, and N is the separation roller 4 to the separation roller 4. Indicates the pressing force to be pressed.

Next, as shown in FIG. 6A, when one document 2 enters the pressure contact portion between the separation roller 4 and the retard roller 5, the separation roller 4 does not slip and feeds the document 2 in the feeding direction (direction of arrow A). ) Is a force (the arrow F1 direction) that the separation roller 4 sends the document 2 in the feeding direction (arrow A direction).
F1 = M1 · N (1).

  On the other hand, at this time, the retard roller 5 must be rotated without slipping with the document 2, and therefore must be larger than the blocking force (in the direction of the arrow F2) due to the non-rotating torque of the retard roller 5, so that F1> F2. Don't be.

F2 = T / Rr ... Because it is two formulas,
F1 = M1 · N> F2 = T / Rr,
N> T / (M1 · Rr)... Is a condition for the retard roller 5 to rotate the document when the document 2 is fed.

Next, as shown in FIG. 6B, when the originals 2-1 and 2-2 enter the press contact portion between the separation roller 4 and the retard roller 5, the first original 2-1 becomes the second one. The force (arrow F3 direction) that tries to pull the original 2-2 in the feeding direction (arrow A direction) by friction must be smaller than the blocking force (arrow F2 direction) caused by the idling torque T of the retard roller 5.
Since F3 = M3 · N ... 4 formulas,
F2 = T / Rr> F3 = M3 · N
N <T / (M3 · Rr) (5) is a condition for separating the second original 2-2. Here, the frictional force (in the direction of arrow Ff) between the retard roller 5 and the document 2-2 must be constantly larger than the blocking force (in the direction of arrow F2) of the retard roller 5.
Ff = M2 · N> T / Rr
That is, N> T / (M2 · Rr)... Since the friction coefficient between rubber and paper is generally the same, as shown in FIG. 7, when Expressions 5 and 6 are graphed, a hatched portion P surrounded by two straight lines S and T is obtained. This is an area where documents can be stably separated one by one. Although the friction coefficient M2 between the originals 2-1 and 2-2 in FIG. 6B is uncontrollable, by increasing the friction coefficient M3 between the retard roller 5 and the original 2-2 in FIG. The straight line S moves upward, the hatched area P surrounded by the straight line S and the straight line T can be widened, and the friction coefficient M3 between the retard roller 5 and the document 2-2 is set to be sufficiently large. However, this is a condition for stable separation and feeding. In the paper feed mechanism, the coefficient of friction between the paper sheet and the roller decreases due to the adhesion or wear of paper dust on the roller surface of the paper feed unit as the number of originals fed. Therefore, in order to constantly stabilize the coefficient of friction without depending on the properties of the roller surface, it is effective to increase the pressure contact area between the separation roller 4 and the retard roller 5, so either the separation roller 4 or the retard roller 5. The retard roller 5 only needs to bend and come into contact with the opposite roller in a wide area, and can be realized by forming the retard roller 5 with a material having a high elastic modulus.

  However, in the separation roller and the retard roller as shown in FIG. 8, the sponge retard roller 5 has a high elastic modulus so that when it comes into contact with the separation roller 4, it becomes concave so as to follow the outer shape of the separation roller 4. Although deformed and the contact area to the original 2 passing through increased, it was possible to realize a good separation performance, but the sponge material has a problem that paper dust adheres to the gap and the coefficient of friction tends to decrease. In addition, there is a problem that permanent deformation is likely to occur when pressure welding is performed for a long time.

Further, for example, as shown in FIG. 8, the retard roller 5 is composed of an outer peripheral portion 5a, an inner peripheral portion 5b, and a rib member 5c connecting them, and is brought into contact with the original so that the press contact portion has a concave shape. The one configured as described above has also been proposed. In this method, since the retard rubber body is integrally formed of synthetic rubber, the problem of paper dust adhering to the gap portion is solved, and the permanent strain is suppressed by forming the rubber material with a material having a small compression set. Thus, it is disclosed that the contact portion can be formed in a wide range between the outer peripheral portion and the separation roller 4.
JP 2003-300640 A

However, in the conventional paper feeding device, in order to separate a document fed in a stable manner, the retard roller 5 that contacts the separation roller 4 needs a predetermined width, and this contact is made. If the width is narrow, a sufficient driving force cannot be applied to the document, and problems such as non-feeding at the separation part and skew due to imbalance of the frictional load between the document left and right conveyance paths are likely to occur. In particular, a paper feed roller that conveys a document, such as the separation roller 4 and the retard roller 5, requires a cylindrical accuracy of a cylindrical outer peripheral surface that comes into contact with the document, in order to increase the coefficient of friction M between the documents. In order to give the surface a texture, and in order to industrially and economically form a roller rubber body of the shape, the synthetic rubber is filled and cured in a mold and taken out from the mold (hereinafter referred to as mold release). ) Is common.

  However, when the mold is released after filling and curing, if the depth of extraction from the mold is deep, it is difficult to form a wide roller because the thin-walled portion is easily broken. In particular, in order to obtain sufficient deflection, it is more effective to reduce the thickness of the outer peripheral part and the rib material that are in contact with the document. However, since the releasability from the mold deteriorates, there is a problem that the thickness cannot be reduced. is there.

  In addition, the inclination of the rib material is appropriately set in the range of 10 to 80 degrees with respect to the normal line of the retard roller, but the inclination angle (around 10 degrees) with respect to the normal line of the retard roller. If it is reduced, the deflection of the outer periphery cannot be increased around the rib material, and conversely if it is increased (around 80 degrees), the joint with the outer periphery becomes an acute angle. There is a problem that the edge is easily damaged and easily broken, and only a narrow retard roller can be formed, and it is difficult to ensure stable paper feeding performance even if it is easy to form a deflection.

  Further, in the paper feeding device of (Patent Document 1), the retard roller is rotated in a direction to return the document to the document (sheet material) storing means, but the retard roller is in contact with the separation roller with a sufficient width. If sufficient deflection can be formed, the retard roller does not need to be rotated in the direction to return it to the document storage means, and can prevent the second original from entering with a predetermined idling load, thereby simplifying the structure of the paper feeding device. You can also

  In order to solve the above problems, the present invention is a roller having a cylindrical outer peripheral portion, an inner peripheral portion pivotally supported by a support shaft, and a plurality of spoke portions connecting the outer peripheral portion and the inner peripheral portion. And the said roller is set as the structure which made the thickness thin about the end surface side of the support shaft direction of a spoke part with respect to the opposite end surface side.

  As a result, even a sufficiently wide roller (retard roller) can be molded while ensuring stable releasability from the mold, and the retard roller can form sufficient deflection. Even if it is, good separation performance can be obtained.

  The roller of the present invention, and a paper feeding device and an image reading device provided with the roller have the above-described configuration, and even a hard rubber material having good wear resistance is thin, bent according to the separation roller, and has a contact area. A retard roller having a large sheet feeding and good separation performance can be configured, and when the separation roller and the retard roller come into contact with each other, the outer peripheral portion of the retard roller bends and the contact area with the separation roller can be increased. .

  The invention described in claim 1 of the present invention is a roller having a cylindrical outer peripheral portion, an inner peripheral portion pivotally supported by a support shaft, and a plurality of spoke portions connecting the outer peripheral portion and the inner peripheral portion. The roller is a roller in which the end surface side in the support shaft direction of the spoke portion is made thinner with respect to the opposite end surface side, and the roller is removed from the rubber body when the mold core is released. Since the core of the mold is easy to come off, there is an effect that the releasability at the time of roller molding can be improved.

  The invention according to claim 2 of the present invention is the roller according to claim 1, wherein the spoke portion is formed so as to have a substantially arc shape from the inner peripheral portion toward the outer peripheral portion. There is an effect that a sufficient deflection can be formed at the contact portion.

  The invention according to claim 3 of the present invention is the invention according to claim 1 or 2, wherein the length of the roller in the support shaft direction is 10 mm to 60 mm, and a sufficient deflection is formed at the contact portion of the roller. The contact area can be formed.

  The invention according to claim 4 of the present invention is the roller according to claim 1, 2 or 3, wherein the outer peripheral part of the roller or the spoke part has a thickness of 1 mm or more, and in the contact part of the roller It has the effect that sufficient deflection can be formed.

  According to a fifth aspect of the present invention, in the first, second, third or fourth aspect of the present invention, a roller having an uneven surface formed on the outer peripheral surface of the roller, the sheet material having high friction. It has the effect that high feed separation performance can be obtained.

  According to a sixth aspect of the present invention, there is provided the paper feeding device according to the first, second, third, fourth, or fifth aspect, wherein the number of the spoke portions of the retard roller is four or more. Since it bends well so as to follow the outer peripheral portion of the separation roller, the contact area between the separation roller and the retard roller can be prevented from becoming permanent distortion.

  According to a seventh aspect of the present invention, there are provided a sheet feeding roller that feeds the stacked sheet materials, a separation roller that is located downstream of the sheet feeding roller in the conveying direction and feeds the sheet material in the conveying direction, and a separation roller The retard roller is arranged to be paired with the retard roller and prevents the conveyance of the sheet material not on the uppermost stage, and the retard roller is pivotally supported by the support shaft and a cylindrical outer peripheral portion that contacts the separation roller. The retard roller has an outer peripheral portion and an inner peripheral portion that are connected by a plurality of spoke portions, and one end surface side in the axial direction of the retard roller is thicker than the opposite end surface side. This is a thin paper feeding device, and when the roller rubber body is released from the mold, the rubber body is easily released from the mold. By bending to the separation roller Since larger contact area, it has the effect that the contact area can be prevented from becoming a permanent distortion.

  The invention according to claim 8 of the present invention is the sheet feeding device according to claim 7, wherein at least one retard roller is provided, and a plurality of rollers whose outer peripheral surfaces are easily bent are arranged. Can be prevented from being skewed and fed, so that it is possible to obtain a stable feeding separation performance.

  The invention according to claim 9 of the present invention is the invention according to claim 7 or 8, wherein the spoke portion is fed from the inner peripheral portion toward the outer peripheral portion at the contact portion between the separation roller and the retard roller. The sheet feeding device is formed so as to have a substantially circular arc shape in the downstream direction, and an effect that a contact area with the separation roller can be increased by sufficiently bending the outer peripheral surface of the retard roller that contacts the separation roller. Have

  According to a tenth aspect of the present invention, in the invention according to the seventh, eighth, or ninth aspect, the retard roller has a length in the support shaft direction of 10 mm to 60 mm, and includes a separation roller, By forming more sufficient deflection and contact surface property in the contact portion, it is possible to improve the feeding / separating performance.

According to an eleventh aspect of the present invention, there is provided the sheet feeding device according to the seventh, eighth, ninth, tenth or eleventh aspect, wherein the number of spoke portions of the retard roller is four or more. Since it bends well so as to follow the outer peripheral portion of the separation roller, the contact area between the separation roller and the retard roller can be prevented from becoming permanent distortion.

  According to a twelfth aspect of the present invention, in the invention according to the seventh, eighth, ninth, tenth or eleventh aspect, the thickness of the outer peripheral portion or the spoke portion of the retard roller is 1 mm or more. In addition, there is an effect that the retard roller can be formed while maintaining a stable releasability from the mold.

  A thirteenth aspect of the present invention is the paper feeding device according to the seventh, eighth, ninth, tenth, eleventh or twelfth aspect, wherein the retard roller has an irregular surface formed on the outer peripheral surface thereof. Even in a high-friction sheet material, there is an effect that high feed separation performance can be obtained.

  According to a fourteenth aspect of the present invention, there are provided a sheet feeding roller for feeding the laminated sheet material, an image reading unit for reading image information of the sheet material fed by the sheet feeding roller, and transported more than the sheet feeding roller. A separation roller that is positioned downstream of the image reading unit and is positioned between the image reading unit and feeds the sheet material in the conveyance direction, and is disposed so as to be paired with the separation roller and prevents conveyance of the sheet material that is not at the uppermost stage. The retard roller has a cylindrical outer peripheral portion that contacts the member and an inner peripheral portion that is pivotally supported by the support shaft, and the outer peripheral portion and the inner peripheral portion of the retard roller are a plurality of spoke portions. An image reading apparatus that is connected and has one end face in the axial direction of the retard roller reduced in thickness relative to the opposite end face. When the roller rubber body is released from the mold, Easily out of shape Therefore, it is possible to improve the releasability at the time of roller molding and to form a large contact area with the separation roller by sufficiently bending following the separation roller, so that the contact area can be prevented from becoming permanent distortion. Has an effect.

  According to a fifteenth aspect of the present invention, in the invention according to the fourteenth aspect, the spoke portion is located in the downstream direction in the paper feeding direction at the contact portion between the separation roller and the retard roller from the inner peripheral portion toward the outer peripheral portion. The sheet feeding device is formed so as to have a generally arcuate shape, and has an effect that a contact area with the separation roller can be increased by sufficiently bending the outer peripheral surface of the retard roller that contacts the separation roller.

  According to a sixteenth aspect of the present invention, in the invention according to the fourteenth or fifteenth aspect, the retard roller has four or more spoke portions, and the retard roller is an outer peripheral portion of the separation roller. Therefore, the contact area between the separation roller and the retard roller can be prevented from becoming permanent set.

  According to a seventeenth aspect of the present invention, there is provided the image reading apparatus according to the fourteenth, fifteenth or sixteenth aspect, wherein the thickness of the outer peripheral portion or the spoke portion of the retard roller is 1 mm or more. Thus, it is possible to form the retard roller while maintaining the stable releasability.

  According to an eighteenth aspect of the present invention, there is provided the image reading apparatus according to the fourteenth, fifteenth, sixteenth or seventeenth aspect, wherein the retard roller is formed with an uneven surface on the outer peripheral surface, and is a high friction sheet. Even in the case of a material, there is an effect that high feed separation performance can be obtained.

  According to a nineteenth aspect of the present invention, in the invention according to the fourteenth, fifteenth, sixteenth, seventeenth or eighteenth aspect, the length of the roller in the spindle direction is 10 mm to 60 mm, There is an effect that a sufficient deflection and a contact area can be formed in the contact portion of the roller.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  1 is a cross-sectional view of a roller according to an embodiment of the present invention, FIG. 2 is a perspective view of a paper feeding device equipped with the roller of FIG. 1, and FIG. 3 is a cross-sectional view of an image reading device equipped with the paper feeding device of FIG. FIG. 4 is a diagram showing a deflection shape of the retard roller when the separation roller and the retard roller of FIG. 2 are in contact with each other, and FIG. 5 is a cross-sectional view of the rubber body molding die.

  As shown in FIG. 1, the roller 5 includes a cylindrical outer peripheral portion 21, an inner peripheral portion 23 press-fitted into a core (not shown), and the outer peripheral portion 21 and the inner peripheral portion 23 are connected by six spoke portions 22. It has a structure to do. When pressed with a predetermined pressure, the roller 5 is mainly bent at the outer periphery. A plurality of retard rollers 5 may be supported on the support shaft.

  Next, with reference to FIGS. 2 and 3, the operation of the image reading apparatus provided with a sheet feeding device including a roller (hereinafter referred to as a retard roller) 5 according to an embodiment of the present invention will be described.

  When the image reading device 30 in FIG. 3 starts the reading operation, the document table 1 is raised to a position where the loaded document 2 comes into contact with the paper feed roller 3 by a lift mechanism (not shown), and the document is fed at a predetermined pressure. It is urged by the paper roller. The paper feed roller 3 and the separation roller 4 are driven to rotate by a motor (not shown) and rotate in the document feed direction (arrow A direction). The document 2 is drawn into the apparatus along with the rotation of the paper feed roller 1 and enters the pressure contact portion between the separation roller 4 and the retard roller 5 as a retard member. As shown in FIG. 2, the retard roller 5 is pivotally supported by a retard roller support shaft 6 suspended non-rotatably on a retard holding member 7 via a torque limiter (not shown) built in the core body. 4 and the pressure contact portion 8 of the retard roller 5 are in direct contact with each other, the retard roller 5 rotates with the separation roller 4 and rotates in the feeding direction (arrow A direction). Even when one document 2 enters the pressure contact portion 8, the retard roller 5 rotates with the document 2 and rotates in the feeding direction (arrow A direction). When two or more documents enter the pressure contact portion 8, the friction between the sheets of the document 2 is smaller than the friction between the separation roller 4 and the first document 2 and between the retard roller and the second document 2. Only the first document 2 in contact with the separation roller 4 is conveyed in the paper feeding direction, and the image of the document is read by the imaging devices 9 a and 9 b and is discharged to the paper discharge unit 10. The second and subsequent originals are prevented from entering at the pressure contact portion between the separation roller 4 and the retard roller 5 and separated.

  FIG. 4 shows a deformed state of the retard roller 5 at the time of press contact with the retard roller 5 having the shape according to the embodiment of the present invention and the separation roller 4 obtained by computer simulation. It can be clearly seen that the contact area of the retard roller 5 with the separation roller 4 can bend so that the outer peripheral portion of the retard roller 5 follows the separation roller, and the contact area can be increased. Furthermore, with this configuration, there is no possibility that the contact area becomes permanent set.

  Further, even with a hard rubber material with good wear resistance, the retard roller 5 can be configured to be thin, bend following the separation roller 4, and have a large contact area and good feed separation performance. In FIG. 4, it can be seen that when the separation roller 4 and the retard roller 5 contact each other as described above, the outer peripheral portion of the retard roller 5 is bent and the contact area with the separation roller 4 is increased.

  Here, the structure of the mold for forming the retard roller rubber body in one embodiment of the present invention is shown in FIG.

In the mold, voids 107a and 107b are formed by a cavity 102 that forms an outer diameter shape and cores 103a, 103b, and 103c that form a core metal part and a spoke part. The retard roller rubber body 50 is molded by pouring molten rubber material into the gaps 107a and 107b formed in the mold and curing it to extract the product from the mold. That is, the molten rubber material is poured into the injection port 101 and the pressure member 100 is processed in the direction of arrow C to pressurize the rubber material. The rubber material flows down through the conduction holes 104a and 104b, flows into the gap 105 formed by the cavity 102 and the cores 103a, 103b, and 103c, is held at a predetermined pressure, and is cured, and then the pressure member 100 and the upper mold 106 is opened and the retard roller rubber body 50 is taken out.

  In order to press-contact with the separation roller 4 with a sufficient area, the thickness of the outer peripheral portion of the retard roller rubber body 50 is desirably about 2 mm or less. On the other hand, if the thickness of the retard roller rubber body 50 to be molded is thin, the rubber body Since the retard roller rubber body 50 may be damaged at the edge of the mold when the mold is taken out from the mold and the thin portion may be broken, it is desirable that the depth of the mold, that is, the width of the retard roller rubber body 50 is small. . Therefore, the retard roller 5 having a wide width and good flexibility is formed by forming a thin retard roller rubber body 50 by reducing the depth of the mold and press-fitting a plurality of them into the core body 6 in the axial direction. Can be produced.

  FIG. 2 shows an embodiment in which the retard roller 5 is divided into two left and right retard roller rubber bodies 50a and 50b. Since the left and right rubber bodies 50a and 50b have the same width and are arranged symmetrically with respect to the document transport center, stable feeding and separation can be performed without skew even during document feeding. In addition, the outer peripheral surface portion of the rubber body in FIG. 1 is divided in the radial direction at the time of mold release, and the portion other than the outer peripheral portion is thinner than the inner portion of the mold so that the thickness of the rubber body is thinner. By providing the slope R, the releasability of the rubber body can be further improved.

  As described above, the outer peripheral surface of the retard roller rubber body can be formed into a cylindrical shape by dividing the mold for injection molding at the time of mold release. For the spoke part, by reducing the thickness of the other end face part with respect to one end face part of the cylindrical shape, the mold core can be easily detached from the rubber body when the mold core is released. Since the releasability at the time of molding can be improved, a desired thin-walled retard roller rubber body can be molded.

  In addition, in order to form the retard roller with a material having a high elastic modulus and good wear resistance, the retard roller is made of a material with good wear resistance such as hard urethane, and one molding depth is reduced. Thus, a plurality of retard roller rubber bodies formed to have a width that ensures releasability are press-fitted into the core body in the axial direction.

  Further, the outer peripheral surface of the roller rubber body can be shaped into a cylindrical shape by dividing the mold for injection molding at the time of mold release, but for the outer peripheral portion inner side and inner peripheral portion outer side and the spoke portion of the rubber body, By reducing the thickness of the other end surface portion relative to one end surface portion of the cylindrical shape, the mold core can be easily detached from the rubber body when the mold core is released. The moldability can be improved. Furthermore, since the outer peripheral surface is separated from the mold, the surface of the rubber body can be roughened or a knurled groove can be formed, and the coefficient of friction can be further increased. .

  As described above, the retard roller according to the embodiment of the present invention can be molded while ensuring stable releasability from the mold even when the retard roller has a sufficiently wide width. In the reading apparatus, it is possible to realize a good separation performance even for a high-friction paper sheet original on which the retard roller according to the embodiment of the present invention is mounted.

  Needless to say, the roller of the present invention can also be applied to the conveyance of computer paper such as a cash dispenser or an electronic device that feeds a sheet material in addition to the above-described apparatus. Can also be used.

  The roller of the present invention is useful for a roller member used for paper feeding of a paper feeding device, an image reading device, a fax machine, and an electronic device.

Sectional drawing of the roller in one embodiment of this invention 1 is a perspective view of a paper feeding device equipped with the roller of FIG. Sectional drawing of the image reading apparatus which mounts the paper feeder of FIG. The figure which shows the bending shape of a retard roller when the separation roller of FIG. 2 and a retard roller contact | abut Cross section of rubber body mold (A) Explanatory diagram of separation principle when one sheet material is fed, (b) Explanatory diagram of separation principle when two sheet materials are fed Stable paper feed condition explanatory diagram Explanatory drawing of a roller provided in a conventional paper feed mechanism

Explanation of symbols

1 Document Placement Table 2 Document 3 Paper Feeding Roller 4 Separation Roller 5 Roller (retard roller)
6 retard roller support shaft 7 retard roller holding member 9 imaging device 10 paper discharge tray 21 outer peripheral portion 22 spoke portion 23 inner peripheral portion 50 retard roller rubber body 100 pressurizing member 101 inlet 102 cavity 103a core 103c core 103b core 104a Conducting hole 104b Conducting hole 105 Gap 106 Upper mold 107a Gap 107b Gap R Inclination angle

Claims (19)

A roller having a cylindrical outer peripheral part, an inner peripheral part pivotally supported by a support shaft, and a plurality of spoke parts connecting the outer peripheral part and the inner peripheral part, wherein the roller is the spoke part A roller characterized in that the end surface side in the spindle direction is made thinner than the opposite end surface side. The roller according to claim 1, wherein the spoke portion is formed to have a substantially arc shape from the inner peripheral portion toward the outer peripheral portion. The roller according to claim 1 or 2, wherein a length of the roller in the direction of the support shaft is 10 mm to 60 mm. The roller according to claim 1, wherein the outer peripheral portion or the spoke portion of the roller has a thickness of 1 mm or more. 5. The roller according to claim 1, wherein an uneven surface is formed on an outer peripheral surface of the roller. 6. The sheet feeding device according to claim 1, wherein the number of spoke portions of the retard roller is four or more. A sheet feeding roller that feeds the stacked sheet material, a separation roller that is positioned downstream of the sheet feeding roller in the transport direction and feeds the sheet material in the transport direction, and is arranged to make a pair with the separation roller A retard roller that prevents conveyance of the sheet material that is not at the uppermost stage, and the retard roller has a cylindrical outer peripheral portion that abuts on the separation roller, and an inner peripheral portion that is pivotally supported by a support shaft, The outer peripheral portion and the inner peripheral portion of the retard roller are connected by a plurality of spoke portions, and one end surface side in the axial direction of the retard roller is made thinner with respect to the opposite end surface side. Paper feeding device to be used. The sheet feeding device according to claim 7, wherein at least one retard roller is provided. The spoke portion is formed so as to have a substantially arc shape in a downstream direction of the paper feeding direction at a contact portion between the separation roller and the retard roller from the inner peripheral portion toward the outer peripheral portion. The paper feeding device according to claim 7 or 8. The sheet feeding device according to claim 7, 8 or 9, wherein a length of the retard roller in the direction of the spindle is from 10 mm to 60 mm. 11. The sheet feeding device according to claim 7, wherein the number of spoke portions of the retard roller is four or more. The sheet feeding device according to claim 7, 8, 9, 10 or 11, wherein the thickness of the outer peripheral portion or the spoke portion of the retard roller is 1 mm or more. The sheet feeding device according to claim 7, wherein an uneven surface is formed on an outer peripheral surface of the retard roller. A sheet feed roller that feeds the stacked sheet material; an image reading unit that reads image information of the sheet material fed by the sheet feed roller; and a downstream side in the transport direction from the sheet feed roller; A separation roller that is positioned between the sheet roller and feeds the sheet material in the conveyance direction; and a retard roller that is arranged to form a pair with the separation roller and prevents conveyance of the sheet material that is not at the uppermost stage, The retard roller has a cylindrical outer peripheral portion that contacts the member and an inner peripheral portion that is pivotally supported by a support shaft, and the outer peripheral portion and the inner peripheral portion of the retard roller are connected by a plurality of spoke portions, and the retard roller An image reading apparatus characterized in that one end face side in the axial direction of the roller is made thinner than the opposite end face side. The spoke portion is formed so as to have a substantially arc shape in a downstream direction of the paper feeding direction at a contact portion between the separation roller and the retard roller from the inner peripheral portion toward the outer peripheral portion. The image reading apparatus according to claim 14. 16. The image reading apparatus according to claim 14, wherein the number of spoke portions of the retard roller is four or more. 17. The image reading apparatus according to claim 14, wherein the thickness of the outer peripheral portion or the spoke portion of the retard roller is 1 mm or more. The image reading apparatus according to claim 14, wherein an uneven surface is formed on an outer peripheral surface of the retard roller. 19. The image reading apparatus according to claim 14, wherein the length of the retard roller in the direction of the support shaft is 10 mm to 60 mm.

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