JP2010132440A - Paper ejecting device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper ejecting device capable of stabilizing carrying force of a paper ejecting roller, without damaging paper, even if the paper is flapped in the orthogonal direction to the paper ejecting direction for strengthening rigidity in the carrying direction of the paper, when ejecting the paper. <P>SOLUTION: This paper ejecting device has the rotatingly driven paper ejecting roller, and a corrugation roller having a roller part oppositely arranged to the paper ejecting roller and ejecting the paper by sandwiching the paper by abutting on the paper ejecting roller and a collar part divided from the roller part, having a diameter larger than the roller part and without abutting on the paper ejecting roller. The collar part freely moves in the axial direction of a rotary shaft, and the roller part is fixed in a position in the axial direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a paper discharge device including a paper discharge roller and a corrugation roller, and an image forming apparatus including the paper discharge device.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile machine, after an image is formed on a sheet, the sheet is discharged onto a discharge tray or the like by a discharge unit. The paper discharge device includes a paper discharge roller that is driven to rotate, and a pinch roller (driven roller) that contacts and contacts the paper discharge roller. The paper discharge roller and the pinch roller feed the paper. The paper is nipped and discharged onto the paper discharge tray.

  However, in the case of a thin sheet or the like having a weak rigidity, so-called stiffness, the leading end of the sheet may hang down and come into contact with the sheet discharge tray, causing a sheet conveyance failure, which may cause a paper jam.

  Therefore, conventionally, a flange portion having a larger diameter (hereinafter referred to as a larger diameter) than the abutting portion of the pinch roll is provided at the end portion of the pinch roll, thereby orthogonally intersecting the paper discharge direction when the paper is discharged. In order to improve the reliability of paper discharge, the sheet is undulated in the direction of the sheet to increase the rigidity in the sheet conveyance direction (hereinafter also referred to as longitudinal rigidity). However, since the peripheral speeds of the abutting part and the flange part of the pinch roller are different, the sheet is rubbed by the flange part, and the sheet may be damaged.

On the other hand, there is disclosed a paper discharge device including a paper discharge roller that is rotationally driven and two identical driven rollers that are rotatably supported by an elastic body and abut against the paper discharge roller (for example, Patent Document 1).
JP-A-5-319657

  In Patent Document 1, when a sheet passes between a paper discharge roller and two driven rollers, the paper is waved by the pressure of the driven roller against the paper discharge roller, and discharged while increasing the vertical rigidity of the paper. Thus, conveyance failure is prevented. Further, since the peripheral speeds of the two driven rollers are the same, the paper is prevented from being rubbed and the paper is prevented from being damaged.

  However, it is difficult to make the pressures of the two driven rollers uniform, and the non-uniformity of the pressure may cause bending in the paper transport direction. Further, since the two driven rollers are supported by a spring and biased, the conveyance force of the paper discharge roller is difficult to stabilize, and there is a possibility that a conveyance failure may occur on thick paper (thick paper).

  The present invention has been made in view of the above situation, and when paper is discharged, the paper is damaged even if the paper is waved in a direction perpendicular to the paper discharge direction in order to increase the vertical rigidity of the paper. It is an object of the present invention to provide a paper discharge device capable of stabilizing the conveyance force of the paper discharge roller and an image forming apparatus including the paper discharge device.

  The above object is achieved by the following configuration.

1. A rotationally driven paper discharge roller;
A rotating shaft provided parallel to the shaft of the paper discharge roller;
A roller portion that is provided on the rotary shaft so as to face the paper discharge roller and that abuts against the paper discharge roller to pinch and discharge the paper, and a roller portion that is provided on the rotary shaft and has a larger diameter than the roller portion A corrugation roller provided with a brim portion that does not come into contact with
The paper discharge device, wherein the brim portion is movable in the axial direction of the rotation shaft, and the roller portion is fixed at a position in the axial direction of the rotation shaft.

  2. 2. The paper discharge device according to claim 1, wherein the roller portion and the flange portion are rotatable independently of a rotation direction.

  3. The flange portion is urged by the urging means in a direction in contact with the side surface of the roller portion, and away from the side surface of the roller portion due to the rigidity strength in a direction perpendicular to the conveyance direction of the discharged paper. 3. The paper discharge device as described in 1 or 2 above, wherein

  4). 3. The paper discharge apparatus according to claim 1 or 2, further comprising a moving unit that moves the collar unit, wherein the collar unit is moved on a rotation shaft according to the type of paper by the moving unit.

  5. An image forming apparatus comprising the paper discharge device according to any one of 1 to 4 above.

  According to the above, it is possible to prevent the leading edge of the paper to be discharged from sagging, to improve the reliability of the paper discharge, to prevent the paper from being bent suddenly, and the undulated bending remains as wrinkles. Can be prevented. Further, it is possible to prevent the paper from rubbing at the brim portion, to prevent damage such as vertical stripes, and to enable stable paper discharge conveyance without damaging the paper.

  Embodiments of a paper discharge device according to the present invention will be described below with reference to the drawings. The present invention is not limited to the following.

  FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus including a paper discharge device according to the present invention.

  The image forming apparatus according to the present invention includes an image forming apparatus main body GH and an image reading apparatus YS. The image forming apparatus main body GH is called a tandem type color image forming apparatus, and includes a plurality of image forming units 10Y, 10M, 10C, and 10K, and an intermediate transfer belt 6 that is an endless belt-like intermediate transfer body. A unit 60, a transfer device 70, a paper feed / conveying means and fixing device 80, a paper discharge device 90, and the like.

  An image reading device YS including an automatic document feeder 201 and a document image scanning exposure device 202 is installed on the upper part of the image forming apparatus main body GH. The document d placed on the document table of the automatic document feeder 201 is transported by a transport unit, and an image on one or both sides of the document is scanned and exposed by the optical system of the document image scanning exposure device 202, and the line image sensor CCD is scanned. Is read.

  The signal formed by photoelectric conversion by the line image sensor CCD is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit, and then exposure means 3Y, 3M, 3C, 3K. Sent to.

  In the image forming unit 10Y that forms a yellow (Y) image, a charging unit 2Y, an exposure unit 3Y, a developing device 4Y, and a cleaning unit 8Y are arranged around the photosensitive drum 1Y. In the image forming unit 10M that forms a magenta (M) color image, a charging unit 2M, an exposure unit 3M, a developing device 4M, and a cleaning unit 8M are arranged around the photosensitive drum 1M. In the image forming unit 10C that forms a cyan (C) color image, a charging unit 2C, an exposure unit 3C, a developing device 4C, and a cleaning unit 8C are arranged around the photosensitive drum 1C. In the image forming unit 10K that forms a black (Bk) image, a charging unit 2K, an exposure unit 3K, a developing device 4K, and a cleaning unit 8K are arranged around the photosensitive drum 1K. The charging unit 2Y and the exposure unit 3Y, the charging unit 2M and the exposure unit 3M, the charging unit 2C and the exposure device 3C, and the charging unit 2K and the exposure device 3K constitute a latent image forming unit.

  The intermediate transfer belt 6 is wound around a plurality of rollers and is rotatably supported.

  The fixing device 80 is stretched between a first pressure roller 83 having an elastic layer on a metal core, a heating roller 82 having a heating means inside, and between the first pressure roller 83 and the heating roller 82. An endless fixing belt 81 and a second pressure roller 84 that is disposed so as to be in pressure contact with the fixing belt 81 at a position facing the first pressure roller 83 and that forms a fixing nip portion, and includes an unfixed image. By passing the fixing nip portion so that the unfixed toner surface of the paper P carrying the toner contacts the fixing belt 81, the unfixed toner is fixed to the paper P by heating and pressing.

  Thus, the images of the respective colors formed by the image forming units 10Y, 10M, 10C, and 10K are sequentially superimposed and transferred onto the rotating intermediate transfer belt 6 by the transfer means 7Y, 7M, 7C, and 7K (primary transfer). ), An image obtained by combining the color images is formed. The paper P stored in the paper feeding cassette 20 is fed by the paper feeding means 21 and is conveyed to the transfer device 70 through the paper feeding rollers 22A, 22B, 22C, 22D, the registration rollers 23, etc. A color image is transferred to (secondary transfer). The paper P on which the color image has been transferred is heated and pressed by the fixing device 80, and the color image on the paper P is fixed. Thereafter, the paper is sandwiched between a paper discharge roller 91 of the paper discharge device 90 and a corrugation roller 92 which is a pinch roller and is placed on the paper discharge tray 25 outside the apparatus.

  On the other hand, after the color image is transferred to the paper P by the transfer device 70, the residual toner is removed by the cleaning means 8A from the intermediate transfer belt 6 from which the paper P is separated by curvature.

  Next, the paper discharge device 90 will be described.

  2 and 3 are partial views of the paper discharge device 90. FIG. 2 is a view as seen from the conveyance direction of the paper P, and FIG. 3 is a cross-sectional view as seen from the side in the conveyance direction of the paper P.

  The paper discharge device 90 includes a paper discharge roller 91 that is integrally formed with the drive shaft 911, a rotary shaft 921 that is provided in parallel with the drive shaft 911, and a rotary shaft 921 that faces the paper discharge roller 91. A corrugation roller 92 is provided. The paper discharge roller 91 is supported by a pair of side plates 90A via a drive shaft 911, and the corrugation roller 92 is supported by a pair of side plates 90A. In the example shown in FIG. 2, two pairs of paper discharge rollers including the paper discharge roller 91 and the corrugation roller 92 are arranged, but the number of paper discharge roller pairs is not limited to this.

  The paper discharge roller 91 and the drive shaft 911 are rotationally driven by drive means (not shown) such as an electric motor. The material of the paper discharge roller 91 is not particularly limited, but rubber is preferably used from the viewpoint of transportability.

  The corrugation roller 92 includes a divided roller portion 92a and a flange portion 92b having a diameter larger than that of the roller portion 92a. The corrugation roller 92 is rotatably supported by the rotating shaft 921 independently.

  FIG. 4 is a perspective view of the corrugation roller 92. The material of the corrugation roller 92 is not particularly limited, but a material having good sliding characteristics, such as polyacetal (POM), is preferably used in order to prevent damage to the paper P and to improve rotation.

  The roller portion 92a is provided on the rotating shaft 921 so as to be rotatable and restricted (fixed) in the axial direction (hereinafter also referred to as the thrust direction). The rotating shaft 921 is supported by the side plate 90 </ b> A so that the roller portion 92 a contacts the paper discharge roller 91. As a result, the paper discharge roller 91 and the roller portion 92a hold the paper P and discharge it.

  The collar portion 92 b is provided on the rotary shaft 921 so as to be rotatable and movable in the thrust direction, and at a position where it does not contact the paper discharge roller 91. In the present embodiment, as shown in FIG. 2, the closest position between the flange 92b and the paper discharge roller 91 is such that the width of the roller 92a is larger than the width of the paper discharge roller 91 so that the side surface of the roller 92a is It protrudes from the side surface of the paper discharge roller 91 and is regulated by the side surface of the roller portion 92a. At the closest position, as shown in FIG. 5A, the side surface of the flange portion 92b and the side surface of the roller portion 92a contact each other, and the positions of the flange portion 92b and the side surface of the paper discharge roller 91 are regulated by the distance X. The As a result, contact between the flange 92b and the paper discharge roller 91 is prevented. Further, a regulating member (not shown) may be provided separately.

  In this embodiment, one brim portion 92b is provided on one side of the roller portion 92, but two brim portions 92b may be provided on both sides.

  The collar portion 92b is urged by a spring 93 as an urging means in a direction in contact with the side surface of the roller portion 92a. When the sheet P is not present, the collar portion 92b is in contact with the side surface of the roller portion 92a as shown in FIG. When the paper P is nipped and conveyed, the flange 92b compresses the spring 93 by the strength in the direction orthogonal to the conveyance direction of the paper P (hereinafter also referred to as lateral rigidity), and moves away from the side surface of the roller 92a. Moved to. The position of the spring 93 opposite to the brim portion 92 b is regulated by a stopper 94.

  The dimensions of the above-described parts are appropriately set by design, experiment, etc. according to the specifications of the apparatus such as the processing speed of the apparatus, the configuration of the apparatus, the type and size of the paper used. For example, the outer diameter of the paper discharge roller 91 is 18 mm, the outer diameter of the roller portion 92 a is 18 mm, the outer diameter of the flange portion 92 b is 21 mm, the distance X between the discharge roller 91 and the side surface of the flange portion 92 b is 2.5 mm, and the like. .

  Next, the discharge of the paper P will be described.

  At the time of paper discharge, the paper P is nipped and conveyed between the paper discharge roller 91 and the roller portion 92 a of the corrugation roller 92, discharged outside the apparatus, and placed on the paper discharge tray 25.

  When the paper P passes between the paper discharge roller 91 and the roller portion 92a, the paper P is waved in a direction perpendicular to the paper discharge direction by the flange portion 92b having a diameter larger than that of the roller portion 92a, thereby improving the longitudinal rigidity. To be strengthened.

  As described above, the flange 92b is supported so as to be movable in the thrust direction. For this reason, the sheet P is moved in a direction in contact with and away from the side surface of the roller portion 92a due to the strength of the lateral rigidity due to the thickness of the sheet P or the like. That is, when the paper P is thick and the lateral rigidity is strong, the flange 92b moves away from the side surface of the roller 92a. When the paper P is thin and the lateral rigidity is weak, the flange 92b is It moves in a direction approaching the side surface of the roller portion 92a.

  FIG. 5 is a diagram illustrating the movement of the brim portion 92b according to the strength of the lateral rigidity of the paper P. FIG. 5A shows an example in which the lateral rigidity is weak and the brim portion 92b is in contact with the side surface of the roller portion 92a. FIG. 5B shows an example in which the lateral rigidity is strong and the brim portion 92b is moved from the side surface of the roller portion 92a. FIG. 5C shows an example in which the lateral rigidity is further strong and the brim portion 92b has moved more than the side surface of the roller portion 92a more than in FIG. 5B. In the figure, L indicates the moving distance of the brim portion 92b. That is, the movement distance L increases as the lateral rigidity increases. FIG. 5A shows a state where L = 0, that is, the brim portion 92b does not move and is in the initial position.

  Here, the undulation of the paper P, that is, the degree of bending, becomes stronger as the distance X, which is the distance X between the side surface of the paper discharge roller 91 and the side surface at the initial position of the flange portion 92b, and the movement distance L is smaller.

The distance L and the moving distance L of the flange 92b relative to the strength of the lateral rigidity of the paper P, that is, the strength of the spring 93 can give the strength of the vertical rigidity necessary for the paper P by design or experiment, In addition, it is set as appropriate so that the bending of the paper P is not left as wrinkles. For example, L = 3 mm for a paper basis weight of 250 g / m ² .

  As described above, the leading edge of the paper P can be prevented from sagging, and the reliability of paper discharge can be improved, so that the paper P can be stably discharged. In addition, it is possible to prevent the paper P from being bent sharply and to prevent the wavy bending from remaining as wrinkles.

  Further, since the flange portion 92b and the roller portion 92a are divided and both can contact and follow the paper P and rotate independently, the vertical stripe generated on the paper P when the flange portion 92b rubs the paper P or the like. Can prevent damage.

  As a result, the paper P can be stably transported without damaging the paper P.

  In the above description, the brim portion 92b is moved by the biasing force of the spring 93 and the lateral rigidity of the paper P. However, as another form, a brim portion moving mechanism that is a moving means for moving the brim portion 92b is provided. The brim portion 92b may be moved mechanically by the brim portion moving mechanism based on the strength of the vertical rigidity of the paper depending on the paper type, for example, the thickness of plain paper, coated paper, and paper P.

  FIG. 6 is a diagram showing an example of another form of movement of the brim portion 92b, and a rack and pinion is used for the brim portion moving mechanism. The rack R meshes with the pinion P, and an arm A951 and an arm B952 are provided on one end side of the rack R, respectively. At the tip of the arm A951 and the arm B952, a notch that engages with the flange 92b is provided.

  When the paper type (or paper feed cassette 20) is selected from the operation panel (not shown) of the image forming apparatus main body GH, the pinion P is rotationally driven by the driving means (not shown), and accordingly, the rack R Is moved in the direction of arrow X1 in the figure. The rack R is moved to a preset position for each paper type (or the paper feed cassette 20), and the collar portion 92b is also moved to a predetermined position accordingly.

  The discharge function is the same as in the example shown in FIG. 2, but the position of the flange 92b can be set to a predetermined position regardless of the variation in the strength of the lateral rigidity of the paper P within the same paper type. In addition, variation in the strength of the longitudinal rigidity can be reduced.

1 is a schematic diagram illustrating an example of an image forming apparatus including a paper discharge device according to the present invention. FIG. FIG. It is a perspective view of a corrugation roller. It is a figure which shows the movement of a collar part by the strength of the stiffness of a paper. It is a figure which shows another form of a collar part movement.

Explanation of symbols

GH Image forming apparatus main body YS Image reading apparatus P Paper 10Y, 10M, 10C, 10K Image forming unit 6 Intermediate transfer belt 70 Transfer device 80 Fixing device 90 Paper discharge device 91 Paper discharge roller 911 Drive shaft 92 Corrugation roller 92a Roller portion 92b Part 93 Spring 94 Stopper 951 Arm A
952 Arm B
P pinion R rack

Claims (5)

A rotationally driven paper discharge roller;
A rotating shaft provided parallel to the shaft of the paper discharge roller;
A roller portion that is provided on the rotary shaft so as to face the paper discharge roller and that abuts against the paper discharge roller to pinch and discharge the paper, and a roller portion that is provided on the rotary shaft and has a larger diameter than the roller portion A corrugation roller provided with a brim portion that does not come into contact with
The paper discharge device, wherein the brim portion is movable in the axial direction of the rotation shaft, and the roller portion is fixed at a position in the axial direction of the rotation shaft. The paper discharge device according to claim 1, wherein the roller portion and the flange portion are rotatable independently of a rotation direction. The flange portion is urged by the urging means in a direction in contact with the side surface of the roller portion, and away from the side surface of the roller portion due to the rigidity strength in a direction perpendicular to the conveyance direction of the discharged paper. The paper discharge device according to claim 1 or 2, wherein 3. The paper discharge device according to claim 1, further comprising a moving unit configured to move the collar unit, wherein the collar unit is moved on a rotation shaft according to a type of paper by the moving unit. An image forming apparatus comprising the paper discharge device according to claim 1.

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