JP2016199375A - Sheet feeding device and image formation apparatus having the same - Google Patents

Abstract

CONSTITUTION: A sheet feeding device 10 includes a pickup roller 78 and a sheet feeding roller 82, takes out and conveys the sheets loaded on a sheet loading base 70, and also includes an endless separation belt 86 which is laid between a first roller 88 and a second roller 90 so as to be in contact with the outer peripheral surface of the sheet feeding roller.EFFECT: The sheet separation performance is improved since a nip part with a sheet feeding roller can be made larger by using a separation belt as a separation member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet feeding device and an image forming apparatus including the sheet feeding device, and more particularly to a sheet feeding device and an image forming apparatus including the sheet feeding device that take out and feed sheets stacked on a sheet stacking sheet one by one.

  An example of a conventional paper feeding device is disclosed in Patent Document 1. The paper feeding device disclosed in Patent Document 1 is a paper feeding device that employs a roller separation system, and includes a pickup roller provided above the paper feeding cassette and a winding portion provided downstream of the pickup roller in the paper feeding direction. Prepare. The separation unit includes a paper feed roller and a separation roller that are arranged to face each other across the paper conveyance path, and the paper feed roller and the separation roller are in contact with each other to form a nip part. Such a separating unit separates and conveys one of the sheets taken out by the pickup roller, which contacts the sheet feeding roller, by utilizing friction with the sheet.

JP 2012-166912 A

  However, the roller separation method as in the technique of Patent Document 1 cannot be said to have sufficient separation performance. For this reason, it is difficult to appropriately cope with the difference in the type of paper, the surface condition of the roller and the environment, and a paper separation error (double feed) may occur. Further, depending on the type of paper, it is necessary to change the setting of the separation condition individually.

  Therefore, a main object of the present invention is to provide a novel sheet feeding device and an image forming apparatus including the same.

  Another object of the present invention is to provide a sheet feeding device and an image forming apparatus including the sheet feeding device, which are excellent in sheet separation performance and can appropriately supply sheets one by one.

  A first aspect of the present invention is a paper feeding device that feeds paper loaded on a paper stacking table, and is provided on the downstream side of the pick-up roller in the paper transport direction with respect to the pick-up roller that picks up the paper from the paper mounting table. So as to be brought into contact with the outer peripheral surface of the paper feed roller by being fed over the paper feed roller for transporting the paper taken out by the first roller and the second roller provided downstream of the first roller and the first roller in the paper transport direction. A paper feeding device provided with an endless separation belt that is provided and separates the paper conveyed by the paper feeding roller into one sheet.

  In the first invention, the paper feeding device is a device that picks up and feeds the paper stacked on the paper stacking table one by one, and includes a pickup roller. On the downstream side of the pickup roller in the paper conveyance direction, a paper feed roller that gives a propulsive force to the paper is provided, and an endless separation belt that is a separation member is provided at a position opposed to the paper feed roller. The separation belt is arranged around the first roller and the second roller so that the outer peripheral surface thereof is in contact with the outer peripheral surface of the paper feed roller. That is, a nip portion is formed between the paper feed roller and the separation belt, and the paper feed roller and the separation belt constitute a separation conveyance unit.

  According to the first invention, since the endless separation belt is used as the separation member, the width of the nip portion in the separation conveyance portion can be increased. That is, since the contact area between the sheet and the nip portion can be increased, the sheet separation performance is improved, and the sheets stacked on the sheet stacking table can be appropriately separated and supplied one by one.

  The second invention is dependent on the first invention, and the outer diameter of the first roller is set smaller than the outer diameter of the second roller.

  In the second invention, the outer diameter of the first roller is set smaller than the outer diameter of the second roller provided on the downstream side in the paper transport direction.

  According to the second invention, it is possible to widen the paper entrance of the nip portion while reducing the thickness of the paper feeding device. By widening the paper entrance of the nip portion, the paper easily enters the nip portion, and the front end portion of the paper is prevented from being broken at the nip portion.

  A third invention is dependent on the first or second invention, and the paper feed roller is disposed on the second roller side with respect to the first roller.

  In the third invention, the paper feed roller is disposed closer to the second roller than the first roller. That is, when a perpendicular is drawn from the axis center of the paper feed roller to the line connecting the axis center of the first roller and the axis center of the second roller, the distance from the axis center of the first roller to the foot of the perpendicular Is made larger than the distance from the axial center of the second roller to the foot of the perpendicular.

  According to the third aspect of the invention, since the belt portion on the upstream side in the paper conveyance direction is wider than the nip portion of the separation belt, it is possible to perform pre-separation of paper by that much, and paper separation performance by the separation belt. Will be improved.

  A fourth aspect of the invention is an image forming apparatus including the paper feeding device according to any one of the first to third aspects of the invention.

  According to the fourth aspect of the present invention, the same effects as in any of the first to third aspects of the invention can be obtained, the paper separation performance can be improved, and the sheets stacked on the paper stacking board can be appropriately separated one by one. Can be supplied separately.

  According to this invention, since the endless separation belt is used as the separation member, the width of the nip portion in the separation conveyance portion can be increased. That is, since the contact area between the sheet and the nip portion can be increased, the sheet separation performance is improved, and the sheets stacked on the sheet stacking table can be appropriately separated and supplied one by one.

  The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

1 is a schematic cross-sectional view illustrating an internal structure of a multifunction machine including a paper feeding device according to a first embodiment of the present invention. FIG. 2 is an illustrative view schematically showing the paper feeding device of FIG. 1. FIG. 2 is an illustrative view schematically showing a state in which the sheet feeding device of FIG. 1 is viewed from above. FIG. 2 is an illustrative view for explaining an arrangement of a sheet feeding roller and a separation belt in the sheet feeding device of FIG. 1. It is an illustration figure which shows schematically the paper feeder of 2nd Example of this invention. It is an illustration figure which shows schematically the paper feeder of 3rd Example of this invention.

[First embodiment]
Referring to FIG. 1, a paper feeding device 10 according to an embodiment of the present invention is a device for taking out papers (recording media) stacked on a paper stacking table 70 one by one and feeding them. And image forming apparatuses such as facsimiles, printers, and multi-function machines. As will be described in detail later, the sheet feeding device 10 includes a separation conveyance unit (a separating unit) 80 including a sheet feeding roller 82 and a separation belt 86, and adopts an endless separation belt 86 as a separation member. The paper taken out from the paper stacking table 70 can be appropriately separated into one sheet. In the first embodiment, an example in which the paper feeding device 10 is applied to a multifunction peripheral (MFP) 100 having a copying function, a printer function, a scanner function, a facsimile function, and the like is shown.

  First, the configuration of the multifunction peripheral 100 will be schematically described. As shown in FIG. 1, the multi-function device 100 includes a multi-function device main body 12 including a paper feeding device 10 and an image reading device 14 disposed above the main body 12.

  The image reading device 14 includes a document placing table 16 formed of a transparent material. A document pressing cover 18 is attached above the document placing table 16 through a hinge or the like so as to be freely opened and closed. The document pressing cover 18 is provided with an ADF (automatic document feeder) 24 that automatically feeds the documents placed on the document placing tray 20 one by one to the image reading position 22. An operation unit (not shown) such as a touch panel and operation buttons for receiving an input operation such as a print instruction by a user is provided on the front side of the document placing table 16.

  The image reading device 14 includes an image reading unit 26 including a light source, a plurality of mirrors, an imaging lens, a line sensor, and the like. The image reading unit 26 exposes the document surface with a light source, and guides the reflected light reflected from the document surface to the imaging lens by a plurality of mirrors. Then, the reflected light is imaged on the light receiving element of the line sensor by the imaging lens. The line sensor detects the luminance and chromaticity of the reflected light imaged on the light receiving element, and generates image data based on the image on the document surface. As the line sensor, a charge coupled device (CCD), a contact image sensor (CIS), or the like is used.

  The multifunction machine main body 12 includes a control unit (not shown) including a CPU, a memory, and the like, an image forming unit 30, and a paper feeding device 10. The control unit transmits a control signal to each part of the multifunction device 100 in accordance with an input operation to the operation unit such as a touch panel, and causes the multifunction device 100 to execute various operations.

  The image forming unit 30 includes an exposure unit 32, a developing unit 34, a photosensitive drum 36, a cleaner unit 38, a charger 40, an intermediate transfer belt unit 42, a transfer roller 44, a fixing unit 46, and the like. An image is formed on the paper conveyed from the paper supply unit 50, and the paper on which the image has been formed is discharged to the paper discharge tray 52. As image data for forming an image on a sheet, image data read by the image reading unit 26 or image data transmitted from an external computer is used.

  Note that the image data handled in the multifunction peripheral 100 corresponds to four color images of black (K), cyan (C), magenta (M), and yellow (Y). For this reason, each of the developing device 34, the photosensitive drum 36, the cleaner unit 38, and the charging device 40 is provided so as to form four types of latent images corresponding to the respective colors, thereby providing four image stations. Composed.

  The photosensitive drum 36 is an image carrier in which a photosensitive layer is formed on the surface of a conductive cylindrical substrate. The charger 40 is a member that charges the surface of the photosensitive drum 36 to a predetermined potential. is there. Further, the exposure unit 32 is configured as a laser scanning unit (LSU) including a laser emitting portion and a reflection mirror, and exposes the surface of the charged photosensitive drum 36 so that an electrostatic latent image corresponding to image data is obtained. An image is formed on the surface of the photosensitive drum 36. The developing device 34 visualizes the electrostatic latent image formed on the surface of the photosensitive drum 36 with toner of four colors (YMCK). The cleaner unit 38 removes toner remaining on the surface of the photosensitive drum 36 after development and image transfer.

  The intermediate transfer belt unit 42 includes an intermediate transfer belt 54, a drive roller 56, a driven roller 58, four intermediate transfer rollers 60, and the like, and is disposed above the photosensitive drum 36. The intermediate transfer belt 54 is provided so as to be in contact with each photosensitive drum 36, and the toner images of the respective colors formed on the respective photosensitive drums 36 are sequentially superimposed on the intermediate transfer belt 54 using the intermediate transfer roller 60. As a result, a multicolor toner image is formed on the intermediate transfer belt 54. Further, a transfer roller 44 is disposed in the vicinity of the driving roller 56, and the toner formed on the intermediate transfer belt 54 by passing the sheet through the nip area between the intermediate transfer belt 54 and the transfer roller 44. The image is transferred to the paper.

  The fixing unit 46 includes a heat roller 62 and a pressure roller 64 and is disposed above the transfer roller 44. The heat roller 62 is set to have a predetermined fixing temperature. When the paper passes through the nip area between the heat roller 62 and the pressure roller 64, the toner image transferred to the paper is melted. The toner image is heat-fixed on the sheet by mixing and pressing.

  A paper feeding device 10 that feeds paper to the image forming unit 30 is provided below the image forming unit 30. In the first embodiment, the paper feeding device 10 sequentially takes out and feeds the topmost paper among the papers stacked on the paper stacking table 70. A specific configuration of the sheet feeding device 10 will be described later.

  In the multifunction machine main body 12, the first sheet for feeding the sheet from the sheet feeding device 10 or the manual sheet feeding unit 50 to the sheet discharge tray 52 via the registration roller 68, the transfer roller 44 and the fixing unit 46. A sheet conveyance path S1 is formed. In addition, when performing duplex printing on a sheet, the sheet after the one-side printing is completed and passed through the fixing unit 46 is returned to the first sheet conveyance path S1 on the upstream side of the transfer roller 44 in the sheet conveyance direction. The second paper transport path S2 is formed. In the first paper transport path S1 and the second paper transport path S2, a plurality of transport rollers 66 are provided as appropriate to supplementarily apply a driving force to the paper.

  When single-sided printing (image formation) is performed in the multifunction machine main body 12, the sheets are guided one by one to the first sheet conveyance path S 1 by the sheet feeding device 10 or the manual sheet feeding unit 50, and the registration rollers 68 are conveyed by the conveyance rollers 66. It is conveyed to. Then, the registration roller 68 conveys the sheet to the transfer roller 44 at a timing when the leading edge of the sheet and the leading edge of the image information on the intermediate transfer belt 54 are aligned, and the toner image is transferred onto the sheet. Thereafter, when the toner passes through the fixing unit 46, the unfixed toner on the paper is melted and fixed by heat, and the paper is discharged onto the paper discharge tray 52 through a conveyance roller (paper discharge roller) 66.

  On the other hand, when performing double-sided printing, when the trailing edge of the paper that has passed through the fixing unit 46 after single-sided printing has reached the paper discharge roller 66 near the paper discharge tray 52, the paper discharge roller 66 is reversed. By rotating, the sheet runs backward and is guided to the second sheet conveyance path S2. The paper guided to the second paper transport path S2 is transported through the second paper transport path S2 by the transport roller 66, and is guided to the first paper transport path S1 on the upstream side of the registration roller 68 in the paper transport direction. At this time, the front and back sides of the sheet are reversed, and thereafter, the sheet passes through the transfer roller 44 and the fixing unit 46, whereby printing is performed on the back side of the sheet.

  Next, the configuration of the sheet feeding device 10 will be specifically described with reference to FIGS. 2 and 3. As shown in FIGS. 2 and 3, the paper feeding device 10 is a device that takes out and feeds the paper stacked on the paper stacking table 70 one by one, and includes a pickup roller 78 and a separation conveyance unit 80. The separation conveyance unit 80 includes a paper feed roller 82 and a separation belt 86.

  The paper stacking base (paper feed tray) 70 can be moved up and down by a driving means or an urging means (not shown), and when the paper is fed, the top and bottom sheets are moved up and down so that the uppermost paper has a predetermined height regardless of the amount of paper loaded. Moved. A front plate 72, a rear plate 74, and a pair of side plates 76 are provided on the peripheral edge of the paper stacking table 70. The front plate 72 functions as a guide plate that regulates the front end of the sheets stacked on the sheet stacking base 70 in the sheet conveyance direction and guides the uppermost sheet to be conveyed along the outer peripheral surface of the separation belt 86. To do. The rear plate 74 regulates the rear end of the paper stacked on the paper stacking base 70 in the paper transport direction, and is provided to be movable in the front-rear direction in the paper transport direction. Further, the side plate 76 regulates each of the paper edges in the direction (paper width direction) orthogonal to the paper conveyance direction of the paper loaded on the paper stacking base 70, that is, both side edges of the paper. It is provided so as to be movable.

  A pickup roller 78 for taking out (picking up) the uppermost sheet from the sheet stacking table 70 is provided above the downstream end of the sheet stacking table 70 in the sheet transport direction. In addition, a paper feed roller 82 for providing a driving force to the paper is provided on the downstream side of the pickup roller 78 in the paper transport direction. The outer diameters of the pickup roller 78 and the paper feed roller 82 are, for example, 26 mm.

  The pickup roller 78 and the paper feed roller 82 are unitized by a first frame 84, and the shafts of the pickup roller 78 and the paper feed roller 82 are rotatably supported by the first frame 84. The shafts of the pickup roller 78 and the paper feed roller 82 are connected to a drive source (motor) (not shown), and the drive force from the drive source is transmitted to each shaft, whereby the pickup roller 78 and the paper feed roller 82 are connected. Rotates.

  A separation belt 86 is provided at a position facing the paper feed roller 82. The separation belt 86 is a separation member for separating the paper conveyed by the paper feed roller 82 into one sheet. As described above, the separation and conveyance unit 80 is separated by the separation belt 86 and the paper feed roller 82. Composed.

  Specifically, the separation belt 86 is formed endlessly with rubber or synthetic resin, and is stretched around the first roller 88 and the second roller 90. The first roller 88 is disposed upstream of the paper feed roller 82 in the paper transport direction, and the second roller 90 is disposed downstream of the paper transport direction. The outer diameters of the first roller 88 and the second roller 90 are, for example, 26 mm. The first roller 88 and the second roller 90 are unitized by a second frame 92, and the shafts of the first roller 88 and the second roller 90 are rotatably supported by the second frame 92.

  The outer peripheral surface of the separation belt 86 is brought into contact with the outer peripheral surface of the paper feed roller 82 with a predetermined pressure (separation pressure), and a nip portion 94 is formed between the paper feed roller 82 and the separation belt 86. The For example, an urging member such as a compression spring (not shown) is connected to the shaft of the paper feed roller 82, and the urging member urges the paper feed roller 82 to abut against the separation belt 86 with a predetermined pressure. . However, the biasing member may be connected to the shafts of the first roller 88 and the second roller 90.

  Further, at least one of the first roller 88 and the second roller 90 is a drive roller connected to a drive source (not shown). In the first embodiment, the second roller 90 is a driving roller and the first roller 88 is a driven roller. The separation belt 86 is capable of rotating around as the second roller 90 rotates.

  Specifically, the second roller 90 is provided with a torque limiter (not shown), and the shaft of the second roller 90 has a direction in which the sheet is returned to the upstream side (the sheet stacking table 70 side) in the sheet conveyance direction. A rotational driving force is applied from a driving source. When only one sheet passes through the nip portion 94, the separation belt 86 is rotated by the paper feed roller 82, and the second roller 90 is driven to rotate by the slip of the torque limiter. It is sent directly to the downstream side in the transport direction. On the other hand, when two sheets of paper are fed to the nip portion 94, the rotational driving force of the second roller 90 overcomes the frictional force between the sheets and rotates in the direction of returning the paper. The rotation of the separation belt 86 in accordance with the rotation drive returns the lower sheet in contact with the separation belt 86 to the sheet stacking table 70 side. As a result, only the upper sheet in contact with the sheet feeding roller 82 is separated and conveyed downstream.

  Here, as shown in FIG. 4, the arrangement position of each roller provided in the paper feeding device 10 is such that the distance X1 between the paper feeding surface (conveyance path) of the paper taken out by the pickup roller 78 and the top of the first roller 88 is. The distance X2 between the sheet feed surface and the bottom of the sheet feed roller 82 is preferably 3-7 mm. The inclination angle θ of the upper surface of the separation belt 86 with respect to the sheet feeding surface is preferably set to 35 ° or less. By disposing each roller in this manner, the sheet taken out by the pickup roller 78 is smoothly guided to the nip portion 94 of the separation conveyance unit 80, and the separation sheet feeding performance is appropriately exhibited. Further, the sheet feeding device 10 can be thinned.

  In the sheet feeding device 10 as described above, the sheet taken out from the sheet stacking table 70 by the pickup roller 78 is separated and conveyed by passing through the nip portion 94 of the separation conveying unit 80 and guided to the first sheet conveying path S1. It is burned. That is, when only one sheet is conveyed to the nip portion 94, the sheet is directly guided to the first sheet conveyance path S1. On the other hand, when the sheets are fed to the nip portion 94, only the upper sheet contacting the sheet feeding roller 82 is returned by returning the lower sheet contacting the separation belt 86 to the sheet stacking table 70 side. It is separated and guided to the first paper transport path S1.

  At this time, in the first embodiment, since the endless separation belt 86 is employed as the separation member of the separation conveyance unit 80, the outer peripheral surface of the paper feed roller 82 and the outer peripheral surface of the separation belt 86 are brought into pressure contact with each other. Sometimes, the shape of the separation belt 86 can be curved and deformed along the outer peripheral surface of the paper feed roller 82. As a result, the contact length between the paper feed roller 82 and the separation belt 86 in the paper conveyance direction, that is, the width of the nip portion 94 (nip region) can be increased. Therefore, compared with using a separation roller as the separation member, the sheet separation performance in the separation conveyance unit 80 is improved.

  As described above, according to the first embodiment, since the endless separation belt 86 is used as the separation member, the width of the nip portion 94 in the separation conveyance unit 80 can be increased. That is, since the contact area between the sheet and the nip portion 94 can be increased, the sheet separation performance is improved, and the sheets stacked on the sheet stacking table 70 can be appropriately separated and supplied one by one.

[Second Embodiment]
Next, with reference to FIG. 5, a paper feeder 10 according to a second embodiment of the present invention will be described. In the second embodiment, the size of the first roller 88 that spans the separation belt 86 is different from that of the first embodiment. Since the configuration of the other parts is the same, parts common to the first embodiment described above are given the same reference numerals, and redundant descriptions are omitted or simplified.

  As shown in FIG. 5, the sheet feeding device 10 includes a separation conveyance unit 80 including a sheet feeding roller 82 and an endless separation belt 86. The separation belt 86 is stretched over a first roller 88 and a second roller 90 provided downstream of the first roller 88 in the sheet conveyance direction, and is provided so that an outer peripheral surface thereof is in contact with an outer peripheral surface of the paper feed roller 82. It is done. Thereby, a nip portion 94 is formed between the paper feed roller 82 and the separation belt 86.

  In the second embodiment, the outer diameter of the first roller 88 is set smaller than the outer diameter of the second roller 90. The outer diameter of the first roller 88 is, for example, 20 mm, and the outer diameter of the second roller 90 is, for example, 26 mm.

  Here, from the viewpoint of reducing the thickness of the paper feeder 10, it is preferable that the outer diameters of the first roller 88 and the second roller 90 are small. However, if the outer diameters of the first roller 88 and the second roller 90 are reduced, the distance between the upper part (nip part 94 side) and the lower part (return side) of the separation belt 86 becomes narrower. There is a possibility that the upper part and the lower part interfere with each other. Further, in order to prevent the sheet from being folded when entering the nip portion 94, it is preferable that the sheet entrance 96 of the nip portion 94 is wide. However, if the paper inlet 96 is widened by moving the position of the first roller 88 downward while the outer diameter of the first roller 88 remains large, the thickness of the sheet feeding device 10 in the vertical direction increases.

  Therefore, in the second embodiment, in order to maintain the distance between the upper portion and the lower portion of the separation belt 86, only one of the first roller 88 and the second roller 90 is reduced in diameter. did. When the diameter of one of the rollers is reduced, the diameter of the first roller 88 is reduced so that the sheet feeding device 10 can be thinned even if the sheet entrance 96 of the nip portion 94 is widened. did.

  According to the second embodiment, as in the first embodiment, since the endless separation belt 86 is used as the separation member, the width of the nip portion 94 in the separation conveyance unit 80 can be increased. Accordingly, the sheet separation performance is improved, and the sheets stacked on the sheet stacking table 70 can be appropriately separated and supplied one by one.

  Further, according to the second embodiment, since the outer diameter of the first roller 88 is set smaller than the outer diameter of the second roller 90, the sheet entry of the nip portion 94 is made while the sheet feeding device 10 is thinned. The mouth 96 can be widened. By widening the paper entrance 96 of the nip portion 94, the paper can easily enter the nip portion 94, and the front end portion of the paper is prevented from being broken at the nip portion 94.

[Third embodiment]
Next, with reference to FIG. 6, a paper feeder 10 according to a third embodiment of the present invention will be described. The third embodiment is different from the first and second embodiments described above in that the disposition position of the separation belt 86 with respect to the paper feed roller 82 is different. Since the configuration of the other parts is the same, parts common to the first and second embodiments described above are given the same reference numerals, and redundant descriptions are omitted or simplified.

  As shown in FIG. 6, the paper feeding device 10 includes a separation conveyance unit 80 including a paper feeding roller 82 and an endless separation belt 86. The separation belt 86 is provided around the first roller 88 and the second roller 90 so that the outer peripheral surface thereof is in contact with the outer peripheral surface of the paper feed roller 82. Thereby, a nip portion 94 is formed between the paper feed roller 82 and the separation belt 86.

  In the third embodiment, the paper feed roller 82 is disposed closer to the second roller 90 than the first roller 88. That is, when a perpendicular line is drawn from the axis center of the paper feed roller 82 to the line connecting the axis center of the first roller 88 and the axis center of the second roller 90, the perpendicular line is drawn from the axis center of the first roller 88. The distance Y1 to the foot is larger than the distance Y2 from the axial center of the second roller 90 to the foot of the perpendicular. As a result, the belt portion 86a on the upstream side in the paper conveyance direction with respect to the nip portion 94 of the separation belt 86 is widened, so that the pre-separation of the paper before entering the nip portion 94 is possible by the increased amount. The paper separation performance is further improved.

  According to the third embodiment, as in the first embodiment, since the endless separation belt 86 is used as the separation member, the width of the nip portion 94 in the separation conveyance unit 80 can be increased. Accordingly, the sheet separation performance is improved, and the sheets stacked on the sheet stacking table 70 can be appropriately separated and supplied one by one.

  Further, according to the third embodiment, since the paper feed roller 82 is disposed on the second roller 90 side with respect to the first roller 88, the pre-separation of the paper can be performed appropriately, and the paper is separated by the separation belt 86. Separation performance is further improved.

  In the multifunction peripheral (image forming apparatus) 100 shown in FIG. 1, only one sheet stacking base 70 and the sheet feeding device 10 are provided below the image forming unit 30, but the sheet stacking provided in the image forming apparatus is performed. The number of the bases 70 and the paper feeders 10 is arbitrary.

  In each of the above-described embodiments, the paper feeding device 10 is applied to the mechanism for feeding paper from the paper stacking base (paper feeding tray) 70 disposed in the multifunction machine main body 12, but the present invention is not limited to this. For example, the paper feeder 10 can also be applied to a mechanism (manual paper feeder) that feeds paper from a manual paper feed tray. The paper feeding device 10 can also be applied to a large-capacity paper feeding device that is externally attached to the image forming device and accommodates a large amount of paper to be fed to the image forming device. Further, the paper feeding device 10 is applied not only to a mechanism that feeds paper (recording medium) on which an image is printed, but also to a mechanism (automatic document feeder or the like) that feeds paper (original) from which an image is read. You can also.

  Further, in each of the above-described embodiments, the separation belt 86 is one that moves around in a direction in which the sheets are returned to the sheet stacking table 70 side when the sheets are double-fed, but is not limited thereto. For example, it is possible to use a separation belt that separates the sheets by stopping the circular movement when the sheets are double-fed.

  Further, in each of the above-described embodiments, the pickup roller 78 is fixedly installed. However, the pickup roller 78 may be configured to be capable of rotating up and down around the paper feed roller 82 as a support shaft, for example.

  It should be noted that the specific numerical values such as the dimensions mentioned above are merely examples, and can be appropriately changed according to the needs of product specifications and the like.

DESCRIPTION OF SYMBOLS 10 ... Paper feeder 12 ... MFP main body 14 ... Image reading device 30 ... Image formation part 70 ... Paper stacking board 78 ... Pick-up roller 80 ... Separation conveyance part 82 ... Paper feed roller 86 ... Separation belt 88 ... 1st roller 90 ... Second roller 94 ... Nip part 100 ... Multi-function machine (image forming apparatus)

Claims (4)

A paper feeding device that feeds paper loaded on a paper loading table,
A pickup roller for taking out the paper from the paper mounting table;
A paper feed roller that is provided downstream of the pickup roller in the paper conveyance direction and that conveys the paper taken out by the pickup roller, and a second roller that is provided downstream of the first roller and the first roller in the paper conveyance direction. A sheet feeding device provided with an endless separation belt which is provided so as to be in contact with the outer peripheral surface of the sheet feeding roller and separates the sheet conveyed by the sheet feeding roller into one sheet.   The paper feeding device according to claim 1, wherein an outer diameter of the first roller is set smaller than an outer diameter of the second roller.   The sheet feeding device according to claim 2, wherein the sheet feeding roller is disposed closer to the second roller than the first roller.   An image forming apparatus comprising the paper feeding device according to claim 1.

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