JP2008024398A - Paper insertion mechanism of paper feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper insertion mechanism of a paper feeder capable of surely inserting paper into a paper carrying path by preventing the defective insertion of paper and the trouble of the paper feeder from occurring by a simple structure. <P>SOLUTION: This paper insertion mechanism 30 of paper feeders comprises a paper loading part 31 which is formed at the inlet of a paper carrying path 22 and on which paper is placed and a pickup roller 24 for inserting the paper placed on the paper loading part 31 to the paper carrying path 22. The paper loading part 31 comprises a flapper 32 so installed as to be vertically swung around the one end. The roller surface 24a of the pickup roller 24 biased downward by the spring power of a coiled spring 46 is pressed against the upper surface of the paper placed on the paper loading part at the upper paper inserting position to which the flapper 32 is swung. The end of the paper placed on the paper loading part abuts on and locked to a wall surface part 55 formed in the paper carrying path 22 at the downward standby position to which the flapper 32 is swung. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a paper feeding mechanism of a paper feeding device, comprising a paper placing portion provided at an entrance of a paper feeding path, and a pickup roller for feeding the paper placed on the paper placing portion into the paper feeding path. It is about.

  A paper feeding device provided in an image forming apparatus such as a facsimile or a copier includes a paper placement unit for placing paper provided at an entrance of a paper conveyance path, and paper conveyance on the paper placement unit. Some have a paper feeding mechanism including a pickup roller that feeds into a road. In this paper feeding mechanism, as shown in Patent Document 1, a pickup roller is rotatably supported at the tip of a swing arm that swings in the vertical direction above the paper placement portion. By swinging downward and being pressed against the upper surface of the paper on the paper stacking portion and rotating, the paper is sequentially fed.

In order to prevent the paper placed on the paper placing portion from entering the paper transport path when the paper feeding mechanism is stopped in the paper feeding device having this type of paper feeding mechanism. Some have a shutter installed at the entrance of the paper transport path. As another mechanism for preventing the paper from entering the paper transport path, there is a mechanism in which the bottom surface of the paper stacking portion is formed in an inclined surface that rises toward the downstream side of the paper transport path.
JP 2002-255363 A

  However, in the paper feeder provided with the shutter described above, when the paper is placed on the paper placement portion, the leading edge of the paper hits the shutter, the shutter breaks down, or the leading edge of the paper contacts the shutter. If the shutter is opened and closed in the state where it is left, there is a problem that a malfunction of the shutter occurs. On the other hand, in the paper feeding device in which the bottom surface of the paper stacking portion is formed into an inclined surface, when the paper is fed by the pickup roller, the paper does not run up the inclined bottom surface, and the paper is poorly fed. There was a possibility of happening.

  The present invention has been made in view of the above-described points, and an object of the present invention is to prevent paper feeding failure and paper feeding device failure with a simple configuration, and to reliably feed paper into the paper transport path. An object of the present invention is to provide a paper feeding mechanism of a paper feeding device.

  In order to solve the above-mentioned problem, the invention according to claim 1 of the present application is directed to a paper placement portion for placing a paper provided at an entrance of a paper conveyance path, and a paper placed on the paper placement portion to the paper. In the paper feeding mechanism of the paper feeding device provided with a pickup roller that feeds into the conveyance path, the paper placing portion includes a flapper that is swingably mounted in the vertical direction with one end as a fulcrum, and the flapper is located above In the standby position where the pickup roller is pressed against the upper surface of the loaded paper, and the flapper swings downward, the leading edge of the loaded paper moves the paper It is characterized in that it is configured to abut against and be locked to a wall surface provided on the road.

  According to a second aspect of the present invention, in the paper feeding mechanism of the paper feeding device according to the first aspect, the first biasing unit that biases the pickup roller toward the flapper, or the flapper. A second urging means for urging the pickup roller is provided.

  According to a third aspect of the present invention, the paper feeding mechanism of the paper feeding device according to the second aspect further includes a push-up mechanism that pushes up the flapper and swings the flapper to the paper feeding position. The urging means is provided between the push-up mechanism and the flapper.

  According to a fourth aspect of the present invention, in the paper feeding mechanism of the paper feeding device according to the third aspect, the push-up mechanism includes a friction roller that rotates in conjunction with the rotation of the pickup roller, and the friction roller. A cam member that abuts on the roller surface and rotates by frictional force with the friction roller, and a push-up member that is attached to the cam member and pushes up the flapper directly or via the second urging means. It is characterized by.

  The invention according to claim 5 of the present application is the sheet feeding mechanism of the sheet feeding device according to any one of claims 2 to 4, wherein the first urging means or the second urging means is A coil spring that repels the pickup roller or the flapper.

  According to the invention described in claim 1 of the present application, the sheet placing portion of the sheet feeding mechanism includes a flapper that is swingably mounted in the vertical direction with one end as a fulcrum, and the sheet in which the flapper swings upward. In the standby position where the pickup roller is pressed against the loaded paper at the retracted position and the flapper swings downward, the leading edge of the loaded paper abuts against the wall surface provided in the paper transport path. Since it is configured to be locked, when the paper feeding mechanism is operated, the flapper is in the paper feeding position so that the paper can be reliably fed, while when the paper feeding mechanism is stopped, the flapper waits. By being in the position, it is possible to reliably prevent the paper on the paper placement unit from entering the paper transport path. Accordingly, a paper feeding mechanism that can prevent paper feeding failure and failure of the paper feeding device with a simple configuration and can reliably feed paper into the paper transport path.

  According to the second aspect of the present invention, the first urging means for urging the pickup roller toward the flapper or the second urging means for urging the flapper toward the pickup roller is provided. Therefore, the pickup roller is pressed against the upper surface of the paper placed on the flapper by the first urging means or the second urging means, so that the paper can be fed more reliably.

  According to the invention described in claim 3 of the present application, the push-up mechanism that pushes up the flapper and swings it to the paper feeding position is provided. Can be carried over.

  According to the invention described in claim 4 of the present application, the push-up mechanism is rotated by the frictional roller that rotates in conjunction with the rotation of the pickup roller, and the frictional roller that is in contact with the roller surface of the friction roller. And a push-up member that pushes up the flapper attached to the cam member. With a simple configuration, when the paper feed mechanism in which the pickup roller is rotating, the flapper is pushed up and the paper feed position is The pickup roller can be brought into contact with the paper with certain pressure. Further, if the frictional force between the friction roller and the cam member is adjusted to a predetermined frictional force with this structure, the pressure contact force between the pickup roller and the paper is changed even if the number of papers placed on the flapper changes. Since it can always be constant, the sheet can be fed more reliably.

  According to the invention described in claim 5 of the present application, since the first urging means or the second urging means is a coil spring that repels the pickup roller or the flapper, the pickup roller is placed on the flapper with a simple configuration. The sheet can be pressed against the upper surface of the placed paper, and the paper can be fed more reliably.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a perspective view showing an image forming apparatus provided with a paper feeding mechanism of a paper feeding device according to a first embodiment of the present invention. First, a schematic overall configuration of the image forming apparatus will be described with reference to FIG. The image forming apparatus to which the present invention is applied may be any of a copier, a facsimile machine, a printer, or a so-called multifunction machine having these functions as long as the image forming apparatus includes a paper feeding device. . The image forming apparatus 1 shown in FIG. 1 includes a recording unit 2 installed on the lower side and a reading unit 3 installed on the upper side. The recording unit 2 includes a recording device 4, a paper feed cassette 5, and a recording paper discharge tray 6. The paper stored in the paper feed cassette 5 is fed to the recording device 4. After recording, the paper is discharged to the recording paper discharge tray 6.

  On the other hand, the reading unit 3 scans and reads an image of a document, the operation panel 7 attached to the front side of the image reading device 10, and one side of the image reading device 10 on the upper side thereof is not illustrated. And a document presser cover 8 attached to the hinge mechanism so as to be opened and closed. An automatic paper feeder (ADF device) 20 that automatically feeds original paper is installed at one end of the document presser cover 8.

  FIG. 2 is a side sectional view showing the detailed configuration of the image reading apparatus 10 and the automatic paper feeder 20. A reading unit 11 is installed on the lower surface side of the platen glass 16 in the image reading apparatus 10. The reading unit 11 includes a light source 12 that irradiates light on a document at a reading position, a reflection mirror 13 that guides reflected light R from the document in a predetermined direction, a condenser lens 14 that converges the reflected light R, A so-called reduction optical system CCD reading unit provided with a charge coupled device (hereinafter referred to as “CCD”) 15 that converts the convergent light into an electrical signal and outputs it, and guides reflected light R from the original to the CCD 15. Although detailed description and illustration are omitted, the image signal converted into an electrical signal is subjected to analog / digital conversion, shading processing, etc. Or is transmitted by a transmission unit such as CODEC.

  On the other hand, the automatic paper feeder 20 includes a plate-shaped document tray 21 on which a plurality of document sheets are stacked, a sheet conveyance path 22 formed in a horizontal U-shape, and a sheet discharge for stacking and holding the document sheets after conveyance. A tray 23 is provided. In addition, the paper feeding mechanism 30 of the present invention including the paper placement unit 31 and the pickup roller 24 installed at the entrance of the paper transport path 22, and the paper separation mechanism 50 including the separation roller 25 and the separation pad 52, The image reading on the back side of the original paper at the reading position P2 in the middle of the sheet conveying path 22 and the sheet discharging roller 27 provided near the exit of the sheet conveying path 22 is performed. A CIS reading unit 28 having a contact image sensor (hereinafter referred to as “CIS”).

  When the image reading apparatus 10 reads a document image as a flat bed scanner, the document pressing cover 8 is closed and the document placed on the platen glass 16 is pressed and fixed. In this state, each carriage 17 to which the reflecting mirror 13 is attached is scanned to read the original image. On the other hand, when reading an original image using the automatic paper feeder 20, the original paper fed from the original tray 21 to the paper feed path 22 by the paper feed mechanism 30 is moved upward along the paper feed path 22. The image reading apparatus 10 is inverted so as to make a U-turn downward and reaches the reading position P1, and the reflection mirror 13 is aligned with the reading position P1 when passing through the reading position P1. Images are read. Further, when the original paper is conveyed through the paper conveyance path 22 and passes the reading position P2, the image on the back side of the original paper is read by the CIS reading unit 28. Thereafter, the original paper is discharged to the paper discharge tray 23.

  Here, the configuration of the paper feeding mechanism 30 provided in the automatic paper feeder 20 will be described in detail. FIG. 3 is a partial enlarged view showing the paper feeding mechanism 30 and the paper separating mechanism 50, and shows a state where a flapper 32 described below of the paper feeding mechanism 30 is in a standby position. FIG. 4 is a diagram showing a state in which the flapper 32 is in the paper feeding position. As shown in these drawings, the document tray 21 is attached with a slight inclination so that the end portion on the entrance side of the sheet conveyance path 22 is lowered. At the entrance of the paper transport path 22, a paper placement portion 31 is formed on which a part of the front end side of the original paper stacked on the original tray 21 is placed. The paper stacking unit 31 includes a flat flapper 32 that is swingably mounted in the vertical direction about a swing shaft 32a. The swing shaft 32 a is arranged in a horizontal direction in which the axial direction is orthogonal to the front-rear direction of the paper transport path 22. The flapper 32 is installed such that its upper surface 32 b is continuous with the upper surface of the document tray 21, and one end (fulcrum end) to which the swing shaft 32 a is attached is the document in the upstream direction of the sheet conveyance path 22. Located on the side of the tray 21, the other end (swinging end) is positioned in the vicinity of a wall surface 55 described below formed in the inner guide 53 in the downstream direction of the paper transport path 22.

  The pickup roller 24 disposed above the flapper 32 is rotatably supported at the tip of a swing arm 29 that swings in the vertical direction with a rotation shaft 25a of a separate roller 25 described below as a fulcrum. A coil spring 46 as a first urging means is attached to the swing arm 29. The coil spring 46 urges the pickup roller 24 toward the upper surface 32 b of the flapper 32 by repelling the swing arm 29 downward. Although illustration is omitted, a separation pad is affixed to a predetermined position on the upper surface 32 b of the flapper 32. This separation pad is for reliably separating and feeding the last two sheets out of the sheets stacked on the flapper 32.

  The upper surface 32b of the flapper 32 is substantially horizontal at the paper retraction position that swings upward as shown in FIG. 4, and the surface of the original paper on the flapper 32 is separated from the separation roller 25 and the separation pad 52 of the paper separation mechanism 50. In this state, the roller surface 24a of the pickup roller 24 is pressed against the upper surface of the uppermost document sheet. On the other hand, at the standby position where the flapper 32 shown in FIG. 3 is swung downward, the upper surface 32b of the flapper 32 is inclined downward toward the downstream side of the sheet conveying path 22, and the tip of the flapper 32 (swing) (Moving end) is arranged to face the wall surface portion 55 of the inner guide 53 provided in front of the sheet separating mechanism 50. The wall surface portion 55 faces the upstream side of the sheet conveyance path 22 and is formed in an inclined flat shape slightly inclined toward the downstream side from the lower end toward the upper end or a substantially vertical flat shape, and the flapper 32. Is in the standby position, the leading edge of the paper stacked thereon is brought into contact with and locked by the wall surface portion 55.

  The paper feed mechanism 30 includes a push-up mechanism 40 that pushes up the flapper 32 and swings it to the paper feed position. The push-up mechanism 40 abuts on a friction roller 41 that rotates by driving of a paper feed motor (not shown) and a roller surface (friction surface) 41a of the friction roller 41, and a rotating shaft portion 42a by frictional force with the roller surface 41a. And a push-up member 43 that is pivotably attached to an attachment portion 42b in the vicinity of the pivot end of the cam member 42 and moves up and down. The friction roller 41 is rotated by a drive transmission mechanism (not shown) in conjunction with the pickup roller 24 that is also rotated by the drive of the paper feed motor. The push-up member 43 is a rod-like member, and its longitudinal direction is arranged in the vertical direction. The upper end portion 43a abuts on the lower surface 32c near the swinging end of the flapper 32 and pushes it up. The roughness of the roller surface 41a is adjusted so that the frictional force between the roller surface 41a of the friction roller 41 and the cam member 42 becomes a predetermined frictional force. As a result, the pick-up roller is always at the same pressure as the upper surface of the uppermost sheet of the stacked original sheets regardless of the thickness dimension (the number of stacked sheets) of the original sheets stacked on the flapper 32 at the above-described sheet feeding position. The 24 roller surfaces 24a can be maintained in pressure contact with each other.

  Next, the sheet separating mechanism 50 provided on the downstream side of the sheet feeding mechanism 30 is separated by being pressed against the separation roller 25 that is rotatably installed on the upper portion of the sheet conveying path 22 and the roller surface 25 b of the separating roller 25. And a pad piece 51 to which a pad 52 is attached. The pad piece 51 is installed in an opening 53 a provided in the inner guide 53 on the lower surface side of the paper conveyance path 22 facing the separating roller 25. The pad piece 51 is repelled toward the roller surface 25b of the separate roller 25 by a coil spring 54 attached to the lower surface thereof. As the separation roller 25, for example, a roller whose roller surface 25b is made of silicon can be used. The separation pad 52 is a sheet made of, for example, a urethane resin material, whose friction coefficient with respect to the original paper is lower than the friction coefficient with respect to the original paper of the roller surface 25b of the separating roller 25 and higher than the friction coefficient between the original papers. A shaped member can be used.

  Here, the original paper feeding operation in the paper feeding mechanism 30 configured as described above will be described. First, in a state where the flapper 32 is at the standby position shown in FIG. 3, a bundle of document sheets is placed on the document tray 21 and set. Then, a part of the original paper is placed on the flapper 32, but both the original tray 21 and the flapper 32 are inclined downward toward the downstream side of the paper conveyance path 22. The original paper on the flapper 32 is set in a state where its leading end is abutted against and locked by the wall surface 55 of the inner guide 53 by its own weight. When the original paper is set on the original tray 21, the pickup roller 24 and the friction roller 41 are rotated by driving the paper feed motor by inputting an original reading instruction on the operation panel 7 shown in FIG. Begin to. When the friction roller 41 rotates in the clockwise direction in FIG. 3, the cam member 42 rotates in the counterclockwise direction in FIG. 3 with the rotation shaft portion 42 a as a fulcrum, and the push-up member 43 attached to the cam member 42 is moved. Accordingly, the flapper 32 is pushed up and swings upward, and is lifted up to the retraction position shown in FIG. At that position, the roller surface 24 a of the pickup roller 24 abuts on the upper surface of the uppermost document sheet on the flapper 32. At this time, the roller surface 24a of the pickup roller 24 is brought into pressure contact with the upper surface of the original paper by the elastic force of the coil spring 46, so that the stacked original paper is sequentially fed by the paper pickup path 22 by the rotating pickup roller 24. It is carried over to.

  Here, as described above, the frictional force between the roller surface 41a of the frictional roller 41 of the push-up mechanism 40 and the cam member 42 is adjusted to a predetermined frictional force. A slip occurs between the roller surface 41 a of the friction roller 41 and the cam member 42 in a state where the pickup roller 24 is pressed against the upper surface of the roller. When the original paper is fed and the number of original papers stacked on the flapper 32 decreases, the cam member 42 rotates and the flapper 32 is pushed up by the push-up member 43, and the uppermost original document. The state where the upper surface of the sheet is always pressed against the roller surface 24a of the pickup roller 24 with the same pressure is maintained. When the original paper on the flapper 32 is further fed and the last two sheets remain, when the upper original paper is fed by the pickup roller 24, the lower original paper is separated from the separation pad. Since it is restrained on the flapper 32 by the frictional force, the last two original sheets can be reliably separated and fed.

  In this way, when all the original sheets placed on the flapper 32 are retracted and disappear, the roller surface 24a of the pickup roller 24 comes into direct contact with the upper surface 32b of the flapper 32, so that the load applied to the pickup roller 24 is increased. Change. By detecting this change in load by a mechanism such as a sensor (not shown), the gear of the drive transmission mechanism that transmits the rotation of the paper feed motor to the friction roller 41 is switched, and the rotation of the friction roller 41 is reversed. As a result, the cam member 42 rotates clockwise in FIG. 4 and the push-up member 43 moves downward, and the flapper 32 swings downward by its own weight and returns to the standby position.

  On the other hand, the original paper fed by the pickup roller 24 at the paper feed position of the flapper 32 is sent to the separation roller 25 of the paper separation mechanism 50 and the pressure contact portion 57 of the separation pad 52 located on substantially the same horizontal plane. . Hereinafter, the operation of the sheet separating mechanism 50 will be described. When the original paper on the flapper 32 is retracted by the pickup roller 24 and sent to the pressure contact portion 57, the following original paper is overlapped on the lower side by following the previous original paper due to the frictional force or static electricity of the original paper. It may be sent in the state. At this time, the upper original paper contacts the roller surface 25 b of the separation roller 25 and the lower original paper contacts the separation pad 52 at the press contact portion 57. Then, the upper document sheet is sent to the downstream side of the sheet conveyance path 22 by the rotation of the separation roller 25, but the lower document sheet is separated by the separation pad 52 having a friction coefficient larger than the friction coefficient between the document sheets. It is in a state of being restrained by the pressure contact portion 57 against the frictional force and static electricity of the paper. As a result, the upper document sheet first passes through the press contact portion 57 and is sent to the downstream sheet conveyance path 22. When the upper document sheet passes through the pressure contact portion 57, the lower document sheet that has been stopped until then comes into contact with the roller surface 25b of the separation roller 25. Then, since the separation roller 25 has a larger coefficient of friction with respect to the original paper than the separation pad 52, the original paper is sent to the downstream paper conveyance path 22 according to the rotation of the separation roller 25 without being stopped by the separation pad 52.

  As described above, according to the paper feeding mechanism 30 of the present invention, the flapper 32 is mounted so as to be swingable in the vertical direction with one end as a fulcrum, and at the paper feeding position where the flapper 32 swings upward. At the standby position where the pickup roller 24 is pressed against the paper loaded thereon and the flapper 32 swings downward, the front surface of the paper placed thereon is a wall surface portion 55 provided in the paper conveyance path 22. Since the flapper 32 is positioned at the paper feeding position when the paper feeding mechanism 30 is operated, the paper can be reliably fed while the paper feeding mechanism 30 is stopped. The flapper 32 is positioned at the standby position, so that it is possible to reliably prevent the paper on the paper stacking unit 31 from entering the paper transport path 22. Accordingly, the paper feeding mechanism 30 that can prevent the paper feeding failure and the failure of the paper feeding device with a simple configuration and can reliably feed the paper into the paper transport path 22 is obtained.

  Further, since the paper feeding mechanism 30 includes a coil spring 46 that is a first urging unit that urges the pickup roller 24 toward the flapper 32, the paper feeding mechanism 30 is placed on the flapper 32 with a simple configuration. The pickup roller 24 can be pressed against the upper surface of the sheet so that the sheet can be fed more reliably. Further, the friction roller 41 that rotates in conjunction with the rotation of the pickup roller 24, the cam member 42 that contacts the roller surface 41a of the friction roller 41 and rotates by the frictional force with the friction roller 41, and the cam member 42 Since the push-up mechanism 40 including the push-up member 43 that pushes up the flapper 32 attached to the paper is provided, the paper feed mechanism 30 that rotates the pickup roller 24 can be pushed up by pushing up the flapper 32 with a simple configuration. Arranged at the loading position, the paper can be reliably fed. Further, by adjusting the elastic force of the coil spring 46 and the frictional force between the friction roller 41 and the cam member 42, the pressure contact force between the pickup roller 24 and the paper even if the number of papers placed on the flapper 32 changes. Can always be constant, so that the paper can be fed more reliably.

  In the paper feeding mechanism 30 described above, when the flapper 32 is at the standby position shown in FIG. 3, the pickup roller 24 is disposed above and spaced from the upper surface 32 b of the flapper 32. In addition to this, when the push-up member 43 is lowered, the pickup roller 24 is urged downward by the elastic force of the coil spring 46 so that the pickup roller 24 pushes down the flapper 32 to the standby position. Also good. In this case, when the flapper 32 is in the standby position, the pickup roller 24 is in elastic contact with the upper surface 32b of the flapper 32. Therefore, when setting the original paper on the flapper 32, the upper surface 32b of the flapper 32 The original paper is placed between the pickup roller 24 and the roller surface 24a.

[Second Embodiment]
Next, an image forming apparatus provided with a sheet feeding mechanism of a sheet feeding device according to a second embodiment of the present invention will be described. In the image forming apparatus according to the present embodiment, the same or corresponding parts as those in the image forming apparatus according to the first embodiment are denoted by the same or corresponding reference numerals, and detailed description thereof is omitted. Further, matters other than those described below and parts other than those shown in the drawings are the same as those in the first embodiment. FIG. 5 is a diagram illustrating a configuration of a sheet feeding mechanism 30-2 included in the image forming apparatus according to the present embodiment. The paper feeding mechanism 30-2 of the present embodiment is different from the paper feeding mechanism 30 of the first embodiment in that the upper end portion 43a of the push-up member 43 is replaced with the coil spring 46 that is the first urging means. And a coil spring 47 which is a second urging means interposed between the lower surface 32c of the flapper 32. The coil spring 47 repels and biases the flapper 32 pushed up by the push-up member 43 toward the pickup roller 24, so that the upper surface of the document sheet placed on the flapper 32 is placed on the roller surface 24 a of the pickup roller 24. It is pressed against. Providing the coil spring 47 also makes it possible for the pickup roller 24 to carry in the paper more reliably. In this case, the pickup roller 24 is attached to a non-oscillating support arm 29-2 so as not to move up and down.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims, the specification, and the drawings. Is possible. It should be noted that any shape, structure, and material not directly described in the specification and drawings are within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, the specific configuration of the push-up mechanism 40 included in the paper feeding mechanism 30 (30-2) is not limited to that shown in the above embodiment, and the flapper 32 can be pushed up to the paper feeding position. If so, other configurations are possible. Further, the first urging means or the second urging means of the present invention may be other types of urging means other than the coil springs 46 and 47. For example, a leaf spring or a rubber member may be used. It is. In each of the above-described embodiments, the case where the flapper 32 is a member different from the document tray 21 has been described. However, the document tray 21 itself can be moved to the main tray 21 by swinging the document tray 21 with one end thereof as a fulcrum. It can also be configured for use as an inventive flapper.

  In the above embodiment, the automatic paper feeder 20 for feeding original paper has been described as an example. However, as the paper feeder according to the present invention, recording paper supplied from a paper feed cassette or a manual feed tray can be used. It may be a sheet feeding device to be fed, or a sheet feeding device having another configuration.

1 is a perspective view illustrating an overall configuration of an image forming apparatus including a sheet feeding device according to a first embodiment of the present invention. 2 is a side cross-sectional view illustrating configurations of an image reading device and an automatic paper feeder. FIG. FIG. 4 is a partially enlarged view showing detailed configurations of a paper feeding mechanism and a paper separating mechanism, and showing a state where a flapper is in a standby position. FIG. 6 is a partially enlarged view showing a detailed configuration of a paper feeding mechanism and a paper separating mechanism, and showing a state where a flapper is in a paper feeding position. It is a figure which shows the structure of the paper feeding mechanism of the paper feeder which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Recording part 3 Reading part 4 Recording apparatus 5 Paper feed cassette 6 Recording paper discharge tray 7 Operation panel 8 Document pressing cover 10 Image reading apparatus 11 Reading unit 12 Light source 13 Reflecting mirror 14 Condensing lens 16 Platen glass 17 Carriage 20 Automatic paper feeder (ADF device)
21 Document tray 22 Paper transport path 23 Paper discharge tray 24 Pickup roller 24a Roller surface 25 Separate roller 25a Rotating shaft 25b Roller surface 26 Transport roller 27 Paper discharge roller 28 CIS reading unit 29 Swing arm 30 Paper feed mechanism 31 Paper placement Portion 32 Flapper 32a Oscillating shaft 32b Upper surface 32c Lower surface 40 Push-up mechanism 41 Friction roller 41a Roller surface 42 Cam member 42a Rotating shaft portion 43 Push-up member 43a Upper end portion 46 Coil spring (first biasing means)
47 Coil spring (second biasing means)
50 Paper Separation Mechanism 51 Pad Piece 52 Separation Pad 53 Inner Guide 53a Opening 54 Coil Spring 55 Wall Surface 57 Pressure Contact

Claims (5)

A sheet feeding portion of a sheet feeding device provided with a sheet placing portion for placing a sheet provided at the entrance of the sheet conveying path and a pickup roller for feeding the sheet placed on the sheet placing section into the sheet conveying path. In
The sheet placing portion includes a flapper attached to one end as a fulcrum so as to be swingable in the vertical direction,
At the paper feeding position where the flapper is swung upward, the pickup roller is pressed against the upper surface of the loaded paper, and at the standby position where the flapper is swung downward, the leading edge of the loaded paper A sheet feeding mechanism of a sheet feeding device, wherein the sheet feeding mechanism is configured to abut against and engage with a wall surface provided in the sheet conveying path. In the paper feeding mechanism of the paper feeding device according to claim 1,
A sheet feeding device comprising: a first urging unit that urges the pickup roller toward the flapper; or a second urging unit that urges the flapper toward the pickup roller. Paper feed mechanism. In the paper feeding mechanism of the paper feeding device according to claim 2,
A push-up mechanism that pushes up the flapper and swings it to the paper feed position;
The paper feeding mechanism of the paper feeding device, wherein the second urging means is provided between the push-up mechanism and the flapper. In the paper feeding mechanism of the paper feeding device according to claim 3,
The push-up mechanism is attached to a friction roller that rotates in conjunction with the rotation of the pickup roller, a cam member that abuts on the roller surface of the friction roller and rotates by a frictional force with the friction roller, and the cam member. And a push-up member that pushes up the flapper directly or via the second urging means. In the paper feeding mechanism of the paper feeding device according to any one of claims 2 to 4,
The paper feeding mechanism of the paper feeding device, wherein the first urging means or the second urging means is a coil spring that repels the pickup roller or the flapper.

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