JP2006008337A - Paper feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeder capable of excellently feeding paper sheets by preventing both sides of a part pressed by a roller from being jumped to rub an upper member or form stripes when paper sheets are fed from a paper feed tray by the paper feed roller. <P>SOLUTION: In the paper feeder which is attached to a paper feed unit of an image forming device to feed paper sheets one by one toward a recording unit, a guide plate member 20 is arranged to cover an upper portion of a paper feed tray, an opening to locate a paper feed roller 4 is opened in the guide plate member 20, and rollers 24, ... are arranged on both sides and on a rear part to guide even a jumped paper sheet, and to consistently perform the paper feed operation from a paper feed tray 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  According to the present invention, in an image forming apparatus such as a copying machine, a narrow paper feed roller is arranged to feed paper from a paper feed tray, and the paper is wrinkled on both sides of the paper feed roller. In order to prevent this, the present invention relates to a sheet feeding device provided with sheet feeding assist means.

In an image forming apparatus such as a copying machine that creates recording paper using an electrophotographic system, the apparatus main body is used to feed a sheet for transferring a toner image to an image forming unit provided with a photosensitive drum. The paper feed unit is provided with a paper feed tray. Then, paper is taken out from the paper feed tray one by one by a paper feed member such as a paper feed roller and sent out toward the image recording unit, and the toner image formed on the photosensitive drum is transferred to the paper. The paper carrying the toner image is prepared as a recording paper by applying a fixing action through a fixing device, and the recording paper is discharged toward a discharge tray. In the paper feeding unit, in addition to the paper separating device in which the separation pad and the paper feeding roller are combined, the paper feeding unit separates and feeds the paper one by one to the recording unit by the joint action of the paper separation claw and the paper feeding roller. (For example, see Document 1).
Japanese Utility Model Publication No. 5-89345

  However, in the case of the paper separating means disclosed in the above-mentioned document, the leading end is locked to the separation claw, and a feeding action by the paper feed roller is applied to the central portion of the paper, so that the paper is largely curved. When the action is applied and the leading edge of the paper comes off the nail, a reaction that largely jumps upward occurs. For this purpose, there is provided a means for suppressing the phenomenon of the paper jumping up, and by arranging an elastic plate above the paper feeding unit in order to project the paper in the paper feeding direction to suppress the paper jumping up. Although it is provided, it is presumed that the effect can be effectively applied when the separation claw method is used. In addition, in a sheet feeding device that combines a sheet feeding roller and a separation pad, if the sheet is separated between the sheet feeding roller and the retard pad and a means for preventing double feeding is operated, the sheet feeding roller The pressing force acting on the paper acts as a different value between the central portion of the paper to be pressed and both side portions where the paper feed roller is not in contact. For this reason, there arises a problem that a long streak is formed in the conveyance direction on the both sides of the portion pressed by the roller or the portion that jumps up with respect to the fed paper. In particular, when a conveyance device is set in the vicinity of the downstream portion of the paper separation device and the direction in which the paper is fed upward is configured, streaks are formed on the fed paper. There remains a problem that undesired phenomena are likely to occur.

  The present invention is intended to solve the problem that streaks are formed on the sheet fed by the sheet feeding roller of the sheet feeding device, and suppresses the jumping of the sheet on both sides of the sheet feeding roller in the sheet feeding unit. Therefore, it is an object of the present invention to provide means for preventing the paper from jumping up by providing a guide member.

The present invention relates to a sheet feeding device configured by arranging a sheet feeding roller for feeding a sheet in a sheet feeding unit from a sheet feeding tray mounted on an image forming apparatus.
According to the first aspect of the present invention, a guide plate member is disposed above the position where the paper is fed out from the paper feed tray, and both sides in the width direction of the paper fed from the paper feed tray by the paper feed roller are arranged on the both sides. The guide plate member is slid on the lower surface of the guide plate member to be guided.

  According to a second aspect of the present invention, the guide plate member disposed at the upper part of the paper feed tray has an opening corresponding to the paper feed roller positioned at the front end of the paper feed side, and a part on the paper feed tray side. A plurality of openings for positioning the protruding roller member is provided, and the sheet is fed while guiding the sheet from the opening provided in the guide plate member to the sheet feeding tray.

  According to a third aspect of the present invention, the guide plate member is attached to the upper part of the main body of the paper feed tray so as to be opened and closed, and can be attached to the paper feed unit integrally with the paper feed tray. It is characterized by.

  According to a fourth aspect of the present invention, the guide plate member is fixedly disposed so as to cover the paper feed tray on the paper feed unit of the apparatus main body on which the paper feed tray is mounted, and the paper feed tray is attached to the paper feed unit. Thus, the guide plate member can suppress the jumping of the paper fed from the paper feed tray.

  As described above, by arranging the guide plate member at the top of the paper feed tray, when the paper is fed from the paper feed tray by the paper feed roller, both sides of the portion pressed by the roller jump up, and the upper member is It can prevent rubbing. Further, by suppressing the jumping of the sheet by the guide plate member, it is possible to prevent the streaks from being formed in the non-pressed portions on both sides of the sheet when pressed by the sheet feeding roller. In addition, by making it possible to feed paper from the paper feed tray in a stable state, it is possible to suppress the occurrence of a jam or the like in the paper feed unit or the paper transport path, and the paper remains faulty. Can be prevented.

  According to the present invention, a paper feed roller that feeds paper is arranged for a paper feed tray that is mounted on a paper feed unit of an image forming apparatus. The present invention relates to a sheet feeding device configured by combining guide plate members as means. In the embodiments of the paper feeding device described below, any conventionally known tray can be used as a paper feeding tray for accumulating and storing paper. That is, a tray of a type in which a bottom plate on which a paper is placed is provided so as to be movable up and down as a whole inside a frame of a tray having a box shape with an open upper surface, or the supply of the bottom plate. It is possible to apply a guide plate member described below in combination with the upper part of the paper feed tray to any of the types of trays in which the paper side leading end portion is greatly swung.

  An embodiment of the paper feeding device of the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 explains the relationship between a paper feed tray 3 mounted on the paper feed unit of the image forming apparatus and a roller positioned in the paper feed unit from the paper feed tray 3. In FIG. 1, a guide plate member 20 that slides on both sides of the paper fed by the paper feed roller 4 is disposed above the portion that feeds the paper from the paper feed tray 3. It is possible to suppress and prevent the both side portions of the paper from jumping greatly. In the separating portion provided with the paper feed roller 4 facing the retard pad 36, streaks are formed on the paper at the boundary between the portion pressed by the paper feed roller 4 and the free portions on both sides thereof. Thus, the sheet to be fed can be sent out toward the sheet conveyance path in a stable state so that the sheet conveyance operation can be performed satisfactorily.

  In the illustrated example, the bottom plate 30 on which the paper is placed inside the paper feed tray 3 is provided with a spring 31 between the bottom plate of the frame 3a and the bottom plate is raised as the amount of paper decreases. The push-up action can be performed. The bottom plate 30 is moved up and down to press the paper against the paper feed roller 3 with a certain pressing force during paper feeding, and the paper is fed with a predetermined frictional force between the surface of the paper feed roller 3 and the paper. The feeding operation is performed in the same manner as in the case of a paper feeding device equipped with a conventionally known general paper feeding tray. In the paper feed tray 3 described in the embodiment of the present invention, a retard pad 36 is provided integrally with the frame 3a on the paper feed side from the frame 3a of the tray. On the other hand, the paper feed roller 4 provided in the paper feed unit is positioned.

  On the other hand, the retard pad is integrated with the tray frame so that the retard pad is disposed in the main body frame on the paper feed side from the tray 3 instead of being incorporated in the paper feed tray. Of course, it is also possible to construct a judgment device. The retard pad 36 is configured by attaching a friction pad on a pad holder 35, and a direction in which the pad 36 is pressed against the paper feed roller 4 by a spring 37 provided between the retard pad 36 and the frame of the tray. Is energized. In the paper separation device, the paper separation roller 36 is pressed with a predetermined pressure against the paper feed roller 4 supported and driven by the drive shaft 4a so that the paper separation operation can be performed satisfactorily. Yes.

  A paper feed roller 4 is supported on the upper part of the paper feed tray 3 so as to correspond to a paper feed portion from the paper feed tray 3, and is driven by a driving means (not shown) during paper feed to be arranged in the paper transport path. The sheet is provided so as to be fed a predetermined distance until the position of the first conveying roller device is reached. As shown in FIG. 2, the paper feed roller 4 is a roller member fixedly attached to a drive shaft 4a. The roller 4 is positioned so as to correspond to the opening 22 provided in the guide plate member 20.

  The guide plate member 20 is disposed so as to cover the upper opening of the paper feed tray 3 to be mounted in the paper feed unit of the image forming apparatus. The guide plate member 20 shown in FIGS. When the tray 3 is inserted into the paper feeding unit, the tray 3 is provided so as to be fixedly disposed on the apparatus main body so as to be positioned below the guide plate member 20. In this embodiment, the leading end of the guide plate member 20 on the side of the paper conveyance path is provided with a curved surface portion 21 so as to warp in accordance with the curved shape of the paper conveyance path, and the curved surface portion 21 is cut out. The paper feed roller 4 is positioned in the provided opening 22. The guide plate member 20 is provided with a plurality of guide rollers 24, 24a... For guiding the paper fed by the paper feed roller, and the guide roller 24. Each of the openings 23... Provided in 20 is provided so as to allow free rotation using a shaft support means (not shown).

  Of the plurality of guide rollers 24... Provided on the guide plate member 20, the guide rollers arranged on both sides of the paper feed roller are on both sides of the paper feed roller 4 against the portion where the paper is pressed. Should be positioned as much as possible. That is, when the paper is fed by the paper feed roller 4, when the paper is pushed by the retard pad and the separating action is performed, both sides of the paper come to warp, and the paper jumps up. The part is slid on the guide roller to guide the sheet to be fed out. In addition to the guide rollers 24 on both sides of the paper feed roller, a guide roller 24a is also arranged at a position farther rearward than the paper feed roller 4, and the guide roller 24a is a sheet to be fed out. When a phenomenon occurs in which the rear end side of the paper jumps up, the roller 24a guides the rear end side of the paper that has jumped up.

  In the example described with reference to FIGS. 1 and 2, the guide plate member 20 and the guide rollers 24 and 24a are arranged in a fixed state above the portion of the apparatus main body where the paper feed tray 3 is mounted. A case has been described in which the guide plate member guides the raised or warped part of the fed paper. On the other hand, in the example shown in FIGS. 3 and 4, the guide plate member 25 is not attached to the paper feed unit of the apparatus main body, but covers the upper surface of the paper feed tray 3. It is provided integrally with the paper feed tray 3. The guide plate member 25 provided integrally with the paper feed tray is provided on the upper side of the tray body via an arbitrary support means. Actually, one end of the guide plate member 25 is supported by a hinge means with respect to the paper feed tray, and when the paper is replenished, the guide plate member is swung through the hinge so as to be opened widely. You can do that.

  In the illustrated embodiment, a guide plate member is provided in the paper feed unit so as to cover the upper part of the paper feed tray mounted in the paper feed unit, or the top of the paper feed tray is covered. In this state, an example in which a guide plate member is provided integrally is described. Further, since the guide plate member is provided with a guide roller for guiding the jumping portion of the paper at both side portions of the paper feed roller, when the paper is fed by the paper feed roller, the other part of the paper Even when a reaction occurs in such a manner that the paper is warped up or the separated part is bounced up, the bottom part of the guide plate member and the guide roller can be used to guide the paper in a stable state by sliding the raised part. .

  As an image forming apparatus for producing recording paper using the paper feeding device configured as described above, it is possible to target all devices that conventionally use cut paper. For example, in addition to a digital image forming apparatus, an apparatus that combines the functions of a FAX and a copying machine, or a general recording apparatus, which forms a toner image using an electrophotographic method and records it on paper It can be applied to a device that creates a copy. In the embodiment of the image forming apparatus described below, a recording unit 10 for recording using an electrophotographic method is provided inside the apparatus main body, and an image reading device and an ADF are provided above the apparatus main body 1. The image forming apparatus can be arbitrarily combined.

  An image forming apparatus 1 as shown in FIG. 5 can be used as an image forming apparatus capable of creating a recording sheet using the paper feeding apparatus having the above-described configuration. The paper feed unit provided in the lower part of the main body of the image forming apparatus 1 is equipped with a paper feed cassette 3 so that the paper is fed toward the paper transport path 5 by the paper feed roller 4. Further, the paper is further transported by the transport roller device 5b arranged in the paper transport path 5, and a loop is formed at the front end portion of the paper in a state where the front end portion of the paper is abutted against the nip portion of the registration roller device 5a. Match. After that, the registration roller device 5a is driven so as to match the timing of the toner image formed on the photosensitive drum 12 of the recording unit 7, and the sheet is passed through the image transfer position from the photosensitive drum 12. Like that.

  The recording unit 7 is configured by combining the photosensitive unit 10 and the developing unit 17 as in the case of an apparatus using a general electrophotographic system. In the photosensitive unit 10, a charging member 15, a writing member 16, and a transfer roller 13 are sequentially arranged around the photosensitive drum 12 along the rotation direction. In addition, a developing unit 17 with a developing roller 18 exposed is disposed downstream of the writing member 13 with respect to the rotation direction of the photosensitive drum 11. The toner supplied from the toner container is supplied from the supply roller 19. Then, by pressing the blade, an electrostatic latent image is formed on the surface of the developing roller 18 so as to be a thin layer of uniform thickness, and the toner is formed on the photosensitive drum at a position in contact with the photosensitive drum 12. The image is transferred toward the image and visualized as a toner image.

  As described above, the toner image formed on the photosensitive drum 12 is applied with a voltage having a predetermined value from the transfer roller 13 when the sheet is conveyed while being nipped between the transfer roller 13 and the sheet. Is transferred to the paper. The sheet on which the toner image has been transferred is fixed through the fixing device 8 and discharged to the discharge tray 9a by the discharge roller device 9. Further, even after the toner image is transferred from the photosensitive drum 12 to the paper, the toner remaining on the surface of the photosensitive drum is removed by the memory removing means 14 to form the next toner image. Make it correspond.

  In the above-described embodiment, a manual paper feed path is connected to the paper transport path 5 from the paper feed tray to the recording unit at a predetermined position. A manual feed tray 6 and a paper feed roller 6a for manual feed are arranged in the section. The manual tray 6 can be used when recording paper is created using irregular-size paper that cannot be fed from the paper feed tray or a small number of different paper sizes. The use of a combination of paper feeding means other than trays is not particularly relevant to the present invention.

  In the embodiment of the present invention, the structure of the photosensitive unit including the photosensitive drum 12 arranged in the recording unit 10, the structure of the writing device and the memory removing unit, etc. are particularly those of the mechanism disclosed in the embodiment. It is not limited to. Further, instead of configuring the photosensitive drum and the developing device arranged in the recording unit as separate units, a mechanism having another conventionally known configuration may be used. Further, as described above, the image forming apparatus using the sheet feeding tray is not limited to an apparatus configured as a copying machine alone, but may be an arbitrary apparatus such as a multifunction peripheral with a fax machine or a printer connected to a personal computer. It can be used as a paper feeding unit for an apparatus called an image forming apparatus.

It is a side view of a paper feeder. It is a perspective view which shows the structure of a guide plate member. It is a side view of another example of a paper feeder. FIG. 4 is a perspective view of the sheet feeding device in FIG. 3. It is explanatory drawing of the image forming apparatus which can equip the paper feeder of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Image forming apparatus, 2 Paper feed part, 3 Paper feed cassette, 4 Paper feed roller, 5 Paper conveyance path, 5a / 5b Roller apparatus, 7 Recording part, 8 Fixing apparatus, 9 Ejection roller apparatus, 9a Ejection tray, 10 Recording 11, 11 frame, 12 photosensitive drum, 13 transfer roller, 14 memory removing means, 15 charging roller, 16 writing device, 17 developing unit, 18 developing roller, 19 supply roller, 20 guide plate member, 21 upper warped portion, 22.23 Opening, 24 Pressing roller, 30 Bottom plate, 35 Pad holder, 36 Pad, 37 Spring.

Claims (4)

In a paper feed device configured by arranging a paper feed roller for feeding paper to a paper feed unit from a paper feed tray mounted on an image forming apparatus,
A guide plate member is disposed above the position for feeding paper from the paper feed tray,
A sheet feeding device that guides the sheet fed from the sheet feeding tray by the sheet feeding roller by sliding both sides in the width direction on the lower surface of the guide plate member. The guide plate member disposed at the upper part of the paper feed tray has an opening corresponding to a paper feed roller located at the front end of the paper feed side,
A plurality of openings for positioning a roller member that partially protrudes toward the paper feed tray side are provided, and paper is fed while guiding the paper from the openings provided in the guide plate member to the paper feed tray side. The paper feeding device according to claim 1, wherein paper feeding is performed.   The guide plate member is attached to the upper part of the main body of the paper feed tray so as to be openable and closable, and can be attached to the paper feed unit integrally with the paper feed tray. Or the sheet feeding device described in 2. The guide plate member is fixedly disposed so as to cover the paper feed tray in the paper feed portion of the apparatus main body to which the paper feed tray is mounted,
3. The sheet feeding device according to claim 1, wherein the guide plate member is configured to suppress jumping of a sheet fed from the sheet feeding tray by mounting the sheet feeding tray on the sheet feeding unit. Paper device.

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