JP2011230893A - Paper feeding mechanism and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding mechanism performing smooth and certain paper feeding, and allowing suppression of generation of vibration sound caused by vibration accompanying paper sheet separation operation by a paper feeding roller and a separation member.SOLUTION: The paper feeding mechanism 12A includes the separation member 122, and the paper feeding roller 121 abutted thereon, and supplies, while separating stacked paper sheets S between two sides, the paper sheets S by the paper feeding roller. The paper feeding mechanism includes: a paper sheet guide plate 126 held by a paper feeding roller support body 124 supporting the paper feeding roller, extending in a paper sheet feeding direction by the paper feeding roller 121; and a connection mechanism SA connecting the guide plate 126 to the paper feeding roller support body 124 in at least a part except a holding portion by the paper feeding roller support body 124. The connection mechanism SA is a connection mechanism movably connecting the paper sheet guide plate 126 to the paper feeding roller support body 124, and includes a cushion member Ks interposed between the paper feeding roller support body 124 and a portion 128 connected to the paper feeding roller support body 124 of the paper sheet guide plate 126.

Description

  The present invention includes a paper feed mechanism that supplies paper from stacked paper sheets or the like (hereinafter collectively referred to as “paper”), in particular, a paper roll member, and a paper feed roller that is in contact with the paper roll member, The present invention relates to a sheet feeding mechanism that feeds stacked sheets with the sheet feeding roller while rolling between the sheet feeding roller and the sheeting member.

  This type of paper feeding mechanism has been adopted in various fields. For example, in an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multi-function machine that combines two or more of these, it is loaded and stored in a paper supply cassette or the like This is used when paper is fed from a group of paper sheets.

With this type of paper feed mechanism, so-called stick-slip occurs along with the paper-rolling operation by the paper feed roller and the paper-rolling member, which causes fine vibrations that are transmitted to the paper-feed roller support and the like. May occur.

  In this regard, Japanese Patent Application Laid-Open No. 2003-155129 prevents vibration noise generated by stick-slip when a sheet stacked and accommodated on a bottom plate pushed up by a spring is picked up by a pickup roller (feed roller) and fed. As a method for this, it is described that a restricting means for absorbing and suppressing vibrations of the rotation shaft is provided for the rotation shaft of the pick allo roller.

JP 2003-155129 A

  The above-described vibration is applied to the paper feed mechanism that includes the webbing member and the paper feed roller that is in contact with the webbing member, and that feeds the stacked sheets with the paper feed roller between the paper feed roller and the webbing member. In addition to the problem of sound generation, the sheet feeding operation may be hindered due to sheet warpage or the like in the stacked sheet group.

  In order to solve this problem, the present inventors have attempted to provide a paper guide plate that is held by a paper feed roller support that supports the paper feed roller and extends in the paper transport direction by the paper feed roller.

  However, when such a paper guide plate is held on the paper feed roller support, vibration due to stick slip accompanying the paper sacking operation is transmitted not only to the paper feed roller support but also to the paper guide plate, so that a large vibration noise is generated as a whole. Will occur. This noise is difficult to suppress only by the vibration suppressing method described in JP-A-2003-155129.

  Therefore, the present invention includes a paper feeding mechanism that includes a webbing member and a paper feed roller facing the webbing member, and feeds the stacked sheets between the paper feed roller and the webbing member with the paper feed roller. However, even if the paper is slightly warped or deformed, such as a wave, smooth and reliable paper feeding can be performed regardless of this, and the paper feeding operation using the paper feeding roller and the paper-rolling member A first problem is to provide a paper feed mechanism that can suppress the generation of noise due to the accompanying vibration.

  Further, according to the present invention, an image can be formed on the sheet by supplying the sheet from the stacked sheet group by the sheet feeding mechanism and passing the sheet through an image forming path passing through the image forming unit. And a sheet feeding roller facing the sheeting member, and an image forming apparatus that is a sheet feeding mechanism that feeds stacked sheets between the sheet feeding roller and the sheeting member with the sheet feeding roller. Even when the paper is slightly warped or deformed, for example, when the paper is fed from the paper feeding mechanism, the paper feeding roller can be fed smoothly and surely. It is a second object to provide an image forming apparatus that can suppress the generation of noise due to vibration caused by the paper-sheeting operation by the paper-making member and can form an image with less noise while smoothly feeding the paper.

In order to solve the first problem, the present invention provides:
A paper feed mechanism that includes a webbing member and a paper feed roller in contact with the webbing member, and feeds the stacked sheets between the paper feed roller and the webbing member with the paper feed roller. A paper guide plate that is held by a paper feed roller support that supports the paper feed roller and extends in a paper transport direction by the paper feed roller; and at least one of the paper guide plates other than a holding portion by the paper feed roller support. A coupling mechanism that couples the paper guide plate to the paper feed roller support, and the coupling mechanism is a coupling mechanism that movably couples the paper guide plate to the paper feed roller support. There is provided a paper feed mechanism including a cushion member interposed between a portion connected to the paper feed roller support and the paper feed roller support.

  According to the paper transport mechanism of the present invention, since the paper guide plate extending in the paper transport direction by the paper feed roller is held by the paper feed roller support, the paper is slightly warped, deformed, etc. However, smooth and reliable paper feeding can be performed regardless of this.

  Further, there is provided a connection mechanism for connecting the paper guide plate to the paper supply roller support at least at a part other than the holding portion by the paper supply roller support, and the connection mechanism connects the paper guide plate to the paper supply roller. Since it is movably connected to the support, the paper guide plate does not move freely, and even if the paper guide plate is slightly warped or twisted, it can be moved within the movable range. Can escape and feed paper.

Further, since the coupling mechanism includes a cushion member interposed between the portion of the sheet guide plate coupled to the sheet feeding roller support and the sheet feeding roller support, The cushion member can absorb at least a part of the vibration caused by the paper-sheeting operation by the paper-making member, and noise generation due to the vibration can be suppressed.
Note that the coupling mechanism may allow the paper guide plate to move within a predetermined range so that the paper guide plate does not move relative to the paper feed roller support.

  The holding portion of the paper guide plate by the paper feed roller support is not particularly limited as long as the function required for the paper guide plate can be realized, but the paper guide plate can be smoothly moved without restricting the movement of the paper guide plate. As an example in which the sheet can be guided, the sheet guide plate is cantilevered by the sheet feed roller support at the upstream end in the sheet conveyance direction by the sheet feed roller and extends toward the sheet feed roller. Can do.

  The cushion member regulates an initial position (a position when the sheet guide plate is not yet used for sheet feeding) of a portion of the sheet guide plate connected to the sheet feeding roller support in the approaching / separating operation direction with respect to the sheet feeding roller support. It may be a thing.

In this case, there is a paper guide plate portion that is biased to approach the paper feed roller support by the elastic restoring force of the paper guide plate itself while the paper guide plate is held by the paper feed roller support. In some cases, the position of the sheet guide plate is regulated with respect to the sheet feed roller support by interposing a previously compressed cushion member between the portion and the sheet feed roller support. it can.

  In addition, the cushion member is connected to the portion of the paper guide plate that is connected to the paper feed roller support with an adhesive, and the paper guide plate is also connected to the paper feed roller support with an adhesive. The position may be regulated with respect to the paper feed roller support.

  The coupling mechanism can be provided, for example, between a support portion of the paper guide plate by the paper feed roller support and the paper feed roller.

  As a simple example, the coupling mechanism is loosely fitted in a hole formed in the paper feed roller support, and is screwed into a portion of the paper guide plate that is connected to the paper feed roller support through the hole. An example of the cushion member is a member interposed between the paper feed roller support and the paper guide plate portion.

  In order to solve the second problem, the present invention can form an image on a sheet by supplying the sheet from the stacked sheet group by the sheet feeding mechanism and passing the sheet through an image forming path passing through the image forming unit. There is also provided an image forming apparatus that is an image forming apparatus and that employs the paper feed mechanism according to the present invention as the paper feed mechanism.

  According to this image forming apparatus, since the paper feed mechanism according to the present invention is adopted as the paper feed mechanism, when the paper is fed from the paper feed mechanism, the paper is slightly warped, deformed, etc. Even in this case, smooth and reliable paper feeding can be performed regardless of this, and noise generation due to vibration caused by paper feeding operation by the paper feeding roller and the paper rolling member can be suppressed, and the paper can be fed smoothly. Images can be formed with less noise.

  As described above, according to the present invention, the sheet feeding member includes the sheet feeding member and the sheet feeding roller facing the sheet separating member, and the stacked sheets are rolled by the sheet feeding roller while being rolled between the sheet feeding roller and the sheet separating member. A paper feeding mechanism that can feed smoothly and surely even if the paper is slightly warped, deformed, etc. Thus, it is possible to provide a paper feed mechanism that can suppress the generation of noise caused by the vibration caused by the paper-sheeting operation.

  Further, according to the present invention, it is possible to form an image on the sheet by supplying the sheet from the overlapped sheet group by the sheet feeding mechanism and passing the sheet through the image forming path passing through the image forming unit. An image forming apparatus that includes a member and a sheet feeding roller facing the sheeting member, and that feeds stacked sheets between the sheet feeding roller and the sheeting member with the sheet feeding roller. Even when the paper is slightly warped or deformed, for example, when the paper is fed from the paper feeding mechanism, the paper can be fed smoothly and reliably. It is possible to provide an image forming apparatus that can suppress the generation of noise due to vibration caused by the paper-rolling operation by the roller and the paper-rolling member, and that can form an image with low noise while feeding the paper smoothly.

1 is a diagram schematically illustrating a configuration of an example of an image forming apparatus according to the present invention. It is a figure which shows the example of a paper feed mechanism which concerns on this invention. FIG. 3 is a diagram illustrating a positional relationship of each unit when the sheet feeding mechanism of FIG. 2 is viewed from above.

FIG. 1 shows a tandem type color punter which is an example of an image forming apparatus according to the present invention.
The image forming apparatus according to the present invention is not limited to a tandem type color printer, but can be applied to a so-called cycle type (for example, 4-cycle type) color image forming apparatus and monochrome image forming apparatus. The present invention can also be applied to a machine, a facsimile machine, a multi-function machine that combines two or more of these.

  A printer 10 illustrated in FIG. 1 includes an image forming unit 11, a paper supply unit 12 below the image forming unit, and an image forming path 13. The image forming unit 11 includes an intermediate transfer belt 111 that is rotationally driven by a belt driving unit (not shown) and is wound around a driving roller d1 and a counter roller d2, and can be rotated in the counterclockwise direction α in the figure. Along the belt running direction, a yellow image forming unit Y, a magenta image forming unit M, a cyan image forming unit C, and a black image forming unit K are arranged in this order.

  The image forming unit in charge of each color is formed on the photoconductor PC by electrophotography based on image information from an image reading device (not shown) or image information transmitted from an external computer or an external facsimile machine (not shown). An electrostatic latent image corresponding to the assigned color image is formed, and the latent image is developed with the assigned color toner to form a toner image, which is applied with a primary transfer bias from a power supply (not shown). Primary transfer can be performed on the belt 111 at tr.

  When forming an image using the image forming unit, a monochrome toner image can be formed using any one of the four image forming units, or a color image can be formed using two or more image forming units. It can also be formed. When two or more image forming units are used, the color toner images formed by these image forming units are primarily transferred to the belt 111 at the timing of being superimposed on the belt 111.

  The image forming unit 11 further includes a secondary transfer roller TR facing the belt on the downstream side of the black image forming unit K in the rotation direction of the intermediate transfer belt 111 and a fixing device 113 disposed above the secondary transfer roller TR.

  As described above, the toner image primarily transferred onto the belt 111 is conveyed along the image forming path 13 by the secondary transfer roller TR to which a secondary transfer bias is applied from a power supply (not shown). Secondary transfer is performed.

  A sheet on which an image is to be formed is supplied from a sheet supply unit 12 described below. The paper supplied from the paper supply unit 12 is abutted against the registration roller 131 located at the entrance of the image forming path 13 and is temporarily stopped. At a timing at which the image forming unit 13 can form an image at a predetermined position on the paper. It is sent to the image forming path 13 by the registration roller 131.

  The toner image secondarily transferred to the paper in this way is fixed under heat and pressure by the fixing device 113 and is discharged to the discharge tray T together with the paper.

The paper supply unit 12 will be further described.
In this example, the paper supply unit 12 includes a paper supply mechanism 12A provided on the printer main body side. The paper supply unit 120 is removably attached to a cassette receiving unit facing the paper supply mechanism 12A to supply paper. To do.

  The paper S previously loaded and accommodated in the paper feed cassette 120 is picked up by a pickup roller 123 that comes down from above by the action of a spring Sp (see FIG. 3), which will be described later, by contacting the paper S. Then, the paper is fed toward the paper feed roller 121. At this time, the sheet is guided by the sheet guide plate 126 held by the sheet feed roller support 124.

The paper feed roller 121 feeds paper sheets picked up by the pickup roller 123 and usually fed in a state where a plurality of sheets are overlapped one by one with the paper roller 122. The separating roller 122 is rotatably supported by a frame 122f on the printer main body side.
Here, a rolling roller that is rotationally driven in the opposite direction to the paper feed roller as the rolling member and has a surface layer formed of a friction member is employed. However, a plate-like board facing the paper feed roller may be used.

The sheet feeding mechanism 12A will be further described with reference to FIGS.
The paper feed roller 121 is supported by a shaft 121a on a paper feed roller support 124 formed by processing a plate. The shaft 121a is rotatably supported by the support body 124. When viewed from above, the sheet feeding roller support 124 has an opening 124h in a part thereof as shown in FIG. The paper feed roller 121 is arranged at a position where a part can be seen from here.

The paper feed roller shaft 121a extends to the outside of the support 124 and is rotatably supported by the frame F of the printer main body. The feed roller 121 is driven to rotate counterclockwise in FIG. 2 when the shaft 121a is driven by the drive motor M.
The whirling roller 122 is driven to rotate counterclockwise in FIG. 2 by the motor M through a transmission mechanism (not shown).

The pickup roller 123 is rotatably supported by the pickup roller support 125 on the upstream side of the roller 121 in the paper conveyance direction by the paper supply roller 121. The support 125 is supported by the paper feed roller support 124.
The pickup roller 123 is rotated in the same direction as the paper feed roller 121 by the transmission mechanism 130 in conjunction with the rotation of the paper feed roller 121.

  The paper guide plate 126 is disposed below the paper feed roller support 124, and a rear end portion 126e thereof is bent upward and is fixed to the paper feed roller support 124 with screws 124a. In this way, the paper guide plate 126 is held by the paper feed roller support 124 at the rear end 126e. Note that the paper guide plate 126 may be connected to the support 124 so as to be rotatable by a hinge.

  The paper guide plate 126 extends from the rear end portion toward the paper feed roller 121 and extends to a position slightly beyond the paper feed roller 121. An opening 126h is formed in the sheet guide plate 126 as shown in FIG. 3, and the pickup roller 123 and the sheet feeding roller 121 can contact the sheet S stacked and accommodated in the sheet feeding cassette 120 through the opening 126h. it can.

The paper guide plate 126 is connected to the paper supply roller support 124 between the rear end portion 126e and the paper supply roller 121 by a connection mechanism SA. The connection mechanism SA is a mechanism for movably connecting the paper guide plate 126 to the paper feed roller support 124 within a predetermined range.
The sheet guide plate 126 has a plate-like column 127 erected on the sheet guide plate 126, and the plate-like column 127 has a shelf 128 having a screw hole formed at the top thereof.

  The connecting mechanism SA includes a plate-like column 127 having a shelf 128, a head screw Sc having a head freely inserted through a hole 1241 formed in a portion of the paper feed roller support 124 facing the shelf 128, A cushion member Ks interposed between the paper roller support 124 and the shelf 128 in a slightly compressed state is included.

  The step screw Sc includes a large-diameter portion Su below the head and a small-diameter male screw portion Sd below the head, the head is located above the paper feed roller support 124, and the large-diameter portion Su is the paper feed roller. The male threaded portion Sd is screwed to the shelf 128 on the paper guide plate side. In this state, there is a gap between the shelf 128 and the paper feed roller support 124, but the cushion member Ks is interposed in a slightly compressed state. The cushion member Ks restricts the initial position of the shelf 128 in the approaching / separating direction with respect to the paper feed roller support 124, that is, the initial position when the paper feed mechanism 12A is not being fed.

  As shown in FIG. 3, a winding spring Sp is fitted to the end of the paper feed roller shaft 121a that protrudes outside the paper feed roller support 124. The spring Sp urges the paper feed roller support 124 downward about the shaft 121a to bring the pickup roller 123 into contact with the paper S of the paper feed cassette 120 mounted on the printer body. Referring to FIG. 2, it is biased downward in the α direction.

  However, as schematically shown in FIG. 3, when the paper feed cassette 120 is not yet mounted on the printer body, a lever L provided on the printer body side and biased by a spring (not shown) is fed. The paper roller support 124 is lifted upward about the shaft 121a. When the paper feed cassette 120 is mounted on the printer main body, the cassette 120 touches the lever L to release the support 124 from being lifted by the lever, and the pickup roller 123 comes into contact with the paper S by the spring Sp force.

  According to the paper feed mechanism 12A described above, since the paper guide plate 126 extending in the paper transport direction by the paper feed roller 121 is held by the paper feed roller support 124, the paper S is slightly warped, wavy, etc. Even if there is a deformation or the like, smooth and reliable paper feeding can be performed regardless of this.

  Further, a coupling mechanism SA for coupling the paper guide plate 126 to the paper feed roller support 124 is provided, and the coupling mechanism SA allows the paper guide plate 126 to move within a predetermined range with respect to the paper feed roller support 124. Since they are connected, the paper guide plate 126 does not move freely, and even if the paper guide plate 126 is slightly warped or twisted, it is allowed to escape within the movable range to feed paper. Yes.

  Further, since the coupling mechanism SA includes a cushion member Ks interposed between the shelf 128 coupled to the paper feed roller support 124 of the paper guide plate 126 and the paper feed roller support 124, The cushion member Ks absorbs at least a part of the vibration caused by the paper-rolling operation by the paper roller 121 and the paper-rolling roller 122, and noise generation due to the vibration can be suppressed.

  Since the paper guide plate 126 is held by the paper feed roller support 124 at the rear end portion 126e and extends toward the paper feed roller 121, the paper guide plate 126 can be smoothly guided without restricting the movement of the paper guide plate 126. Can be done.

  The present invention can smoothly and surely feed a sheet even if the sheet is slightly warped, deformed, etc., and is capable of sheet feeding operation by a sheet feeding roller and a separating member. The present invention can be used to provide a paper feed mechanism that can suppress the generation of noise due to the accompanying vibration and an image forming apparatus using the paper feed mechanism.

DESCRIPTION OF SYMBOLS 10 Printer 11 Image forming part 12 Paper supply part 13 Image forming path 131 Registration roller 113 Fixing device T Discharge tray 12A Paper feed mechanism 121 Paper feed roller 121a Paper feed roller shaft 122 Rolling roller 122f Rolling roller support frame 123 Pickup roller 124 Paper feed Roller support 1241 Step screw through hole 125 Pickup roller support 126 Paper guide plate 127 Plate column 128 Shelf portion 120 Paper feed cassette SA Connection mechanism Sp Spring L Lever Sc Step screw Su Large diameter portion Sd Male screw portion Ks Cushion member M Motor

Claims (6)

  A paper feed mechanism that includes a webbing member and a paper feed roller in contact with the webbing member, and feeds the stacked sheets between the paper feed roller and the webbing member with the paper feed roller. A paper guide plate that is held by a paper feed roller support that supports the paper feed roller and extends in a paper transport direction by the paper feed roller; and at least one of the paper guide plates other than a holding portion by the paper feed roller support. A coupling mechanism that couples the paper guide plate to the paper feed roller support, and the coupling mechanism is a coupling mechanism that movably couples the paper guide plate to the paper feed roller support. A paper feed mechanism comprising a cushion member interposed between a portion connected to the paper feed roller support and the paper feed roller support. The paper guide plate is cantilevered by the paper feed roller support at the upstream end in the paper transport direction by the paper feed roller, and extends toward the paper feed roller. The paper feed mechanism according to claim 1, wherein at least a part of a free portion other than the cantilever support portion of the guide plate is connected to the paper feed roller support.   The sheet feeding mechanism according to claim 1, wherein the cushion member regulates an initial position of a portion of the sheet guide plate connected to the sheet feeding roller support in an approaching / separating operation direction with respect to the sheet feeding roller support. .   The paper feed mechanism according to claim 1, 2 or 3, wherein the coupling mechanism is provided between a support portion of the paper guide plate by the paper feed roller support and the paper feed roller.   The coupling mechanism includes a stepped screw that is loosely fitted into a hole formed in the paper feed roller support, and is screwed into a portion of the paper guide plate that passes through the hole and is coupled to the paper feed roller support. 5. The sheet feeding mechanism according to claim 1, wherein the cushion member is interposed between the sheet feeding roller support and the sheet guide plate portion.   An image forming apparatus capable of forming an image on a sheet by supplying the sheet from the stacked group of sheets by a sheet feeding mechanism and passing the sheet through an image forming path passing through an image forming unit, and claims the sheet feeding mechanism. An image forming apparatus, wherein the paper feeding mechanism according to any one of 1 to 5 is employed.

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