JP2003192174A - Paper sheet carrier, and image forming device using the carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper sheet carrier capable of preventing any defective carriage even when manually-fed paper sheets are carried, and to provide an image forming device with the paper sheet carrier provided as a bypass paper feeder. <P>SOLUTION: A driven roller 92 has one shaft 92a extending longer than the width of the paper sheet in the carrying width direction orthogonal to the carrying direction of the paper sheet, and has a plurality of (for example, 6) roll bodies 92b fitted to the shaft 92a at predetermined intervals. A pressing unit 96a is provided at other positions than both ends of the shaft 92a. Bearings 97 of the pressing unit 96a are provided in the carrying width direction of the shaft 92a, respectively at the positions of 1/3 and 2/3 of the shaft length from the ends of the shaft 92a, and prevent any defective paper sheet carriage caused by the deflection in the paper sheet carrying direction. The nip pressure at a center part is increased, the nip pressure in the carrying width direction is equal, and any defective paper sheet carriage can be eliminated. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device such as a copying machine, a printer, a facsimile, and more particularly to a sheet conveying device capable of conveying a wide sheet. Further, the present invention relates to an image forming apparatus using the sheet conveying device.

[0002]

2. Description of the Related Art Conventionally, there is known an image forming apparatus capable of forming an image on a wide sheet of A1 or A0 size. In such an image forming apparatus, the sheet is a roll paper because it is easy to handle. Is used to configure a paper feed unit including a plurality of roll papers. On the other hand, there are some that are equipped with a bypass sheet feeding device so that an image can be formed even on a sheet that the user has misplaced. The bypass sheet feeding device includes a drive roller extending in the conveyance width direction orthogonal to the paper conveyance direction, and a driven roller pressed against the drive roller. Paper that is manually fed by the user is sandwiched and conveyed by the contact portion of the roller, and the roller provided in such an image forming apparatus is
Since the length is about 1 m, the sheet is easily bent, and in the bent state, the sheet cannot be properly sandwiched and the sheet may not be properly conveyed.

Therefore, a structure is adopted in which both ends of the roller are pivotally supported and pressed, but with this alone, the vicinity of both ends in the paper width direction is sufficiently nipped, but the roller bends at the center of the paper. As a result, there is a problem that the paper cannot be conveyed properly due to wrinkles on the paper.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, Japanese Patent Application No. 2001-362548 discloses
A technique for preventing a conveyance failure of a sheet by providing a roller pressing unit for pressing one of a plurality of driving rollers or a driven roller to the other in the sheet width direction to prevent a decrease in nip pressure due to bending of the roller in the vertical direction. Is disclosed.
However, by simply pressing one of the driving roller and the driven roller against the other to suppress the vertical deflection, the conveyance failure caused by the deviation of the nip position due to the deflection of the roller in the sheet conveyance direction is completely eliminated. Could not be resolved. An object of the present invention is to solve the above-mentioned technical problem and to provide a sheet conveying device in which there is no possibility of conveyance failure even when a sheet of paper that is manually fed is conveyed. Another object of the present invention is to provide an image forming apparatus equipped with this sheet conveying device as a bypass sheet feeding device.

[0005]

According to a first aspect of the present invention for achieving the above object, the leading edge of a placed sheet is received between a pair of drive roller and driven roller,
A registration roller that nips and conveys a sheet by the drive roller and a driven roller by rotating the drive roller at a predetermined timing, and the drive roller includes one shaft extending in the conveyance width direction and its axis. A plurality of rolls attached to the shaft at a predetermined interval, the driven roller is provided in parallel with the drive roller, one shaft extending in the conveyance width direction, and the shaft at a predetermined interval. It has a plurality of roll bodies attached to the drive roller and a plurality of roll bodies whose peripheral surfaces are in axial contact with each other, and one of the drive roller and the driven roller is a sheet of the roll body. A sheet conveying device characterized by comprising a bearing that regulates bending of the sheet in the conveying direction. By providing a bearing that regulates the rollers so that they do not bend in the sheet conveying direction, the sheet cannot be conveyed. It is possible to prevent. Further, the invention of claim 2 is the image forming apparatus, wherein the sheet conveying device is provided as a registration roller of a bypass sheet feeding device. According to the above configuration, in the image forming apparatus equipped with the paper feeding device according to claim 1 as a bypass paper feeding device, even if paper of various widths is manually fed, wrinkles are generated during the feeding of the paper. Therefore, there is no risk of defective conveyance.

[0006]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic sectional view showing the configuration of a copying machine 1 including a bypass sheet feeding device 9 according to an embodiment of the present invention. Copier 1
The image forming apparatus is capable of forming an image on a wide sheet of A1 or A0 size. The copying machine 1 is partitioned by a housing 2 having a substantially rectangular outer shape, and has an image reading unit 3 for reading an image of a document, a paper storage unit 4 for storing paper such as roll paper, and transporting paper. A sheet conveying path 6 for forming a toner image based on the read image of the original, and an image forming unit 11 for transferring the toner image to the conveyed sheet, and fixing the toner image transferred to the sheet. The fixing device 12 and the like are provided for this purpose.

The image forming section 11 is arranged in the upper part of the housing 2 and includes a photosensitive drum 13 which is rotationally driven counterclockwise in FIG. The photoconductor drum 13 has a photoconductive layer on the outer peripheral surface thereof, and after being uniformly charged by the discharge of the main charger 14, the LED is based on the image of the document read by the image reading unit 3.
It is exposed by the light emitted from the print head 15. As a result, a so-called electrostatic latent image is formed on the surface of the photoconductor drum 13.

Toner is adhered by the developing device 16 to the surface of the photosensitive drum 13 on which the electrostatic latent image is formed, so that a toner image is formed. At this time, the sheet accommodated in the sheet accommodating section 4 is conveyed through the sheet conveying path 6 for guiding the sheet. A feed roller 7, a registration roller 8 and a pre-transfer roller 5 are provided in the middle of the paper transport path 6 for transporting the paper stored in the paper storage unit 4. The feed roller 7 has a pair of rollers, and by driving the pair of rollers, the paper transport path 6 is driven.
The sheet guided by is fed to the registration roller 8.

The registration roller 8 has a pair of rollers and receives a sheet supplied from the feed roller 7 and has a predetermined timing so as to match the timing with the toner image formed by the image forming section 11. Then, the sheet is supplied to the image forming unit 11 via the pre-transfer roller 5. Further, the copier 1 is provided with a bypass paper feeding device 9 so that the user can manually feed the cut paper. The bypass sheet feeding device 9 includes a bypass sheet feeding port 94, a feed roller 93, a registration roller 90, and a bypass conveyance path 95.

Bypass sheet feeding port 94 and registration roller 90
A feed roller 93 is provided between and. The paper manually fed by the user is fed by the feed roller 93.
The leading end side of the sheet passes through the registration roller 90. The registration roller 90 has a pair of rollers, and receives the leading edge of the sheet manually fed by the user and conveys the sheet to the image forming unit 11 at a predetermined timing.

The toner image formed in the image forming section 11 is transferred onto a sheet by the transfer device 17, and the toner remaining on the surface of the photosensitive drum 13 after the toner image transfer is collected by the cleaning device 18. The sheet on which the toner image is transferred is guided to the fixing device 12, is subjected to a fixing process by the fixing device 12, and is then discharged to the outside of the housing 2 by the discharging roller 19. Figure 2
Is a bypass sheet feeding device 9 according to an embodiment of the present invention.
The registration roller 90 provided in the
It is the top view seen from the side.

The registration roller 90 is a drive roller 91 provided on the side of the lower surface 95b of the conveyance path of the bypass sheet feeding device 9.
And a driven roller 92 provided on the side of the upper surface 95a of the transport path. Drive roller 91 and driven roller 92
Has a single shaft 91a, 92a extending longer than the width of the paper in the widthwise direction of conveyance which is orthogonal to the direction of conveyance of the paper. In this embodiment, the shaft 92a is the shaft 9
Since it is provided above 1a, the driven roller 92 is
It is provided above the drive roller 91. Also, each axis 9
1a, 92a are a plurality of attached at a predetermined interval,
For example, in this embodiment, six rolls 91 each.
b, 92b.

The shaft 91a of the drive roller 91 is rotatably provided by a drive system (not shown) such as a motor, and both ends thereof are pivotally supported on the lower surface 95b side of the conveying path. Further, the roll body 91b provided on the shaft 91a is provided such that the peripheral surface thereof slightly projects from the lower surface 95b of the transport path toward the driven roller 92 located above. As the roll body 91b, for example, a rubber roll made of rubber is used. When the shaft 91a is rotated by the drive system, the roll body 91b is integrally rotated together with the shaft 91a.

The shaft 92a of the driven roller 92 is rotatably provided, and holding portions 92f are provided near both ends thereof. Furthermore, near both ends of the shaft 92a,
Bearing 92d is provided, which allows shaft 92a
The bearings 92d at both ends are axially supported by the holding portions 92f on the side of the upper surface 95a of the conveyance path. Further, the roll body 92b provided on the shaft 92a is provided with its peripheral surface slightly protruding from the upper surface 95a of the transport path toward the drive roller 91 located below. As the roll body 92b, for example, a resin roll made of resin is used.

The roll body 92b is provided such that its peripheral surface abuts on the peripheral surface of the roll body 91b provided on the drive roller 91. Thereby, each roll body 91b, 92b
Are provided so that their peripheral surfaces come into contact with each other in the axial direction, and in the driven roller 92, the shaft 92a and the roll body 92b are integrally rotated as a whole as the drive roller 91 is driven. ing. When the leading edge of the sheet manually fed by the user is brought into contact with the contact portion between the driving roller 91 and the driven roller 92, the rollers 91 and 92 are driven at a predetermined timing to roll the roll body 91b and the roll body 92.
The sheet nipped between the sheet b and the sheet b is conveyed.

In the copying machine 1 equipped with a carrying device capable of carrying wide paper, for example, the shafts 91a, 9a
Since 2a has a length of about 1 m, the driving roller 91 and the driven roller 92 are bent. Therefore, the shaft 92a
Both ends of are pressed by the pressing portions 96b toward the drive roller 91 side. For example, a coil spring 92e is provided on the pressing portion 96b.
An elastic body such as the above is used, and a part of the side surface of the coil spring 92e is provided in contact with the peripheral surface of a bearing 92d provided at both ends of the shaft 92a. The shaft 92a is pressed toward the drive roller 91 by the elastic force of the coil spring 92e.

Here, in this embodiment, for example, the shaft 9
In addition to the pressing portions 96b provided at both ends of the 2a, the pressing portion 9b
6a is provided. The pressing portion 96a is provided at a position other than both ends of the shaft 92a.
It is pressed toward the drive roller 91 side by 6a and 96b. That is, if the pressing portions 96b are provided at both ends of the shaft 92a, the balance of the nip pressure in the conveyance width direction becomes poor,
The nip pressure generated between the roll body 92c at the center of the driven roller 92 and the roll body 91c at the center of the drive roller 91 becomes weak. Therefore, the pressing portion 96a has the shaft 92a
At positions other than both ends of the shaft, for example, divide the shaft 92a into three equal parts,
Position 1/3 and 2/3 respectively from the end of the shaft 92a
It is equipped in the position. As a result, the nip pressure of the roll bodies 91c and 92c at the central portion in the transport width direction is improved, so that the balance of the nip pressure in the transport width direction is improved,
There is no risk of defective transportation.

FIG. 3 is an exploded perspective view showing an example of the structure of the pressing portion 96a. The pressing portion 96 is a fixing member 101 for fixing the pressing portion 96a to the transport path upper surface 95a, and a holding member 9 for holding the pressing portion 96a on the fixing member 101.
8, a coil spring 99 housed in the holding member 98, a movable member 100 for pressing the shaft 92a from above by the coil spring 99, and these members forming the pressing portion 96 and covering the shaft 92a in the sheet conveying direction. It is composed of a bearing 97 that prevents bending.

A movable member 10 for pressing the shaft 92a from above.
In the case of 0, the main body 100e is substantially prismatic, and the plate-shaped body 1 is horizontally arranged from both of the facing one side surfaces.
00f is provided. The plate-shaped body 100f has a thickness and a width smaller than the thickness and width of the main body portion 100e, and is provided substantially at the center of one side surface.
On the other pair of opposite side surfaces of the main body portion 100e, a concave portion that opens downward is provided in the lower portion,
The shaft 92a is fitted from above. On the upper surface of the main body portion 100e of the movable member 100, there is provided a cross body 100g in which vertically standing plates form a cross. The width of the cross 100g is matched with the inner diameter of the coil spring 99, and is fitted to one end of the coil spring 99.

The other end of the coil spring 99 abuts on the inside of the upper surface of the holding member 98. The upper surface of the holding member 98 is slightly larger than the upper surface of the movable member 100, and a screw hole 98k is provided at the center thereof. A side plate 98b and a retaining plate 98c are provided vertically below the four sides of the upper surface. The retaining plate 98c is provided so that the coil spring 99 does not come off the upper surface of the holding member 98. The side surface plate 98b forms a side surface of the holding member 98, and a lower portion thereof is bent outward at a right angle to form a retaining portion 98e.

The side plate 98b has a substantially rectangular outer shape, and has a substantially rectangular through hole 98i at the center thereof. On one side 98h of the side surface plate 98b, a recess 98d is provided substantially at the center, and the recess 98d is
It is almost rectangular in the horizontal direction. The recess 98d is perpendicular to one of the through holes 98i and is connected to the side plate 98b at substantially the center thereof. The retaining portion 98e is provided with a screw hole 98k at substantially the center thereof, and the retaining path 98e has an upper surface 95a of the conveying path.
It can be screwed to the fixing member 101 provided on the.

The fixing member 101 is composed of a pair of plate-shaped members having the same shape, and one plate-shaped member is bent in multiple stages. The pair of plate-shaped members are arranged on the upper surface 95a of the transport path with the shaft 92a interposed therebetween. Book fixing surface 101
A screw hole 101f for fixing the fixing member 101 to the upper surface 95a of the transport path is provided in the center of b. A screw hole 101f for fixing the holding member 98 is provided in the center of the sub fixing surface 101c.

In the bearing 97 for preventing the shaft 92a from bending in the sheet conveying direction of the present invention, the upper surface 97a has a square surface, and a screw hole 97i is provided at the center thereof, and a screw is inserted from here. It can be assembled by passing it through and pressing it against the cross 100g of the movable member 100. Upper surface 97a
Side plates 97b are provided vertically below the upper surface 97a on the pair of opposite sides 97e. Side plate 97b
Has a length such that, when the pressing portion 96a is assembled, the tip end portion 97d of the side surface plate 97b approaches the transport path upper surface 95a. The side plate 97b has a concave shape in which the central portion is recessed downward, and the width 97h of the opening 97g is slightly larger than the diameter of the shaft 92a.
When a is assembled, the shaft 92a can be regulated by pressing even if the shaft 92a bends in the carrying direction. The protruding portion 97c of the concave side surface plate 97b has an inclined side 97f, so that the bearing 97 can be easily attached and detached when the pressing portion 96a is assembled.

Although one embodiment of the present invention has been described above, the present invention can be applied to other embodiments. For example, in the above-described embodiment, the example in which the pressing portion 96a is provided at two positions other than both ends of the shaft 92a is described. However, the pressing portion 96a is provided at one position at the center position in the transport width direction of the shaft 92a. Alternatively, it may be provided at three or more locations. The position where the pressing portion 96a is provided is the shaft 92.
Although the positions are set to ⅓ and ⅔ from the end of a, they may be provided at other positions. Furthermore, although the pressing portion 96a presses the shaft 92a of the driven roller 92 from above toward the driving roller 91 side, the shaft 91a of the driving roller 91 may be pressed toward the driven roller 92a side. The structure of the pressing portion 96a described above is an example, and another structure may be used. Further, instead of using the coil spring 99, another elastic body may be used.

[0025]

As described above, in the wide-width machine for A1 and A0 sizes, the conveyance failure such as wrinkles caused by the deviation of the nip position due to the bending of the central portion of the registration roller reaching about 1 m in the paper conveyance direction. On the other hand, by providing a bearing that regulates the displacement of the shaft in the paper transport direction, the above problem could be solved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the configuration of a copying machine provided with a bypass sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a plan view of a registration roller included in the bypass sheet feeding device according to the embodiment of the present invention, as viewed from the feed roller side.

FIG. 3 is an exploded perspective view showing a configuration of a pressing portion.

[Explanation of symbols]

1 Copier 9 Bypass paper feeder 91 drive roller 92 Driven roller 91a, 92a axes 91b, 92b Roll body 96a, 96b pressing part 97 bearing

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3F049 AA01 AA02 CA33 DA12 LA02                       LA05 LA07 LB03                 3F063 AA01 AB01 BA08 BA10                 3F102 AA02 AA10 AA11 AB01 BA02                       BB02 DA08 EA03

Claims (2)

[Claims] 1. A front end of a placed paper is received between a pair of driving roller and a driven roller, and the driving roller is rotated at a predetermined timing to sandwich the paper by the driving roller and the driven roller. The drive roller has one shaft extending in the width direction of conveyance and a plurality of rolls attached to the shaft at a predetermined interval, and the driven roller is It is provided parallel to the drive roller,
It has one shaft extending in the conveyance width direction, and a plurality of roll members attached to the shaft at a predetermined interval and provided on the drive roller, and a plurality of roll members whose circumferential surfaces are in axial contact with each other. A sheet conveying device, characterized in that one of the driving roller and the driven roller is provided with a bearing that regulates the bending of the roll body in the sheet conveying direction. 2. An image forming apparatus, wherein the sheet conveying device is provided as a registration roller of a bypass sheet feeding device.