JPH1179458A - Endless belt feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the movement of an endless belt in the lateral direction so that less burden is applied to the endless belt and also the endless belt is not damaged nor image records on a transfer material are affected in an endless belt feeding device. SOLUTION: A belt 15 is suspended tensely between a drive roller and a driven roller 18, a rib 15a is provided at both end edge parts of the belt 15 in circumferential direction, and a flange 32 is provided, movably in axial direction, at both end parts of the driven roller 18 through a spring 31. Because the rib 15a is brought in contact with the flange 32 from its inside, the movement of the belt 15 in lateral direction is controlled. With this configuration, the movement of the belt 15 in lateral direction can be controlled without applying any pressure, by the flange 32, to the belt 1 in the direction to compress it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer, and the like, which are required to transport various belts such as a photoreceptor belt, a transfer belt for transferring a toner image onto a transfer material, and a belt for transporting the transfer material. The present invention relates to an endless belt transport device used for a device or the like.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, a photoreceptor belt, a transfer belt for transferring a toner image onto a transfer material, a belt for transferring a transfer material, and the like are transported from each other. An endless belt transport device having a configuration in which an endless endless belt is stretched over a plurality of rollers arranged in parallel is provided. In this apparatus, in order to prevent the endless belt from being deflected during conveyance, (1) the roller on which the endless belt is stretched has a stepped shape of a rubber material to reduce the meandering force of the endless belt. When the endless belt hits the guide provided on the roller so that the force acts in the compression direction of the endless belt by the spring, the balance is maintained between the meandering force and the regulating force by the guide. (2) With respect to the endless belt stretched over a plurality of rollers, the end of the endless belt is urged in the compression direction from the outside thereof by a guide formed of a spring provided in the conveying device, and the conveying path of the endless belt. (See Japanese Patent Application Laid-Open No. 5-319611) has been proposed.

[0003]

However, according to the above-described conventional endless belt conveying device, the guide provided outside the endless belt in the width direction applies a force to the end of the endless belt in the compression direction. When the belt is used as a photoreceptor belt or a transfer belt, the toner image on the belt is deformed, and the endless belt is easily damaged. There is a problem that the recorded image is disturbed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and the endless belt is urged in a direction in which the endless belt is not compressed so as to regulate the conveying path of the endless belt. It is an object of the present invention to provide an endless belt transport device capable of preventing endless belt meandering without damaging or adversely affecting image recording on a transfer material.

[0005]

According to the present invention, an endless endless belt is stretched between a plurality of rollers, and the endless belt is conveyed by the plurality of rollers. An endless belt conveying device, wherein ribs are provided in the circumferential direction at both end edges of the endless belt, and end rollers of at least one of the plurality of rollers at or around both ends of the endless belt via an elastic member. It is provided so as to be movable within a predetermined range in the axial direction,
When the rib contacts the end roller from the inside, the movement of the belt in the width direction is restricted.

In this configuration, since the pressing force of the end roller against the endless belt acts from the inside to the outside of the endless belt, the endless belt is conveyed without applying pressure toward the inside to compress the endless belt. Meandering can be prevented. For this reason,
Due to the regulation of the end rollers, the endless belt is not seriously damaged, and damage to the endless belt can be avoided, so that the durability is improved. In addition, since the impact at the time of contact between the end roller and the rib is absorbed by the elastic member, the elastic member plays a role of a damper, and even if the straightness of the rib (endless belt) is slightly distorted, the endless belt can be smoothly moved. Can be transported. Further, since the endless belt is not deformed by bending or the like due to the pressing by the end roller, even when the endless belt is used as a photoreceptor belt or the like, there is no adverse effect on a recorded image.

[0007] The rib may be provided integrally with the endless belt or a separate member may be attached thereto. When the rib is provided on the inner peripheral surface of the endless belt, the end roller is located inside the endless belt. Then, it suffices if the belt is provided on both ends coaxially with the roller on which the belt is stretched. When the rib is provided on the outer peripheral surface of the endless belt, the end roller may be provided on a shaft provided separately from the roller on which the belt is stretched, as a separate member from the roller.

If the spring constant of the elastic member is set lower than the spring constant of the endless belt, the movement of the endless belt is restricted by the end roller. This pressing force is absorbed by the member side shrinking. Therefore, the load on the endless belt is reduced by the movement restriction, and damage to the endless belt can be avoided.

Further, the length between both ends in the axial direction of the roller provided with the end roller is longer than the length between the both ends in the axial direction of the roller not provided with the end roller, and both ends of the endless belt are provided. The above operation can be accurately obtained if the distance between the ribs provided in the portion is set shorter than the interval between the ribs.

Further, if the concave portion of the end roller is configured to engage with the rib of the endless belt, the rib is restricted by the end roller no matter which direction the endless belt moves in the width direction. In addition, meandering of the endless belt is prevented. Further, if the engagement between the concave portion of the end roller and the rib is released by dividing the end roller, the endless belt can be easily removed from the roller.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an endless belt conveying device according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the endless belt conveying device is applied to a copying machine which is an example of an image forming apparatus.

FIG. 1 is a schematic diagram showing the entire configuration of the copying machine 1. As shown in FIG. As shown in FIG. 1, the copying machine 1 includes an image reader unit 10 for reading a document image, and a printer unit 20 for printing the read image on a recording sheet S and reproducing it.

The image reader section 10 is a known one which reads an image of a document placed on a document glass plate (not shown) by moving a scanner. The document image is composed of red (R) and green (G). ), Blue (B), and separated into three colors, and a CCD image sensor (not shown)
), Thereby obtaining R, G, B image data of the document.

The image data for each color component obtained by the image reader unit 10 is transmitted to a control unit 30 in the printer unit 20.
Undergoes various data processing, and further receives cyan (C),
The image data is converted into image data of each reproduction color of magenta (M), yellow (Y), and black (K) (hereinafter, each reproduction color of cyan, magenta, yellow, and black is converted to C, M, Y, and K).
And the number of the component related to each reproduction color is C,
M, Y, and K are added as subscripts). This image data is stored in the image memory in the control unit 30 for each reproduced color.

The printer section 20 forms an image by a known electrophotographic method, and forms an image by forming a toner image on a photosensitive drum by scanning a laser beam.
And a sheet feeding unit 50 for supplying the recording sheet S, a sheet conveying unit 60 for conveying the supplied recording sheet S to a transfer position for each color, and a fixing unit 70 for fixing the recording sheet S to which the toner has been transferred. Etc.

Image data of each reproduced color is read out from the image memory in the control unit 30 for each scanning line and output to the printer head 41 of the image forming unit 40, and the internal laser diode is driven. Four laser beams corresponding to each color are emitted. Each laser beam light is changed in optical path while being adjusted by the folding mirror group 45 so that the optical path length becomes equal, and the peripheral surfaces of the corresponding photosensitive drums 44C to 44K are exposed and scanned in the main scanning direction to form an electrostatic latent image. To form This electrostatic latent image is stored in the developing device 42
The C, M, Y, and K toners are supplied from C to 42K and are visualized as toner images.

On the other hand, when the recording sheet S is
Sheets are fed one by one, and are conveyed by a sheet conveying unit (endless belt conveying device) 60 to a transfer position immediately below each photoconductor. The sheet transport section 60 stretches a transport belt 64 that transports the recording sheet S for transfer between a driving roller 61 and a driven roller 62 to apply necessary tension with a tension roller 63, and rotates the driving roller 61. Accordingly, the recording sheet S is transported at a predetermined transport speed in synchronization with the image forming operation for each color.

Transfer chargers 43C to 43K are disposed immediately below the conveyor belt 64 at the transfer positions of the respective colors, and the toner images on the surfaces of the photosensitive drums 44C to 44K are sequentially transferred onto the recording sheet S by these electrostatic forces. You. At this time, the image forming operation of each color is performed with a timing shifted from the upstream side to the downstream side in the conveying direction so that the toner image is transferred to the same position of the conveyed recording sheet S in a superimposed manner. Is done. The recording sheet S on which the toner images of each color have been transferred is conveyed to the fixing unit 70, where it is pressed at a high temperature, and the toner on the surface of the recording sheet S melts and adheres to the sheet surface and is fixed. The paper is discharged onto the paper tray 80.

Next, an endless belt conveying device having the same configuration as the above-mentioned sheet conveying section 60 will be described with reference to FIG. 2 is a perspective view of the endless belt transport device, FIG. 3 is a sectional view taken along line AA of FIG. 2, and FIG. 4 is a transparent top view of the endless belt transport device. In the endless belt conveyance device 100 of the present embodiment, the illustration of the tension roller 63 (FIG. 1) is omitted. An endless belt (endless belt) 15 that conveys the transfer material, a driving roller (roller) 17 that is connected to a driving device such as a motor (not shown) and drives the belt 15 to rotate, and a driving roller 17 that is parallel to the driving roller 17. Driven roller (roller) 1 which is disposed at a position and rotates according to the rotation of the belt 15 and the driving roller 17
8 are provided. The drive roller 17 and the driven roller 18 are supported by a frame (not shown) of the copying machine main body.

At both ends of the driven roller 18, a flange (end roller) 32 is rotatable around the axis of the driven roller 18 via a spring (elastic member) 31, and is rotatable in the axial direction of the driven roller 18. It is provided so as to be movable.
The flange 32 is configured to be detachable, and has a cylindrical shape whose diameter is equal to the diameter of the driven roller 18.
A stopper 34 is provided outside the flange 32 in the axial direction to restrict the axial movement of the flange 32 due to the urging force of the spring 31. Ribs 15a are provided at both ends on the inner peripheral side of the belt 15. The flange 32 is set so as to be disposed with a slight gap between itself and the inside of the rib 15a during normal conveyance of the belt 15 due to the regulation by the stopper 34 and the urging force of the spring 31.
Further, the spring constant of the spring 31 is set lower than the spring constant of the belt 15 so that the spring 31 contracts before the belt 15 bends at the time of contact between the flange 32 and the rib 15a and the belt 15 is protected. Have been.

The driving roller 17 and the driven roller 18
The surface of the driven roller 18 is kept in a low friction state in order to minimize the meandering force of the belt 15, and is located between both ends in the axial direction of the driven roller 18 provided with the flange 32 (the flanges 3 at both ends).
The length L1 is longer than the length L2 between both ends in the axial direction of the drive roller 17 where the flange 32 is not provided, and the ribs 15a provided on both end edges of the belt 15 are provided.
It is set shorter than the interval L3 on the inner edge side between them.

The operation of the endless belt transport device 100 having the above-described configuration when the belt 15 is deflected will be described. When the belt 15 moves in the width direction,
The ribs 15 a provided on the belt 15 also move accordingly, and the inside of any one of the ribs 15 a provided on both ends of the belt 15 contacts the flange 32. Accordingly, the axial movement of the belt 15 toward the driven roller 18 is restricted, and the lateral displacement of the belt 15 with respect to the driven roller 18 is prevented. Further, even if the straightness of the belt 15 and the rib 15a is slightly lost, the spring 31 is
Since the belt 15 functions as a damper for a, smooth conveyance of the belt 15 is maintained. Further, when the force of the belt 15 to move is strong and the rib 15a comes into contact with the flange 32 with a large pressure, the pressure by the rib 15a is absorbed by the spring 31, so that the belt 15 is damaged or deformed. Without movement, the axial movement of the rib 15a and the belt 15 is regulated.

As described above, according to the endless belt conveying device 100 of the present embodiment, the movement of the belt 15 in the width direction with respect to the driven roller 18 is restricted from the inside of the rib 15a by the flange 32. On the other hand, no pressure is applied in the direction of compressing the belt 15. Therefore, the load imposed on the belt 15 by the above-described movement regulation is small, and the durability of the belt 15 is improved. Further, when the rib 15a and the flange 32 come into contact with each other, the impact at the time of the contact is buffered by the spring 31, so that the load on the belt 15 is further reduced. Also,
Since the flange 32 is configured to be detachable, if the flange 32 is removed, the belt 15 from the driven roller 18 can be removed.
Can be easily removed and replaced. Also,
Since the spring constant of the spring 31 is set lower than the spring constant of the belt 15, when the belt 15 is restricted from moving by the flange 32, the spring 31 contracts and the shock generated at the time of contact between both members is absorbed. You. Therefore, the load on the belt 15 is further reduced by the movement restriction, and damage to the belt 15 can be avoided.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the above embodiment, the driven roller 18 is provided with the flange 32 and the spring 31. However, the driven roller 17 may be provided with the flange 32 and the spring 31. Flange 3 on both rollers 17
2 and a spring 31 may be provided. In the above-described embodiment, the endless belt conveying device 100 has been described as a belt conveying device that conveys a transfer material. However, for example, a belt such as a photosensitive belt or a transfer belt for transferring a toner image onto a transfer material may be used. You may apply to what is conveyed. In this case, the belt 1 is restricted by the movement restriction by the flange 32.
Since No. 5 does not cause deformation such as bending, there is no adverse effect on the recorded image.

Next, another embodiment of the endless belt conveying device according to the present invention will be described with reference to FIG.
FIG. 5 is a cross-sectional view of an endless belt transport device according to another embodiment. The above-described endless belt conveying device 100
Although the rib 15a of the belt 15 is provided on the inner peripheral side of the belt 15, in the endless belt transport device 101 according to the present embodiment, the rib 15a ' It is provided in. The length between both ends in the axial direction of the driven roller 18 is set to be larger than the width of the belt 15 '. And the driven roller 1
8 and on the inside of the rib 15a ',
A flange 32 'and a spring 31 are provided. The flange 32 'has a circular cross section, and the belt 1
The driven roller 18 is rotatably supported by a bar 35 that is configured separately from the driven roller 18 so as to be rotatable by contact with 5 ′.
The flange 32 ′ is moved by the urging force of the spring 31
5 between the two flanges 32 ′ provided on the belt 1.
It is set so as to be slightly shorter than the space between the ribs 15a 'provided at both ends of 5'. When the belt 15 ′ moves in the width direction, the rib 15 a ′ comes into contact with the flange 32 ′, so that the axial movement of the rib 15 a ′ is restricted as in the above-described endless belt transport device 100. .

Next, still another embodiment of the endless belt conveying device according to the present invention will be described with reference to FIG. FIG. 6A is a cross-sectional view of an endless belt conveyance device according to another embodiment, and FIG. 6B is a side view of an inner flange. Endless belt transport device 102 according to the present embodiment
In the figure, the driven roller 18 is supported via a bearing 2 on a side plate 1a of the apparatus main body. Driven roller 18
A rib 115a is provided in the circumferential direction of one edge of the belt 115 stretched around the belt 115. A flange 132 is provided at the end of the driven roller 18 via the spring 31, and the flange 132 has a recess 132 for engaging with the rib 115 a.
a is formed.

The flange 132 is composed of two flanges, an inner flange 132b and an outer flange 132c, and a protrusion 132d provided on the outer flange 132c and a recess 132e provided on the inner flange 132b engage. The ribs 115a can be guided from both sides. The uniting of the inner flange 132b and the outer flange 132c is performed by the protrusion 1 of the outer flange 132c.
32d is inserted into the circular portion of the concave portion 132e of the inner flange 132b, and is rotated clockwise in FIG. 6 (b).
The outer flange 132c combined with the outer flange 32b is rotated in a counterclockwise direction to move the outer flange 132c from the circular portion of the concave portion 132e to the convex portion 13e.
This is done by extracting 2d.

In the endless belt conveying device 102 having the above-described structure, when the belt 115 is displaced in the direction a in FIG. 6A, the rib 115 provided on the belt 115 is used.
a is restricted by the outer flange 132c, and when the belt 115 is deviated in the direction b in FIG.
15a is restricted from moving by the inner flange 132b. This regulation prevents the belt 115 from meandering.
Further, since the spring 31 is provided between the flange 132 and the end of the driven roller 18, when the rib 115a is restricted by the inner flange 132b, the rib 115a is restricted by the outer flange 132c in the direction of compression. At this time, an elastic force acts in the pulling direction, so that the elastic force and the meandering force of the belt 115 can be balanced. Further, by disassembling the outer flange 132c and the inner flange 132b, the rib 115a
In the recess 132a.
Can easily be disengaged from the rib 115a,
The belt 115 can be easily removed from the driven roller 18.

[0029]

As described above, according to the endless belt conveying device according to the present invention, since the endless belt is restricted from moving in the width direction, no pressure is applied in the direction of compressing the endless belt, so that the endless belt is greatly damaged. The endless belt can be prevented from meandering at the time of conveyance without giving the edge, and the durability of the endless belt is improved. Further, since the endless belt is not deformed such as flexure by this regulation, even when the endless belt is used as a photoreceptor belt or the like, the recorded image is not adversely affected. Further, when the rib and the end roller come into contact with each other, the pressure from the end roller is buffered by the elastic member, so that even if the straightness of the rib is slightly collapsed, the deviation is absorbed by the elastic member, and the rib is stably absorbed. Belt movement can be restricted.

Further, if the end roller is formed with a concave portion so as to be engaged with the rib of the endless belt, the rib is restricted by the end roller no matter which direction the endless belt moves in the width direction. Therefore, the endless belt can be prevented from meandering only by providing an end roller at one end of the driven roller.
In addition, if the engagement between the concave portion of the end roller and the rib is released by dividing the end roller, the endless belt can be easily removed from the roller.

[Brief description of the drawings]

FIG. 1 is a central sectional view of a copying machine to which an endless belt transport device is applied.

FIG. 2 is a perspective view of an endless belt conveying device.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a transparent top view of the endless belt conveying device.

FIG. 5 is a cross-sectional view of an endless belt transport device according to another embodiment of the present invention.

FIG. 6A is a cross-sectional view of an endless belt conveying device according to another embodiment, and FIG. 6B is a side view of an inner flange.

DESCRIPTION OF SYMBOLS 15, 15 ', 115 Belt (endless belt) 15a, 15a', 115a Rib 17 Drive roller (roller) 18 Follower roller (roller) 31 Spring (elastic member) 100, 101, 102 Endless belt transport device

Claims (4)

[Claims] 1. An endless belt conveying device, wherein an endless endless belt is stretched between a plurality of rollers, and the endless belt is conveyed by the plurality of rollers. A rib is provided in the direction, an end roller is provided movably in a predetermined range in the axial direction via an elastic member at both ends or around the at least one roller of the plurality of rollers, The endless belt conveying device, wherein the rib contacts the end roller from the inside thereof, thereby restricting movement of the belt in the width direction. 2. The apparatus according to claim 1, wherein a spring constant of the elastic member is lower than a spring constant of the endless belt. 3. A length of the roller provided with the end roller between both ends in the axial direction is longer than a length of the roller not provided with the end roller between both ends in the axial direction. The endless belt conveying device according to claim 1, wherein a distance between the ribs provided at both ends of the belt is shorter. 4. An endless belt conveying device, wherein an endless endless belt is stretched between a plurality of rollers, and the endless belt is conveyed by the plurality of rollers. A rib is provided in the direction, and at least one of the plurality of rollers has an end formed with a concave portion that engages with the rib via an elastic member at an end thereof so that the end roller can move in the axial direction. An endless belt conveyance device, wherein the end roller is provided so as to be splittable, and engagement with the rib is released by splitting the roller.