JP2821293B2 - Transfer conveyor belt system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer / transport belt system which is incorporated in an electrophotographic apparatus and uses a transfer / transport belt.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Laid-Open No. 64-484.
As disclosed in Japanese Patent Application Publication No. 57-57, in an electrophotographic apparatus, for the purpose of reducing the weight and size of the apparatus, a plurality of flat belts having a dielectric layer or the like on the surface thereof are arranged substantially parallel to each other. It has been known that the flat belt is used as a transfer conveyance belt instead of a transfer drum or the like by being wound around a transfer belt.

[0003] When an attempt is made to use a flat belt of this type of belt system as a transfer conveyance belt, a recording paper (copy paper) is electrostatically attracted and a toner image on a photosensitive drum is transferred to the recording paper. In addition, a means for charging the transfer conveyance belt is required. Conventionally, as a means for charging the transfer / transport belt, a device in which a corona charger is arranged to face a part of the transfer / transport belt and the transfer / transport belt is charged by corona discharge of the corona charger is generally known. Have been.

[0004]

However, the above-mentioned conventional structure has the following disadvantages. To solve these disadvantages, this type of belt system must be replaced by an electronic device. This greatly improves the practicality of assembling in a photographic apparatus, and a configuration for solving this problem has been required in advance.

One of the disadvantages of using this corona charger is that ozone is generated due to the corona discharge of the corona charger, and this ozone adversely affects the belt system.

Another disadvantage is that the transfer / transport belt shifts in the belt width direction when the transfer / transport belt travels, so that accurate image formation cannot be performed.

In order to prevent the transfer / transport belt from eccentrically, a regulation member is conventionally provided as shown in Japanese Patent Application Laid-Open No. 56-127501 to force the transfer / transport belt to deflect. Although there has been devised a device that restricts the transfer, it is necessary to increase the strength of the member that restricts the deviation when the transfer force due to the deviation of the transfer conveyance belt becomes large. There is. Further, it is necessary to increase the buckling strength of the transfer conveyance belt itself in the width direction, and at the same time, it is necessary to increase the strength of the end of the transfer conveyance belt so that the end of the transfer conveyance belt is not damaged.

Further, as disclosed in Japanese Utility Model Laid-Open Publication No. Sho 58-110609, one roller is used as an eccentricity adjusting roller and a belt position sensor for detecting eccentricity is provided. When the deviation of the transfer conveyance belt is detected by the position sensor, the deviation is corrected by displacing the shaft end of the deviation adjusting roller according to the deviation amount. In order to detect and correct the deviation using a complicated mechanism, an expensive and extra space is required, which leads to an increase in the size of the entire apparatus. Not only that, but because of the complicated mechanism, the number of parts increases,
As a result, the number of failure occurrence factors increases, and it is difficult to say that the reliability of the device is sufficiently ensured.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and does not use a corona charger and has a simple structure to prevent the above-described generation of ozone and the amount of deviation of the transfer conveyance belt. It is an object of the present invention to obtain a configuration capable of greatly improving the practicality of the belt system by reducing the power consumption.

[0010]

In order to achieve this object, the present invention employs, as means for charging the transfer / transport belt, a charging roller which rotates with the travel of the transfer / transport belt. The deflection of the transfer / transport belt is corrected by the charging roller. Specifically, the invention according to claim 1 is based on a transfer / conveyance belt system that drives a transfer / conveyance belt that transfers and conveys a toner image formed on the surface of a photoconductor onto recording paper. A transfer transport belt that is wound around a plurality of rollers and transports the recording paper while electrostatically adsorbing the same; a charging roller that contacts a surface of the transfer transport belt so as to charge the transfer transport belt; A configuration in which, when a deviation occurs in the transfer conveyance belt, a deviation adjusting unit that generates a deviation component in a direction opposite to the deviation direction by displacing the shaft end of the charging roller. did.

According to a second aspect of the present invention, there is provided the transfer / conveying belt system according to the first aspect, further comprising a biasing means for biasing the transfer / conveying belt toward one shaft end of the charging roller. An eccentricity detecting member is supported on the shaft end of the charging roller on the side of eccentricity of the transfer / conveying belt by the offset imparting means so as to be rotatable independently of the charging roller. When the transfer conveyance belt contacts the deviation detection member and the rotational torque acts on the deviation detection member due to the deviation of the transfer conveyance belt by the offset applying unit, the deviation detection member With the rotation, the shaft end of the charging roller is displaced in a predetermined direction so as to deflect the transfer conveyance belt in a direction opposite to the direction of eccentricity by the offset imparting means.

[0012]

According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, the transfer conveyance belt is charged by the charging roller, and the transfer conveyance belt conveys the recording paper while electrostatically attracting the recording paper. When the conveyed recording paper comes into contact with the surface of the photoreceptor, the toner image formed on the surface of the photoreceptor is transferred. Then, when a deviation occurs during the movement of the transfer conveyance belt, the shaft end of the charging roller is displaced by the deviation adjustment means, and a deviation component in a direction opposite to the deviation direction is given to the transfer conveyance belt. To correct the initial deviation. As described above, while the charging roller is used as a means for charging the transfer conveyance belt, the charging roller also sequentially corrects the deviation of the transfer conveyance belt, thereby providing the conventional electrophotographic apparatus. This eliminates the need for a corona charger, thereby avoiding the generation of ozone due to the corona discharge, which can prevent the generation of ozone and reduce the amount of deviation of the transfer conveyance belt. A single roller can be used as a roller for canceling and a roller for charging the transfer conveyance belt,
The number of parts can be reduced, and the practicality of this belt system is greatly improved.

According to the second aspect of the present invention, the transfer / conveying belt is deflected toward the position where the deviation detecting member is disposed by the action of the offset imparting means. The detection member rotates due to contact friction with the transfer conveyance belt. The shaft end of the deviation adjusting roller is displaced in a predetermined direction with the rotation of the deviation detecting member. When the shaft end of the deviation adjusting roller is displaced in this manner, the initial deviation is corrected because a deviation in the direction opposite to the deviation direction occurs on the transfer / conveying belt. That is, the amount of displacement of the shaft end of the deviation adjusting roller according to the initial deviation is automatically given to the charging roller for charging the transfer conveyance belt. For this reason, the transfer conveyance belt can run stably, and in particular, when this belt system is applied to an electrophotographic apparatus, accurate image formation can be performed. Therefore, according to the present invention, it is possible to prevent the generation of ozone and to reduce the amount of deviation of the transfer / transport belt.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view showing a peripheral structure of a belt system housed in an electrophotographic apparatus according to the present embodiment. In FIG. 1, 1, 2 and 3 are first, second and third rollers, respectively. Each of the rollers 1, 2 and 3 is a shaft member 1 respectively.
a, 2a, 3a, and a cylindrical member made of rubber or the like formed with a slightly larger diameter concentrically with the shaft members 1a, 2a, 3a except for the left and right ends of the shaft members 1a, 2a, 3a. Body 1b, 2
b, 3b. These cylindrical bodies 1b, 2b, 3
As the material b, for example, an EPDM-based crosslinked rubber is employed. However, each of the cylindrical bodies 1b, 2b, 3b may be made of a material other than an elastic material such as resin or aluminum.

A transfer / conveying belt 4 having a dielectric layer formed on the surface of a base material is stretched around each of the rollers 1, 2 and 3 so as to run. Therefore, this belt system
The transfer conveyance belt 4 functions as a transfer conveyance body of an electrophotographic apparatus. The base material of the transfer / conveying belt 4 is, for example, biaxially stretched polyester, and has a tensile modulus of 200 kg / mm ² or more. Further, the frictional resistance of the transfer conveyance belt 4 on the front surface is larger than that on the rear surface.

The first roller 1 has a shaft member 1a connected to a drive shaft of a drive motor (not shown) so that the drive force of the drive motor can be transmitted. That is, the first roller 1 functions as a driving roller. And
At a position adjacent to the first roller 1, the first roller 1
An assist roller 5 is provided to travel toward the second roller 2 while sandwiching the transfer / conveying belt 4 between them.

The second roller 2 is a transfer roller and is arranged in parallel with the first roller 1. Also,
At a position adjacent to the second roller 2, a photosensitive drum 6 as a photosensitive member according to the present invention is disposed. The photosensitive drum 6 sandwiches the transfer / conveying belt 4 between the photosensitive drum 6 and the second roller 2, and has an outer peripheral surface in contact with the surface of the transfer / conveying belt 4. And this photosensitive drum 6
When the electrophotographic apparatus in which the belt system is incorporated is driven, the toner image formed by the developing device 7 disposed adjacent to the photosensitive drum 6 is electrostatically attracted to the transfer / conveying belt 4. The image is transferred onto the surface of a recording sheet (copy sheet) (not shown) which is integrally conveyed with the transfer / conveyance belt 4.

The third roller 3 is a driven roller, and its axis is inclined with respect to the axis of the first roller 1. In other words, for example, only the shaft end of the third roller 3 in the direction of the front side of the drawing in FIG. 1 is slightly displaced downward (for example, 0.5 mm) with respect to the horizontal parallel position with the first roller 1. ing.

By arranging the rollers 1, 2, and 3 in this manner, the transfer / conveying belt 4 stretched over the rollers 1, 2, and 3 moves at the time of traveling ( In the traveling direction arrow A), the front side of the paper in FIG.
(Direction B).
In other words, the offset imparting means according to the present invention is constituted by the fact that the axis of the third roller 3 is inclined with respect to the axis of the first roller 1.

In FIG. 1, reference numeral 8 denotes a fixing roller provided in the fixing device, 9 denotes a fur brush, 10 denotes a cleaning blade, and 11 denotes a cleaning roller.

As one of the features of the present embodiment, a charging roller 12 is provided between the first roller 1 and the third roller 3. Hereinafter, the configuration of the charging roller 12 will be described in detail. The charging roller 12 includes a shaft member 12a and a cylindrical body 12b, like the first to third rollers 1, 2, and 3 described above. The cylindrical body 12b is made of EPDM rubber in which carbon black is dispersed and blended, and has a volume resistance of 10 ⁸ Ω-cm and an outer diameter of 1.
It is set to 6 mm. This charging roller 12 is
An electric charge is applied to the outer peripheral surface, and the electric charge is applied to the surface of the transfer / conveying belt 4. As shown in FIG. 3 and FIG.
The shaft end on the near side in FIG. 2 of 2a is inserted into an elongated hole 13a formed in the bearing member 13 and is rotatably supported. The charging roller 12 is provided with a downward urging force (2 kgf on one side) in FIG. 1 by springs (not shown) disposed at both left and right shaft ends. Part 4 is bent downward to adjust its tension.

The cylindrical body 12 of the charging roller 12
A deviation detecting member 14 is provided between the bearing member 13 and the bearing member 13. The deflection detecting member 14 is made of a super-polymer P
E and the like. The deflection detecting member 14 has its inner end face disposed close to the end face of the cylindrical body 12b of the charging roller 12 with a small gap.
Also, the deviation detecting member 14 has an outer diameter of the inner end surface portion facing the end surface of the cylindrical body 12b of the charging roller 12 set to be the same as the outer diameter of the cylindrical state 12b of the charging roller 12. And
Further, the cylindrical body 12b has a climbing surface 14a which is tapered (having a taper angle of 3 °) such that its diameter gradually increases as the cylindrical body 12b moves away from the end surface. As a result, when the transfer / conveyor belt 4 is deflected in the direction B, the transfer / transport belt 4 rides on the ride-up surface 14a of the deviation detecting member 14 due to the deviation, as indicated by a virtual line in FIG. It has become.

Further, the deviation detecting member 14 is formed integrally with a cylindrical portion 14b at a position outside the riding surface 14a. The cylindrical member 14b has a string member 15 attached thereto.
Are connected at one end. On the other hand, the other end of the string member 15 is a fixing member S such as a frame of the system (see FIG. 4).
Mounted on In other words, the transfer conveyance belt 4 is shifted (arrow B 1 in FIG. 2) generated by the operation of the offset imparting means formed by the inclined arrangement of the third roller 3 so that the transfer conveyance belt 4 moves on the riding surface of the deviation detection member 14. 14a, when a rotational torque is applied to the deviation detecting member 14, the rotation of the deviation detecting member 14 causes the string member 15 to be wound around the cylindrical portion 14b of the deviation detecting member 14, thereby causing the charging roller to rotate. The first shaft end on the front side in FIG.
The roller 1 is displaced in the direction approaching the shaft end, that is, in the direction of arrow C in FIG. That is, the charging roller 12
Of the transfer conveyance belt 4 in the direction opposite to the initial deviation direction (arrow D in FIG. 2).
Direction). This constitutes a deviation adjusting means for displacing the shaft end of the third roller 3 in a predetermined direction when a rotational torque acts on the deviation detecting member 14. That is, when the shaft end of the charging roller 12 is displaced in the direction C, the transfer conveyance belt 4 travels while being wound in the direction D, so that the initial deviation component (component in the direction B) is generated. In this case, an opposite deflection component is generated, and the shaft end of the shaft member 12a is displaced until the initial deflection component cancels out. Further, an electric attraction force is generated between the charging roller 12 and the transfer conveyance belt 4, and even if the amount of displacement of the charging roller 12 is small, the influence of the displacement on the transfer conveyance belt 4 is not affected. Therefore, the deviation component in the direction of arrow D can be reliably generated with a small winding amount of the string member 15.

The operation of the above configuration will be described below. First, due to the inclined arrangement of the third roller 3 with respect to the first roller 1, when the transfer / conveyance belt 4 travels, a force is exerted on the transfer / conveyance belt 4 such that the transfer / conveyance belt 4 always deviates in the direction B in FIG. As a result, the transfer conveyance belt 4
While traveling, it deviates toward the deviation detecting member 14.

When the end of the transfer belt 4 rides on the running surface 14a of the deviation detecting member 14 due to the deflection of the transfer belt 4, the transfer conveying belt 4 and the running surface 14a of the deviation detecting member 14 Due to the frictional force acting between the shaft member 12a and the shaft member 12a of the charging roller 12,
, And the rotation causes the cord member 15 to rotate.
Will be wound up.

When the string member 15 is wound, the end of the shaft of the charging roller 12 on which the deviation detecting member 14 is disposed is C
The transfer conveyance belt 4 travels while being wound in the D direction. At this time, the friction coefficient between the surface of the transfer conveyance belt 4 and the outer peripheral surface of the deviation detecting member 14 is large, and the above-described electric suction force is acting. The slight displacement of the shaft end limits the deviation of the transfer and conveyance belt 4 in the B direction. At the same time, a spring force of a spring that applies an urging force to both shaft ends of the charging roller 12 is also acting, so that the balance between the winding force of the string member 15 and the spring force of the spring causes the charging roller 12 to rotate. The amount of displacement of the roller 12 is regulated, and the position of the end of the transfer conveyance belt 4 is maintained at a certain fixed position.

Since the transfer / transport belt 4 travels in this manner, large deviation of the transfer / transport belt 4 is prevented.
Can be suppressed. That is, the transfer conveyance belt 4
Is automatically corrected one by one while eccentrically moving in one direction, the amount of eccentricity can be reduced to a small amount, and the transfer conveyance belt 4 can run stably. In an electrophotographic apparatus such as this one, accurate image formation can be performed.

The inventor of the present invention conducted experiments on an electrophotographic apparatus incorporating the belt system of this embodiment. Explaining the results, as a result of printing 20,000 sheets, the amount of deviation during the printing was 40 μm or less, there was no adverse effect on the image, and accurate image formation was performed. Further, the amount of generated ozone was suppressed to 1/5 or less as compared with the case where a conventional corona charger was employed. Thus, the effects of the present invention were also supported by experiments.

In each of the above-described examples, the bias applying means may be configured so that the biasing force of the spring for applying tension to the transfer / conveying belt 4 differs between the left and right. In addition, as the operation for eliminating the deviation, the charging roller 12 is used.
1, the moving direction of the shaft end may be set to the lower side in FIG. 1, and the belt tension may be changed to generate a deviation component in a direction opposite to the initial deviation. Further, in the present embodiment, the deviation adjusting means is arranged only on one side of the charging roller 12, but in the invention according to claim 1, it may be arranged such that it is arranged on both right and left sides. Also,
The present invention may be applied to a belt system incorporated in an apparatus other than the electrophotographic apparatus.

[0030]

As described above, according to the present invention,
The following effects are exhibited. According to the first aspect of the present invention, when the transfer / transport belt is deflected, the shaft end of the charging roller that applies electric charges to the transfer / transport belt is displaced so that the transfer roller is deflected in a direction opposite to the deviating direction. By providing an eccentricity adjusting means for generating a component, by sequentially eliminating the amount of eccentricity of the transfer conveyance belt by a charging roller as a means for charging the transfer conveyance belt, eliminating the need for a corona discharger, It is possible to both prevent the generation of ozone and reduce the amount of deviation of the transfer conveyance belt. Further, a roller for eliminating the deviation and a roller for charging the transfer conveyance belt are formed by a single roller. The belt system can also be used, the number of parts can be reduced, and the practicality of the belt system can be greatly improved.

According to the second aspect of the present invention, there is provided a bias imparting means for deflecting the transfer / conveying belt toward one shaft end of the charging roller, and a deviation adjusting means for controlling the axis of the charging roller. Since the end portion is displaced in a predetermined direction and the transfer / conveying belt is deflected in a direction opposite to the direction of deviation by the offset applying means, in this case also, prevention of ozone generation and transfer The amount of deviation of the conveyor belt can be reduced. Further, since the deviation adjusting means is provided only at one end of the shaft of the charging roller, the size of the system can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a state where a belt system is incorporated in an electrophotographic apparatus.

FIG. 2 is a perspective view around a deviation detection member.

FIG. 3 is a front view of the vicinity of a deviation detecting member.

FIG. 4 is a side view of the vicinity of the deviation detecting member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st roller 2 2nd roller 3 3rd roller 4 Transfer conveyance belt 6 Photoconductor drum (photoconductor) 12 Charging roller 14 Deflection detection member

Claims (2)

(57) [Claims] 1. A transfer / transport belt system for driving a transfer / transport belt that transfers and conveys a toner image formed on a surface of a photoconductor onto a recording sheet, wherein the transfer sheet belt is wound around a plurality of rollers to transfer the recording sheet. A transfer conveyance belt that conveys while being electrostatically attracted; a charging roller that contacts the surface of the transfer conveyance belt so as to charge the transfer conveyance belt; and A transfer / conveying belt system comprising: a displacement adjusting unit that generates a displacement component in a direction opposite to the displacement direction by displacing a shaft end. 2. The transfer conveying belt system according to claim 1, further comprising: a bias applying unit that deflects the transfer conveying belt toward one axial end of the charging roller; A bias detection member rotatably supported independently of the charging roller is provided at the shaft end of the charging roller on the side of the transfer conveying belt that is biased by the bias applying means. When the transfer / transport belt comes into contact with the deviation detection member and a rotational torque acts on the deviation detection member due to the deviation of the transfer / transport belt by the applying means, the charging roller is rotated with the rotation of the deviation detection member. Wherein the end of the transfer belt is displaced in a predetermined direction so as to deflect the transfer conveyance belt in a direction opposite to the direction of deviation by the offset applying means.