JP2002268508A - Belt-shaped image forming body and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt-shaped photoreceptor and a photoreceptor unit manufacturing method in which a detent prevention guide is kept to a necessary minimum for the purpose of energy saving and resource saving in manufacturing, and a method of manufacturing a belt. To provide an endless belt photoreceptor and a photoreceptor unit which can effectively control the deviation and have less possibility of peeling of the guide, and provide an image forming apparatus which can obtain a stable image for a long time during use. In an endless belt-shaped image forming body supported and driven by at least two or more rollers at the time of image formation, the endless belt-shaped image forming body has a seam in an oblique direction with respect to a belt end surface, and Finally, when driving the belt, contact the roller with respect to the belt travel direction,
An image forming body, wherein a non-stop guide is provided only at the end of a seam passing therethrough.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, an endless belt-shaped image forming member, and an image forming apparatus, and is applied to a copying machine, a printer, and a facsimile.

[0002]

2. Description of the Related Art A flexible belt having an oblique seam shape is described in JP-A-7-5701, and an endless belt-shaped electrophotographic photosensitive member is described in Japanese Utility Model Registration No. 2544456. ing.

Conventionally, as the electrophotographic method, the Carlson process and other various deformation processes are known, and are widely used in copiers and printers. Electrophotographic photosensitive members used in such an electrophotographic method include those using an organic photosensitive material and those using an inorganic photosensitive material. Organic electrophotographic photoreceptors include
A photoconductive resin represented by polyvinyl carbazole (PVK), a charge transfer complex represented by PVK-TNF (2,4,7-trinitrofluorenone), a pigment dispersion represented by phthalocyanine-binder, A function-separated type photoconductor using a combination of a charge generation material and a charge transport material is known, and has recently begun to be used because of its advantages such as low cost, mass productivity, and no pollution. In addition, as an inorganic electrophotographic photoreceptor, a photoconductive layer mainly composed of selenium or a selenium alloy is provided on a conductive support, and an inorganic photoconductive material such as zinc oxide and cadmium oxide is dispersed in a binder. And those using amorphous silicon are generally known.

[0004] As the form of the electrophotographic photosensitive member, there are a drum-like photosensitive member having a photosensitive layer formed on a metallic hollow drum, a flexible endless belt-like photosensitive member, and the like.
There are various advantages in terms of design form and the like, and at present, the shape of the electrophotographic photosensitive member is properly used according to the characteristics of the electrophotographic apparatus to be developed.

The endless belt-shaped photoreceptor includes, for example, a seamless seamless belt-shaped photoreceptor having a photosensitive layer provided on the surface of a flexible cylindrical nickel belt made by, for example, an electroforming method. Using a polyester film (PET) on which aluminum is deposited as a support, a photosensitive layer is continuously coated on the support to form a photosensitive sheet,
The obtained photoreceptor sheet was roughly cut into a desired size, punched out, and both ends of the obtained sheet-shaped photoreceptor were fused into a belt-shaped photoreceptor by a method such as ultrasonic bonding. There is a seam belt photoreceptor with seams.

[0006] In recent years, the colorization of images has been advanced in electrophotographic apparatuses, and higher image quality and higher speed, as well as lower cost and smaller size, have been demanded.

The seam belt type photoreceptor has a large belt outer shape, but can be used in a desired form due to its flexibility. The photoreceptor can be coated with a photosensitive layer by nozzle coating, and can be mass-produced. There are advantages such as low loss, low cost, and the ability to design a four-color developing machine in a convenient form to face them, and the advantages of the seam belt photoreceptor are being reviewed in color electrophotographic apparatuses. ing. However, the endless belt-shaped photoreceptor moves in the vertical direction (belt width direction) with respect to the traveling direction of the belt when driving the belt (belt widthwise), and (1) the image forming position on the belt is shifted. 2) There are drawbacks such as that the end face is damaged by contact with the image forming member installed around the belt, and (3) it is detached from the support roller.

Various proposals have been made to control the belt shift. For example, a method of detecting the position of the end face in the width direction of the belt and moving the support roller back and forth or up and down in accordance with the detection signal to change the moving direction of the belt, controlling the axial diameter from the center to the end direction. There is a method that uses rollers (taiko-shaped rollers) that are continuously reduced, but in the former case the cost is high. In the latter case, the length of the rollers must be at least equal to the width of the belt and the width of the belt. There is a disadvantage that the device becomes large.

In recent years, a method has been proposed in which a rubber is adhered to the back surface of the belt-shaped photosensitive member with an adhesive for the purpose of preventing the belt from shifting, or a guide is provided by fusing a hot melt resin such as polyester elastomer to the back surface of the belt. Has been presented.
This method of providing a guide on the back of the belt is a simple and inexpensive method of preventing the belt from shifting. It is common to provide a guide. Providing guides at both ends wastes production energy in the belt manufacturing process, and reduces the manufacturing yield due to the complexity of the manufacturing process. Furthermore, it leads to unnecessary waste of resources. Further, the present inventors investigated the cause of the life of the conventional belt-shaped photoconductor, and found that the belt deviation prevention guide was stressed by the small-diameter roller when the belt was driven, peeled off from the back of the belt, and fragments thereof were formed between the belt and the roller. There is a disadvantage that the belt is damaged by being pinched and the life of the belt is shortened. Providing guides at both ends increases the probability of belt damage and reduces the life of the photoconductor.

As described above, the guide for preventing belt deviation of the endless belt-shaped photosensitive member having a seam has a minimum necessary amount from the viewpoint of not only prolonging the life of the photosensitive member but also saving energy for production and resources. It is desired to hold down.
However, no specific and effective proposal has been made so far to reduce the number of guides toward the belt to one.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems and reduce the number of non-stop guides to a necessary minimum for the purpose of saving energy and resources in manufacturing. Endless belt photoreceptor and photoreceptor unit manufacturing method, providing a long-life endless belt photoreceptor and photoreceptor unit with effective control of belt deviation, less establishment of guide peeling, and stable images for a long time during use To provide an image forming apparatus capable of obtaining the following.

[0012]

Means for Solving the Problems The inventors of the present invention have made intensive studies on the above-mentioned problems, and as a result, have driven an endless belt-shaped image forming body having an oblique seam using two or more supporting / driving rollers. In the case, by providing an anti-snagging guide for meandering prevention on the back side of the belt on the side of the end of the diagonal seam that finally passes over the roller in the belt traveling direction,
The present inventors have found that the belt can be prevented from leaning without deviating from the supporting drive roller, and the present invention has been achieved.

An object of the present invention is to provide (1) an endless belt-shaped image forming body which is supported and driven by at least two or more rollers at the time of image formation, wherein the endless belt-shaped image forming body is located An image forming body having a seam in a diagonal direction, and a roller that comes into contact with the roller last in the belt advancing direction when the belt is driven, and a stopper guide is provided only on the seam end side passing therethrough, (2) "an image forming unit comprising at least two or more rollers and an endless belt-shaped image forming member having a seam in an oblique direction with respect to a belt end surface and having one non-stop guide. Endless belt-shaped image forming so that the belt end surface on the non-stop guide side lastly contacts and passes the roller in the belt traveling direction when the belt rotates. Imaging member unit "which is characterized by installing a, (3)" at least, two or more rollers having a seam in an oblique direction with respect to the belt end surface,
(4) The image forming body unit according to the above (2), comprising an endless belt-shaped image forming body having one non-stop guide and a cleaning member. (5) the image forming body is an electrophotographic photoreceptor, wherein the image forming body is an electrophotographic photosensitive member. And (4) the image forming body unit.

The object of the present invention is to provide at least (6) an image forming unit, a charging unit, an optical writing unit,
In an image forming apparatus having a developing unit and an intermediate transfer unit, an image forming apparatus equipped with the image forming unit according to the above item (1) or (2) ”, (7)“ at least the image forming unit, Charging means, optical writing means,
(8) In an image forming apparatus having a developing unit and an intermediate transfer unit, an image forming apparatus including the image forming unit according to the above (3) or (5) is mounted. (6) The image forming apparatus according to the above (6), wherein the intermediate transfer belt is used.

The image forming body of the present invention includes, in addition to a photoreceptor, a conveying belt for conveying a recording medium such as paper, film, cloth, etc., a so-called intermediate transfer body for temporarily transferring an image,
Any type of endless belt, such as a fixing belt, having a seam supported and driven by two or more rollers can be used. When driven by using two or more supporting / driving rollers of the present invention, a detent guide for preventing meandering is provided on the back surface of the belt at the end of the oblique seam that passes over the roller last in the traveling direction of the belt. The angle (seam angle θ shown in FIG. 2 (a)) of the oblique seam with respect to the belt end surface at which deviation is reliably prevented is 0.5-10.
Good degree range.

The non-stop guide used in the present invention is such that when the belt rotates, it comes into contact with the end face of the driving / supporting roller to overcome the force of moving the belt in the direction perpendicular to the belt traveling direction. The belt is provided on the end surface of the belt so as to prevent the belt from moving in the lateral direction. For example, a strip-shaped rubber-like elastic body is provided on the back of the belt using an adhesive or an adhesive tape, or a hot-melt resin such as a polyester elastomer is heated on the back of the belt in a belt shape from a hot melt gun. Those extruded, cooled, and fixed to the back surface of the belt can be used.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments relating to a belt-shaped photoreceptor, but the present invention is not limited by the embodiments. (Example 1) Thickness 75 μm, width 500 mm, length 50 m
The coating liquid for the intermediate layer, the coating liquid for the charge generation layer, and the coating liquid for the charge transport layer were sequentially coated on Al vapor-deposited PET by a nozzle and dried to form an electrophotographic photosensitive member. 28 parts by weight of titanium oxide (CR-EL: manufactured by Ishihara Sangyo), 12 parts by weight of alcohol-soluble polyamide (CM-8000: manufactured by Toray Industries), methanol / n-butanol = 8/2 (vol ratio) )
Of a mixed solvent of 200 wt.
The dispersion was formed for 2 hours, and dried at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of 1 μm. Next, 10 parts by weight of the trisazo pigment represented by the structural formula of the general formula (1) was added to a resin solution obtained by dissolving 4 parts by weight of polyvinyl butyral (BM-2: manufactured by Sekisui Chemical Co., Ltd.) in 150 parts by weight of cyclohexanone. Dispersion was performed for 72 hours in a ball mill. After the dispersion was completed, 210 parts by weight of cyclohexanone was added and the mixture was dispersed for 3 hours to prepare a charge generation layer coating solution. This was applied on the intermediate layer and dried at 130 ° C. for 10 minutes to form a film having a thickness of 0.2
A μm charge generation layer was formed.

[0018]

Embedded image

Next, 7 parts by weight of the compound represented by the structural formula (2) and a polycarbonate resin (Iupilon Z20)
0: 10 parts by weight of Mitsubishi Gas Chemical Co., Ltd. and 0.002 parts by weight of silicone oil (KF-50: Shin-Etsu Chemical Co., Ltd.) were dissolved in 100 parts by weight of tetrahydrofuran to prepare a coating solution for the charge transport layer. This was applied on the charge generation layer and dried at 130 ° C. for 20 minutes to form a charge transport layer having an average film thickness of 20 μm, thereby obtaining an electrophotographic photosensitive member. A grounding conductive paint layer as shown in FIG. 1 was formed on one end surface of the photosensitive layer surface.

[0020]

Embedded image

The obtained electrophotographic photosensitive sheet was roughly cut and punched into a rhombus having a width of 340 mm, a length of 421 mm, and an intersection angle of 85 degrees between the long and short sides. Company: Elitel UE4200) was melt-extruded from a 0.5 mm × 3.0 mm nozzle at a speed of 5 to 10 mm / sec from a 0.5 mm × 3.0 mm nozzle with a hot melt gun heated to a temperature of 180 ° C., height 0.4 mm, width 3 mm One guide was provided. Next, the diamond-shaped short sides were overlapped by 1 mm so that the photosensitive layer was on the surface side, and ultrasonic welding was performed under the conditions of a bonding speed of 20 mm / s, a horn gap of 80 μm, and a horn load of 1000 g, as shown in FIG. As described above, 50 belt-shaped photoconductors having a diagonal seam having a circumference of 420 mm and a length (length in the width direction) of 340 mm and having one guide were produced. The obtained belt-shaped electrophotographic photoreceptor is mounted on an image forming unit including two support rollers of 25 mmφ, one drive roller and a case, and the seam is last in the drive direction of the belt as shown in FIG. Was installed so that there was a detent guide on the side passing over the roller.

The image forming unit was subjected to a belt drive test of 50,000 revolutions by using a belt drive tester. As a result, all 50 belt photoreceptors rotated normally without detachment from the rollers. Next, as shown in FIG. 3, the belt drive test passed product is charged around the image forming unit by a charging unit,
Exposure means, developing means, mounted on the image forming apparatus in which the transfer means is arranged, and a 50,000 image forming test was performed,
All of the belt photoreceptors did not deviate from the rollers and were not damaged, and the belt photoreceptors operated normally and good images were obtained.

(Comparative Example 1) A belt-shaped photosensitive member was prepared in the same manner as in Example 1. The obtained belt-shaped electrophotographic photoreceptor is
Attached to the image forming unit consisting of two support rollers of 25 mmφ, one drive roller and the case, so that the seam end face with the detent guide in the drive direction of the belt is the side that first passes over the roller. installed. When a belt drive test was performed on this image forming unit using a belt drive tester, all the belt photoreceptors were detached from the support rollers, and the belt was damaged.

[0024]

As is apparent from the detailed and concrete description, the present invention has at least two rollers supported and driven, and has an oblique seam and one non-stop guide. In an endless belt-shaped image forming body, when a belt is driven, a detent guide is provided at an end of an oblique seam that finally passes over a roller in a belt traveling direction, so that energy loss during manufacturing of a belt during image formation, It is possible to provide an endless belt-shaped image forming body including an electrophotographic photoreceptor, which can be saved, has no damage due to belt deviation at the time of forming an image, and has a long life. Further, the present invention has an extremely excellent effect that an image forming unit and an image forming apparatus capable of stably recording high-quality information for a long time at low cost can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a belt-shaped photoconductor according to the present invention.

FIG. 2 is a diagram showing a positional relationship between a belt-shaped photoconductor and a non-stopping guide according to the present invention.

FIG. 3 is a diagram illustrating an example of an image forming apparatus according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoreceptor belt 2 charging charger 3 exposure unit 4 developing unit 5 paper feeding unit 6 registration roller 7 transfer paper 8 fixing unit 9 cleaning unit 10 static elimination unit 11 drive roller 12 driven roller 13 tension roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Nakamori 1-3-6 Nakamagome, Ota-ku, Tokyo Stock inside Ricoh Company (72) Inventor Takeshi Tsuyoshi 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Inside the Ricoh Company (72) Inventor Toshiyuki Kabata 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Naohiro Toda 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company F-term (Reference) 2H035 CA05 CB06 CE03 CF02 CG03 2H068 AA55 2H071 BA42 CA02 CA05 DA16 DA26 2H200 FA04 GA24 GB02 GB12 HA12 HB03 JA02 JC03 JC17 MC01

Claims (8)

[Claims] 1. An endless belt-like image forming body supported and driven by at least two or more rollers at the time of image formation, wherein the endless belt-like image forming body has a seam in an oblique direction with respect to a belt end surface, And, at the time of driving the belt, finally contact the roller in the belt traveling direction,
An image forming body, wherein a non-stop guide is provided only at the end of a seam passing therethrough. 2. An endless belt-like image forming body having at least two or more rollers and a seam in a diagonal direction with respect to a belt end face and having one detent guide. An image forming body unit, wherein the endless belt-shaped image forming body is installed such that the belt end surface on the side of the detent guide at the time of rotation of the belt comes into contact with and passes through the roller in the belt traveling direction. . 3. An endless belt-like image forming body having at least two rollers, a seam in a diagonal direction with respect to the belt end face, and one non-stop guide, and a cleaning member. The image forming unit according to claim 2. 4. The image forming body according to claim 1, wherein the image forming body is an electrophotographic photosensitive member. 5. The image forming unit according to claim 3, wherein the image forming body is an electrophotographic photosensitive member. 6. An image forming apparatus having at least an image forming unit, a charging unit, an optical writing unit, a developing unit, and an intermediate transfer unit, wherein the image forming unit according to claim 1 or 2 is mounted. 7. An image forming apparatus having at least an image forming unit, a charging unit, an optical writing unit, a developing unit, and an intermediate transfer unit, wherein the image forming unit according to claim 3 or 5 is mounted. 8. The image forming apparatus according to claim 6, wherein an intermediate transfer belt having an elastic layer is used as a transfer unit.