JP2002268455A - Endless belt-like image forming body, image forming unit, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt-like photoreceptor and a method for manufacturing a photoreceptor unit in which the number of deviation prevention guides is reduced to the minimum number necessary for energy saving the resource saving in its manufacturing, to provide an endless belt photoreceptor and a photoreceptor unit in which the deviation of the belt is effectively controlled, and which are durable and are hardly deviated from a guide, and to provide an image forming device by which an image is obtained over a long period of time when used. SOLUTION: This endless belt-like image forming body which is bridged over at least two or more rollers, and is supported and driven by these rollers, has a deviation stop guide provided at the end part having a longer peripheral length of both end parts in a width direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless belt-shaped image forming body, an image forming unit and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, a Carlson process and other various deformation processes are known, and are widely used in copying machines 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 typified by polyvinyl carbazole (PVK), a charge transfer complex type typified by PVK-TNF (2,4,7-trinitrofluorenone), and a phthalocyanine-
Pigment dispersion type represented by a binder, a function-separated type photoreceptor using a combination of a charge generating material and a charge transporting material, and the like, are known, and are advantageous in that they are inexpensive, mass-produced, and pollution-free. It has begun to be used in recent years. 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.

[0003] Electrophotographic photoreceptors include a drum-shaped photoreceptor having a photosensitive layer formed on a metal hollow drum, a sheet-shaped photoreceptor having a photosensitive layer formed on a flexible conductive support, and an endless belt-shaped. There is a photoreceptor and the like, which has various advantages in terms of cost, design form, and the like. Currently, the shape of the electrophotographic photoreceptor is properly used according to the characteristics of the electrophotographic apparatus to be developed.

The endless belt-shaped photoreceptor includes a seamless seamless belt-shaped photoreceptor having a photosensitive layer provided by a method such as coating on a surface of a flexible cylindrical nickel belt made by electroforming. Using a polyester film (PET) with aluminum deposited as a support,
A photosensitive layer is continuously coated on a support to form a photosensitive sheet, and the obtained photosensitive sheet is roughly cut into a desired size, punched, and both ends of the obtained sheet-shaped photosensitive body are, for example, There is a seam belt photoconductor having a seam formed as a belt-shaped photoconductor by fusing by a method such as sonic bonding.

On the other hand, in recent years, the colorization of images has been advanced in electrophotographic apparatuses, and higher image quality, higher speed, lower cost, smaller size, and the like have been required.

Although the seam belt-shaped photoreceptor has a large belt outer shape, it 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. The advantages of the seam belt type photoreceptor are being reviewed in the color electrophotographic apparatus. I have.

However, endless belt-shaped photoconductors often have slightly different circumferential lengths at both ends due to manufacturing problems and the like. In this case, the belt is driven in a direction perpendicular to the traveling direction of the belt (belt width direction). ) (Toward the belt), and the image forming position on the belt often shifts. When such a belt shift occurs,
Inconveniences such as damage to the end face due to contact with the image forming member installed around the belt and detachment from the support roller occur.

Various proposals have been made to control the belt shift. For example, a method in which the width direction end face position of the belt is detected, and the support roller is moved back and forth or up and down in accordance with the detection signal to change the movement direction of the belt, and the diameter in the axial direction is continuously changed from the center to the end direction. A method using a roller (drum-shaped roller) that has been made smaller in size has been proposed. However, in the former case, the cost is high, and in the latter case, the roller length is equal to the width of the belt and the width of the belt. And 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. Proposed.
This method of providing a guide on the back side of the belt is a simple and inexpensive method of preventing the belt from shifting. However, it is difficult to specify the direction of the shift of the belt when driving the belt. It is common to provide a guide in the area.

Providing guides at both ends increases the number of manufacturing steps in the belt manufacturing step, and reduces the manufacturing yield due to the complexity of the manufacturing steps. Furthermore, it leads to unnecessary waste of resources.

Conventionally, the guide for preventing belt deviation has been stressed by the small-diameter roller when the belt is driven, and has been peeled off from the back of the belt, and fragments of the guide have been caught between the belt and the roller to damage the belt, thereby shortening the life of the belt. Had. Therefore, providing guides at both ends increases the probability of belt breakage. Further, when assembling an image forming unit having an endless belt-shaped photosensitive member and two or more supporting and driving rollers, it is necessary to insert a driving and supporting roller inside the endless belt-shaped photosensitive member to assemble. For this reason, in the conventional endless belt photoreceptor, the assembly parts such as rollers contact the photoreceptor end and the back surface, and the belt end portion and the photoreceptor come into contact with the non-conveying guide which is convex inside both ends of the belt-shaped photoreceptor. And significantly impaired productivity.

As described above, the guide for preventing belt deviation of the endless belt-shaped photosensitive member having a seam not only extends the life of the photosensitive member, but also saves energy for manufacturing, resources, and the like.
From the viewpoint of improving productivity, it is desired to keep the minimum required amount. However, no specific and effective proposal has been made so far to reduce the number of guides toward the belt to one.

[0013]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems of the prior art and aims to save energy and resources in the production process by using an endless guide having a minimum required amount of non-stop guides. The method of manufacturing the belt-shaped image forming body and the image forming unit, the provision of a long-life endless belt image forming body and the image forming body unit in which the deviation of the belt is effectively controlled, and the establishment of the guide peeling is small and the use thereof is long. It is an object to provide an image forming apparatus capable of obtaining a stable image.

[0014]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. The above problem is solved by adopting the following technical means. (1) In an endless belt-shaped image forming body that is mounted on at least two or more rollers and is supported and driven by these rollers, a non-centering guide is provided at an end on a longer circumferential side of both ends in a width direction. An image forming body characterized in that: (2) The image forming body according to the above (1), wherein the image forming body is an electrophotographic photosensitive member. (3) An image forming body unit comprising the image forming body according to (1) or (2) and at least two or more belt supporting / driving rollers. (4) The image forming unit according to (3), further including a cleaning member. (5) 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 (3) or (4) is mounted. An image forming apparatus comprising: (6) The image forming apparatus according to (5), wherein an intermediate transfer belt is used as a transfer unit.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The image forming body of the present invention is mounted on at least two or more rollers, and is supported and driven by these rollers. A non-stop guide is provided.

As the image forming body of the present invention, in addition to the photoreceptor, for example, a conveying belt for conveying a recording medium such as paper or film cloth, a so-called intermediate transfer body for temporarily transferring an image,
Any type of endless belt that is supported and driven by two or more rollers, such as a fixing belt, may be used.

The image forming body may be a seam belt having a seam or a seamless belt having no seam. The inventors of the present invention have conducted intensive studies and found that in a seamless image forming body such as a seamless belt-shaped photoconductor, the peripheral lengths at both ends are different due to various factors such as manufacturing, and the above-described problem is solved. To do
Conventionally, non-centering guides had to be provided at both ends. However, it has been found that the above-mentioned problems can be solved at once by providing the non-centering guides only at the end having a long circumference. This is supported by the following examples.

[0018]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

(Example 1) Thickness 75 μm, width 500 m
m, 200m long Al-deposited PET coating solution for intermediate layer,
The coating liquid for the charge generation layer and the coating liquid for the charge transport layer were sequentially coated with a nozzle and dried to form an electrophotographic photoreceptor. 28 parts by weight of titanium oxide (CR-EL: manufactured by Ishihara Sangyo) and alcohol-soluble polyamide (CM-8000:
12 parts by weight, manufactured by Toray Industries, Inc., methanol / n-butanol =
A mixture comprising 200 parts by weight of a mixed solvent of 8/2 (vol ratio) was prepared by dispersing in a ball mill for 72 hours.
After drying for 0 minutes, an intermediate layer having a thickness of 1 μm was formed. Next, 10 parts by weight of the trisazo pigment shown in the structural formula of FIG. 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, and then subjected to 72 ball milling. Time dispersion was performed. After completion of the dispersion, 210 parts by weight of cyclohexanone was added and the mixture was dispersed for 3 hours to prepare a coating liquid for a charge generation layer. This was applied on the intermediate layer and dried at 130 ° C. for 10 minutes to form a film having a thickness of 0.1 μm.
A 2 μm charge generation layer was formed. Next, 7 parts by weight of the compound represented by the structural formula in FIG. 2, 10 parts by weight of a polycarbonate resin (Iupilon Z200: manufactured by Mitsubishi Gas Chemical Company), and 0.002 of silicone oil (KF-50: manufactured by Shin-Etsu Chemical Co., Ltd.)
Parts by weight were dissolved in 100 parts by weight of tetrahydrofuran to prepare a coating liquid for a charge transport layer. This was applied on the charge generation layer and dried at 130 ° C. for 20 minutes to obtain an average film thickness of 20 μm.
Was formed to obtain an electrophotographic photosensitive member. A ground conductive paint layer as shown in FIG. 3 was formed on one end surface of the photosensitive layer surface. After the obtained electrophotographic photosensitive member sheet was roughly cut, the height was 340 mm and the length of the upper base was 421.
0.5 mm with a hot melt gun heated at a temperature of 180 ° C. of a saturated copolymerized polyester elastomer (Elitel UE4200, manufactured by Unitika Ltd.) at the lower bottom of the photoreceptor sheet cut into a trapezoid having a lower base length of 425 mm. ×
Speed 5-1 from 3.0mm nozzle to sheet edge
Melt extrusion at 0mm / sec, height 0.4mm, width 3m
One m guide was provided. Next, the side of the trapezoid was overlapped by 1 mm so that the photosensitive layer was on the surface side, and the bonding speed was 20 m.
m / s, horn gap 80μm, horn load 1000
Ultrasonic fusion was performed under the conditions of g, and as shown in FIG. 4 (a), the belt ends at the both ends of the belt having a circumference of 420 mm and 424 mm, a length in the belt width direction of 340 mm, and a circumference of 424 mm. Belt-like photoreceptor with one guide
0 were produced. The obtained belt-shaped electrophotographic photosensitive member is shown in FIG.
As shown in the figure, the photoconductor unit was mounted on a photoreceptor unit comprising two support rollers of 25 mmφ, one drive roller and a case. When a belt drive test of 50,000 revolutions was performed on this photoreceptor unit using a belt drive tester, all 20 belt photoreceptors rotated normally without detachment from the rollers. Next, the belt drive test-passing product was mounted on the image forming apparatus shown in FIG. 5, and an image forming test was performed on 50,000 sheets. The belt photoreceptor operated normally without damage to the body, and a good image was obtained.

(Example 2) As in Example 1, one guide is provided at the end of the belt having a circumference of 420 mm and 422 mm, a length in the belt width direction of 340 mm, and a circumference of 422 mm, respectively. Twenty belt-shaped photoconductors were produced. The obtained belt-shaped electrophotographic photoreceptor was mounted on the photoreceptor unit in the same manner as in Example 1, and a belt drive test was performed. As a result, all 20 belt photoreceptors rotated normally without detachment from the rollers. . Next, the belt drive test-passing product was mounted on the image forming apparatus shown in FIG. 5 and an image forming test of 50,000 sheets was performed. The belt photoreceptor operated normally without damage to the body, and a good image was obtained.

(Comparative Example 1) Except that a guide was provided only on the end of the belt having a circumference of 420 mm,
When 20 belt-shaped photoconductors were prepared and subjected to a belt driving test in the same manner as in Example 1, all of the 20 belt-shaped photoconductors were rotated from the supporting roller during the driving test at a rotation speed of 50 to 100 rotations. It came off and the belt was damaged.

(Comparative Example 2) Except that a guide was provided only on the end of the belt having a circumference of 420 mm,
When 20 belt-shaped photoconductors were produced and subjected to a belt drive test in the same manner as in Example 2, all of the 20 belt-shaped photoconductors were separated from the support rollers during the drive test within 1000 rotations, and the belt was damaged. .

[0023]

As described above, according to the present invention,
By adopting the above configuration, it is possible to save energy loss and material at the time of belt production at the time of image formation, and there is no damage due to belt deviation at the time of image formation, including a long-life electrophotographic photosensitive member, and endless belt-like image formation. Body can be provided. Further, according to the present invention, it is possible to provide an image forming unit and an image forming apparatus capable of recording high-quality information stably for a long time at a lower cost.

[Brief description of the drawings]

FIG. 1 is a structural formula showing a trisazo pigment of Example 1.

FIG. 2 is a structural formula showing a compound used in Example 1.

FIG. 3 is an explanatory view of a conductive paint layer for grounding.

FIG. 4 is a view schematically showing the electrophotographic photosensitive member obtained in Example 1.

FIG. 5 is a diagram illustrating an image forming apparatus according to the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Nakamori 1-3-6 Nakamagome, Ota-ku, Tokyo Stock inside Ricoh Company (72) Inventor Shinji Shinjo 1-3-6, Nakamagome, Ota-ku, Tokyo Stock Inside Ricoh Company (72) Inventor Toshi Taniguchi 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 Terms (reference) 2H035 CA05 CB06 CF02 CG03 2H071 CA02 CA05 DA09 DA16 DA26 2H200 JC04 JC05 JC10

Claims (6)

[Claims] 1. An endless belt-shaped image forming body that is mounted on at least two or more rollers and supported and driven by these rollers, a non-centering guide at an end having a longer circumferential length among both ends in a width direction. An image forming body comprising: 2. The image forming body according to claim 1, wherein the image forming body is an electrophotographic photosensitive member. 3. An image forming body unit comprising the image forming body according to claim 1 and at least two or more belt supporting / driving rollers. 4. The image forming unit according to claim 3, further comprising a cleaning member. 5. 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 4 is mounted. Characteristic image forming apparatus. 6. The image forming apparatus according to claim 5, wherein an intermediate transfer belt is used as a transfer unit.