JP2000267506A - Image forming device and image forming method and belt type photoreceptor used therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage and the impossibility of traveling caused by belt type photoreceptor's running-on and to prevent the crack of a photoreceptive layer, the peeling of film and image defect even in the case of long-term repetitive use. SOLUTION: In this image forming device, the electrophotographic belt-type photoreceptor 1 having the photoreceptive layer consisting of a charge generating layer and a charge transporting layer on a supporting body consisting of high polymer material whose thickness is 50 to 100 μm is used and at least one of belt laid rollers 203 for the photoreceptor 1 abuts on the surface of the photoreceptive layer. The device is provided with a guide 201 on the back surface of the supporting body in order to regulate the traveling of the photoreceptor 1, and a distance L1 between the end/end of the guide 201 is shorter than the length of a circular arc L2 where the supporting body comes in contact with the roller 203 (L1<L2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus or an image forming method used as a copying machine, a printer or the like, and a belt-shaped photosensitive member used for the same.

[0002]

2. Description of the Related Art In recent years, many image forming apparatuses such as copiers, printers and facsimile machines using electrophotography have been developed.

The image forming apparatus using the electrophotographic method has a high speed and a high image quality, but is slightly larger in equipment than other image forming methods, and has recently been required to be installed in an ordinary office. There is a strong demand for miniaturization to respond.

In particular, a color image forming apparatus usually requires an image forming mechanism for each of the colors cyan, magenta, yellow, and black, which is liable to be larger and more difficult to miniaturize. The point belt-shaped flexible photoreceptor has an advantage that the space to be routed can be made smaller than that of the drum-shaped photoreceptor, and that the arrangement of the image forming mechanism for each color is more flexible.

As described above, recently, belt-shaped photoconductors that can be laid out more flexibly than drum-shaped photoconductors have been used in image forming apparatuses that are particularly required to be miniaturized. However, the belt photoreceptor is subjected to much more severe external force than the drum-type photoreceptor, such as the stress caused by the curvature of the tension roller that comes into contact with the belt drive roller and the tension during driving and at rest. In this case, image defects are likely to occur due to cracks on the photoreceptor surface or peeling of the photosensitive layer.

In order to further reduce the size, it is necessary to make the space formed by the belt-shaped photosensitive member and the stretching roller as small as possible. That is, the diameter of the tension roller is preferably as small as possible. However, reducing the diameter of the tension roller gives a larger curvature stress to the belt-shaped photoconductor,
Mechanical damage is more severe.

In addition, it is necessary to regulate the running of the belt-shaped photoreceptor, that is, to make the belt run straight and not to be offset to either of the right and left sides. There is a method such as providing a guide. However, in this case, when the end of the guide collides with the tension roller including the driving roller while the belt is running, the guide end is likely to be a trigger for climbing onto the roller. The portion on which the photosensitive member and the support are applied gives a large stress to the photosensitive member and the support, and the film of the photosensitive member is peeled off and the belt is more easily damaged.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems while using a belt-shaped photosensitive member.

That is, an object of the present invention is to provide an image forming apparatus and an image forming apparatus which can prevent breakage and running inability of a belt-shaped photoreceptor even when used repeatedly for a long period of time, free from cracks or film peeling of a photosensitive layer and image defects. An object of the present invention is to provide a method and a belt-shaped photoreceptor used for the method.

[0010]

As a result of intensive studies, the present inventors have found that a guide for regulating the running of the belt-shaped photoreceptor can be easily manufactured by installing the guide under specific conditions. The present inventors have found that the present invention is extremely effective, and have reached the present invention.

That is, the object of the present invention is achieved by adopting the following constitution.

[1] An electrophotographic belt-shaped photoconductor having at least a photosensitive layer comprising a charge generation layer and a charge transport layer on a support made of a polymer material having a thickness of 50 to 100 μm is used. An image forming apparatus in which at least one of the stretching rollers is in contact with the surface of the photosensitive layer, and a guide is provided on the back surface of the support for regulating the running of the photosensitive member; An image forming apparatus, wherein a length of a body is shorter than a length of an arc L2 in contact with a belt stretching roller (L1 <L2).

[2] End L / Distance L of the Guide
1. The image forming apparatus according to [1], wherein the length of the circular arc L2 where the support 1 and the support contact the belt stretching roller satisfies the following condition: 0 mm ≦ L1 ≦ 20 mm 0 mm <L2 ≦ 30 mm

[3] Width W and height H of the guide
The image forming apparatus according to [1] or [2], wherein 1 mm ≦ W ≦ 20 mm 0.5 mm <H ≦ 5 mm is satisfied.

[4] The guide is characterized in that urethane, silicone, polyester, acrylic resin or metal is used as the material of the guide, and the guide is provided on the back surface of the support with an adhesive, a double-sided tape or a hot melt. The image forming apparatus according to [1], [2] or [3].

[5] At least one of the belt stretching rollers has a diameter of 15 to 40 mm [1].
The image forming apparatus according to claim 1.

[6] The process of developing the electrostatic latent image formed by writing on the photoreceptor by laser light is repeated, and a multicolor superimposed toner image is formed on the photoreceptor and then transferred collectively. The image forming apparatus according to any one of [1] to [5], wherein the image forming apparatus adopts a system.

[7] A belt-shaped photosensitive member used in the image forming apparatus according to any one of [1] to [6].

[8] An electrophotographic belt-shaped photoreceptor having at least a photosensitive layer comprising a charge generation layer and a charge transport layer on a support made of a polymer material having a thickness of 50 to 100 μm is used. An image forming method in which at least one of the stretching rollers is in contact with the surface of the photosensitive layer. An image forming method, wherein the body is shorter than a length of an arc L2 in contact with the belt stretching roller (L1 <L2).

Regarding the image forming apparatus of the present invention,
Examples of such aspects will be described later with reference to FIGS. In the apparatus, the belt-shaped photoreceptor is an electrophotographic photoreceptor having a photosensitive layer composed of a charge generation layer and a charge transport layer on a belt-shaped support made of a polymer material. In the image forming apparatus of the present invention, it is supported and transported by several stretching rollers including a roller for driving the same, but in the image forming apparatus of the present invention, in order to reduce the transport space, at least one of them is used. It is supported and run in contact with the photosensitive layer surface.

Further, as shown in FIG.
The guide provided on the back surface of the support for regulating the running of the vehicle is a guide 201 having a convex shape for preventing meandering, and a concave portion provided on a stretching roller 203 provided correspondingly. 202, and can play a role of preventing fluctuation during running.

The width (W) and height (H) of the projection are:
1mm ≦ W ≦ 20mm, 0.5mm ≦ H ≦ 5m
m is preferable. This is a result brought about from the balance of the increase in the load on the driving power source due to the increase in the joint area when the engagement is made with the appropriate regulating force.

The material of the guide portion is not particularly limited, but any one of urethane, silicone, polyester and acrylic resin or metal is preferably used in view of ease of processing and strength. You. In these cases, an adhesive or a double-sided tape can be used for the belt-like support, or the support can be relatively easily installed by hot melt.

FIG. 7 is an enlarged view of a portion where the belt-shaped photosensitive member is supported and conveyed by a stretching roller. In this figure, (a) shows a case where the guide end / end is not at the portion where it comes into contact with the tension roller, and (b) shows a case where the guide end / end is at a portion where it comes into contact with the tension roller. I have.

L1 is the distance between the ends / ends of the guide 201, L2 is the length of the arc where the support comes into contact with the belt stretching roller, and the arrow indicates the transport direction of the belt-shaped photosensitive member 1. Here, r represents the radius of the tension roller, and θ represents the angle of the abutting portion.

The easiest way to install the guide is to attach a guide made of urethane resin or silicone resin prepared in advance to the belt. In this case, the distance between the guide ends / ends is determined by the riding characteristics of the guide. This is an important point in Of course, the guide is preferably connected to the entire back surface of the belt without any gap, that is, the guide has a guide end / end distance of zero, but it is difficult in the manufacturing process.

On the other hand, if the distance between the guide ends / ends is too large, the guide travels without contacting the rollers at all, that is, the belt travel is not sufficiently regulated by the guide. There can be. In such a case, the belt may run obliquely, and then when the guide again contacts (collides with) the roller, the belt easily rides on, and strong stress is applied to both the support and the photosensitive layer. As a result, the support is damaged from the vicinity of the guide end, and the photosensitive layer is peeled off, which is not preferable.

Next, an electrophotographic photosensitive member having a photosensitive layer provided on a support according to the present invention will be described.

At present, in an electrophotographic photosensitive member having a photosensitive layer provided on an aluminum drum substrate (also referred to as a support), which is most frequently used, since the drum substrate itself also serves as a conductive layer, the conductive layer is not used. It is not necessary to provide a conductive layer in particular. However, in the case of a belt-shaped photoconductor using a support having a flexible portion as in the present invention, the support is usually insulative, and in this case, a conductive layer needs to be separately provided.

As a method for forming the conductive layer, aluminum or I
Examples thereof include those obtained by vapor deposition or sputtering of a metal or metal oxide such as TO (indium tin oxide) and those obtained by forming a conductive resin film by mixing ITO or alumina conductive fine particles with a resin. .

As the material for the belt-shaped photoreceptor support that can be used in the present invention, a generally known engineering plastic base can be used, and it is not particularly limited. Examples thereof include polyethylene terephthalate and polyethylene. Examples include naphthalate, polyetherimide, polyethersulfone, polycarbonate, polyarylate and the like. The thickness of the support is 50 to 100 μm in order to balance rigidity and flexibility.

If the belt-shaped photosensitive member is driven under the conditions as in the present invention, good characteristics can be obtained even in an image forming apparatus having a mechanism in which the belt stretching roller has a small diameter and at least one of which is in contact with the photosensitive layer surface. I can do it. That is, according to the present invention, it is possible to solve the problem that occurs when a roller for driving the photoconductor in a stretched state uses a small-diameter roller.

Furthermore, since a latent image can be easily formed by laser light exposure and a very small image forming apparatus can be obtained, an electrostatic latent image formed by writing on a photoreceptor by laser light can be used. The present invention can be preferably applied to an image forming apparatus that employs a method in which a multi-color superimposed toner image is formed on a photoreceptor by repeating the developing step and then transferred collectively.

Hereinafter, the technique used in the present invention will be described in more detail.

The photosensitive layer used in the present invention is formed of a function-separated type containing both a charge transport material (CTM) and a charge generation material (CGM), and in particular, is formed by separately coating each layer.

The binder resin and the charge transporting material of the charge transporting layer (CTL) are not particularly limited as long as they satisfy the above requirements, and known materials can be used.

Specific examples are shown below, but the binder resin and the charge transporting substance are not limited to those shown here.

For example, as the binder resin, bisphenol A type polycarbonate, bisphenol Z type polycarbonate, other polycarbonates, organometallic compounds, polyvinyl butyral, polystyrene, styrene resin
Butadiene copolymer, polyvinyl acetate, polyamide, polypropylene, polyurethane, acrylic resin, methacrylic resin, phenolic resin, epoxy resin, silicone resin, poly-N-vinyl carbazole, polyketone, polyvinyl formal, polyarylate, polybutylene terephthalate, polyolefin Vinylidene fluoride, polyvinyl fluoride, polysulfone, polyimide, polyetherimide,
Polyvinyl chloride, polyvinylidene chloride, polyvinyl acetal, polyacrylamide, polyethylene terephthalate, polyacetylene, high-density polyethylene, low-density polyethylene, etc. can be used alone or in the form of a mixture of two or more or a copolymer of two or more. .

Examples of the charge transport material include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives,
Fluorenone derivatives, bisimidazolidine derivatives, styryl derivatives, hydrazone compounds, butadiene derivatives, triphenylmethane, pyrazoline compounds, amine derivatives,
Oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, diphenoquinone derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-
Vinylcarbazole, poly-1-vinylpyrene, poly-
9-vinylanthracene and the like.

These charge transporting substances may be used alone or as a mixture of two or more. Also,
The weight ratio of the charge transporting substance to the binder resin in the charge transporting layer can also be arbitrarily set so as to satisfy the requirements of the present invention. Further, the thickness of the charge transport layer can be arbitrarily determined so as to satisfy the requirements of the present invention.

When an intermediate layer is provided in the present invention, a resin-based intermediate layer using a polyamide-based compound such as nylon, or a so-called ceramic-based intermediate layer using an organometallic compound and / or a silane coupling agent (curable layer). Intermediate layer) is preferred.

The charge generation layer is formed by dispersing a charge generation substance in a binder resin as required. As the charge generating substance, a metal or metal-free phthalocyanine compound,
Azo compounds such as bisazo compounds and trisazo compounds, squarium compounds, azurenium compounds, perylene compounds, indico compounds, quinacridone compounds polycyclic quinone compounds, cyanine dyes, xanthene dyes, poly-N
A charge transfer complex comprising vinyl carbazole and trinitrofluorenone, etc., but not limited thereto. These may be used as a mixture of two or more as necessary.

However, in order to achieve the object of the present invention at the highest level, a kind of perylene compound, an imidazole perylene compound or a kind of metal phthalocyanine compound, titanyl phthalocyanine (TiOPc) is preferable. Here, when titanyl phthalocyanine is used as the charge generating substance, it is preferable that the X-ray diffraction spectrum with respect to the Cu-Ka line is titanyl phthalocyanine having a maximum peak at a Bragg angle 2θ of 27.2 ± 0.2 °. Further, other remarkable peaks of the titanyl phthalocyanine preferably have 24.1 ± 0.2 ° and 9.5 ± 0.2 °.

Examples of the binder resin usable for the charge generation layer include polystyrene resin, polyethylene resin, polypropylene resin, polyacryl resin, polymethacryl resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl butyral resin, and polyepoxy resin. Resins, polyurethane resins, polyphenol resins, polyester resins, polyalkyd resins, polycarbonate resins, polysilicone resins, polymelamine resins, and copolymer resins containing two or more of these resin repeating units, for example, vinyl chloride-vinyl acetate Examples include, but are not limited to, copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, and high-molecular organic semiconductors such as poly-N-vinyl carbazole.

Among the above, when the imidazole perylene compound is used as the charge generating substance, the preferred binder is polyvinyl butyral resin, and when TiOPc is used, the preferred binder is polysilicone resin and polyvinyl butyral resin, or both. A mixture thereof is given.

In order to reduce fatigue deterioration upon repeated use or to further improve durability, a known antioxidant (hindered phenols, hindered amines, etc.) may be added to each layer of the photoreceptor. Etc.), a heat-resistant agent, an ultraviolet absorber, an electron-accepting substance, a surface modifier, a plasticizer and the like, and an environment-dependent reducing agent.

In order to further improve the durability, a protective layer or the like may be provided in addition to the photosensitive layer, if necessary. The protective layer may further contain inorganic fine particles, organic fine particles, and the like.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a typical color image forming apparatus of the present invention and an image forming process will be described with reference to FIGS.

In this apparatus, the incident angle of exposure differs depending on the color, but dot exposure is performed in each case.

First, as shown in FIGS. 1 and 4, a photoreceptor cartridge 2 removably provided in the image forming apparatus will be described. Upper roller 3 which is a tension roller
Endless belt-shaped photoreceptor 1 wound by a roller, a lower roller 5, a lateral roller 7, and a pressing roller 9 in contact with the photosensitive layer surface
Is vertically stretched by the upper roller 3 and the lower roller 5, and is driven in the direction of arrow I. In addition, each of these rollers has a diameter of 22 mm.

Further, on the surface on which the photoconductor 1 moves upward, the photoconductor 1 is moved in the direction of the closed space formed by the photoconductor 1.
A pressing roller 9 is provided as guide means for pressing the photosensitive member 1 in the closed space direction.

A cleaning unit 1 for removing the developer on the photoconductor 1 is provided above the surface on which the photoconductor 1 moves upward.
1 is provided. This cleaning means 11 is shown in FIG.
This will be described with reference to FIG. On a bracket 15 rotatably provided on the shaft 13, a blade 17 that can contact a surface that moves from below to above the photoconductor 1 is attached.
Further, a spring 1 whose one end is locked to the main body side of the photoreceptor cartridge 2 and the other end is locked to the bracket 15.
9, the bracket 15 is urged in the direction in which the blade 17 presses against the photoconductor 1.

Returning to FIG. 1, below the cleaning means 11, a collection box 21 is provided along the photoreceptor 1 as a collection means for collecting the developer removed by the cleaning means 11.

Next, a latent image forming means for forming a latent image on the photosensitive member 1 will be described. Since the image forming apparatus of the present embodiment is a four-color image forming apparatus, it has four latent image forming means for each color. That is, a Y optical writing section 25Y for forming a Y (yellow) latent image on the photoconductor 1 using a laser beam, and an M (magenta) latent image on the photoconductor 1 using a laser beam. And a C optical writing unit 2 for forming a C (cyan) latent image on the photoconductor 1 using a laser beam.
9C and K (black) using a laser beam for the photoreceptor 1
K writing unit 31K for forming a latent image for use.

Since the constructions of these four optical writing sections are the same, the Y optical writing section 25Y will be described with reference to FIGS.
Will be described, and description of other optical writing units will be omitted. In these figures, reference numeral 33 denotes a laser light source that emits a laser light on which a Y image signal is superimposed. The laser light from the laser light source 33 is
The light is reflected and scanned by the movement of the rotating surface, and passes through the fθ lens 39 and the cylindrical lens 41 to scan and expose the photosensitive surface of the photosensitive member 1. By this scanning exposure, an electrostatic latent image is formed on the photosensitive surface of the photoconductor 1.

Next, as shown in FIGS. 1 and 5, an image forming cartridge 3 detachably provided in the image forming apparatus.
5 will be described. In the image forming cartridge 35, four developing means for developing the electrostatic latent images of each color formed on the photoconductor 1 are provided. That is, the Y optical writing unit 2
Y developing section 42Y for developing the latent image formed in 5Y, M
An M developing section 43M for developing the latent image formed by the optical writing section 27M, a C developing section 45C for developing the latent image formed by the C optical writing section 29C, and a K optical writing section 31
A K developing section 47K for developing a latent image formed by K.

Since the construction of these four developing units is the same,
The Y developing unit 42Y will be described, and the description of the other developing units will be omitted. Numerals 51 and 52 stir and transport the Y developer (in the present embodiment, the developer is a two-component developer composed of a toner and a carrier) transported from a developer reservoir (not shown). Screw 53, developing sleeve 5
5 is a supply roller for supplying the developer to the developing roller 5. The developing sleeve 55 carries a developer, reversely develops the electrostatic latent image on the photoconductor 1, and forms a toner image on the photoconductor 1.

Further, in the image forming cartridge 35,
A band electrode of a charging unit that applies a charge to the photoconductor 1 is provided corresponding to the developing units 42Y, 43M, 45C, and 47K of the respective colors. That is, a band electrode 61 for Y, a band electrode 63 for M, a band electrode 65 for C, and a band electrode 67 for K.

On the other hand, the charging means for each color in the present embodiment comprises grids 71, 7 for controlling the charging potential on the photosensitive member 1.
3,75,77 but these grids 7
1, 73, 75 and 77 are provided on the side of the photoreceptor cartridge 2 as shown in FIG.

Returning to FIG. 1, reference numeral 81 denotes a paper feed unit,
Is provided in the cassette 83. The transfer paper P in the cassette 83 is carried out by the carry roller 85, nipped and carried by the carry roller pair 87 and the registration roller 88, and fed to the transfer unit 91.

The transfer section 91 includes a transfer pole 93 for transferring the developer image on the photoreceptor 1 to transfer paper P by corona discharge,
A separation pole 95 for separating the transfer paper P from the photoconductor 1 by an AC discharge is provided.

Reference numeral 100 denotes a heat roller pair 101 sandwiched between
A fixing unit that applies heat and pressure to the transfer sheet P to fuse the toner to the transfer sheet P. Reference numeral 110 denotes a pair of conveyance rollers that pinch and convey the transfer sheet P that has been thermally fixed to a discharge tray 111.

Reference numeral 120 denotes a paper feed path through which transfer paper P of another size conveyed from a paper feed unit provided outside the apparatus passes.

Next, the operation of the above configuration will be described. When the photoconductor 1 is driven in the direction of arrow I, first, the photoconductor 1 is charged by a charging means for Y including a band electrode 61 and a grid 71.
The upper portion has a predetermined charging potential.

Next, an electrostatic latent image is formed on the photosensitive member 1 by the Y optical writing section 25Y. Then, the Y developing unit 42
The toner in the developer carried on the Y developing sleeve 55 moves onto the photoconductor 1 due to Coulomb force, and a toner image is formed on the photoconductor 1.

The same operation is performed for the remaining colors, that is, M,
The process is performed for C and K to form Y, M, C, and K toner images on the photoconductor 1.

On the other hand, the transfer paper P is conveyed from the paper supply unit 81 to the transfer unit 91 by the conveyance roller 85 and the conveyance roller pair 87.

The fed transfer paper P is transferred to registration rollers 8.
8, the timing is adjusted with respect to the toner image on the photoreceptor 1, and then fed synchronously to the transfer unit 91, charged by the transfer pole 93 of the transfer unit 91, and the developer image on the photoreceptor 1 is transferred to the transfer paper. Transferred to P.

Further, the transfer paper P is separated from the photoreceptor 1 by the charge eliminating action of the separation pole 95.

Next, the transfer sheet P is heated and pressed by the fixing unit 100, the toner is fused to the transfer sheet P, and is discharged onto the discharge tray 111 by the pair of conveying rollers 110.

The surplus toner on the photosensitive member 1 after the transfer is removed by the blade 17 of the cleaning means 11 and stored in the collection box 21.

According to the image forming apparatus having the above-described structure, the cleaning means 11 for removing excess toner on the photosensitive member 1 is provided above the surface on which the photosensitive member 1 moves from the bottom to the top. By providing the collection box 21 for collecting the surplus toner, the removed toner can be dropped by gravity without using the conveying means, and the mechanism can be simplified and the apparatus can be downsized. or,
By providing the cleaning unit 11 and the collection box 21 along the photoconductor 1, it is possible to prevent the heat from the fixing unit 100 from adversely affecting the photoconductor 1.

Further, the photosensitive member 1 is bent using the pressing roller 9 in the direction of the closed space formed by the photosensitive member 1, and the collection box 21 is provided in the space formed by the bending, thereby further reducing the size of the apparatus. Can be achieved.

If the grids 71, 73, 75 and 77 having the same life as the photoconductor 1 are provided in the photoconductor cartridge 2, the photoconductor 1 and the grids 71, 73, 77 can be formed in one operation.
75 and 77 can be exchanged, and parts exchange becomes easy.

Further, grids 71, 73, 75, 77
Are provided in the photoreceptor cartridge 2 and grids 71 and 7 are provided.
By integrating 3,75,77 and photoconductor 1,
The distance between the grids 71, 73, 75, 77, which have strict distance accuracy, and the photoconductor 1 can always be maintained at a constant accuracy.

Further, the developing units 42Y, 43M, 45C, 4
The strip electrodes 61, 63, 65, 6 having the same life as the life of 7K
By providing the image forming cartridge 7 in the image forming cartridge 35, the developing unit and the band electrode can be exchanged by one operation, and the parts exchange becomes easy.

Further, since the developing unit for each color and the respective band electrodes of the charging means for each color are integrated into the image forming cartridge 35, even a multi-color image forming apparatus requires only one operation. The developing section and the band electrode can be exchanged, and parts exchange becomes easy.

The present invention is not limited to the above embodiment. In the above embodiment, the description has been given of a multicolor image forming apparatus, but the present invention can be applied to a monochromatic image forming apparatus.

[0079]

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

Example 1 A belt-shaped photoreceptor was formed by laminating an intermediate layer and a charge generation layer on a polyester resin on which aluminum was deposited in this order, and then drying the coating liquid for a charge transport layer to 20 μm. Obtained by coating.

The intermediate layer was made of polyamide (manufactured by Toray Industries, Inc., CM-
8000) 3 parts by weight, 80 parts by weight of methanol and 1-
It was formed by dip-coating to a thickness of 1.0 μm using a coating solution in which 20 parts by weight of butanol was mixed and dissolved.

The coating solution for the charge generation layer was prepared by mixing 20 parts by weight of a Y-type titanyl phthalocyanine compound represented by the following structural formula A, 10 parts by weight of a silicone resin (KR-5240, manufactured by Shin-Etsu Chemical Co., Ltd.), and 800 parts by weight of 2-butanone. Then, the mixture was dispersed in a sand mill for 10 hours. This was dip-coated on the intermediate layer to prepare a charge generation layer having a thickness of 0.25 μm.

The coating liquid for the charge transport layer is a polycarbonate resin having a viscosity average molecular weight of about 50,000 (BP-PC, manufactured by Idemitsu Co., Ltd.) as shown in the following structural formula B.
In addition to a binder film coating solution dissolved in an appropriate amount in dichloroethane, a compound represented by the following structural formula C is added as a charge transport material,
It was obtained by mixing and dissolving 65 parts by weight of the polycarbonate resin.

[0084]

Embedded image

The produced photoreceptor is adhered by ultrasonic waves in a belt shape such that the photosensitive layer faces outward, and a urethane guide member (width W10 mm, height H2.0
mm) with an adhesive. At this time, the guide was set so that there was no gap between the ends / ends (0 mm).

[0086] Using a running test machine shown in FIG.
The belt running property was examined.

In FIG. 8, the roller 211 has an outer diameter of 15 m.
m, the roller 212 is an outer diameter of 15 mm, the roller 213 is an outer diameter of 15 mm, and the roller 214 is a roller having an outer diameter of 15 mm and stretched (25 gf / mm). At this time, the length of the photoreceptor wound around (contacting) the roller is at least 4
The belt-shaped photoreceptor was stretched in such a positional relationship as to be mm. In the vicinity of both ends of each roller, there are grooves corresponding to the guides for passing the guides. The driving device thus obtained is driven to rotate, and a test is performed in which a stress caused by repeated bending is applied to the photoconductor. The guide does not run on the rollers while the photoconductor rotates 5,000 times. The condition was observed.

Example 2 In Example 1, the guide was set so that the distance between the ends was 1 mm, and the outer diameter of the roller 211 was 20 mm,
A belt-shaped photoconductor is used in which the outer diameter of the photoconductor is 20 mm, the outer diameter of the roller 213 is 20 mm, the outer diameter of the roller 214 is 20 mm, and the shortest length of the photoconductor wound around the roller is 7 mm. A driving test was performed in the same manner as in Example 1 except that

Example 3 In Example 1, the guide was set so that the distance between the ends was 3 mm.
A belt-shaped photoconductor is used in which a roller having an outer diameter of 20 mm, an outer diameter of 20 mm for the roller 213, and an outer diameter of 20 mm for the roller 214 is used, and the shortest length around which the photoconductor is wound is 10 mm. A driving test was performed in the same manner as in Example 1 except that

Example 4 In Example 1, the guide was set so that the distance between the ends was 5 mm.
A belt-shaped photoconductor is used in which a roller having an outer diameter of 30 mm, an outer diameter of 30 mm for the roller 213, and an outer diameter of 20 mm for the roller 214 is used, and the shortest length of the photoconductor wound around the roller is 10 mm. A driving test was performed in the same manner as in Example 1 except that

Example 5 In Example 1, the guide was set so that the distance between the ends was 20 mm. The outer diameter of the roller 211 was 40 mm, the outer diameter of the roller 212 was 30 mm, and the outer diameter of the roller 213 was 30 m.
m, a roller having an outer diameter of 40 mm is used as the roller 214, and the shortest length of the photosensitive member wound around the roller is 25 mm.
A driving test was performed in the same manner as in Example 1 except that the belt-shaped photosensitive member was stretched in such a positional relationship as follows.

Comparative Example 1 In Example 1, the guide was set so that the distance between the ends was 10 mm, and the belt was positioned so that the shortest length of the photosensitive member wound around the roller was 7 mm. A driving test was performed in the same manner as in Example 1 except that the photoconductor was stretched.

Comparative Example 2 In Example 2, the guide was set so that the distance between the ends was 12 mm, and the belt was positioned so that the shortest length of the photosensitive member wound around the roller was 8 mm. A driving test was performed in the same manner as in Example 2 except that the photoconductor was stretched.

Comparative Example 3 In Example 1, the guide was set so that the distance between the ends was 15 mm, the outer diameter of the roller 211 was 20 mm, the outer diameter of the roller 212 was 30 mm, the outer diameter of the roller 213 was 20 mm, and
In the same manner as in Example 1 except that a roller having an outer diameter of 20 mm was used as the roller 214 and the belt-shaped photosensitive member was stretched in a positional relationship such that the shortest length of the photosensitive member wound around the roller was 10 mm. Then, a driving test was performed.

Comparative Example 4 In Example 1, the guide was set so that the distance between the ends was 22 mm. The outer diameter of the roller 211 was 30 mm, the outer diameter of the roller 212 was 30 mm, and the outer diameter of the roller 213 was 30 mm.
Except that a roller having an outer diameter of 30 mm is used as the roller 214 and the belt-shaped photoconductor is stretched in a positional relationship such that the shortest length of the photoconductor wound around the roller is 13 mm, the same as in Example 1 And a driving test.

The results are shown in Table 1.

[0097]

[Table 1]

According to Table 1, the distance L1 between the ends / ends of the guide for running control is shorter than the arc L2 in which the belt-like support is in contact with the belt stretching roller including the belt transport roller (L1 <L2). In this case, it is clear that the belt photoreceptor does not climb from the end during running and does not cause damage to the belt support or the photosensitive layer.

[0099]

According to the present invention, there is provided an image forming apparatus and an image forming method which prevent breakage of a belt-shaped photosensitive member due to running thereon even when used repeatedly for a long period of time, and prevent the photosensitive layer from cracking, film peeling, and image defects. It is possible to provide a belt-shaped photoreceptor used therefor.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged configuration diagram of a cleaning unit in FIG.

FIG. 3 is a plan view of an optical writing unit in FIG. 1;

FIG. 4 is a configuration diagram when the photosensitive member cartridge is detached from the image forming apparatus in FIG.

FIG. 5 is a configuration diagram when the image forming cartridge is detached from the image forming apparatus in FIG.

FIG. 6 is a view for explaining a guide provided on the back surface of the support for regulating the running of the belt-shaped photoconductor.

FIG. 7 is a diagram illustrating a situation when a belt-shaped photoconductor is run.

FIG. 8 is a perspective view illustrating a traveling test machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Belt-shaped photoreceptor (there is simply a photoreceptor) 2 Photoreceptor cartridge 3 Upper roller 5 Lower roller 7 Lateral roller 9 Pressing roller 11 Cleaning means 35 Image forming cartridge 61, 63, 65, 67 Strip electrodes 71, 73 , 75, 77 Grid 201 Guide 202 Recess 203 Stretch roller L1 Distance between end / end of guide L2 Length of arc where belt-shaped photoreceptor supports abut on stretch roller

Claims (8)

[Claims] 1. An electrophotographic belt-shaped photoconductor having at least a photosensitive layer having a charge generation layer and a charge transport layer on a support made of a polymer material having a thickness of 50 to 100 μm. An image forming apparatus in which at least one of the frame rollers is in contact with the surface of the photosensitive layer, wherein a guide is provided on the back surface of the support for regulating the movement of the photosensitive member, and the distance L1 between the ends / ends of the guide is determined by the support Is shorter than the length of an arc L2 in contact with the belt tension roller (L1 <L2). 2. The end / end distance L1 of the guide and the length of an arc L2 at which the support comes into contact with the belt tension roller satisfy the following condition: 0 mm ≦ L1 ≦ 20 mm 0 mm <L2 ≦ 30 mm The image forming apparatus according to claim 1. 3. The image forming apparatus according to claim 1, wherein a width W and a height H of the guide satisfy 1 mm ≦ W ≦ 20 mm 0.5 mm <H ≦ 5 mm. 4. The guide according to claim 1, wherein urethane, silicone, polyester, acrylic resin or metal is used as the material of the guide, and the guide is provided on the back surface of the support with an adhesive, a double-sided tape or a hot melt. Item 4. The image forming apparatus according to item 1, 2 or 3. 5. The belt tension roller has a diameter of at least one of 15 to 40 mm.
The image forming apparatus according to claim 1. 6. A method in which a process of developing an electrostatic latent image formed by writing on a photoconductor by a laser beam is repeated to form a multicolor superimposed toner image on the photoconductor, and then collectively transfer the images. Claim 1 characterized by taking
6. The image forming apparatus according to claim 5, wherein: 7. A belt-shaped photoconductor, which is used in the image forming apparatus according to claim 1. 8. An electrophotographic belt-like photoreceptor having at least a photosensitive layer comprising a charge generation layer and a charge transport layer on a support made of a polymer material having a thickness of 50 to 100 μm. An image forming method in which at least one of the frame rollers is in contact with the surface of the photosensitive layer, wherein a guide is provided on the back surface of the support for regulating the running of the photosensitive member, and the distance L1 between the ends of the guide is determined by the support. Is shorter than the length of an arc L2 in contact with the belt stretching roller (L1 <L2).