JP2000276005A - Electrophotographic endless belt photoreceptor, and electrophotographic image forming method and device and photoreceptor cartridge using photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an endless belt photoreceptor which does not cause faulty carrying or image defect by providing a specified joint angle and a specified backup rib and the like and stretching and laying the belt photoreceptor so that the flatness thereof may be equal to or under a specified value. SOLUTION: By stretching and laying the endless belt photoreceptor so that the joint part angle thereof may be >=1.0 deg. and further the flatness of the belt photoreceptor at an image writing position and a developing position may be <=0.2 mm, the shake of the belt photoreceptor at an exposure part and a developing part is made small so as to prevent the image defect due to the occurrence of blur and the color slurring. The belt photoreceptor is provided with the backup rib on its back surface, and its flatness is made <=0.2 mm by at least adjusting the perpendicularity of the rib within O to O.3 mm and the flatness of the roller within 0 to 0.3 mm. The angle of the rib is adjusted by enlarging and observing a position where the rib is stuck to the photoreceptor and sticking the rib to the photoreceptor while setting a ruler and performing positioning. The parallelism of the roller for laying is adjusted while measuring the position of the roller by a laser length measuring machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic endless belt photoreceptor used for copying machines, printers, and the like, an electrophotographic image forming method using the photoreceptor, an electrophotographic image forming apparatus, and a photoreceptor cartridge. The present invention particularly relates to an electrophotographic endless belt photoconductor effective for forming a color image, an electrophotographic image forming method using the photoconductor, an electrophotographic image forming apparatus, and a photoconductor cartridge.

[0002]

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

[0003] An image forming apparatus based on the electrophotographic method has a high speed.
Although it has high image quality, it is slightly larger in terms of equipment than other image forming methods, and there is a strong demand for miniaturization in order to respond to the needs such as installation in an ordinary office as recently. . In particular, in recent color trends, this has become a very serious problem.

In a color image forming apparatus, an image forming mechanism for each color of cyan, magenta, yellow and black is usually required, and there is a greater obstacle to downsizing. In the electrophotography system, the belt photoreceptor has the advantage that the space around the photoreceptor can be made smaller than that of the drum photoreceptor, and the arrangement of the image forming mechanism for each color is more flexible. However, on the other hand, the photoreceptor of the belt is liable to bend and the image quality is liable to deteriorate.

In particular, as described in JP-A-60-75850, a color image forming method for forming a multicolor superimposed toner image by repeating formation of an electrostatic latent image and color development on an electrophotographic photosensitive member. When the belt photoreceptor is applied to the belt, the deflection of the photoreceptor of the belt causes the edge to be distorted, which causes discharge breakdown and film peeling of the photoconductive layer, causing image defects and poor conveyance of the belt photoreceptor. Cause

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic endless belt photoreceptor which does not cause the above-described conveyance failure or image defect, an electrophotographic image forming method using the photoreceptor, and an electrophotographic method. An object of the present invention is to provide an image forming apparatus and a photoreceptor cartridge.

[0007]

SUMMARY OF THE INVENTION The present inventors have improved the above-mentioned problems of the belt photoreceptor and designed the end of the belt by a fusing method or a stretching method so that the belt can be designed into a compact color electrophotographic apparatus. Various examinations were made on roller contact and the like, and a measure for minimizing the deflection of the belt and preventing image defects was found.

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

1. At least a conductive layer and a photosensitive layer are provided on a flexible support, and at least three are provided on the back side of the support and at least one is provided on the front side of the photosensitive layer by a stretching roller. The formation of an electrostatic latent image on the supported and conveyed electrophotographic endless belt photoreceptor and the subsequent development of the electrostatic latent image are repeated in a non-contact manner under the condition of applying an alternating voltage of 1.8 kV or more. An electrophotographic endless belt photoreceptor capable of forming an image by forming a multi-color superimposed toner image on the surface of the photosensitive layer and then transferring the toner image collectively onto a transfer material has a seam of 1.0 ° or more. Having a seam having an outer angle, and having a squareness of 0 to 0.3 m on the back surface of the belt photoreceptor.
m has a backup rib at both ends, and by adjusting the parallelism of the tension roller to 0 to 0.3 mm,
An electrophotographic endless belt photoconductor, wherein the flatness of the belt photoconductor at an image writing position and a developing position is stretched to 0.2 mm or less.

[0010] 2. 2. The electrophotographic endless belt photoconductor according to the above item 1, wherein a joint angle of the electrophotographic endless belt photoconductor is 1.0 ° to 20.0 ° or less.

3. At least three conductive layers and a photosensitive layer are provided on a flexible support, and three or more are provided on the back side of the support and one or more support rollers are provided on the front side of the photosensitive layer. On the conveyed electrophotographic endless belt photoreceptor, the formation of an electrostatic latent image and the subsequent development of the electrostatic latent image are repeated in a non-contact manner under an application condition of an alternating voltage of 1.8 kV or more. An electrophotographic image forming method in which a multicolor superimposed toner image is formed on an endless belt photoreceptor and the toner image is collectively transferred onto a transfer material, wherein the electrophotographic endless belt photoreceptor is It has a seam having a seam angle of 1.0 ° or more, and has backup ribs having a squareness of 0 to 0.3 mm at both ends on the back surface of the belt photoreceptor. Degree 0
By adjusting to 0.3 mm, the flatness of the belt photoconductor at the image writing position and the developing position is 0.2
An electrophotographic image forming method, wherein the electrophotographic image forming method is stretched to a length of not more than mm.

4. At least three conductive layers and a photosensitive layer are provided on a flexible support, and three or more are provided on the back side of the support and one or more support rollers are provided on the front side of the photosensitive layer. On the conveyed electrophotographic endless belt photoreceptor, the formation of an electrostatic latent image and the subsequent development of the electrostatic latent image are repeated in a non-contact manner under an application condition of an alternating voltage of 1.8 kV or more. In an electrophotographic image forming apparatus of a type in which a multicolor superimposed toner image is formed on an endless belt photoconductor and the toner image is collectively transferred onto a transfer material, the electrophotographic endless belt photoconductor is A belt having a seam having a seam angle of 1.0 ° or more, a backup rib having a squareness of 0 to 0.3 mm at both ends on the back surface of the belt photoreceptor, and a stretching roller To adjust the parallelism of the Ri, electrophotographic image forming apparatus characterized by flatness of the belt photoreceptor in the image writing position and the developing position is stretched 0.2mm or less.

5. At least a conductive layer and a photosensitive layer are provided on a flexible support, and at least three are provided on the back side of the support and at least one is provided on the front side of the photosensitive layer by a stretching roller. A photoconductor cartridge having a supported and conveyed electrophotographic endless belt photoconductor, wherein the electrophotographic endless belt photoconductor and the stretching roller are integrally and replaceably combined; The photo endless belt photoreceptor has a seam portion having a seam angle of 1.0 ° or more, and has a back rib having a squareness of 0 to 0.3 mm at both ends on the back surface of the belt photoreceptor, By adjusting the parallelism of the stretching roller to 0 to 0.3 mm, the flatness of the belt photoconductor at the image writing position and the developing position is stretched to 0.2 mm or less. Photoconductor Cartridges.

Hereinafter, the present invention will be described in detail.

At present, the most frequently used electrophotographic photosensitive member has a structure in which an aluminum drum is used as a support (also referred to as a substrate) and a photosensitive layer is provided thereon. In this case, since the drum substrate itself also serves as the conductive layer, the conductive layer does not have to be particularly provided. However, when a belt photoreceptor is used by using a flexible belt support as in the present invention, the support is usually insulative and a conductive layer is generally applied separately.

As a method for forming the conductive layer, aluminum or I
Metals or metal oxides such as TO (Indium Tetan Oxide) or the like by vapor deposition or sputtering, or those formed by coating a conductive resin with a mixture of a resin and conductive fine particles such as ITO or alumina. No.

As the material for the support of the belt photoreceptor that can be used in the present invention, generally known engineering plastic bases can be used. For example, polyethylene terephthalate, polyethylene naphthalate, polyetherimide, polyether sulfide Phone, polycarbonate, polyarylate and the like. The material is not limited to these, and any material having characteristics as a belt support may be used. Among the above-mentioned support materials, polyethylene naphthalate is particularly easy to satisfy the requirements. Further, the thickness of the belt support is often 50 to 200 μm in order to balance rigidity and flexibility.

In order to design a compact color electrophotographic apparatus using a belt electrophotographic photoreceptor, a stretch roller is brought into contact with the front and back surfaces of the photoreceptor to reduce the space formed by the belt and the stretch roller as much as possible. A method of reducing the size is considered, but such an image forming method, that is, at least a conductive layer and a photosensitive layer are provided on a flexible support, and three or more conductive layers and a photosensitive layer are provided on the back side of the support, The formation of an electrostatic latent image on the electrophotographic endless belt photoreceptor supported and transported by one or more stretching rollers provided on the front surface side and the subsequent development of the electrostatic latent image are not in contact with each other. An electrophotographic image forming method for repeatedly forming a multicolor superimposed toner image on the surface of the photosensitive layer under the condition of applying an alternating voltage of 8 kV or more, and then transferring the toner image collectively to a transfer material, Electron used here If the seam angle of the endless belt photoreceptor is 1.0 ° or more, and the flatness of the belt photoreceptor at the image writing position and the developing position is not stretched to 0.2 mm or less, the exposure unit and the developing unit In this case, blurring of the belt photoreceptor becomes large, blurring occurs in a finished image, and color misregistration of a color image occurs. In particular, when the seam angle is less than 1.0 °, even if the flatness of the belt photoconductor at the image writing position and the developing position can be stretched to 0.2 mm or less, it is difficult to sufficiently achieve the conveyance stability. It turned out that. The reason for this is still unknown, but one is that when the seam angle is less than 1.0 °, the belt photoconductor becomes unstable when the seam portion of the belt hits the roller contact portion. As a result, the belt photoreceptor does not have sufficient running stability, and the belt photoreceptor is derailed, or the belt itself is broken, and eventually the belt photoreceptor is damaged or broken. . That is, it has been found that when the seam portion of the endless belt is brought into contact with the roller contact portion with the rotation of the endless belt during image formation, if the seam portion is prevented from contacting all at once over the entire length, it has been found that the conveyance stability is good. . Therefore, the joint angle defined later is set to 1.
By setting the flatness of the belt photoreceptor at the image writing position and the developing position to 0.2 mm or less in addition to 0 ° or more, the formation of a color image using the endless belt photoreceptor is successfully achieved. I can do it. If the seam angle is 1.0 ° or more, the seam of the belt and the roller contact portion hardly come into contact at once, and the belt running stability is improved. On the other hand, if the seam angle is too large, Useless seams increase, and a compact device cannot be designed. For this reason, the joint angle is preferably 20.0 ° or less.

Next, as a method of processing the belt-shaped photoconductor to obtain the electrophotographic endless belt photoconductor of the present invention, a method of fusing the end surface of the belt with an adhesive, a method of heat fusing,
Although there are various methods such as a method of ultrasonic fusion, any of those methods may be used. In short, the point at which the joint angle in the present invention is designed to be 1.0 ° or more is that the belt end is cut obliquely at a desired angle before fusing the belt photoreceptor, and the angle is adjusted along the angle. What is necessary is just to fuse.

Further, in a color process in which different kinds of color toners are accurately superimposed on the photosensitive member, it is necessary to reduce the flatness of the endless belt photosensitive member, and the flatness limit is limited to the image writing position and the developing position. At 0.2
mm or less. For this reason, the belt photoreceptor has a backup rib on the back surface, and the flatness is adjusted by adjusting at least the perpendicularity of the rib to a range of 0 to 0.3 mm and the parallelism of the roller to a range of 0 to 0.3 mm. Needs to be 0.2 mm or less. The perpendicularity of the rib is 0 to 0.3 mm and the parallelism of the roller is 0 to 0.3 mm.
The method of adjusting the thickness to the range of mm can be achieved by the following measures.

The adjustment of the rib angle can be achieved by, for example, observing the attached position on a magnified scale when attaching the rib to the photoreceptor, and attaching the rib to the photoreceptor while positioning it with a ruler. On the other hand, the parallelism of the tension roller is adjusted while accurately measuring the position of the roller with a laser length measuring device or the like.

Hereinafter, the structure and image forming process of a typical color image forming apparatus of the present invention will be described with reference to FIGS.

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

FIG. 2 is an enlarged view of the cleaning means in FIG.

FIG. 3 is a plan view of the optical writing section in FIG.

FIG. 4 is a structural view when the photosensitive 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.

First, as shown in FIGS. 1 and 4, a photoreceptor cartridge 2 removably provided in the image forming apparatus will be described. The photoconductor 1 of the endless belt wound around the upper roller 3, the lower roller 5, and the horizontal roller 7 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 photosensitive member 1 moves from the bottom to the top, the photosensitive member 1 is moved in the direction of a closed space formed by the photosensitive member 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 collecting 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 unit 25 that forms a Y (yellow) latent image on the photoconductor 1 using laser light, and an M (magenta) latent image on the photoconductor 1 using laser light. And an M optical writing portion 27 for forming
C optical writing section 29 for forming a latent image for (cyan)
And a K optical writing unit 31 that forms a K (black) latent image on the photoreceptor 1 using laser light.

The four optical writing units 25, 27,
Since the configurations of 29 and 31 are the same, the Y optical writing unit 25 will be described with reference to FIGS. 1 and 3 and the description of the other optical writing units will be omitted. In this apparatus, the exposure incident angle differs depending on the color, but dot exposure is performed in each case.

In these figures, reference numeral 33 denotes a laser light source which emits a laser light on which a Y image signal is superimposed. The laser light from the laser light source 33 is reflected by the movement of the rotating surface of the polygon mirror 37, scanned, and f
The photosensitive surface of the photoconductor 1 is scanned and exposed through the θ lens 39 and the cylindrical lens 41. 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
5, a Y developing unit 42 for developing the latent image formed, and an M developing unit 4 for developing the latent image formed by the M optical writing unit 27.
3, a C developing section 45 for developing the latent image formed by the C optical writing section 29, and a K developing section 47 for developing the latent image formed by the K optical writing section 31.

The four developing units 42, 43, 45, 4
7, the configuration of the Y developing unit 42 will be described, and the description of the other developing units will be omitted. Screws 51 and 52 agitate 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); 53
Reference numeral denotes a supply roller for supplying a developer to the developing sleeve 55. 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.

Since one of the objects of the present invention is a color image forming method for forming a superimposed toner image on an endless belt photoreceptor, a non-contact developing method is most suitable for this developing condition. It is necessary to apply an alternating electric field of .8 kV or more. If the alternating electric field is less than 1.8 kV, the developability is significantly deteriorated.

Further, in the image forming cartridge 35,
A band electrode of a charging unit for applying a charge to the photoconductor 1 is provided corresponding to the developing units 42, 43, 45, and 47 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 of 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.

Referring back to FIG. 1, reference numeral 81 denotes a paper feeding 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 photosensitive member 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 fixing unit that applies heat and pressure to the transfer paper P by sandwiching the pair of heat rollers 101 to fuse the toner to the transfer paper P. Reference numeral 110 denotes a discharge tray for transferring the transfer paper P that has been thermally fixed. It is a pair of transport rollers for nipping and transporting up to 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. As a charging method, a normal scorotron may be used, or a sawtooth electrode may be used as a discharge electrode. In this case, the applied voltage of the grid may be set to a value close to the charging potential of the photosensitive member.
About 00V is preferable.

Next, an electrostatic latent image is formed on the photosensitive member 1 by the Y optical writing section 25. Then, the toner in the developer carried on the developing sleeve 55 of the Y developing unit 42 moves onto the photoconductor 1 due to the 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 fed from the paper feeding section 81 by the transport roller 85 and the transport roller pair 87 to the transfer section 9.
It is conveyed toward 1.

After the fed transfer paper P is adjusted in timing with the toner image on the photosensitive member 1 by the registration roller 88, the transfer paper P is synchronously fed to the transfer unit 91, and is transferred to the transfer unit 91.
And the developer image on the photoconductor 1 is transferred to the transfer paper 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 paper P is heated by the fixing unit 100,
The toner is pressed, the toner is fused to the transfer paper P, and is discharged onto the discharge tray 111 by the pair of transport rollers 110.

Excess 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 above-described image forming apparatus, 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.
The cleaning means 11 and the collection box 21
Is provided 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 by 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. The size can be reduced.

Further, since the photoreceptor cartridge 2 is provided with the grids 71, 73, 75, 77 having the same life as the photoreceptor 1, the photoreceptor 1 and the grid 7 can be operated in one operation.
1, 73, 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, since the band electrodes 61, 63, 65, and 67 having the same life as the developing units 42, 43, 45, and 47 are provided in the image forming cartridge 35, the developing unit 42, 43 43, 45, 47 and band electrodes 61, 63,
65, 67 can be replaced, and parts replacement is simplified.

Further, the developing units 42, 43, 4 of the respective colors
5, 47 and the respective band electrodes 6 of the charging means for each color.
1, 63, 65, 67 are integrated into the image forming cartridge 35, so that even in a multicolor image forming apparatus, the developing sections 42, 43, 45, 47 and
1, 63, 65 and 67 can be replaced, and parts replacement is simplified.

Next, the photosensitive layer constituting the electrophotographic photosensitive member of the present invention will be described.

The electrophotographic endless belt photoreceptor of the present invention has a photosensitive layer on the endless belt support. That is, an organic photoconductive photoreceptor containing both a charge transport material (CTM) and a charge generation material (CGM) is preferable, and in particular, CGM, CT
A function-separated type photosensitive layer in which M has a different layer structure is preferred.

A binder resin for the charge transport layer (CTL),
A generally known charge transporting substance 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, organic metal compounds, polyvinyl butyral, polystyrene, styrene
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. Examples of the charge generating material include metal or metal-free phthalocyanine compounds, 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. And a charge transfer complex composed of poly-N-vinylcarbazole and trinitrofluorenone, and the like, but are 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, one of a perylene compound, an imidazole perylene compound and a metal phthalocyanine compound, and titanyl phthalocyanine (TiOPc) are 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 °.

As the binder resin usable for the charge generation layer, for example, polystyrene resin, polyethylene resin,
Polypropylene resin, polyacrylic resin, polymethacrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl butyral resin, polyepoxy resin, polyurethane resin, polyphenol resin, polyester resin, polyalkyd resin, polycarbonate resin, polysilicone resin, Polymelamine resins, and copolymer resins containing two or more of the repeating units of these resins, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, and polymers Examples include, but are not limited to, 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 silicon-modified polyvinyl butyral resin, silicon resin or both. A mixture thereof is given.

Further, in order to reduce the fatigue deterioration upon repeated use or to further improve the durability, a known antioxidant (hindered phenols, hindered amines, etc.) may be added to each layer of the photoreceptor. et
c. ), 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.

For further improving 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.

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.

[0073]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto. In this embodiment, “parts” means “parts by weight”.

Examples 1 to 5 and Comparative Examples 1 to 5 Teijin U4z (thickness 75 mm) having a length of 602 mm and a width of 348 mm
An aluminum vapor-deposited layer having a thickness of 0.2 μ was provided on the polyester base of μ).

The following layers were sequentially formed on this layer by dip coating.

Subbing layer Titanium chelate compound TC-750 (Matsumoto Pharmaceutical Co., Ltd.) 20 parts by weight Silane coupling agent KRM-503 (Shin-Etsu Chemical Co., Ltd.) 13 parts by weight 2-propanol 100 parts by weight 100 ° C 90mi by dip coating on transparent conductive layer
n was dried to provide an undercoat layer having a thickness of 1.0 μm.

Charge generation layer Y-type titanyl phthalocyanine (Titanyl phthalocyanine having a maximum diffraction angle of 27.3 ° at Bragg angle 2θ in Cu-Kα X-ray diffraction) 45 parts by weight Silicone resin solution KR-5240 (manufactured by Shin-Etsu Chemical Co., Ltd.) 45 parts by weight of 2-butanone 100 parts by weight were mixed and dispersed in a sand mill for 10 hours to obtain a charge generating layer coating liquid. This coating solution was applied onto the undercoat layer by dip coating to obtain a charge generation layer having a thickness of 0.25 μm.

Charge transporting layer Charge transporting substance (triphenylamine stilbene type) 8 parts by weight Bisphenol Z type polycarbonate Z-300 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 12 parts by weight 1,100 parts by weight of 1,2-dichloroethane are mixed and dissolved. Thus, a charge transport layer coating solution was obtained. This coating solution was dip-coated on the charge generation layer and heat-treated at 90 ° C. for 60 minutes to form a charge transport layer having a thickness of 25 μm.

The photosensitive layer surface of the above-mentioned photosensitive member is turned to the surface,
mm and ultrasonic fusion was performed. At this time, the seam inclination was changed by appropriately selecting the conditions for ultrasonic fusion.

The flatness of the belt is adjusted by stretching the belt for a long period (one month, 30 ° C.-50% RH).
In addition, some parts were intentionally added and adjusted. The cartridge for stretching the belt photoreceptor has the structure shown in FIG. 4B, and three rollers are in contact with the back surface of the belt photoreceptor and one roller is in contact with the front surface. The belt photoreceptor's driving condition when the belt photoreceptor with the perpendicularity of the backup rib adjusted in advance is stretched over the cartridge, the roller parallelism is adjusted, and the belt photoreceptor's flatness and seam angle are changed. The effect on the image quality was evaluated by incorporating the color image forming apparatus in FIG. 1 to form a color image.

Table 1 shows the conditions of the examples and the comparative examples and the evaluation results.

[0082]

[Table 1]

Definition of Belt Photoreceptor Flatness and Measurement Method Definition: The shortest distance when the belt position is sandwiched between two planes is defined as the belt flatness.

Measurement method: The surface position of the belt was measured at a writing position and a development position using a laser displacement meter (Keyence Corporation LC2400) in accordance with JIS B0021, and flatness was created based on the data. did.

Definition and Measurement Method of Rib Squareness Definition: The position of the rib end is measured under the condition that the belt photoreceptor is stretched as shown in FIG. 6, and the shortest distance when the position is sandwiched between two planes is measured. Angle.

Measurement method: Measurement is performed using a three-dimensional shape measuring instrument, a laser displacement meter, or the like.

Definition and Measurement Method of Roller Parallelism Definition: When the center axes of two adjacent rollers are virtually translated under the condition that the belt is stretched over the stretching rollers, and the two are sandwiched between two planes Is the parallelism.

Measurement method: The measurement is performed by measuring the roller position using a three-dimensional shape measuring instrument or a laser displacement meter.

Definition and Measurement Method of Seam Angle The angle of the seam portion is defined and measured as an angle θ from the end to the perpendicular under the stretched condition as shown in FIG.

Evaluation Method and Judgment Criteria of Belt Driving Condition Using the prototype shown in FIG. 1, an image printing run of 60,000 prints was actually performed, and it was determined whether or not a belt running defect occurred.

Color Image Quality Evaluation Method and Judgment Criteria The finished image was examined to determine whether color shift or unevenness due to belt running failure occurred.

[0092]

As shown in Table 1, in the examples satisfying the conditions of the present invention, the transportability of the belt photoreceptor was good, and a good image with a small color shift was obtained. On the other hand, with the belt photoreceptor of the comparative example, the transportability was not sufficient, and
0 μm or more, which indicates that the image quality is not sufficient. From the above results, in the design of the electrophotographic color image forming apparatus, the electrophotographic endless belt photoconductor that is compact, has good running properties, and has no color unevenness, and an image forming method using the photoconductor, an image forming apparatus, And a photoreceptor cartridge were obtained.

[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 an explanatory diagram of an angle of a seam portion at an end portion of a belt photoconductor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor 2 photoconductor cartridge 3 upper roller 5 lower roller 7 horizontal roller 9 pressing roller 11 cleaning means 35 image forming cartridge 61, 63, 65, 67 band electrode 71, 73, 75, 77 grid 200 rib attachment position

Claims (5)

[Claims] At least a conductive layer and a photosensitive layer are provided on a flexible support, and three or more conductive layers and a photosensitive layer are provided on the back side of the support and one or more layers are provided on the front side of the photosensitive layer. For forming an electrostatic latent image on the electrophotographic endless belt photoreceptor supported and transported by the stretching roller and subsequent development of the electrostatic latent image in a non-contact manner, and applying an alternating voltage of 1.8 kV or more An electrophotographic endless belt photoreceptor capable of forming an image by repeatedly forming a multi-color superimposed toner image on the surface of the photosensitive layer and then transferring the toner image onto a transfer material at one time is described below. A seam having a seam angle of 0 ° or more, and a perpendicularity of 0 to 0.3 m on the back surface of the belt photoconductor;
m has a backup rib at both ends, and by adjusting the parallelism of the tension roller to 0 to 0.3 mm,
An electrophotographic endless belt photoconductor, wherein a flatness of the belt photoconductor at an image writing position and a developing position is stretched to 0.2 mm or less. 2. The electrophotographic endless belt photoconductor according to claim 1, wherein a seam angle of the electrophotographic endless belt photoconductor is 1.0 ° to 20.0 ° or less. 3. At least three or more conductive layers and a photosensitive layer are provided on a flexible support, and three or more are provided on the back side of the support and one or more are provided on the front side of the photosensitive layer. The formation of an electrostatic latent image and the subsequent development of the electrostatic latent image on the electrophotographic endless belt photoreceptor supported and conveyed by the stretching roller are performed in a non-contact manner by applying an alternating voltage of 1.8 kV or more. In the electrophotographic image forming method of a system in which a multicolor superimposed toner image is formed on the endless belt photoreceptor, and then the toner image is collectively transferred onto a transfer material, The endless belt photoreceptor has a seam portion having a seam angle of 1.0 ° or more, and the back surface of the belt photoreceptor has a back rib having a squareness of 0 to 0.3 mm at both ends. Set the parallelism of the tension roller to 0
By adjusting to 0.3 mm, the flatness of the belt photoreceptor at the image writing position and the developing position is set to 0.2.
An electrophotographic image forming method, wherein the electrophotographic image forming method is stretched to a length of not more than mm. 4. At least three or more conductive layers and a photosensitive layer are provided on a flexible support, and three or more are provided on the back side of the support and one or more are provided on the front side of the photosensitive layer. The formation of an electrostatic latent image and the subsequent development of the electrostatic latent image on the electrophotographic endless belt photoreceptor supported and conveyed by the stretching roller are performed in a non-contact manner by applying an alternating voltage of 1.8 kV or more. In the electrophotographic image forming apparatus of the type in which a multicolor superimposed toner image is formed on the endless belt photoreceptor, and then the toner image is collectively transferred onto a transfer material, The endless belt photoreceptor has a seam having a seam angle of 1.0 ° or more, and has a back rib having a squareness of 0 to 0.3 mm at both ends on the back surface of the belt photoreceptor. , And adjust the parallelism of the tension roller to 0 to 0.3 mm. By electrophotographic image forming apparatus characterized by flatness of the belt photoreceptor in the image writing position and the developing position is stretched 0.2mm or less. 5. At least a conductive layer and a photosensitive layer are provided on a flexible support, and at least three conductive layers and photosensitive layers are provided on the back side of the support and at least one conductive layer and photosensitive layer are provided on the front side of the photosensitive layer. A photoconductor cartridge having an electrophotographic endless belt photoconductor supported and conveyed by a stretching roller, wherein the electrophotographic endless belt photoconductor and the stretching roller are integrally replaceably combined. And the electrophotographic endless belt photoreceptor has a seam portion having a seam angle of 1.0 ° or more, and backup ribs having a squareness of 0 to 0.3 mm at both ends on the back surface of the belt photoreceptor. By adjusting the parallelism of the stretching roller to 0 to 0.3 mm, the flatness of the belt photoconductor at the image writing position and the developing position is stretched to 0.2 mm or less. Features Photoconductor cartridge.