JPH09292732A - Electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the constitution of an electrophotographic device and to form a clear image without causing fogging and image flowing by environmental fluctuation such as temperature by providing an electrophotographic photoreceptor constituted so that the elemental percentage composition formula of the surface layer thereof is specified and the dynamic identation hardness of the outermost surface is set to be a specified value and an elastic rubbing roller which rubs the surface of the photoreceptor. SOLUTION: The electrophotographic device is constituted so that a developing action is executed by selectively attaching toner to the photoreceptor 1 covered by laminating a photoconductive layer 1b and the surface layer 1c on a base body 1a and a latent image formed on the photoreceptor 1. When the surface layer 1c of the photoreceptor 1 is represented by the elemental percentage composition formula of (a-Si.1-xCx;H),(x) is 0.05<=x<1 and the dynamic identation hardness of the outermost surface is <=300kgf/mm<2> . Besides, the hardness of the inner side on the layer 1b side is harder than that on the outermost surface side. Preferably, the hardness is set so as to be gradually harder as it is toward the inner side. Then, the elastic rubbing roller 9 rubs the surface of the photoreceptor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an invention applied to an electrophotographic apparatus such as a printer, a copying machine and a facsimile machine using an a-Si drum.

[0002]

2. Description of the Related Art Conventionally, process means for exposing, developing, transferring, cleaning (removing residual toner), discharging, and charging are arranged on the outer peripheral surface of a photosensitive drum, and an image is formed by a predetermined electrophotographic process. Electrophotographic devices based on the so-called Carlson process are well known.

In this type of electrophotographic apparatus, generally, corona discharge is used to charge the surface of the photosensitive member, but the corona discharge is generally 4 to 8 KV.
It is necessary to apply the above high voltage to the wire, so that ozone or nitrogen oxide or ammonium salt which is a discharge product thereof is generated by the corona discharge, and these are easily adsorbed on the surface of the photoconductor to cause image deletion. Become. The image deletion is remarkable in a high humidity environment.

In order to solve such a defect, a roller is constituted so that a conductive roller is brought into contact with the photosensitive drum, and a DC voltage is applied to the conductive roller to perform contact charging of the photosensitive drum in a dark place. There are charging methods. However, even in such a charging method, since there is a minute wedge-shaped void between the photosensitive drum and the charging roller, a slight discharge phenomenon occurs at that portion, and ozone generation is recognized. I don't get it.

In order to solve such a drawback, a technique using a particle charging means as the charging means has been disclosed, but the particle charging means must store particles in a charging container with the photoconductor side being opened. Not only does the handling become complicated, but since particles are constantly rubbed against the photoconductor to be uniformly charged, fatigue of the particles easily occurs and durability is also poor. For this reason, in the current technology, the technology using a corona discharger or a charging roller is predominant.

On the other hand, as a photosensitive drum used in an electrophotographic apparatus, an a-Si drum has been used in recent years for the purpose of improving durability and achieving free maintenance.
Since Si has a harder surface and is less likely to be shaved than organic semiconductors such as OPC, an adhered matter adheres to the surface, and the adhering matter absorbs moisture, so that the image flow easily occurs in the a-Si drum. Therefore, in the prior art, a sheet heater or other heating element is arranged on the back side of the photosensitive drum to heat the photosensitive drum to prevent the image deletion.

However, the provision of the heater not only complicates the structure because it also requires a heat control means, but especially when the heater is used in downsizing and personalization of copying machines and printers, the system becomes complicated. turn into.
In addition, a certain time is required for raising the temperature of the heater, and the time from when the power is turned on to when printing is performed (warm-up time) is long, which requires power consumption. When the photoconductor is heated, the TG temperature (glass transition temperature) of the toner is increased.
Since the temperature is raised to a value close to the temperature, toner adheres to the surface of the photoconductor. Various problems occur.

In order to eliminate such a drawback, various techniques have been developed, focusing on the surface layer on the photosensitive drum side.
For example, Japanese Patent Laid-Open No. 62-272275 discloses a-S
The i-based photoconductive layer is covered with a surface layer, and the surface layer is mainly composed of silicon (Si) and C, is made of an amorphous material containing oxygen (O) / hydrogen (H) and fluorine (F), and its dynamic Indentation hardness of 300 Kgf / mm ² ~
A photosensitive drum set at 1000 Kgf / mm ² has been proposed.

The reason for this is that the dynamic indentation hardness of the surface layer is 1
When it is as high as 000 Kgf / mm ² or more, the Si content in the surface layer is high, and the surface is apt to be chemically affected, and the above-mentioned image defect is likely to occur. Also, 300 Kgf /
When it is as small as less than mm ² , the C content in the surface layer is high, the photoconductivity deteriorates, the residual potential becomes large, and the hardness becomes considerably small, so that the abrasion of the surface layer due to the image copying process becomes large. It is said that image defects are likely to occur.

[0010]

However, the above-mentioned prior art has the following problems. First, the above-mentioned prior art realizes the so-called heaterless structure of the photosensitive drum by mentioning only the surface layer of the photosensitive drum. However, image deletion does not occur only in the surface layer, but rather in the surface layer and the photoconductive layer. It is determined by the relationship with the layer and the relationship between the photoconductive layer via the surface layer and the process means. Therefore, it is practically difficult to specify only the surface layer of the photoconductor drum to realize so-called heaterless use of the photoconductor drum.

Further, the above-mentioned prior art attempts to prevent the image flow due to high humidity while avoiding the abrasion of the surface layer of the photoconductor drum. However, the image flow is caused by the generation of ozone due to the discharge phenomenon at the time of charging. Due to deterioration of the surface of the photoconductor and adhesion of discharge products to the drum, the hygroscopicity of the photoconductor surface becomes high, and the drum surface resistance decreases in a high humidity environment, causing the photoconductor surface potential to decrease. Even if the surface layer is devised, discharge products are generated on the surface layer, and image deletion occurs due to the degree of generation of the deposits over time, which makes stable image formation difficult for a long period of time.

On the other hand, in order to make the photoconductor drum heaterless, the applicant of the present invention uniformly charges the photoconductive layer supported on the substrate by including a discharge phenomenon, and then exposes the photoconductive layer. In an electrophotographic apparatus for forming an image by reversal development while writing an image, the photoconductive layer is 25 μm or less,
Proposed is an electrophotographic apparatus characterized in that it is formed of an a-Si layer having a thickness of preferably 2 to 20 μm and the surface potential of the photoconductive layer generated by the charging is set to about 360 V or less. (Japanese Patent Laid-Open No. 7-17526
issue).

However, even in the related art, no reference is made to the relationship between the surface layer and the photoconductive layer. The surface potential is also limited to about 360 V or less, which is a great limitation for applications other than the so-called low electric field development method.

An object of the present invention is to use an a-Si drum,
In particular, in an electrophotographic apparatus such as a corona discharger, a charging roller, or a charging brush, in which the photoconductor is uniformly charged by including a discharge phenomenon, a clear image can be formed without causing image deletion or fogging. It is to provide a device.

Another object of the present invention is that, in an electrophotographic apparatus using an a-Si drum, fog and image deletion may occur due to environmental changes such as temperature while considering simplification and safety. An object of the present invention is to provide an electrophotographic apparatus that can form a clear image without any trouble.

[0016]

The present invention provides an electrophotographic photosensitive member comprising a substrate and a photoconductive layer and a surface layer laminated and coated on the substrate.
In an electrophotographic apparatus that selectively attaches toner to a latent image formed on the photoconductor to perform development, the surface layer of the photoconductor is represented by an element ratio composition formula (a-Sil-xCx: H). In the case, x is 0.95 ≦ x <1, the dynamic indentation hardness of the outermost surface is 300 Kgf / mm ² or less, and the hardness is larger on the photoconductive layer side than on the outermost side. Is configured to include an electrophotographic photosensitive member set to gradually increase in hardness as it goes deeper, and a rubbing roller having an elastic force for rubbing the surface of the photosensitive member. And

Further, the rubbing roller is provided with 4
A magnet having a magnetic force of 60 Gauss or more on the surface of the rubbing roller, which is more than the pole, may be incorporated, or the rubbing roller may be configured to rotate at a peripheral speed higher than that of the photoconductor. Further, it is an effective means of the present invention to set the nip width at which the rubbing roller comes into contact with the photoconductor to 1 mm or more.

Since the present invention is constituted in this way, it is possible to provide an electrophotographic apparatus capable of forming a clear image without causing image deletion or fog. In order to explain this reason, first, the cause of image deletion will be described.
As shown in an enlarged view in FIG. 1A, in the a-Si photosensitive member, a photoconductive layer 1b and a surface layer 1c are laminated on a conductive substrate 1a generally made of an aluminum cylinder, and the surface layer 1c is , Α-SiC based inorganic high resistance or insulating material is used to maintain the surface potential Vo and the latent image potential distribution on the photoconductive layer 1b.

Therefore, discharge products such as nitrate ions and ammonium ions generated by corona discharge during the electrophotographic process are adsorbed on the surface layer 1c, and these are deposited on the photoconductive layer 1b in a high temperature and high humidity environment. Based on the surface potential Vo and the latent image potential distribution, the latent image charges formed on the surface layer 1c move in the surface direction, and a charge flow, that is, an image flow occurs. It is also considered that the photoreceptor surface is oxidatively degraded by continuous printing and becomes hydrophilic, which is also a factor of image deletion.

Further, in order to obtain a clear image while preventing image deletion, it is necessary to study the relationship between the photosensitive drum and the developer. That is, in the case of the electrophotographic apparatus described above, the latent image is visualized by using a high-resistance or insulating toner as the developer, but when the toner component has dew condensation or moisture content, the latent image is exposed. When it adheres to the body drum surface layer 1c, image deletion occurs.

Therefore, in the present invention, the photoconductive layer 1b and the surface layer 1 are provided.
The present invention provides an electrophotographic apparatus capable of forming a clear image without causing image deletion or fogging by effectively combining c, a rubbing roller, and the like.

That is, in the present invention, the surface layer of the photoreceptor is
When expressed as an element ratio composition formula (a-Sil-xCx: H), x is 0.95 ≦ x <1, and the dynamic indentation hardness of the outermost surface is 300 Kgf / mm ² or less, Hardness is greater on the back side of the photoconductive layer side than the outermost surface side, preferably an electrophotographic photosensitive member set so that the hardness gradually increases toward the back side, and an elastic force for rubbing the surface of the photosensitive member. And a rubbing roller having the same.

In this case, the surface layer 1c has a dynamic indentation hardness on the outermost surface side of 50 to 200 Kgf / mm ² , and the surface layer 1c has a thickness of 0.4 to 1.2 μm, preferably 0. It is preferable to set the thickness to 5 to 0.8 μm, and the surface layer 1c
In the case of a two-layer region, the dynamic indentation hardness of the second layer region on the outermost surface side is 50 to 200 Kgf / mm ² and the thickness is set to 800 to 3000 (angstrom), and the second layer region on the back side is It is preferable that the hardness of the one-layer region is larger than that of the second-layer region.

Further, in the present invention, when the above-mentioned discharge product is adsorbed, polishing is carried out in order to positively remove it. As a means for effectively removing the discharge products, the hardness is set so that the dynamic indentation hardness of the outermost surface is 300 Kgf / mm ² or less so that the surface layer of the photoconductor can also be polished. . The hardness is greater on the inner side of the photoconductive layer side than on the outermost surface side, and is preferably set so that the hardness gradually increases toward the inner side. It is possible to maintain high durability.

Further, the rubbing roller is provided with 4
In the case where a magnet having a magnetic pole of more than the pole and having a magnetic force of 60 gauss or more is built in on the surface of the rubbing roller, the toner can be more uniformly held on the peripheral surface of the rubbing roller, so that the discharge product on the surface of the photoreceptor Can be satisfactorily removed. Also,
When the rubbing roller is configured to rotate at a peripheral speed higher than that of the photoconductor, the area in which the rubbing roller is in sliding contact with the area of the photoconductor where the discharge products are removed is large,
Even if there is a difference in the toner holding density on the circumferential surface of the rubbing roller, the rubbing degree is averaged, and the discharge product can be removed satisfactorily. Further, by setting the nip width at which the rubbing roller comes into contact with the photosensitive member to be 1 mm or more, an effective rubbing surface of the rubbing roller can be held, and good rubbing can be maintained.

By adopting such a constitution, the photoconductive layer 1
Even in the state where the heater supporting the substrate b is not built in, it is possible to form an image without causing image deletion.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be illustratively described in detail with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. Not just.

FIG. 1 shows an electrophotographic apparatus to which the present invention is applied. The a-Si photosensitive drum 1 rotates clockwise in the figure.
An optical system including the LED head 2 for exposure and the SELFOC lens 3, a developing unit 4, a transfer roller 5, a cleaning blade 6, a charge eliminating lamp 7, and a charging unit 8 are arranged around the circumference of. .

Next, each component will be described.
As shown in A, the photosensitive drum 1 has a conductive support 1a.
A photoconductive layer 1b and a surface layer 1c are laminated and formed thereon, a carrier injection blocking layer 1e is provided between the conductive support 1a and the photoconductive layer 1b, and a photoconductive layer 1b and the surface layer 1c are formed.
A transition layer 1f is interposed between them. The support 1a is generally made of an aluminum cylindrical body.
It is formed of a metal material such as S, Ti, Ni, Au, Ag, etc., an inorganic material such as glass having a conductive film adhered on the surface, or a transparent resin such as epoxy, and has a thickness of 3 mm in this embodiment.
The outer diameter is set to 30 mm, and it is 254 in the axial direction.
An aluminum cylindrical body having a length of mm is used.

The carrier injection blocking layer 1e is a photoconductive layer 1
Various materials are used depending on the material of b. When an a-Si-based material is used for the photoconductive layer 1b, it is preferable to use the a-Si-based carrier injection blocking layer 1e.

The a-Si photoconductive layer 1b is formed into a film by a glow discharge decomposition method, a sputtering method, an ECR method, an evaporation method or the like, and in forming the film, an element for terminating the dangling bond, for example, (H). And halogen 5-40w
It is better to contain t%. That is, a-
A photoconductor made of Si: H is used, and when the developing bias is positive, non-doped or a Va group element is contained in order to increase the mobility of electrons, and when the developing bias is negative, hole movement occurs. In order to increase the degree, it is preferable to include a Group IIIa element. If necessary, elements such as C, O, and N may be contained in order to obtain desired characteristics such as electric characteristics such as dark conductivity and photoconductivity, and optical band gap.

The thickness of the entire photoconductive layer 1b is:
The thickness is preferably about 3 to 50 μm in order to ensure necessary charging and insulation withstand voltage, absorb exposed light, and suppress the above-described residual potential.

The surface layer 1c is formed by a glow discharge decomposition method, a sputtering method, an ECR method, an evaporation method, or the like,
When expressed as an element ratio composition formula (a-Si1-xCx: H), x is 0.95 ≦ x <1 and the dynamic indentation hardness of the outermost surface (free surface layer) is 50 to 200 Kgf. / Mm
It consists ^{2. The} term hydroxide amorphous silicon carbide, in particular to set the resistance value to the resistance value of 10 ¹² ~10 ¹³ Ω · cm range. The surface layer 1c is set so that the hardness gradually increases from the outermost surface side toward the inner side on the photoconductive layer 1b side.

In order to form a gradient of the hardness as described above (a gradient such that the hardness gradually increases from the outermost surface toward the photoconductive layer 1b side), for example, the surface layer 1c is glowed. When a film is formed by the discharge decomposition method, the ratio of the C-containing gas to the Si-containing gas in the source gas is gradually increased with time, the gas pressure during film formation is gradually increased, and the hydrogen gas as the source gas is used. , The discharge power is gradually reduced, and the substrate temperature of the aluminum cylindrical drum is gradually lowered.

The thickness of the surface layer 1c is 0.4-1.
2 μm, preferably 0.5 to 0.8 μm. As will be described later, since the surface layer 1c is polished, a sufficient hardness gradient cannot be obtained if the surface layer 1c is 0.4 μm or less, the durability is lowered, and image streaks and the like are generated as the number of printed sheets increases. 1.2μ
If it is m or more, the residual potential on the side of the photoconductive layer 1b becomes high, and image fogging or the like is likely to occur.

Further, between the photoconductive layer 1b and the surface layer 1c,
It is preferable to provide a transition layer 1f in which the C content in a-SiC: H is smaller than the C content in the surface layer 1c. Further, the C content of the transition layer 1f may be changed in the layer to have a gradient of the content. Such a transition layer 1
By providing f, the traveling of the photocarriers generated in the photoconductive layer 1b becomes smooth, the photosensitivity is high, the residual potential is low, and the image characteristics are good. The thickness of such a transition layer 1f is 1 μm or less, preferably 0.05 to
It is set in the range of 0.5 μm.

The surface layer 1c may have a two-layer structure instead of a single-layer structure. For example, on the surface layer 1c, the photoconductive layer 1b
Side first layer region 1c ₁ and free surface side second layer region 1c ₂
And the second layer region 1c ₂ is represented by an elemental ratio composition formula (a-Sil-xCx: H), x is 0.
95 ≦ x <1, and the dynamic indentation hardness is 50 to 2
00Kgf / mm ² , thickness is set to 800 to 3000 (angstrom), and as shown in B, the hardness of the first layer region 1c ₁ on the back side thereof is larger than that of the second layer region 1c ₂ , specifically, polishing. The dynamic indentation hardness is 300 Kgf / m, which is such a hardness that it will not be abraded by polishing even when agents are used.
It is better to have m ² or more. As a result, the second layer region 1c ₂ is appropriately polished by an independent rubbing means for each copying process to remove the discharge products adsorbed on the surface of the second layer region, and the surface is smoothed. At that stage, the polishing is stopped in the first layer region 1c ₁ on the inner side, whereby the life is further extended.

The first layer region 1c ₁ has a thickness of the surface layer 1c including the second layer region 1c ₂ of 0.4 to 1.2.
μm, preferably 0.5 to 0.8 μm.

In the present embodiment, the a-Si: H photoconductive layer 1b is formed by using a capacitively coupled glow discharge decomposition apparatus.
And a-SiC surface layer 1c are sequentially laminated to form a photoconductive layer 1b.
The photosensitive drum 1 can be manufactured so as to have layers having a thickness of 15, 25, 40, and 60 μm, respectively. In this case, the surface layer 1c is formed as a single layer without providing the first layer region and the second layer region, and the thickness thereof is set to 0.6 μm.

The exposure LED head 2 has an exposure wavelength of 6
A head array of 85 nm is used, and the head array is configured to perform a dynamic drive to divide the exposure into 64 bits × 40 times for each scanning line.

The developing unit 4 comprises a developing container 41 containing a multi-component developer consisting of a carrier and toner, and a developing roller 42 containing a fixed magnet assembly 43, and the roller 42 is between 50 and 1200 V, for example. A direct-current developing bias power source 44, which can be arbitrarily set by, is connected to perform development. The present invention is not necessarily limited to two-component development.

The carrier has an average particle size of 70 μm.
However, the carrier is not limited to the ferrite carrier, and a carrier such as iron powder or magnetite or a magnetic resin carrier may be used.

Ordinary high-resistance or insulating toner is used as the toner. For example, a binder resin, a colorant, a charge control agent, an offset preventive agent and the like are added with a magnetic material to have an average central particle size of 5 to 15 μm. It is configured as a front and rear magnetic toner, and the proper mixing ratio of the carrier and the toner is set to, for example, 85 to 90:15 to 10% by weight. The toner has a specific surface area of 40 to 60 (m as an abrasive / fluidizing agent.
² / g), resistance 10 ³ (Ω · cm), hydrophobicity 0%,
A toner (hereinafter referred to as A toner) to which conductive titanium oxide (hereinafter referred to as A abrasive), which is made of surface-treated Sd-doped (SiO ₂ ) with a water content of 1.0% and whose average particle size is set to 0.1 μm, is added. Surface area 10 to 15 (m ² / g), resistance 10 ³ (Ω · cm), hydrophobicity 0%, moisture 0.5
%, Surface-treated Sd-doped (SiO ₂ ), and added with conductive titanium oxide (hereinafter referred to as B abrasive) having an average particle size of 0.3 μm (hereinafter referred to as B toner)
Two toners are used.

As the transfer roller 5, a conductive roller is used in order to improve transfer efficiency, a transfer bias having a polarity opposite to the charging potential of the toner is applied, and the photosensitive drum 1 is used.
It is uniformly pressed against the peripheral surface and is rotatable in synchronization with the drum 1.

The rubbing roller 9 is rotatable by an elastic body 11 formed of urethane sponge covering the peripheral surface and internal magnets 12a-12d interposed between the shaft 10 and the shaft. The urethane sponge of the elastic body 11 uses 30 to 80 cells per 1 inch of foaming rate.
As the magnet 12, 300 to 700 gauss having four or more equal poles is used. Further, the rubbing roller 9 and the photoconductor 1 rotate in the same direction at their contact positions, and the rubbing roller 9 and the photoconductor 1 are rotated.
The peripheral speed ratio at the contact position is set to 1.2 or more with respect to the photoconductor 1. The nip width of the rubbing roller 9 at the contact position is set to 1 to 2 mm.

The charging unit 8 was uniformly charged on the photosensitive member by a known corotron charger.
In the figure, 81 is a corona discharge line, 82 is a control grid, 83 is a discharge bias, and 84 is a charge control bias.

Since the present embodiment is constructed in this way, the residual toner of the magnetic toner which is not transferred to the transfer roller 5 is moved by the internal magnet 12 to the elastic body 1 of the rubbing roller 9.
1, the rubbing roller 9 is rotated at a peripheral speed higher than that of the photoconductor 1 at the contact position with the photoconductor 1, so that the abrasive contained in the toner is exposed to light. The surface of the body 1 is polished.

Then, the cleaning blade 6 scrapes off the residual toner, and the charging device 8 sets the charging control bias to an appropriate bias between 150V and 1200V. Therefore, it is necessary to apply this high voltage discharge bias. After charging the surface potential Vo of the photoconductor drum 1 to the above-mentioned set value by the above, after exposing a predetermined latent image by the exposure head 2, after the toner image is attached to the latent image by the developing unit 4, Transfer to the transfer roller 5.

As described above in detail, this embodiment is based on the premise that the discharge products attached to the surface layer of the photoconductor are deleted. Therefore, in the present invention, when the above-mentioned discharge product is adsorbed at the initial stage of image formation, polishing is performed by a rubbing roller in order to positively remove it. In other words,
In order to remove the discharge products, it is desirable to be able to polish the surface layer of the photoconductor, and the dynamic indentation hardness of the outermost surface is set to 300 Kgf / mm ² or less so that the polishing can be done positively. And Further, by using an abrasive added to the toner and a rubbing roller or the like as a means for polishing, the surface layer 1c of the photoreceptor having the fine irregularities is obtained.
Is formed while polishing.

Therefore, since discharge products such as nitrate ions and ammonium ions generated by the adsorbed corona discharge can be removed by polishing in the concave and convex portions of the photosensitive member surface layer 1c, the adsorbed image flow and No fogging will occur.

Further, in the present embodiment, it is desirable that the hardness is increased from the outermost surface of the surface layer 1c toward the inner side in contact with the photoconductive layer 1b. From this structure, the amount of abrasion is gradually reduced. It is possible to maintain long life and high durability. That is, the surface is smoothed by the polishing, the above-mentioned molecular ends and minute irregularities are removed, and adsorption of discharge products can be suppressed. In addition, the present invention suppresses the generation of an oxide film formed on the a-Si surface layer 1c by corona discharge, and therefore the element ratio composition formula (a-Sil- xCx: H)
X is set to 0.95 ≦ x <1.

Therefore, the present embodiment is premised on polishing the surface layer 1c and smoothing the surface by the polishing,
Therefore, the abrasive for polishing the surface layer 1c has a particle size of 0.05
It is preferable to use an abrasive set in the range of ˜5 μm, preferably 0.1˜3 μm.

In addition, the rubbing roller is 4
In the case where a magnet having a magnetic force of 60 Gauss or more is incorporated on the surface of the rubbing roller, the magnetic toner containing an abrasive can be more evenly held on the peripheral surface of the rubbing roller. The surface of the body can be rubbed well and polished to remove the discharge products. Further, when the rubbing roller is configured to rotate at a peripheral speed higher than that of the photoconductor, the area where the photoconductor rubs and the area where the rubbing roller rubs and abrades the area to be abraded. Therefore, even if there is a difference in the holding density of the magnetic toner on the peripheral surface of the rubbing roller, the degree of rubbing and polishing is averaged, and the discharge products can be satisfactorily removed. Further, by setting the nip width at which the rubbing roller comes into contact with the photosensitive member to be 1 mm or more, effective rubbing and polishing surface of the rubbing roller can be held, and good discharge product removal can be performed. it can.

By adopting such a configuration, the photoconductive layer 1
Even in the state where the heater supporting the substrate b is not built in, it is possible to form an image without causing image deletion. Therefore, according to this embodiment, fogging or the like does not occur even when image formation is performed without using a heater. Therefore, in addition to drastically reducing power consumption, a heater, a thermistor for detecting a drum surface temperature, and a thermistor It is possible to reduce the number of electric components such as a heater control circuit based on the detected temperature and simplify the circuit structure. Also, since the heater is not used, the warm-up time becomes unnecessary, and the apparatus startup time can be greatly reduced.

[0055]

As described above, according to the present invention, a
-A clear image can be obtained without causing image deletion or fogging in an electrophotographic apparatus that uses a Si drum and uniformly charges a photosensitive member by including a discharge phenomenon, such as a corona discharger, a charging roller, and a charging brush. Can be formed.

Further, according to the present invention, in the electrophotographic apparatus using the a-Si drum, simplification of structure and safety are taken into consideration, and fog and image deletion do not occur due to environmental changes such as temperature. It has various remarkable effects such that a clear image can be formed.

[Brief description of drawings]

FIG. 1 is a schematic view showing an electrophotographic apparatus to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photoconductor drum 1a Conductive substrate 1b Photoconductive layer 1c Surface layer 1c ₁ First layer area 1c ₂ Second layer area 2 Exposure head 3 Optical system 4 Two-component developing unit 41 Developing container 8 Charging device 9 Rubbing roller 11 Elastic body 12 Internal magnets (12a-12d)

Claims (4)

[Claims] 1. An electrophotographic photosensitive member comprising a substrate and a photoconductive layer and a surface layer laminated and coated thereon, and an electrophotographic device for selectively developing toner by selectively adhering toner to a latent image formed on the photosensitive member. In the above, in the surface layer of the photoreceptor, an element ratio composition formula (a-Sil-xC
x: H), x is 0.95 ≦ x <1 and the dynamic indentation hardness of the outermost surface is 300 Kgf / m
m ² or less, the hardness of which is greater on the inner side of the photoconductive layer side than on the outermost surface side, and is preferably set such that the hardness gradually increases as it goes to the inner side; An electrophotographic apparatus comprising a rubbing roller having an elastic force for rubbing. 2. The rubbing roller is characterized in that it has four or more homopolar poles inside and has a magnet having a magnetic force of 60 gauss or more on the surface of the rubbing roller. Electrophotographic device. 3. The rubbing roller is configured to rotate at a peripheral speed higher than that of the photosensitive member.
An electrophotographic apparatus according to the above. 4. The electrophotographic apparatus according to claim 1, wherein the nip width with which the rubbing roller contacts the photoconductor is set to 1 mm or more.