JP2010276795A - Electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic device for satisfying all of image deletion due to high humidity, abrasion resistance and energy-saving property by suppressing oxidation of the surface of an electrophotographic photoreceptor. <P>SOLUTION: In the electrophotographic device, a corona charger includes a sheet-like shielding member for shielding an opening part facing the electrophotographic photoreceptor and a mechanism for winding the shielding member, wherein the electrophotographic photoreceptor is made by successively forming a photo-conductive layer made of hydrogenated amorphous silicon and a surface layer made of hydrogenated amorphous silicon carbide at least on the surface of a base body, and the surface layer has the sum of atomic density of silicon atom and atomic density of carbon atom, of 6.60×10<SP>22</SP>atom/cm<SP>3</SP>or more and has the ratio of number of atoms of carbon atom to the sum of number of atoms of silicon atom and number of atoms of carbon atom, of 0.61 to 0.75. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrophotographic apparatus such as a copying machine, a printer, and a fax machine using an electrophotographic photosensitive member having a surface layer (hereinafter also referred to as “a-SiC surface layer”) composed of hydrogenated amorphous silicon carbide. It is about.

An electrophotographic photoreceptor is known in which an amorphous material is formed as a photosensitive layer on the surface of a substrate. In particular, a layer of amorphous silicon (hereinafter also referred to as “a-Si”) is formed on the surface of a substrate such as a metal by a film forming technique such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). The a-Si photosensitive member on which is formed has already been commercialized.
As a basic configuration of such an a-Si photosensitive member, a positive charging a-Si photosensitive member as shown in FIG. 5 is known. The positive charging a-Si photosensitive member has a structure in which a light-receiving layer 5002 made of a-Si is formed on the surface of a conductive substrate 5001, and an a-SiC surface layer 5005 is further laminated.

Since the a-SiC surface layer is excellent in wear resistance, it has been mainly used in an electrophotographic apparatus having a high process speed. However, when the conventional a-SiC surface layer is used in an environment with a high absolute humidity, characters may be blurred or white spots may occur without printing characters (hereinafter referred to as “high humidity flow”). ").
The high humidity flow is the following phenomenon. An image is output using an electrophotographic apparatus installed in an environment with high absolute humidity, and after a while, the image is output again. This is an image defect in which characters are blurred in the image output at this time, or white spots occur without characters being printed.
This high-humidity flow is considered to occur because moisture is adsorbed on the surface of the electrophotographic photosensitive member, the surface resistance is reduced, and electric charges cause a lateral flow. For this reason, it is more likely to occur when the absolute humidity of the environment where the electrophotographic apparatus is installed is high or when the photoreceptor heater provided near the a-Si photoreceptor is not used. Therefore, in order to suppress the generation of this high humidity flow, the electrophotographic photoreceptor is always heated by a photoconductor heater to reduce charged products and moisture adsorbed on the surface of the photoconductor that is the cause of the high humidity flow or It has been done to remove.

On the other hand, an electrophotographic process for suppressing a high-humidity flow by a method other than the photoreceptor heater has been proposed.
For example, there has been proposed a technique for preventing the occurrence of image flow by providing a mechanism for inserting a shielding member for a photosensitive member protection shutter made of stainless steel containing 2 to 20% by weight or more of nickel between a charger and a photosensitive member. (See Patent Document 1).
In addition, a technique for preventing the occurrence of image flow by electrostatically adhering a film that can be wound when the copying operation is stopped to the surface of the photosensitive member and shielding between the charger and the photosensitive member is proposed (patent). Reference 2).
Further, a technique has been proposed in which a sheet-like heater that can open and shield between the charger and the photosensitive drum is provided to prevent image flow by heating the drum surface facing the charger (see Patent Document 3). .
Further, a technique has been proposed in which a bias is applied to a conductive charger shutter capable of shielding the opening of the corona charger facing the photoconductor to adsorb ions such as charged products and ozone by an electric field (Patent Literature). 4).

Japanese Patent Application Laid-Open No. 07-104564 Japanese Patent Application Laid-Open No. 07-104565 JP 2008-46297 A JP 2008-145851 A

In recent years, in the market, the speed and color of electrophotographic apparatuses have been increased, and the electrophotographic process is more easily worn than before. In addition, with the increase in speed and color, there is a demand for an electrophotographic apparatus that can stably output a high-quality image. Furthermore, there is a high interest in environmental issues, and there is a demand for improved energy savings by reducing the power consumption of electrophotographic apparatuses.
In response to these market requirements, improvements in electrophotographic apparatus are also necessary. At the same time, there is a need for an electrophotographic photoreceptor that maintains high wear resistance, improves high-humidity flow, and is excellent in energy saving.
However, in order to suppress the generation of the high-humidity flow, a certain amount of wear is required in order to remove the adsorbing substance that causes the high-humidity flow formed on the outermost surface of the electrophotographic photoreceptor.
In such an a-SiC surface layer that easily wears, it is necessary to ensure durability by increasing the thickness of the surface layer.

However, when the thickness of the a-SiC surface layer is increased, the light absorption increases, and thus the sensitivity may be lowered.
In addition, as an electrophotographic apparatus, by providing a photoconductor heater in the vicinity of the photoconductor, moisture adsorbed on the outermost surface of the electrophotographic photoconductor is removed, and the flow of high humidity can be suppressed while suppressing the amount of wear. However, since the photoconductor heater requires a large amount of electric power, it is difficult to reduce the power consumption when using the photoconductor heater.
From the above, in the conventional electrophotographic photoreceptor and electrophotographic apparatus, it has been a difficult problem to achieve both improvement of wear resistance and reduction of power consumption while suppressing high humidity flow.
Therefore, the present inventors have intensively studied to realize high humidity flow suppression while achieving both wear resistance improvement and power consumption reduction. As a result, it was found that the phenomenon of high-humidity flow roughly includes the following two phenomena.

Phenomenon A: A phenomenon in which when an image is output in an environment where the absolute humidity is high and left as it is overnight, an image is output the next morning, and a decrease in image density occurs in a part of the image. This decrease in image density occurs in an area where the electrophotographic photosensitive member and the charger face each other when left standing. Such a high-humidity flow generated in the region facing the charger of the electrophotographic photosensitive member when left untreated is also referred to as “flow below the charger”.
Phenomenon B: Similar to phenomenon A, when an image is output the next morning, a flow under the charger occurs, and at the same time, a decrease in image density occurs even in an area that does not face the charger when left unattended.
This phenomenon may occur when a large amount of image is output (the image output is continued for a long period of time), and is generated on the entire surface of the image unlike a flow under the charger that occurs locally on the image.
Hereinafter, the high-humidity flow generated in a region not facing the charger when left standing different from the flow under the charger is also referred to as “endurance flow”.
From these two phenomena, it was found that the high-humidity flow is a complex phenomenon consisting of the flow under the charger and the durable flow. That is, the flow under the charger is a high-humidity flow that occurs in the area where the electrophotographic photoreceptor and the charger face each other when left standing, and the durable flow is a high-humidity flow that occurs during long-term use and occurs over the entire image. .

The present inventors inferred the mechanism by which the above two phenomena occur as follows. The above two phenomenon occurrence mechanisms will be described with reference to FIGS.
FIG. 1 is a schematic explanatory diagram for explaining the phenomenon A, and shows the relationship between the amount of adsorbed material adsorbed on the outermost surface of the electrophotographic photoreceptor and the generation of a high-humidity flow. When the amount of adsorbed substances such as moisture and charged products exceeds the threshold for generating a high-humidity flow, a high-humidity flow is generated on the image.
First, at the initial stage before image output, there is little adsorbed material on the outermost surface of the electrophotographic photoreceptor.
Next, a state after image output in which image output is repeatedly performed will be considered. In this state, the surface layer of the electrophotographic photoreceptor is oxidized mainly by the influence of charging, and a polar group is generated on the outermost surface.
The following two effects can be considered as the influence of the generation of polar groups by this oxidation on the high-humidity flow.

First, the polar group itself has the effect of facilitating the reduction of the surface resistance by increasing the amount of moisture adsorbed. Second, by generating polar groups, the surface is changed to a surface on which charged products are easily adsorbed. It is considered that the charged product further promotes lowering the resistance of the surface by adsorbing moisture.
Therefore, as a result, the two synergistic actions described above are considered to increase the amount of adsorbed substances such as moisture and charged products, and create a situation where high humidity flow is likely to occur.

Next, consider the case where the electrophotographic photoreceptor is left in the electrophotographic apparatus in this state. In the area facing the charger when left unattended, in addition to the presence of a large amount of charged products around the charger, the charged products are easily adsorbed by oxidation, resulting in a large amount on the surface. The charged product will be adsorbed. As a result, it is considered that the amount of the adsorbed substance composed of the charged product and moisture exceeds the threshold value and a high-humidity flow is generated.
On the other hand, in the area that is not facing the charger when left unattended, the adsorption of moisture and charged products has increased due to oxidation, but the amount of adsorbed substance has a threshold value because the amount of charged products to be adhered is small. It does not lead to exceeding.
As a result of the above, it is considered that only the portion facing the charger when left standing causes a high-humidity flow to generate the “flow under the charger”.

FIG. 2 is a schematic explanatory diagram for explaining the phenomenon B, and shows the relationship between the amount of adsorbed material adsorbed on the outermost surface of the electrophotographic photoreceptor and the generation of high-humidity flow as in FIG. It is. The difference from FIG. 1 is that the image formation is repeated over a longer period than the case shown in FIG.
Oxidation further proceeds as compared with the case of FIG. 1 due to the influence of charging that has been repeatedly performed on the outermost surface of the a-SiC surface layer over a long period of time, and the adsorptivity to the charged product and moisture further increases.
Therefore, not only the part that faces the charger when left with a large amount of charged product, but also the part that does not face the charger when left with little charged product, mainly due to the increased amount of moisture adsorbed, The amount of adsorbed substance will exceed the threshold value. As a result, it is considered that a high-humidity flow is generated even in a region that does not face the charger when left standing.
As described above, it has been clarified that the high-humidity flow has two elements, “under-charger flow” and “endurance flow”. It can be said that this is an increase in the amount of adsorbed moisture and charged products.
In particular, in an extremely high temperature and high humidity environment, generation of a high humidity flow mainly due to the “flow under the charger” is remarkable.
Therefore, in order to suppress both the flow under the charger and the durable flow, it has been found that it is extremely important to suppress the oxidation of the a-SiC surface layer that affects the adsorptivity of the adsorbed substance.
Further, in the electrophotographic apparatus using the electrophotographic photosensitive member, by providing a shielding member that shields the opening portion of the corona charger facing the electrophotographic photosensitive member, a further great effect on the high humidity flow is provided. Is obtained.
By adopting such a configuration, even when a large amount of charged product that is one cause of the flow under the charger is generated, a shielding member is provided between the charger and the electrophotographic photoreceptor at the end of the electrophotographic process. Thus, it is possible to suppress adhesion of the charged product to the surface of the electrophotographic photoreceptor.
However, the configuration in which the shielding member is provided between the corona charger and the electrophotographic photosensitive member at the end of the electrophotographic process may have a negative effect on the electrophotographic photosensitive member because the shielding member contacts the electrophotographic photosensitive member. .

  In such a configuration, the shielding member may rub against the electrophotographic photosensitive member every time the opening and closing movement is performed, and streaky scratches are generated on the surface of the electrophotographic photosensitive member, and a good image cannot be obtained. There is a case. In addition, the charged adult product attached to the shielding member may be attached to the surface of the photosensitive member due to rubbing with the photosensitive member. In order to avoid these problems, it is conceivable to increase the accuracy of the mechanism around the shielding member or to increase the gap between the shielding member and the electrophotographic photoreceptor. However, in order to further improve the accuracy of the mechanism around the shielding member, the materials and structures used are often limited. For this reason, the degree of freedom in design may be reduced or the cost may be increased. Further, when the gap between the shielding member and the electrophotographic photosensitive member is increased, it may be an obstacle to downsizing the apparatus. In addition, the distance between the corona charger and the electrophotographic photosensitive member may be increased, and the chargeability may be reduced.

As described above, regarding electrophotographic photoreceptors, it is required to suppress the amount of adsorption of charged products, moisture, and the like by suppressing oxidation of the a-SiC surface layer. Further, it is demanded that even if the surface of the electrophotographic photosensitive member is rubbed by the shielding member as described above, no adverse effect is caused.
If such a requirement can be met, it is not necessary to increase the amount of wear in order to remove the oxide layer and the adsorbed substance on the a-SiC surface layer, so that the wear resistance can be improved.
Further, since it is not necessary to reduce the adsorbed material on the a-SiC surface layer by the photoconductor heater, the photoconductor heater becomes unnecessary, and the power consumption can be reduced.

Therefore, the object of the present invention is to reduce the adhesion of adsorbed materials by suppressing the oxidation due to corona charging of the a-SiC surface layer, and further, for electrophotography having excellent wear resistance and mechanical strength. The object is to provide a photoreceptor.
It is another object of the present invention to provide an electrophotographic apparatus that can reduce adverse effects on the electrophotographic photosensitive member due to opening / closing movement of the shielding member even if the corona charger is provided close to the electrophotographic photosensitive member. .
Accordingly, an object of the present invention is to provide an electrophotographic apparatus that is excellent in all of high humidity flow, wear resistance, and energy saving.

As a result of diligent studies to achieve the above object, by providing a shielding member that shields the opening of the corona charger facing the electrophotographic photoreceptor, the charged product adheres to the surface of the electrophotographic photoreceptor. It was confirmed that suppression was possible.
At the same time, the ratio of carbon atoms to silicon atoms and carbon atoms constituting the a-SiC surface layer of the electrophotographic photoreceptor is set within a predetermined range.
Furthermore, by making the sum of the atomic densities of silicon atoms and carbon atoms larger than a predetermined value, it has been found that there is a significant effect on the above-described problems, and the present invention has been completed.
That is, the present invention comprises a corona charger having at least an electrophotographic photoreceptor and an opening facing the electrophotographic photoreceptor,
The corona charger is an electrophotographic apparatus having a sheet-like shielding member capable of shielding in the longitudinal direction of the opening, and a mechanism for winding the shielding member in the longitudinal direction,
The electrophotographic photoreceptor is one in which a photoconductive layer formed of hydrogenated amorphous silicon and a surface layer formed of hydrogenated amorphous silicon carbide are sequentially formed on at least the surface of the substrate.
In the surface layer, the sum of the atomic density of silicon atoms and the atomic density of carbon atoms is 6.60 × 10 ²² atoms / cm ³ or more, and carbon relative to the sum of the number of silicon atoms and the number of carbon atoms. The ratio of the number of atoms is from 0.61 to 0.75.

According to the electrophotographic apparatus of the present invention, since the a-SiC surface layer of the electrophotographic photoreceptor has a high atomic density, the oxidation reaction of the surface layer by the charging means for corona discharge can be suppressed.
Therefore, the generation of polar groups on the outermost surface of the electrophotographic photoreceptor can be suppressed, the adsorption of moisture and charged products is reduced, and the high-humidity flow can be suppressed.
At the same time, since the bonding force of the skeleton atoms forming the film structure of the surface layer is improved, an a-SiC surface layer that is harder than the conventional a-SiC surface layer is obtained, and wear resistance and mechanical strength are obtained. Will also improve.
Moreover, in this invention, it is set as the structure which can shield the opening part of a corona charger with a sheet-like member. As a result, the charged product generated by the corona charger is prevented from adhering to the surface of the electrophotographic photosensitive member when the electrophotographic apparatus is stopped. As a result, the high humidity flow is suppressed.
In the present invention, since the shielding member is composed of a sheet-like member, even if the shielding member rubs the surface of the electrophotographic photosensitive member, the adverse effect on the electrophotographic photosensitive member is small.
Furthermore, as described above, the electrophotographic photosensitive member used in the present invention has high wear resistance and mechanical strength and reduced adsorption of charged products, etc., so that the shielding member rubs the surface. Also, adverse effects on the electrophotographic photosensitive member are reduced.
As described above, according to the present invention, it is possible to provide an electrophotographic apparatus that is excellent in suppressing high-humidity flow, wear resistance, mechanical strength, and energy saving.

FIG. 6 is a schematic explanatory diagram for explaining a phenomenon A (flow under the charger). It is a typical explanatory view for explaining phenomenon B (endurance flow). It is a schematic diagram of an example of the plasma CVD apparatus used for preparation of the electrophotographic photoreceptor of the present invention. (A) It is a schematic sectional drawing which shows the state which the opening part of the corona charger opened. (B) It is a schematic sectional drawing which shows the state which shielded the opening part of the corona charger. FIG. 6 is a schematic cross-sectional view showing a layer structure of a conventional positive charging a-Si photoconductor. It is a schematic sectional drawing of the electrophotographic apparatus used in the Example.

Embodiments of the present invention will be described in detail with reference to the drawings.
The electrophotographic photoreceptor used in the present invention has a photoconductive layer formed of hydrogenated amorphous silicon (a-Si) and a surface formed of hydrogenated amorphous silicon carbide (a-SiC) at least on the surface of the substrate. The layers are sequentially formed. In the present invention, the ratio of the atomic density of carbon atoms to the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer is in the range of 0.61 to 0.75, and the a-SiC surface The sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the layer is 6.60 × 10 ²² atoms / cm ³ or more.
By making the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer equal to or greater than 6.60 × 10 ²² atoms / cm ³ , it is highly effective in suppressing high-humidity flow and improving wear resistance. Is obtained. The reason is shown below.

By increasing the atomic density of silicon atoms and carbon atoms constituting the a-SiC surface layer, it is difficult to break the bond between silicon atoms and carbon atoms, and the space ratio is reduced, so It is considered that the reaction probability can be reduced.
This is because the a-SiC oxidation reaction occurs when the bond between the silicon atom and the carbon atom is broken by the oxidation and desorption of the carbon atom, and the oxidizing substance reacts with the newly formed dangling bond of Si. It is.
In the electrophotographic process, it is considered that oxidation and desorption of carbon atoms occur due to the reaction between ionic species generated in the charging step and carbon atoms.
Therefore, it is considered that the oxidation of silicon atoms is suppressed by suppressing the oxidation of carbon atoms as much as possible, and the high-humidity flow can be suppressed.
For this purpose, it is necessary to make the bond between the silicon atom and the carbon atom difficult to break, or to reduce the reaction probability in order to suppress the oxidation of the carbon atom.
In order to realize this, it is considered necessary to shorten the distance between each atom and the space ratio.

Therefore, by increasing the atomic density of silicon atoms and carbon atoms constituting the a-SiC surface layer, it is possible to shorten the distance between each atom and to reduce the space ratio. Therefore, the polarity at the outermost surface of the a-SiC surface layer It is considered that the production of the group can be suppressed. As a result, the high humidity flow can be suppressed. Furthermore, since the bonding force of the constituent atoms of the surface layer is increased, a surface layer having a high hardness is obtained, and as a result, it is presumed that the wear resistance is also improved.
Therefore, it is more preferable that the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer is higher, and by controlling the density to 6.81 × 10 ²² atoms / cm ³ or more, further suppressing high-humidity flow. Great effect on improving wear resistance. In a-SiC, 13.0 × 10 ²² atoms / cm ³ , which is the most dense state of SiC crystals in the above composition range, is the upper limit of the sum of the atomic density of silicon atoms and the atomic density of carbon atoms. .

The sum of the atomic density of silicon atoms and the atomic density of carbon atoms is in the above range, and the ratio of the atomic density of carbon atoms to the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer is 0.00. A composition range of 61 or more and 0.75 or less is necessary in order to obtain excellent electrophotographic photoreceptor characteristics.
When the ratio of the atomic density of carbon atoms to the sum of the atomic density of silicon atoms and the atomic density of carbon atoms is made smaller than 0.61 in the a-SiC surface layer, particularly when a-SiC having a high atomic density is produced. The resistance of a-SiC may decrease.
In such a case, the carrier tends to cause a lateral flow in the surface layer when forming the electrostatic latent image. Therefore, when an isolated dot is formed as an electrostatic latent image, the isolated dot becomes smaller due to the lateral flow of carriers in the surface layer. As a result, in the output image, particularly, the image density on the low density side is lowered, so that gradation may be lowered.
For this reason, in the a-SiC surface layer having a high atomic density, the ratio of the atomic density of carbon atoms to the sum of the atomic density of silicon atoms and the atomic density of carbon atoms needs to be 0.61 or more.

Further, when the ratio of the atomic density of carbon atoms to the sum of the atomic density of silicon atoms and the atomic density of carbon atoms is made larger than 0.75, particularly when an a-SiC having a high atomic density is produced, the a-SiC surface layer In some cases, the light absorption at the abruptly increases.
In such a case, the amount of image exposure necessary for forming the electrostatic latent image increases, and the sensitivity is extremely lowered. In addition, since the sensitivity fluctuation with respect to the wear amount of the a-SiC surface layer becomes large, when the electrophotographic photosensitive member is shaved and uneven, image density unevenness may occur.
For this reason, in the a-SiC surface layer having a high atomic density, the ratio of the atomic density of carbon atoms to the sum of the atomic density of silicon atoms and the atomic density of carbon atoms needs to be 0.75 or less.
For the above reason, in order to improve the oxidation resistance of the a-SiC surface layer and suppress the high-humidity flow while maintaining the practically preferable electrophotographic photoreceptor characteristics, silicon atoms in the a-SiC surface layer are used. Atoms of carbon atoms with respect to the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer is 6.60 × 10 ²² atoms / cm ³ or more. The density ratio needs to be in the composition range of 0.61 to 0.75.

In the present invention, the ratio of the number of hydrogen atoms to the sum of the atomic density of silicon atoms, the atomic density of carbon atoms and the atomic density of hydrogen atoms (hereinafter also referred to as “H atomic ratio”) is 0.30 or more. It is preferable to make it 0.45 or less. As a result, an electrophotographic photoreceptor having good electrophotographic photoreceptor characteristics and further excellent high-humidity flow suppression and wear resistance can be obtained.
In an a-SiC surface layer having a high atomic density, the optical band gap is narrowed, and the light absorption increases, so that the sensitivity may decrease. However, when the H atomic ratio is 0.30 or more, the optical band gap is widened, and the sensitivity can be improved. Therefore, the H atomic ratio is preferably set to 0.30 or more.

On the other hand, when the H atom ratio is larger than 0.45, there is a tendency that terminal groups with many hydrogen atoms such as methyl groups increase in the a-SiC surface layer. When a terminal group having a plurality of hydrogen atoms such as a methyl group is present in the a-SiC surface layer, a large space is formed in the structure of the a-SiC, and a bond between adjacent atoms is distorted. Let Such a structurally weak part is considered to be a very weak part against oxidation.
Further, when a large amount of hydrogen atoms are contained in the a-SiC surface layer, it becomes difficult to promote networking of silicon atoms and carbon atoms, which are skeleton atoms in the a-SiC surface layer.
For these reasons, by setting the H atom ratio to 0.45 or less, the networking of silicon atoms and carbon atoms, which are skeleton atoms, in the a-SiC surface layer is promoted, and the strain generated in the bonds between the atoms is reduced. It is thought that reduction is possible. As a result, the oxidation of the a-SiC surface layer is further suppressed, and the wear resistance is improved.
Therefore, in the a-SiC surface layer having a high atomic density, by setting the H atomic ratio to 0.30 or more and 0.45 or less, the electrophotographic photoreceptor characteristics are good, and further high humidity flow and resistance Abrasion can be improved.

Further, the ratio of the peak intensity _{I D} of 1390 cm ^-1 to the peak intensity _{I G} of 1480 cm ^-1 in the Raman spectrum of the a-SiC surface layer, by 0.20 to 0.70, further high humidity flows and A great effect is obtained in improving the wear resistance.
First, the Raman spectrum of the a-SiC surface layer will be described in comparison with diamond-like carbon (hereinafter also referred to as “DLC”).
Raman spectra of DLC formed of sp ³ structure and sp ² structure has a main peak near 1540 cm ^-1, asymmetrical Raman spectrum having a shoulder band is observed around 1390 cm ^-1. The RF-CVD method a-SiC surface layer made of, has a main peak near 1480 cm ^-1, the Raman spectrum similar to the DLC having a shoulder band around 1390 cm ^-1 is observed. The main peak of the a-SiC surface layer is shifted to the lower wavenumber side than DLC because the a-SiC surface layer contains silicon atoms. From this, it can be seen that the a-SiC surface layer produced by the RF-CVD method is a material having a structure very close to DLC.
In general, it is known that in the Raman spectrum of DLC, the smaller the ratio of the peak intensity of the low wave number band to the peak intensity of the high wave number band, the higher the sp ³ property of DLC. Therefore, since the a-SiC surface layer has a structure very close to DLC, it is considered that the smaller the ratio of the peak intensity of the low wave number band to the peak intensity of the high wave number band, the higher the sp ³ property. It is done.

At high a-SiC surface layer of atom density of the present invention, that the ratio of the peak intensity _{I D} of 1390 cm ^-1 to the peak intensity _{I G} of 1480 cm ^-1 in the Raman spectrum of the a-SiC surface layer to 0.70 or less Thus, a great effect can be obtained for further improvement of wear resistance.
The reason for this is that if the sp ³ property is improved, the number of sp ² two-dimensional networks decreases and the number of sp ³ three-dimensional networks increases, so the number of skeletal atoms increases and a strong structure is formed. I think it is possible.
Therefore, it is more preferred ratio had decreased how the peak intensity _{I D} of 1390 cm ^-1 to the peak intensity _{I G} of 1480 cm ^-1 in the Raman spectrum of the a-SiC surface layer, a-SiC surface layer is made of a mass-production level Then, the sp ² structure cannot be completely removed. Therefore, in the present invention, the lower limit of the ratio of the peak intensity _{I D} of 1390 cm ^-1 to the peak intensity _{I G} of 1480 cm ^-1 in the Raman spectrum of the a-SiC surface layer, the high-humidity image flow and耐磨in this embodiment It is set to 0.2, which has been confirmed as a good range of wear.

In the electrophotographic photoreceptor of the present invention, when the surface of the electrophotographic photoreceptor is measured in the range of 10 μm × 10 μm with an atomic force microscope (AFM) from the viewpoint of the cleaning property of the surface of the electrophotographic photoreceptor with a cleaning blade. The surface roughness Ra obtained from the microscopic shape obtained in the above is preferably in the range of 10 nm to 80 nm, and more preferably in the range of 10 nm to 50 nm.
Similarly, from the viewpoint of cleaning properties, the average inclination Δa obtained from the microscopic shape obtained when the surface of the electrophotographic photoreceptor is measured in the range of 10 μm × 10 μm by AFM is 0.10 or more and 0.40. The following ranges are preferred.

<Production apparatus and production method for producing the electrophotographic photoreceptor of the present invention>
FIG. 3 is a diagram schematically showing an example of an apparatus for depositing a photoconductor by the RF plasma CVD method using a high frequency power source for producing the a-Si type photoconductor of the present invention.
This apparatus is roughly composed of a deposition apparatus 3100 having a reaction vessel 3110, a source gas supply device 3200, and an exhaust device (not shown) for depressurizing the inside of the reaction vessel 3110.
In the reaction vessel 3110 in the deposition apparatus 3100, a conductive substrate 3112, a conductive substrate heating heater 3113, and a source gas introduction pipe 3114 connected to the ground are installed. Further, a high frequency power source 3120 is connected to the cathode electrode 3111 via a high frequency matching box 3115.
The source gas supply device 3200 includes source gas cylinders 3221 to 3225 such as SiH ₄ , H ₂ , CH ₄ , NO, and B ₂ H ₆ , valves 3231 to 3235, pressure regulators 3261 to 3265, inflow valves 3241 to 3245, and outflow valves. 3251 to 3255 and mass flow controllers 3211 to 3215. A gas cylinder filled with each source gas is connected to a source gas introduction pipe 3114 in the reaction vessel 3110 via an auxiliary valve 3260.

Next, a method for forming a deposited film using this apparatus will be described. First, a conductive substrate 3112 that has been degreased and washed in advance is placed in the reaction vessel 3110 via a cradle 3123. Next, an exhaust device (not shown) is operated to exhaust the reaction vessel 3110. While viewing the display of the vacuum gauge 3119, when the pressure in the reaction vessel 3110 reaches a predetermined pressure of, for example, 1 Pa or less, power is supplied to the heater 3113 for heating the substrate, and the conductive substrate 3112 is moved from 50 ° C. to 350 ° C., for example. Heat to the desired temperature of ° C. At this time, an inert gas such as Ar or He can be supplied from the source gas supply device 3200 into the reaction vessel 3110 and heated in an inert gas atmosphere.
Next, a gas used to form a deposited film is supplied from the gas supply device 3200 to the reaction vessel 3110. That is, if necessary, the valves 3231 to 3235, the inflow valves 3241 to 3245, and the outflow valves 3251 to 3255 are opened, and the flow rate is set in the mass flow controllers 3211 to 3215. When the flow rate of each mass flow controller is stabilized, the main valve 3118 is operated while viewing the display of the vacuum gauge 3119 to adjust the pressure in the reaction vessel 3110 to a desired pressure. When a desired pressure is obtained, high-frequency power is applied from the high-frequency power source 3120 and simultaneously the high-frequency matching box 3115 is operated to generate plasma discharge in the reaction vessel 3110. Thereafter, the high frequency power is quickly adjusted to a desired power, and a deposited film is formed.

When the formation of the predetermined deposited film is finished, the application of the high-frequency power is stopped, the valves 3231 to 3235, the inflow valves 3241 to 3245, the outflow valves 3251 to 3255, and the auxiliary valve 3260 are closed, and the supply of the raw material gas is finished. At the same time, the main valve 3118 is fully opened, and the reaction vessel 3110 is evacuated to a pressure of 1 Pa or less.
The formation of the deposited layers is completed as described above. When a plurality of deposited layers are formed, the above procedure is repeated again to form each layer. The bonding region can also be formed by changing the raw material gas flow rate, pressure, and the like to the conditions for forming the photoconductive layer in a certain time.
After all the deposited films are formed, the main valve 3118 is closed, an inert gas is introduced into the reaction vessel 3110 to return to atmospheric pressure, and then the conductive substrate 3112 is taken out.

The electrophotographic photoreceptor of the present invention is a film structure having a high atomic density by increasing the atomic density of silicon atoms and carbon atoms constituting a-SiC as compared with the surface layer of a conventionally known electrophotographic photoreceptor. The surface layer is formed. As described above, when the a-SiC surface layer having a high atomic density according to the present invention is produced, generally, the amount of gas supplied to the reaction vessel is smaller, although it depends on the conditions at the time of forming the surface layer. It is better that the high frequency power is higher, the pressure in the reaction vessel is higher, and the temperature of the conductive substrate is higher.
First, the gas decomposition can be promoted by reducing the amount of gas supplied into the reaction vessel and increasing the high-frequency power. Thereby, a carbon atom supply source (for example, CH ₄ ) that is harder to decompose than a silicon atom supply source (for example, SiH ₄ ) can be efficiently decomposed. As a result, active species having a small number of hydrogen atoms are generated, and the number of hydrogen atoms in the film deposited on the surface of the substrate is reduced, so that an a-SiC surface layer having a high atomic density can be formed.

In addition, by increasing the pressure in the reaction vessel, the residence time of the raw material gas supplied into the reaction vessel becomes longer, and a weakly bonded hydrogen abstraction reaction occurs due to hydrogen atoms generated by the decomposition of the raw material gas. This is because the networking of silicon and carbon atoms has been promoted.
Furthermore, by increasing the temperature of the conductive substrate, the surface movement distance of the active species that has reached the conductive substrate becomes longer, and a more stable bond can be created. As a result, it is considered that each atom can be bonded to a more structurally stable arrangement as the a-SiC surface layer.

<Electrophotographic apparatus using electrophotographic photoreceptor of the present invention>
An electrophotographic forming method using an electrophotographic apparatus using an a-Si based electrophotographic photoreceptor will be described with reference to FIG. First, the photosensitive member 6001 is rotated, and the surface of the photosensitive member is uniformly charged by the main charger 6002. Thereafter, the electrostatic latent image means 6006 irradiates the surface of the photosensitive member with exposure light to form an electrostatic latent image on the surface of the photosensitive member, and then develops using toner supplied from the developing device 6012. As a result, a toner image is formed on the surface of the photoreceptor. The toner image is transferred to a transfer material 6010 by a transfer charger 6004, and the transfer material 6010 is separated from the photoreceptor 6001, and then the toner image is fixed to the transfer material 6010.
On the other hand, the toner remaining on the surface of the photoconductor to which the toner image has been transferred is removed by a cleaner 6009, and thereafter, the surface of the photoconductor is exposed to discharge the remaining carrier when forming the electrostatic latent image on the surface of the photoconductor. Image formation is continuously performed by repeating this series of processes.
Even in the conventional electrophotographic apparatus shown in FIG. 6, by mounting the electrophotographic photoreceptor of the present invention, it is more effective than the conventional electrophotographic photoreceptor in suppressing high-humidity flow and wear resistance. Is obtained.

However, in an environment where the absolute humidity is very high, a high-humidity flow may occur mainly due to “flow under the charger”.
Under such circumstances, in the electrophotographic apparatus using the electrophotographic photoreceptor of the present invention, by providing a shielding member capable of shielding the opening of the charger facing the electrophotographic photoreceptor, high humidity is provided. An even greater effect on the flow is obtained.
By adopting such a configuration, even when a large amount of charged product that is one cause of the flow under the charger is generated, a shielding member can be inserted between the charger and the electrophotographic photoreceptor at the end of the electrophotographic process. Thus, it is possible to suppress adhesion of the charged product to the surface of the electrophotographic photoreceptor.
As a result, in addition to the decrease in adsorbability due to the suppression of oxidation at the outermost surface of the a-SiC surface layer, it is possible to reduce the amount of adhered substances, so even in an electrophotographic process in which a large amount of charged products are generated, high humidity flow can be suppressed. A greater effect can be obtained.

The shielding means for shielding the opening of the corona charger facing this electrophotographic photoreceptor will be described with reference to FIG. 4 which is a schematic diagram.
4A shows a state where the opening of the corona charger is opened, and FIG. 4B shows a state where the opening of the corona charger is shielded by a shielding member.
The opening of the corona charger 4111 indicates an opening formed by the shield 4110, and corresponds to the charging region W by the corona charger 4111. Accordingly, the charging region W substantially coincides with the region where the electrophotographic photoreceptor 4101 can be charged by the corona discharge of the charging wire 4102.
FIG. 4A shows a state where the opening of the corona charger 4111 is opened by winding the shielding member 4103 in the X direction indicated by the arrow.
The corona charger 4111 includes a charging wire 4102 and a shield 4110, and an opening is disposed to face the electrophotographic photoreceptor 4101.
In the corona charger 4111, a charging line cleaning member 4108 for cleaning the charging line 4102 is installed on the moving member 4107.
The charging wire cleaning member 4108 is configured to move in the longitudinal direction of the corona charger 4111 and clean the charging wire 4102 when the rotating member 4109 is rotated by the drive motor 4106.
A shield member 4103 is attached to the moving member 4107, and the shield member 4103 supported by the guide roller 4105 is wound up by the winding device 4104 in conjunction with the drive motor 4106. The winding device 4104 is an example of a mechanism that winds the shielding member in the longitudinal direction.
Accordingly, the shielding member 4103 is configured to be movable to a retracted position that does not affect the corona discharge during an image forming operation in which the corona discharge is turned on.

FIG. 4B shows a state where the print job is finished, the shielding member 4103 is moved from the retracted position to the closed position, and the opening of the corona charger 4111 is closed.
The shielding member 4103 installed on the moving member 4107 is configured to shield the opening of the corona charger 4111 when the moving member 4107 moves in the Y direction of the arrow.
As a result, the charged product floating in the corona charger 4111 is adsorbed on the surface of the shielding member 4103, so that adsorption to the surface of the electrophotographic photoreceptor can be suppressed.
In the present invention, as shown in FIGS. 4A and 4B, a sheet-like shielding member that can be stored in a roll shape by the winding device 4104 is used as the shielding member 4103 that shields the opening of the corona charger 4111. Adopted.
Thereby, during the image forming operation, the sheet-like shielding member 4103 is stored in a roll state on one end side of the corona charger 4111, and thus can be stored in a small space.
Further, regarding the material of the sheet-like shielding member 4103, a polyimide resin sheet is employed because it may come into contact with the surface of the electrophotographic photoreceptor 4101 when moving through the opening of the corona charger 4111.
Further, since the surface of the electrophotographic photoreceptor 4101 used in the present invention has high mechanical strength, the charged product on the surface of the electrophotographic photoreceptor 4101 can be removed by positively contacting the shielding member 4103. Is possible.
In this case, it is desirable to provide a fur brush on the surface of the shielding member 4103 facing the electrophotographic photoreceptor 4101.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited at all by these.
<Example 1>
Using the plasma processing apparatus shown in FIG. 3, a charge injection blocking layer, a photoconductive layer, and a surface layer are formed in this order on the surface of the cylindrical substrate under the conditions shown in Tables 1 and 2, and a positively charged a-Si photoconductor Was made. A high frequency power source having a frequency in the RF band was used. As the cylindrical substrate, a cylindrical aluminum substrate having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm and subjected to mirror finishing was used. The high frequency power, the SiH ₄ flow rate, and the CH ₄ flow rate at the time of preparing the surface layer were the conditions shown in Table 2. Two electrophotographic photoreceptors were produced under each film forming condition.
The produced electrophotographic photosensitive member was installed in an electrophotographic apparatus having the following configuration, and evaluation described below was performed.
An Canon electrophotographic apparatus iR-5065 having the configuration shown in FIG. 6 was used as a base, and an electrophotographic apparatus was prepared for the experiment by removing the blower fan for main charging means. Further, the main charging device 6002, the transfer charging device 6004, and the separation charging device 6005 are modified to charging means having the configuration shown in FIG.
The shielding member 4103 is made of a polyimide resin sheet having a thickness of 30 μm.
Further, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

The surface roughness of the two electrophotographic photoreceptors produced in Example 1 was measured under the conditions described below, and Ra and Δa were calculated. Thereafter, using one electrophotographic photoreceptor for each film formation condition, the ratio of the number of carbon atoms to the sum of the number of silicon atoms and the number of carbon atoms (hereinafter referred to as C / (Si + C)) The atomic density of silicon atoms (hereinafter also referred to as “Si atomic density”) was calculated under the conditions described below. Further, the atomic density of carbon atoms (hereinafter also referred to as “C atom density”) and the sum of the Si atom density and the C atom density (hereinafter also referred to as “Si + C atom density”) under the conditions described later. Calculated. Furthermore, the ratio of the number of hydrogen atoms to the sum of the number of silicon atoms, the number of carbon atoms and the number of hydrogen atoms (hereinafter also referred to as “H atom ratio”), the atomic density of hydrogen atoms (hereinafter, Also referred to as “H atom density”), and sp ³ properties were calculated under the conditions described below. The remaining one electrophotographic photosensitive member under each film formation condition was evaluated under the conditions described later under high humidity flow, wear resistance, gradation, and sensitivity under the evaluation conditions described later. These results are shown in Table 5.

<Comparative Example 1>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce two positively charged a-Si photosensitive members. However, the high frequency power, the SiH ₄ flow rate, and the CH ₄ flow rate during the surface layer preparation were set as the conditions shown in Table 3.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Comparative Example 1, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. These results are shown in Table 5.

<Comparative example 2>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 4 to produce two positively charged a-Si photosensitive members. The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed.
Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Comparative Example 2, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. These results are shown in Table 5. The film forming condition No. of the electrophotographic photoreceptor produced in Comparative Example 2 was measured. Was set to 6.

(Measurement of C / (Si + C), Si + C atom density, H atom ratio)
First, a reference electrophotographic photoreceptor in which only the charge injection blocking layer and the photoconductive layer shown in Table 1 were laminated was prepared, and a central portion in the longitudinal direction in an arbitrary circumferential direction was cut out by 15 mm □ to prepare a reference sample. Next, the electrophotographic photoreceptor in which the charge injection blocking layer, the photoconductive layer and the surface layer were laminated was cut out in the same manner to prepare a measurement sample. The reference sample and the measurement sample were measured by spectroscopic ellipsometry (manufactured by JA Woollam: high-speed spectroscopic ellipsometry M-2000) to determine the film thickness of the surface layer.
Specific measurement conditions of spectroscopic ellipsometry are incident angles: 60 °, 65 °, 70 °, measurement wavelengths: 195 nm to 700 nm, and beam diameter: 1 mm × 2 mm.
First, the relationship between the wavelength, the amplitude ratio Ψ, and the phase difference Δ was determined for each reference angle by spectroscopic ellipsometry for the reference sample.

Next, using the measurement result of the reference sample as a reference, the relationship between the wavelength, the amplitude ratio Ψ, and the phase difference Δ at each incident angle was obtained by spectroscopic ellipsometry for the measurement sample in the same manner as the reference sample.
Furthermore, a charge injection blocking layer, a photoconductive layer, and a surface layer are sequentially laminated, and a layer structure having a roughness layer in which the surface layer and the air layer coexist on the outermost surface is used as a calculation model. By changing the volume ratio of the surface layer to the air layer, the relationship between the wavelength at each incident angle and Ψ and Δ was calculated. Then, a calculation model was selected when the mean square error of the relationship between the wavelength, Ψ and Δ obtained by measuring the measurement sample and the relationship between the wavelength obtained by the above calculation at each incident angle and Ψ and Δ was minimized. . The film thickness of the surface layer was calculated using the selected calculation model, and the obtained value was used as the film thickness of the surface layer. The analysis software is J.I. A. Woolase WVASE32 was used. The volume ratio of the surface layer to the air layer in the roughness layer was calculated by changing the ratio of the air layer in the roughness layer by 1 from 10: 0 to 1: 9 in the surface layer: air layer. In the positively charged a-Si photoconductor of the present embodiment, it is obtained by measuring the relationship between the wavelength obtained by calculation and Ψ and Δ when the volume ratio of the surface layer to the air layer of the roughness layer is 8: 2. The mean square error of the relationship between the obtained wavelength and Ψ and Δ was minimized.

After the measurement by spectroscopic ellipsometry is completed, silicon atoms in the surface layer in the RBS measurement area are measured by RBS (Rutherford backscattering method) using AN-2500 manufactured by Nisshin High Voltage Co., Ltd. The number of carbon atoms was measured. C / (Si + C) was determined from the measured number of silicon atoms and carbon atoms. Next, Si atom density, C atom density, and Si + C atom density were determined using the surface layer thickness determined by spectroscopic ellipsometry for silicon atoms and carbon atoms determined from the RBS measurement area.
Simultaneously with RBS, the number of hydrogen atoms in the surface layer in the measurement area of HFS was measured by HFS (hydrogen forward scattering method) using AN-2500 manufactured by Nissin High Voltage Co., Ltd. for the measurement sample. The H atom ratio was determined from the number of hydrogen atoms determined from the HFS measurement area and the number of silicon atoms and carbon atoms determined from the RBS measurement area. Next, H atom density was calculated | required using the film thickness of the surface layer calculated | required by spectroscopic ellipsometry with respect to the atomic number of the hydrogen atom calculated | required from the measurement area of HFS.
Specific measurement conditions for RBS and HFS are incident ion: 4He +, incident energy: 2.3 MeV, incident angle: 75 °, sample current: 35 nA, incident beam length: 1 mm, and the detector of RBS has a scattering angle. : 160 °, aperture diameter: 8 mm, HFS detector measured at recoil angle: 30 °, aperture diameter: 8 mm + Slit.

(High humidity flow evaluation)
The electrophotographic apparatus used in the high-humidity flow evaluation was based on the Canon electrophotographic apparatus iR-5065 having the configuration shown in FIG. 6, and an electrophotographic apparatus was prepared for the experiment by removing the blower fan for main charging means. . Further, the main charging device 6002, the transfer charging device 6004, and the separation charging device 6005 are modified to charging means having the configuration shown in FIG. The shielding member 4103 is made of a polyimide resin sheet having a thickness of 30 μm.
Further, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.
The A3 character before the continuous paper passing test in a high humidity environment where the electrophotographic photosensitive member produced in the above electrophotographic apparatus was installed and the temperature was 30 ° C. and the relative humidity was 80% (volume absolute humidity 24.3 g / unit cm ³ ). A chart (4 pt, printing rate 4%) is output. At this time, it carried out on the conditions which turn on a photoconductor heater.
After the image output before the continuous paper passing test, the continuous paper passing test was performed. The continuous sheet passing test was performed under the condition that the photoconductor heater was always turned off while the electrophotographic apparatus was operated and the continuous sheet passing test was performed and while the electrophotographic apparatus was stopped.

Specifically, using the A4 test pattern with a printing rate of 1%, a continuous sheet passing test of 25,000 sheets per day is performed for 10 days and up to 250,000 sheets. After completion of the continuous paper passing test, the photoconductor heater is left off for 15 hours in an environment of a temperature of 30 ° C. and a relative humidity of 80%.
After 15 hours, the shielding member 4103 was stored by the winding device 4104 with the photoconductor heater turned off, and then an A3 character chart (4 pt, printing rate 4%) was output. An image output before the continuous paper passing test and an image output after being left for 15 hours were digitized into PDF files using a Canon digital electrophotographic apparatus iRC-5870 under binary conditions of monochrome 300 dpi.

Then, using the Adobe image editing software “Adobe Photoshop” (trade name), the electrophotographic photoreceptor faces the main charger 6002, transfer charger 6004, and separation charger 6005 in the image output after being left for 15 hours. The black ratio of the area corresponding to the spot was measured. In addition, the black ratio of the area corresponding to the portion not facing the charger was also measured. A similar black ratio measurement was also performed on an image output before the continuous paper passing test. Then, the high-humidity flow was evaluated by determining the ratio of the black ratio of the image output after being left for 15 hours to the black ratio of the image output before the continuous paper passing test in each region.
In this evaluation, the ratio of the black ratio in the area facing the charger is the evaluation of the flow under the charger, and the ratio of the black ratio in the area not facing the charger is the evaluation of the durable flow.

When the flow under the charger and the endurance flow are generated, characters are blurred in the entire image, or the characters are not printed and white spots are lost, so that the black ratio is reduced when compared with the image before the continuous paper passing test. Therefore, as the ratio of the black ratio of the image output after standing for 15 hours with respect to the image before the continuous paper passing test is closer to 100%, the high humidity flow becomes better. In addition, it was judged that the effect of this invention was acquired by D or more. The contents of A to F are as follows.
A: The black ratio of the image output after the continuous sheet passing test to the image output before the continuous sheet passing test is 95% or more and 105% or less.
B: The black ratio of the image output after the continuous paper test to the image output before the continuous paper test is 90% or more and less than 95%.
C: The black ratio of the image output after the continuous paper test to the image output before the continuous paper test is 85% or more and less than 90%.
D: The black ratio of the image output after the continuous paper passing test to the image output before the continuous paper passing test is 80% or more and less than 85%.
E. The black ratio of the image output after the continuous sheet passing test to the image output before the continuous sheet passing test is 70% or more and less than 80%.
F: The black ratio of the image output after the continuous paper test to the image output before the continuous paper test is less than 70%.

(Abrasion resistance evaluation)
The abrasion resistance evaluation method is as follows. The film thickness of the surface layer of the electrophotographic photoreceptor immediately after the production is 9 points in the longitudinal direction in the arbitrary circumferential direction of the electrophotographic photoreceptor (based on the longitudinal center of the electrophotographic photoreceptor). , And measuring the total of 18 points in the longitudinal direction at the position rotated by 180 ° from the arbitrary circumferential direction, and the average value of the 18 points as 0 mm, ± 50 mm, ± 90 mm, ± 130 mm, ± 150 mm) Calculated by
The measurement was performed by irradiating light with a spot diameter of 2 mm perpendicularly to the surface of the electrophotographic photosensitive member, and performing spectroscopic measurement of reflected light using a spectrometer (manufactured by Otsuka Electronics: MCPD-2000). The surface layer thickness was calculated based on the obtained reflection waveform. At this time, the wavelength range was 500 nm to 750 nm, the refractive index of the photoconductive layer was 3.30, and the refractive index of the surface layer was a value obtained from the spectroscopic ellipsometry measurement performed during the Si + C atom density measurement described above. .
After film thickness measurement, as in the high humidity flow evaluation, an electrophotographic photoconductor was installed on a Canon digital electrophotographic apparatus iR-5065 remodeled machine, and the high humidity was maintained in a high humidity environment at a temperature of 30 ° C. and a relative humidity of 80%. A continuous paper feeding test was performed under the same conditions as in the flow evaluation. After completion of the 250,000-sheet continuous sheet passing test, the electrophotographic photoreceptor is taken out of the electrophotographic apparatus, the film thickness is measured at the same position as immediately after the preparation, and the surface layer after the continuous sheet passing test is performed in the same manner as immediately after the preparation. The film thickness was calculated. And the difference was calculated | required from the average film thickness of the surface layer obtained immediately after preparation and after a continuous paper passing test, and the amount of wear in 250,000 sheets was computed.

Film formation conditions No. 1 prepared in Comparative Example 2 were used. The ratio of the difference in the average film thickness of each electrophotographic photoreceptor surface layer to the difference in the average film thickness of the surface layer obtained immediately after the production of the electrophotographic photoreceptor of No. 6 and after the continuous paper passing test was obtained, and the relative evaluation was performed. Went. In addition, it was judged that the effect of this invention was acquired by D or more with respect to abrasion resistance evaluation. The contents of A to F are as follows.
A: Film formation conditions No. 1 prepared in Comparative Example 2 The ratio of the difference in the average film thickness of the surface layer of the electrophotographic photosensitive member produced under each film forming condition to the difference in the average film thickness of the surface layer of the electrophotographic photosensitive member 6 is 60% or less.
B: Film formation condition No. 1 prepared in Comparative Example 2 The ratio of the difference in the average film thickness of the surface layer of the electrophotographic photosensitive member produced under each film forming condition to the difference in the average film thickness of the surface layer of the electrophotographic photosensitive member 6 is more than 60% and not more than 70%. .
C: Film formation condition No. 1 prepared in Comparative Example 2 The ratio of the difference in the average film thickness of the surface layer of the electrophotographic photoreceptor produced under each film forming condition to the difference in the average film thickness of the surface layer of the electrophotographic photoreceptor of 6 is greater than 70% and 80% or less. .
D: Film formation condition No. 1 prepared in Comparative Example 2 The ratio of the difference in the average film thickness of the surface layer of the electrophotographic photosensitive member produced under each film forming condition to the difference in the average film thickness of the surface layer of the electrophotographic photosensitive member 6 is greater than 80% and 90% or less. .
E ... Film formation conditions No. 1 prepared in Comparative Example 2 The ratio of the difference in the average film thickness of the surface layer of the electrophotographic photoreceptor produced under each film forming condition to the difference in the average film thickness of the surface layer of the electrophotographic photoreceptor of 6 is greater than 90% and less than 100%. .
F: Film formation condition No. 1 prepared in Comparative Example 2 The ratio of the difference in the average film thickness of the surface layer of the electrophotographic photoreceptor produced under each film forming condition with respect to the difference in the average film thickness of the surface layer of the electrophotographic photoreceptor of 6 is 100% or more.

(Gradation evaluation)
For the gradation evaluation, a modified machine of Canon digital electrophotographic apparatus iR-5065 used for high humidity flow evaluation was used. First, gradation data was created in which the entire gradation range was evenly distributed in 18 stages according to the area gradation of the dot portion for image exposure. At this time, the darkest gradation is set to 17, the thinnest gradation is set to 0, and a number is assigned to each gradation to obtain a gradation step.
Next, an electrophotographic photosensitive member is installed in the modified electrophotographic apparatus, and is output to A3 paper in the text mode using the gradation data. At this time, if high-humidity flow occurs, the evaluation of image blurring will be affected. Therefore, in an environment of 22 ° C. and 50%, the photoconductor heater is turned on to keep the surface of the electrophotographic photoconductor at about 40 ° C. Was output under different conditions.

The image density of the obtained image was measured with a reflection densitometer (manufactured by X-Rite Inc: 504 spectral densitometer) for each gradation. In the reflection density measurement, three images were output for each gradation, and the average value of the densities was used as the evaluation value.
The correlation coefficient between the evaluation value thus obtained and the gradation stage is calculated, and the correlation coefficient = 1.00, which is a case where a gradation expression in which the reflection density of each gradation changes completely linearly is obtained. The difference of was calculated. And film-forming conditions No. The ratio of the difference calculated from the correlation coefficient of the electrophotographic photosensitive member manufactured under each film forming condition with respect to the difference calculated from the correlation coefficient of the electrophotographic photosensitive member manufactured in Step 2 is an index of gradation. As evaluated. In this evaluation, the smaller the numerical value is, the better the gradation is, and it is shown that gradation expression that is close to linear is performed. Note that it was judged that the effect of the present invention was obtained with A for the gradation evaluation. The contents of A and B are as follows.
A ... Film formation condition No. Correlation coefficient calculated from the correlation coefficient of the electrophotographic photoreceptor prepared in Step 2 = correlation coefficient calculated from the electrophotographic photoreceptor prepared under each film forming condition with respect to the difference from 1.00 = The ratio of the difference from 1.00 is 1.80 or less.
B ... Film formation condition No. Correlation coefficient calculated from the correlation coefficient of the electrophotographic photoreceptor prepared in Step 2 = correlation coefficient calculated from the electrophotographic photoreceptor prepared under each film forming condition with respect to the difference from 1.00 = The ratio of the difference from 1.00 is greater than 1.80.

(Sensitivity evaluation)
A Canon digital electrophotographic apparatus iR-5065 modified machine similar to the high-humidity flow evaluation was used. With the image exposure turned off, a high voltage power supply is connected to the charger wire and grit, the grit potential is set to 820 V, and the current supplied to the charger wire is adjusted so that the surface potential of the electrophotographic photoreceptor is 400 V. It set so that it might become.
Next, the image exposure light was irradiated in a state where it was charged under the previously set charging conditions, and the potential at the developing unit position was set to 100 V by adjusting the irradiation energy.

The image exposure light source of the electrophotographic apparatus used for sensitivity evaluation is a semiconductor laser having an oscillation wavelength of 658 nm. The evaluation result is the film formation condition No. 1 prepared in Comparative Example 2. The results are shown in a relative comparison in which the irradiation energy when the electrophotographic photosensitive member No. 6 is mounted is 1.00. In addition, it was judged that the effect of this invention was acquired by B or more with respect to sensitivity evaluation. The contents of A to C are as follows.
A: Film formation conditions No. 1 prepared in Comparative Example 2 The ratio of the irradiation energy to the irradiation energy in the electrophotographic photoreceptor of 6 is less than 1.10.
B: Film formation condition No. 1 prepared in Comparative Example 2 The ratio of the irradiation energy to the irradiation energy in the produced electrophotographic photoreceptor of 6 is 1.10 or more and less than 1.15.
C: Film formation condition No. 1 prepared in Comparative Example 2 The ratio of the irradiation energy to the irradiation energy in the electrophotographic photosensitive member 6 is 1.15 or more.

(Sp ³ sex evaluation)
The sp ³ property is determined by using a laser Raman spectrophotometer (manufactured by JASCO Corporation: NRS-2000) from a sample obtained by cutting a central portion in the longitudinal direction of an electrophotographic photoreceptor in an arbitrary circumferential direction with 10 mm □. Calculated.
The specific measurement conditions were as follows: light source: Ar + laser wavelength 514.5 nm, laser intensity: 20 mA, objective lens: 50 times, center wavelength 1380 cm ⁻¹ , exposure time 30 seconds, total 5 times. The analysis method of the obtained Raman spectrum is shown below. The peak wavenumber of a shoulder Raman band was fixed at 1390 cm ^-1, the peak wavenumber of a main Raman band without fixation is set to 1480 cm ^-1, were curve fitting using a Gaussian distribution. At this time, the baseline was linear approximation. Seeking I _D / I _G of the peak intensity I _D of curve fitting from the resulting main Raman band (G-band) of the peak intensity I _G and the shoulder Raman band (D-band), the average value of sp ³ of the three Used for evaluation.

(Measurement of surface roughness)
In two electrophotographic photoreceptors, the central portion in the longitudinal direction in an arbitrary circumferential direction is measured with an atomic force microscope (AFM, manufactured by Questant: Q-SCOPE250 Version 3.181), and Ra and average inclination Δa are calculated. did. The average values of Ra and Δa obtained were taken as Ra and Δa values.
Specifically, a head: Tape 10 and a probe: NSC 16 are used, and a range of 10 μm × 10 μm is measured with Wave mode under the measurement conditions of SCAN RATE: 4 Hz, Integral Gain: 600, Proportional Gain: 500, and Scan Resolution: 300. did. Analysis software: AFM observation image obtained by Q-SCOPE250 manufactured by Questant Co. was corrected by using Parabolic Line By Line of Tilt Removal. Ra and Δa were calculated from the corrected AFM observation image by Histogram Analysis. However, for Ra in Histogram Analysis, a value represented by Meas Deviation was used.
About Example 1 and Comparative Examples 1 and 2, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, sp ³ property, high humidity flow, wear resistance, Table 5 shows the results regarding gradation and sensitivity.

As shown in Table 5, it was found that the high-humidity flow and the wear resistance were improved by setting the Si + C atomic density of the surface layer to 6.60 × 10 ²² atoms / cm ³ or more. It was also found that the high humidity flow and the wear resistance are further improved by setting the Si + C atom density to 6.81 × 10 ²² atoms / cm ³ or more.
From this result, it was found that an electrophotographic photoreceptor excellent in high-humidity flow can be obtained by setting the Si + C atom density of the surface layer within the above range.
In addition, since the high-humidity flow is good even without the photoreceptor heater, an electrophotographic photoreceptor excellent in energy saving can be obtained by setting the Si + C atom density of the surface layer in the above range. I understood that.
In Comparative Examples 1 and 2, the high-humidity flow at the retreating side of the shielding member sometimes deteriorated. It is considered that this part is frequently contacted with the shielding member by repeating the shielding operation and the opening operation of the corona charger opening.
The surface roughness of the electrophotographic photoreceptors produced in Example 1 and Comparative Examples 1 and 2 was in the range of Ra of 32 nm to 36 nm and Δa of 0.13 to 0.16.

<Example 2>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the conditions shown in Table 6 were the high-frequency power and the flow rates of SiH ₄ and CH ₄ when the surface layer was produced.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Example 2, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The results are shown in Table 8.

<Comparative Example 3>
Using the plasma processing apparatus having the same configuration as that of Example 2, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the high frequency power and SiH ₄ and CH ₄ flow rates at the time of preparing the surface layer were the conditions shown in Table 7.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Comparative Example 3, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The evaluation results are shown in Table 8 together with Example 2.

As shown in Table 8, the surface layer has a Si + C atom density of 6.60 × 10 ²² atoms / cm ³ or more, and C / (Si + C) is set to 0.61 or more. Was found to be good. Further, by setting the Si + C atom density of the surface layer to 6.60 × 10 ²² atoms / cm ³ or more and setting C / (Si + C) to 0.75 or less, light absorption is suppressed, and sensitivity is increased. Was found to be good.
From this result, Si + C atom density is 6.60 × 10 ²² atoms / cm ³ or more, and C / (Si + C) of the surface layer is in the above range, the high humidity flow is suppressed, and It was found that an electrophotographic photoreceptor excellent in gradation and sensitivity was obtained, and an electrophotographic photoreceptor excellent in electrophotographic photoreceptor characteristics was obtained.
However, by repeating the shielding operation and the opening operation of the opening portion of the corona charger, in Comparative Example 3, the high-humidity flow on the retracting side of the shielding member that frequently contacts the shielding member may be deteriorated.
The surface roughness of the electrophotographic photoreceptors produced in Example 2 and Comparative Example 3 was such that Ra was in the range of 32 nm to 36 nm, and Δa was in the range of 0.13 to 0.16.

<Example 3>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the high-frequency power and the flow rates of SiH ₄ and CH ₄ at the time of preparing the surface layer were the conditions shown in Table 9.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Example 3, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The evaluation results are shown in Table 10 together with the film formation condition No. 9 of Example 2.

As shown in Table 10, when the H atomic ratio of the surface layer was set to 0.30 or more, the light absorption was suppressed, so that the sensitivity was improved. Further, by setting the H atom ratio of the surface layer to 0.45 or less, the high-humidity flow and wear resistance were further improved.
From this result, the Si + C atom density is set to 6.60 × 10 ²² atoms / cm ³ or more and C / (Si + C) is set to 0.61 or more and 0.75 or less, and the H atom ratio of the surface layer is determined. It was found that by setting the value in the above range, an electrophotographic photosensitive member having a high gradation flow and excellent sensitivity can be obtained.
Further, even if the photoconductor heater is omitted, high-humidity flow is good. Therefore, by setting the H atom ratio of the surface layer within the above range (0.3 or more and 0.45 or less), energy saving is also good. It was found that a satisfactory electrophotographic photoreceptor was obtained.
Further, it has been found that even if the shielding operation and the opening operation of the corona charger opening are repeated, there is no deterioration of the high-humidity flow on the retracting side of the shielding member that frequently contacts the shielding member.
The surface roughness of the electrophotographic photoreceptor produced in Example 3 was such that Ra was 32 nm to 36 nm, and Δa was 0.13 to 0.16.

<Example 4>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the conditions shown in Table 11 were used for the high-frequency power and the flow rate of SiH ₄ and CH ₄ during the surface layer preparation.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Example 4, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The results are shown in Table 12 together with the film formation conditions No. 4 of Example 1, the film formation conditions Nos. 8 and 10 of Example 2, and Example 4.

As shown in Table 12, it was found that when the sp ³ property of the surface layer was 0.70 or less, the high-humidity flow and the wear resistance were further improved. Then, sp ³ of the surface layer is at 0.20 or higher, high-humidity image flow resistance and wear resistance was found to be good.
Further, it has been found that even if the shielding operation and the opening operation of the corona charger opening are repeated, there is no deterioration of the high-humidity flow on the retracting side of the shielding member that frequently contacts the shielding member.
From this result, it was found that an electrophotographic apparatus with even higher wet flow and excellent wear resistance can be obtained by setting the sp ³ property of the surface layer in the range of 0.20 to 0.70.

<Comparative example 4>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the high frequency power at the time of producing the surface layer was set to the conditions shown in Table 13.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Comparative Example 4, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The results are shown as film formation conditions No. 4 in Example 1, film formation conditions No. 11 in Example 2, and film formation conditions No. 11 in Example 3. These are shown in Table 14 together with 21 and 22.

As shown in Table 14, by setting the surface layer Si + C atom density to 6.60 × 10 ²² atoms / cm ³ or more and C / (Si + C) to 0.61 or more and 0.75 or less. An electrophotographic photoreceptor excellent in high humidity flow, abrasion resistance, gradation and sensitivity was obtained.
It has also been found that by setting the H atomic ratio range to 0.30 or more and 0.45 or less, an electrophotographic photoreceptor excellent in higher humidity flow, wear resistance and sensitivity can be obtained.
Furthermore, it has been found that an electrophotographic photoreceptor having further excellent wear resistance can be obtained by setting the sp ³ property range to 0.20 or more and 0.70 or less.
In other words, by setting the Si + C atom density, C / (Si + C), H atom ratio, and sp ³ property in the above ranges, it becomes possible to suppress oxidation at the outermost surface of the a-SiC surface layer, and to achieve high humidity. It has been found that an electrophotographic photoreceptor excellent in flow, energy saving, abrasion resistance and electrophotographic photoreceptor characteristics can be obtained.
However, by repeating the shielding operation and opening operation of the corona charger opening, in Comparative Example 4, the high-humidity flow on the retreat side of the shielding member that frequently contacts the shielding member may be deteriorated.
As for the surface roughness of the electrophotographic photoreceptors produced in Example 4 and Comparative Example 4, Ra was in the range of 32 nm to 36 nm, and Δa was in the range of 0.13 to 0.16.

<Example 5>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the high frequency power at the time of producing the surface layer was set to the conditions shown in Table 15.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Example 5, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The results are shown in Table 17.

<Comparative Example 5>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the high frequency power at the time of preparing the surface layer was set to the conditions shown in Table 16.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Comparative Example 5, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The results are shown in Table 17.
For Example 5 and Comparative Example 5, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, sp ³ property, high humidity flow, wear resistance, The results relating to the gradation and sensitivity are shown in Table 17 together with the film formation condition No. 7 of Example 2, the film formation condition No. 14 of Comparative Example 3, and the film formation conditions No. 17, 18, and 20 of Example 3. Shown in

As shown in Table 17, the surface layer has a Si + C atom density of 6.60 × 10 ²² atoms / cm ³ or more and C / (Si + C) of 0.61 or more and 0.75 or less. It has been found that an electrophotographic photoreceptor excellent in high humidity flow, abrasion resistance, gradation and sensitivity can be obtained.
It has also been found that by setting the H atomic ratio range to 0.30 or more and 0.45 or less, an electrophotographic photoreceptor excellent in higher humidity flow, wear resistance and sensitivity can be obtained.
Furthermore, it has been found that an electrophotographic photoreceptor having further excellent wear resistance can be obtained by setting the sp ³ property range to 0.20 or more and 0.70 or less.
In other words, by setting the Si + C atom density, C / (Si + C), H atom ratio, and sp ³ property in the above ranges, it becomes possible to suppress oxidation at the outermost surface of the a-SiC surface layer, and to achieve high humidity. It has been found that an electrophotographic photoreceptor excellent in flow, energy saving, abrasion resistance and electrophotographic photoreceptor characteristics can be obtained.
However, by repeating the shielding operation and the opening operation of the corona charger opening, in Comparative Example 5, the high-humidity flow on the retracting side of the shielding member that frequently contacts the shielding member may be deteriorated.
As for the surface roughness of the electrophotographic photoreceptors produced in Example 5 and Comparative Example 5, Ra was in the range of 32 nm to 36 nm, and Δa was in the range of 0.13 to 0.16.

<Comparative Example 6>
Using the plasma processing apparatus having the same configuration as in Example 1, each layer was formed on the surface of the cylindrical substrate under the conditions shown in Table 1 to produce a positively charged a-Si photosensitive member. However, the high frequency power at the time of producing the surface layer was set to the conditions shown in Table 18.
The produced electrophotographic photoreceptor was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the evaluation described later was performed. Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.

For the electrophotographic photoreceptor produced in Comparative Example 6, after calculating the surface roughness in the same manner as in Example 1, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom The ratio, H atom density, and sp ³ property were determined to evaluate high-humidity flow, wear resistance, gradation, and sensitivity. The results are shown in Table 19 together with the film formation condition No. 1 of Example 1, the film formation condition No. 10 of Example 2, and the film formation conditions No. 26 and 28 of Example 4.

As shown in Table 19, the surface layer has a Si + C atom density of 6.60 × 10 ²² atoms / cm ³ or more and C / (Si + C) of 0.61 or more and 0.75 or less. It has been found that an electrophotographic photoreceptor excellent in high humidity flow, abrasion resistance, gradation and sensitivity can be obtained.
It has also been found that by setting the H atomic ratio range to 0.30 or more and 0.45 or less, an electrophotographic photoreceptor excellent in higher humidity flow, wear resistance and sensitivity can be obtained.
Furthermore, it has been found that an electrophotographic photoreceptor having further excellent wear resistance can be obtained by setting the sp ³ property range to 0.20 or more and 0.70 or less.
In other words, by setting the Si + C atom density, C / (Si + C), H atom ratio, and sp ³ property in the above ranges, it becomes possible to suppress oxidation at the outermost surface of the a-SiC surface layer, and to achieve high humidity. It has been found that an electrophotographic photoreceptor excellent in flow, energy saving, abrasion resistance and electrophotographic photoreceptor characteristics can be obtained.
However, by repeating the shielding operation and the opening operation of the opening portion of the corona charger, in Comparative Example 6, the high-humidity flow on the retracting side of the shielding member that frequently contacts the shielding member may be deteriorated.
The surface roughness of the electrophotographic photoreceptor produced in Comparative Example 6 was in the range of Ra of 32 nm to 36 nm and Δa of 0.13 to 0.16.

<Example 6>
The electrophotographic photoreceptor produced under the film forming condition No. 24 of Example 3 was installed in an electrophotographic apparatus having the same configuration as that of Example 1, and the high humidity flow was evaluated. The results are shown in Table 20 together with the results of film formation condition No. 24 of Example 3.
Similarly to Example 1, the shielding member 4103 was formed of a polyimide resin sheet having a thickness of 30 μm. As in Example 1, while the electrophotographic apparatus was stopped, the shielding member 4103 was moved in the Y direction to shield the openings of the main charger 6002, the transfer charger 6004, and the separation charger 6005.
Further, in the sixth embodiment, a fur brush is provided on the surface of the shielding member 4103 facing the electrophotographic photoreceptor 4101 so that the surface of the electrophotographic photoreceptor 4101 can be rubbed. That is, while the electrophotographic apparatus is stopped, the opening of each charger is shielded by the shielding member 4103 while the fur brush is in contact with the surface of the electrophotographic photoreceptor 4101.

<Comparative Example 7>
The electrophotographic photoreceptor produced under the film forming condition No. 24 of Example 3 was installed in the following electrophotographic apparatus, and the high humidity flow was evaluated. The electrophotographic apparatus used in this comparative example was the same as that in Example 6 except that the shielding member 4103 shown in FIG. 4 was not provided. Table 20 shows the evaluation results regarding the high-humidity flow for Example 6, Example 3, and Comparative Example 7.

As shown in Table 20, by blocking the opening of the corona charger with a shielding member, the adhesion of charged products to the surface of the electrophotographic photosensitive member is reduced when the electrophotographic apparatus is stopped. It turns out to be effective.
Further, when a fur brush is provided on the shielding member and the surface of the electrophotographic photosensitive member is rubbed, the high-humidity flow is further improved in the area facing the charger and the area not facing, and there is no rubbing scratch. It was found that a good image with excellent image uniformity can be obtained.

4101 · · · · · · · · · · Electrophotographic photoconductor 4102 · · · · · · · · · Charged wire 4103 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Winding device 4105 ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Corona Chargers.

Claims (5)

A corona charger having at least an electrophotographic photoreceptor and an opening facing the electrophotographic photoreceptor,
The corona charger is an electrophotographic apparatus having a sheet-like shielding member capable of shielding the opening and a mechanism for winding the shielding member in a longitudinal direction,
The electrophotographic photoreceptor is one in which a photoconductive layer formed of hydrogenated amorphous silicon and a surface layer formed of hydrogenated amorphous silicon carbide are sequentially formed on at least the surface of the substrate.
In the surface layer, the sum of the atomic density of silicon atoms and the atomic density of carbon atoms is 6.60 × 10 ²² atoms / cm ³ or more, and carbon relative to the sum of the number of silicon atoms and the number of carbon atoms An electrophotographic apparatus wherein the ratio of the number of atoms is from 0.61 to 0.75. The ratio of the number of hydrogen atoms to the sum of the number of silicon atoms, the number of carbon atoms and the number of hydrogen atoms in the surface layer is 0.30 or more and 0.45 or less. 2. The electrophotographic apparatus according to 1. ^3. The electrophotographic apparatus according to claim 1, wherein in the surface layer, a sum of an atomic density of silicon atoms and an atomic density of carbon atoms is 6.81 × 10 ²² atoms / cm ³ or more. In the surface layer, the ratio of the peak intensity _{I D} of 1390 cm ^-1 to the peak intensity _{I G} of 1480 cm ^-1 in the Raman spectrum of claims 1 to 3, characterized in that 0.20 to 0.70 The electrophotographic apparatus according to any one of the above. 5. The electrophotographic apparatus according to claim 1, wherein the shielding member also serves as a cleaning member that rubs the surface of the electrophotographic photoreceptor.

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