JP2002082463A - Electrophotographic photoreceptor and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoreceptor and an image forming device in which melt sticking of toner during cleaning is prevented and formation of good images is maintained. SOLUTION: In the electrophotographic photoreceptor produced by successively laminating a photoconductive layer 102 containing amorphous Si and a surface protective layer 103 consisting of an amorphous material on a conductive substrate 101, the refractive index is stepwise or continuously varied between the photoconductive layer 102 and the surface layer 103. The center line average roughness Ra1 on the interface of the photoconductive layer in the surface side in 10 μm×10 μm area and the center line average roughness Ra2 of the outermost surface of the surface layer are controlled to satisfy Ra1/Ra2>=1.1 and 22<=Ra1<=100 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member and an electrophotographic apparatus. More specifically, the present invention relates to an amorphous silicon (amorphous Si) based photoconductor and an electrophotographic apparatus using the same.

[0002]

2. Description of the Related Art In an electrophotographic apparatus such as a copying machine, a facsimile, and a printer, the outer peripheral surface of a photoreceptor having a photoconductive layer on its surface is charged by charging means such as corona charging, roller charging, fur brush charging, and magnetic brush charging. It is uniformly charged, and then the copy image of the copy object is exposed by a laser or an LED according to the reflected light or the modulation signal to form an electrostatic latent image on the outer peripheral surface of the photoreceptor. A toner image is formed by attaching toner on the photoreceptor, and the toner image is transferred to copy paper or the like to perform copying.

After copying in the electrophotographic apparatus as described above, a part of the toner remains on the outer peripheral surface of the photosensitive member, and it is necessary to remove the residual toner. The removal of such residual toner is generally performed by a cleaning process using a cleaning blade, a fur brush, a magnet brush, or the like.

[0004] In recent years, in consideration of the environment, an electrophotographic apparatus in which a cleaning device is omitted for the purpose of reducing or eliminating waste toner has been proposed and is on the market. This method uses a direct charger such as a brush charger disclosed in Japanese Patent Application Laid-Open No. 6-118741, which also serves as a cleaning step, and a developing device disclosed in Japanese Patent Application Laid-Open No. 10-307455. Although there is a cleaning step and the like, any of the methods includes a step of rubbing and removing the toner and the surface of the photoconductor.

However, in recent years, in order to improve the quality of a printed image, a toner having a smaller average particle size and a toner having a lower melting point corresponding to energy saving have been used, and the toner is fused to the surface of the photoreceptor. There is a phenomenon that does. In the toner removing step for removing even the initial state of the fusion, the load on the cleaning step is increased, and the surface layer of the photoreceptor is unevenly scraped, and the charging member is unevenly distributed and the contact is continued. In some cases, the surface layer was unevenly scraped.

In such a situation, when image exposure is performed, unevenness occurs due to unevenness in the thickness of the surface layer, and a difference occurs in light incident on the photoconductive layer, thereby causing a band-like unevenness in a halftone image. There was a problem. In addition, in recent years, with the progress of digitalization of electrophotographic apparatuses, latent image formation by a light source mainly having a single wavelength has become mainstream, and interference has been remarkably generated, and the problem has been promoted.

[0007] As a measure to solve the above problem,
JP-B 5-49108, JP-B 5-73232,
As disclosed in JP-A-73233 and 73234, in a photoreceptor using amorphous Si (hereinafter abbreviated as a-Si) as a photosensitive layer, an intermediate layer may be provided between the photoconductive layer and the surface layer. , By continuously changing the composition of the interface,
There has been proposed a method of reducing or eliminating reflection at an interface to prevent halftone image unevenness caused by uneven incident light amount due to unevenness of surface layer shaving. Such photoconductors are used in digital copiers and printers in recent years, but halftone image unevenness caused by sharp film thickness unevenness with a fine pitch of several tens μm to several mm caused by the cleaner or contact charger is prevented. Is often insufficient.

Japanese Patent Application Laid-Open No. 11-2996 proposes that the surface of the photoreceptor is polished to regulate the surface roughness Rz to a predetermined value. However, there is no disclosure of generation or prevention of halftone image unevenness due to sharp film thickness unevenness with a fine pitch of several tens μm to several mm due to a cleaner or a contact charger.

[0009]

In recent years, with the progress of digitization of electrophotographic apparatuses, latent image formation by a light source mainly having a single wavelength such as a laser or an LED array has become mainstream, and at the same time, electric circuit elements have been developed. With the development of copying speed,
That is, the number of rotations of the photoconductor also keeps increasing. As a result, the intermediate layer is provided between the photoconductive layer and the surface layer, or the composition of the interface is continuously changed to reduce or eliminate the reflection at the interface. There is a problem that a difference occurs in the amount of light incident on the photoconductive layer due to the interference of a single wavelength, and as a result, a band-like density difference occurs on a printed image. Further, it is not preferable to newly provide a step of preliminarily roughening the surface of the conductive substrate because it leads to an increase in cost. Further, when the substrate is processed with a roughness in a range where the density difference does not occur, a new problem such as a decrease in image sharpness may occur.

Therefore, as a result of intensive studies conducted by the present inventors, the effect of preventing halftone stripe unevenness due to uneven scraping of the surface layer is not necessarily determined only by controlling the interface composition and controlling the roughness of the substrate. -It has been found that the surface roughness is greatly dependent on the microscopic (specifically, on the order of several nm to several tens of nm) surface roughness inherent to the surface of the Si photoreceptor.

Accordingly, the present invention has been completed based on the above findings, and an object of the present invention is to provide a photoreceptor and an image forming apparatus in which toner fusion during cleaning is prevented and good image formation is maintained. It is in.

[0012]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have found that a photoconductive layer containing amorphous Si and an amorphous material And a surface protective layer composed of the following. The refractive index is changed stepwise or continuously between the photoconductive layer and the surface layer.
Assuming that the center line average roughness of the photoconductive layer surface side interface in the range of m × 10 μm is Ral and the center line average roughness of the outermost surface layer is Ra2, Ral / Ra2 ≧ 1.1, preferably Ral / Ra2 ≧ 1.3, more preferably Ral /
It has been found that by using a photoreceptor having a range of Ra2 ≧ 2.0 and 22 ≦ Ral ≦ 100 nm, it is possible to prevent toner fusion and maintain good image formation.
The present invention has been completed.

The microscopic surface roughness in the present invention refers to an atomic force microscope (AFM) [Q-Sc manufactured by Questant Corporation].
ope 250], and in order to measure the microscopic surface roughness with high accuracy and high reproducibility, a measurement range of 10 μm × 10 μm and a curvature gradient of the sample ( It is desirable that the measurement result is obtained so as to avoid an error due to tilt. Specifically, Ti of Q-Scope250 manufactured by Questant
In the Le Removal mode, a correction (parabolic) for flattening after fitting a curvature of an AFM image of a sample to a parabola is given. The electrophotographic photosensitive member generally has a cylindrical shape, which is a suitable method. Furthermore, if the image remains tilted, the correction (L
ineby line). As described above, it is possible to appropriately correct the inclination of the sample within a range that does not cause distortion in the data.

The center line average roughness Ra in the range of 10 μm × 10 μm of the present invention is determined by an atomic force microscope (AFM).
[Q-Scope250 (Ver.
3.181)]] indicates a value calculated from the three-dimensional shape.

The present inventors determined the two-dimensional center line average roughness Ra of an arbitrary cross-sectional curve from the three-dimensional shape measured by the atomic force microscope.
It almost coincided with the center line average roughness Ra in the range of μmm × 10 μm. However, from the viewpoints of the stability of measured values and the mechanism of occurrence of interference, Ra determined from the three-dimensional shape is more preferable.

The essential point of the present invention is a relational expression Ral / Ra2 ≧ 1.1 for disturbing the parallelism of the surface layer.
Can be achieved by controlling the photoreceptor film forming conditions described later and selecting the surface material, and if necessary, furthermore, a photoreceptor surface treatment method as described in JP-B-07-077702. May be polished to a desired surface fine roughness. Specifically, a polishing treatment may be performed by pressing a wrapping tape manufactured by Fuji Film Co., Ltd. or 3M Co., Ltd. against a rotating photoconductor under pressure.

In particular, Ral is controlled by the roughness of the substrate by surface treatment and the conditions for forming the photoconductive layer, specifically, the source gas ratio, gas flow rate, substrate temperature, and discharge power. Ra2 is controlled by the conditions for forming the surface layer, specifically, the ratio of the raw material gas, the gas flow rate, the substrate temperature, the discharge power, and the post-treatment surface polishing treatment and the steps involving polishing in an electrophotographic apparatus.

The photosensitive member preferably has a surface spectral reflectance satisfying the following expression. Wavelength from 600 nm to 700 nm
When the minimum value of the reflectance (%) is defined as Min and the maximum value of the reflectance (%) is defined as Max, 0 ≦ (Max−Min) /
(Max + Min) ≦ 0.20, preferably 0 ≦ (Max−Min) / (Max + Min) ≦ 0.10, more preferably 0 ≦ (Max−Min) / (Max + Min) ≦ 0.05 The reflectance refers to the value of the reflectance (percentage) measured using a spectrophotometer [MCPD-2000 manufactured by Otsuka Electronics Co., Ltd.]. In brief, first, the spectral emission intensity I (0) of the light source of the spectroscope is taken, then the spectral reflection intensity I (D) of the photoconductor is taken, and the reflectance R = I (D) / I
Find (0). In order to measure with high accuracy and high reproducibility, it is desirable to fix the detector with a jig so that the angle is constant with respect to the photoreceptor having a curvature.

FIGS. 4A and 4B show specific examples of interface control.
Shown in FIG. 4A shows the wavelength range in the range of 400 to 720 nm, and FIG. 4B shows the wavelength range in the range of 600 to 700 nm. The data are the same. A and B are examples of “no interface reflection control” at the interface between the photoconductive layer and the surface layer, and C, D, and E are examples of “with interface reflection control” at the interface between the photoconductive layer and the surface layer. However, A, B and C are examples outside the scope of the present invention.

The two lines A and B are the differences due to the difference in the thickness of the surface protective layer, and the waveform moves right and left on the graph according to the difference in the film thickness. Since the maximum value corresponds to the amplitude of the waveform, “without interfacial reflection control” greatly fluctuates with respect to a change in film thickness when viewed at a fixed wavelength compared to “with interfacial reflection control”. That is, the sensitivity varies greatly with the film thickness variation.

On the contrary, C, D and E perform "interface reflection control" in which the composition is changed stepwise or continuously at the interface between the photoconductive layer and the surface layer to change the refractive index stepwise or continuously. Therefore, the fluctuation is remarkably small.

Further, with respect to D and E, which are the embodiments of the present invention, the fluctuations are almost negligible, and if the photosensitive member surface layer is unevenly scraped in the cleaning step, or the charging member is unevenly distributed. Therefore, even when the surface layer of the photoreceptor is unevenly scraped, the appearance of image unevenness can be prevented.

"Fine Surface Roughness of Surface Interface of Photoconductive Layer and Top Surface Layer and Parallelism of Surface Layer" The fine parallelism of the surface layer portion, which is an important index of the present invention, will be described below. Atomic force microscopy
The horizontal resolution (resolution in the direction parallel to the sample surface) is greater than 0.5 nm, the vertical resolution (resolution in the direction perpendicular to the sample surface) is 0.01 to 0.02 nm, and the three-dimensional It is possible to measure various shapes, and the major difference from the surface roughness meter that has been widely used in the past lies in its high resolution.

The present inventors measured AFM at several scan sizes for some samples. The scan size is the length of one side of the square to be scanned, and therefore, the scan size 1
0 μm means 10 μm × 10 μm, that is, 100 μm ²
Means to scan the range. The horizontal axis of the graph is the scan size, and a part of the result is shown in FIG.

When the scan size is large, that is, when the measurement range is widened, the measured value is stable, but the minute shape becomes difficult to be reflected due to the influence of a peculiar shape such as undulations and projections of the sample base and the processed shape, and the viewing angle is small. Therefore, the present invention is described in a 10 μm × 10 μm field of view in which the detection capability and the stability of the measurement are excellent overall. From the above circumstances, the inventive idea of the present invention is 10 μm
It is not limited to the x10 μm visual field.

At such a high resolution, it is possible to measure the roughness of the photoconductive substrate, not the dominant order of roughness, but the roughness of the deposited film itself such as the photoconductive layer and the surface layer. It is.

The roughness of the photoreceptor substrate depends on the "teeth" such as the lathe, the ball mill, and the dimple processing, and the "mold" such as the "processing member". There is no "form" and there are complex form factors.

FIG. 8 shows an example of an observation image. The details will be described later in the description of experimental examples and examples.

Regarding the interference of the surface layer, not only the surface layer thickness parameter on the order of submicron, but also the parallelism of the surface layer taking into account the extremely fine surface roughness of the interface between the surface of the photoconductive layer and the outermost surface of the surface layer is large. The present inventors thought that it might be involved and verified it by analysis.

More specifically, a focused ion beam (FIB; Focused) is used using a field emission scanning electron microscope (FE-SEM) (S-4200 manufactured by Hitachi, Ltd.).
Ion Beam) (FIB-200 type F manufactured by fei)
(IB apparatus) and observed the sample processed in cross section.

FIGS. 6 and 7 show examples of observed images.

The sample shown in FIG. 6 is a cross-sectional observation image of the surface layer portion unfamiliar with the present invention, and has a Ra Ra value of the present invention that is lower than the roughness of the photoconductive layer surface side interface corresponding to the Ral value of the present invention.
The roughness of the outermost surface of the surface layer corresponding to two values is small. In comparison, the sample shown in FIG. 7 has a surface layer whose outermost surface has substantially the same roughness as that of the surface-side interface of the photoconductive layer, that is, a shape substantially parallel to a fine surface shape. . The detailed numerical comparison will be described later in the description of Experimental Examples and Examples.

"Relationship between surface layer non-uniformity and halftone image density non-uniformity" FIG. 5 shows the conventional mechanism of surface layer non-uniformity and half-tone image density non-uniformity and the effect of the present invention based on the above analysis results and electrophotographic evaluation results. The mechanism will be described.

As described above, since the surface of the a-Si photosensitive member has almost the same Ral and Ra2 due to its manufacturing method,
In each part, the surface layer thickness is constant, that is, the surface is almost parallel to the interface between the surface and the photoconductive layer. The light incident from the surface is reflected at the interface between the surface and the photoconductive layer and interferes with the reflected light from the surface.Therefore, from the principle of interference, the amount of incident light is determined according to the layer thickness of the surface layer. If different, the potentials are different and appear in the image. This is as described in FIGS. 4A and 4B. In reality, Figure 5
As shown in (A), an unevenly cut portion is generated on the surface layer. Regardless of the shape of the uneven cut, at least the portion other than the uneven cut portion satisfies the interference condition. To cause image unevenness.

However, as shown in FIG. 5B, the relationship between the photoconductive layer and the surface layer is Ral / Ra2 ≧ 1.1, preferably Ral / Ra2 ≧ 1.1.
al / Ra2 ≧ 1.3, more preferably Ral / Ra
In the photoreceptor having the relationship of 2 ≧ 2.0, the interference condition is not satisfied, and the potential does not depend on the thickness of the surface layer. However, if Ral is less than 30 nm, some interference may occur, and in such a portion, scratches and streaks will appear in the image.

When Ral is controlled by processing the substrate, the surface of the substrate is substantially parallel to the surface, so that interference between the two cannot be ignored. Unlike the surface layer,
Since the photoconductive layer has a large absorption, in order to prevent the light reflected from the substrate from interfering with the light reflected on the surface, the photoconductive layer can sufficiently absorb the reflected light from the substrate so as not to return to the surface. The thickness or the wavelength may be set.

In the present invention, the microscopic surface roughness refers to the surface roughness R measured using an atomic force microscope (AFM) [Q-Scope 250 manufactured by Questant] as described above.
In order for the value of a to be easy to handle and to measure the microscopic surface roughness with high accuracy and high reproducibility, it is desirable that the result is within a measurement range of 10 μm × 10 μm. Further, in order to measure Ral on a photoreceptor formed up to the surface layer, the surface roughness and A obtained by observing the cross section of the photoreceptor with FE-SEM, TEM, etc.
A calibration curve is created from the relationship of the surface roughness obtained by FM,
The operation of replacing the roughness up to the photoconductive layer obtained from the cross-sectional observation with Ra2 can be used instead.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings as necessary.

"A-Si Photoreceptor According to the Present Invention" FIG. 1 shows a partial cross section of a functional layer laminated on a substrate in an example of an electrophotographic photoreceptor according to the present invention.

The electrophotographic photoreceptor of this embodiment is shown in FIGS.
As shown in (c), a photoconductive layer 102 and a surface protection layer 103 are sequentially laminated on a base 101 made of a conductive material such as Al or stainless steel. In addition,
In addition to these layers, various functional layers such as a blocking layer 104, an antireflection layer or an interface layer 107 may be provided as necessary. For example, by providing the blocking layer 104, the interface layer 107, and the like, and selecting the dopant of the group III element, the group V element, or the like, the charge polarity such as positive charge and negative charge can be controlled. The shape of the substrate may be a desired one according to the driving method of the electrophotographic photosensitive member. As the base material, conductive materials such as the above Al and stainless steel are generally used. For example, various conductive materials such as plastics and ceramics, especially those having no conductivity, are deposited by vapor deposition of such conductive materials. Can be used.

The photoconductive layer 102 may be organic or inorganic as long as it has photoconductivity. Examples of the inorganic photoconductor include a silicon atom containing a hydrogen atom and a halogen atom. Amorphous materials ("a-Si
(Abbreviated as (H, X))) or a-Se etc. can be mentioned as typical examples. Further, the layer thickness of the photoconductive layer 102 is not particularly limited, but considering the manufacturing cost and the like,
About 15 to 50 μm is appropriate.

Further, in order to improve the characteristics, a plurality of layers such as the lower photoconductive layer 105 and the upper photoconductive layer 106 may be used. In particular, for a light source having a relatively long wavelength and almost no wavelength variation, such as a semiconductor laser, a revolutionary effect appears by devising such a layer configuration.

The surface protective layer 103 is generally made of a-SiC (H,
X), but may be aC (H, X). Also,
It is preferable that the interface composition 107 between the photoconductive layer 102 and the surface protective layer 103 be continuously changed so as to control the interface reflection at the relevant portion (see FIGS. 1B and 1C).

"A-Si Photoreceptor Film Forming Apparatus According to the Present Invention" An example of the a-Si photoreceptor film forming apparatus according to the present invention will be described below.

In the present invention, the photosensitive drum is an a-Si photosensitive member, and the a-Si photosensitive layer is formed by high-frequency plasma CVD.
The film was formed by the (PCVD) method. PC used in the present invention
The VD device is shown in FIG. The apparatus shown in FIG. 3 is a general PCVD apparatus used for manufacturing an electrophotographic photoconductor.
This PCVD apparatus includes a deposition apparatus 300, a source gas supply apparatus, and an exhaust apparatus (both not shown). The deposition apparatus 300 has a reaction vessel 301 composed of a vertical vacuum vessel, and a plurality of vertical source gas introduction pipes 303 are provided around the inside of the reaction vessel 301.
A number of pores are provided on the side surface of the gas introduction pipe 303 along the longitudinal direction. In the center of the reaction vessel 301,
A spirally wound heater 302 extends in the vertical direction,
The cylindrical body 312 serving as a base of the photosensitive drum is
The upper lid 301a is opened and inserted into the heater 302.
Is set vertically inside the container 301 with the inside as the inside. High-frequency power is supplied from a protrusion 304 provided on one of the side surfaces of the reaction vessel 301.

A source gas supply pipe 305 connected to a source gas introduction pipe 303 is attached to a lower portion of the reaction vessel 301, and this supply pipe 305 is connected to a gas supply device (not shown) via a supply valve 306. I have. An exhaust pipe 307 is attached to a lower portion of the reaction vessel 301, and the exhaust pipe 307 is connected to an exhaust device (vacuum pump) (not shown) via a main exhaust valve 308. The exhaust pipe 307 has a vacuum gauge 309, a sub exhaust valve 31 and the like.
0 is attached.

A- by the PCVD method using the above apparatus
The formation of the Si photosensitive layer is performed as follows. First, the cylindrical body 312 serving as the base of the photosensitive drum is set in the reaction vessel 301, the lid 301a is closed, and then the inside of the vessel 301 is evacuated to a predetermined low pressure or lower by an exhaust device (not shown). While continuing, the base 312 is heated from the inside by the heater 302, and
The temperature is controlled to a predetermined temperature within the range of 0 ° C. When the base 312 is maintained at a predetermined temperature, the feed pipe 3 is adjusted while controlling a desired raw material gas by a flow controller (not shown).
03 into the reaction vessel 301. After the introduced source gas fills the inside of the reaction vessel 301, the exhaust pipe 30
7 and is exhausted out of the container 301.

In this way, when it is confirmed by the vacuum gauge 309 that the inside of the reaction vessel 301 filled with the raw material gas has reached a predetermined pressure and stabilized, a high-frequency power source (not shown) (RF band of 13.56 MHz or 50 ~ 150M
(VHF band of Hzz, etc.), a high frequency is introduced into the container 301 at a desired input power amount, and a glow discharge is generated in the container 301. Due to the energy of the glow discharge, the components of the source gas are decomposed to generate plasma ions, and an a-Si deposition layer is formed on the surface of the base 312 mainly with silicon. At this time, by adjusting parameters such as a gas type, a gas introduction amount, a gas introduction ratio, a pressure, a substrate temperature, an input power, and a film thickness, an a-Si deposited layer having various characteristics is formed, thereby obtaining electrophotographic characteristics. Can be controlled.

As described above, the surface of the base 312 is a-S
When the i-deposited layer is formed with a desired film thickness, the supply of the high-frequency power is stopped, the supply valve 306 and the like are closed, and the
01, the introduction of the raw material gas is stopped, and one layer of a-Si
Finish the formation of the deposition layer. By repeating the same operation a plurality of times, an a-Si deposited layer having a desired multilayer structure, ie, a-
The photosensitive layer having the multilayered a-Si photosensitive layer on the surface of the base 312 is manufactured.

Further, with respect to the reduction and control of the interface reflection between the surface protective layer and the photoconductive layer according to the present invention, the high frequency power is not stopped when the formation of the above-mentioned one a-Si deposition layer is completed. In addition, it is achieved by continuously changing the power condition and the gas composition of the next layer without stopping the supply of the raw material gas. Alternatively, although the high-frequency power is temporarily stopped, it can be achieved by starting the raw material gas from the configuration of the previous layer and forming the film while continuously changing the configuration to a desired configuration.

In the above, the flow rate distribution of the raw material gas to be introduced into the reaction vessel 301 through the pores distributed in the longitudinal direction of the gas introducing pipe 303 in the longitudinal direction of the introducing pipe 303, the outflow speed of the exhaust gas from the exhaust pipe, By adjusting the discharge energy and the like, the electrophotographic characteristics along the longitudinal direction of the a-Si deposition layer on the base 312 can be controlled.

[Electrophotographic Apparatus According to the Present Invention] FIG. 2 shows an example of the electrophotographic apparatus of the present invention using the electrophotographic photosensitive member manufactured as described above. The apparatus of the present example is suitable when a cylindrical electrophotographic photosensitive member is used, but the electrophotographic apparatus of the present invention is not limited to this example,
The shape of the photoconductor may be a desired one such as an endless belt shape.

In FIG. 2, around the electrophotographic photosensitive member 204 according to the present invention, a primary charger 205 for charging the photosensitive member 204 for forming an electrostatic latent image and an electrostatic latent image are formed. A developing device 206 for supplying a developer (toner) to the photoconductor 204, a transfer charger 207 for transferring toner on the photoconductor surface to a transfer material 213 such as paper,
A cleaner 208 for cleaning the surface of the photoconductor is provided. In this embodiment, in order to effectively remove the photosensitive member surface uniformly, the photosensitive member surface is purified using the elastic roller 208-1 and the cleaning blade 208-2 as described above. Absent. Also,
Between the cleaner 208 and the primary charger 205, a charge removing lamp 210 for removing charge on the surface of the photoconductor in preparation for the next copying operation is provided. The transfer material 213 is fed by a feed roller 214. As the light source for the exposure A, a halogen light source or a light source mainly having a single wavelength is used.

The formation of a copy image using such an apparatus is performed, for example, as follows.

First, the electrophotographic photosensitive member 204 is rotated at a predetermined speed in the direction of the arrow, and the surface of the photosensitive member 204 is uniformly charged using the primary charger 205. Next, exposure A of an image is performed on the charged surface of the photoconductor 204 to form an electrostatic latent image of the image on the surface of the photoconductor 204. The portion of the surface of the photoconductor 204 where the electrostatic latent image is formed is the developing device 2
06, the toner is supplied to the surface of the photoconductor 204 by the developing device 206, and the electrostatic latent image is visualized (developed) as an image by the toner 206a. With the rotation of the transfer roller 204, the transfer charger 207 reaches the installation portion, where the feed roller 214
Is transferred to the transfer material 213 sent by the printer.

After the transfer is completed, the residual toner is removed from the surface of the electrophotographic photosensitive member 204 by the cleaner 208 in order to prepare for the next copying step, and further the discharging lamp 210 is used so that the potential on the surface becomes zero or almost zero. The charge is removed, and one copy process is completed.

"Electrophotographic Photoreceptor Surface Polishing Apparatus According to the Present Invention" As shown in FIG. 10, the electrophotographic photoreceptor surface polishing apparatus has a photoreceptor support mechanism 1020 for supporting both ends of the a-Si photoreceptor 1000. . The photoreceptor support mechanism 1020 is specifically a pneumatic holder. In this example, a pneumatic holder manufactured by Bridgestone Corporation (trade name: air pick, model number: P
O45TCA * 820) was used.

The photosensitive member 1000 has a polishing tape 1031
A pressure elastic roller 1030 that winds and presses the photoreceptor 1000 is disposed adjacently. Further, the photoreceptor support mechanism 1020 moves forward and backward with an accuracy of about 0.01 mm by the holding table 1040 (arrow 141 in FIG. 1) in order to adjust the pressure between the photoreceptor 1000 and the pressure elastic roller 1030.
Control direction). The forward / backward movement of the photoconductor supporting mechanism 120 utilizes a mechanism typified by a stepping motor.

The polishing tape 1031 is supplied to the delivery roll 10
32, a fixed amount is sent out by a fixed amount sending roll 1034 and a capstan roller 1035, and the photosensitive member 1000
And between the pressure elastic roller 1030 and the take-up roll 1033. As the polishing sheet 1031, what is usually called a wrapping sheet is preferable,
SiC, Al ₂ O ₃ , Fe ₂ O _{3 and the} like are used as the abrasive grains. Here, wrapping tape L made by Fuji Film Co., Ltd.
TC2000 was used.

The pressure elastic roller 1030 is made of a material such as neoprene rubber or silicone rubber and has a JIS rubber hardness of 20 to 80, preferably a JIS rubber hardness of 30.
~ 40 is suitable. Further, the shape of the roller 1030 is preferably such that the diameter of the central portion is larger than that of both ends, and the difference in diameter is preferably 0.0 to 0.6 mm, more preferably 0.2 to 0.4 mm. The wrapping tape is fed and the surface of the photoconductor 1000 is polished while the photoconductor 1000 rotating with respect to the roller 1030 is pressed against 0.5 kg to 2.0 kg.

[0061]

Experimental Examples Hereinafter, the present invention will be described in detail based on various experimental examples.

"Experimental Example 1 (Effect by Exclusion of Parallelism)" The parameters of the substrate shape and the manufacturing conditions were varied by using the a-Si photoreceptor film forming apparatus to 10 μm × 10
In the range of μm, the center line average roughness of the interface on the surface side of the photoconductive layer is Ral, and when the center line average roughness of the outermost surface of the surface layer is Ra2, Ral / Ra2 is 0.95 to 1.25.
al was changed from 15 to 120 nm. 101-115 were produced.

As the conductive substrate, a cylindrical substrate made of Al was used, which had been subjected to various substrate surface machining such as cutting and dimple processing. However, in order to clarify the effect of controlling the fine roughness depending on the manufacturing conditions, and to minimize the occurrence of image defects, the conductive substrate should be 10 μm ×
The cutting and cleaning treatment was performed so that the surface roughness Ra in the range of 10 μm was less than 10 nm.

When the minimum value of Ral / Ra2 and the value of Ral and the reflectance (%) of light in the wavelength range of 600 nm to 700 nm is Min, and the maximum value is Max, (Max−Min) / ( Max + Min), and
Table 1 shows the results of the image evaluation.

The image was evaluated by a Canon electrophotographic apparatus GP6.
05 (pre-exposure 700nm LED array, image exposure 6
75nm laser, process speed 300mm / se
Using c), 1 million sheets of paper are passed through the test pattern with a printing rate of 1%, which is lower than the normal printing rate, and a halftone image is output periodically, and halftone uniformity and roughness Sensory evaluation was performed.

The symbols in Table 1 mean ◎: excellent, ：: no practical problem, x: practical problem.

From the results in Table 1, Ral / Ra2 ≧ 1.1
In addition, it was found that 22 ≦ Ral ≦ 100 nm was preferable.

[0068]

[Table 1] "Experimental Example 2 (Effects of Polishing Treatment)" Electrophotography in which Ral / Ra2, Ral, and reflectance were changed by varying each parameter of the substrate shape and manufacturing conditions using the a-Si photoreceptor film forming apparatus. Photoconductor No. 201-215
Was manufactured.

The conductive substrate was subjected to a cutting and cleaning treatment so that the surface roughness Ra in a range of 10 μm × 10 μm was less than 10 nm.

Next, the photoreceptor on which the film was formed was polished on the outermost surface of a surface layer corresponding to Ra2 of the present invention using a polishing apparatus as shown in FIG. A specific example is shown in FIG. The roughness of the outermost surface, which was initially about 40 nm Ra, was gradually polished and smoothed to about Ral0 nm. During this time, since the roughness of the photoconductive layer surface side interface corresponding to Ral of the present invention does not change, the value of Ral / Ra2 increases. And
The layer configuration is as shown in FIG. 5B, and the color of the surface layer appears black to the naked eye.

The values of Ral / Ra2 and Ral, and the minimum value of the reflectance (%) in light in the wavelength range of 600 nm to 700 nm is Min, and the maximum value is (Max−Min) / ( Max + Min), and
Table 2 shows the results of the image evaluation.

The image evaluation was performed using a Canon electrophotographic apparatus GP6.
05 (pre-exposure 700nm LED array, image exposure 6
75nm laser, process speed 300mm / se
Using c), 1 million sheets of paper were passed through a test pattern with a printing rate of 1%, which was lower than usual, and a halftone image was output periodically to evaluate the uniformity of halftone. The sharpness of the digital image is 60-500 μm in line width,
Patterns were formed at intervals of 60 to 500 μm, and the reproducibility of the patterns was determined.

The symbols in Table 2 are: ：: very excellent,
：: excellent, ：: no practical problem, x: practical problem.

From the results shown in Table 2, Ral / Ra2 ≧ 1.1
Preferably, Ral / Ra2 ≧ 1.3 and 22 ≦
Ral ≦ 100 nm, in addition, wavelengths from 600 nm to 70
(Max−Min) / where the minimum value of the reflectance (%) in the light in the range of 0 nm is Min and the maximum value is Max.
It was found that the reflectance ratio indicated by the value of (Max + Min) ≦ 0.20 was suitable.

[0075]

[Table 2] "Experimental example 3 (effect by surface layer material)" Nos. 301 to 303 are a-SiC: H; 304
Electrophotography in which Ral / Ra2 and Ral were changed in the same manner as in Experimental Examples 1 and 2, after forming a film up to the photoconductive layer under the same conditions, except that -306 was changed to two types of aC: H. A photoreceptor was manufactured.

The conductive substrate was subjected to a cutting and cleaning treatment so that the surface roughness Ra in a range of 10 μm × 10 μm was less than 10 nm.

Table 3 shows Ral / Ra2, Ral values and the results of image evaluation.

The image evaluation was performed using a Canon electrophotographic apparatus GP6.
05 (pre-exposure 700nm LED array, image exposure 6
75nm laser, process speed 300mm / se
Using c), 1 million sheets of paper were passed through a test pattern with a printing rate of 1%, which was lower than usual, and a halftone image was output periodically to evaluate the uniformity of halftone. The sharpness of the digital image is 60-500 μm in line width,
Patterns were formed at intervals of 60 to 500 μm, and the reproducibility of the patterns was determined.

The symbols in Table 3 represent ◎: excellent, ：: no practical problem, x: practical problem.

From the results shown in Table 3, the use of a layer made of amorphous carbon containing hydrogen on the outermost surface provides an effect of flattening the coating and makes it easier to obtain the condition of Ral / Ra2 ≧ 1.1. It has been found that good results can be obtained.

[0081]

[Table 3]

[0082]

The present invention will be described below with reference to examples and comparative examples.

(Example 1) Using the a-Si photoreceptor film forming apparatus, the parameters of the mirror-finished substrate having a diameter of 108 mm and the manufacturing conditions were varied to obtain Ral / Ra.
2. Electrophotographic photoconductors (Examples 1 to 3 and Comparative Examples 1 to 3) having different Ral and reflectance were manufactured.

Ral / Ra2 and Ral of each photoreceptor
Table 4 shows the results of the image evaluation.

Further, the FE-S of the photosensitive member used in Example 1 was used.
FIG. 6 shows a cross-sectional observation image of the surface layer portion measured by EM.
The spectral reflection data is shown in E of FIG. in addition,
FIG. 7 shows a cross-sectional observation image of the surface layer portion of the photoreceptor used in Comparative Example 1 measured by FE-SEM, and FIG. 4B shows its spectral reflection data.

The image was evaluated by a Canon electrophotographic apparatus GP6.
05 (pre-exposure 700nm LED array, image exposure 6
75nm laser, process speed 300mm / se
Using c), 5 million sheets of paper were passed, and the uniformity of the halftone image and the sharpness of the digital image were evaluated.
A comprehensive evaluation was made from the results.

The symbols in Table 4 are ☆: very excellent,
：: excellent, ：: no practical problem, x: practical problem.

[0088]

[Table 4] Example 2 φ3 using the a-Si photoreceptor film forming apparatus
By varying each parameter of the mirror-finished substrate shape of 0 mm and the manufacturing conditions, electrophotographic photoreceptors (Example 4, Comparative Example 4) were manufactured in which Ral / Ra2, Ral, and reflectance were changed.

Ral / Ra2 and Ral of each photoreceptor
Table 5 shows the results of the image evaluation.

The image evaluation was performed using a Canon electrophotographic apparatus GP4.
Perform 1 million sheets of paper endurance using the 05, evaluate the uniformity of the halftone image and the sharpness of the digital image,
A comprehensive evaluation was made from the results.

The symbols in Table 5 are: ☆: very excellent
：: excellent, ：: no practical problem, x: practical problem.

[0092]

[Table 5]

[0093]

As described above, according to the electrophotographic photoreceptor and the electrophotographic apparatus of the present invention, a photoconductive layer containing amorphous Si and a surface made of an amorphous material are formed on a conductive substrate. The protective layer is sequentially laminated, and the refractive index is changed stepwise or continuously between the photoconductive layer and the surface layer, and the
When the center line average roughness of the photoconductive layer surface side interface in the range of m × 10 μm is Ral and the center line average roughness of the outermost surface of the surface layer is Ra2, Ral / Ra2 ≧ 1.1, preferably Ral / Ra2 ≧ 1.3 and 22 ≦ Ral ≦ 10
By setting the thickness to 0 nm, toner fusion at the time of cleaning was prevented, and good halftone image quality could be maintained.

Further, in the above, the interface composition between the surface protective layer of the photoreceptor and the photosensitive layer is continuously changed, and the spectral reflectance at the above interface composition is given by the following equation:
In the range from nm to 700 nm, when the minimum value of the reflectance (%) is Min and the maximum value is Max, 0 ≦ (Max−Min) / (Max + Min) ≦ 0.20, preferably 0 ≦ (Max−Min) ) / (Max + Min) ≦ 0.10 More preferably, in a region that satisfies 0 ≦ (Max−Min) / (Max + Min) ≦ 0.05, toner fusion during cleaning can be more effectively prevented, Halftone image quality can be maintained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an example of the electrophotographic photosensitive member of the present invention.

FIG. 2 is a schematic sectional view of an example of the electrophotographic apparatus of the present invention.

FIG. 3 is a schematic sectional view of an a-Si photoreceptor film forming apparatus used in the present invention.

FIG. 4 is a view for explaining interface reflection control of the surface protective layer of the present invention.

FIG. 5 is a diagram illustrating a phenomenon that uneven shaving of a surface protective layer according to the present invention causes a difference in image density.

FIG. 6 is a diagram showing an example of an image observed by a field emission scanning electron microscope (FE-SEM) according to an example of the present invention.

FIG. 7 is a diagram showing an example of an image observed by a field emission scanning electron microscope (FE-SEM) of a comparative example of the present invention.

FIG. 8 is a view showing an example of an atomic force microscope observation image of a conductive substrate according to the present invention.

FIG. 9 is a diagram illustrating a measurement range of the AFM of the present invention.

FIG. 10 is a schematic sectional view of a surface polishing apparatus applied to the present invention.

[Explanation of symbols]

 Reference Signs List 101 conductive substrate 102 photoconductive layer 103 surface protective layer 104 blocking layer 105 lower photoconductive layer 106 upper photoconductive layer 107 interface layer 204 electrophotographic photoreceptor 205 primary charger 206 developing device 206a toner 207 transfer charger 208 cleaner 210 charge removal Lamp 213 Transfer material 214 Feed roller A Image exposure (analog light or digital light) 300 Deposition device 301 Reaction vessel 302 Heater 303 Source gas introduction pipe 304 Convex part 305 Source gas supply pipe 306 Supply valve 307 Exhaust pipe 308 Main exhaust valve 309 Vacuum gauge 310 Sub exhaust valve 312 Base 1000 a-Si photoreceptor 1020 Photoreceptor support mechanism 1031 Polishing tape 1032 Delivery roll 1033 Take-up roll 1034 Fixed-rate delivery roll 1035 Cap Stan roller 1040 holder

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hironori Owaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Kunimasa Kawamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Toshiyuki Ehara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Koji Yamazaki 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc. F Terms (reference) 2H068 DA12 DA20 DA23 DA35 DA37 DA41 DA70 EA43

Claims (9)

[Claims] A photoconductive layer containing amorphous Si and a surface protective layer made of an amorphous material are sequentially laminated on a conductive substrate, and a step is provided between the photoconductive layer and the surface layer. When the refractive index is changed continuously or continuously and the center line average roughness of the photoconductive layer surface side interface in the range of 10 μm × 10 μm is Ral and the center line average roughness of the outermost surface layer is Ra 2, Ra
1 / Ra2 ≧ 1.1 and 22 ≦ Ral ≦ 100 nm
An electrophotographic photoreceptor, characterized in that: 2. The electrophotographic photoconductor according to claim 1, wherein the surface of the photoconductor is polished. 3. When the spectral reflectance of the photoreceptor is expressed by the following formula, and the minimum value of the reflectance (%) is Max and the minimum value of the reflectance (%) is Min in a light in a wavelength range of 600 nm to 700 nm, 0 ≦ ( (Max−Min) / (Max + Min) ≦ 0.2
3. The electrophotographic photoreceptor according to claim 1, wherein 0 is satisfied. 4. The photosensitive member according to claim 1, wherein
Surface roughness Ra in the range of μm × 10 μm is 10 nm
4. The method according to claim 1, wherein
13. The electrophotographic photoreceptor according to item 6. 5. The semiconductor device according to claim 1, further comprising a layer made of amorphous carbon containing hydrogen on the outermost surface.
The electrophotographic photosensitive member according to any one of the above items. 6. An intermediate layer is provided between a surface protective layer and a photoconductive layer of the photoreceptor, wherein the refractive index of the surface layer is nl, the refractive index of the intermediate layer is n2, and the refractive index of the photoconductive layer is n. 6. The electrophotographic photosensitive member according to claim 1, wherein when n3 is set, the relationship is changed to satisfy nl <n2 <n3. 7. The electron according to claim 1, wherein an element composition ratio and a refractive index between the surface protective layer and the photoconductive layer of the photoconductor are continuously changed. Photoreceptor. 8. A photoconductive layer containing amorphous Si and a surface protective layer made of an amorphous material are sequentially laminated on a conductive substrate, and a step between the photoconductive layer and the surface layer is formed stepwise. Alternatively, when the refractive index is continuously changed and the center line average roughness of the photoconductive layer surface side interface in the range of 10 μm × 10 μm is Ral and the center line average roughness of the outermost surface layer is Ra2, Ral
/Ra2≧1.1 and 22 ≦ Ral ≦ 100 nm, and the spectral reflectance in the wavelength range of 600 nm to 700 nm is represented by the following formula. The minimum value of the reflectance (%) is defined as Min, and the maximum value is defined as Max. When 0 ≦ (Max−Min) / (Max + Min) ≦ 0.2
An electrophotographic apparatus, wherein a photoreceptor that satisfies 0 is used. 9. The electrophotographic apparatus according to claim 8, wherein a surface of the electrophotographic apparatus is polished.