JP2002049171A - Electrophotographic photoreceptor and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an Si photoreceptor and a device for image formation which prevent deposition of toner during cleaning and which realize good image formation. SOLUTION: The photoreceptor has a photoconductive layer 102 containing a-Si formed on a conductive substrate 101 having <9 nm surface roughness Ra, preferably <6 nm in a 10 μm×10 μm area. In the cumulative frequencies of height from the deepest point in the surface roughness as the referential in a 10 μm×10 μm area of the photoconductive layer 102, the difference in height between at 90% and at 50% cumulative values ranges 35 to 200 nm, preferably 45 to 180 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photoconductor in which a photoconductive layer containing amorphous Si and a surface protective layer are sequentially laminated, and an electrophotographic apparatus provided with the photoconductor of the present invention.

[0002]

2. Description of the Related Art In an electrophotographic apparatus such as a copying machine, a facsimile, a printer, or the like, charging means such as corona charging, roller charging, fur brush charging, and magnetic brush charging are applied to the outer peripheral surface of a photoconductor provided with a photoconductive layer on its surface. To form an electrostatic latent image on the outer peripheral surface of the photoreceptor by exposing the image to be copied of the object to be copied and a laser or LED corresponding to reflected light or a modulation signal, and further forming 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.

[0003] After the copying is performed by the electrophotographic apparatus in this manner, since a part of the toner remains on the outer peripheral surface of the photoreceptor, it is necessary to remove the residual toner. The removal of such residual toner is performed by using a cleaning blade, a fur brush,
It is generally performed by a cleaning process using a magnet brush or the like.

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 disclosed. This method is disclosed in
A direct charger such as a brush charger disclosed in JP-A-1188741, which also serves as a cleaning step, and a developing apparatus disclosed in JP-A-10-307455, which also serves as a cleaning step. However, both methods include a step of rubbing and removing the toner and the surface of the photoreceptor.

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. It is difficult to remove the residual toner even in the toner removing process that proceeds simultaneously with the process, and as a result of repeated copying, the residual toner adheres to the surface of the photoreceptor, resulting in toner adhesion that causes image defects such as black spots or white spots on the image. In some cases.

As a measure for solving the above problem,
As disclosed in Japanese Patent Application Laid-Open No. 9-297420, in a photosensitive member having a photosensitive layer of amorphous Si,
A method has been proposed in which the surface of the conductive substrate on which the photosensitive layer is formed is roughened by cutting or using a rotary ball mill in advance, and the surface of the substrate is defined by a surface roughness value of μm order measured by a surface roughness meter. Have been.

In Japanese Patent Application Laid-Open No. Hei 8-129266, the value of the surface roughness Ra is defined, but this defines the processed shape of the conductive substrate. It is defined by the value of the surface roughness on the order of μm measured by the following method.

[0008]

However, in recent years,
With the progress of digitalization of electrophotographic apparatuses, latent image formation by a light source mainly having a single wavelength is becoming mainstream. As a result, in the proposed method of cutting the substrate in advance, a difference occurs in the amount of light incident on the photoconductive layer due to the shape of the substrate,
As a result, there is a problem that a stripe pattern is generated on a printed image. In addition, it is not preferable to newly provide a step of roughening the surface of the conductive substrate in advance, since this increases the cost. Conversely, when the substrate is processed with a roughness in a range where the stripe pattern does not occur, there has been a problem that toner adhesion cannot be sufficiently suppressed.

Therefore, as a result of diligent studies conducted by the present inventors, the effect of preventing toner adhesion is not always determined by the surface roughness of the substrate on the order of μm measured by a surface roughness meter, but rather, the microscopic property inherent to the amorphous Si film. (Specifically, on the order of several nm to several tens of nm).

Accordingly, the present invention has been completed based on the above findings, and an object of the present invention is to provide a photosensitive member and an image forming apparatus which achieve good image formation by preventing toner from adhering during cleaning.

[0011]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a photosensitive layer containing at least amorphous Si and a surface protective layer are sequentially laminated on a conductive substrate. 10 μm ×
90% of the cumulative frequency of the unevenness height based on the deepest point of the surface roughness unevenness in the range of 10 μm, in other words, the low point
And the difference between the height of the unevenness equivalent to 50% is 35 nm to 200 n.
m, preferably in the range of 45 to 180 nm, it has been found that toner adhesion can be suppressed, and the present invention has been completed.

Means of the present invention for adjusting the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the unevenness height to a suitable range based on the deepest point of the unevenness of the surface roughness in the range of 10 μm × 10 μm. The following method can be used.

For example, fine powders such as silica, chromium oxide, titanium oxide, iron oxide, zirconium oxide, diamond, nitrogen carbide, silicon carbide, silicon nitride, and cerium oxide are used as an abrasive and polished by a dry or wet method. And a method for obtaining a desired surface roughness. Also, buff polishing, magnetic polishing, magnetic fluid FFF, electrophoresis FFF, plasma FFF (FFF: Field assisted Fine Finishin)
g), there is a method of obtaining a desired surface roughness by polishing with EEH (Elastic Emission Haching) and a wrapping film. By this method, 90% and 50% of the cumulative frequency
When the difference between the heights of the irregularities is larger than a desired value, the difference can be reduced.

FIG. 12 is an explanatory view of a polishing apparatus for polishing the surface of an electrophotographic photosensitive member.

In FIG. 12, reference numeral 1 denotes an electrophotographic photosensitive drum, and a surface layer to be processed is provided on the surface thereof. Reference numeral 2 denotes a polishing tape having a polished surface coated with crystal SiC (trade name: Wrapping Tape LT-C2000,
Manufacturer: Fuji Film). Reference numeral 3 denotes a cylindrical support for bringing the surface of the photosensitive drum 1 into contact with the polishing tape 2.

The polishing tape used in the present invention includes:
In addition to the polished surface coated with crystalline SiC,
A material coated with iron oxide, alumina, diamond powder or the like can also be used as a suitable material. Reference numeral 4 denotes a pedestal for the cylindrical support 3. The pedestal 4 is arranged parallel to the rotation axis direction of the photosensitive drum 1, and a load is applied by a weight 5. Reference numeral 6 denotes a feed motor for feeding the polishing tape 2. The motor 6 feeds the polishing tape 2 at a constant speed, and the weight 7 pulls the polishing tape 2 to be fed at a constant speed. At this time, since the polishing tape is sent in the forward direction of the rotation of the photoconductor, the polishing powder and foreign matter of SiC are polished without accumulating in the gap between the polishing tape 2 and the photoconductor drum 1 to obtain a desired surface roughness. be able to. If the surface roughness is larger than a desired value by this method, it can be reduced.

FIG. 13 is a cross-sectional view of the polishing apparatus of FIG. 12 taken along the line AA '. In FIG. 13, the photosensitive drum 1 can move in the rotation axis direction (X direction). Conversely, the polishing tape 2 and the cylindrical support 3 may be moved. As a result, two-dimensional polishing control becomes possible, and a desired surface roughness can be more easily obtained.

The term “microscopic surface roughness” in the present invention refers to the value of surface roughness Ra measured using an atomic force microscope (AFM) [Q-Scope 250 manufactured by Quesant Co.] In order to measure roughness with high accuracy and high reproducibility, 10 μm ×
It is desirable that the measurement result is obtained in a measurement range of 10 μm so as to avoid an error due to a tilt of the curvature of the sample (tilt). Specifically, Q-Scope manufactured by Quesant
Correction to flatten after fitting the curvature of the AFM image of the sample to the parabola by Tile Removal mode of 250
bolic). The electrophotographic photosensitive member generally has a cylindrical shape, which is a suitable method. Further, when the image remains tilted, a correction (Line by line) for removing the tilt is performed. Thus, it is possible to appropriately correct the inclination of the sample within a range that does not cause distortion in the data.

Further, the present inventors have found that, in addition to the above surface shape, the formation of the photoconductive layer from a plurality of layers promotes suppression of toner adhesion.

Variations in the substantial absorption depth of image exposure caused by the band gap of the photoconductive layer cause potential variations in the electrostatic latent image. It is considered that the potential unevenness, specifically, the residual potential and the ghost potential deteriorates fog serving as a nucleus of toner adhesion or sharpness of an image.

It has also been found that by continuously changing the composition of the interface between the surface protective layer of the photoreceptor and the photosensitive layer, toner adhesion can be more effectively suppressed.

The above-mentioned interface composition has a spectral reflectance of the following formula: where the minimum value of the reflectance (%) is Min and the maximum value is Max, with light having a wavelength of 450 nm to 650 nm: 0 ≦ (Max−Min) /(Max+Min)≦0.4 It is desirable to satisfy Expression (1).

Here, the reflectance according to the present invention refers to a reflectance (percentage) value measured using a spectrophotometer [MCPD-2000 manufactured by Otsuka Electronics Co., Ltd.]. In summary, first, the spectral emission intensity I (O) of the light source of the spectroscope is taken, then the spectral reflection intensity I (D) of the photoreceptor is taken, and the reflectance R = I (D) / I (O)
Ask for. 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 photoconductor having a curvature.

FIG. 9 shows a specific example of the interface control. FIG.
Example A shown in (a) (the value of the above formula (1): 0.48), Example B
(Value of the above formula (1): 0.41) is out of the range of the above formula, the measurement example of “with interface”, the example C shown in FIG. 9B (the above formula)
The value of (1): 0.28), and Example D (the value of the above formula (1): 0.16) is a measurement example of “no interface” that satisfies the formula according to the present invention. 2
Each line has a difference due to a 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, the reflectivity greatly changes with a change in the film thickness when viewed at a fixed wavelength when there is an interface and when there is no interface. That is, the sensitivity varies greatly with the film thickness variation.

In other words, substantial unevenness in the thickness of the surface protective layer on the image exposure incident optical path caused by the fine roughness occurs. It is considered that the film thickness unevenness causes a greater variation in sensitivity when there is an interface than when there is no interface, and deteriorates fog, which is a nucleus of toner adhesion, or sharpness of an image.

[Frequency Distribution of Surface Roughness] The frequency distribution of surface roughness, which is an important index of the present invention, will be described below.

Atomic Force Microscop
y) is lateral resolution (resolution in the direction parallel to the sample surface) is 0.5
Longer resolution than nm (resolution in the vertical direction of the sample surface)
Has a thickness of 0.01 to 0.02 nm, and can measure the three-dimensional shape of a sample. A major difference from a surface roughness meter that has been widely used in the past is its high resolution.

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

The roughness of the photoreceptor gas depends on the "teeth" such as the above-mentioned lathe, ball mill, or dimple processing, and the "mold" such as "processing member".
There is no “type” in the roughness of the deposited film itself, and there are form factors that cannot be simply expressed by Ra (center line average roughness) or Rz (ten point average roughness) specified by JIS. The present inventors have thought that this may be a clue for preventing the toner adhesion.

Specifically, the same visual field (10 μm × 10 μm)
m) On a conductive substrate having a surface roughness Ra of less than 10 nm in the range of m), an amorphous silicon photosensitive layer (blocking layer, photoconductive layer, surface layer, all layers including interfaces of each layer) under various conditions.
And observe the height of the irregularities with an atomic force microscope,
The frequency distribution was determined and compared.

A similar difference can not be observed with a surface roughness meter widely used in the past, for example, a contact surface roughness meter (SE-3400) manufactured by Kosaka Laboratory Co., Ltd., and is used in the present application. The index is considered to be a new index indicating the characteristics of the material of the amorphous silicon photoreceptor.

The inventors of the present invention measured AFM at several scan sizes for several samples. The scan size is the length of one side of the square to be scanned, so a scan size of 10 μm is 10 μm × 10 μm or 100 μm.
means to scan the range of m ^2. The horizontal axis of the graph is the scan size, and a part of the result is shown in FIG.

This figure shows two samples, one with relatively small roughness and the other with medium roughness, which were formed on the same substrate under different conditions.
For each of the samples, a visual field of measurement and a roughness index JIS-Ra (center line average roughness) that is generally easy to image are shown.

When the scan size is large, that is, when the measurement range is widened, the measured value is stable, but the minute shape is hardly reflected and the viewing angle is small due to the influence of the peculiar shape such as undulations and projections of the sample substrate and the processed shape. 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, the inventive idea of the present invention is 10
The visual field is not limited to the μm × 10 μm visual field.

[0036]

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

[A-Si Photoconductor According to the Present Invention] FIG. 1 shows a partial cross section of a functional layer laminated on a substrate in an example of the electrophotographic photoconductor 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 material ("a-S
i (H, X) ") or a-Se etc. can be mentioned as typical examples. The thickness of the photoconductive layer 102 is not particularly limited, but is preferably about 15 to 50 μm in consideration of manufacturing costs and the like.

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 a-C (H, X). Further, the interface composition 10 between the photoconductive layer 102 and the surface protective layer 103
7 is continuously changed, and control is preferably performed so as to suppress the interfacial reflection of the relevant portion (FIGS. 1B and 1C).
reference).

Further, the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the unevenness height is adjusted to a suitable range based on the deepest point of the unevenness of the surface roughness in the range of 10 μm × 10 μm of the present invention. As a means for this, it can be obtained by appropriately adjusting the unevenness of the surface of the substrate before forming the deposited film, and after forming the deposited film, performing post-processing such as polishing as necessary.

Specifically, (1) In order to control the unevenness of the surface of an extremely fine deposited film according to the present invention, it is preferable that the substrate is smooth within the range of the measurement of the present invention. (2) Deposition depends on the characteristics of the deposited film, depending on the film deposition conditions, mainly the gas decomposition frequency, input power, and, of course, the deposition film formation conditions. Will be Polishing can be performed, for example, by using a tape (SiC polishing tape) to which fine particles of SiC are adhered, and rubbing the surface of the photoconductor on which a film is formed.

"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 １５０150 MHz VHF band, etc.), a high frequency is introduced into the container 301 with a desired input power amount, and a glow discharge is generated in the container 301. By 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 with silicon as a main component. At this time, by adjusting parameters such as a gas type, a gas introduction amount, a gas introduction ratio, a pressure, a substrate temperature, a supplied electric power, and a film thickness, an a-Si deposited layer having various characteristics is formed to obtain 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 high-frequency power is stopped, the supply valve 306 and the like are closed, and the reaction vessel 3
01, the introduction of the raw material gas is stopped, and 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, that is, a-
The photosensitive layer having the multilayered a-Si photosensitive layer on the surface of the base 312 is manufactured.

Regarding 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 a-Si deposition layer for one 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 of the a-Si deposition layer on the base 312 along the longitudinal direction 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.

FIG. 4 is a schematic view showing an electrophotographic apparatus in which the cleaning device according to the present invention is omitted. The electrophotographic apparatus 401 shown in the figure has a drum-shaped photoconductor 401 in which a light-transmitting conductive layer 404, an insulating carrier injection blocking layer 405a, a photoconductive layer 405, and a surface layer 406 are stacked on a light-transmitting support 403. , An LED head 407 as an exposure unit, a developing device 408, and a transfer roller 409. The LED head 407 and the developing device 408 are arranged substantially symmetrically via a part of the photoconductor 402. Although an LED array 410 as an erase light source is arranged inside the photoconductor 402, it may be arranged outside the photoconductor 402.
The developing device 408 includes, for example, a columnar magnetic pole roller 411 having eight poles, and a conductive sleeve 412 disposed around the outer periphery thereof, and further includes a one-component magnetic material as a developer stored in a toner receiver 413. The conductive toner is delivered to the outer circumference of the sleeve 412 to form a magnetic brush 414. A bias power supply 415 is provided between the sleeve 412 and the light-transmitting conductive layer 404,
During 415, a positive voltage or a negative voltage of 0 to 300 V is applied according to the potential characteristics of the photoconductor 402.
A toner layer 416 is formed on the surface of the photoconductor 402, and is in contact with the recording paper 417. Reference numeral 418 denotes residual toner on the surface of the photoconductor after contact with the recording paper 417. In addition, a rotating means for the developer and a rotating means for the photoconductor 402 are provided.

The surface of the photoreceptor is rubbed with a magnetic brush made of conductive magnetic toner on the developing device to which a light is exposed from the translucent support side by an exposing device and to which a bias voltage is applied by a power supply for developing bias. As a result, charging, exposure and development are performed almost simultaneously, and a toner image is formed on the photoconductor. The toner image is transferred to recording paper using a transfer roller and fixed by a fixing unit to form a recorded image. On the other hand, the toner remaining on the photoreceptor is collected by the developing device and reused, so that the cleaning device is omitted.

[0059]

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

[Experimental Example 1] The parameters of the substrate shape and the manufacturing conditions were changed by using the a-Si photoreceptor film forming apparatus, thereby obtaining 90% and 50% of the cumulative frequency of the surface roughness at the AFM measurement level. The electrophotographic photosensitive member No. 1 in which the difference in the height of the irregularities corresponding to the surface roughness Rz and the surface roughness Rz at the level measured by the surface roughness meter was changed. 101-113 were produced. A cylindrical substrate made of Al was used as the conductive substrate, and a substrate subjected to various substrate surface processing such as cutting and dimple processing was used.

Regarding some of the above photoreceptors, specifically, AFM in the range of 10 μm × 10 μm
FIG. 5 shows the difference between the heights of the irregularities corresponding to 90% and 50% of the cumulative frequency of the surface roughness measured by the method shown in FIG. As can be seen from this figure, a characteristic appears in the cumulative frequency from the width, height, and left / right balance of the frequency distribution. Further, the difference between the heights of the irregularities corresponding to 90% and 50% of the cumulative frequency corresponds to the irregularities on the outermost surface portion, and is considered to be a portion that greatly affects characteristics such as prevention of toner fusion.

In the present invention, focusing on the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency, 101-11
No. 3, the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the surface roughness measured by AFM in the range of 10 μm × 10 μm and the surface roughness Rz measured by the contact type surface roughness meter. Table 1 shows the results of the image evaluation.

Here, the surface roughness of the order of μm in the present invention means a contact length type surface roughness meter [Surfcoder SE-3400 manufactured by Kosaka Laboratory Co., Ltd.] and a measurement length of 1.25 m.
The value of the surface roughness Rz measured at m.

The present inventors measured several samples with several evaluation lengths when measuring the surface roughness meter. FIG. 11 shows a part of the result.

This figure shows the evaluation length and the roughness index JIS-B0601, which is generally easy to imagine, for two samples having relatively small and medium roughnesses formed by changing the substrate and preparation conditions. Rz (ten-point average roughness).

Since there is a correlation between the evaluation length and Rz, that is, if the evaluation length is not specified, it is not possible to accurately express the roughness, and therefore the present invention is expressed by the surface roughness Rz measured at the evaluation length of 1.25 mm. .

The image evaluation was performed using a Canon electrophotographic apparatus NP6.
Using a 350 machine, 500,000 sheets of paper were passed through a test pattern with a printing rate of 3%, a printing rate lower than normal, and a solid white or solid black image was periodically output to evaluate toner adhesion. Was.

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

From the results shown in Table 1, no correlation was found between the conventional value of the surface roughness Rz and the toner adhesion. Conversely,
A correlation was found between the difference in the height of the irregularities corresponding to 90% and 50% of the cumulative frequency and the toner adhesion.

[0070]

[Table 1]

[Experimental Example 2] Next, the frequency distribution of the surface roughness at the AFM measurement level and the measurement with the surface roughness meter were performed by changing each parameter of the manufacturing conditions using the a-Si photosensitive member film forming apparatus. Photoconductors Nos. 201 to 212 having different surface roughnesses Rz at the same level as the photoconductors No. 201 to 212 except that no interface was provided. 213, 21
4 were produced. A with a purity of 99.9% or more on the conductive substrate
The microscopic surface roughness Ra, which was mirror-finished by cutting using a cylindrical substrate made of l, was unified to less than 9 nm.

No. 201-212 of each of the photoconductors
The difference between the height of unevenness corresponding to 90% and 50% of the cumulative frequency of surface roughness measured by AFM in the range of 0 μm × 10 μm, the surface roughness Rz measured by a contact type surface roughness meter, and the result of image evaluation are shown. It is shown in Table 2.

The image evaluation was performed using a Canon electrophotographic apparatus NP6.
Using 350 as it is, or using an image exposure modified to an LED array or laser, with a printing rate of 3% and a test pattern with a printing rate lower than usual, endurance of 500,000 sheets is passed, toner adhesion and cleaning failure , And the sharpness of digital images were evaluated.

A solid white or solid black image is output periodically for toner adhesion and poor cleaning, and a sharpness of a digital image forms a pattern with a line width of 60 to 500 μm and an interval of 60 to 500 μm. It was judged by pass / fail.

The symbols in Table 2 mean ◎: excellent, ：: no practical problem, x: practical problem.

From the results shown in Table 2, the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the unevenness height was 35 nm to 200 nm based on the deepest point of the unevenness of the surface roughness in the range of 10 μm × 10 μm. For photoconductors in the range,
Both toner adhesion and cleaning failure were good.

Further, in the case of a photoconductor in which the difference between the heights of the irregularities corresponding to 90% and 50% of the cumulative frequency is in the range of 45 nm to 180 nm, all of the toner adhesion, poor cleaning and sharpness of the digital image are extremely good. there were. In addition, the absence of an interface broadened the area of toner adhesion or image sharpness.

[0078]

[Table 2]

[Experimental Example 3] Next, using a conductive substrate having a microscopic surface roughness Ra measured by AFM in a range of 10 μm × 10 μm, an electrophotographic photosensitive member No. 1 was used. 30
1 to 306 were manufactured. 99.9% purity for conductive substrate
Using the above cylindrical substrate made of Al, the film forming conditions were adjusted so that the difference between the heights of the irregularities corresponding to 90% and 50% of the cumulative frequency of the surface roughness measured by AFM was approximately 100 nm to 120 nm.

No. Table 3 shows the results of the microscopic surface roughness Ra and the image evaluation of the conductive substrates 301 to 306 of the photoconductors.

The image evaluation was performed using a Canon electrophotographic apparatus NP6.
Using a modified 350 machine, 500,000 sheets were passed through a test pattern with a printing rate of 7%, and the defectiveness of the punch was evaluated.
Pocking failure means that black spots or white spots rarely occur on a printed image as a result of partial abnormal growth of a film during formation of a photosensitive layer.

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

From the results shown in Table 3, it was found that the photosensitive member having a microscopic surface roughness Ra of the conductive substrate of less than 9 nm, preferably less than 6 nm did not cause spotting defects and provided an extremely good image.

[0084]

[Table 3]

[Experimental Example 4] Next, 90% and 50% of the cumulative frequency of the surface roughness at the AFM measurement level were changed by changing each parameter of the manufacturing conditions using the a-Si photosensitive member film forming apparatus. The electrophotographic photosensitive member No. 1 has a single-layer photoconductive layer in which the height difference of the unevenness corresponding to the surface roughness and the surface roughness Rz at the surface roughness meter measurement level are changed. 401-406,
The electrophotographic photoreceptor No. 407,
412 and the same photoreceptor No. 412 except that the photoconductive layer is a multilayer and has no interface. 413 and 414 were produced. A cylindrical substrate made of Al having a purity of 99.9% or more was used as the conductive substrate, and mirror-finished by cutting to uniform a microscopic surface roughness Ra of less than 6 nm.

No. One of the photoconductors 401 to 414
The difference between the height of the irregularities corresponding to 90% and 50% of the cumulative frequency of the surface roughness measured by AFM in the range of 0 μm × 10 μm, the surface roughness Rz measured by the contact type surface roughness meter, and the result of the image evaluation are shown. It is shown in Table 4.

The image evaluation was performed using a Canon electrophotographic apparatus NP6.
Using 350 as it is, or using an image exposure modified to an LED array or laser, with a printing rate of 3% and a test pattern with a printing rate lower than usual, endurance of 500,000 sheets is passed, toner adhesion and cleaning failure , And the sharpness of digital images were evaluated.

A solid white or solid black image is output periodically for toner adhesion and poor cleaning. A digital image is formed with a pattern having a line width of 60 to 500 μm and a spacing of 60 to 500 μm. It was judged by pass / fail.

The symbols in Table 4 represent ◎: excellent, ：: no practical problem, x: practical problem.

From the results in Table 4, the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the unevenness height is 35 nm to 200 nm based on the deepest point of the unevenness of the surface roughness in the range of 10 μm × 10 μm. For photoconductors in the range,
Both toner adhesion and poor cleaning were good.

Further, in the case of a photoconductor in which the difference between the heights of the concavities and convexities corresponding to 90% and 50% of the cumulative frequency is in the range of 35 nm to 200 nm, preferably 45 nm to 180 nm, toner adhesion, poor cleaning, and sharpness of digital images. Both were extremely good. Further, by eliminating the interface, the area of toner adhesion or image sharpness was widened.

[0092]

[Table 4]

[0093]

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

Using the a-Si photoreceptor film forming apparatus, φ8
By changing each parameter of the cylindrical substrate shape of 0 mm and the manufacturing conditions, the photoreceptor was 10 μm × 10 μm.
Charged electrophotography in which the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the unevenness and the surface roughness Rz on the order of μm are changed based on the deepest point of the unevenness in the range of Photoconductors (Examples 1 to 4 and Comparative Examples 1 to 3) were manufactured.

The difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the surface roughness in the range of 10 μm × 10 μm of each of the photosensitive members of Examples 1 to 4 and Comparative Examples 1 to 3;
Table 5 shows the results of the microscopic surface roughness Ra and the image evaluation of the conductive substrate.

The conductive substrate used in Example 1
FIG. 8 shows an observation image of microscopic roughness measured by AFM in a range of μm × 10 μm.
FIGS. 6 and 7 show observation images of microscopic roughness measured by AFM in a range of × 10 μm.

The image evaluation was performed using a Canon electrophotographic apparatus NP6.
Using a machine converted from 350 to digital exposure, 1,000,000 sheets of paper were passed, and toner adhesion, poor cleaning,
In addition, the sharpness of the digital image was evaluated, and a comprehensive evaluation was performed from the results. Here, in Example 2 and Comparative Example 2, an analog image was evaluated using a modified electrophotographic apparatus NP6350 manufactured by Canon.

The symbols in Table 5 mean ◎: excellent, ：: no practical problem, x: practical problem.

[0099]

[Table 5]

Further, by changing the parameters of the shape of the cylindrical substrate having a diameter of 30 mm and the manufacturing conditions by using the a-Si photoreceptor film forming apparatus, the photoreceptor was 10 μm × 1
The difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the unevenness and the surface roughness Rz on the order of μm of the negative charge, based on the deepest point of the unevenness of the surface roughness in the range of 0 μm. An electrophotographic photoreceptor (Example 5, Comparative Example 4) was produced.

In each of the photosensitive members of Example 5 and Comparative Example 4, 10
9 of cumulative frequency of surface roughness in the range of μm × 10 μm
Table 6 shows the difference between the heights of the unevenness corresponding to 0% and 50%, the microscopic surface roughness Ra of the conductive substrate, and the results of the image evaluation.

The image evaluation was performed using a Canon electrophotographic apparatus GP4.
Using a remodeling machine 05, 300,000 sheets were passed, and toner adhesion, poor cleaning, and sharpness of a digital image were evaluated. From the results, a comprehensive evaluation was performed.

The symbols in Table 6 indicate ◎: excellent, ：: no practical problem, x: practical problem.

[0104]

[Table 6]

[0105]

As described above, according to the electrophotographic photoreceptor and the electrophotographic apparatus of the present invention, a photoreceptor obtained by sequentially laminating a photosensitive layer containing at least amorphous Si and a surface protective layer on a conductive substrate. 10 μm × 10
Based on the deepest point of the surface roughness in the range of μm, the difference between the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the height of the unevenness is in the range of 35 nm to 200 nm, more preferably 45 nm to 180 nm. As a result, it was possible to prevent toner from adhering at the time of cleaning and to form a good image.

Further, according to the electrophotographic photoreceptor and the electrophotographic apparatus of the present invention, the conductive substrate has a size of 10 μm × 10 μm.
The surface roughness Ra in the range of m is less than 9 nm, more preferably less than 6 nm, and the height of the unevenness corresponding to 90% and 50% of the cumulative frequency of the unevenness height based on the deepest point of the unevenness of the surface roughness. When the difference is in the range of 35 nm to 200 nm, and more preferably 45 nm to 180 nm, it is possible to prevent toner adhesion and spot defects during cleaning, and to form a better image.

Further, in the above, the interface composition between the surface protective layer and the photosensitive layer of the photoreceptor is continuously changed, and the spectral reflectance at the interface composition is in the range of 450 nm to 650 nm. (%) Minimum value of Mi
When n and the maximum value are Max, 0 ≦ (Max−Min) / (Max
+ Min) ≦ 0.4 It is possible to more effectively suppress toner adhesion in a region satisfying 0.4.

Further, by forming the photoconductive layer of the photoreceptor from a plurality of layers in the above, it has become possible to more effectively suppress toner adhesion and improve image sharpness.

[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 schematic sectional view of another example of the electrophotographic apparatus of the present invention.

FIG. 5 is a diagram showing an example of a frequency distribution of surface roughness according to the present invention.

FIG. 6 is a diagram showing an example of an image observed by an atomic force microscope according to an example of the present invention.

FIG. 7 is a diagram showing an example of an image observed by an atomic force microscope according to an example of the present invention.

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

FIG. 9 is a diagram for explaining interface reflection control of the surface protective layer of the present invention.

FIG. 10 is a diagram illustrating a measurement range of the AFM of the present invention.

FIG. 11 is a diagram illustrating a measurement length of the surface roughness meter according to the present invention.

FIG. 12 is an explanatory view of a polishing apparatus for a surface of an electrophotographic photosensitive member.

13 is a cross-sectional view of the polishing apparatus of FIG. 12, taken along line AA '.

[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 209 AC Static eliminator 210 Static elimination 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

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiyuki Ehara 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Tetsuya Karaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Kunimasa Kawamura 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H035 CA07 CB02 CB03 2H068 DA17 DA18 2H076 AB42 AB63 DA37

Claims (9)

[Claims] 1. An electrophotographic photoreceptor comprising a photoconductive layer containing at least amorphous Si and a surface protective layer sequentially laminated on a conductive substrate, wherein the surface roughness of the photoreceptor is within the range of 10 μm × 10 μm. 90 of cumulative frequency of uneven height based on deep point
% And the height of the unevenness corresponding to 50% are 35 nm to 200 nm.
An electrophotographic photoreceptor characterized by being in the range of nm. 2. The electrophotographic photoreceptor according to claim 1, wherein the difference between the heights of the irregularities corresponding to 90% and 50% of the cumulative frequency is in the range of 45 nm to 180 nm. 3. The electrophotographic photoreceptor according to claim 1, wherein the photoconductive layer comprises a plurality of layers. 4. The photosensitive member according to claim 1, wherein
4. The electrophotographic photosensitive member according to claim 1, wherein a surface roughness Ra in a range of μm × 10 μm is less than 9 nm. 5. The photosensitive member according to claim 1, wherein
5. The electrophotographic photoreceptor according to claim 4, wherein the surface roughness Ra in a range of μm × 10 μm is less than 6 nm. 6. The electrophotographic photoconductor according to claim 1, wherein an interface composition between the surface protective layer and the photoconductive layer of the photoconductor is continuously changed. 7. The spectral reflectance at the interface composition is represented by the following formula: reflectance (%) with light having a wavelength in the range of 450 nm to 650 nm.
When the minimum value of Min is Min and the maximum value is Max, 0 ≦ (Ma
7. The electrophotographic photoconductor according to claim 6, wherein (x−Min) / (Max + Min) ≦ 0.4 is satisfied. 8. An electrophotographic apparatus comprising the photoreceptor according to claim 1. Description: 9. An electrophotographic apparatus comprising the photosensitive member according to claim 1, wherein an image is formed by a light source mainly having a single wavelength.