JP2000187344A - Electrophotographic method and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic method (electrophotographic device) that attains both enhancement of electrostatic chargeability and the reduction of optical memory, improves temperature characteristics, the temperature dependence of sensitivity and the linearity of sensitivity and has superior potential characteristics and image characteristics. SOLUTION: In the electrophotographic method for forming an image by static discharge, electrification, latent image exposure, development, transfer, etc., a photoreceptor with a photoconductive layer comprising a silicon-base non-single crystal material containing at least hydrogen atoms, halogen atoms and (part or all) of a conductivity type controlling element is used. The photoconductive layer is formed by laminating specified at least 1st and 2nd layer regions on an electrically conductive substrate and the 2nd layer region has a film thickness necessary for a specified absorbance of a wavelength used for latent image exposure. A light source comprising a laser or LED having a specified wavelength is also used as an exposure light source 509 for stctic discharge in a region above the 1st layer region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic apparatus using a visible laser as a light source for exposing a latent image. More specifically, an amorphous silicon photoconductor (hereinafter a-Si
Electrophotographic apparatus using a photosensitive member).
The present invention relates to an electrophotographic image forming method and an electrophotographic apparatus which can reduce a ghost memory latent in an i photoreceptor and provide a high quality copy image.

[0002]

2. Description of the Related Art In the field of image formation, a photoconductive material for forming a photosensitive layer in a photoreceptor has a high sensitivity, a high SN ratio (photocurrent (Ip) / dark current (Id)), and a high sensitivity to electromagnetic waves to be irradiated. Having an absorption spectrum adapted to the spectral characteristics, quick light response, having a desired dark resistance value,
Characteristics such as being harmless to the human body during use are required. In particular, in the case of a photoreceptor incorporated in an electrophotographic apparatus used in an office as an office machine, the above-mentioned non-pollutability during use is important.

A photoconductive material exhibiting such excellent properties is hydrogenated amorphous silicon (hereinafter a-Si: H). For example, Japanese Patent Publication No. 60-35059 discloses an electrophotographic photosensitive material. Application as a body is described.

In such a photoreceptor, generally, a conductive support is heated to 50 to 350 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, A photoconductive layer made of a-Si is formed by a film forming method such as a CVD method and a plasma CVD method. Above all, the source gas is decomposed by a high frequency or microwave glow discharge, and the a-Si
A method for forming a deposited film has been put to practical use as a suitable method.

Japanese Patent Application Laid-Open No. 56-83746 discloses an electrophotographic method comprising a conductive support and an a-Si (hereinafter a-Si: X) photoconductive layer containing a halogen atom as a constituent element. Photoreceptors have been proposed. In the publication, by including a halogen atom in a-Si of 1 to 40 atom%, heat resistance is high, and good electrical and optical characteristics can be obtained as a photoconductive layer of an electrophotographic photoreceptor. And

Japanese Patent Application Laid-Open No. 57-115556 discloses that a photoconductive member having a photoconductive layer composed of an a-Si deposited film has electrical and electrical properties such as dark resistance, photosensitivity, and photoresponsiveness. In order to improve the use environment characteristics such as optical and photoconductive properties and moisture resistance, and the stability over time, silicon atoms and carbon atoms are formed on a photoconductive layer composed of an amorphous material containing silicon atoms as a base material. A technique for providing a surface barrier layer made of a non-photoconductive amorphous material containing is described.

Further, Japanese Patent Application Laid-Open No. 60-67951 describes a technique relating to a photoconductor in which a light-transmitting insulating overcoat layer containing amorphous silicon, carbon, oxygen and fluorine is laminated. 1962-16816
No. 1 describes a technique using, as a surface layer, an amorphous material containing silicon atoms, carbon atoms, and 41 to 70 atomic% of hydrogen atoms as constituent elements.

Further, Japanese Patent Application Laid-Open No. 62-83470 discloses a photoconductive layer of an electrophotographic photoreceptor in which the characteristic energy at the exponential function tail of the light absorption spectrum is set to 0.09 eV or less so that the afterimage phenomenon can be prevented. Techniques for obtaining quality images have been disclosed.

Japanese Patent Application Laid-Open No. 58-21257 discloses that the bandgap width in the photoconductive layer is changed by changing the temperature of the support during the formation of the photoconductive layer, and the photoconductive layer has a high resistance. A technique for obtaining a photoreceptor having a wide sensitivity region is disclosed. Japanese Patent Application Laid-Open No. 58-121042 discloses that the energy gap state density of the surface layer is changed from 10 ¹⁷ to 10 ¹⁷ by changing the energy gap state density in the thickness direction of the photoconductive layer. A technique for preventing the surface potential from lowering due to humidity by adjusting the pressure to 10 ¹⁹ cm ⁻³ is disclosed. JP-A-59-143379 and JP-A-61-201481 disclose techniques for obtaining a photosensitive member having high dark resistance and high sensitivity by laminating a-Si: H having different hydrogen contents. ing.

On the other hand, Japanese Patent Application Laid-Open No. Sho 60-95551 discloses that in order to improve the image quality of an amorphous silicon photoreceptor, charging, exposure, development and transfer are performed while maintaining the temperature near the photoreceptor surface at 30 to 40 ° C. By performing such an image forming process, there is disclosed a technique for preventing a reduction in surface resistance due to the adsorption of moisture on the surface of a photoreceptor and an image deletion caused thereby.

Also, various measures have been taken for the exposure. For example, Japanese Patent Application Laid-Open No. 60-168187 discloses an optical memory by using a near-infrared exposure laser and using a 600-800 nm exposure as a neutralizing light. There is disclosed a technique for preventing a ghost phenomenon accompanying the above. Also, Japanese Patent Application Laid-Open
Japanese Patent Application Laid-Open No. 102970 describes that a laser exposure of 600 to 7
A technique for preventing deterioration and improving mechanical chemical durability using a wavelength of 00 nm is disclosed.

[0012] These techniques have improved the electrical, optical, photoconductive and operating environment characteristics of the electrophotographic photoreceptor, and accordingly the image quality.

[0013]

However, a conventional electrophotographic photoreceptor having a photoconductive layer made of an a-Si-based material has a low electrical resistance, such as dark resistance, photosensitivity and photoresponsiveness. In terms of physical properties, photoconductive properties, and use environment properties, and in terms of stability over time and durability, the properties have been individually improved, but in order to improve the overall properties, The fact is that there is room for improvement.

In particular, high quality, high speed, and high durability of an electrophotographic apparatus are rapidly progressing. As a result of improvements in an optical exposure apparatus, a developing apparatus, a transfer apparatus, and the like in the electrophotographic apparatus, an electrophotographic apparatus has been developed. In the photoreceptor, it is required to further improve the electrical characteristics and photoconductive characteristics, and to significantly extend the performance in all environments while maintaining the charging ability and the sensitivity.

For example, as the speed and size of the electrophotographic apparatus are increased, the size of the charging device is reduced, and the speed at which the object passes through the copying process (hereinafter referred to as process speed) increases. The passage time of the photoreceptor in the inside becomes short, and it has become increasingly difficult to obtain high charge. In addition, since the time from the exposure to the next charging is shortened, an optical memory due to the exposure is easily generated, and a phenomenon called a ghost, in which the previous copy history appears on the image, is likely to occur. Ghosts can be prevented by excessively applying static elimination exposure, but in that case, the charging ability is significantly reduced, and the charging ability may be incompatible with the ghost.

Further, with the spread of computers in offices and general homes in recent years and the digitization of texts and images, the electrophotographic apparatus is expected to play the role of not only a conventional copier but also a facsimile machine and a printer for the multimedia age. Digitalization has been required. Semiconductor lasers and LEDs used for digitization are monochromatic light or light sources equivalent thereto, and those having a longer wavelength than halogen light are mainly used. For this reason, there has been a demand for improvements in characteristics not found in conventional analog copiers optimized for halogen light.

Under these circumstances, the above-mentioned prior art has made it possible to improve the above-mentioned problems to some extent, but it is still not enough to further improve the charging performance and image quality. In particular, as issues for further improving the image quality of the amorphous silicon-based photoreceptor, a reduction in fluctuation of electrophotographic characteristics due to a change in ambient temperature and a reduction in optical memory such as a ghost have been increasingly demanded. In addition, with the use of lasers and LEDs with visible wavelengths along with digitalization, the slope of the linear portion of the light intensity / charging ability curve changes with temperature (temperature characteristics of sensitivity), and the linear portion decreases. A slow and hyperbolic change (linearity of sensitivity) has been attracting attention as a new issue.

Until now, especially in digital machines using laser light or LEDs, when the temperature characteristics of sensitivity and the linearity of sensitivity are poor, and when the temperature of the photosensitive member is not controlled by a drum heater or the like, When the body temperature changes, there is a possibility that a problem occurs that the sensitivity changes and the image density changes.

Therefore, when designing an electrophotographic photosensitive member, it is necessary to improve the layer structure of the electrophotographic photosensitive member and the chemical composition of each layer from a comprehensive viewpoint so as to solve the above-mentioned problems. At the same time, it is necessary to further improve the characteristics of the a-Si material itself. Also, it has become increasingly important to match the photoreceptor with the copying process and to select an optimal copying process that maximizes the characteristics of the photoreceptor.

An object of the present invention is to solve the above-mentioned problems in the electrophotographic method and the electrophotographic apparatus having the electrophotographic photosensitive member composed of a-Si. That is, a main object of the present invention is to provide a photoconductor having a photoconductive layer composed of a non-single-crystal material having a silicon atom as a base, and a latent image exposure of visible light of about 600 to 660 nm is most suitable. Provided is an electrophotographic method and an electrophotographic apparatus capable of combining a copying process and improving charging performance, reducing temperature characteristics and reducing optical memory at a high level, thereby dramatically improving image quality. It is in.

In particular, the electrical, optical and photoconductive properties are practically stable at all times almost independent of the use environment, are excellent in light fatigue resistance, do not cause deterioration when repeatedly used, and have durability. An object of the present invention is to provide an electrophotographic method and an electrophotographic apparatus using an a-Si photoreceptor having excellent moisture resistance, little residual potential, and good image quality.

[0022]

Means for Solving the Problems To solve the above problems, the present inventors focused on the distribution and behavior of carriers due to exposure of a photoconductive layer, and investigated the local state density within the band gap of a-Si. As a result of studying the relationship between distribution, temperature characteristics, and optical memory, the wavelength of the light source for latent image formation and the light source for static elimination were appropriately selected, and the hydrogen content of the photoconductive layer, the optical band gap, and the It has been found that the above-mentioned object can be achieved by controlling the distribution of the localized state density based on the film thickness calculated from the penetration depth of the exposure light.

That is, it is designed to specify a layer structure of an electrophotographic photosensitive member having a photoconductive layer composed of a non-single-crystal material containing a silicon atom as a base and a hydrogen atom and / or a halogen atom, In addition, it has been found that the electrophotographic method in which the wavelengths of the respective light sources are appropriately combined not only can obtain remarkably excellent characteristics in practical use, but also outperforms the conventional electrophotographic method in every respect.

Further, since the present invention can obtain the maximum effect when a visible laser or an LED compatible with digitization is used, in designing the photoreceptor, particularly, in the second layer region related to photoelectric conversion, the latent area is hidden. By setting the characteristics to efficiently absorb image exposure and controlling the optical band gap, the hydrogen content, and the distribution of localized state densities within the band gap, the optical memory, the temperature characteristics of sensitivity, and the sensitivity We have found that the objective of improving linearity can be achieved.

In the present invention, further consideration is given to the intrusion of the charge-removal exposure having a larger exposure amount than the latent image light source, and the concentration of the conduction type control element in the region where the charge-removal exposure penetrates is set lower than in other regions. As a result, the present inventors have found that by improving the mobility of carriers generated by the charge removal exposure, it is possible to further improve the optical memory and temperature characteristics, and have completed the present invention.

Accordingly, the present invention provides an invention having the following features. That is,
In the electrophotographic method of the present invention, first, in an electrophotographic method in which an image is formed by static elimination, charging, latent image exposure, development, transfer, and the like, as a photosensitive element as a recording element, silicon is used as a base and at least hydrogen atoms and / Or a halogen atom and / or a conduction type control element (Group IIIb or Group Vb of the periodic table) containing a non-single-crystal photoconductive layer containing a material, the photoconductive layer, at least an optical band gap and It is assumed that at least a first layer region and a second layer region having different characteristic energies of an exponential function tail obtained from a light absorption spectrum are laminated on a conductive substrate in this order, and the thickness of the second layer region is Is the film thickness necessary to make the light absorptance of the wavelength used for image exposure 80 to 95%.
Layer region can be divided into at least two regions,
In the upper region of the first layer region, a photoreceptor having a configuration in which the concentration of the conduction type control element is reduced in a region to which the light for exposure for static elimination reaches is used, and a wavelength of 500 to 660 nm is used for forming a latent image. Using a light source consisting of a laser or LED having
When the charge is removed, a light source composed of a laser or an LED having a wavelength longer than that of the image exposure for forming a latent image and having a wavelength of 600 to 680 nm or less is used.

Second, in the photoreceptor, the first layer region has a hydrogen atom and / or halogen atom content of 15 to 30 atomic% and an optical band gap of 1.
75 to 1.85 eV, and the characteristic energy of the exponential function tail obtained from the light absorption spectrum is 55 to 65 meV.

Third, in the photoreceptor, the second layer region has a hydrogen atom and / or halogen atom content of 10 to 25 atom% and an optical band gap of 1.
70 to 1.80 eV, the characteristic energy of the exponential function tail obtained from the light absorption spectrum is 50 to 60 meV, and the content of the conduction type control element is the same as or less than that of the first layer region. And

Fourth, in the first layer region of the photoreceptor, the content of the conduction type control element in the lower region is 0.2 to 30 ppm with respect to silicon atoms, and further, when the exposure for discharging has been completed. In the upper region, the average content of the lower region is at least one third or less and 0.01.
-10 ppm.

Fifth, the content of the conductivity type control element in the first layer region decreases from the conductive substrate side toward the surface side. Sixth, the content of the conduction type control element in the second layer region of the photoconductor is 0.01 to 10 ppm with respect to silicon atoms.

Further, the electrophotographic apparatus of the present invention firstly comprises:
An electrophotographic apparatus that forms an image by static elimination, charging, latent image exposure, development, transfer, and the like, and a photoconductor that is a recording element,
Silicon as a base material and at least hydrogen atoms and / or halogen atoms and / or conduction type control elements (Periodic Table No.
A group IIIb or group Vb) containing a non-single-crystal material, wherein the photoconductive layer has at least an optical bandgap and a characteristic energy of an exponential function tail obtained from a light absorption spectrum. It is assumed that at least the first layer region and the second layer region are laminated in this order on the conductive substrate, and the thickness of the second layer region is such that the light absorptance of the wavelength used for image exposure is 80 to 80. The film thickness is required to be 95%, and the first layer region can be further divided into at least two regions. In the upper region of the first layer region, the light for the charge erasing exposure reaches. The concentration of the conduction type control element in the region is reduced, and the image exposure light source for forming a latent image uses a light source composed of a laser or LED having a wavelength of 500 to 660 nm. When the light source is Longer than light, its range is 600
It is characterized by comprising a light source consisting of a laser or LED having a wavelength of up to 680 nm.

Second, the first layer region of the photoreceptor has a hydrogen atom and / or halogen atom content of 15%.
~ 30 atomic%, 1.75 ~ as optical band gap
1.85 eV, and characteristic energy of an exponential function tail obtained from a light absorption spectrum is 55 to 65 meV.

Third, the second layer region of the photoreceptor has a hydrogen atom and / or halogen atom content of 10%.
~ 25 at%, 1.70 ~ as optical band gap
1.80 eV, the characteristic energy of the exponential function tail obtained from the light absorption spectrum is 50 to 60 meV, and the content of the conduction type control element is equal to or less than that of the first layer region. .

Fourth, in the first layer region of the photoreceptor, the content of the conduction type control element in the lower region is 0.2 to 30 ppm with respect to silicon atoms, and furthermore, when the exposure for the charge elimination is reached. In the upper region, the average content of the lower region is at least one third or less and 0.01.
-10 ppm.

Fifth, the content of the conduction type control element in the first layer region decreases from the conductive substrate side toward the surface side. Sixth, the content of the conduction type control element in the second layer region of the photoconductor is 0.01 to 10 ppm with respect to silicon atoms.

The "exponential function tail" used in the present invention refers to an absorption spectrum obtained by subtracting the tail toward the low energy side from the absorption of the light absorption spectrum.
The “characteristic energy” means the slope of the exponential function tail. This will be described in detail with reference to FIG.

FIG. 1 is a diagram showing an example of an a-Si subgap light absorption spectrum in which the abscissa represents the photon energy hν and the ordinate represents the absorption coefficient α as a logarithmic axis. This spectrum is roughly divided into two parts. That is, a part B (exponential function tail or Urbach tail) in which the absorption coefficient α changes exponentially, that is, linearly, with respect to the photon energy hν, and a part A in which α has a more gradual dependence on hν. .

The B region corresponds to light absorption due to an optical transition from the tail level on the valence band side to the conduction band in a-Si, and the exponential dependence of the absorption coefficient α on hν in the B region is
It is represented by (I).

Α = α. exp (hν / Eu) (I) Taking the logarithm of both sides gives the following equation (II): lnα = (1 / Eu) · hν + α1 (II) (where α1 = 1nα), and the characteristic energy Eu
(1 / Eu) represents the slope of the B portion.
Since Eu corresponds to the characteristic energy of the exponential energy distribution of the tail level on the valence band side, a smaller Eu means that the tail level on the valence band side is smaller.

(Function) By using light of the wavelength determined in the present invention for latent image exposure and static elimination light, the present inventors can improve ghost even under severe conditions of charging ability such as high speed. I discovered that. As a result, it is not necessary to irradiate excessive charge removing light, and it is possible to reduce ghost while maintaining a sufficient charging potential.

According to the present invention, by setting the wavelength used for latent image exposure to 500 to 660 hm, the optical memory can be reduced and the ghost memory can be improved. It was also found that the ghost can be reduced with a small exposure amount by using a wavelength longer than the wavelength of the latent image exposure and 600 to 680 nm. The details will be described below.

FIG. 2A shows the sensitivity at each wavelength of the a-Si photosensitive member, and FIG. 2B shows the wavelength dependence of the optical memory. The a-Si photoreceptor has a sensitivity peak at about 700 nm, and it is considered that the sensitivity is sharply lowered at a wavelength of 700 nm or more because sufficient energy of a band gap or more cannot be applied.

However, it has been found that simply using a wavelength having good sensitivity for latent image exposure is not sufficient. This is because, in a-Si, an optical memory is generated by exposure, and it is difficult to achieve compatibility with ghost improvement only by using the wavelength having the highest sensitivity.

Therefore, the present inventors examined the correlation between the latent image exposure wavelength and the optical memory in detail, and examined the value of the optical memory for each wavelength in detail. Then, the peak wavelength of the optical memory was not changed irrespective of the exposure amount or the time from the exposure to the charging, and the result was obtained that the worst was around 730 nm.

From the above test, in order to reduce the optical memory such as a ghost while maintaining the sensitivity, the wavelength at which the optical memory generated when the difference (contrast) between the dark area and the bright area is constant is reduced. It turned out to be important to choose. As a result, the wavelength used for latent image exposure is preferably from 500 to 660 nm, and within this range, the rank of a ghost on an image (index by visual inspection) has been improved. More preferably, 600 to 660 nm was effective.

This is considered for the following reason. When the latent image exposure is 660 nm or more, the sensitivity approaches a local maximum and the optical memory becomes large. Conversely, at a wavelength of 500 nm or less, when a monochromatic light exposure light source is used, the residual potential is increased, which causes a reduction in apparent sensitivity. For this reason, excessive exposure is required, and the optical memory is considered to increase.

On the other hand, it is better to use a longer wavelength for the neutralizing light for latent image exposure. This is for the following reasons. Most of the carriers generated by the latent image exposure run through the film and disappear instantaneously, but some are trapped in the film. In order to cancel this, the static elimination exposure used for erasing the residual potential is effectively used. Since the amount of the neutralization light is larger than that of the latent image exposure, a large amount of carriers can be emitted and the trapped charges can be discharged.

At this time, trapped charges are more easily neutralized when carriers are generated in a region wider than the region where carriers are generated in the latent image exposure. At this time, it was found that the ghost can be suppressed most efficiently when the wavelength of the static elimination exposure is 600 to 680 nm.

The reason for this is considered to be that the sensitivity at 600 to 680 nm is relatively high and the amount of generated carriers is large. In addition, when a wavelength longer than 680 nm is used, the amount of optical memory by static elimination light increases, and the unevenness of the optical memory also increases. As a result, not only the ghost level is deteriorated, but also the charging ability becomes uneven, and there is a possibility that the ghost level becomes apparent in an image. Conversely, when a wavelength shorter than 600 nm is used, the residual potential unevenness occurs, so that the ghost level is also deteriorated, which is similarly unfavorable.

From the above results, it was found that for each exposure, a wavelength of 500 to 660 nm is preferable for the latent image exposure, and a wavelength of 600 to 680 nm is longer for the neutralization light than for the latent image exposure. The effects of the present invention can be maximized by designing the photoreceptor in consideration of the film characteristics and the film thickness distribution that are optimal for the exposure wavelength.

The present inventors have studied the optical band gap (hereinafter abbreviated as Eg) and the constant photocurrent method (Constant Photo
current Method: hereinafter, abbreviated as “CPM”) characteristic energy of an exponential tail (Urbak tail) obtained from the light absorption spectrum measured by the above (hereinafter abbreviated as “Eu”)
And the photoreceptor characteristics were examined over various conditions.
Further, they have found that the lamination of these different films exhibits good photoreceptor characteristics, and have completed the present invention.

In particular, in order to optimize the visible light laser and the LED of the present invention, Eg and Eu of the light incident part are compared with the laser and L.
As a result of a detailed study of the photoreceptor characteristics when an ED is used as a light source, it was found that Eg, Eu and the charging ability, the temperature properties of the charging ability, the temperature properties of the sensitivity, and the linearity of the sensitivity were closely related. Was. Also, Eg, E in the region where the latent image exposure is absorbed
By reducing u and setting the hydrogen content within a specific range, it is possible to suppress the generation of deep level recombination centers and to obtain good photoreceptor characteristics suitable for visible light lasers and LEDs. The present invention has been completed by using a layer configuration that enhances the traveling properties of carriers in the absorption region of the charge removal exposure.

That is, a layer region (second layer region) having a relatively small optical bandgap as a photoconductive layer and a small trapping ratio of carriers to localized levels is disposed on the surface side to form a main photoelectric conversion portion. It has been found that by doing so, the optical memory is improved, and the temperature characteristics of sensitivity and the linearity of sensitivity can be significantly improved.

Further, by arranging a layer region (first layer region) having a relatively large optical band gap and a suppressed carrier capture ratio (the first layer region) on the side of the conductive substrate, the chargeability is improved, the temperature characteristics and the optical memory are improved. Can be reduced. Further, the improvement was performed by focusing on the upper region of the first layer region. Latent image exposure is mostly absorbed in the second layer area,
The neutralization light having a longer wavelength than the latent image exposure penetrates to the upper portion of the first layer region. At this time, the temperature characteristics of sensitivity, the linearity, and the optical memory characteristics were further improved by improving the traveling properties of the carriers in the region where the charge-removing light penetrated, and these could be substantially eliminated.

More specifically, in the band gap of a-Si: H, the tail (tail) level based on the structural disorder of the Si-Si bond and the dangling hand of Si (dangling) are generally included. There are deep levels due to structural defects such as bonds. It is known that these levels function as trapping and recombination centers for electrons and holes, and cause deterioration of device characteristics.

As a method for measuring the state of the localized level in the band gap, generally, deep level spectroscopy, isothermal capacity transient spectroscopy, photothermal deflection spectroscopy, photoacoustic spectroscopy, constant photocurrent method, etc. Is used. Above all, the constant photocurrent method (C
PM) is useful as a simple method for measuring the subgap light absorption spectrum based on the localized level of a-Si: H.

When the photoreceptor is heated by a drum heater or the like, the charging ability is reduced.
Carriers that are thermally excited are attracted to the electric field at the time of charging and travel to the surface while repeatedly trapping and emitting to the localized level at the band tail and deep localized level in the band gap, canceling the surface charge It is mentioned. At this time, the carrier that has reached the surface while passing through the charger has little effect on the reduction of the charging ability, but the carrier captured at a deep level reaches the surface after passing through the charger. It is observed as a temperature characteristic to cancel the surface charge.

Also, carriers that are thermally excited after passing through the charger also cancel the surface charge, causing a reduction in charging ability. Therefore, it is necessary to increase the optical band gap of the main photoconductive layer to suppress the generation of thermally excited carriers, and to improve the mobility of the carriers by reducing the deep localized levels. Necessary for improvement.

Further, in the optical memory, the optical carriers generated by the exposure are captured at the localized levels in the band gap,
It is caused by carriers remaining in the photoconductive layer.
That is, of the photocarriers generated in a certain copying process, the carriers remaining in the photoconductive layer are swept out by the electric field due to the surface charge at the next charging or thereafter, and the potential of the light-irradiated portion is changed to the other. Lower than the area, resulting in shading on the image. Therefore, it is necessary to improve the traveling property of the carrier so that the optical carrier travels in one copying process without remaining as much as possible in the photoconductive layer.

The temperature characteristic of sensitivity is caused by a large difference between the traveling properties of holes and electrons in the photoconductive layer, and also because the traveling properties change with temperature. Electron-hole pairs are generated in the light-incident part, and the holes travel toward the support and the electrons travel toward the surface layer. The rate of recombination before reaching is increased.

Since the rate of recombination changes due to thermal excitation from the recapture center, the amount of exposure, that is, the number of photogenerated carriers and the number of carriers that cancel the surface potential, change with temperature. It will change with temperature.

Therefore, long-wavelength light is emitted so as to reduce the rate of recombination at the light incident portion, that is, to reduce the deep level serving as a recapture center and to reduce the mixed region of holes and electrons. It is necessary to increase the absorption rate and to improve the running property of the carrier. Furthermore, the sensitivity linearity increases as the exposure of the long-wavelength laser increases.
Carriers that increase the number of photogenerated carriers relatively deep from the surface and cancel the surface potential (electrons if positively charged)
Occurs because the mileage of the vehicle increases. Therefore, it is necessary to increase the light absorptance of the light incident part and to improve and balance the traveling property of electrons in the light incident part and the traveling property of holes on the support side.

Therefore, by providing a layer region (second layer region) in which Eu is controlled (reduced) while reducing Ch and narrowing Eg as a light incident portion, thermally excited carriers and optical carriers are localized. Therefore, the ratio of carrier capture can be reduced, and the traveling performance of the carrier is dramatically improved. By reducing Eg, absorption of long-wavelength light is increased and the light incident portion can be reduced, so that the hole-electron mixed region can be reduced.

As a further effect, the photoconductive layer (first layer region) on the support side can be designed as a layer in which the main carrier is holes and the traveling property is improved.

More specifically, Ch is increased in the main photoconductive layer, Eu is controlled (reduced) while Eg is enlarged, and a suitable impurity (in the case of positive charge) is used in order to improve the hole mobility. IIIb
Group element. Hereinafter, taking positive charge as an example), the use of a doped layer suppresses the generation of thermally excited carriers,
In addition, the rate at which the thermally excited carriers and the optical carriers are trapped in the localized levels can be reduced, and the traveling properties of the carriers are dramatically improved.

In addition, in the present invention, the conduction type control element (in this case, a group IIIb element) is reduced in the upper region of the first layer region, that is, in the range where the charge removal exposure enters. Carriers excited by the charge removal light include electrons, and therefore, it is necessary to ensure the traveling property in the first layer region. If the group IIIb element is excessively doped, the Fermi level shifts and the electron mobility decreases. Therefore, in the region where the electron-hole pairs are excited by the neutralization light,
In particular, it has been found that it is necessary to consider the traveling properties of electrons.

Here, although a method of absorbing the charge removal light in the second layer region up to the absorption region can be considered, the layer structure of the present invention surpasses all of the charging ability, sensitivity linearity, and temperature characteristics. Was. It is considered that the layer configuration of the present invention was optimal for the electrophotographic method of the present invention because the process of generating and annihilating the carrier and the amount of the generated carrier are significantly different between the latent image exposure and the charge erasing light. Conversely, if the region where the impurity concentration is reduced is made larger than the region where the static elimination light is absorbed, not only the hole traveling property deteriorates and the linearity of the temperature characteristics and sensitivity deteriorates, but also the residual due to the increase in dark resistance. It was found to be undesirable because the potential increased.

The thickness of the region where the impurity concentration is reduced is not good even if it is too thick or too thin. By setting the thickness corresponding to the penetration region of the static elimination light, an exquisite balance can be obtained and the effect of the present invention is maximized. It is thought that was obtained. Further, it has been clarified from the test that the decrease in the concentration is most preferably at least 1/3 or less of the average value in the lower region of the first layer region. The impurity concentration in the first layer region may be changed continuously or stepwise. In this case, the impurity concentration in the upper region is set to be equal to or less than １ of the average value of the concentration in the lower region. Then, it was found that there was no increase in the residual potential, and it was more preferable.

That is, the photoconductive layer of the photoreceptor is divided into at least two or more layers having different characteristics, and a second layer region is provided on the surface side so that a region which substantially absorbs latent image exposure is formed in the second layer. By using only the area, the temperature characteristics of sensitivity and the linearity of sensitivity are improved especially when laser light or LED is used, and a remarkable effect is obtained in terms of memory. Further, in the first layer region, by improving the carrier mobility (particularly in the case of positive charging, the electron mobility) of a portion of the static elimination light into which light not absorbed by the second layer region enters. Further, the charging ability has been further improved, and the memory, the temperature characteristic of the charging ability, the temperature characteristic of the sensitivity, and the linearity of the sensitivity can be further greatly improved.

At this time, the thickness of each layer structure is
The effect of the present invention can be obtained to the maximum by reducing the concentration of the conduction type control substance in the layer region of the first region, which absorbs most of the latent image exposure, and in the first region where the static elimination light enters. . When the thickness of the second layer region is larger than this, the charging ability and the temperature characteristics of the sensitivity cannot surpass the present invention, and when the thickness is thin, the linearity of the sensitivity and the memory characteristics are significantly deteriorated. Resulting in. Further, when the region where the concentration of the conductive element is low in the upper region of the first layer region is thinner than this, it is difficult to surpass the present invention in terms of temperature characteristics and optical memory. It was found that the residual potential increased, which was not preferable.

Therefore, according to the present invention, as described above,
500-680 using visible light, especially laser or LED
nm latent image exposure, the wavelength is longer than the latent image exposure, 600 ~
By using 700nm static elimination light and selecting the characteristics and layer structure optimized for each exposure for the photoreceptor, the temperature characteristics of sensitivity, sensitivity linearity and chargeability are improved, temperature characteristics are reduced, and optical memory is reduced. And excellent at the same time, and can solve all of the above-mentioned problems in the prior art with excellent electrical, optical, photoconductive properties, image quality, durability and use environment. The following electrophotographic method and electrophotographic apparatus can be obtained.

[0072]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the electrophotographic photosensitive member of the present invention will be described below with reference to the drawings. FIG. 3 is a schematic configuration diagram for explaining a layer configuration of the electrophotographic photoreceptor of the present invention.

The electrophotographic photosensitive member 300 shown in FIG.
A photosensitive layer 302 is provided on a support 301 for an electrophotographic photosensitive member. The photosensitive layer 302 has a-Si: H,
The photoconductive layer 303 is made of X and has photoconductivity. The photoconductive layer 303 is composed of a first layer region 311 and a second layer region 312 in order from the support 301 side. In addition, a region 313 where the concentration of the conductivity control element is low is provided above the first layer region 311.

The electrophotographic photosensitive member 300 shown in FIG.
A photosensitive layer 302 is provided on a support 301 for an electrophotographic photosensitive member. The photosensitive layer 302 has a-Si: H,
It is composed of a photoconductive layer 303 made of X and having photoconductivity, and an amorphous silicon-based surface layer 304.
The photoconductive layer 303 is composed of a first layer region 311 and a second layer region 312 in order from the support 301 side.
In addition, a region 313 where the concentration of the conductivity control element is low is provided above the first layer region 311.

The electrophotographic photosensitive member 300 shown in FIG.
A photosensitive layer 302 is provided on a support 301 for an electrophotographic photosensitive member. The photosensitive layer 302 is formed on the support 30.
Amorphous silicon-based charge injection blocking layer 3 in order from the first side
5, an a-Si: H, X photoconductive layer 303 having photoconductivity, and an amorphous silicon-based surface layer 304.

The photoconductive layer 303 is a charge injection blocking layer 3
The first layer region 311 and the second layer region 31 are arranged in this order from the 05 side.
It consists of two. Above the first layer region 311, a region 313 where the concentration of the conductivity type control element is low is provided.

(Support) The support used in the present invention may be either conductive or electrically insulating. Examples of the conductive support include Al, Cr, Mo, Au, In, Nb, Te, V,
Examples include metals such as Ti, Pt, Pd, and Fe, and alloys thereof, such as stainless steel. Also, polyester, polyethylene, polycarbonate, cellulose acetate,
It is also possible to use a film of a synthetic resin such as polypropylene, polyvinyl chloride, polystyrene, polyamide or the like, or a support in which at least the surface on the side on which the photosensitive layer is formed of an electrically insulating support such as seed glass or ceramic is subjected to conductive treatment.

The shape of the support 301 used in the present invention may be a cylindrical or endless belt having a smooth surface or an uneven surface, and the thickness thereof is selected so that the desired photoreceptor 300 can be formed. The photoconductor 3 is determined as appropriate.
When flexibility as 00 is required, the support 30
The thickness can be reduced as much as possible within a range where the function as 1 can be sufficiently exhibited. However, the support 301 is usually 1 in terms of production, handling, mechanical strength and the like.
0 μm or more.

(Photoconductive Layer) In the present invention, the photoconductive layer 303 formed on the support 301 and constituting a part of the photosensitive layer 302 is formed by a vacuum deposition film forming method in order to effectively achieve the object. It is formed by appropriately setting numerical conditions of film forming parameters so as to obtain desired characteristics. Specifically, for example, an AC discharge CV such as a glow discharge method (a low-frequency CVD method, a high-frequency CVD method, or a microwave CVD method) is used.
D method or DC discharge CVD method), sputtering method, vacuum evaporation method, ion plating method, photo CVD
And a thin film deposition method such as a thermal CVD method.

These thin film deposition methods are appropriately selected and employed depending on factors such as the manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for the photosensitive member to be manufactured. The glow discharge method, in particular, the high-frequency glow discharge method using a power supply frequency in the RF band is suitable because the control of the conditions for manufacturing the photoreceptor having the above is relatively easy.

In order to form the photoconductive layer 303 by the glow discharge method, basically, a source gas for supplying Si which can supply silicon atoms (Si) and a source gas for supplying H which can supply hydrogen atoms (H) are used. And / or a source gas for X supply capable of supplying a halogen atom (X) is introduced in a desired gas state into a reaction vessel capable of reducing the pressure therein, thereby causing a glow discharge in the reaction vessel. Then, a layer made of a-Si: H, X may be formed on a predetermined support 301 which is previously set at a predetermined position.

In the present invention, it is necessary that the photoconductive layer 303 contains a hydrogen atom and / or a halogen atom, which compensates for dangling bonds of silicon atoms and improves the quality of the layer. This is because it is indispensable to improve photoconductivity and charge retention characteristics. Therefore, the content of hydrogen atoms or halogen atoms, or the sum of hydrogen atoms and halogen atoms, is 15 to 30 in the first layer region.
Atomic% and the second layer region are desirably 10 to 25 atomic%.

In the present invention, substances that can be used as the Si supply gas include SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ ,
Silicon hydrides (silanes) in a gas state such as Si ₄ H ₁₀ or capable of being gasified can be used effectively.
Further, SiH ₄ and Si ₂ H ₆ are preferred in terms of ease of handling at the time of forming the layer and good Si supply efficiency.

Then, hydrogen atoms are structurally introduced into the formed photoconductive layer 303 so that the introduction ratio of hydrogen atoms can be more easily controlled, and a film characteristic which achieves the object of the present invention is obtained. Therefore, it is necessary to form a layer by mixing a desired amount of a gas of a silicon compound containing H ₂ and / or He or a hydrogen atom with these gases. Also,
Each gas is not limited to a single species, and a plurality of species may be mixed at a predetermined mixture ratio.

The raw material gas for supplying halogen atoms used in the present invention is, for example, a gaseous or gaseous gas such as a halogen gas, a halide, an interhalogen compound containing halogen, or a silane derivative substituted with halogen. The obtained halogen compounds are preferred. Further, a gaseous or gasifiable silicon hydride compound containing a halogen atom, which contains a silicon atom and a halogen atom as constituent elements, can also be mentioned as an effective compound.

The halogen compounds which can be suitably used in the present invention include, specifically, fluorine gas (F ₂ ), BrF, Cl
Examples thereof include interhalogen compounds such as F, ClF ₃ , BrF ₃ , BrF ₅ , IF ₃ and IF ₇ . As a silicon compound containing a halogen atom, that is, a silane derivative substituted with a so-called halogen atom, specifically, for example, silicon fluoride such as SiF ₄ or Si ₂ F ₆ is preferable.

In order to control the amount of hydrogen atoms and / or halogen atoms contained in the photoconductive layer 303, for example, the temperature of the support 301, a raw material used for containing hydrogen atoms and / or halogen atoms, What is necessary is just to control the amount of the substance introduced into the reaction vessel, the discharge power and the like.

In the present invention, it is preferable that the photoconductive layer 303 contains atoms for controlling conductivity as necessary. The atoms controlling the conductivity may be contained in the respective layers 311, 312, 313 in the photoconductive layer in a state of being uniformly distributed without unevenness, or in a state of non-uniform distribution in the layer thickness direction. May be present. However, the concentration of 312, 313 needs to be lower than the concentration of 311.

Examples of the atoms for controlling the conductivity include so-called impurities in the field of semiconductors.
An atom belonging to Group IIIb of the Periodic Table that gives p-type conduction properties
(Hereinafter abbreviated as “Group IIIb atom”) or an atom belonging to Group Vb of the periodic table that provides n-type conduction characteristics (hereinafter abbreviated as “Group Vb atom”).

As the Group IIIb atom, specifically, boron
(B), aluminum (Al), gallium (Ga), indium (I
n), thallium (Tl) and the like, and B, Al, and Ga are particularly preferable. As the group Vb atom, specifically, phosphorus (P), arsenic (A
s), antimony (Sb), bismuth (Bi), etc.
As is preferred.

The content of atoms controlling the conductivity contained in the photoconductive layer 311 is preferably 0.2 to 100.
Atomic ppm, more preferably 0.2 to 50 atomic ppm, and most preferably 0.2 to 30 atomic ppm. Further, the content of the atoms for controlling the conductivity contained in the photoconductive layers 312 and 313 is preferably 0.01 to 30 atomic ppm,
More preferably 0.01 to 20 atomic ppm, most preferably 0.0
Desirably, it is 1 to 10 atomic ppm.

In the present invention, when the conductivity type control element is contained in the second layer regions 312 and 313 so as to be smaller than that in the first layer region 311, the improvement of the optical memory becomes more remarkable. It is considered that the mobility of the carrier obtained from the physical properties such as Eg and Eu of the conductive layer is adjusted to balance the mobility at a higher order.

In order to further improve the optical memory, the second layer region 312, which is a portion where hole electron pairs are mainly generated, is a region where the peak wavelength light of the exposure wavelength absorbs 80 to 95%. The content of the element belonging to Group IIIb of the periodic table is desirably controlled to 0.2 to 30 ppm with respect to silicon atoms in the first layer region 311. In particular, in the upper portion 313 of the first layer region, , 0.01 to 10 ppm. In the second layer region 312, 0.01 to
It is desirable to control to 10 ppm.

Atoms controlling conductivity, for example, IIIb
To structurally introduce a group V atom or a group Vb atom,
When forming a layer, a raw material for introducing a Group IIIb atom or a raw material for introducing a Group Vb atom is introduced into the reaction vessel in a gas state together with another gas for forming the photoconductive layer 303. Good. As a source material for introducing a Group IIIb atom or a source material for introducing a Group Vb atom, a gaseous material at ordinary temperature and normal pressure or a material which can be easily gasified at least under layer forming conditions is employed. It is desirable.

As such a raw material for introducing a Group IIIb atom, specifically, for introducing a boron atom,
_{2 H 6, B 4 H 10} , B 5 H 9, B 5 H 11, B 6 H 10, B 6 H 12, B 6 H
₁₄ borohydride; and boron halide such as BF ₃ , BCl ₃ and BBr ₃ . In addition, AlCl ₃ , GaCl ₃ , Ga
(CH ₃ ) ₃ , InCl ₃ , TlCl _{3 and the} like can also be mentioned.

[0096] being effectively used as a raw material for the Vb atoms introduced as the for introducing phosphorus atoms, PH _3, P ₂
Hydrogenated phosphorus such as H ₄ , PH ₄ I, PF ₃ , PF ₅ , PCl ₃ , PC
_{l 5, PBr 3, PBr 5} , halogenated phosphorus PI ₃ and the like. In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , AsF ₅ ,
SbH ₃ , SbF ₃ , SbF ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ , BiCl
₃ , BiBr _{3 and the} like can also be mentioned as effective starting materials for introducing Group IIIb atoms.

Further, these raw materials for introducing atoms for controlling conductivity may be diluted with H ₂ and / or He if necessary.

Further, in the present invention, the photoconductive layer 303
It is also effective to include a carbon atom and / or an oxygen atom and / or a nitrogen atom. The content of carbon atoms and / or oxygen atoms / and / or nitrogen atoms is preferably 1 × 10 ⁻⁵ to 10 at%, more preferably 1 × 10 ⁵ %, based on the sum of silicon atoms, carbon atoms, oxygen atoms and nitrogen atoms. ^-4 to 8 atomic%, optimally 1 × 10 ^{-3 to} 5 atomic% is desirable. The carbon atoms and / or oxygen atoms and / or nitrogen atoms may be uniformly contained in the photoconductive layer, or may have an uneven distribution such that the content changes in the thickness direction of the photoconductive layer. May be provided.

In the present invention, the layer thickness of the photoconductive layer 303 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economical effects.
It is desirable that the thickness be 0 to 50 μm, more preferably 23 to 45 μm, and most preferably 25 to 40 μm. 20μ layer thickness
When the thickness is less than m, electrophotographic characteristics such as charging ability and sensitivity become practically insufficient, and when the thickness is more than 50 μm, the production time of the photoconductive layer becomes longer and the production cost becomes higher.

In the present invention, it is desirable that the second layer region 312 disposed on the surface side of the photoconductive layer be a region that absorbs 80 to 95% of the peak wavelength light of the exposure wavelength. It is desirable that 313, which is the upper part of the first layer region, be set to a thickness up to a region where static elimination light enters. Outside of the above range, the chargeability, the temperature characteristic of the chargeability, the temperature characteristic of the sensitivity, the linearity of the sensitivity, the sensitivity unevenness, and the improvement of the optical memory are determined based on the balance between the absorption region of the charge removal exposure and the image exposure and the phototacticity of the generated carrier. The effect of can not be fully exhibited.

In order to achieve the object of the present invention and to form the photoconductive layer 303 having desired film characteristics, the mixing ratio between the gas for supplying Si and the diluent gas, the gas pressure in the reaction vessel, the discharge power, It is necessary to appropriately set the temperature of the support.

[0102] The flow rate of H ₂ and / or He used as a dilution gas is properly selected within an optimum range in accordance with the layer design, if the first layer region, with respect to Si supplying gas H ₂ and / or The flow rate of He is usually 3 to 20.
Times, preferably 4 to 15 times, and most preferably 5 to 10 times. In the case of the second layer region, Si is controlled.
The flow rate of H ₂ and / Main other to supply gas for the He, 2 to 12 times the normal case, is preferably 3 to 10 times, the optimal 4
It is desirable to control to a range of up to 8 times.

Similarly, the optimum range of the gas pressure in the reaction vessel is appropriately selected according to the layer design.
^{10-2 2} ~ × 10 ³ Pa, preferably 5 × 10 ^over 2 to 5 × 1
It is preferably 0 ² Pa, most preferably 1 × 10 ^-1 to 2 × 10 ² Pa.

Similarly, the optimum range of the discharge power is appropriately selected according to the layer design. The ratio of the discharge power to the flow rate of the Si supply gas is set to 2 to 2 in the first layer region.
It is desirable to set it in the range of 8, preferably 1 to 6. Further, the second layer region is smaller than the first layer region, and is desirably set to a range of 0.5 to 4.

Further, an optimum range of the temperature of the support 301 is appropriately selected according to the layer design.
Preferably from 200 to 350 ° C, more preferably from 210 to
Desirably, the temperature is 340 ° C, and most preferably, 220 to 330 ° C.

In the present invention, the preferable ranges of the temperature of the support and the gas pressure for forming the photoconductive layer include the above-mentioned ranges, but the conditions are not usually determined independently and separately. It is desirable to determine the optimum value based on mutual and organic relationships to form a photoreceptor having desired properties.

(Surface Layer) In the present invention, it is preferable to further form an amorphous silicon-based surface layer 304 on the photoconductive layer 303 formed on the support 301 as described above. This surface layer 304 is a free surface 3
It is provided in order to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electric pressure resistance, use environment characteristics, and durability.

In the present invention, since each of the amorphous materials forming the photoconductive layer 303 and the surface layer 304 forming the photosensitive layer 302 has a common component of silicon atoms, Ensuring sufficient chemical stability at the interface.

The surface layer 304 may be made of any material as long as it is an amorphous silicon material. For example, the surface layer 304 contains a hydrogen atom (H) and / or a halogen atom (X) and further contains a carbon atom. Amorphous silicon
(Hereinafter a-SiC: H, X), a hydrogen atom (H) and / or
Or containing a halogen atom (X) and further containing an oxygen atom containing amorphous silicon (hereinafter a-SiO: H, X), containing a hydrogen atom (H) and / or a halogen atom (X), and Amorphous silicon containing nitrogen atoms (hereinafter a-SiN: H, X), hydrogen atoms (H) and
/ Or a halogen atom (X), and further a carbon atom,
A material such as amorphous silicon containing at least one of an oxygen atom and a nitrogen atom (hereinafter referred to as a-SiCON: H, X) is preferably used.

In the present invention, in order to effectively achieve the object, the surface layer 304 is formed by a vacuum deposition film forming method by appropriately setting numerical conditions of film forming parameters so as to obtain desired characteristics. . Specifically, for example, a glow discharge method (an AC discharge CVD method such as a low-frequency CVD method, a high-frequency CVD method or a microwave CVD method, or a DC discharge CVD method or the like), a sputtering method, a vacuum evaporation method,
It can be formed by various thin film deposition methods such as an ion plating method, a photo CVD method, and a thermal CVD method.

These thin film deposition methods are appropriately selected and employed depending on factors such as the manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for the photoconductor to be produced. It is preferable to use the same deposition method as that for the photoconductive layer from the viewpoint of productivity.

For example, a-SiC:
In order to form the surface layer 304 made of H and X, a source gas for supplying Si that can supply silicon atoms (Si) and a source gas for supplying C that can supply carbon atoms (C) are basically used. When,
A source gas for supplying hydrogen capable of supplying hydrogen atoms (H) or /
And a source gas for X supply capable of supplying a halogen atom (X) in a desired gas state into a reaction vessel capable of reducing the pressure therein to cause a glow discharge in the reaction vessel, and a predetermined A layer made of a-SiC: H, X may be formed on the support 301 on which the photoconductive layer 303 provided at the position is formed.

The material of the surface layer used in the present invention may be any amorphous material containing silicon, but is preferably a compound with a silicon atom containing at least one element selected from carbon, nitrogen and oxygen. a
Those containing -SiC as a main component are preferable.

When the surface layer is composed mainly of a-SiC, the amount of carbon is preferably in the range of 30 to 90% with respect to the sum of silicon atoms and carbon atoms.

In the present invention, it is necessary for the surface layer 304 to contain hydrogen atoms and / or halogen atoms, which compensates for dangling bonds of silicon atoms and improves the quality of the layer, especially the optical quality. It is indispensable to improve the conductivity characteristics and the charge retention characteristics.

The hydrogen content is usually 30 to 70 atomic%, preferably 35 to 65 atomic%, based on the total amount of the constituent atoms.
Most preferably, it is set to 40 to 60 atomic%. Also,
The content of fluorine atoms is usually 0.01 to 15
Atomic%, preferably 0.1-10 atomic%, optimally 0.6-4
Desirably, it is set to atomic%.

The photoreceptor formed within the above range of the content of hydrogen and / or fluorine can be sufficiently applied as an unprecedented one in practical use. That is, it is known that defects (mainly dangling bonds of silicon atoms and carbon atoms) existing in the surface layer adversely affect the characteristics of the electrophotographic photosensitive member.
For example, deterioration of charging characteristics due to injection of charges from the free surface,
Usage environment, for example, changes in the charging characteristics due to changes in the surface structure under high humidity, further charge is injected into the surface layer from the photoconductive layer at the time of corona charging or light irradiation, the charge in the defects in the surface layer Is trapped, and the occurrence of an afterimage phenomenon at the time of repeated use is cited as this adverse effect.

However, when the hydrogen content in the surface layer is 30
By controlling the atomic percentage or more, the number of defects in the surface layer is greatly reduced, and as a result, the electrical characteristics and the high-speed continuous usability can be significantly improved as compared with the related art.

On the other hand, if the hydrogen content in the surface layer exceeds 70 atomic%, the hardness of the surface layer is reduced, so that the surface layer cannot withstand repeated use. Therefore, controlling the hydrogen content in the surface layer within the above-mentioned range is one of the very important factors in obtaining extremely excellent desired electrophotographic properties. The hydrogen content in the surface layer can be controlled by the flow rate (ratio) of the raw material gas, the temperature of the support, the discharge power, the gas pressure, and the like.

Further, by controlling the fluorine content in the surface layer to 0.01 atomic% or more, it is possible to more effectively achieve the generation of the bond between silicon atoms and carbon atoms in the surface layer. Become. Further, as a function of fluorine atoms in the surface layer, it is possible to effectively prevent the bond between silicon atoms and carbon atoms from being broken due to damage such as corona.

On the other hand, the fluorine content in the surface layer is 15 atomic%.
If it exceeds 300, the effect of generating the bond between the silicon atom and the carbon atom in the surface layer and the effect of preventing the break of the bond between the silicon atom and the carbon atom due to damage such as corona can hardly be recognized. Furthermore, since excess fluorine atoms hinder the mobility of carriers in the surface layer, remnant potential and image memory are remarkably observed. Therefore, controlling the fluorine content in the surface layer within the above range is one of the important factors for obtaining desired electrophotographic characteristics. Like the hydrogen content, the fluorine content in the surface layer can be controlled by the flow rate (ratio) of the raw material gas, the temperature of the support, the discharge power, the gas pressure, and the like.

The substance that can serve as a silicon (Si) supply gas used in forming the surface layer of the present invention is Si (Si).
Silicon hydrides (silanes) in a gas state such as H ₄ , Si ₂ H ₆ , Si ₃ H ₈ , and Si ₄ H ₁₀ are effectively used. Ease of handling,
SiH ₄ and Si ₂ H ₆ are preferred in terms of Si supply efficiency. Further, these raw material gases for supplying Si may be diluted with a gas such as H ₂ or He, Ar, Ne or the like as necessary.

Examples of the substance that can serve as a carbon supply gas include:
CH_Four, C_TwoH_Two, C_TwoH₆, C_ThreeH₈, C_FourH _TenEtc. in the gas state,
Or that gasifiable hydrocarbons are used effectively
In addition, ease of handling at the time of layer preparation, C supply
CH in terms of efficiency etc._Four, C _TwoH_Two, C_TwoH₆Is also preferred
It is listed as In addition, the raw material gas for supplying C
H if necessary_TwoDiluted with gases such as He, Ar, Ne, etc.
You may use it.

Substances that can be nitrogen or oxygen supply gas include NH ₃ , NO, N ₂ O, NO ₂ , O ₂ , CO, CO ₂ , N
Compounds in a gaseous state or capable of being gasified, such as ₂ , are effectively used. The source gas for supplying nitrogen and oxygen may be replaced with H ₂ or He, A as required.
It may be diluted with a gas such as r or Ne before use.

In order to further facilitate the control of the introduction ratio of hydrogen atoms introduced into the surface layer 304 to be formed, these gases are further mixed with a hydrogen gas or a silicon compound gas containing hydrogen atoms. Also, it is preferable to form a layer by mixing desired amounts. Further, each gas is not limited to a single species, and a plurality of species may be mixed at a predetermined mixture ratio.

As the effective source gas for supplying a halogen atom, a gaseous or gasifiable halogen compound such as a halogen gas, a halide, an interhalogen compound containing halogen, a silane derivative substituted with halogen, and the like are preferably mentioned. . Further, a gaseous or gasifiable silicon hydride compound containing a halogen atom, which contains a silicon atom and a halogen atom as constituent elements, can also be mentioned as an effective compound. Specific examples of the halogen compound that can be preferably used in the present invention include fluorine gas (F ₂ ), BrF, ClF, ClF ₃ , BrF ₃ , BrF ₅ , IF ₃ ,
And a halogen compound between IF ₇ or the like.

As a silicon compound containing a halogen atom, that is, a silane derivative substituted with a so-called halogen atom, specifically, for example, silicon fluoride such as SiF ₄ or Si ₂ F ₆ is preferable.

In order to control the amount of hydrogen atoms and / or halogen atoms contained in the surface layer 304, for example, the temperature of the support 301, a raw material used to contain hydrogen atoms and / or halogen atoms The amount to be introduced into the reaction vessel, the discharge power and the like may be controlled.

The carbon atoms and / or oxygen atoms and / or nitrogen atoms may be uniformly contained in the surface layer, or may be non-uniform such that the content changes in the thickness direction of the surface layer. There may be a portion having a distribution.

Further, in the present invention, it is preferable that the surface layer 304 contains atoms for controlling conductivity as necessary. The atoms for controlling the conductivity may be contained in the surface layer 304 in a state of being uniformly distributed evenly,
Alternatively, there may be portions contained in a non-uniform distribution state in the layer thickness direction.

Examples of the atoms for controlling the conductivity include so-called impurities in the field of semiconductors. An atom belonging to Group IIIb of the Periodic Table that gives p-type conduction characteristics (hereinafter, referred to as a “Group IIIb atom”) ) Or an atom belonging to Group Vb of the Periodic Table that gives n-type conduction characteristics (hereinafter referred to as “V
abbreviated as “group b atom”).

Specific examples of Group IIIb atoms include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). In particular, B, Al, and Ga include It is suitable. Specific examples of group Vb atoms include phosphorus.
(P), arsenic (As), antimony (Sb), bismuth (Bi) and the like, and P and As are particularly preferable.

The content of atoms controlling conductivity contained in the surface layer 304 is preferably 1 × 10 ⁻³ to 1 ×.
10 ³ atomic ppm, more preferably 1 × 10 ^{−2 to} 5 × 10 ²
Atoms and ppm Most preferably, 1 × 10 ^-1 to 1 × 10 ² atoms ppm. Atoms that control conductivity, for example,
In order to structurally introduce a Group IIIb atom or a Group Vb atom, a source material for introducing a Group IIIb atom or a source material for introducing a Group Vb atom in a gaseous state into a reaction vessel during layer formation. It may be introduced together with another gas for forming the surface layer 304.

As a raw material for introducing a Group IIIb atom or a raw material for introducing a Group Vb atom, those which can be gaseous at ordinary temperature and normal pressure or which can be easily gasified at least under layer forming conditions can be used. It is desirable to be adopted. As such a raw material for introducing a Group IIIb atom, specifically, for introducing a boron atom, B ₂ H ₆ , B
_{4 H 10, B 5 H 9} , B 5 H 11, B 6 H 10, B 6 H 12, B 6 H 14 borohydride such as, BF, BCl _3, BBr boron halides such as ₃ can be mentioned . In addition, AlCl ₃ , GaCl ₃ , Ga (CH ₃ ) ₃ , I
nCl ₃ , TlCl _{3 and the} like can also be mentioned.

As a raw material for introducing a group Vb atom, those which can be effectively used include PH ₃ , P
Phosphorus hydride such as ₂ H ₄ , PH ₄ I, PF ₃ , PF ₅ , PCl ₃ , PCl
₅ , phosphorus halides such as PBr ₃ , PBr ₅ , and PI ₃ . In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , AsF ₅ ,
SbH ₃ , SbF ₃ , SbF ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ , BiCl
₃ , BiBr _{3 and the} like can also be mentioned as effective starting materials for introducing Group Vb atoms.

Further, these raw materials for introducing atoms for controlling conductivity may be diluted with a gas such as H ₂ or He, Ar, Ne or the like as necessary.

The thickness of the surface layer 304 in the present invention is usually 0.01 to 3 μm, preferably 0.05 to 2 μm,
Optimally, the thickness is desirably 0.1 to 1 μm. If the layer thickness is less than 0.01 μm, the surface layer is lost due to abrasion or the like during use of the photoreceptor, and if it exceeds 3 μm, the electrophotographic characteristics such as an increase in residual potential are reduced.

The surface layer 304 according to the present invention is carefully formed so that its required properties are provided as desired. That is, a substance containing Si, C and / or N and / or O, H and / or X as a constituent element takes a form from crystalline to amorphous depending on its forming conditions, and has electrical conductivity as a conductive substance. In the present invention, a compound having desired properties according to the purpose is shown, since the properties between the properties from a semiconductive property to an insulating property, and properties from a photoconductive property to a non-photoconductive property are respectively shown. The formation conditions are strictly selected as desired so that is formed. For example, in order to provide the surface layer 304 with an improvement in pressure resistance as a major feature, the surface layer 304 is formed as a non-single-crystal material having a remarkable electrical insulating behavior in a use environment.

When the surface layer 304 is provided for the purpose of mainly improving the continuous repetitive use characteristics and the use environment characteristics, the above-described degree of electrical insulation is alleviated to some extent, and a certain Formed as a non-single-crystal material having a sensitivity of

In order to form the surface layer 304 having characteristics capable of achieving the object of the present invention, it is necessary to appropriately set the gas mixing ratio, the gas pressure in the reaction vessel, the discharge power, and the temperature of the support. However, these layer forming factors are not usually independently determined separately, but it is necessary to determine the optimum values based on mutual and organic relations to form a charge injection blocking layer having desired characteristics. desirable.

Further, in the present invention, it is also possible to provide a blocking layer (lower surface layer) having a lower content of carbon atoms, oxygen atoms and nitrogen atoms than the surface layer between the photoconductive layer and the surface layer. It is effective to further improve the characteristics of.

Further, a region where the content of carbon atoms and / or oxygen atoms and / or nitrogen atoms changes so as to decrease toward photoconductive layer 303 may be provided between surface layer 304 and photoconductive layer 303. Good. As a result, the adhesion between the surface layer and the photoconductive layer is improved, the movement of the photocarrier to the surface is smooth, and the influence of light reflection at the interface between the photoconductive layer and the surface layer is further reduced. Can be.

(Charge Injection Blocking Layer) In the photoreceptor of the present invention, a charge injection blocking layer having a function of blocking charge injection from the conductive support side is provided between the conductive support and the photoconductive layer. It is always so effective to provide.

That is, the charge injection blocking layer has a function of preventing charge from being injected from the support side to the photoconductive layer side when the photosensitive layer is subjected to a charging treatment of a fixed polarity on its free surface. Such a function is not exhibited when it is subjected to a charging treatment having a polarity of, that is, it has a so-called polarity dependency. In order to provide such a function, the charge injection blocking layer contains a relatively large number of atoms for controlling conductivity as compared to the photoconductive layer.

The atoms for controlling the conductivity contained in the layer may be uniformly distributed throughout the layer, or may be uniformly distributed in the thickness direction of the layer, but may not be distributed uniformly. Some portions may be contained in a state of being uniformly distributed. When the distribution concentration is non-uniform, it is preferable that the compound be contained so as to be distributed more on the support side. However, in any case, it is necessary to uniformly contain the particles in the in-plane direction parallel to the surface of the support from the viewpoint of making the properties uniform in the in-plane direction.

Examples of the atoms for controlling the conductivity contained in the charge injection blocking layer include so-called impurities in the field of semiconductors, and atoms belonging to Group IIIb of the Periodic Table giving p-type conduction characteristics (hereinafter referred to as “atoms”). (Abbreviated as "Group IIIb atom")
Alternatively, an atom belonging to Group Vb of the Periodic Table that gives n-type conduction characteristics (hereinafter abbreviated as “Vb Group atom”) can be used.

As the Group IIIb atom, specifically, B
(Boron), Al (aluminum), Ga (gallium), In (indium), Ta (thallium), etc., and B, Al, and Ga are particularly preferable. Specific examples of Group Vb atoms include P (phosphorus), As (critical element), Sb (antimony), and Bi (bismuth), and P and As are particularly preferable.

In the present invention, the content of atoms for controlling conductivity contained in the charge injection blocking layer is appropriately determined as desired so that the object of the present invention can be effectively achieved. 10 to ¹ × 10 ⁴ atomic ppm, more preferably 50 to ⁵ × 10 ³ atomic ppm, most preferably 1 × 10 ²
Desirably, it is set to ３3 × 10 ³ atomic ppm.

Further, a carbon atom,
By containing at least one of a nitrogen atom and an oxygen atom, the adhesion to another layer provided in direct contact with the charge injection blocking layer can be further improved. The carbon atoms, nitrogen atoms, or oxygen atoms contained in the layer may be uniformly distributed throughout the layer, or may be uniformly distributed in the layer thickness direction, but may be unevenly distributed. There may be a portion contained in a distributed state.

However, in any case, it is necessary to uniformly contain the particles in the in-plane direction parallel to the surface of the support from the viewpoint of making the characteristics uniform in the in-plane direction. .

The content of carbon atoms and / or nitrogen atoms and / or oxygen atoms contained in the entire region of the charge injection blocking layer in the present invention is appropriately determined so that the object of the present invention can be effectively achieved. However, in the case of one kind, the amount is used, and in the case of two or more kinds, the sum is preferably used.
× 10 ⁻³ to 30 atomic%, more preferably 5 × 10 ^{−3 to} 20
Atomic%, optimally 1 × 10 ^-2 to 10 atomic% is desirable.

In the present invention, the hydrogen atoms and / or halogen atoms contained in the charge injection blocking layer compensate for dangling bonds existing in the layer, and are effective in improving the film quality.
The content of hydrogen atoms or halogen atoms or the sum of hydrogen atoms and halogen atoms in the charge injection blocking layer is preferably 1
~ 50 atomic%, more preferably 5-40 atomic%, optimally 1
Desirably, the content is 0 to 30 atomic%.

In the present invention, the thickness of the charge injection blocking layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 4 μm, from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. , And most preferably 0.5 to 3 μm. When the layer thickness is less than 0.1 μm, the ability to prevent charge injection from the support is insufficient, and sufficient charging ability cannot be obtained. Even if the layer thickness is more than 5 μm, improvement in electrophotographic properties cannot be expected, Only the production cost is increased due to the extension of the production time.

In the present invention, to form the charge injection blocking layer, a vacuum deposition method similar to the above-described method of forming the photoconductive layer is employed. In order to form the charge injection blocking layer 305 having characteristics capable of achieving the object of the present invention, it is necessary to appropriately set the gas mixing ratio, the gas pressure discharge power in the reaction vessel, and the support temperature. These layer formation factors are not usually determined separately and independently, but it is desirable to determine optimum values based on mutual and organic relevance in order to form a charge injection blocking layer having desired characteristics.

In addition, in the photoreceptor of the present invention,
It is desirable to have a layer region containing at least aluminum atoms, silicon atoms, hydrogen atoms and / or halogen atoms in a non-uniform distribution state in the layer thickness direction on the support 301 side of the photosensitive layer 302.

In the photoreceptor of the present invention, the support 301 and the photoconductive layer 303 or the charge injection blocking layer 305 are used.
For the purpose of further improving the adhesiveness between the substrate and, for example, Si ₃
N ₄ , SiO ₂ , SiO or silicon atom as a base,
An adhesion layer formed of an amorphous material containing a hydrogen atom and / or a halogen atom, a carbon atom and / or an oxygen atom and / or a nitrogen atom, or the like may be provided. further,
A light absorbing layer for preventing generation of an interference pattern due to light reflected from the support may be provided.

Next, an apparatus for forming a photosensitive layer and a film forming method will be described in detail. FIG. 4 shows a high-frequency plasma CVD method using an RF band power supply frequency (hereinafter referred to as “RF-PC
FIG. 1 is a schematic configuration diagram illustrating an example of a photoconductor manufacturing apparatus according to (VD). The configuration of the manufacturing apparatus shown in FIG. 4 is as follows.

This apparatus is roughly classified into a deposition apparatus (41)
00), a source gas supply device (4200), a reaction vessel (41
11) It is composed of an exhaust device (not shown) for reducing the pressure inside. The reaction vessel (41) in the deposition apparatus (4100)
In 11), a cylindrical support (4112), a heater for heating the support (4113), a raw material gas introduction pipe (4114) are installed, and a high-frequency matching box (4115) is connected.

The source gas supply device (4200) is composed of SiH ₄ ,
Gas cylinder for source gas such as GeH ₄ , H ₂ CH ₄ , B ₂ H ₆ , PH ₃
(4221-4226) and valves (4231-4236,4
241 to 4246, 4251 to 4256) and mass flow controllers (4211 to 4216),
The cylinder of each source gas is connected to a gas introduction pipe (4114) in the reaction vessel (4111) via a valve (4260).

The formation of a deposited film using this apparatus can be performed, for example, as follows. First, the reaction vessel (41
11), a cylindrical support (4112) is installed therein, and a reaction vessel (4111) is provided by an exhaust device (for example, a vacuum pump) (not shown).
Exhaust the inside. Subsequently, the heater for heating the support (411)
According to 3), the temperature of the cylindrical support (4112) is set to 200 to 3
It is controlled at a predetermined temperature of 50 ° C.

A source gas for forming a deposited film is supplied to a reaction vessel (41).
11), the gas cylinder valve (4231)
4237), the leak valve (4117) of the reaction vessel was confirmed to be closed, and the inflow valve (4241) was confirmed.
4246), the outflow valves (4251 to 4256), and the auxiliary valve (4260) are opened. First, the main valve (4118) is opened to open the reaction vessel (4111) and the gas pipe (4116). Exhaust.

Next, the reading of the vacuum gauge (4119) was about 1 × 10
^{When the} pressure reaches ^-2 Pa, the auxiliary valve (4260) and the outflow valves (4251 to 4256) are closed. Then the gas cylinder
From (4221 to 4226), each gas is supplied to a valve (4231 to 4231).
4236) is opened and introduced, and the pressure regulators (4261-42) are opened.
66), each gas pressure is adjusted to ² kg / cm ² . Then, gradually open the inflow valves (4241 to 4246),
Each gas is supplied to a mass flow controller (4211-421).
6).

After the preparation for film formation is completed as described above, each layer is formed in the following procedure. Cylindrical support (4
When the temperature reaches a predetermined temperature, the outflow valve (42)
Necessary ones of 51 to 4256) and auxiliary valves
(4260) is gradually opened and gas cylinders (4221 to 422) are opened.
26), a predetermined gas is introduced into the reaction vessel (4111) via the gas introduction pipe (4114). Next, the mass flow controllers (4211 to 4216) adjust each source gas to a predetermined flow rate.

At this time, the opening of the main valve (4118) is adjusted while watching the vacuum gauge (4119) so that the pressure in the reaction vessel (4111) becomes a predetermined pressure of 1.5 × 10 ² Pa or less. . When the internal pressure becomes stable, the frequency is 13.5.
Set a 6 MHz RF power supply (not shown) to the desired power,
Reaction vessel through high frequency matching box (4115)
RF power is introduced into (4111) to generate glow discharge.

The raw material gas introduced into the reaction vessel is decomposed by the discharge energy, and the raw material gas is introduced into the cylindrical support (411).
2) A deposited film mainly containing predetermined silicon is formed thereon. After the desired thickness is formed, R
The supply of the F power is stopped, the outflow valve is closed, the flow of gas into the reaction vessel is stopped, and the formation of the deposited film is completed. By repeating the same operation a plurality of times, a photosensitive layer having a desired multilayer structure is formed.

When forming each layer, it goes without saying that all outflow valves other than the necessary gas are closed, and each gas is supplied to the reaction vessel (4111).
And the reaction vessel (4) from the outflow valves (4251-4256).
In order to avoid remaining in the piping leading to 111),
Close the outflow valves (4251-4256) and set the auxiliary valve
(4260) is opened, the main valve (4118) is fully opened, and the operation of once evacuating the system to a high vacuum is performed as necessary.

In order to make the film formation uniform, the support (4112) is driven by a driving device during the layer formation.
(Not shown), it is also effective to rotate at a predetermined speed. Further, it goes without saying that the above-mentioned gas types and valve operations are changed according to the conditions for forming each layer. In any method, the temperature of the support during the formation of the deposited film is preferably 200 to 350 ° C., and more preferably 21 to 350 ° C.
The range of 0-340 degreeC, More preferably, the range of 220-330 degreeC is desirable.

The heating method of the support may be a heating element having a vacuum specification, and more specifically, an electric resistance heating element such as a winding heater of a sheath heater, a plate heater, or a ceramic heater, a halogen lamp, an infrared lamp, or the like. Examples of the heating element include a heat radiation lamp heating element such as a lamp, and a heating element using a liquid or a gas as a heating medium and a heat exchange unit.

As the surface material of the heating means, metals such as stainless steel, nickel, aluminum and copper, ceramics, heat-resistant polymer resins and the like can be used. In addition, a method is also used in which a container dedicated to heating is provided in addition to the reaction container, and after heating, the support is transferred into the reaction container in a vacuum.

(Image Forming Apparatus) FIG. 5 is a schematic view showing an image forming process of a digital copying machine using an a-Si photosensitive member. Charger 502, electrostatic latent image forming unit 503, developing machine 5
04, transfer paper supply system 505, transfer charger 506 (a), separation charger 506 (b), cleaner 507, transport system 50
8, a static elimination light source 509 and the like are provided.

Hereinafter, the image forming process will be described more specifically. The photosensitive member 501 is uniformly charged by the main charger 502 to which a high voltage is applied, and the electrostatic latent image is charged by the light emitted from the laser unit 518. An image is formed. The signal from the CCD is used for controlling the laser unit 518.

That is, the light emitted from the lamp 510 is reflected on the original 512 placed on the original platen glass 511, passes through mirrors 513, 514, and 515, forms an image by the lens unit 516, and is converted into an electric signal by the CCD 517. The converted signal is derived. A negative polarity toner is supplied to this latent image from the developing device 504 to form a toner image.

On the other hand, the tip end timing is adjusted by the registration roller 522 through the transfer paper supply system 505, and the transfer material P supplied in the direction of the photoconductor 501 is exposed to the transfer charger 506 (a) to which a high voltage is applied. A positive electric field having a polarity opposite to that of the toner is applied from the back surface in the gap between the bodies 501, whereby the negative polarity toner image on the surface of the photoconductor is transferred to the transfer material P. Next, the transfer material P is transferred to the transfer conveyance system 5 by the separation charger 506 (b) to which a high AC voltage is applied.
08 to the fixing device 524 where the toner image is fixed and carried out of the device.

The toner remaining on the photoconductor 501 is collected by the magnet roller 507 of the cleaning unit 507 and the cleaning blade 52, and the remaining electrostatic latent image is erased by the static elimination light source 509.

In the present invention, the wavelength of the latent image exposure and charge elimination light optimized for the optical characteristics of the a-Si photosensitive member is important. For the latent image exposure, a wavelength of 500 to 660 nm is preferably used, and more preferably, a wavelength of 600 to 660 nm. By using wavelengths in such a range, it is possible to minimize optical memory.

Further, since the thickness of the layer structure of the photoreceptor and the carrier generation region are determined depending on the wavelength, it is preferable that the light source has a monochromatic light or a wavelength distribution close to it as much as possible. Such a wavelength range can be realized by using white light and a filter, but semiconductor lasers and LEDs have been developed, and these are more preferable as light sources. Use of such a light source is most suitable for a digital copying machine or a printer.

On the other hand, it is preferable to use a wavelength of 600 to 680 nm for the neutralizing light, which has a longer wavelength than that of the latent image exposure. Within this range, static elimination is possible even with a small amount of light, the amount of optical memory is small, the decrease in charging ability is minimized, and the temperature characteristics, the temperature characteristics of sensitivity, and the linearity of sensitivity are excellent. Characteristics can be realized. For the static elimination light, monochromatic light or a light having a wavelength distribution close to the monochromatic light is preferable as the light source for the same reason as the latent image exposure.
An ED or the like is simple and optimal in configuration.

Hereinafter, the effects of the present invention will be specifically described with reference to Test Examples and Examples, but the present invention is not limited thereto.

(Test Example) (Test Example 1) Charge injection under the conditions shown in Table 1 on a mirror-finished aluminum cylinder having a diameter of 108 mm using an apparatus for manufacturing a photoreceptor for an image forming apparatus by the RF-PCVD method. A photoreceptor comprising a blocking layer, a photoconductive layer and a surface layer was prepared. The photoconductive layer includes a first layer region and a second layer region. In addition, the upper portion of the first layer region can be divided into an upper region in which the concentration of the conduction type control element is reduced and a region other than the upper region. The thickness of each layer is shown as a guide, but the thickness of the absorption region is used as needed according to the wavelength.

[0180]

[Table 1] *: Film thickness at which latent image exposure is absorbed by 90% (value calculated from the measured value of absorption coefficient) **: Region where all static elimination light is absorbed (subtract the amount absorbed in the second layer region, (Thickness calculated from the absorption coefficient of the first layer region) (All calculated values are calculated from the absorption coefficient measured by preparing a single-layer thin film sample in advance.) When the optical memory of the photoconductor is measured by a spectroscope, As shown in FIG. 2B, the value was low in the range of 500 to 660 nm.

This photoreceptor was used in an electrophotographic apparatus (Canon N
P6060 was modified for digital test), and the charging ability and the rank of the ghost memory were evaluated. The charge removal light is a 680 nm LED, and the image exposure is a 700 nm LED.
Using the head, the photoreceptor was rotated at a speed of 300 mm / s. As the charger, a corona charger was used, and the value of the charging ability was measured when the current of the primary charger was 1000 μA.

The measurement of the ghost potential was performed by using the dark potential 4
It was determined by measuring the dark area potential after one round of the exposed photoreceptor at 00 V and the exposed area potential of 50 V. Under these conditions,
The light quantity of the neutralization light was changed from 1 Lux.sec to 11 Lux.sec, and the charging ability and ghost potential at each image exposure wavelength were determined. FIG. 6 shows the results. The potential appearing as a ghost was reduced as the amount of the charge removing light was increased, but the charging ability was reduced.

Next, the wavelength of the charge removing light is 680 nm and the light amount is 4 Lu.
x.sec and the wavelength of the latent image exposure was changed. The ghost potential was measured using 565, 610, 635, 660, and 700 LEDs or semiconductor lasers as the light source for the latent image exposure. FIG. 7 shows the results. As can be seen from FIG. 7, when the wavelengths of 565, 610, 635, and 660 are used as the image exposure light source, the ghost potential is improved while suppressing the amount of static elimination light, and the ghost potential is reduced while minimizing the decrease in charging ability. Was found to be able to be reduced.

(Test Example 2) A ghost memory was evaluated by the electrophotographic apparatus used in Test Example 1 using a photoconductor prepared in the same manner as that used in Test Example 1. At this time, the static elimination light was set to 580, 630, 660, 680, and 700 nm, and the latent image exposure at that time was set to 565, 610, 635, and 650.
The wavelength dependence of the static elimination light was examined under the condition that the wavelength of the static elimination light was 660 nm and the wavelength of the static elimination light was always long. FIG. 8 shows the results. From this result, it was found that the ghost memory can be suppressed most when the wavelength range of the static elimination light is 600 to 680 nm.

(Test Example 3) Using the apparatus for manufacturing a photoreceptor shown in FIG. 4, a charge injection blocking layer and light were applied on a mirror-finished aluminum cylinder (support) having a diameter of 108 mm under the conditions shown in Table 1. A photoconductor comprising a conductive layer and a surface layer was prepared. At this time, a photoconductive layer is formed in the order of the first layer region and the second layer region from the side of the charge injection blocking layer, and the upper portion where the concentration of the conduction type control element is reduced is formed above the first layer region. Created an area.

On the other hand, in order to examine the characteristics of the film, instead of the aluminum cylinder, a cylindrical sample holder having a groove for mounting a sample substrate was used, and a glass substrate (Corning Co., Ltd. 7059) and a Si wafer were used. The thickness of the photoconductive layer is about 1
A μm a-Si film was deposited. The deposited film on the glass substrate is
After measuring the optical band gap (Eg), the comb-shaped Cr
Electrodes were deposited and the characteristic energy (Eu) of the exponential function tail was measured by CPM. The deposited film on the Si wafer was FTIR
Was used to measure the hydrogen content (Ch).

In the example of Table 1, the first layer region is Ch, Eg,
Eu is 20 atom%, 1.79 eV and 60 meV, respectively, and Ch, Eg and Eu in the second layer region are each 15 atom.
%, 1.73 eV and 56 meV.

Next, in order to change the characteristics of the second layer area (the area absorbing most of the latent image exposure), the SiH ₄
The gas flow rate, the mixing ratio of the SiH ₄ gas and the H ₂ gas, the ratio between the SiH ₄ gas flow rate and the discharge power, and the temperature of the support were variously changed, and samples having different Eg (Ch) and Eu were prepared to obtain characteristics. Various photoreceptors were produced based on this. The prepared photoreceptor was set in an electrophotographic apparatus (NP-6060 manufactured by Canon Inc. was modified for testing), and the potential characteristics were evaluated.

At this time, the process speed was 380 mm / sec,
The potential of the surface voltmeter (TREK Model 344) set at the developing device position of the electrophotographic apparatus under the condition that the light quantity of the static elimination light (LED of wavelength 660 nm) is 4 Lux · sec and the current value of the charging wire of the corona charger is 1000 μA. The surface potential (dark potential) of the photoreceptor in a dark state was measured by a sensor, and the measured value was used as the charging ability. Next, the temperature was changed from room temperature (about 25 ° C.) to 45 ° C. by a drum heater built in the photoreceptor, and the charging ability was measured under the above conditions. The temperature characteristics of the charging ability were used. When the surface temperature of the photoconductor is room temperature and 45 ° C., the dark potential is 400
The charging conditions were set so as to obtain V, and an LED having a peak wavelength of 630 nm was used as a latent image exposure light source. The EV amount (curve) was measured while changing the amount of exposure, and the temperature characteristics of sensitivity and the linearity of sensitivity were measured. Was evaluated.

The sensitivity unevenness is determined by first increasing the surface temperature of the photoreceptor to 45 ° C. by a drum heater and setting the dark potential to 40 ° C.
The charging condition is set so as to be 0V. Then, an LED having a peak wavelength of 630 nm is used as a latent image exposure light source,
The amount of light at which the potential became 50 V was measured at 10 points in the axial direction of the photoreceptor, and the difference between the maximum value and the minimum value was defined as sensitivity unevenness.

As in the sensitivity measurement, the 630 nm LED was used as a latent image exposure light source in the same manner as in the measurement of the sensitivity. The difference from the potential when charged was measured.

FIGS. 9, 10 and 11 show the relationship between Eg and Eu in this test example and the optical memory, the temperature characteristic of sensitivity, and the linearity of sensitivity, respectively. Each characteristic is shown as a relative value when 1 is set when the photoconductive layer is entirely composed of only the first layer region.

As is clear from FIGS. 9, 10 and 11,
In the second layer region, Eg is 1.70 to 1.80 eV,
It was found that when u is 50 to 60 meV, good characteristics can be obtained in all of the optical memory, the temperature characteristic of the sensitivity, and the linearity of the sensitivity.

(Test Example 4) Next, under the conditions shown in Table 1, the film thickness of the second layer region was adjusted so that the latent image exposure absorption was 60% and 8%.
0%, 90%, 95%, 105% (105% here means 100%
(Which means that the layer is made 5% thicker from the calculated value), and the other layers were prepared in the same manner as in Test Example 3 under the conditions shown in Table 1. This photoconductor was set in the same test copying machine as in Test Example 3, and
The same evaluation was performed.

The thickness of the second layer region in this test example was
The relationship among the optical memory, the temperature characteristic of the sensitivity, and the linearity of the sensitivity is shown in FIG. 12, FIG. 13, and FIG. For each characteristic, the thickness of the second layer region is shown as a relative value when the thickness at which 90% of latent image exposure is absorbed is set to 1. As is clear from FIGS. 12 to 14, it is understood that the characteristics are extremely good when the ratio is 60% or more, and when the ratio is 80% or more.

On the other hand, for the case of 105%,
Although the two characteristics were good, the result was a little inferior in charging ability per film thickness. This is probably because the ratio of the thickness of the first layer region, which is advantageous for the charging ability, was too small. From the above, it was found that it is important to select a film thickness of the second layer region such that absorption of latent image exposure is 80 to 95%.

[0197] Next (Test Example 5), the conditions shown in Table 1, mixing ratios in order to change the characteristics of the first layer region, SiH ₄ gas flow rate, the SiH ₄ gas and H ₂ gas, SiH ₄ gas The ratio between the flow rate and the discharge power and the temperature of the support were varied to obtain
Samples having different g (Ch) and Eu were prepared to determine the characteristics, and various photoconductors were prepared based on the characteristics.

The film thickness of the upper portion (impurity reduced region) of the second layer region and the first layer region is obtained by calculating a value suitable for latent image exposure and static elimination light, and there is no difference under this condition. I did it. The prepared photoreceptor was set in the same modified copying machine as in Test Example 3, and the same evaluation was performed.

Eg, Eu, charging ability and temperature characteristics of this test example
15 and 16 show the relationship with (temperature characteristic of charging ability), respectively.
Shown in For each property, all the photoconductive layers
Are shown as relative values when the case where only the layer region is constituted is set to 1.

As is clear from FIG. 15 and FIG. 16, the charging ability and the temperature characteristics are clearly improved as compared with the case where all the layers are in the second layer region.
Of 1.75 to 1.85 eV and Eu of 55 to 65 meV, it was found that good characteristics can be obtained in all of the optical memory, the temperature characteristic of sensitivity, and the linearity of sensitivity.

Test Example 6 Next, under the conditions shown in Table 1, the film thickness of the upper region (impurity concentration reduced region) of the first layer region was
100% absorption of static elimination light, and set to a thickness such that it becomes 120% (here, 120% means to create a further 20% thicker from the calculated value of 100%), With respect to the other layers, photoconductors were prepared in the same manner as in Test Example 3 under the conditions shown in Table 1. This photoreceptor was set in the same test copying machine as in Test Example 3, and the same evaluation was performed.

FIG. 17 shows the relationship between the film thickness above the first layer region and the optical memory in this test example. Each characteristic is shown as a relative value when 1 is set when the upper region of the first layer region is not provided. As is clear from FIG. 17, the optical memory characteristics are further improved when the ratio is 100% or more as compared with the result in the case of not providing.

On the other hand, in the case of 120%, the residual potential slightly increased. This is probably because the region with high resistance increased too much due to the low impurity concentration.

As described above, the film thickness of the impurity concentration reduced region, which is the upper region of the first layer region, is such that the absorption of the neutralization light is 1
It has been found that it is important to select a film thickness that is not more than 00%.

Next, the absorption of the static elimination light is set to 100%, and the impurity concentration is set to, of the value of the lower region of the first layer region,
1/3, 1/10, 1/50 and the same evaluation was performed. FIG. 18 shows the relationship between the impurity concentration and the optical memory. From this result, it was found that the case where the impurity concentration in the upper region was set to 1/3 or less of that in the lower region was more preferable. Further, when the impurity concentrations of the samples prepared in this test example were measured, it was confirmed that all of them were within the concentration range specified in the present invention.

[0206]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Example 1 A charge injection blocking layer, a photoconductive layer, and a surface layer were formed on an aluminum cylinder (support) having a mirror-finished surface with a diameter of 80 mm by using a photoreceptor manufacturing apparatus by RF-PCVD shown in FIG. Was produced. In this case, the first layer region of the photoconductive layer from the charge injection blocking layer side, and the order of the second layer region further divided first layer region into two by the B concentration of the upper region B ₂ H ₆ The addition amount was 0.1 ppm with respect to SiH ₄ , and the addition amount of B ₂ H _{6 in the} lower region was 2 ppm.
Table 2 shows the conditions for manufacturing the photoconductor at this time.

In this example, the C in the first layer region of the photoconductive layer
h, Eg, and Eu are respectively 20 atomic%, 1.82 eV, 60
meV and Ch, Eg, and Eu in the second layer region are each 1
The results were 2 atomic%, 1.73 eV and 52 meV.

The produced photoreceptor was converted to an electrophotographic apparatus (NP-6550 manufactured by Canon Inc. for testing, and latent image exposure was 630 nm).
LED, static elimination light is set to 660nm LED)
When the potential characteristics were evaluated, favorable characteristics were obtained in all of the temperature characteristics of sensitivity, the linearity of sensitivity, the charging ability, the temperature characteristics, and the memory.

When the produced photoreceptor was positively charged and the image was evaluated, no optical memory was observed on the image, and good electrophotographic characteristics were obtained with respect to other image characteristics (pockets, image deletion). .

That is, 500 to 660 as latent image exposure
nm, longer than latent image exposure for charge removal exposure and 600-68
Using a wavelength of 0 nm, the photoconductive layer is arranged in the order of the first layer region and the second layer region from the charge injection blocking layer side, and Ch, Eg, and Eu are respectively 15 to 15 in the first layer region of the photoconductive layer. 30
Atomic%, 1.75 to 1.85 eV, 55 to 65 meV,
In the second layer region, Eg is 1.70 to 1.80 eV, Eg
It has been found that extremely good electrophotographic characteristics can be obtained by reducing u to 50 to 60 meV and reducing the impurity concentration of the first layer region in the upper region and balancing them.

[0211]

[Table 2] *: Film thickness at which latent image exposure is absorbed by 90% (value calculated from the measured value of absorption coefficient) **: Region where all static elimination light is absorbed (subtract the amount absorbed in the second layer region, (The film thickness calculated from the absorption coefficient of the first layer region) (All calculated values are calculated from the absorption coefficient measured by preparing a single-layer thin film sample in advance.) [Example 2] In this example, the photoconductive layer Are laminated in the order of the first layer region and the second layer region from the charge injection blocking layer side, and the content of silicon atoms and carbon atoms in the surface layer is not changed in the thickness direction in place of the surface layer of Example 1. A surface layer with a uniform distribution was provided. Table 3 shows the conditions for producing this photoreceptor.

In this example, the C in the first layer region of the photoconductive layer
h, Eg, and Eu are 22 atomic%, 1.81 eV, 61, respectively.
meV and Ch, Eg, and Eu in the second layer region are each 1
The result was 2 atomic%, 1.72 eV, 58 meV.

When the produced photoreceptor was evaluated in the same manner as in Example 1, similarly good electrophotographic characteristics were obtained. That is, the photoconductive layer is placed in the first layer region from the charge injection blocking layer side,
The present invention is also applicable to a case where the surface layer is laminated in the order of the second layer region and the content of silicon atoms and carbon atoms is unevenly distributed in the layer thickness direction to improve the properties of the surface layer. It was found that the effect of was obtained.

[0214]

[Table 3] *: Film thickness at which latent image exposure is absorbed by 90% (value calculated from the measured value of absorption coefficient) **: Region where all static elimination light is absorbed (the amount absorbed by the second layer region is subtracted. (Thickness calculated from the absorption coefficient of layer region 1) (All calculated values are calculated from the absorption coefficient measured by preparing a single-layer thin film sample in advance.) [Example 3] In this example, the photoconductive layer was The first layer region and the second layer region are stacked in this order from the charge injection blocking layer side, and instead of the surface layer of Example 1, the content of silicon atoms and carbon atoms in the surface layer is uneven in the thickness direction. In addition to providing a surface layer in such a distributed state, all the layers contained at least one element selected from a fluorine atom, a boron atom, a carbon atom, an oxygen atom, and a nitrogen atom. Table 4 shows the conditions for manufacturing the photoconductor at this time. In this example, Ch, Eg, and Eu in the first layer region of the photoconductive layer are 26 atomic%,
1.83 eV, 62 meV, Ch, Eg, E in the second layer region
u was 14 atomic%, 1.75 eV, and 58 meV, respectively.

The content of the element belonging to Group IIIb of the periodic table is changed from 2.5 ppm on the support side to 1 ppm on the surface side in the lower region of the first layer region, and is changed to 1 ppm on the upper layer region of the first layer region. The concentration was set to be 0.05 ppm constant in the region and the second layer region. The shape of the change in the lower region of the first layer region was linearly distributed.

The photosensitive member thus produced was evaluated in the same manner as in Example 1. As a result, similarly good electrophotographic characteristics were obtained. That is, even when the content of the element belonging to Group Шb of the periodic table in the photoconductive layer is changed and contained, the concentration of the Group IIIb element contained in the upper region of the first layer region is reduced to the first concentration. III or less of the average concentration of the same element contained in the lower region of the layer region and contained in the second layer region
The b group concentration was the same as or lower than the concentration in the first layer region, and satisfied the film thickness conditions limited by the present invention, and used a light source of each exposure wavelength limited by the present invention. In this case, it was found that the effects of the present invention can be obtained to the maximum.

[0219]

[Table 4] *: Film thickness at which latent image exposure is absorbed by 90% (value calculated from the measured value of absorption coefficient) **: Region where all static elimination light is absorbed (the amount absorbed by the second layer region is subtracted. (The thickness calculated from the absorption coefficient of the layer region of No. 1) (All calculated values are calculated from the absorption coefficient measured by preparing a single-layer thin film sample in advance.) [Example 4] In this example, the photoconductive layer was The first layer region and the second layer region are stacked in this order from the charge injection blocking layer side, and instead of the surface layer of Example 1, the content of silicon atoms and carbon atoms in the surface layer is non-uniform in the layer thickness direction. In addition to providing a surface layer with a good distribution state, all layers have fluorine atoms, boron atoms,
At least one of carbon, oxygen and nitrogen atoms was contained. Table 5 shows the conditions for manufacturing the photoconductor at this time. In this example, C in the first layer region of the photoconductive layer
h, Eg, and Eu are 20 atomic%, 80 eV, and 59 m, respectively.
eV and Ch, Eg and Eu of the second layer region are 15
Atomic%, 1.75 eV and 55 meV were obtained.

Further, the content of the element belonging to Group IIIb of the periodic table is adjusted from 5.0 ppm on the support side of the first layer region to the second layer region.
Was continuously changed so as to be 0.01 ppm on the outermost surface side of the layer region. The shape of the change shows a distribution form in which the lower portion of the first layer region changes sharply, and then gradually connects to the upper region and connects to the second layer region.
At this time, from the profile predicted in advance, the average concentration of the IIIb group in the lower region of the first layer region is 1 /
The distribution was made such that the point 3 became an interface with the upper region.

The produced photoreceptor was evaluated in the same manner as in Example 1. As a result, similarly good electrophotographic characteristics were obtained. That is, even when the content of the element belonging to Group IIIb of the periodic table in the photoconductive layer is continuously distributed and contained, the concentration of the Group IIIb (conduction type control element) in the upper region of the first layer region is The concentration of the Group IIIb element contained in the lower region of the first layer region is one third or less of the average value of the concentration of the Group IIIb element contained in the lower region, and the concentration of the Group IIIb element contained in the second layer region is included in the first layer region. It has been confirmed that the effect of the present invention can be favorably obtained by using a light source of each exposure wavelength limited by the present invention, which is equal to or smaller than the concentration and satisfies the film thickness conditions limited by the present invention. .

[0220]

[Table 5] *: Film thickness at which latent image exposure is absorbed by 90% (value calculated from the measured value of absorption coefficient) **: Region where all static elimination light is absorbed (subtract the amount absorbed in the second layer region, (The film thickness calculated from the absorption coefficient of the first layer region) (All calculated values are calculated from the absorption coefficient measured by preparing a single-layer thin film sample in advance.) [Example 5] In this example, the photoconductive layer Were laminated in the order of the first layer region, the second layer region, and the surface layer from the charge injection blocking layer side, and all the layers contained carbon atoms. Table 6 shows the conditions for manufacturing the photoconductor at this time. The other points were the same as in Example 1. In this example, Ch, Eg, and Eu in the first layer region of the photoconductive layer are 27 atomic% and 1.83 eV and 63 meV, respectively, and Ch, Eg and Eu in the second layer region are 18 atomic% and 18 atomic%, respectively. 1.74e
V, a result of 59 meV was obtained.

When the produced photoreceptor was evaluated in the same manner as in Example 1, similarly good electrophotographic characteristics were obtained. In other words, even when a layer configuration in which carbon atoms are contained in all layers is used, a film capable of obtaining characteristics within the scope of the present invention is used, and the film thickness condition limited by the present invention is satisfied, and the film thickness is limited by the present invention. It was found that when the light source of each exposure wavelength was used, the effect of the present invention was favorably obtained.

[0222]

[Table 6] *: Film thickness at which latent image exposure is absorbed by 90% (value calculated from the measured value of absorption coefficient) **: Region where all static elimination light is absorbed (subtract the amount absorbed in the second layer region, (The film thickness calculated from the absorption coefficient of the first layer region) (All calculated values are calculated from the absorption coefficient measured by preparing a single-layer thin film sample in advance.) [Example 6] In this example, the photoconductive layer Is used instead of H ₂ , and the first layer region and the second layer region are stacked in this order from the charge injection blocking layer side, and a nitrogen atom is used instead of a carbon atom as an atom constituting a surface layer. It was provided so as to be contained in the surface layer. Table 7
The conditions for producing the photoreceptor at this time are shown below. Other points were the same as in Example 1. In this example, Ch, Eg, and Eu in the first layer region of the photoconductive layer are 23 atomic%, 1.81 eV, 6 respectively.
0 meV, and Ch, Eg, and Eu of the second layer region were 21 atomic%, 1.76 eV, and 64 meV, respectively. The content of the element belonging to Group IIIb of the periodic table was 2 ppm in the lower region of the first layer region, 0.05 ppm in the upper region, and 0.01 ppm in the second layer region.

The produced photoreceptor was evaluated in the same manner as in Example 1. As a result, similarly good electrophotographic characteristics were obtained. That is, even if the diluent gas is changed from hydrogen to He or the material of the surface layer is changed from SiC to SiN, the characteristics in the range specified in the present invention can be obtained, and the film thickness condition limited in the present invention is satisfied, Further, it was found that the effects of the present invention can be favorably obtained when the light sources having the respective exposure wavelengths limited in the present invention are used.

[0224]

[Table 7] *: Film thickness at which latent image exposure is absorbed by 90% (value calculated from the measured value of absorption coefficient) **: Region where all static elimination light is absorbed (subtract the amount absorbed in the second layer region, (The film thickness calculated from the absorption coefficient of the first layer region) (All calculated values are calculated from the absorption coefficient measured by preparing a single-layer thin film sample in advance.)

[0225]

According to the present invention, the wavelength of the latent image exposure and the charge elimination light are optimized to the characteristics of the photoreceptor, thereby suppressing the charge elimination light amount and minimizing the deterioration of the charging ability while causing the ghost or other optical memory. An electrophotographic method and an electrophotographic apparatus which hardly cause image defects can be obtained.

The optimized wavelength and the optimized layer structure of the photoreceptor dramatically improve the temperature characteristics of sensitivity, the linearity of sensitivity, and the temperature characteristics, and further improve the chargeability. In addition, it is possible to provide an electrophotographic method and apparatus capable of improving the stability of a photosensitive member in a use environment, and stably obtaining a high-quality image with a clear halftone and high resolution.

Therefore, the electrophotography method and apparatus of the present invention have a specific configuration as described above, and
A conventional electrophotographic apparatus using a Si photoreceptor exhibits more excellent electrical characteristics, optical characteristics, photoconductive characteristics, image characteristics, durability and use environment characteristics than ever before.

In particular, in the present invention, the latent image exposure and charge elimination light in the digital copying machine are respectively changed from the infrared region to the visible region, and the photoconductive layer has a different optical band gap and a different level in the gap. Divided into regions and second
The thickness of the layer region of the first layer region is set to a thickness that absorbs most of the latent image exposure, and the concentration of the conduction type control element in the upper region of the first layer region is reduced. And the temperature dependence (slope or curve) of the sensitivity straight line is suppressed to a small value. In addition, the change in the surface potential due to the fluctuation of the surrounding environment is suppressed, and the device has extremely excellent potential characteristics and image characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an a-Si subgap light absorption spectrum for explaining characteristic energy of an exponential function tail in the present invention.

FIG. 2 shows the sensitivity of the photoconductor of the present invention to each wavelength.
FIG. 2A shows an optical memory for each wavelength (FIG. 2B).

FIG. 3 is a schematic explanatory view showing a layer structure of a preferred embodiment of the photoconductor of the present invention.

FIG. 4 is a schematic explanatory view showing an example of an apparatus for forming a photoreceptive layer of the photoreceptor of the present invention, which shows an apparatus for producing a photoreceptor by a glow discharge method using an RF band high frequency power supply.

FIG. 5 is a schematic explanatory view showing an electrophotographic method and apparatus according to the present invention.

FIG. 6 is a graph showing the relationship between the amount of static elimination light, charging ability, and ghost potential when the electrophotographic apparatus of the present invention is used.

FIG. 7 is a graph showing the relationship between the wavelength of latent image exposure and the ghost potential when the electrophotographic apparatus of the present invention is used.

FIG. 8 is a graph showing the relationship between the wavelength of neutralizing light and the ghost potential when the electrophotographic apparatus of the present invention is used.

FIG. 9 is a graph showing the relationship between the characteristic energy (Eu) and the optical band gap (Eg) of the Urbach tail and the optical memory in the second layer region of the photoconductive layer in the photoconductor of the present invention.

FIG. 10 is a graph showing the relationship between the characteristic energy (Eu) and the optical band gap (Eg) of the Urbach tail in the second layer region of the photoconductive layer in the photoconductor of the present invention, and the temperature characteristics of sensitivity.

FIG. 11 is a graph showing the relationship between the characteristic energy (Eu) and optical band gap (Eg) of the Urbach tail in the second layer region of the photoconductive layer and the linearity of sensitivity in the photoconductor of the present invention.

FIG. 12 is a graph showing the relationship between the thickness of the second layer region of the photoconductive layer and the optical memory in the photoreceptor of the present invention.

FIG. 13 is a graph showing the relationship between the thickness of the second layer region of the photoconductive layer and the temperature characteristic of sensitivity in the photoreceptor of the present invention.

FIG. 14 is a graph showing the relationship between the thickness of the second layer region of the photoconductive layer and the linearity of sensitivity in the photoconductor of the present invention.

FIG. 15 is a graph showing the relationship between the characteristic energy (Eu) and the optical band gap (Eg) of the Urbach tail in the first layer region of the photoconductive layer in the photoconductor of the present invention, and the charging ability.

FIG. 16 is a graph showing the relationship between the characteristic energy (Eu) and optical band gap (Eg) of the Urbach tail in the first layer region of the photoconductive layer and the temperature characteristics of the charging ability in the photoconductor of the present invention. .

FIG. 17 is a graph showing the relationship between the thickness of the upper region (low impurity concentration region) of the first layer region of the photoconductive layer and the optical memory in the photoconductor of the present invention.

FIG. 18 is a graph showing a relationship between an impurity concentration in an upper region (low impurity concentration region) of the first layer region of the photoconductive layer and the optical memory in the photoconductor of the present invention.

[Explanation of symbols]

 Reference Signs List 300 photosensitive member 301 conductive support 302 photosensitive layer 303 photoconductive layer 304 surface layer 305 charge injection blocking layer 310 free surface 311 lower region of first layer region 312 second layer region 313 upper region of first layer region 4100 Deposition device 4111 Reaction vessel 4112 Cylindrical support 4113 Heater for support heating 4114 Source gas introduction pipe 4115,4116 Matching box 4116 Source gas pipe 4117 Reaction vessel leak valve 4118 Main exhaust valve 4119 Vacuum gauge 4200 Source gas supply device 4211 4216 Mass flow controller 4221 to 4226 Raw material gas cylinder 4231 to 4236 Raw material gas cylinder valve 4241 to 4246 Gas inflow valve 4251 to 4256 Gas outflow valve 4261 to 4266 Pressure regulator 50 Reference Signs List 1 photoconductor 502 main charger 503 electrostatic latent image forming unit 504 developing unit 505 transfer paper supply system 506 (a) transfer charger 506 (b) separation charger 507 cleaner 508 transport system 509 static elimination light source 510 lamp 511 platen glass 512 Original document 513 to 515,519 Mirror 516 Lens unit 517 CCD 518 Laser unit 520 Blank exposure 521 Cleaning blade 522 Registration roller 523 Drum heater 524 Fixing unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Furushima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroaki Shinno 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term (reference) 2H035 AA10 AB03 AC02 AZ09 2H068 DA24 DA28 DA29 DA34 DA35 DA37 FB07 FB08 FC05 FC17 2H076 AB05 AB16 AB42

Claims (16)

[Claims] 1. An electrophotographic method for forming an image by static elimination, charging, latent image exposure, development, transfer, etc., wherein a photosensitive element as a recording element contains at least a hydrogen atom and / or a halogen atom with silicon as a base. A photoconductive layer made of a non-single-crystal material, wherein the photoconductive layer has at least a first layer region and a second layer region which are different from each other in at least an optical band gap and a characteristic energy of an exponential skirt obtained from an optical absorption spectrum. The layer region is laminated on the conductive substrate in this order, and the thickness of the second layer region is a film necessary for adjusting the light absorptance of the wavelength used for image exposure to 80 to 95%. And the first layer region can be further divided into at least two regions. In the upper region of the first layer region, the concentration of the conduction type control element in the region where the light for the charge erasure exposure reaches is adjusted. Decrease When a latent image is formed using a laser or an LED light source having a wavelength in the range of 500 to 660 nm, and the charge is removed, the latent image is formed longer than the image exposure for forming a latent image. An electrophotographic method characterized by using a laser or LED light source having a wavelength in the range of from 680 to 680 nm. 2. A photoconductor as a recording element, comprising a photoconductive layer made of a non-single-crystal material containing silicon as a base material and further containing a conduction type control element at least in hydrogen atoms and / or halogen atoms. The electrophotographic method according to claim 1, wherein 3. The method according to claim 1, wherein the conduction type control element is selected from the periodic table III.
3. The electrophotographic method according to claim 2, wherein the electrophotographic method is a group b element or a group Vb element. 4. The photoconductor according to claim 1, wherein the first layer region includes:
The content of hydrogen atoms and / or halogen atoms is 1
The characteristic energy is in the range of 5 to 30 atomic%, the optical band gap is in the range of 1.75 to 1.85 eV, and the characteristic energy of the exponential function tail obtained from the light absorption spectrum is in the range of 55 to 65 meV. Item 4. The electrophotographic method according to any one of Items 1 to 3. 5. The photoconductor, wherein the second layer region includes:
The content of hydrogen atoms and / or halogen atoms is 1
0 to 25 atomic%, an optical band gap of 1.70 to 1.80 eV, an exponential function characteristic energy obtained from an optical absorption spectrum of 50 to 60 meV, and a conduction type control element. The electrophotographic method according to any one of claims 1 to 4, wherein the content is the same as or less than that of the first layer region. 6. In the first layer region of the photoreceptor, the content of the conduction type control element in the lower region is in the range of 0.2 to 30 ppm with respect to silicon atoms, and further, the discharge exposure for static elimination is achieved. In the upper region, the content of the lower region is at least one-third or less of the average value of the content of the lower region, and is not more than 0.3.
5. The electrophotographic method according to claim 4, wherein the amount is in the range of 01 to 10 ppm. 7. The electrophotographic method according to claim 6, wherein the content of the conduction type control element in the first layer region decreases from the conductive substrate side to the surface side. 8. The content of the conduction type control element in the second layer region of the photoconductor is 0.01 to silicon atom.
6. The electrophotographic method according to claim 5, wherein the concentration is in the range of 10 to 10 ppm. 9. An electrophotographic apparatus for forming an image by static elimination, charging, latent image exposure, development, transfer, etc., wherein a photosensitive element as a recording element contains silicon as a base material and at least hydrogen atoms and / or halogen atoms. A photoconductive layer made of a non-single-crystal material, wherein the photoconductive layer has at least a first energy difference between at least an optical bandgap and a characteristic energy of an exponential function tail obtained from a light absorption spectrum.
Layer region and the second layer region are laminated on the conductive substrate in this order, and the thickness of the second layer region is such that the light absorptance of the wavelength used for image exposure is in the range of 80 to 95%. And the first layer region should be at least 2
And a region in which the concentration of the conduction control element is reduced in a region where the light for the charge erasure exposure reaches in the upper region of the first layer region. The image exposure light source uses a light source composed of a laser or LED having a wavelength in the range of 500 to 660 nm, and the exposure light source for static elimination is longer than the image exposure for latent image formation and has a range of 600 to 680 nm. An electrophotographic apparatus comprising a light source comprising a laser or LED having a wavelength in a range. 10. A photoconductor as the recording element includes a photoconductive layer made of a non-single-crystal material containing silicon as a base material and further containing a conduction type control element in at least hydrogen atoms and / or halogen atoms. Claim 9
An electrophotographic apparatus as described in the above. 11. The method according to claim 11, wherein the conduction type control element is selected from the group II of the periodic table.
The electrophotographic method according to claim 10, wherein the electrophotographic method is a Group Ib or Group Vb element. 12. The photoconductor according to claim 1, wherein the first layer region has a hydrogen atom and / or halogen atom content in the range of 15 to 30 atomic% and an optical band gap of 1.7.
In the range of 5 to 1.85 eV, the characteristic energy of the exponential function tail obtained from the light absorption spectrum is 55 to 6
The electrophotographic apparatus according to any one of claims 9 to 11, wherein the range is 5 meV. 13. The photoconductor according to claim 1, wherein the second layer region has a hydrogen atom and / or halogen atom content in the range of 10 to 25 atomic% and an optical band gap of 1.7.
In the range of 0 to 1.80 eV, the characteristic energy of the exponential function tail obtained from the light absorption spectrum is 50 to 6
The electrophotographic apparatus according to any one of claims 9 to 12, wherein the electroconductive device has a range of 0 meV and the content of the conduction type control element is equal to or less than that of the first layer region. 14. In the first layer region of the photoreceptor, the content of the conduction type control element in the lower region is in the range of 0.2 to 30 ppm with respect to silicon atoms. 13. The electrophotographic apparatus according to claim 12, wherein in the reaching upper region, the content is at least one third or less of the average value of the content of the lower region, and is in a range of 0.01 to 10 ppm. 15. The electrophotographic apparatus according to claim 14, wherein the content of the conductivity type control element in the first layer region decreases from the conductive substrate side toward the surface side. 16. The content of the conduction type control element in the second layer region of the photoconductor is 0.0 with respect to silicon atoms.
14. The electrophotographic apparatus according to claim 13, wherein the concentration is in the range of 1 to 10 ppm.