JP2002149029A - Image forming method, image forming apparatus, and photoreceptor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To realize good cleaning performance with little fluctuation with respect to environmental (particularly temperature) changes and to improve durability between a photosensitive member and a cleaning member. SOLUTION: A cleaning blade is brought into contact with the surface of a photoconductor to remove transfer residual toner on the surface of the photoconductor. When the standard deviation coefficient of dynamic friction representing the load dependency of the variation of the dynamic friction force acting between the photosensitive member surface and the cleaning member is defined as the dynamic friction deviation coefficient, the contact between the photosensitive member surface and the cleaning member is established. Temperature in the part is 15-6
In the range of 0 ° C., the dynamic friction deviation coefficient is set to be within 0.1. Further, the temperature at the contact portion is 15 to 60.
At any point in the temperature range, the coefficient of friction between the photosensitive member surface and the cleaning member is 1 or less, and
Is set so that the variation width of the friction coefficient in an arbitrary range of the above is within 0.4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method, an image forming apparatus, and a photoreceptor such as a copying machine and a printer.

[0002]

2. Description of the Related Art In recent years, electrophotographic apparatuses have been widely used not only as copiers but also as printers which are output means of computers and word processors whose demand has been remarkably growing in recent years. Because of the increase in personal use in addition to conventional office use, economics such as low cost, energy saving and maintenance-free are emphasized.

[0003] Environmental performance such as energy saving and reduction or elimination of waste is required as well as economic efficiency.

In such an image forming apparatus, generally, a toner image is formed on the surface of a photoreceptor by a charger, an exposure device, a developing device, and the like, and the toner image is transferred to a recording material such as paper. The recording material after the transfer of the toner image is discharged outside the image forming apparatus main body after the toner image is fixed on the surface by the fixing device. On the other hand, the toner remaining on the surface of the photoreceptor after the transfer of the toner image without being transferred to the recording material (transfer residual toner) is removed by a cleaning member of a cleaning device. As the cleaning member, for example, a member formed in a blade shape (cleaning blade), a brush shape (cleaning brush), or a roller shape (cleaning roller) is used. Each of the cleaning members is brought into contact with the surface of the photoreceptor at a predetermined pressure, thereby rubbing the surface of the photoreceptor to scrape off the transfer residual toner on the surface of the photoreceptor.

[0005]

Generally, in an electrophotographic image forming apparatus, when cleaning the photosensitive member, the cleaning member and the surface of the photosensitive member move relatively at a predetermined relative speed. At this time, the friction characteristic between the two is an important characteristic relating to the life of the cleaning member and the photosensitive member, including the quality of the cleaning property.

If the frictional force acting between the cleaning member and the surface of the photoreceptor is too low, it causes a cleaning failure. On the other hand, if it is too high, failures such as damage to the cleaning member and the photoreceptor and turning or chipping of the cleaning member may occur. It becomes a factor. Further, if the toner is used in an area having an inappropriate frictional force, the removal of the transfer residual toner or the like becomes insufficient, and the transfer residual toner may adhere to the surface of the photoreceptor to cause an image defect.

Further, frictional force = frictional coefficient × load [gf]. Therefore, the coefficient of friction is specified, but the coefficient of friction is a value obtained by the correlation between the members that come into contact with each other. In the present invention, the coefficient of friction can change depending on the characteristics of the photosensitive member surface and the characteristics of the cleaning member.

As the characteristics of the cleaning member, for example, the resilience of the elastic material, the coefficient of friction, and the like are defined as follows.

Japanese Patent Application Laid-Open No. 09-292722 proposes a device in which rebound resilience, a contact pressure, a contact angle, and a coefficient of static friction are specified. Japanese Patent Application Laid-Open No. 08-286510 proposes a device in which the rate of change of the dynamic friction coefficient is specified, and a device in which the rebound resilience, contact pressure, contact angle, bite amount, and static friction coefficient are specified. ing.

However, since the elastic material uses a thermoplastic member or the like, its characteristics greatly vary depending on the environment, particularly temperature. However, these documents do not disclose the correlation between the fluctuation of the environment, particularly the temperature, and the fluctuation of the friction characteristics.

The evaluation of the rebound resilience and the hardness is generally measured under JIS standard conditions. The measurement conditions of this JIS standard are a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%.

When the power of the image forming apparatus is turned on, after a certain warm-up operation and when the image forming process is continuously performed,
Inside the fixing device or other image forming apparatus main body
That. Due to the influence of the heat source and the friction at the contact portion between the cleaning member and the photosensitive member, the temperature inside the device such as the cleaning device including the contact portion fluctuates. Particularly, in a system in which the photosensitive member does not have a drum heater or a system in which the fixing device has a large capacity, the temperature change tends to be large.

For this reason, temperature fluctuations in the system to be used include environmental fluctuations, a temperature rise by a heater or the like in the machine, and a temperature rise due to friction in a contact portion locally. In some cases, a structural defect such as turning up or chipping of the cleaning blade occurs, or a required setting load fluctuates, resulting in poor cleaning.

[0014] In addition, vibration of frictional force at a contact portion for cleaning has hardly been considered in the past. For example, even when the friction coefficient is used in a prescribed state, cleaning failure due to toner slippage due to vibration of the cleaning member or partial wear of the photoconductor may occur. However, there is no disclosure relating to the vibration of the frictional force, and of course, there is no disclosure relating to the correlation between the fluctuation of the vibration or the frictional force and the cleaning performance and durability.

For this reason, when designing the image forming apparatus, in various environments where the image forming apparatus is used, various items such as the cleaning property and the life of the cleaning member and the photoreceptor are taken into consideration. At present, trial and error such as performing a durability test by adjusting the selection of cleaning members, setting conditions, and the like is performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and realizes a good cleaning property with little fluctuation with respect to environmental (particularly temperature) changes, and improves the durability between a photosensitive member and a cleaning member. It is still another object of the present invention to provide an image forming method, an image forming apparatus, and a photoreceptor capable of broadening the setting latitude.

[0017]

According to a first aspect of the present invention, there is provided a charging step of charging a surface of a photoreceptor, and exposing the surface of the photoreceptor after charging to form an electrostatic latent image. An exposure step of forming an image, a development step of developing the electrostatic latent image as a toner image, a transfer step of transferring the toner image from the photoconductor surface to another member, and a transfer step remaining on the photoconductor surface after the transfer. And a cleaning step of removing the transfer residual toner, wherein the cleaning step includes the step of transferring the surface of the photoconductor by a cleaning member contacting the surface of the photoconductor. A standard deviation of dynamic friction representing a load dependency of a variation in dynamic friction force acting between the photosensitive member surface and the cleaning member during the image forming step. When the number is a dynamic friction deviation coefficient, the dynamic friction deviation coefficient is within 0.1 in a temperature range of 15 to 60 ° C. at a contact portion where the photosensitive member surface and the cleaning member are in contact with each other. It is characterized by the following.

According to a second aspect of the present invention, in the image forming method according to the first aspect, the temperature of the contact portion is 15 to 6 degrees.
The dynamic friction deviation coefficient may be changed within a range of 0.02 in an arbitrary range of 0 ° C.

According to a third aspect of the present invention, there is provided a charging step of charging a photoreceptor surface, an exposing step of exposing the charged photoreceptor surface to form an electrostatic latent image, and A series of steps including a development step of developing as a toner image, a transfer step of transferring the toner image from the photoconductor surface to another member, and a cleaning step of removing transfer residual toner remaining on the photoconductor surface after transfer. In an image forming method for forming an image by an image forming step, the cleaning step includes:
A step of removing transfer residual toner on the surface of the photoconductor by a cleaning member in contact with the surface of the photoconductor;
At an arbitrary point in a temperature range of 15 to 60 ° C. at a contact portion where the photosensitive member surface and the cleaning member are in contact with each other, a coefficient of friction between the photosensitive member surface and the cleaning member is 1 or less, and The variation range of the friction coefficient in an arbitrary range of the 15 to 60 ° C. is 0.4 or less;
It is characterized by the following.

According to a fourth aspect of the present invention, in the image forming method according to the third aspect, the variation width of the friction coefficient is 0.1.
2 or less.

According to a fifth aspect of the present invention, there is provided the first or second aspect.
Wherein the amount of change in the coefficient of dynamic friction deviation before and after endurance after repeating the image forming process 150,000 times is within 0.02.

The present invention according to claim 6 is the invention according to claim 3 or 4.
Wherein the amount of change in the friction coefficient before and after the endurance after repeating the image forming process 150,000 times is within 0.4.

According to a seventh aspect of the present invention, in the image forming method according to any one of the first to sixth aspects, the cleaning member is an elastic cleaning blade, and the cleaning blade conforms to JIS K-7311. Has a rebound resilience of 5 to 75%.
The hardness of the cleaning blade according to −6253 is 60 to 90 degrees.

According to an eighth aspect of the present invention, in the image forming method of the seventh aspect, the contact pressure at which the cleaning blade contacts the surface of the photosensitive member is 49 to 490 mN /.
cm (5 to 50 gf / cm).

The present invention according to claim 9 is the invention according to claim 7 or 8.
In the image forming method described in the item (1), a substantially constant amount of a lubricant is interposed in a contact portion between the cleaning blade and the surface of the photoreceptor and in the vicinity thereof.

According to a tenth aspect of the present invention, in the image forming method according to the ninth aspect, the lubricant is a toner.

The present invention according to claim 11 is the invention according to claims 1-1.
0. The image forming method according to any one of Items 1 to 3, wherein the photoconductor has a surface layer mainly composed of amorphous silicon and / or carbon.

According to a twelfth aspect of the present invention, there is provided the present invention.
2. The image forming method according to claim 1, wherein the photoreceptor is mainly made of amorphous silicon, and a temperature characteristic, which is a rate of change in charging characteristics with temperature, is within ± 2 V / deg. I do.

According to a thirteenth aspect of the present invention, in the image forming method according to the twelfth aspect, the photoreceptor is mainly made of amorphous silicon, and at least a sub-band gap at a portion exposed in the exposing step. The characteristic energy of the exponential function tail obtained from the light absorption spectrum is 50
７０70 meV.

The invention according to claim 14 is the invention according to claims 1 to 1
3. The image forming method according to claim 3, wherein the exposure in the exposure step is a background exposure for exposing a non-image portion.

According to a fifteenth aspect of the present invention, there is provided a photoreceptor having a toner image formed on a surface thereof, and a transfer residual toner remaining on the photoreceptor surface after transferring the toner image on the photoreceptor surface to another member. The cleaning unit has a cleaning member that is in contact with the surface of the photoreceptor and removes transfer residual toner on the surface of the photoreceptor. When the standard deviation coefficient of dynamic friction representing the load dependency of the variation of the dynamic friction force acting between the photosensitive member surface and the cleaning member is defined as the dynamic friction deviation coefficient, the photosensitive member surface and the cleaning member are in contact with each other. The dynamic friction deviation coefficient is within 0.1 when the temperature at the contact portion in contact is in the range of 15 to 60 ° C.

According to a sixteenth aspect of the present invention, in the image forming apparatus according to the fifteenth aspect, the temperature of the contact portion is set to 15
The dynamic friction deviation coefficient may vary within a range of 0.02 within an arbitrary range of 60 ° C to 60 ° C.

According to a seventeenth aspect of the present invention, there is provided a photoreceptor having a toner image formed on a surface thereof, and a transfer residual toner remaining on the photoreceptor surface after transferring the toner image on the photoreceptor surface to another member. The cleaning unit has a cleaning member that is in contact with the surface of the photoconductor and removes transfer residual toner on the surface of the photoconductor. The temperature at the contact portion where the cleaning member comes into contact with the cleaning member is 15 to
At any point in the range of 60 ° C., the coefficient of friction between the photosensitive member surface and the cleaning member is 1 or less, and the variation range of the friction coefficient in the arbitrary range of 15 ° C. to 60 ° C. is 0.4. Within.

According to an eighteenth aspect of the present invention, in the image forming apparatus according to the seventeenth aspect, the variation range of the friction coefficient is within 0.2.

According to a nineteenth aspect of the present invention, in the image forming apparatus according to the fifteenth or sixteenth aspect, the amount of change in the coefficient of dynamic friction deviation between before and after endurance after repeating the image forming process 150,000 times is as follows. 0.02 or less.

According to a twentieth aspect of the present invention, in the image forming apparatus according to the seventeenth or eighteenth aspect, the amount of change in the friction coefficient between before and after endurance after repeating the image forming step 150,000 times is zero. .4 or less.

The present invention according to claim 21 is based on claims 15 to
20. The image forming apparatus according to any one of the above items 20, wherein the cleaning member is a cleaning blade having elasticity, and the rebound resilience of the cleaning blade according to JIS K-7311 is 5 to 75%.
The hardness of the cleaning blade according to K-6253 is 60 to 90 degrees.

According to a twenty-second aspect of the present invention, in the image forming apparatus of the twenty-first aspect, the contact pressure at which the cleaning blade contacts the photosensitive member surface is 49 to 490 m.
N / cm (5 to 50 gf / cm).

According to a twenty-third aspect of the present invention, in the image forming apparatus according to the twenty-first or twenty-second aspect, a substantially constant amount of a lubricant is provided at a contact portion between the cleaning blade and the surface of the photoreceptor and in the vicinity thereof. It is characterized by comprising a lubricant supply means for supplying.

According to a twenty-fourth aspect of the present invention, in the image forming apparatus according to the twenty-third aspect, the lubricant is a toner.

According to a twenty-fifth aspect of the present invention, in the image forming apparatus according to the twenty-third aspect or the twenty-fourth aspect, the lubricant supply means is provided upstream of the cleaning blade along a moving direction of the photosensitive member surface. And being driven at a predetermined relative speed with respect to the surface of the photoreceptor.

The present invention according to claim 26 is the invention according to claims 23 to
25. The image forming apparatus according to claim 25, wherein the lubricant supply unit magnetically and / or mechanically holds or supplies the lubricant.

The present invention according to claim 27 is the invention according to claims 15 to
26. The image forming apparatus according to any one of items 26, wherein the photoconductor has a surface layer mainly composed of amorphous silicon and / or carbon.

The present invention according to claim 28 is the invention according to claims 15 to
27. The image forming apparatus according to any one of Items 27 to 27, wherein the photoconductor is mainly made of amorphous silicon, and a temperature characteristic, which is a rate of change in charging characteristics with temperature, is within ± 2 V / deg. I do.

According to a twenty-ninth aspect of the present invention, in the image forming apparatus according to the twenty-eighth aspect, the photoreceptor is mainly made of amorphous silicon, and the absorption spectrum of sub-bandgap light at least in a portion to be exposed. Wherein the characteristic energy of the exponential function tail obtained from is from 50 to 70 meV.

The present invention according to claim 30 is the invention according to claims 15 to
30. The image forming apparatus according to claim 29, wherein the exposure on the surface of the photoconductor is a background exposure for exposing a non-image portion.

According to a thirty-first aspect of the present invention, in the photoreceptor, the transfer residual toner remaining on the surface of the photoreceptor after transfer of the toner image to another member is removed by a cleaning member in contact with the surface of the photoreceptor. When the standard deviation coefficient of dynamic friction representing the load dependency of the variation in dynamic friction force acting between the photosensitive member surface and the cleaning member during the image forming process is defined as a dynamic friction deviation coefficient, the photosensitive member surface and The dynamic friction deviation coefficient is within 0.1 when the temperature at the contact portion where the cleaning member comes into contact is in the range of 15 to 60 ° C.

According to a thirty-second aspect of the present invention, in the photoreceptor according to the thirty-first aspect, the temperature of the contact portion is 15 to 60.
The variation width of the coefficient of dynamic friction deviation in an arbitrary range of ° C is within 0.02.

According to a thirty-fourth aspect of the present invention, in the photoreceptor, the transfer residual toner remaining on the photoreceptor surface after the transfer of the toner image to another member is removed by a cleaning member in contact with the photoreceptor surface. When the temperature at the contact portion where the surface of the photoreceptor contacts the cleaning member is 1
At any point in the range of 5 to 60C, the coefficient of friction between the photosensitive member surface and the cleaning member is 1 or less,
In addition, the variation range of the friction coefficient in an arbitrary range of 15 to 60 ° C. is within 0.4.

According to a thirty-fourth aspect of the present invention, in the photoreceptor according to the thirty-first aspect, the variation range of the friction coefficient is 0.2.
Within.

According to a thirty-fifth aspect of the present invention, in the photoreceptor according to the thirty-first or thirty-second aspect, the amount of change in the coefficient of dynamic friction deviation between before and after endurance after repeating the image forming process 150,000 times is zero. .02 or less.

According to a thirty-sixth aspect of the present invention, in the photoreceptor according to the thirty-third or thirty-fourth aspect, the amount of change in the friction coefficient before and after endurance after repeating the image forming process 150,000 times is 0.1. 4 or less.

According to a thirty-seventh aspect of the present invention,
36. The photoconductor according to any one of 36, wherein the photoconductor has a surface layer mainly composed of amorphous silicon and / or carbon.

The present invention according to claim 38 is characterized in that:
36. The photoconductor according to any one of 36, wherein the photoconductor is mainly composed of amorphous silicon, and a temperature characteristic, which is a rate of change in charging characteristics with temperature, is within ± 2 V / deg.

The present invention according to claim 39 relates to claims 31 to
38. The photoconductor according to any one of items 38 to 38, wherein the temperature characteristic, which is a rate of change of the charging characteristic with temperature, is within ± 2 V / deg.

According to a forty-ninth aspect of the present invention, in the photoreceptor according to the thirty-ninth aspect, an exponential function base mainly consisting of amorphous silicon and obtained from an absorption spectrum of a sub-bandgap light at least in an exposed portion. Has a characteristic energy of 50 to 70 meV.

[0057]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the general outline of the present invention will be described.

The present inventors have found that suppressing the vibration of the frictional force acting between the photosensitive member surface and the cleaning member is effective for cleaning performance and durability. However, it was found that the frictional characteristics including vibration of frictional force depended on temperature.

In addition to adjusting the characteristics of the cleaning member and improving the surface layer of the photoreceptor, it has been found that not only the friction coefficient and the dynamic friction deviation coefficient but also their temperature dependence can be controlled.

FIGS. 1A and 1B show the temperature of the friction coefficient (described later) and the dynamic friction deviation coefficient (described later) when the composition of the surface layer of the photosensitive member and / or the composition of the cleaning member are changed, respectively. An example of dependency will be described. The same symbols in these figures indicate the same combination. Note that “●”, “▲”, and “■” are “combinations of a known a-SiC surface layer photoreceptor and a certain known cleaning member”, “●”, respectively.
In contrast, only the cleaning member was replaced, and "▲, the photosensitive member having an amorphous carbon (a-C) surface layer."

As is apparent from these figures, the value of the friction characteristic itself and the rate of change also vary depending on the combination of the photosensitive member and the cleaning member depending on the temperature of the contact portion with the leaning member.

In view of the above, the present invention has a cleaning step using a cleaning member that comes into contact with a photoreceptor, and in an image forming method and an image forming apparatus for repeatedly forming an image, one or both of the contacting members are used. By using in a limited combination, the value of the friction characteristic is controlled within a predetermined range, and further, the dependence of the friction characteristic on the environment, especially on the temperature, is reduced or suppressed.

By limiting the contacting materials, contacting conditions, and the like to good ranges, focusing on the above items,
Good cleaning properties can be stably obtained regardless of the environment.

Specifically, when the temperature at the contact portion between the photosensitive member surface and the cleaning member is in the range of 15 to 60 ° C., the load dependency of the variation of the dynamic friction force acting between the photosensitive member surface and the cleaning member is determined. (Hereinafter referred to as "dynamic friction deviation coefficient" or "dynamic friction deviation coefficient") is within 0.1.

Further, in the same temperature range, the variation width of the dynamic friction deviation coefficient is within 0.02.

With the above arrangement, the variation in the frictional force of the cleaning member and the variation in the amount of variation due to the use environment, particularly the temperature, are defined, and the vibration of the cleaning member, so-called "chatter" caused thereby is prevented and stabilized. Cleanability can be obtained. In addition, by suppressing the variation in frictional force, it is possible to prevent a local load on the photoreceptor, and reduce or eliminate “uneven shaving” in which the photoreceptor is partially worn. .

Regarding the friction coefficient, the lower the dynamic friction coefficient, the wider the latitude of the contact pressure at the time of cleaning. That is, it is effective in preventing a cleaning member from being damaged, such as defective cleaning or blade turning. Also,
In recent years, from the viewpoint of energy saving, development of low melting point toner,
In addition, there is a demand for a longer life of the photosensitive member and the cleaning member, and therefore, it is important to reduce the dynamic friction coefficient.

For the reasons described above, the dynamic friction coefficient is 1.0 or less in the same temperature range, and the variation range of the friction coefficient due to temperature is within 0.4, more preferably within 0.2. I do. With this configuration, it is possible to suppress fluctuation due to the use environment and to obtain a stable and good cleaning property.

On the other hand, if the friction coefficient is too low, the load for obtaining the frictional force required for cleaning increases,
It is not practically preferable, for example, the toner may slip through due to poor contact. Therefore, the friction coefficient is preferably 0.2 or more. It is more preferably at least 0.3.

Further, the image forming process is performed for 150,000 (150K).
The variation of the coefficient of dynamic friction deviation before and after the endurance is defined within 0.02 and the variation of the friction coefficient within 0.4. With such a configuration, the load and friction required for cleaning can be kept constant, and the durability characteristics can be improved.

It is effective to use the contact pressure between the surface of the photoreceptor and the cleaning member in an area suitable for both the cleaning property and the durability. Specifically, 49-
It is preferable to set it to 490 mN / cm (5 to 50 gf / cm).

Further, in order to maintain a stable cleaning property and a contact state, it is effective to interpose a certain amount of lubricant. As a solid lubricant, for example, PTFE,
Examples thereof include resin powders such as fluorine compounds such as PFA and PVDF, spherical acrylic resins and polyethylene resins, and metal oxide powders such as silicon oxide and aluminum oxide. In particular, a fluorine atom-containing resin containing a large amount of fluorine atoms has a remarkably low surface energy, and thus has a large effect as a lubricant. Further, the toner may be used as a lubricant.

In selecting a lubricant, it is preferable to appropriately select a lubricant according to electrophotographic specifications such as toner reusability (toner reusability) and hardness of a photoreceptor, in addition to lubricity.

As a means for defining the friction characteristics, it is effective to improve the characteristics of one or both of the cleaning member and the photosensitive member.

The cleaning member has a rebound resilience of 5 to 75.
%, Characterized in that the elastic blade has a hardness of 60 to 90 degrees. The rebound resilience and hardness referred to here are each a method according to JIS K-7311 and a method according to JIS K-62.
The evaluation is performed by a method according to No. 53, but the measurement environment such as the temperature includes those outside the JIS range.

The surface of the photoreceptor is preferably made of a material having excellent releasability and durability as well as low frictional temperature dependence as well as electrical characteristics. It is also effective to use an amorphous carbon (amorphous carbon: aC) material or the like as the surface layer. The aC-based material has a hardness equal to or higher than that of a-SiC, is excellent in water repellency, and exhibits good durability and printing durability. By using such an aC surface layer for the surface layer, cleaning properties, printing durability, and environmental properties can be further improved.

It is also possible to change the composition according to the balance with other characteristics. The electric resistivity of the surface layer is 1 from the viewpoint of charge stopping ability and prevention of image blur.
× 10 ^{10 to} 5 × 10 ¹⁵ Ω · cm is preferred.

Further, it is preferable that fluctuations in the electrical characteristics of the photosensitive member due to the environment are reduced. As the environmental dependence of the electric characteristics, the temperature dependence of the charging ability (hereinafter referred to as “temperature characteristic”) is set to within ± 2 V / deg. With this configuration, the characteristics of the photoconductor relating to latent image formation and visible image formation (toner image formation) are stable irrespective of the environment.
In addition to maintaining stable cleaning conditions,
High quality images can be provided.

As a method for controlling the temperature characteristics, the energy of the exponential function of the photoreceptor (Urbuck tail: Eu)
Is also effective.

In general, the sub-gap light absorption spectrum of a-Si is roughly divided into two parts. That is, a portion where the absorption coefficient α changes exponentially, that is, linearly with respect to the photon energy hν (exponential function tail or Urbach tail: Eu), and a portion where α shows a more gradual dependence on hν. is there.

The above-mentioned linear region corresponds to light absorption due to optical transition from the tail level on the valence band side in a-Si to the conductor, and the exponential dependence of the absorption coefficient α in the linear region on hν. The sex is represented by the following equation.

Α = α₀exp (hν / Eu) If the logarithm of both sides is taken, lnα = (1 / Eu) · hν + α1, where α1 = lnα₀  And the reciprocal (1 / Eu) of the characteristic energy Eu is
It represents the slope of the line. Eu is the valence band side
Energies of the exponential energy distribution of the Gaussian level
Therefore, if Eu is small, the tail on the valence band side
It means that there are few levels.

In the present invention, specifically, Eu is set to 50
By setting the temperature to 70 meV, more preferably 50 to 65 meV, the temperature characteristic can be within ± 2 V / deg, more preferably ± 1.5 V / deg.

The reason why the lower limit of Eu is set to 50 meV is that it is difficult to form a practical film because the film forming rate is reduced in the production of a photoreceptor having Eu smaller than 50 meV.

Further, by adopting background exposure (BAE) as an exposure method and regular development in a developing method, the latitude of cleaning is further widened.

For example, in the case of a configuration in which a light beam is scanned by a rotating polygon mirror (polygon mirror), the angle of the light beam incident on the surface of the photoreceptor is different in principle. Although the distribution (angle-of-view characteristics) is produced, the use of a coherent surface layer changes the amount of incident light due to interference, so that the angle-of-view characteristics can be controlled by the film quality. Have.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Embodiment 1> FIG. 2 shows an example of an image forming apparatus according to the present invention. FIG. 1 is a longitudinal sectional view showing a schematic configuration of an electrophotographic laser printer. First, an outline of the entire image forming apparatus and an image forming process will be described with reference to FIG.

[Image Forming Process] The image forming apparatus shown in FIG. 2 includes a drum type photosensitive member (photosensitive drum). Around the photosensitive member 1, a main charger (primary charger) 2,
An exposing device 3, a developing device 4, a recording material feeding system 8, a transfer / separation charger 5, a transport system 9, a cleaning device 6, a main static elimination light source 7, and the like are provided. The temperature of the photoreceptor 1 may be adjusted by a heating means such as an inner surface heater (not shown) (hereinafter, appropriately referred to as a “drum heater”) as necessary.

The photoreceptor 1 is driven to rotate in the direction of arrow R1, and the surface is uniformly charged by the main charger 2 (charging step). The photoreceptor surface after the charging is irradiated with light according to the image information by the exposure device 3 to form an electrostatic latent image (exposure step). The electrostatic latent image is developed as a toner image with toner attached by the developing device 4 (developing step).

On the other hand, a recording material (other member) P passes through a recording material supply system 8 having a recording material passage 8a, a registration roller 8b, and the like, to a transfer portion T between the photosensitive member 1 and the transfer charger 5a. Supplied. The supplied recording material P is applied with an electric field having a polarity opposite to that of the toner from the back surface by the transfer charger 5a in the transfer section T, whereby the toner image on the photoreceptor surface is transferred (transfer step). The recording material P after the transfer of the toner image is separated from the photoreceptor surface by the separation charger 5b. The separated recording material P is conveyed to a fixing device (not shown) through a recording material conveyance system 9, where the toner image is fixed on the surface thereof, and then discharged outside the image forming apparatus main body.

Incidentally, the so-called untransferred toner remaining on the photosensitive member surface without being transferred onto the recording material P in the transfer portion T is
The cleaning device 6 reaches the cleaning blade 6a.
Are removed as foreign matter together with rosin, talc, paper dust (hereinafter, appropriately referred to as “paper dust, etc.”) by a cleaning member (cleaning step). The photoreceptor 1 from which foreign matters such as transfer residual toner and paper dust (hereinafter, appropriately referred to as “transfer residual toner and the like”) are further removed by the main discharge light source 7 and used for the next image forming process.

Next, the cleaning device 6 will be described.

[Cleaning Apparatus] As described above, in a known image forming apparatus in which a transfer step of transferring a transferable toner image formed on the surface of a photoreceptor to a recording material P such as paper is repeated, It is necessary to remove transfer residual toner and the like remaining on the surface. As a cleaning member used for this purpose, a cleaning blade made of a resin such as rubber, a cleaning brush made of a resin fiber or the like has been practically used. In addition, there is a method of adsorbing and removing magnetic powder such as toner remaining on the surface of the photoreceptor by magnetism.

The cleaning device 6 shown in FIG. 2 includes a cleaning blade 6a, a waste toner reservoir 6b, a waste toner transport system 6c, a leakage prevention sheet 6d, and the like.

The cleaning blade 6a is generally formed in a plate shape using an elastic material such as polyurethane rubber. The cleaning blade 6a has elasticity,
Properties such as hardness are appropriately adjusted. Further, it is used in a state where the contact pressure and the contact angle with the photoreceptor 1 are adjusted according to the system to be used. The transfer residual toner scraped off from the photoreceptor surface by the cleaning blade 6a is collected in the waste toner reservoir 6b while being prevented from falling to the lower conveying system 9 or the like by the leak prevention sheet 6d.
The collected transfer residual toner and the like are collected in a waste toner collecting container (not shown) by the waste toner conveying system 6c or are reused through a toner reuse mechanism (not shown).

As the cleaning member, in addition to the above-described cleaning blade 6a, a brush-like member (cleaning brush) having a bristle brush made of natural fiber or synthetic fiber on the surface, or an elastic material such as silicone rubber or sponge is used. (Cleaning block) made of These cleaning brushes and cleaning blocks are brought into contact with the surface of the photoconductor and rubbed, thereby scraping off transfer residual toner and the like on the surface of the photoconductor. Further, there is a type in which a transfer residual toner is electromagnetically attracted and cleaned by using a magnet or a roller-shaped member (cleaning roller) to which a bias having a polarity opposite to that of the toner is applied. The cleaning roller is coated with the collected transfer residual toner or the like, and the coated layer is brought into contact with the photoreceptor 1 and rubs against the photoreceptor surface at a predetermined relative speed. There is also.

FIGS. 3 (a), 3 (b), 3 (c) and 3 (d)
It is an operation explanatory view schematically showing each operation in the repetition of the cleaning process. Hereinafter, the outline of the cleaning process will be sequentially described with reference to FIG. In these figures, reference numeral 1 denotes a photosensitive member, 6a denotes a cleaning blade, 6e denotes a cleaning roller, and 6f denotes a doctor roller (a doctor blade may be used instead of the doctor blade).

Step 1: Corresponding to FIG.

The surface of the photosensitive member 1 with which the cleaning blade 6a of the cleaning device 6 is in contact rotates at a predetermined speed. In FIGS. 3A to 3D, the surface of the photoconductor 1 is illustrated as a plane, and moves from left to right.

A toner image is formed on the surface of the photoreceptor by the charging process by the main charger 2, the exposing process by the exposing device 3, and the developing process by the developing device 4 shown in FIG.
The toner image is transferred to the surface of the recording material P at the transfer portion T. At this time, the transfer residual toner and the like remaining on the surface of the photoreceptor without being transferred to the recording material P are generated by electrostatic force (Coulomb force) or molecular force. The cleaning device 6 approaches the cleaning device 6 while being adhered to the surface of the photoreceptor due to an intermediate force, a frictional force, or another adhesion force.

Here, the photoreceptor 1 may be maintained at a predetermined temperature by, for example, a drum heater if necessary. Further, the cleaning roller 6e and the doctor roller 6f may not be attached.

It is preferable that the cleaning blade 6a is used in a state where powder is applied at a contact portion with the photoreceptor surface so as to have lubricity with the photoreceptor 1. Toner may be used as a lubricant. In this figure, a part of the waste toner (transfer residual toner) already collected from the cleaning roller 6e via the toner pool 6b (see FIG. 2) or the toner applied to the cleaning roller 6e by an appropriate method. Are supplied as appropriate.

Step 2: corresponds to FIG.

In the system having the cleaning roller 6e,
The above-mentioned transfer residual toner and the like are rubbed by the cleaning roller 6e, scraped off, or collected by suction. The transfer residual toner and the like are taken into the cleaning roller 6e.

Step 3: Corresponding to FIG.

The transfer residual toner and the like taken into the cleaning roller 6e are partially collected by the doctor roller 6f. The collected transfer residual toner and the like are sent to a toner pool 6b (see FIG. 2) in the cleaning device 6. The transfer residual toner and the like thus collected are further collected or sorted into a waste toner collecting container (not shown) via the waste toner transport system 6c and the like, and a part of the transfer residual toner is removed by a toner reuse mechanism. (Not shown) in some cases.

Step 4: Corresponding to FIG.

The transfer residual toner not collected by the cleaning roller 6e or the transfer residual toner of a system not having the cleaning roller 6e approaches the cleaning blade 6a in a state of being attached to the surface of the photosensitive member.

The transfer residual toner and the like are scraped off and collected by the cleaning blade 6a of the cleaning device 6 as follows, for example.

The cleaning blade 6a is in contact with the surface of the photoreceptor, and its tip is bent in the direction from m to n by the elasticity of the cleaning blade 6a due to the frictional force with the surface of the photoreceptor. The bending further proceeds, and the contact area with the photoconductor surface and the frictional force increase. When the cleaning blade 6a reaches the limit point, the cleaning blade 6a is restored from n to m by its rebound resilience (restoring force), and at the same time, the transfer residual toner and the like on the photoreceptor surface are scraped off. The transfer residual toner and the like scraped off in this manner are collected by the cleaning blade 6a or the cleaning roller 6e. The transfer residual toner and the like after collection are conveyed and discharged from a waste toner reservoir 6b (see FIG. 2) to a waste toner collection container (not shown) via a waste toner conveyance system (for example, a screw) 6c. Alternatively, the toner may be reused by a toner reuse mechanism (not shown) as described later.

The waste toner collecting container may be installed inside the main body of the image forming apparatus. In an image forming apparatus using a process cartridge detachable from the main body of the image forming apparatus, the waste toner collecting container is integrated with the process cartridge. In some cases. After the transfer of the toner image, the charge remaining on the surface of the photoconductor 1 is removed by the main charge removing light source 7 (see FIG. 2).

In place of the above-described cleaning roller 6e, a brush-like cleaning brush may be rubbed against the surface of the photoreceptor to remove the transfer residual toner and the like. Also, use a cleaning roller made of a magnetic material, a cleaning roller in which a bias is applied to a polarity opposite to that of the toner, or a cleaning roller itself configured to have a characteristic opposite to that of the toner. There has already been proposed a method of removing the transfer residual toner and the like by indirectly rubbing the surface of the photoreceptor with the collected toner or the like brought into contact with or suctioned from the surface. These members (a cleaning blade, a cleaning brush, a cleaning roller, and the like) are disposed in the cleaning device 6 and are used alone or in appropriate combination to remove transfer residual toner and the like from the photoreceptor surface. ing.

[Reuse of Toner] It is also important to reduce transfer residual toner in order to reduce or eliminate waste.

For this reason, it is necessary to improve the efficiency when the toner image (visible image) formed on the surface of the photoreceptor is transferred onto the recording material P, that is, the so-called transfer efficiency. Use (reuse) is also an important technology.

As described above, the transfer residual toner and the like are removed from the photoreceptor 1 by the cleaning device 6 shown in FIG. 2 and collected, and then transported to the developing device 4 by the toner reuse mechanism (not shown) for reuse ( May be reused).

The toner is used to maintain good image quality.
The particle size and characteristics are strictly regulated, and the intrusion of foreign matter into the toner must be avoided as much as possible. The same applies to transfer residual toner (recovered toner) to be reused. Paper dust other than transfer residual toner is separately removed from foreign substances (transfer residual toner, etc.) composed of transfer residual toner and paper dust as necessary. You.

Although various methods have been proposed for toner reuse, basically, paper dust and the like are removed from the collected transfer residual toner and the like, and only the transfer residual toner is efficiently selected. This is very important.

[Normal Development and Reversal Development] The electrophotographic image forming method is broadly classified into regular development and reversal development in relation to latent image formation and a development area. The former normal development forms a visible image by attaching a toner having the opposite polarity to the charge on the surface of the photoreceptor to a portion other than the portion from which the charge has been removed by exposure. This is to form a visible image by adhering a toner having the same polarity as the charge on the surface to a portion from which the charge has been removed by exposure.

[Image Exposure and Background Exposure] Electrophotographic image forming methods are roughly classified into image exposure (IAE) and background exposure (BAE) according to the relationship between image information and an exposure unit. You. The former image exposure is for exposing (irradiating) an image portion, and the latter is for exposing (irradiating) a non-image portion (background portion).

Although both the above-described image exposure and background exposure have been put to practical use, they are often determined by the limitations of the photoreceptor and developer used.

In terms of structure, a combination of normal development and background exposure, and a combination of reversal development and image exposure are generally put to practical use.

In image recording by light beam scanning which is frequently used in digital electrophotography, background exposure generally has a smaller latitude (degree of freedom) than image exposure, as described below. Image exposure is employed.

In the image recording technique using the light beam scanning, the size, shape, power, etc. of the spot of the light beam greatly affect the image quality and stability.

FIG. 4A shows the state of one line of image exposure on the left side of the vertical axis Y, ie, the latent image state of the light beam ON only on one line, and the state of one background exposure on the right side. line state, i.e., shows the latent image state of the light beam OFF only one line, the latitude of the image exposure is V _D -V _i, latitude background exposure V
_b is -V _2.

This latent image can be derived from the light distribution of the exposure means and the EV characteristics of the photosensitive member as shown in FIG.

As can be seen from FIG. 4A, in the background exposure, when the spot diameter of the light beam is too small or the light beam power is too small with respect to the scanning line interval, the light beam is irradiated to the light beam irradiation part. a gap potential, since latitude is small becomes higher V _2, there is a lower limit for the spot diameter or power of the light beam with respect to the scanning line interval.
As described above, it is known that the latitude of the background exposure is narrower than that of the image exposure when forming a latent image by irradiating a light beam.

On the other hand, the transfer / separation performance is greatly influenced by the transfer efficiency and the latitude of separation / retransfer. However, in image exposure, the potential of the non-image area (background area) is higher than that of the image area. -Regarding separation performance, latitude is wider in background exposure than in image exposure.

Further, since the potential of the photosensitive member when entering the cleaning device is attenuated, in the image exposure of a system in which development is performed on a portion having a low potential, a large amount of developer tends to adhere to the photosensitive member in the cleaning portion. Regarding cleaning, the latitude of background exposure is wider than that of image exposure.

As described above, the background exposure is easier to design and, as a result, has the potential to supply a stable electrophotographic apparatus having a wide latitude.

[Photoconductor] (OPC, a-Si) Electrophotographic photoconductors are roughly classified into two types: organic and inorganic.

<Organic Photoconductor (OPC)> In recent years, various organic photoconductive materials have been developed as photoconductive materials for electrophotographic photoreceptors, and in particular, a function-separated type in which a charge generation layer and a charge transport layer are laminated. Has already been put to practical use and mounted on copiers and laser beam printers.

However, one of the major drawbacks of these photosensitive members is that their durability is generally low. The durability is roughly classified into durability of physical properties of electrophotography such as sensitivity, residual potential, charging ability, image blur, and mechanical durability such as abrasion and scratching of the photoreceptor surface due to rubbing. . Both the durability of these physical properties and the mechanical durability are major factors that determine the life of the photoconductor.

Among them, the durability of the physical properties of electrophotography, particularly image blur, is caused by the active substances such as ozone and NOx generated from the corona charger used in the main charger and the transfer / separation charger. It is known that the cause is that the charge transporting substance contained in the body surface layer is deteriorated.

On the other hand, the mechanical durability is caused by the fact that the recording material, cleaning member (cleaning blade, cleaning roller, etc.), toner and the like physically contact the photosensitive layer and rub against it. It has been known.

In order to improve the durability of the physical properties of electrophotography, it is important to use a charge transporting substance which is hardly deteriorated by an active substance such as ozone or NOx. It is known to be good.

On the other hand, in order to increase mechanical durability,
To withstand rubbing caused by recording materials and cleaning members,
It is important to increase the lubricity of the surface to reduce friction, and to improve the releasability of the surface to prevent toner filming and fusing. It is known that a lubricant such as graphite graphite and polyolefin resin powder is blended in a surface layer of a photoreceptor. However, when the abrasion is significantly reduced, a hygroscopic substance generated by an active substance such as ozone or NOx accumulates on the surface of the photoreceptor, and as a result, the surface resistance decreases, and the surface charge moves in the lateral direction to blur the image ( (Image deletion).

In addition, the potential characteristics such as sensitivity and charging ability need to be worn due to durability for the above-mentioned reasons. Therefore, there is a change in durability, and light scattering or the like caused by a change in surface shape due to wear causes There is a problem that image quality is deteriorated.

<Inorganic Photoconductor: Amorphous Silicon-Based Photoconductor (a-Si)> In an electrophotographic image forming apparatus, the photoconductive material for forming the photosensitive layer in the photoconductor has high sensitivity and SN ratio [ Photocurrent (Ip) / dark current (I
d)] is high, has an absorption spectrum suitable for the spectral characteristics of the electromagnetic wave to be irradiated, has a fast light response, has a desired dark resistance value, is harmless to the human body during use, and the like. Characteristics are required. In particular, in the case of a photoconductor for an image forming apparatus incorporated in an image forming apparatus used in an office as an office machine, the above-described non-pollution during use is an important point. Hydrogenated amorphous silicon (hereinafter referred to as "a-Si: H") is a photoconductive material exhibiting such excellent properties. For example, JP-B-60-35059 discloses a photosensitive material for an image forming apparatus. Application as a body is described.

FIGS. 5 (a), 5 (b), 5 (c) and 5 (d)
3 is a schematic view for explaining different layer configurations of a photoconductor for an image forming apparatus according to the present invention. These drawings show a part of a cross section of the photoconductor 50 cut by a plane including the axis thereof.

In the photosensitive member 50 for an image forming apparatus shown in FIG. 5A, a photosensitive layer 52 is provided on a support (drum base) 51 for the photosensitive member. This photosensitive layer 52
Is composed of a photoconductive layer 53 made of a-Si: H, X (amorphous silicon containing hydrogen atoms (H) and / or halogen atoms (X)) and having photoconductivity.

The photoreceptor 50 for an image forming apparatus shown in FIG. 5B has a photosensitive layer 5 on a support 51 for the photoreceptor.
2 are provided. This photosensitive layer 52 is made of a-Si:
It comprises a photoconductive layer 53 made of H and X and having photoconductivity, and an amorphous silicon-based surface layer 54. The surface of the surface layer 54 is a free surface 58.

The photoreceptor 50 for an image forming apparatus shown in FIG. 5C has a photosensitive layer 5 on a support 51 for the photoreceptor.
2 are provided. This photosensitive layer 52 is made of a-Si:
It is composed of a photoconductive layer 53 made of H and X and having photoconductivity, an amorphous silicon based surface layer 54, and an amorphous silicon based charge injection blocking layer 55. The surface of the surface layer 54 is a free surface 58.

The photoreceptor 50 for an image forming apparatus shown in FIG. 5D has a photosensitive layer 5 on a support 51 for the photoreceptor.
2 are provided. This photosensitive layer 52 comprises a photoconductive layer 53
And a charge generation layer 56 and a charge transport layer 57 made of a-Si: H, X, and an amorphous silicon-based surface layer 54. The surface of the surface layer 54 is a free surface 58.

A photoreceptor for an image forming apparatus using a-Si: H generally has a conductive support at 50 ° C. to 400 ° C.
° C, and vacuum deposition, sputtering, ion plating, thermal CVD, photo-CVD on this support
Method, plasma CVD method (hereinafter referred to as "PCVD method")
A photoconductive layer made of a-Si is formed by a film forming method such as the above. Among them, the PCVD method, that is, a method in which a raw material gas is decomposed by direct current, high frequency, or microwave glow discharge to form an a-Si deposited film on a support has been put to practical use.

Further, in Japanese Patent Application Laid-Open No. 54-83746, an a-Si (hereinafter referred to as “a-Si: X”) photoconductive material containing a conductive support and a halogen atom (X) as a constituent element. A photoreceptor for an image forming apparatus composed of layers has been proposed. In this publication, a-Si contains 1 to 40 atomic% of halogen atoms to obtain high heat resistance and obtain good electrical and optical characteristics as a photoconductive layer of a photoreceptor for an image forming apparatus. It can be done.

Japanese Patent Application Laid-Open No. 57-11556 discloses that a photoconductive member having a photoconductive layer composed of an a-Si deposited film has an electrical property such as a dark resistance value, a photosensitivity, and a photoresponsive property. In order to improve the use environment characteristics such as optical, photoconductive, and moisture resistance, and the stability over time, silicon atoms and silicon atoms are formed on a photoconductive layer composed of an amorphous material based on silicon atoms. A technique of providing a surface layer made of a non-photoconductive amorphous material containing carbon atoms is described.

Furthermore, Japanese Patent Application Laid-Open No. Sho 60-67951 describes a technique for a photoreceptor in which a light-transmitting insulating overcoat layer containing amorphous silicon, carbon, oxygen and fluorine is laminated. 62-1681
No. 61 describes a technique of using, as a surface layer, an amorphous material containing silicon atoms, carbon atoms, and 41 to 70 atomic% of hydrogen atoms as constituent elements.

[0149] Then, the JP-A-57-158650, hydrogen containing 10 to 40 atomic%, the absorption coefficient ratio of the absorption peak of 2100 cm ^-1 and 2000 cm ^-1 in the infrared absorption spectrum 0.2 It is described that a photosensitive member for an image forming apparatus having high sensitivity and high resistance can be obtained by using a-Si: H of 1.7 to 1.7 for the photoconductive layer.

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, the temperature near the surface of the photoreceptor is maintained at 30 ° C. to 40 ° C. to charge, expose, develop, A technique is disclosed in which an image forming process such as transfer and transfer is performed to prevent a reduction in surface resistance due to the adsorption of moisture on the surface of a photoreceptor and an image flow (high-humidity flow) that occurs with the reduction.

With these techniques, the electrical, optical and photoconductive properties of the photoreceptor for an image forming apparatus and the use environment properties have been improved, and the image quality has been improved accordingly.

Further, since it is not essential to wear due to durability, there is little change in the durability of the photoconductor, that is, the EV characteristic, and there is no problem associated with wear such as OPC.

[Support] The support 51 used in the present invention may be either conductive or electrically insulating. Examples of the conductive support 51 include well-known metals such as Al and Fe, and alloys thereof, for example, stainless steel. Further, a support 51 in which at least the surface on the side on which the photosensitive layer is formed of an electrically insulating support 51 made of a synthetic resin film or sheet, glass, ceramic or the like is subjected to conductive treatment.
Can also be used.

The shape of the support 51 used in the present invention may be a cylindrical or endless belt having a smooth surface or an uneven surface.

In particular, when performing image recording (latent image formation) using coherent light such as laser light, a visible image (toner image)
In order to more effectively eliminate an image defect due to a so-called interference fringe pattern appearing in the above, unevenness may be provided on the surface of the support body 51 in a range where the charge carrier is not substantially reduced. The irregularities provided on the surface of the support 51 are described in
JP-168156, JP-A-60-178457,
It can be formed by a known method described in JP-A-60-225854 and the like.

As another method for more effectively eliminating image defects due to interference fringe patterns when coherent light such as laser light is used, the support 51 is supported within a range where the charge carriers are not substantially reduced. The surface may be provided with an uneven shape by a plurality of spherical trace depressions. That is, it is assumed that the surface of the support 51 has irregularities smaller than the resolving power required for the photoconductor 50 for an image forming apparatus, and the irregularities are caused by a plurality of spherical trace depressions. The unevenness due to the plurality of spherical trace depressions provided on the surface of the support 51 is disclosed in
It can be formed by a known method described in JP-A-31561.

Further, as another method for more effectively eliminating image defects due to interference fringe patterns when coherent light such as laser light is used, the photosensitive layer 52 or the photosensitive layer 52 may be used.
An interference prevention layer or region, such as a light absorption layer, may be provided underneath.

[Photoconductive Layer] In the present invention, in order to effectively achieve the object, a part of the photosensitive layer 52 is formed on the support 51 and, if necessary, on the undercoat layer (not shown). The photoconductive layer 53 can be formed by appropriately setting the numerical conditions of the film forming parameters so as to obtain desired characteristics by a vacuum deposited film forming method. Specifically, for example, a glow discharge method (low-frequency CVD method, high-frequency C
AC discharge CV such as VD method or microwave CVD method
D method or DC discharge CVD method), sputtering method,
It can be formed by various thin film deposition methods such as a vacuum evaporation method, an ion plating method, a photo CVD method, and a thermal CVD method. These thin film deposition methods are appropriately selected and adopted depending on factors such as the manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for a photoconductor for an image forming apparatus to be manufactured. The glow discharge method is preferable because the conditions for manufacturing the photoconductor 50 for an image forming apparatus having the above characteristics can be relatively easily controlled.

In order to form the photoconductive layer 53 by the glow discharge method, a source gas for supplying Si that can supply silicon atoms (Si) and a gas for supplying H that can supply hydrogen atoms (H) are basically used. And / or / or 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, and glowing into the reaction vessel. A discharge is generated, and a-Si:
What is necessary is just to form the layer which consists of H and X.

In the present invention, it is necessary for the photoconductive layer 53 to contain hydrogen atoms and / or halogen atoms, which compensates for dangling bonds of silicon atoms and improves the layer quality, especially This is because it is indispensable to improve photoconductivity and charge retention characteristics. Therefore, the content of the hydrogen atom or the halogen atom, or the sum of the hydrogen atom and the halogen atom is 10 to 30 atom%, more preferably 15 to 25 atom%, based on the sum of the silicon atom and the hydrogen atom and / or the halogen atom. % Is desirable.

Gas for supplying Si used in the present invention
Substances that can be in the gaseous state or gasified
Silicon hydrides (silanes) shall be used effectively
In addition, ease of handling during layer production, Si supply
In terms of efficiency, etc., SiH ₄, Si₂H₆Is preferred
Are listed.

Then, hydrogen atoms are structurally introduced into the formed photoconductive layer 53 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. Further, each gas may be mixed not only with a single species but also with a plurality of species at a predetermined mixture ratio.

The source gas for supplying a halogen atom 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.

In order to control the amount of hydrogen atoms and / or halogen atoms contained in the photoconductive layer 53, for example, the temperature of the support 51, a raw material used to contain 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 53 contain atoms for controlling conductivity as necessary. The atoms that control the conductivity may be contained in the photoconductive layer 53 in a state of being distributed uniformly and evenly, or there may be a portion that is contained in the layer thickness direction in a non-uniform distribution state. You may.

The above-mentioned atoms for controlling conductivity include so-called impurities in the field of semiconductors. As is well known, the periodic table 13 which gives p-type conductivity is known.
An atom belonging to Group (IIIB) (Group 13 atom) or an atom belonging to Group 15 (Vb) of the periodic table that provides n-type conduction characteristics (Group 15 atom) can be used.

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, it is also effective that the photoconductive layer 53 contains carbon atoms and / or oxygen atoms and / or nitrogen atoms. The carbon atoms and / or oxygen atoms and / or nitrogen atoms may be evenly and uniformly contained in the photoconductive layer, or may have a uniform distribution such that the content changes in the thickness direction of the photoconductive layer. There may be a raised part.

In the present invention, the thickness of the photoconductive layer 53 is
It is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics, economic effects, and the like.
50 μm, more preferably 23-45 μm, optimally 2
Desirably, the thickness is 5 to 40 μm.

In order to achieve the object of the present invention and to form the photoconductive layer 53 having desired film characteristics, the mixing ratio of the gas for supplying Si and the diluent gas, the gas pressure in the reaction vessel, the discharge power, In addition, it is necessary to appropriately set the temperature of the support.

The above conditions are not usually determined separately and independently, but are determined based on mutual and organic relevance in order to form a photoreceptor 50 having desired characteristics. It is desirable.

[Surface Layer] In the present invention, on the photoconductive layer 53 formed on the support 51 as described above,
Further, it is preferable to form the surface layer 54. The surface layer 54 has a free surface 58, and is provided to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electric pressure resistance, use environment characteristics, and durability.

The surface layer 54 is made of amorphous silicon (a
-Si) based material or amorphous silicon containing, for example, a hydrogen atom (H) and / or a halogen atom (X) and further containing a carbon atom (hereinafter referred to as "a-SiC: H,
X ". ), Amorphous silicon containing a hydrogen atom (H) and / or a halogen atom (X), and further containing an oxygen atom (hereinafter referred to as “a-SiO: H, X”), a hydrogen atom (H) and / or Halogen atom (X)
, And further contains a nitrogen atom, amorphous silicon (hereinafter referred to as “a-SiN: H, X”), a hydrogen atom (H) and / or a halogen atom (X), and further contains a carbon atom and an oxygen atom. , Amorphous silicon containing at least one nitrogen atom (hereinafter referred to as “a-SiCON:
H, X ". ) Are suitably used.

In the present invention, in order to achieve the object effectively, the surface layer 54 is appropriately set with a numerical condition of film forming parameters by a vacuum deposited film forming method so as to obtain desired characteristics. It is made. Specifically, for example, a glow discharge method (low-frequency CVD method, high-frequency CVD method,
Or an AC discharge CVD method such as a microwave CVD method, or a DC discharge CVD method), a sputtering method, a vacuum deposition method, an ion plating method, an optical CVD method, a thermal CVD method, or any other thin film deposition method. Can be. These thin film deposition methods are appropriately selected and adopted depending on factors such as manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for the photoconductor 50 for an image forming apparatus to be manufactured. From the viewpoint of the productivity of the photoconductor 50, it is preferable to use the same deposition method as that for the photoconductive layer 53.

For example, a-Si is formed by a glow discharge method.
In order to form the surface layer 54 composed of C: H, X, a source gas for supplying Si that can supply silicon atoms (Si) and a C for supplying C that can supply carbon atoms (C) are basically used. A source gas and a source gas for supplying H that can supply hydrogen atoms (H) and / or a source gas for supplying X that can supply halogen atoms (X) are placed in a reaction vessel that can reduce the pressure inside the reaction vessel. Introduced in a gaseous state, a glow discharge is generated in the reaction vessel, and the photoconductive layer 5 previously set at a predetermined position is formed.
A layer made of a-SiC: H, X may be formed on the support 51 on which the substrate 3 is formed.

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

In the present invention, it is necessary that hydrogen atoms and / or halogen atoms be contained in the surface layer 54, 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. In general, the hydrogen content is desirably 30 to 70 atomic%, preferably 35 to 65 atomic%, and most preferably 40 to 60 atomic%, based on the total amount of the constituent atoms. The content of fluorine atoms is usually 0.01 to 15 atomic%, preferably 0.1 to 10 atomic%, and most preferably 0.6 to 4 atomic%.

Defects in the surface layer (mainly dangling bonds of silicon atoms and carbon atoms) include, for example, deterioration of charging characteristics due to injection of charges from the free surface 58 to the photoconductive layer 53,
In the use environment, for example, a change in the charging characteristics due to a change in the surface structure under high humidity, and further, charges are injected into the surface layer 54 by the photoconductive layer 53 during corona charging or light irradiation, causing defects in the surface layer. It is known that the characteristics of the photoconductor 50 for an image forming apparatus are adversely affected, such as the occurrence of residual image development during repeated use due to trapped charges.

By controlling the hydrogen content in the surface layer to 30 atomic% or more, the above-mentioned defects in the surface layer are greatly reduced, and the electrical characteristics and the high-speed continuous usability can be improved. . On the other hand, if the hydrogen content in the surface layer exceeds 70 atomic%, the hardness of the surface layer 54 decreases, and the durability decreases.

The fluorine content in the surface layer is set to 0.01
By controlling the content to the range of at least atomic%, it is possible to more effectively achieve the generation of the bond between the silicon atom and the carbon atom in the surface layer. Further, as a function of the fluorine atoms in the surface layer, it is possible to effectively prevent the bond between the silicon atom and the carbon atom from being broken due to damage such as corona.
On the other hand, when the fluorine content in the surface layer exceeds 15 atomic%, the effect of generating the bond between the silicon atom and the carbon atom in the surface layer and the effect of preventing the breaking of the bond between the silicon atom and the carbon atom are hardly recognized. . Furthermore, since excess fluorine atoms hinder the mobility of carriers in the surface layer, residual potential and image memory are noticeably observed.

The fluorine content and hydrogen content in the surface layer are as follows:
It can be controlled by the flow rate of H ₂ gas, support temperature, discharge power, gas pressure, and the like.

The thickness of the surface layer 54 in the present invention is usually 0.01 to 3 μm, preferably 0.05 to 2 μm.
m, and most preferably 0.1 to 1 μm. If the thickness is less than 0.01 μm, the surface layer 54 is lost due to abrasion or the like during use of the photoreceptor 50, and if it exceeds 3 μm, a decrease in electrophotographic characteristics such as an increase in residual potential is observed. .

The surface layer 54 according to the present invention is carefully formed so that its required properties are provided as desired. That is, Si, C and / or N and / or O, H
And / or a substance having X as a constituent element structurally takes a form from crystalline to amorphous depending on its forming conditions, and has electrical properties from conductive to semiconductive and insulating properties, and Since the properties between photoconductive properties and non-photoconductive properties are respectively shown, in the present invention, the formation conditions are selected as desired so that a compound having desired properties according to the purpose is formed. Strictly done.

For example, in order to provide the surface layer 54 mainly for the purpose of improving the pressure resistance, the surface layer 54 is made of a non-single-crystal material having a remarkable electric insulating behavior in a use environment.

When the main purpose is to improve the characteristics of continuous repetitive use and the characteristics of use environment, the above-described degree of electrical insulation is relaxed to some extent, and non-single-crystals having a certain sensitivity to irradiated light are used. Formed as a material.

Further, in order to prevent the image flow due to the low resistance of the surface layer 54 or the effect of the residual potential, etc.
On the other hand, in order to improve the charging efficiency, it is preferable to appropriately control the resistance value when preparing the layer.

Further, in the present invention, a blocking layer (lower surface layer) having a lower content of carbon atoms, oxygen atoms and nitrogen atoms than the surface layer 54 is provided between the photoconductive layer 53 and the surface layer 54. This is also effective for further improving characteristics such as charging ability.

Further, a region where the content of carbon atoms and / or oxygen atoms and / or nitrogen atoms changes so as to decrease toward the photoconductive layer 53 may be provided between the surface layer 54 and the photoconductive layer 53. Good. As a result, the surface layer 54 and the photoconductive layer 53
Can be improved, and the influence of interference due to light reflection at the interface can be further reduced.

[Charge Injection Blocking Layer] In the photoreceptor 50 for an image forming apparatus of the present invention, a charge is injected between the conductive support 51 and the photoconductive layer 53 from the conductive support side. The charge injection blocking layer 55 having a blocking function (FIG. 5C)
Is more effective. That is, the charge injection blocking layer 55 has a function of preventing charge from being injected from the support side to the photoconductive layer side when the photosensitive layer 52 is subjected to a charging treatment of a fixed polarity on its free surface 58. However, such a function is not exhibited when it is subjected to charging treatment of the opposite polarity, that is, it has a so-called polarity dependency. In order to provide such a function, the charge injection blocking layer 55 contains a relatively large number of atoms for controlling conductivity as compared with the photoconductive layer 53.

The atoms for controlling the conductivity contained in the charge injection blocking layer 55 may be uniformly distributed in the charge injection blocking layer, or may be uniformly distributed in the layer thickness direction. However, there may be portions that are contained in a non-uniformly distributed state. 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 each case, the support 5
In the in-plane direction parallel to the surface of No. 1, it is necessary to be uniformly contained in a uniform distribution in order to make the characteristics in the in-plane direction uniform.

As the atoms for controlling the conductivity contained in the charge injection blocking layer 55, there can be mentioned so-called impurities in the field of semiconductors. It is possible to use an atom belonging to Group 15 of the Periodic Table that gives properties.

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.

Further, by including at least one of carbon atoms, nitrogen atoms, and oxygen atoms in the charge injection blocking layer 55, the charge injection blocking layer 55 can be interposed between other layers provided in direct contact with the charge injection blocking layer 55. The improvement in adhesion can be further enhanced.

The carbon atoms, nitrogen atoms, or oxygen atoms contained in the charge injection blocking layer 55 may be uniformly distributed in the charge injection blocking layer, or may be contained uniformly in the thickness direction. However, there may be portions that are contained in a state of being non-uniformly distributed. However, in each case, it is necessary to uniformly contain the particles in a uniform distribution in a direction parallel to the surface of the support 51 in order to make the characteristics uniform in the direction parallel to the surface.

In the present invention, the contents of carbon atoms and / or nitrogen atoms and / or oxygen atoms contained in the entire region of the charge injection blocking layer 55 are appropriately determined so that the object of the present invention is effectively achieved. Is determined.

The charge injection blocking layer 55 of the present invention
The hydrogen atoms and / or halogen atoms contained in the compound compensate for dangling bonds present in the charge injection blocking layer, and are effective in improving the film quality.

In the present invention, the thickness of the charge injection blocking layer 55 is preferably from 0.1 to 5 μm, more preferably from 0.3 to 5 μm, from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. It is desirable that the thickness be 4 μm, most preferably 0.5 to 3 μm.

In the present invention, to form the charge injection blocking layer 55, a vacuum deposition method similar to the above-described method of forming the photoconductive layer 53 is employed.

In addition, in the photoreceptor 50 for an image forming apparatus of the present invention, at least aluminum, silicon, hydrogen and / or halogen atoms are provided on the support 51 side of the photosensitive layer 52 in the layer thickness direction. It is desirable to have a layer region that contains in a non-uniform distribution.

The photosensitive member 5 for an image forming apparatus of the present invention
0, for the purpose of further improving the adhesion between the support 51 and the photoconductive layer 53 or the charge injection blocking layer 55, for example, Si ₃ N ₄ , SiO ₂ , SiO, or a silicon atom is used as a base material. Alternatively, 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, as described above, a light absorbing layer for preventing the occurrence of an interference pattern due to the reflected light from the support 51 may be provided.

[Production Apparatus] The photoconductor 50 as described above is
It is manufactured using a well-known CVD apparatus (film forming apparatus).

FIG. 6 shows a high-frequency plasma C using the RF band.
An example of an apparatus of a VD method (hereinafter, referred to as “RF-PCVD”) is described. This device is roughly composed of a deposition device 100, a source gas supply device 200, and an exhaust device (not shown) for reducing the pressure inside the reaction vessel 111. A cylindrical support 5 is provided in the reaction vessel 111 in the deposition apparatus 100.
1. Heater 113 for heating support, source gas introduction pipe 11
4 and a high-frequency matching box 115
Is connected.

The raw material gas supply device 200 is composed of SiH ₄ , H
₂ , CH ₄ , B ₂ H ₆ , PH _{3 and} other source gas cylinders 2
21 to 226, valves 231 to 236, 241 to 24
6, 251 to 256 and the mass flow controller 211
To 216, and cylinders 221 to 2 for each source gas.
Reference numeral 26 is connected to a source gas introduction pipe 114 in the reaction vessel 111 via a valve 260 and a main introduction pipe 116.
In addition, 261 to 266 in FIG.
8 is an exhaust valve, and 119 is a gas tank.

FIG. 7 shows a high-frequency plasma CVD method using a VHF band (hereinafter referred to as "VHF-PCVD").
1 shows an example of the device. This apparatus corresponds to the deposition apparatus 10 shown in FIG.
This is an example in which a manufacturing apparatus by the VHF-PCDV method is obtained by replacing 0 with a deposition apparatus 300 shown in FIG. This apparatus is roughly classified into a reaction vessel 311 capable of reducing the pressure of the vacuum-tight structure,
It comprises a source gas supply device 200 (see FIG. 6) and an exhaust device (not shown) for reducing the pressure inside the reaction vessel. A cylindrical support 50, a heater 313 for heating the support, a raw material gas introduction pipe 321, and an electrode 315 are installed in the reaction vessel 311, and a diffusion pump (not shown) is further provided on the electrode 315 through a high frequency matching box 316. It is connected. Inside the reaction vessel 311, a discharge space 330 surrounded by a plurality of cylindrical supports 50 is formed. These supports 50 include a motor 320,
The outer peripheral surface is rotated by the gears 322 and 323, and is uniformly exposed to electric discharge.

Hereinafter, the present invention will be described in more detail with reference to Experimental Examples 1 to 7, Examples 1 to 9, and Comparative Examples 1 to 7. However,
The present invention is not limited to these.

<Experimental Example 1> Friction coefficient, dynamic friction deviation coefficient, and temperature dependence thereof Friction characteristics such as dynamic friction deviation coefficient and friction coefficient in the present invention were measured by the following apparatus and method.

FIG. 8 shows an outline of the friction characteristic evaluation apparatus.

The photosensitive member 11, which is a sample, is moved at a predetermined surface velocity (peripheral velocity) in the direction of arrow R11 by a driving system (not shown).
To rotate. Around the photoreceptor 11, a holder 13, which fixes the cleaning member 12 at a predetermined contact angle α, a charger 15, an exposure system 16, and a developing unit 17 are arranged at appropriate angles. In addition, a non-contact thermometer (not shown) is arranged,
The temperature at the contact portion between the cleaning member 12 and the photoconductor 11 is monitored. Further, members such as a lubricant supply member (lubricant supply means) and a cleaning roller (both not shown) are arranged as necessary.

The holder 13 is adjusted by the balance arm 18 so as to abut against the photoconductor 11 horizontally without load. Further, the holder 13 has an upper plate 19 to which a load for contact pressure is applied. Further, a load converter 14 is installed on the holder 13 and detects a force applied in the left-right direction in FIG. Further, the load converter 14 is connected to an oscilloscope, a computer, and the like 20 via a dynamic strain amplifier (HEIDON 3K-84A manufactured by Shinto Kagaku).

Further, a load is placed on the cleaning member 12 having a predetermined length, the contact pressure is adjusted, and then the photosensitive member 11 is brought into contact. Further, a photoreceptor 11 is rotated at a predetermined speed by a driving system (not shown) for a certain period of time, and a force applied to the load converter 14 at the start of rotation and before the rotation is used as a frictional force as a frictional force. Detected by the device.

FIG. 9A shows an example of the detected frictional force. The horizontal axis represents time, and the vertical axis represents frictional force. The cleaning member 12 has a resistance, that is, a load,
The photosensitive member 11 and the cleaning member 1
2 is driven at a predetermined relative speed, immediately before the start of driving, the frictional force becomes the maximum maximum static frictional force. Then, at the time of the subsequent steady rotation (at the time of steady driving), the frictional force varies within a substantially constant range. Here, the average value in the steady rotation is called dynamic friction force.

Due to the surface roughness of the photosensitive member 11 and the cleaning member 12 such as surface adhesion and adhesion, etc.
The frictional force is not always stable to the kinetic frictional force and involves a slight fluctuation. The standard deviation (dynamic friction deviation) of the dynamic friction force was calculated as the dispersion of the friction force at the time of the steady rotation, that is, when the dynamic friction force acts.

Further, the load of the upper plate 19 attached to the holder 12 is changed as a drag, and the load dependency of the maximum static friction force, the dynamic friction force, and the dynamic friction deviation is evaluated. A blade-shaped member is used as the cleaning member 12, and the contact pressure per length of the contact portion (hereinafter referred to as "linear pressure").
FIG. 9B shows an example of the correlation among the friction coefficient, the maximum static friction force, the dynamic friction force, and the dynamic friction deviation. The slopes of the maximum static friction force, dynamic friction force, and dynamic friction deviation are calculated as the static friction coefficient,
Dynamic friction coefficient and dynamic friction deviation coefficient.

As described above, the coefficient of kinetic friction deviation means the fluctuation of the friction of the contact portion of the cleaning member 12, and the fact that the coefficient of kinetic friction deviation is small means that the cleaning member 1
This indicates that the contact portion of the cleaning member 12 with the photosensitive member 11 is smoothly rubbed without flapping or catching of the cleaning member 12.

As described above, the friction coefficient is a characteristic related to the cleaning property, the durability, and the design latitude.

The friction evaluation device shown in FIG. 7 is installed in a known environmental test box or environment test room capable of controlling the environment. After setting the environmental test chamber to a predetermined temperature and humidity, the photoreceptor 11 and the cleaning member 12 are left to stand for at least 24 hours to adjust the environment to the set environment. Is measured.

Thereafter, unless otherwise specified, the environment is based on a temperature of 23 ° C. and a relative humidity of 50%, and the temperature and humidity are changed as required. Hereinafter, this reference environment (normal temperature and normal humidity environment) is referred to as “N / N environment”.

The form of the friction evaluation device is not limited to that of this experimental example, and any device can be used as long as the above-described principle can be realized. A well-known piezo element strain gauge or the like may be used for evaluating the frictional force, or an experiment may be performed by incorporating the cleaning member 12 into a well-known image forming apparatus, for example.

<Experimental Example 2>: Eu and temperature characteristics Production of a photoconductive layer on a glass substrate (Corning 7059) and a Si wafer placed on a cylindrical sample holder using the film forming apparatus shown in FIG. Approximately 1μm under conditions
A-Si film samples were deposited. A thin film (deposited film) sample on a glass substrate is deposited with a skewer electrode of Al, and the characteristic energy of the exponential function tail (Urbak tail: Eu)
Was measured. As a method of measuring the state of the localized level in such a band gap, generally, deep level spectroscopy, isothermal capacity transient spectroscopy, photothermal deflection spectroscopy, photoacoustic spectroscopy, constant photocurrent method, etc. are used. ing. Above all, constant photocurrent method (C
instant Photocurrent Meth
od: Hereinafter referred to as “CPM”. ) Is useful as a method for easily measuring the subgap light absorption spectrum based on the localized level of a-Si: H.

This measurement was performed with the above-mentioned CPM. C
PM is a method of measuring the energy level of a thin-film sample by irradiating light with a varied wavelength so that the photocurrent of the thin-film sample is constant while changing the amount of light. In this experimental example, a spectrophotometer (SS-25G manufactured by JASCO Corporation) was used.
D) Evaluation was performed using a current application amplifier (LI-76 made by NF circuit) and a lock-in amplifier (5610B made by NF circuit).

A photoreceptor having a photoconductive layer having the same formulation as that of the sample was prepared.

On the other hand, as an image forming apparatus for evaluation, an image forming apparatus as shown in FIG.
A modified photoconductor surface potential sensor with a built-in NP6750 was separately installed at 6750 for electrical characteristic evaluation. Furthermore, the drum heater was modified, the contact pressure adjustment mechanism for the cleaning member was modified, and a non-contact thermometer was installed.

The temperature characteristics of the photosensitive member surface potential (dark potential: Vd) in a state where exposure light is not irradiated (image exposure is not performed) using an image forming apparatus as shown in FIG. The charging characteristics were measured while changing the surface temperature from 15 to 50 ° C., and the rate of change of Vd per 1 ° C. at this time was measured. Further, at this time, a change in charging ability per 1 ° C. of temperature was measured, and a result within ± 2 V / deg was determined to be acceptable. The result is shown in FIG.

From these results, Eu was 50 to 70 me.
It can be seen that when the temperature is equal to or lower than V, good characteristics with a temperature characteristic within ± 2 V / deg can be obtained. The range of 65 meV or less is more preferable.

<Experimental Example 3>: Resistance Value of Surface Layer Using the same apparatus as that used for producing the sample in Experimental Example 2, a-Si film having a thickness of about 0.5 to 1 μm was formed on an Al substrate.
C type and aC type surface layer samples were prepared. A main electrode and a guard electrode were further deposited on this sample.
The resistivity was measured by a method according to JIS-K6911.

On the other hand, the same prescription was made up to the photoconductive layer.
On the photoconductive layer, various surface layers prepared by the same prescription as the above-mentioned samples were formed, and various photoconductors were prepared.

Image exposure was performed using the same apparatus as in Experimental Example 2.
F, the chargeability was evaluated, and the remaining charge was evaluated with the image exposure in the strongest state. Also, when the image exposure is OFF,
The amount of charge in the main charger was made excessive, and electrophotographic characteristics such as withstand voltage characteristics that caused dielectric breakdown of the photoreceptor were evaluated. FIG. 11 shows the correlation with the resistivity of the surface layer.

FIG. 11 shows that the resistivity of the surface layer is 1 × 10 ^10-
It can be seen that the electrophotographic characteristics are good when the range is 5 × 10 ¹⁵ Ω · cm.

<Experimental example 4>: Characteristics of cleaning blade (rebound resilience, hardness) As a cleaning member, a blade-shaped member made of urethane rubber was used, and a plurality of members having different rebound resilience and hardness were produced.

The temperature of the contact portion of the cleaning member was detected by a non-contact thermometer disposed inside the cleaning member.

The rebound resilience is measured in accordance with JIS K-7311, and the hardness is measured in accordance with JIS which is A hardness measurement.
It evaluated by the method according to K-6253. The measurement environment was the aforementioned N / N environment.

Further, in the film forming apparatus shown in FIG. 6, a-form having the same formulation as the preferred range obtained from Experimental Examples 2 and 3 was used.
A Si-based photoconductor was manufactured. This was provided in the same image forming apparatus as in Experimental Example 2. As the toner, genuine toner for NP6750 was used. In an N / N environment, the drum heater of the photoconductor was turned off, and the image forming apparatus and the cleaning member were used to the environment.

In this environment, the potential (dark potential Vd) when no image exposure is applied and the potential when image exposure of a solid white image exposure amount is applied (hereinafter referred to as “bright potential Vl”) are adjusted. Further, the image was optimized using an NA-7 chart (Canon test chart: FY9-9060-000), and a three-color [black / halftone / white] chart (Canon test chart: FY9-9017-0) was used.
00), the presence or absence of cleaning failure was confirmed.

After the above initial adjustment, 150,000 (150
K) A continuous paper passing durability test was performed. For the durability, a TC-A1 chart (Canon test chart: FY9-9045-000) was used as a durability chart. At this time, an image of an image sample was formed for each appropriate number of sheets using the test chart used for the above-described initial adjustment. In order to prevent the initial turning of the cleaning blade, a predetermined amount of the above toner is applied to the cleaning blade when a new cleaning blade is attached.

[Cleaning Property] The cleaning property including defective cleaning and “fogging” in which a solid white portion has a density due to toner was determined as follows.

The image is inspected for black streaks that have passed through the cleaning member, and the density of the solid white portion is measured with a reflection densitometer (Reflectometer / Tokyo Denshoku Co., Ltd.).
(Model TC-6DS), and the reflection density of the recording material before image formation was Dr, the worst value of the white background reflection density of the recording material after image formation was Ds, and ΔDsΔDs−Dr was evaluated as the fog amount. .

Further, after an adhesive such as Cellotape (registered trademark) was attached to the surface of the photoreceptor after passing through the cleaning member, the value obtained by applying the adhesive to the recording material and measuring the reflection density was designated as Dt. The body was wiped with alcohol and dried, and after removing the toner and the like, a pressure-sensitive adhesive was similarly adhered, and the value obtained by measuring the reflection density was defined as Dn, and ΔDt≡Dt-Dn was determined. -Very good cleaning performance "A": ΔDs is 1.0
%, And ΔDt is less than 1.0%, and there is no black streak. ・ Good cleaning property “」 ”: ΔDs is 1.0 to 1.0.
Less than 5%, ΔDt is less than 1.0 to 1.5%, and no black stripes ・ No problem in cleaning performance in practical use “△”: ΔDs is less than 1.5 to 2.0%, and ΔDt is 1. 5-2.0%
Less than 5 and black streaks within 1.5 mm and within 5 places ・ Cleaning is somewhat problematic in practical use. “×”: Other than the above range.

[Cleaning Blade Turning] Cleaning blade turning (hereinafter referred to as “CLN turning”) was performed according to the following criteria. In addition to the actual turning of the CLN, the judgment was made including the vibration sound at the contact portion between the cleaning blade and the photoconductor, so-called “squeal”. -Good CLN roll-up "◎": No CLN roll-up and no "squeal"-CLN roll-up has no practical problem "○": CLN no roll-up
"Squealing" may occur.-There is a practical problem with CLN turning. "X": CLN turning occurs or "squealing" occurs frequently.

[Cleaning of the cleaning blade] The chipping of the cleaning blade (hereinafter referred to as "CLN chipping") was determined according to the following criteria. The end of the cleaning blade after the endurance, which was in contact with the surface of the photoreceptor, was evaluated by microscopic observation at 100 times.・ CLN chipping is very good “◎”: CLN chipping is not seen ・ CLN chipping is good “○”: CLN chipping not less than 50 μm in diameter, CLN chipping not less than 10 to 50 μm in diameter,
No CLN defect ・ CLN chipping has no practical problem “△”: CLN chip with a diameter of 50 μm or more, 5 or less, 10 to 50 μm diameter CLN chip, but no CLN defect ・ CLN chipping has a slight problem in practical use “×” ": There is a thing other than the above-mentioned range, or there is a CLN lacking which leads to a CLN defect.

[Damage to Photoreceptor] a-Si photoreceptor Also, abrasion of the surface layer of a-Si photoreceptor such as a-SiC and aC due to abrasion of the surface of the a-Si photoreceptor causes damage to the photoreceptor. The damage was determined by observing the photoreceptor surface after durability, measuring the surface layer thickness, and evaluating the image. In addition, the measurement of the surface layer thickness was calculated from the reflection peak by a reflection spectrometer (MCPD-2000 manufactured by Otsuka Electronics Co., Ltd.). FIG. 12 shows an example of the result. The refractive index of the surface layer to be measured is measured separately, and the thickness of the surface layer is calculated from the reflection peak wavelength and the refractive index in FIG.・ Excellent photoreceptor damage degree “◎”: No reduction in overall or partial surface layer thickness, no change in sensitivity due to change in surface layer thickness or unevenness in image. ": Overall surface layer thickness is 5
There is a decrease within%. However, there is no partial decrease in surface layer thickness (hereinafter referred to as "shaving unevenness"), no change due to surface layer thickness change, and no unevenness in the image.-There is no practical problem with the degree of damage to the photoconductor. Overall surface layer thickness reduction within 5%. There is also uneven shaving, but there is no change in sensitivity or unevenness in the image due to the change in surface layer thickness. ・ The degree of damage to the photoconductor is somewhat problematic in practice. 5% or more, or "uneven shaving". There is a change in sensitivity and unevenness in the image due to the change in surface layer thickness.

OPC On the other hand, the damage to the photoreceptor of the OPC was judged by the stage at which the image was affected from the image sampled during the endurance. -Very good photoreceptor damage level "◎": No unevenness in shaving, no change in sensitivity due to abrasion or unevenness on the image occurs when less than 80,000 sheets.-Good damage degree of photoreceptor "「 ":" Uneven shaving " Changes in sensitivity and unevenness in images due to wear and abrasion 50,000 to 80000
Occurs when the number of sheets is less than the number of sheets.-There is no practical problem with the degree of damage to the photoconductor.
Occurs when the number of sheets is less than 50,000 sheets. The degree of damage to the photoconductor is slightly problematic in practical use.
Occurs when less than 0 sheets.

As a result of the above evaluation, if the hardness is too low, the cleaning blade is pushed by the photosensitive member at the contact portion, and the contact state cannot be maintained stably. Further, the rubbing force of foreign matter such as transfer residual toner is reduced. On the other hand, if the hardness is too high, the photoconductor or the like to be contacted may be damaged, or conversely, the cleaning blade may be chipped or damaged. Therefore, the hardness is preferably 60 to 90 degrees.

The rebound resilience is a very important factor in the cleaning characteristics, but the higher the resilience is, the more the rubbing force is.
Good cleaning properties can be obtained. However, if it is too high, the photoreceptor surface may be damaged. On the other hand, if the rebound resilience is too low, the cleaning blade is liable to be turned over, which may result in poor cleaning.
Therefore, the rebound resilience is preferably 5 to 75%.

<Experimental Example 5>: Contact Pressure Range, Temperature Range of Contact Section The image forming apparatus uses the same apparatus as in Experimental Examples 2 to 4 described above, and furthermore, a drive motor for rotating and driving the photosensitive member. (Not shown) torque measurement can be performed. Pure toner for NP6750 was used as the toner as in Experimental Example 4, and various urethane rubber cleaning blades as in Experimental Example 4 were used as the cleaning member. In addition, the contact pressure is 0 (adjustment mechanism is open) to 490 mN / cm.
(0 to 50 gf / cm). The photoreceptor was the same as that of Experimental Example 4, and a photoreceptor having different surface friction characteristics was produced by adjusting the composition of the raw material gas, the discharge power, and the like.

For each of the above-mentioned cleaning blades and photoconductors, the image forming apparatus was placed in an environmental test room at a temperature of 10 ° C. and a low-temperature low-humidity environment of 15% humidity (hereinafter referred to as “L / L environment”), a temperature of 23 ° C. and a humidity. 50% N / N environment, temperature 3
High-temperature, high-humidity environment of 3 ° C and 85% humidity (hereinafter “H / H environment”)
) To endure paper passing.

As for the drum heater, L / L environment, N
/ N environment was set to OFF, and H / H environment was set to ON when the drum heater was turned OFF and the set temperature was changed. Further, the temperature of the contact portion of the cleaning member during the durability was observed.

The adjustment of the initial potential and the image, and the evaluation of the image before and after the durability, such as the cleaning property, are in accordance with the judgment of Experimental Example 4.

[Fusing] In the process of cleaning and collecting, the transfer residual toner is not removed from the surface of the photoreceptor, and repeatedly passes through the above-mentioned steps to be fixed to the surface of the photoreceptor, thereby forming black stripes on the image. The state in which it occurs (hereinafter "fusion")
That. The determination of ()) was performed according to the following criteria. The judgment was made by observing the image and the photoreceptor surface.・ Excellent fusion “◎”: no toner adhered to photoreceptor surface ・ Excellent fusion “○”: less than 1.5 mm and less than 3 toner adhered, no black streak ・ Practical problem of fusion None “Δ”: Sticking to the photoreceptor surface outside the above-mentioned range, and black streaks accompanying this sticking were 1.
Within 5 mm within 5 places ・ Fusing is slightly problematic in practical use. “×”: Black streaks other than those described above due to toner sticking to photoconductor surface

With respect to the contact pressure, when the contact pressure of the cleaning blade was 49 mN / cm (5 gf / cm) or less, the cleaning blade fluttered largely due to insufficient contact pressure, and cleaning failure occurred. On the other hand, 490m
Above N / cm (50 gf / cm), the cleaning blade was chipped or the tip of the cleaning blade was deformed, that is, so-called "set" occurred. In addition, the cleaning blade may be turned up. Therefore, the range of 49 to 490 mN / cm (5 to 50 gf / cm) was a suitable range.

The temperature of the contact portion of the cleaning member was approximately 10 to 70 ° C. Among these, when the temperature was in the range of 15 to 60 ° C, the cleaning property was favorably maintained.

As described above, a thermoplastic resin is generally used as the elastic material for cleaning. Therefore, at low temperatures, hardness increases and rebound resilience decreases. In the present embodiment, when the temperature is 15 ° C. or less, cleaning failure due to chipping of the cleaning blade during running or toner slippage may occur.

In some cases, the toner may adhere to the surface of the photosensitive member or the cleaning member. If the temperature is too high, the toner is melted and adheres to a photoreceptor or the like and appears on an image, that is, so-called fusion occurs, which is not preferable.

In the case where the contact pressure was set higher than the above-mentioned preferable range to increase the frictional force, and the case where the set temperature of the drum heater was changed, the temperature was further increased. If the temperature is higher than 0 ° C., the toner may adhere to the surface of the photoconductor or the cleaning member in some cases. If the temperature is too high, the latitude for toner, which is fixed to a photoreceptor or the like and appears on an image, that is, the so-called fusing or the like becomes narrow, which is not preferable.

<Experimental Example 6>: Variations in Dynamic Friction Deviation Coefficient and Friction Coefficient Before and After Endurance For each combination of cleaning blades and photoreceptors in Experimental Example 5, the dynamic friction deviation coefficient and friction coefficient of the photoreceptor and cleaning blade before and after endurance. Was measured.

As the measuring method, the method shown in Experimental Example 1 was used. The measurement environment was the same as that of the durability of Experimental Example 5, ie, L /
L environment, N / N environment, and H / H environment.

As a result of the measurement of the friction characteristics and the endurance of Experiment 5 described above, when the variation of the dynamic friction deviation coefficient before and after the endurance was within 0.02, a stable cleaning property was obtained.
Further, durability against cleaning failure such as toner slip-through was good.

The variation in friction coefficient due to durability was 0.4
In the case of the above, torque fluctuation was small, and stable cleaning property could be obtained as described above.

The torque of the motor for driving the photosensitive member also increases,
From the viewpoint of energy saving, it is preferable that fluctuations in the dynamic friction deviation coefficient and the friction coefficient are suppressed.

<Experimental Example 7>: Superiority of Background Exposure The image forming apparatus is a modification of the apparatus of Experimental Example 5, in which a document reading apparatus generally called a reader or a scanner and a laser optical system known as image exposure are used. The one mounted was used. The laser wavelength (IE wavelength) used was 655 nm. The photoconductor used was the same a-Si photoconductor as in Experimental Example 4.

The cleaning device was configured to remove the cleaning roller and the like and perform cleaning using only the cleaning blade. Further, the developing bias applied to the developing device and the bias applied to the transfer / separation charger can be adjusted, including changing the polarity. Further, an ON / OFF mechanism for exposure (hereinafter, referred to as “blank exposure”) between papers (between the rear end of the preceding recording material and the front end of the subsequent recording material) was installed.

The environment was an N / N environment, and various cleaning blades made of urethane rubber similar to those in Experimental Example 4 were used as the cleaning member. Further, the contact pressure was changed from 0 (opening of the adjustment mechanism) to 490 mN / cm (0 to 50 gf / cm).

Using genuine toner for NP6750, under normal bias and blank exposure conditions, image exposure was performed by the above-described background exposure. Under these conditions, the potential and the image were adjusted in the same manner as in Example 5, and continuous paper passing was performed.

On the other hand, in a similar device, the toner
Using a toner of the opposite polarity to the genuine toner for P6750, changing the polarity of the developing bias, the transfer / separation bias, and turning off the blank exposure, the image exposure is used as the image exposure. The image was adjusted, and continuous paper passing was performed.

As a result, with respect to a decrease in the contact pressure of the cleaning member, the background exposure suppressed the occurrence of cleaning defects such as toner slip-through and provided good cleaning performance.

Therefore, with respect to cleaning, background exposure or normal development is preferable because of a wider latitude.

The present invention will be further described by the following examples, which should not be construed as limiting the invention thereto.

<Example 1> The photoreceptor used was an a-Si type photoreceptor to which an a-SiC surface layer having a resistivity of 2 × 10 ¹⁶ Ω · cm was attached to approximately 0.8 μm. Regarding image formation, PWM of 256 gradations was used as a control method.

As the cleaning member, a urethane rubber cleaning blade was used.

The friction characteristics between the photosensitive member and the cleaning blade were measured by using the apparatus shown in Experimental Example 1 while changing the temperature of the contact portion. , The initial dynamic friction deviation coefficient is 1
It was in the range of 0.035 to 0.068 at 5 to 60 ° C.
The initial coefficient of dynamic friction is 0.40 at 15 to 60 ° C.
It was in the range of 0.68.

In evaluating the images of the photosensitive member and the cleaning blade, an analog Canon copier NP6
750 was modified to mount a laser optical system as in Experimental Example 7. The IE wavelength was 655 nm, and the latent image forming method of the optical system was image exposure.

Further, in order to prevent the heat of the fixing unit from affecting the cleaning device side, a plate for shutting off heat, an exhaust fan and the like are additionally provided. The drum heater was turned off.

Further, a so-called reuse mechanism for removing foreign matters or unnecessary substances other than toner from so-called collected toner such as transfer residual toner collected by the cleaning device and reusing the developed toner is provided.

The cleaning device employs a method of removing transfer residual toner and the like by rubbing a cleaning blade.
The contact pressure of the cleaning blade against the photosensitive member was variable.

Further, a load conversion element was set on the holder of the cleaning member so that the same evaluation as in Experimental Example 1 could be performed. The evaluation results of the friction characteristics of the modified copier were the same as those described above. Thereafter, the evaluation of the friction characteristics before or after the endurance is performed by the modified copier.

The temperature of the contact portion between the cleaning blade and the photosensitive member in use in this embodiment is 25 ° C., and the rebound resilience and hardness of the cleaning blade at this temperature are 35 ° and 73 °, respectively. . The coefficient of dynamic friction deviation is 0.054, and the coefficient of dynamic friction is 0.58.

In this example, the contact pressure during image output and paper passing durability was set to 98 mN / cm (10 gf / cm).

In the same manner as in Experimental Example 5, potential adjustment of Vd, Vl, etc., and initial evaluation of image output and the like were performed in the above state.

Further, continuous running durability of 150,000 sheets was performed in this environment, the state of the image after cleaning, the state of the cleaning blade and the surface of the photosensitive member were observed, and the friction characteristics were evaluated as in the initial stage.

The initial cleaning property, poor cleaning after running, fusing, CLN chipping, CLN curling, damage to the photoreceptor, high-humidity image flow, and toner reusability were evaluated.

In this embodiment, the cleaning property, CL
Deletion of N or the like conforms to the determination described in the above experimental example. In addition,
The following judgments were made on the high humidity image flow and toner reusability.

[High Humidity Image Flow] In an N / N environment, 1
Forming an image light beam of dots forming pixels with one dot,
An image was formed. Further, under an “H / H environment” of 33 ± 3 ° C. and 80 ± 3%, an image is formed with the same dot diameter in a state in which the image forming apparatus including the photosensitive member and the cleaning device to be evaluated has been used to this environment. I went out. The deviation ratio between the dot diameter of the image under the N / N environment and the dot diameter of the image under the H / H environment with respect to the same dot diameter of the optical system was evaluated as a high humidity image flow.・ Highly humid flow is very good “◎”: within 10% of deviation between N / N environment and H / H environment ・ Good humid flow is “○”: deviation between N / N environment and H / H environment is 10 ２０20% or less ・ High humidity flow is practically acceptable “△”: N / N environment and H /
Within 20 to 25% of deviation in H environment ・ High image quality flow is slightly problematic in practical use. “×”: Difference between N / N environment and H / H environment is 25% or more.

[Toner Reusability] As part of toner reusability, the toner is removed from the surface of the photoreceptor by a cleaning device.
The difference in the density of the developed image with respect to the surface potential of the photoreceptor between the so-called collected toner such as collected transfer residual toner and a new toner (normal toner) was evaluated, and the reusability was evaluated.
This density difference was evaluated as follows.

The N / N of each of the reused toner and the normal toner that is not reused (new toner)
In an environment, the intensity of the laser beam for image exposure of the above-described image forming apparatus was adjusted, and the image exposure was performed by solid shooting to form an electrostatic latent image. After developing the electrostatic latent image, the density of the image is measured with a reflection densitometer (Reflectometer / Model T, manufactured by Tokyo Denshoku Co., Ltd.).
C-6DS), and the reflection density of the image with the reused toner is Dreuse, and the reflection density of the image with the new toner is Dnew, and ΔDrn≡Dreuse-D
new was evaluated as an index of reusability. -Very good reusability "A": ΔDrn is 1.0%
Less-Good reusability "O": ΔDrn is 1.0 to 2.0
% Reuseability is practically acceptable "問題": ΔDrn is 2.
0 to less than 4.0%-Reusability is slightly problematic in practical use "x": Other than the above range

FIG. 13 shows the above-described evaluations, and the design latitude and overall judgment from the viewpoint of variation and accuracy of characteristics.
Very good, ○: good, Δ: no problem in practical use, ×: problem in practical use.

As can be seen from the figure, the result of the system of this example was generally good.

Example 2 The same apparatus as in Example 1 was used except that the latent image type system of the optical system was set to background exposure.

The same photoreceptor as in Example 1 was used.

The coefficient of dynamic friction deviation between the photosensitive member and the urethane rubber blade used in this embodiment is 15 to 6 as in the first embodiment.
0.035 to 0.068 in the range of 0 ° C, the dynamic friction coefficient is 1
It was 0.40 to 0.68 in the range of 5 to 60 ° C.

In the cleaning device, the cleaning blade was used to remove the rubbing, and the contact pressure of the cleaning blade against the photosensitive member was 98 mN / cm (10 gf / cm).

The temperature of the contact portion between the cleaning blade and the photosensitive member during use in this embodiment is 25 ° C., and the rebound resilience and hardness of the cleaning blade at this temperature are 35 ° and 73 °, respectively. . The coefficient of dynamic friction deviation is 0.054, and the coefficient of dynamic friction is 0.58.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: problem in practical use, the result of judgment is shown in FIG.

The friction coefficient after durability was 0.85, and the difference between the friction coefficients before and after durability was 0.4 or less. In this example, a result with very good cleaning properties was obtained.

As can be seen from the above, the result of the system of this example was generally good.

<Embodiment 3> The same apparatus as that of Embodiment 2 was used for the durability and evaluation machine of this embodiment.

The photoreceptor was manufactured by adjusting the flow rate and discharge power of the raw material gas of the a-SiC surface layer, thereby producing a photoreceptor having friction characteristics different from those in Example 1. The resistivity of the surface layer is 7 × 10 ¹⁵ Ω
Cm and the thickness was approximately 0.8 μm. Further, a cleaning blade having a different composition was prepared.

The coefficient of kinetic friction deviation of the photosensitive member and the urethane rubber cleaning blade used in this embodiment is 15 to 6
0.031 to 0.045 at 0 ° C, and the difference due to temperature is 0.014.

The coefficient of kinetic friction is 0.4 at 15-60 ° C.
1 to 0.67.

In the cleaning device, the cleaning blade was used to remove rubbing, and the contact pressure of the cleaning blade against the photosensitive member was 147 mN / cm (15 gf / cm).

The temperature of the contact portion between the cleaning blade and the photoreceptor in use in this embodiment was 21 ° C. and 50 ° C., and a new cleaning blade and a photoreceptor of the same manufacturing method were used. Was evaluated.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

Further, by using the photoreceptor and the cleaning blade in a limited combination, it is possible to reduce the fluctuation range of the dynamic friction deviation coefficient due to the temperature. As a result, the cleaning performance and the durability are different even in different temperature environments. Good results could be obtained. That is,
Good characteristics are obtained in both endurance with changing temperature,
Very good design latitude was obtained.

As can be seen from the above, the result of the system of this example was generally good.

<Embodiment 4> An a-Si-based photoreceptor having an a-SiC surface layer whose surface properties have been adjusted to about 0.8 μm was mounted using the same background exposure apparatus as in Embodiment 2, and the characteristics were adjusted. A cleaning blade was prepared.

The variation of the dynamic friction coefficient with temperature and the variation of the dynamic friction coefficient with temperature are 0.18 and 0.15, respectively.
It is.

In the cleaning device, the cleaning blade is used to remove the rubbing, and the contact pressure of the cleaning blade against the photosensitive member is 147 mN / cm (15 gf / cm).
When the temperature of the contact portion between the cleaning blade and the photosensitive member during use was 20 ° C. and 45 ° C., the evaluation before and after the endurance was performed using a new photosensitive member and a cleaning blade, respectively.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ：: very good, ：: good, Δ: practically problematic, ×: practically problematic, and the results are shown in FIG.

As can be seen from the above, the result of the system of this example was generally good.

Further, by using the photoreceptor and the cleaning blade in a limited combination, the fluctuation range of the dynamic friction deviation coefficient due to the temperature can be reduced. As a result, even in different temperature environments, the cleaning performance and the durability are the same. Good results could be obtained. That is,
Good characteristics are obtained in both endurance with changed temperature,
Very good design latitude was obtained.

<Embodiment 5> Using the same background exposure apparatus as in Embodiment 2, an a-Si based photoreceptor having an a-SiC surface layer whose surface properties are adjusted to about 0.8 μm, and characteristics adjusted. A cleaning blade was prepared. In addition,
In this embodiment, a device (lubricant supply means) for supplying PVDF particles to the contact portion between the cleaning blade and the photoconductor as a lubricant is provided upstream of the cleaning blade in the rotation direction of the photoconductor.

The change of the dynamic friction deviation coefficient with temperature and the change of the dynamic friction coefficient with temperature are 0.013 and 0.1, respectively.
5

[0312] In the cleaning device, the cleaning blade is used to remove rubbing. The contact pressure of the cleaning blade against the photoreceptor is 98 mN / cm (10 gf / cm). Was evaluated at 40 ° C. before and after endurance.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the above, the result of the system of this example was very good overall.

Further, the dynamic friction coefficient, the dynamic friction deviation, and their changes were suppressed, and particularly good results were obtained even with CLN chipping or CLN curling.

Example 6 Using the same background exposure apparatus as in Example 2, an a-Si-based photoreceptor having an a-SiC surface layer whose surface properties were adjusted to about 0.8 μm, and characteristics were adjusted. A cleaning blade was prepared. In addition,
In this embodiment, a method is used in which a toner as a lubricant is developed at a predetermined number of durability and supplied to a contact portion between the cleaning blade and the photosensitive member. Hereinafter, it is referred to as a black belt sequence.

The variation of the dynamic friction coefficient with temperature and the variation of the dynamic friction coefficient with temperature are 0.018 and 0.1, respectively.
6.

In the cleaning device, the cleaning blade is used to remove the rubbing. The contact pressure of the cleaning blade against the photoconductor is 98 mN / cm (10 gf / cm). Assuming that the temperature was 40 ° C., evaluations before and after endurance were performed.

The potential and image are adjusted as in Example 1,
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the above, the result of the system of the present example was generally good.

Further, particularly good results were obtained in toner reusability. It is considered that the effect is obtained by supplying new toner.

<Embodiment 7> As a lubricant supply, a member made of a roller-shaped magnet is provided on the upstream side of the cleaning blade in the rotation direction of the photoconductor, and the magnetically attached toner is brought into contact with the surface of the photoconductor. A mechanism for supplying the cleaning blade to the contact portion between the photosensitive member and the cleaning blade was provided. Hereinafter, it is referred to as an Mg roller.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

In addition, particularly good results were obtained in high-humidity image deletion and fusion. It is considered that the effect of the rubbing of the Mg roller contributed favorably.

As can be seen from the above, the result of the system of this example was very good overall.

<Embodiment 8> Using the same background exposure apparatus as in Embodiment 2, an a-SiC surface layer whose surface properties were adjusted in the same manner as in Embodiment 7 was mounted at about 0.7 μm, and a high A as surface layer material with excellent hardness and water repellency
-C: An a-Si-based photoreceptor equipped with H and having a total surface layer thickness of approximately 0.8 μm, and a cleaning blade with adjusted characteristics were produced.

[0327] No lubricant supply means is provided.

In the cleaning device, the cleaning blade is used to remove the rubbing. The contact pressure of the cleaning blade against the photoconductor is 98 mN / cm (10 gf / cm). Assuming that the temperature was 40 ° C., evaluations before and after endurance were performed.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the above, the result of the system of this example was very good overall.

Further, by using the aC surface layer on the outermost surface, the friction characteristics such as the friction coefficient and the dynamic friction deviation coefficient were further improved.

Also, very good results were obtained for fusing and high-humidity image flow without an additional mechanism such as a Mg roller. Further, the friction coefficient and the dynamic friction deviation coefficient are suppressed to be small, and the driving torque of the photoconductor is suppressed, which is preferable from the viewpoint of energy saving.

<Embodiment 9> Using an apparatus for background exposure similar to that in Embodiment 2, an a-Si photosensitive member having an aC surface layer of approximately 0.8 μm in which surface properties are adjusted, and characteristics adjusted. A cleaning blade was prepared.

The surface layer of the photoreceptor used was aC: H as a surface layer material having high hardness and excellent water repellency.

The lubricant supply means used a black belt sequence.

In the cleaning device, the cleaning blade is used to remove the rubbing. The contact pressure of the cleaning blade with the photoconductor is 98 mN / cm (10 gf / cm). Assuming that the temperature was 40 ° C., evaluations before and after endurance were performed.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the above, the result of the system of this example was very good overall.

Further, in this embodiment, in addition to the effects of the eighth embodiment, a very good result was obtained in which the toner reusability was excellent.

Comparative Example 1 The photoreceptor used was an a-Si type photoreceptor having an a-SiC surface layer having a resistivity of 4 × 10 ¹⁶ Ω · cm substantially 0.8 μm. As in the case of Example 1, an image exposure apparatus was used.

The cleaning member was a urethane blade, and the temperature of the contact portion between the cleaning member and the photosensitive member was 40 ° C.
° C.

In this environment, the initial coefficient of kinetic friction deviation was 0.41, and the coefficient of kinetic friction was 0.89.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the results, the system of this comparative example had a problem that there was a practical problem overall.

Comparative Example 2 The photoreceptor used was an a-Si type photoreceptor to which an a-SiC surface layer having a resistivity of 1 × 10 ¹⁶ Ω · cm was attached to approximately 0.8 μm. As in Comparative Example 1, an image exposure apparatus was used.

The cleaning member is a urethane blade, and the temperature of contact between the cleaning member and the photosensitive member is 40 ° C.
It was made to become.

The initial coefficient of dynamic friction deviation under this environment was 0.089, and the coefficient of dynamic friction was 1.20.

The potential and the image were adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the above, the result of the system of the present comparative example was that there was no practical problem overall.

Comparative Example 3 An OPC was used for the photoreceptor, and a PTFE-containing cured resin was used for the surface layer. Comparative Example 1
An image exposure apparatus similar to that described above was used.

The cleaning member was a urethane blade, and the temperature of the contact portion between the cleaning member and the photosensitive member was 30 °.
° C. The contact pressure is 343 mN / cm (35
gf / cm).

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the results, it was found that the system of this comparative example had no practical problem in general.

<Comparative Example 4> The photoreceptor used was an a-Si type photoreceptor to which an a-SiC surface layer having a resistivity of 8 × 10 ¹⁵ Ω · cm was attached to approximately 0.8 μm. As in Comparative Example 1, an image exposure apparatus was used.

The cleaning member is a urethane blade, and the temperature of the contact portion between the cleaning member and the photosensitive member is 65 ° C.
° C, and the contact pressure is 98 mN / cm (10 gf
/ Cm).

The initial dynamic friction coefficient under this environment is 0.1
0 and the coefficient of dynamic friction was 0.74.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the results, sagging and fusing of the cleaning member due to high temperature occurred, and the system of this comparative example was found to have a problem in practical use as a whole, and the result was obtained.

Comparative Example 5 The photoreceptor used was an a-Si type photoreceptor to which an a-SiC surface layer having a resistivity of 6 × 10 ¹⁵ Ω · cm was attached to approximately 0.8 μm. As in Comparative Example 1, an image exposure apparatus was used.

The cleaning member was a urethane blade, and the temperature of the contact portion between the cleaning member and the photosensitive member was 10
° C, and the contact pressure is 245 mN / cm (25 g
f / cm).

In this environment, the initial coefficient of dynamic friction deviation was 0.032, and the coefficient of dynamic friction was 0.35.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the above, it was found that the system of this example had no practical problem overall.

Comparative Example 6 The photoreceptor used was an a-Si type photoreceptor having an a-SiC surface layer having a resistivity of 6 × 10 ¹⁵ Ω · cm substantially 0.8 μm. As in Comparative Example 1, an image exposure apparatus was used.

The cleaning member is a urethane blade, and the temperature of the contact portion between the cleaning member and the photosensitive member is 25.
° C, and a contact pressure of 588 mN / cm (60 gf
/ Cm).

In this environment, the initial coefficient of dynamic friction deviation was 0.050, and the coefficient of dynamic friction was 0.58.

The potential and the image are adjusted as in the first embodiment.
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ：: very good, ：: good, Δ: no problem in practical use, ×: problematic in practical use, the results are shown in FIG.

As can be seen from the results, CLN chipping or the like, which is considered to be caused by excessive contact pressure, occurred, and the result of this comparative example was that there was a practical problem overall.

Comparative Example 7 The photoreceptor used was an a-Si type photoreceptor having an a-SiC surface layer having a resistivity of about 6 × 10 ¹⁵ Ω · cm and a thickness of about 0.8 μm. As in Comparative Example 1, an image exposure apparatus was used.

The cleaning member is a urethane blade, and the temperature of the contact portion between the cleaning member and the photosensitive member is 40 °.
° C and a contact pressure of 9.8 mN / cm (1 gf /
cm).

In this environment, the initial coefficient of dynamic friction deviation was 0.053, and the coefficient of dynamic friction was 0.59.

The potential and image were adjusted as in Example 1,
Initial cleaning performance, poor cleaning after running, fusing, CLN chipping, CLN curling, photoreceptor damage, high-humidity image flow, toner reusability evaluation, design latitude and comprehensive judgment based on characteristic fluctuation and accuracy , ◎: very good, ：: good, Δ: no problem in practical use, ×: no problem in practical use, and the results are shown in FIG.

As can be seen from the results, the result that CLN failure occurred and the system of this comparative example had a problem in terms of practical use as a whole was obtained.

As for the drum heater, a-Si
It may be mounted on an image forming apparatus using a system photoconductor. However, from the viewpoint of energy saving, it is preferable to reduce the capacity of the heater and further to make it heaterless.
As the surface temperature of the photoreceptor decreases, the latitude for fusing the toner also increases. However, when the capacity of the drum heater is reduced or the drum heater itself is eliminated, it is preferable that characteristics such as the charging ability of the photoconductor do not practically change with temperature.

[0375]

As described above, according to the present invention,
It is possible to achieve good cleaning performance with little fluctuation with respect to environmental (particularly temperature) changes, improve the durability between the photosensitive member and the cleaning member, and further widen the set latitude.

[Brief description of the drawings]

FIG. 1 (a) is a diagram showing the temperature dependence of friction coefficient and differences due to combinations. (B) is a diagram showing the temperature dependence of the dynamic friction deviation coefficient and the difference due to the combination.

FIG. 2 is a longitudinal sectional view illustrating a schematic configuration of an image forming apparatus according to the present invention.

FIGS. 3A to 3D are schematic views illustrating a cleaning step.

FIG. 4A is a model diagram of a one-line latent image of image exposure and background exposure. (B) is a conceptual diagram for deriving a latent image model from the light quantity distribution and the EV characteristics.

FIGS. 5A to 5D are schematic configuration diagrams for explaining layer configurations of different photoconductors. FIG.

FIG. 6 is a diagram illustrating an example of an RF-PCVD apparatus.

FIG. 7 is a diagram showing an example of a VHF-PCVD apparatus.

FIG. 8 is a schematic configuration diagram illustrating an example of a friction characteristic evaluation device.

FIG. 9A is a diagram showing an example of data obtained in frictional property evaluation. (B) is a figure for explaining the term about friction characteristic evaluation.

FIG. 10 is a diagram showing a correlation between Eu and temperature characteristics.

FIG. 11 is a diagram showing the evaluation results of the resistivity, chargeability, withstand voltage, and residual charge of the surface layer.

FIG. 12 is a diagram illustrating an example of spectral reflection measurement of a surface layer of an a-Si photoconductor.

FIG. 13 is a diagram showing conditions and results of Examples 1 to 9 and Comparative Examples 1 to 7.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 50 Photoreceptor 2 Main charging device 3 Exposure device 4 Developing device 5 Transfer / separation charging device 6 Cleaning means (Cleaning device) 6a Cleaning member (Cleaning blade) 7 Main static elimination light source 51 Support 52 Photosensitive layer 53 Photoconductive layer 54 Surface layer 55 Charge injection blocking layer 56 Charge generation layer 57 Charge transport layer 58 Free surface P Other member (recording material)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kunimasa Kawamura, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Koji Yamazaki 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon F term in reference (reference) 2H034 BA01 BC00 BF03 BF05 BF06 CA01 CA04 2H068 CA03 DA02 DA03 DA17 DA37 FC15

Claims (40)

[Claims] 1. A charging step of charging a surface of a photoconductor, an exposure step of exposing the surface of the photoconductor after charging to form an electrostatic latent image, and a developing step of developing the electrostatic latent image as a toner image Forming an image by a series of image forming steps including: a transfer step of transferring the toner image from the photoconductor surface to another member; and a cleaning step of removing transfer residual toner remaining on the photoconductor surface after transfer. In the image forming method, the cleaning step is a step of removing transfer residual toner on the surface of the photoconductor by a cleaning member in contact with the surface of the photoconductor. When the standard deviation coefficient of the dynamic friction representing the load dependency of the variation of the dynamic friction force acting between the photosensitive member and the cleaning member is defined as the dynamic friction deviation coefficient, An image forming method, wherein the coefficient of dynamic friction deviation is within 0.1 when the temperature at the contact portion where the leaning member comes into contact is in the range of 15 to 60 ° C. 2. The image according to claim 1, wherein the dynamic friction deviation coefficient has a variation width within 0.02 in an arbitrary temperature range of 15 to 60 ° C. of the contact portion. Forming method. 3. A charging step of charging a photoconductor surface, an exposure step of exposing the charged photoconductor surface to form an electrostatic latent image, and a developing step of developing the electrostatic latent image as a toner image Forming an image by a series of image forming steps including: a transfer step of transferring the toner image from the photoconductor surface to another member; and a cleaning step of removing transfer residual toner remaining on the photoconductor surface after transfer. In the image forming method described above, the cleaning step is a step of removing transfer residual toner on the surface of the photoconductor by a cleaning member that is in contact with the surface of the photoconductor, and the cleaning member contacts the surface of the photoconductor. At any point where the temperature at the contact portion is in the range of 15 to 60 ° C., the coefficient of friction between the photosensitive member surface and the cleaning member is 1 or less, and Any variation of the friction coefficient in the range is within 0.4, the image forming method characterized in that the. 4. The image forming method according to claim 3, wherein a variation width of the friction coefficient is within 0.2. 5. The method according to claim 1, wherein a change amount of the dynamic friction deviation coefficient before and after the endurance after repeating the image forming process 150,000 times is within 0.02. Image forming method. 6. The amount of change in the coefficient of friction between before and after the endurance after repeating the image forming step 150,000 times is 0.1.
The image forming method according to claim 3, wherein the number is within four. 7. The cleaning member is a cleaning blade having elasticity, the cleaning blade has a rebound resilience of 5 to 75% according to JIS K-7311, and JIS K-6.
The hardness of the cleaning blade according to 253 is 60
The image forming method according to any one of claims 1 to 6, wherein the angle is from 90 to 90 degrees. 8. A contact pressure at which the cleaning blade contacts the surface of the photoreceptor is 49 to 490 mN / cm (5 to 490 mN / cm).
The image forming method according to claim 7, wherein the pressure is 50 gf / cm). 9. The image forming method according to claim 7, wherein a substantially constant amount of a lubricant is interposed in a contact portion between the cleaning blade and the surface of the photoreceptor and in the vicinity thereof. 10. The image forming method according to claim 9, wherein the lubricant is a toner. 11. The image forming method according to claim 1, wherein the photoconductor has a surface layer mainly composed of amorphous silicon and / or carbon. 12. The photoconductor according to claim 1, wherein the photoconductor is mainly made of amorphous silicon, and a temperature characteristic, which is a rate of change in charging characteristics with temperature, is within ± 2 V / deg. The image forming method according to any one of the above. 13. The photoreceptor is mainly composed of amorphous silicon, and has a characteristic energy of an exponential function tail obtained from an absorption spectrum of a sub-bandgap light at least in a portion exposed in the exposure step, in a range of 50 to 70 meV.
The image forming method according to claim 12, wherein: 14. The image forming method according to claim 1, wherein the exposure in the exposure step is a background exposure for exposing a non-image portion. 15. A photoreceptor having a toner image formed on a surface thereof, and cleaning means for removing transfer residual toner remaining on the photoreceptor surface after transferring the toner image on the photoreceptor surface to another member. In the image forming apparatus, the cleaning unit has a cleaning member that is in contact with the surface of the photoconductor and removes transfer residual toner on the surface of the photoconductor, and the cleaning member and the cleaning member during an image forming process. When the standard deviation coefficient of dynamic friction representing the load dependency of the dynamic friction force variation acting between the photosensitive member surface and the cleaning member is defined as a dynamic friction deviation coefficient, the temperature at the contact portion where the cleaning member contacts the photosensitive member surface is The image forming apparatus, wherein the coefficient of dynamic friction deviation is within 0.1 in a range of 15 to 60 ° C. 16. The image according to claim 15, wherein the dynamic friction deviation coefficient has a variation width within 0.02 in an arbitrary temperature range of 15 to 60 ° C. of the contact portion. Forming equipment. 17. A photoreceptor having a toner image formed on a surface thereof, and cleaning means for removing transfer residual toner remaining on the photoreceptor surface after transferring the toner image on the photoreceptor surface to another member. In the image forming apparatus, the cleaning unit has a cleaning member that is in contact with the surface of the photoconductor and removes transfer residual toner on the surface of the photoconductor, and a cleaning member that contacts the surface of the photoconductor and the cleaning member. The friction coefficient between the photosensitive member surface and the cleaning member is 1 or less at an arbitrary point where the temperature at the contact portion is in the range of 15 to 60 ° C., and the friction coefficient in the arbitrary range of 15 to 60 ° C. An image forming apparatus, wherein the change width of the image is within 0.4. 18. The image forming apparatus according to claim 17, wherein a variation width of the friction coefficient is within 0.2. 19. The image forming apparatus according to claim 15, wherein a change amount of the dynamic friction deviation coefficient before and after the image forming process is repeated 150,000 times is within 0.02. Image forming device. 20. The image according to claim 17, wherein a change amount of the friction coefficient before and after the endurance after repeating the image forming process 150,000 times is within 0.4. Forming equipment. 21. The cleaning member is a cleaning blade having elasticity, the rebound resilience of the cleaning blade according to JIS K-7311 is 5 to 75%, and JIS K-6.
The hardness of the cleaning blade according to 253 is 60
The image forming apparatus according to any one of claims 15 to 20, wherein the angle is from 90 to 90 degrees. 22. A contact pressure at which the cleaning blade contacts the surface of the photoreceptor is 49 to 490 mN / cm (5 to 490 mN / cm).
22. The image forming apparatus according to claim 21, wherein 23. The apparatus according to claim 21, further comprising a lubricant supply unit configured to supply a substantially constant amount of lubricant to a contact portion between the cleaning blade and the surface of the photoconductor and the vicinity thereof. The image forming apparatus as described in the above. 24. The image forming apparatus according to claim 23, wherein the lubricant is a toner. 25. The lubricant supply means is disposed upstream of the cleaning blade along a moving direction of the photoconductor surface, and is driven at a predetermined relative speed with respect to the photoconductor surface. The image forming apparatus according to claim 23, wherein: 26. The image forming apparatus according to claim 23, wherein the lubricant supply unit magnetically and / or mechanically holds or supplies the lubricant. 27. The image forming apparatus according to claim 15, wherein the photoconductor has a surface layer mainly composed of amorphous silicon and / or carbon. 28. The photoconductor according to claim 15, wherein the photoconductor is mainly made of amorphous silicon, and a temperature characteristic which is a rate of change of the charging characteristic with temperature is within ± 2 V / deg. An image forming apparatus according to any one of the above. 29. The photoreceptor is mainly composed of amorphous silicon, and has a characteristic energy of an exponential function tail obtained from an absorption spectrum of sub-bandgap light in at least a portion to be exposed is 50 to 70 meV. 29. The image forming apparatus according to claim 28, wherein: 30. The image forming apparatus according to claim 15, wherein the exposure on the photoconductor surface is a background exposure for exposing a non-image portion. 31. A photoreceptor, wherein transfer residual toner remaining on the surface of a photoreceptor after transfer of a toner image to another member is removed by a cleaning member in contact with the surface of the photoreceptor, When the standard deviation coefficient of dynamic friction representing the load dependency of the dynamic friction force variation acting between the body surface and the cleaning member is defined as a dynamic friction deviation coefficient, the photosensitive member surface and the cleaning member come into contact with each other. The photosensitive member, wherein the coefficient of dynamic friction deviation is within 0.1 when the temperature at the contact portion is in the range of 15 to 60 ° C. 32. The photosensitive material according to claim 31, wherein the dynamic friction deviation coefficient has a variation width within 0.02 in an arbitrary temperature range of 15 to 60 ° C. of the contact portion. body. 33. A photoreceptor in which transfer residual toner remaining on the surface of a photoreceptor after transfer of a toner image to another member is removed by a cleaning member in contact with the surface of the photoreceptor. At any point where the temperature at the contact portion where the member abuts is in the range of 15 to 60 ° C., the coefficient of friction between the surface of the photoconductor and the cleaning member is 1 or less and the arbitrary temperature of 15 to 60 ° C. Wherein the width of change of the friction coefficient in the range of is within 0.4. 34. The photoconductor according to claim 31, wherein a variation width of the friction coefficient is within 0.2. 35. The method according to claim 31, wherein a change amount of the dynamic friction deviation coefficient before and after the endurance after repeating the image forming process 150,000 times is within 0.02. Photoconductor. 36. The photosensitive material according to claim 33, wherein the amount of change in the friction coefficient before and after the endurance after repeating the image forming process 150,000 times is within 0.4. body. 37. The photoconductor according to claim 31, having a surface layer mainly composed of amorphous silicon and / or carbon. 38. A temperature characteristic which is mainly composed of amorphous silicon and has a temperature characteristic of ± 2 V / d, which is a rate of change in charging characteristic with temperature.
The photoreceptor according to any one of claims 31 to 36, wherein the photoreceptor is within EG. 39. A temperature characteristic which is mainly composed of amorphous silicon and has a temperature characteristic of ± 2 V / d, which is a rate of change in charging characteristic with temperature.
The photoreceptor according to any one of claims 31 to 38, wherein the photoreceptor is within an EG. 40. A characteristic energy of an exponential function tail obtained mainly from an absorption spectrum of sub-bandgap light in at least a portion to be exposed, which is mainly made of amorphous silicon, is 50 to 70 meV. 39. The photoconductor according to item 39.