JPH11212413A - Electrophotographic image forming method and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic image forming method and an electrophotographic image forming device free from environmental pollution caused by using an inorganic photoreceptor, and capable of obtaining a stable copied image high in image quality for a long period. SOLUTION: In this the electrophotographic image forming method using a cleaning member for cleaning an organic photoreceptor surface provided with a photoreceptive layer formed on a conductive supporting body by using an elastic rubber blade, a relation expressed by the following inequalities is established between the coefficient μa of static friction between the photoreceptor 14 and the elastic rubber blade 8 and the coefficient μb of dynamic friction between them, μa<=1.5 and 0.1<=μa-μb<=1.0, and the elastic rubber blade 8 is substantially held by a supporting member 9 for fixing the blade to the cleaning member on the side of the surface coming into contact with the photoreceptor, and the blade 8 is brought into contact with the photoreceptor 14 in a counter direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electrophotographic image forming method and an image forming apparatus used for a copying machine, a printer and the like.

[0002]

2. Description of the Related Art Conventionally, in an image forming method using electrophotography, a visible image is formed by forming an electrostatic latent image on a photoreceptor and then developing with a toner composed of a so-called resin and a colorant. A method is adopted in which the image is transferred onto a paper or the like as an image support (recording material) and then fixed by applying heat or the like. The photoreceptor removes residual toner in a cleaning step after the transfer step, and is repeatedly used for image formation. On the other hand, a fur brush, a magnetic brush, a blade, or the like is representative of the cleaning means, but a blade is mainly used in terms of performance, configuration, and the like. At this time, a plate-shaped rubber elastic body is generally used as the blade member.

In recent years, as an electrophotographic photosensitive member,
There is a shift from inorganic photoconductors such as selenium, which have a problem in disposal, to organic photoconductors in view of prevention of environmental pollution. As this organic photoreceptor, a laminated organic photoreceptor composed of a charge generation layer and a charge transport layer on a conductive support via an undercoat layer as necessary is often used. This charge transport layer is usually composed of a binder resin containing a charge transport substance and usually has a surface close to a mirror surface, but is repeatedly used in a cleaning step for removing toner, a developing step, a transfer step, and the like. During use, the surface is unevenly worn due to friction or the like, unevenness is generated, or the surface is scratched. At present, uneven wear, unevenness, scratches, thickness reduction, and the like mainly occurring in the cleaning process affect the durability of the entire photoconductor.

On the other hand, Japanese Patent Application Laid-Open Nos. 62-75575 and 4-33587 focus on the coefficient of kinetic friction with a photosensitive member. However, the cleaning process is an extremely complicated engineering process using the photoreceptor surface, the cleaning blade, the cleaning process, and its apparatus, and the favorable condition range is considerably limited, and is not yet satisfactory.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic image forming method and an electrophotographic image forming apparatus capable of obtaining a high quality and stable copy image for a long period without environmental pollution such as an inorganic photoreceptor. On offer.

[0006]

The object of the present invention is attained by adopting one of the following constitutions.

(1) In an electrophotographic image forming method having a cleaning member for cleaning a surface of an organic photoreceptor having a photosensitive layer provided on a conductive support with an elastic rubber blade, the stationary state between the photoreceptor and the elastic rubber blade is provided. The following relationship holds between the friction coefficient μa and the dynamic friction coefficient μb,
A support member for fixing the elastic rubber blade to the cleaning member is substantially held on a photosensitive member contact surface side of the blade, and the blade is contacted in a counter direction. Electrophotographic image forming method.

Μa ≦ 1.5 0.1 ≦ μa−μb ≦ 1.0 (2) Electrophotography having a cleaning member for cleaning the surface of an organic photoreceptor provided with a photosensitive layer on a conductive support with an elastic rubber blade In the image forming apparatus, the following relationship is established between the static friction coefficient μa and the dynamic friction coefficient μb between the photoconductor and the elastic rubber blade, and a support member for fixing the elastic rubber blade to the cleaning member, An electrophotographic image forming apparatus, wherein the blade is held substantially on the photosensitive member contact surface side of the blade, and the blade is contacted in a counter direction.

Μa ≦ 1.5 0.1 ≦ μa−μb ≦ 1.0 (3) The blade has a rubber hardness of 55 to 75 °, a rebound resilience of 30 to 70%, and a plate thickness of 1 mm or more and 5 mm or less (1). The electrophotographic image forming method according to the above.

(4) An end face in the length direction of the photosensitive member contact surface of the blade is square-cut (1) or (3).
The electrophotographic image forming method according to the above.

(5) The blade has a rubber hardness of 55 to 7
(2) The electrophotographic image forming apparatus according to (2), wherein the resilience is 5 °, the rebound resilience is 30 to 70%, and the plate thickness is 1 mm or more and 5 mm or less.

(6) The end face in the length direction of the photosensitive member contact surface of the blade is subjected to square cutting (2) or (5).
An electrophotographic image forming apparatus as described in the above.

Basically, when the elastic rubber blade is supported as in the present invention, as described in detail below, the blade is likely to be caught on the surface of the photoreceptor and turned up.

The support member in the configuration of the present invention is a support member for fixing the cleaning blade to the cleaning member. In addition, the squaring process refers to a process of cutting off at least one end of the cleaning blade in the length direction on the photosensitive member contact surface side and rounding the corner by heat treatment or the like.

The configuration of the present invention will be further described.

The elastic rubber blade used in the present invention comprises:
As shown in FIG. 1, the support member has a free end on a support member.

In FIG. 1, reference numeral 14 denotes a photosensitive drum of an organic photosensitive member, 8 denotes an elastic rubber blade, and 9 denotes a support member.

In the present invention, the method of fixing the elastic rubber blade to the support member can achieve the object by substantially holding the elastic rubber blade on the support member on the photosensitive member contact surface side. If the support is provided on the opposite side, the object of the present invention cannot be achieved. FIG.
In the above, (A) is a method of contacting the present invention, and (B)
Is outside the present invention.

The conditions for properly pressing the elastic rubber blade against the surface of the photoreceptor are determined by a delicate balance of various characteristics, and have a considerably narrow range. It depends on the characteristics of the blade, such as its thickness and mechanical characteristics, and high accuracy is required for the support setting. However, when a blade with a small variation suitable for this high precision is obtained, the yield is deteriorated,
Significant cost increase. Since the thickness of the elastic rubber blade is inevitably somewhat varied at the time of manufacture, it cannot be said that the elastic rubber blade is always supported and set under appropriate conditions. Even if it is properly supported at the beginning of the setting, the proper area tends to be deviated from the appropriate area in the process of use because the appropriate area is narrow.

In particular, if it is out of the proper range, the surface of the photoreceptor will not be uniformly worn, and will be unevenly worn, or the blade will be turned up, causing toner filming on the surface of the photoreceptor. Image defects such as spots are likely to occur.

Therefore, it is necessary to take measures for canceling the variation in the characteristics of the elastic rubber blade, etc. Even if the thickness of the elastic rubber blade varies, it does not affect the pressing force against the photosensitive member surface. The setting method of the present invention is effective.

Conventionally, as a method of setting an elastic rubber blade that does not cause a change in the pressure contact force on the photosensitive member surface, a supporting member is held via a fulcrum, and a weight is placed on the opposite side of the elastic rubber blade from contact with the photosensitive member surface. In addition, there has been adopted a method of press-fitting by applying the load. However, this method must be structurally complex and rugged, is expensive, and cannot be incorporated into a small machine with a sufficient pressing force.

The coefficient of static friction μ between the photoreceptor surface and the blade
When the relationship between a and the dynamic friction coefficient μb satisfies the relations of μa ≦ 1.5 and 0.1 ≦ μb ≦ 1.0, the weight accuracy applied to the photoreceptor is high and the toner The ability to scrape is high. However, in the case of this setting method, the difference between μa and μb is important. When the μa of the photoreceptor surface is larger than 1.5, blade turning (especially under high humidity) is likely to occur. μ
When a-μb is smaller than 0.1, the blade tip slips, and the rebound resilience of the tip cannot be utilized, so that a mistake in scraping off the toner is likely to occur, and image unevenness is likely to occur.
When μa−μb is greater than 1.0, blade vibration is likely to occur due to friction of the photoreceptor surface, and image unevenness is likely to occur. Preferably, μa-μb is 0.2-0.9.

The method of measuring the static friction coefficient and the dynamic friction coefficient conforms to the method described on page 3 of JP-A-9-90843.

In the present invention, the free end of the elastic rubber blade is pressed against the opposite side (counter) of the photosensitive member in the rotation direction.

The rubber hardness of the elastic rubber blade is J
IS A 55 ° to 75 ° (measured using JIS K6301 spring hardness test (A type)), preferably 60
° to 70 ° is good. The rebound resilience is 30-70% (JISK
6301 rebound resilience test), preferably 55
~ 60% is good. Young's modulus is 30-60 kgf / cm
^{2. The} thickness is preferably from 1.0 to 5.0 mm, more preferably from 1.5 to 3.0 mm. Free length is 7-1
The pressure applied to the photosensitive member is preferably 2 to 30 g / cm.

The structure of the photoreceptor used in the present invention is as follows.

The charge generation material (CGM) is not particularly limited, but includes, for example, phthalocyanine pigment, polycyclic quinone pigment, azo pigment, perylene pigment, indigoid pigment and the like.

The use of a fluorenone-based disazo pigment, an imidazole perylene pigment, an anthrone-based pigment, or an oxytitanyl-based phthalocyanine pigment in the electrophotographic photoreceptor of the present invention exhibits improved effects in terms of sensitivity, durability and image quality.

These charge generating substances can be used alone or in combination of two or more.

The charge transport material (CTM) is not particularly limited, but may be, for example, an oxazole derivative, an oxadiazole derivative, a thiazole derivative, a thiadiazole derivative, a triazole derivative, an imidazole derivative, an imidazolone derivative, an imidazolidine derivative, a bisimidazolidine derivative. , Styryl compounds, hydrazone compounds, pyrazoline derivatives, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1 -Vinyl pyrene,
And poly-9-vinylanthracene.

Further, as the charge transporting substance, those which are excellent in the ability to transport holes generated upon light irradiation and which are suitable for combination with oxytitanyl phthalocyanine and the like are preferable.

Many of the above-mentioned charge generating substances and charge transporting substances have poor film-forming ability by themselves, and the photosensitive layer may be formed by using various binders.

Any binder resin can be used for forming the photosensitive layer, but it is preferable to use a film-forming high molecular polymer which is hydrophobic, has a high dielectric constant, and is electrically insulating. . Examples of such a high-molecular polymer include polycarbonate, polyester, methacrylic acid resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate,
Styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol formaldehyde resin, styrene -Alkyd resin, poly-N-vinyl carbazole, polyvinyl acetal (for example, polyvinyl butyral) and the like. These binder resins can be used alone or as a mixture of two or more.

An antioxidant can be added to the photosensitive layer for the purpose of preventing ozone deterioration. As antioxidants,
Hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof,
Organic sulfur compounds, organic phosphorus compounds and the like can be mentioned.

[0036] These specific compounds are disclosed in
Nos. 3-14154, 63-18355, 63-4
No. 4662, No. 63-50848, No. 63-5084
9, No. 63-58455, No. 63-71856,
Nos. 63-71857 and 63-146046.

The amount of the antioxidant to be added is 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight, particularly preferably 5 to 25 parts by weight, per 100 parts by weight of CTM.

The organic photoreceptor is provided on a support with a charge generation layer (C
GL), the charge transport layer (CTM), and if necessary,
Auxiliary layers such as a protective layer, an undercoat layer, a barrier layer, and an adhesive layer may be laminated.

The undercoat layer functions as an adhesive layer or a blocking layer. In addition to the binder resin, for example, polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, casein, copolymerized nylon, N-alkoxymethylated nylon, Starch or the like is used.

Solvents or dispersion media used for forming the charge generation layer and the charge transport layer include butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, and the like.
N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, 1,
2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl Sulfoxide, methylcellosolve and the like.

FIG. 2 shows the form of the organic photoreceptor according to the present invention.
Examples are shown in (1) to (6).

As shown in FIGS. 2 (1) and 2 (2), the organic photoreceptor is composed of a conductive support 1 on which CGM2 containing CGM as a main component and CTL3 containing CTM as a main component. Is provided. Of these, the uppermost layer refers to the layer on the outermost surface of the photoreceptor.

The photosensitive layer 4 may be provided via an undercoat layer 5 provided on the conductive support 1, as shown in FIGS.

As described above, an electrophotographic photosensitive member having excellent electrophotographic characteristics can be obtained when the photosensitive layer has a multilayer structure.

In the present invention, as shown in FIGS. 5 and 6, the photosensitive layer 4 comprising fine particles of CGM 7 dispersed in the layer 6 containing CTM as a main component is electrically conductively supported. It may be provided directly on the body 1 or via the undercoat layer 5.

Further, a protective layer may be provided on the photosensitive layer, if necessary.

Here, when the photosensitive layer has a multilayer structure, CGL
2 can be formed by the following method directly on the conductive support 1 or the CTL 3, or after providing an undercoat layer such as an adhesive layer or a blocking layer as necessary.

(1) Vacuum evaporation method (2) Method of applying a solution in which CGM is dissolved in an appropriate solvent (3) CGM is converted into fine particles in a dispersion medium by a ball mill, a sand grinder or the like, and a binder is used, if necessary. And applying a dispersion obtained by mixing and dispersing.

That is, specifically, a vapor deposition method such as vacuum evaporation, sputtering, or CVD, or a coating method such as dipping, spray, blade, or roll method is optionally used.

The thickness of the CGL thus formed is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm.

The CTL 3 can be formed in the same manner as the CGL 2.

At this time, the thickness of the CTL 3 can be changed as required, but is usually preferably 5 to 40 μm, particularly preferably 23 to 35 μm, and excellent characteristics in terms of sensitivity and durability. can get. The composition ratio in this CTL is 0.1 to 1 part by weight of CTM and 0.1 to 0.1 parts of binder.
The amount is preferably 5 parts by weight, but when forming the photosensitive layer 4 in which fine-grained CGM is dispersed, it is preferable to use the binder in a range of 5 parts by weight or less based on 1 part by weight of CGM.

When the CGL is dispersed in a binder, the binder is preferably used in an amount of 5 parts by weight or less based on 1 part by weight of CGM.

The material of the conductive support used in the present invention is mainly aluminum, copper, brass, steel,
A belt-shaped or drum-shaped metal material such as stainless steel or another plastic material is used. Among them, aluminum excellent in cost, workability and the like is preferably used, and a thin-walled cylindrical aluminum tube usually formed by extrusion or drawing is often used.

Next, although not limited to this, FIG. 3 shows an example of a digital copying machine, and the image forming method and apparatus of the present invention will be described.

In the image forming apparatus shown in FIG. 3, although not shown in the figure, light from a light source is applied to a document, reflected light is converted into an electric signal by an image reading unit, and this image data is converted into an image by the image writing unit 11. To 13 (11 is a laser light source, 12 is a polygon mirror, and 13 is an fθ lens).

On the other hand, the photosensitive drum 14 for forming an image is uniformly charged by corona discharge in the charging unit 15, and subsequently, image exposure light is irradiated onto the photosensitive drum 14 from the laser light source 11 in the image writing section. Then, the image is reverse-developed by the next developing unit 16 and transferred to a recording sheet (recording material) by the transfer pole 17. The recording material (recording paper) 18 is a separation pole 19
As a result, the photosensitive drum is separated from the photosensitive drum and fixed by the fixing device 20. On the other hand, the photosensitive drum 14 is
1 is cleaned. Reference numeral 22 denotes a pre-charging exposure lamp, which may be provided after the separation pole 19 and before the cleaning device.

In the above description, the process using a single color has been described. However, in some cases, an image in a plurality of colors such as two colors may be used. The process of charging, image writing by laser light exposure, and developing the corresponding color toner is repeated by applying the signal for each color separated at the time of image reading, and the four color toners of yellow, magenta, cyan, and black toner are repeated. The image may be formed on the photoreceptor and transferred to the recording material at one time.

Further, the method of forming the toner image and the method of transferring the toner image to the recording material may be different.

Further, in addition to the above, image information is previously stored in RO
The information can be stored in an image memory such as an M or a floppy disk, and the information in the image memory can be extracted as needed and output to an image forming unit. Therefore, an apparatus that does not have an image reading unit but stores information from a computer or the like in a memory and outputs the information to an image forming unit as in this example is also included in the image forming apparatus of the present invention. The most common of these are LED printers and LBPs (laser beam printers).

[0061]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

(Examples 1 and 2, Comparative Examples 1 and 2) 30 g of the polyamide resin Amilan CM-8000 (manufactured by Toray Industries, Inc.) was put into a mixed solvent of 900 ml of methanol and 100 ml of 1-butanol, and dissolved by heating at 50 ° C. This liquid was applied on four cylindrical aluminum conductive supports having an outer diameter of 80 mm and a length of 360 mm to form an undercoat layer having a thickness of 0.5 μm.

Next, 10 g of a silicone resin KR-5240 (manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 1000 ml of t-butyl acetate, and Y-TiOPc (Japanese Patent Laid-Open No. 64-17066) was added thereto.
No., Fig. 1) 10 g was mixed and 20
After time dispersion, a charge generation layer coating liquid (CGL liquid-1) was obtained. This solution was applied onto the undercoat layer to form a 0.3 μm-thick charge generation layer.

Next, 150 g of CTM (T-1) and 200 g of BPZ type polycarbonate resin Iupilon Z-300 (manufactured by Mitsubishi Gas Chemical Company) having a viscosity average molecular weight of 30,000 were added to 1,2-
It was dissolved in 1,000 ml of dichloroethane to obtain a coating solution for the charge transport layer (CTL solution-1). Using this solution, each of the charge generation layers was coated, and dried at 100 ° C. for 1 hour to form a charge transport layer having a thickness of 22 μm.

In this manner, four photoreceptor samples (OPC-1 to 4) comprising an undercoat layer, a charge generation layer and a charge transport layer and having different surface roughness as shown in Table 1 were obtained. The friction coefficient between the surface of the photoconductor and the elastic rubber blade was adjusted by adding the surface oil of the photoconductor and silicone oil to the CTL liquid-1.

[0066]

Embedded image

[0067]

[Table 1]

The photoreceptor produced as described above was incorporated in a remodeled digital copier Konica 7050 (manufactured by Konica).

At this time, an elastic rubber blade used as a cleaning member was attached to the supporting member with a hot melt adhesive, and the supporting member was fixed to the cleaning device. In addition, in order to avoid toner contamination, an end face in the length direction of the blade was subjected to a square cutting process. Further, the surface on which the elastic rubber blade was attached to the support member had the same configuration as the surface in contact with the photoreceptor. The elastic rubber blade has a rubber hardness of JIS A 70 °, a rebound resilience of 60%, a thickness of 1.9 mm, and a free length of 9 mm. The contact was performed at 18 g / cm. In this state, a 200,000 copy actual shooting test was performed to evaluate the quality of the copied image.

Example 3 In Example 1, the rubber hardness of an elastic rubber blade used as a cleaning member was measured using a photosensitive member sample (OPC-2) according to JISA 60 °.
The actual shooting test of 200,000 copies was performed in the same manner except that the above was replaced.

Example 4 200,000 copies were prepared in the same manner as in Example 1 except that the photoreceptor sample (OPC-2) was replaced with a rebound resilience of 55% of an elastic rubber blade used as a cleaning member. Was tested live.

Comparative Example 3 The procedure of Example 2 was repeated, except that the surface on which the elastic rubber blade was attached to the support member was opposed to the surface that was in contact with the photosensitive member (see FIG. 1B). A live-action test of 200,000 copies was performed.

The results were evaluated by visual evaluation and image density measurement with a Macbeth densitometer. The evaluation criteria are shown below.

Fog: Judgment based on white background density (WD) “」 ”WD ≦ 0.005“ Δ ”0.005 <WD ≦ 0.01“ × ”0.01 <WD Image blur: Judgment by fine line reproducibility ○: 8 lines / mm or more “Δ”: 5.6 lines / mm or more, 7.1 lines / mm or less “×” 5 lines / mm or less Density unevenness: Density difference of entire halftone (density 0.2) image ( ΔHD = maximum density−minimum density) Judgment “≦” ΔHD ≦ 0.05 “△” 0.05 <ΔHD ≦ 0.1 “×” 0.1 <ΔHD Practical application is possible.

Table 2 shows the results of the test.

[0076]

[Table 2]

As shown in Examples 1 to 4, in the present invention,
Good image quality is obtained from the beginning to 200,000 copies.

On the other hand, in Comparative Examples 1 to 3, it can be seen that the image quality deteriorates due to repeated use, and there is a problem.

[0079]

According to the present invention, it is possible to provide an electrophotographic image forming method and an electrophotographic image forming apparatus capable of obtaining a high quality and stable copy image for a long period without environmental pollution such as an inorganic photoreceptor.

[Brief description of the drawings]

FIG. 1 is a sectional view illustrating a method for holding an elastic rubber blade according to the present invention.

FIG. 2 is a cross-sectional view illustrating a layer configuration of the photoconductor of the present invention.

FIG. 3 is a cross-sectional view illustrating the image forming apparatus of the present invention.

DESCRIPTION OF SYMBOLS 8 Elastic rubber blade 9 Elastic rubber blade support member 11 Laser light source of image writing section 14 Photoconductor drum 15 Charging unit 16 Developing unit 17 Transfer pole 19 Separating pole 20 Fixing device 21 Cleaning device 22 Pre-charge exposure lamp

Continued on the front page (72) Inventor Yoko Kitahara 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Takeshi Shimoda 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Isao Endo Tokyo Konica Corporation, 2970 Ishikawa-cho, Hachioji-shi, Tokyo

Claims (6)

[Claims] 1. An electrophotographic image forming method comprising a cleaning member for cleaning a surface of an organic photoreceptor provided with a photosensitive layer on a conductive support with an elastic rubber blade, wherein static friction between the photoreceptor and the elastic rubber blade is provided. Coefficient μa
And the dynamic friction coefficient μb satisfy the following relationship, and the elastic rubber blade is substantially held on a photosensitive member contact surface side of a blade by a support member for fixing the blade to the cleaning member. Contacting in the counter direction. μa ≦ 1.5 0.1 ≦ μa−μb ≦ 1.0 2. An electrophotographic image forming apparatus having a cleaning member for cleaning a surface of an organic photoreceptor having a photosensitive layer provided on a conductive support with an elastic rubber blade, wherein static friction between the photoreceptor and the elastic rubber blade is provided. Coefficient μa
And the dynamic friction coefficient μb satisfy the following relationship, and the elastic rubber blade is substantially held on a photosensitive member contact surface side of a blade by a support member for fixing the blade to the cleaning member. An electrophotographic image forming apparatus, wherein the image forming apparatus contacts the counter direction. μa ≦ 1.5 0.1 ≦ μa−μb ≦ 1.0 3. The blade has a rubber hardness of 55 to 75 °,
The electrophotographic image forming method according to claim 1, wherein the rebound resilience is 30 to 70%, and the plate thickness is 1 mm or more and 5 mm or less. 4. The electrophotographic image forming method according to claim 1, wherein an end surface of the blade in the length direction of the photosensitive member contact surface is subjected to a square cutting process. 5. The method according to claim 1, wherein the blade has a rubber hardness of 55 to 75 °,
3. The electrophotographic image forming apparatus according to claim 2, wherein the rebound resilience is 30 to 70%, and the plate thickness is 1 mm or more and 5 mm or less. 6. The electrophotographic image forming apparatus according to claim 2, wherein an end surface of the blade in the length direction of the photosensitive member contact surface is subjected to a square cutting process.