JPH05150696A - Cleaning method - Google Patents

Abstract

PURPOSE:To prevent a cleaning blade from being peeled up and inverted by contact with a photosensitive body and to enable the stable removal of a developer remaining on the surface of the photosensitive body even if the torque on the cleaning blade on the extreme surface layer of the photosensitive body is high at the time of removing the developer remaining on the surface of the photosensitive body by bringing the front end of the cleaning blade into pressurized contact with the surface of the photosensitive body. CONSTITUTION:The surface of the photosensitive body 2 in the part where both transverse ends of the cleaning blade 1 come into contact is constituted of a material having the torque to the cleaning blade 1 smaller by >=0.5kg.cm than to the extreme surface layer if the torque on the cleaning blade 1 on the extreme surface layer of the photosensitive body 2 with which the cleaning blade 1 is brought into pressurized contact is >=4.0kg.cm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine or a printer, in which a toner image formed on the surface of a photoconductor is transferred onto a transfer paper, and then the surface of the photoconductor is cleaned with a cleaning blade. The cleaning blade removes the developer remaining on the surface of the photoconductor by pressing the tip of the cleaning blade, and in particular, the outermost surface layer of the photoconductor that presses the cleaning blade is the torque against the cleaning blade. The present invention relates to a cleaning method in the case of using a photoconductor composed of a material having a high

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, a toner image formed on the surface of a photoconductor is conventionally transferred onto a transfer paper, and then the developer remaining on the surface of the photoconductor is removed. In order to remove from the surface of the photoconductor, generally, the tip of the cleaning blade made of a material such as urethane rubber is brought into pressure contact with the surface of the photoconductor, and the developer remaining on the surface of the photoconductor as described above. Was removed by this cleaning blade.

Here, as the above-mentioned photoreceptor, selenium,
In addition to the photoconductor on which an inorganic photosensitive layer such as cadmium sulfide and amorphous silicon is formed, a photoconductor on which an organic photosensitive layer formed by mixing a photosensitive material with a binder resin is also widely used. became.

However, in the photoconductor in which the organic photosensitive layer is formed by mixing the photosensitive material with the binder resin as described above, the hardness of the organic photosensitive layer on the surface thereof is generally low, and thus the tip of the cleaning blade as described above. When the cleaning blade removes the developer remaining on the surface of the photosensitive member by pressing the portion against the surface of the photosensitive member, the photosensitive layer on the surface of the photosensitive member is contacted with the cleaning blade. There was a problem that it was gradually scraped.

Therefore, in recent years, a surface protective layer made of an amorphous hydrocarbon film is provided on the surface of a photoreceptor on which an organic photosensitive layer containing a resin component is formed as described above by a method such as plasma polymerization. A photoreceptor has been used in which the surface protection layer suppresses abrasion of the photosensitive layer by a cleaning blade.

However, when the surface protective layer made of an amorphous hydrocarbon film is provided on the surface of the photoconductor by the method such as the plasma polymerization method, the friction coefficient on the surface of the photoconductor becomes high, and the photoconductor has a high friction coefficient. When the cleaning blade was brought into pressure contact with the surface of the above, the torque of the photoreceptor with respect to the cleaning blade was increased.

For this reason, the cleaning blade is brought into pressure contact with the surface of the photoconductor on which the surface protective layer made of the amorphous hydrocarbon film is provided, and the photoconductor is driven in this state. When the developer remaining on the surface of the photoconductor is removed, the cleaning blade is turned up by friction with the photoconductor or flipped over. As a result, the cleaning blade remains on the surface of the photoconductor. There arises a problem that the developer cannot be sufficiently removed by the cleaning blade.

[0008]

SUMMARY OF THE INVENTION According to the present invention, after a toner image formed on the surface of a photoconductor is transferred onto a transfer paper,
An object of the present invention is to solve the above-mentioned problems in the case where the tip of the cleaning blade is brought into pressure contact with the surface of the photoconductor to remove the developer remaining on the surface of the photoconductor with the cleaning blade.

That is, in the present invention, when the cleaning blade is used to remove the developer remaining on the surface of the photoconductor by pressing the tip of the cleaning blade against the surface of the photoconductor, the surface of the photoconductor is amorphous. Even when the friction coefficient of the outermost surface layer of the photoconductor is increased and the torque of the photoconductor with respect to the cleaning blade is increased due to the provision of the surface protective layer made of a high-quality hydrocarbon film, etc. It is an object of the present invention to prevent the developer remaining on the surface of the photoconductor from being stably removed by a cleaning blade without being flipped up or reversed by friction with the photoconductor.

[0010]

According to the present invention, in order to solve the above-mentioned problems, the tip of the cleaning blade is brought into pressure contact with the surface of the photoconductor to remove the developer remaining on the surface of the photoconductor. In the cleaning method which is designed to be removed by the cleaning blade, the torque applied to the cleaning blade at the outermost surface layer of the photosensitive member which is brought into pressure contact with the cleaning blade is 4.0 k.
In the case of g · cm or more, the surface of the photoconductor at the portion where both ends in the width direction of the cleaning blade come into contact is made of a material having a torque smaller than the outermost surface layer by 0.5 kg · cm or more for the cleaning blade. I did so.

Here, when the surface of the photoconductor at the portion where the widthwise ends of the cleaning blade come into contact with each other as described above is made of a material whose torque to the cleaning blade is smaller than the outermost surface layer by 0.5 kg · cm or more. For example, a photosensitive layer made of a material whose torque to the cleaning blade is smaller than the outermost surface layer by 0.5 kg · cm or more is provided below the outermost surface layer, or the conductive support of the photosensitive body is set to the above-mentioned uppermost layer. Torque on the cleaning blade from the surface layer is 0.5 kg · c
The photosensitive layer and the conductive support are exposed at the portions where both ends in the width direction of the cleaning blade come into contact with each other, and thus the photosensitive layer and the conductive support are exposed. The both ends of the cleaning blade in the width direction are brought into contact with each other, and the torque to the cleaning blade is 0.5 kg · cm from the outermost surface layer on the surface of the photoconductor at the portion where the both ends of the cleaning blade in the width direction contact. It is possible to provide another outermost surface layer made of a small material as described above and to contact both end portions in the width direction of the cleaning blade with the other outermost surface layer.

The photosensitive member and the cleaning blade used in the present invention have a width direction of the cleaning blade when the torque applied to the cleaning blade in the outermost surface layer of the photosensitive member is 4.0 kg · cm or more as described above. Any material as long as it satisfies the condition that the surface of the photoreceptor at the portion where both ends are in contact is made of a material having a torque of 0.5 kg · cm or more smaller than the outermost surface layer with respect to the cleaning blade. It may be configured with.

Further, in the present invention, in order to more reliably prevent the cleaning blade from flipping up and turning over due to friction with the photoconductor, the photoconductor which both ends in the width direction of the cleaning blade come into contact with each other. It is desirable that the surface of the above is made of a material having a torque with respect to the cleaning blade of less than 4.0 kg · cm.

Under such conditions, when the tip of the cleaning blade is pressed against the surface of the photoconductor to remove the developer remaining on the surface of the photoconductor with the cleaning blade, the surface of the photoconductor is removed. Between the contact surface of the cleaning blade and the tangent line of the photoreceptor at the contact point, that is, the contact angle of the cleaning blade is 8 to 20 °, and the contact pressure of the cleaning blade to the photoreceptor is 0.1 to 10 g / mm. It is preferable to set so that

When the cleaning blade is pressed against the surface of the photosensitive member to remove the developer remaining on the surface of the photosensitive member as described above, the cleaning blade keeps the cleaning agent constant for a long time depending on the type of the photosensitive member used. When the half image is copied, there are some things that cause so-called contact memory where the contact part appears as image noise when the position of is continuously pressed.Therefore, when the photoconductor is not rotating, the cleaning blade is exposed. It is preferable to keep it away from the body surface.

[0016]

According to the present invention, the tip of the cleaning blade is pressed against the surface of the photoconductor as described above to remove the developer remaining on the surface of the photoconductor with the cleaning blade. When the torque to the cleaning blade in the outermost surface layer of the photoconductor is 4.0 kg · cm or more, the surface of the photoconductor in the portion where both ends in the width direction of the cleaning blade contact is Torque for cleaning blade is 0.5k
Since the cleaning blade is made of a material smaller than g · cm, even if the center of the cleaning blade that comes into contact with the outermost surface layer is turned upside down or the force of reversing acts, both ends of the cleaning blade in the width direction come into contact with each other. Since the torque applied to the part is weak, at both ends in the width direction of this cleaning blade, the force that acts on the central part of the cleaning blade as described above, such as curling up or reversing, is released, and the cleaning blade contacts the photoreceptor. There is no need to flip up or flip over.

Further, when the surface of the photoconductor which the widthwise ends of the cleaning blade come into contact with is made of a material having a torque with respect to the cleaning blade of less than 4.0 kg.cm, cleaning at the widthwise ends of the cleaning blade is performed. The blade slides well, and the force acting on the cleaning blade in the central portion thereof to be turned up or to turn over is released more smoothly, so that the cleaning blade is surely prevented from turning over and turning over.

[0018]

EXAMPLE An example of a specific cleaning method for removing the developer remaining on the surface of the photoconductor by bringing the tip of the cleaning blade into pressure contact with the surface of the photoconductor will be described below. By comparing the cleaning method satisfying the condition of the invention with the cleaning method not satisfying the condition of the invention, it is revealed that the cleaning method satisfying the condition of the invention is excellent.

Here, an example of the cleaning device used for carrying out these cleaning methods will be specifically described with reference to FIG.

Here, the cleaning device 10 shown in FIG.
In this case, a flat plate-shaped cleaning blade 1 is used, the cleaning blade 1 is held by a blade holding member 11, and the tip of the cleaning blade 1 rotates at a high peripheral speed of 26 to 50 cm / sec. It was made to press-contact with the surface of.

When the tip portion of the cleaning blade 1 is brought into pressure contact with the surface of the rotating photoconductor 2 as described above, the blade holding member 11 holding the cleaning blade 1 is attached to the end portion of the pressure adjusting spring. The cleaning blade 1 is attached to the pressing member 13 provided with the pressure adjusting spring 12, and the tip of the cleaning blade 1 is brought into pressure contact with the surface of the photoconductor 2 rotating as described above by the urging force of the pressure adjusting spring 12.

In order to adjust the angle of the cleaning blade 1 which is brought into pressure contact with the surface of the photosensitive member 2 in this manner, the blade holding member 11 for holding the cleaning blade 1 has a proper shape, The angle of the cleaning blade 1 with respect to the photoconductor 2 is adjusted.

Then, here, the contact surface 1a of the cleaning blade 1 contacting the photoconductor 2 and the tangent line X of the photoconductor 2 at the contact point are formed on the rotation direction side of the photoconductor 2 at the pressure contact angle of the cleaning blade 1. The angle θ is set to 15 °, and the pressure contact force of the cleaning blade 1 to the photoconductor 2 is adjusted by the pressure adjusting spring 12 so that the pressure contact force of the cleaning blade 1 to the photoconductor 2 becomes 8 g / cm. I did it.

In this way, the tip of the cleaning blade 1 is brought into pressure contact with the surface of the photoconductor 2 rotating at a high peripheral speed of 26 cm / sec or more, and the cleaning blade 1 allows the surface of the photoconductor 2 to remain. The developer that has been scraped off is scraped off, and the thus scraped off developer is attached to the rotary blade holder 14.
The developer scraped by the collecting blade 16 is conveyed to the collecting blade 16 in the rotary blade holder 14 by 5 and is collected in a collecting bottle (not shown).

Next, as shown in FIG. 2, the cleaning device 10 as described above is mounted on the electrophotographic device 20, and the cleaning device 10 causes the photoreceptor 2 after transfer to be completed.
The case of removing the developer remaining on the surface of is specifically described.

Here, as the electrophotographic apparatus 20,
Commercially available copy machine (EP87 manufactured by Minolta Camera Co., Ltd.)
0) is modified, and depending on the charging polarity of the photoconductor 2 to be used,
Transfer the cleaning device 10 described above by using a device that can switch between positive charging and negative charging.
It was arranged between the separator 21 and the eraser lamp 22.

Then, the photoconductor 2 to be tested is mounted on the electrophotographic apparatus 20, and the photoconductor 2 is 26 to 50 cm / cm 2.
After being rotated at a high speed of sec, the surface of the photoconductor 2 is charged by the charger 23, and then exposure is performed based on image information by the optical system 24 to form an electrostatic latent image on the surface of the photoconductor 2. To form.

Next, a developer is supplied from the developing device 25 to the electrostatic latent image thus formed on the surface of the photoconductor 2,
A toner image is formed on the surface of the photoconductor 2.

Then, the toner image thus formed on the surface of the photoconductor 2 is transferred to the recording paper 2 via the transfer / separator 21.
The toner image thus transferred is fixed on the recording paper 26 by the fixing roller 27, and then the recording paper 26 is discharged to the discharge tray 28.

On the other hand, after the toner image is transferred from the photoconductor 2 to the recording paper 26 as described above, the cleaning device 1
0, the tip of the cleaning blade 1 is brought into pressure contact with the surface of the photoconductor 2 rotating as described above, and the developer remaining on the surface of the photoconductor 2 is scraped off by the cleaning blade 1. , The surface of the photoconductor 2 is removed from the surface of the photoconductor 2 and then the eraser lamp 2
I tried to eliminate the charge with 2.

Next, using the electrophotographic apparatus 20 as described above, the type of the cleaning blade 1 to be brought into pressure contact with the surface of the photoconductor 2, the type of the photoconductor 2 to be used, and the photoconductor 2
By changing the state where the cleaning blade 1 is in contact with the surface of the cleaning blade 1 and removing the developer remaining on the surface of each photoconductor 2 by each cleaning blade 1, the occurrence of curling or reversal of the cleaning blade 1 is examined. I did it.

Here, as the cleaning blade 1, the following two types of cleaning blades A1 and A2 made of urethane rubber were used.

In the cleaning blade A1, as the urethane rubber, the product number 23 manufactured by Hokushin Kogyo Co., Ltd.
8678 was used, and in the cleaning blade A2, product number 231780 manufactured by Hokushin Kogyo Co., Ltd. was used as the urethane rubber.

Incidentally, each of these cleaning blades A
The thickness, Young's modulus, tensile strength and impact resilience of the blades 1 and A2 are as shown in Table 1 below.

[0035]

[Table 1]

As the photosensitive member 2, first, two kinds of photosensitive members B and C were manufactured as follows.

In producing the photoconductor B, the conductive support is made of an aluminum alloy containing 0.7% by weight of magnesium and 0.4% by weight of silicon and has an outer diameter of 80 mm. A cylindrical shape having a length of 340 mm and a wall thickness of 2 mm was used.

Then, in order to form a charge generation layer on the conductive support, 0.45 parts by weight of an azo compound represented by the following structural formula (Formula 1) and a polyester resin (Vylon 200, manufactured by Toyobo Co., Ltd.) are used. 0.45 parts by weight and 50 parts by weight of cyclohexanone were put into a sand grinder and dispersed for 24 hours to prepare a charge generation layer coating solution having a viscosity of 20 cp at 20 ° C.

[0039]

[Chemical 1]

Then, the above conductive support is immersed in the thus prepared charge generating layer coating liquid, and the charge generating layer coating liquid is applied to the surface of this conductive support by a dipping method. Then, this is circulated in circulating air at 20 ℃ for 30
After drying for a minute, a film thickness of 0.3μ is formed on the surface of the conductive support.
m charge generating layer was formed.

Next, in order to form a charge transport layer on this charge generating layer, 10 parts by weight of a styryl compound represented by the following structural formula (Formula 2) and a polycarbonate resin (Panlite K-1300 manufactured by Teijin Chemicals Ltd.) are used. 20 parts by weight of 7 parts by weight were dissolved in a solvent consisting of 40 parts by weight of 1,4-dioxane.
A coating liquid for charge transport layer having a viscosity at 240 ° C. of 240 cp was prepared.

[0042]

[Chemical 2]

Then, the conductive support having the charge generating layer formed thereon as described above is dipped in the coating liquid for the charge transport layer, and the charge generating layer formed on the conductive support is dipped by a dipping method. The above charge transport layer coating liquid was applied, and this was dried in circulating air at 100 ° C. for 30 minutes to form a charge transport layer having a film thickness of 32 μm.

Further, in manufacturing the photoconductor C,
In the production of the photoconductor B, 10% of the polycarbonate resin used for forming the charge transport layer is replaced with a fluororesin, and otherwise the photoconductor B is used.
Photoreceptor C was manufactured in the same manner as in (1).

Then, a surface protective layer made of an amorphous hydrocarbon film is provided on the surface of the two kinds of photoconductors B and C thus obtained by the plasma-CVD apparatus shown in FIG. I chose

Here, in the plasma-CVD apparatus shown in FIG. 3, the first to sixth tanks 101 to 106 are made to seal the raw material and the carrier gas in a vapor phase state at room temperature, and each of these tanks is sealed. 101-106,
Corresponding first to sixth control valves 107 to 112, respectively.
And the first to sixth flow rate controllers 113 to 118 are connected.

Further, the first to third containers 119 to 121 are made to enclose the raw materials in a liquid phase or solid state at room temperature, and the respective raw materials enclosed in these containers 119 to 121 are enclosed. In order to vaporize, each container 119-1
21 corresponding to the first to third temperature controllers 122-1
24 are provided. Furthermore, each of these containers 119-12
1 to the corresponding seventh to ninth control valves 125 to 125, respectively.
127 and the seventh to ninth flow rate controllers 128 to 130 are connected.

After these gases are mixed in the mixer 131, they are fed into the reaction chamber 133 via the main pipe 132. In the middle of the pipe part, the pipe heater 134 can be placed and heated at an appropriate position of the pipe part so that the gas obtained by vaporizing the raw material compound in the liquid phase or the solid phase at room temperature does not condense. I am trying.

Also in the reaction chamber 133, the reaction chamber heater 1 is provided around it so that the gas obtained by vaporizing the raw material compound in the liquid phase or the solid phase at room temperature does not condense.
51 is arranged so that heating can be performed.

In the reaction chamber 133,
As the ground electrode 135, the drum-shaped photoreceptor 2 manufactured as described above is used.
The electrode heater 137 is placed inside the
The power applying electrode 13 having a cylindrical shape is also provided around 35.
6 is arranged, and an electrode heater 137 is further provided outside thereof.
These electrodes 135 and 136 are respectively connected to the electrode heater 1
It can be heated by 37.

As for the photoconductor 2 used as the ground electrode 135 as described above, the photoconductor 2 can be rotated from the outside by using the drive motor 154.

On the other hand, the high-frequency power matching device 13 is connected to the power applying electrode 136 via the connection selection switch 144.
8 is provided, the low-frequency power supply 141 provided with the low-frequency power matching device 140, and the DC power supply 143 provided with the low-pass filter 142 are connected to each other. Different powers can be appropriately selected and applied.

Further, a pressure control valve 145 is provided to adjust the pressure in the reaction chamber 133, and the reaction chamber 13
When the pressure inside 3 is reduced, it is performed by the diffusion pump 147 and the oil rotary pump 148 via the exhaust system selection valve 146, or by the cooling exclusion device 149, the mechanical booster pump 150, and the oil rotary pump 148. There is. It should be noted that the exhaust gas is further detoxified with safety through an appropriate exclusion device 153 and then exhausted into the atmosphere.

Also in these exhaust system pipes, the pipe heater 134 is arranged at an appropriate position so that the gas obtained by vaporizing the raw material compound in the liquid phase or the solid phase at room temperature does not condense on the way. And is able to heat.

When a surface protection layer made of an amorphous hydrocarbon film is provided on the photoconductor 2 used as the ground electrode 135 by using this plasma-CVD apparatus, the reaction chamber 133 is generally set in the diffusion pump 147. By 1
The pressure is reduced to about 0 ⁻⁴ to 10 ⁻⁶ Torr, the degree of vacuum is confirmed and the gas adsorbed inside the apparatus is desorbed, and, if necessary, the photoconductor 2 used as the ground electrode 135 by the electrode heater 137. The temperature is raised to a predetermined temperature.

When the temperature of the photoconductors 2 is increased in this manner, the temperature of the organic photoconductive layers formed on the photoconductors 2 is kept at 100 ° C. or less (normal temperature to room temperature to prevent thermal denaturation). 100 ° C.).

Next, each of the first to sixth tanks 101 to 1
06 and the first to third containers 119 to 121 to appropriately supply hydrocarbon-based raw material gas to the first to ninth flow rate controllers 113 to
It is introduced into the reaction chamber 133 while making the flow rate constant using 118 and 128 to 130, and the pressure inside the reaction chamber 133 is kept constant by the pressure adjusting valve 145. The pressure in the reaction chamber 133 at this time is set to about 0.3 to 3 Torr.

After the gas flow rate is stabilized, the connection selection switch 144 selects, for example, the low-frequency power source 141, and the low-frequency power is applied to the power application electrode 136 to discharge between the electrodes 135 and 136. Then, the solid phase film is formed on the surface of the photoconductor 2 used as the ground electrode 135.

When the solid phase film is formed on the surface of the photoconductor 2 as described above, the film thickness is controlled by the reaction time and the discharge is stopped when the predetermined film thickness is reached. A surface protective layer made of a desired amorphous hydrocarbon film is provided on the surface of 2.

When the surface protective layer made of an amorphous hydrocarbon film is provided on the photoconductor 2 in this manner, oxygen, nitrogen, and the third element of the periodic table are added to the amorphous hydrocarbon film, if necessary.
Impurities such as group atoms, group 4 atoms of the periodic table, and group 5 atoms of the periodic table may be contained.

Here, using butadiene as the source gas,
When the surface protective layer made of the amorphous hydrocarbon film is provided on the surface of the photoconductor on which the organic photosensitive layer is formed, the amorphous hydrocarbon film formed is as follows. Has physical properties. Hole mobility 10 ⁻⁷ to 10 ⁻¹⁰ [cm ² / V
/ Sec] Electronic mobility 10 ⁻⁷ to 10 ⁻¹⁰ [cm ² / V
/ Sec] Ionization potential 5.0 to 5.8 [eV] Optical band gap 2.0 to 2.8 [eV] Relative permittivity 2.4 to 3.0 Visible light absorption coefficient 200 to 4000 [l / c
m] spin density 2.0 × 10 ^{18 to} 9.0 × 1
0 ¹⁹ [l / cm] Flexibility 1.5-1.7 Vickers hardness 200-1000 Thermal conductivity 5-12 [W / mK]

Depending on the raw material gas used, there are some that deviate from the above-mentioned physical properties, but the surface protective layer formed on the surface of the photosensitive member and formed of an amorphous hydrocarbon film is generally one of the following 1 to 4. It has structural features. 1. Contain at least carbon atoms and hydrogen atoms. 2. Having a C = C bond in the structure. 3. Having a dangling bond in the structure. 4. It has an amorphous structure and has no clear peak in X-ray diffraction or Raman scattering.

Here, in this experiment, the above-mentioned plasma was applied to the surfaces of the photoconductors B and C manufactured as described above.
When providing a surface protective layer made of an amorphous hydrocarbon film by using a CVD apparatus, the types of source gas and carrier gas thereof and their flow rates, the degree of vacuum in the reaction chamber, the photoreceptor used as the ground electrode, and the power application electrode And the distance between the electrodes, the number of rotations of the photoconductor used as the ground electrode, the power applied to the power application electrode from the power supply and its frequency, the temperature at which the photoconductor is heated by the electrode heater, the surface of the photoconductor is amorphous. Film formation time and film thickness of the surface protection layer when a surface protection layer made of a porous hydrocarbon film is provided under the four kinds of film formation conditions shown in Table 2 below, and four kinds of amorphous hydrocarbon films The surface protective layers D1 to D4 are formed.

[0064]

[Table 2]

Regarding the photoconductor B, the surface protective layers D1 to D4 made of the above-mentioned four types of amorphous hydrocarbon films were provided on the outermost surface thereof under the film forming conditions 1 to 4 4
Create a type of photoconductor, and for the photoconductor C,
Three types of photoconductors provided with the surface protective layers D1 to D3 made of three types of amorphous hydrocarbon films were prepared under the above film forming conditions 1 to 3.

Further, in this experiment, when the tip of the cleaning blade is pressed against the surface of each photoconductor, the tip of the cleaning blade is brought into contact with the surface of the photoconductor in four states as shown in FIGS. It was made to press against.

Here, in the structure shown in FIG. 4, the photoconductor 2 is manufactured at both axial ends of the photoconductor 2 having the surface protective layer 2c made of an amorphous hydrocarbon film on the outermost surface. The conductive support 2a used for the exposure is exposed, and a roller (not shown) in the developing device (not shown) is brought into contact with the exposed portion of the conductive support 2a. The surface protective layer 2c on the outermost surface of the photoconductor 1 is in contact with both ends in the width direction of the cleaning blade 1 which is pressed against the surface of the photoconductor 2.
The organic photosensitive layer 2b under the surface protective layer 2c was exposed without providing the above, and both widthwise ends of the cleaning blade 1 were brought into contact with the organic photosensitive layer 2b thus exposed.

Further, in the structure shown in FIG. 5, as in the structure shown in FIG. 4, both axial ends of the photoconductor 2 having the surface protective layer 2c made of an amorphous hydrocarbon film on the outermost surface thereof. Section, the conductive support 2a used to manufacture the photoconductor 2 is exposed, and the conductive support 2a is thus exposed.
While a roller (not shown) in a developing device (not shown) is brought into contact with the exposed portion of the photosensitive member 2, the above-mentioned surface protective layer 2c is provided on the other portion of the photoconductor 2, and the cleaning blade 1 The entire tip portion of was contacted with the surface protective layer 2c.

Further, in the structure shown in FIG. 6, the width of the conductive support 2a exposed at both axial ends of the photoconductor 2 having the surface protective layer 2c made of an amorphous hydrocarbon film on the outermost surface. The width of the cleaning blade 1 pressed against the surface of the photoconductor 2 in the width direction is in contact with the exposed conductive support 2a.

Further, in the structure shown in FIG. 7, similarly to the structure shown in FIGS. 4 and 5, the photosensitive member 2 having the surface protective layer 2c made of an amorphous hydrocarbon film on the outermost surface is provided. At both ends in the axial direction, the conductive support 2a used for manufacturing the photoconductor 2 is exposed, and a roller (not shown) in a developing device (not shown) is exposed at the exposed part of the conductive support 2a. (Not shown) is made to abut, and the surface protection layer 2c on the outermost surface is not provided on one side (right side in the example shown in the drawing) of the photoconductor 2 under the surface protection layer 2c. A certain organic photosensitive layer 2b is exposed, and one end in the width direction of the cleaning blade 1 is brought into contact with the organic photosensitive layer 2b thus exposed,
In the other portions, the cleaning blade 1 was brought into contact with the surface protective layer 2c.

Here, each of the above cleaning blades A
1, A2 are conductive supports used for manufacturing the photoconductors B and C, the respective photosensitive layers formed on the photoconductors B and C, and the photoconductor B,
Each cleaning blade A1, A2 when brought into contact with each surface protective layer D1 to D4 provided on the surface of C
These torques were measured for the and the results are shown in Table 3 below.

Here, in measuring these torques, the electrophotographic apparatus 20 is used, and a torque gauge (TP-10KCE, manufactured by Kyowa Denki Co., Ltd.) is attached to the drive shaft for rotating the object to be measured. Each torque was measured using an amplifier WGA-700A (trade name) manufactured by the same company. In addition, in this measurement,
The object to be measured was rotated at a peripheral speed of 38 cm / sec.

[0073]

[Table 3]

Then, the electrophotographic apparatus 2 shown in FIG.
0 is used to press the cleaning blade 1 against the surface of the photoconductor 2 to remove the developer remaining on the surface of the photoconductor 2. , Types of the cleaning blades A1 and A2, types of the photoconductors B and C, and surface protection layers D1 to D4 provided on the surfaces of the photoconductors B and C.
Tables 4 to 6 below show the types, the contact state between the cleaning blade and the photoconductor (FIGS. 4 to 7), and the rotation speed of the photoconductor.
The experiment was performed by changing the settings as shown in.

Here, in performing these experiments, in the electrophotographic apparatus 20, the surface of the photoconductor 2 was charged to −800 V by the charger 23, and the surface of the photoconductor 2 charged in this way was optically. Exposure is performed from the system 24 using a 6% chart to form an electrostatic latent image on the surface of the photoconductor 2, and then a developer is supplied from the developing device 25 to the surface of the photoconductor 2 to A toner image is formed on the electrostatic latent image portion formed on the surface of the photoconductor 2, and the toner image thus formed on the surface of the photoconductor 2 is transferred to the recording paper 26, and then remains on the surface of the photoconductor 2. The cleaning toner is removed by the cleaning blade 1.

When the developer is supplied from the developing device 25 as described above to form a toner image on the surface of the photoconductor 1, the developer is a two-component system containing toner and carrier. I decided to use it.

As the toner in the developer, 100 parts by weight of styrene-n-butyl methacrylate resin (softening point 132 ° C., glass transition point 60 ° C.) and carbon black (MA # 8 manufactured by Mitsubishi Kasei Co., Ltd.) are used. 5 parts by weight, Nigrosine dye (manufactured by Orient Chemical Co., Ltd., Bontron N-01) 3 parts by weight, low molecular weight polypropylene (manufactured by Sanyo Kasei Co., Ltd., Viscole 550P) 2
Mix well with 1 part by weight in a ball mill, then
After kneading on a triple roll heated to 40 ° C., this was left to cool and then coarsely pulverized using a Fizer mill and further finely pulverized with a jet mill. And
The powder thus finely pulverized was classified by wind force, and a positively chargeable toner having an average particle diameter of 9 μm was used.

When using this toner, 0.01 parts of colloidal silica R-974 (trade name) manufactured by Nippon Aerosil Co., Ltd. is used with respect to 100 parts by weight of this toner.
A part which was post-treated by adding parts by weight was used.

On the other hand, as the carrier, polyester resin (softening point 123 ° C., glass transition point 65 ° C., AV23,
OHV40) 100 parts by weight, Fe-Zn ferrite fine particles (TMD-2, MRP-2) 500 parts by weight, carbon black (Mitsubishi Kasei Co., MA #).
8) 2 parts by weight are sufficiently mixed and crushed by a Henschel mixer, and then the mixture is melted and kneaded by using an extrusion kneader set to a cylinder part 180 ° C. and a cylinder head part 170 ° C., and this kneaded product is cooled. After that, coarse pulverization was performed with a Fizer mill, fine pulverization was further performed with a jet mill, and classification was performed using a classifier so that a carrier having an average particle size of 60 μm was used.

As described above, the cleaning blade 1 removes the toner remaining on the surface of the photoconductor 2 to perform a printing durability test on 5,000 sheets, and during the printing durability test, the cleaning blade is turned up and The case where the reversal occurred even once was evaluated as x, and the case where the cleaning blade was not flipped or never occurred was evaluated as the good, and the results are shown in Tables 4 to 6 below.

[0081]

[Table 4]

[0082]

[Table 5]

[0083]

[Table 6]

As is clear from these results, as shown in FIG. 5, the entire tip of the cleaning blade 1 pressed against the surface of the photosensitive member 2 has a torque of 4.0 kg.cm for the cleaning blade 1. As shown in FIG. 7, only one end of the cleaning blade 1 which is brought into contact with the surface protective layer 2c is pressed against the surface of the photoconductor 2 from the surface protective layer 2c to the cleaning blade 1. Those which are only brought into contact with the photosensitive layer 2b having a low torque, or those in which both ends of the cleaning blade 1 are brought into contact with the photosensitive layer 2b located below the surface protective layer 2c as shown in FIG. Even if the torque difference between the photosensitive layer 2b and the surface protective layer 2c with respect to the cleaning blade 1 is less than 0.5 kg · cm, Of turning up and inverted cleaning blade 1 occurs during the serial printing test.

On the other hand, in any of the experiments conducted under the conditions of the present invention, the cleaning blade 1 was not turned over or turned over, and the toner remaining on the surface of the photoconductor 2 was stabilized. Could be removed.

[0086]

As described above in detail, in the cleaning method according to the present invention, the tip of the cleaning blade is brought into pressure contact with the surface of the photoconductor to remove the developer remaining on the surface of the photoconductor. When the torque for the cleaning blade in the outermost surface layer of the photoconductor to which the cleaning blade is brought into pressure contact with the cleaning blade is 4.0 kg · cm or more, the photoconductor at the portion where both ends in the width direction of the cleaning blade come into contact with each other is removed. Since the surface of the cleaning blade is made of a material having a torque for the cleaning blade smaller than that of the outermost surface layer by 0.5 kg · cm or more, the cleaning blade is liable to turn up or turn over at its central portion in contact with the outermost surface layer. Even the width of this cleaning blade Since the torque applied to both ends in the opposite direction is weak, the above-mentioned force acting on the central part of the cleaning blade is released at both ends in the width direction of this cleaning blade, and the cleaning blade flips up or turns over due to contact with the photoconductor. There is no longer a problem.

As a result, when the cleaning blade is used to remove the developer remaining on the surface of the photosensitive member by the cleaning method according to the present invention, the surface of the photosensitive member is an amorphous hydrocarbon having a high torque to the cleaning blade. Even when a surface protective layer made of a film is provided, the cleaning blade does not flip up or turn over due to contact with the photoconductor, and the developer remaining on the surface of the photoconductor is stably stabilized by the cleaning blade. It can now be removed.

Further, in the present invention, when the surface of the photoconductor which the widthwise ends of the cleaning blade come into contact with is made of a material having a torque of less than 4.0 kg · cm for the cleaning blade, It is possible to more reliably prevent the cleaning blade from being turned over or reversed due to contact, and it is possible to more stably remove the developer remaining on the surface of the photoconductor by the cleaning blade.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a cleaning device used for conducting an experiment.

FIG. 2 is a schematic cross-sectional view of an electrophotographic apparatus using the cleaning device used for conducting an experiment.

FIG. 3 is a schematic view showing a plasma-CVD apparatus used for providing a surface protective layer made of an amorphous hydrocarbon film on the surface of a photoreceptor.

FIG. 4 is a diagram showing a state in which a cleaning blade is brought into pressure contact with the surface of a photoconductor, in which the central portion of the cleaning blade is in contact with the surface protective layer, while both ends of the cleaning blade are in contact with the photosensitive layer. is there.

FIG. 5 is a diagram showing a state in which the cleaning blade is brought into pressure contact with the surface of the photoconductor, and a state in which the entire cleaning blade is in contact with the surface protective layer.

FIG. 6 shows a state in which the cleaning blade is brought into pressure contact with the surface of the photosensitive member, showing a state where the central portion of the cleaning blade is in contact with the surface protective layer and both ends of the cleaning blade are in contact with the conductive support. It is a figure.

FIG. 7 is a diagram showing a state in which a cleaning blade is brought into pressure contact with the surface of a photoconductor, in which only one end of the cleaning blade is in contact with the photosensitive layer and the rest is in contact with the surface protective layer.

[Explanation of symbols]

 1 cleaning blade 2 photoconductor

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Shuji Iino 2-3-13 Azuchi-cho, Chuo-ku, Osaka City Osaka International Building Minolta Camera Co., Ltd. 3-13 No. 13 Osaka International Building Minolta Camera Co., Ltd.

Claims (2)

[Claims] 1. A cleaning method in which the tip of a cleaning blade is brought into pressure contact with the surface of the photoconductor and the developer remaining on the surface of the photoconductor is removed by the cleaning blade. When the torque for the cleaning blade in the outermost surface layer of the photosensitive member is 4.0 kg · cm or more, the surface of the photosensitive member in the portion where both ends in the width direction of the cleaning blade come in contact with the cleaning blade from the outermost surface layer. Torque is 0.5 kg
A cleaning method characterized in that it is made of a material having a size of at least cm. 2. The torque according to claim 1, wherein the cleaning blade has a torque of 4.0 kg.cm on the surface of the photoconductor that is in contact with both ends of the cleaning blade in the width direction.
A cleaning method characterized in that the cleaning method is composed of a material below.