JPH02282281A - Image forming device - Google Patents

Abstract

PURPOSE:To stably form a high-quality image for a long time by driving an electrostatic charging member so that it moves in terms of plane and subjecting an image carrier to the driving of the plane movement of the electrostatic charging member with contact frictional force between the electrostatic charging member and the image carrier. CONSTITUTION:A primary electrostatic charging roller 1 which is the electrostatic charging member is moved in terms of plane and a photostatic charging member is moved in terms of plane and a photosensitive drum 2 which is the image carrier is moved in terms of plane by being subjected to the driving of the plane movement of the roller 1 with the contact frictional force between the roller 1 and the drum 2. In such case, the hardness of the electrostatic charging member which comes in contact with the drum 2 to be driven to move in terms of plan is set <=30 degrees in JIS-A hardness. As to the surface hardness of the drum 2, load(scratch hardness) necessary for putting the scratch of 50mum width is>=15g at the time of setting the surface of the drum as a test surface, applying the vertical load to a diamond conical indenter(its conical angle is 90 deg. and it has a hemi-spherical tip whose diameter is 0.01mm) and moving the indenter along the test surface at the speed of 50mm/min.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention applies to copying machines, laser beam printers, LED printers,
The present invention relates to image forming devices such as liquid crystal printers and image display devices.

More specifically, the present invention relates to an image forming apparatus that forms an image by causing an image forming process means to act on an image carrier, including a means for charging (including discharging) the surface of the image carrier.

(Prior Art) As an example of a device for producing a bipedal image 1f', a schematic configuration 1 of a transfer-type/mutram-type electrophotographic device using the Calson process is shown in Fig. 13(a). Shown in b).

Reference numeral 2 denotes a drum-shaped electrophotographic photoreceptor (hereinafter referred to as photoreceptor drum) as an image carrier, which is driven to rotate clockwise as indicated by an arrow at a predetermined circumferential speed (process speed) around a support shaft 2a. be done.

During its rotation, the photosensitive drum 2 is sequentially charged uniformly to a predetermined negative potential by a negative charging means (corona charger in this example) 9, exposed to target image information 3, and developed by a developing device 4. As a result, a toner image corresponding to the target image information is formed on the circumferential surface of the photosensitive drum.

On the other hand, a transfer material 5 is fed from a paper feed section (not shown) to a transfer section between the photosensitive tram 2 and the transfer corona charger 6 in synchronization with the rotation of the drum 2. The toner images on the drum 2 side are sequentially transferred onto the surface.

The transfer material that has passed through the transfer section is separated from the two surfaces of the drum and is conveyed to a fixing device (not shown), where the image is fixed.

After the toner image has been transferred, the surface of the drum 2 is cleaned by a cleaning device 7 to remove residual toner and other adhered contaminants, and is also subjected to pre-exposure 8 (full-surface light irradiation) to erase electrical memory. The image is then repeatedly subjected to image formation.

GD (FIG. 6(b)) is a tram gear provided concentrically at one end of the photosensitive tram 2, M is a drive source motor of the drive system, and GM is a final gear of the drive system, which is the drum gear GD described above.
This is one mesh. The photosensitive drum 2 has a drive system motor M.
The rotating force is received through the final gear GM and the tram gear GD, and the shaft 2a is rotated in a predetermined direction at a predetermined circumferential speed around the support shaft 2a.

In addition to the rotating tram type, the image carrier 2 can also be of a rotating belt type, a running web type, or the like. In the case of electrostatic recording, the image carrier is a dielectric (insulator) of a rotating drum type, rotating heald type, running web type, etc., and the uniformly charged surface is selectively neutralized by a static eliminating means. A latent image is formed.

(Problems to be Solved by the Invention) As a means for uniformly primary charging the surface of an image carrier such as an electrophotographic photoreceptor or an electrostatic recording dielectric, a corona charger has conventionally been used in most cases. 7. That is, the image bearing member is charged by corona generated by applying a high voltage (DC 5 to 8 KV) to a metal wire, and has good uniform charging properties.

However, when corona occurs, corona products such as ozone and NOx alter the surface of the image carrier, causing blurring and deterioration of the image, and dirt on the wires affects the image quality, causing white spots and black lines in the image. was there. On the other hand, in terms of electric power, only 5 to 30% of the current flows toward the image carrier, and most of it flows through the shield plate, making it inefficient as a charging means.

Generally, to drive the image carrier, a drive gear is attached to the end of the image carrier, and the drive gear of the drive system is meshed with this gear, so that the driving force of the drive source motor of the drive system is transferred to the image carrier. However, this type of drive mechanism makes the device difficult to operate.

It is necessary that the width of the gear and near wire mounting section and motor be larger than the width of the transfer layer 5.

Furthermore, when the image bearing member is driven through gears, the teeth of the gear cause vibrations in the surface movement of the image bearing member, making charging, exposure, development, and transfer uneven, resulting in gear unevenness on the image. Sometimes I do.

The present invention aims to solve the problems mentioned in F in the conventional apparatus.

(Means for Solving the Problems) The present invention is an image forming apparatus that forms an image by causing an image forming process means to act on an image bearing member, including a means for charging the surface of the image bearing member, and the charging The processing means charges the surface of the image carrier by bringing the charging member into contact with the surface of the image carrier and moving it relatively.
(direct) charging means, wherein the charging member is driven to move in a plane, and the image carrier is driven to move in a plane by being driven by the plane movement of a charging portion by the frictional force of contact with the charging member. An image forming apparatus.

Further, the present invention is an image forming apparatus characterized in that the charging member which is driven in plane movement in contact with the image carrier has a hardness of 30 degrees or less in terms of JIS-A hardness.

Furthermore, in the above-mentioned apparatus, the present invention provides a method in which the surface hardness of the image carrier is determined by applying a vertical load to a diamond cone indenter (with a cone angle of 90° and a hemispherical tip with a diameter of 0.01 mm) using the surface of the image carrier as a test surface. 50mm/min along the test surface
The image forming apparatus is characterized in that the load (scratching hardness) required to make a scratch with a width of 50 μm is 15 grams or more when the image forming device is moved at a speed of .

(Function) Contact charging means (direct charging means) itself is already known;
It has advantages such as almost no generation of corona products such as ozone and the ability to lower the power supply voltage, so it is being considered to be used as a means of charging the image carrier instead of the corona charger, which has many problems. ing. In other words, in contact charging, a voltage (for example, 1 to 2 K
By contacting a conductive member (charging member) to which a DC voltage of Vn degree, or a superimposed voltage of DC voltage and AC voltage, etc. has been applied, charges are directly injected into the image carrier surface to maintain the image carrier surface at a predetermined level. It is charged to a potential, and roller charging type (JP-A No. 56-91253) and blade charging type (JP-A-58-1989) are used.
- IT14349 e No. 80-147758),
Charging/cleaning type (Japanese Patent Application Laid-Open No. 58-185188
No.) etc. have been devised.

The present invention eliminates the problems encountered when using a corona charger by charging an image carrier using this contact charging means.

Further, in the present invention, in the contact charging means, a charging member brought into contact with the image carrier is driven to move in a plane, and the image carrier is driven to move in a plane by following the plane moving drive of the charging member by the contact friction force with the charging member. In other words, since the charging member in contact with the image carrier is also used as the drive means for the image carrier, there is no need for a gear to drive the image carrier, and the device can be significantly downsized. It became.

Furthermore, since the image carrier is driven continuously, image defects (gear pitch unevenness) are eliminated.

Specifically, the image carrier can be in the form of a rotating drum, a rotating bell I type, a running web type, etc., and the charging member can be in the form of a rotating roller, a rotating belt, a running web type, etc. By keeping the charging member in contact with the surface of the image carrier with a predetermined pressing force and driving it to rotate, rotate, or travel, that is, drive the image carrier to move the surface of the image carrier, the charging member The surface movement drive of the charging member is driven by the contact friction force between the charging member and the charging member to rotate or rotate or run, that is, to drive the surface movement.

The charging member that is driven in plane movement in contact with the image carrier to contact charge the surface of the image carrier and driven in plane movement while the image carrier is driven is set to have a hardness of 30 degrees or less in JIS-A hardness. As a result, the surface movement of the image carrier can be stably and smoothly driven, and defects such as uneven charging can no longer occur.

In addition, the image carrier has a surface hardness of 15 g or more as determined by the above-mentioned measurement method, so that no scratches occur on the image carrier and high-quality image formation can be maintained stably over a long period of time. I can do it.

(Example) (1) Outline of device configuration FIG. 1 is a schematic configuration diagram of an example device according to the present invention, and this example device is also a transfer type/rotating drum type electronic This is a photographic device, and common constituent members and portions are given the same reference numerals and repeated explanations will be omitted.

The photosensitive drum 2 as an image carrier has support shafts 2a at both ends thereof.
is rotatably supported by a bearing (not shown).

Reference numeral 1 denotes a charging member of a contact charging means that comes into contact with the optical drum 2 and uniformly charges the drum surface primarily, and in this example, it is a roller body (hereinafter referred to as a -order charging roller).

The primary charging roller 1 has support shafts 1a at both ends thereof supported by bearings (not shown) to allow movement in the direction of the photosensitive tram and freely rotate. is applied to maintain the secondary charging roller l in full pressure contact with the photosensitive drum 1 with a predetermined pressing force.

Reference numeral 11 denotes a power source for applying a voltage to the negative and next charging roller 1, and in this example, the voltage is applied via the conductive roller support shaft 2a.

2nd Φ3 and 4 respectively show an example of a rotational drive mechanism for the secondary charging roller l. That is, in the example shown in FIG. 2, a gear 12 is coaxially attached to one end of the primary charging roller 1, and a drive gear 1 driven by a drive source motor 14 is attached to this gear 12.
3 are engaged with each other to transmit the rotational force of the motor 14 to the roller 1 via the gear 1311 and the gear 12, thereby rotating the roller 1 in a predetermined direction at a predetermined circumferential speed.

In the example shown in FIG. 3, a drive roller 15 rotated by a drive source motor 14 is brought into pressure contact with the surface of the primary charging roller 1, and the frictional force of contact with the drive roller 15 causes the primary charging roller 1 to be moved in a predetermined direction. In the example shown in FIG. 6, which is driven to rotate at a predetermined circumferential speed, the rotational force of the drive source motor 14 is transmitted to the primary charging roller 1 via the belt 16 to move the roller l in a predetermined direction. The shaft is rotated at a predetermined circumferential speed.

In any of the above examples, when the primary charging roller 1 is rotationally driven, the photosensitive drum 2, which is an image carrier, is driven by the rotational force of the primary charging roller 1 due to the frictional force of contact with the primary charging roller 1, and is rotated in a predetermined direction. It is rotated at a predetermined circumferential speed. Then, the surface of the rotating photosensitive drum 2 is uniformly charged to a predetermined positive or negative potential by the primary charging roller 1, and image formation is performed in the same manner as in the apparatus shown in FIG. 6 described above.

For the exposure 3, development 4φ transfer 6, cleaning 7, and pre-exposure (static charge removal) 8 of the image forming process, various known methods and methods can be adopted. For example, exposure 3 is an analog exposure method, laser scanning exposure method, LEDM light method, etc., development 4 is an l-component toner development method, 2-component toner development method, etc., and transfer 6 is a corona charging transfer method, a charging roller direct charging method, a pressure transfer. Regarding the cleaning method, the cleaning method 7 is a web 0-1 la method, a rubber blade method, etc., and the pre-exposure method 8 is an AC voltage neutralization method in addition to eraser lamp exposure.

As for the cleaning 7, a rubber band type is usually used, but in the case of the apparatus configuration of the present invention, it is desirable that the driving torque of the photosensitive drum 2, which is an image bearing member, be as small as possible. Since this has the disadvantage of increasing the torque of the motor, it is preferable to adopt, for example, a web roller system.

(2) Regarding the next charging roller.

The primary charging roller as a contact charging member has, for example, a structure in which a conductive elastic layer is provided on a conductive support, and a resistance layer is provided on the surface if necessary. The material of the elastic layer may include rubber, thermoplastic elastomer, sponge, etc., and the material of the resistive layer is preferably a material having a volume resistivity of 1010ff1 or more -51'0J2c11 or less. Further, the surface hardness of the secondary charging roller is preferably 30 degrees or less in terms of JIS-A hardness.

- There is a method of applying a voltage to the next charging roller by applying a DC voltage or a superimposition of a DC voltage and an AC voltage.

In particular, from the viewpoint of charging efficiency, it is preferable to superimpose a DC voltage and an AC voltage.

In order to properly rotate the photosensitive drum 2 with the primary charging roller l, an appropriate pressure nip and frictional resistance are required between the two. The pressure nip width is preferably 2fflII1 or more, and by making the roller 1 made of an elastic material, the required nip width can be obtained. Frictional resistance is a dynamic friction coefficient of 1.0
The above is preferable.

To measure the frictional resistance, a photosensitive drum and a primary charging roller are prepared, and the measurement is performed as follows. That is, the photosensitive drum is, for example, a HEI.
Fix it on the sample stage of a DN 14 surface property measuring machine (manufactured by Shinraikagaku), and perform 1. A vertical load of 3.0 g was applied via a primary charging roller cut to Omn+ width.

Move the sample stage at a speed of 50 mrM/win,
Measure frictional resistance. The coefficient of dynamic friction is calculated by dividing the frictional resistance by the vertical load.

(3) Regarding the photosensitive drum 2.

The photosensitive drum 2 used is one in which a photosensitive layer is provided on a conductive cylindrical support. As the photosensitive layer, an organic photoconductive photosensitive layer, a selenium photosensitive layer, an amorphous silicon photosensitive layer, etc. are used.

In particular, an organic photoconductive photoreceptor is preferred because it is easy to drive due to the large frictional resistance between the charging roller and the organic photoconductive photoreceptor.

Since the photoreceptor is driven by a primary charging roller, it must be scratch-resistant.

The surface hardness of the photoreceptor was measured using a diamond conical indenter (cone angle 90°, tip diameter 0.01 m) using the photoreceptor surface as the test surface.
A vertical load is applied to the hemispherical shape of 5 m along the test surface.
When moving at a speed of 0IIIIII/lll1n,
It is necessary that the load (scratching hardness) required to make a scratch with a width of 50 μm is 15 grams or more.

Specifically, the surface hardness of the image carrier used in the present invention is measured as follows.

For example, the image carrier is fixed to the sample stage of 1 (Er[]0N14 type surface property measuring machine (Shinraikagaku)), and the surface of the image carrier is attached to a diamond needle (circular anchor color, cone angle 90°, but the tip is The sample stage is moved at a speed of 50 mm/jlin by applying a vertical load to the surface of the image carrier (which has a hemispherical shape with a diameter of 0.01 mm), and scratches are made on the surface of the image carrier. Total MVK-F (newly manufactured by Akashi Seisaku)
Measure using the attached microscope.

Perform the above operation to change the vertical load to Log, 15g, 20g, etc.
, 25g, 30g, 35g, 40g, etc., and repeating this at every 5g, and from the linear regression relationship between the scratch width and the load, calculate the load that will cause a scratch of 50Ii, m.
The hardness of the image carrier. If the image carrier is a drum, the image carrier is set on the sample so that scratches are made in the axial direction of the drum.

The surface hardness of the image carrier used in the present invention needs to be 15 g or more under vertical load according to the above definition.

(4) Examples 1 to 3 and Comparative Examples 1 and 2 Specific examples and comparative examples will be described below.

(2) Photoreceptor 2 First, the following samples 1 to 5 were prepared as OPC photoreceptors used in the examples.

Sample 1 An aluminum cylinder of 60 φ x 210 mm was used as a base. To this, polyamide resin (product name: Amilan CM8
A 5% methanol solution of 000, Toshi Co., Ltd.) was applied by dipping to form a subbing layer of 1.7 parts m pressure.

Next, 10 parts (parts by weight, the same applies hereinafter) of bisazo facial sticks with the following structural formula, polyvinyl butyral resin (product name: S-LEC BXL)
(manufactured by Sekisui Chemical Co., Ltd.) and 60 parts of cyclohexanone were dispersed for 20 minutes using a sand mill device δ using 1φ glass beads. Add methyl ethyl ketone 7O-120 to this dispersion.
(appropriate) and coated on the F layer I-.

1 depressurization was 0.17 JLm.

Next, 7 parts of a hydrazone compound having the structural formula shown below and 10 parts of polystyrene resin (trade name: Dialex HF55, manufactured by Mitsubishi Monsanto Chemicals) were dissolved in 50 parts of monochlorobenzene. This liquid was applied onto the charge generation layer described in -. The film thickness after drying was 1 full m. When the hardness of the photoreceptor surface prepared in this way was measured using the above-mentioned measuring method, it was found to be 13.
The value of g was obtained.

Sample 2゜Styrene-acrylonitrile copolymer (trade name: Sunrex 5AN) was used instead of the polystyrene resin of sample 1.
A photoreceptor was prepared in the same manner as Sample 1 except that Sample 1 was used. The surface hardness of this photoreceptor was 17 g.

Sample 3゜Styrene-methyl methacrylate copolymer (trade name: Estyrene MS-) was used instead of the polystyrene resin of Sample 1.
A photoreceptor was prepared in the same manner as Sample 1 except that Sample 300 (manufactured by Nippon Steel Chemical) was used. The surface hardness of this photoreceptor was 21 g.

Sample 4: A photoreceptor was prepared in the same manner as in Sample 1, except that a bisazo pigment having the structural formula below was used instead of the bisazo pigment in Sample 1, and a polycarbonate resin with a weight average molecular weight of 5000 was used instead of polystyrene resin. Created. The surface hardness of this photoreceptor was 8 gr.

Sample 5゜ Weight average molecular weight of polycarbonate resin of sample 4 2
A photoconductor was prepared in the same manner as Sample 1 except that Sample No. 2000 was used. The surface hardness of this photoreceptor is 2
It was 2g.

(2)-Secondary Charging Roller 1 Next, the following samples-a-C were prepared as primary charging rollers used in the examples.

Sample-a 100 parts by weight of EPDM rubber and 5 parts by weight of conductive carbon were melted and kneaded, and a stainless steel shaft of φ5 x 210 mm was passed through the center and molded to have a size of φ30 x 200 mm to create a secondary charging roller. J I of this -next charging roller
The SA hardness is 25 degrees.

Sample-b 100 parts by weight of chloroprene rubber and 5 parts by weight of conductive carbon were melted and kneaded, and a stainless steel shaft of 5 mm x 210 mm was passed through the center and molded to have a diameter of 30 mm x 200 mm to create a primary charging roller.・JIS of this next charging roller
-A hardness is 20 degrees.

Sample-C 100 parts by weight of butyl rubber and 5 parts by weight of conductive carbon were melted and kneaded, and a stainless steel shaft of 5 x 210 mm was passed through the center and molded to 30 x 200 mm to form a secondary charging roller. JIS-A of this next charging roller
Hardness is 33 degrees.

■Example 1 Sample-a of the primary charging roller and samples 1 to 5 of the organic photoreceptor are prepared.

A gear was attached to this secondary charging roller, and the roller was attached together with an organic photoreceptor to the regular development type copying machine shown in FIG.

The drive system is as shown in Figure 2, from the motor 14 to the gears 13 and 1.
2, the primary charging roller l is rotated, and the organic photoreceptor 2 is driven. - The linear velocity of the secondary charging roller is 60 mm/sec.

The nip width between the primary charging roller 1 and the organic photoreceptor 2 is 5III.
ffl. - Secondary charging was carried out at a DC voltage of -750 cm and an AC peak-to-peak voltage of 1500 V, exposure 3 was carried out at 6 lux·sec, and pre-exposure 8 was carried out at 20 lux·sec.

The output images were examined and shown in Table 1.

The coefficient of dynamic friction between the photoreceptor 2 and the primary charging roller 1 was also measured and shown in Table 1.
It was shown to.

Example 2 Samples a to C of primary charging rollers and sample 5 of organic photoreceptor are prepared.

This secondary charging roller and organic photoreceptor were installed in a regular development type copying machine shown in FIG.

The drive system is φIOX10 from motor 14 as shown in Figure 3.
A shaft 15 made of 0 am polyurethane rubber is rotated, the primary charging roller 1 is rotated by the shaft 15, and the organic photoreceptor 2 is driven. -The linear speed of the next charging roller is 6
0/sec.

- The nip width between the secondary charging roller 1 and the organic photoreceptor 2 was 3 mm. The charging and exposure conditions were the same as in Example 1, and the output images were examined and shown in Table 2.

The coefficient of dynamic friction between the photoreceptor 2 and the primary charging roller 1 was also measured and shown in Table 2.

■Example 3 Primary charging roller sample a and organic photoreceptor sample 5
Prepare.

This secondary charging roller 1 and organic photoreceptor 2 were installed in a regular development type copying machine shown in FIG.

As shown in FIG. 4, the driving system was such that a primary charging roller 1 was rotated by a belt 16 driven by a motor 14, and the primary charging of the organic photoreceptor 2 was driven by the roller 1.

- The linear velocity of the next charging roller is 60/sec.

-Nip width between charging roller 1 and organic photoreceptor 2 is 3m11
It was set to 1.

The charging and exposure conditions were the same as in Example 1, and the output images were examined and shown in Table 3.

The coefficient of dynamic friction between the photoreceptor 2 and the primary charging roller 1 was also measured and shown in Table 2.

■Comparative example 1 Primary charging roller sample a and organic photoreceptor sample 5
Prepare. As shown in FIG. 5, the organic photoreceptor 2 has a width of 1 Or
I installed the nffi drive gear GD.

This secondary charging roller and organic photoreceptor were attached to the regular image type copying machine shown in FIG.

As shown in FIG. 5, the drive system is such that a motor M rotates the gear GD of the organic photoreceptor 2 through an intermediate gear GA to rotate the photoreceptor 2, and the second charging roller l is driven by the organic photoreceptor 2. .

The linear velocity of the organic photoreceptor 2 is 60/SeC.

-The nip width between the next charging roller l and the organic photoreceptor 2 is 3Ill.
ffi.

The charging and exposure conditions were the same as in Example 1, and the output image was divided into ridges, which are shown in Table 3.

Comparative Example 2 A corona charger 9 (FIG. 6) having a width of 230 mff1 and an organic photoreceptor sample 5 were prepared. Organophotoreceptor 2 has a width of 10
A mm drive gear GD was installed. This corona charger 9 and organic photoreceptor 2 were installed in a normal development type copying machine shown in FIG.

The driving method was to rotate the photoreceptor 2 by directly rotating the gear CD of the organic photoreceptor 2 using a gear GM from a motor M having a width of 40 mm.

The linear velocity of the organic photoreceptor is 60/see.

For primary charging 9, a direct voltage of 16 KV is applied, and for exposure 3, 6 KV is applied.
Pre-exposure 8 was carried out at 20 lux·sec.

The output images were examined and the results shown in Table 3 were as follows: As can be seen from Example 1, when the hardness of the photoreceptor 2 is 15 g or more, high quality images can be obtained without scratches on the photoreceptor.

Furthermore, as can be seen from Example 2, since the hardness of the primary charging roller 1 was 30 degrees or less, the photoreceptor 2 was driven smoothly, and defects such as uneven charging did not occur.

Furthermore, as can be seen from Examples 1 and 2 and Comparative Examples 1 and 2, the image forming apparatus in which the photoreceptor 2 is driven by the primary charging roller 1 makes it possible to obtain high quality images without gear pitch unevenness. Furthermore, since a photoreceptor drive gear is not required, the device can be downsized to the width of the transfer material.

The above example uses a roller body as the charging member, but the charging member can be shaped like a rotating bell or a running web, and the rotating force of the belt or the running force of the web can be used to create a drum-type, belt-shaped, or web-shaped charging member. Similar actions and effects can be obtained in the case of a configuration in which an image carrier such as a mold is driven to rotate, pivot, and travel, that is, to drive surface movement.

(Effects of the Invention) As described above, since the image forming apparatus of the present invention employs the contact charging method as the charging processing means for the image bearing member, when a corona charger is used, the generation of corona products etc. There are no problems, and by using a configuration system in which the charging member is also used as a driving means to drive the image carrier, it is possible to smoothly move the image carrier and form a high-quality image. It also allows for miniaturization, and the intended purpose is well achieved.

Furthermore, by setting the hardness of the charging member and the surface hardness of the image carrier within the specified value ranges, the charging member can always drive the driven surface of the image carrier stably and smoothly, and defects such as uneven charging can be prevented. It is possible to obtain effects such as no occurrence of scratches, no scratches on the image carrier, and improved durability.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment. Figures 2 to 4 are configuration diagrams of the rotational drive mechanism of the secondary charging roller, Figure 5 is the same diagram as above of a comparative example, Figure 6 (a) is a schematic diagram of the conventional device, and Figure 6 (b) FIG. 2 is a configuration diagram of a rotational drive mechanism for the photosensitive drum. 2 is a photosensitive drum as an image carrier, 1 is a primary charging roller as a contact charging member, 14.M is a drive source motor, and 9 is a corona charger. Patent applicant Canon Co., Ltd.

Claims (3)

[Claims] (1) An image forming apparatus that forms an image by applying an image forming process means that includes a means for charging the surface of the image bearing member to an image bearing member, and the charging processing means brings a charging member into contact with the surface of the image bearing member. Contact charging means that charges the surface of an image carrier by relative movement, the charging member is driven to move in plane, and the image carrier is driven to move in plane by the contact friction force with the charging member to move the image carrier in plane. An image forming apparatus characterized in that the image forming apparatus is driven. (2) The image forming apparatus according to claim 1, wherein the charging member which is driven in plane movement in contact with the image carrier has a hardness of 30 degrees or less in JIS-A hardness. (3) The surface hardness of the image carrier is determined using a diamond cone indenter (cone angle 90°, tip diameter 0) using the image carrier surface as the test surface.
．． When a vertical load was applied to a 01 mm hemisphere) and it was moved at a speed of 50 mm/min along the test surface, 50
Claim 1 characterized in that the load (scratching hardness) required to make a scratch with a μm width is 15 grams or more.
The image forming apparatus described above.