JP3042005B2 - Image forming device - Google Patents

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 and a printer, and more particularly to an image forming apparatus configured to charge an electrostatic latent image carrier with a charging brush.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, an electrostatic latent image carrier such as a photosensitive drum is charged by a charging device, and an image is exposed to the charged area to form an electrostatic latent image. The latent image is developed into a visible image, which is transferred to a transfer material and fixed. Various types of charging devices are known, but roughly classified into a corona charging device using corona discharge, and a charging brush, a charging roller, or an endless belt for rotationally driven charging. It is classified into a contact-type charging device that makes contact with the surface of the carrier.

A charging device using corona discharge has an advantage that stable charging can be performed. However, a problem arises in that a large amount of ozone is generated, which causes deterioration of the electrostatic latent image carrier and adversely affects a human body. For this reason, attention has been paid to a contact-type charging device in which the amount of ozone generated is significantly smaller than that of a corona charging device. Above all, a brush charging device, particularly a charging brush that contacts and charges the surface of an electrostatic latent image carrier whose surface moves, has attracted attention as a relatively simple structure.

In general, as shown in FIG. 16, a base cloth A having a large number of charged brush bristles F fixed to a holding member (back plate) P made of aluminum or the like with an adhesive or the like, as shown in FIG. The brush B comes into contact with the moving surface S of the electrostatic latent image carrier PC.

[0005]

However, in an image forming apparatus in which the surface of the electrostatic latent image carrier is charged by a charging brush, unevenness in charging occurs if the brush bristles of the charging brush have grouping or unevenness. Streak-like image noise occurs. In addition, when such grouping or unevenness of the bristles occurs in a direction opposite to the moving direction of the surface of the electrostatic latent image carrier, the rotational load of the electrostatic latent image carrier increases or fluctuates. Therefore, a predetermined number of rotations of the electrostatic latent image carrier cannot be obtained, or rotation unevenness occurs, which causes an image defect.

Further, if the image forming apparatus is stored or stopped after use while the grouping and the rags of the brush bristles are in the direction opposite to the moving direction of the surface of the electrostatic latent image carrier, the brush bristles between them are stopped. The creep causes the defective brush bristle state to be fixed, so that even when the electrostatic latent image carrying surface is driven, the brush bristle is not easily adapted to the surface, and a considerable amount of the brush bristle remains in the opposite direction.

Although there are various possible causes of the bristle grouping and unevenness of the charging brush, such a defective state of the bristle easily occurs when the electrostatic latent image carrier and the charging brush are assembled. . SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of assembling an electrostatic latent image carrier and a charging brush such that brush bristle grouping and unevenness of the charging brush do not occur.

[0008]

According to the present invention, there is provided an image forming apparatus, comprising: an image forming apparatus configured to charge an electrostatic latent image carrier with a charging brush; The body or the charging brush is detachable, and the detachable electrostatic latent image carrier or the charging brush is moved to the normal position of the charging brush in the surface moving direction of the electrostatic latent image carrier at the regular position in the image forming apparatus. A mounting guide is provided for mounting the charging brush so that the brush bristles of the charging brush are pushed further toward the downstream side.

Assuming that the charging brush is already provided at a predetermined regular position and the electrostatic latent image carrier is detachable, the mounting direction of the electrostatic latent image carrier with respect to the charging brush is as follows. , The direction α shown in FIG. That is, the surface S1 constituted by the direction of the brush bristles F at the center of the charging brush B (the average direction when irregular) and a line perpendicular to the moving direction a of the surface S of the electrostatic latent image carrier PC When the entrance side where any one point on the surface S of the electrostatic latent image carrier comes into contact with the charging brush B is defined as the upstream side, and the exit side away from the charging brush B is defined as the downstream side, from the upstream side to the downstream side It is the direction of the arrow α. As shown in FIG. 1B, the direction β from the downstream side to the upstream side is prohibited.

Further, if the electrostatic latent image carrier is previously provided at a predetermined regular position, and the charging brush is detachable therefrom, assuming that the charging brush is attached to the electrostatic latent image carrier in a mounting direction. Is the direction γ shown in FIGS. 2A and 2B. That is, assuming that the charging brush B is disposed at a regular position with respect to the electrostatic latent image carrier PC, the direction of the brush hairs F at the center of the charging brush B (in the case of irregularities, the average Direction) and a plane S2 formed by a line perpendicular to the moving direction a of the electrostatic latent image carrier surface S,
When an inlet side at which an arbitrary point on the surface of the electrostatic latent image carrier starts to contact the charging brush is an upstream side, and an outlet side away from the charging brush is a downstream side, a direction γ from the downstream side to the upstream side.
It is. As shown in FIGS. 2C and 2D, the direction θ from the upstream side to the downstream side is not included.

[0011]

According to the image forming apparatus of the present invention, a detachable electrostatic latent image carrier or a charging brush is mounted at a predetermined regular position along a mounting guide, and both are assembled to each other. At the time of mounting, the brush bristles of the charging brush are pressed and aligned in a direction toward the downstream side from the charging brush in the surface moving direction of the electrostatic latent image carrier.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Each of the embodiments described below is a printer, and its basic configuration is as shown in FIG. The printer shown in FIG. 3 is provided with a photosensitive drum 1 as an electrostatic latent image carrier at a central portion, and this drum is driven to rotate in the direction of arrow CW by driving means (not shown). Around the drum 1, a charging brush 2, a developing device 3, a transfer charger 4, a cleaning device 5, and an eraser 6 are sequentially arranged. The drum 1, the charging brush 2, the developing device 3, the cleaning device 5, and the eraser 6 are incorporated in an imaging cartridge 10 (see FIG. 4) that is detachable from the printer main body.

An optical system 7 is disposed above the photosensitive drum 1. This optical system is provided in a housing 71 with a semiconductor laser generator, a polygon mirror, a toroidal lens, a half mirror, a spherical mirror, a folding mirror, and a reflection mirror. An exposure slit is formed on the floor of the housing 71, from which a charging device 2 and a developing device 3 are arranged.
The image can be exposed on the photosensitive drum 1 through the gap.

On the right side of the photosensitive drum 1 in the figure, a pair of timing rollers 81, a pair of intermediate rollers 82, and a sheet cassette 83 are provided.
Are sequentially arranged, and a paper feed roller 84 faces the paper feed cassette 83. A pair of fixing rollers 91 and a pair of discharge rollers 92 are sequentially arranged on the left side of the photosensitive drum 1 in the drawing, and a discharge tray 93 faces the pair of discharge rollers 92.

According to this printer, the surface of the photosensitive drum 1 is charged to a predetermined potential by the charging device 2, and the charged area is image-exposed from the optical system 7 to form an electrostatic latent image. The electrostatic latent image thus formed is developed by the developing device 3 to become a toner image, and moves to a transfer area facing the transfer charger 4. On the other hand, the paper feed rollers 84
As a result, the transfer paper is pulled out, reaches the timing roller pair 81 via the intermediate roller pair 82, and is fed to the transfer area in synchronization with the toner image on the drum 1. Thus, in the transfer area, the toner image on the drum 1 is transferred onto the transfer paper by the action of the transfer charger 4, and the transfer paper reaches the fixing roller pair 91, where the toner image is fixed and then discharged by the discharge roller pair 92. The sheet is discharged to the paper tray 93.

After the toner image is transferred onto the transfer paper, the toner remaining on the photosensitive drum 1 is cleaned by a cleaning device 5 and the residual charge is erased by an eraser 6. The system speed of the printer (the peripheral speed of the photosensitive drum 1) is 3.5 cm / sec, and the developing device 3 is a contact-type developing device using a one-component developer, and performs reversal development.

The photosensitive drum 1 in each of the specific examples and comparative examples of the present invention, which will be described later, is manufactured as described below, and has a function separation type for negative charging having a sensitivity to long wavelength light. Organic photoreceptor. First, 1 part by weight of τ-type metal-free phthalocyanine, 2 parts by weight of a polyvinyl butyral resin (acetylation degree: 3 mol% or less, butylation degree: 70 mol%, polymerization degree: 1000), and 100 parts by weight of tetrahydrofuran are put into a ball mill pot, After dispersing for a time, a photosensitive coating solution was obtained. This was applied to the entire surface of a cylindrical aluminum substrate having an outer diameter of 30 mm and a length of 240 mm by dipping, and then dried to form a charge generation layer having a thickness of 0.4 μm.

Next, on this charge generation layer, a structural formula

[0019]

Embedded image

8 parts by weight of a hydrazone compound represented by the following formula, 0.1 parts by weight of an orange dye (Sumiplast Orange 12; manufactured by Sumitomo Chemical Co., Ltd.), and 10 parts by weight of a polycarbonate resin (Panlite L-1250; manufactured by Teijin Chemicals Ltd.) A coating solution dissolved in a solvent consisting of 180 parts by weight of tetrahydrofuran was applied by a dipping method, and then dried to form a charge transport layer having a thickness of 18 μm.

Here, the τ-type metal-free phthalocyanine is Cu
When using Kα ₁ / Ni X-ray of 1.541 ° wavelength,
Bragg angle (2θ ± 0.2 degrees) is 7.6, 9.2, 1
It has an X-ray diffraction pattern showing strong peaks at 6.8, 17.4, 20.4 and 20.9. In particular, 751 ± infrared absorption spectrum between 700～760Cm ^-1
The two absorption bands at 2 cm ⁻¹ are the strongest,
Almost absorption band of the same intensity of two between 0 cm ^-1, 328
It has a characteristic absorption at 8 ± 3 cm ⁻¹ .

The electrostatic latent image carrier applicable to the image forming apparatus of the present invention is not limited to the one described above. In an imaging system using a long-wavelength light source such as a laser optical system or an LED array, a photoconductor having a long-wavelength sensitivity as described above may be used, and a liquid crystal shutter array, a PLZT shutter array, etc. Imaging system, or a lens used in normal analog PPC,
In a visible light image forming system using a mirror optical system, a photoconductor having sensitivity in a relative visual range may be used.

The constitution is not limited at all, and the function-separated type photoreceptor or the single-layer type photoreceptor may be used. As the charge generation material and the charge transport material, all known materials can be used.
That is, hydrazone, an inorganic material such as zinc oxide, cadmium sulfide, selenium alloy, amorphous silicon, or phthalocyanine, an azo compound, etc.
An organic material using a styryl compound or the like as a charge transporting material can also be used.

A surface protective layer may be provided on the outermost surface of the photoreceptor. Examples of such a material include a resin such as an ultraviolet curable resin, a room temperature curable resin, and a thermosetting resin. A resin in which a resistance adjusting material is dispersed, and further, a material obtained by forming a thin film of a metal oxide, a metal nitride, a metal carbide, a metal sulfide, and the like by a vapor deposition method, an ion plating method, and the like, and An amorphous carbon film obtained by plasma polymerization of a hydrocarbon gas can be used.

The substrate material is not particularly limited as long as it has electrical conductivity, and the shape of the substrate also depends on the imaging system.
It may be in the shape of a drum, a flat plate, or a belt.
If the light source used is coherent light, the substrate may be roughened or blackened to prevent the generation of a so-called interference pattern.

In each of the specific examples and comparative examples of the present invention which will be described later, the toner used in the developing device 3 is of a negative charge type, and the bisphenol A type polyester resin 1
00 parts by weight, 5 parts by weight of carbon black MA # 8 (manufactured by Mitsubishi Kasei Kogyo Co., Ltd.), 3 parts by weight of Bontron S-34 (manufactured by Orient Chemical Co., Ltd.)
A composition consisting of 2.5 parts by weight of S-200 (manufactured by Sanyo Chemical Industry Co., Ltd.) was kneaded, crushed and classified by a known method, and had an average particle size of 10 μm, and 80 parts by weight in the range of 7 to 13 μm. % Of toner particles, and 0.75% by weight of hydrophobic silica (Tanolux 500, manufactured by Talco) was added as a fluidizing agent to the toner particles, followed by mixing and stirring with a homogenizer.

Such a toner is stored in the developing device 3 and is developed. As shown in FIG. 5, for example, the charging brush 2 of the printer can be configured such that the brush portion 20 is formed of a band-shaped pile cloth. The pile cloth can be obtained, for example, by weaving brush hairs 21 made of conductive fibers of 3 to 10 denier into a base cloth 22, and coating the back surface of the base cloth with a conductive adhesive.

As shown in FIG. 6A, the bristles of the bristles 22 are formed by bundling 50 to 100 bristles, for example.
a can be woven into a V shape or a W shape as shown in FIG. The brush 20 is fixed to a holding member (back plate) by the adhesive. Also,
As the charging brush, a brush in which the brush bristles 21 are sandwiched between openable and closable brush support plates AL as shown in FIG. 7 is also conceivable. The present invention can be applied to such a brush.

The material of the brush bristle is not particularly limited as long as it has appropriate conductivity. Examples of such conductive materials include metal wires such as tungsten, stainless steel, gold, platinum, iron, copper, and aluminum. In addition, as a conductive resin material, in a fiber such as rayon, nylon, acetate, cuprammonium, vinylidene, vinylon, ethylene fluoride, promix, benzoate, polyurethane, polyester, polyethylene, polyvinyl chloride, polyclar, polynosic, and polypropylene. A material in which a resistance adjuster such as carbon black, carbon fiber, metal powder, metal whisker, metal oxide, and semiconductor material is dispersed can be used. in this case,
A desired resistance value can be appropriately obtained by the amount of dispersion. Also, instead of dispersion, the surface of the fiber may be coated with a resistance adjusting material, and conversely, the surface of the low-resistance fiber may be coated with a high-resistance resin.

In each of the specific examples and comparative examples of the present invention which will be described later, the charging brush 2 has a brush bristles 21 of 12 watts based on the total weight of the conductive carbon powder.
t% -containing rayon fiber, the electrical resistance of which is 1 × 10 ⁵ Ωcm, the fiber thickness is 6 denier and 15000.
The base fabric 22 is W-woven at a density of book / cm ² . The base cloth 22 is fixed to an aluminum back plate. The dimensions of each part of the brush (see FIG. 5)
Length L = 240mm, width W = 10mm, height H = 5mm
It is.

Next, specific examples of the printer according to the present invention will be sequentially described together with comparative examples.
A method of evaluating image noise based on uneven charging on the surface of the photosensitive drum 1 by the following will be described. The uneven charging occurs in a direction crossing the surface traveling direction of the photosensitive drum 1. Even after the image exposure, the charge unevenness remains as unevenness of the potential (V _i ) after the image exposure. That is, of the potential (V _o ) immediately after being charged by the charging brush 2, a portion having a partially high potential also has a partially high potential (V _i ) after image exposure.

When reversal development is performed in the printer, a portion having a lower potential (V _i ) is developed with a larger amount of toner. That is, the unevenness of the potential (V _o ) results in the unevenness of the potential (V _i ), and finally the unevenness of the image.
One of the performances of the device according to the present invention is the degree of occurrence of this image unevenness. The evaluation of the degree of the image unevenness is performed by the following image noise evaluation.

The evaluation of the image noise is performed as follows. Using the printer, after charging by the charging brush 2, a repetition pattern of 2 dots on (lighting) and 2 dots off (light off) is written by the laser from the optical system 7 in the main scanning direction, and the same is applied in the sub scanning direction. The laser lighting timing is adjusted so that a writing pattern of two dots on (lighting) and two dots off (light off) is obtained. Thereafter, through a reversal development, transfer and fixing processes, a print image as shown in FIG. 8 is obtained.

[0034] The main scanning direction of the maximum width of the fine black solid pattern consisting of 2 dots × 2 dots on the printed image and W _M. The standard deviation of W _M thirty minute black solid pattern that is continuous in the main scanning direction and sigma, to rank the streak image noise, such as: by this sigma. Standard deviation σ Evaluation symbol 0 μm ≦ σ <20 μm ２０ 20 μm ≦ σ × If the standard deviation σ is large, it means that the width of the fine black solid in the main scanning direction is largely varied in the main scanning direction.

A circle in the image evaluation symbol indicates a state in which streak-like image noise cannot be recognized or the image noise is practically acceptable, and a cross indicates a state in which the image noise poses a practical problem. Next, specific examples and comparative examples will be sequentially described. Embodiment 1 The printer of Embodiment 1 is different from the printer shown in FIG.
The imaging cartridge 10 has the configuration shown in FIGS. 9 to 12.

The cartridge 10 is configured such that a portion 101 including the eraser 6 and the cleaning device 5 can be opened and closed by rotating about a fulcrum 103 with respect to a portion 102 including the charging brush 2 and the developing device 3. The charging brush 2 is fixed to the portion 102 from the beginning, and the photosensitive drum 1 is detachable from the portion 102. The photoreceptor drum 1 has a gear 11 fixed to one end thereof in the same rotation axis direction as the drum.
Is protruding. A hole 121 is provided in the end face of each rotating shaft 12.

The two shafts 12, 12 can be fitted into grooves 131, 131 of guide members 13, 13 provided on the inner surfaces of both side walls 10a, 10a of the portion 102 where the drum 1 is to be arranged. Therefore, as shown in FIG. 11, the drum 1 is disposed at the regular position from the upstream side of the charging brush 2 by fitting the shafts 12, 12 into the grooves 131, 131 and pushing it in. By this drum arrangement, the brush bristles of the charging brush 2 are pushed and aligned toward the downstream side from the brush 2 position in the drum surface moving direction CW. The drum 1 also comes into contact with the developing sleeve 31 of the developing device. In FIG. 11, S
Reference numeral 1 denotes a boundary surface on the upstream and downstream sides of the charging brush 2 (see FIG. 1).

Stoppers 14, 14 are arranged outside the side walls 10a, 10a of the portion 102, and each stopper 14 has an inner surface (an end face hole of a drive roller arranged inside the developing sleeve 31). 3) and a projection 142 that fits into the end face hole 121 of the drum shaft 12. Each side wall 10a is provided with a recess 10b in which the stopper 14 is fitted, and holes 10c and 10d through which both projections 141 and 142 pass. Accordingly, the developing sleeve 31 and its driving roller and the drum 1 are arranged at the proper positions, and the protrusions 141 and 142 of each stopper are fitted into the end face hole of the sleeve driving roller and the drum shaft end face hole 121 through these through holes. The sleeve and drum can be mounted in the correct position.

After the drum 1 is mounted, as shown in FIG.
The part 101 is closed to complete the imaging cartridge 10. Here, the pressing amount of the charging brush 2 onto the photosensitive drum 1, that is, the pressing amount of the charging brush 2 toward the center of the drum 1 from the position where the brush tip contacts the drum 1 is 1.5 mm. Such a cartridge 10
3, the photosensitive drum 1 is rotated in the CW direction at a peripheral speed of 3.5 cm / sec. On the other hand, the charging brush 2 is moved through the aluminum back plate 23 to about -1.1 [KV]. The surface of the drum 1 is charged to an average of -750 [V], and the charged area is image-exposed to form an electrostatic latent image corresponding to the pattern of FIG. The developing bias is about -300
Under [V], the image was developed by the developing device 3 and transferred and fixed on a transfer paper.

When the evaluation of the streak noise was performed, the rank of the streak noise was ○. Second Embodiment A printer according to a second embodiment differs from the printer shown in FIG.
The imaging cartridge 10 has the same configuration as the cartridge 10 of the first embodiment. However, the pushing amount of the charging brush is 2.5 mm.

This cartridge is incorporated into a printer,
The image was formed under the same operating conditions as in Example 1 to form an image, and the streak noise was evaluated.
Met. Comparative Example 1 The printer of Comparative Example 1 is an imaging cartridge 10
As shown in FIG. 1B, the photosensitive drum 1 is mounted from the downstream side of the charging brush 2. The pushing amount of the charging brush is 1.5 mm.

This cartridge is incorporated into a printer,
When an image was formed by operating under the same operating conditions as in Example 1, the rank of streak noise was x. In this example, a part of the bristles of the charging brush 2 was displaced in a direction opposite to the direction of movement of the drum surface. Comparative Example 2 In this printer, the pushing amount of the charging brush 2 was 2.5 mm.
It has the same configuration as Comparative Example 1 except that

When this apparatus was operated under the same operating conditions as in the first embodiment, the drum 1 failed to rotate.
Also in the case of this example, it is assumed that a part of the bristles of the charging brush 2 was displaced in the direction opposite to the direction of movement of the drum surface, and that the pushing amount was large, so that the rotating torque of the drum 1 was remarkably increased, resulting in poor rotation. Conceivable. Third Embodiment A printer according to a third embodiment differs from the printer shown in FIG. 3 in that the imaging cartridge 10 is configured as shown in FIGS.

The cartridge 10 includes the photosensitive drum 1
Is provided at a regular position from the beginning so that the charging brush 2 can be attached to and detached from the cartridge. The cartridge case 100 has a charging brush mounting guide 24 having a brush insertion port at a portion where the charging brush is to be mounted.
Reference numeral 3 denotes a part in which a part 230 supporting the brush and a part 231 rising obliquely from the part 230 are integrally formed.
31 has a screw hole 23a.

The charging brush mounting guide 24 of the cartridge case 100 includes the brush support portion 2 of the back plate.
A recess 241 into which the tip 230a of the thirty engages is provided. After the charging brush 2 is inserted into the mounting guide 24 and the tip 230a is engaged with the recess 241, the charging brush 2 is rotated in the direction of arrow X as shown in FIG. 231 is screwed to the guide inner wall 242 via the screw hole 23a with a screw 232. The pushing amount of the charging brush 2 into the photosensitive drum 1 in this state is 1.5 mm.

The mounting of the charging brush 2 is performed from the upstream side and the downstream side of the boundary surface S2 (see FIG. 2) of the drum 1 shown in FIG. At step 1, the charging brush is pushed downstream from the regular position of the charging brush. When the cartridge 10 was assembled in the printer of FIG. 3 and operated under the same operating conditions as in Example 1 to form an image and evaluated, the streak noise rank was ○. Embodiment 4 In this printer, the pushing amount of the charging brush 2 was 2.5 mm.
The configuration is the same as that of the third embodiment except that

When an image was formed by operating this apparatus under the same operating conditions as in Example 1, the rank of streak noise was ○. Comparative Example 3 The printer according to Comparative Example 3 uses the imaging cartridge 10
As shown in FIG. 2C, the charging brush 2 is mounted from the downstream side of the surface S2. The pushing amount of the charging brush is 1.5 mm.

This cartridge is installed in a printer,
When an image was formed by operating under the same operating conditions as in Example 1, the rank of streak noise was x. In this example, a part of the bristles of the charging brush 2 was displaced in a direction opposite to the direction of movement of the drum surface. Comparative Example 4 In this printer, the pushing amount of the charging brush 2 was 2.5 mm.
It has the same configuration as Comparative Example 3 except that

When the apparatus was operated under the same operating conditions as in the first embodiment, the drum 1 failed to rotate.
In the case of this example as well, since a part of the bristles of the charging brush 2 was displaced in the direction opposite to the direction of movement of the drum surface, and the pushing amount was large, the rotational torque of the drum 1 was significantly increased, resulting in poor rotation. Conceivable.

[0050]

As described above, according to the present invention, there is provided an image forming apparatus capable of assembling an electrostatic latent image carrier and a charging brush so as not to cause grouping or loosening of the bristle of the charging brush. Can be.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a mounting direction of an electrostatic latent image carrier according to the present invention.

FIG. 2 is an explanatory diagram of a mounting direction of a charging brush according to the present invention.

FIG. 3 is a schematic cross-sectional view illustrating a basic configuration of a printer according to an embodiment of the present invention.

FIG. 4 is a perspective view of an image cartridge in the printer shown in FIG.

FIG. 5 is a perspective view showing a basic configuration of a charging brush.

FIG. 6 is a diagram showing how to weave brush bristles on a base cloth in the charging brush.

FIG. 7 is a perspective view of another example of the charging brush.

FIG. 8 is a diagram of a print image example for image evaluation.

FIG. 9 is an exploded perspective view of the imaging cartridge according to one embodiment of the present invention.

FIG. 10 is an exploded cross-sectional view of the cartridge of FIG.

11 is a cross-sectional view of the cartridge of FIG. 9 in the process of mounting the photosensitive drum.

FIG. 12 is a sectional view of the cartridge of FIG. 9 after assembly.

FIG. 13 is an exploded perspective view of an imaging cartridge according to another embodiment of the present invention.

14 is an exploded sectional view of the cartridge of FIG.

FIG. 15 is a sectional view of the cartridge of FIG. 13 immediately before assembly is completed.

FIG. 16 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor drum 2 charging brush 10 imaging cartridge 13 photoconductor drum mounting guide 24 charging brush mounting guide

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Issei Osawa 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi Osaka International Building Minolta Camera Co., Ltd. (56) References JP-A-62-168173 (JP, A) Japanese Utility Model 60-133464 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 15/02

Claims (1)

(57) [Claims] 1. An image forming apparatus configured to charge an electrostatic latent image carrier with a charging brush, wherein the electrostatic latent image carrier or the charging brush is detachable, and the detachable electrostatic latent image is removed. The carrier or the charging brush is moved in such a manner that the brush bristles of the charging brush are pushed toward the downstream side from the normal position of the charging brush in the surface movement direction of the electrostatic latent image carrier at the normal position in the image forming apparatus. An image forming apparatus provided with a mounting guide for mounting.