JP2535405Y2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image forming apparatus using an endless belt-shaped photoconductor as a photoconductor.

[Conventional technology]

When a belt-shaped photoconductor is used in an image forming apparatus such as a copying machine, a facsimile or a printer, when the belt-shaped photoconductor is driven to rotate, the belt itself is distorted and becomes wavy, or the belt-shaped photoconductor surface is perpendicular to the surface. The belt vibrates in the direction, causing blurring or blurring in the image,
In the color image forming apparatus, there is a problem that a “position shift” occurs in the superimposed image.

Therefore, in order to suppress waviness and vibration during driving of the endless belt-shaped photoconductor, there has already been proposed a photoconductor in which a convex plate is pressed against the back surface of the belt (Japanese Patent Application Laid-Open No. Sho 59/1984).
-107373).

[Problems to be solved by the invention]

In the case of using such a pressing member, when the belt-shaped photoconductor is rotated at a high speed, the belt portion may momentarily separate from the pressing member. Although it is necessary to increase the tension of the belt-shaped photoconductor, a large torque is required to drive the belt-shaped photoconductor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which eliminates the above-mentioned conventional drawbacks, and which has a simple configuration in which the belt-shaped photosensitive member is less likely to undulate or vibrate during driving.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a photosensitive member on which an electrostatic latent image is formed by performing image exposure or optical writing, and is stretched over at least two rollers. In an image forming apparatus using an endless belt-shaped photoconductor on which a photosensitive layer is formed, the base is made of a magnetic material, and a backing plate made of a non-magnetic material is provided on the base in a width direction of the belt-shaped photoconductor. A magnetic force generator is provided through the substrate, and the magnetic force generator is disposed opposite to a surface of a substrate corresponding to a recording unit for performing image exposure or optical writing on a photosensitive layer of the photosensitive member, and a back surface facing the substrate. On the surface of the patch,
An image forming apparatus including a brush provided in contact with the base is proposed.

Similarly, in order to achieve the above object, the present invention provides a photosensitive member having an electrostatic latent image formed on its surface by performing image exposure or optical writing, and is stretched over at least two rollers. In an image forming apparatus using an endless belt-shaped photoreceptor having a photosensitive layer formed thereon, the base is formed of a magnetic material, and the belt-shaped photoreceptor is formed with respect to the base in a width direction of the belt-shaped photoreceptor. A magnet roller that rotates with the movement is provided, and the magnet roller is disposed in contact with a surface of a substrate corresponding to a recording unit that performs image exposure or optical writing on a photosensitive layer of the photosensitive member. An image forming apparatus is proposed.

〔Example〕

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

In FIG. 1, an endless belt-shaped photosensitive member 1 is stretched around two rollers 21 and 22, and is arranged in a vertical direction in this example. The photoreceptor 1 is driven to rotate in the direction of the arrow, and the surface thereof is first uniformly charged by the charging charger 3. When the optical writing is performed, an electrostatic latent image is formed on the surface of the photoconductor 1. In an image forming apparatus of the type that performs image exposure, an electrostatic latent image is formed by forming and projecting a document image in such a recording unit.

As described above, in the illustrated image forming apparatus, at least two rollers 2 are used as a photoconductor on which an electrostatic latent image is formed on the surface by performing image exposure or optical writing.
An endless belt-shaped photoreceptor 1 is used, which is stretched between 1, 22 and has a photosensitive layer formed on a substrate as described later.

On the right side of the photoconductor 1, developing units 5, 6, 7, 8 are arranged in order from the top.
Are respectively arranged, and each of them contains a developer of a different color, for example, a color toner such as a yellow toner, a magenta toner, a cyan toner, a black toner, and the like. The image is visualized for each color.

On the other hand, the transfer paper is fed from the paper feed unit 9 in the direction of the arrow, and is conveyed toward the transfer belt 2 at the registration roller 11 with a timing.

Then, the transfer paper is adsorbed on the transfer belt 2 rotating in the direction of the arrow by the paper adsorption charger 12, and is conveyed to the left on the belt in this adsorbed state. At this time, the photoconductor 1
The first color image formed on the transfer paper is transferred to the transfer paper.
Is transferred. During this transfer, the contact / separation switching roller 13 is raised, so that the transfer belt portion on the side facing the transfer charger 14 comes into contact with the photoconductor 1.

After the transfer, the transfer paper is fed to the position shown by the broken line, and thereafter, the transfer belt 2 rotates in the direction opposite to the arrow direction with the contact / separation switching roller 13 lowered, and the transfer paper is returned to the virtual line position. It has become. Next, the transfer belt 2 rotates forward in the direction of the arrow again, and at this time, a visible image of the second color on the photoreceptor 1 is transferred to the transfer paper fed with the belt. At that time, the contact / separation switching roller 13 is raised. Thereafter, the above-described operation is performed in the same manner, and four times of transfer are performed in the most cases. That is, the four color toner images are transferred onto the transfer paper in a superimposed manner. After all such transfer is completed, the transfer paper is guided to the fixing device 16 side by the path switching member 15 switched to the virtual line position, and the visible toner image transferred through this device section is fixed. After that, it is discharged to the tray 17.

The belt-shaped photoreceptor 1 shown in FIG. 2 has an endless loop shape as described above.
For example, as shown in FIG. 5, a photosensitive layer 1B is formed on a substrate 1A. The base 1A of the photoconductor 1 is made of a magnetic material. For example, the base 1A can be made of a seamless magnetic material made of electroformed nickel or the like, and the photosensitive layer 1B is applied and coated on the surface to form the belt-like photosensitive member 1 without any seams. .

Here, as shown in FIG. 2, the base 1A of the belt-shaped photoconductor 1 (FIG. 5) is lined with a non-magnetic material such as aluminum over the width of the belt-shaped photoconductor 1. Board
A magnet 18, which is a configuration example of a magnetic force generator, is provided via 19. That is, the backing plate 19 fixed to the magnet 18
Is brought into contact with the externally exposed surface of the base 1A made of a magnetic material, and this is disposed immediately below the recording unit 4. The magnet 18 is arranged opposite to the surface of the base 1A corresponding to the recording section 4 (FIG. 2) for performing image exposure or optical writing on the photosensitive layer 1B (FIG. 5) of the photoconductor 1.

With this configuration, the belt portion of the recording unit 4 is attracted by the magnetic force of the magnet 18 and moves while being in close contact with the backing plate 19.
In the above, the waving and vibration (flapping) of the belt portion are suppressed, and the "blurring" and "blurring" of the image caused by the vibration and the like can be suppressed, so that an image of good image quality can be obtained. . In addition, in the color-compatible image forming apparatus shown in FIG. 1, it is difficult for the superimposed image to be misaligned, and a color image of good quality can be obtained.

Further, as shown in FIG. 3, a brush 23 is provided on the surface of the backing plate 19 facing the substrate of the photoreceptor 1 to contact the substrate. With this configuration, the frictional force acting on the backing plate 19 and the photoreceptor 1 can be effectively reduced, and the rear surface of the photoreceptor 1, that is, the surface of the base 1A can be hardly damaged.

It is desirable that the backing plate 19 be in a flat state so as to be substantially perpendicular to the optical path 20 for exposure or optical writing. However, it is also possible to have a curvature.

Also, instead of arranging the magnet 18 opposite to the base 1A of the photoreceptor 1 via the backing plate 19, the base 1A made of a magnetic material is moved across the width of the belt-like photoreceptor 1 in FIG. Is provided in contact with the surface of the substrate 1A corresponding to the recording unit 4 which performs image exposure or optical writing on the photosensitive layer 1B (FIG. 5) of the photosensitive member 1 as shown in FIG. And can be arranged facing each other. The magnet roller 28 rotates with the movement of the belt-shaped photoconductor 1, whereby the frictional force acting on the belt-shaped photoconductor 1 can be further reduced.
The photosensitive member 1 can be operated more smoothly while suppressing the waving and vibration of the photosensitive member 1.

[Effect of the invention]

According to the configuration of the first and second aspects, the belt-shaped photoreceptor moves while being attracted to the magnetic force generator or the magnet roller side by the magnetic force in the recording unit,
Since the waving and vibration of the belt portion in the recording unit are suppressed, image blur and image blur are less likely to occur, and a stable image with good image quality can be obtained. Further, in the color image forming apparatus, since the displacement of the superimposed image is less likely to occur, a color image of good quality can be obtained. Further, since the flatness is maintained in the width direction of the belt-shaped photoconductor, it is effective to suppress the occurrence of image blurring and image blurring in this direction. Further, it is possible to make it difficult for the photosensitive member to be displaced in the width direction, and it is also difficult to generate noise due to belt vibration.

Furthermore, since the base of the belt-shaped photoreceptor itself is made of a magnetic material and attracted by a magnetic force generator or a magnetic force of a magnet roller, an increase in the cost of the photoreceptor can be prevented.
The cost of the image forming apparatus can be reduced.

According to the first aspect of the present invention, a brush is provided on the backing plate, and the brush contacts the substrate of the photoreceptor, so that a frictional force acting between the moving photoreceptor and the backing plate is provided. Can be effectively reduced, and the photosensitive member can be operated smoothly.

Furthermore, in particular, according to the configuration of the second aspect, since the magnet roller rotates around while contacting the moving body of the photosensitive member, the frictional force acting on the photosensitive member can be further reduced, and the photosensitive member can be further reduced. Can be operated more smoothly.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention,
2 is an enlarged view of a main part thereof, FIG. 3 is a detailed view of a magnet and a backing plate, FIG. 4 is a view showing a magnet roller, and FIG. 5 is a sectional view of a photoreceptor. DESCRIPTION OF SYMBOLS 1 ... Photoreceptor, 1A ... Base 1B ... Photosensitive layer, 4 ... Recording part 19 ... Backing plate, 21, 22 ... Roller 23 ... Brush, 28 ... Magnet roller

Claims (2)

(57) [Scope of request for utility model registration] An endless belt stretched around at least two rollers and having a photosensitive layer formed on a substrate as a photosensitive member having a surface on which an electrostatic latent image is formed by performing image exposure or optical writing. In an image forming apparatus using a photoreceptor in a shape, the base is made of a magnetic material, and a magnetic force generator is applied to the base via a backing plate made of a nonmagnetic material over the width of the belt-shaped photoreceptor. The magnetic force generator is disposed opposite to the surface of the substrate corresponding to the recording unit that performs image exposure or optical writing on the photosensitive layer of the photosensitive member, and the surface of the backing plate facing the substrate is provided. An image forming apparatus comprising a brush provided in contact with a base. 2. An endless belt which is stretched around at least two rollers and has a photosensitive layer formed on a substrate as a photosensitive member having a surface on which an electrostatic latent image is formed by performing image exposure or optical writing. In an image forming apparatus using a photoconductor in a shape, the base is made of a magnetic material, and a magnet roller that rotates with the movement of the photoconductor over the photoconductor over the width of the photoconductor with respect to the base is provided. An image forming apparatus, wherein the magnet roller is disposed in contact with a surface of a substrate corresponding to a recording unit for performing image exposure or optical writing on a photosensitive layer of a photosensitive member.