JPS63194272A - Image forming device - Google Patents

Abstract

PURPOSE:To efficiently transfer the toner image on the surface of a photosensitive body to a transfer form by constituting the photosensitive body and a transfer body of endless belts and setting the roughness of surfaces of endless belts to a value smaller than the particle size of a developer. CONSTITUTION:The roughness of the surface of a transfer sheet 2 is set to a value smaller than the particle size of toner 3, and that of a photosensitive sheet 1 is set similarly. therefore, toner 3 cannot penetrate recessed parts on surfaces of the photosensitive sheet and the transfer sheet, and toner is easily separated from these surfaces at the time of transfer. Consequently, toner is easily separated from surfaces of the photosensitive sheet and the transfer sheet in this image forming device when the toner image formed on the photosensitive sheet 1 is transferred to the transfer sheet 2 or the toner image transferred to the transfer sheet is transferred to the transfer form. Thus, the toner image is efficiently transferred and shading of the image does not occur after transfer to improve the image quality.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an image forming apparatus in which a photoreceptor and a transfer member are constituted by an endless belt.

(bl) Conventional technology In image forming apparatuses such as electrophotographic copying machines, in order to perform color copying, toner images of different colors are once superimposed and transferred onto a transfer body, and the different colors transferred to the transfer body are Some types perform color copying by transferring a toner image onto transfer paper.

An example of a color copying machine as described above is shown in FIG. Third
The figure is a schematic configuration diagram showing a photosensitive sheet, a transfer sheet, and their surrounding areas of a color copying machine.

In the color copying machine shown in FIG. 3, a belt-shaped photosensitive sheet 31 is placed on a rack between driving rollers 32 and 33 arranged on the left and right, and is driven by either one of the driving rollers 32 or 33. Rotate counterclockwise.

The belt-shaped transfer sheet 34 is placed diagonally across drive rollers 35 and 36, and its right side surface is opposite to the drive roller 3.
It is in contact with the surface of the photosensitive sheet 31 placed over the photosensitive sheet 2. Furthermore, a transfer charger 37 is located inside the sheet at the contact portion.
is located.

In the above color copying machine, when the transfer sheet 34 rotates clockwise in synchronization with the counterclockwise rotation of the photosensitive sheet 31 during the copying process, the toner image formed on the surface of the photosensitive sheet 31 is transferred to the transfer charger 37 and transferred to the transfer sheet. 34. In the case of color copying, this transfer is repeated multiple times until the toner images of the specific colors (magenta, yellow, cyan, black) are superimposed, and then the transfer sheet is
The color toner image formed on 4 is transferred to a transfer sheet (not shown).

In this manner, the above-mentioned color copying machine enables color copying by once forming a color toner image by overlapping toner images of different colors on a transfer sheet, and then transferring this toner image onto a transfer sheet.

(C) Problems to be Solved by the Invention However, the above-mentioned image forming apparatus has the drawback that when the surface smoothness of the photosensitive sheet and the transfer sheet is poor, sufficient transfer is not achieved, resulting in unevenness of the image after transfer. .

SUMMARY OF THE INVENTION In view of the above drawbacks, an object of the present invention is to provide an image forming apparatus in which the surface of a transfer belt is formed to have a roughness equal to or less than the particle diameter of the developer, so that a toner image on the surface of a photoreceptor is efficiently transferred to a transfer sheet. There is a particular thing.

(Means for Solving Problem d1) The image forming apparatus of the present invention comprises a photoreceptor and a transfer member as an endless belt, and the surface of the endless belt is formed to have a roughness equal to or less than the particle diameter of the developer. Features.

(1) 4) Function In the image forming apparatus according to the present invention, when an image formed on the surface of an endless belt-like photoreceptor contacts the surface of an endless belt-like transfer member and is transferred to the surface of the transfer member, the photoreceptor Since the surfaces of the photoreceptor and transfer member have a roughness that is less than the particle size of the developer that forms the image, the developer (toner) on the photoreceptor is efficiently transferred to the surface of the transfer member without remaining on the surface of the photoreceptor. . Furthermore, the toner image on this transfer body is transferred onto paper. During this transfer, the developer (toner) from the surface of the transfer body is efficiently transferred to the paper without remaining on the transfer body, similar to when the developer (toner) is transferred from the photoreceptor to the transfer body.

(fl Example) FIG. 1 is a partial cross-sectional view of a transfer sheet used in the image forming apparatus of the present invention and a partial schematic diagram showing toner. FIG. FIG. 2 is a schematic configuration diagram showing a peripheral part.

The configuration of the image forming apparatus shown in FIG. 2 differs from the conventional image forming apparatus shown in FIG. 3 in that the surface of the photosensitive sheet 1 and the surface of the transfer sheet 2 are configured to have a particle size smaller than that of the developer. be. The other configurations are the same as in FIG. 3. That is, the belt-shaped photosensitive sheet 1 is attached to the left and right drive rollers 4.
, 5, and is rotated counterclockwise by driving one of the drive rollers 4.5. In addition, the transfer sheet 2 is passed diagonally to the drive roller 6.7,
Its right side surface is in contact with the surface of the photosensitive sheet 1 placed over the drive roller 4. Further, a transfer charger 8 is arranged inside the sheet at the contact portion.

The surfaces of the photosensitive sheet and transfer sheet of this embodiment are formed to have a roughness equal to or less than the particle size of the toner constituting the developer, as shown in FIG. FIG. 1 is a partially enlarged view comparing the surface of the transfer sheet 2 and the toner.

As shown in the figure, the surface of the transfer sheet 2 is formed to have a particle size smaller than that of the toner 3. The surface of the photosensitive sheet 1 is also formed in the same manner. This prevents the toner 3 from entering the recesses on the surface of the photosensitive sheet and the transfer sheet, making it easier for the toner to separate from the surface during transfer.

With this configuration, in this image forming apparatus, when the toner image formed on the photosensitive sheet 1 is transferred to the transfer sheet 2, or when the toner image transferred to the transfer sheet is transferred to the transfer paper, the toner is removed. The toner image is easily separated from the photosensitive sheet surface and the transfer sheet surface, and the toner image is efficiently transferred. As a result, the image quality becomes good after transfer without causing unevenness in the image as in the conventional case.

(g) Effects of the Invention As described above, according to the present invention, the photoreceptor and the transfer member are constituted by an endless belt, and the surface of the endless belt is formed to have a roughness equal to or less than the particle size of the developer. The toner is transferred efficiently when transferred from the body to the transfer body or from the transfer body to the transfer paper, eliminating the problem of image unevenness caused by white spots on some parts of the toner image as in the past. This has the effect that a good image can be obtained on subsequent paper.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view showing a transfer sheet and toner used in an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing a photosensitive sheet, a transfer sheet, and their peripheral parts of the image forming apparatus. FIG. 3 is a schematic diagram showing a photosensitive sheet, a transfer sheet, and their surrounding areas in a conventional image forming apparatus. 1-Photosensitive sheet (photoreceptor), 2-Transfer sheet (transfer body), 3-Toner (developer).

Claims (1)

[Claims] (1) An image forming apparatus characterized in that the photoreceptor and the transfer member are constituted by an endless belt, and the surface of the endless belt is formed to have a roughness equal to or less than the particle diameter of the developer.