Image forming apparatus and method

Abstract

To prevent the local deterioration of a gear for colors and a gear for black and to prevent the occurrence of a color smear of a color image with an image forming apparatus which has a photoreceptor for colors for forming a chromatic color toner image, the gear for colors for rotationally driving the photoreceptor, a photoreceptor for black for forming a black toner image and the gear for black for rotationally driving the photoreceptor and permits the selection of a color mode to transfer the toner image formed on the photoreceptor for colors and the photoreceptor for black and a monochromatic mode to transfer only the toner image formed on the photoreceptor for black to a recording material. In the color mode, while the prescribed positions of the gear 32Y, 32M, and 32C for colors and the gear 32BK for black are maintained, their gear 32Y, 32M, and 32C for colors and the gear 32BK for black are stopped in the positions different from their rotation start positions. In the monochromatic mode, the gear 32BK for black is stopped in the same position as the rotation start positions.

Description

technical field [0001] The present invention relates to an image forming method and device thereof. More specifically, the image forming apparatus of the present invention includes a color photoreceptor for forming a color toner image, a color gear for driving the color photoreceptor to rotate, and a black photoreceptor for forming a black toner image. The black body is used to drive the black gear for rotating the black photoreceptor. The image forming apparatus of the present invention can select color mode (color mode) or monochrome mode (monochrome mode). A black toner image is formed on the black photoreceptor driven to rotate by the black gear, and the color toner image and the black toner image are transferred on the transfer material to obtain a color image; The gear and the photoreceptor for color are stopped, and a black toner image is formed only on the photoreceptor for black driven to rotate by the gear for black, and the black toner image is transferred to a tr...

AI Technical Summary

Problems solved by technology

[0006] However, in the monochrome mode, the above-mentioned color gear and the color photoreceptor are stopped, and a black toner image is formed only on the black photoreceptor driven to rotate by the black gear. If it stops at a position different from its rotation start position, the predetermined phase relationship between the color gear and the black gear will be disturbed, and the color image formed by the subsequent image forming operation will have a color shift.

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