Image forming apparatus

Abstract

One of aspects of the present invention is to provide an image forming apparatus includes an intermediate transfer member rotating at a first circumferential speed, and an image carrier capable of having a plurality of toner images formed thereon in turn, each of the toner images having a color different from one another, for transferring the toner images onto the intermediate transfer member, the image carrier rotating at a second circumferential speed. At least one of the first and second circumferential speeds are adjustable in accordance with a driving mode selected from a group consisting of a monochrome mode and a color mode. Also, a first difference between the first and second circumferential speeds in the monochrome mode is greater than a second difference between the first and second circumferential speeds in the color mode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an image forming apparatus with a four-cycle engine according to the first embodiment of the present invention.

FIG. 2 is a time chart of various signals in a color mode of the image forming apparatus of FIG. 1.

FIG. 3 is a time chart of various signals in a monochrome mode of the image forming apparatus of FIG. 1.

FIG. 4 is a schematic view of an image forming apparatus with a tandem engine according to the second embodiment of the present invention.

FIG. 5 is a graph of an experimental result showing the relationship between a ratio of a circumferential speed of an intermediate transfer belt to a circumferential speed of photoreceptor, and a durability of a photoreceptor cleaning blade.

Claims

1. An image forming apparatus, comprising: an intermediate transfer member rotating at a first circumferential speed; andan image carrier capable of having a plurality of toner images formed thereon in turn, each of the toner images having a color different from one another, for transferring the toner images onto said intermediate transfer member, said image carrier rotating at a second circumferential speed;wherein at least one of the first and second circumferential speeds are adjustable in accordance with a driving mode selected from a group consisting of a monochrome mode and a color mode, andwherein a first difference between the first and second circumferential speeds in the monochrome mode is greater than a second difference between the first and second circumferential speeds in the color mode.

2. The image forming apparatus according to claim 1, wherein the second circumferential speed is not less than the first circumferential speed; andwherein the first circumferential speed in the color mode is greater than the first circumferential speed in the monochrome mode.

3. The image forming apparatus according to claim 1, wherein the second circumferential speed is not greater than the first circumferential speed; andwherein the first circumferential speed in the color mode is less than the first circumferential speed in the monochrome mode.

4. The image forming apparatus according to claim 1, wherein in the monochrome mode, the first circumferential speed is less than the second circumferential speed.

5. The image forming apparatus according to claim 1, wherein in the color mode, a color-mode ratio of the first circumferential speed to the second circumferential speed falls within a range between 0.9934 through 1.0000, andwherein in the monochrome mode, a monochrome-mode ratio of the first circumferential speed to the second circumferential speed is less than 0.9934.

6. The image forming apparatus according to claim 5, wherein the color-mode ratio falls within a range between 0.9954 through 0.9983, andwherein the monochrome-mode ratio falls within a range between 0.9500 through 0.9934.

7. The image forming apparatus according to claim 1, wherein the second circumferential speed is constant while the first circumferential speed is adjustable in accordance with the driving mode.

8. The image forming apparatus according to claim 1, wherein the first circumferential speed is constant while the second circumferential speed is adjustable in accordance with the driving mode.

9. An image forming apparatus, comprising: an intermediate transfer member rotating at a first circumferential speed; anda plurality of image carriers, each capable of having a toner image of a color different from one another, said color image carriers rotating at a second circumferential speed;wherein the first circumferential speed is adjustable in accordance with a driving mode selected from a group consisting of a monochrome mode and a color mode, andwherein a first difference between the first and second circumferential speeds in the monochrome mode is greater than a second difference between the first and second circumferential speeds in the color mode.

10. The image forming apparatus according to claim 9, wherein the second circumferential speed is not less than the first circumferential speed; andwherein the first circumferential speed in the color mode is greater than the first circumferential speed in the monochrome mode.

11. The image forming apparatus according to claim 9, wherein the second circumferential speed is not greater than the first circumferential speed; andwherein the first circumferential speed in the color mode is less than the first circumferential speed in the monochrome mode.

12. The image forming apparatus according to claim 9, wherein in the monochrome mode, the first circumferential speed is less than the second circumferential speed.

13. The image forming apparatus according to claim 9, wherein in the color mode, a color-mode ratio of the first circumferential speed to the second circumferential speed falls within a range between 0.9934 through 1.0000, andwherein in the monochrome mode, a monochrome-mode ratio of the first circumferential speed to the second circumferential speed is less than 0.9934.

14. The image forming apparatus according to claim 13, wherein the color-mode ratio falls within a range between 0.9954 through 0.9983, andwherein the monochrome-mode ratio falls within a range between 0.9500 through 0.9934.

15. An image forming apparatus, comprising: an intermediate transfer member rotating at a first circumferential speed;a plurality of color image carriers, each capable of having a colored toner image of a color different from one another, said color image carriers rotating at a second circumferential speed; anda monochrome image carrier capable of having a monochrome toner image, said monochrome image carrier rotating at a third circumferential speed;wherein the second and third circumferential speeds are adjustable in accordance with a driving mode selected from a group consisting of a monochrome mode and a color mode, andwherein a first difference between the first and third circumferential speeds in the monochrome mode is greater than a second difference between the first and second circumferential speeds in the color mode.

16. The image forming apparatus according to claim 15, wherein the second and third circumferential speeds are not less than the first circumferential speed; andwherein the second circumferential speed in the color mode is greater than the third circumferential speed in the monochrome mode.

17. The image forming apparatus according to claim 15, wherein the second and third circumferential speeds are not greater than the first circumferential speed; andwherein the second circumferential speed in the color mode is less than the third circumferential speed in the monochrome mode.

18. The image forming apparatus according to claim 15, wherein in the monochrome mode, the first circumferential speed is less than the third circumferential speed.

19. The image forming apparatus according to claim 15, wherein in the color mode, a color-mode ratio of the first circumferential speed to the second circumferential speed falls within a range between 0.9934 through 1.0000, andwherein in the monochrome mode, a monochrome-mode ratio of the first circumferential speed to the third circumferential speed is less than 0.9934.

20. The image forming apparatus according to claim 19, wherein the color-mode ratio falls within a range between 0.9954 through 0.9983, andwherein the monochrome-mode ratio falls within a range between 0.9500 through 0.9934.