| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device capable of almost evenly consuming the developer of respective color, and increasing output frequency of the monocromatic image without deteriorating the image quality. SOLUTION: In this, a color copying machine is provided with image forming units 15Y, 50M, 50C and 50B outputting respective images in yellow, magenta, cyan and black. By irradiating photoreceptor drum 51Y, 51M, 51C and 51B of respective units with laser beam 41Y, 41M, 41C and 41B whose beam diameter and exposure strength is respectively adjusted, respective latent images are formed. In the case of outputting the monocromatic image, at the time point when a near empty sensor 532b for black toner detects the near empty, by reducing density of the black toner by adjusting the exposure strength of the laser beam for the black 41B, and while forming the toner image in respective color by reducing the beam diameter of other colors, the monoclomatic image is outputted by laminating the toner image in respective colors on the black toner image. |
