| 摘要 |
PURPOSE:To accurately control the density of an image by providing a latent image forming means, a reference latent image forming means, a developing means and a transfer device, using the developer of the same color system as copying paper, forming a reference image on the copying paper and detecting the density of the image. CONSTITUTION:The reference latent image forming means 3 forms a reference latent image for detecting the density of the reference image on a photosensitive body 21. The reference latent image is developed with the developer of the same color system as the copying paper by a developing device 4 for forming the reference image and the reference image is transferred on the copying paper P by the transfer device 5. The reference image on the copying paper is detected as the measured value of the density of the reference image by an image density control means 6, then comparison-operated with a reference image density set value. Based on the operated result, an output from the transfer charger of the device 5, that means, the charge quantity added to the copying paper from a transfer charger 51, is controlled. The image is developed with the developer having the color except the same color system as the copying paper by the latent image forming means 2 to be transferred. In such a case, transfer efficiency corresponds to an output from the transfer charger controlled based on the arithmetic result of the means 6 and the density becomes nearly same as a reference set value. |
