| 摘要 |
PURPOSE:To prevent toner from sticking on a no-image area without any limitation of the position of an original and copy paper side by bringing an eraser under the control of an eraser control means so that necessary photodetecting elements in the photodetecting element group of a reflection density detecting means illuminate according to an original position. CONSTITUTION:The eraser 41 turns on corresponding to respective picture elements of the photodetecting element group 71 of the reflection density detector 53 and a set of picture elements with a reflection factor lower than a predetermined value, i.e. no-image area is obtained on the basis of image density stored in a RAM56. Then, LEDs of the eraser 41 corresponding to the no-image area are turned on according to copy magnification to prevent toner from sticking in the no-image area. Further, picture elements on the border between the no-image area and an image area are lower in reflection factor than a white ground original when an original pressure plate 21 has a specular surface, etc., and when a development copy is taken in this state, the toner sticks on the contour of an original. For the purpose, LEDs of the eraser 41 corresponding to the picture elements on said border are turned on to prevent the sticking of the toner. |
