| 摘要 |
PURPOSE:To obtain a contour image as a positive image by forming a negative electrostatic latent image where the contour part of an original image part is left as a low potential part on the surface of an electrostatic latent image carrier in the 2nd electrostatic charging process and further performing reversal development in a developing process. CONSTITUTION:In the 2nd electrostatic charging process, the surface of a photosensitive drum 1 where an electrostatic latent image is formed is given a charge having the same polarity with the electrostatic latent image by a scorotron charger 4, and a voltage of +500V is applied to a grid 42. The charge of the scorotron charger part 4 has the same polarity with the 1st electrostatic charging process and the voltage applied to the grid 42 is lower than the surface potential (+600V) of the electrostatic latent image part and has the same polarity with the 1st electrostatic charging process. In this 2nd electrostatic charging process, the contours of image parts A and B are formed as negative electrostatic latent images and in the next developing process, the images are developed by a developing device 5. Consequently, insulating toner which is charged positively stick on the contour parts of the images A and B which are low potential parts of the photosensitive drum 1 to form what is called a 'external- edge removed' toner image by the reversal development. |
