| 摘要 |
PURPOSE:To improve the reproducibility of a half tone for a continuous tone image and also to improve the image reproducibility of a low density part in the original of an image by providing a digital optical system which superposes a meshed dot pattern and performs exposure with an image exposure optical system and also providing a density control means. CONSTITUTION:The title device is provided with a 1st exposure optical system (image exposure optical system) 8 which forms the images of an original on an original placing glass 7 on a photosensitive drum 1 (image carrier) and exposes it and a 2nd exposure optical system (digital optical system) 9 consisting of a collimator lens 93, a cylindrical lens 94, a polygon mirror 92 and a toric lens 95, where a semiconductor laser 91 is directly modulated on a photosensitive drum 1 and exposure is performed in dot-shaped. At the time of forming the image of the continuous tone image original such as a photograph, etc., the meshed dot pattern is superposed on the exposed image of the original formed on the photosensitive drum 1 by the image exposure optical system 8 so as to be exposed with the aid of the digital optical system 9, and pseudo-mesh is executed to an electrostatic latent image. The half tone gradation is improved with such a dot-effect. Meanwhile, the image reproducibility of the low density part in the original of the image can be improved because the set density can be changed by the set density control means 20. |
