| 摘要 |
PURPOSE:To produce an image output of high resolution at high speed with a simple structure by generating principal scanning direction and subscanning direction screen signals in synchronism to light beam scanning, and comparing them with image signals to generate dotted signals. CONSTITUTION:Subscanning direction screen signals (a) generated in synchronism to light beam scanning and image signals (b) are added to form signals (c). These signals (c) are compared with principal scanning direction screen signals (d) generated in synchronism to the light beam scanning, and signals (d) exceeding the signals (c) as a threshold value are produced as the high level of dotted signals. As a result, an image output high in resolution and equivalent to the case of numerically arranging contact screens 2-dimensionally can be produced at high speed with a simple structure requiring no large capacity memory. |
