| 摘要 |
PURPOSE:To facilitate the registering of a halftone plate and a mask plate by applying filter processing to a binarizing image signal to generated an unsharp signal, binarizing the signal and exposing and recording a duplicate image on an unexposed film. CONSTITUTION:An output image signal of a gradation circuit (1st binarization circuit) 34 is inputted to a filter processing circuit in a peak intensifying circuit 35, from which the unsharp signal U being the arithmetic means between an image signal S and image signals of plural surrounding image elements is generated, the signal U is inputted to a 2nd binarization circuit 37. Laser light is subjected to on/off-control by a photomodulator 39 in an exposure recording section 43 based on the image data subjected to binarization, a duplicate image is exposed and recorded on the unexposed film 42, and a mask plate 7 is formed by a development section 44. In setting the threshold value of the 2nd binarization circuit 37 lower, the mask plate of a transparent region 14 of a slightly smaller size than that of a reflected original is formed and the registering is facilitated in overlapping the mask plate 7 and the halftone plate at the forming of a pattern plate. |
