| 摘要 |
PURPOSE:To obtain a character image as a sharp and high-quality image by providing a pattern signal generating means for generating plural kinds of pattern signals different in signal amplitude and signal period and a selecting means to use properly the plural kinds of pattern signals thereby reproducing a photographic image with fidelity. CONSTITUTION:When gradation is important for an image such as a photographic image, the maximum value of a pattern signal SAW1 is increased more than the white level of an image signal VA as shown in figure (a) and the minimum value of the pattern signal SAW1 is lowered than the black level of the image signal VA. Thus, a laser beam is lighted at the white level actually but lighted even at a very low level VA1, then the gradation at the very light region is attained sufficiently. In taking the sharpness of cutting of lines important for an image such as a character image, the maximum value of a pattern signal SAW2 is lowered more than the white level of the image signal VA as shown in figure (b) and the minimum value of the pattern signal SAW2 is increased more than the black level of the image signal VA.
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