| 摘要 |
PURPOSE:To obtain a proper quantizing output by controlling a threshold value quantizing a picture signal by an output from a level comparing means. CONSTITUTION:When a photoelectrically transduced output signal having a high white level and clear contrast is outputted from a photoelectric transducing part 1, the white level is aligned to a fixed level by an automatic level control circuit 2 and then quantized in a slice circuit 3 by a threshold (f) from a switch part 10 to obtain a precise quantized picture signal output. If a photoelectrically transduced output signal with a low white level and faded contrast is outputted, the white level is aligned to the fixed level and quantized in the slice circuit 3 by a threshold (g) to obtain a precise quantized output. Even if a transduced output having a different white level due to the difference of the ground of an original is inputted, a proper quantized picture signal can be obtained. |
