| 摘要 |
PURPOSE:To prevent the contrast lowering of a minute pattern, by using devided CCDs, which constitute high pass transversal filters respectively, to control the gain. CONSTITUTION:When the signal charge is transferred in the direction of (b), a signal of a large amplitude corresponding to a region A is outputted to an output terminal 2a of a CCD2 in time series. However, a transversal filter 5a functions as a high pass filter though the space frequency is low in the region A, a low output signal is outputted. Since the space frequency is highest in a region C, a high pass transversal filter 5c outputs a high output signal. When the largest one of signals held in a sample holding circuit 7c is applied to a gain control terminal 3b of a detecting amplifier 3a through a switch S3, a small signal just under the transversal filter 5c is amplified with the highest gain. |
