| 摘要 |
A position Z of an image sensor (27) is moved to an initial position A (image forming position) in a Z axis direction. An exposing operation is performed at a position A, and it is determined whether or not an exposing time counted by a timer has reached ta. If the exposing time has reached ta, an image sensor (27) is moved to a position B. The exposing operation is performed at the position, and it is determined whether or not a total exposing time has reached ta + tb. If the total exposing time t has reached ta + tb, the image sensor (27) is moved to a position C, and the exposing operation is performed at the position. Thus, the output distribution of the image sensor (27) can be assigned a desired low pass filter characteristic. |
