| 摘要 |
PURPOSE:To perform accurate focusing and to quicken the operation by scanning an image surface, obtained by an optical image formation system for a picture to be read out, by a linear solid image pickup element. CONSTITUTION:Linear solid image pickup element 4 reads out picture 1 by scanning its projected image 2 from a read start position to a read end position. Then, the picture is replaced with new picture 2'. When this picture is replaced, image pickup element 4 is moved from the read end position toward the read start position and positioned at a focus detection position between both the said positions. Focusing on the focus detection position is performed by using stopped image pickup element 4. On the completion of this focusing, image pickup element 4 is returned to the read start position and reads image 2'. Said process is repeated to read out many pictures while performing the focusing on every picture. Thus, the focusing is made accurate and its operation is quickened. |
