| 摘要 |
PURPOSE:To make camera compact and thin by changing an optical path length by moving a reflecting mirror. CONSTITUTION:A semi-transparent mirror 14 and the reflecting mirror 16 are installed on an optical axis, and an incident light from a lens 12 is reflected by the reflecting mirror 16 and the semi-transparent mirror 14, and made incident upon an image sensor 18. The image sensor 18 and the lens 12 are fixed to the casing of the camera, and a distance between them is made constant, and a focal length is adjusted by changing the optical path length by moving the reflecting mirror 16. For this purpose, the output of the image sensor 18 is given to an optical system drive circuit 22 through a high pass filter 26, an absolute evaluation circuit 28 and a control circuit 24, so that a piezo electric element 20 is driven. |
