| 摘要 |
PURPOSE:To slant an image plane mask frame automatically by providing a multi-spot distance measurement sensor, an arithmetic circuit which operates the output of the multi-spot distance measurement sensor to find a tilt quantity, and a driving part which slants an image plane mask part according to the arithmetic result. CONSTITUTION:An infrared-light (IR) LED 20 emits three infrared light beams, which are projected on an object through a projection lens 18. Their reflected light beams are made incident on a position detecting element (PSD) 14 through a photodetection lens 12, and the beam incidence position on the PSD 14 are detected by an AFIC 16, which inputs distance information on the three points to a microcomputer 10. The microcomputer 10 operates the distance information on the three points and supplies control signals to a tilt driving circuit 34 and a lens driving circuit 28. Therefore, a lens extension quantity is found from the distance information and tilt quantity information to extend the lens, thereby focusing the lens on plural subjects. Consequently, the swing and tile mechanism which can slant the image plane mask automatically is obtained. |
