| 摘要 |
<p>Autofocusing device comprising a housing (2), a light source (1) for generating a light beam (B) along an optical axis (19), movable lens means (3) for receiving and transmitting the light beam (B) coming from the light source (1), and having a predetermined first focal distance (f3), image-forming lens means (17, 18) for receiving and transmitting the light beam (B) coming from the movable lens means (3), and having a predetermined second focal distance (f1), the first (f3) and second (f1) focal distances being situated at a predetermined first distance (x1) from each other on the optical axis (19), and light beam interception means (16) provided with a small aperture (15) around the optical axis (19), for transmitting at least part of the light beam (B), which light beam interception means (16) are disposed between the movable lens means (3) and the image-forming lens means (17, 18). <IMAGE></p> |
