| 摘要 |
The invention relates to an objective (4) and to a method for designing said objective (4) for a dental camera (1), the objective (4) comprising at least two lenses (9, 10, 20, 21) and the dental camera (1) comprising a light source (3) and an image sensor (7). An illuminating beam emitted by the light source (3) is focused by the objective (4), imaged on an object (8) to be measured, and reflected by the object (8) to be measured to form a monitoring beam (12). The monitoring beam (12) passes through the objective (4) and is directed toward the image sensor (7), the illuminating beam (11) being partially reflected by surfaces (9′, 9′, 9″, 10′, 10″, 20′, 20″, 21′, 21″) of the lenses (9, 10, 20, 21) to form reflected beams (17.1 to 17.8). The objective (4) comprises means (27) for tilting each lens (9, 10, 20, 21) relatively to the illuminating beam (11) such that the optical axis (9′″ 10′″, 15.1, 15.2) of each lens (9, 10, 20, 21) forms an angle of tilt (α,&bgr;) with the illuminating beam (11), the size of said angle being such that the reflected beams (17.1 to 17.8) can be reflected in a direction away from the pupil of the monitoring beam (12). |
