| 摘要 |
An afocal apparatus for the optical-mechanical scanning of an object in two dimensions includes a collimation objective (O), a first scanning means (1) for scanning the object in a first dimension via the objective (O), a second scanning means (2) for scanning the object in a second dimension, intermediate optics (M) between the first and the second scanning means, a detector (D) and a relay optical system (OR) between the detector (D) and the second scanning means (2). The intermediate optics is formed by a primary mirror (12) and a secondary mirror (11) which are substantially concentric and face-to-face with a substantially common centre (3) of curvature and a mutual spacing sustantially corresponding to the radius of curvature of the secondary mirror. A pupil position (P') can be arranged at one of the scannig means, the other scanning means being situated at a conjugate point (P'') to the pupil position in relation to the intermediate optics (M). The width ( DELTA ) of the secondary mirror (11) is adjusted to the width of the detector image (D) so that the longitudinal edges of the secondary mirror (11) constitute a field line aperture (F). The bundles of rays incident on, and coming from the intermediate optics can be limited and situated as close to the secondary mirror as posible. The primary mirror can be parted in the symmetrical plane of the optics, the mirror halves being outwardly turned a small angle. The mirrors of the intermediate optics may consist of ellipsoid cutouts. Of the possible combinations of ellipsoid cutouts, there are some which are significantly better than the others. |
