| 摘要 |
A focus detector adaptable to a camera or other similar optical instrument is disclosed. The focus detector includes a pair of concave mirrors as refocusing optical system for forming secondary images the positional relationship of which is detected for focus detection. In order to eliminate the adverse effect of aberrations on the secondary image formation and to improve the accuracy of focus detection, the concave mirrors are inclined to satisfy a particularly determined condition on the incident angle to the mirrors. The condition is that the incidence angle should be less than about 2ROOT 0.04/R wherein R is the maximum diameter of the mirror measured in mm.
|
