Projector for rotary test signs for eye test - allows precise indication of angular position of signs

摘要

Projector for test signs for eye test comprises a control apparatus (3) for electronically controlling rotation of at least one sign about the axis (12) of projection by means of a rotary prism (11), and providing a digital indication (4) of the angular position of the sign. Pref. a coding plate (14) cooperating with sliding contacts (15) is non-rotatably connected to the prism, and is coded so as to produce electrical signals required for the digital indication. The projector also includes a light source (7), a condenser assembly (8), and a rotary test plate (9) containing test signs and switched from one sign to the next by a drive motor (10).