| 摘要 |
400,115. Photophones. BUSCH AKT.- GES. OPTISCHE INDUSTRIE, E., 5, Berliner Strasse, Rathenow, Germany. May 2, 1933, No. 12819. Convention date, June 9, 1932. [Class 40 (v).] The transmitted light is projected by a mirror m or lens and is modulated by moving the image of a grating f in accordance with the sound to be transmitted, and the parts of the mirror or lens permanently unused for transmission are used for reception. A fixed grid f is projected, by a mirror k, oscillated by the microphone currents, a lens h and a convex mirror l, on the concave mirror m. An auxiliary grid n on the mirror l consists of unsilvered strips so that the light reflected is modulated by the movement of the mirror k. Unreflected light is absorbed by a. screen o. Received light is reflected by the mirror m through the unsilvered stripes and an opening p in the screen to alight-sensitive cell q. Theco-operating station is located by a telescope r receiving light through the unsilvered grid on the mirror l, a mirror round the opening p and a point s on the mirror m. |
