| 摘要 |
<p>The invention relates to an apparatus for transmitting and receiving infrared signals. In the region of the focal point of a concave mirror there is placed a comparatively small infrared sensitive area (9) of an infrared sensitive diode. For the purpose of adjusting said infrared sensitive area its mounting (8) is made longitudinally movable by about 2 to 3 cm along the axis of said concave minor. Several infrared-transmitter-diodes are placed near the edge of the opening of the concave mirror their axes of radiation being generally parallel to the axis of said mirror. Comparatively weak signals incident in the direction of the axes of the mirror can be received by this arrangement. Disturbances by other infrared transmitters, e.g. at transmissions in large workshops by arcs of welding equipment, by lighting up signal lamps, furnaces and incident sun light can be practically fully avoided. <IMAGE></p> |
