|Wirephoto receiver TM 4006 (1981)|
The wirephoto receiver TM 4006 records black-and-white pictures with a helium-neon laser on dry photo paper (dry-silver-paper), modulating the intensity of the laser beam by the received electrical signal.
The laser beam is deflected by a galvanometer mirror and a light path deflecting mirror, such that the beam records the photo paper line by line. The mirror of the galvanometer is rotated according to a sawtooth function, rotating the mirror steadily and then jumping back quickly to the starting position. This sweeps the laser beam continuously along a recording line on the photo paper, and then moves it immediately to the start of the next line.
The photo paper is developed by heating after the recording.