GB182928A - Improvements in and relating to telautography - Google Patents

Abstract

182,928. Bartholomew, H. G. April 13, 1921. Copying telegraphs.-A representation of the matter to be transmitted, such as a half-tone or other etched plate or an impression in wax such as is used in phonograph records, is used to control production of sound signals corresponding with the elements to be sent, and the sound signals are transmitted by line or wireless telephony. At the receiving end, the signals are used to control the reproduction. The representation may produce the sound signals by direct action, for example, by means of a stylus connected with a diaphragm, and cause to traverse the representation. Preferably, however, the representation controls the circuit of a sound-producing device such as a buzzer. The plate &c. 6, bent to or made of cylindrical form, is mounted on a mandrel the spindle 2 of which has a leading-screw 3 to give axial movement during rotation, and a contact stylus 5 co-operates with the plate to make and break the circuit of a buzzer 8. The sounds produced are transmitted by telephone 9 to a receiver 10, which causes a phonograph-like recording device 11 to produce a record corresponding with the impression on the plate 6. The receiver 10 may be replaced by an electromagnet with a sluggishly-acting armature which carries the recording-stylus. The record may be used to control a stylus-operated make-and-break wire, which in turn controls the movement of a lightsensitive surface so as to vary the exposure of successive areas or picture elements to give a photographic reproduction. Control signals may be sent at intervals by means of a commutator associated with the transmitter mandrel. As shown, a cam 18 driven through gear 19, 20 from the spindle 2 closes contacts 21 at intervals to operate a recording device for control signals, or to control directly the speed of the receiving apparatus. Specification 197,402 is referred to.