GB558512A - Facsimile recording system and apparatus - Google Patents

Abstract

558,512. Facsimile apparatus; piezo-electric devices. CREED & CO., Ltd. Nov. 10, 1942, No. 15862. Convention date, Nov. 27, 1941. [Classes 40 (iii) and 40 (v)] A facsimile copying apparatus comprises means for scanning a subject matter carried by an original sheet, means for modulating an alternating carrier current wave in accordance with the brightness of elemental areas of the scanned matter, a pressure recording stylus operated by a piezoelectric device, means for causing the stylus to scan a record sheet, and means for applying the modulated alternating current wave to the piezo-electric device in such manner that the stylus is caused to mark the record sheet intermittently in accordance with the brightness of the said elemental areas. Specification 476,922 is referred to for the prior proposal of a piezo-electric device in a telegraph apparatus for printing representations of characters. The apparatus shown in Fig. 1 comprises transmitting and receiving drums 29, 35 and scanning units 25, 26 operating generally as described in Specification 549,782. The transmitting unit 25 shown is an optical one and may be as described in U.S.A. Specifications 2,158,391 and 2,176,442. The piezo-electric device comprises plates 71, 72, Fig. 7, rigidly fixed together along the principal contacting surfaces and assembled with tin foil electrodes 73, 74. The inner electrodes 73 are connected to a lead 76, and the outer electrodes to a lead 77. One end of the assembly is clamped in resilient pads 80 in a casing 70. Figs. 5 and 6. The other end of the plates has a recess 79 into which a stylus 33 is clamped by a wedge 81 tightened by a screw 83. The resonant frequency is adjusted by a small lump of solder 180 on the stylus. The casing 70 of the piezo-electric device is adjustably mounted on hinges carried by the carriage 26, Fig. 1. Specification 543,037 also is referred to.