GB1430861A - Method of recording information on electrosensitive material - Google Patents

Abstract

1430861 Recording apparatus ROBERT BOSCH GmbH 29 March 1973 [30 March 1972] 15065/73 Heading H4F [Also in Division G1] In a method of recording an electrosensitive material 20 using a group of adjacent electrodes S 0 -S 15 electrically insulated from each other, for producing an arc to locally destroy the material 20, electrodes selected according to a video input E 1 , 0 are energized sequentially so that there is always a time gap between the energization of adjacent electrodes, thereby preventing bridge formation between electrodes. For recording using metallized paper, the connection time for each electrode is preferably less than that required for the burning out process to be completed, i.e. for the arc to cease. In Fig. 1, with sixteen electrodes, the signal E 1 , 0 is scanned at a NAND gate No by a continuous pulse train E 2,0 . The sample pulses are adjusted in length by a monostable 40 (itself being adjustable as to pulse length) and fed to an enable input G 1 , 1 of a decoderdemultiplexer 31. The pulse train E 2 , 0 also forms the input of a four stage binary divider 50 with outputs A 0 -D 0 which control the sequential scanning of the outputs 0-15 of circuit 31, the signal at the operative output being determined by the input G 1 , 1 and controlling the associated transistor switch T 0 -T 15 . In a second embodiment, eighty electrodes are divided into five equal groups, all of which are scanned simultaneously by signals from a single four stage divider, but each group is enabled in turn by logic circuitry receiving the output of the final stage of the divider so that there is a sequential scan over all eighty electrodes. Each electrode group has an associated decoderdemultiplexer as in Fig. 1, and the enabling is effected by switching the input G 2 , 1 to earth. By varying the length of pulses provided by monostable 40, the recorded dot size and density may be controlled for grey scale recording. The electrodes may be tungsten wires, plate at one end with copper, gold, silver or tin for soldering to the transistor collectors.