| 摘要 |
1,207,357. Selective printing. ROBBERT BOSCH G.m.b.H. 18 Oct., 1967 [12 Nov., 1966], No. 47352/67. Heading B6F. [Also in Divisions G1 and H4] A recording device for recording information on a recording carrier 10 having a metal coating, comprises an electrically conductive contact point 20 adapted to be brought into contact with the metal coating so that the recording current burns the metal coating at the point of contact and a semi-conductor element 24 having a thyratron-like characteristic being provided for controlling the recording current. The metal coating is formed on a base of cellulose and the recording carrier 10 is drawn over a roller 13 of insulating material by a device (not shown). A roller 15 of electrically conductive material such as carbon maintains contact between a voltage source 16 and the metal coating. A pointer 18 moved mechanically by a device (not shown) such as a measuring instrument is journalled in a bearing 19 and is connected to the voltage source through a thyristor 24 and a resistor 23. A pulse generator 26, which may be a facsimile transmitting device is connected to an amplifier 25, the output of which is connected to the cathode and control electrode of the thyristor. A recording current flows when a pulse is applied to the thyristor from the generator, the pulse switching on the thyristor. The recording current is interrupted when the metal coating has burnt at the point of contact and therefore becomes non-conducting. Modifications are described in which the semi-conductor element comprises a four-layer diode or a photo-thyristor, the latter receiving light pulses produced by a light source and stroboscope disc arrangement. |
