| 摘要 |
<p>A matrix switching element, particularly for telephone exchanges comprises a wafer (1) of transparent ferro-electric material having thin transparent strip electrodes. The horizontal electrode (2) corresponds to the lines of the usual mechanical coupling system and the vertical strips (3) to the columns. In front of the columns is a polariser (4) and after the lines is an analyser (5) to increase contrast. Each crossing point has a light-emiting diode (6) and a phototransistor (7) associated therewith. On application of an electric field between the electrode (2, 3) the ferroelectric ceramic at the respective crossing point is rendered opaque, thus cutting off the transmission of light between the diode and transistor.</p> |
