| 摘要 |
<p>PURPOSE:To simplify a photocoupling circuit and to decrease power consumption, by constituting a photocoupler by placing a liquid crystal between a light emitting element and a light receiving element, controlling the liquid crystal by an electric signal, and transmitting a light signal to the light receiving element. CONSTITUTION:For example, the liquid crystal 9 (19) is arranged in a light path of the photocoupler comprising a light emitting diode 11 (18) and a phototransistor 12 (20) and enclosed in a container 10, and a unified device 21 is obtained. In the case said device 21 is used in a circuit, wherein, e.g., a digital signal is transmitted to the light receiving element and the signal is processed, the light emitting diode 18 is continuously lighted, the signal is transmitted to the liquid crystal 19 from a signal generating circuit 17 comprising, e.g., CMOS, and the light is transmitted or cut out. Said signal is transmitted to the phototransistor 20, and processed in a signal processing circuit 22. In comparison with the method by which the light emitting element is directly controlled, the driving can be performed at a low power, and the circuit constitution can be simplified.</p> |
