| 摘要 |
PURPOSE:To obtain an inexpensive optical type displacement transducer having a simple structure, by providing a light screening plate, which is displaced in response to the change in physical quantity between a light emitting part and a light receiving part, detecting the change in the quantity of received light, and measuring the amount of displacement which is changed in response to the physical quantity. CONSTITUTION:A light screening plate 13, which is displaced in response to a physical quantity to be detected, is arranged between a light emitting part 11 and a light receiving part 12. The quantity of received light of the light receiving part 12 is changed in response to the displacement of the light screening plate 13. The output is amplified by an amplifier 14 and becomes the detection output. A plate whose quantity of transmitted light can be controlled (e.g., a liquid crystal shutter) is used as the light screening plate 13. A voltage E1 of a power source 16 is applied to the liquid crystal plate 13 through a switch 15 under the synchronized control of an oscillator circuit 21. The output of the amplifier 14 when the plate 13 becomes opaque is sent out through a smoothing circuit 18 by the synchronized switching of a switch 17. The output becomes a displacement quantity signal. When the switch 15 is opened and the plate 13 becomes transparent, the output of the amplifier 14 controls a power source 25 of the light source 11 through a switch 17, a smoothing circuit 19, and a differential amplifier 23. |
