To satisfy the demand for minimizing an optical sensor size, we have previously Proposed reflection-type compact optical sensors1 and showed that these detecting limits are below 5 μm. In this study we present a novel micro-displacement sensor using a twin-micro Fresnel lens and a position sensitive device (PSD). The sensor has two major advantages over other types of optical sensors by the arrangement of the PSD position. First, the sensor shows a high resolution of ±10 μm, and second, it can offer a linear output to displacement without a linear adjustment circuit.
© 1991 Optical Society of AmericaPDF Article