Patent ID: 8773668
Filing Date: 2014-07-08
Classification: G01B,G01S

Abstract:
1. A displacement sensor, comprising: a light projecting unit configured to project light for detection; a light receiving unit configured to receive reflected light from an object reflecting the light from the light projecting unit, and generate light receiving amount data indicating a light receiving state thereof; a measurement unit configured to repeat detection processing by said light projecting unit and said light receiving unit and measure a displacement of the object using the light receiving amount data obtained by each detection processing; and a sensitivity adjustment unit configured to adjust sensitivity in said detection processing, wherein said light receiving unit includes a light receiving element and a plurality of signal processing units, each of said plurality of signal processing units generating said light receiving amount data by applying different magnifications to a light receiving amount signal output from the light receiving element, said measurement unit performs measurement processing of said displacement using the light receiving amount data generated by a specific signal processing unit of said plurality of signal processing units, and said sensitivity adjustment unit selects one of the light receiving amount data generated by said plurality of signal processing units according to said detection processing based on a prescribed rule, determines a correlation between a value of the light receiving amount data generated by said specific signal processing unit and a predetermined appropriate value based on a ratio of a magnification applied to a signal processing unit generating said selected light receiving amount data to a magnification applied to said specific signal processing unit and the selected light receiving amount data, and adjusts sensitivity in subsequent detection processing based on the correlation.