Abstract: [Problem] To provide a displacement detection apparatus that offers high measurement accuracy while maintaining high versatility. [Solution] A second birefringent unit 121 and a third birefringent unit 123 are configured to change the phase difference between the first light beam L1 and the second light beam L2 in response to movement of the target T in the measurement direction.

Abstract: A rotary encoder 1 includes a rotary scale 2 having a cylindrical surface 2a as a detected surface and having a relative angle track 2b formed circumferentially on the cylindrical surface 2a, a sensor head 3 arranged with an interval from the cylindrical surface 2a and detecting the relative angle track 2b and outputting a detection signal, and a first angle calculator 4 calculating a rotation angle of the rotary scale 2 based on the detection signal from the sensor head 3. The rotary encoder 1 includes an angle error storage 7 storing an angle error corresponding to the size of the interval at each rotation angle calculated based on the detection signal from the sensor head 3, and an angle compensator 8 compensating the rotation angle calculated by the first angle calculator 4 based on the angle error at each rotation angle stored in the angle error storage 7.

Abstract: [Problems] To provide a weighting information generating apparatus capable of generating weighting information for improving integral nonlinearity without using a high precision digital-to-analog converter. [Solution to the Problem] The weighting information generating apparatus 20 includes: a voltage input unit 21, 22, 23, 24a that has a voltage generation unit 21, 22 configured to generate predetermined binary voltages; and a voltage offset unit 21, 23 configured to apply a voltage for offset to the binary voltages generated by the voltage generation unit 21, 22 to offset the binary voltages, and is configured to sequentially input the offset binary voltages, which are offset stepwise for each predetermined voltage, into an analog-to-digital converter 10; and an information generating unit 21 that is configured to acquire output values corresponding to the binary voltages output from the analog-to-digital converter 10, and generate weighting information based on the acquired output values.

Abstract: Aim To provide a position detection apparatus capable of detecting a position with a high accuracy and a high resolution. Solution Included are: a moving body 13 having an elongated shape, disposed so as to be movable in its longitudinal direction, and having plural detection object portions 15a, 15b, 15c, 15d disposed along the longitudinal direction, the plural detection object portions 15a, 15b, 15c, and 15d having a conductivity; a first detection part 20 and a second detection part 25 arranged along a moving direction of the moving body 13, and disposed so as to be capable of facing the respective detection object portions 15a, 15b, 15c, 15d of the moving body 13 with a predetermined interval therebetween; and a displacement detection parts 40, 41 for detecting a displacement of the moving body 13 by processing output signals from the first detection part 20 and the second detection part 25.

Abstract: A displacement calculation device 30 calculates a displacement based on two or more displacement detection signals differing in phase. The displacement calculating device 30 includes a detected displacement calculation unit 32 calculating a detected displacement based on the displacement detection signals, a signal analysis unit 33 calculating an amplitude error, a vibration center error, and a phase error between the displacement detection signals and a reference signal, a periodic displacement error calculation unit 34 calculating a periodic displacement error and a period of the displacement error based on the errors calculated by the signal analysis unit 33, and a displacement correction unit 35 correcting the detected displacement calculated by the detected displacement calculation unit 32, based on the displacement error and its period calculated by the periodic displacement error calculation unit 34, and outputting a corrected calibrated displacement.

Abstract: A rotary encoder 1 includes a rotary scale 2 having a cylindrical surface 2a as a detected surface and having a relative angle track 2b formed circumferentially on the cylindrical surface 2a, a sensor head 3 arranged with an interval from the cylindrical surface 2a and detecting the relative angle track 2b and outputting a detection signal, and a first angle calculator 4 calculating a rotation angle of the rotary scale 2 based on the detection signal from the sensor head 3. The rotary encoder 1 includes an angle error storage 7 storing an angle error corresponding to the size of the interval at each rotation angle calculated based on the detection signal from the sensor head 3, and an angle compensator 8 compensating the rotation angle calculated by the first angle calculator 4 based on the angle error at each rotation angle stored in the angle error storage 7.

Abstract: A displacement detecting device includes a non-contact sensor having a light source, an objective lens focusing output light from the light source onto a measurement surface, and a light receiving element detecting displacement information based on a focal length of the objective lens by using reflected light from the measurement surface; a control unit adjusting the focal length based on the displacement information; a displacement-amount measuring unit having a linear scale attached to the objective lens with a link member therebetween and measuring an amount of displacement of the linear scale when the focal length is adjusted. A light adjustment member is disposed between the light source and the objective lens or between the objective lens and the light receiving element and has an aperture section transmitting the output and/or reflected light therethrough and a light blocking section that blocks a specific light component of the output and/or reflected light.