POSITION DETECTION SYSTEM, POSITION DETECTION METHOD, IMAGE GENERATION UNIT, AND IMAGE PROJECTION APPARATUS

A position detection system (PS) for detecting a position of a movable member includes a magnetic field generation unit (PSF1, 541) to generate a magnetic field (M), a magnetic field detection unit (PSF2, 542) to detect a magnetic flux density (B) of the magnetic field (M) effecting the magnetic field detection unit (PSF2, 542) from the magnetic field generation unit (PSF1, 541), the magnetic flux density (B) of the magnetic field (M) effecting the magnetic field detection unit (PSF2, 542) changeable depending on a change of a position of the magnetic field detection unit (PSF2, 542) relative to a position of the magnetic field generation unit (PSF1, 541), and to output a detection voltage (V H ) corresponding to the detected magnetic flux density (B) of the magnetic field (M), the magnetic field detection unit (PSF2, 542) disposed on the movable member, and at least one processor (101) to generate a corrected voltage (Vcor) based on the detection voltage (V H ) output from the magnetic field detection unit (PSF2, 542), perform an analog-digital (AD) conversion to the corrected voltage (Vcor) to generate a digital value, set an offset value (OF) used for specifying a characteristic relationship of the corrected voltage (Vcor) and the digital value, calculate a displacement of the magnetic field detection unit (PSF2, 542) relative to the magnetic field generation unit (PSF1, 541) by applying the specified characteristic relationship to the digital value, and detect the position of the movable member based on the calculated displacement of the magnetic field detection unit (PSF2, 542).