Patent ID: 8854337

Claim:
An optical position detection device that detects a position of a target object, comprising: a light source section that emits detection light toward the target object, the detection light being distributed into a first light intensity distribution and a second light intensity distribution that is different from the first light intensity distribution; a light receiving section that has a light receiving element, the light receiving element receiving reflected light of the detection light reflected from the target object; and a position detecting section that detects the position of the target object based on a light receiving result of the light receiving section, wherein the first light intensity distribution and the second light intensity distribution are alternatively formed, the light receiving result includes at least two reflected light intensities corresponding to the first and second light intensity distributions, and the light receiving section includes: a concave mirror with a reflective surface, the reflecting surface having a first cross section and a second cross section perpendicular to the first cross section, the first cross section is an arc, and the second cross section is a quadratic curve; and the light receiving element that is located at the center of the arc in a plan view of the first cross section and on an axis of symmetry of the quadratic curve in a plan view of the second cross section.