Patent ID: 7542130

Claim:
A moving body measuring apparatus that measures movement information of a moving body as an object to be measured, the moving body measuring apparatus comprising: an optical member having a boundary surface on which light is incident, the optical member transmitting a part of the light and reflecting a remainder of the light at the boundary surface to emit two irradiation lights in two different directions; an irradiation light source that emits light toward the optical member to irradiate the moving body with the irradiation lights from two different directions; a camera that photographs via the optical member an image of light reflected from a reflection marker, provided on a surface of the irradiated moving body; and a movement information computation portion that computes movement information for the moving body based on the image of the light reflected by the reflection marker and photographed by the camera, wherein the reflection marker is a retroreflection marker that reflects the irradiation lights backward to incoming directions of the irradiation lights, wherein arrangement of the irradiation light source, the camera, and the optical member is adjusted such that respective outgoing angles at which the irradiation lights outgo from the boundary surface of the optical member in the two different directions substantially coincide with respective incoming angles at which two reflected light beams, obtained by irradiating the moving body with the irradiation lights in the two different directions, enter the boundary surface.