Patent ID: 8638423
Filing Date: 2014-01-28
Classification: G01C,G01S

Abstract:
1. A distance measuring apparatus comprising: a collimating optical system composed of, in order from a target object side, an objective lens, a partial reflection member and an erecting prism; a first-optical-path-diverging surface that is disposed in the partial reflection member and diverges a first measurement optical path from an optical path of the collimating optical system; a second-optical-path-diverging surface that is one reflection surface of the erecting prism and diverges a second measurement optical path from the optical path of the collimating optical system; a light source that is disposed on one of the first measurement optical path or the second measurement optical path and emits light for projecting onto the target object through said objective lens; and a photodetector that is disposed on the other of the first measurement optical path or the second measurement optical path and detects light that is reflected from the target object and converged by the objective lens; and the following conditional expression being satisfied: where di denotes a distance along the optical axis from each optical surface that includes the first-optical-path-diverging surface and is disposed between the first-optical-path-diverging surface and the second-optical-path-diverging surface to the image side next optical surface, ni denotes a refractive index of the medium disposed image side of each optical surface, and f denotes a focal length of the objective lens.