| 摘要 |
PURPOSE:To allow the multipoint distance measurement over the entire part of an image plane with high accuracy by providing a condenser lens face and a deflecting means consisting of plural divided deflecting planes which deflect a part of the luminous flux transmitted through the lens face in plural directions forming the prescribed angle from the optical axis of an optical system. CONSTITUTION:The rear face of the deflecting means 22 has the plural divided deflecting planes 22b to 22d which deflect a part of the luminous flux from the photodetecting lens 21 in the plural directions forming the prescribed angle from the optical axis L. The deflecting plane 22b among these faces constitutes the coaxial system having the optical axis L with the 1st lens face 22a of the deflecting means 22 and the shape of this lens face is approximately concentric around the central part of the photodetector 23. The deflecting planes 22c, 22d constitute the concave lens faces having a deflecting effect and respectively have the optical axes L22c, L22d. The multipoint measurement with the high accuracy is execute at the plural points in a photographing range while the luminous flux is effectively utilized by one light source or one photodetector. |
