| 摘要 |
PROBLEM TO BE SOLVED: To provide a range finder capable of separating a light flux without exerting an influence of deterioration of hue on visible light. SOLUTION: This range finder includes a measuring light source (1) for irradiating measuring light, an objective lens (3), a collimation optical system (6-9) having an eye lens, an optical path separating member (2) having a plane vertical to an optical axis of the objective lens and a first inclined plane inclined with respect to the optical axis of the objective lens, and a light receiving element (4) for receiving the measuring light reflected by an object through the optical path separating member. The first inclined plane has a wavelength separating function for separating a wavelength of light used in the collimation optical system and a wavelength of the measuring light respectively, and satisfies following conditions: (Sin<SP>-1</SP>(1/n)+Sin<SP>-1</SP>(1/n(Sinθ<SB>FNO</SB>)))/2<θ<SB>1</SB><30°, wherein,θ<SB>1</SB>: an angle formed between a plane vertical to the optical axis of the objective lens and the first inclined plane,θ<SB>FNO</SB>:θ<SB>FNO</SB>=tan<SP>-1</SP>(1/2FNO), FNO: F number of the objective lens, n: a refractive index of the wavelength of the measuring light of a member constituting the optical path separating member. COPYRIGHT: (C)2011,JPO&INPIT |
