| 摘要 |
PURPOSE:To clarify the pattern of the luminous flux formed on an object in the longitudinal direction of the base line length by making the optical system used for the projecting lens or photodetecting lens of the active type range finder so that the F number in the base line longitudinal direction becomes larger. CONSTITUTION:A spot light is irradiated on the object 4 by lighting a light source 1 and it is reflected on the surface thereof and one part of the luminous flux thereof is made incident on a photodetecting lens 8 according to the reflecting optical axis 12. This reflection optical axis 12 is made incident at a large angle for the optical axis 7 as the distance of the object approaches. It coincides with the optical axis 7 when the distance of the object becomes infinite. And the image of the spot light reflected from the object 4 at the different position respectively for the incident angle of the reflection optical axis 12 is formed on the photodetecting body 10. Therefore, by taking the signal concerning the light incident position out of the photodetecting body 10 the distance upto the object 4 can be decided. The photodetecting lens 8 is formed in the rectangular shape becoming in short diameter in the base line longitudinal (l) direction to deepen the focus depth. And the image of the spot light with less blurring on the base line length (l) direction and like easy to discriminate the distance of the object. |
