| 摘要 |
PURPOSE:To provide the focus detecting optical system of an active type capable of making good focus detection and effectively activating a space. CONSTITUTION:The light emitting light source 1 of the focus detecting optical system which has a projecting system for irradiating a subject 3 with the luminous flux emitted from a light emitting light source via a projecting lens 2 and a light receiving system for condensing the reflected luminous flux from the subject 3 via a light receiving lens 4 onto a light receiving element 5 and is used to detect the focal position by measuring the distance up to the subject 3 in accordance with a change in the imaging position on the light receiving element 5 is positioned with a deviation by a specified distance in a direction orthogonal with the longitudinal direction of a base line from the center of the lens outside diameter of the projecting lens 2. The central position of the paraxial curvature of at least one lens face of the projecting lens 2 is determined with a deviation by the prescribed distance in the direction orthogonal with the longitudinal direction of the base line from the center of the lens outside diameter so as to correct the fluctuation in the centroid position of the projecting spot based on the emitting light source 1 with respect to the center of the lens outside diameter. |
