| 摘要 |
PURPOSE:To make the projection contrast of a light projection pattern high and to improve the utilization efficiency of a light source by projecting patterns different from each other so that they may be superposed in the case of offering a pattern image reflected on an object substance to a focus detection means. CONSTITUTION:Since the lens parts 108a and 108b of a light projecting lens 108 constituting an axial illuminating system are eccentric in an up-and-down direction, that means, optical axes 112 and 113 are positioned above and below an optical axis 111, points 115 and 116 on a pattern film are superposed and projected on one point 118 on the range-finding object. On the other hand, since the optical axes 122 and 123 of a luminous flux passing through the lens parts 108c and 108d of the lens 108 are eccentric in the up-and-down direction, a point 117 on the pattern film 107 is projected on the range-finding object 114 as two points out of the axis, so that illumination in wide range is accomplished. Thus, a light beam omitted at a large angle against the optical axis by an LED is effectively guided to the range-finding object and the utilization efficiency of the light from the LED is enhanced without lowering the contrast of the projection pattern. |
