| 摘要 |
PURPOSE:To provide a focal point detecting device which satisfies both the enlargement of range finding scope and the improvement of focusing accuracy, is not susceptible to be influenced by the contrast direction of a half mirror and an object and is manufactured and mounted easily. CONSTITUTION:A focal point detecting device includes a half mirror 2 disposed in front with a gradient to its optical axis and plural focal point detecting systems in each of which a phase difference of output signals indicating light intensity distribution of two beams of light passing different areas of a photographing lens 1 is used. A difference between incident angles of two beams of light to the half mirror for the focal point detecting systems having the highest focal point detecting accuracy among plural focal point detecting systems is not larger than a difference between incident angles of two beams of light to the half mirror for the other focal point detecting systems. Further the device includes an opening diaphragm 6, a split lens 7 and a photo receiving element array 8 and so forth. |
