| 摘要 |
<p>There is provided a focal point detection device capable of easily enlarging the lead-in range of the auto focus operation. The device includes: means for illuminating an object surface (11) via a first field stop (16); first image formation means (19, 20, 41) for forming an intermediate image of the first field stop on an arrangement surface of a second field stop (41) according to light L2 generated from the object surface and passing the intermediate image without cutting off by the second field stop when the object surface is positioned within a predetermined range including the focal surface while cutting off a part of the intermediate image by the second field stop and passing the remaining part when the object surface is positioned out of the predetermined range; second image formation means (42 to 46) for dividing into two parts the final image of the first field stop according to the light L5 from the first image formation means; and generation means (47, 48) for detecting the interval between the two final images divided and generating a focus signal according to the positional relationship with respect to the focal surface of the object surface.</p> |
