초록 ▼

A focus state detection device includes focus state detection optical systems having focus state detection regions off the optical axis of the object lens (in the lateral areas of the field) that extend in a radial direction relative to the optical axis of the shooting lens. In each focus state dete

A focus state detection device includes focus state detection optical systems having focus state detection regions off the optical axis of the object lens (in the lateral areas of the field) that extend in a radial direction relative to the optical axis of the shooting lens. In each focus state detection optical system, images from the object lens are composed into secondary images on a pair of rows of photosensitive elements, and the focussing state of the object lens is detected from the positional relationship between these secondary images. The focus state detection optical systems have a first focus state detection region located on the optical axis of the predicted focussing plane of the object lens, and a second focus state detection region located off the optical axis of the predicted focussing plane and along a radial direction relative to the optical axis. The distance between outer edges of the pair of apertures of the diaphragm mask corresponding to the second focus state detection region is established so as to be smaller than the distance between outer edges of the pair of apertures of the diaphragm mask corresponding to the first focus state detection region. Such structure provides a focus state detection device having a high degree of focus state detection precision without the problems of eclipsing of focus state detection light rays caused by exit pupils of the shooting lens.

대표청구항 ▼

A focus state detection device having an object lens, an object lens exit pupil and an optical axis extending through a center of the object lens and the exit pupil, the focus state detection device comprising: at least first and second focus state detection optical systems, each of said first and s

A focus state detection device having an object lens, an object lens exit pupil and an optical axis extending through a center of the object lens and the exit pupil, the focus state detection device comprising: at least first and second focus state detection optical systems, each of said first and second focus state detection optical systems comprising a diaphragm mask having a pair of apertures that divide the object lens exit pupil into two regions, the first and second focus state detection optical systems further including first and second focus state detection regions positioned off the optical axis of the object lens, wherein a distance between outer edges of the pair of apertures corresponding to the second focus state detection region is smaller than a distance between outer edges of the pair of apertures of the diaphragm mask corresponding to the first focus state detection region, and wherein a line extending between and terminating at a center of each of the pair of apertures corresponding to the first focus state detection region intersects a line extending between and terminating at a center of each of the pair of apertures corresponding to the second focus state detection region.