Photography – With exposure objective focusing means – focusing aid – or... – Optical detail with photoelement system
Patent
1995-02-21
1997-04-29
Perkey, W. B.
Photography
With exposure objective focusing means, focusing aid, or...
Optical detail with photoelement system
G03B 1336
Patent
active
056258496
ABSTRACT:
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.
REFERENCES:
patent: 4774539 (1988-09-01), Suda et al.
patent: 4908504 (1990-03-01), Karasaki et al.
patent: 4949116 (1990-08-01), Karasaki et al.
patent: 5109154 (1992-04-01), Higashihara et al.
patent: 5160834 (1992-11-01), Moriyama
patent: 5233173 (1993-08-01), Moriyama
Nikon Corporation
Perkey W. B.
LandOfFree
Focus state detection device and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Focus state detection device and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Focus state detection device and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-715124