Patent US345046A successfully refreshed from Google Patents.
Patent US4650845A successfully refreshed from Google Patents.
Patent US4698492A successfully refreshed from Google Patents.
US4698492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focus detector system with a distortion compensation mask
Assignee: Canon Inc
•
Filing: 1985-06-27
•
Granted: 1987-10-06
•
Expires: 2005-06-27
Abstract
Abstract A focus detection system includes an object lens for focusing an image of an object, a refocusing optical system for refocusing a plurality of component image having parallax from the image of the image, a view field mask arranged between the object lens and the refocusing optical system and having a laterally extending aperture, and a sensing device having a photo-sensor array for sensing the component images. Focus detection error is prevented by determining a sense area of the photo-sensor array in accordance with a distortion created in an aperture image by the refocusing optical system.
Inventors
- 👤 Keiji Ohtaka
- 👤 Akira Hiramatsu
- 👤 Yasuo Suda
- 👤 Akira Akashi
- 👤 Akira Ishizaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:04
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/0025; G02B7/00; G02B7/28; G02B7/34; G02B7/343
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
A focus detection system comprising: object optical means for forming an image of an object; refocusing means for relaying a light flux from said object optical means and forming a plurality of component images having parallax; light restriction means arranged between said object optical means and said refocusing means and having an aperture; sensing means having a photo-sensor array for sensing said component images; and mask means for determining a shape of a photo-sensing area of said photo-sensor array in accordance with a distortion created in a long side of an aperture image by said refocusing means, said mask means having an aperture of a distorted long side for masking said photo-sensor array.
Claim 2
Dependent Claim
113 words
A focus detection system comprising: object optical means for forming an image of an object; refocusing means for relaying a light flux from said object optical means and forming a plurality of component images having parallax; light restriction means arranged between said object optical means and said refocusing means and having an aperture; sensing means having a photo-sensor array for sensing said component images; and mask means for determining a shape of a photo-sensing area of said photo-sensor array in accordance with a distortion created in a long side of an aperture image by said refocusing means, said mask means having an aperture of a distorted long side for masking said photo-sensor array.
Claim 3
Dependent Claim
15 words
A focus detection system according to claim 1 wherein said refocusing means includes a biprism.
Claim 4
Dependent Claim
16 words
A focus detection system according to claim 2 wherein said refocusing means includes a focusing lens.
Claim 5
Dependent Claim
130 words
A focus detection system comprising: object optical means for forming an image of an object; refocusing means for relaying a light flux from said object optical means and forming a plurality of component images having parallax; light restriction means arranged between said object optical means and said refocusing means and having an aperture; sensing means having photo-sensor arrays arranged in parallel with one another for sensing said component images, each of said photo-sensor arrays having a photo-sensing area of a predetermined shape; and mask means for determining the shape of a photo-sensing area of said photo-sensor array in accordance with distortion created in a long side of an aperture image by said refocusing means, said mask means having an aperture of a distorted long side for masking said photo-sensor array.
Claim 6
Dependent Claim
130 words
A focus detection system comprising: object optical means for forming an image of an object; refocusing means for relaying a light flux from said object optical means and forming a plurality of component images having parallax; light restriction means arranged between said object optical means and said refocusing means and having an aperture; sensing means having photo-sensor arrays arranged in parallel with one another for sensing said component images, each of said photo-sensor arrays having a photo-sensing area of a predetermined shape; and mask means for determining the shape of a photo-sensing area of said photo-sensor array in accordance with distortion created in a long side of an aperture image by said refocusing means, said mask means having an aperture of a distorted long side for masking said photo-sensor array.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-05 | 1991-04-06 | 1991-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-05 | 1995-04-06 | 1995-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-05 | 1999-04-06 | 1999-10-06 | $7700.00 | Window Closed / Lapsed |