Photography – Having variable focal length of camera objective – Automatic change of focal length
Patent
1996-05-14
1998-06-16
Gray, David M.
Photography
Having variable focal length of camera objective
Automatic change of focal length
396 80, G03B 1700
Patent
active
057686351
ABSTRACT:
An image magnification control device for a camera having a photographic lens. The image magnification control device includes a first detector that functions to detect a focal length "f0" of the photographic lens. A distance "X0" between a rear focal point of the photographic lens and an image taking plane of the camera is then determined based on a delivery-amount of a focusing lens of the photographic lens and the detected focal length "f0". A second detector detects a defocusing amount "dx" by analyzing a light passed through the photographic lens, in which the defocusing amount "dx" represents a displacement of an image formed by the photographic lens from the image taking plane. An image magnification "m0" is determined based on a formula "m0=X0/f0", while a control focal length "f1" is calculated based on a formula "f1=(f).sup.2 .multidot.m0)/(X0+dx)". The focal length of the photographic lens is thus controlled so as to meet the control focal length "f1".
REFERENCES:
patent: 4145732 (1979-03-01), Pandres, Jr.
patent: 4156933 (1979-05-01), Pandres, Jr.
patent: 4446526 (1984-05-01), Iwande
patent: 4491396 (1985-01-01), Isobe et al.
patent: 4500778 (1985-02-01), Kusaka et al.
patent: 4508443 (1985-04-01), Matsuzaki et al.
patent: 4509842 (1985-04-01), Taniguchi et al.
patent: 4560267 (1985-12-01), Nakai et al.
patent: 4623238 (1986-11-01), Taniguchi et al.
patent: 4717933 (1988-01-01), Ando et al.
patent: 4724454 (1988-02-01), Misawa
patent: 4857951 (1989-08-01), Nakajima et al.
patent: 4908643 (1990-03-01), Tamada et al.
patent: 4935763 (1990-06-01), Itoh et al.
patent: 4951075 (1990-08-01), Tokumaru et al.
patent: 4962400 (1990-10-01), Otani et al.
patent: 5063402 (1991-11-01), Shimada et al.
patent: 5093680 (1992-03-01), Suzuki et al.
patent: 5113209 (1992-05-01), Ueyama et al.
patent: 5159377 (1992-10-01), Suzuki et al.
patent: 5283607 (1994-02-01), Suzuki et al.
patent: 5428419 (1995-06-01), Suzuki et al.
English Language Abstract of JP 1-99012.
English Language Abstract of JP 1-99011.
English Language Abstract of JP 64-79713.
English Language Abstract of JP 64-62608.
English Language Abstract of JP 64-56406.
English Language Abstract of JP 64-44429.
English Language Abstract of JP 64-44428.
English Language Abstract of JP 63-220118.
English Language Abstract of JP 63-5331.
English Language Abstract of JP 63-200340.
English Language Abstract of JP 62-133431.
English Language Abstract of JP 62-133430.
English Language Abstract of JP 62-118328.
English Language Abstract of JP 61-230111.
Patent Abstracts of Japan, vol. 10, No. 195 (P-475) (2251), Jul. 9, 1986.
English Language Abstract of JP 61-26015.
English Language Abstract of JP 53-113527.
English Language Abstract of JP 57-165806.
Patent Abstracts of Japan, vol. 9, No. 33 (P-334) (1756).
Infinity Super Zoom 300 Camera Instruction Manual, p. 67, published Jul. 1988.
An English language Abstract of JP-A-60 001602.
European Search Report and Annex with respect to EP 94 10 8436.
European Search Report and Annex with respect to EP 94 10 6154.
English Language Abstract of JP 61-38917.
Office Action issued by the E.P.O. on Aug. 11, 1994.
English Language Abstract of JP 1-131509.
English Language Abstract of JP 1-123026.
Kawasaki Masahiro
Suzuki Noboru
Toji Shigeo
Asahi Kogaku Kogyo Kabushiki Kaisha
Gray David M.
LandOfFree
Image magnification control device for a camera does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image magnification control device for a camera, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image magnification control device for a camera will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1739619