US4754299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photometric method and apparatus for cameras
Assignee: Nikon Corp
•
Filing: 1986-09-08
•
Granted: 1988-06-28
•
Expires: 2006-09-08
Abstract
Abstract In a camera a field to be photographed is divided into a plurality of metering sections which produce a plurality of metering outputs, respectively. The metering outputs are processed to produce a value corresponding to a desired proper brightness value in order to control exposure in the camera. The type of lens mounted on the camera body is discriminated, and the information thus obtained is used for changing the photometry processing. A focal length detector produces a focal length signal which changes with the focal length of the phototaking lens. A teleconverter detector detects that a conversion lens is mounted on the camera body and produces a detection signal. Photometry processing is placed in a high speed mode in response to the detection signal, irrespective of the focal length of the phototaking lens mounted on the camera body.
Inventors
- 👤 Takashi Saegusa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:19
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/091; G03B7/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
200 words
A camera body capable of mounting components including a phototaking lens and conversion means, in which said conversion means can be mounted between said phototaking lens and the camera body, the composite focal length of the conversion means with the phototaking lens being larger than the focal length of the phototaking lens, comprising: (a) exposure control means operative to control an amount of exposure and having first and second states at which exposure time is controlled to provide a proper amount of exposure, the exposure time at said second state being shorter than the exposure time at said first state; (b) focal length detection means for producing a focal length signal which changes with focal length of said phototaking lens; (c) conversion detection means for detecting that said conversion means is mounted on said camera body and producing a detection signal; (d) selection means responsive to said focal length signal for causing said exposure control means to select one of said first and said second states; and (e) means responsive to said detection signal for causing said exposure control means to be at said second state irrespective of the focal length of the phototaking lens mounted on said camera body.
Claim 2
Dependent Claim
200 words
A camera body capable of mounting components including a phototaking lens and conversion means, in which said conversion means can be mounted between said phototaking lens and the camera body, the composite focal length of the conversion means with the phototaking lens being larger than the focal length of the phototaking lens, comprising: (a) exposure control means operative to control an amount of exposure and having first and second states at which exposure time is controlled to provide a proper amount of exposure, the exposure time at said second state being shorter than the exposure time at said first state; (b) focal length detection means for producing a focal length signal which changes with focal length of said phototaking lens; (c) conversion detection means for detecting that said conversion means is mounted on said camera body and producing a detection signal; (d) selection means responsive to said focal length signal for causing said exposure control means to select one of said first and said second states; and (e) means responsive to said detection signal for causing said exposure control means to be at said second state irrespective of the focal length of the phototaking lens mounted on said camera body.
Claim 3
Dependent Claim
98 words
A camera body according to claim 1, wherein said exposure control means has first and second programs each of which determines the exposure time and an aperture value of the phototaking lens in order to provide a proper amount of exposure, and wherein said exposure control means controls the amount of exposure on the basis of said first program at said first state, controls the amount of exposure on the basis of said second programs at said second state, and controls the amount of exposure on the basis of said second program in response to said detection signal.
Claim 4
Dependent Claim
106 words
A camera body according to claim 2, wherein said focal length detection means produces said focal length signal which indicates whether the focal length of the phototaking lens is larger than a predetermined value, and wherein said selection means causes said exposure control means to be at said first state when said focal length signal indicates that the focal length of the phototaking lens is not larger than said predetermined value and said selection means causes said exposure control means to be at said second state whe said focal length signal indicates that the focal length of the phototaking lens is larger than said predetermined value.
Claim 5
Dependent Claim
196 words
A camera body capable of mounting components including a phototaking lens and conversions means, in which said conversion means can be mounted between said phototaking lens and the camera body, the composite focal length of the conversion means with the phototaking lens being larger than the focal length of the phototaking lens, comprising: (a) exposure contorl means operative to control an amount of exposure and having first and second states at which exposure time is controlled to provide a proper amount of exposure, the exposure time at said second state being shorter than the exposure time at said first state; (b) means for detecting that a focal length of said phototaking lens is larger than a predetermined value and producing a focal length signal; (c) selection means responsive to said focal length signal for causing said exposure control means to select said second state; (d) conversion detection means for detecting that said conversion means is mounted on said camera body and producing a conversion signal; and (e) said selection means causing said exposure control means to be at said second state in response to said conversion signal irrespective of the focal length of said phototaking lens.
Claim 6
Dependent Claim
196 words
A camera body capable of mounting components including a phototaking lens and conversions means, in which said conversion means can be mounted between said phototaking lens and the camera body, the composite focal length of the conversion means with the phototaking lens being larger than the focal length of the phototaking lens, comprising: (a) exposure contorl means operative to control an amount of exposure and having first and second states at which exposure time is controlled to provide a proper amount of exposure, the exposure time at said second state being shorter than the exposure time at said first state; (b) means for detecting that a focal length of said phototaking lens is larger than a predetermined value and producing a focal length signal; (c) selection means responsive to said focal length signal for causing said exposure control means to select said second state; (d) conversion detection means for detecting that said conversion means is mounted on said camera body and producing a conversion signal; and (e) said selection means causing said exposure control means to be at said second state in response to said conversion signal irrespective of the focal length of said phototaking lens.
References Cited (Backward Citations)
US4352548A
Cited
US4306787A
Cited
US4329040A
Cited
US4372663A
Cited
US4391500A
Cited
US4477164A
Cited
US4548488A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |