US4051494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic camera with built-in strobo flash light device
Assignee: Fujifilm Holdings Corp
•
Filing: 1975-09-12
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Granted: 1977-09-27
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Expires: 1995-09-12
Abstract
Abstract In a photographic camera provided with a built-in strobo flash light device, the distance from the strobo flash tube to the optical axis of the taking lens of the camera is selected within the range of 4.5cm to 6.5cm. In order to prevent the red eye effect in color photography, the guide number of the strobo flash tube is selected within the range determined with respect to the distance from the strobo flash tube to the optical axis of the taking lens in accordance with the following formula; ##EQU1## WHERE GN is the guide number of the strobo flash tube and d is the distance from the flash tube to the optical axis of the taking lens.
Inventors
- 👤 Yoshihiro Fujita
- 👤 Ikuo Fuutagawa
- 👤 Katsuji Muramatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:55
CPC Classifications
G; G03; G03B; G03B15/00; G03B15/02; G03B15/03; G03B15/05; G03B2215/00; G03B2215/05; G03B2215/0503
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
120 words
A photographic camera with a built-in strobo flash light device comprising a camera body having a taking lens on the front face thereof and a strobo flash tube provided on the front face of the camera body wherein in order to minimize the occurrence of a so-called "red-eye phenomenon" the distance from the center of the strobo flash tube to the optical axis of the taking lens is within the range of 4.5cm to 6.5cm, and that the guide number of the strobo flash tube is selected to satisty the following formula; ##EQU6## where GN is the guide number and d is the distance from the center of the strobo flash tube to the optical axis of the taking lens.
Claim 2
Dependent Claim
120 words
A photographic camera with a built-in strobo flash light device comprising a camera body having a taking lens on the front face thereof and a strobo flash tube provided on the front face of the camera body wherein in order to minimize the occurrence of a so-called "red-eye phenomenon" the distance from the center of the strobo flash tube to the optical axis of the taking lens is within the range of 4.5cm to 6.5cm, and that the guide number of the strobo flash tube is selected to satisty the following formula; ##EQU6## where GN is the guide number and d is the distance from the center of the strobo flash tube to the optical axis of the taking lens.
Claim 3
Dependent Claim
25 words
A photographic camera with a built-in strobo flash light device as claimed in claim 1 wherein said guide number GN is not less than 3.6.
References Cited (Backward Citations)
US3383994A
Cited
US3348188A
Cited
GB1211105A
Cited
GB1174373A
Cited
US3852790A
Cited
US3851163A
Cited
US3866033A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-26 | 1981-03-28 | 1981-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-26 | 1985-03-28 | 1985-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-26 | 1989-03-28 | 1989-09-27 | $7700.00 | Window Closed / Lapsed |