US3733988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light measuring apparatus for a single-lens reflex camera
Assignee: HASSELBLAD
•
Filing: 1971-06-21
•
Granted: 1973-05-22
•
Expires: 1991-06-21
Abstract
Abstract A single-lens reflex camera comprises an exposure meter disposed in the ray path of the camera. A portion of the viewfinder mirror surface is made partially specular to allow for the passage of the measuring light, and the viewfinder mirror holder on its rear side is provided with a folding deviating mirror to deflect the light in the direction of a measuring cell. The motion of the deviating mirror which deflects the measuring light to a measuring cell disposed in a side wall of the camera housing is controlled by a parallel motion guide bar which is a part of the viewfinder mirror linkage.
Inventors
- 👤 L Tenne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:40
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/02; G03B19/12; G03B17/00; G03B17/02; G03B17/17
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
266 words
In a single lens reflex camera, apparatus for the deflection of light from the ray path of the lens to a measuring cell in an exposure meter including: a folding viewfinder mirror, means for actuating said viewfinder mirror comprising a parallel motion guide bar disposed Behind said viewfinder mirror and a pair of hinged arms on the respective sides of the said viewfinder mirror which are interconnected by said guide bar, the distance between said parallel motion guide bar and said viewfinder mirror being the greatest when the viewfinder mirror is in folded-down position and reducing to a minimum when the viewfinder mirror is in its folded-up position, said viewfinder mirror having at least a portion thereof which is partially specular to permit the passage of measuring light, a folding deviating mirror mounted at the rear side of the viewfinder mirror in such manner as to have impinge thereupon the light which passes through the partially specular portion of the viewfinder mirror and being further arranged so as to deflect the light which impinges thereupon to a measuring cell mounted in the interior of the camera, a holder for said deviating mirror and means supporting said holder in such manner that its axis of rotation forms an angle with said parallel motion guide bar, spring means normally maintaining an edge of said deviating mirror holder in folded-out position against the parallel motion guide bar, said edge of said deviating mirror holder sliding against the parallel motion guide bar when said bar upon forward and downward folding of the viewfinder mirror moves relative to the viewfinder mirror.
Claim 2
Dependent Claim
266 words
In a single lens reflex camera, apparatus for the deflection of light from the ray path of the lens to a measuring cell in an exposure meter including: a folding viewfinder mirror, means for actuating said viewfinder mirror comprising a parallel motion guide bar disposed Behind said viewfinder mirror and a pair of hinged arms on the respective sides of the said viewfinder mirror which are interconnected by said guide bar, the distance between said parallel motion guide bar and said viewfinder mirror being the greatest when the viewfinder mirror is in folded-down position and reducing to a minimum when the viewfinder mirror is in its folded-up position, said viewfinder mirror having at least a portion thereof which is partially specular to permit the passage of measuring light, a folding deviating mirror mounted at the rear side of the viewfinder mirror in such manner as to have impinge thereupon the light which passes through the partially specular portion of the viewfinder mirror and being further arranged so as to deflect the light which impinges thereupon to a measuring cell mounted in the interior of the camera, a holder for said deviating mirror and means supporting said holder in such manner that its axis of rotation forms an angle with said parallel motion guide bar, spring means normally maintaining an edge of said deviating mirror holder in folded-out position against the parallel motion guide bar, said edge of said deviating mirror holder sliding against the parallel motion guide bar when said bar upon forward and downward folding of the viewfinder mirror moves relative to the viewfinder mirror.
Claim 3
Dependent Claim
40 words
The apparatus of claim 1 in which said deviating mirror holder is so mounted on the viewfinder mirror holder that said deviating mirror deflects the measuring light to a measuring cell disposed in one side wall of the camera housing.
Claim 4
Dependent Claim
46 words
The apparatus of claim 1 wherein an edge of said parallel motion guide bar is provided with a tongue which can be bent toward or away from said deviating mirror holder to provide for adjustment of the angle of the deviating mirror in its folded-out position.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |