US3779146A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reflex photographic cameras
Assignee: Pentacon GmbH Foto und Feinwerktechnik
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Filing: 1972-04-04
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Granted: 1973-12-18
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Expires: 1992-04-04
Abstract
Abstract A reflex camera having a photoelectric exposure meter includes a light concentrator guide having reflective surfaces mounted on and arranged behind the reflex mirror which is partially transparent (half silvered). The light concentrator guide is provided with a first reflective surface lying transversely of the optical axis of the object lens of the camera and a second reflective surface lying transversely of the optical axis. The second reflective surface reflects light rays entering the light concentrator guide from the object lens of the camera towards a light emergent surface thereof. A photoelectric receiver is situated opposite the light emergent surface of the light concentrator guide to receive the light rays.
Inventors
- 👤 W Trankner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:09
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/099; G03B7/0993; G03B7/0997; G03B7/09971; G03B7/09972
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
248 words
In a photographic mirror reflex camera having a reflex mirror pivotable between a first position in which light rays from the object lens of the camera are deflected towards the viewfinder eyepiece and a second position out of the light ray path to expose film to the light rays from the object lens and a photoelectric receiver located within the camera to receive a portion of the object light rays incident upon the reflex mirror in its first position the provision of a photoelectric exposure meter comprising light concentrator guide means mounted in a plane parallel manner on and arranged behind the reflex mirror, relative to the direction of the object light rays, which reflex mirror is partially transparently mirror coated, the photoelectric receiver positioned within the camera being located so as to receive light from a light emergent surface of the light concentrator guide means, said light concentrator guide means being provided with a first reflective surface lying transversely of the optical axis of the camera object lens and obliquely to the near wall of the reflex mirror, and a second reflective surface lying transversely of said optical axis, wherein the second surface deflects light rays from the first surface to concentrate light rays in the direction of the face of the light emergent surface of the light guide to illuminate the photoelectric receiver, and wherein light from the viewfinder eyepiece being incident upon the first reflective surface is reflected away from the light concentrator guide means.
Claim 2
Dependent Claim
248 words
In a photographic mirror reflex camera having a reflex mirror pivotable between a first position in which light rays from the object lens of the camera are deflected towards the viewfinder eyepiece and a second position out of the light ray path to expose film to the light rays from the object lens and a photoelectric receiver located within the camera to receive a portion of the object light rays incident upon the reflex mirror in its first position the provision of a photoelectric exposure meter comprising light concentrator guide means mounted in a plane parallel manner on and arranged behind the reflex mirror, relative to the direction of the object light rays, which reflex mirror is partially transparently mirror coated, the photoelectric receiver positioned within the camera being located so as to receive light from a light emergent surface of the light concentrator guide means, said light concentrator guide means being provided with a first reflective surface lying transversely of the optical axis of the camera object lens and obliquely to the near wall of the reflex mirror, and a second reflective surface lying transversely of said optical axis, wherein the second surface deflects light rays from the first surface to concentrate light rays in the direction of the face of the light emergent surface of the light guide to illuminate the photoelectric receiver, and wherein light from the viewfinder eyepiece being incident upon the first reflective surface is reflected away from the light concentrator guide means.
Claim 3
Dependent Claim
174 words
A camera as claimed in claim 1, including a photoelectric exposurE meter comprising light concentrator guide means in the form of a flat transparent plate mounted in a plane parallel manner on and arranged behind the reflex mirror which is partially transparently mirror-coated, said light concentrator guide means being provided with a first group of several reflective surfaces lying transversely of the optical axis of the camera object lens and a second group opposite to this first group of reflective surfaces having several reflective and refractive surfaces lying transversely of and inclined at substantially 45* to the said optical axis, wherein the latter surfaces deflect light rays from the first group of reflective surfaces to concentrate the light rays in the direction of the face of the light emergent surface of the light concentrator guide to illuminate a photoelectric receiver situated opposite the light emergent surface of the light guide, and wherein light from the viewfinder eyepiece being incident upon the first group of reflective surfaces is reflected away from the light concentrator guide.
Claim 4
Dependent Claim
170 words
A camera as claimed in claim 2, wherein the light concentrator guide means comprises a flat elongate plate having the reflective surfaces of the first group provided on one longitudinal edge of the light guide, these surfaces in vertical section being so inclined in use in relation to the optical axis of the object lens of the camera that both axial and oblique extra-axial rays, extending nearly parallel with the plane surface in the light guide, arrive upon the second group of reflective and refractive surfaces deflecting the light rays and conducting them towards the light emergence face of the light guide, the second group of surfaces being arranged along the other longitudinal edge of the light guide as wedge-shaped incisions forming air wedges lying side by side, in such a way that the first reflective and at the same time refractive surface of the second group is inclined at substantially 45* to the said optical axis, and the second refractive surface forms the wedge angle for the air wedge.
Claim 5
Dependent Claim
27 words
A camera as claimed in claim 3, wherein the incision depth of the air wedges diminishes towards the lateral light emergence surface of the light concentrator guide.
Claim 6
Dependent Claim
28 words
A camera as claimed in claim 4 wherein the oblique reflective surface of the light concentrator guide is situated approximately in the middle region of the reflex mirror.
Claim 7
Dependent Claim
30 words
A camera as claimed in claim 5, wherein between the light emergence surface of the light concentrator guide and the photoelectric receiver a conical light ray concentrator guide is provided.
Claim 8
Dependent Claim
17 words
A camera as claimed in claim 6, including a movable diphragm arranged between the light concentrator guides.
Claim 9
Dependent Claim
16 words
A camera as claimed in claim 7, wherein the surfaces of the wedge-shaped incisions are de-reflected.
Claim 10
Dependent Claim
46 words
A camera as claimed in claim 8, wherein between the reflex mirror and the light concentrator guide there is situated a thin apertured mask consisting of non-transparent material, the apertures of which permit only the passage of light rays for the first group of reflective surfaces.
Claim 11
Dependent Claim
19 words
A camera as claimed in claim 9, wherein the reflex mirror and the light concentrator guide are formed integrally.
Claim 12
Dependent Claim
129 words
A camera as claimed in claim 1, wherein the first light concentrator guide means has two longitudinal edges and two shorter edges interconnecting the longer edges and wherein the first reflective surface is formed by at least a part of the one of said longitudinal edges innermost of the reflex mirror, which part is at an oblique angle with the optical axis of the object lens, and the second reflective surface is formed by the one of the said shorter edges which is furthermost from the photoelectric receiver, said second reflective surface subtending an angle of substantially 45* with the first reflective surface, so that light rays entering the first light concentrator guide means are reflected through substantially 90* towards the light emErgent surface thereof and the photoelectric receiver.
Claim 13
Dependent Claim
53 words
A camera as claimed in claim 11, wherein between the first and second reflective surfaces at least two additional reflective surfaces are provided, the longitudinal axes of which are parallel to the longitudinal axis of the first reflective surface, to enable light to pass through the first and additional reflective surfaces in succession.
Claim 14
Dependent Claim
31 words
A camera as claimed in claim 12, wherein longitudinal edges of the first light concentrator guide means converge towards the light emergent surface of the said first light concentrator guide means.
Claim 15
Dependent Claim
25 words
A camera as claimed in claim 13, wherein the first second and additional reflective surfaces are in the main situated centrally of the reflex mirror.
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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |