US4219264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Close-up device for photographic viewfinder cameras
Assignee: Individual
•
Filing: 1978-09-07
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Granted: 1980-08-26
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Expires: 1998-09-07
Abstract
Abstract Disclosed is an interchangeable attachment for photographic viewfinder cameras for increasing the close-up focusing power thereof. This device comprises a supplementary lens optically aligned with the camera objective lens; a parallax correction prism optically aligned with the camera viewfinder; a common view rangefinder system; and a support member for carrying the optically active elements of the device, adapted to be mounted on the camera in front of the camera objective lens. In order to compensate for the change in object distance resulting from the attachment of the device to the camera, the parallax correction prism and the rangefinder system have their optical powers adjusted to correspond to this change, enabling one to directly see through the viewfinder whether the object is in focus and to permit simultaneous correction of the parallax through the viewfinder.
Inventors
- 👤 Hans-Jurgen Rodeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:44
CPC Classifications
G; G03; G03B; G03B13/00; G03B13/02; G03B13/10; G03B13/14
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
162 words
An interchangeable close-up focusing device for use with a photographic viewfinder camera having a front wall containing a viewfinder system and an opening for a camera objective lens, comprising: a. a support member adapted to be mounted to the front wall of said camera; b. a supplementary lens mounted on said support member so as to be in optical alignment with said camera objective lens for enhancing the close-up focusing power of said objective lens; c. a parallax correction prism mounted on said support so as to be in optical alignment with said camera viewfinder system; and d. a non-symmetric base view rangefinder system arranged on said support member such that the rangefinder beam is deflected into the field of view of said camera viewfinder, said parallax correction prism and said rangefinder system having their optical powers adjusted to correspond to the change in object distance resulting from interposition of said supplemental lens in the optical field of said camera objective lens.
Claim 2
Dependent Claim
162 words
An interchangeable close-up focusing device for use with a photographic viewfinder camera having a front wall containing a viewfinder system and an opening for a camera objective lens, comprising: a. a support member adapted to be mounted to the front wall of said camera; b. a supplementary lens mounted on said support member so as to be in optical alignment with said camera objective lens for enhancing the close-up focusing power of said objective lens; c. a parallax correction prism mounted on said support so as to be in optical alignment with said camera viewfinder system; and d. a non-symmetric base view rangefinder system arranged on said support member such that the rangefinder beam is deflected into the field of view of said camera viewfinder, said parallax correction prism and said rangefinder system having their optical powers adjusted to correspond to the change in object distance resulting from interposition of said supplemental lens in the optical field of said camera objective lens.
Claim 3
Dependent Claim
28 words
The device of claim 1, further comprising a cover cap adapted to be mounted on said support member over said supplementary lens, parallax correction prism, and rangefinder system.
Claim 4
Dependent Claim
21 words
The device of claim 2, wherein said cover cap has openings therein for the viewfinder, rangefinder, and supplementary lens optical field.
Claim 5
Dependent Claim
16 words
The device of claim 1, wherein said parallax correction prism forms part of said rangefinder system.
Claim 6
Dependent Claim
73 words
The device of claim 4, wherein said parallax correction prism has a concavely ground portion forming a concave lens; and said rangefinder system comprises said concave lens, a beam-splitter prism disposed on said parallax correction prism in optical alignment with said concave lens, and a reflex prism having its face directed toward an object formed as a convex lens, said reflex prism being laterally displaced from said parallax correction prism and beam-splitter prism.
Claim 7
Dependent Claim
33 words
The device of claim 5, wherein said support member is comprised of thermoplastic; and said supplementary lens, parallax correction prism and beam-splitter prism, and said reflex prism are embedded in said support member.
Claim 8
Dependent Claim
26 words
The device of claim 5, wherein said supplementary lens, said parallax correction prism, and said support member comprise an integral single piece of transparent thermoplastic material.
Claim 9
Dependent Claim
13 words
The device of claim 5, wherein said reflex prism has a fixed position.
Claim 10
Dependent Claim
13 words
The device of claim 8, wherein said camera objective has a fixed focus.
Claim 11
Dependent Claim
18 words
The device of claim 8, wherein said camera objective has an adjustable focus which is adjusted to infinity.
Claim 12
Dependent Claim
27 words
The device of claim 5, wherein said reflex prism is moveable about a pivot point normal to its optical axis, and said camera having an adjustable focus.
Claim 13
Dependent Claim
35 words
The device of claim 11, wherein said reflex prism is mounted on said support member by means of an elastic mount, and said device further comprises means for moving said reflex prism about its axis.
Claim 14
Dependent Claim
40 words
The device of claim 12, wherein said means comprises a setting ring rotatably mounted on said support around said supplemental lens, said ring carrying an axial cam which engages said reflex prism and moves said prism about its pivot point.
Claim 15
Dependent Claim
77 words
The device of claim 13, wherein said camera objective lens has a focusing scale, and said setting ring has a focusing scale formed thereon which corresponds to said camera objective lens focusing scale and has said cam associated therewith such that when said scales have identical settings, the optical power of said rangefinder is matched to correspond to the object distance resulting from interposition of said supplemental lens in the optical field of said camera objective lens.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-26 | 1984-02-25 | 1984-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-26 | 1988-02-25 | 1988-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-26 | 1992-02-25 | 1992-08-26 | $7700.00 | Window Closed / Lapsed |