US3589236A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Viewfinder having a variable size frame image
Assignee: Polaroid Corp
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Filing: 1969-02-10
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Granted: 1971-06-29
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Expires: 1989-02-10
Abstract
Abstract With many optical devices it is not possible for the operator to directly determine the field of view of the optical device he is using. To assist the operator in the proper use of such optical devices, they are commonly fitted with viewfinders through which the operator can sight as a means of properly aiming the optical device. An example of such an arrangement is found in simple box cameras.
Inventors
- 👤 Richard R Wareham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:05
CPC Classifications
G; G03; G03B; G03B13/00; G03B13/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
73 words
A viewfinder comprising: an entrance window; an exit window; reticle means at said exit window; movably mounted image-forming light reflecting means, proximate said entrance window and coaxial with said viewfinder, for forming a virtual image of said reticle means and directing the light forming said image through said exit window; means for adjustably altering the distance between said imageforming means and said reticle means for changing the size of said virtual reticle image.
Claim 2
Dependent Claim
73 words
A viewfinder comprising: an entrance window; an exit window; reticle means at said exit window; movably mounted image-forming light reflecting means, proximate said entrance window and coaxial with said viewfinder, for forming a virtual image of said reticle means and directing the light forming said image through said exit window; means for adjustably altering the distance between said imageforming means and said reticle means for changing the size of said virtual reticle image.
Claim 3
Dependent Claim
31 words
A viewfinder as in claim 1 wherein said adjusting means varies said distance between a distance equal to the focal length of said image-forming light reflecting means and a lesser distance.
Claim 4
Dependent Claim
13 words
A viewfinder as in claim 1 wherein said reticle means defines a frame.
Claim 5
Dependent Claim
17 words
A viewfinder as in claim 1 wherein said image-forming light reflecting means is a partially transparent mirror.
Claim 6
Dependent Claim
24 words
A viewfinder as in claim 1 wherein said image-forming light reflecting means is a mirror with a transparent aperture coincident with said entrance window.
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) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |