US3397023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light apertures
Assignee: Polaroid Corp
•
Filing: 1964-12-16
•
Granted: 1968-08-13
•
Expires: 1984-12-16
Abstract
No abstract record available.
Inventors
- 👤 Edwin H Land
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:51
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/23
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
53 words
A LIGHT-FILTERING DEVICE COMPRISING A SOLID, TRANSPARENT ELEMENT HAVING IN CONJUCTION THEREWITH PHOTOCHROMIC BODIES DISTRIBUTED IN A PLURALITY OF CONCENTRIC ZONES, THE MAGNITUDE OF THE RESPONSE OF SAID PHOTOCHROMIC BODIES TO ITINERANT LIGHT IN EACH RESPECTIVE ZONE INCREASING AS A FUNCTION OF THE DISTANCE OF SAID ZONE FROM THE CENTER OF SAID ELEMENT.
Claim 2
Dependent Claim
53 words
A LIGHT-FILTERING DEVICE COMPRISING A SOLID, TRANSPARENT ELEMENT HAVING IN CONJUCTION THEREWITH PHOTOCHROMIC BODIES DISTRIBUTED IN A PLURALITY OF CONCENTRIC ZONES, THE MAGNITUDE OF THE RESPONSE OF SAID PHOTOCHROMIC BODIES TO ITINERANT LIGHT IN EACH RESPECTIVE ZONE INCREASING AS A FUNCTION OF THE DISTANCE OF SAID ZONE FROM THE CENTER OF SAID ELEMENT.
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) | 1971-08-13 | 1972-02-12 | 1972-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-08-13 | 1976-02-12 | 1976-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-08-13 | 1980-02-12 | 1980-08-13 | $7700.00 | Window Closed / Lapsed |