US3741628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling the intensity of a light beam using photochromic compounds
Assignee: Individual
•
Filing: 1970-12-29
•
Granted: 1973-06-26
•
Expires: 1990-12-29
Abstract
Abstract The disclosure herein relates to reversible phototropic systems, compounds and compositions and the discovery of photochromic structures which regularly undergo reversible phototropism as photo induced reversible color change in water and water containing substrates including particularly the control of their back reactions and the method of use thereof by providing a multiple color and color change indicator and/or light filters.
Inventors
- 👤 J Margerum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:57
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73; H; H01; H01S; H01S3/00; H01S3/10; H01S3/11; H01S3/1123; H01S3/113
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
16 words
A method of claim 1 wherein said light beam is a laser beam with ultraviolet light.
Claim 2
Dependent Claim
12 words
A method of claim 1 wherein said anion corresponds to formula I.
Claim 3
Dependent Claim
12 words
A method of claim 1 wherein said anion corresponds to formula II.
Claim 4
Dependent Claim
12 words
A method of claim 2 wherein said anion corresponds to formula I.
Claim 5
Dependent Claim
12 words
A method of claim 2 wherein said anion corresponds to formula II.
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) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |