US4080051A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of photochromic gradient lenses of cosmetically improved color
Assignee: American Optical Corp
•
Filing: 1976-03-18
•
Granted: 1978-03-21
•
Expires: 1996-03-18
Abstract
Abstract Glass lenses, or lens blanks, containing all the ingredients necessary to produce phototropic, or photochromic, behavior, are treated in a conventional production furnace to produce a locally variable heat treatment, wherein at least one portion thereof is raised to a temperature exceeding the glass strain point but not the softening point, and other portions are heated to variable temperature decreasing from the strain point. The treatment causes development of phototropic, or photochromic, behavior only in those portions of the lenses, or lens blanks, exposed to the temperature above the strain point. The lenses resulting are characterized by trichromatic coefficients, x=0.306 and y=0.307, in the unactivated state and x=0.324 and y=0.321, in an activated state and including a small but effective quantity of cobalt oxide.
Inventors
- 👤 David A. Krohn
- 👤 Emil W. Deeg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:42
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/04; C03C4/06; G; G02; G02C; G02C7/00; G02C7/10; G02C7/102; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
174 words
In ophthalmic quality lenses and lens blanks exhibiting local reversible, progressive variation in phototropic behavior, said lenses and lens blanks including a portion ultimately to serve as a distance portion and another portion ultimately to serve as a near portion, the distance portion and the near portion to be continuous with the near portion being below the distance portion when a lens made from a said lens blank is glazed in a frame, the reversible, progressive local variation in photochromic behavior being substantially more resistant to light transmission near an upper edge thereof and substantially less resistant to light transmission in the near portion when said lens is glazed in a frame, the transmission in light from the top of the lens to the bottom being substantially uniform laterally of a said lens when glazed, the improvement comprising said lens characterized by including a small, but effective, amount of cobalt oxide to thereby provide a lens characterized by a slight gray color in the unexposed state to a gray-brown color in the exposed state.
Claim 2
Dependent Claim
174 words
In ophthalmic quality lenses and lens blanks exhibiting local reversible, progressive variation in phototropic behavior, said lenses and lens blanks including a portion ultimately to serve as a distance portion and another portion ultimately to serve as a near portion, the distance portion and the near portion to be continuous with the near portion being below the distance portion when a lens made from a said lens blank is glazed in a frame, the reversible, progressive local variation in photochromic behavior being substantially more resistant to light transmission near an upper edge thereof and substantially less resistant to light transmission in the near portion when said lens is glazed in a frame, the transmission in light from the top of the lens to the bottom being substantially uniform laterally of a said lens when glazed, the improvement comprising said lens characterized by including a small, but effective, amount of cobalt oxide to thereby provide a lens characterized by a slight gray color in the unexposed state to a gray-brown color in the exposed state.
Claim 3
Dependent Claim
22 words
The lens according to claim 1 including cobalt oxide on an oxide basis, by weight, in the range 0.01 to 0.001 percent.
Claim 4
Dependent Claim
20 words
The lens according to claim 2 in which the cobalt oxide is present in a quantity of 0.007 weight percent.
Claim 5
Dependent Claim
26 words
Ophthalmic quality glass lenses of the type described in claim 1 characterized by color variation along the line 400 in FIG. 2 of the attached drawings.
References Cited (Backward Citations)
US2675740A
Cited
CA739404A
Cited
US3208860A
Cited
US3255026A
Cited
US3197296A
Cited
US3419370A
Cited
DE2107343A1
Cited
DE2107344A1
Cited
GB1380781A
Cited
US3892582A
Cited
US3920463A
Cited
US3957499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |