US4035082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method to test for chemically hardened glass lenses
Assignee: Kirk Optical Lens Co Inc
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Filing: 1975-04-07
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Granted: 1977-07-12
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Expires: 1995-04-07
Abstract
Abstract A device to test for the presence of chemically hardened glass wherein a collimated light source and a windowed container are filled with a fluid of refractive index substantially equalling that of the glass. The glass is immersed in the container with the container placed between crossed polarizers. When the glass is chemically hardened, light traversing therethrough is refractively bent thereby to produce a component of the light vector in the optical axis of one of the polarizers and an observable light pattern emanating therefrom.
Inventors
- 👤 Morris Kirschen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:21
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/21
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
95 words
A method to determine if a glass lens is chemically hardened including the steps of, immersing the glass lens to be tested in a fluid medium having a refractive index substantially that of the glass lens with the peripheral rim of the glass lens unobstructed and visible, placing the immersed glass lens between spaced crossed polarizers, and passing an illuminating beam serially through one of the polarizers, the immersed glass lens and then the other of the polarizers to produce a light halo perimetrically about the glass lens when the same has been chemically treated.
Claim 2
Independent Claim
95 words
A method to determine if a glass lens is chemically hardened including the steps of, immersing the glass lens to be tested in a fluid medium having a refractive index substantially that of the glass lens with the peripheral rim of the glass lens unobstructed and visible, placing the immersed glass lens between spaced crossed polarizers, and passing an illuminating beam serially through one of the polarizers, the immersed glass lens and then the other of the polarizers to produce a light halo perimetrically about the glass lens when the same has been chemically treated.
Claim 3
Dependent Claim
13 words
The method of claim 1, the illuminating beam being in the optical spectrum.
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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |