Patent US4562162A successfully refreshed from Google Patents.
US4562162A
Expired / Lapsed
US
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Glass for multi-focal eyeglass lens
Assignee: Hoya Corp
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Filing: 1984-10-26
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Granted: 1985-12-31
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Expires: 2004-10-26
Abstract
Abstract A glass for multi-focal eyeglass having a refractive index (nd) of 1.67 to 1.73, an Abbe number ( nu d) of 33 or more, a coefficient of thermal expansion of 82 to 95x10-7 and a softening point of 560 DEG to 640 DEG C., comprising, in % by weight, 32 to 40% SiO2+B2O3+Al2O3; 22 to 40% SiO2; 0 to 10% B2O3; 0 to 4% Al2O3; 4 to 10% Li2O+Na2O+K2O; 0 to 4% Li2O; 0 to 7% Na2O; 0 to 7% K2O; 30 to 47% PbO; 3 to 24% BaO+SrO+CaO+MgO+ZnO; 0 to 20% BaO; 0 to 15% SrO; 0 to 10% CaO; 0 to 8% MgO; 0 to 15% ZnO; and 1 to 7% ZrO2; wherein a weight ratio of alkali metal oxides/PbO ranges from 0.1 to 0.3.
Inventors
- 👤 Hiroji Sagara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:02
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/062; C03C3/07; C03C3/072; C03C3/074; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
165 words
A glass for a multi-focal eyeglass having a refractive index (n d ) of 1.67 to 1.73, an Abbe number (ν d ) of 33 or more, a coefficient of thermal expansion of 82 to 95×10 -7 and a softening point of 560° to 640° C., consisting of, in % by weight, 32 to 40% SiO 2 +B 2 O 3 +Al 2 O 3 ; 22 to 40% SiO 2 ; 0 to 10% B 2 O 3 ; 0 to 4% Al 2 O 3 ; 4 to 10% Li 2 O+Na 2 O +K 2 O; 0 to 4% Li 2 O; 0 to 7% Na 2 O; 0 to 7% K 2 O; 30 to 47% PbO; 3 to 24% BaO+SrO+CaO+MgO+ZnO; 0 to 20% BaO; 0 to 15% SrO; 0 to 10% CaO; 0 to 8% MgO; 0 to 15% ZnO; and 1 to 7% ZrO 2 ; wherein the weight ratio of alkali metal oxides/PbO ranges from 0.1 to 0.3.
Claim 2
Dependent Claim
165 words
A glass for a multi-focal eyeglass having a refractive index (n d ) of 1.67 to 1.73, an Abbe number (ν d ) of 33 or more, a coefficient of thermal expansion of 82 to 95×10 -7 and a softening point of 560° to 640° C., consisting of, in % by weight, 32 to 40% SiO 2 +B 2 O 3 +Al 2 O 3 ; 22 to 40% SiO 2 ; 0 to 10% B 2 O 3 ; 0 to 4% Al 2 O 3 ; 4 to 10% Li 2 O+Na 2 O +K 2 O; 0 to 4% Li 2 O; 0 to 7% Na 2 O; 0 to 7% K 2 O; 30 to 47% PbO; 3 to 24% BaO+SrO+CaO+MgO+ZnO; 0 to 20% BaO; 0 to 15% SrO; 0 to 10% CaO; 0 to 8% MgO; 0 to 15% ZnO; and 1 to 7% ZrO 2 ; wherein the weight ratio of alkali metal oxides/PbO ranges from 0.1 to 0.3.
References Cited (Backward Citations)
US4351906A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |