Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
129 words
A photochromic glass article especially suitable for spectacle lenses having an integral colored surface layer and exhibiting near-zero transmittance of radiations having wavelengths shorter than a selected cutoff wavelength ranging between about 440-550 nm, said glass consisting essentially, expressed in weight percent on the oxide basis, of about 0-2.5% Li 2 O, 0-9% Na 2 O, 0-17% K 2 O, 0-6% Cs 2 O, 8-20% Li 2 O+Na 2 O+K 2 O+Cs 2 O, 14-23% B 2 O 3 , 5-25% Al 2 O 3 , 0-25% P 2 O 5 , 20-65% SiO 2 , 0.004-0.02% CuO, 0.15-0.3% Ag, 0.1-0.25% Cl, and 0.1-0.2% Br, wherein the molar ratio of alkali metal oxides:B 2 O 3 varies between about 0.55-0.85 and the weight ratio Ag:(Cl+Br) ranges between about 0.65-0.95.
Claim 2
Dependent Claim
129 words
A photochromic glass article especially suitable for spectacle lenses having an integral colored surface layer and exhibiting near-zero transmittance of radiations having wavelengths shorter than a selected cutoff wavelength ranging between about 440-550 nm, said glass consisting essentially, expressed in weight percent on the oxide basis, of about 0-2.5% Li 2 O, 0-9% Na 2 O, 0-17% K 2 O, 0-6% Cs 2 O, 8-20% Li 2 O+Na 2 O+K 2 O+Cs 2 O, 14-23% B 2 O 3 , 5-25% Al 2 O 3 , 0-25% P 2 O 5 , 20-65% SiO 2 , 0.004-0.02% CuO, 0.15-0.3% Ag, 0.1-0.25% Cl, and 0.1-0.2% Br, wherein the molar ratio of alkali metal oxides:B 2 O 3 varies between about 0.55-0.85 and the weight ratio Ag:(Cl+Br) ranges between about 0.65-0.95.
Claim 3
Dependent Claim
83 words
A photochromic glass article according to claim 1 also including, as optional components, 1-50 parts per million Pd and/or Au, and/or up to 1% transition metal colorants, and/or up to 5% rare earth metal colorants, and/or up to 10% total of other ingredients selected from the group in the indicated proportions of 0-6% ZrO 2 , 0-3% TiO 2 , 0-0.5% PbO, 0-7% BaO, 0-4% CaO, 0-3% MgO, 0-6% Nb 2 O 5 , 0-4% La 2 O 3 , and 0-2% F.
Claim 4
Dependent Claim
16 words
A photochromic glass article according to claim 2 wherein cobalt oxide constitutes the transition metal colorant.
Claim 5
Dependent Claim
21 words
A photochromic glass article according to claim 1 wherein said integral colored surface layer has a depth of about 25-100 microns.
Claim 6
Dependent Claim
33 words
A photochromic glass article according to claim 1 especially suitable for spectacle lenses for aphakics or for persons subject to photoretinitis exhibiting near-zero transmittance of radiations having wavelengths shorter than about 440 nm.
Claim 7
Dependent Claim
76 words
A photochromic glass article according to claim 1 especially suitable for spectacle lenses for persons subject to retinitis pigmentosa exhibiting near-zero transmittance of radiations having wavelengths shorter than about 550 nm, a photopic transmittance in the faded state no greater than about 25% and no greater than about 10% in the darkened state, and a scotopic transmittance in the faded state no greater than about 10% and no greater than about 5% in the darkened state.
Claim 8
Dependent Claim
17 words
A photochromic glass article according to claim 6 demonstrating a photopic:scotopic transmittance ratio of at least 4:1.
Claim 9
Dependent Claim
13 words
A photochromic glass article according to claim 1 having polarizing capability incorporated therein.
Claim 10
Independent Claim
167 words
A method for making a photochromic glass article especially suitable for spectacle lenses having an integral colored surface layer and exhibiting near-zero transmittance of radiations having wavelengths shorter than a selected cutoff wavelength ranging between about 440-550 nm which comprises subjecting a photochromic glass consisting essentially, expressed in weight percent on the oxide basis, of about 0-2.5% Li 2 O, 0-9% Na 2 O, 0-17% K 2 O, 0-6% Cs 2 O, 8-20% Li 2 O+Na 2 O+K 2 O+Cs 2 O, 14-23% B 2 O 3 , 5-25% Al 2 O 3 , 0-25% P 2 O 5 , 20-65% SiO 2 , 0.004-0.02% CuO, 0.15-0.3% Ag, 0.1-0.25% Cl, and 0.1-0.2% Br, wherein the molar ratio of alkali metal oxide:B 2 O 3 varies between about 0.55-0.85 and the weight ratio Ag:(Cl+Br) ranges between about 0.65-0.95, to a strongly reducing atmosphere at a temperature between about 350°-520° C. for a period of time of at least 12 hours to develop an integral colored surface layer therein.
Claim 11
Independent Claim
167 words
A method for making a photochromic glass article especially suitable for spectacle lenses having an integral colored surface layer and exhibiting near-zero transmittance of radiations having wavelengths shorter than a selected cutoff wavelength ranging between about 440-550 nm which comprises subjecting a photochromic glass consisting essentially, expressed in weight percent on the oxide basis, of about 0-2.5% Li 2 O, 0-9% Na 2 O, 0-17% K 2 O, 0-6% Cs 2 O, 8-20% Li 2 O+Na 2 O+K 2 O+Cs 2 O, 14-23% B 2 O 3 , 5-25% Al 2 O 3 , 0-25% P 2 O 5 , 20-65% SiO 2 , 0.004-0.02% CuO, 0.15-0.3% Ag, 0.1-0.25% Cl, and 0.1-0.2% Br, wherein the molar ratio of alkali metal oxide:B 2 O 3 varies between about 0.55-0.85 and the weight ratio Ag:(Cl+Br) ranges between about 0.65-0.95, to a strongly reducing atmosphere at a temperature between about 350°-520° C. for a period of time of at least 12 hours to develop an integral colored surface layer therein.
Claim 12
Dependent Claim
85 words
A method according to claim 9 wherein said photochromic glass also includes, as optical components, 1-50 parts per million Pd and/or Au, and/or up to 1% transition metal colorants, and/or up to 5% rare earth metal colorants, and/or up to 10% total of other ingredients selected from the group in the indicated proportions of 0-6% ZrO 2 , 0-3% TiO 2 , 0-0.5% PbO, 0-7% BaO, 0-4% CaO, 0-3% MgO, 0-6% Nb 2 O 5 , 0-4% La 2 O 3 , and 0-2% F.
Claim 13
Dependent Claim
14 words
A method according to claim 10 wherein cobalt oxide constitutes the transition metal colorant.
Claim 14
Dependent Claim
18 words
A method according to claim 9 wherein said integral surface layer has a depth of about 25-100 microns.
Claim 15
Dependent Claim
15 words
A method according to claim 9 wherein said strongly reducing atmosphere consists essentially of hydrogen.
Claim 16
Dependent Claim
14 words
A method according to claim 9 wherein said temperature ranges between about 380°-400° C.
Claim 17
Dependent Claim
14 words
A method according to claim 9 wherein said time ranges between about 12-168 hours.
Claim 18
Dependent Claim
103 words
A method according to claim 9 wherein said glass is subjected to said strongly reducing atmosphere for a period of time of at least about 96 hours to achieve near-zero transmittance therein of radiations having wavelengths shorter than about 550 nm, a photopic transmittance in the faded state no greater than about 25% and no greater than about 10% in the darkened state, and a scotopic transmittance no greater than about 10% in the faded state and no greater than about 5% in the darkened state so as to render said glass especially suitable for spectacle lenses for persons subject to retinitis pigmentosa.
Claim 19
Dependent Claim
16 words
A method according to claim 9 including the step of incorporating polarizing capability to said glass.