Claims
- 1. A glass-ceramic substrate for a light filter having Young's modulus (GPa) within a range from 95 to 120 and surface roughness (Ra) of the 8.0 Å or below and comprising 5.3-8 weight percent of Al2O3, 0.5-3.5 weight percent of ZrO2 and 71-81 weight percent of SiO2 based respectively on the total content of the oxides.
- 2. A glass-ceramic substrate for a light filter as defined in claim 1 having specific gravity within a range from 2.4 to 2.6.
- 3. A glass-ceramic substrate for a light filter as defined in claim 1 wherein a coefficient of thermal expansion is within a range from 65×10−7/° C. to 130×10−7/° C. within a temperature range from −50° C. to +70° C.
- 4. A glass-ceramic substrate for a light filter as defined in claim 1 wherein a coefficient of thermal expansion is within a range from 65×10−7/° C. to 140×10−7/° C. within a temperature range from −50° C. to +70° C.
- 5. A glass-ceramic substrate for a light filter as defined in claim 1 wherein predominant crystal phases are (a) lithium disilicate (Li2O.2SiO2) and (b) at least one of α-quartz (α-SiO2). and α-quartz solid solution (α-SiO2 solution).
- 6. A glass-ceramic substrate for a light filter as defined in claim 1 which is substantially free of Na2O and PbO.
- 7. A glass-ceramic substrate for a light filter as defined in claim 1 which comprises 0.3 weight percent or over of MgO based on the total content of the oxides.
- 8. A glass-ceramic substrate for a light filter as defined in claim 1 having a composition which comprises in weight percent based on the total content of the oxides:SiO271-81%Li2O8-11%K2O0-3%MgO0.3-2%ZnO0-1%P2O51-3%ZrO20.5-3.5%TiO20-3%Al2O35.3-8%Sb2O30.1-0.5%SnO20-5%MoO30-3%NiO0-2%CoO0-3%Cr2O30-3%and having, as predominant crystal phases, (a) lithium disilicate (Li2O.2SiO2) and (b) at least one of α-quartz (α-SiO2). and α-quartz solid solution (α-SiO2 solid solution).
- 9. A glass-ceramic substrate for a light filter as defined in claim 1 having, as its predominant crystal phases, lithium disilicate (Li2O.2SiO2), α-quartz (α-SiO2) and α-quartz solid solution (α-SiO2 solid solution) which have fine globular crystal grains.
- 10. A glass-ceramic substrate for a light filter as defined in claim 1 wherein average grain diameter of the crystal phases is 0.30 μm or below.
- 11. A glass-ceramic substrate for a light filter as defined in claim 1 obtained by melting glass materials, forming molten glass, annealing formed glass and then heat treating the formed glass for nucleation under nucleation temperature within a range from 550° C. to 650° C. for one to twelve hours and further heat treating the formed glass for crystallization under crystallization temperature within a range from 680° C. to 800° C. for one to twelve hours.
- 12. A light filter provided by forming a multi-layer film on a glass-ceramic substrate for a light filter as defined in claim 1.
- 13. A glass-ceramic substrate for a light filter having a Young's modulus (Gpa) within a range from 95 to 120, containing, as a predominant crystal phase, α-quartz (α-SiO2) having an average grain diameter of 0.2 μm or below, and comprising 5.3-8 weight percent of Al2O3, 0.5-3.5 weight percent of ZrO2 and 71-81 weight percent of SiO2 based respectively on the total content of the oxides.
- 14. A glass-ceramic substrate for a light filter as defined in claim 13 having specific gravity within a range from 2.4 to 2.6.
- 15. A glass-ceramic substrate for a light filter as defined in claim 13 wherein a coefficient of thermal expansion is within a range from 65×10−7/° C. to 130×10−7/° C. within a temperature range from −50° C. to +70° C.
- 16. A glass-ceramic substrate for a light filter as defined in claim 13 wherein a coefficient of thermal expansion is within a range from 65×10−7/° C. to 140×10−7/° C. within a temperature range from −50° C. to +70° C.
- 17. A glass-ceramic substrate for a light filter as defined in claim 13 wherein predominant crystal phases are (a) lithium disilicate (Li2O.2SiO2) and (b) at least one of α-quartz (α-SiO2) and α-quartz solid solution (α-SiO2 solution).
- 18. A glass-ceramic substrate for a light filter as defined in claim 13 which is substantially free of Na2O and PbO.
- 19. A glass-ceramic substrate for a light filter as defined in claim 13 which comprises 0.3 weight percent or over of MgO based on the total content of the oxides.
- 20. A glass-ceramic substrate for a light filter as defined in claim 13 having a composition which comprises in weight percent based on the total content of the oxides:SiO271-81%Li2O 8-11%K2O0-3%MgO0.3-2% ZnO0-1%P2O51-3%ZrO20.5-3.5%TiO20-3%Al2O35.3-8% Sb2O30.1-0.5%SnO20-5%MoO30-3%NiO0-2%CoO0-3%Cr2O30-3%and having, as predominant crystal phases, (a) lithium disilicate (Li2O.2SiO2) and (b) at least one of α-quartz (α-SiO2) and α-quartz solid solution (α-SiO2 solid solution).
- 21. A glass-ceramic substrate for a light filter as defined in claim 13 having, as its predominant crystal phases, lithium disilicate (Li2O.2SiO2), α-quartz (α-SiO2) and α-quartz solid solution (α-SiO2 solid solution) which have fine globular crystal grains.
- 22. A glass-ceramic substrate for a light filter as defined in claim 13 obtained by melting glass materials, forming molten glass, annealing formed glass and then heat treating the formed glass for nucleation under a nucleation temperature within a range from 550° C. to 650° C. for one to twelve hours and further heat treating the formed glass for crystallization under crystallization temperature within a range from 680° C. to 800° C. for one to twelve hours.
- 23. A light filter provided by forming a multi-layer film on a glass-ceramic substrate for a light filter as defined in claim 13.
Priority Claims (3)
Number |
Date |
Country |
Kind |
10-94020 |
Mar 1998 |
JP |
|
10-125316 |
Apr 1998 |
JP |
|
10-351682 |
Dec 1998 |
JP |
|
Parent Case Info
This application is a division of Ser. No. 09/594,105, filed Jun. 14, 2000, now U.S. Pat. No. 6,582,826, which is a continuation-in-part of Ser. No. 09/260,768, filed Mar. 2, 1999, now U.S. Pat. No. 6,383,645, which claims priority from JP-10-094020, filed Mar. 23, 1998; JP-10-125316, filed Apr. 20, 1998 and JP-10-351682, filed Dec. 10, 1998.
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Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09/260768 |
Mar 1999 |
US |
Child |
09/594105 |
|
US |