Glass plate, light guide plate unit, planar light-emitting device, and liquid crystal display device
To provide a glass plate excellent in the internal transmittance of light rays in the visible region. A glass plate consisting of multicomponent oxide glass, which has an effective optical path length of from 25 to 200 cm, a thickness of from 0.5 to 10 mm, and an average internal transmittance in the visible region of at least 80% and a chromaticity Y of tristimulus values in the XYZ colorimetric system as defined in JIS Z8701 (Appendix) of at least 90%, under the effective optical path length.
1. A glass plate, consisting of multicomponent oxide glass, having an effective optical path length of from 25 to 200 cm, a thickness of from 0.5 to 10 mm, a total iron content in the glass plate as calculated as Fe 2 O 3 of from 5 to 50 ppm and an average internal transmittance in the visible region of at least 80% and a chromaticity Y of tristimulus values in the XYZ colorimetric system as defined in JIS Z8701 (Appendix) of at least 90%, under the effective optical path length, and satisfying the relation of 2.5 (cm·ppm)<L×B<3,000 (cm·ppm), where L (cm) is the effective optical path length of the glass plate, and B (mass ppm) is the content of Fe 2+ in total iron as calculated as Fe 2 O 3 of the glass plate,
wherein the effective optical path length is a distance from an edge surface from which light enters the glass plate to an edge surface on the opposite side.
2. A glass plate, consisting of multicomponent oxide glass, having an effective optical path length of from 25 to 200 cm, a thickness of from 0.5 to 10 mm, a total iron content in the glass plate as calculated as Fe 2 O 3 of from 5 to 50 ppm, and an average internal transmittance in the visible region of at least 80% and a chromaticity Y of tristimulus values in the XYZ colorimetric system as defined in JIS Z8701 (Appendix) of at least 90%, under the effective optical path length, and satisfying the relation of 2.5 (cm·ppm)<L×B<2,400 (cm·ppm), where L (cm) is the effective optical path length of the glass plate, and B (mass ppm) is the content of Fe 2+ in total iron as calculated as Fe 2 O 3 of the glass plate,
wherein the effective optical path length is a distance from an edge surface from which light enters the glass plate to an edge surface on the opposite side.
3. A glass plate, consisting of multicomponent oxide glass, having an effective optical path length of from 25 to 200 cm, a thickness of from 0.5 to 10 mm, a total iron content in the glass plate as calculated as Fe 2 O 3 of from 5 to 50 ppm, and an average internal transmittance in the visible region of at least 80% and a chromaticity Y of tristimulus values in the XYZ colorimetric system as defined in JIS Z8701 (Appendix) of at least 90%, under the effective optical path length, and satisfying the relation of 2.5 (cm·ppm)<L×B<1,850 (cm·ppm), where L (cm) is the effective optical path length of the glass plate, and B (mass ppm) is the content of Fe 2+ in total iron as calculated as Fe 2 O 3 of the glass plate,
wherein the effective optical path length is a distance from an edge surface from which light enters the glass plate to an edge surface on the opposite side.
4. The glass plate according to claim 1 , wherein if at least one component selected from the group consisting of MnO 2 , TiO 2 , NiO, CoO, V 2 O 5 , CuO and Cr 2 O 3 is contained, the total content of such components is at most 0.1% (at most 1,000 ppm) as represented by mass percentage based on oxides.
5. The glass plate according to claim 2 , wherein if at least one component selected from the group consisting of MnO 2 , TiO 2 , NiO, CoO, V 2 O 5 , CuO and Cr 2 O 3 is contained, the total content of such components is at most 0.1% (at most 1,000 ppm) as represented by mass percentage based on oxides.
6. The glass plate according to claim 3 , wherein if at least one component selected from the group consisting of MnO 2 , TiO 2 , NiO, CoO, V 2 O 5 , CuO and Cr 2 O 3 is contained, the total content of such components is at most 0.1% (at most 1,000 ppm) as represented by mass percentage based on oxides.
7. The glass plate according to claim 1 , wherein if at least one component selected from the group consisting of CeO 2 , Sb 2 O 3 , SnO 2 and As 2 O 3 is contained, the total content of such components is at most 0.3% (at most 3,000 ppm) as represented by mass percentage based on oxides.
8. The glass plate according to claim 2 , wherein if at least one component selected from the group consisting of CeO 2 , Sb 2 O 3 , SnO 2 and As 2 O 3 is contained, the total content of such components is at most 0.3% (at most 3,000 ppm) as represented by mass percentage based on oxides.
9. The glass plate according to claim 3 , wherein if at least one component selected from the group consisting of CeO 2 , Sb 2 O 3 , SnO 2 and As 2 O 3 is contained, the total content of such components is at most 0.3% (at most 3,000 ppm) as represented by mass percentage based on oxides.
10. The glass plate according to claim 1 , wherein if at least one component selected from the group consisting of MnO 2 , TiO 2 , NiO, CoO, V 2 O 5 , CuO and Cr 2 O 3 is contained, the total content of such components is at most 0.05% (at most 500 ppm) as represented by mass percentage based on oxides.
11. The glass plate according to claim 2 , wherein if at least one component selected from the group consisting of MnO 2 , TiO 2 , NiO, CoO, V 2 O 5 , CuO and Cr 2 O 3 is contained, the total content of such components is at most 0.05% (at most 500 ppm) as represented by mass percentage based on oxides.
12. The glass plate according to claim 3 , wherein if at least one component selected from the group consisting of MnO 2 , TiO 2 , NiO, CoO, V 2 O 5 , CuO and Cr 2 O 3 is contained, the total content of such components is at most 0.05% (at most 500 ppm) as represented by mass percentage based on oxides.
13. The glass plate according to claim 1 , wherein if at least one component selected from the group consisting of CeO 2 , Sb 2 O 3 , SnO 2 and As 2 O 3 is contained, the total content of such components is at most 0.2% (at most 2,000 ppm) as represented by mass percentage based on oxides.
14. The glass plate according to claim 2 , wherein if at least one component selected from the group consisting of CeO 2 , Sb 2 O 3 , SnO 2 and As 2 O 3 is contained, the total content of such components is at most 0.2% (at most 2,000 ppm) as represented by mass percentage based on oxides.
15. The glass plate according to claim 3 , wherein if at least one component selected from the group consisting of CeO 2 , Sb 2 O 3 , SnO 2 and As 2 O 3 is contained, the total content of such components is at most 0.2% (at most 2,000 ppm) as represented by mass percentage based on oxides.
16. The glass plate according to claim 1 , wherein the composition, except for iron, substantially comprises, as represented by mass percentage based on oxides, from 60 to 80% of SiO 2 , from 0 to 7% of Al 2 O 3 , from 0 to 10% of MgO, from 4 to 20% of CaO, from 7 to 20% of Na 2 O and from 0 to 10% of K 2 O.
17. The glass plate according to claim 2 , wherein the composition, except for iron, substantially comprises, as represented by mass percentage based on oxides, from 60 to 80% of SiO 2 , from 0 to 7% of Al 2 O 3 , from 0 to 10% of MgO, from 4 to 20% of CaO, from 7 to 20% of Na 2 O and from 0 to 10% of K 2 O.
18. The glass plate according to claim 3 , wherein the composition, except for iron, substantially comprises, as represented by mass percentage based on oxides, from 60 to 80% of SiO 2 , from 0 to 7% of Al 2 O 3 , from 0 to 10% of MgO, from 4 to 20% of CaO, from 7 to 20% of Na 2 O and from 0 to 10% of K 2 O.
19. The glass plate according to claim 1 , wherein the composition except for iron substantially comprises, as represented by mass percentage based on oxides, from 45 to 80% of SiO 2 , more than 7% and at most 30% of Al 2 O 3 , from 0 to 15% of B 2 O 3 , from 0 to 15% of MgO, from 0 to 6% of CaO, from 7 to 20% of Na 2 O, from 0 to 10% of K 2 O and from 0 to 10% of ZrO 2 .
20. The glass plate according to claim 2 , wherein the composition except for iron substantially comprises, as represented by mass percentage based on oxides, from 45 to 80% of SiO 2 , more than 7% and at most 30% of Al 2 O 3 , from 0 to 15% of B 2 O 3 , from 0 to 15% of MgO, from 0 to 6% of CaO, from 7 to 20% of Na 2 O, from 0 to 10% of K 2 O and from 0 to 10% of ZrO 2 .
21. The glass plate according to claim 3 , wherein the composition except for iron substantially comprises, as represented by mass percentage based on oxides, from 45 to 80% of SiO 2 , more than 7% and at most 30% of Al 2 O 3 , from 0 to 15% of B 2 O 3 , from 0 to 15% of MgO, from 0 to 6% of CaO, from 7 to 20% of Na 2 O, from 0 to 10% of K 2 O and from 0 to 10% of ZrO 2 .
22. The glass plate according to claim 1 , wherein the composition except for iron substantially comprises, as represented by mass percentage based on oxides, from 45 to 70% of SiO 2 , from 10 to 30% of Al 2 O 3 , from 0 to 15% of B 2 O 3 , from 5 to 30% in total of at least one component selected from the group consisting of MgO, CaO, SrO and BaO, and at least 0% and less than 7% in total of at least one component selected from the group consisting of Li 2 O, Na 2 O and K 2 O.
23. The glass plate according to claim 2 , wherein the composition except for iron substantially comprises, as represented by mass percentage based on oxides, from 45 to 70% of SiO 2 , from 10 to 30% of Al 2 O 3 , from 0 to 15% of B 2 O 3 , from 5 to 30% in total of at least one component selected from the group consisting of MgO, CaO, SrO and BaO, and at least 0% and less than 7% in total of at least one component selected from the group consisting of Li 2 O, Na 2 O and K 2 O.
24. The glass plate according to claim 3 , wherein the composition except for iron substantially comprises, as represented by mass percentage based on oxides, from 45 to 70% of SiO 2 , from 10 to 30% of Al 2 O 3 , from 0 to 15% of B 2 O 3 , from 5 to 30% in total of at least one component selected from the group consisting of MgO, CaO, SrO and BaO, and at least 0% and less than 7% in total of at least one component selected from the group consisting of Li 2 O, Na 2 O and K 2 O.
25. The glass plate according to claim 22 , which has a content of Fe 2+ in total iron as calculated as Fe 2 O 3 of from 0.02 to 30 ppm.
26. The glass plate according to claim 23 , which has a content of Fe 2+ in total iron as calculated as Fe 2 O 3 of from 0.02 to 30 ppm.
27. The glass plate according to claim 24 , which has a content of Fe 2+ in total iron as calculated as Fe 2 O 3 of from 0.02 to 30 ppm.
28. A light guide plate unit, comprising a light guide plate, a dot pattern as a light scattering part on a light-reflecting surface on the opposite side of the light guide plate from a light-emitting surface, and a reflecting plate arranged on the light-reflecting surface side of the light guide plate, wherein the light guide plate is the glass plate according to claim 1 .
29. A light guide plate unit, comprising a light guide plate, a dot pattern as a light scattering part on a light-reflecting surface on the opposite side of the light guide plate from a light-emitting surface, and a reflecting plate arranged on the light-reflecting surface side of the light guide plate, wherein the light guide plate is the glass plate according to claim 2 .
30. A light guide plate unit, comprising a light guide plate, a dot pattern as a light scattering part on a light-reflecting surface on the opposite side of the light guide plate from a light-emitting surface, and a reflecting plate arranged on the light-reflecting surface side of the light guide plate, wherein the light guide plate is the glass plate according to claim 3 .
31. A planar light-emitting device, comprising the light guide plate unit according to claim 28 , and a light source disposed on a side surface of the light guide plate in the light guide plate unit.
32. A planar light-emitting device, comprising the light guide plate unit according to claim 29 , and a light source disposed on a side surface of the light guide plate in the light guide plate unit.
33. A planar light-emitting device, comprising the light guide plate unit according to claim 30 , and a light source disposed on a side surface of the light guide plate in the light guide plate unit.
34. A liquid crystal display device, comprising the planar light-emitting device according to claim 31 , and a liquid crystal unit disposed on the light-emitting surface side of the planar light-emitting device.
35. A liquid crystal display device, comprising the planar light-emitting device according to claim 32 , and a liquid crystal unit disposed on the light-emitting surface side of the planar light-emitting device.
36. A liquid crystal display device, comprising the planar light-emitting device according to claim 33 , and a liquid crystal unit disposed on the light-emitting surface side of the planar light-emitting device.
37. The glass plate according to claim 1 , wherein the total iron content in the glass plate as calculated as Fe 2 O 3 is from 5 to 20 ppm.