Glass plate, light guide plate unit, planar light-emitting device, and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-2016238778-A1
Application number	US-201615139586-A
Country	US
Kind code	A1
Filing date	Apr 27, 2016
Priority date	Nov 8, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

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.

First claim

What is claimed is:

1 . 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.

2 . The glass plate according to claim 1 , which satisfies the relation of 125(cm·ppm)≦L×A≦10,000(cm·ppm), where L (cm) is the effective optical path length of the glass plate, and A (mass ppm) is the content of total iron as calculated as Fe 2 O 3 of the glass plate.

3 . The glass plate according to claim 1 , which satisfies 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+ as calculated as Fe 2 O 3 in total iron as calculated as Fe 2 O 3 of the glass plate.

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 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.

6 . 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.

7 . 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 .

8 . 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.

9 . The glass plate according to claim 8 , which has a content of total iron as calculated as Fe 2 O 3 of from 5 to 150 ppm.

10 . The glass plate according to claim 8 , which has a content of Fe 2+ as calculated as Fe 2 O 3 in total iron as calculated as Fe 2 O 3 of from 0.02 to 30 ppm.

11 . A light guide plate unit, comprising a light guide plate, a dot pattern as a light scattering part provided 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 as the light guide plate, the glass plate as defined in claim 1 is used.

12 . A planar light-emitting device, comprising the light guide plate unit as defined in claim 11 , and a light source disposed on a side surface of the light guide plate in the light guide plate unit.

13 . A liquid crystal display device, comprising the planar light-emitting device as defined in claim 12 , and a liquid crystal unit disposed on the light-emitting surface side of the planar light-emitting device.

Assignees

• Asahi Glass Co Ltd

Inventors

• Hijiya Hiroyuki
• Arai Yusuke
• Kuroiwa Yutaka
• Nakashima Tetsuya
• Kondo Yuki

Classifications

• C03C3/095

  containing rare earths · CPC title

• C03C3/087 Primary

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03C3/085

  containing an oxide of a divalent metal · CPC title

• G02B6/0065 Primary

  Manufacturing aspects; Material aspects · CPC title

• G02B6/0055

  Reflecting element, sheet or layer · CPC title