Optical member

Patent metadata

Field	Value
Publication number	US-9322965-B2
Application number	US-201414166080-A
Country	US
Kind code	B2
Filing date	Jan 28, 2014
Priority date	Jul 28, 2011
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

An optical member has: a transparent substrate; and a dielectric multilayer on the transparent substrate formed by stacking a plurality of unit refractive index layers each formed of a high-refractive index layer having a refractive index of 2 or more and a low-refractive index layer having a refractive index of 1.6 or less. In the optical member, a total number of the unit refractive index layers is 15 or more, and a number of the unit refractive index layers satisfying a condition of n H d H /n L d L ≧3 is 10 or more, n H d H represents an optical thickness of the high-refractive index layer, and n L d L represents an optical thickness of the low-refractive index layer.

First claim

What is claimed is:

1. An optical member, comprising:
a transparent substrate; and
a dielectric multilayer provided on the transparent substrate, the dielectric multilayer comprising unit stacks each of which consists of: a high-refractive index layer having a refractive index of 2 or more; and a low-refractive index layer having a refractive index of 1.6 or less and stacked on the high-refractive index layer, wherein each of the unit stacks has an optical thickness ratio (n H d H /n L d L ) which is a ratio of an optical thickness of the high-refractive index layer (n H d H ) to an optical thickness of the low-refractive index layer (n L d L ),
wherein a total number of the unit stacks is 15 or more,
wherein a number of the unit stacks having an optical thickness ratio of 3 or more is 10 or more, and
wherein the dielectric multilayer further comprises at least 5 unit stacks each of which consists of: a high-refractive index layer having a refractive index of 2 or more; and a low-refractive index layer having a refractive index of 1.6 or less and stacked on the high-refractive index layer, the at least 5 unit stacks satisfying in formula: T H /T L ≦1.5 where T H represents an average optical thickness of the high-refractive index layers included in the at least 5 unit stacks and, T L represents an average optical thickness of the low-refractive index layers included in the at least 5 unit stacks.

2. The optical member according to claim 1 ,
wherein the total number of the unit stacks is 15 or more, and a number of the unit stacks the optical thickness ratio of 5 or more is 10 or more.

3. The optical member according to claim 2 ,
wherein the total number of the unit stacks is 30 or more, and a number of the unit stacks having the optical thickness ratio of 5 or more is 15 or more.

4. The optical member according to claim 2 ,
wherein an average optical thickness ratio of all of the unit stacks is 4.5 to 5.3.

5. The optical member according to claim 1 ,
wherein each of the high-refractive index layers is made of one oxide selected from the group consisting of TiO 2 , Nb 2 O 5 , Ta 2 O 5 , and a composite oxide thereof, and each of the low-refractive index layers is made of one selected from the group consisting of SiO 2 , MgF 2 , and a composite oxide thereof.

6. The optical member according to claim 1 ,
wherein the transparent substrate has a plate shape.

7. The optical member according to claim 1 ,
wherein the transparent substrate has a lens shape.

8. The optical member according to claim 1 ,
wherein the transparent substrate absorbs light in an infrared-wavelength region.

9. The optical member according to claim 1 ,
wherein the optical member is used as a luminosity factor correction filter.

10. The optical member according to claim 1 , wherein the at least 5 unit stacks are consecutively stacked.

11. The optical member according to claim 1 , wherein the at least 5 unit stacks satisfies formula: T H /T L ≦1.0.

12. The optical member according to claim 1 , wherein the at least 5 unit stacks satisfies formula: T H /T L ≦0.9.

13. The optical member according to claim 1 , wherein the at least 5 unit stacks satisfies formula: T H /T L ≧0.1.

14. The optical member according to claim 1 , wherein the at least 5 unit stacks satisfies formula: T H /T L ≧0.3.

Assignees

• Asahi Glass Co Ltd

Inventors

• Osawa Mitsuo
• Mori Masahiro
• Miyake Katsushi
• Kamijyo Katsushi
• Tatemura Mitsuyuki

Classifications

• G02B5/286

  having four or fewer layers, e.g. for achieving a colour effect · CPC title

• G02B5/285

  comprising deposited thin solid films (G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361) · CPC title

• G02B5/282 Primary

  reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection · CPC title