Wire grid polarizer and backlight unit using the same

Patent metadata

Field	Value
Publication number	US-9488764-B2
Application number	US-201113240028-A
Country	US
Kind code	B2
Filing date	Sep 22, 2011
Priority date	Sep 29, 2010
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

Provided are a wire grid polarizer and a backlight unit using the wire grid polarizer. The wire grid polarizer comprises a first grid layer formed on a substrate and provided with at least one of a first grid pattern, and a second grid layer formed on the first grid pattern and provided with at least one of a second grid pattern made of metal material wherein the first grid layer is made of high molecular substance having a lower refraction index than that of the substrate. By forming a first grid pattern on a substrate using a high molecular substance layer and by forming a metal grid pattern on the first grid pattern, transmission rates of respective wavelengths depending on light angles of incident light are controlled and thereby minimize color variations depending on view angle.

First claim

What is claimed is:

1. A wire grid polarizer, comprising:
a first grid layer formed on a substrate and provided with at least one first grid pattern; and
a second grid layer formed on the at least one first grid pattern and provided with at least one second grid pattern made of metal material,
wherein the first grid layer is made of a high molecular substance formed with a polymer and having a refraction index lower than that of the substrate,
wherein the substrate is made of a film base material having a predetermined flexibility,
wherein a cycle of the second grid pattern is 100 nm through 250 nm and a height of the first grid pattern is 200 nm for providing a maximum value of transmission rate of visible light and a ratio of width to height of the at least one first grid pattern is in a range of 1:0.2-4,
wherein a ratio of a width of the first grid pattern to a width of the second grid pattern is at least 1:0.2 and less than 1:1,
wherein a length of the second grid pattern is shorter than a length of the first grid pattern,
wherein the widths of the first and second grid patterns are measured in a first direction parallel to an upper surface of the substrate, and
wherein the lengths of the first and second grid patterns are measured in a second direction parallel to the upper surface of the substrate and perpendicular to the first direction.

2. The wire grid polarizer of claim 1 , wherein the width of the first grid pattern is in a range of 50-200 nm.

3. The wire grid polarizer of claim 1 , wherein the second grid pattern is made of one or alloy of Aluminum, Chrome, Silver, Copper, Nickel and Cobalt.

4. The wire grid polarizer of claim 3 , wherein the width of the second grid pattern is in a range of 2-250 nm.

5. The wire grid polarizer of claim 4 , wherein a ratio of width to height of the second grid pattern is 1:0.5-1.5.

6. The wire grid polarizer of claim 3 , wherein a sectional shape of the second grid pattern is one of being rectangular, triangular and semi-circular.

7. A backlight unit, comprising:
a first substrate for guiding forwardly light emitted from a light source;
a second substrate arranged on the first substrate; and
a wire grid polarizer of claim 1 , which is arranged on an upper surface or a lower surface of the first substrate or the second substrate.

8. The backlight unit of claim 7 , which further comprises a reflection plate arranged on a lower side of the first substrate.

9. The backlight unit of claim 7 , wherein the first substrate is a substrate or an optical sheet performing at least one function of diffusing light, guiding light, and collecting light.

10. The backlight unit of claim 9 , wherein a thickness of the second substrate is 10 μm-5 mm.

11. The backlight unit of claim 10 , wherein a visible light transmission rate of the second substrate is 70% or more.

Assignees

• Lee Young-Jae
• Kim Jin Su
• Lee Jun
• Lg Innotek Co Ltd

Inventors

• Lee Young-Jae
• Kim Jin Su
• Lee Jun

Classifications

• G02B5/3058 Primary

  comprising electrically conductive elements, e.g. wire grids, conductive particles · CPC title