Optical filter

Patent metadata

Field	Value
Publication number	US-9268149-B2
Application number	US-201213567751-A
Country	US
Kind code	B2
Filing date	Aug 6, 2012
Priority date	Aug 5, 2011
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

Provided is an optical filter and a display device. In the optical filter, patterns of first and second regions therein may be stably maintained, and therefore the optical filter capable of ensuring excellent light division characteristics for a long time may be provided.

First claim

What is claimed is:

1. An optical filter, comprising:
a substrate layer, of which an elastic modulus in a first in-plane direction is different from an elastic modulus in a second in-plane direction which is perpendicular to the first in-plane direction, the elastic modulus in the first in-plane direction is lower than that in the second in-plane direction, the elastic modulus in the first in-plane direction is in the range from 1,500 MPa to 4,000 MPa at 25° C., and the elastic modulus in the second in-plane direction is in the range from 2,000 MPa to 5,000 MPa at 25° C.; and
a polarization control layer that comprises first and second regions configured to divide incident light into two kinds of lights having different polarized states from each other, the first and second regions having stripe shapes extending in a common direction and being disposed adjacently and alternately to each other, the common direction being parallel to one direction among the first and second in-plane directions, in which the elastic modulus is relatively lower.

2. The optical filter according to claim 1 , wherein a ratio (MH/ML) of the elastic modulus (MH) in the second in-plane direction at 25° C. with respect to the elastic modulus (ML) in the first in-plane direction at 25° C. is more than 1 and also not more than 3.

3. The optical filter according to claim 1 , wherein the elastic modulus in the first in-plane direction is lower than that in the second in-plane direction, and the elastic modulus in the first in-plane direction is in the range from 1,400 MPa to 3,900 MPa at 60° C.

4. The optical filter according to claim 3 , wherein the elastic modulus in the second in-plane direction of the substrate layer is in the range from 1,900 MPa to 4,400 MPa at 60° C.

5. The optical filter according to claim 3 , wherein a ratio (MH/ML) of the elastic modulus (MH) in the second in-plane direction at 60° C. with respect to the elastic modulus (ML) in the first in-plane direction at 60° C. is more than 1 and also not more than 3.

6. The optical filter according to claim 1 , wherein the polarization control layer is a liquid crystal layer satisfying the condition of Expression 1:
X< 8%  [Expression 1]

where the “X” is a percentage of the absolute value of a change in value of phase difference after maintaining the optical filter at 80° C. for 100 hours with respect to the initial phase difference of the liquid crystal layer.

7. The optical filter according to claim 1 , wherein the polarization control layer is a liquid crystal layer comprising a multifunctional polymerizable liquid crystal compound and a monofunctional polymerizable liquid crystal compound, the monofunctional polymerizable liquid crystal compound being included in an amount of more than 0 parts by weight and also not more than 100 parts by weight, relative to 100 parts by weight of the multifunctional polymerizable liquid crystal compound.

8. The optical filter according to claim 7 , wherein the liquid crystal compound is represented by Formula 1:

where A is a single bond, —COO— or —OCO—, R 1 to R 10 are each independently hydrogen, halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group, —O-Q-P or a substituent of Formula 2, or an adjacent pair among R 1 to R 5 or an adjacent pair among R 6 to R 10 are connected with each other so as to from benzene ring substituted with —O-Q-P, with the proviso that at least one of R 1 to R 10 is —O-Q-P or a substituent of Formula 2 or the adjacent pair among R 1 to R 5 or the adjacent pair among R 6 to R 10 are connected with each other so as to from benzene ring substituted with —O-Q-P; where Q is an alkylene group or an alkylidene group, and P is an alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, or a methacryloyloxy group,

where B is a single bond, —COO— or —OCO—, R 11 to R 15 are each independently hydrogen, halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group or —O-Q-P, or an adjacent pair among R 11 to R 15 are connected with each other so as to form benzene ring substituted with —O-Q-P, with the proviso that at least one of R 11 to R 15 is —O-Q-P or the adjacent pair among R 11 to R 15 are connected with each other so as to form benzene ring substituted with —O-Q-P, where Q is an alkylene group or an alkylidene group, and P is an alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, or a methacryloyloxy group.

9. The optical filter according to claim 7 , wherein the polymerizable liquid crystal compound is comprised in the liquid crystal layer in a parallel-aligned state.

10. The optical filter according to claim 1 , wherein the polarization control layer is a liquid crystal layer, of which the difference between an in-plane refractive index in a direction of a slow axis and an in-plane refractive index in a direction of a fast axis is in the range from 0.05 to 0.2, and of which the a thickness is in the range from 0.5 μm to 2.0 μm.

11. An optical filter, comprising:
a substrate layer, of which a coefficients of thermal expansion in a first in-plane direction is different from that in a second in-plane direction vertical to the first in-plane direction, and in which the coefficient of thermal expansion in the first in-plane direction is higher than that in the second in-plane direction, the coefficient of thermal expansion in the first in-plane direction is in the range from 35 to 80 ppm/K, and the coefficient of thermal expansion in the second in-plane direction is in the range from 10 to 65 ppm/K; and
a polarization control layer comprising first and second regions configured to divide incident light into two kinds of lights having different polarized states from each other, the first and second regions being formed in a stripe shape extending in a common direction and positioned adjacently and alternately to each other, the common direction being parallel to one direction among the first and second in-plane directions in which the coefficients of thermal expansion is relatively higher.

12. The optical filter according to claim 11 , wherein the ratio (CH/CL) of the coefficient (CH) of thermal expansion in the first in-plane direction with respect to the coefficient (CL) of thermal expansion in the second in-plane direction is more than 1 and also not more than 5.

13. An optical filter, comprising:
a substrate layer, of which an elastic modulus and a coefficient of thermal expansion in a first in-plane direction are different respectively from those in a second in-plane direction vertical to the first in-plane direction, and in which the elastic modulus in the first in-plane direction is lower than that in the second in-plane direction, the elastic modulus in the first in-plane direction is in the range from 1,500 MPa to 4,000 MPa at 25° C., the elastic modulus in the second in-plane direction is in the range from 2,000 MPa to 5,000 MPa at 25° C., the coefficient of thermal expansion in the first in-plane direction is higher than that in the second in-plane direction, the coefficient of thermal expansion in the first in-plane direction is in the range from 35 to 80 ppm/K, and the coefficient of thermal expansion in the second in-plane direction is in the range from 10 to 65 ppm/K; and
a polarization control lay

Assignees

• Chae Seung Hun
• Hong Kyung Ki
• Yeo Jung Hyun
• Cho Yong Il
• Park Moon Soo
• Kim Sang Seop
• Lg Chemical Ltd

Inventors

• Chae Seung Hun
• Hong Kyung Ki
• Yeo Jung Hyun
• Cho Yong Il
• Park Moon Soo
• Kim Sang Seop

Classifications

• G02B5/20

  Filters (polarising elements G02B5/30) · CPC title

• G02F1/13363

  Birefringent elements, e.g. for optical compensation · CPC title

• G02B30/27

  involving lenticular arrays · CPC title

• G02B5/3083

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title

• G02B30/25 Primary

  using polarisation techniques · CPC title