# US 2014/0153093 A1 · Optical filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153093 A1 - Document ID: US20140153093A1 - Status: Published application - Kind: A1 - Application number: 14/172,460 - Filed: 2014-02-04 - Published: 2014-06-05 - Earliest claimed: 2011-08-09 - Assignees: LG Chem, Ltd. - Applicants: LG Chem, Ltd. - Inventors: Moon Soo PARK; Byoung Kun JEON; Sang Seop KIM; Kyung Ki HONG; Dong Ho KO; Doo Young HUH; Su Young RYU; Seung Ryong LEE - Web page: https://patentgrep.com/patent/US20140153093A1 ## CPC - G02B 5/3083: {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)} - G02B 5/3016: {involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Provided are an optical filter and a stereoscopic display device. The exemplary optical filter may be applied to the stereoscopic display device to observe a stereoscopic image in a wide viewing angle without the loss of brightness. ## Claims ### Claim 1 Optical filter having a polarization control layer, comprising: first and second regions having different retardation characteristics and formed to divide incident light into two kinds of light having different polarization states; and a third region having a different retardation characteristic from the first and second regions as an isotropic or light scattering region. ### Claim 2 (depends on 1) The optical filter according to claim 1, wherein the first and second regions are formed to divide linearly polarized incident light into two kinds of circularly polarized light or elliptically polarized light having opposite rotation directions and output the divided light. ### Claim 3 (depends on 1) The optical filter according to claim 1, wherein the third region is formed to output the linearly polarized incident light as linearly polarized light or non-polarized light. ### Claim 4 (depends on 1) The optical filter according to claim 1, wherein the first and second regions have a stripe shape extending in the common direction and are adjacently and alternately disposed, and the third region is disposed between the first and second regions. ### Claim 5 (depends on 1) The optical filter according to claim 1, wherein the first and second regions are adjacently and alternately disposed in a lattice shape, and the third region is disposed between the first and second regions. ### Claim 6 (depends on 1) The optical filter according to claim 1, wherein the first region is a retardation region having an optical axis formed in a first direction, the second region is a retardation region having an optical axis in a direction different from or the same as the first direction, and the third region is a retardation region having an optical axis in a direction different from the first and second directions, an isotropic region, or a light scattering region. ### Claim 7 (depends on 1) The optical filter according to claim 1, wherein the first region is a retardation region having an optical axis formed in a first direction, the second region is a retardation region having an optical axis in a direction different from the first direction, and the third region is a retardation region having an optical axis in a direction different from the first and second directions. ### Claim 8 (depends on 7) The optical filter according to claim 7, wherein the first and second directions are perpendicular to each other. ### Claim 9 (depends on 7) The optical filter according to claim 7, wherein a line bisecting an angle between the first and second directions is parallel to the third direction. ### Claim 10 (depends on 1) The optical filter according to claim 1, wherein the first and second regions include a horizontally-aligned polymerizable liquid crystal compound. ### Claim 11 (depends on 1) The optical filter according to claim 1, wherein the first and second regions have a difference in an in-plane refractive index between a slow axis direction and a fast axis direction of 0.05 to 0.2, and a thickness of 0.5 to 2.0 μm. ### Claim 12 (depends on 10) The optical filter according to claim 10, wherein the third region includes a non-aligned liquid crystal compound. ### Claim 13 (depends on 1) A display device, comprising: a display element including regions for generating signals for the right and left eyes, which can generate signals for the right and left eyes, respectively; and the optical filter of claim 1, wherein, in the optical filter, one of the first and second regions is disposed in a location in which the signal for the right eye is incident, and the other is disposed in a location in which the signal for the left eye is incident. ### Claim 14 (depends on 13) The device according to claim 13, wherein the display element further includes a light transmittance control region adjacent to the regions for generating signals for the right and left eyes. ### Claim 15 (depends on 14) The device according to claim 14, wherein the light transmittance control region is placed on the boundary between the regions for forming signals for the right and left eyes, when the device is observed from front, to overlap a part of the region for forming a signal for the right or left eye. ### Claim 16 (depends on 14) The device according to claim 14, wherein the optical filter is disposed to have the maximum values of an angle (θU) satisfying Equation 1 and an angle (θL) satisfying Equation 2 which are all 3 degrees or more: tan θU=(H1+2y)/2T [Equation 1] tan θL=(H1+2H2−2y)/2T [Equation 2] where H1 is a width of the light transmittance control region, H2 is a width of the third region of the optical filter, T is a distance from the light transmittance control region to the third region of the optical filter, and y is a distance between a position at which a virtual normal line with respect to a surface of the light transmittance control region of a line bisecting the width of the light transmittance control region is in contact with the third region and a part having the third region. ### Claim 17 (depends on 16) The device according to claim 16, wherein relative brightness observed from front is 60% or more.