# US 2014/0192300 A1 · Compensation System for Liquid Crystal Panel and Liquid Crystal Display Device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192300 A1 - Document ID: US20140192300A1 - Status: Published application - Kind: A1 - Application number: 13/810,463 - Filed: 2013-01-11 - Published: 2014-07-10 - Earliest claimed: 2013-01-09 - Assignees: Shenzhen China Star Optoelectronics Technology Co., Ltd. - Inventors: Chih-tsung Kang; Bo Hai - Web page: https://patentgrep.com/patent/US20140192300A1 ## 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)} - G02F 1/133634: {the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis} - G02F 1/1393: {the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells (G02F1/1396, G02F1/141 take precedence)} - G02F 2413/02: Number of plates being 2 - G02F 2413/05: Single plate on one side of the LC cell - G02F 2413/12: Biaxial compensators - G02F 2413/13: Positive birefingence - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract The present invention provides a compensation system for liquid crystal panel and liquid crystal display device. The compensation system includes first biaxial compensation film and second biaxial compensation film, disposed on two sides of liquid crystal panel respectively, first biaxial compensation film having planar compensation value Ro1 for incident light of 550 nm wavelength and compensation value Rth1 along thickness direction, second biaxial compensation film having planar compensation value Ro2 for incident light of 550 nm wavelength and compensation value Rth2 along thickness direction; wherein 15 nm≦Ro1≦94 nm; 35 nm≦Rth1≦214 nm; 35 nm≦Rth1≦214 nm; 14 nm≦Ro2≦101 nm; Y1≦Rth2≦Y2; Y1=0.004302×Rth12−1.96894×Rth1+259.7; Y2=−0.00234308×Rth12−0.32227×Rth1+245. As such, the present invention effectively reduces dark state light leakage of liquid crystal panel by disposing biaxial compensation films of appropriate compensation values. ## Claims ### Claim 1 A compensation system for liquid crystal panel, which comprises: a first biaxial compensation film and a second biaxial compensation film, disposed on two sides of the liquid crystal panel respectively, the first biaxial compensation film having a planar compensation value Ro1 for incident light of 550 nm wavelength and a compensation value Rth1 along thickness direction, the second biaxial compensation film having a planar compensation value Ro2 for incident light of 550 nm wavelength and a compensation value Rth2 along thickness direction; wherein: 15 nm≦Ro1≦94 nm; 35 nm≦Rth1≦214 nm; 35 nm≦Rth1≦214 nm; 14 nm≦Ro2≦101 nm; Y1≦Rth2≦Y2; Y1=0.004302×Rth12−1.96894×Rth1+259.7; Y2=−0.00234308×Rth12−0.32227×Rth1+245. ### Claim 2 (depends on 1) The compensation system for liquid crystal display device as claimed in claim 1, characterized in that 104 nm≦Rth1=Rth2≦147.2 nm. ### Claim 3 (depends on 1) The compensation system for liquid crystal display device as claimed in claim 1, characterized in that the liquid crystal optical path difference Δn×d of the liquid crystal panel is: 305.8 nm≦Δn×d≦324.3 nm. ### Claim 4 A liquid crystal display device, which comprises: a liquid crystal panel, disposed with a liquid crystal layer having a plurality of liquid crystal molecules, the liquid crystal layer having a refractive index anisotropy Δn for incident light of 550 nm wavelength, a thickness d and pretilt angle θ: a first biaxial compensation film and a second biaxial compensation film, disposed on two sides of the liquid crystal panel respectively, the first biaxial compensation film having a planar compensation value Ro1 for incident light of 550 nm wavelength and a compensation value Rth1 along thickness direction, the second biaxial compensation film having a planar compensation value Ro2 for incident light of 550 nm wavelength and a compensation value Rth2 along thickness direction; wherein 305.8 nm≦Δn×d≦324.3 nm; 85°≦θ≦90°; 15 nm≦Ro1≦94 nm; 35 nm≦Rth1≦214 nm; 35 nm≦Rth1≦214 nm; 14 nm≦Ro2≦101 nm; Y1≦Rth2≦Y2; Y1=0.004302×Rth12−1.96894×Rth1+259.7; Y2=−0.00234308×Rth12−0.32227×Rth1+245. ### Claim 5 (depends on 4) The liquid crystal display device as claimed in claim 4, characterized in that 104 nm≦Rth1=Rth2≦147.2 nm. ### Claim 6 (depends on 4) The liquid crystal display device as claimed in claim 4, characterized in that the liquid crystal display device further comprises a first polarizing film and a second polarizing film, disposed on two sides of the liquid crystal panel respectively; the first polarizing film and the first biaxial compensation film are located on one side of the liquid crystal panel, and the second polarizing film and the second biaxial compensation film are located on the other side of the liquid crystal panel. ### Claim 7 (depends on 6) The liquid crystal display device as claimed in claim 6, characterized in that the absorption axis of the first polarizing film forms 90° with the slow axis of the first biaxial compensation film, and the absorption axis of the second polarizing film forms 90° with the slow axis of the second biaxial compensation film. ### Claim 8 (depends on 6) The liquid crystal display device as claimed in claim 6, characterized in that the first polarizing film and a second polarizing film are polyvinyl alcohol (PVA) films. ### Claim 9 (depends on 6) The liquid crystal display device as claimed in claim 6, characterized in that the first biaxial compensation film is disposed between the first polarizing film and the liquid crystal panel; the second biaxial compensation film is disposed between the second polarizing film and the liquid crystal panel. ### Claim 10 (depends on 4) The liquid crystal display device as claimed in claim 4, characterized in that the liquid crystal panel is a vertical alignment (VA) cell.