液晶背光显示核心技术

1、1THE THEORY AND DEVELOPMENT OF THE BACKLIGHT SYSTEM FOR LIQUID CRYSTAL DISPLAYS Hsiuwen ChenSenior R&D EngineerRadiant Opto-electronic Co.2Color filterLCDPCBBacklight module液晶顯示器的結構 實物圖3contentsSection 1 I, Introduction to Fundamental Optics II,Apply Optics to LGPSection 2 III,Applied Optics in the

2、Construction of the Back-light Modules IV,The future of the Back-light Modules4The main optical units constructed in back-light modules prism lens diffuserLGP reflectorLamp reflectorCCFLPatterns (elements)5The Reflection and Refraction of Light 1,Reflection and refraction phenomena will happen on th

3、e interface when light transports through it. 2, the reflection of light acts according to the reflection rule. 3, the refraction of light acts according to the refraction rule.6The Reflection Rule of Light InNOut1,insert line( ),normal( ) and reflect line( ) are on the same plane.2,insert angle is

4、equal to the reflection angle. InNOut7The Refraction Rule of Light InNRfrn n1, ,insert line( ),normal( ) and reflect line( ) are on the same plane.2,insert angle and refraction angle act according to the Snells lawInNRfrsinsinnn8The meanings of the Snells Law1,if2,if nn sinsin2020 nn sinsin2020Whats

5、 happened when ? 29The Critical Angle and Total Reflectionn nc2When and nn 22sinsinnn11nncsin1Critical anglecTotal reflectioncNormal refraction10Diffusion When parallel light waves through rough surfaces or particles, diffusion will be formed by the reason that non-parallel factor of the normal for

6、those surfaces and particles.11Roughness1R2R3R4R4321RRRRThe diffusion effect depends on the roughness of the interface of the media.12Applied optics to LGPfundamental principles- total reflection and diffusionthe optical properties of the printed unitsthe optical properties for different types of re

7、flection unitsthe properties of the print-less LGPs13Critical angles and total reflection of LGPnc21n2nc11sinCritical angle1c14Refraction Index v.s. LGP12sinsin11nsinsin22n2121 nnRefraction indexproper energy1n21nn ;15Refraction index v.s. LGPrefraction indexeffective area of luminary2L1L1c2cnc11sin

8、212121LLnncc161x2x1d2d1n2n1c2c)()(),(dgxfx折射率大者,單位面積能量使用率較大21nn 21cc21xx21dd21Refraction Index v.s. LGP17折射率大小對導光板選擇的影響折射率大者,單位面積有效出光角較小1n2n1c2c21nn 21cc12122118印刷點的光學性質 印刷點係用光高反射或高折射材料混合油墨印刷在導光板的反光側,藉由改變光路徑形成漫射效果導光板反光面出光面印刷點19n n11 nn1p2p3p4pp20印刷點對光能的有效使用率cAc油墨比入射至印刷點單位面積光能量印刷點截面積21SiO2油墨比對輝度影響050

9、010001500200025003000350040001112131415161718191101111121131141151161171181191201211measuring length (mm)brightness (cd/m2)01:1501:1701:191c2c3c油墨比與光能的有效使用率22印刷點截面積,入射至印刷點單位面積光能量與光能的有效使用率1x2x)();(11xAx)();(22xAx)(1x)(2xAxxxx)()(;21)()(21xx)()(21xAxA23量測與設計的修正1x2x)();(11xAx)();(22xAx)(1x)(2xmAAxxx)(

10、)( ;21量測區域,區域面積AAAmAc24印刷點的極限 容易受環境條件改變而減短壽命 受印刷網板網目極限限制點的dimension(250m)25無印刷導光板的光學性質定義:何謂“無印刷” “無印刷”的方法種類 1,機械加工 2,蝕刻 3,薄板取代 4,其它各種“無印刷”的方法所形成patterns的光學特性26機械加工蝕刻薄板取代27無印刷的定義: 把所需的光反射元件先行轉置在模具上,然後用一體成型 得到所要物件的方法無印刷導光板: 用無印刷方法所製作的導光板28機械加工法光反射元件的光學原理與特性V-groove typeU-groove type2922223022wpd gfpww

11、22tandwcc31pp反射元件間隙(pitch)的影響32蝕刻法光反射元件的光學原理與特性mAcmARf)()(Rf33薄板取代法: 師法於“半導體”的製程,主要是微小光反射元件,可增加局 部區域能量調整的程度m100m10intensityintensity34dPhoto maskPhoto resistsubstrateParallel lightForm the metal plate by electro-forming35機械加工蝕刻法薄板取代法尺度極限-120m10m光學特性Refraction-reflectiondiffusionTotal reflection各種無印刷方法的比較36背光模組整體結構之光學應用稜鏡片(prism lens)擴散片(diffuser)導光板(LGP)反射片(reflector)37反射板與導光板間 反射板一般為“擴散反射”,用以增加回授的光 能可用率38擴散板與導光板間39Diffuser - prism lens40no90