LCD COMPONENTS

GoalsGoals 1.Light Guiding Plates 2.Reflector Sheet 3.Light Collimator Films 4.Diffusers 5.Polarizers 6.Non - Absorptive Polarizers 7.Quarter Wave Plates 8.Compensation Films 9.Color Filters 10.Transparent Electrode Films 11.Anti-Glare and Anti-Reflection Films

TN Display ON state OFF state

Light Efficiency in LCDs 100 %  60%  40%  30% Light Guiding Plate (60%) Rear Polarizer (40%) Active Matrix (70%) Liquid Crystal Layer Color Filter (30%) ITO Coated Glass Front Polarizer 0.60  0.40  0.70  0.30 = 0.05% Light Efficiency  70%

Light Guiding Place (LGP) Reflector Sheet Fluorescent Lamp Light Guiding Plate Lamp Reflector Fluorescent Lamp Dot Patterns Dot patterns scatter a light to change a direction of propagation

Light Guiding Place (LGP) II Fluorescent Lamp a) Single lampb) Double lamps How to produce a homogenous plane illumination? Dot pattern (white ink) Dots get bigger as they are farther from the lamp

Novel LGP HSOT Highly Scattering Optical Transmission (HSOT) Polymer II Fluorescent Lamp Reflector Sheet SiO 2 Particles

Novel LGP Highly Scattering Optical Transmission (HSOT) Polymer, Koike, Y., Japanese Patent Number H (1990) by the courtesy of Koike

Novel LGP Homogeneity of plane illumination

Light Collimator Angle Intensity Angle Intensity Light Collimator Steer more light into narrow – viewing cone

Light Collimator Brightness Enhancement Foil (BEF) Angle of Collimated Light BEF 3M Product

Light Collimator Brightness Enhancement Foil II BEF Double reflection Refraction Reflection refraction Diffuser Light Guiding Plate

DiffusionDiffusion Surface diffusion typeInner diffusion type Improve spatial uniformity of backlight

Diffusion II Diffuser LGP Improve an unevenness of backlight

Polarization States x y z x y z x y z x y x y x y a) Linear b) Elliptical c) Circular ExEx EyEy

PolarizerPolarizer Iodine (Forms Complex) PVA Protect Film Stretch Axis

Polarizer IV y x z Transmission Axis Absorption Axis Iodine Complex

PolarizerPolarizer Transmission Axis

PolarizerPolarizer T // TT T

Non Absorptive Polarizer Brightness Enhancement Applications Recycle Brightness Enhanced (b) Reflecting Polarizer 50% absorbed (a) Absorbing Polarizer

Non Absorptive Polarizer ne2ne2 ne1ne1 ne1ne1 nono nono nono a) b) a)b) Stretch Axis Birefringent Polymer 1 nono ne2ne2 Birefringent Polymer 2 Reflecting polarizer – dual brightness enhancement film (DBEF, 3M)

Non Absorptive Polarizer DBEF

Non Absorptive Polarizer Reflecting polarizer – cholesteric LC film (TRANSMAX, Merck NIPOCS, Nitto) Incident Light Reflected Light Incident Light Transmitted Light Cholesteric LC Layer Quarter Wave Plate

Non Absorptive Polarizer Mismatch  Scattering Axis Material A Material B Refractive Indices of Material A Refractive Indices of Material B Match  Transmission Axis

Non Absorptive Polarizer VI Stretch Axis Scattering polarizer Diffuse reflective polarizer film (DRPF) Green – positive birefringent polymer Pink – negative birefringent polymer stretches

Non Absorptive Polarizer VIII Stretch Axis Scattering polarizer Particle dispersed polymer Green –positive birefringent polymer Pink – isotropic particles particle polymer

Non Absorptive Polarizer IX Stretch Axis Scattering polarizer Stretched PDLC Green –LC droplets Pink – polymer polymer Liquid crystal

Quarter Wave Plate (QWP) Application – Reflective LCDs Linear Polarizer Quarter Wave Plate LC Cell Reflective Electrode (Aluminum) White State (E OFF ) Black State (E ON )

Viewing Angle Compensation Film Compensation Film Compensation Film TN-LC Cell Compensation Film Substrate Alignment Layer Structure of the Wide View Film Concept Wide View Film (FUJIFILM) Use discotic liquid crystal molecule for viewing angle compensation

Viewing Angle Compensation Film Viewing Angle Improvement with the Wide View Film

Color Filters Only about 1/3 of the input light can transmit Decrease the light efficiency

Color Filters II Non – Absorptive CF Cholesteric CF Light Guiding Plate can be recycled

Transparent Electrodes (ITO) Indium tin Oxide NOW, Zinic Oxides ?

Transparent Electrode II Optical Property of ITO ITO: n = % SiO 2 : n=1.45, d=550/4n=94.8nm Anti – reflection coating

Anti–Glare / Anti–Reflection Film Anti – Glare Film (AG Film) How does it work?Surface structure of AG Film 100nm 0nm871nm

Anti–Glare / Anti–Reflection Film II Anti–Reflection Film (AR Film) Substrate (EX. CTA: n =1.48) (Ex. n =2.3 / d =30 nm) (Ex. n =1.45 / d =25 nm) High n Layer (Ex. TiO 2 : n =2.3 / d =55 nm) Low n Layer (Ex. SiO 2 : n =1.45 / d =100 nm) Improve the contrast ratio under ambient light

SummarySummary Interference Diffraction Reflection Refraction Birefrigerence Scattering Optics Absorption Near Field & Quantum