LCD (Liquid Crystal Display) Edited by Chi Hun, Kim

History of LCD

Liquid Crystal

Liquid Crystal Disply

Operation Mechanism ( TN-LCD & STN-LCD )

Operation Mechanism (TFT-LCD)

Structure of LCD Glass substrate Color filter Polarizers Liquid crystal Signal lines Transparent common electrode Scan line Thin film transistor Transparent display electrode Glass substrate Back light

Process – Color Filter

Process – TFT

Process – LCD Panel

Black Matrix Role - Isolation of light source from adjacent pixel - Effect of increase in contrast - Prevention of inaccurate operation

Component - Black Matrix

Color in LCD

Color in LCD

Pigment Type

Function of Components

Color Filter Material

Over Coat

PVA Mode

ITO Etching Margin in PVA Mode

Over Coat

Spacer

Two Types of Spacer

Two Types of Spacer It can be expected that the demand of column spacer increase according to increasing of market of LCD-TV.

Organic Insulating Layer Black Matrix type - VGA 60% Organic insulator - VGA 80 ~ 82%

Materials of Organic Insulating Layer • Photosensitive resin • PAC

Polarizer

Structure Structure of polarizer in LCD - PVA (Poly vinyl alcohol) - TAC (Tri-acetyl cellulose) - Protection Film - AR(Anti-reflection) AG(Anti-Glare)

Backlight Unit

BLU : Light Source

BLU : Optical Sheets & LGP

The Functional of Alignment Layer • LC Alignment by Rubbed Alignment Layer • Regulation of LC Movement

What is Pretilt Angle (θp)?

Necessity of Pretilt Angle

Polyimide (Alignment Layer)

Steric Effect ⇒ 2.4° ⇒ 6.2° ⇒ 13.3°

Substitution Effect

Ultra Violet Arrangement Polysiloxane cinnamate: PSCN Photo-dimerized monolayer : PDML Poly(ω(4-chalconyloxy) alkoxyphenylmaleimide) 6FD-HAB-CI polyimide

Voltage Holding Ratio (VHR) PI-1 : 99% PI-2 : 90% PI-3 : 80% PI-4 : 60% PI-5 : 50%

Liquid Crystal Nematic, Smectic, Cholesteric, Ferroelectric Themotropic LC, Lyotropic LC Nematic, Smectic, Cholesteric, Ferroelectric Anti-ferroelectric, Discotic, Polymer LC

Molecular Structure of Liquid Crystal Compounds Terminal group(Alkyl, Alkoxy, CN, Halogen atm etc. Central Groups: Benzene or cyclohexane ring Lateral Substituted group : H, Halogen atom, CN, OH, NO2etc.) Linkage Groups: Ester, Ethylene, Methyloxy, Acetylene,

History of Liquid Crystal Compounds / H 2 1972/3 1973 1973/4 1976/77 1980 1983 : BDH Halle D.D.R Hoffmann -La Roche Merck, F.R.G , D.D.R Hull, BDH

Fluorine Substituted Liquid Crystal Compounds

Components for Use in Wide Working Range TN Mixtures ' C H 2 R ' C H 2 Low viscosity R ' F C H 2 High clearing point Wide range, low viscosity

Chiral Liquid Crystal Compound

Current Materials in TFT-LCD Item Function Materials Color Filter PR Black Matrix Liquid Crystal Alignment Layer Polarizer Prism Film Retardation Film Substrates Full Color Pixel Light Valve LC Aligning Polarization of Light Light Pass Phase Compensation Panel substrate Acrylic Polymer, Pigment Cr/CrOx, Resin Organic Polyimide PVA, TAC, Adhesives PET film, UV-Curing resin Polycarbonate, LC film Glass, Plastic

New TFT-LCD Technology with (New) Polymer Materials Wide Viewing Angle Brightness Enhancing UV-Alignment Layer - IPS* Mode - VA** Mode High Aperture Tech - Organic Passivation Layer - TFT on CF Array (TOC) Photopolymers Photo-Polyacrylates Polyimides Dielectric Polymers Hybrid Polymers Flexible Display Plastic Substrate Organic TFT Organic Gate Insulator Optical Polymers Conducting Polymers Target Application Polymer Materials New Color Technology Novel PDPR for TV Ink - Jet Technology New Polymer Binders Fast Response Time TV Application (~6 msec) New type LC * : In Plane Switching ** : Vertical Alignment

Large Area TFT-LCD Market (Quantity)

Large Area TFT-LCD Market (Revenue)

Mobile TFT-LCD Applications & Market Size

Reference Chem. Rev. 2000, 100, 1847-1873 J. R. Park, G. Ryu, J. Byun, H. Hwang S. T. Kim, and I. Kim, Optical review, 9, 207 (2002) http://smdl.snu.ac.kr/lecture/dis/ybkim/kyb.ppt 4) Polymer Science and Technology Vol. 15, No. 6, pp.674-682 December 2004 5) Polymer Science and Technology Vol. 14 No. 2, pp.174-180 April 2003 Polymer Science and Technology Vol. 12, No. 3, pp.674-682 June 2001 B. O. Myrvold, H. Yokokura, Y. Iwakabe, K. Kondo and S. Ohhara, Japan display, 827 (1992) 8) http://en.wikipedia.org/wiki/LCD 9) http://www.webopedia.com/TERM/L/LCD.html 10) http://web.media.mit.edu/~stefan/liquid-crystals/liquid-crystals.html 11) http://en.wikipedia.org/wiki/Liquid_crystal_display