chapter 2广视角技术原理

chapter 2广视角技术原理

Chapter 7廣視角技術原理

chapter 2广视角技术原理

Viewing angle issues for LCD 1. Crossed polarizer off axis light leakage 2. Compensation films (ex.λ/4-plate) off axis light leakage

≠ 90o Normal direction Off axis

3. LC light leakage

Δn=0

Δn≠0

chapter 2广视角技术原理

How to achieve wide viewing angleFilm compensation -TN+film Multi-domain configuration -MVA, Multi-domain TN, Super-IPS, ASV Intrinsically LC configuration -IPS, FFS Self-Compensated -OCB, Reflective modes

chapter 2广视角技术原理

Basic concept for viewing angle improvementTN VA MVA

chapter 2广视角技术原理

Basic concept for viewing angle improvementIPS S-IPS

chapter 2广视角技术原理

Summary of wide view modeWide view mode TN+ Film Type TN+ WV film TN+ SWV film TN+NH film MVA phase 1 MVA phase 2 PMVA PVA ASV IPS Super IPS Advanced Super IPS FFS Ultra FFS AFFS IPS pro Company Fuji film Fuji film Nippon Oil Fujitsu Fujitsu Fujitsu Samsung Sharp Hitachi Hitachi/Matsushita Hitachi/ IBM Japan/ LG Hydis Hydis Hydis Hitachi Proposed year Productivity Application Phase out Medium-small size 1996 Yes Medium-small size 2002 Yes Medium-small size 1998 Phase out TV 1996 Phase out TV 1997 Yes TV 2001 Yes TV/Medium-small size 2001 Yes TV/Medium-small size 2002 Phase out TV 1995 Yes TV 1998 Yes TV 1999 Yes TV 1999 Yes TV 2001 Yes TV/Medium-small size 2004 Yes TV/Medium-small size 2005

MVA

IPS

chapter 2广视角技术原理

Optical comparison

TN MVA IPS TN TN+SWV TN+NH MVA PVA AS-IPS AFFS Viewing angle 15/45/45/45 75/60/75/75 30/ 85/85/85/85 85/85/85/85 85/85/85/85 85/85/85/85 45/135 viewing 60 60 50 85 85 85 85 50~60%TN (depend on pixel size) 80%TN Transmittance 90%TN 85%TN~0.02<0.02 Color shift>0.02>0.02>0.02 Response time (on+off) 16ms 5ms 16ms 15~25ms 20~30ms LC modes

chapter 2广视角技术原理

Optical property of Film compensated TN

chapter 2广视角技术原理

Residual LC phaseRubbing direction Rubbing direction

EResidual LC phase

Rubbing direction

Rubbing direction

Voff

Von

Residual LC phase Viewing angle degrade

chapter 2广视角技术原理

Fuji Wide Viewing Angle FilmCompensation filmΔn< 0 Polarizerabsorption axis0

Fuji WV filmrubbing direction

90oTNΔn> 0

90o TN cellrubbing direction

Fuji WV filmabsorption axis

Compensation filmΔn< 0

Polarizer

Reduce LC residual phase

Widen viewing angle

chapter 2广视角技术原理

Iso-Contrast Contour

Conventional TN

TN+ Compensation Film

chapter 2广视角技术原理

Grayscale inversion improvementDifferent grayscale vs viewing angle

Grayscale inversion

TN

TN+ Fuji WV film

chapter 2广视角技术原理

Optical characteristics of EA-WV

Wide viewing angle in CR and color shift

chapter 2广视角技术原理

MVA TFT-LCD

chapter 2广视角技术原理

MVA mode featuresVertically aligned Perfectly dark Multi-domain No grayscale inversion Auto Domain Formation (ADF) No rubbing process

ITO

Δε<0 LC

OFF stateBump or Protrusion

ON state

chapter 2广视角技术原理

Perfect Dark for vertical alignmentresidual LC phase Homogeneous alignment

off

on

No residual LC phase

Δε<0 LC

Vertical alignment

Δn=0

off

on High CR

Normally black for VA