Liquid Crystal Displays Addressing Schemes and Electro-Optical Effects

THE NEW EDITION OF THE GOLD-STANDARD IN TEACHING AND REFERENCING THE FUNDAMENTALS OF LCD TECHNOLOGIES

This book presents an up-to-date view of modern LCD technology. Offering balanced coverage of all major aspects of the field, this comprehensive volume provides the theoretical and practical information required for the development and manufacture of high-performance, energy-efficient LCDs.

The third edition incorporates new technologies and applications throughout. Several brand-new chapters discuss topics such as the application of Oxide TFTs and high mobility circuits, high-mobility TFT-semiconductors in LCD addressing, liquid crystal displays in automotive instrument clusters and touch-screen systems, and the use of ultra-high-resolution LCD panels in augmented reality (AR) and virtual reality (VR) displays. This practical reference and guide:

• Provides a complete account of commercially relevant LCD technologies, including their physics, mathematical descriptions, and electronic addressing
• Features extensively revised and expanded information, including more than 150 pages of new material
• Includes the addition of Oxide Transistors and their increased mobilities, the advances of fringe field switching and an overview of automotive displays
• Presents quantitative results with full equation sets, their derivation, and tabular summaries of related information sets

Ernst Lueder is Emeritus Professor, Department of Electrical Communications, University of Stuttgart, Germany, where he was Director of the Institute of Network and Systems Theory. Now retired, he has authored more than 200 publications on LCDs, network and system theory and optimization, and sensors and electro- optical signal processing.

Seung Hee Lee is Professor, Chonbuk National University, South Korea. He has published more than 200 papers in international SCI journals and holds more than 100 registered international patents. He was awarded King of Invention twice and has received several major awards such as the Merck Award-Major from the Korean Information Display Society.

Peter Michael Knoll was employed at Robert Bosch GmbH, Karlsruhe, Germany, from 1980 until his retirement in 2006. He is now a retired Associate Professor for Driver Assistance Systems and associated Human Machine Interaction at the KIT, formerly University of Karlsruhe, Germany.

Series Editor's Preface to the Third Edition

Foreword to the Second Edition

Preface to the Third Edition

Preface to the Second Edition

Preface to the First Edition

About the Authors

1 Introduction 1

2 Liquid Crystal Materials and Liquid Crystal Cells 3

2.1 Properties of Liquid Crystals 3

2.1.1 Shape and phases of liquid crystals 3

2.1.2 Material properties of anisotropic liquid crystals 6

2.2 The Operation of a Twisted Nematic LCD 11

2.2.1 The electro-optical effects in transmissive twisted nematic LC cells 11

2.2.2 The addressing of LCDs by TFTs 18

3 Electro-optic Effects in Untwisted Nematic Liquid Crystals 21

3.1 The Planar and Harmonic Wave of Light 21

3.2 Propagation of Polarized Light in Birefringent Untwisted Nematic Liquid Crystal Cells 26

3.2.1 The propagation of light in a Fre´edericksz cell 26

3.2.2 The transmissive Fre´edericksz cell 31

3.2.3 The reflective Fre´edericksz cell 37

3.2.4 The Fre´edericksz cell as a phase-only modulator 39

3.2.5 The DAP cell or the vertically aligned cell 42

3.2.6 The HAN cell 44

3.2.7 The p cell 46

3.2.8 Switching dynamics of untwisted nematic LCDs 48

3.2.9 Fast blue phase liquid crystals 54

4 Electro-optic Effects in Twisted Nematic Liquid Crystals 57

4.1 The Propagation of Polarized Light in Twisted Nematic Liquid Crystal Cells 57

COPYRIGHTED MATERIAL

4.2 The Various Types of TN Cells 67

4.2.1 The regular TN cell 67

4.2.2 The supertwisted nematic LC cell (STN-LCD) 70

4.2.3 The mixed mode twisted nematic cell (MTN cell) 74

4.2.4 Reflective TN cells 76

4.3 Electronically Controlled Birefringence for the Generation of Colour 80

5 Descriptions of Polarization 83

5.1 The Characterizations of Polarization 83

5.2 A Differential Equation for the Propagation of Polarized Light through Anisotropic Media 91

5.3 Special Cases for Propagation of Light 95

5.3.1 Incidence of linearly polarized light 95

5.3.2 Incident light is circularly polarized 97

6 Propagation of Light with an Arbitrary Incident Angle through Anisotropic Media 99

6.1 Basic Equations for the Propagation of Light 99

6.2 Enhancement of the Performance of LC Cells 107

6.2.1 The degradation of picture quality 107

6.2.2 Optical compensation foils for the enhancement of picture quality 109

6.2.2.1 The enhancement of contrast 109

6.2.2.2 Compensation foils for LC molecules with different optical axis 110

6.2.3 Suppression of grey shade inversion and the preservation of grey shade stability 115

6.2.4 Fabrication of compensation foils 116

6.3 Electro-optic Effects with Wide Viewing Angle 116

6.3.1 Multidomain pixels 116

6.3.2 In-plane switching 117

6.3.3 Optically compensated bend cells 119

6.4 Multidomain VA Cells, Especially for TV 121

6.4.1 The torque generated by an electric field 122

6.4.2 The requirements for a VA display, especially for TV 124

6.4.2.1 The speeds of operation 124

6.4.2.2 Colour shift, change in contrast and image sticking 124

6.4.3 VA cells for TV applications 129

6.4.3.1 Multidomain VA cells with protrusions (MVAs) 129

6.4.3.2 Patterned VA cells (PVAs) 130

6.4.3.3 PVA cells with two subpixels (CS-S-PVAs) 132

6.4.3.4 Cell technologies avoiding a delayed optical response 136

– Polymer sustained alignment (PSA) 136

– Mountain shaped cell surface 137

6.4.3.5 The continuous pinwheel alignment (CPA) 139

6.5 Polarizers with Increased Luminous Output 140

6.5.1 A reflective linear polarizer 140

6.5.2 A reflective polarizer working with circularly polarized light 141

6.6 Two Non-birefringent Foils 142

7 Modified Nematic Liquid Crystal Displays 145

7.1 Polymer Dispersed LCDs (PDLCDs) 145

7.1.1 The operation of a PDLCD 145

7.1.2 Applications of PDLCDs 149

7.2 Guest-Host Displays 150

7.2.1 The operation of Guest-Host Displays 150

7.2.2 Reflective Guest-Host Displays 154

8 Bistable Liquid Crystal Displays 159

8.1 Ferroelectric Liquid Crystal Displays (FLCDs) 159

8.2 Chiral Nematic Liquid Crystal Displays 168

8.3 Bistable Nematic Liquid Crystal Displays 174

8.3.1 Bistable twist cells 174

8.3.2 Grating aligned nematic devices 175

8.3.3 Monostable surface anchoring switching 177

9 Continuously Light Modulating Ferroelectric Displays 179

9.1 Deformed Helix Ferroelectric Devices 179

9.2 Antiferroelectric LCDs 181

10 Addressing Schemes for Liquid Crystal Displays 185

11 Direct Addressing 189

12 Passive Matrix Addressing of TN Displays 191

12.1 The Basic Addressing Scheme and the Law of Alt and Pleshko 191

12.2 Implementation of PM Addressing 196

12.3 Multiple Line Addressing 201

12.3.1 The basic equations 201

12.3.2 Waveforms for the row selection 203

12.3.3 Column voltage for MLA 205

12.3.4 Implementation of multi-line addressing 206

12.3.5 Modified PM addressing of STN cells 210

12.3.5.1 Decreased levels of addressing voltages 210

12.3.5.2 Contrast and grey shades for MLA 212

12.4 Two Frequency Driving of PMLCDs 218

13 Passive Matrix Addressing of Bistable Displays 223

13.1 Addressing of Ferroelectric LCDs 223

13.1.1 The V–tmin addressing scheme 225

13.1.2 The V–1/t addressing scheme 226

13.1.3 Reducing crosstalk in FLCDs 228

13.1.4 Ionic effects during addressing 228

13.2 Addressing of Chiral Nematic Liquid Crystal Displays 231

14 Addressing of Liquid Crystal Displays with a-Si Thin Film Transistors (a-Si-TFTs) 239

14.1 Properties of a-Si Thin Film Transistors 239

14.2 Static Operation of TFTs in an LCD 244

14.3 The Dynamics of Switching by TFTs 252

14.4 Bias-Temperature Stress Test of TFTs 259

14.5 Drivers for AMLCDs 260

14.6 The Entire Addressing System 266

14.7 Layouts of Pixels with TFT Switches 269

14.8 Fabrication Processes of a-Si TFTs 272

14.9 Addressing of VA Displays 277

14.9.1 Overshoot and undershoot driving of LCDs 277

14.9.2 The dynamic capacitance compensation (DCC) 281

14.9.3 Fringe field accelerated decay of luminance 288

14.9.4 The addressing of two subpixels 292

14.9.5 Biased vertical alignment (BVA) 295

14.10 Motion Blur 298

14.10.1 Causes, characterization and remedies of blur 298

14.10.2 Systems with decreased blur 310

14.10.2.1 Edge enhancement for reduced blur 310

14.10.2.2 Black insertion techniques 312

14.10.2.3 Scanning backlights 313

14.10.2.4 Higher frame rates for reducing blur 315

14.10.3 Modelling of blur 320

14.11 The Optical Response of a VA Cell 329

14.12 Reduction of the Optical Response Time by a Special Addressing Waveform 334

15 Addressing of LCDs with Poly-Si TFTs 339

15.1 Fabrication Steps for Top- and Bottom-Gate Poly-Si TFTs 340

15.2 Laser Crystallization by Scanning or Large Area Anneal 344

15.3 Lightly Doped Drains for Poly-Si TFTs 345

15.4 The Kink Effect and its Suppression 347

15.5 Circuits with Poly-Si TFTs 349

16 Liquid Crystal on Silicon Displays 353

16.1 Fabrication of LCOS with DRAM-Type Analog Addressing 353

16.2 SRAM-Type Digital Addressing of LCOS 355

16.3 Microdisplays Using LCOS Technology 360

17 Addressing of Liquid Crystal Displays with Metal-Insulator-Metal Pixel Switches 363

18 Addressing of LCDs with Two-Terminal Devices and Optical, Plasma, Laser and e-beam Techniques 373

19 Components of LCD Cells 381

19.1 Additive Colours Generated by Absorptive Photosensitive Pigmented Colour Filters 381

19.2 Additive and Subtractive Colours Generated by Reflective Dichroic Colour Filters 383

19.3 Colour Generation by Three Stacked Displays 385

19.4 LED Backlights 386

19.4.1 The advantages of LEDs as backlights 386

19.4.2 LED technology 386

19.4.3 Optics for LED backlights 395

19.4.4 Special applications for LED backlights 405

19.4.4.1 Saving power and realizing scanning with LED backlights 405

19.4.4.2 Field sequential displays with LED backlights 407

19.4.4.3 Active matrix addressed LED backlights 409

19.4.5 The electronic addressing of LEDs 409

19.5 Cell Assembly 411

20 Projectors with Liquid Crystal Light Valves 415

20.1 Single Transmissive Light Valve Systems 415

20.1.1 The basic single light valve system 415

20.1.2 The field sequential colour projector 416

20.1.3 A single panel scrolling projector 417

20.1.4 Single light valve projector with angular colour separation 418

20.1.5 Single light valve projectors with a colour grating 418

20.2 Systems with Three Light Valves 420

20.2.1 Projectors with three transmissive light valves 420

20.2.2 Projectors with three reflective light valves 421

20.2.3 Projectors with three LCOS light valves 422

20.3 Projectors with Two LC Light Valves 422

20.4 A Rear Projector with One or Three Light Valves 422

20.5 A Projector with Three Optically Addressed Light Valves 423

21 Liquid Crystal Displays with Plastic Substrates 427

21.1 Advantages of Plastic Substrates 427

21.2 Plastic Substrates and their Properties 428

21.3 Barrier Layers for Plastic Substrates 429

21.4 Thermo-Mechanical Problems with Plastics 430

21.5 Fabrication of TFTs and MIMs at Low Process Temperatures 435

21.5.1 Fabrication of a-Si:H TFTs at low temperature 435

21.5.2 Fabrication of low temperature poly-Si TFTs 435

21.5.3 Fabrication of MIMs at low temperature 437

21.5.4 Conductors and transparent electrodes for plastic substrates 438

21.6 Transfer of High Temperature Fabricated AMLCDs to a Flexible Substrate 438

22 Printing of Layers for LC Cells 443

22.1 Printing Technologies 443

22.1.1 Flexographic printing 443

22.1.2 Knife coating 444

22.1.3 Ink-jet printing 444

22.1.4 Silk screen printing 448

22.2 Surface Properties for Printing 449

22.3 Printing of Components for Displays 455

22.3.1 Ink-jet printed colour filters, alignment layers and phosphors for LED Backlights 455

22.3.2 Flexographic printing of alignment layers and of nematic liquid crystals 456

22.3.3 Printing of OTFTs 457

22.4 Cell Building by Lamination 461

23  Advances in TFTs and Structures for Enhancing Mobility

24  Fringe-Field Switching (FFS) Technologies

25  Automotive Applications of Liquid Crystal Displays

Appendix 1: Formats of Flat Panel Displays 463

Appendix 2: Optical Units of Displays 465

Appendix 3: Properties of Polarized Light 467

References 473

Index

The New copy of this book will include any supplemental materials advertised. Please check the title of the book to determine if it should include any access cards, study guides, lab manuals, CDs, etc.

The Used, Rental and eBook copies of this book are not guaranteed to include any supplemental materials. Typically, only the book itself is included. This is true even if the title states it includes any access cards, study guides, lab manuals, CDs, etc.