Addressing Techniques of Liquid Crystal Displays

Temkar N. Ruckmongathan, Raman Research Institute, Bangalore, IndiaDr. Ruckmongathan is a Senior Professor at the Raman Research Institute, Bangalore, India. He has over 30 years' experience of research and development in the area of addressing techniques for driving LCDs. Professor Ruckmongathan has authored approximately 50 publications on driving matrix LCD. He has 16 US and European patents.

• Series Editor’s Foreword xiiiAcknowledgements xv1 Introduction 12 Liquid Crystal Displays 32.1 Matrix Displays 32.2 Display Fonts and Formats 52.3 Liquid Crystals 82.4 Physical Properties of Liquid Crystals 92.5 Basics of Electro-optic Effects with Liquid Crystals 102.6 Twisted Nematic Effect 112.7 Super Twisted Nematic (STN)-LCD 132.8 STN-LCD with a 270◦ Twist (STN-270) 132.9 STN-LCD with a 180◦ Twist (STN-180) 142.10 In-plane Switching 142.11 Ferroelectric LCD (FLCD) 142.12 Summary 153 Review of Addressing Techniques 173.1 Addressing Techniques 173.2 Matrix Addressing 183.3 Nonlinear Characteristics 193.4 Cross-Talk in a Matrix LCD 213.5 Driving Matrix Displays 223.6 Bi-phase Addressing 233.7 Line-by-Line Addressing (LLA) 253.8 Half-Select Technique 273.9 Two-Third-Select Technique (TTST) 293.10 Selection Ratio (SR) and the Maximum Selection Ratio 303.11 Limitations of Matrix Addressing 373.12 Principle of Restricted Pattern Addressing 383.13 Pulse Coincidence Technique (PCT) 403.14 Pseudo Random Technique (PRT) 423.15 Restricted Pattern Addressing Technique (RPAT) 433.16 Addressing Technique for Dial Type Displays 473.17 Frame Frequency 473.18 Large Area Display 483.19 Dielectric Relaxation 483.20 Supply Voltage of Drivers 493.21 Nonuniformity Due to Resistance Mismatches 493.22 Need for Multiline Addressing Techniques 514 Binary Addressing 534.1 Principle 534.2 Binary Addressing Technique (BAT) 554.3 Analysis of the BAT 584.4 Practical Aspects of the BAT 664.5 Drivers for Driving the LCD with the BAT 695 Orthogonal Functions and Matrix Addressing 715.1 Orthogonal Functions 715.2 Multiplexing 785.3 Matrix Addressing 805.4 Line-by-Line Addressing 815.5 Multiline Addressing 825.6 Discussion 856 Active Addressing 876.1 Principle 876.2 Active Addressing Technique (AAT) 876.3 Summary 937 Hybrid Addressing 957.1 Principle 957.2 Hybrid Addressing Technique (HAT) 967.3 Analysis of the HAT 987.4 Drivers of the Hybrid Addressing Technique 1037.5 Discussion 1038 Improved Hybrid Addressing 1058.1 Principle 1058.2 Improved Hybrid Addressing Technique (IHAT) 1068.3 Analysis of IHAT 1088.4 Discussion 1159 Improved Hybrid Addressing Special Case 3 1199.1 Principle 1199.2 Analysis 1209.3 Summary 12610 Improved Hybrid Addressing Special Case 4 12710.1 Principle 12710.2 Analysis 12710.3 Summary 13611 Sequency Addressing 13711.1 Principle 13711.2 Technique 13711.3 Discussion 14112 Restricted Pattern Addressing 14512.1 Principle 14512.2 Technique 14512.3 Analysis 14912.4 Summary 15213 Review of Methods to Display Greyscales 15313.1 Greyscales in Liquid Crystal Displays 15313.2 Basics of Greyscale 15313.3 Frame Modulation 15513.4 Pulse Width Modulation 15713.5 Row Pulse Height Modulation 15713.6 Data Pulse Height Modulation 15913.7 Summary 16114 Amplitude Modulation 16314.1 Principle 16314.2 Amplitude Modulation – Split Time Interval 16414.3 Amplitude Modulation in Multiline Addressing 17014.4 Pulse Height Modulation 17214.5 Discussion 17315 Successive Approximation 17515.1 Principle 17515.2 Technique 17715.3 Analysis 17915.4 Discussion 18116 Cross-Pair Method 18316.1 Principle 18316.2 Technique 18616.3 Analysis 18716.4 Cross Pairing with Four Pairs of Data Voltages 19016.5 Discussion 19617 Wavelet-Based Addressing 19717.1 Principle 19717.2 Line-by-line Addressing with Wavelets 20117.3 Analysis 20717.4 Principle of Multiline Addressing with Wavelets 21017.5 Technique 21518 Bit Slice Addressing 22318.1 Principle 22418.2 Bit Slice Addressing Technique 22918.3 Bit Slice Addressing with a Light Source 23118.4 Bit Slice Addressing with Multiple Light Sources 23218.5 Merits of Bit Slice Addressing 23618.6 Demerits of Bit Slice Addressing 23818.7 Discussion 23919 Multibit Slice Addressing 24119.1 Principle 24119.2 Dual Bit Addressing of the LCD 24219.3 Nibble Slice Addressing 24619.4 Summary 24820 Micro Pulse Width Modulation 24920.1 Principle 24920.2 Micro Pulse Width Modulation 25020.3 Results 26120.4 Summary 26621 Comparison of Addressing Techniques 26721.1 Line-by-Line Addressing 26721.2 Multiline Addressing 26821.3 Methods to Display Greyscales 27121.4 Summary 27222 Low Power Dissipation 27322.1 Background 27322.2 Principle 27422.3 Multistep Waveform for Low Power 27522.4 Static Drive with a Multistep Waveform 27822.5 Power Dissipation in a Multiplexed Matrix LCD 27822.6 Waveforms to Reduce Power Dissipation 28122.7 Low Power Dissipation in the Successive Approximation Method 28322.8 Summary 29023 Low Power Consumption of Backlight 29123.1 Principle of Backlight Switching 29123.2 Reduction of Power with White Backlight and Monochrome Images 29223.3 Power Reduction in the Colour Sequential Mode 30023.4 Power Reduction of Backlight with Micro Pulse Width Modulation 30023.5 Power Reduction with Micro PWM in the Colour Sequential Mode 30423.6 Summary 30824 Drivers for Liquid Crystal Displays 30924.1 Basics 30924.2 Drivers for Direct Drive 31024.3 Drivers for the Matrix LCD 31324.4 Drivers for Multiline Addressing Techniques 31524.5 Summary 31725 Active and Passive Matrix Addressing 31925.1 Switched Passive Matrix Addressing (Line-by-Line) 31925.2 Switched Passive Matrix Addressing (Line-by-Line) with Reduced External Connections 32125.3 Multiplexed Active Matrix Addressing 32225.4 An Ideal Active Matrix LCD 32326 Conclusion 325Bibliography 329Index 333