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LCD Backlights


Research and development on liquid crystal display (LCD) backlight technologies are becoming increasingly important due to the fast growth of the LCD business. Backlight technologies contribute to functional improvements of LCDs in terms of wide colour reproduction, uniformity improvements of luminance and colour temperature, high luminance, long life, less power consumption, thinner backlight unit, as well as cost. As LCD panel technology progresses, the lighting technology that provides the illumination for the panel must similarly evolve.

LCD Backlights is written by a global panel of leading researchers and practitioners in this field from both academia and industry.  The first part of LCD Backlights details the variety of applications of backlights including those in LCD-TV, PC monitors and mobile devices. The second part is a full examination of the different light sources that are used including the latest technological trends in amongst others, cold cathode fluorescent lamps (CCFLs), mercury-free fluorescent lamps and light emitting diodes (LEDs). The final part of the book analyses the optical component of backlights such as diffusers and brightness enhancement films.

Key features:


  • Provides a comprehensive analysis of the latest status of LCD backlight research and development.
  • Discusses the design considerations and technical requirements for the multiple applications of LCD backlights.
  • Considers techniques used for power saving and picture quality improvement.
  • Examines the requirements for backlight units used for TVs, PC monitors and mobile phones.

LCD Backlights is of significant interest to practising electronics and display engineers as well as scientists working on the development of liquid crystal displays. This book is also of value to graduate students and researchers involved in display technologies.

The Society for Information Display (SID) is an international society, which has the aim of encouraging the development of all aspects of the field of information display. Complementary to the aims of the society, the Wiley-SID series is intended to explain the latest developments in information display technology at a professional level. The broad scope of the series addresses all facets of information displays from technical aspects through systems and prototypes to standards and ergonomics

Series Editor’s Foreword.

About the Editors.

List of Contributors.



1 Technical Trends and Requirements/Specifications for LCD TV Backlights (S. Y. Lee, SAMSUNG Electronics).

1.1 Introduction.

1.2 Structure of LCD TV Backlights.

1.3 Trends in LCD TV Backlights.

1.4 Requirements/Specifications for LCD TV Backlights.

1.5 Conclusions.


2 Improvement of Moving Picture Quality by Means of Backlight Control (T. Yamamoto, Hitachi, Ltd).

2.1 Introduction.

2.2 Blur of Moving Images on LC Displays.

2.3 Methods of Reducing Motion Blur.

2.4 Backlight Blinking.

2.5 Conclusions.


3 Multiple Primary Color Backlights (H. Sugiura, Mitsubishi Electric Corporation).

3.1 Present Status.

3.2 Technological Impacts.

3.3 Operation of Prototype, Six-primary-color Monitor.

3.4 Details of a Six-primary-color Backlight Unit.

3.5 Signal Processing of Transforming from Three Primaries to Six Primaries.

3.6 Color Gamut of the Prototype Monitor.

3.7 Other Techniques for Multiple Primary Color LC-TVs.

3.8 Remaining Issues.


4 Reduction of Backlight Power Consumption of LCD-TVs (T. Shiga, The University of Electro-Communications).

4.1 Introduction.

4.2 Display Method of LCD and Power Reduction.

4.3 Principle of the Adaptive Dimming Technique.

4.4 Adaptive Dimming Control and Power Consumption.

4.5 Other Features of the Adaptive Dimming Technique.


5 Notebook PC/Monitor Backlights (B. H. Hong, Kwangwoon University).

5.1 Introduction.

5.2 Characteristics Required for Backlights.

5.3 Optical Systems for Backlights.

5.4 Light Sources for Backlights.

5.5 Optical Components of Backlights.


6 Backlights for Handheld Data Terminals (S. Aoyama, Omron Corporation).

6.1 Introduction.

6.2 Basic Structure and Principles of LED Backlights.

6.3 Constituents of LED BLUs.

6.4 Various LED Backlight Configurations.

6.5 Conclusions.



7 CCFL Backlights (K. Yamaguchi, Panasonic Photo & Lighting).

7.1 Introduction.

7.2 Structure and Operating Principle of CCFLs.

7.3 Basic Characteristics of CCFLs.

7.4 Future Trends in CCFLs.

7.5 Conclusions.

8 CCFL Inverters (T. Uematsu, TDK).

8.1 Introduction.

8.2 Various Drive Schemes of CCFL Inverters.

8.3 Equivalent Circuit of CCFLs.

8.4 Inverter Circuits.

8.5 Driving of CCFLs with Inverters.

8.6 Lamp Current Balancers for Driving Multiple Lamps.

8.7 Conclusions.


9 HCFL Backlights (A. A. S. Sluyterman, Philips Lighting).

9.1 HCFL Light Source as a Member of the Fluorescent Lamp Family.

9.2 Introduction of the Hot Cathode in Fluorescent Lamps.

9.3 Driving the HCFL.

9.4 Cathode Life Properties of HCFL.

9.5 Lumen Maintenance and Color Point Shift during Life.

9.6 Designing a Backlight with HCFL.

9.7 The Scanning Feature, Cost-effectively Enabled by HCFL.

9.8 The Dimming Feature.

9.9 Conclusions.


10 EEFL Backlights (J.-H. Ko, Hallym University).

10.1 Introduction.

10.2 Basic Characteristics of EEFLs.

10.3 Advantages and Disadvantages of EEFL Backlights.

10.4 Technological Trends of EEFL Backlights.

10.5 Development Targets.

10.6 Conclusions.


11 FFL Backlights (G. Kim, GLD Co., Ltd. and Mirae Corporation, and S. Lim, Dankook University).

11.1 Introduction.

11.2 The History of FFL Development.

11.3 Characteristics of FFLs.

11.4 Features of the FFL.


12 Magnetically Coupled Electrodeless Lamps (F. Okamoto, Matsushita Electric Works).

12.1 Introduction.

12.2 The Operating Principle of Electrodeless Lamps.

12.3 Environmental Protection.

12.4 Features of Electrodeless Lamps.

12.5 Commercial Products with Electrodeless Lamps.

12.6 Trends in Research and Development.

12.7 Application to LCD Backlights.

12.8 Conclusions.


13 Mercury-free Fluorescent Lamp Backlights (T. Shiga, The University of Electro-Communications).

13.1 Introduction.

13.2 Basic Characteristics of Mercury Discharge.

13.3 Basic Characteristics of Xenon Discharge.

13.4 Mercury-free Xe Discharge Fluorescent Lamps.

13.5 Mercury-free Xe Flat Discharge Lamp.

13.6 Conclusions.


14 LED Backlights (M. Zeiler and J. Hüttner, OSRAM Opto Semiconductors GmbH).

14.1 Introduction.

14.2 LED Device Principle.

14.3 LED Backlight Solutions for Different LCD Sizes.

14.4 Conclusions.


15 Technological Trends of LED Backlight Units (Y. Kondo, NEC LCD Technologies).

15.1 Introduction.

15.2 Structure of LED Backlight Units.

15.3 Design of LED Backlight Units.

15.4 Requirements for Backlight Units.

15.5 Technical Trends of LED Backlights.

15.6 Applications of LED Backlights.

15.7 Conclusions.

16 White OLED Backlights (J. Jang, Kyung Hee University).

16.1 Introduction.

16.2 White OLED with a Single-layer Emission.

16.3 White OLED with Multi-layer Emission.

16.4 WOLED with Color Conversion.

16.5 Stacked WOLED Devices.

16.6 Applications of WOLEDs.

16.7 Research and Development Status.


17 Inorganic EL Backlights (S. Okamoto, NHK Science & Technical Research Laboratories).

17.1 Introduction.

17.2 Classification of Inorganic EL Devices.

17.3 Device Structures and Characteristics.

17.4 High-luminance Inorganic EL Devices.

17.5 Practical Examples of Backlight Use.


18 Field Emission Backlights (M. Ushirozawa, NHK Science & Technical Research Laboratories).

18.1 Introduction.

18.2 Field Electron Emitter.

18.3 Lamp Container and Vacuum Seal.

18.4 Cathodoluminescent Phosphor.

18.5 Issues Relating to Practical Field Emission Backlights.



19 Light-guide Plates (Y. Ishiwatari, Asahi Kasei Chemicals).

19.1 Introduction.

19.2 Market Demands for PMMA.

19.3 Characteristics of PMMA.

19.4 Manufacturing Method for PMMA Plates.

19.5 Applications to LCD Backlight Units.

19.6 Characteristics Required for Materials of Light-guide Plates.

19.7 Materials for Extrusion Molding and Injection Molding.

19.8 Conclusions.


20 Optical Diffuser Plates (Y. Ishiwatari, Asahi Kasei Chemicals).

20.1 Introduction.

20.2 PMMA Light Diffuser Plates.

20.3 MS and PS Light Diffuser Plates.

20.4 Trends in Light Diffuser Plates.

20.5 LED Light Sources and Diffusing Plates.

21 Lens Films and Reflective Polarization Films (F. Hanzawa, Sumitomo 3M).

21.1 Introduction.

21.2 Fundamentals of Reflection and Refraction.

21.3 Lens Films (Upward Direction).

21.4 Lens Films (Downward Direction).

21.5 Reflective Polarization Films.

21.6 Resin-type Specular Reflection Films.

21.7 Applications of Films.

21.8 Standards.



"LCD Backlights is an invaluable resource for researchers and general readers alike. . . includes an impressive spectrum of topics. Having specialized for nearly 10 years in this field, I can attest to the fact that it would be hard to find anywhere else the range of backlighting technology and information covered in this book."  (SID ID Magazine, 2010)

"LCD Backlights is an invaluable resource for researchers and general readers alike.... [It] would be hard to find any where else the ‘fullness’ of backlighting technology and information covered in this book." (Information Display, May 2009)