Single Cell Gap Transflective Liquid Crystal Displays and the Use of Photoalignment Technology

Single Cell Gap Transflective Liquid Crystal Displays and the Use of Photoalignment Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Transflective liquid crystal display (LCD) is required for mobile and portable applications, because of their superior performance in both indoor and outdoor environment. Transflective LCD is developed based on the conventional transmissive and reflective LCD by combining their characteristics together. For common transflective LCD, the pixels are separated into the transmissive and reflective sub-pixels. The transmissive sub-pixels in a transflective display are transmitting with backlight illumination and the reflective sub-pixels are reflecting light from the environment under ambient illumination. Commercialized conventional transflective LCDs are mostly fabricated by double cell gap approach, which show good performance and well matched optical performance of both transmissive and reflective parts. However; on the other hand, the fabrication process is very complicated, which makes the products expensive. For mobile and portable applications, cheap transflective LCDs are in great need. So people put effort on single cell gap approach to make the display with good performance and matched Transmittance versus Voltage Curve (TVC) and Reflectance versus Voltage Curve (RVC). In this thesis, several new configurations of transflective LCD with single cell gap approach are proposed. Two general types of transflective LCD are proposed. Firstly, the dual mode single cell gap transflective configurations. Secondly, the single mode single cell gap transflective configurations with patterned retardation films. Photoalignment technology has been studied and is used in the fabrication of the single cell gap transflective LCD configurations. By photoalignment technology, we can easily produce different alignment domains on the same alignment layer; also, we can produce patterned retardation films with domain alignment.

Single Cell Gap Transflective Liquid Crystal Displays and the Use of Photoalignment Technology

Single Cell Gap Transflective Liquid Crystal Displays and the Use of Photoalignment Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Transflective liquid crystal display (LCD) is required for mobile and portable applications, because of their superior performance in both indoor and outdoor environment. Transflective LCD is developed based on the conventional transmissive and reflective LCD by combining their characteristics together. For common transflective LCD, the pixels are separated into the transmissive and reflective sub-pixels. The transmissive sub-pixels in a transflective display are transmitting with backlight illumination and the reflective sub-pixels are reflecting light from the environment under ambient illumination. Commercialized conventional transflective LCDs are mostly fabricated by double cell gap approach, which show good performance and well matched optical performance of both transmissive and reflective parts. However; on the other hand, the fabrication process is very complicated, which makes the products expensive. For mobile and portable applications, cheap transflective LCDs are in great need. So people put effort on single cell gap approach to make the display with good performance and matched Transmittance versus Voltage Curve (TVC) and Reflectance versus Voltage Curve (RVC). In this thesis, several new configurations of transflective LCD with single cell gap approach are proposed. Two general types of transflective LCD are proposed. Firstly, the dual mode single cell gap transflective configurations. Secondly, the single mode single cell gap transflective configurations with patterned retardation films. Photoalignment technology has been studied and is used in the fabrication of the single cell gap transflective LCD configurations. By photoalignment technology, we can easily produce different alignment domains on the same alignment layer; also, we can produce patterned retardation films with domain alignment.

Transflective Liquid Crystal Displays

Transflective Liquid Crystal Displays PDF Author: Zhibing Ge
Publisher: John Wiley & Sons
ISBN: 9780470689066
Category : Technology & Engineering
Languages : en
Pages : 246

Get Book Here

Book Description
Sunlight readable transflective liquid crystal displays, used on devices from cell phones and portable media players, to GPS and even some desktop monitors, have become indispensable in our day-to-day lives. Transflective Liquid Crystal Displays is a methodical examination of this display technology, providing a useful reference to the fundamentals of the topic. Including thorough descriptions of the essential physics of transflective LCD technologies, the book also compares transflective LCD technology with alternatives, such as OLED displays, to enable display engineers to appropriately select the correct device for their particular application. Includes detailed descriptions of both pure transmissive and reflective LCDs, and the design considerations and performance of combining these into small mobile displays. Focuses on fundamental elements, such as double cell gap transflective LCDs, wide-viewing angle technology, light polarization and wide-view linear and circular polarizers, video rate display by colour sequential technologies, colour sciences and engineering, and backlights. Describes the latest LCD technologies, such as polymer-sustained surface alignment technology, and the possible trends which could be applied to transflective LCDs in the future. Its focus on the fundamentals of transflective liquid crystal displays makes this an ideal graduate text, while display engineers, scientists, developers and technicians working with this technology will also welcome this resource. 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

Modeling and Optimization of LCD Optical Performance

Modeling and Optimization of LCD Optical Performance PDF Author: Dmitry A. Yakovlev
Publisher: John Wiley & Sons
ISBN: 1118706730
Category : Technology & Engineering
Languages : en
Pages : 584

Get Book Here

Book Description
Focusing on polarization matrix optics in many forms, this book includes coverage of a wide range of methods which have been applied to LCD modeling, ranging from the simple Jones matrix method to elaborate and high accuracy algorithms suitable for off-axis optics. Researchers and scientists are constantly striving for improved performance, faster response times, wide viewing angles, improved colour in liquid crystal display development, and with this comes the need to model LCD devices effectively. The authors have significant experience in dealing with the problems related to the practical application of liquid crystals, in particular their optical performance. Key features: Explores analytical solutions and approximations to important cases in the matrix treatment of different LC layer configurations, and the application of these results to improve the computational method Provides the analysis of accuracies of the different approaches discussed in the book Explains the development of the Eigenwave Jones matrix method which offers a path to improved accuracy compared to Jones matrix and extended Jones matrix formalisms, while achieving significant improvement in computational speed and versatility compared to full 4x4 matrix methods Includes a companion website hosting the authors' program library LMOPTICS (FORTRAN 90), a collection of routines for calculating the optical characteristics of stratified media, the use of which allows for the easy implementation of the methods described in this book. The website also contains a set of sample programs (source codes) using LMOPTICS, which exemplify the application of these methods in different situations

Liquid Crystal Displays

Liquid Crystal Displays PDF Author: Ernst Lueder
Publisher: John Wiley & Sons
ISBN: 1119667917
Category : Technology & Engineering
Languages : en
Pages : 644

Get Book Here

Book Description
LIQUID CRYSTAL DISPLAYS 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

Photoalignment of Liquid Crystalline Materials

Photoalignment of Liquid Crystalline Materials PDF Author: Vladimir G. Chigrinov
Publisher: John Wiley & Sons
ISBN: 0470751797
Category : Technology & Engineering
Languages : en
Pages : 248

Get Book Here

Book Description
Photoalignment possesses significant advantages in comparison with the usual ‘rubbing’ treatment of the substrates of liquid crystal display (LCD) cells as it is a non-contact method with a high resolution. A new technique recently pioneered by the authors of this book, namely the photo-induced diffusion reorientation of azodyes, does not involve any photochemical or structural transformations of the molecules. This results in photoaligning films which are robust and possess good aligning properties making them particularly suitable for the new generation of liquid crystal devices. Photoalignment of Liquid Crystalline Materials covers state-of-the-art techniques and key applications, as well as the authors’ own diffusion model for photoalignment. The book aims to stimulate new research and development in the field of liquid crystalline photoalignment and in so doing, enable the technology to be used in large scale LCD production. Key features: Provides a full examination of the mechanisms of photoalignment. Examines the properties of liquid crystals during photoalignment, with particular reference made to the effect on their chemical structure and stability. Considers the most useful photosensitive materials and preparation procedures suitable for liquid crystalline photoalignment. Presents several methods for photoalignment of liquid crystals. Compares various applications of photoalignment technology for in-cell patterned polarizers and phase retarders, transflective and micro displays, security and other liquid crystal devices. Through its interdisciplinary approach, this book is aimed at a wide range of practising electrical engineers, optical engineers, display technologists, materials scientists, physicists and chemists working on the development of liquid crystal devices. It will also appeal to researchers and graduate students taking courses on liquid crystals or 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

Active Matrix Liquid Crystal Displays

Active Matrix Liquid Crystal Displays PDF Author: Willem den Boer
Publisher: Elsevier
ISBN: 008045576X
Category : Technology & Engineering
Languages : en
Pages : 252

Get Book Here

Book Description
Active matrix liquid crystal displays (AMLCDs) are the preferred choice when thin, low power, high quality, and lightweight flat panel displays are required. Here is the definitive guide to the theory and applications of AMLCDs.Contemporary portable communication and computing devices need high image quality, light weight, thin, and low power flat panel displays. The answer to this need is the color active matrix liquid crystal display (AMLCD). The rides of AMLCD technology over less than two decades to undisputed dominance as a flat panel display has been breathtaking, and designers of portable devices need a thorough understanding of the theory and applications of AMLCDs. Willem den Boer, a holder of over 30 patents in imaging technologies, has created this guide to AMLCD theory, operating principles, addressing methods, driver circuits, application circuits, and alternate flat display technologies (including active matrix flat panel image sensors). Numerous design and applications examples illustrate key points and make them relevant to real-world engineering tasks. Need more information on Mobile Displays, go to: http://www.insightmedia.info/newsletters.php#mdr · Systematically discusses the principles of liquid crystal displays and active matrix addressing.· Describes methods of enhancing AMLCD image quality.· Extensive coverage of AMLCD manufacturing techniques.· Thorough examination of performance characteristics and specifications of AMLCDs.

Reflective Liquid Crystal Displays

Reflective Liquid Crystal Displays PDF Author: Shin-Tson Wu
Publisher: John Wiley & Sons
ISBN: 0471496111
Category : Technology & Engineering
Languages : en
Pages : 354

Get Book Here

Book Description
The evolution of portable communications applications has been facilitated largely by the development of reflective LCD technology. Offering a unique insight into state-of-the art display technologies, Reflective Liquid Crystal Displays covers the basic operations principles, exemplary device structures and fundamental material properties of device components. Display engineers, scientists and technicians active in the field will welcome this unique resource, as will developers of a wide range of systems and applicaations. Graduate students and researchers will appreciated the introduction and technical insight into this exciting technology. Featuring: * Direct-view, projection and micro (virtual projection) reflective displays in the context of multi-media projectors, mobile internet and personal entertainment displays. * Optimisation of critical display attributes: fast response time, low voltage operation and wide angle viewing. * Description of the basic properties of liquid crystal materials and their incorporation into configurations for transmissive and reflective applications. * Examination of the various operations modes enabling the reader to slect the appropriate display type to meet a variety of needs. * Overview and comparison of the complete range of reflective display technologies, and reflective LCD effects. 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.

JJAP

JJAP PDF Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 676

Get Book Here

Book Description


Fast-response Liquid Crystal Displays

Fast-response Liquid Crystal Displays PDF Author: Meizi Jiao
Publisher:
ISBN:
Category : Liquid crystal displays
Languages : en
Pages : 122

Get Book Here

Book Description
After about five decades of extensive material research and device development, followed by massive investment in manufacturing technology, thin-film-transistor liquid-crystal-display (TFT-LCD) has finally become the dominant flat panel display technology. Nowadays, LCD performances, such as viewing angle, contrast ratio, and resolution, have reached acceptable levels. The remaining major technical challenges are response time, light efficiency, and sunlight readability. Fast response time is desired to reduce motion blur and to enable field sequential color displays using red (R), green (G), and blue (B) LEDs (light emitting diodes) without noticeable color breakup. Sequential RGB colors would eliminate the commonly used spatial color filters which in turn enhances light efficiency and resolution density by ~ 3X. In this dissertation, several new approaches for achieving fast-response LCDs are explored. From material viewpoint, the most straightforward approach for achieving fast response time is to employ a thin cell gap with high birefringence and low viscosity liquid crystal (LC). We investigated the thin cell approach theoretically and experimentally. Voltage shielding effect and anchoring energy effect of alignment layers are found to play important roles on operating voltage and response time. Simulations are carried out to understand the underlying physics and confirm the experimental results quantitatively. Another approach to realize fast response time is to explore novel device configuration. Here, we proposed a dual fringing-field switching (DFFS) mode in which small LC domains are formed following the distribution of fringing fields. Therefore, it exhibits submillisecond response time without using thin cell or overdrive/undershoot voltage method. The response time of the DFFS mode is ~20X faster than a conventional vertical aligned LCD. In addition, high optical efficiency is achieved from the complementary top and bottom active LC domains. Two transmissive and one transflective LCDs using DFFS mode are conceived and their electro-optical properties investigated. A shortcoming of DFFS LCDs is their fabrication complexity. To keep the advantages of this fast-response mode while avoiding the requirement of double-TFTs and pixel registration, we modified the device structure to transflective LCD which uses a single TFT in each pixel and vertical aligned positive dielectric anisotropy LC. Two types of electrodes are considered: fringing-field switching (FFS) and in-plane switching (IPS). Besides fast response time and high transmittance, such a transflective LCD shows good sunlight readability. As nematic LC is gradually approaching to its limit in term of response time, polymer-stabilized blue phase (PSBP) LCD is emerging. It has potential to become next-generation display because of following revolutionary features: submillisecond response time, no need for alignment layer, good dark state and symmetric viewing angle, and cell gap insensitivity if IPS electrode is employed. In this dissertation, we studied the material-property correlation of Kerr effect-induced birefringence in nano-structured PSBP LC composites. Furthermore, a new device configuration of BP LCD with corrugated electrodes is proposed to solve two critical technical issues: high driving voltage and relatively low transmittance. The on-state voltage can be reduced from ~35 V[subscript rms] to ~10 V[subscript rms] which will enable TFT addressing, and the transmittance is improved from ~65% to ~85%. This new device configuration will accelerate the emergence of PSBP LCD. Wide view is another important requirement for a high-end display. Several new LCD configurations with negative A-plate and biaxial plate as phase compensation films are proposed to achieve wide view and broadband operation. The underlying working principles are studied and detailed display performances are included in this dissertation.

High Quality Liquid Crystal Displays and Smart Devices

High Quality Liquid Crystal Displays and Smart Devices PDF Author: Shoichi Ishihara
Publisher: Institution of Engineering and Technology
ISBN: 1785619233
Category : Technology & Engineering
Languages : en
Pages : 405

Get Book Here

Book Description
This book celebrates 50 years since liquid crystal display (LCD) technologies were first demonstrated. LCDs have grown in that short time from a laboratory curiosity to a US$100 billion industry and are now indispensable in our daily life and careers - an impressive example of successful innovation and commercialisation. The shifting focus of research follows a pattern of improved definition, increased display size, wider viewing angles and faster responses, with improvements in each area influencing the next. There is also growing interest in the use of liquid crystal materials in novel applications including sensing devices, spatial modulators, light-shielding windows, and flexible and wearable technologies. This book discusses the latest LCD technologies, with their challenges, opportunities, and problems to be solved, at a level suited to an academic and research-professional audience. There is a particular focus on display quality such as image sticking, contrast ratio and colour hue that has not been dealt with thoroughly elsewhere. Current and future trends in liquid crystal materials and technologies based on their evolving role and new applications are discussed in detail. This volume covers LC alignment issues, new technologies and smart device applications.