In commemoration of the 50th anniversary of liquid crystal display (LCD), we review a chronological development of the history of LCD from the 1950s, when liquid crystal (LC) was a laboratory curiosity, to the growth arriving upon 100 BD industry, and thus, LCD is now an indispensable information terminal in our ordinary life and business. In this chapter, we place an emphasis on how individual research group has resolved problems for getting across barriers for producing historical original products that were the rank of milestone that became seeds for the next development and current LCD. Further, we briefly introduce the current state-of-the-art LCD technologies and foresee the next direction.

Fringe-field switching (FFS) liquid crystal display (LCD) mode has been the mainstream for thin-film transistor (TFT) LCDs with superior image quality and low power consumption since the advent of tablet PC like iPad and high-resolution retina mobile displays in 2010. Its application has expanded to displays for automobiles, mobile phones, high-resolution notebooks and monitors, televisions, and also most of the displays that require high-quality images. This chapter first describes switching fundamentals and electrode-structural advantages of the FFS mode for high-resolution and high-aperture displays with the introduction of lowtemperature poly-silicon (LTPS). In recent progress, the FFS mode has interesting features such that the flexoelectric effect arises noticeably when the driving frequency becomes approximately lower than 30 Hz as a power-saving mode. The flexoelectric effect basically gives rise to deterioration in image-quality, causing the so-called image-flickering. Thus, second, this chapter discusses the flexoelectric effect associated with structural conditions and physical properties of liquid crystals and possible solutions to minimise the flexoelectric effects in the FFS mode. Afterwards, superior electro-optic performance and low-power consumption driving of the flexoelectric FFS mode will be discussed in detail, such as light efficiency, high transmittance at the low-frequency driving.

Liquid crystal display-television (LCD-TV) has made remarkable progress, starting with a pocket size of only 2 in. and now large TVs with 65 in. and 4K2K resolution are about to become the center products of the market. More recently, a larger TV with 70 in. and 8K4K resolution was also released. In addition to the evolution of diagonal size and resolution, image quality performance such as viewing angle, contrast ratio, and color reproducibility has also been greatly improved. The competing IPS with VA mode LCD TV splits the market into two, total shipments exceeding 200 million units. In this chapter, we will explain in detail how the performances of both IPS and VA modes have been improved since entering the TV era. Finally, we will introduce the IPS pixel technology which realizes a high aperture ratio with resolution 8K4K LCD, and the IPS liquid crystal technology which realizes a contrast ratio of more than 1 million to 1 comparable to that of organic light-emitting diode (OLED).

This chapter discusses comparison of thin-film transistor-liquid-crystal display (TFT-LCD) with active-matrix organic light-emitting diode (AMOLED) regarding their display performance and manufacturing. AMOLED has been expected to realize much excellent display quality, lower power consumption, and lower manufacturing cost than TFT-LCD. Such expectation has been partly realized in the category of small-sized organic light-emitting diode (OLED). However, manufacturing cost remains as an issue, the feasibility of production on glass whose size is comparable to the size of substrate of large format TFT-LCD has yet to be established. Furthermore, we discuss how to build a firm position for TFT-LCD.

In this chapter, we would like to give a brief outline of the areas in which automotive displays will be used today and in the future. We would also like to give an insight into the environmental requirements placed on such displays and which aspects must be taken into account during development in order to achieve good optical performance and also to guarantee the required robustness over the lifetime of the display.

Flexible liquid crystal displays (LCDs) have advantages of thin, light weight and afford high-level resolution and reliability, and low power consumption. It dramatically expands portability, installation, and design of displays and creates new viewing methods via novel interfaces and many new applications such as curved automotive displays, large digital signages, and rollable televisions. In this chapter, we introduce the manufacturing technologies required to create flexible LCDs focusing on the optical design of, and bonding spacers and thin flexible substrates for, flexible LCDs.

A polyethylene naphthalate (PEN) film is excellent in mechanical properties, heat resistance, transparency, and chemical properties. It is very suitable as a substrate material for flexible devices. In this chapter, the characteristics of the PEN film is explained while contrasting with the properties of the other types of films.

Along with the development of liquid crystal displays, semiconductor technology for driving these screens has advanced dramatically. This chapter explains the latest technology, the oxide semiconductor thin-film transistor (TFT), and its display application. The oxide semiconductor TFT features low leakage current and high electron mobility, which are not found in conventional amorphous silicon (a-Si) and low-temperature polycrystalline silicon (LTPS) semiconductors. These characteristics are effective for liquid crystal displays with high definition, a narrow frame and low power consumption, and the oxide semiconductor TFT is widely used in small high-definition displays such as smartphones up to large nextgeneration 8K TVs (7,680 × 4,320 pixel).

Organic thin film transistor (OTFT) is expected as a switching device for flexible displays because organic semiconductor thin films can be fabricated by solution process at highest process temperatures lower than 150 °C, which allows us to use flexible and inexpensive plastic substrates. In this chapter, in the light of requirements for practical thin film transistor materials, how the requirements can be satisfied with a new type of organic semiconductor, i.e., liquid crystalline organic semiconductors, is described. At the same time, the state of the art of OTFT materials is described with a representative liquid crystalline organic semiconductor of 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene, Ph-BTBT-10 exhibiting highly ordered smectic liquid crystalline phase.

Quantum dots (QDs) are nanometer-scale semiconductor crystals that work as a phosphor with a very sharp emission spectrum caused by a QD's quantum confinement effect. QD's sharp emission properties are expected to bring a wide color gamut and high energy efficiency to liquid-crystal displays (LCDs), and QDs have already been introduced in some LCDs. However, researchers and engineers working on display technology have insufficient knowledge of QDs. This chapter gives an overview of QDs and describes the principles of their emission and chemical synthesis method. In addition to this general information on QDs, applications for their use in displays, from the backlights of LCDs to an electroluminescent (EL) QD-light-emitting diode (QD-LED), are also described.