Abstract— For better front‐of‐screen performance for transflective LCDs, a technology with extra free optimization parameters for the optical stack is needed. Thin wet coatable retarders which enable adjustment of the optical activity on the (sub)pixel level have been developed. Isotropic domains have been created in nematic retardation films by thermal patterning or photopatterning. Employing such a patterned retarder in a transflective LCD leads to an LCD that is lighter and thinner with good reflectivity, high transmission, and low chromaticity at all gray levels and wide viewing angles. The patterned thin‐film technology has been proven to be versatile and applicable in various LCD designs.

A 3.8‐inch transflective thin‐film‐transistor liquid crystal display TFT‐LCD with a wide viewing angle that enables operation over a small driving voltage range between 1.5V and 4.0V has been developed. This is achieved by optimizing the retardation of the LC layer and the parameters of the compensation film, which minimizes a viewing angle dependence of the total retardation of the LC layer and the compensation films.

In this paper, we describe a new MVA technology for wider viewing angle. The MVA mode has a color-wash-out issue when the panel is seen from a large viewing angle. In order to solve this, we have optimized a halftone-grayscale method for MVA mode. We have also developed a new pixel structure with an ITO etched pattern on the CF side for transmissive panels. As a result, we have obtained a better viewing angle performance with less color-wash-out.

We analyzed the grayscale inversion mechanism of birefringent-type liquid crystal displays (LCDs). As a result, we propose a new LCD that prevents grayscale inversion, without using the multidomain alignment method. In addition, using this new method, we established the design rules for a compensation film that can compensate for the retardation of the black state from any viewing angle. We call this new LCD the OCP cell, which is an abbreviation for optically compensated parallel cell. This OCP is very promising as a next-generation LCD, due to its wide range of viewing angles, simple fabrication process, which is almost the same as that for a twisted nematic (TN) cell, and large aperture ratio.

The spectrum sequential LCD has fewer columns than the equivalent conventional RGB LCD, a large aperture ratio, a very large colour gamut and it transmits more light. We demonstrate a 1.9" QVGA spectrum sequential LCD and discuss its implementation, including array, addressing, colour filter, backlight and processing. Objective and BackgroundDisplays for mobile applications should be low power, low cost and lightweight. At the same time the front of screen performance should be very good, which means high contrast, high brightness, large colour gamut, good viewing angle and a high resolution. In conventional RGB LCDs, the colour filter absorbs two thirds of the backlight output, and three sub-pixels are needed to form one full colour pixel. This leads to a large number of columns (3 times the horizontal resolution), which severely limits the aperture ratio. Colour Sequential LCDs [1,2,3] which flash R,G,B in three subframes per frame in the backlight only partly overcome these problems. The colour filter is completely absent, giving a factor 3 brightness advantage, and the number of column lines is a factor three lower than for the conventional LCD. To avoid flicker, the frame rate should be at least 3x60Hz, which means that the LC response has to be very fast. Addressing at 180Hz, however, is not sufficient to avoid the so-called colour break-up (colour flash) problem [5]. For this to be absent, frame rates as high as 600Hz are needed, which are not practical for a mobile LCD. Alternatives to Colour Sequential technology have been presented in [4], which discusses a display solution between conventional RGB and colour sequential. We have been working on similar methods [6] which all follow the principle of a "Spectrum Sequential" display. A variant of these, described in this paper, uses only 2 colour filters (x and y in figure 1) and 2 sub-frames. In each sub-frame, a different spectrum is offered, resulting in a total of 4 primaries. Figures 1 and 2 show the principle of operation. In a first subframe, LEDs 1 and 3 are flashed, giving the possibility to make combinations of blue, yellow (and black). In the 2 nd sub-frame, combinations of red and cyan are possible.In a spectrum sequential LCD, the colour flash effect can be minimised or even completely avoided by choosing the backlight spectra and colour filter in such a way that a white pixel is made by two sub-frames with colour points which are very close to each other.