Sander Jurgen Roosendaal

8.1: Novel High Performance Transflective LCD with a Patterned Retarder

For a better optimization of the transflective AM-LCD, a new technology with extra free parameters is inevitable. Our novel transflective AM-LCD with in-cell patterned retarder enables us to optimize further, resulting in a good brightness, contrast ratio, viewing angle and low chromaticity for reflection and transmission at the same time.

Low Temperature Poly-Si on Flexible Polymer Substrates for Active Matrix Displays and Other Applications

A variety of polymer materials including polyimide (PI), polyarylate (PAR), polynorbonene (PNB) and polyethersulphone (PES) have been studied for use as substrates in the formation of active matrix displays based upon polycrystalline silicon (poly-Si) thin film transistors (TFTs). A process used to fabricate transflective mobile phone displays at 250°C on such substrates is described in detail. The NMOS TFTs show a mobility of 100cm 2 /Vs, and a threshold voltage of 3.9V; the PMOS devices have a mobility of 52cm 2 /Vs, and a threshold voltage of -6V. Issues relating to performance of these devices, yield of the arrays, and manufacturability are discussed.

LP-11: Late-News Poster: Novel Transflective LCD with Ultra-wide Viewing Angle

A novel transflective LCD with ultra-wide viewing angle has been developed. This display contains an in-cell patterned retarder with two different values of the birefringence in each pixel, which replaces the conventional external retarders. As a result this display is brighter, thinner and has lower power consumption and wider viewing angle than conventional transflective LCDs.

14.2: Technologies Towards Patterned Optical Foils

Thin retardation layers are developed. The thin films can be applied in- or outside the LCD cell by wet coating techniques. The cell thickness can be reduced considerably since carrier sheets, protective layers and adhesive layers are no longer a necessity. In addition, the optical properties can be patterned on subpixel level which improves the LCD on grey scale inversion, contrast and/or brightness depending on the display type. Photoalignment and thickness patterning are presented as technologies towards patterned optical foils.

Hybrid spatial‐temporal color synthesis and its applications

— A novel approach of synthesizing display color by hybrid color processing in both the spatial and temporal domains is introduced. The rational basis for this approach is found in vision science, and more particularly in the spatial and temporal characteristics of the human visual system. Various examples of the new approach, aiming at different display-performance objectives, are described. Hybrid spatial-temporal color synthesis can be used to generate a three-primary RGB display, the analysis of which reveals a higher spatial resolution and a lower fixed-pattern noise. The concept has also been used to build, based on a conventional LCD panel in combination with an adapted backlight system, a six-primary LCD TV with a 22% wider color gamut. Finally, the approach is demonstrated in a four-primary mobile LCD and results in lower cost combined with a higher display luminance and a wider color gamut.

46.1: Invited Paper: Novel Design for Full‐Color Electronic Paper

Despite a steep increase in commercial devices comprising paper-like displays, a much desired feature is still missing: bright full-color electronic paper. We have developed a new reflective display technology to solve this issue. for the first time we will report about the principles behind our in-plane electrophoretic technology, which enables the realization of full-color reflective displays with a higher brightness than all present e-paper technologies, without compromising paper-like properties like viewing angle and ultra-low power consumption. An additional major advantage (e.g. for future low-cost manufacturing) is that, besides direct-drive and active-matrix configurations, a passive-matrix option has been developed successfully.

Technologies towards patterned optical foils applied to transflective LCDs

— 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.

Next‐generation mobile LCDs with in‐cell retarders

In-cell retarders can be a major breakthrough for mobile LCDs. When a patterned in-cell retarder replaces the external retarders on transflective LCDs, brighter and thinner transflective LCDs with lower power consumption and wider viewing angle can be obtained. Additionally, when in-cell retarders are applied in reflective LCDs, the thickness of the LCD is considerably reduced without affecting the optical performance of the reflective LCD. This paper presents the technology needed to make in-cell retarders and the performance of reflective and transflective LCDs with in-cell retarders.