Stéphane Joly

Development of low anchoring strength liquid crystal mixtures for bistable nematic displays

Abstract The recent Bistable Nematic (BiNem®) LCD technology presents long term bistability, high level passive matrix multiplexing, gray levels capabilities and high optical quality. The BiNem® device, based on anchoring breaking, needs specific low anchoring strength materials – alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.

Demonstration of a technological prototype of an active-matrix BiNem liquid-crystal display

— The first implementation of active-matrix addressing on a BiNem bistable nematic liquid-crystal display has been demonstrated. Compared to previous passive-matrix addressing, major improvements have been made for the bistable mode: a smoother image refreshment, shorter refreshing frame time compatible with that of high-resolution e-book displays, the use of a touch screen for interactive functions such as hand-writing, a virtual keyboard, improved functionality for scrolling menus, partial refreshment, etc. On the same display but in the monostable mode, by using electrically controlled birefringence (ECB), the potential of displaying moving pictures at a rate of 25 images/sec, at an extended room temperature, has been demonstrated. In the ECB monostable mode, static images can be displayed down to −20°C. A new transflective single-polarizer optical mode has been developed to optimize the indoor and outdoor readability of the display. By lowering the surface reflection and enhancing the panel transmission, a contrast ratio of 94:1 and a transmittance of 17% have been achieved.

51.4L: Late‐News Paper: Development of 5.1‐inch High Speed SVGA Bistable BiNem® Display for Electronic Document Applications

A high speed 200 dpi passive matrix bistable SGVA display panel have been developed using BiNem® display technology. Images are addressed and displayed in 240 ms at ambient temperature. High fabrication yield and simple manufacturing process have been achieved by using newly developed, second generation BiNem® alignment material. The reflectance is 32 % and the contrast ratio 6.5: 1. The manufacturing uses 14 × 16 inch glass plates processed on commercial LCD manufacturing equipment.