Key parameters for any bistable device are operating voltage and temperature range. The development of liquid crystal mixtures for use with grating aligned Zenithal Bistable Displays (ZBD™) is described for the first time. Latching at voltages less than 5V, with 20V addressing faster than 80μs per line and operation over a temperature range from −20°C to 80°C are all demonstrated in the same 4μm device.

Abstract— Zenithal bistable devices (ZBD™) exhibit rugged image storage, excellent optical performance, fast latching, and infinite multiplexibility. The excellent performance characteristics are achieved using a surface‐relief grating to align the nernatic liquid crystal. Such gratings offer a high degree of design flexibility, at manufacturing costs equivalent to today's STN displays. In the present work, the grating shape is varied within each pixel to produce several separate latching thresholds, thereby introducing error‐free analog gray scales. Passive‐matrix waveforms, suitable for use with commercial STN drivers, are reported and shown to discriminate between at least seven error‐free grays in a test cell. The combination of analog and digital grays was considered. Careful selection of the digital dither weighting factors allows for a large total number of grays to be achieved, while reducing the effect of errors if all of the analog levels are not achieved.

A 7" diagonal 200dpi resolution, ultra low power Zenithal Bistable LCD ideal for portable applications is demonstrated for the first time. The lightweight module exhibits the same high contrast, wide viewing angle and rugged bistability shown previously but the design gives high quality text and graphics using conventional STN drivers.

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Grating aligned zenithal bistable LCDs offer a low cost route to ultra‐low power displays with excellent appearance. The flexibility of the grating design and embossing fabrication method allows each pixel to have several latching thresholds without extra fabrication cost. Combining this approach with a novel addressing method allows each row driver to address several lines of information. For example, this technique allows high numbers of greys to be addressed using digitally weighted spatial dither, but without the extra‐cost of additional electronic drivers.