John Christopher Rudin

Bright color reflective displays with interlayer reflectors

A good solution to the reflective display of color has been a major challenge for the display industry, with very limited color gamuts demonstrated to date. Conventional side-by-side red, green and blue color filters waste two-thirds of incident light. The alternative of stacking cyan, magenta and yellow layers is also challenging--a 10% loss per layer compounds to nearly 50% overall. Here we demonstrate an architecture that interleaves absorbing-to-clear shutters with matched wavelength selective reflectors. This increases color gamut by reducing losses and more cleanly separating the color channels, and gives much wider choice of electro-optic colorants.

43.2: Colour Plastic Bistable Nematic Display Fabricated by Imprint and Inkjet Technology

Plastic displays require new manufacturing processes and techniques to achieve acceptable cost and performance. We present a novel additive, low temperature, atmospheric pressure, self-aligned means of fabricating a plastic, bistable, full colour LC display. By using imprinting rather than photolithographic patterning, a scalable, low cost manufacturing route is possible.

Color plastic bistable nematic display fabricated by imprint and ink-jet technology

— Plastic displays require new manufacturing processes and techniques to achieve acceptable cost and performance. A novel additive, low-temperature atmospheric-pressure self-aligned means of fabricating integrated plastic substrates for full-color LCDs and a bistable LC mode based on microstructure alignment are presented. By using imprinting rather than photolithographic patterning, a scalable, low-cost manufacturing route is possible. A 2-in.-diagonal 128 × 128-pixel display was made to demonstrate the principles involved, which has retained an image for in excess of 2 years.

67.3: Electrophoretically Controlled Nematic LCD: Plastic Bistable Technology with Memorized Intrinsic Grey Scale

Here is presented a nematic LCD based on an electrophoretically controlled orientational effect in suspension of solid nanoparticles in nematic liquid crystal: electrophoretically controlled nematic (EPCN). Polarity controlled electromigration of the nanoparticles, results in the stabilization of the molecular alignment and provides the bistable/multistable switching in a conventional nematic LC cell. The EPCN display allows multiplexing with intrinsic grey scale capability, high resolution and contrast, uses standard LCD materials and techniques and is easily producible by plastic technology.

32-channel arbitrary waveform generator for bistable nematic devices

All commercially available liquid crystal nematic displays use cells with strong surface anchoring conditions and under field bulk monostable texture distortions. About ten years ago, a technological research line started to study liquid crystal nematic displays with intrinsic bistable textures. It implies pixels with two distinct stable states in the absence of field, but electrically switchable. Bistability allows infinite multiplexing for passive matrix displays: It suppresses the need of refreshing permanent informations. At present, commercial active matrix displays behave like bistable displays by means of electronic elements (TFT or diodes), one for each pixel. This is not an intrinsic bistability, because it is due to external active devices placed on the screen surface. The aim of the present research is to design a suitable and flexible experimental setup to create addressing waveforms for passive electro-optical intrinsically bistable devices.

An Auto-Aligning Photopolarimeter

A new auto-aligning photopolarimeter, that will be used to probe a liquid crystal (LC) cell, is described. As the LC cell is rotated, it steers the probing laser beam and the photopolarimeter head must be re-aligned to allow for this. To efficiently collect data this re-alignment must be done automatically. We show that using a quadrant photodetector (QD) and a two dimensional duo-lateral position sensing detector (PSD) it is possible to dynamically re-align the head. Also we introduce a new method to calibrate this auto-aligning system. We can collect data from points distributed over the Poincairé sphere and then use all of these to find the instrument matrix M c that minimizes the error (in the least squares sense).