LCI Research - Bistable Cholesteric LCs

Electronic Document Viewer Prototype
Principal Investigators - J.W. Doane, J.L. West, D.K. Yang

An electronic document viewer prototype display featuring a low-power, reflective display technology was invented in the ALCOM Center and developed further with the support of ARPA and an industrial partner, Kent Displays, Inc.

Using stabilized cholesteric liquid crystals, the display is the first of its kind with page-size, ultra-high resolution, bistable memory capabilities on a passive matrix (low cost) without need of a backlight. The technology is being developed for a lightweight, paper-like viewer for electronic newspapers, books, and document viewing. Software was provided by Knight-Ridder.
FEATURES
Specifications
Image size: 8 1/2" x 11"
Resolution: 100 dpi
Contrast: 20:1    Low Cost
No active matrix
No polarizers
No backlight    Applications
Documents
Electronic books
Electronic newspapers
Manuals and Maps

Plastic Displays
Principal Investigators - J.L. West

The Liquid Crystal Institute is a leader in the development of high resolution displays on plastic substrates. The figure shows one of the world's first plastic high-resolution displays.
The LCI's reflective display technologies are well-suited for low-cost plastic substrates since they do not require polarized light. Such developments are important for lightweight, paper-like displays for hand-held display applications.
One of the benefits of this technology is that it can utilize mylar, an easily available, inexpensive plastic. Mylar is more durable than previously used materials, making it a practical alternative to glass for use in large-size, portable displays.

MIM Active Matrix Display
Principal Investigator - J.W. Doane

ALCOM researchers have succeeded in producing a video-rate flat panel display based on a novel liquid crystal technology called reverse-mode PSCT (Polymer Stabilized Cholesteric Texture). The display does not require polarizers as do traditional liquid crystal displays. A picture element (pixel) is either transparent so that the background can be seen or scatters light as paper does.

Like conventional high-resolution liquid crystal displays, it requires active matrix addressing. Each pixel contains a MIM (metal insulator metal) element, replacing the transistor in conventional TFT displays.

Direct view
High brightness
No polarizers
No off-angle haze
No backlight
Projection
High transmission
Large collection angle
High contrast

The advantage of using the MIM elements is that they require less area, so that the actual pixels can be larger, contributing to brighter images. This technology can display information at the same speed as a computer monitor. One possible use is in “heads-up” displays in automobiles, where the car instrument panel is projected on the windshield.

Field-controlled Cholesteric Diffraction Grating
Principal Investigator - Oleg D. Lavrentovich

U=0 V,
planar texture    U=4 V,
modulated structure
(0.6-60 micron period)    U=6 V,
homeotropic texture
D.Subacius, S. Shiyanovskii, P. Bos and ODL, Appl.Phys.Lett. 71, 1350 and 3323 (1997)

S. Shiyanovskii, D. Voloschenko, ODL, Proc. SPIE 3475, 56 (1998)

ODL, S. Shiyanovskii, D. Voloschenko, Proc. SPIE 3787, 149 (1999)
Diffraction
pattern on a screen    Large-angle
Beam Steering

LCI Home Page ALCOM Home Page LCI Research ALCOM Research Projects

Text Only Options