Optical design tools for backlight displays

Paul Boughton

Backlights are used for compact, portable electronic devices with flat panel liquid crystal displays (LCDs) that require illumination from behind.

Applications include devices as small as hand-held palm pilots and as large as big-screen TVs. Goals for backlight design include low power consumption, large area with small thickness, high brightness, uniform luminance and controlled viewing angle, either wide or narrow.
To achieve these challenging design goals with a cost effective and timely solution, it is necessary to use computer-aided optical design tools to expedite the design. Optical Research Associates' LightTools illumination design and analysis software is leading the way in enabling state-of-the-art backlight designs.
LightTools models the surface textures used for backlights, with built-in flexibility to vary the shape, size, and spacing of the texture elements. Optical properties can be defined for every surface, and every solid object can have bulk optical properties, such as absorption and volume scattering. Both CCFL and LED sources can be used, and a library of over 300LED models is provided.
LightTools includes a backlight utility that automates the setup of the common elements of a backlight system, allowing you to perform rapid tradeoff studies of different approaches. Detailed illumination analysis can be done using Monte Carlo ray tracing with many special enhancements. All of these features dramatically reduce the design cycle time for new backlight development.

Optical Research Associates is based in Pasadena, CA, USA. " target="_blank">www.opticalres.com