Enhancement of the Optical Performances for the LED Backlight Systems with a Novel Dual Lens-Cap


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A novel dual-cone-shaped side-emitting lens cap for High Brightness Light Emitting Diodes (HB-LEDs) is proposed for improving brightness and high uniformity of the direct LED backlight Units (BLUs) for large-sized LCD-TVs. Combining the designed lens cap with red, green and blue (RGB) chips on a Metal Core Printed Circuit Board (MCPCB), the LED module with the proposed cap is able to provide a compact white light source with unique features such as instant color variability and lower power usage, etc. The dual-cone-shaped of the proposed lens cap is designed to emit most of the light rays to the sides, only a small portion of light upward along the optical axis of the lens, providing a uniform luminance distribution and the high brightness on the backlight. In addition, a small reflective surface in semi-circular shape is designed and placed upon the proposed LED module about 10mm, the surfaces of which are attached with reflective films to increase the level of light mixing in the larger, global reflector optical box. With the structure of the LED module well designed, the LED backlight Module would be designed for the large-sized LCDTV using the fewer number of LEDs to lead to lower power consumption. The results indeed identify the attributes of the BLU, which make it possible to achieve excellent backlight performance using a direct illumination approach from the light source of “Dual-Cone-Shaped Side- Emitting Lens Cap of LEDs.”



Key Engineering Materials (Volumes 364-366)

Edited by:

Guo Fan JIN, Wing Bun LEE, Chi Fai CHEUNG and Suet TO




P. C.P. Chao et al., "Enhancement of the Optical Performances for the LED Backlight Systems with a Novel Dual Lens-Cap", Key Engineering Materials, Vols. 364-366, pp. 132-137, 2008

Online since:

December 2007




[1] Shirley and N. George, Diffuser radiation patterns over a large dynamic range. 1: Strongdiffusers, Appl. Opt. 27, 1850 (1988).

[2] Robert Scott West, Huub Konijn, Willem Sillevis Smith, Simon Kuppens, Nicola Pfeffer, Yourii Martynov, Takaaki Yagi, Stefan Eberle, Gerard Harbers, Tien Wei Tan, Choon Earn Chan, High Brightness Direct LED Backlight for LCD-TV, SID Intl Symp. Digest Tech Papers BooK II, pp.1262-1265(2003).

DOI: 10.1889/1.1832516

[3] G. Harbers and C.G.A. Hoelen, High Performance LCD Backlighting using High Intensity Red, Green and Blue Light Emitting Diodes, SID Digest Tech Papers 702-706 (2001).

DOI: 10.1889/1.1831960

[4] D. Schertler and N. George, Uniform Scattering Patterns from Grating Diffuser Cascades for Display Applications, Appl. Opt. 38, 291-303 (1999).

DOI: 10.1364/ao.38.000291

[5] TracePro Reference Manual, Lambda Research Corporation , 80 Taylor Street, P.O. Box 1400, Littleton, MA. USA, http: /www. lambdares. com.

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