[OPTICAL REVIEW Vol. 16, No. 3 (2009) 323-325]
© 2009 The Optical Society of Japan

Nonspherical LED Packaging Lens for Uniformity Improvement

Yu-Cheng CHANG1*, Chung-Jen OU2, Yu-Sheng TSAI1, and Fuh-Shyang JUANG1

1Institute of Electro-Optical and Materials Science, National Formosa University, Huwei Township, Yunlin County 632, Taiwan
2Department of Electrical Engineering, Hsiuping Institute of Technology, Dali City, Taichung County 412, Taiwan

(Received June 17, 2008; Accepted March 13, 2009)

Light emitting diode (LED) has more advantages compared with a traditional incandescent light bulb and a fluorescent lamp, such as small size, low quantity of heat, long life, low power consumption, fast response, plain packaging and ease of develop ment of a frivolous short product. A methodology is proposed to improve the uniformity of the LED illumination system. As a light source in a backlight unit (BLU), the requirement for optical characteristics of a LED is different from highly directional conventional ones. New diffused-type LEDs need to be developed to fulfill the requirement of the BLU industry. A non-spherical lens is designed to optimize uniformity, and a great improvement in uniformity from 28.4 to 64% is demonstrated. In the future, it may used in an LED display to improve the unevenness of illumination.

Key words: light emitting diode, lens design, simulation, LED lens, uniformity

*E-mail address: r2498@ms53.hinet.net