title: Homogenized LED-illumination using microlens arrays for a pocket-sized projector.
abstract: We present an LED-based ultra-mini DMD projector with a size of 75 mm x 67 mm x 42 mm. A compact homogenizer consisting of a double-side microlens array and two condensers was proposed to reduce the size of the pocket-sized projector. The homogenizer not only allowed for a reduction in the total track length of the system, but also reduced the angle of the rays emitted from the LED with the micro field lens array. The double-side well-aligned 124 x 146 microlens array was fabricated using backside alignment and hot embossing techniques. The microlens array was square-arranged and the fill-factor was extremely high. The uniformity and total throughput of this projector were higher than those of the current pocket-sized projectors. Moreover, the optical performances of the projector such as color difference and the LED alignment tolerance were also measured and discussed.
authors: Jui-Wen
authors: JW
authors: Pan
authors: Chih-Ming
authors: CM
authors: Wang
authors: Hsiao-Chin
authors: HC
authors: Lan
authors: Wen-Shin
authors: WS
authors: Sun
authors: Jenq-Yang
authors: JY
authors: Chang