Yong-kweun Mun

Laser TV for home theater

The laser TV using blue, green diode-pumped solid state lasers and a red diode laser is developed. The wavelengths of the blue, green and red are 457 nm, 532 nm and 648 nm, and the output powers are 350 mW, 700 mW and 500 mW, respectively. The power levels of lasers are adjusted for white color balance. The polygon mirror and the galvanometer are used for horizontal scanning and vertical scanning, respectively. The image size of 80 inches with high-brightness and VGA resolution (640 X 480 Progressive scanning) is obtained. The acousto-optic modulator (AOM) is fabricated for laser beam modulation, for which the carrier frequency of 350 MHz for XGA resolution is applied. TeO2 crystal, which is cut at Brewster angle, is used as an optical medium and LiNbO3 is attached as a transducer. In order to get a compact size, low cost, low-power consumption and lightweight, a scanning mirror using MEMS technology is fabricated by the size of 1500 micrometers X 1200 micrometers . This scanning mirror can be used as a galvanometric vertical scanner for laser TV.

Laser Graphic Video Display using Silicon Scanning Mirrors with Vertical Comb Fingers

We acquired a two-dimensional (2D) laser vector graphic video image using 1500 µm×1200 µm silicon scanning mirrors with vertical comb fingers. Vector image signals from the graphic board were applied to two scanning mirrors, and a SHG green laser was directly modulated to shape independent graphic images. These scanning mirrors were originally designed for laser raster video display as a galvanometric vertical scanner, and are controlled perfectly by the ramp waveform of 60 Hz with the duty cycle of 90%.