Color sequential silicon microdisplay for three-dimensional virtual reality applications

We have developed a highly integrated liquid-crystal-on-silicon microdispla y for virtual reality applications. The silicon panel of 704 x 576 pixels w as designed and fabricated by a custom 0.35 mum complementary metal oxide s emiconductor (CMOS) technology with emphasis on surface planarization. Topo graphic variation of less than 100 Angstrom within the pixels was achieved. The pixel pitch was 9.6 mum, fill factor was 88% and display area was 0.36 " in diagonal. Eight-bit digital data drivers and gamma-correction circuit ry were integrated onto the silicon panel for true gray scale and full colo r representation. The display panel was assembled with a mixed twisted nema tic and birefringence liquid crystal cell for high contract at CMOS compati ble voltage. Chromatic characterization of the display using 3-color-in-1 l ight emitting diode (LED) as light source was performed. Contrast ratios on the pixel array were 95, 72 and 56, respectively, for red, green and blue colors at 3V root-mean-squared voltage. In addition, a three-dimensional (3 D) video stream in interlaced format was generated by a 3D modeling code fo r test and demonstration. Control logic was implemented to extract the left and right video frames and perform system timing synchronization. The sili con microdispray was driven in frame inversion and by color sequence. With two sets of silicon microdisplays and eyepieces for each eye, we have demon strated a 3D stereoscopic display based on the silicon microdisplay technol ogy.