New type of LCD projector with separately processed low-frequency chrominance and wideband luminance signals

We have developed an LCD projector based on a new concept utilizing human vision characteristics. It is known that human vision has high spatial resolution for monochrome images and low spatial resolution for color images. The new projector generates a wide-band frequency luminance signal, and low-frequency color signals from input signals. The present system uses an LCD panel of high definition for high resolution luminance image and three panels of low definition for low resolution color image. Use of low definition LCD panels, which are available at low cost, permits reduction in the cost of the system. In the developed projector, all the LCD panels have 640 X 480 pixels, but the number of pixels is electrically limited to 320 X 480 for the color panel. Light from a lamp is split by a polarizing beam splitter into two linearly polarized beams, one of which irradiates the luminance panel and the other of which irradiates the color panels, and thus both the polarized beams are utilized unlike conventional projectors where only one polarized component is utilized and the other component is lost away as heat. The projected NTSC (National Television System Committee) images were substantially of the same quality as the images which are obtained using three panels of 640 X 480 pixels. The projected VGA images had a picture quality sufficient for presentations at conferences.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.