| 摘要 |
<p>A large flat-display on a screen 48 is provided by projection, using reflection or transmission, e.g. by lens 47, from a liquid crystal display cell 46, possibly in series in the beam with a controlled colour or grey filter 44 comprising multiple liquid crystal elements associated with coloured or grey filter elements. Three beams in different colours from separate sources may be projected on to the same screen to provide a coloured display. Frequency modulation provides convenient control of the display intensity. <IMAGE></p> |
