| 摘要 |
PURPOSE:To constitute the device of high brightness and high contrast by optimizing the optical system of a projection display device using a transmission- scattering mode liquid crystal light bulb. CONSTITUTION:The light source 10 of the projection display device irradiates the transmission-scattering mode liquid crystal light bulb 3 with a luminous flux for illumination 21 as a parallel luminous flux. In the luminous flux transmitting the light bulb, undesired scattered light is removed by a light transmission tube 30, and only the parallel luminous flux effectively contributing to the formation of a picture, can be obtained. The luminous flux 22 transmitting the light transmission tube 30 is efficiently made incident on the entrance pupil of a projection lens 6 by a lens 4, and turned into projection light 26, to form a magnified picture on a screen 7, and obtain a large screen video. The contrast of the projection display device is determined by an angle (angle for fetching) at which the light transmission tube 3 fetches the scattered light, and the luminous intensity distribution characteristic of the liquid crystal light bulb 3, and the angle for fetching the scattered light are optimally designed, so that the display device of the high brightness and high contrast can be realized. |
