| 摘要 |
PURPOSE: To brighten a projection picture seen on a screen surface by providing a TN liquid crystal display device with an incidence side polarizing plate, a TN liquid crystal panel, and a polarizing plate for image formation and projecting a display picture on a back projection type screen. CONSTITUTION: Incident light from a light source 9 passes a light source side mirror 10, and light in a prescribed oscillating direction is transmitted by an incidence side polarizing plate 7 and is made incident on a TN panel 6. The polarizing plate 7 and a polarizing plate 8 for image formation are so arranged that directions of axes of light transmission are parallel or perpendicular, and liquid crystal of the panel 6 is twisted based on these axes of light transmission. Then, a normally black or white picture is projected on a liquid crystal display device 5. Next, exit light of the polarizing plate 8 is led to a projection lens 4 through refracting optical path. The lens 4 expands incident light to project it on a back projection type screen 2, and the image is formed by a renticular lens 3. When the lens 3 is so arranged that the surface reflection factor of oscillation in the breadthwise direction of the lens 3 is minimized, the projection picture on the screen is made bright. |
