| 摘要 |
PURPOSE:To reduce moire disturbance by adding a vertical lenticular lens which diffuses light vertically, setting the pictch of a Fresnel lens to <=150% of the length converted equivalent of the half-value angle of a diffusing element, and increasing the product of a gain and the half-value angle. CONSTITUTION:A screen 1 consists of a Fresnel sheet 4 and a front sheet 5; and the Fresnel sheet 4 has a concentric lenticular lens 8 formed at its projection surface side and a vertical lenticular lens 8 which diffuses light vertically at the incidence surface side and the front sheet 5 has a horizontal lenticular lens on the incidence surface and is provided with a longitudinal stripe type horizontal lenticular lens 9 with fine pitch on the projection surface side. Consequently, the light utilization rate of an image projecting device is improved by about >=1.4 time in terms of the product of the gain and half-value angle and a beautiful image is therefore formed with small power consumption.
|
