| 摘要 |
A transmission type projection screen comprises a plurality of sheets. The front sheet nearest to the front observation side is an ambient light attenuating front sheet (10; 10A; 10B) which is provided on its surface facing the rear side with first prism lenses (11; 18) formed by successively and horizontally arranging unit triangular prisms (11a; 18a). Each unit triangular prism has a sharply inclined surface (13; 20) inclined at an angle of about 90 DEG to the surface of the front sheet, and a gently inclined surface inclined at an angle in the range of 5 DEG to 40 DEG to the surface of the front sheet. The first prism lenses are disposed with the gently inclined surfaces of the unit triangular prisms thereof facing upward. Second prism lenses (14) may be provided on its surface facing the front observation side, each of the second prism lenses (14) also having a sharply inclined surface (16) and a gently inclined surface (15). <IMAGE> |
