| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sheet which is arranged in front of an observation side of a back projection type television, liquid crystal display, etc., and has a high contrast and superior directivity and a back projection screen which has the sheet. <P>SOLUTION: The contrast improvement sheet 11 has a 1st optical element 1 and a 2nd optical element 2 which is arranged further on an observation side of the 1st optical element; and the optical element 1 is constituted by arraying a plurality of ribs 3, having total reflecting surfaces 5 totally reflecting video light 4 incident vertically or nearly vertically from a back side, in one direction or in plane, forming flat surfaces 6 between the opposite total reflecting surfaces 5 of the ribs 3, and forming light absorbing layers 7 between the ribs 3, and the 2nd optical element 2, on the other hand, is constituted by forming optical path correction layers 9 where oblique surfaces 8, projecting the video light 4 totally reflected by the total reflecting surfaces 5 of the ribs are formed zigzag. <P>COPYRIGHT: (C)2004,JPO |
