| 摘要 |
PROBLEM TO BE SOLVED: To provide a light diffusion sheet which causes no light and shade stripe and has a high uniformity ratio of luminance by changing arrangement of quadrilateral pyramid shaped protrusions and inverted quadrilateral pyramid shaped recessions and so on formed on the upper surface of the sheet for the specified region-by-region. SOLUTION: The light diffusion sheet S1 is placed above a plurality of linear light sources L arranged in parallel to one another. Inverted quadrilateral pyramid shaped or inverted truncated quadrilateral pyramid shaped recessions 1, or quadrilateral pyramid shaped or truncated quadrilateral pyramid shaped protrusions 2 are formed on above-light source regions A1 in an upper surface of the sheet so as to be aligned in rows and columns, and at the same time, the recessions 1 or the protrusions 2 are formed on between-light source regions A2 in an upper surface of the sheet so as to be aligned in oblique lines. The uniformity ratio of luminance is heightened by emitting light to the upper side of the linear light source L via inclined planes 10a or 20a of which the upper edges or bases are normal to the longitudinal direction of the linear light source L, out of four inclined planes of the recession 1 or the protrusion 2 of the above-light source region A1, and heightening luminance of the above-light source region A1 to the same level as that of the between-light source region A2. COPYRIGHT: (C)2007,JPO&INPIT
|
