| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical diffusion sheet with high light diffusibility, with wide angle of visibility and high total transmittance of light rays and further with high scratch resistance even when used in an overlapped state and with excellent easiness for handling and to provide a backlight unit using the same. SOLUTION: The optical diffusion sheet 1 is provided with an opening part 4 on which polygonal concave lens parts 3 having polygonal shapes and curved in recession are tightly formed with no space between themselves. |
