LIGHT DIFFUSING DEVICE FOR BACK LIGHT

PROBLEM TO BE SOLVED: To provide a light diffusing device for back light, a device capable of suppressing generation of moire or diffraction interference fringes by devising and applying algorithm that concretely decides the extent of nonuniformity of grooves or ridges. SOLUTION: The light diffusing device for back light is arranged along a liquid crystal display panel face and formed with grooves or ridges on the surface. In this device, assuming that n is an arbitrary one groove or ridge, that n+1 is a groove or a ridge adjacent to n for which the position is strictly determined by a suitably prescribed procedure, that P(n) is the pitch interval size of the grooves or the ridges of n and n+1, and that ΔP(n) is a fluctuation based on a divisor calculated with the maximum absolute value of a deviation from the size determined by the procedure as a denominator, and with the individual deviation in each groove or ridge as a numerator; the fluctuation ΔP(n+1) of the pitch interval P(n+1) from the groove or ridge n to the next groove or ridge n+1 is determined by ΔP(n+1)=kΔPn(1-ΔPn), and also the constant k is ≥3.56 and ≤4. COPYRIGHT: (C)2005,JPO&NCIPI