| 摘要 |
PURPOSE:To provide inconspicuousness of the rough feel by stopping down by disposing microlenses on a focal plate in such a manner that randomness is slightly provided near a periodic structure as a premise with regard to the disposition of said lenses on the focal plate. CONSTITUTION:Microlens-shaped curved surfaces having nearly the same shapes are two-dimensionally disposed diffusion plates. The average pitch P of the microlenses is 8mu approx.<P approx.<30mu. The central coordinates X, Y of the microlenses are determined from the average pitch P and the sets I, J of integers. Said coordinates are determined with the fluctuations within a prescribed distance range with respect to the periodic grating points X', Y' expressed by equations I, II. This prescribed distance range is limited in the range of width KXP centering at the periodic grating points by using the constant K which is 0.1 approx.<K approx.<0.4.
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