| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a diffusion plate capable of emitting light brightly, uniformly and evenly over the whole surface independent of arrangement and shape of a light source, and capable of removing lamp irregularity. <P>SOLUTION: A plurality of elliptic cylinder lenses 7 of the same shape of which each cross-section takes the form of a part of an ellipse are arranged side by side on one side surface such that the major axis of the ellipse orthogonally crosses the face 8, wherein elliptical rate (major diameter/minor diameter) b/a of the ellipse and angle θ of a valley part formed by neighboring elliptic cylinder lenses 7 fall into the following ranges. The ranges are respectively 1.5≤b/a and 0°<θ≤70°. <P>COPYRIGHT: (C)2009,JPO&INPIT |
