Patent ID: 7695165
Filing Date: 2010-04-13
Classification: G02B,G02F

Abstract:
1. An optical plate comprising: at least one transparent plate unit having: a first surface; a second surface opposite to the first surface; a plurality of elongated V-shaped protrusions formed on the first surface; a plurality of stacked conical frustum protrusions formed on the second surface; and at least a lamp-receiving portion defined in at least one of the first surface and the second surface, wherein each stacked conical frustum protrusion has a first conical frustum protrusion and a second conical frustum protrusion, the second conical frustum protrusion positioned on top of the first conical frustum protrusion, an inclined angle defined by a conical surface of the first conical protrusion relative to its base surface is equal to or smaller than an inclined angle defined by a conical surface of the second conical protrusion relative to its base surface.