LIGHTGUIDE

摘要

A lightguide (3) which guides a light from at least one side end plane. A number of approximately trapezoidal protruding patterns whose apices in the cross sections perpendicular to the axis of a linear light sources have straight parts partially are arranged in patterns of specks, solid lines or broken lines on a rear surface which is opposite to a light emitting surface at a low density in a region close to the linear light source and at a high density in a region far from the linear light source so as to make the luminance distribution of the light emitted from the light emitting surface approximately uniform. It is recommended that the protruding pattern has an approximately trapezoidal shape having two round corners corresponding to both the edges of the apex in a cross section perpendicular to the axis of the linear light source, both the surface roughness of parts of which the apices of the protruding patterns are composed and the surface roughness of the parts in the protruding pattern forming surface where the protruding patterns are not formed are not larger than 0.2 /m respectively, the ratio H/W satisfies the relation, 0.1