| 摘要 |
<P>PROBLEM TO BE SOLVED: To output incident light efficiently onto a front face of a light guide plate, and restrain the occurrence of bright lines without using a prism sheet, even with the use of a point light source. <P>SOLUTION: A plurality of grooves 19 constituting a natural lighting face 19a reflecting the incident light from the point light source 15 to the light guide plate 14 toward an irradiation face 18 are formed in parallel. The grooves are formed so that the natural lighting face 19 rising and slanting toward an opposite face 14b side from the incident face 14a side and a light guide face 19b sinking and slanting are alternately continued. The natural lighting face 19c totally reflects the light incident from the incident face 14a and reaching the natural lighting face 19a toward a direction of the irradiation face 18 at nearly right angles with a virtual plane 21 in contact with a tiptop of each protruded lines formed on the irradiation face 18. A plurality of the lens-like protruded lines 20 are provided so as to be extended in a direction crossing a direction to which the natural lighting face is extended. The surface of each protruded line 20 is formed in a shape in which convex curved surfaces are continued toward a rear face of the light guide plate 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
