| 摘要 |
<p>A sidelight type surface light source apparatus provided with a primary light source, a reflection sheet, a light scattering/transmitting sheet, a light guide plate, and a prism sheet functioning as a light control member. The light scattering/transmitting sheet is given a scattering power by roughening both its surfaces and incorporating fine particles therein. Light leaking from the back of the light scattering guide plate is reflected by the reflection sheet back to the light guide plate, during which time it is scattered by the light scattering/transmitting sheet. The reflection sheet is a specular reflection member with a high reflectance. The light radiated from a fluorescent lamp (7) is introduced into the light guide plate, where it is repetitively reflected between the back surface and the outgoing surface of the light guide plate as it propagates. In the meantime, the components of light at angles smaller than the critical angle to the outgoing surface are sent out of the outgoing surface. The repetitively formed raised portions (indicated by arrows B and C) on the back surface of the light guide plate and on the prism sheet correct the directivity in the planes parallel to and perpendicular to the incident surface of the light guide plate toward the front surface. The light scattering/transmitting sheet may be omitted and the reflection sheet may be provided with the light scattering power. The scattering near the back surface of the light guide plate prevents the formation of interference fringes.</p> |
