| 摘要 |
PURPOSE:To obtain the illuminating device which is a thin type and has high brightness and high quality, such as uniformity, by constituting the illuminating device in such a manner that the direction of the lines of linear patterns and the direction of the ridge lines of a prism structure are approximately perpendicular to each other. CONSTITUTION:A transparent plate 1 is a transparent plate which is approximately rectangular and has a specified thickness. At least its light exit surface 2 and counter light exit surface 3, more preferably all the surfaces are constituted of mirror finished surface. The plane side of a prism sheet 7 having the prism structure is disposed toward the light exit surface 2 of the transparent plate 1, by which the illuminating device is provided with the effect of admitting the rays emitted from the light exit surface 2 into the prism sheet 7 from its plane side and refracting the rays emitted from the prism surface to the direction distributing the many rays perpendicularly to the light exit surface 2. Then, the brightness is increased by the effect of such prism sheet 7. The direction of fine line-shaped diffusion systems 5 and the direction of the ridge lines of the prism sheet 7 are disposed approximately perpendicularly, the angles of the refracted light emitted from the prism sheet 7 are continuous and the uniform illumination having the high brightness is obtd. without generating dark parts and bright parts. |
