Abstract: In the side light system of the spread illuminating apparatus in which a bar-like light source is disposed close to one side of the transparent substrate made of a transparent material, on the other end 17 of the light conductive member 13 where the spot-like light source 12 is not disposed, the light reflection means 26 is provided. From one end 14 of the light conductive member 13 the light L1 emitted from the spot-like light source 12 enters the light conductive member. The emitted light L1 is reflected by the groove 20 of the optical path conversion means 15 and discharged from the surface 18 of the light conductive member 13 opposing to the transparent substrate. Further one part L2 of the emitted light from the spot-like light source 12 is reflected by the light reflection means 26 and progresses again in the light conductive member 13 toward the spot-like light source 12.

Abstract: The light dispersion portion is formed with the grooves having an identical depth D, and the spacing P between the light dispersions 15 is set 0.01 mm minimum and 0.2 mm maximum. In order to prevent the stripe pattern of brightness and darkness generated due to the light reflection at the light dispersion portion 15, it is preferable to make the spacing as small as possible. However, too small spacing makes it difficult to ensure workability. Accordingly, the minimum value of spacing is set 0.01 mm in view of workability. And, the maximum value of spacing is set 0.2 mm, which does not allow visual recognition of the stripe of brightness and darkness.