| 摘要 |
An electric signboard (10) has a recessed and projecting structure provided on the surface of a light-guide plate (35) that faces an opaque white semi-transparent plate (15) or on the surface of the opaque white semi-transparent plate (15) that faces the light-guide plate (35), or, alternatively, a lens sheet (14) having a recessed and projecting structure on at least one surface thereof is further provided between the light-guide plate (35) and the opaque white semi-transparent plate (15). Thus, uneven luminance in a light source device comprising a light source, a light-guide plate and a diffusion plate is suppressed. |
