Patent ID: 7438429

Claim:
A planar lighting device, comprising: rod type light sources; a light guide plate comprising light guide plate blocks that are arranged side by side and each of which is formed of an integral assembly of at least two tabular light guide plate units each having a rear surface with a groove formed to accommodate a rod type light source and a light exit surface that is away from said rear surface and which is for emitting the light from said rod type light source; and a transmittance adjuster unit that is provided on a side closer to said light exit surface of said light guide plate, which diffuses the light emitted from said light exit surface of said light guide plate and emits the thus diffused light and which has a sheet type optical member capable of transmitting light and transmittance adjusters provided on at least one surface of said sheet type optical member, wherein said transmittance adjusters in said transmittance adjuster unit at a position corresponding to a seam between adjacent light guide plate blocks are distributed at a different density than said transmittance adjusters in said transmittance adjuster unit at a position corresponding to a joint between adjacent light guide plate units.