Planar light source device and liquid crystal display apparatus

A planar light source device comprising:

• a first light source that emits a first light beam having directivity;
• a reflection member including a single bottom-plate part, an opening part facing the bottom-plate part, and side-plate parts delimiting a space between the bottom-plate part and the opening part so that the space has a columnar shape, wherein the side-plate parts are disposed on positions of respective sides of the bottom-plate part, the bottom-plate part and the side-plate parts having inner surfaces which are reflection surfaces, and
• a second light source that emits a second light beam having a divergence angle wider than that of the first light beam,
• wherein the opening part has a quadrilateral shape including two facing short sides and two facing long sides;
• the quadrilateral shape being formed by the side-plate parts,
• wherein the first light beam enters an inside of the reflection member through a side of a first side-plate part which is one of the side-plate parts disposed on positions of the short sides of the opening part, travels in a direction of the long sides while being reflected at second side-plate parts which are the side-plate parts disposed on positions of the long sides of the opening part, and is emitted through the opening part;
• wherein the reflection surface of the second side-plate part includes a region at which the first light beam is spectrally reflected and a region at which the first light beam is diffused and reflected, such that a density of a diffusion reflection material of the reflection surface of the second side-plate part increases in the traveling direction of the first light beam;
• and
• wherein the second light beam enters the inside of the reflection member through a side of the second side-plate part or a side of the bottom-plate part, and is emitted through the opening part.