US Patent 9638852 Point light source, planar light source device, and display device

An envelope of a point light source includes first to fourth surfaces. The first surface protrudes ahead of a light-emitting element and extends to a left side and a right side of the light-emitting element when viewed from the light-emitting element. The second surface is connected to the first surface on the left side and the right side of the light-emitting element and is in contact with the light-emitting element. The third surface is connected to an upper end of the first surface and an upper end of the second surface and forms a first depression that sinks from the first surface toward the second surface. The fourth surface is connected to a lower end of the first surface and a lower end of the second surface and forms a second depression that sinks from the first surface toward the second surface.