Patent ID: 7621665

Claim:
A light source device comprising: a light source; a light guiding member having an exit surface, wherein a reference plane is substantially parallel to the exit surface of the light guiding member, and wherein the light guiding member receives light from the light source and emits in a first direction which forms a first angle with respect to the reference plane, wherein the first direction is different from a direction in which light is emitted from the light source; an optical member which receives light emitted from the light guiding member and emits light in a second direction which forms a second angle, different from the first angle, with respect to the reference plane; a light-direction regulating element, which receives light emitted from the optical member, for regulating a direction of emitted light; and a transparent/scattering state switching element, which receives light emitted from the light-direction regulating element, capable of switching between a state of transmitting light without scattering, and a state of scattering light; wherein the light source is disposed along a light-incident surface of the light guiding member; the optical member comprises a plurality of optical elements having a projection shape and two-dimensionally arranged in a plurality of rows and columns on a light-incident surface thereof, the plurality of optical elements pointing toward the light guiding member; and the optical member totally reflecting light that has been emitted from the light guiding member, entered the optical elements, and reached side surfaces of the optical elements, and emitting the light; thus light that has been transmitted through the optical member has a directivity that is increased in two perpendicular directions in the reference plane.