Patent ID: 7821611
Filing Date: 2010-10-26
Classification: G02B,G02F

Abstract:
1. A light source device comprising: a planar light source for emitting light in a plane; and a transparent/scattering state switching element capable of switching between a state for transmitting light emitted from the planar light source, and a state for scattering the light; wherein: said transparent/scattering state switching element comprises: the luminance of light that has passed through the region in which the seal member is disposed in the transparent/scattering state switching element is lower than before the light passed through this region; and a frontal luminance of light that has passed through the region in which the seal member is disposed is not greater than a frontal luminance of light that has passed through the transparent/scattering state switching layer in the scattering state, wherein said transparent/scattering state switching element has a light-shielding layer for blocking light; and wherein a cross-sectional area of said light-shielding layer is the same as a cross-sectional area of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.