Patent ID: 8368639
Filing Date: 2013-02-05
Classification: G02F

Abstract:
1. A planar light source device comprising: a light source unit for emitting light in a plane; a transparent/scattering state switching element capable of switching between a transparent state for transmitting the light incident from the light source unit, and a scattering state for scattering the light; and a control unit for controlling an intensity of said light source unit and a state of said transparent/scattering state switching element; wherein said control unit controls the intensity of said light source unit to be a first light intensity when said transparent/scattering state switching element is in said transparent state, controls the intensity of said light source unit to be a second light intensity, that is higher than the first light intensity, when said transparent/scattering state switching element is in said scattering state, and controls the intensity of said light source unit to be lower than the first light intensity and the second light intensity during a transition in which said transparent/scattering state switching element is transferred from said transparent state to said scattering state.