Patent ID: 6049649
Filing Date: 2000-04-11
Classification: G02B

Abstract:
A surface light source device of side-light type, comprising:a light guide plate with emitting directivity;a light supply means disposed along a side end surface of said light guide plate;a propagation direction characteristics modifier disposed along an emitting surface of said light guide plate; anda reflection pattern means for controlling light incident on said propagation direction characteristics modifier;wherein said propagation direction characteristics modifier includes one-dimensional array of a large number of projection elements each having a distal end provided with a flat region serving as an input surface substantially parallel to said emitting surface;at least a part of a side portion of each projection element has a reflective deflection surface having a function of deflection to a frontal direction based on reflection including the total reflection; andsaid reflection pattern means includes reflection portions formed in a distributed state so as to restrain a flux outputted with directivity from the emitting surface of said light guide plate from being incident on portions other than the flat regions of said projection elements.