Patent attributes
A diffractive light guide plate including a light guide unit; an input diffractive optical element that receives lights output from a light source and diffracts the received lights to be guided on the light guide unit; and two output diffractive optical elements disposed in a predetermined region of the light guide unit and having different linear grating patterns from each other, wherein the two output diffractive optical elements are configured so that each one output diffractive optical element receives the lights from the input diffractive optical element and allows the received lights to be directed to the other output diffractive optical element by diffraction, and so that each one output diffractive optical element receives lights from the other output diffractive optical element and allows the received lights to be output from the light guide unit by diffraction, and the two output diffractive optical elements having different linear grating patterns are alternately arranged in at least one dimension in a central region having at least a predetermined width within the predetermined region and partitioned longitudinally from a side adjacent to the input diffractive optical element to an opposite side thereto.
