CPC G02B 6/0016 (2013.01) [G02B 27/0172 (2013.01); G02B 27/4205 (2013.01); G02B 2027/0178 (2013.01); G02B 2207/117 (2013.01)] | 12 Claims |
1. A diffraction light guide plate, comprising:
a light guide unit configured to guide light;
an input diffraction optical device configured to receive light from a light source and diffract the received light so that the received light is guided on the light guide unit;
an intermediate diffraction optical device configured to receive the diffracted light from the input diffraction optical device and allow the received light to be one-dimensionally extended by diffraction; and
an output diffraction optical device configured to receive the extended light from the intermediate diffraction optical device and allow the received light to be output from the light guide unit by diffraction,
wherein the intermediate diffraction optical device and the output diffraction optical device are separately disposed in regions divided horizontally on the light guide unit,
the intermediate diffraction optical device includes a main intermediate diffraction optical device and an auxiliary intermediate diffraction optical device, which are disposed separate apart from each other in a vertical direction on the light guide unit,
the main intermediate diffraction optical device is optically coupled to the input diffraction optical device through the light guide unit and directs the diffracted light received from the input diffraction optical device to the auxiliary intermediate diffraction optical device by diffraction,
the auxiliary intermediate diffraction optical device is optically coupled to the main intermediate diffraction optical device through the light guide unit and directs the diffracted light received from the main intermediate diffraction optical device to the output diffraction optical device by diffraction, and
an extension direction of the auxiliary intermediate diffraction optical device is at an angle toward a lower side of the light guide unit with respect to the extension direction of the main intermediate diffraction optical device.
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