Patent ID: 8251565

Claim:
A display device, comprising: at least one light source; a light guide plate having an incident surface for inputting light from the at least one light source, an exit surface for outputting illumination light, and an opposing surface opposed to the exit surface; a plurality of square pyramidal microprisms each having a mirror surface for reflecting the light from the at least one light source, each of the plurality of square pyramidal microprisms having a height in the range of from 1 μm to 10 μm and being formed on the opposing surface of the light guide plate so that the mirror surface intersects with a base surface of the square pyramidal microprism at an angle in the range of from 40 to 50 degrees, and each of the plurality of square pyramidal microprisms being arranged so that a base of a mirror surface thereof is perpendicular to a light path of the light from the at least one light source; and a display element disposed above the exit surface of the light guide plate and having dots for displaying image information, at least two of the plurality of square pyramidal microprisms being formed in an area corresponding to each of the dots of the display element.