| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in which: an optical sensor detecting an object may be difficult to provide on the back face of a light guide plate.SOLUTION: An optical device comprises a light guide plate that guide light in a plane parallel to a light emission surface, and a sensor that is provided on the opposite side of the emission surface with respect to the light guide plate for detecting an object located on the emission surface side with light transmitting through the back face on the opposite side of the emission surface and the emission surface; the light guide plate comprises a plurality of light convergence parts each include an optical surface that emits, from the emission surface, emission light in a direction to substantially converge to one convergence point or convergence line on a space or substantially emitted from one convergence point or convergence line on the space; the plurality of light convergence parts have different convergence points or convergence lines from each other; the plurality of convergence points or convergence lines are gathered to form an image on a space on the emission surface side.SELECTED DRAWING: Figure 3 |
