LIGHT GUIDE PRISM AND IMAGE DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a light guide prism that has stray light or ghost light reduced and an image display device using the light guide prism.SOLUTION: A light guide prism 5 guiding video image light from a display element 31 to an eyeball of an observer and displaying a virtual image of the display element 31 within a field of view of the observer comprises: four side surfaces 53a to 53d that are arranged so as to surround an optical path of the video image light incident from one end part; a reflection surface 52 that causes the video image light guided by these four side surfaces 53a to 53d to be reflected; and an emitting surface 54 that emits the video image light reflected on the reflection surface 52 toward the eyeball of the observer. In at least one side surfaces 53c and 53d of the four side surfaces 53a to 53d, a plurality of V-shape grooves 63c and 64c;63d and 64d are formed at a different position in an advancing direction of the video image light, and these V-shape grooves are mutually different in anglesθandθof inclined surfaces forming the V-shape.