LIGHT GUIDE, LIGHT GUIDE DEVICE AND IMAGE READER

摘要

PROBLEM TO BE SOLVED: To provide a light guide ensuring excellent light beam extraction efficiency while maintaining an appropriate light distribution, and to provide a light guide device and an image reader.SOLUTION: A light guide 30 includes a prism 40 for reflecting a light beam. The prism 40 is constituted of a plurality of protrusions and recesses 42 provided in a reflecting surface parallel with the extension direction of the light guide 30. When viewing from a direction perpendicular to the reflecting surface, some of the plurality of protrusions and recesses 42 include a portion extending in parallel with a predetermined curve, or a predetermined straight line that is inclining against the extension direction of the light guide 30.