Patent ID: 9325874
Filing Date: 2016-04-26
CPC Classification: G02B,H04N

Claim Text:
1. A light guide comprising: a first guide portion extending in a first direction and configured to guide light entering thereto through a first end at a first side in the first direction to a reading position, the first guide portion including: a plurality of first prisms provided on a first bottom surface of the first guide portion to be arranged in the first direction, the first bottom surface extending in the first direction, and configured to total-reflect light traveling in the first guide portion to the reading position; and a turn-back member configured to turn light coming to a second end of the first guide portion back in the first direction toward the first end, the second end located at a second side that is an opposite side in the first direction to the first side, wherein: each of the first prisms includes a first total-reflecting surface facing to the first side in the first direction and a second total-reflecting surface facing to the second side in the first direction; and with respect to at least one of the first prisms located within an area extending parallel to the first direction from the second end of the first guide portion toward the first end by a first predetermined distance, an angle of the first total-reflecting surface to the first bottom surface is greater than an angle of the second total-reflecting surface to the first bottom surface.