Patent ID: 8068194

Claim:
A line light source device comprising: a board extending in a longitudinal direction thereof and having a surface, a plurality of light emission elements placed on the surface of the board at intervals along the longitudinal direction, and resin parts that are placed so as to cover the plurality of light emission elements, wherein the resin parts have first recesses on a surface in a direction of a normal to the surface of the board positioned between the light emission elements adjoining in the longitudinal direction, second recesses in regions corresponding to the light emission elements in the direction of the normal, and portions in which distance from the surface of the board to the first recess in the direction of the normal decreases with distance from the light emission element in the longitudinal direction within a range from center of the light emission element to a midpoint between the light emission element and the next light emission element in the longitudinal direction, and the surface of the board has a property of reflecting light, whereby the light is guided in the resin part in the longitudinal direction.