Linear light source

A reading device, comprising:

• a substrate,
• a plurality of light emitting diodes placed on said substrate in line for applying a light to a document,
• a frame member provided with side walls along said line of plurality of light emitting diodes and mounted on said substrate, said side walls having top portions which face away from said substrate and which are further from said substrate than are other portions of said side walls that are between said top portions and said substrate, and
• a rod lens made of resin having a crest line parallel to said line of a plurality of light emitting diodes, said rod lens being mounted on said frame member so as to be positioned opposite to said light emitting diodes, said rod lens and said side walls having a plurality of interengaging members which are interengaged with each other, said rod lens also having a plurality of wing members in contact with the top portions of the side walls of said frame member, said rod lens having a surface facing said substrate, said wing members including a pair of wing members extending outward in opposite directions from each other and away from said surface so that said top portions are between said wing members and said substrate and free of being between said surface and said substrate.

A linear light source, comprising:

• a substrate,
• a plurality of light emitting diodes placed on said substrate in line,
• a frame member surrounding said plurality of light emitting diodes and mounted on said substrate, and
• a rod lens having a crest line parallel to said line of a plurality of light emitting diodes, said rod lens being mounted on said frame member so as to be positioned opposite to said light emitting diodes, said rod lens having a lens surface covering all of a width of an opening of said frame member and a counter surface formed of a curved surface having a radius larger than that of said lens surface, said lens surface having a center of curvature which is positioned in said rod lens, said rod lens being elongated and having a surface facing said substrate and having pairs of wing members, said wing members of each pair of wing members extending outward away from said surface in opposite directions, said wing members being arranged in a straight line along a direction of elongation of said rod lens, said wing members being in contact with top portions of said frame member.