Optical member and image reading device

An optical member, comprising:

• a lens array including lens bodies that are arranged in contact with each other in a line in a main scanning direction, have a circular cylindrical shape, and are configured to converge light from an object-to-be-read;
• transmissive members made of a material having a uniform refractive index, the transmissive members being disposed at positions nearer the object-to-be-read than the corresponding lens bodies being disposed or at positions farther from the object-to-be-read than the corresponding lens bodies being disposed, with the transmissive members spaced apart and adjacent to each other, the transmissive members having a circular cylindrical shape extending along optical axes of the lens bodies, the transmissive members being configured to allow light incident through one end faces to exit through other end faces;
• and
• one or more light-blocking members disposed between the lens bodies and the transmissive members, the one or more light-blocking members being disposed between straight lines formed by extending the optical axes of the lens bodies arranged adjacent to each other, each of the one or more light-blocking members being configured to separate optical paths of light to be incident to mutually adjacent ones of the lens bodies or optical paths of light converged by mutually adjacent ones of the lens bodies, wherein
• the lens bodies have a diameter larger than a diameter of the corresponding transmissive members.