Original reading apparatus for reading image of an original

摘要

A light guide includes a plurality of boss portions. A round hole portion is provided near the center of a base member for fixing the light guide, and slit portions are provided on both ends thereof. The round hole portion supports one boss portion in both the longitudinal direction and the lateral direction of the light guide. The slit portions support boss portions in the lateral direction of the light guide, but are free in the longitudinal direction of the light guide. That is, the center of the light guide is fixed from both directions, and thus both ends of the light guides can expand away in the longitudinal direction. This cuts the influence of expansion by half.

主权项

1. An original reading apparatus comprising:
a platen on which an original is placed; an illumination unit configured to illuminate the original ; and a photoelectric conversion element configured to convert reflected light from the original illuminated by the illumination unit into an electrical signal, wherein the illumination unit includes: a plurality of light-emitting elements; a base member; and a light guide having a first boss portion and second boss portions that engage with the base member, configured to guide light emitted from the plurality of light-emitting elements toward the original; wherein the first boss portion arranged in a central area of the light guide in the longitudinal direction is supported in both the longitudinal direction and the lateral direction of the light guide; and wherein the second boss portions arranged on end areas of the light guide in the longitudinal direction are free in the longitudinal direction of the light guide and are supported in the lateral direction of the light guide.