Optical line sensor with pair of holding members separably attached at ends of illumination and light receiving units

An optical line sensor that reads, by a reading line extending in a main screening direction, a reading target object conveyed in a sub-scanning direction by a reading line extending in a main scanning direction, the optical line sensor comprising:

• an illumination unit that irradiates said reading target object with light;
• a light receiving unit that receives light emitted from said illumination unit and reflected by said reading target object along a light receiving optical axis or transmitted through said reading target object along said light receiving optical axis, photoelectrically converts said light, and outputs said light as an electric signal;
• and
• a pair of holding members separably attached to said light receiving unit at both ends in said main scanning direction;
• wherein said illumination unit further comprises:
• a fitting portion at said both ends in said main scanning direction;
• each of said pair of holding members further comprises a fitted portion to be fitted to said fitting portion of said illumination unit;
• and
• in a state where said fitting portion is fitted to said fitted portion, an irradiation optical axis of light emitted from said illumination unit overlaps said light receiving optical axis at a position substantially coinciding with said reading line.