Image-reading apparatus

An image-reading apparatus comprising

• at least one light source configured to illuminate a surface of a document with light;
• a light-guiding mechanism including a light incoming face and a light outgoing face, the light-guiding mechanism configured to allow light emitted from said light source to travel in the light-guiding mechanism and guide the light to a linear objective reading region;
• an optical system configured to collect light reflected on the surface of said document;
• and
• a reading sensor configured to read an image of the document, wherein
• said light-guiding mechanism includes, at its top face, said light outgoing face in a shape of a substantially rectangular parallelopiped which extends in a longer axial direction of said linear objective reading region, and includes, at its base, a light source-accommodating section in which said light source is disposed, a wall of said light source-accommodating section serving as said light incoming face;
• a first wall and a second wall of said light-guiding mechanism serve as a first face and a second face and are formed to extend parallel to the longer axial direction of said light-guiding mechanism, and a third side wall and a fourth side wall of said light-guiding mechanism serve as a seventh face and an eighth face and are formed to extend perpendicular to the longer axial direction of said light-guiding mechanism;
• in the shorter axial direction of said linear objective reading region of said document, light fluxes, which are emitted from said light source and pass through said light source-accommodating section and enter the light incoming face of said light-guiding mechanism, are reflected on said first face and said second face so as to be guided to said light outgoing face and to said linear objective reading region, and
• said light guiding mechanism further includes a reflecting face configured to reflect a part of the light fluxes from said light outgoing face of said light-guiding mechanism onto the surface of the document, so as to guide said part of the light fluxes to said linear objective reading region.