Image sensor unit, paper sheet distinguishing apparatus, image reading apparatus, and image forming apparatus

摘要

An image sensor unit includes: a light source; a rod-shaped light guide; a light condenser that condenses light from an illuminated object; and a frame. The frame includes: a light guide housing chamber that houses the light guide; a light condenser housing chamber that houses the light condenser; and a partition wall provided between the light guide housing chamber and the light condenser housing chamber. The light guide includes: a light incident surface that receives light emitted by the light source; a light diffusing surface that diffuses the light entered from the light incident surface; and an abutment surface abutted to one side of the partition wall, which covers at least a part of the abutment surface of the light guide, where an incident angle to the abutment surface of the light directly reaching the abutment surface from the light diffusing surface is smaller than a critical angle.

主权项

1. An image sensor unit comprising: a light source; a rod-shaped light guide that shapes light emitted by the light source into a line to illuminate an illuminated object; a light condenser that condenses light from the illuminated object; and a frame that houses the light guide and the light condenser,
the frame comprising: a light guide housing chamber that houses the light guide; a light condenser housing chamber that houses the light condenser; a partition wall provided between the light guide housing chamber and the light condenser housing chamber, the light guide comprising: a light incident surface that receives the light emitted by the light source; a light diffusing surface that diffuses light entered from the light incident surface; a light emission surface that emits light toward the illuminated object; and an abutment surface abutted to one side of the partition wall, wherein a part of the abutment surface of the light guide, where an incident angle to the abutment surface of light directly reaching the abutment surface from the light diffusing surface is smaller than a critical angle, is covered by the partition wall, and the light condenser and the partition wall are bonded by an adhesive.