Patent ID: 7083097
Filing Date: 2006-08-01
Classification: G06K

Abstract:
1. An optical information reading apparatus comprising: an illumination optical system for projecting illumination light, elongated in a read width direction, onto an object of reading, said illumination optical system including an illumination light source made using an LED and illumination lens means made to output light incident thereon from said illumination light source while condensing and/or diffusing the incident light; and a light-receiving optical system including a light-receiving sensor for receiving light reflected from said object of reading, said illumination lens means including a multi-tiered lens unit in which a plurality of concave lens tiers and a plurality of convex lens tiers are alternately disposed in succession in said read width direction and a condensing lens unit for condensing said illumination light in a direction perpendicular to said read width direction, with said multi-tiered lens unit and said condensing lens unit being formed integrally with each other, and said illumination lens means is made such that a peripheral portion of said illumination lens means and a central side portion of said illumination lens means in said read width direction differ in optical characteristic from each other so that said peripheral portion has a light diffusion range smaller than that of said central side portion, wherein, in said illumination lens means, said multi-tiered lens unit is made such that a radius of curvature of said peripheral portion of said multi-tiered lens is set to be larger than a radius of curvature of said central side portion thereof configured to make a variation in radius of curvature vary between said peripheral portion and said central side portion for producing the different optical characteristics.