| 摘要 |
PURPOSE:To obtain the optical system of a high-performance reader which has small aberrations while having a wide visual angle by determining the surface shape and arrangement of lenses which constitute three groups of lens arrays so that specific conditions are satisfied. CONSTITUTION:Optical axes of lenses constituting respective three groups of lens arrays wherein plural lenses are arrayed regularly so that the optical axis of each lens is distant from and nearly parallel to optical axes of other lenses are made coincident with optical axes of lenses constituting other arrays to constitute the optical system of the reader which forms an unmagnification erect real image of an original so that the surface shape of the lenses constituting the arrays satisfy specific inequalities. When three lenses on the same axis which constitute one element of the optical system are denoted as the 1st - the 3rd lenses from an original surface side, the inequalities I-III hold, where (a) is the maximum height of an object corresponding to one element of the optical system, (f) the focal length of one element of the optical system, C1-C6 curvature values of the 1st - the 6th surfaces of the 1st - the 3rd lenses from the original surface side nearby peaks of the respective surfaces.
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