| 摘要 |
PROBLEM TO BE SOLVED: To obtain an original reading lens, capable of excellently reading an original by extremely excellently performing color corrections and realizing high contrast in a high spatial frequency area, while maintaining an F-number of full brightness conditions and keeping an aperture efficiency up to about 100% to the periphery part of a viewing angle. SOLUTION: This original reading lens consisting of four groups has a configuration of six lenses of four groups. In the reading lens, a 1st group consists of a 1st lens being a positive lens and a 2nd lens being a negative lens bonded to the image side of the 1st lens, a 2nd group consists of a 3rd lens being a meniscus lens whose convex surface faces to an object side, a 3rd group consists of a 4th lens being a meniscus lens whose convex surface faces to an image side, and the 4th group consists of a 5th lens being a negative lens and a 6th lens being a positive lens bonded to the image side of the 5th lens, in order from the object side to the image surface side, and respective conditional expressions are satisfied.
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