Patent ID: 7006302
Filing Date: 2006-02-28
Classification: G02B

Abstract:
1. An image-formation lens system comprising a plurality of lenses with aspheric lenses, wherein: any one of said aspheric lenses has an aspheric surface on an entrance side or an exit side thereof, and satisfies the following conditions: where Y max is a maximum value of a distance of said aspheric lens surface from an optical axis, ΔZ max is an absolute value of a distance from a plane vertical to the optical axis including a lens surface apex at Y max , and ΔZ half is an absolute value of a distance from a plane vertical to the optical axis including a lens surface apex at a half distance of said maximum value Y max , provided that the lens surface refers to an entire area wherein a surface shape inclusive of an effective diameter exists continuously, indicative of a boundary between that area and an area where the surface shape becomes discontinuous.