Patent ID: 6111704
Filing Date: 2000-08-29
Classification: G02B

Abstract:
<f.sub.1 /f<0.93(2) -0.90<f.sub.2 /f.sub.3 <-0.84(3) 0.025<d.sub.2 /f<0.043(4) 0.09<d.sub.5 /f<0.16(5) -2.5<r.sub.3 /r.sub.4 <-2.1(6) .vertline.d.sub.6 .vertline./f.ltoreq.0.03where:f is a focal length of said readout lens as a whole;f.sub.1 is a focal length of the first lens;f.sub.2 is a focal length of the second lens;f.sub.3 is a focal length of the third lens;d.sub.2 is an air gap between the first and second lenses;d.sub.5 is a center thickness of the third lens;r.sub.3 is a radius of curvature on the object side surface of the second lens;r.sub.4 is a radius of curvature on the imaging side surface of the second lens; andd.sub.6 is a distance between the imaging side surface of the third lens and the stopwherein said lens system is a readout lens for an imaging device.