Patent ID: 6404564
Filing Date: 2002-06-11
Classification: G02B

Abstract:
A projection lens formed of only two lens groups which are arranged sequentially in order from the enlarging side of the projection lens as follows:a first lens group having negative refractive power; a second lens group having positive refractive power, said second lens group consisting of four lens elements of positive, positive, negative, and positive refractive power, respectively, in sequential order from the enlarging side; a stop positioned within a distance of |0.5 f| from the lens element surface nearest the reducing side of the projection lens, where f is the focal distance of the projection lens; said projection lens further satisfying the following conditions: 0.72/f<1.4 0.5<1.3 whered is the distance between the first lens group and the second lens group, and f2 is the focal distance of the second lens group.