| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact projection lens which has high optical performance and light resistance for satisfactorily correcting chromatic aberrations with a smaller number of lenses though having no cemented lenses, and a projector including the same.SOLUTION: A projection lens LN substantially telecentric on the reduction side includes, in order from the enlargement side, a first lens L1 having a meniscus shape convex to the enlargement side, a second lens L2 having a meniscus shape convex to the enlargement side and having a negative power, a third lens L3 having a negative power, a fourth lens L4 being convex to the reduction side and having a positive power, and a fifth lens L5 being convex to the reduction side and having a positive power. Faces facing each other of the third and fourth lenses L3 and L4 are aspherical surfaces having different surface shapes, and at least one of positive lenses closer to the reduction side than the fourth lens L4 satisfies conditional expressions 0.66<0.0018×Vd+P and 60<Vd (where Vd represents an Abbe number relating to the d line, P=(Ng-NF)/(NF-NC) is true, and Ng, NF, and C represent refractive indexes at the g line, the F line, and C line respectively). |
