Projection lens and projection-type display apparatus using the lens

摘要

To provide a projection lens that is compact, lightweight, low-cost, and readily portable, a first lens having a positive power and at least one surface that is an aspheric surface; a second lens having a negative power and having a concave surface on the magnification side; a third lens having a positive power and having a convex surface on the reduction side; and a fourth lens having a positive power are arranged in order from the magnification side. In addition to arranging the lenses telecentrically on the reduction side, the following formulas are satisfied simultaneously, and images formed on the conjugation surface on the reduction side are enlarged and projected on the conjugation surface on the magnification side: formula (A) 0.8

主权项

1. A projection lens which is telecentric on a reduction side, which enlarges and projects images formed on a conjugation surface on the reduction side onto a conjugation surface on a magnification side, comprising only:
a first lens having a positive power and at least one surface that is an aspheric surface; a second lens having a negative power and having a concave surface on the magnification side; a third lens having a positive power and having a convex surface on the reduction side; and a fourth lens having a positive power, which are arranged in order from the magnification side, wherein the following formulas (A), (B), (C), and (D) are simultaneously satisfied:
0.8