WIDE-ANGLE PROJECTION LENS AND PROJECTION TELEVISION USING THESE LENS

摘要

PURPOSE:To obtain the projection lens having a wide angle by satisfying the lens constitution and various conditions. CONSTITUTION:The lens is constituted of a first lens being aspherical and having negative refracting power, a second lens being a meniscus and aspherical and whose convex face faces to the screen side, a third lens being biconvex and having positive refracting power, a fourth lens being a meniscus and aspherical and whose concave face faces to the screen side, and a fifth lens whose aspherical concave face faces to the screen side in order from the screen side, and the next condition is satisfied. -0.15=f/f10, 0.05=d2/f=0.2. In this regard, (f):f1: and d2 denote a focal distance of the whole lens system, a focal distance of a first lens, and an interval of a first lens and a second lens, respectively.