| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-resolution projecting zoom lens capable of reducing the fluctuations of characteristics resulting from the variation of the power of the zoom lens, and to provide a projection type display apparatus on which the projecting zoom lens is mounted, in the projecting zoom lens which is composed of six groups and in which three groups or four groups are moved. SOLUTION: The projecting zoom lens includes, sequentially from its magnification side, a negative first lens group G<SB>1</SB>, a positive second lens group G<SB>2</SB>, a negative third lens group G<SB>3</SB>, a positive fourth lens group G<SB>4</SB>, a positive or negative fifth lens group G<SB>5</SB>, and a positive sixth lens group G<SB>6</SB>, while the reduction side of the projecting zoom lens is formed as a telecentric system. When the power of the zoom lens is varied, the first lens group G<SB>1</SB>and sixth lens group G<SB>6</SB>are fixed, while the second to fifth lens groups G<SB>2</SB>to G<SB>5</SB>move. In such power varying operation, the movement of the third lens group G<SB>3</SB>advances from the magnification side to the reduction side as the zoom lens goes from the wide angle end toward the telephoto end. The zoom lens satisfies the following expression (1):¾M2/M3¾<1.0, wherein Mi is a zoom movement amount along an optical axis from the wide angle end to the telephoto end in an i-th lens group. COPYRIGHT: (C)2011,JPO&INPIT |
