| 摘要 |
A projection zoom lens has three negative, positive, and position group configuration in order from a magnification side. A first group G<SUB>1 </SUB>includes a positive L<SUB>1</SUB>, a negative meniscus lens L<SUB>2</SUB>, a negative lens L<SUB>3</SUB>, a positive L<SUB>4</SUB>, and a negative lens L<SUB>5</SUB>. The positive lens L<SUB>4 </SUB>and the negative lens L<SUB>5 </SUB>constitute a cemented lens. The second group G<SUB>2 </SUB>includes a biconvex lens L<SUB>6 </SUB>and a biconvex lens L<SUB>7</SUB>. The third group G<SUB>3 </SUB>includes an aspheric lens L<SUB>8</SUB>, a negative lens L<SUB>9</SUB>, a positive lens L<SUB>10</SUB>, and a positive lens L<SUB>11</SUB>. The first to third lens groups satisfy: <?in-line-formulae description="In-line Formulae" end="lead"?>|M3/f3|<|M1/f1|<|M2/f2| (1)<?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>0.40<|M2/f2|<0.80 (2)<?in-line-formulae description="In-line Formulae" end="tail"?> where Mi denotes a movement amount of the i-th lens group between the wide-angle end and the telephoto end during the varying of the power, and fi denotes a focal length of the i-th lens group.
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