| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compact zoom lens having a simple lens configuration while securing a high zoom ratio. <P>SOLUTION: The zoom lens has a group of first lenses having positive refractive power, a group of second lenses having negative refractive power, a group of third lenses having positive refractive power and a group of fourth lenses having positive refractive power arranged sequentially in this order from an object side to an image side. Two or more groups of lenses can move for zooming. When performing focusing, the group of the second lenses move. A lens in the group of second lenses, which has negative refractive power and is positioned on a side nearest the object, is called a second a lens and a refractive index n2a and an Abbe number ν2a of a material of the second a lens are respectively properly set. <P>COPYRIGHT: (C)2010,JPO&INPIT |
