| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens with which the thickness dimension of an imaging device is reduced, cost reduction effect by use of a plastic lens is enhanced, the productivity is excellent, and various aberrations are favorably corrected. SOLUTION: The zoom lens consists of, in the order from an object, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens group having a positive refractive power, and varies power by changing the intervals between the respective lens groups. The first lens group consists of, in the order from the object, a negative lens, a reflective optical element acting so as to bend an optical path by reflecting light beams, a negative lens, and a positive lens. The second lens group consists of, in the order from the object, a positive lens, a negative 2n lens made of plastic, and a positive 2p2 lens made of plastic, and satisfies a conditional expression: 0.1<fW/fc2<0.5, where fW is a focal distance of the entire system at the wide angle end, and fc2 is a synthetic focal distance of the 2n lens and the 2p2 lens. COPYRIGHT: (C)2011,JPO&INPIT
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