| 摘要 |
PROBLEM TO BE SOLVED: To provide a small zoom lens which ensures compactness and high resolution are ensured, relaxes the tolerance sensitivity, and has proper shading characteristics, and to provide its optical system. SOLUTION: The zoom lens includes, in the order starting from the object side, a first group having a negative power, a second group having a positive power, a third group having a weak power, and an imaging element. The first group is constituted of a negative lens. The second group is composed of a cemented lens, having positive power, diaphragm, and a meniscus lens or a flat concave lens. The third group is constituted of a positive lens or a negative lens. To bring a zooming state, the zoom lens shifts from the wide end to the tele-end, by narrowing the interval between the first and second groups or from the tele-end to the wide end by increasing the interval, and the third group may further move in matching with to the zooming operation. COPYRIGHT: (C)2007,JPO&INPIT
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