发明名称 Telephoto zoom lens system for camera
摘要 A telephoto zoom lens system comprises a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. In a zooming operation, the first lens group moves arithmetically, the second lens group moves from the objective side toward the image side in the first half of the movement and then from the image side toward the objective side in the latter half of movement, and the third lens group moves so as to maintain the image side focal point thereof in a fixed position in conjunction with the first and second lens groups.
申请公布号 US4729643(A) 申请公布日期 1988.03.08
申请号 US19860821445 申请日期 1986.01.22
申请人 TOKINA OPTICAL CO., LTD. 发明人 KAWAGUCHI, ISAO;TAI, MASAKUNI;IKEDA, SHIN
分类号 G02B15/20;G02B15/173;(IPC1-7):G02B15/16;G02B9/64 主分类号 G02B15/20
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