| 摘要 |
A two-focus switchable lens comprises a taking lens system selectively using a wide-angle-side lens and a telephoto-side lens having respective focal lengths different from each other; and a fixed shutter 1, disposed on an image surface side of the taking lens system, for determining an amount of exposure. The wide-angle-side lens comprises two meniscus lenses L1, L2 each having a concave surface directed onto the object side; whereas an aperture stop 2 for defining brightness is disposed between the lens L2 and the fixed shutter 1, with a single blade configuration, positioned on the image surface side of the lens L2. The telephoto-side lens comprises a single positive meniscus lens L1' having a convex surface directed onto the object side, whereas an aperture stop 2' is disposed between the lens L1' and the fixed shutter 1, with a single blade configuration, positioned on the image surface side of the lens L1'. Also, a marginal luminous flux restricting mask 4 is disposed on the image surface side of the fixed shutter 1.
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