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US 6,661,583 B2Granted
Close-up attachment lens
AssigneeFuji Photo Optical Co., Ltd.
InventorYoshikazu Shinohara
Life of this patent
Estimating the term…
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AssigneeFuji Photo Optical Co., Ltd.
InventorYoshikazu Shinohara
Estimating the term…
Provided is a close-up attachment lens suitably applicable to a taking lens body comprising a lens group in charge of a focus function and a lens group in charge of a zoom function completely separate from each other. The attachment lens is mounted on the taking lens body on an object side for close-up shooting. The attachment lens comprises a cemented lens having a negative refractive power as a whole, the cemented lens including a first lens with a convex surface on an object side having a positive refractive power and a second lens with a convex surface on an image plane having a negative refractive power, and a third single lens having a positive refractive power. The taking lens body comprises a focus lens group, a zoom lens group and a master lens group which are disposed independently of one another. The use of the attachment lens allows close-up shooting while maintaining various aberrations in a taking lens in a favorable condition.
A close-up attachment lens used through mounting on a taking lens body on an object side, the taking lens including successively from an object side a first lens group having a focus function and a positive refractive power, a second lens group having a magnification change function and a negative refractive power, a third lens group having a function of compensating a shift of an image plane accompanied by a magnification change and a negative refractive power, and a fourth lens group having an imaging function and a positive refractive power,
Dependencies are inferred from the claim text.