| 摘要 |
PROBLEM TO BE SOLVED: To provide a large-aperture lens which makes photographic image quality higher, by minimizing influence of spherical aberrations at a lens part, by correcting the position of the lens part corresponding to a diaphragm even in a large-aperture lens having a small F-number, and contributes to miniaturization, reduction of weight and further reduction of cost of the large-aperture lens as a whole. SOLUTION: The large-aperture lens 1, including a diaphragm ring 3 for manual operation to perform diaphragm adjustment and a focus ring 4 for manual operation to perform focus adjustment, includes: a lens position correcting mechanism Ms, which converts a turning displacement amount of the diaphragm ring 3, in terms of motion into a displacement amount in an axial direction Da, thereby transmitting it to an incorporated lens part 2; and displaces the lens part 2 in the axial direction Da, thereby correcting the position of the lens part 2 at least corresponding to the diaphragm, when the large-aperture lens 1 is to be constituted. COPYRIGHT: (C)2011,JPO&INPIT
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