| 摘要 |
PROBLEM TO BE SOLVED: To make a focal length variable lens small-sized and to improve reliability of the lens. SOLUTION: The focal length variable lens is provided with: a cylindrical giantmagnetostrictive element 11 of which the hollow part 11c serves as an optical path; elastic sealing members 14a and 14b arranged in the optical path; a fluid 15 filled in the hollow part 11c of the giantmagnetostrictive element 11 with the sealing members 14a and 14b; and a coil 12. The giantmagnetostrictive element 11 is dislocated in an axial direction when the electric current flowing in the coil 12 is varied, and the pressure applied to the fluid 15 varies, and the sealing members 14a and 14b are deformed. In this way, in the focal length variable lens of the present invention, the focal length is varied according to the change in the electromagnetic field given to the giantmagnetostrictive element 11 and the movement of the fluid does not follow. Consequently, the entire focal length variable lens is made small and fluid leakage or the like is hardly caused. COPYRIGHT: (C)2006,JPO&NCIPI
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