| 摘要 |
PROBLEM TO BE SOLVED: To provide a light quantity adjusting device capable of ensuring and smoothing the low-speed operation of a light quantity adjusting member, and also securing the high-speed operation thereof. SOLUTION: The light quantity adjusting device 1 is equipped with a magnet driving device 2 for actuating the light quantity adjusting members 14 and 15. In the magnet driving device 2, a bobbin 4 is arranged to surround a rotor magnet 3, and further a yoke 5 is arranged to surround the bobbin 4. The outside diameter (d) of the rotor magnet 3 is set to≤1/2 of the outside diameter D of the yoke 5, and the maximum energy product of the rotor magnet 3 is set to≥30. COPYRIGHT: (C)2007,JPO&INPIT
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