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US 6,618,211 B2Granted
Lens barrel free from influence of magnetic flux leakage
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsNaoto Yumiki, Takayuki Hayashi, Yutaka Takahashi
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Abstract
A lens barrel according to the present invention includes a first lens group; a second lens group; a third lens group; a first actuator for driving the first lens group; a second actuator for driving the second lens group; and third and fourth actuators for driving the third lens group. At least one of the first through fourth actuators is provided at a position such that magnetic flux leakage from at least one of the first through fourth actuators is canceled.
Claims4
A lens barrel comprising:
- a first lens group;
- a second lens group;
- a first actuator for driving the first lens group including a magnetic sensor;
- a second actuator for driving the second lens group including a magnetic circuit,
- and means for providing the magnetic sensor of the first actuator at a position such that the magnetic sensor of the first actuator detects substantially no magnetic flux leakage from the magnetic circuit of the second actuator.
2 more elements
A lens barrel comprising:
- a first lens group;
- a second lens group;
- a first actuator for driving the first lens group;
- and
- a second actuator for driving the second lens group,
- wherein the first actuator includes:
- a stepping motor;
- a first magnet in the shape of a barrel or column, magnetized to have multiple poles in a circular direction, and attached coaxially to the stepping motor in such a manner as to rotate;
- and
- a first magnetic sensor provided opposing an outer edge of the first magnet,
- wherein the second actuator includes:
- a second magnet magnetized perpendicular to a driving direction;
- a yoke;
- a coil provided at a predetermined gap from the second magnet, capable of freely moving in the driving direction when a current is supplied thereto in such a manner as to flow in a direction perpendicular to magnetic flux generated by the second magnet;
- and
- a second magnetic sensor, and
- means for providing the first magnetic sensor at a position such that magnetic flux leakage from a magnetic circuit including the second magnet and the yoke is canceled.
14 more elements
Dependencies are inferred from the claim text.