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US 7,679,848 B2Granted
Actuator and lens drive apparatus
AssigneeFujinon Corporation
InventorRyota Sasaki
Life of this patent
Estimating the term…
Abstract
An actuator is provided and has an electro-mechanical conversion element; a driving frictional member attached at one end of the electro-mechanical conversion element with respect to a direction of expansion and contraction thereof; a plurality of driven members frictionally engaged with the driving frictional member; a plurality of biasing units, each biasing one of the plurality of driven members to be frictionally engaged with the driving frictional member; and a biasing-force adjusting unit that adjusts respective biasing-forces of the plurality of biasing units.
Claims19
An actuator comprising:
- an electro-mechanical conversion element;
- a driving frictional member attached at one end of the electro-mechanical conversion element with respect to a direction of expansion and contraction thereof;
- a plurality of driven members frictionally engaged with the same driving frictional member;
- a plurality of biasing units, each biasing one of the plurality of driven members with a biasing force which is perpendicular to said same driving frictional member, to frictionally engage said driven members with said same driving frictional member;
- a biasing-force adjusting unit that adjusts said respective biasing-forces of the plurality of biasing units;
- and
- a controller that controls the biasing-force adjusting unit to vary a value of said biasing force applied to one of said driven members.
4 more elements
An actuator comprising:
- an electro-mechanical conversion element;
- a driving frictional member attached at one end of the electro-mechanical conversion element with respect to a direction of expansion and contraction thereof;
- a plurality of driven members frictionally engaged with the same driving frictional member;
- a plurality of biasing units, each biasing one of the plurality of driven members to be frictionally engaged with said same driving frictional member;
- and
- a biasing-force adjusting unit that adjusts respective biasing-forces of the plurality of biasing units,
- wherein one of said biasing units are placed under heating-control in accordance with a position of one of said driven members, to frictionally engage and disengage said driven member from said driving frictional member.
4 more elements
An actuator comprising:
- an electro-mechanical conversion element;
- a driving frictional member attached at one end of the electro-mechanical conversion element with respect to a direction of expansion and contraction thereof;
- a plurality of driven members frictionally engaged with the same driving frictional member;
- a plurality of biasing units, each biasing one of the plurality of driven members to be frictionally engaged with said same driving frictional member;
- a biasing-force adjusting unit that adjusts respective biasing-forces of the plurality of biasing units;
- and
- a weight member to impart a load to an end face of said electro-mechanical conversion element,
- wherein said electro-mechanical conversion element is a piezoelectric element, and said weight member is made of a non-rigid material, to lower a resonant frequency of a system formed by said the piezoelectric element, said driving frictional member and said weight member, and
- wherein a resonant frequency f0 is lowered and a drive frequency f is set within an anti-vibrating region of f≧21/2·f0, to reduce an effect of resonance and provide a stable drive force.
6 more elements
An actuator comprising:
- an electro-mechanical conversion element;
- a driving frictional member attached at one end of the electro-mechanical conversion element with respect to a direction of expansion and contraction thereof;
- a plurality of driven members frictionally engaged with the same driving frictional member;
- a plurality of biasing units, each biasing one of the plurality of driven members with a biasing force which is perpendicular to said same driving frictional member, to frictionally engage said driven members with said same driving frictional member;
- a weight member to impart a load to an end face of said electro-mechanical conversion element, said weight member being made of a rigid material;
- a biasing-force adjusting unit that adjusts said respective biasing-forces of the plurality of biasing units;
- and
- a controller that controls the biasing-force adjusting unit to vary a value of said biasing force applied to one of said driven members.
5 more elements
Dependencies are inferred from the claim text.