Motion controlled actuator
View Patent ↗A device can have an outer frame and an actuator. The actuator can have a movable frame and a fixed frame. At least one torsional flexure and at least one hinge flexure can cooperate to provide comparatively high lateral stiffness between the outer frame and the movable frame and can cooperate to provide comparatively low rotational stiffness between the outer frame and the movable frame.
1. A device, comprising:
a generally planar outer frame; and
an actuator having a generally planar movable frame and a generally planar fixed frame,
the fixed frame being disposed at an angle relative to the outer frame,
the moveable frame being coupled to the outer frame by at least one flexure for rotation between a first position generally coplanar with the outer frame and a second position generally coplanar with the fixed frame.
2. The device as recited in claim 1 , wherein the at least one flexure has a stiffness in a direction parallel to the outer frame that is greater than a stiffness in a direction perpendicular to the outer frame.
3. The device as recited in claim 1 , wherein the at least one flexure has a stiffness along a rotation axis that is greater than a stiffness for rotation about the rotation axis.
4. The device as recited in claim 1 , wherein the at least one flexure is X-shaped.
5. The device as recited in claim 1 , wherein:
the outer frame, the actuator, and the at least one flexure are of monolithic construction; and
the at least one flexure is substantially thinner than the outer frame, the movable frame and the fixed frame.
6. The device as recited in claim 1 , wherein the outer frame, the actuator, and the at least one flexure comprise MEMS structures.
7. The device as recited in claim 1 , wherein the actuator comprises a rotational comb drive actuator.
8. An electronic device comprising the device of claim 1 .
9. A system, comprising:
a generally planar outer frame;
a plurality of actuators, each having a generally planar movable frame and a generally planar fixed frame,
each of the fixed frames being deployed at an angle relative to the outer frame, and
each of the moveable frames being rotatably coupled to the outer frame by at least one associated flexure for rotational movement between an un-actuated position generally coplanar with the outer frame and an actuated position generally coplanar with a corresponding one of the fixed frames, wherein
each of the at least one associated flexures has an in-plane stiffness in a direction parallel to a plane of the outer frame and an out-of-plane stiffness in a direction perpendicular to a plane of the outer frame and,
the in-plane stiffness is greater than the out-of-plane stiffness.
10. The system as recited in claim 9 , wherein at least one of the at least one associated flexures is X-shaped.
11. The system as recited in claim 9 , further comprising:
a platform; and
wherein the movable frame of each actuator cooperates to facilitate translation of the platform with respect to the corresponding fixed frame.
12. The system as recited in claim 9 , wherein the outer frame, the actuator, and the at least one associated flexures comprise MEMS structures.
13. The system as recited in claim 9 , wherein the actuator comprises a rotational comb actuator.
14. An electronic device comprising the system of claim 9 .
15. A method, comprising:
forming a generally planar outer frame having a central opening;
forming a generally planar actuator within the central opening of and coplanar with the outer frame, the actuator having a generally planar movable frame and a generally planar fixed frame;
deploying the fixed frame at an angle relative to the outer frame;
forming a torsional flexure connecting the outer frame and the movable frame;
forming a hinge flexure connecting the outer frame and the movable frame; and
configuring the torsional flexure and the hinge flexure so as to facilitate rotational movement of the moveable frame about the flexures between a first position generally coplanar with the outer frame and a second position generally coplanar with the fixed frame and so as to resist movement of the moveable frame to all other possible positions.
16. The method as recited in claim 15 , wherein the outer frame, the actuator, the torsional flexure, and the hinge flexure are of monolithic construction.
17. The method as recited in claim 15 , wherein the outer frame, the actuator, the torsional flexure, and the hinge flexure are formed by a MEMS process.
18. The method as recited in claim 15 , wherein the torsional flexure and the hinge flexure are formed to be substantially thinner than the outer frame and the actuator.
19. The method as recited in claim 15 , wherein the hinge flexure is X-shaped.
20. A method, comprising:
rotating a generally planar movable frame of an actuator between a position generally coplanar with a generally planar outer frame and a position generally coplanar with a generally planar fixed frame that is disposed at an angle relative to the outer frame;
providing at least one torsional flexure having a comparatively high lateral stiffness between the movable frame and the outer frame; and
providing at least one hinge flexure having a comparatively low rotational stiffness between the movable frame and the outer frame.
21. The method as recited in claim 20 , further comprising:
twisting the torsional flexure as the movable frame rotates; and
bending the hinge flexure as the movable frame rotates.