Autofocus camera
View Patent ↗A method and system for facilitating focusing of a miniature camera are disclosed. One or more lenses can be attached to a MEMS stage. The MEMS stage can be moved by a Lorentz actuator. The MEMS stage can be configured to limit movement of the lens(es) to a single degree of freedom to inhibit misalignment thereof with respect to an imaging sensor. The stage can be biased to a predefined position thereof, e.g., for focus at infinity. A metal cover can inhibit electromagnetic interference and can limit movement of the lens(es).
1. A stage for a miniature camera, the stage comprising:
a generally planar moving portion that is configured to move generally within the plane of the moving portion;
a generally planar stationary portion surrounding the moving portion;
a flexure coupling the moving portion to the stationary portion; and,
a snubber assembly surrounding the moving portion, the stationary portion and the flexure and operable to constrain the moving portion to move substantially in only one degree of freedom with respect to the stationary portion.
2. The stage as recited in claim 1 , wherein the moving portion, the stationary portion and the flexure are formed by a MEMS process.
3. The stage as recited in claim 1 , wherein the moving portion is also constrained by the flexure to move substantially in the only one degree of freedom with respect to the stationary portion.
4. The stage as recited in claim 1 , wherein the stage is formed monolithically of a single piece of silicon.
5. The stage as recited in claim 1 , wherein the stage is formed by etching.
6. The stage as recited in claim 1 , wherein the stage is formed by micromachining.
7. The stage as recited in claim 1 , wherein the stage is configured to facilitate attachment of camera optics thereto.
8. The stage as recited in claim 1 , wherein the stage is configured to facilitate attachment of an actuator thereto.
9. A stage assembly for a miniature camera, the stage assembly comprising:
a generally planar stage;
at least one magnet of an actuator attached to the stage for effecting movement of the stage in the plane of the stage;
at least one lens attached to the stage, movement of the lens effecting focusing of the camera;
a housing within which the stage, the magnet and the lens are at least partially disposed;
a bias spring for biasing the stage at one extreme of its motion; and,
a clip configured to attach to the housing for holding the bias spring in place with respect thereto.
10. The stage assembly as recited in claim 9 , wherein the stage comprises a stationary portion and a moving portion and the stationary portion is attached to a snubber assembly that substantially limits motion of the moving portion to a single degree of freedom.
11. The stage assembly as recited in claim 9 , wherein the bias spring biases the stage for focus at infinity.