Mirror tilt actuation
Some embodiments include an image sensor and a zoom lens assembly including a plurality of movable lens elements arranged to be moved independent of one another. In some embodiments, the plurality of movable lens elements share an optical axis. Some embodiments include a lens and mirror assembly for admitting light to the miniature camera. The lens and mirror assembly includes a folded optics arrangement such that light enters the lens and mirror assembly through a first lens with an optical axis of the first lens orthogonal to the plurality of moveable lens elements. The lens and mirror assembly includes a mirror for folding the path of light from the optical axis of the first lens to the optical axis of the plurality of movable lens elements, and the lens and mirror assembly further includes an actuator for tilting the mirror.
1. A camera, comprising:
an image sensor;
a mirror that receives light along a first optical axis and that folds a path of the light from the first optical axis to a plurality of lens elements that share a second optical axis;
an actuator to tilt the mirror, wherein the actuator comprises:
a movable magnet;
one or more coils; and
a sensor arrangement comprising a sensor to sense magnetic interaction between the movable magnet and the one or more coils to produce at least one output that indicates a position of the movable magnet; and
a zoom lens assembly that includes the plurality of lens elements, wherein each of the plurality of lens elements is adjustable to change a focal length of the zoom lens assembly.
2. The camera of claim 1 , wherein the sensor arrangement comprises at least two sensors for monitoring motion of the movable magnet in two orthogonal directions.
3. The camera of claim 2 , wherein the at least two sensors comprise a Hall sensor.
4. The camera of claim 1 , wherein the sensor is located at a plane of symmetry of the movable magnet when the movable magnet is not moving, the plane of symmetry being orthogonal to a poling direction of the movable magnet.
5. The camera of claim 1 , wherein:
the one or more coils comprise:
a first coil at a first side of the movable magnet; and
a second coil at a second side of the movable magnet, the second side being orthogonal to the first side;
the sensor is a first sensor located proximate the first coil; and
the sensor arrangement further comprises a second sensor located proximate the second coil.
6. The camera of claim 1 , wherein the one or more coils comprise:
stationary coils disposed around sides of the movable magnet, wherein when driven with electric signals, the stationary coils generate Lorentz forces that tend to tilt the movable magnet and the mirror.
7. The camera of claim 1 , wherein the actuator is attached to a driver circuit to tilt the mirror to compensate for movement of the camera.
8. The camera of claim 1 , wherein a fringing field of the movable magnet includes components of a magnetic field in directions that generate Lorentz forces when the one or more coils are electrically driven.
9. An optics system, comprising:
a mirror that receives light along a first optical axis and that folds a path of the light from the first optical axis to a plurality of lens elements that share a second optical axis;
an actuator to tilt the mirror, wherein the actuator comprises:
a movable magnet;
one or more coils; and
a sensor arrangement comprising a sensor to sense magnetic interaction between the movable magnet and the one or more coils to produce at least one output that indicates a position of the movable magnet; and
a zoom lens assembly that includes the plurality of lens elements, wherein each of the plurality of lens elements is adjustable to change a focal length of the zoom lens assembly.
10. The optics system of claim 9 , wherein the sensor arrangement comprises at least two Hall sensors for monitoring motion of the movable magnet in two orthogonal directions.
11. The optics system of claim 9 , wherein:
the one or more coils comprise:
a first coil at a first side of the movable magnet; and
a second coil at a second side of the movable magnet, the second side being orthogonal to the first side;
the sensor is a first sensor located proximate the first coil; and
the sensor arrangement further comprises a second sensor located proximate the second coil.
12. The optics system of claim 9 , wherein the one or more coils comprise a plurality of coils fabricated in a single component layer-by-layer in sheet form.
13. The optics system of claim 9 , wherein the one or more coils comprise:
four stationary coils disposed around four sides of the movable magnet, wherein when driven with electric signals, the four stationary coils generate Lorentz forces that tend to tilt the movable magnet and the mirror.
14. The optics system of claim 9 , wherein the actuator is configured to receive electrical signals causing generation of Lorentz forces that tend to tilt the movable magnet and the mirror about a pivot in two substantially orthogonal tilt degrees of freedom.
15. The optics system of claim 9 , wherein:
the actuator tilts the mirror to stabilize an image captured by an image sensor of a camera.
16. A device, comprising:
a camera module, comprising:
a mirror that receives light along a first optical axis and that folds a path of the light from the first optical axis to a plurality of lens elements that share a second optical axis;
an actuator to tilt the mirror, wherein the actuator comprises:
a movable magnet;
one or more coils; and
a sensor arrangement comprising a sensor to sense magnetic interaction between the movable magnet and the one or more coils to produce at least one output that indicates a position of the movable magnet;
a zoom lens assembly that includes the plurality of lens elements, wherein each of the plurality of lens elements is adjustable to change a focal length of the zoom lens assembly; and
an image sensor to capture light that has passed through the plurality of lens elements of the zoom lens assembly and to convert the captured light into image signals;
a display; and
one or more processors to:
cause the display to present an image based at least in part on one or more of the image signals from the image sensor; and
cause the actuator to tilt the mirror.
17. The device of claim 16 , wherein the sensor arrangement comprises at least two Hall sensors for monitoring motion of the movable magnet in two orthogonal directions.
18. The device of claim 16 , wherein the sensor is located at a plane of symmetry of the movable magnet when the movable magnet is not moving, the plane of symmetry being orthogonal to a poling direction of the movable magnet.
19. The device of claim 16 , wherein the one or more coils comprise:
stationary coils disposed around sides of the movable magnet, wherein when driven with electric signals, the stationary coils generate Lorentz forces that tend to tilt the movable magnet and the mirror.
20. The device of claim 16 , wherein the one or more coils comprise a plurality of coils fabricated in a single component layer-by-layer in sheet form.