Auto focus and optical image stabilization in a compact folded camera
Compact folded camera modules having auto-focus (AF) and optical image stabilization (OIS) capabilities and multi-aperture cameras including such modules. In an embodiment, a folded camera module includes an optical path folding element (OPFE) for folding light from a first optical path with a first optical axis to a second optical path with a second optical axis perpendicular to the first optical axis, an image sensor and a lens module carrying a lens with a symmetry axis parallel to the second optical axis. The lens module can be actuated to move in first and second orthogonal directions in a plane perpendicular to the first optical axis, the movement in the first direction being for auto-focus and the movement in the second direction being for OIS. The OPFE can be actuated to tilt for OIS.
1. A lens actuation sub-assembly, comprising:
a) a plurality of flexible hanging members that hang a lens module over a base, the lens module carrying a lens with an optical axis along a first direction;
b) at least three actuators for actuating two linear motions of the lens module, a first linear motion along the first direction for autofocus (AF) and a second linear motion along a second direction orthogonal to the first direction for optical image stabilization (OIS), and for actively preventing a tilt motion of the lens module around a tilt axis, the tilt axis being along a third direction orthogonal to both the first and second directions;
c) at least three position sensors for sensing the two linear motions and the tilt motion; and
d) an actuation controller configured to receive data inputs from the position sensors, and, responsive to the data inputs, configured to generate instructions to the at least three actuators to actuate the two linear lens module motions and to actively prevent the tilt motion.
2. The lens actuation sub-assembly of claim 1 , wherein the at least three position sensors include Hall-bar sensors.
3. The lens actuation sub-assembly of claim 2 , wherein each actuator includes a magnet-coil pair and wherein each Hall-bar sensor is co-located with a respective coil on the base.
4. The lens actuation sub-assembly of claim 1 , wherein the flexible hanging members are parallel to each other.
5. The lens actuation sub-assembly of claim 1 , included in a folded camera module.
6. The lens actuation sub-assembly of claim 2 , included in a folded camera module.
7. The lens actuation sub-assembly of claim 3 , included in a folded camera module.
8. The lens actuation sub-assembly of claim 4 , included in a folded camera module.
9. The lens actuation sub-assembly of claim 1 , included together with a folded camera module in a smart-phone.
10. The lens actuation sub-assembly of claim 2 , included together with a folded camera module in a smart-phone.
11. The lens actuation sub-assembly of claim 3 , included together with a folded camera module in a smart-phone.
12. The lens actuation sub-assembly of claim 4 , included together with a folded camera module in a smart-phone.
13. A method, comprising:
a) providing a lens actuation sub-assembly that includes:
a plurality of flexible hanging members that hang a lens module over a base, the lens module carrying a lens with an optical axis along a first direction,
at least three actuators,
at least three position sensors for sensing two linear motions and a tilt motion, and
an actuation controller configured to receive data inputs from the position sensors;
b) configuring the actuation controller to, responsive to the data inputs, generate instructions to the at least three actuators to actuate the two linear lens module motions and to actively prevent the tilt motion; and
c) using the at least three actuators to actuate two linear motions of the lens module, a first linear motion along the first direction for autofocus (AF) and a second linear motion along a second direction orthogonal to the first direction for optical image stabilization (OIS), and to actively prevent a tilt motion of the lens module around a tilt axis, the tilt axis being along a third direction orthogonal to both the first and second directions.
14. The method of claim 13 , wherein the at least three position sensors include Hall-bar sensors.
15. The method of claim 14 , wherein each actuator includes a magnet-coil pair and wherein each Hall-bar sensor is co-located with a respective coil on the base.
16. The method of claim 13 , wherein the flexible hanging members are parallel to each other.