Optical-path folding-element with an extended two degree of freedom rotation range
Actuators for rotating an optical-path-folding-element with two, first and second, degrees of freedom in an extended rotation range around two respective rotation axes, folded cameras including such actuators and dual-cameras including a folded camera as above together with an upright camera.
1. An actuator for rotating an optical path folding element (OPFE), the actuator comprising:
a) a first sub-assembly, a second sub-assembly and a stationary sub-assembly, the first sub-assembly configured to rotate the OPFE relative to the stationary sub-assembly in an extended rotation range around a yaw rotation axis and the second sub-assembly configured to rotate the OPFE relative to the first sub-assembly in an extended rotation range around a pitch rotation axis that is substantially perpendicular to the yaw rotation axis;
b) a first sensor configured to sense rotation around the yaw rotation axis and a second sensor configured to sense rotation around the pitch rotation axis, the first and second sensors being fixed to the stationary sub-assembly, wherein at least one of the first sensor or the second sensor is a magnetic flux sensor; and
c) a voice coil motor (VCM) comprising a magnet and a coil, wherein the magnet is fixedly attached to one of the first sub-assembly or the second sub-assembly, wherein the coil is fixedly attached to the stationary sub-assembly, wherein a driving current in the coil creates a force that is translated to a torque around a respective rotation axis, and wherein the second sensor is positioned such that sensing by the second sensor is decoupled from the rotation of the OPFE around the yaw rotation axis.
2. The actuator of claim 1 , wherein the second sensor position is such that the yaw rotation axis passes through the second sensor.
3. The actuator of claim 2 , wherein the yaw rotation axis passes through a center of the second sensor.
4. The actuator of claim 1 , further comprising a first curved ball-guided mechanism operative to enable the rotation around the pitch rotation axis and a second curved ball-guided mechanism operative to enable the rotation around the yaw rotation axis.
5. The actuator of claim 4 , wherein the first curved ball-guided mechanism is located on a side of the OPFE that is opposite to a side of the OPFE facing an image sensor.
6. The actuator of claim 1 , wherein the extended rotation range is equal to or greater than ±5 degrees around the pitch and yaw rotation axes.
7. The actuator of claim 1 , wherein the extended rotation range is equal to or greater than ±10 degrees around the pitch and yaw rotation axes.
8. The actuator of claim 1 , wherein the extended rotation range is between ±15-40 degrees around the pitch and yaw rotation axes.
9. The actuator of claim 1 , wherein the extended rotation range around the pitch rotation axis is different from the extended rotation range around the second rotation axis.
10. The actuator of claim 1 , wherein the magnet and the coil are used for the rotation around the pitch rotation axis and wherein the magnet is designed with a flat surface facing the coil.
11. The actuator of claim 1 , designed to be installed in a folded camera that comprises a lens module accommodating a plurality of lens elements along a lens optical axis, wherein the OPFE redirects light that enters the folded camera from the direction of a view section along a first optical path toward a second optical path along the lens optical axis, and wherein the magnet is a pitch magnet located at a side of the OPFE that is opposite to a side facing the view section.
12. The actuator of claim 1 , designed to be installed in a folded camera that comprises a lens module accommodating a plurality of lens elements along a lens optical axis, wherein the OPFE redirects light that enters the folded camera from the direction of a view section along a first optical path toward a second optical path along the lens optical axis, and wherein the magnet is a yaw magnet located at a side of the OPFE that is opposite to a side facing the lens module.
13. The actuator of claim 1 , wherein the magnetic flux sensor is a Hall sensor.
14. The actuator of claim 1 , further comprising a second magnet shaped or formed such that a central part of the second magnet is further away from a projection line of motion of the first sensor relative to an end of the second magnet.
15. The actuator of claim 1 , further comprising a second magnet shaped such that width of a cross section of the second magnet increases from a point substantially at its center towards each end of the second magnet, thereby resulting in a variable distance between the first sensor and the second magnet when relative movement occurs between the second magnet and the first sensor.
16. The actuator of claim 1 , further comprising a first magnet-yoke pair that pulls the first sub-assembly to the second sub-assembly in a radial direction relative to the pitch rotation axis, and a second magnet-yoke pair that pulls the first sub-assembly to the stationary sub-assembly in a radial direction relative to the yaw rotation axis.
17. The actuator of claim 16 , wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the first magnet-yoke pair pulls the OPFE holder to the middle moving frame and wherein the second magnet-yoke pair pulls the middle moving frame to the base.
18. The actuator of claim 1 , wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the rotation around the yaw rotation axis is generated by rotating the middle moving frame relative to the base, and wherein rotation around the pitch rotation axis is generated by rotating the OPFE holder relative to the middle moving frame.
19. The actuator of claim 1 , wherein the magnet is characterized by having a cut sphere shape, wherein the coil is characterized by a circular shape and wherein the coil is symmetrically positioned with the circular shape around the cut sphere shape.
20. The actuator of claim 1 , wherein the magnet is a single magnet used for creating an actuation force for rotation around the yaw rotation axis, creating a pre-load force in a magnet-yoke pair for holding together the first sub-assembly and the stationary sub-assembly, and sensing the rotation around the yaw rotation axis.
21. The actuator of claim 20 , wherein the magnetic flux sensor is a single magnetic flux sensor used for sensing the rotation around the yaw rotation axis.
22. The actuator of claim 20 , wherein the single magnet is a polarization magnet characterized by continuous changes in direction of a magnetic field of the magnet along a length of the magnet.