Rotational ball-guided voice coil motor
Actuators for rotating or tilting an optical element, for example an optical path folding element, comprising a voice coil motor (VCM) and a curved ball-guided mechanism operative to create a rotation or tilt movement of the optical element around a rotation axis upon actuation by the VCM. In some embodiments, an actuator includes two, first and second VCMs, and two curved ball-guided mechanisms operative to create rotation or tilt around respective first and second rotation axes.
1. An actuator for rotating or tilting an optical path folding element (OPFE) for optical image stabilization (OIS), the actuator comprising:
a voice coil motor (VCM) including a first magnet, a first coil and a second coil;
a first curved ball-guided mechanism operative to create a first rotation movement of the OPFE around a first rotation axis upon actuation by the VCM; and
a second curved ball-guided mechanism operative to create a second rotation movement of the OPFE around a second rotation axis upon actuation by the VCM, wherein the first and the second rotation axes are perpendicular to each other, and wherein the first rotation movement and the second rotation movement are created by a combination of currents passing through the first coil and the second coil.
2. The actuator of claim 1 , wherein the first rotation movement is created by passing a first current in a first direction through the first coil and by passing a second current in the first direction through the second coil.
3. The actuator of claim 1 , wherein the second rotation movement is created by passing a first current in a first direction through the first coil and by passing a second current in a direction opposite to the first direction through the second coil.
4. The actuator of claim 3 , wherein the first current and the second currents are identical.
5. The actuator of claim 1 , wherein the actuator further comprises a second magnet.
6. The actuator of claim 5 , wherein the first and second magnets are unified as a single magnet.
7. The actuator of claim 1 , further comprising a ferromagnetic yoke used to pull the first magnet to prevent the first curved ball-guided mechanism from coming apart.
8. The actuator of claim 1 , wherein the actuator includes three balls.
9. The actuator of claim 1 , wherein the OPFE is used to fold light from a first optical path to a second optical path, and wherein the first rotation axis is oriented perpendicular to both the first optical path and the second optical path.
10. The actuator of claim 1 , wherein the OPFE is used to fold light from a first optical path to a second optical path, and wherein the second rotation axis is oriented parallel to the first optical path.
11. The actuator of claim 1 , wherein the OPFE is a prism or a mirror.
12. The actuator of claim 1 , wherein the actuator further comprises one or more position sensors.
13. The actuator of claim 1 , included in a digital camera that is part of a mobile device.
14. The actuator of claim 13 , wherein the mobile device is a smartphone.
15. The actuator of claim 2 , included in a digital camera that is part of a mobile device.
16. The actuator of claim 15 , wherein the mobile device is a smartphone.
17. The actuator of claim 3 , included in a digital camera that is part of a mobile device.
18. The actuator of claim 17 , wherein the mobile device is a smartphone.
19. The actuator of claim 4 , included in a digital camera that is part of a mobile device.
20. The actuator of claim 19 , wherein the mobile device is a smartphone.