Energy transfer via rolling elements of rolling-element bearings
View Patent ↗Systems and methods are disclosed for x-y tables wherein rolling elements of rolling-element bearings are transferring electrical energy between a fixed part of the x-y table and a movable part of the x-y table. The electrical energy transferred could be power to electrical devices as well as signals to and from devices on the movable part of the x-y table. Electrically conducting rolling elements are moving on electrically conducting grooves on the fixed and movable part of the x-y table. Conductor tracks on the fixed and movable part are connected to the grooves and to devices on the movable platform. In a preferred embodiment of the invention the x-y table is part of a camera wherein linear motors, preferably with integrated position sensing, are moving the x-y table back to a home position in case of a dislocation due to a mechanical shock. The invention allows an exact and fast positioning of an x-y table without requiring a flexible cable. The rolling-element bearings could be ball bearings, roller bearings, needle bearings, or other kind of bearings having electrically conductive rolling elements.
1. A method to transfer electrical energy via rolling elements of one or more rolling-element bearings of an x-y table of a camera, comprising the following steps:
(1) providing a camera comprising a x-y table having a fixed part and a movable part, a number of linear motors to position the movable part of the x-y table, and one or more rolling-element bearings to guide the movable part of the x-y table, wherein a number of rolling elements are made of electrically conductive material;
(2) deploying electrical conductor tracks as required on the fixed and on the movable part of the x-y table;
(3) connecting the electrical conductor tracks with electrically conducting grooves of the one or more rolling-element bearings on the fixed part and on the movable part of the x-y table; and
(4) connecting the electrical conductor tracks on the movable part of the x-y table with one or more electrical devices as desired.
2. The method of claim 1 wherein four linear motors are driving the movable part of the x-y table.
3. The method of claim 1 wherein three linear motors are driving the movable part of the x-y table.
4. The method of claim 1 wherein at least a part of said linear motors has an integrated position sensing capability.
5. The method of claim 1 wherein said x-y table is positioned to a home position after a mechanical shock.
6. The method of claim 1 wherein at least one rolling element is used to transfer electrical power.
7. The method of claim 1 wherein three rolling elements are used for a rolling-element bearing.
8. The method of claim 1 wherein four rolling elements are used for a rolling-element bearing.
9. The method of claim 1 wherein said rolling elements are balls.
10. The method of claim 1 wherein the rolling elements are made of steel.
11. The method of claim 1 wherein the rolling elements are made of brass.
12. The method of claim 1 wherein the method is applied for an optical stabilization of a camera in case of a mechanical shock.
13. The method of claim 12 wherein a lens barrel is stabilized by the x-y table.
14. The method of claim 13 wherein a shutter is mounted on said lens barrel and wherein said shutter is guided by one or more rolling-element bearings having electrically conductive rolling-elements.
15. The method of claim 1 wherein an image sensor is stabilized by the x-y table.
16. The method of claim 1 wherein said rolling elements are cylinders.
17. A camera module having a precise ball bearing and low friction, comprises:
an image sensor;
a shutter with an aperture function driven by a linear motor;
said motor driving the shutter, wherein the motor has an integrated position sensing system;
a lens barrel;
a carrier;
one or more actuators to move the lens barrel;
one or more rolling-element bearings between the lens barrel and the carrier to guide the movements of the lens barrel; and
an x-y table wherein rolling elements of said one or more rolling-element bearings are transferring electrical energy, comprising:
a fixed part of the x-y table, comprising
electrical conductor tracks;
at least three linear motors wherein each linear motor comprises at least one coil wrapped around an iron and a permanent magnet deployed on a movable part of the x-y table; and
electrical conducting grooves guiding a number of rolling elements of one or more rolling-element bearings to move between the fixed part of the x-y table and the movable part of the x-y table, wherein the groves are electrically connected to said conductor tracks;
a number of said rolling elements of the rolling-element bearings, wherein at least two of the rolling elements are made of electrically conducting material; and
said movable part of the x-y table, comprising
electrical conductor tracks connected to electrical conducting grooves on the movable part and to electrical devices deployed on the movable part of the x-y table; and
said electrically conducting grooves on the movable part of the x-y table guiding the rolling elements to move between the fixed part and the moving part of the x-y table.
18. The camera module of claim 17 wherein said x-y table is guiding the lens barrel.
19. The camera module of claim 17 wherein four linear motors are driving the movable part of the x-y table.
20. The camera module of claim 17 wherein three linear motors are driving the movable part of the x-y table.
21. The camera module of claim 17 wherein at least a part of said linear motors has an integrated position sensing capability.
22. The camera module of claim 17 wherein said x-y table is carrying the lens barrel.
23. The camera module of claim 22 wherein a shutter is mounted on said lens barrel and wherein said shutter is guided by a ball bearing having electrically conductive balls.
24. The camera module of claim 17 wherein said x-y table is positioned to a home position after a mechanical shock.
25. The camera module of claim 17 wherein the x-y table is used for an optical stabilization of the camera in case of a mechanical shock.
26. The camera module of claim 17 wherein the image sensor is stabilized by the x-y table.
27. The camera module of claim 17 wherein the lens barrel is stabilized by the x-y table.
28. The camera module of claim 17 wherein said rolling elements are balls.
29. The camera module of claim 17 wherein said rolling elements are cylinders.
30. A x-y table wherein rolling elements of one or more rolling-element bearings are transferring electrical energy, comprising:
a fixed part of the x-y table, comprising
electrical conductor tracks;
at least three linear motors wherein each linear motor comprises at least one coil wrapped around an iron and a permanent magnet deployed on a movable part of the x-y table; and
electrical conducting grooves guiding a number of rolling elements of rolling-element bearings to move between the fixed part of the x-y table and the movable part of the x-y table, wherein the grooves are electrically connected to said conductor tracks;
a number of said rolling elements of the rolling-elements bearings, wherein at least two of the rolling elements are made of electrically conducting material; and
said movable part of the x-y table, comprising
electrical conductor tracks connected to electrical conducting grooves on the movable part and to electrical devices deployed on the movable part of the x-y table; and
said electrically conducting grooves on the movable part of the x-y table guiding the rolling elements to move between the fixed part and the moving part of the x-y table.
31. The x-y table of claim 30 wherein four linear motors are driving the movable part of the x-y table.
32. The x-y table of claim 30 wherein three linear motors are driving the movable part of the x-y table.
33. The x-y table of claim 30 wherein at least a part of said linear motors has an integrated position sensing capability.
34. The x-y table of claim 30 wherein said x-y table is positioned to a home position after a mechanical shock.
35. The x-y table of claim 30 wherein at least one rolling element is used to transfer electrical power.
36. The x-y table of claim 30 wherein three rolling elements are used for a rolling-element bearing.
37. The x-y table of claim 30 wherein four rolling elements are used for a rolling-element bearing.
38. The x-y table of claim 30 wherein each rolling element is supported by springs.
39. The x-y table of claim 30 wherein rolling elements are made of electrically conducting material.
40. The x-y table of claim 39 wherein the rolling elements are made of steel.
41. The x-y table of claim 39 wherein the rolling elements are made of brass.
42. The x-y table of claim 30 wherein the method is applied for an optical stabilization of a camera in case of a mechanical shock.
43. The x-y table of claim 30 wherein a lens barrel is stabilized by the x-y table.
44. The x-y table of claim 30 wherein an image sensor is stabilized by the x-y table.
45. The x-y table of claim 30 wherein said x-y table is carrying a lens barrel.
46. The x-y table of claim 45 wherein a shutter is mounted on said lens barrel and wherein said shutter is guided by one or more rolling-element bearings having electrically conductive rolling elements.
47. The x-y table of claim 30 wherein said rolling elements are balls.
48. The x-y table of claim 30 wherein said rolling elements are balls.