1. A wrist-worn device comprising a background plate to be illuminated for a display of the wrist-worn device, and a light source for illuminating the background plate, wherein the wrist-worn device comprises a guide chamber at least partly surrounding the light source for collecting light emitted by the light source and for directing it to the background plate.
2. A wrist-worn device according to claim 1, wherein the background plate and the guide chamber are interconnected.
3. A wrist-worn device according to claim 1, wherein the background plate and the guide chamber form a uniform piece.
4. A wrist-worn device according to claim 1, wherein the background plate and the guide chamber are made of the same material.
5. A wrist-worn device according to claim 1, wherein the background plate and the guide chamber are made of a thin, film-like material.
6. A wrist-worn device according to claim 1, wherein the guide chamber comprises a first end and a second end.
7. A wrist-worn device according to claim 6, wherein the first end and the second end are circular.
8. A wrist-worn device according to claim 1, wherein the inner surface of the guide chamber comprises a guide surface.
9. A wrist-worn device according to claims 6 and 8, wherein the guide surface is in the area between the first end and the second end.
10. A wrist-worn device according to claim 7, wherein the guide chamber is positioned with regard to a light source such that substantially all the light emitted by the light source to its numerical aperture is arranged to be directed inside the circle formed by the first end of the guide chamber.
11. A wrist-worn device according to claim 7, wherein the guide chamber is conical in shape, the diameter of the cross-section of the first end being greater than the diameter of the cross-section of the second end.
12. A wrist-worn device according to claim 7, wherein the guide chamber is roll-shaped, the diameter of the first end being substantially equal to the diameter of the second end.
13. A wrist-worn device according to claim 8, wherein the space defined by the guide surface is open.
14. A wrist-worn device according to claim 1, wherein the guide chamber comprises at least one guide means for directing the light that meets the guide means from the guide chamber to the background plate.
15. A wrist-worn device according to claims 8 and 14, wherein the guide means is located on the guide surface.
16. A wrist-worn device according to claim 14, wherein the guide means is a mirror, prism, air bubble, or a similar means changing the direction of light.
17. A wrist-worn device according to claim 1, wherein the background plate comprises at least one diffractive element for directing light from the surface of the background plate towards the display of the wrist-worn device.
18. A wrist-worn device according to claim 1, wherein the light source is a LED.
19. A method for illuminating a background plate of a display of a wrist-worn device, the method comprising the step of emitting light with a light source for collecting the light into a guide chamber at least partly surrounding the light source in the wrist-worn device and for directing it to the background plate.
20. A method according to claim 19, wherein the background plate and the guide chamber are interconnected.
21. A method according to claim 19, wherein the background plate and the guide chamber form a uniform piece.
22. A method according to claim 19, wherein the background plate and the guide chamber are made of the same material.
23. A method according to claim 19, wherein the background plate and the guide chamber are made of a thin, film-like material.
24. A method according to claim 19, wherein the guide chamber is positioned with regard to a light source such that substantially all the light emitted by the light source to its numerical aperture is directed inside the area surrounded by the first end of the guide chamber.
25. A method according to claim 19, wherein the guide chamber is conical in shape, the diameter of the cross-section of the first end of the guide chamber being greater than the diameter of the cross-section of the second end of the guide chamber.
26. A method according to claim 19, wherein the guide chamber is roll-shaped, the diameter of the first end being substantially equal to the diameter of the second end.
27. A method according to claim 19, wherein the space defined by the guide surface of the wrist-worn device is open.
28. A method according to claim 19, the method further comprising the step of directing the light that meets the guide means of the guide chamber with the guide means to the background plate.
29. A method according to claim 19, wherein the guide surface is provided with a guide means that changes the direction of light.
30. A method according to claim 29, wherein the guide means is a mirror, prism, air bubble, or a similar means changing the direction of light.
31. A method according to claim 19, the method further comprising the step of directing the light from the surface of the background plate towards the display of the wrist-worn device by means of at least one diffractive element.
32. A method according to claim 19, wherein the light source is a LED.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A commutation system for a DC motor having a stator including a plurality of windings and a permanent magnet assembly, the assembly comprising:
a housing;
at least three collector segments connected to stator windings inside the housing; and
a rotor assembly in the housing including a rotor having brushes for connecting the collector segments, the brushes extending from the rotor parallel to the motor axis; wherein the brushes are attached to the rotor to rotate coaxially therewith and to contact a surface of the collector segments.
2. A commutation system according to claim 1, wherein the brushes are moveable parallel to the axis of the motor.
3. A commutation system according to claim 1 or 2, wherein the contact surfaces of the brushes and collector segments lie substantially in the radial plane with respect to the motor rotation axis.
4. A commutation system according to claim 1, 2 or 3, wherein the collector segments are stationary and the brushes are arranged to rotate about the axis of the motor.
5. A commutation system according to any preceding claim, wherein brushes of the same polarity are connected to a spring to ensure contact between the brush and a collector segment.
6. A commutation system according to any preceding claim, wherein the collector segments are graphite.
7. A commutation system according to any preceding claim, wherein the brushes are made from a copper based material.
8. A commutation system according to any preceding claim, wherein the collector segments are connected in equivalent group and the windings attached to the collector segments are connected in parallel.
9. A commutation system according to any preceding claim, wherein the contact surface between the collector segments and the brushes is conical shaped.
10. A commutation system according to any preceding claim, comprising sliding contacts to supply power to the brushes.
11. A commutations system according to claim 10, wherein the sliding contacts are axially concentric tubular electrodes.
12. A commutation system according to claim 11, wherein the springs axially compress the tubular electrodes against the brushes.
13. A commutation system according to claim 12, wherein the springs conduct electrical current to the tubular electrode.
14. A commutation system according to any preceding claim, wherein the space between each contact segment is filled with a wearable isolating material
15. A commutation system according to claim 14, wherein the isolating material is a calcareous material.
16. A commutation system according to claim 14, wherein the isolating material is a mixture of talc and set resin.
17. A commutation system according to claim 16, wherein the talc is greater than 55% by weight of the mixture.
18. A commutation system according to claim 16, wherein a lubricating element is included in the set mixture.
19. A commutation system according to claim 18, wherein the lubricating agent is paraffin comprising greater than 55% by weight of mixture.
20. A commutation system according to any preceding claim, further comprising an air cleaning system.
21. A commutation system according to claim 20, wherein the air cleaning system comprises a fan.
22. A commutation system according to claim 21, wherein the air cleaning system comprises a dust collector.
23. A commutation system according to any preceding claim, comprising friction pads positioned between relatively moveable parts of the system.
24. A commutation system according to claim 23, wherein the pads act as conductive paths for the heat generated by the friction of brushes sliding.
25. A commutation system according to claim 24, where the pads comprise a spring element, a conductive soft deformable material, or a combination thereof.
26. A commutation system according to any preceding claim, wherein the brushes are driven in synchronized rotation with the motor drive shaft via a magnetic coupling.
27. A commutation system according to claim 26, wherein the housing is a non-magnetic metal tube.
28. A commutation system according to claim 27, wherein the external surface of the non-magnetic steel tube comprises circumferential grooves or spiral grooves that extend over the zone of magnetic coupling.
29. A commutation system according to claim 26, wherein the tube is formed from non-magnetic lamination plates
30. A commutation system according to claim 29, wherein the tube comprises a fluid sealing layer covering the inner surface of the tube formed from the lamination plates.
31. A commutation system according to claim 26, wherein the combination of magnets in the magnetic coupling ensures reorientation of the commutation system after any loss of synchronization,
32. A commutation system according to claim 26, wherein the combination of magnets in the magnetic allows the brushes to move axially.
33. A commutation system according to any preceding claim, wherein the commutation system is located in a housing separate from the motor stator.
34. A commutation system according to any preceding claim, wherein the commutation housing is an atmospheric chamber.
35. A commutation system according to any of claims 1-34, wherein the commutation system is located in a chamber comprising an electrically isolative fluid.
36. A commutation system according to any preceding claim, wherein the brushes are stranded brushes.
37. A commutation system according to any preceding claim, wherein the commutation system has commutation angles between 120 to 180 degrees
38. A commutation system according to claim 37, wherein the commutation angle is between 130 to 150 degrees.
39. A commutation system according to claim 1 wherein diodes are installed in parallel to the collector segments.
40. An electric motor for use in a submersed applications comprising a commutation system according to any one of claims 1-39.