Coil structure for wireless power transmissions and wireless power transmitter including the same
A coil structure for wireless power transmissions includes: a body having a cylindrical shape; an upper transmission coil formed on the body and configured to generate an electromagnetic field passing through an upper surface of the body; and at least one side transmission coil formed on the body and configured to generate an electromagnetic field passing through a side surface of the body.
1. A coil structure for wireless power transmissions comprising:
a body comprising an upper surface and a side surface extending from the upper surface;
an upper transmission coil disposed on the upper surface and configured to generate an electromagnetic field passing through the upper surface;
at least one side transmission coil wound around a perimeter of the side surface and configured to generate an electromagnetic field passing through the side surface; and
a magnetic shield layer formed in an upper portion of the body below the upper surface, and configured to block the magnetic field generated by the upper transmission coil from propagating toward a lower portion of the body.
2. The coil structure for wireless power transmissions of claim 1 , wherein the at least one side transmission coil comprises
a first side transmission coil disposed around an upper portion of the side surface and configured to generate a first electromagnetic field perpendicular to the side surface, and
a second side transmission coil disposed around a lower portion of the side surface and configured to generate a second electromagnetic field perpendicular to the side surface.
3. The coil structure for wireless power transmissions of claim 2 , further comprising an insulator configured to prevent a short circuit between a portion of the at least one side transmission coil formed in a vertical direction and a portion of the at least one side transmission coil formed in a horizontal direction.
4. The coil structure for wireless power transmissions of claim 3 , further comprising a groove formed in the side surface, wherein
the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction cross each other,
one of the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction is inserted into the groove, and
a remaining region of the groove is filled with the insulator.
5. The coil structure for wireless power transmissions of claim 1 , wherein the at least one side transmission coil comprises a single coil by wound around one of an upper portion and a lower portion of the side surface, extending in a vertical direction of the body, wound around the other one of the upper portion and the lower portion of the side surface, and extending in one of the upper portion and the lower portion of the side surface.
6. The coil structure for wireless power transmissions of claim 5 , wherein a region formed by a portion of the at least one side transmission coil extending in the vertical direction from the upper portion of the side surface to the lower portion of the side surface and a region formed by a portion of the at least one side transmission coil extending in the vertical direction from the lower portion of the side surface to the upper portion of the side surface partially overlap.
7. The coil structure for wireless power transmissions of claim 5 , further comprising an insulator configured to prevent a short circuit between a portion of the at least one side transmission coil formed in the vertical direction and a portion of the at least one side transmission coil formed in a horizontal direction of the body.
8. The coil structure for wireless power transmissions of claim 7 , wherein
the insulator is disposed on top of one of the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction, and
the other of the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction is disposed on top of the insulator.
9. A wireless power transmitter comprising:
a direct current-alternating current converter configured to convert a direct current voltage into an alternating current voltage; and
a transmission resonator comprising a wireless power transmission coil structure configured to wirelessly transmit power based on the alternating current voltage converted by the direct current-alternating current converter,
wherein the wireless power transmission coil structure comprises
a body comprising an upper surface and a side surface extending from the upper surface,
an upper transmission coil disposed on the upper surface and configured to generate an electromagnetic field passing through the upper surface,
at least one side transmission coil wound around a perimeter of the side surface and configured to generate an electromagnetic field passing through the side surface, and
a magnetic shield layer formed in an upper portion of the body below the upper surface, and configured to block the magnetic field generated by the upper transmission coil from propagating toward a lower portion of the body.
10. The wireless power transmitter of claim 9 , wherein the at least one side transmission coil comprises
a first side transmission coil disposed around an upper portion of the side surface and configured to generate a first electromagnetic field perpendicular to the side surface, and
a second side transmission coil formed to surround a lower portion of the side surface and configured to generate a second electromagnetic field perpendicular to the side surface.
11. The wireless power transmitter of claim 10 , further comprising an insulator configured to prevent a short circuit between a portion of the at least one side transmission coil formed in a vertical direction and a portion of the at least one side transmission coil formed in a horizontal direction.
12. The wireless power transmitter of claim 11 , further comprising a groove formed in the side surface, wherein
the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction cross each other,
one of the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction is inserted into the groove, and
a remaining region of the groove is filled with the insulator.
13. The wireless power transmitter of claim 9 , wherein the at least one side transmission coil comprises a single coil wound around one of an upper portion and a lower portion of the side surface, extending in a vertical direction of the body, wound around the other one of the upper portion and the lower portion of the side surface, and extending in one of the upper portion and the lower portion of the side surface.
14. The wireless power transmitter of claim 13 , wherein a region formed by a portion of the at least one side transmission coil extending in the vertical direction from the upper portion of the side surface to the lower portion of the side surface and a region formed by a portion of the at least one side transmission coil extending in the vertical direction from the lower portion of the side surface to the upper portion of the side surface partially overlap.
15. The wireless power transmitter of claim 13 , further comprising an insulator configured to prevent a short circuit between a portion of the at least one side transmission coil formed in the vertical direction and a portion of the at least one side transmission coil formed in a horizontal direction of the body.
16. The wireless power transmitter of claim 15 , wherein
the insulator is disposed on top of one of the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction, and
the other of the portion of the at least one side transmission coil formed in the vertical direction and the portion of the at least one side transmission coil formed in the horizontal direction is disposed on top of the insulator.