# US 10,312,745 B2 · Wireless power transfer system with automatic foreign object rejection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,745 B2 - Document ID: US10312745B2 - Status: Granted - Kind: B2 - Application number: 15/635,495 - Filed: 2017-06-28 - Published: 2017-10-19 - Granted: 2019-06-04 - Earliest claimed: 2016-03-28 - Assignees: Chargedge, Inc. - Applicants: ChargEdge, Inc. - Inventors: Sanjaya Maniktala - Web page: https://patentgrep.com/patent/US10312745B2 ## CPC - H02J 50/60: responsive to the presence of foreign objects, e.g. detection of living beings - H02J 7/731: {specially adapted for holding portable devices containing batteries (H02J7/751 takes precedence)} - H02J 50/10: using inductive coupling - H02J 50/12: of the resonant type - H02J 50/402: {the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas} - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY ## Abstract In one embodiment, a wireless power transmitter comprises a transmitter coil structure comprising a magnetic layer having a geometric center line, the magnetic layer being curved symmetrically about a geometric center line, a first coil coupled to a second coil, the first coil and second coil wound in such a way that when a current flows in the first coil in a first spatial direction the current flows in the second coil in a second spatial direction, the first coil and the second coil disposed on the magnetic layer substantially symmetrically about the geometric center line of the magnetic layer, a power circuit configured to provide a time-varying current to the transmitter coil structure; and a housing including an outer surface having a convex shape, the transmitter coil structure being disposed underneath the outer surface of the housing. The convex outer surface of the wireless power transmitter exploits gravity to cause foreign objects to slide or roll away from the magnetic field generated by the transmitter. ## Claims ### Claim 1 A wireless power transmitter comprising: a transmitter coil structure comprising a magnetic layer having a geometric center line, the magnetic layer being curved symmetrically about the geometric center line; a first coil coupled to a second coil, the first coil and the second coil wound in such a way that when a current flows in the first coil in a first spatial direction the current flows in the second coil in a second spatial direction, the first coil and the second coil disposed on the magnetic layer substantially symmetrically about the geometric center line of the magnetic layer; and a housing including an outer surface having a convex shape, the transmitter coil structure being disposed underneath the outer surface of the housing. ### Claim 2 (depends on 1) The wireless power transmitter of claim 1, wherein the outer surface of the housing is curved substantially symmetrically about the geometric center line of the magnetic layer. ### Claim 3 (depends on 1) The wireless power transmitter of claim 1, wherein the housing has a cross-sectional area of a semicircular shape. ### Claim 4 (depends on 1) The wireless power transmitter of claim 1, wherein the outer surface of the housing has a shape substantially the same as the shape of the magnetic layer. ### Claim 5 (depends on 1) The wireless power transmitter of claim 1, further comprising at least one slot in the outer surface of the housing configured to hold a mobile device in a substantially upright position. ### Claim 6 (depends on 1) The wireless power transmitter of claim 1, further comprising at least one device holder coupled to the outer surface of the housing configured to hold a mobile device in a substantially upright position. ### Claim 7 (depends on 1) The wireless power transmitter of claim 1, wherein the magnetic layer is curved to form an angle from about 30° to about 150°. ### Claim 8 A wireless power transmitter comprising: a transmitter coil structure comprising a magnetic layer having a geometric center line, the magnetic layer being curved symmetrically about the geometric center line; a first coil coupled to a second coil, the first coil and the second coil wound in such a way that when a current flows in the first coil in a first spatial direction the current flows in the second coil in a second spatial direction, the first coil and the second coil disposed on the magnetic layer substantially symmetrically about the geometric center line of the magnetic layer; a power circuit configured to provide a time-varying current to the transmitter coil structure; and a housing including an outer surface having a convex shape, the transmitter coil structure being disposed underneath the outer surface of the housing. ### Claim 9 (depends on 8) The wireless power transmitter of claim 8, wherein the outer surface of the housing is curved substantially symmetrically about the geometric center line of the magnetic layer. ### Claim 10 (depends on 8) The wireless power transmitter of claim 8, wherein the housing has a cross-sectional area of a semicircular shape. ### Claim 11 (depends on 8) The wireless power transmitter of claim 8, wherein the outer surface of the housing has a shape substantially the same as the shape of the magnetic layer. ### Claim 12 (depends on 8) The wireless power transmitter of claim 8, further comprising at least one slot in the outer surface of the housing configured to hold a mobile device in a substantially upright position. ### Claim 13 (depends on 8) The wireless power transmitter of claim 8, further comprising at least one device holder coupled to the outer surface of the housing configured to hold a mobile device in a substantially upright position. ### Claim 14 (depends on 8) The wireless power transmitter of claim 8, wherein the magnetic layer is curved to form an angle from about 30° to about 150°. ### Claim 15 A wireless power transmitter comprising: a transmitter coil structure comprising a magnetic layer having a geometric center line, the magnetic layer forming an angle at the geometric center line; a first coil coupled to a second coil, the first coil and second coil wound in such a way that when a current flows in the first coil in a first spatial direction the current flows in the second coil in a second spatial direction, the first coil and the second coil disposed on the magnetic layer substantially symmetrically about the geometric center line of the magnetic layer; and a housing including an outer surface having a convex shape, the transmitter coil structure being disposed underneath the outer surface of the housing. ### Claim 16 (depends on 15) The wireless power transmitter of claim 15, wherein the outer surface of the housing is curved substantially symmetrically about the geometric center line of the magnetic layer. ### Claim 17 (depends on 15) The wireless power transmitter of claim 15, wherein the housing has a cross-sectional area of a semicircular shape. ### Claim 18 (depends on 15) The wireless power transmitter of claim 15, wherein the angle formed by the magnetic layer is an angle from about 30° to about 150°. ### Claim 19 (depends on 15) The wireless power transmitter of claim 15, further comprising at least one slot in the outer surface of the housing configured to hold a mobile device in a substantially upright position. ### Claim 20 (depends on 15) The wireless power transmitter of claim 15, further comprising at least one device holder coupled to the outer surface of the housing configured to hold a mobile device in a substantially upright position.