# US 9,882,437 B2 · Power feeding apparatus, power receiving apparatus, power feeding system, and method of controlling power feeding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,882,437 B2 - Document ID: US9882437B2 - Status: Granted - Kind: B2 - Application number: 15/088,077 - Filed: 2016-03-31 - Published: 2016-08-25 - Granted: 2018-01-30 - Earliest claimed: 2013-08-28 - Assignees: Sony Corporation - Applicants: Sony Corporation - Inventors: Hiroaki Nakano; Toru Terashima; Keigo Bunsen; Osamu Kozakai; Kenichi Fujimaki - Web page: https://patentgrep.com/patent/US9882437B2 ## CPC - H02J 50/60: responsive to the presence of foreign objects, e.g. detection of living beings - H02J 50/12: of the resonant type - H02J 50/80: involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices - H04L 25/028: {Arrangements specific to the transmitter end} - H04L 25/03343: {Arrangements at the transmitter end} - H04L 25/03878: {Line equalisers; line build-out devices} - H02J 7/42: with electronic devices having internal batteries, e.g. mobile phones - H04L 25/0272: {Arrangements for coupling to multiple lines, e.g. for differential transmission} - H04L 25/4917: {using multilevel codes} - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A power feeding apparatus is provided. The power feeding apparatus includes a power feeding unit configured to supply electric power to a power receiving apparatus through a magnetic field; a measuring unit configured to measure an electric characteristic value and to generate a measurement value; a power receiving unit configured to provide a set value; and a foreign substance detection unit configured to detect a foreign substance in the magnetic field based on the set value and the measurement value. A power receiving apparatus, a power feeding system, and a method of controlling power feeding are also provided. ## Claims ### Claim 1 A power transmitting device comprising: a resonance circuit; and circuitry configured to: electronically perform a measurement on the resonance circuit to obtain a quality factor of the resonance circuit, electrically obtain a threshold value based on a reference value received from a power receiving device after feeding first electric energy from the resonance circuit to the power receiving device, electronically detect an absence of a foreign object in a magnetic field generated by the power transmitting device or a presence of the foreign object in the magnetic field by comparing the quality factor with the threshold value, and electronically perform a transmission of second electric energy from the resonance circuit to the power receiving device in a case where the absence is detected, the second electric energy is larger than the first electric energy. ### Claim 2 (depends on 1) The power transmitting device according to claim 1, wherein the resonance circuit wirelessly emits the magnetic field. ### Claim 3 (depends on 1) The power transmitting device according to claim 1, wherein the circuitry performs the measurement when the power receiving device is on a surface of the power transmitting device. ### Claim 4 (depends on 1) The power transmitting device according to claim 1, wherein the circuitry detects the presence of the foreign object in the magnetic field when the quality factor is less than the threshold value. ### Claim 5 (depends on 1) The power transmitting device according to claim 1, wherein the circuitry detects the presence of the foreign object in the magnetic field when the quality factor is equal to the threshold value. ### Claim 6 (depends on 1) The power transmitting device according to claim 1, wherein the circuitry detects the absence of the foreign object in the magnetic field when the quality factor is not less than the threshold value. ### Claim 7 (depends on 1) The power transmitting device according to claim 1, wherein the threshold value is less than the reference value. ### Claim 8 (depends on 1) The power transmitting device according to claim 1, wherein the threshold value is calculated from the reference value. ### Claim 9 A wireless power system comprising: a power transmitting device that has a resonance circuit, the power transmitting device configured to perform a measurement on the resonance circuit to obtain a quality factor of the resonance circuit; and a power receiving device configured to communicate a reference value to the power transmitting device after feeding first electric energy from the resonance circuit to the power receiving device, wherein the power transmitting device is configured to obtain a threshold value based on the reference value, and configured to detect an absence of a foreign object in a magnetic field generated by the power transmitting device or a presence of the foreign object in the magnetic field by comparing the quality factor with the threshold value, and electronically perform a transmission of second electric energy from the resonance circuit to the power receiving device in a case where the absence is detected, the second electric energy is larger than the first electric energy. ### Claim 10 (depends on 9) The wireless power system according to claim 9, wherein the power transmitting device detects the absence of the foreign object in the magnetic field when the quality factor is not less than the threshold value. ### Claim 11 (depends on 9) The wireless power system according to claim 9, wherein the power transmitting device detects the presence of the foreign object in the magnetic field when the quality factor is less than the threshold value. ### Claim 12 (depends on 9) The wireless power system according to claim 9, wherein the power transmitting device is configured to inhibit a wireless transfer of electric power from the power transmitting device to the power receiving device when the quality factor is lower than the threshold value. ### Claim 13 (depends on 9) The wireless power system according to claim 9, wherein the power transmitting device is configured to inhibit a wireless transfer of electric power from the power transmitting device to the power receiving device when the quality factor is equal to the threshold value. ### Claim 14 A power transmitting method for operating a power transmitting device that has a resonance circuit, the method comprising: performing a measurement on the resonance circuit to obtain a quality factor of the resonance circuit; receiving a reference value from a power receiving device after feeding first electric energy from the resonance circuit to the power receiving device; determining a threshold value based on the reference value; detecting an absence of a foreign object in a magnetic field generated by the power transmitting device or a presence of the foreign object in the magnetic field by comparing the quality factor with the threshold value; and electronically performing a transmission of second electric energy from the resonance circuit to the power receiving device in a case where the absence is detected, the second electric energy is larger than the first electric energy. ### Claim 15 (depends on 14) The power transmitting method according to claim 14, further comprising: terminating a wireless transfer of electric power from a power transmitting device to the power receiving device when the quality factor is lower than the threshold value. ### Claim 16 (depends on 14) The power transmitting method according to claim 14, further comprising: wirelessly transferring electric power from a power transmitting device to the power receiving device when the quality factor is not less than the threshold value. ### Claim 17 (depends on 14) The power transmitting method according to claim 14, wherein the measurement is performed before electric power is added to the magnetic field. ### Claim 18 (depends on 17) The power transmitting method according to claim 17, further comprising: terminating an addition of the electric power into the magnetic field after determining the presence of the foreign object in the magnetic field. ### Claim 19 (depends on 17) The power transmitting method according to claim 17, further comprising: adding the electric power to the magnetic field after determining the absence of the foreign object in the magnetic field.