# US 10,375,639 B2 · Power transmission apparatus for wirelessly supplying power to power reception apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,375,639 B2 - Document ID: US10375639B2 - Status: Granted - Kind: B2 - Application number: 15/297,976 - Filed: 2016-10-19 - Published: 2017-04-27 - Granted: 2019-08-06 - Earliest claimed: 2015-10-23 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Nobuyuki Tsukamoto - Web page: https://patentgrep.com/patent/US10375639B2 ## CPC - H04W 52/0235: {where the received signal is a power saving command} - H04W 4/80: Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication - H04W 24/08: Testing, {supervising or monitoring} using real traffic - H04W 52/0261: {managing power supply demand, e.g. depending on battery level} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A power transmission apparatus includes a communication unit that executes communication with an electronic apparatus, a power transmission unit that wirelessly supplies power to the electronic apparatus, and a control unit that controls communication and power supply to be executed alternately, wherein the control unit adjusts communication power of the communication unit and transmission power of the power transmission unit and/or a length of a communication period and a length of a power transmission period, so that an average magnetic field intensity does not exceed a first magnetic field intensity in a predetermined region throughout the communication period of communication executed by the communication unit and the power transmission period of power transmission executed by the power transmission unit. ## Claims ### Claim 1 A power transmission apparatus comprising: a communication interface configured to execute communication with an electronic apparatus; a power transmitter configured to wirelessly supply power to the electronic apparatus; and a controller configured to control communication executed by the communication interface and power supply executed by the power transmitter to be executed alternately, wherein the controller adjusts communication power of the communication interface and transmission power of the power transmitter and/or a length of a communication period and a length of a power transmission period so that an average magnetic field intensity does not exceed a first magnetic field intensity in a predetermined region throughout the communication period of communication executed by the communication interface and the power transmission period of power transmission executed by the power transmitter; wherein the controller adjusts the communication power of the communication interface and the transmission power of the power transmitter and/or the length of the communication period and the length of the power transmission period so that a maximum magnetic field intensity does not exceed a second magnetic field intensity in the predetermined region throughout the communication period of communication executed by the communication interface and the power transmission period of power transmission executed by the power transmitter, and wherein the first magnetic field intensity is set to 10 A/m and the second magnetic field intensity is set to 12 A/m. ### Claim 2 (depends on 1) The power transmission apparatus according to claim 1, wherein the controller reduces the first magnetic field intensity or the second magnetic field intensity according to a lapse of time from a start of the power transmission executed by the power transmitter. ### Claim 3 (depends on 1) The power transmission apparatus according to claim 1, further comprising a temperature detection sensor configured to detect a temperature of the power transmission apparatus, wherein the controller reduces the first magnetic field intensity or the second magnetic field intensity according to an increase of the temperature detected by the temperature detection sensor. ### Claim 4 (depends on 1) The power transmission apparatus according to claim 1, wherein the predetermined region is a region where the communication interface can communicate with the electronic apparatus. ### Claim 5 (depends on 1) The power transmission apparatus according to claim 1 further comprising an antenna, wherein the communication interface wirelessly communicates with the electronic apparatus via the antenna, and wherein the power transmitter wirelessly supplies power to the electronic apparatus via the antenna. ### Claim 6 (depends on 1) The power transmission apparatus according to claim 1, wherein the communication interface executes communication based on a specification specified by a near field communication standard. ### Claim 7 (depends on 1) The power transmission apparatus according to claim 1, wherein the communication interface operates as a reader/writer. ### Claim 8 A control method for a power transmission apparatus including a communication interface for executing communication with an electronic apparatus and a power transmitter for wirelessly supplying power to the electronic apparatus, the control method comprising: controlling communication executed by the communication interface and power supply executed by the power transmitter to be executed alternately; adjusting communication power of the communication interface and transmission power of the power transmitter and/or a length of a communication period and a length of a power transmission period so that average magnetic field intensity does not exceed a first magnetic field intensity in a predetermined region throughout the communication period of communication executed by the communication interface and the power transmission period of power transmission executed by the power transmitter; and adjusting the communication power of the communication interface and the transmission power of the power transmitter and/or the length of the communication period and the length of the power transmission period so that a maximum magnetic field intensity does not exceed a second magnetic field intensity in the predetermined region throughout the communication period of communication executed by the communication interface and the power transmission period of power transmission executed by the power transmitter, wherein the first magnetic field intensity is set to 10 A/m and the second magnetic field intensity is set to 12 A/m. ### Claim 9 (depends on 8) The control method according to claim 8, further comprising reducing the first magnetic field intensity or the second magnetic field intensity according to a lapse of time from a start of the power transmission executed by the power transmitter. ### Claim 10 (depends on 8) The control method according to claim 8, further comprising detecting a temperature of the power transmission apparatus, wherein the first magnetic field intensity or the second magnetic field intensity is reduced according to detection of an increase of the temperature. ### Claim 11 (depends on 8) The control method according to claim 8, wherein the predetermined region is a region where the communication interface unit can communicate with the electronic apparatus. ### Claim 12 (depends on 8) The control method according to claim 8, wherein communication executed by the communication interface is based on a specification specified by a near field communication standard. ### Claim 13 A non-transitory computer-readable storage medium storing computer executable instructions for causing a power transmission apparatus including a communication interface unit configured to communicate with an electronic apparatus and a power transmitter configured to wirelessly supply power to the electronic apparatus to execute a control method, the control method comprising: controlling communication executed by the communication interface and power supply executed by the power transmitter to be executed alternately; adjusting communication power of the communication interface and transmission power of the power transmitter and/or a length of a communication period and a length of a power transmission period so that average magnetic field intensity does not exceed a first magnetic field intensity in a predetermined region throughout the communication period of communication executed by the communication interface and the power transmission period of power transmission executed by the power transmitter; and adjusting the communication power of the communication interface and the transmission power of the power transmitter and/or the length of the communication period and the length of the power transmission period so that a maximum magnetic field intensity does not exceed a second magnetic field intensity in the predetermined region throughout the communication period of communication executed by the communication interface and the power transmission period of power transmission executed by the power transmitter, wherein the first magnetic field intensity is set to 10 A/m and the second magnetic field intensity is set to 12 A/m.