US-12620840-B2 - Power transmission apparatus, power reception apparatus, and method

US12620840B2US 12620840 B2US12620840 B2US 12620840B2US-12620840-B2

Abstract

In a case where a power reception apparatus communicates with a power transmission apparatus using a first communication unit, the power reception apparatus transmits a packet and then transmits a next packet after a time T_silent elapses, and in a case where the power reception apparatus communicates with the power transmission apparatus using a second communication unit, the power reception apparatus transmits the packet and then transmits the next packet even in a case where the time T_silent does not elapse.

Inventors

Takahiro Shichino
Wataru Tachiwa

Assignees

CANON KABUSHIKI KAISHA

Dates

Publication Date: 20260505
Application Date: 20240325
Priority Date: 20210927

Claims (19)

1 . A power reception apparatus comprising: a power reception unit configured to wirelessly receive power from a power transmission apparatus via a first antenna; a first communication unit configured to perform communication via the first antenna; and a second communication unit configured to perform communication via a second antenna, wherein in a case where the power reception apparatus communicates with the power transmission apparatus using the first communication unit, the first communication unit transmits a packet and then transmits a next packet after a predetermined period during which at least transmission of a packet is prohibited elapses, and wherein in a case where the power reception apparatus communicates with the power transmission apparatus using the second communication unit, the second communication unit transmits a packet and then transmits a next packet even in a case where the predetermined period has not elapsed.
2 . The power reception apparatus according to claim 1 , wherein in a case where the power reception apparatus communicates with the power transmission apparatus using the first communication unit, the first communication unit does not to start transmitting a preamble of the next packet within the predetermined period.
3 . The power reception apparatus according to claim 1 , wherein the predetermined period is a silent time defined by a Wireless Power Consortium (WPC) standard.
4 . The power reception apparatus according to claim 1 , wherein in a case where the power reception apparatus communicates with the power transmission apparatus using the first communication unit, the first communication unit transmits a packet for controlling power and then transmits a next packet after a waiting period at least including another predetermined period different from the predetermined period elapses, and wherein in a case where the power reception apparatus communicates with the power transmission apparatus using the second communication unit, the second communication unit transmits a packet for controlling power and then transmits a next packet after the waiting period that does not include another predetermined period elapses.
5 . The power reception apparatus according to claim 4 , wherein the another predetermined period is a power control hold-off time defined by the WPC standard.
6 . The power reception apparatus according to claim 4 , wherein the packet for controlling power is a control error packet defined by the WPC standard.
7 . The power reception apparatus according to claim 1 , wherein the second communication unit performs communication according to Bluetooth (registered trademark) Low Energy (BLE) defined by a Bluetooth (registered trademark) 4.0 standard or later.
8 . The power reception apparatus according to claim 1 , further comprising: a battery configured to store power received by the power reception unit; and a motor configured to drive a wheel using the power in the battery.
9 . The power reception apparatus according to claim 1 , further comprising: a battery configured to store power received by the power reception unit; and a display unit to which the power in the battery is supplied.
10 . The power reception apparatus according to claim 1 , further comprising: a battery configured to store power received by the power reception unit; and a notification unit configured to give a notification of a remaining amount of the battery.
11 . A power transmission apparatus comprising: a power transmission unit configured to wirelessly transmit power to a power reception apparatus via a first antenna; a first communication unit configured to perform communication via the first antenna; and a second communication unit configured to perform communication via a second antenna, wherein in a case where the power transmission apparatus communicates with the power reception apparatus using the first communication unit, the first communication unit receives a packet from the power reception apparatus and then receives a next packet after a predetermined period during which at least transmission of a packet from the power reception apparatus is prohibited elapses, and wherein in a case where the power transmission apparatus communicates with the power reception apparatus using the second communication unit, the second communication unit receives a packet from the power reception apparatus and then receives a next packet even in a case where the predetermined period has not elapsed.
12 . The power transmission apparatus according to claim 11 , wherein the predetermined period is a silent time defined by a Wireless Power Consortium (WPC) standard.
13 . The power transmission apparatus according to claim 11 , wherein in a case where the power transmission apparatus communicates with the power reception apparatus using the first communication unit, the first communication unit receives a packet for controlling power from the power reception apparatus and then receives a next packet after a waiting period at least including another predetermined period different from the predetermined period elapses, and in a case where the power transmission apparatus communicates with the power reception apparatus using the second communication unit, the second communication unit receives a packet for controlling power from the power reception apparatus and then receives a next packet after the waiting period that does not include another predetermined period elapses.
14 . The power transmission apparatus according to claim 13 , wherein the another predetermined period is a power control hold-off time defined by the WPC standard.
15 . The power transmission apparatus according to claim 13 , wherein the packet for controlling power is a control error packet defined by the WPC standard.
16 . The power transmission apparatus according to claim 11 , further comprising: a wheel; and a battery, wherein the power transmission unit wirelessly transmits power to the power reception apparatus using power in the battery.
17 . The power transmission apparatus according to claim 11 , wherein the power transmission apparatus is installed in a vehicle.
18 . A method for a power reception apparatus including a first antenna, and a second antenna, the method comprising: in a case where the power reception apparatus communicates with the power transmission apparatus using the first antenna, transmitting a packet and then transmitting a next packet after a predetermined period during which at least transmission of a packet is prohibited elapses, and in a case where the power reception apparatus communicates with the power transmission apparatus using the second antenna, transmitting a packet and then transmitting a next packet even in a case where the predetermined period has not elapsed.
19 . A method for a power transmission apparatus including a first antenna, and a second antenna, the method comprising: in a case where the power transmission apparatus communicates with the power reception apparatus using the first antenna, receiving a packet from the power reception apparatus and then receiving a next packet after a predetermined period during which at least transmission of a packet from the power reception apparatus is prohibited elapses, and in a case where the power transmission apparatus communicates with the power reception apparatus using the second communication unit, receiving a packet from the power reception apparatus and then receiving a next packet before the predetermined period elapses.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation of International Patent Application No. PCT/JP2022/034808, filed Sep. 16, 2022, which claims the benefit of Japanese Patent Application No. 2021-156856, filed Sep. 27, 2021, both of which are hereby incorporated by reference herein in their entireties. BACKGROUND Field The present disclosure relates to a wireless power transmission technique. Background Art In recent years, a technique for a wireless power transmission system has been widely developed. Patent literature 1 discusses a power transmission apparatus and a power reception apparatus compliant with a standard formulated by a standards body called the Wireless Power Consortium (WPC) (hereinafter referred to as the “WPC standard”). The transmission power of wirelessly transmitted power changes according to the state of the power reception apparatus or the positional relationship between the power transmission apparatus and the power reception apparatus. In the WPC standard, the power reception apparatus transmits a control error (hereinafter referred to as “CE”) packet to the power transmission apparatus, and the power transmission apparatus adjusts the transmission power based on the CE packet. The power reception apparatus transmits the CE packet at a timing determined in advance, whereby the power transmission apparatus can control the transmission power almost in real time. On the other hand, patent literature 2 discusses a communication method in which a power transmission apparatus or a power reception apparatus performs communication using a frequency different from a frequency used in wireless power transmission via an antenna different from an antenna used to transmit and receive power in the wireless power transmission. CITATION LIST Patent Literature PTL 1: Japanese Patent Laid-Open No. 2016-007116PTL 2: Japanese Patent Laid-Open No. 2019-187070 In the WPC standard, in communication for controlling wireless power transmission performed by a power transmission apparatus and a power reception apparatus via an antenna used to transmit and receive power in the wireless power transmission, the communication timing of the communication is defined. However, in a case where communication for controlling the wireless power transmission is performed via an antenna different from the antenna used to transmit and receive power in the wireless power transmission, the communication timing of the communication defined by the WPC standard may not be appropriate. For example, a communication prohibition period that is not necessary in the communication via the antenna different from the antenna used to transmit and receive power in the wireless power transmission may be set. Then, the period between communication and communication may become long, and accurate control according to the situation may not be able to be performed. SUMMARY The present disclosure provides a technique for, in a case where a plurality of communication methods for controlling wireless power transmission can be used, controlling an appropriate communication timing. According to an aspect of the present disclosure, a power reception apparatus wirelessly receives power from a power transmission apparatus via a first antenna, performs communication via the first antenna, and performs communication via a second antenna. In a case where the power reception apparatus communicates with the power transmission apparatus using the first communication unit, the first communication unit transmits a packet and then transmits a next packet after a predetermined period during which at least transmission of a packet is prohibited elapses, and in a case where the power reception apparatus communicates with the power transmission apparatus using the second communication unit, the second communication unit transmits a packet and then transmits a next packet even in a case where the predetermined period has not elapsed. Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a configuration of a wireless power transmission system. FIG. 2 is a diagram illustrating a configuration of a power transmission apparatus. FIG. 3 is a diagram illustrating a configuration of a power reception apparatus. FIG. 4 is a flowchart of a process performed by the power transmission apparatus according to a first exemplary embodiment. FIG. 5 is a flowchart of a process performed by the power reception apparatus according to the first exemplary embodiment. FIG. 6 is a flowchart of a timing constraint determination process performed by the power reception apparatus. FIG. 7 is a flowchart of a timing constraint determination process performed by the power transmission apparatus. FIG. 8 is a diagram illustrating a relationship between a Bluetooth (registered trademark) Low Energy (BL