US-12627171-B2 - Power transmission apparatus, control method executed by power transmission apparatus, and storage medium

Abstract

When a communication unit receives an end power transfer (EPT) packet including information about a power transmission stop period from a power reception apparatus, a power transmission apparatus controls a power transmission coil to transmit a checking signal for checking existence of the power reception apparatus during the power transmission stop period, detects at least one of a voltage or a current applied to the power transmission coil when the checking signal is transmitted, and determines whether the power reception apparatus that has transmitted the EPT packet exists, based on the detection result.

Inventors

• Hiroshi Mashimo

Assignees

• CANON KABUSHIKI KAISHA

Dates

Publication Date

20260512

Application Date

20241023

Priority Date

20190424

Claims (8)

1. 1 . A power transmission apparatus wirelessly transmitting power, the power transmission apparatus comprising: a transmission unit configured to transmit a signal; a receiving unit configured to receive configuration information from a power reception apparatus; and a detection unit configured to perform processing for detecting an object, wherein the transmission unit transmits a second signal to wake up a power reception apparatus in a case where an object is detected by the detection unit after a first signal is transmitted by the transmission unit, the transmission unit transmits a third signal after the second signal is transmitted, the detection unit performs, after the third signal is transmitted, processing for detecting an object based on a parameter obtained when there is no object and a parameter obtained after the third signal is transmitted, and the transmission unit transmits the first signal in a case where an object is not detected by the detection unit after the third signal is transmitted.
2. 2 . The power transmission apparatus according to claim 1 , wherein the transmission unit transmits the second signal, in a case where an object is not detected after the third signal is transmitted and, in a case where an object is detected after the first signal is transmitted.
3. 3 . The power transmission apparatus according to claim 1 , wherein in a case where the object which is detected after the first signal is transmitted is a power reception apparatus, power to the power reception apparatus is transmitted.
4. 4 . The power transmission apparatus according to claim 1 , wherein the second signal is a Digital Ping compliant with a standard of the Wireless Power Consortium.
5. 5 . The power transmission apparatus according to claim 1 , wherein the first signal is an Analog Ping compliant with a standard of the Wireless Power Consortium.
6. 6 . The power transmission apparatus according to claim 1 , wherein the third signal is a signal to check presence of a power reception apparatus that has requested to stop power transfer.
7. 7 . A method for a power transmission apparatus wirelessly transmitting power, the method comprising: transmitting a first signal; performing processing for detecting an object after the first signal is transmitted; transmitting a second signal to wake up a power reception apparatus in a case where an object is detected after the first signal is transmitted; transmitting a third signal after the second signal is transmitted; performing, after the third signal is transmitted, processing for detecting an object based on a parameter obtained when there is no object and a parameter obtained after the third signal is transmitted; transmitting the first signal in a case where an object is not detected after the third signal is transmitted; and receiving configuration information from a power reception apparatus, in a case where the object which is detected after the first signal is transmitted is the power reception apparatus.
8. 8 . A non-transitory computer-readable storage medium storing a program causing a computer to execute a method for a power transmission apparatus that wirelessly transmits power, the method comprising: transmitting a first signal; performing processing for detecting an object after the first signal is transmitted; transmitting a second signal to wake up a power reception apparatus in a case where an object is detected after the first signal is transmitted; transmitting a third signal after the second signal is transmitted; and performing, after the third signal is transmitted, processing for detecting an object based on a parameter obtained when there is no object and a parameter obtained after the third signal is transmitted; transmitting the first signal in a case where an object is not detected after the third signal is transmitted; and receiving configuration information from a power reception apparatus, in a case where the object which is detected after the first signal is transmitted is the power reception apparatus.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 17/718,911, filed on Apr. 12, 2022, which is a continuation of U.S. patent application Ser. No. 16/853,056, filed on Apr. 20, 2020, now U.S. Pat. No. 11,329,512 issued May 10, 2022, which claims priority from Japanese Patent Application No. 2019-083243 filed Apr. 24, 2019, which are hereby incorporated by reference herein in their entireties. BACKGROUND Field The present disclosure relates to a power transmission apparatus, a control method executed by the power transmission apparatus, and a storage medium. Description of the Related Art In recent years, a wireless power transfer system such as a wireless charging system has been developed extensively. Japanese Patent Application Laid-Open No. 2015-165761 discusses a power transfer apparatus and a power reception apparatus compliant with a standard (hereinafter, called as “WPC standard”) established by a standard-setting organization of a wireless charging system, the Wireless Power Consortium (WPC). Japanese Patent Application Laid-Open No. 2015-165761 further discusses a technique in which a signal indicating a stop of power transmission is transmitted when the power reception apparatus detects abnormality. Using the above-described signal indicating a stop of power transmission, a power transmission stop period can be specified. More specifically, information specifying a power transmission stop period can be contained in the signal indicating a stop of power transmission. If the power transmission apparatus receives the signal, indicating a stop of power transmission, containing the information specifying a power transmission stop period, the power transmission apparatus stops power transmission during the specified power transmission stop period. Accordingly, transmission of a signal for detecting an object may also not be transmitted. In this case, even if the power reception apparatus placed on the power transmission apparatus is removed from the power transmission apparatus during the power transmission stop period, the removal of the power reception apparatus cannot be detected until after the power transmission stop period has passed. Consequently, it may take time to detect the removal of the power reception apparatus. SUMMARY Various embodiments of the present disclosure are directed to a technique for enabling a power transmission apparatus that receives a power transmission stop signal specifying a power transmission stop period to detect removal of a power reception apparatus even during a period when power transmission is stopped. According to one embodiment of the present disclosure, a power transmission apparatus includes an antenna configured to wirelessly transmit power to a power reception apparatus, a receiving unit configured to receive a signal from the power reception apparatus, a detection unit configured to detect at least one of a voltage or a current applied to the antenna, and a control unit configured to control the antenna, based on reception of a signal from the power reception apparatus, the signal indicating a stop of power transmission and including information about a power transmission stop period, to transmit a checking signal for checking existence of the power reception apparatus that has transmitted the signal indicating a stop of power transmission, during the power transmission stop period, wherein the detection unit detects at least one of a voltage or a current applied to the antenna when the checking signal is transmitted, and wherein the control unit determines whether the power reception apparatus that has transmitted the signal indicating a stop of power transmission exists, based on a detection result acquired by the detection unit. Further features will become apparent from the following description of example embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a configuration example of a power transmission apparatus according to one example embodiment. FIG. 2 is a block diagram illustrating a configuration example of a power reception apparatus according to one example embodiment. FIG. 3 is a diagram illustrating an example of a wireless power transfer system according to one example embodiment. FIG. 4 is a diagram illustrating an example of a sequence of processing, according to one example embodiment, which is executed when a power reception apparatus is not removed. FIG. 5 is a diagram illustrating an example of a sequence of processing, according to one example embodiment, which is executed when a power reception apparatus is removed and a new power reception apparatus is placed. FIG. 6 is a flowchart illustrating an example of processing executed by the power transmission apparatus according to one example embodiment. DESCRIPTION OF THE EMBODIMENTS Hereinafter, an example embodiment of the present disclosure will be d