Method, apparatus, and computer-readable storage medium for contactless power supply and power control

• US 9,525,209 B2
• Filed: 08/25/2011
• Issued: 12/20/2016
• Est. Priority Date: 08/31/2010
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tanabe, Akihiro
• Primary Examiner(s): Rodas, Richard Isla
• Assistant Examiner(s): Henze-Gongola, David V
• Application Number:
  US13/218,326
• Publication Number:
  US 20120049791A1
• Time in Patent Office: 1,944 Days
• Field of Search: 320/108
• US Class Current: 1/1
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A power supply apparatus includes a supply unit that supplies power to an external apparatus wirelessly by using a quality factor that indicates the resonance characteristic of the power supply apparatus and a control unit that controls the quality factor.

Claims

1. A power supply apparatus comprising:

an antenna unit that is used to wirelessly supply power to a power receiving apparatus;

a matching unit coupled to the antenna unit; and

a control unit that (a) determines whether a value of quality factor is larger than a predetermined value or not before a process of transmitting a predetermined command to the power receiving apparatus via the antenna unit is performed and after the antenna unit wirelessly supplies the power to the power receiving apparatus, (b) changes the value of quality factor to be less than the predetermined value by controlling the matching unit before the process of transmitting the predetermined command to the power receiving apparatus via the antenna unit is performed and after the antenna unit wirelessly supplies the power to the power receiving apparatus, when the value of quality factor is larger than the predetermined value, (c) performs the process of transmitting the predetermined command to the power receiving apparatus via the antenna unit without changing the value of quality factor to be less than the predetermined value by controlling the matching unit, when the value of quality factor is not larger than the predetermined value, and (d) after receiving a response from the power receiving apparatus, increases the quality factor to a value larger than the predetermined value wherein the quality factor is increased regardless of whether a response is received once a predetermined time period has elapsed.

2. The power supply apparatus according to claim 1, wherein the control unit decreases the value of quality factor by controlling the matching unit when a condition for decreasing power to be supplied to the power receiving apparatus is satisfied, and

wherein the control unit increases the value of quality factor by controlling the matching unit when a condition for increasing power to be supplied to the power receiving apparatus is satisfied.

6. The power supply apparatus according to claim 1, wherein the control unit adjusts a resonance frequency of the power supply apparatus to be a predetermined frequency by controlling the matching unit, when the value of quality factor is changed to be less than the predetermined value.

7. The power supply apparatus according to claim 1, wherein the control unit adjusts a resonance frequency of the power supply apparatus to be a predetermined frequency by controlling the matching unit, when the value of quality factor is changed to be larger than the predetermined value.

8. The power supply apparatus according to claim 1, wherein the matching unit includes:

a coil that is connected to the antenna unit in series;

a first capacitor that is connected to the antenna unit in parallel; and

a second capacitor that is connected to the coil in series.

9. The power supply apparatus according to claim 1, wherein the predetermined command is used to obtain identification information of the power receiving apparatus.

10. The power supply apparatus according to claim 1, wherein the predetermined command is used to obtain capability information of the power receiving apparatus.

11. The power supply apparatus according to claim 1, wherein the antenna unit is used to wirelessly supply power to the power receiving apparatus by electromagnetic induction or magnetic field resonance.

12. The power supply apparatus according to claim 1, wherein the power receiving apparatus includes a camera, a phone, or an audio player.

3. A method comprising:

determining whether a value of quality factor is larger than a predetermined value or not before a process of transmitting a predetermined command to a power receiving apparatus via an antenna unit is performed and after wirelessly supplying power to the power receiving apparatus, wherein the antenna unit is used to wirelessly supply power to the power receiving apparatus;

changing the value of quality factor to be less than the predetermined value by controlling a matching unit coupled to the antenna unit before the process of transmitting the predetermined command to the power receiving apparatus via the antenna unit is performed and after wirelessly supplying the power to the power receiving apparatus, when the value of quality factor is larger than the predetermined value;

performing the process of transmitting the predetermined command to the power receiving apparatus via the antenna unit without changing the value of quality factor to be less than the predetermined value by controlling the matching unit, when the value of quality factor is not larger than the predetermined value, and

after receiving a response from the power receiving apparatus, increases the quality factor to a value larger than the predetermined value wherein the quality factor is increased regardless of whether a response is received once a predetermined time period has elapsed.

5. The method according to claim 3, further comprising:

decreasing the value of quality factor by controlling the matching unit when a condition for decreasing power to be supplied to the power receiving apparatus is satisfied; and

increasing the value of quality factor by controlling the matching unit when a condition for increasing power to be supplied to the power receiving apparatus is satisfied.

13. The method according to claim 3, further comprising adjusting a resonance frequency of a power supply apparatus to be a predetermined frequency by controlling the matching unit, when the value of quality factor is changed to be less than the predetermined value.

14. The method according to claim 3, further comprising adjusting a resonance frequency of a power supply apparatus to be a predetermined frequency by controlling the matching unit, when the value of quality factor is changed to be larger than the predetermined value.

15. The method according to claim 3, wherein the matching unit includes:

a coil that is connected to the antenna unit in series;

a first capacitor that is connected to the antenna unit in parallel; and

a second capacitor that is connected to the coil in series.

16. The method according to claim 3, wherein the predetermined command is used to obtain identification information of the power receiving apparatus.

17. The method according to claim 3, wherein the predetermined command is used to obtain capability information of the power receiving apparatus.

18. The method according to claim 3, wherein the antenna unit is used to wirelessly supply power to the power receiving apparatus by electromagnetic induction or magnetic field resonance.

19. The method according to claim 3, wherein the power receiving apparatus includes a camera, a phone, or an audio player.

4. A non-transitory storage medium that stores a program for causing a computer to perform a method, the method comprising:

determining whether a value of quality factor is larger than a predetermined value or not before a process of transmitting a predetermined command to a power receiving apparatus via an antenna unit is performed and after wirelessly supplying power to the power receiving apparatus, wherein the antenna unit is used to wirelessly supply power to the power receiving apparatus;

changing the value of quality factor to be less than the predetermined value by controlling a matching unit coupled to the antenna unit before the process of transmitting the predetermined command to the power receiving apparatus via the antenna unit is performed and after wirelessly supplying the power to the power receiving apparatus, when the value of quality factor is larger than the predetermined value; and

performing the process of transmitting the predetermined command to the power receiving apparatus via the antenna unit without changing the value of quality factor to be less than the predetermined value by controlling the matching unit, when the value of quality factor is not larger than the predetermined value,

after receiving a response from the power receiving apparatus, increases the quality factor to a value larger than the predetermined value wherein the quality factor is increased regardless of whether a response is received once a predetermined time period has elapsed.