CLOCK TUNING FOR A WIRELESS CHARGING SYSTEM

• US 20180351389A1
• Filed: 09/14/2017
• Published: 12/06/2018
• Est. Priority Date: 06/01/2017
• Status: Active Grant

• Current Assignee: Logitech Europe S A (Logitech International SA)
• Original Assignee: Logitech Europe S A (Logitech International SA)
• Inventors: Morier, Francois, Plancherel, Laurent, Jeannerat, Florian, Salathe, Jean, Favey, Hugues, Fortin, Frederic, Sauterel, Fabrice
• Granted Patent: US 10,749,368 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 2203/0384 Wireless input, i.e. hardware and software details of wireless interface arrangements for pointing devices
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: G06F 3/0395 Mouse pads
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034

Abstract

A method of operating a computer mouse includes receiving electromagnetic (EM) radiation emitted from a source external to the computer mouse, the received EM radiation induces noise within one or more bands of noise frequencies and an image sensor circuit of the computer mouse generates erroneous movement detection signals in response to an operating frequency of the image sensor circuit being within the one or more bands of noise frequencies. The method further includes determining the operating frequency of the image sensor circuit, comparing the operating frequency to a target frequency, wherein the target frequency is outside of the one or more bands of noise frequencies, and tuning the operating frequency of the image sensor circuit towards the target frequency.

Claims

1. A computer mouse comprising:

a housing;

one or more processors coupled to the housing; and

an image sensor circuit coupled to the housing and operatively coupled to the one or more processors, the image sensor circuit configured to image a surface to detect movement of the computer mouse with respect to the surface,

wherein the image sensor circuit is configured to operate at an operating frequency while imaging the surface and wherein the operating frequency drifts as a result of a change of temperature of the computer mouse; and

wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit towards a target frequency in response to the operating frequency of the image sensor circuit deviating from the target frequency.

2. The computer mouse of claim 1, wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit towards the target frequency in response to the operating frequency deviating from the target frequency by a threshold frequency value.

3. The computer mouse of claim 1, wherein the image sensor circuit is configured to be tunable by at least a minimum frequency step, and wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit towards the target frequency in response to the operating frequency deviating from the target frequency by at least the minimum frequency step.

4. The computer mouse of claim 1, wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit towards the target frequency in response to the operating frequency deviating from the target frequency and a noise level increases to a threshold value, wherein the noise level is based on a surface quality measurement that is measured with a light emitting component of the computer mouse disabled from emitting light.

5. The computer mouse of claim 1, wherein the target frequency of the image sensor circuit is between sixty-six MHz and sixty-eight MHz.

6. The computer mouse of claim 1, further comprising an external oscillator operatively coupled to the image sensor circuit, the external oscillator configured to drive the image sensor circuit to operate at the operating frequency.

7. The computer mouse of claim 1, wherein the target frequency is a frequency of the image sensor circuit that produces a noise signal in the image sensor circuit that is at a local minimum within a portion of a noise interference distribution.

8. The computer mouse of claim 7, wherein the noise interference distribution is induced by a wireless charging device electromagnetically coupled to the computer mouse to provide the computer mouse with electrical power.

9. The computer mouse of claim 7, wherein the target frequency is within a range of 66.9 MHz+/−

500 kHz.

10. An input device comprising:

one or more processors;

an energy storage component electrically coupled to the one or more processors;

a charging circuit electrically coupled to the energy storage component, the charging circuit configured to wirelessly receive electromagnetic (EM) power from a base device to charge the energy storage component, the base device having a surface and the EM power having an EM frequency; and

an image sensor circuit controlled by the one or more processors, the image sensor circuit configured to image the surface of the base device to detect movement of input device with respect to the surface of the base device and the image sensor circuit is configured to operate at an operating frequency,

wherein the EM frequency generates noise on the image sensor circuit to cause erroneous movement detection of the input device in response to the operating frequency of the image sensor circuit being within one or more bands of noise frequencies, and

wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit to prevent the operating frequency of the image sensor circuit from falling within the one or more bands of noise frequencies.

11. The input device of claim 10, wherein the operating frequency of the image sensor circuit is within a range of 66.9 MHz+/−

500 kHz.

12. The input device of claim 10, wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit towards a target frequency in response to the operating frequency deviating from the target frequency by a threshold frequency value.

13. The input device of claim 10, wherein the image sensor circuit is configured to be tunable by at least a minimum frequency step, and wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit towards a target frequency in response to the operating frequency deviating from the target frequency by at least the minimum frequency step.

14. The input device of claim 10, wherein the one or more processors are configured to tune the operating frequency of the image sensor circuit in response to the operating frequency being closer than a minimum allowable distance from the one or more bands of noise frequencies.

15. A method of operating a computer mouse, the method comprising:

receiving electromagnetic (EM) radiation emitted from a source external to the computer mouse, wherein the received EM radiation induces noise within one or more bands of noise frequencies and an image sensor circuit of the computer mouse generates erroneous movement detection signals in response to an operating frequency of the image sensor circuit being within the one or more bands of noise frequencies;

determining the operating frequency of the image sensor circuit;

comparing the operating frequency to a target frequency, wherein the target frequency is outside of the one or more bands of noise frequencies; and

tuning the operating frequency of the image sensor circuit towards the target frequency.

16. The method of claim 15, further comprising waking the computer mouse from a sleep mode before determining the operating frequency of the image sensor circuit.

17. The method of claim 15, further comprising:

suspending a position measurement of the computer mouse before determining the operating frequency; and

resuming the position measurement after tuning the operating frequency of the image sensor circuit.

18. The method of claim 15, wherein the target frequency is within a range of 66.9 MHz+/−

500 kHz.

19. The method of claim 15, wherein:

the EM radiation is received by an antenna of the computer mouse;

the source external to the computer mouse is a base device; and

the antenna is electrically coupled to an energy storage component of the computer mouse configured to be charged with power provided by the EM radiation.

20. A method of operating an input device, the method comprising:

suspending, for a suspension time period, a transmission of position data;

determining an operating frequency of an image sensor circuit;

comparing the operating frequency of the image sensor circuit to a target frequency, wherein the target frequency is selected based on an interference-induced noise within one or more frequency bands, the interference-induced noise is caused by a wireless charging system operatively coupled to the input device, the interference-induced noise causes the image sensor circuit to generate erroneous movement tracking data in response the operating frequency of the image sensor circuit falling within the one or more frequency bands, and the target frequency is not included in the one or more frequency bands;

determining that the operating frequency deviates from the target frequency;

in response to determining that the operating frequency deviates from the target frequency, tuning the operating frequency of the image sensor circuit to converge towards the target frequency; and

resuming the transmission of position data.

21. The method of claim 20, further comprising waking the input device from a sleeping state before determining the operating frequency of the image sensor circuit.

22. The method of claim 20, wherein resuming the transmission of position data further comprises sending position data that has accumulated during the suspension time period.

23. The method of claim 20, wherein the determining an operating frequency,

the comparing and the tuning are accomplished within the suspension time period.

24. The method of claim 20, wherein the suspension time period is less than a time period for accumulating a single report of position data.

25. The method of claim 20, wherein the target frequency is within a range of 66.9 MHz+/−

500 kHz.

26. A method of operating an input device, the method comprising:

monitoring an interference level in an output of an image sensor circuit, the interference level induced by an electromagnetic (EM) field;

determining one or more frequency bands where the interference level is below a threshold value;

determining that an operating frequency of the image sensor circuit is drifting away from the one or more frequency bands in response to a change in an operating temperature of the image sensor circuit; and

in response to determining that the operating frequency of the image sensor circuit is drifting away from the one or more frequency bands in response to a change in an operating temperature of the image sensor circuit, dynamically adjusting the operating frequency of the image sensor circuit to remain in the one or more frequency bands.