Electronic devices with calibrated compasses

Patent metadata

Field	Value
Publication number	US-9329038-B2
Application number	US-201113250785-A
Country	US
Kind code	B2
Filing date	Sep 30, 2011
Priority date	Sep 30, 2011
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

Electronic devices may be provided with compasses for detecting the Earth's magnetic field. Electronic devices may be provided with other electronic components. A compass may include a magnetic sensor and control circuitry configured to apply offsets or other compass calibration data to compass data to compensate for magnetic interference from the other electronic components. Other electronic components may include components such as cameras, auto-focus lens mechanisms, light sources, and displays. The control circuitry may be configured to apply compass calibration data that is specific to an electronic component and that is specific to an operational status of the component. The control circuitry may be configured to recognize a replacement electronic component and revert to an average compass calibration correction. The control circuitry may be configured to output interference-corrected compass data to applications running on the electronic device.

First claim

What is claimed is:

1. A method for operating an electronic device having control circuitry, an electronic component comprising a camera having a lens and an image pixel array that is operated using the control circuitry, and a compass that is operated using the control circuitry, the method comprising:
operating the electronic component, wherein operating the electronic component produces magnetic interference for the compass;
obtaining compass data with the compass;
with the control circuitry, obtaining a position of the lens with respect to the image pixel array; and
with the control circuitry, applying compass calibration data to the compass data in response to the operation of the electronic component that produces the magnetic interference, wherein applying the compass calibration data comprises applying the compass calibration data based on the position of the lens with respect to the image pixel array.

2. A method for operating an electronic device having control circuitry, an electronic component comprising a light source that is operated using the control circuitry, and a compass that is operated using the control circuitry, the method comprising:
operating the electronic component, wherein operating the electronic component produces magnetic interference for the compass;
obtaining compass data with the compass;
with the control circuitry, obtaining a power level associated with electrical power that is supplied to the light source; and
with the control circuitry, applying compass calibration data to the compass data in response to the operation of the electronic component that produces the magnetic interference, wherein applying the compass calibration data comprises applying the compass calibration data based on the power level.

3. The method defined in claim 1 wherein the control circuitry is provided with component-specific calibration data associated with the electronic component and wherein applying the compass calibration data comprises applying the component-specific calibration data to the compass data to calibrate the compass data.

4. The method defined in claim 3 wherein the electronic component has a serial number, wherein the component-specific calibration data is associated with the serial number, and wherein applying the compass calibration data comprises applying the component-specific calibration data that is associated with the serial number to the compass data to calibrate the compass data.

5. The method defined in claim 1 wherein applying the compass calibration data comprises applying the compass calibration data based at least partly on which manufacturer produced the electronic component.

6. A method of using a calibration system to calibrate an electronic device having an electronic component and a compass that generates compass data and that is susceptible to magnetic interference from the electronic component, the method comprising:
operating the electronic component to produce the magnetic interference, wherein the electronic component has a first operational state and a second operational state;
with the calibration system, collecting test data from the compass while operating the component, wherein the test data is influenced by the magnetic interference; and
generating compass calibration data from the test data, wherein the electronic device uses the compass calibration data to adjust the compass data based on the operation of the electronic component that produces the magnetic interference, wherein the compass calibration data comprises compass calibration data specific to the first operational state and compass calibration data specific to the second operational state and wherein the electronic device is configured to apply the compass calibration data specific to the first operational state to the compass data when the electronic component is in the first operational state and is configured to apply the compass calibration data specific to the second operational state to the compass data when the electronic component is in the second operational state.

7. The method defined in claim 6 further comprising:
placing the electronic device in a test chamber to magnetically isolate the electronic device, wherein collecting the test data comprises collecting the test data from the compass while the electronic device is located within the test chamber.

8. The method defined in claim 6 wherein operating the electronic component comprises controlling the electronic component with the calibration system to change the electronic component from the first operational state to the second operational state.

9. The method defined in claim 8 wherein the electronic component comprises a camera having a lens and wherein controlling the electronic component comprises moving the lens.

10. The method defined in claim 8 wherein the electronic component comprises a light source and wherein controlling the electronic component comprises increasing power to the light source.

11. The method defined in claim 6 further comprising:
loading the compass calibration data into the electronic device.

12. The method defined in claim 6 further comprising:
with the calibration system, gathering additional test data for compasses in additional electronic devices;
producing additional compass calibration data from the additional test data for the additional electronic devices; and
loading the compass calibration data and the additional compass calibration data into the electronic device.

13. An electronic device, comprising:
a compass that produces compass data;
an electronic component that generates a magnetic field that interferes with the compass during operation of the electronic component; and
control circuitry that applies compass calibration data to the compass data in response to the operation of the electronic component that generates the magnetic field that interferes with the compass, wherein the control circuitry is configured to obtain operational status information for the electronic component, wherein the electronic component has a first operational state and a second operational state, wherein the compass calibration data comprises compass calibration data specific to the first operational state and compass calibration data specific to the second operational state and wherein the control circuitry is configured to apply the compass calibration data specific to the first operational state to the compass data when the electronic component is in the first operational state and is configured to apply the compass calibration data specific to the second operational state to the compass data when the electronic component is in the second operational state.

14. The electronic device defined in claim 13 wherein the electronic component comprises a camera having a lens, at least one fixed magnet, and a wire coil, wherein an electric current that flows through the wire coil generates the magnetic field, and wherein the control circuitry is configured to change the electric current to move the lens.

15. The electronic device defined in claim 13 wherein the electronic component comprises a light source with an associated power supply line, wherein an electric current that flows through the power supply line generates at least a portion of the magnetic field, and wherein the control circuitry is configured to control the electric current.

16. The electronic device defined in claim 13 wherein the control circuitry is configured to apply the compass calibration data by applying at least one pre-calibrated offset that is specific to the electronic component.

Assignees

• Wade Jeremy L
• Garrone Ryan J
• Apple Inc

Inventors

• Wade Jeremy L
• Garrone Ryan J

Classifications

• G01C17/38 Primary

  Testing, calibrating, or compensating of compasses · CPC title