Methods and apparatus for optical image stabilization
Various embodiments of the present technology may provide methods and apparatus for optical image stabilization. The methods and apparatus for optical image stabilization may be integrated within an electronic device. An exemplary system may include an actuator control circuit responsive to a sensor and a feedback signal from an actuator. The actuator control circuit may be configured to calibrate a gain applied to a drive signal based on a relative position between the actuator and the sensor and an output signal generated by the actuator control circuit.
1. A control circuit adapted to communicate with a sensor and capable of controlling an actuator of an image system, comprising:
an input terminal configured to receive an input signal, wherein the input signal comprises an x-component, a y-component, and a z-component;
a first circuit connected to the input terminal and configured to:
receive the y-component and generate a first correction signal according to the y-component;
receive the z-component and generate a second correction signal and a third correction signal according to the z-component; and
generate a first drive signal according to the first, second, and third correction signals; and
a second circuit connected to the input terminal and configured to:
receive the x-component and generate a fourth correction signal according to the x-component;
receive the z-component and generate a fifth correction signal and a sixth correction signal according to the z-component; and
generate a second drive signal according to the fourth, fifth, and sixth correction signals.
2. The control circuit of claim 1 , wherein the first circuit comprises:
a first sub-circuit configured to:
compute a square of the y-component; and
generate the first correction signal according to the square of the y-component and a first correction gain;
a second sub-circuit configured to:
compute:
a square of the z-component; and
a derivative of the z-component; and
generate:
the second correction signal according to the square of the z-component and a second correction gain; and
the third correction signal according to the derivative of the z-component and a third correction gain; and
a third sub-circuit connected to the first and second sub-circuits and configured to:
receive the first, second, and third correction signals;
compute a first sum of the first, second, and third correction signals; and
generate the first drive signal according to the first sum.
3. The control circuit of claim 2 , wherein the second circuit comprises:
a fourth sub-circuit configured to:
compute a square of the x-component; and
generate the fourth correction signal according to the square of the x-component and a fourth correction gain;
a fifth sub-circuit configured to generate:
the fifth correction signal according to the square of the z-component and a fifth correction gain; and
the sixth correction signal according to the derivative of the z-component and a sixth correction gain; and
a sixth sub-circuit connected to the fourth and fifth sub-circuits and configured to:
receive the fourth, fifth, and sixth correction signals;
compute a second sum of the fourth, fifth, and sixth correction signals; and
generate the second drive signal according to the second sum.
4. The control circuit of claim 3 , wherein the first drive signal is equal to the first sum, and wherein the second drive signal is equal to the second sum.
5. The control circuit of claim 3 , wherein each correction gain is predetermined, and wherein:
the first correction gain is determined according to a first distance between the sensor and the actuator, wherein the first distance is along an x-axis direction;
the second correction gain is determined according to a second distance between the sensor and the actuator, wherein the second distance is along the x-axis direction;
the third correction gain is determined according to a third distance between the sensor and the actuator, wherein the third distance is along a y-axis direction;
the fourth correction gain is determined according to a fourth distance between the sensor and the actuator, wherein the fourth distance is along the y-axis direction;
the fifth correction gain is determined according to a fifth distance between the sensor and the actuator, wherein the fifth distance is along the y-axis direction; and
the sixth correction gain is determined according to a sixth distance between the sensor and the actuator, wherein the sixth distance is along the x-axis direction.
6. The control circuit of claim 5 , wherein:
the first correction gain is proportional to the first distance, wherein the first distance is determined according to a first relative position of the sensor with respect to the actuator;
the second correction gain is proportional to the second distance, wherein the second distance is determined according to a second relative position of the sensor with respect to the actuator;
the third correction gain is proportional to the third distance, wherein the third distance is determined according to a third relative position of the sensor with respect to the actuator;
the fourth correction gain is proportional to the fourth distance, wherein the fourth distance is determined according to a fourth relative position of the sensor with respect to the actuator;
the fifth correction gain is proportional to the fifth distance, wherein the fifth distance is determined according to a fifth relative position of the sensor with respect to the actuator; and
the sixth correction gain is proportional to the sixth distance, wherein the sixth distance is determined according to a sixth relative position of the sensor with respect to the actuator.
7. A method for driving an actuator of an image system according to a sensor, comprising:
receiving, from the sensor, an input signal comprising an x-component, a y-component, and a z-component;
generating:
a first correction signal according to the y-component;
a second correction signal and a third correction signal according to the z-component;
a fourth correction signal according to the x-component; and
a fifth correction signal and a sixth correction signal according to the z-component; and
generating:
a first drive signal according to the first, second, and third correction signals; and
a second drive signal according to fourth, fifth, and sixth correction signals.
8. The method of claim 7 , wherein generating:
the first correction signal comprises:
computing a square of the y-component; and
applying a first correction gain to the square of the y-component;
the second correction signal comprises:
computing a square of the z-component; and
applying a second correction gain to the square of the z-component;
the third correction signal comprises:
computing a derivative of the z-component; and
applying a third correction gain to the derivative of the z-component;
the fourth correction signal comprises:
computing a square of the x-component; and
applying a fourth correction gain to the square of the x-component;
the fifth correction signal comprises applying a fifth correction gain to the square of the z-component; and
the sixth correction signal comprises applying a sixth correction gain to the derivative of the z-component.
9. The method of claim 8 , wherein generating:
the first correction signal further comprises applying a seventh correction gain to the square of the y-component;
the second correction signal further comprises applying an eighth correction gain to the square of the z-component;
the third correction signal further comprises applying a ninth correction gain to the derivative of the z-component;
the fourth correction signal further comprises applying a tenth correction gain to the square of the x-component;
the fifth correction signal further comprises applying an eleventh correction gain to the square of the z-component; and
the sixth correction signal further comprises applying a twelfth correction gain to the derivative of the z-component.
10. The method of claim 9 , wherein each correction gain is predetermined, and wherein:
the first correction gain is determined according to a first distance between the sensor and the actuator, wherein the first distance is along an x-axis direction;
the second correction gain is determined according to a second distance between the sensor and the actuator, wherein the second distance is along the x-axis direction;
the third correction gain is determined according to a third distance between the sensor and the actuator, wherein the third distance is along a y-axis direction;
the fourth correction gain is determined according to a fourth distance between the sensor and the actuator, wherein the fourth distance is along the y-axis direction;
the fifth correction gain is determined according to a fifth distance between the sensor and the actuator, wherein the fifth distance is along the y-axis direction; and
the sixth correction gain is determined according to a sixth distance between the sensor and the actuator, wherein the sixth distance is along the x-axis direction.
11. The method of claim 10 , wherein:
the first correction gain is proportional to the first distance, wherein the first distance is determined according to a first relative position of the sensor with respect to the actuator;
the second correction gain is proportional to the second distance, wherein the second distance is determined according to a second relative position of the sensor with respect to the actuator;
the third correction gain is proportional to the third distance, wherein the third distance is determined according to a third relative position of the sensor with respect to the actuator;
the fourth correction gain is proportional to the fourth distance, wherein the fourth distance is determined according to a fourth relative position of the sensor with respect to the actuator;
the fifth correction gain is proportional to the fifth distance, wherein the fifth distance is determined according to a fifth relative position of the sensor with respect to the actuator; and
the sixth correction gain is proportional to the sixth distance, wherein the sixth distance is determined according to a sixth relative position of the sensor with respect to the actuator.
12. The method of claim 7 , wherein generating:
the first drive signal comprises computing a first sum of the first, second, and third correction signals; and
the second drive signal comprises computing a second sum of the fourth, fifth, and sixth correction signals.
13. The method of claim 12 , wherein the first drive signal is equal to the first sum, and wherein the second drive signal is equal to the second sum.
14. An image system, comprising:
a sensor configured to generate an input signal comprising an x-component, a y-component, and a z-component;
an actuator responsive to a first drive signal and a second drive signal;
a control circuit in communication with the sensor and capable of controlling the actuator, comprising:
an input terminal configured to receive the input signal;
a first circuit connected to the input terminal and configured to:
receive the y-component and generate a first correction signal according to the y-component;
receive the z-component and generate a second correction signal and a third correction signal according to the z-component; and
generate the first drive signal according to the first, second, and third correction signals; and
a second circuit connected to the input terminal and configured to:
receive the x-component and generate a fourth correction signal according to the x-component;
receive the z-component and generate a fifth correction signal and a sixth correction signal according to the z-component; and
generate the second drive signal according to the fourth, fifth, and sixth correction signals.
15. The system of claim 14 , wherein the sensor comprises at least one of a gyro sensor or an acceleration sensor.
16. The system of claim 14 , wherein the first circuit is further configured to:
compute:
a square of the y-component;
a square of the z-component; and
a derivative of the z-component;
generate:
the first correction signal according to the square of the y-component and a first correction gain;
the second correction signal according to the square of the z-component and a second correction gain; and
the third correction signal according to the derivative of the z-component and a third correction gain;
compute a first sum of the first, second, and third correction signals; and
generate the first drive signal according to the first sum.
17. The system of claim 16 , wherein the second circuit is further configured to:
compute a square of the x-component;
generate:
the fourth correction signal according to the square of the x-component and a fourth correction gain;
the fifth correction signal according to the square of the z-component and a fifth correction gain; and
the sixth correction signal according to the derivative of the z-component and a sixth correction gain;
compute a second sum of the fourth, fifth, and sixth correction signals; and
generate the second drive signal according to the second sum.
18. The system of claim 17 , wherein the first drive signal is equal to the first sum, and wherein the second drive signal is equal to the second sum.
19. The system of claim 17 , wherein each correction gain is predetermined, and wherein:
the first correction gain is determined according to a first distance between the sensor and the actuator, wherein the first distance is along an x-axis direction;
the second correction gain is determined according to a second distance between the sensor and the actuator, wherein the second distance is along the x-axis direction;
the third correction gain is determined according to a third distance between the sensor and the actuator, wherein the third distance is along a y-axis direction;
the fourth correction gain is determined according to a fourth distance between the sensor and the actuator, wherein the fourth distance is along the y-axis direction;
the fifth correction gain is determined according to a fifth distance between the sensor and the actuator, wherein the fifth distance is along the y-axis direction; and
the sixth correction gain is determined according to a sixth distance between the sensor and the actuator, wherein the sixth distance is along the x-axis direction.
20. The system of claim 19 , wherein:
the first correction gain is proportional to the first distance, wherein the first distance is determined according to a first relative position of the sensor with respect to the actuator;
the second correction gain is proportional to the second distance, wherein the second distance is determined according to a second relative position of the sensor with respect to the actuator;
the third correction gain is proportional to the third distance, wherein the third distance is determined according to a third relative position of the sensor with respect to the actuator;
the fourth correction gain is proportional to the fourth distance, wherein the fourth distance is determined according to a fourth relative position of the sensor with respect to the actuator;
the fifth correction gain is proportional to the fifth distance, wherein the fifth distance is determined according to a fifth relative position of the sensor with respect to the actuator; and
the sixth correction gain is proportional to the sixth distance, wherein the sixth distance is determined according to a sixth relative position of the sensor with respect to the actuator.