Optical image stabilization synchronization of gyroscope and actuator drive circuit

Patent metadata

Field	Value
Publication number	US-10459243-B2
Application number	US-201815927387-A
Country	US
Kind code	B2
Filing date	Mar 21, 2018
Priority date	Oct 22, 2015
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

Various embodiments provide an optical image stabilization circuit that synchronizes its gyroscope and drive circuit using gyroscope data ready signals and gyroscope reset signals. In response to a gyroscope data ready signal, the optical image stabilization circuit synchronously obtains position measurements of a camera lens when power drive signals are not transitioning from one power level to another power level, and synchronously transitions the power drive signals simultaneously with gyroscope reset signals. By synchronizing the gyroscope and the drive circuit, the gyroscope and other onboard sensing circuits are isolated from noise generated by the drive circuit.

First claim

The invention claimed is:

1. A method, comprising:
receiving a first data ready signal from a gyroscope, the first data ready signal indicating that first movement data is ready;
receiving a reset signal from the gyroscope, the reset signal being active indicating that the gyroscope is in a non-measuring state;
outputting, during a first control cycle, a first power drive signal to an actuator configured to move a lens;
transitioning, concurrently with the reset signal being active, a power level of the first power drive signal from a first power level to a second power level;
receiving, during the first control cycle, position data of a position of the lens from a position sensor while the first power drive signal is at a constant power level;
determining, during a second control cycle that is subsequent to the first control cycle, a second power drive signal based on the first movement data and the position data; and
outputting, during a third control cycle that is subsequent to the second control cycle, the second power drive signal to the actuator.

2. The method of claim 1 , further comprising:
receiving a second data ready signal from the gyroscope, the second data ready signal indicating that second movement data is ready; and
receiving a third data ready signal from the gyroscope, the third data ready signal indicating that third movement data is ready.

3. The method of claim 2 , further comprising:
initiating the first, second, and third control cycles in response to receiving the first, second, and third data ready signals, respectively.

4. The method of claim 1 , further comprising:
outputting, during the second control cycle, a third power drive signal to the actuator, the second power drive signal being determined while the third power drive signal is being outputted.

5. The method of claim 1 wherein the first and second power drive signals are different from each other.

6. A method, comprising:
receiving a data ready signal from a gyroscope, the data ready signal indicating that movement data is ready;
receiving a reset signal from the gyroscope, the reset signal being active indicating the gyroscope is in a non-measuring state;
executing a control cycle in response to the data ready signal being received, the executing of the control cycle including:
outputting a first power drive signal to an actuator configured to move a lens, the first power drive signal being calculated in a previous control cycle;
receiving position data of a position of the lens from a position sensor; and
calculating a second power drive signal based on position data received in the previous control cycle and the movement data; and

tracking a frequency of the first power drive signal based on the reset signal.

7. The method of claim 6 wherein the position data is received when the first power drive signal is at a constant power level.

8. The method of claim 6 wherein the first power drive signal includes a transition from one power level to another power level, and the transition is synchronized to be concurrent with the reset signal being active.

9. The method of claim 6 wherein the outputting of the first power drive signal and the receiving of the position data are performed concurrently.

10. The method of claim 6 wherein the second power drive signal is outputted in a subsequent control cycle.

11. The method of claim 6 , further comprising:
generating a control cycle start signal in response to the data ready signal being received, the control cycle being executed in response to the control cycle start signal being generated.

12. A method, comprising:
receiving a first data ready signal from a gyroscope, the first data ready signal indicating that first movement data is ready to be processed;
generating, in response to receiving the first data ready signal, a first control cycle start signal to initiate a first control cycle;
receiving, during the first control cycle, first position data of a position of a lens from a position sensor;
receiving a second data ready signal from a gyroscope, the second data ready signal indicating that second movement data is ready to be processed;
generating, in response to receiving the second data ready signal, a second control cycle start signal to initiate a second control cycle;
determining, during the second control cycle, a first power drive signal based on the first movement data and the first position data that was received during the first control cycle;
receiving a third data ready signal from a gyroscope, the third data ready signal indicating that third movement data is ready to be processed;
generating, in response to receiving the third data ready signal, a third control cycle start signal to initiate a third control cycle; and
outputting, during the third control cycle, the first power drive signal that was determined during the second control cycle to an actuator configured to move the lens.

13. The method of claim 12 , further comprising:
outputting, during the first control cycle, a second power drive signal to the actuator configured to move the lens, the first position data being received while the second power drive signal is at a constant power level.

14. The method of claim 12 , further comprising:
receiving a reset signal from the gyroscope, the reset signal being active indicating that the gyroscope is in a non-measuring state.

15. The method of claim 14 wherein the first power drive signal includes a transition from one power level to another power level, and the transition is synchronized to be concurrent with the reset signal being active.

Assignees

• St Microelectronics Inc

Inventors

• Tai Chih-Hung
• Kim Felix
• Lysinger Mark A

Classifications

• H04N23/685

  performed by mechanical compensation · CPC title

• H04N23/6812 Primary

  based on additional sensors, e.g. acceleration sensors · CPC title

• G02B27/646 Primary

  compensating for small deviations, e.g. due to vibration or shake (movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68) · CPC title