Optical image stabilization actuator driver power distribution control

Patent metadata

Field	Value
Publication number	US-10649229-B2
Application number	US-201916697028-A
Country	US
Kind code	B2
Filing date	Nov 26, 2019
Priority date	Dec 21, 2015
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Various embodiments provide an optical image stabilization circuit including a drive circuit having a power waveform generator and a power waveform conversion circuit. The power waveform generator generates a power waveform. The power waveform conversion circuit converts the power waveform to a power drive signal. An actuator is then driven by the power drive signal to move a lens accordingly and compensate for any movements and vibrations of a housing of the lens.

First claim

The invention claimed is:

1. A method, comprising:
measuring a position of a lens in a housing;
measuring movement of the housing;
determining drive signal data based on the position of the lens and the movement of the housing;
generating a waveform based on the drive signal data, the waveform including a plurality of time intervals, the waveform having a minimum non-zero amplitude value in one or more of the plurality of time intervals, a maximum non-zero amplitude value in one or more of the plurality of time intervals, and an intermediate non-zero amplitude value in one or more of the plurality of time intervals, the generating of the waveform including:
calculating the minimum non-zero amplitude value, the maximum non-zero amplitude value, and the intermediate non-zero amplitude value based on the drive signal data; and
minimizing a total number of transitions between the minimum non-zero amplitude value and the maximum non-zero amplitude value in the waveform by arranging the order of the plurality of time intervals in the waveform;

converting the waveform to a drive signal; and
moving the lens by driving an actuator with the drive signal.

2. The method of claim 1 wherein the arranging of the order of the plurality of time intervals in the waveform includes grouping time intervals in which the waveform has the minimum non-zero amplitude value together, and grouping time intervals in which the waveform has the maximum non-zero amplitude value together.

3. The method of claim 1 wherein the generating of the waveform includes calculating durations of the plurality of time intervals based on the drive signal data.

4. The method of claim 3 wherein a duration of a first time interval of the plurality of time intervals has a first length, and a duration of a second time interval of the plurality of time intervals has a second length twice as long as the first length.

5. The method of claim 1 wherein the drive signal data includes a power input parameter that sets a total power value for the waveform.

6. The method of claim 1 wherein the drive signal data includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval of the plurality of time intervals to a subsequent time interval of the plurality of time intervals.

7. A method, comprising:
receiving, by a power waveform generator, drive signal data;
calculating, by the power waveform generator, a minimum non-zero amplitude value, a maximum non-zero amplitude value, and an intermediate non-zero amplitude value based on the drive signal data;
assigning, by the power waveform generator, the minimum non-zero amplitude value, the maximum non-zero amplitude value, and the intermediate non-zero amplitude value to a plurality of time intervals of a waveform;
reducing, by the power waveform generator, a total number of transitions between the minimum non-zero amplitude value and the maximum non-zero amplitude value in the waveform by arranging the order of the plurality of time intervals in the waveform;
generating, by the power waveform generator, the waveform;
converting, by a power waveform conversion circuit, the waveform to a drive signal; and
driving, by the power waveform conversion circuit, an actuator with the drive signal.

8. The method of claim 7 wherein the arranging of the order of the plurality of time intervals in the waveform includes selecting a time interval in which the waveform has the minimum non-zero amplitude value to be adjacent to another time interval in which the waveform has the minimum non-zero amplitude value.

9. The method of claim 7 wherein the arranging of the order of the plurality of time intervals in the waveform includes selecting a time interval in which the waveform has the maximum non-zero amplitude value to be adjacent to another time interval in which the waveform has the maximum non-zero amplitude value.

10. The method of claim 7 , further comprising:
calculating durations of the plurality of time intervals based on the drive signal data.

11. The method of claim 10 wherein a duration of a first time interval of the plurality of time intervals has a first length, and a duration of a second time interval of the plurality of time intervals has a second length twice as long as the first length.

12. The method of claim 7 wherein the drive signal data includes a power input parameter that sets a total power value for the waveform.

13. The method of claim 7 wherein the drive signal data includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval of the plurality of time intervals to a subsequent time interval of the plurality of time intervals.

14. A method, comprising:
receiving, by a power waveform generator, drive signal data;
calculating durations of a plurality of time intervals for a waveform based on the drive signal data calculating, by the power waveform generator, a minimum non-zero amplitude value, a maximum non-zero amplitude value, and an intermediate non-zero amplitude value based on the drive signal data;
assigning, by the power waveform generator, the minimum non-zero amplitude value, the maximum non-zero amplitude value, and the intermediate non-zero amplitude value to the plurality of time intervals;
arranging, by the power waveform generator, the order of the plurality of time intervals in the waveform to reduce a total number of transitions between the minimum non-zero amplitude value and the maximum non-zero amplitude value in the waveform;
generating, by the power waveform generator, a multi-cycle waveform having a plurality of cycles, the multi-cycle waveform including the waveform in each of the plurality of cycles;
converting, by a power waveform conversion circuit, the multi-cycle waveform to a drive signal; and
driving, by the power waveform conversion circuit, an actuator with the drive signal.

15. The method of claim 14 wherein the arranging of the order of the plurality of time intervals in the waveform includes selecting a time interval in which the waveform has the minimum non-zero amplitude value to be adjacent to another time interval in which the waveform has the minimum non-zero amplitude value.

16. The method of claim 14 wherein the arranging of the order of the plurality of time intervals in the waveform includes selecting a time interval in which the waveform has the maximum non-zero amplitude value to be adjacent to another time interval in which the waveform has the maximum non-zero amplitude value.

17. The method of claim 14 wherein a duration of a first time interval of the plurality of time intervals has a first length, and a duration of a second time interval of the plurality of time intervals has a second length twice as long as the first length.

18. The method of claim 14 wherein the drive signal data includes a power input parameter that sets a total power value for the waveform.

19. The method of claim 14 wherein the drive signal data includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval of the plurality of time intervals to a subsequent time interval of the plurality of time intervals.

Assignees

• St Microelectronics Inc

Inventors

• Lysinger Mark A
• Tai Chih-Hung
• Worley James L
• Nallamothu Pavan

Classifications

• G03B5/00

  Adjustment of optical system relative to image or object surface other than for focusing · 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

• G03B2205/0007

  Movement of one or more optical elements for control of motion blur · CPC title

• H02K41/0354

  Lorentz force motors, e.g. voice coil motors · CPC title

• G03B2205/0069

  using electromagnetic actuators, e.g. voice coils · CPC title