Optical image stabilization actuator driver power distribution control

Patent metadata

Field	Value
Publication number	US-10520748-B2
Application number	US-201815944421-A
Country	US
Kind code	B2
Filing date	Apr 3, 2018
Priority date	Dec 21, 2015
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

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 device, comprising:
a lens;
an actuator configured to move the lens;
a position sensor configured to measure a position of the lens;
a gyroscope configured to measure movement of the device;
a controller configured to determine drive signal data based on the position of the lens and the movement of the device; and
a drive circuit configured to:
calculate a base amplitude value based on the drive signal data;
calculate a minimum non-zero amplitude value by shifting bits of the base amplitude value,
calculate a maximum non-zero amplitude value based on the minimum non-zero amplitude value,
calculate durations for the minimum non-zero amplitude value, the maximum non-zero amplitude value, and an intermediate non-zero amplitude value based on the drive signal data,
generate a waveform using the minimum, the maximum, and the intermediate non-zero amplitude values and the durations for the minimum, the maximum, and the intermediate non-zero amplitude values,
convert the waveform to a drive signal, and
drive the actuator to move the lens, the waveform including a plurality of cycles, each of plurality of cycles including the minimum, the maximum, and the intermediate non-zero amplitude values.

2. The device of claim 1 , wherein the drive circuit includes a digital to analog converter and a voltage to current converter circuit.

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

4. The device of claim 3 wherein the drive circuit is configured to calculate an incremental amplitude value by parsing a bit range of the power input parameter, and to calculate the intermediate non-zero amplitude value based on the incremental amplitude value and the minimum non-zero amplitude value.

5. The device 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 to a subsequent time interval for the waveform.

6. The device of claim 1 wherein the drive circuit is configured to:
calculate a timing value based on the drive signal data;
calculate a maximum amplitude output value length by shifting bits of the timing value, the maximum amplitude output value length indicating a time duration for the maximum non-zero amplitude value in each of the plurality of cycles; and
calculate a minimum amplitude output value length based on the maximum amplitude output value length, the minimum amplitude output value length indicating a time duration for the minimum non-zero amplitude value in each of the plurality of cycles.

7. A device, comprising:
a lens;
an actuator configured to move the lens;
a position sensor configured to measure a position of the lens;
a gyroscope configured to measure movement of the device;
a controller configured to calculate parameters based on the position of the lens and the movement of the device, the calculated parameters including:
a base amplitude value that is calculated based on the position of the lens and the movement of the device,
a minimum non-zero amplitude value that is calculated by shifting bits of the base amplitude value, and
a maximum non-zero amplitude value that is calculated based on the minimum non-zero amplitude value;

a power waveform generator configured to generate a waveform based on the calculated parameters, the waveform including a plurality of cycles, each of plurality of cycles including the minimum non-zero amplitude value, the maximum non-zero amplitude value, and an intermediate non-zero amplitude value;
a power waveform converter configured to convert the waveform to a to a drive signal; and
a drive circuit configured to drive the actuator with the drive signal to move the lens.

8. The device of claim 7 wherein the parameters includes the intermediate non-zero amplitude value for the waveform.

9. The device of claim 8 wherein the parameters includes timing values of the minimum, the maximum, and the intermediate non-zero amplitude values for the waveform.

10. The device of claim 7 wherein the parameters includes a power input parameter that sets a total power value for the waveform, and the controller is configured to calculate an incremental amplitude value by parsing a bit range of the power input parameter, and to calculate the intermediate non-zero amplitude value based on the incremental amplitude value and the minimum non-zero amplitude value.

11. The device of claim 7 wherein the parameters includes a power input parameter that sets a total power value for the waveform.

12. The device of claim 7 wherein the parameters includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval to a subsequent time interval for the waveform.

13. The device of claim 7 wherein the power waveform converter includes a digital to analog converter and a voltage to current converter.

14. The device of claim 7 wherein the power waveform converter is configured to dynamically adjust the voltage signal to minimize an offset error.

15. A device, comprising:
an actuator;
a waveform generator configured to:
receive drive signal data;
calculate a base amplitude value based on the drive signal data;
calculate a minimum non-zero amplitude value by shifting bits of the base amplitude value,
calculate a maximum non-zero amplitude value based on the minimum non-zero amplitude value,
calculate durations of the minimum non-zero amplitude value, the maximum non-zero amplitude value, and an intermediate non-zero amplitude value based on the drive signal data; and
generate a waveform based on the minimum, the maximum, and the intermediate non-zero amplitude values and durations of the minimum, the maximum, and the intermediate non-zero amplitude values, the waveform including a plurality of cycles, each of plurality of cycles including the minimum, the maximum, and the intermediate non-zero amplitude values;

a waveform converter configured to convert the waveform to a drive signal; and
a drive circuit configured to drive the actuator with the drive signal.

16. The device of claim 7 wherein the controller is configured to:
calculate a timing value based on the position of the lens and the movement of the device;
calculate a maximum amplitude output value length by shifting bits of the timing value, the maximum amplitude output value length indicating a time duration for the maximum non-zero amplitude value in each of the plurality of cycles; and
calculate a minimum amplitude output value length based on the maximum amplitude output value length, the minimum amplitude output value length indicating a time duration for the minimum non-zero amplitude value in each of the plurality of cycles.

17. The device of claim 15 wherein the drive signal data includes a power input parameter that sets a total power value for the waveform.

18. The device of claim 17 wherein the waveform generator is configured to calculate an incremental amplitude value by parsing a bit range of the power input parameter, and to calculate the intermediate non-zero amplitude value based on the incremental amplitude value and the minimum non-zero amplitude value.

19. The device of claim 15 wherein the drive signal data includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval to a subsequent time interval for the waveform.

20. The device of claim 15 wherein the wavefor

Assignees

• St Microelectronics Inc

Inventors

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

Classifications

• H04N23/55 Primary

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N23/685

  performed by mechanical compensation · 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

• H02P7/025

  the DC motors being of the moving coil type, e.g. voice coil motors · CPC title

• H02K41/0356

  moving along a straight path · CPC title