Optical image stabilization actuator driver power distribution control

Patent metadata

Field	Value
Publication number	US-10649228-B2
Application number	US-201916694749-A
Country	US
Kind code	B2
Filing date	Nov 25, 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 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;
a power waveform generator configured to generate a power waveform based on the drive signal data, the power waveform having a calculated minimum non-zero amplitude value, a calculated maximum non-zero amplitude value, and a calculated intermediate non-zero amplitude value; and
a power waveform conversion circuit including:
a digital to analog converter configured to convert the power waveform into a voltage signal having amplitude values corresponding to the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value;
a voltage to current converter circuit configured to apply a gain to the voltage signal, and convert the voltage signal to an electric current signal; and
a driver circuit configured to drive the actuator with the electric current signal to move the lens.

2. The device of claim 1 wherein the voltage to current converter circuit includes:
an amplifier including a first input, a second input, and an output, the first input electrically coupled to the digital to analog converter;
a resistor electrically coupled to the second input of the amplifier and ground;
a first capacitor electrically to the second input of the amplifier and ground;
a first transistor electrically coupled to the output of the amplifier;
a second transistor electrically coupled to the first transistor;
a third transistor electrically coupled to the second transistor and the driver circuit; and
a second capacitor electrically coupled to the second transistor and the third transistor.

3. The device of claim 1 wherein the driver circuit is an H bridge circuit.

4. The device of claim 1 wherein the power waveform generator is configured to calculate durations of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value based on the drive signal data.

5. The device of claim 4 wherein a duration of one of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, or the calculated intermediate non-zero amplitude value is twice as long as a duration of another one of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, or the calculated intermediate non-zero amplitude value.

6. The device of claim 1 wherein the power waveform is a multi-cycle power waveform that includes the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value in each cycle.

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

8. 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 power waveform.

9. A device, comprising:
a power waveform generator configured to receive drive signal data, and generate a power waveform based on the drive signal data, the power waveform having a calculated minimum non-zero amplitude value, a calculated maximum non-zero amplitude value, and a calculated intermediate non-zero amplitude value; and
a power waveform conversion circuit, including:
a digital to analog converter configured to convert the power waveform into a voltage signal;
a voltage to current converter circuit configured to apply a gain to the voltage signal, and convert the voltage signal to an electric current signal; and
a driver circuit configured to output the electric current signal.

10. The device of claim 9 wherein the voltage to current converter circuit includes:
an amplifier including a first input, a second input, and an output, the first input electrically coupled to the digital to analog converter;
a resistor electrically coupled to the second input of the amplifier and ground;
a first capacitor electrically to the second input of the amplifier and ground;
a first transistor electrically coupled to the output of the amplifier;
a second transistor electrically coupled to the first transistor;
a third transistor electrically coupled to the second transistor and the driver circuit; and
a second capacitor electrically coupled to the second transistor and the third transistor.

11. The device of claim 9 wherein the driver circuit is an H bridge circuit.

12. The device of claim 9 wherein the power waveform generator is configured to calculate durations of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value based on the drive signal data.

13. The device of claim 9 wherein the power waveform is a multi-cycle power waveform that includes the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value in each cycle.

14. The device of claim 9 wherein the drive signal data includes a power input parameter that sets a total power value for the power waveform.

15. The device of claim 9 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 power waveform.

16. A device, comprising:
an actuator;
a power waveform generator configured to receive drive signal data, and generate a power waveform based on the drive signal data, the power waveform including a plurality of cycles, the power waveform having a calculated minimum non-zero amplitude value, a calculated maximum non-zero amplitude value, and a calculated intermediate non-zero amplitude value in each of the plurality of cycles;
a power waveform conversion circuit including:
a digital to analog converter configured to convert the power waveform into a voltage signal;
a voltage to current converter circuit configured to apply a gain to the voltage signal, and convert the voltage signal to an electric current signal; and
a driver circuit configured to drive the actuator with the electric current signal to move a lens.

17. The device of claim 16 wherein the voltage to current converter circuit includes:
an amplifier including a first input, a second input, and an output, the first input electrically coupled to the digital to analog converter;
a resistor electrically coupled to the second input of the amplifier and ground;
a first capacitor electrically to the second input of the amplifier and ground;
a first transistor electrically coupled to the output of the amplifier;
a second transistor electrically coupled to the first transistor;
a third transistor electrically coupled to the second transistor and the driver circuit; and
a second capacitor electrically coupled to the second transistor and the third transistor.

18. The device of claim 16 wherein the driver circuit is an H bridge circuit.

19. The device of claim 16 wherein the drive signal data includes a power input parameter that sets a total power value for the power waveform

Assignees

• St Microelectronics Inc

Inventors

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

Classifications

• 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

• H02K41/0356

  moving along a straight path · CPC title

• H02P7/025

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

• H04N23/55 Primary

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

• H04N23/685

  performed by mechanical compensation · CPC title