Optical image stabilization actuator driver power distribution control

Patent metadata

Field	Value
Publication number	US-9964776-B2
Application number	US-201514976924-A
Country	US
Kind code	B2
Filing date	Dec 21, 2015
Priority date	Dec 21, 2015
Publication date	May 8, 2018
Grant date	May 8, 2018

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 of moving a lens relative to a camera housing in which the lens is located, the method comprising: receiving position data of a position of the lens from a position sensor; receiving movement data of a movement of the camera housing; determining a power input parameter based on the position data and the movement data; determining a power waveform by a power waveform generator, the power waveform having a first power level for a first time duration and a second power level for a second time duration, the determining of the power waveform including: calculating an initial amplitude value of the power waveform, a minimum amplitude value of the power waveform, a maximum amplitude value of the power waveform, and timings of the minimum and maximum amplitude values using the power input parameter; setting the first power level to the initial amplitude value; and setting the second power level to the maximum amplitude value or the minimum amplitude value based on the calculated timings of the minimum and maximum amplitude values; outputting the power waveform to a power waveform conversion circuit; converting the power waveform to a power drive signal by the power waveform conversion circuit; and driving an actuator with the power drive signal to move the lens.

2. The method of claim 1 , wherein the outputting of the power waveform includes:
outputting the second power level subsequent to the first power level.

3. The method of claim 1 , wherein the power waveform has a third power level for a third time duration, the outputting of the power waveform further includes outputting the first, second, and third power levels in an order that minimizes a number of transitions between one power level to another power level.

4. The method of claim 1 , wherein the power waveform has a third power level for a third time duration, the first time duration is the same length as the second time duration, and the third time interval is twice as long as the second time duration.

5. The method of claim 1 , wherein the power waveform has a third power level during a third time duration and a fourth power level during a fourth time duration, the determining of the power waveform further includes:
setting the third power level to be equal to the first power level; and
setting the fourth power level to be equal to the second power level.

6. The method of claim 1 , wherein the power input parameter is a bit value having a first subset of bits, a second subset of bits, and a third subset of bits, the first subset of bits being used for the calculating of the minimum amplitude value and the maximum amplitude value, the second subset of bits being used for the calculating of the timings of the minimum and maximum amplitude values, the third subset of bits being used for the calculating of the initial amplitude value.

7. A method of moving a lens relative to a camera housing in which the lens is located, the method comprising:
receiving position data of a position of the lens from a position sensor;
receiving movement data of a movement of the camera housing;
determining a power input parameter based on the position data and the movement data;
determining a power waveform by a power waveform generator, the power waveform having a plurality of power levels, each power level of the plurality of power levels being determined by the power input parameter;
outputting the power waveform to a power waveform conversion circuit;
converting the power waveform to a power drive signal by a power waveform conversion circuit; and
driving an actuator with the power drive signal to move the lens.

8. The method of claim 7 , wherein the outputting of the power waveform includes:
outputting the plurality of power levels in an order that minimizes the number of transitions between one power level to another power level.

9. The method of claim 7 , further comprising:
generating a periodic power waveform by repeating the power waveform for a plurality of cycles;
outputting the periodic power waveform to the power waveform conversion circuit;
converting the periodic power waveform to a periodic power drive signal by a power waveform conversion circuit; and
driving an actuator with the periodic power drive signal to move the lens.

10. The method of claim 7 , wherein the power input parameter is a bit value having a first subset of bits, a second subset of bits, and a third subset of bits, the first subset of bits being used for the calculating of the minimum amplitude value and the maximum amplitude value, the second subset of bits being used for the calculating of the timings of the minimum and maximum amplitude values, the third subset of bits being used for the calculating of the initial amplitude value.

11. A method, comprising: receiving a power input parameter; determining a power waveform, the determining of the power waveform including: calculating an initial amplitude value of the power waveform, a minimum amplitude value of the power waveform, a maximum amplitude value of the power waveform, and timings of the minimum and maximum amplitude values using the power input parameter; outputting the power waveform to a power waveform conversion circuit; converting the power waveform to a power drive signal; and driving an actuator with the power drive signal.

12. The method of claim 11 , wherein the power waveform has a first power level for a first time duration and a second power level for a second time duration, the determining of the power waveform further includes:
setting the first power level to the initial amplitude value; and
setting the second power level to the maximum amplitude value or the minimum amplitude value based on the calculated timings of the minimum and maximum amplitude values.

13. The method of claim 11 , wherein the converting of the power wave to the power drive signal includes:
converting the power waveform to a voltage signal by a digital to analog converter; and
converting the voltage signal to a current signal.

14. The method of claim 11 , wherein the power input parameter is a bit value having a first subset of bits, a second subset of bits, and a third subset of bits, the first subset of bits being used for the calculating of the minimum amplitude value and the maximum amplitude value, the second subset of bits being used for the calculating of the timings of the minimum and maximum amplitude values, the third subset of bits being used for the calculating of the initial amplitude value.

Assignees

• St Microelectronics Inc

Inventors

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

Classifications

• H04N23/687 Primary

  by shifting the lens or sensor position · CPC title

• H04N23/51

  Housings · CPC title

• H04N23/60

  Control of cameras or camera modules · CPC title

• H04N23/681

  Motion detection · CPC title

• H04N23/6812

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