System and methods for damping lens ringing

An apparatus for damping lens movement imparted on a lens by an actuator in an imaging device, comprising:

• a lens;
• a lens actuator;
• a processor, operably coupled to the lens actuator;
• a memory, operably coupled to the processor, and configured to store:
• an autofocus module, configured to determine a current lens position and a target lens position, wherein the distance between the current lens position and target lens position is a target distance;
• a damping parameter determination module, configured to determine damping parameters based on at least one characteristic of the actuator, the lens damping parameter include:
• a plurality of steps having a total distance that is equal to the target distance;
• and
• a delay between each of the plurality of steps;
• wherein the damping parameters are determined to substantially cancel out vibration imparted to the lens due to the actuator moving the lens of each of the plurality of steps;
• a lens movement parameter determination module, configured to determine lens movement parameters based on the damping parameters;
• and
• a lens movement control module, configured to move the lens to autofocus an image based on the lens movement parameters.

An apparatus for damping lens ringing imparted on a lens in an imaging device, comprising:

• a means for determining a current lens position and a target lens position, wherein the distance between the current lens position and target lens position is a target distance;
• a means for determining damping parameters based on at least one characteristic of an actuator, the damping parameters include:
• a plurality of steps having a total distance that is equal to the target distance;
• and
• a delay between each of the plurality of steps;
• wherein the damping parameters are determined to substantially cancel out lens vibrations imparted to the lens as a result of the actuator moving the lens each of the plurality of steps;
• a means for determining lens movement parameters based on the damping parameters;
• and
• a means for moving the lens to autofocus an image based on the lens movement parameters.

A non-transitory computer readable medium comprising instructions that when executed cause a processor to perform a method of autofocusing a lens, the method comprising:

• determining a target distance to move a lens by an actuator toward or away from an image sensor to focus a scene on the image sensor;
• dividing the target distance into a plurality of steps having at least a first and subsequent step;
• moving the lens by the first step, via the actuator, the moving of the first step causing a first vibration;
• retrieving a damping parameter indicative of a time delay before each subsequent step, the damping parameter being based on at least one characteristic of the actuator and the number of steps;
• and
• repeating said moving the lens at least one subsequent step after delaying the subsequent step by one of the damping parameters, each moving of the lens a subsequent step causing a corresponding subsequent vibration, the damping parameters affecting the vibration caused by each step such that the first and subsequent vibrations at least in part modify each other to lower overall vibration.