Auto-focus control in a camera to prevent oscillation

An electronic device comprising:

• a lens;
• an image sensor;
• and
• a processor coupled to the image sensor and the lens, the processor being configured to:
• obtain a first lens position phase difference of signals captured by a focus sensor pair when the lens is at a first lens position;
• after obtaining the first lens position phase difference, detect lens movement, the lens movement including transition of the lens from the first lens position to a second lens position;
• obtain a second lens position phase difference of signals captured by the focus sensor pair when the lens is at the second lens position;
• compare the second lens position phase difference obtained when the lens was at the second lens position to the first lens position phase difference obtained when the lens was at the first lens position to determine whether the second lens position phase difference is greater than the first lens position phase difference;
• and
• in response to determining, based on the signals captured by the focus sensor pair, that the second lens position phase difference is greater than the first lens position phase difference, determine autofocus settings by a contrast detection method.

A non-transitory computer-readable storage medium comprising processor-executable instructions which, when executed by a processor of an electronic device, causes the electronic device to:

• obtain a first lens position phase difference of signals captured by a focus sensor pair when the lens is at a first lens position;
• after obtaining the first lens position phase difference, detect lens movement, the lens movement including transitioning a lens from the first lens position to a second lens position;
• obtain a second lens position phase difference of signals captured by the focus sensor pair when the lens is at the second lens position;
• compare the second lens position phase difference obtained when the lens was at the second lens position to the first lens position phase difference obtained when the lens was at the first lens position to determine whether the second lens position phase difference is greater than the first lens position phase difference;
• and
• in response to determining, based on the signals captured by the focus sensor pair, that the second lens position phase difference is greater than the first lens position phase difference, determine autofocus settings by a contrast detection method.