Imaging device having autofocus capability

A method, comprising:

• in an imaging device:
• generating, by an imager, an image signal of a subject;
• determining, by the imager, an in-focus position of a focus lens based on a contrast focus evaluation value and a phase difference focus defocus value,
• wherein the contrast focus evaluation value is determined based on a contrast auto focus (AF) method from a first part of the image signal read from a normal pixel of the imager, and the phase difference focus defocus value is determined based on a phase difference AF method from a second part of the image signal read from a phase difference pixel of the imager;
• and
• driving, by at least one processor, the focus lens to the in-focus position that corresponds to a peak focus evaluation value among a plurality of focus evaluation values,
• wherein the focus lens is driven based on determination that a ratio of the peak focus evaluation value to a previous focus evaluation value, prior to the peak focus evaluation value is within a range of values.

A non-transitory computer-readable medium having stored thereon, computer-executable instructions, which when executed by a computer, cause the computer to execute operations, the operations comprising:

• generating an image signal of a subject;
• determining an in-focus position of a focus lens based on a contrast focus evaluation value and a phase difference focus defocus value,
• wherein the contrast focus evaluation value is determined based on a contrast auto focus (AF) method from a first part of the image signal read from a normal pixel of an imager, and
• the phase difference focus defocus value is determined based on a phase difference AF method from a second part of the image signal read from a phase difference pixel of the imager;
• and
• driving the focus lens to the in-focus position that corresponds to a peak focus evaluation value among a plurality of focus evaluation values,
• wherein the focus lens is driven based on determination that a ratio of the peak focus evaluation value to a previous focus evaluation value, prior to the peak focus evaluation value is within a range of values.