Automatic focus searching using focal sweep technique
AssigneeHimax Imaging Limited
InventorPo-Chang Chen
Life of this patent
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Abstract
An automatic focus searching method for an image capture device is provided. The image capture device has a lens and an image sensor. The method includes: setting an exposure time of the image sensor; computing a focal sweep trajectory of the lens based on at least the exposure time; during the exposure time, moving the lens along the focal sweep trajectory while exposing the image sensor; reading out pixel data of the image sensor that is generated during the exposure time; and applying a filtering operation upon the pixel data to generate an output image.
Claims22
An automatic focus searching method for an image capture device, the image capture device having a lens and an image sensor, the method comprising:
- setting an exposure time of the image sensor;
- computing a focal sweep trajectory of the lens based on at least the exposure time;
- during the exposure time, moving the lens along the focal sweep trajectory while exposing the image sensor;
- reading out pixel data of the image sensor that is generated during the exposure time;
- and
- applying a filtering operation upon the pixel data to generate an output image.
An image capture device, comprising:
- a lens;
- an image sensor;
- an image signal processor (ISP), comprising:
- an automatic focus searching (AF) engine, arranged for computing a focal sweep trajectory of the lens based on at least the exposure time;
- and
- an auto-exposure (AE) engine, arranged for exposing the image sensor, wherein the lens is moved along the focal sweep trajectory while exposing the image sensor during the exposure time;
- and
- a lens moving mechanism, controllable by the AF engine to move the lens along the focal sweep trajectory;
- wherein the ISP applies a filtering operation upon pixel data that is read out from pixels of the image sensor and generated during the exposure time to generate an output image.
Dependencies are inferred from the claim text.