CMOS image sensor for 2D imaging and depth measurement with ambient light rejection

A method comprising:

• configuring an image sensor to capture an image of an object illuminated by, at least, a first light source, wherein the image sensor has a plurality of pixels arranged in a first row and a second row;
• configuring a second light source to illuminate the object, wherein the object is concurrently illuminated by the first and the second light sources;
• generating a pixel-specific output, at least, for each pixel in the first row of pixels;
• and
• determining a depth of the object based, at least in part, on the pixel-specific output of each pixel in the first row of pixels,
• wherein generating the pixel-specific output includes:
• determining an illuminance level of light from the first light source;
• preparing the image sensor to operate in one of the following modes:
• a first mode of operation when the light from the first light source is at or below a pre-defined illuminance level, and
• a second mode of operation when the light from the first light source is above the pre-defined illuminance level;
• and
• generating the pixel-specific output for each pixel in the first row of pixels using either the first mode of operation or the second mode of operation.

A system comprising:

• an image sensor that captures an image of an object illuminated by, at least, a first light source, wherein the image sensor has a plurality of pixels arranged in a first row and a second row;
• a second light source that illuminates the object, wherein the object is concurrently illuminated by the first and the second light sources;
• and
• a processing unit that determines a depth of the object, using at least the first row of pixels, wherein the processing unit determines the depth of the object based, at least in part, on an output of the first row of pixels,
• wherein the processing unit performs the following operations to determine the depth of the object:
• determining an illuminance level of light from the first light source;
• for a given pixel in the first row of pixels, receiving a pixel-specific output from the image sensor as one of the following:
• when the light from the first light source is at or below a pre-defined illuminance level, receiving the pixel-specific output as a linear integration of photoelectrons collected by the given pixel over a pre-determined time period, and
• when the light from the first light source is above the pre-defined illuminance level, receiving the pixel-specific output based on a natural logarithm of an instantaneous photo-current produced by the given pixel during the pre-determined time period upon detecting light from the second light source reflected from the object;
• and
• determining the depth of the object based on the pixel-specific output of each pixel in the first row of pixels.