Imaging systems having image sensor pixel arrays with phase detection capabilities
An image sensor may have a pixel array that includes an array of pixels arranged in rows and columns. Each pixel may include a number of adjacent sub-pixels covered by a single microlens. The adjacent sub-pixels of each pixel may include color filter elements of the same color. Image signals from the sub-pixels may be used to calculate phase information in each pixel in the array. This information may be used to generate a depth map of the entire captured image. The pixels may each be able to detect vertical, horizontal, or diagonal edges. Additionally, the image signals from each photodiode in a pixel may be binned or average to obtain image data for each pixel. The image sensor also may generate high-dynamic-range images using the pixel array.
1. A method of operating an imaging system having an array of pixels arranged in rows and columns, wherein each pixel comprises four adjacent photosensitive areas located in two adjacent columns and two adjacent rows, and wherein each pixel comprises a microlens that covers the four adjacent photosensitive areas, the method comprising:
generating image signals in the four adjacent photosensitive areas of each pixel;
processing the image signals of each of the four adjacent photosensitive areas of a first pixel of the array of pixels to determine phase information, wherein only the image signals of each of the four adjacent photosensitive areas of the first pixel are used to determine the phase information, wherein processing the image signals of each of the four adjacent photosensitive areas of the first pixel to determine phase information comprises processing the image signals of each of the four adjacent photosensitive areas of the first pixel to detect vertical edges, horizontal edges, and diagonal edges, and wherein only the image signals of each of the four adjacent photosensitive areas of the first pixel are used to detect the vertical edges, horizontal edges, and diagonal edges; and
processing the image signals of each of the four adjacent photosensitive areas of the first pixel to determine image information, wherein only the image signals of each of the four adjacent photosensitive areas of the first pixel are used to determine the image information, and wherein processing the image signals of each of the four adjacent photosensitive areas of the first pixel to determine the image information comprises averaging the image signals of each of the four adjacent photosensitive areas to obtain a single image signal value for the first pixel.
2. The method defined in claim 1 , wherein each pixel comprises a color filter element that covers the four adjacent photosensitive areas.
3. The method defined in claim 2 , wherein the color filter element of each pixel is part of a Bayer color pattern.
4. The method defined in claim 1 , wherein processing the image signals of each of the four adjacent photosensitive areas of the first pixel to determine phase information comprises processing the image signals to detect at least one of red edges and blue edges.
5. A method of operating an imaging system having an array of pixels arranged in rows and columns, wherein each pixel comprises four adjacent photosensitive areas located in two adjacent columns and two adjacent rows, and wherein each pixel comprises a microlens that covers the four adjacent photosensitive areas, the method comprising:
generating image signals in the four adjacent photosensitive areas of each pixel;
processing the image signals of each of the four adjacent photosensitive areas of at least one pixel to determine phase information, wherein processing the image signals of each of the four adjacent photosensitive areas of the at least one pixel to determine phase information comprises processing the image signals of each of the four adjacent photosensitive areas of the at least one pixel to detect vertical edges, horizontal edges, and diagonal edges, and wherein only the image signals of each of the four adjacent photosensitive areas of the at least one pixel are used to detect the vertical edges, horizontal edges, and diagonal edges; and
processing the image signals of each of the four adjacent photosensitive areas of the at least one pixel to determine image information wherein the four adjacent photosensitive areas include first, second, third, and fourth photosensitive areas, wherein the first photosensitive area in a plurality of the pixels has a first integration time, wherein the second photosensitive area in the plurality of the pixels has a second integration time, and wherein the first integration time is longer than the second integration time.
6. The method defined in claim 5 , wherein the first photosensitive area is positioned diagonally opposite the second photosensitive area.
7. The method defined in claim 5 , wherein the first photosensitive area is positioned in the same row as the second photosensitive area.
8. The method defined in claim 5 , further comprising generating a high dynamic range image using the image signals from the plurality of the pixels.