Imaging systems having image sensor pixel arrays with phase detection capabilities

Patent metadata

Field	Value
Publication number	US-2016286108-A1
Application number	US-201514667286-A
Country	US
Kind code	A1
Filing date	Mar 24, 2015
Priority date	Mar 24, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

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.

First claim

What is claimed is:

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 at least one pixel to determine phase information; and processing the image signals of each of the four adjacent photosensitive areas of the at least one pixel to determine image information.

2 . The method defined in claim 1 , wherein processing the image signals of each of the four adjacent photosensitive areas of the at least one pixel to determine image information comprises averaging the image signals of each of the four adjacent photosensitive areas to obtain a single image signal value for each pixel of the at least one pixel.

3 . The method defined in claim 2 , wherein each pixel comprises a color filter element that covers the four adjacent photosensitive areas.

4 . The method defined in claim 3 , wherein the color filter element of each pixel is part of a Bayer color pattern.

5 . The method defined in claim 1 , 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 to detect vertical edges, horizontal edges, and diagonal edges.

6 . The method defined in claim 1 , 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 to detect red edges and blue edges.

7 . The method defined in claim 1 , wherein the at least one pixel comprises each pixel in the pixel array.

8 . The method defined in claim 7 , further comprising using the phase information from each pixel in the pixel array to create a depth map.

9 . The method defined in claim 1 , 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 exposure, wherein the second photosensitive area in the plurality of the pixels has a second exposure, and wherein the first exposure is different from the second exposure.

10 . The method defined in claim 9 , wherein the first photosensitive area is positioned diagonally opposite the second photosensitive area.

11 . The method defined in claim 9 , wherein the first photosensitive area is positioned in the same row as the second photosensitive area.

12 . The method defined in claim 9 , wherein the first photosensitive area in the plurality of the pixels has a first integration time, and wherein the second photosensitive area in the plurality of the pixels has a second integration time that is different than the first integration time.

13 . The method defined in claim 9 , further comprising generating a high dynamic range image using the image signals from the plurality of the pixels.

14 . An image sensor having a pixel array that includes an array of pixels arranged in rows and columns, wherein each pixel in the pixel array comprises:
a plurality of adjacent photodiodes; a microlens that covers the plurality of adjacent photodiodes; and a color filter element formed over the plurality of adjacent photodiodes, and wherein the pixel array is configured to generate both image data and phase detection data using each pixel in the pixel array.

15 . The image sensor defined in claim 14 , wherein the color filter element of each pixel is configured to pass light of a color to each of the four adjacent photodiodes, and wherein the color filter element of each pixel is part of a Bayer color pattern.

16 . The image sensor defined in claim 14 , wherein the color filter element of each pixel is part of a color pattern, and wherein the color pattern comprises a repeating unit square with first and second broadband pixels positioned diagonally opposite each other, a red pixel positioned adjacent to the first and second broadband pixels, and a blue pixel positioned adjacent to the first and second broadband pixels.

17 . The image sensor defined in claim 14 , wherein the plurality of adjacent photodiodes comprises four adjacent photodiodes, and wherein the four adjacent photodiodes are located in two adjacent columns and two adjacent rows.

18 . The image sensor defined in claim 14 , wherein the plurality of adjacent photodiodes comprises nine adjacent photodiodes, wherein the nine adjacent photodiodes are located in three adjacent columns and three adjacent rows.

19 . The image sensor defined in claim 14 , wherein at least two photodiodes of the plurality of photodiodes have different angular responses, and wherein the at least two photodiodes are used to calculate phase information.

20 . The image sensor defined in claim 19 , wherein the plurality of adjacent photodiodes in each pixel are each configured to generate an image signal in response to being exposed to light, wherein the image signals of each photodiode of the plurality of adjacent photodiodes have an average value, and wherein the average value is used to generate image data.

21 . A method comprising:
forming an array of photodiodes in a substrate, wherein the array of photodiodes are arranged in a plurality of rows and columns; forming a plurality of microlenses over the array of photodiodes, wherein each microlens covers a respective plurality of photodiodes to form a respective pixel; and forming an array of color filter elements over the array of photodiodes, wherein a respective color filter element covers each respective plurality of photodiodes, wherein the substrate comprises first portions that are interposed between each pixel and second portions that are interposed between each photodiode in the respective plurality of photodiodes, wherein the first portions of the substrate are processed using a first method and the second portions of the substrate are processed using a second method that is different than the first method.

22 . The method defined in claim 21 , wherein the first portions of the substrate are implanted with a first dose of ions, wherein the second portions of the substrate are implanted with a second dose of ions, and wherein the first dose is different than the second dose.

Assignees

• Semiconductor Components Ind Llc

Inventors

• Fettig Douglas
• Mlinar Marko
• Gravelle Jr Robert M

Classifications

• H04N23/73

  by influencing the exposure time · CPC title

• H04N25/704

  Pixels specially adapted for focusing, e.g. phase difference pixel sets · CPC title

• H04N25/583

  with different integration times · CPC title

• H04N25/46 Primary

  by combining or binning pixels · CPC title

• H04N23/741

  by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors · CPC title