Imaging systems with high dynamic range and phase detection pixels
An image sensor may include a pixel array with high dynamic range functionality and phase detection pixels. The phase detection pixels may be arranged in phase detection pixel groups. Each phase detection pixel group may include three adjacent pixels arranged consecutively in a line. A single microlens may cover all three pixels in the phase detection pixel group, or two microlenses may combine to cover the three pixels in the phase detection pixel group. The edge pixels in each phase detection pixel group may have the same integration time and the same color. The middle pixel in each phase detection pixel group may have the same or different color as the edge pixels, and the same or different integration time as the edge pixels. Phase detection pixel groups may also be formed from two pixels that each are 1.5 times the size of neighboring pixels.
1. An image sensor having a pixel array, wherein the pixel array comprises:
a plurality of image pixels that gather image data; and
a plurality of phase detection pixels that gather phase information, wherein the phase detection pixels are arranged in phase detection pixel groups, wherein each phase detection pixel group includes three adjacent pixels, wherein the three adjacent pixels of each phase detection pixel group comprise a first pixel, a second pixel, and a third pixel, wherein the second pixel is interposed between the first and third pixels, wherein a first microlens covers the first pixel and at least a portion of the second pixel, and wherein a second microlens covers the third pixel and at least an additional portion of the second pixel.
2. The image sensor defined in claim 1 , wherein the first microlens covers all of the first pixel and a first half of the second pixel, and wherein the second microlens covers all of the third pixel and a second half of the third pixel.
3. The image sensor defined in claim 1 , wherein a third microlens covers the first pixel, wherein a fourth microlens covers the second pixel, wherein a fifth microlens covers the third pixel, wherein the first microlens covers the third microlens and at least a portion of the fourth microlens, and wherein the second microlens covers the fifth microlens and at least an additional portion of the fourth microlens.
4. The image sensor defined in claim 1 , wherein the phase detection pixel groups are arranged in interrupted lines.
5. The image sensor defined in claim 1 , further comprising:
a color filter array, wherein each phase detection pixel includes a respective color filter element, and wherein the color filter elements of the phase detection pixels are all the same color.
6. The image sensor defined in claim 1 , further comprising:
a color filter array, wherein each phase detection pixel includes a respective color filter element, wherein the first and third pixels include color filter elements of a first color, and wherein the second pixel includes a color filter element of a second color that is different than the first color.
7. The image sensor defined in claim 6 , wherein the second pixel is separated from the first and third pixels by backside deep trench isolation.
8. The image sensor defined in claim 6 , further comprising shielding elements interposed between color filter elements of the color filter array.
9. The image sensor defined in claim 6 , wherein the second pixel is at least partially covered by a shielding element.
10. The image sensor defined in claim 1 , wherein the plurality of image pixels includes a first group of image pixels that are configured to generate charge for a first integration time and a second group of image pixels that are configured to generate charge for a second integration time, wherein the first integration time is different than the second integration time.
11. The image sensor defined in claim 10 , wherein the first and third pixels are configured to generate charge for the first integration time, and wherein the second pixel is configured to generate charge for the second integration time.
12. The image sensor defined in claim 10 , wherein the three adjacent pixels of each phase detection pixel group are configured to generate charge for the first integration time.
13. An image sensor having a pixel array, wherein the pixel array comprises:
a plurality of image pixels that gather image data, wherein the plurality of image pixels includes a first group of image pixels with a first integration time and a second group of image pixels with a second integration time, wherein the first integration time is different than the second integration time; and
a plurality of phase detection pixels that gather phase information, wherein the plurality of phase detection pixels is arranged in phase detection pixel groups, wherein each phase detection pixel group includes a first pixel, a second pixel, and a third pixel arranged consecutively in a line, wherein the second pixel is interposed between the first and third pixels, wherein the first, second, and third pixels are the only pixels in each phase detection pixel group, wherein the first and third pixels of each phase detection pixel group have the first integration time, and wherein the second pixel of each phase detection pixel group has the second integration time.
14. The image sensor defined in claim 13 , wherein the first integration time is longer than the second integration time.
15. A method of operating an image sensor with a pixel array that includes a plurality of image pixels and a plurality of phase detection pixels, wherein the plurality of phase detection pixels comprises phase detection pixel groups, and wherein each phase detection pixel group includes a first pixel, a second pixel, and a third pixel, the method comprising:
with a first portion of the plurality of image pixels, generating charge for a first integration time;
with a second portion of the plurality of image pixels, generating charge for a second integration time that is different than the first integration time;
with the first and third pixels of each phase detection pixel group, generating charge for the first integration time; and
with the second pixel of each phase detection pixel group, generating charge for the second integration time.