Image sensor including auto-focusing pixel and image processing system including the same

Patent metadata

Field	Value
Publication number	US-9973682-B2
Application number	US-201615210602-A
Country	US
Kind code	B2
Filing date	Jul 14, 2016
Priority date	Jul 15, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

An image sensor includes a pixel array including first to fourth pixels having an R, G, and B Bayer pattern. An analog-to-digital converter (ADC) block converts a pixel signal of each of the first to fourth pixels into a digital pixel signal. At least one among the first to fourth pixels includes two photo diodes separated in a first direction, and at least one other of the first to fourth pixels includes two photo diodes separated in a second direction which is different from the first direction.

First claim

What is claimed is:

1. An image sensor comprising:
a pixel array including first to fourth pixels having an R, G, and B Bayer pattern;
an analog-to-digital converter (ADC) block configured to convert a pixel signal of each of the first to fourth pixels into a digital pixel signal; and
a control block configured to control the pixel array and the ADC block, wherein:
the first and fourth pixels are green pixels each including a green filter, the second pixel is a red pixel including a red filter, and the third pixel is a blue pixel including a blue filter,
each of the first and fourth pixels comprises two photo diodes separated in a first direction, and
at least one of the second and third pixels comprises two photo diodes separated in a second direction, which is different from the first direction.

2. The image sensor of claim 1 , wherein a difference between the first direction and the second direction is an angle of 90 degrees.

3. The image sensor of claim 1 , wherein
each of the second and third pixels comprises the two photo diodes separated in the second direction.

4. The image sensor of claim 1 , wherein
the other of the second and third pixels comprises the two photo diodes separated in the first direction.

5. The image sensor of claim 1 , wherein:
the first pixel comprise the two photo diodes separated in the first direction and the two photo diodes accumulate a photocharge corresponding to intensity of incident light passing through one micro-lens, and
the first pixel comprises a plurality of transistors configured to convert the photocharge accumulated in the two photo diodes thereof into first and second sub-pixel signals which are electrical signals and output the first and second sub-pixel signals, wherein a number of the plurality of transistors of each pixel is two or more.

6. The image sensor of claim 5 , wherein auto-focusing information is calculated based on a difference between the first and second sub-pixel signals.

7. The image sensor of claim 5 , wherein the first and second sub-pixel signals are simultaneously output via different sub-column lines.

8. The image sensor of claim 5 , wherein the first and second sub-pixel signals are sequentially output via the same column line.

9. An image sensor comprising:
a pixel array including a plurality of pixels having an R, G, and B Bayer pattern; and
an analog-to-digital converter (ADC) block configured to convert a pixel signal of each of the plurality of pixels into a digital pixel signal, wherein:
the plurality of pixels comprises:
a first-type pixel including two photo diodes separated in a first direction;
a second-type pixel including two photo diodes separated in a second direction which is different from the first direction; and
a third-type pixel including two photo diodes separated in the first direction,

each of the first-type pixel and third-type pixel is a green pixel including a green filter and the second-type pixel is a red pixel including a red filter or a blue pixel including a blue filter,
first auto-focusing information for the first direction is calculated based on a signal output from the first-type pixel, and
second auto-focusing information for the second direction is calculated based on a signal output from the second-type pixel.

10. The image sensor of claim 9 , wherein a difference between the first direction and the second direction is an angle of 90 degrees.

11. The image sensor of claim 9 , wherein each of the plurality of pixels further comprises:
one micro-lens; and
a plurality of transistors configured to convert photocharges accumulated in the two photo diodes into first and second sub-pixel signals, which are electrical signals, according to an intensity of light passing through the micro-lens, and output the first and second sub-pixel signals, wherein a number of the plurality of transistors of each pixel is two or more.

12. The image sensor of claim 11 , wherein:
the first auto-focusing information for the first direction is calculated based on a difference between the first and second sub-pixel signals of the first-type pixel, and
the second auto-focusing information for the second direction is calculated based on a difference between the first and second sub-pixel signals of the second-type pixel.

13. An image processing system comprising:
an image sensor comprising:
a pixel array including a plurality of auto-focusing pixels;
an analog-to-digital converter (ADC) block configured to convert a pixel signal of each of the plurality of auto-focusing pixels into a digital pixel signal; and
an image processor configured to extract auto-focusing information for an auto-focusing operation from the digital pixel signal, wherein:
the auto-focusing pixels comprise:
a first-type pixel including two photo diodes separated in a first direction;
a second-type pixel including two photo diodes separated in a second direction which is different from the first direction; and
a third-type pixel including two photo diodes separated in the first direction, and

each of the first-type pixel and third-type pixel is a green pixel including a green filter and the second-type pixel is a red pixel including a red filter or a blue pixel including a blue filter.

14. The image processing system of claim 13 , wherein a difference between the first direction and the second direction is an angle of 90 degrees.

15. The image processing system of claim 13 , wherein the auto-focusing information comprises:
auto-focusing information for the first direction; and
auto-focusing information for the second direction, wherein
the image processor calculates the auto-focusing information for the first direction, based on a digital pixel signal output from the first-type pixel, and calculates the auto-focusing information for the second direction, based on a digital pixel signal output from the second-type pixel.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Ham Seog Heon

Classifications

• H04N25/704

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

• H04N23/672 Primary

  based on the phase difference signals · CPC title

• H04N25/76 Primary

  Addressed sensors, e.g. MOS or CMOS sensors · CPC title

• H04N25/134 Primary

  based on three different wavelength filter elements · CPC title

• H04N25/77

  Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components · CPC title