Image sensor including at least one autofocusing pixel and at least one normal pixel and driving method thereof

1. An image sensor in a semiconductor substrate comprising:

a pixel array unit including a plurality of nor-ma-photoelectric conversion element groups having first to eighth photoelectric conversion elements,

wherein the plurality of photoelectric conversion element groups include a first photoelectric conversion element group and a second photoelectric conversion element group,

wherein in the first photoelectric conversion element group,

the first and second photoelectric conversion elements are place under a first filter passing through red color wavelength,

the third and fourth photoelectric conversion elements are placed under a second filter passing through white color wavelength,

the fifth and sixth photoelectric conversion elements are placed under a third filter passing through blue color wavelength

wherein the first filter and the third filter are arranged in a first diagonal direction

wherein signals readout from the third and fourth photoelectric conversion elements are provided as autofocusing pixel signals, and

wherein signals readout from the first, second, fifth and sixth photoelectric conversion elements are provided as normal pixel signals.

2. The image sensor of claim 1 , wherein, in the first photoelectric conversion element group, the seventh and eighth photoelectric conversion elements are placed under a fourth filter passing through green color wavelength, and

the second filter and the fourth filter are arranged in a second diagonal direction intersecting the first diagonal direction.

3. The image sensor of claim 1 , wherein, in the first photoelectric conversion element group, the seventh and eighth photoelectric conversion elements are placed under a fourth filter passing through white color wavelength, and

the second filter and the fourth filter are arranged in a second diagonal direction intersecting the first diagonal direction.

4. The image sensor of claim 3 , wherein, in the second photoelectric conversion element group, the first and second photoelectric conversion elements are laced under a fifth filter passing through green color wavelength,

the third and fourth photoelectric conversion elements are placed under a sixth filter passing through white color wavelength,

the fifth and sixth photoelectric conversion elements are placed under a seventh filter passing through green color wavelength, and

the seventh and eighth photoelectric conversion elements are placed under an eighth filter passing through white color wavelength.

5. The image sensor of claim 4 , wherein, in the second photoelectric conversion element group, the fifth filter and the seventh filter are arranged in the first diagonal direction, and the sixth filter and the eighth filter are arranged in the second diagonal direction.

6. The image sensor of claim 3 , wherein, in the second photoelectric conversion element group, the first and second photoelectric conversion elements are placed under a fifth filter passing through red color wavelength,

the third and fourth photoelectric conversion elements are placed under a sixth filter passing through green color wavelength,

the fifth and sixth photoelectric conversion elements are placed under a seventh filter passing through blue color wavelength, and

the seventh and eighth photoelectric conversion elements are placed under an eighth filter passing through green color wavelength.

7. The image sensor of claim 6 , wherein the second photoelectric conversion element group is disposed closer to a border of the pixel array unit than the first photoelectric conversion element group.

8. The image sensor of claim 1 , further comprising:

a plurality of isolators between each of the first to eighth photoelectric conversion elements.

9. The image sensor of claim 8 , wherein the plurality of isolators includes a first isolator and a second isolator, and

the second isolator is surrounded by the first isolator.

10. The image sensor of claim 9 , wherein a length of the second isolator is shorter than a length of the first isolator.

11. The image sensor of claim 9 , wherein the pixel array unit includes a first pixel and a second pixel,

the second pixel is disposed closer to a border of the pixel array unit than the first pixel, and

a position of the second isolator disposed in the first pixel with respect to a center of the first pixel is different from a position of the second isolator disposed in the second pixel with respect to a center of the second pixel.

12. The image sensor of claim 11 , wherein a distance between the second isolator disposed in the first pixel and the center of the first pixel is shorter than a distance between the second isolator disposed in the second pixel and the center of the second pixel.

13. The image sensor of claim 11 , wherein the second pixel includes a micro-lens, and a center of the micro-lens positioned in the second pixel deviates from the center of the second pixel.

14. An image sensor, comprising:

a pixel array unit including a plurality of photoelectric conversion element groups, each having first to eighth photoelectric conversion elements,

wherein the first and second photoelectric conversion elements are placed under a first filter passing through red color wavelength,

wherein the third and fourth photoelectric conversion elements are placed under a second filter passing through white color wavelength,

wherein the fifth and sixth photoelectric conversion elements are placed under a third filter passing through blue color wavelength,

wherein the first to sixth photoelectric conversion elements are arranged in a counter clockwise direction,

wherein the third and fourth photoelectric conversion elements are connected to first and second transmission signal lines, respectively, and

wherein the first and second photoelectric conversion elements are commonly connected to a third transmission signal line.

15. The image sensor of claim 14 , wherein the first filter and the third filter are arranged in a first diagonal direction.

16. The image sensor of claim 14 , wherein the first to eighth photoelectric conversion elements are connected to eight transmission transistors.

17. The image sensor of claim 16 , wherein the first photoelectric conversion element is connected to a first transmission transistor and the second photoelectric conversion element is connected to a second transmission transistor, and

wherein a gate of the first transmission transistor and a gate of the second transmission transistor are commonly connected the third transmission signal line.

18. The image sensor of claim 16 , wherein the third photoelectric conversion element is connected to a third transmission transistor and the fourth photoelectric conversion element is connected to a fourth transmission transistor, and

wherein a gate of the third transmission transistor is connected to the first transmission signal line and a gate of the fourth transmission transistor is connected the second transmission signal line.

19. The image sensor of claim 15 , wherein the seventh and eighth photoelectric conversion elements are placed under a fourth filter passing through green color wavelength, and

the second filter and the fourth filter are arranged in a second diagonal direction, intersecting to the first diagonal direction.

20. The image sensor of claim 19 , wherein the seventh and eighth photoelectric conversion elements are placed under a fourth filter passing through white color wavelength, and

the second filter and the fourth filter are arranged in a second diagonal direction, intersecting the first diagonal direction.