Imaging device camera system and driving method of the same

1. An imaging device comprising a pixel array on a substrate in which a plurality of pixels with different characteristics of spectral sensitivity are arranged in an array and in which the pixels convert light into an electric signal, said pixels comprising a plurality of color filter pixels and at least one clear pixel,

wherein,

the plurality of color filter pixels include

(i) a first color filter pixel with a first filter effective to cause the first color filter pixel to have a peak spectral sensitivity for red light,

(ii) a second color filter pixel with a second filter effective to cause the second color filter pixel to have a peak spectral sensitivity for blue light, and

(iii) a third color filter pixel with a third filter effective to cause the third color filter pixel to have a peak spectral sensitivity for green light,

the first, second and third color pixels are arranged in a sub-array,

the at least one clear pixel has no filter or a fourth filter with a high transmittance such that the clear pixel is sensitive to white light,

the clear pixel is arranged in the sub-array at a given position of a given row and a given column with respect to a first color pixel, a second color pixel, and a third color pixel,

the clear pixel has a photoconversion region with an implantation region that is deeper than those of the color filter pixels, and

the clear pixel has a microlens that is positioned at a height that is less than a height of the microlenses of the color filter pixels.

2. The imaging device of claim 1 , wherein the clear pixel has a photoconversion region that extends deeper into the substrate than do those of the color filter pixels.

3. The imaging device of claim 1 , wherein in cross section, the color filter pixels and the clear pixel have photoconversion regions that are trapezoidal.

4. The imaging device of claim 1 , wherein in cross section, the clear pixel has a photoconversion region that is larger than those of the color filter pixels.

5. A camera system comprising:

a shutter; and

an imaging device with a pixel array on a substrate in which a plurality of pixels with different characteristics of spectral sensitivity are arranged in an array and in which the pixels convert light into an electric signal, said pixels comprising a plurality of color filter pixels and at least one clear pixel,

wherein,

the plurality of color filter pixels include

(i) a first color filter pixel with a first filter effective to cause the first color filter pixel to have a peak spectral sensitivity for red light,

(ii) a second color filter pixel with a second filter effective to cause the second color filter pixel to have a peak spectral sensitivity for blue light, and

(iii) a third color filter pixel with a third filter effective to cause the third color filter pixel to have a peak spectral sensitivity for green light,

the first, second and third color pixels are arranged in a sub-array,

the at least one clear pixel has no filter or a fourth filter with a high transmittance such that the clear pixel is sensitive to white light,

the clear pixel is arranged in the sub-array at a given position of a given row and a given column with respect to a first color pixel, a second color pixel, and a third color pixel,

the clear pixel has a photoconversion region with an implantation region that is deeper than those of the color filter pixels, and

the clear pixel has a microlens that is positioned at a height that is less than a height of the microlenses of the color filter pixels.

6. The camera system of claim 5 , wherein the clear pixel has a photoconversion region that extends deeper into the substrate than do those of the color filter pixels.

7. The camera system of claim 5 , wherein in cross section, the color filter pixels and the clear pixel have photoconversion regions that are trapezoidal.

8. The camera system of claim 5 , wherein in cross section, the clear pixel has a photoconversion region that is larger than those of the color filter pixels.

9. A method for driving a camera system, comprising:

providing a camera system having (a) an imaging device, (b) an optical system operable to lead incident light to an imaging part of the imaging device, and (c) a signal processing circuit operable to process an output signal of the imaging device, the imaging device comprising a pixel array on a substrate in which a plurality of pixels with different characteristics of spectral sensitivity are arranged in an array and in which the pixels convert light into an electric signal, said pixels comprising a plurality of color filter pixels and at least one clear pixel, the plurality of color filter pixels including (i) a first color filter pixel with a first filter effective to cause the first color filter pixel to have a peak spectral sensitivity for red light, (ii) a second color filter pixel with a second filter effective to cause the second color filter pixel to have a peak spectral sensitivity for blue light, and (iii) a third color filter pixel with a third filter effective to cause the third color filter pixel to have a peak spectral sensitivity for green light, a first read channel being exclusively coupled to the at least one clear pixel and a second read channel is exclusively coupled to the plurality of color filter pixels;

separately performing electronic shutter drives for the at least one clear pixel and for the plurality of color filter pixels; and

separately changing, for the at least one clear pixel and for the plurality of color filter pixels, at least one of time period, rate and gain in processing,

wherein,

the first, second and third color pixels are arranged in a sub-array,

the at least one clear pixel has no filter or a fourth filter with a high transmittance such that the clear pixel is sensitive to white light,

the clear pixel is arranged in the sub-array at a given position of a given row and a given column with respect to a first color pixel, a second color pixel, and a third color pixel, and

the clear pixel has a photoconversion region with an implantation region that is deeper than those of the color filter pixels.

10. The method of claim 9 , further comprising:

at bright places, adjusting a white balance of signals of the clear pixel and the color filter pixels based on a signal of a green color filter pixel.

11. The method of claim 9 , further comprising:

at dark places, adjusting a white balance of signals of the clear pixel and the color filter pixels based on a signal of the clear pixel.

12. The method of claim 10 , further comprising:

performing an interpolation process only for the color filter pixels after white balance is adjusted.

13. The method of claim 11 , further comprising:

performing an interpolation process only for the color filter pixels after white balance is adjusted.