Solid-state imaging device, signal processing method therefor, and electronic apparatus for enabling sensitivity correction
The present disclosure relates to a solid-state imaging device, a signal processing method therefor, and an electronic apparatus enabling sensitivity correction in which a sensitivity difference between solid-state imaging devices is suppressed. The solid-state imaging device includes a pixel unit in which one microlens is formed for a plurality of pixels in a manner such that a boundary of the microlens coincides with boundaries of the pixels. The correction circuit corrects a sensitivity difference between the pixels inside the pixel unit based on a correction coefficient. The present disclosure is applicable to, for example, a solid-state imaging device and the like.
1. A solid-state imaging device comprising:
a pixel unit in which a microlens is formed for a plurality of pixels; and
a correction circuit configured to correct a sensitivity difference between pixels inside the pixel unit based on a correction coefficient,
wherein the correction coefficient is calculated based on an added signal obtained by adding pixel signals of respective pixels of the pixel unit,
wherein the correction coefficient is calculated based on a pixel average value obtained by dividing the added signal by a number of pixels of the pixel unit, and
wherein the correction coefficient is calculated by a ratio between the pixel average value and a pixel signal of each pixel of the pixel unit.
2. The solid-state imaging device according to claim 1 , wherein the pixel unit includes an adding unit configured to generate the added signal.
3. The solid-state imaging device according to claim 2 , wherein the adding unit is a floating diffusion (FD) shared by respective pixels of the pixel unit.
4. The solid-state imaging device according to claim 1 , wherein the correction circuit also performs adding processing in which the added signal is calculated by adding the pixel signals of the respective pixels of the pixel unit.
5. The solid-state imaging device according to claim 1 , further including:
a memory configured to store the correction coefficient,
wherein the correction circuit performs correction based on the correction coefficient obtained from the memory.
6. The solid-state imaging device according to claim 1 ,
wherein a plurality of pixel units are arranged inside a pixel array unit in which pixels are two-dimensionally arrayed in a matrix, and
wherein the correction coefficient is provided for each pixel constituting the pixel unit.
7. The solid-state imaging device according to claim 1 , wherein
a plurality of pixel units are arranged inside a pixel array unit in which pixels are two-dimensionally arrayed in a matrix, and
the correction coefficient is provided for each region obtained by dividing the pixel array unit into a predetermined number.
8. The solid-state imaging device according to claim 1 , wherein the correction coefficient is provided per wavelength of light received by a pixel.
9. The solid-state imaging device according to claim 1 ,
wherein the correction coefficient is provided per color temperature of light received by a pixel.
10. The solid-state imaging device according to claim 9 , wherein the correction circuit uses a pixel signal of another pixel to estimate a color temperature of light received by a pixel, and performs correction based on the correction coefficient corresponding to the estimated color temperature.
11. The solid-state imaging device according to claim 10 , wherein the pixel for which the color temperature of light is estimated is a white pixel formed with a white color filter.
12. The solid-state imaging device according to claim 1 , wherein the solid-state imaging device is a back-illumination type.
13. The solid-state imaging device according to claim 1 , wherein the solid-state imaging device has a stacked structure in which a plurality of semiconductor substrates are stacked.
14. A signal processing method in a solid-state imaging device, wherein the solid-state imaging device includes:
a pixel unit in which a microlens is formed for a plurality of pixels; and
a correction circuit of the solid-state imaging device configured to correct a sensitivity difference between pixels inside the pixel unit based on a correction coefficient,
wherein the correction coefficient is calculated based on an added signal obtained by adding pixel signals of respective pixels of the pixel unit,
wherein the correction coefficient is calculated based on a pixel average value obtained by dividing the added signal by a number of pixels of the pixel unit, and wherein the correction coefficient is calculated by a ratio between the pixel average value and a pixel signal of each pixel of the pixel unit.
15. An electronic apparatus provided with a solid-state imaging device that includes:
a pixel unit in which a microlens is formed for a plurality of pixels; and
a correction circuit configured to correct a sensitivity difference between pixels inside the pixel unit based on a correction coefficient,
wherein the correction coefficient is calculated based on an added signal obtained by adding pixel signals of respective pixels of the pixel unit,
wherein the correction coefficient is calculated based on a pixel average value obtained by dividing the added signal by a number of pixels of the pixel unit, and
wherein the correction coefficient is calculated by a ratio between the pixel average value and a pixel signal of each pixel of the pixel unit.