Imaging apparatus, signal processing method for imaging apparatus, and electronic equipment

1. An imaging apparatus, comprising:

a plurality of analog-digital conversion units that performs parallel processing on a signal of each pixel output in units of a plurality of pixel rows from a pixel array unit in which pixels including photoelectric conversion units are arranged, and converts the signal into a digital signal;

a plurality of reference voltage generation units that is provided corresponding to the plurality of analog-digital conversion units and generates a reference voltage used for analog-digital conversion;

a voltage setting unit that sets a plurality of pixel voltage levels and outputs the plurality of pixel voltage levels through each of the plurality of analog-digital conversion units; and

a computing unit that calculates a correction amount for performing correction on a result of the analog-digital conversion of the signal of each pixel of the pixel array unit, wherein

the computing unit calculates the correction amount on a basis of the result of the analog-digital conversion of each of the plurality of pixel voltage levels by each of the plurality of analog-digital conversion units.

2. The imaging apparatus according to claim 1 , wherein

the computing unit calculates the correction amount for correcting an error in analog-digital conversion performance between reference voltages in a case where settings of the reference voltages generated by the plurality of reference voltage generation units are same.

3. The imaging apparatus according to claim 1 , wherein

the computing unit calculates the correction amount on a basis of a characteristic difference in analog-digital conversion value with respect to the pixel voltage levels between reference voltages.

4. The imaging apparatus according to claim 1 , wherein

the plurality of pixel voltage levels includes a first pixel voltage level set to a black level and a second pixel voltage level set to a white level.

5. The imaging apparatus according to claim 4 , wherein

the computing unit calculates the correction amount from a difference in characteristics of analog-digital conversion values with respect to the pixel voltage levels between characteristics based on an analog-digital conversion value in an imaging frame at a time of setting the first pixel voltage level and characteristics based on an analog-digital conversion value in an imaging frame at a time of setting the second pixel voltage level.

6. The imaging apparatus according to claim 5 , wherein

the computing unit calculates the correction amount from a difference in slope and intercept of the characteristics of the analog-digital conversion value with respect to the pixel voltage level.

7. The imaging apparatus according to claim 6 , wherein

the computing unit integrates an analog-digital conversion value of one imaging frame with respect to each of the first pixel voltage level and the second pixel voltage level, acquires an average value of the analog-digital conversion values, and calculates an error amount of the slope and the intercept of the characteristics of the analog-digital conversion values with respect to the pixel voltage levels on a basis of the acquired average value.

8. The imaging apparatus according to claim 1 , wherein

the voltage setting unit includes a dummy pixel formed in the pixel array unit.

9. The imaging apparatus according to claim 8 , wherein

the dummy pixel is provided for at least one pixel column corresponding to each of the plurality of reference voltage generation units.

10. The imaging apparatus according to claim 9 , wherein

in a stacked structure in which a first semiconductor substrate and a second semiconductor substrate are stacked,

the pixel array unit is formed on the first semiconductor substrate, and

the dummy pixel is formed on a semiconductor substrate other than the first semiconductor substrate.

11. The imaging apparatus according to claim 1 , wherein

the computing unit uses the calculated correction amount to perform correction on the result of the analog-digital conversion of the signal of each pixel of the pixel array unit.

12. The imaging apparatus according to claim 11 , wherein

the computing unit includes an image processing unit provided outside a substrate of the pixel array unit, and

the image processing unit uses the calculated correction amount to perform correction on an analog-digital conversion result of an effective pixel of the pixel array unit.

13. The imaging apparatus according to claim 11 , wherein

the computing unit includes an external computing apparatus provided outside a substrate of the pixel array unit,

the external computing apparatus supplies the calculated correction amount to a signal processing unit provided in the substrate of the pixel array unit, and

the signal processing unit uses the correction amount supplied from the external computing apparatus to perform correction on the analog-digital conversion result of an effective pixel of the pixel array unit.

14. The imaging apparatus according to claim 11 , wherein

the computing unit includes a signal processing unit provided in a substrate of the pixel array unit, and

the signal processing unit uses the calculated correction amount to perform correction on an analog-digital conversion result of an effective pixel of the pixel array unit.

15. A signal processing method for an imaging apparatus,

in performing signal processing of the imaging apparatus including:

a plurality of analog-digital conversion units that performs parallel processing on a signal of each pixel output in units of a plurality of pixel rows from a pixel array unit in which pixels including photoelectric conversion units are arranged, and converts the signal into a digital signal; and

a plurality of reference voltage generation units that is provided corresponding to the plurality of analog-digital conversion units and generates a reference voltage used for analog-digital conversion,

the method comprising:

setting a plurality of pixel voltage levels and outputting the plurality of pixel voltage levels through each of the plurality of analog-digital conversion units; and

calculating a correction amount for performing correction on a result of the analog-digital conversion of the signal of each pixel of the pixel array unit on a basis of the result of the analog-digital conversion of each of the plurality of pixel voltage levels by each of the plurality of analog-digital conversion units.

16. An electronic equipment, comprising:

an imaging apparatus including:

a plurality of analog-digital conversion units that performs parallel processing on a signal of each pixel output in units of a plurality of pixel rows from a pixel array unit in which pixels including photoelectric conversion units are arranged, and converts the signal into a digital signal;

a plurality of reference voltage generation units that is provided corresponding to the plurality of analog-digital conversion units and generates a reference voltage used for analog-digital conversion;

a voltage setting unit that sets a plurality of pixel voltage levels and outputs the plurality of pixel voltage levels through each of the plurality of analog-digital conversion units; and

a computing unit that calculates a correction amount for performing correction on a result of the analog-digital conversion of the signal of each pixel of the pixel array unit, wherein

the computing unit calculates the correction amount on a basis of the result of the analog-digital conversion of each of the plurality of pixel voltage levels by each of the plurality of analog-digital conversion units.