Solid-state imaging device, signal processing device and signal processing method for solid-state imaging device, and imaging apparatus

1. A solid-state imaging device comprising:

a pixel array unit in which unit pixels including photoelectric conversion elements for converting light signals into signal charges are arranged in a matrix; and

a signal processing circuit that obtains a first video signal at a first sensitivity and a second video signal at a second sensitivity and performs processing for combining the first and second video signals, wherein

the signal processing circuit includes:

judging means for comparing a level of a luminance value of the first video signal and a level of a luminance value of the second video signal of a pixel of interest in the pixel array unit with respect to a reference luminance value to thereby judge whether the pixel of interest is a pixel to be saturated during an exposure period;

calculating means for setting the pixel of interest, which is judged by the judging means as the pixel to be saturated, as a correction pixel and calculating a correction amount on the basis of a luminance value of the second video signal of a peripheral pixel of the correction pixel; and

correcting means for applying the correction amount calculated by the calculating means to a luminance value of the first video signal of the correction pixel to thereby correct a noise signal amount due to photo-charges leaking from the peripheral pixel into the correction pixel,

wherein the calculating means subtracts the reference luminance value from the luminance value of the second video signal of the peripheral pixel and sets a value obtained by multiplying a result of the subtraction with a correction coefficient as the correction amount,

wherein there is a plurality of peripheral pixels, and the calculating means subtracts, for each respective peripheral pixel of the plurality of peripheral pixels, the reference luminance value from luminance values of the second video signal of the plurality of peripheral pixels, calculates values obtained by multiplying results of the subtraction with a correction coefficient, and sets a sum of the values as the correction amount.

2. A solid-state imaging device comprising:

a pixel array unit in which unit pixels including photoelectric conversion elements for converting light signals into signal charges are arranged in a matrix; and

a signal processing circuit that obtains a first video signal at a first sensitivity and a second video signal at a second sensitivity and performs processing for combining the first and second video signals, wherein

the signal processing circuit includes:

judging means for comparing a level of a luminance value of the first video signal and a level of a luminance value of the second video signal of a pixel of interest in the pixel array unit with respect to a reference luminance value to thereby judge whether the pixel of interest is a pixel to be saturated during an exposure period;

calculating means for setting the pixel of interest, which is judged by the judging means as the pixel to be saturated, as a correction pixel and calculating a correction amount on the basis of a luminance value of the second video signal of a peripheral pixel of the correction pixel; and

correcting means for applying the correction amount calculated by the calculating means to a luminance value of the first video signal of the correction pixel to thereby correct a noise signal amount due to photo-charges leaking from the peripheral pixel into the correction pixel, wherein the solid-state imaging device has a plurality of unit columns or sets of plural columns and the signal processing circuit is provided in each unit column or in each set of plural columns.

3. A solid-state imaging device according to claim 2 , wherein the signal processing circuit has a storing circuit that stores luminance value of one or more pixels.

4. A signal processing method of obtaining a first video signal at a first sensitivity and a second video signal at a second sensitivity and performing processing for combining the first and second video signals in a solid-state imaging device including a pixel array unit in which unit pixels including photoelectric conversion elements for converting light signals into signal charges are arranged in a matrix, the signal processing method comprising the steps of:

comparing a level of a luminance value of the first video signal and a level of a luminance value of the second video signal of a pixel of interest in the pixel array unit with respect to a reference luminance value to thereby judge whether the pixel of interest is a pixel to be saturated during an exposure period;

setting the pixel of interest, which is judged in the judging step as the pixel to be saturated, as a correction pixel and calculating a correction amount on the basis of a luminance value of the second video signal of a peripheral pixel of the correction pixel; and

applying the correction amount calculated in the calculating step to a luminance value of the first video signal of the correction pixel to thereby correct a noise signal amount due to photo-charges leaking from the peripheral pixel into the correction pixel,

wherein, in the calculating step, the reference luminance value is subtracted from a luminance value of the second video signal of the peripheral pixel and a value obtained by multiplying a result of the subtraction with a correction coefficient is set as the correction amount, and

wherein there is a plurality of peripheral pixels, and the calculating step, for each respective peripheral pixel of the plurality of peripheral pixels, the reference luminance value is subtracted from luminance values of the second video signal of the peripheral pixels, values obtained by multiplying results of the subtraction with a correction coefficient are calculated, and a sum of the values is set as the correction amount.

5. An imaging apparatus comprising:

a solid-state imaging device including a pixel array unit in which unit pixels including photoelectric conversion elements for converting light signals into signal charges are arranged in a matrix and a signal processing circuit that obtains a first video signal at a first sensitivity and a second video signal at a second sensitivity and performs processing for combining the first and second video signals; and

an optical system that focuses incident light on an imaging surface of the solid-state imaging device, wherein

the signal processing circuit includes:

judging means for comparing a level of a luminance value of the first video signal and a level of a luminance value of the second video signal of a pixel of interest in the pixel array unit with respect to a reference luminance value to thereby judge whether the pixel of interest is a pixel to be saturated during an exposure period;

calculating means for setting the pixel of interest, which is judged by the judging means as the pixel to be saturated, as a correction pixel and calculating a correction amount on the basis of a luminance value of the second video signal of a peripheral pixel of the correction pixel; and

correcting means for applying the correction amount calculated by the calculating means to a luminance value of the first video signal of the correction pixel to thereby correct a noise signal amount due to photo-charges leaking from the peripheral pixel into the correction pixel.

6. A solid-state imaging device comprising:

a pixel array unit in which unit pixels including photoelectric conversion elements for converting light signals into signal charges are arranged in a matrix; and

a signal processing circuit that obtains a first video signal at a first sensitivity and a second video signal at a second sensitivity and performs processing for combining the first and second video signals, wherein

the signal processing circuit includes:

a judging unit comparing a level of a luminance value of the first video signal and a level of a luminance value of the second video signal of a pixel of interest in the pixel array unit with respect to a reference luminance value to thereby judge whether the pixel of interest is a pixel to be saturated during an exposure period;

a calculating unit setting the pixel of interest, which is judged by the judging unit as the pixel to be saturated, as a correction pixel and calculating a correction amount on the basis of a luminance value of the second video signal of a peripheral pixel of the correction pixel; and

a correcting unit applying the correction amount calculated by the calculating unit to a luminance value of the first video signal of the correction pixel to thereby correct a noise signal amount due to photo-charges leaking from the peripheral pixel into the correction pixel.