Solid-state imaging apparatus and imaging apparatus
A solid-state imaging apparatus includes a plurality of high-sensitivity pixels that are arranged in a matrix, and perform a photoelectric conversion at a predetermined sensitivity; a plurality of low-sensitivity pixels that are arranged in a matrix in gaps between the plurality of high-sensitivity pixels, and perform a photoelectric conversion at a lower sensitivity than the predetermined sensitivity; and a signal processor that generates a pixel signal by (i) detecting a difference signal between a signal from the plurality of high-sensitivity pixels and a signal from the plurality of low-sensitivity pixels, and (ii) correcting the signal from the plurality of high-sensitivity pixels using the difference signal.
1. A solid-state imaging apparatus, comprising:
a plurality of high-sensitivity pixels that are arranged in a matrix, and perform a photoelectric conversion at a predetermined sensitivity;
a plurality of low-sensitivity pixels that are arranged in a matrix in gaps between the plurality of high-sensitivity pixels, and perform a photoelectric conversion at a lower sensitivity than the predetermined sensitivity; and
a signal processor that generates a pixel signal by (i) detecting a difference signal between a signal from the plurality of high-sensitivity pixels and a signal from the plurality of low-sensitivity pixels, and (ii) correcting the signal from the plurality of high-sensitivity pixels using the difference signal,
wherein:
the solid-state imaging apparatus generates, within one vertical scanning period, a first high-sensitivity frame, a second high-sensitivity frame, and a third high-sensitivity frame by respectively performing a first exposure operation that exposes the plurality of high-sensitivity pixels for a first exposure time, a second exposure operation that exposes the plurality of high-sensitivity pixels for a second exposure time, and a third exposure operation that exposes the plurality of high-sensitivity pixels for a third exposure time,
the first exposure time is longer than the second exposure time and the second exposure time is longer than the third exposure time, and
the signal processor generates:
a first low-sensitivity frame, a second low-sensitivity frame and a third low-sensitivity frame by multiplying a frame including the signal from the plurality of low-sensitivity pixels by, respectively, a first coefficient corresponding to a first exposure time, a second coefficient corresponding to a second exposure time and a third coefficient corresponding to a third exposure time;
a first correction signal by detecting a difference signal between a signal from the first high-sensitivity frame and a signal from the first low-sensitivity frame, and correcting the signal from the first high-sensitivity frame using the difference signal;
a second correction signal by detecting a difference signal between a signal from the second high-sensitivity frame and a signal from the second low-sensitivity frame, and correcting the signal from the second high-sensitivity frame using the difference signal;
a third correction signal by detecting a difference signal between a signal from the third high-sensitivity frame and a signal from the third low-sensitivity frame, and correcting the signal from the third high-sensitivity frame using the difference signal; and
the pixel signal by synthesizing the first correction signal, the second correction signal and the third correction signal.
2. The solid-state imaging apparatus according to claim 1 , wherein
the plurality of high-sensitivity pixels are exposed in parallel with the plurality of low-sensitivity pixels, and
an exposure time of the plurality of low-sensitivity pixels is longer than an exposure time of the plurality of high-sensitivity pixels, shorter than one vertical synchronization period, and longer than a predetermined flicker cycle.
3. The solid-state imaging apparatus according to claim 1 , wherein the signal processor adds the difference signal to the signal from the plurality of high-sensitivity pixels as the correcting of the signal from the plurality of high-sensitivity pixels.
4. The solid-state imaging apparatus according to claim 1 , wherein
the solid-state imaging apparatus generates, within one vertical scanning period, a plurality of high-sensitivity frames by performing an exposure operation a plurality of times, each having a different exposure time, on the plurality of high-sensitivity pixels, and
the signal processor:
corrects a signal of each of the plurality of high-sensitivity frames using the signal from the plurality of low-sensitivity pixels; and
synthesizes the plurality of high-sensitivity frames corrected.
5. The solid-state imaging apparatus according to claim 1 , wherein
the solid-state imaging apparatus generates, within one vertical scanning period, a first high-sensitivity frame, a second high-sensitivity frame, and a third high-sensitivity frame by respectively performing a first exposure operation that exposes the plurality of high-sensitivity pixels for a first exposure time, a second exposure operation that exposes the plurality of high-sensitivity pixels for a second exposure time, and a third exposure operation that exposes the plurality of high-sensitivity pixels for a third exposure time,
the first exposure time is longer than the second exposure time and the second exposure time is longer than the third exposure time, and
the signal processor generates:
a second low-sensitivity frame and a third low-sensitivity frame by multiplying a frame including the signal from the plurality of low-sensitivity pixels by, respectively, a second coefficient corresponding to the second exposure time and a third coefficient corresponding to the third exposure time;
a second correction signal by detecting a difference signal between a signal from the second high-sensitivity frame and a signal from the second low-sensitivity frame, and correcting the signal from the second high-sensitivity frame using the difference signal;
a third correction signal by detecting a difference signal between a signal from the third high-sensitivity frame and a signal from the third low-sensitivity frame, and correcting the signal from the third high-sensitivity frame using the difference signal; and
the pixel signal by synthesizing a signal from the first high-sensitivity frame, the second correction signal and the third correction signal.
6. The solid-state imaging apparatus according to claim 1 , wherein
the plurality of low-sensitivity pixels include a plurality of first low-sensitivity pixels and a plurality of second low-sensitivity pixels, and
at least one of a signal saturation level and a sensitivity of the plurality of first low-sensitivity pixels is different from the at least one of a signal saturation level and a sensitivity of the plurality of second low-sensitivity pixels.
7. The solid-state imaging apparatus according to claim 6 , wherein
the solid-state imaging apparatus includes a plurality of first pixel groups and a plurality of second pixel groups,
the plurality of first pixel groups each include four of the plurality of high-sensitivity pixels disposed in a square region, and four of the plurality of first low-sensitivity pixels disposed in the square region,
the plurality of second pixel groups each include four of the plurality of high-sensitivity pixels disposed in a square region, and four of the plurality of second low-sensitivity pixels disposed in the square region, and
the plurality of first pixel groups and the plurality of second pixel groups are alternately disposed in rows and columns.
8. A solid-state imaging apparatus, comprising:
a plurality of high-sensitivity pixels that are arranged in a matrix, and perform a photoelectric conversion at a predetermined sensitivity;
a plurality of low-sensitivity pixels that are arranged in a matrix in gaps between the plurality of high-sensitivity pixels, and perform a photoelectric conversion at a lower sensitivity than the predetermined sensitivity; and
a signal processor that generates a pixel signal by (i) detecting a difference signal between a signal from the plurality of high-sensitivity pixels and a signal from the plurality of low-sensitivity pixels, and (ii) correcting the signal from the plurality of high-sensitivity pixels using the difference signal,
wherein:
the plurality of low-sensitivity pixels include a plurality of first low-sensitivity pixels and a plurality of second low-sensitivity pixels,
at least one of a signal saturation level and a sensitivity of the plurality of first low-sensitivity pixels is different from the at least one of a signal saturation level and a sensitivity of the plurality of second low-sensitivity pixels,
the solid-state imaging apparatus includes a plurality of first pixel groups and a plurality of second pixel groups,
the plurality of first pixel groups each include four of the plurality of high-sensitivity pixels disposed in a square region, and four of the plurality of first low-sensitivity pixels disposed in the square region,
the plurality of second pixel groups each include four of the plurality of high-sensitivity pixels disposed in a square region, and four of the plurality of second low-sensitivity pixels disposed in the square region,
the plurality of first pixel groups and the plurality of second pixel groups are alternately disposed in rows and columns, and
wherein:
the signal processor generates:
a first interpolated frame including a plurality of first pixel signals obtained from the plurality of first low-sensitivity pixels, and a plurality of first interpolated signals obtained through interpolation using the plurality of first pixel signals;
a second interpolated frame including a plurality of second pixel signals obtained from the plurality of second low-sensitivity pixels, and a plurality of second interpolated signals obtained through interpolation using the plurality of second pixel signals; and
the pixel signal by (i) detecting a difference signal between the signal from the plurality of high-sensitivity pixels and a signal obtained by synthesizing the first interpolated frame and the second interpolated frame, and (ii) correcting the signal from the plurality of high-sensitivity pixels using the difference signal.
9. The solid-state imaging apparatus according to claim 8 , wherein
the solid-state imaging apparatus generates, within one vertical scanning period, a first high-sensitivity frame, a second high-sensitivity frame, and a third high-sensitivity frame by respectively performing a first exposure operation that exposes the plurality of high-sensitivity pixels for a first exposure time, a second exposure operation that exposes the plurality of high-sensitivity pixels for a second exposure time, and a third exposure operation that exposes the plurality of high-sensitivity pixels for a third exposure time,
the first exposure time is longer than the second exposure time and the second exposure time is longer than the third exposure time, and
the signal processor:
generates a first low-sensitivity frame, a second low-sensitivity frame, and a third low-sensitivity frame by synthesizing the first interpolated frame and the second interpolated frame, each using a first coefficient corresponding to a first exposure time, a second coefficient corresponding to a second exposure time, and a third coefficient corresponding to a third exposure time;
a first correction signal by detecting a difference signal between a signal from the first high-sensitivity frame and a signal from the first low-sensitivity frame, and correcting the signal from the first high-sensitivity frame using the difference signal;
a second correction signal by detecting a difference signal between a signal from the second high-sensitivity frame and a signal from the second low-sensitivity frame, and correcting the signal from the second high-sensitivity frame using the difference signal;
a third correction signal by detecting a difference signal between a signal from the third high-sensitivity frame and a signal from the third low-sensitivity frame, and correcting the signal from the third high-sensitivity frame using the difference signal; and
the pixel signal by synthesizing the first correction signal, the second correction signal and the third correction signal.
10. The solid-state imaging apparatus according to claim 1 , comprising:
a plurality of pixel circuits arranged in a matrix, wherein
the plurality of pixel circuits each include:
at least one of the plurality of high-sensitivity pixels;
a floating diffusion layer that retains signal charge;
a first transfer transistor that is disposed corresponding to the at least one of the plurality of high-sensitivity pixels, and transfers signal charge of the at least one of the plurality of high-sensitivity pixels to the floating diffusion layer;
at least one of the plurality of low-sensitivity pixels;
a second transfer transistor that is disposed corresponding to the at least one of the plurality of low-sensitivity pixels, and transfers signal charge of the at least one of the plurality of low-sensitivity pixels to the floating diffusion layer; and
a transistor that electrically disconnects or connects the second transfer transistor and the floating diffusion layer.
11. The solid-state imaging apparatus according to claim 1 , further comprising:
a control electrode that is disposed at each of the plurality of low-sensitivity pixels, and covers a portion of the plurality of low-sensitivity pixels, wherein
the control electrode controls a potential of a surface of each of the plurality of low-sensitivity pixels in accordance with a voltage applied to the control electrode.
12. A solid-state imaging apparatus comprising:
a plurality of high-sensitivity pixels that are arranged in a matrix, and perform a photoelectric conversion at a predetermined sensitivity;
a plurality of low-sensitivity pixels that are arranged in a matrix in gaps between the plurality of high-sensitivity pixels, and perform a photoelectric conversion at a lower sensitivity than the predetermined sensitivity;
a signal processor that generates a pixel signal by (i) detecting a difference signal between a signal from the plurality of high-sensitivity pixels and a signal from the plurality of low-sensitivity pixels, and (ii) correcting the signal from the plurality of high-sensitivity pixels using the difference signal; and
a plurality of pixel circuits arranged in a matrix,
wherein the plurality of pixel circuits each include:
at least one of the plurality of high-sensitivity pixels;
a floating diffusion layer that retains signal charge;
a first transfer transistor that is disposed corresponding to the at least one of the plurality of high-sensitivity pixels, and transfers signal charge of the at least one of the plurality of high-sensitivity pixels to the floating diffusion layer;
at least one of the plurality of low-sensitivity pixels; and
a second transfer transistor that is disposed corresponding to the at least one of the plurality of low-sensitivity pixels, and transfers signal charge of the at least one of the plurality of low-sensitivity pixels to the floating diffusion layer, and
the solid-state imaging apparatus:
repeatedly performs a normal exposure operation and an intermediate exposure operation on the plurality of low-sensitivity pixels within one vertical scanning period;
during the normal exposure operation, a gate electrode of the second transfer transistor is at a low level;
during the intermediate exposure operation, the gate electrode of the second transfer transistor is at a high level or a medium level; and
simultaneously switches all rows of the plurality of low-sensitivity pixels from the normal exposure operation to the intermediate exposure operation, and simultaneously switches all rows of the plurality of low-sensitivity pixels from the intermediate exposure operation to the normal exposure operation.
13. An imaging apparatus, comprising:
the solid-state imaging apparatus according to claim 1 ; and
any one of a view system, an advanced driver-assistance sensing system, and an automated driving sensing system.
14. The imaging apparatus according to claim 13 , wherein the imaging apparatus is installed on at least one of a front-view mirror, a left side mirror, a right side mirror, and a rear-view mirror of transportation machinery.