Signal processing apparatus, image pickup apparatus, and image pickup system

Patent metadata

Field	Value
Publication number	US-9264601-B2
Application number	US-201414149082-A
Country	US
Kind code	B2
Filing date	Jan 7, 2014
Priority date	Jan 18, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A signal processing apparatus which processes signals obtained from an image pickup element including a plurality of first pixels sharing a first microlens and a plurality of second pixels sharing a second microlens, the first pixels and the second pixels having saturation characteristics different from each other, and the signal processing apparatus includes a saturation detector configured to detect a saturated pixel whose charge amount has reached a saturation level among the first pixels and the second pixels, and an estimating portion configured to estimate the charge amount of the saturated pixel using a nearby pixel of the saturated pixel.

First claim

What is claimed is:

1. A signal processing apparatus which processes signals obtained from an image pickup element including a first plurality of pixels sharing a first microlens and a second plurality of pixels sharing a second microlens, the first plurality of pixels and the second plurality of pixels having saturation characteristics different from each other, the signal processing apparatus comprising:
a saturation detector configured to detect a saturated pixel whose charge amount has reached a saturation level among the first plurality of pixels and the second plurality of pixels; and
an estimating portion configured to estimate the charge amount of the saturated pixel using a nearby pixel of the saturated pixel.

2. The signal processing apparatus according to claim 1 , wherein the estimating portion estimates the charge amount of the saturated pixel using a charge amount of the nearby pixel, having different saturation characteristics, located in a vicinity of the saturated pixel.

3. The signal processing apparatus according to claim 1 , wherein the estimating portion estimates the charge amount of the saturated pixel using an added pixel value whose linearity is kept of the nearby pixels located in a vicinity of the saturated pixel.

4. The image pickup apparatus according to claim 1 , wherein the estimating portion estimates a charge amount of a first pixel, sharing a first microlens, which is saturated with the following steps:
calculating a charge amount of another first pixel, which is not saturated, sharing the first microlens using a charge amount of second pixels, sharing a second microlens different from the first microlens and being around the another first pixel, wherein a charge is movable from the first pixel to the another first pixel in a case where the charge amount of the first pixel is saturated,
comparing the calculated charge amount of the another first pixel and the obtained charge amount of the another first pixel by the image pickup element,
estimating the charge amount of the first pixel using the comparison result.

5. The image pickup apparatus according to claim 1 , wherein the estimating portion estimates a charge amount of a first pixel, sharing a first microlens, which is saturated by calculating a charge amount which is moved from the first pixel to another first pixel, which is not saturated, sharing the first microlens using a charge amount of second pixels, sharing a second microlens different from the first microlens and being around the another first pixel, wherein a charge is movable from the first pixel to the another first pixel in a case where the charge amount of the first pixel is saturated.

6. An image pickup apparatus comprising:
an image pickup element including a first plurality of pixels sharing a first microlens and a second plurality of pixels sharing a second microlens, the first plurality of pixels and the second plurality of pixels having saturation characteristics different from each other;
a saturation detector configured to detect a saturated pixel whose charge amount has reached a saturation level among the first plurality of pixels and the second plurality of pixels; and
an estimating portion configured to estimate the charge amount of the saturated pixel using a nearby pixel of the saturated pixel.

7. The image pickup apparatus according to claim 6 ,
wherein the first plurality of pixels includes:
a first pixel, a second pixel, and a third pixel;
a first boundary provided between the first pixel and the second pixel; and
a second boundary provided between the first pixel and the third pixel,

wherein when the charge amount of the first pixel is saturated, a first charge amount that moves from the first pixel to the second pixel via the first boundary is greater than a second charge amount that moves from the first pixel to the third pixel via the second boundary,
wherein the second plurality of pixels includes:
a fourth pixel, a fifth pixel, and a sixth pixel;
a third boundary provided between the fourth pixel and the fifth pixel, and
a fourth boundary provided between the fourth pixel and the sixth pixel, and

wherein when the charge amount of the fourth pixel is saturated, a third charge amount that moves from the fourth pixel to the fifth pixel via the third boundary is greater than a fourth charge amount that moves from the fourth pixel to the sixth pixel via the fourth boundary.

8. The image pickup apparatus according to claim 7 ,
wherein when the charge amount of the first pixel is saturated, the first boundary is configured so that a charge is movable from the first pixel to the second pixel, and the second boundary is configured so that the charge is prevented from moving from the first pixel to the third pixel, and
wherein when the charge amount of the fourth pixel is saturated, the third boundary is configured so that a charge is movable from the fourth pixel to the fifth pixel, and the fourth boundary is configured so that the charge is prevented from moving from the fourth pixel to the sixth pixel.

9. The image pickup apparatus according to claim 7 , wherein the first boundary and the third boundary are provided in directions different from each other so that the saturation characteristics of the first plurality of pixels and the second plurality of pixels are different from each other.

10. The image pickup apparatus according to claim 6 ,
wherein the first plurality of pixels includes a first pixel, a second pixel, and a first boundary provided between the first pixel and the second pixel,
wherein the second plurality of pixels includes a third pixel, a fourth pixel, and a second boundary provided between the third pixel and the fourth pixel, and
wherein when the charge amounts of the first pixel and the third pixel are saturated, a first charge amount that moves from the first pixel to the second pixel via the first boundary is greater than a second charge amount that moves from the third pixel to the fourth pixel via the second boundary.

11. The image pickup apparatus according to claim 10 , wherein when the charge amounts of the first pixel and the third pixel are saturated, the first boundary is configured so that a charge is movable from the first pixel to the second pixel, and the second boundary is configured so that a charge is prevented from moving from the third pixel to the fourth pixel.

12. The image pickup apparatus according to claim 10 , wherein the first microlenses and the second microlenses are alternately arrayed in two dimensions so that the saturation characteristics of the first plurality of pixels and the second plurality of pixels are different from each other.

13. The image pickup apparatus according to claim 6 ,
wherein each of the first boundary and the second boundary is configured by a P-type semiconductor, and
wherein a P-type impurity concentration of the first boundary is lower than a P-type impurity concentration of the second boundary.

14. An image pickup system comprising:
an image pickup optical system;
an image pickup element including a first plurality of pixels sharing a first microlens and a second plurality of pixels sharing a second microlens, the first plurality of pixels and the second plurality of pixels having saturation characteristics different from each other;
a saturation detector configured to detect a saturated pixel whose charge amount has reached a saturation level among the first plurality of pixels and the second plurality of pixels; and
an estimating portion configured to estimate the charge amount of the saturated pixel using a nearby pixel of the saturated pixel.

Assignees

• Canon Kk

Inventors

• Ishida Chisato
• Ogawa Takeshi

Classifications

• H04N25/50

  Control of the SSIS exposure · CPC title

• H04N25/59

  by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance · CPC title

• H04N25/704 Primary

  Pixels specially adapted for focusing, e.g. phase difference pixel sets · CPC title

• H04N23/672 Primary

  based on the phase difference signals · CPC title

• H04N23/71

  Circuitry for evaluating the brightness variation · CPC title