Solid-state image sensor, and ranging apparatus and imaging apparatus using same

Patent metadata

Field	Value
Publication number	US-2016337608-A1
Application number	US-201515111242-A
Country	US
Kind code	A1
Filing date	Jan 21, 2015
Priority date	Jan 28, 2014
Publication date	Nov 17, 2016
Grant date	—

Abstract

A solid-state image sensor includes first and second ranging pixels that detect an incident light beam in the solid-state image sensor by separating the incident light beam in a first and second direction, respectively. The angle between the second direction and a column direction is smaller than the angle between the first direction and the column direction. A difference in exposure timings of second ranging pixels disposed in different rows is made smaller than that of first ranging pixels disposed in different rows, by causing to vary, for each row, a time over which charge is held in the in-pixel memories, in the plurality of second ranging pixels disposed in different rows.

First claim

1 . A solid-state image sensor having a plurality of pixels disposed in the form of a matrix, and acquiring signals of respective pixels in a unit of a row, wherein
the solid-state image sensor is configured in such a manner that first ranging pixels that detect an incident light beam toward the solid-state image sensor by separating the incident light beam in a first direction, and second ranging pixels that detect the incident light beam toward the solid-state image sensor by separating the incident light beam in a second direction, an angle between the second direction and a column direction being smaller than an angle between the first direction and the column direction, are disposed in the form of a matrix; and the second ranging pixels have in-pixel memories, such that a difference in exposure timings of a plurality of second ranging pixels disposed in mutually different rows is made smaller than a difference in exposure timings of a plurality of first ranging pixels disposed in mutually different rows, by causing to vary, for each row, a time over which charge is held in the in-pixel memories, between second ranging pixels disposed in different rows.

2 . The solid-state image sensor according to claim 1 , wherein the first direction is a row direction.

3 . The solid-state image sensor according to claim 1 , wherein the second direction is the column direction.

4 . The solid-state image sensor according to claim 1 , wherein the exposure timings of second ranging pixels disposed in different rows are simultaneous.

5 . The solid-state image sensor according to claim 1 , wherein an aperture ratio of photoelectric conversion units in the first ranging pixels is larger than an aperture ratio of photoelectric conversion units in the second ranging pixels.

6 . The solid-state image sensor according to claim 5 , wherein the image information is generated by selecting, for each pixel, image information acquired in the first ranging pixel in a case where a value of pixel signal acquired in the second ranging pixels is smaller than a first value, and image information acquired in the second ranging pixel in a case where a value of a pixel signal acquired in the first ranging pixels is larger than a second value that is greater than the first value.

7 . The solid-state image sensor according to claim 1 , wherein the in-pixel memories are disposed so as to straddle respective boundaries between adjacent first ranging pixels and second ranging pixels.

8 . The solid-state image sensor according to claim 1 , wherein charge acquired in the plurality of photoelectric conversion units of the second ranging pixels is sequentially read by being transferred to same respective in-pixel memories in the second ranging pixels.

9 . The solid-state image sensor according to claim 8 , wherein processing of correcting image shift in the row direction is performed on an image acquired in the plurality of photoelectric conversion units of the second ranging pixels.

10 . The solid-state image sensor according to claim 1 , wherein
the second ranging pixels have a first photoelectric conversion unit, a second photoelectric conversion unit of lower sensitivity than that of the first photoelectric conversion unit, a first in-pixel memory, and a second in-pixel memory; and charge acquired in the second photoelectric conversion unit is transferred to the second in-pixel memory simultaneously with transfer of charge acquired in the first photoelectric conversion unit to the second in-pixel memory, and thereafter, a signal of the first in-pixel memory is read, while a signal of the second in-pixel memory is read after transfer to the first in-pixel memory.

11 . The solid-state image sensor according to claim 10 , wherein the structure of the second ranging pixels is asymmetrical with respect to a plane that is perpendicular to the second direction.

12 . The solid-state image sensor according to claim 10 , wherein the arrangements of the first photoelectric conversion unit and of the second photoelectric conversion unit are reversed at a boundary which is a straight line that runs through the center of the solid-state image sensor and that is perpendicular to the second direction.

13 . The solid-state image sensor according to claim 1 , wherein the first ranging pixels have an in-pixel memory, and signals from the first ranging pixels are read using correlated double sampling.

14 . The solid-state image sensor according to claim 13 , wherein
the first ranging pixels have a third photoelectric conversion unit and a fourth photoelectric conversion unit, and charge acquired in the third photoelectric conversion unit is read after transfer to the in-pixel memory, and thereafter, charge acquired in the fourth photoelectric conversion unit is transferred to the in-pixel memory, and then a sum of the charge acquired in the third photoelectric conversion unit and the charge acquired in the fourth photoelectric conversion unit is read.

15 . The solid-state image sensor according to claim 1 , wherein rows with no second ranging pixels are provided.

16 . The solid-state image sensor according to claim 15 , wherein exposure time differs between rows that include second ranging pixels and rows that include no second ranging pixels.

17 . The solid-state image sensor according to claim 16 , wherein the exposure time in rows that include second ranging pixels is longer than that of rows that include no second ranging pixels.

18 . The solid-state image sensor according to claim 16 , wherein the exposure time in rows that include second ranging pixels is shorter than that of rows that include no second ranging pixels.

19 . A solid-state image sensor having a plurality of pixels disposed in the form of a matrix and acquiring signals of respective pixels are acquired in a unit of a row, wherein
at least some of the plurality of pixels are ranging pixels including an in-pixel memory and being capable of operating in a first ranging mode of detecting an incident light beam toward the solid-state image sensor by separating the incident light beam in a first direction, and a second ranging mode of detecting an incident light beam toward the solid-state image sensor by separating the incident light beam in a second direction, an angle between the second direction and a column direction being smaller than an angle between the first direction and the column direction; and in the second ranging mode, a difference in exposure timings of ranging pixels that are disposed in different rows and that operate in the second ranging mode is made smaller than a difference in the exposure timing of ranging pixels that are disposed in different rows and that operate in the first ranging mode, by causing to vary, for each row, a time over which charge is held in the in-pixel memories, in a plurality of ranging pixels disposed in different rows.

20 . The solid-state image sensor according to claim 19 , wherein in the first ranging mode, signals from the ranging pixels are read using correlated double sampling, by being read through transfer to the in-pixel memories in the ranging pixels.

21 . The solid-state image sensor according to claim 19 or 20 , wherein the number of in-pixel memories in the ranging pixels is smaller than the number of photoelectric conversion units in the ranging pixels.

22 . The solid-state image sensor according to claim 19 , wherein
the ranging pixels have four photoelectric conversion units disposed ove

Assignees

• Canon Kk

Inventors

• Numata Aihiko

Classifications

• H04N25/77

  Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components · CPC title

• H04N25/70

  SSIS architectures; Circuits associated therewith · CPC title

• H04N25/616

  involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling · CPC title

• H04N25/585

  with pixels having different sensitivities within the sensor, e.g. fast or slow pixels or pixels having different sizes · CPC title

• H04N25/445

  by skipping some contiguous pixels within the read portion of the array · CPC title