US 7,605,855 B2Granted

Dual sensitivity image sensor

AssigneeAptina Imaging Corporation

InventorsYibing Michelle Wang, Sandor Barna

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Abstract

A system of taking images of different sensitivities at the same time uses both an image sensor, and an auxiliary part to the image sensor. The image sensor element can be a photogate, and the auxiliary part can be the floating diffusion associated with the photogate. Both the photogate and the floating diffusion accumulate charge. Both are sampled at different times. The floating diffusion provides a lower sensitivity amount of charge than the photogate itself. The system can have a photogate and floating diffusion in each pixel along with a select transistor, a reset transistor, and a follower transistor. All of this circuitry can be formed of CMOS for example. The system can also operate in a column/parallel mode, where each column of the photo sensor array can have a column signal processor which samples and holds the reset signal, the floating diffusion signal and the photogate signal.

Claims25

Dependent claims

An image sensing pixel comprising:

a first image sensing portion having a first light sensitivity and producing charge based on an amount of incident light during a first integration period;
and
a second image sensing portion having a second sensitivity to light and producing charge based on the amount of incident light during a second integration period, said first image sensing portion being operable to be read out by a transfer of charge to said second image sensing portion;
and
readout circuitry operable to:
sample charge produced by said second image sensing portion during said second integration period,
cause said charge produced by said first image sensing portion during said first integration period to be transferred to said second image sensing portion,
sample said charge transferred to said second image sensing portion from said first image sensing portion, and
produce output signals corresponding to said charge produced by each of said first image sensing portion during said first integration period and said second image sensing portion during said second integration period.

6 more elements

A method of imaging, comprising:

obtaining both a high sensitivity signal and a low sensitivity signal from each of a plurality of pixels, wherein said high sensitivity signal is obtained by integration of a first image sensing portion within each pixel over a first integration period, and said low sensitivity signal is obtained by integration of a second first image sensing portion within each pixel over a second integration period, said first and second image sensing portions having different image sensitivities, said first image sensing portion being operable to be read out by transfer of charge to said second image sensing portion, and wherein said high sensitivity signal is obtained by transfer to and subsequent sampling of said second image sensing portion after said low sensitivity signal has been obtained;
and
outputting both of said high sensitivity signal and low sensitivity signal from each of said plurality of pixels each time each of said plurality of pixels are read out.

Dependencies are inferred from the claim text.

Facts

Application: 11/216,172Filed 1 Sep 2005 · continuation
Priority: 15 Jun 1999
Published: US 2006/0050163 A19 Mar 2006
Granted: 20 Oct 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H04N 25/585
Acquired simultaneously: with pixels having different sensitivities within the sensor, e.g. fast or slow pixels or pixels having different sizes
H04N 25/59
Control of the dynamic range: by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the…
H04N 25/76
SSIS architectures; Circuits associated therewith: addressed sensors, e.g. MOS or CMOS sensors
H04N 25/78
Addressed sensors, e.g. MOS or CMOS sensors: readout circuits for addressed sensors, e.g. output amplifiers or A/D converters

Family

Application60/139,345Us provisional application · filed 15 Jun 1999
Application09/596,757Parent of this continuation · filed 15 Jun 2000
US 2006/0050163 A1Pre-grant publication · published 9 Mar 2006
US 6,972,794 B1Parent of this continuation
US 7,605,855 B2This patent

From the US filing history. Foreign family members aren’t listed.