Patent EP0989741A2 successfully refreshed from Google Patents.
EP0989741A2
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EP
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Variable high spatial resolution and low bit resolution CMOS area image sensor
Assignee: Pixim Inc
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Filing: 1999-09-22
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Granted: —
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Expires: 2019-09-22
Abstract
Abstract The invention relates to a CMOS image sensor that can be embedded in portable imaging systems. This high spatial resolution and low bit resolution CMOS area image sensor not only enables portable imaging systems such as cellular fax phone, portable copy machines, barcode reader, but also it can be fabricated in standard digital CMOS processes, particularly at 0.35 micron and below. This invention also discloses several portable imaging systems using such a CMOS image sensor. This invention further discloses a CMOS image sensor that has variable spatial resolution and bit resolution. Starting as a high spatial resolution low-bit resolution image sensor, the high bit-resolution is achieved by combining information from a group of nearest-neighbor pixels into a single super-pixel via spatial oversampling. This variable CMOS image sensor can be used in a multiple function imaging device for both document and video imaging, or photography.
Inventors
- 👤 D. Yang Xiao
- 👤 Deng Zhongang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:16
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/04; H04N1/19; H04N1/195; H04N25/00; H04N25/40; H04N25/46; H04N25/70; H04N25/76; H04N25/78; H04N1/00127; H04N1/00281; H04N1/00307; H04N1/10; H04N1/107; H04N2201/00; H04N2201/04; H04N2201/0402; H04N2201/0458
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
A process-scalable and resolution-variable
image sensor comprises: a plurality of sensor circuits configured in
a two-dimensional array; each of said sensor circuits
comprising a sensor pixel and an adjusting circuit;
said sensor pixel producing an analog signal when being
exposed to incident light; said adjusting circuit
adjusting said analog signal in accordance with a
predefined parameter; wherein said predefined parameter
is selectively configurable to be different from
parameters of adjusting circuits in adjacent sensor
pixels to said sensor pixel; and a column processor comprising a plurality of
readout circuits; each of said readout circuits,
coupled to a column of said sensor circuits, receiving
said adjusted analog signal therefrom and converting
said adjusted analog signal to a digital signal.
Claim 2
Dependent Claim
51 words
The process-scalable and resolution-variable
image sensor as recited in claim 1; wherein each of said readout circuits is a
comparator with a predefined threshold; and wherein said comparator outputs said digital
signal in a single bit format representing said
adjusted analog signal being either higher or lower
than said predefined threshold.
Claim 3
Dependent Claim
54 words
The process-scalable and resolution-variable
image sensor as recited in claim 2; wherein said column
processor combines a group of digital signals in said
bit format into a single combined digital signal
represented in a higher bit resolution and reduced
spatial resolution format in accordance with a set of
rules related to said predefined parameter.
Claim 4
Dependent Claim
47 words
The process-scalable and resolution-variable
image sensor as recited in claim 3; wherein there are N by M said digital signals
in said group; said higher bit resolution is at least
[1+0.5 log 2 (NXM)] bit precision and said reduced spatial
resolution format is no more than 1/(NXM).
Claim 5
Dependent Claim
76 words
The process-scalable and resolution-variable
image sensor as recited in claim 8 further comprising: a memory for storing code instructions; and a digital signal processor; coupled to said
memory; executing said code instructions to combine a
number of digital signals originating from a block of
said sensor circuits to form a single digital signal
represented in a higher bit resolution and reduced
spatial resolution format in accordance with a set of
rules related to said predefined parameter.
Claim 6
Dependent Claim
57 words
The process-scalable and resolution-variable
image sensor as recited in claim 5; wherein said single bit format is a binary
format; and wherein there are N by M said digital signals
in said group; said higher bit resolution is at least
0.5 log 2 (NXM) bit precision and said reduced spatial
resolution format is no more than 1/(NXM).
Claim 7
Dependent Claim
57 words
The process-scalable and resolution-variable
image sensor as recited in claim 6; wherein said column
processor combines a number of digital signals
originating from a block of said sensor circuits to
form a single digital signal represented in a higher
bit and reduced spatial resolution format in accordance
with a set of rules related to said predefined
parameter.
Claim 8
Dependent Claim
114 words
A process-scalable and resolution-variable
image sensor comprises: a plurality of sensor pixels arranged in a
two-dimension array; each of said sensor pixels
producing an analog signal when said sensor pixels are
exposed to incident light; and a column processor comprising a plurality of
readout circuits, each of said readout circuits,
coupled to a column of said sensor pixels outputting
analog signals, comprising an adjusting circuit that
adjusts each of said analog signals in accordance with
a predefined parameter designated to said each of said
readout circuits, before or during converting said each
of said analog signals to a digital signal; wherein
said predefined parameter is different from respective
parameters in adjacent said readout circuits.
Claim 9
Dependent Claim
71 words
The process-scalable and resolution-variable
image sensor as recited in claim 8, wherein each of said readout circuits further
comprises a comparator with a predefined threshold;
said comparator receiving said adjusted analog signals
from said adjusting circuit; and wherein said comparator outputs digital
signals, respectively, in a single bit format from said
adjusted analog signals; said digital signals
representing said adjusted analog signal being either
higher or lower than said predefined threshold.
Claim 10
Independent Claim
88 words
A method for providing process-scalable and
resolution-variable digital image signals from an image
sensor, said method comprises: generating image signals from an array of
sensor circuits arranged in a two-dimensional array;
each of said sensor circuits comprising a sensor pixel
generating one of said image signals when being exposed
to incident light; adjusting said image signals in accordance
with an array of parameters, at least one of said
parameters different from at least two of its immediate
neighboring parameters; and converting said adjusted image signals into
digital images.
Claim 11
Dependent Claim
35 words
The method as recited in claim 10; wherein
each of said sensor circuits further comprises an
adjusting circuit that causes one of said image signals
to be adjusted in accordance with one of said
parameters.
References Cited (Backward Citations)
No citation records indexed.
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