EP0739039A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Pixel structure, image sensor using such pixel, structure and corresponding peripheric circuitry
Assignee: FillFactory NV
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Filing: 1996-04-18
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Granted: —
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Expires: 2016-04-18
Abstract
Abstract A pixel (100 or 500) structure for CMOS imaging applications, comprising: a photosensitive element (10 or 50) a load transistor (11 or 51) in series with the photosensitive element (10 or 50); means comprising at least another transistor (13, 14 or 22, 23 or 32 or 53) coupled to said photosensitive element (10 or 50) and said load transistor (11 or 51) for reading out the signals acquired in said photosensitive element (10 or 50) and converting to a voltage drop across said load transistor (11 or 51), characterized in that the gate length of at least the load transistor (11 or 51) is increased by at least 10% compared to the gate length of the transistors manufactured according to the layout rules imposed by CMOS manufacturing process, whereby increasing the light sensitivity of said pixel structure.
Inventors
- 👤 Bart Dierickx
- 👤 Nico Ricquier
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:53
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/50; H04N25/57; H04N25/571; H04N25/573; H04N25/70; H04N25/76; H10; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/18
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
140 words
A pixel (100 or 500) structure for CMOS imaging applications, comprising: - a photosensitive element (10 or 50) - a load transistor (11 or 51) in series with the photosensitive element (10 or 50); - means comprising at least another transistor (13, 14 or 22, 23 or 32 or 53) coupled to said photosensitive element (10 or 50) and said load transistor (11 or 51) for reading out the signals acquired in said photosensitive element (10 or 50) and converting to a voltage drop across said load transistor (11 or 51), characterized in that the gate length of at least the load transistor (11 or 51) is increased by at least 10% compared to the gate length of the transistors manufactured according to the layout rules imposed by CMOS manufacturing process, whereby increasing the light sensitivity of said pixel structure.
Claim 2
Dependent Claim
65 words
A CMOS image sensor having a geometric configuration of pixels (100) consisting in a structure as claimed in claim 1, each pixel having at least one photodiode (10) and a load transistor (11) having its gate tied to a voltage (12) and wherein the read-out means comprise at least a second transistor which is an emitter follower (13) connected to a data read-out line (16).
Claim 3
Dependent Claim
73 words
A CMOS image sensor having a geometric configuration of pixel (100) consisting in a structure as claimed in claim 1, each pixel having at least one photodiode (10) and a load transistor (11) of which the drain is not tied to a voltage and wherein the read-out means comprise a second transistor (22) and a third transistor (23) which is acting as a switch and is connected to a data read-out line (26).
Claim 4
Dependent Claim
55 words
A CMOS image sensor having a geometric configuration of pixel (100) consisting in a structure as claimed in claim 1, each pixel having at least one photodiode (10) and a load transistor (11) and read-out means comprising only another transistor (32), said pixel being read-out in both X - Y, and Y - X modes.
Claim 5
Dependent Claim
53 words
A CMOS image sensor having a geometric configuration of pixels (500) comprising a structure as claimed in claim 1 characterized in that each pixel (500) includes only a photodiode (50) and a switch (52), the load transistor (51) and the readout means (53) being common for one unit of several individual pixels (500).
Claim 6
Dependent Claim
44 words
A CMOS image sensor as claimed in any one of the claims 2 to 5 characterized in that it further comprises at least one pseudopixel comprising a current source instead of a photodiode, in order to determine the absolute light intensity of the pixels.
Claim 7
Dependent Claim
60 words
A CMOS image sensor as claimed in anyone of the claims 2 to 6 characterized in that it further comprises defined groups of (n x m) pixels (70, 71, 72 ,73) yielding one output voltage signal, said output voltage signal being some kind of average or minimized value of the individual output voltage signals of non-defective pixels in one group.
Claim 8
Dependent Claim
34 words
A CMOS image sensor as claimed in any one of the claims 2 to 7 characterized in that it further comprises a mosaic color filter which has preferably the structure of the pixel array.
Claim 9
Dependent Claim
78 words
Device comprising an image sensor as claimed in anyone of the claims 2 to 8 with a corresponding peripheric circuitry characterized in that it comprises - a signal processing unit (83), - a control circuit (84, 85) to adjust the output voltage signal (80) of the pixels (100) or units of pixel (500) in the sensor (800) within the input voltage (82) range of said signal processing unit (83), thereby providing an automatic brightness control of said sensor.
Claim 10
Dependent Claim
84 words
Method for increasing the homogeneity of the image found in an image sensor as claimed in anyone of the claims 2 to 6 characterized in that it comprises the following steps: - selecting an individual pixel (100 or 500), - loading a high current density on one of the transistors (11, 13, 14 or 53) of one pixel for a time span, said time span being chosen to shift the threshold voltage of said transistor (11, 13, 14 or 53) to a predetermined value.
Claim 11
Dependent Claim
97 words
Method for the fabrication of a color filter to be deposited on a CMOS image sensor according to claim 8 comprising the following steps: - preparation of a color mixture in the form of a suspension, dispersion or solution containing at least polyvinyl alcohol, dichromat and the required pigment or dye - spinning this color preparation on the pixel structure of the CMOS image sensor - illuminating using preferably the same mask set as the one used for manufacturing the pixel structure of the CMOS image sensor - etching the illuminated part including rinsing and/or flashing steps
Claim 12
Dependent Claim
17 words
Method according to claim 11 wherein the processing steps as recited therein are repeated for further colors.
Claim 13
Dependent Claim
32 words
Use of anyone of the devices claimed in any one of the claims 1 to 9 or of the methods claimed in claim 10, 11, and 12 for manufacturing a vision camera.
References Cited (Backward Citations)
No citation records indexed.
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