Patent US5528043A successfully refreshed from Google Patents.
US5528043A
Expired / Lapsed
US
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X-ray image sensor
Assignee: Thermo Fisher Scientific Inc
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Filing: 1995-04-21
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Granted: 1996-06-18
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Expires: 2015-04-21
Abstract
Abstract This invention provides an imaging system for producing images from electromagnetic radiation such as x-rays. The system includes a detector comprised of a radiation-absorbing layer sandwiched between an array of CMOS integrated circuits (which we call pixel circuits) and a surface electrode layer transparent to the radiation. Each of the pixel circuits in the array has a charge collecting electrode. An external voltage applied between the surface electrode layer and the charge collecting electrodes produces an electric field across the thickness of the absorbing layer. Radiation passing through the transparent surface electrode layer is absorbed in the absorbing layer creating electron/hole pairs in the absorbing layer. A portion of the liberated holes (or electrons) migrates under the influence of the electric field toward the charge collecting electrodes, which collect the holes and store them as charges on small capacitors located within each circuit. This process results in a discrete distribution of stored voltages across the array proportional to the distribution of radiation photons incident on the absorbing layer. Circuitry in each pixel provides for the voltage on each pixel capacitor to be recorded via readout circuitry and permits the resetting of the pixel capacitors. Preferred embodiments provide fine resolution with a large number of pixels with dimensions about the size of the thickness of human hair.
Inventors
- 👤 Brett Spivey
- 👤 Peter Martin
- 👤 Lee Morsell
- 👤 Eugene Atlas
- 👤 Anthony Pellegrino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:11
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/42; A61B6/4208; A61B6/4233; A61B6/48; A61B6/482; A61B6/50; A61B6/502; A61B6/505; H; H04; H04N; H04N25/00; H04N25/30; H04N25/60; H04N25/68; H10; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/18; H10F39/189; A61B6/40; A61B6/4035
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
254 words
An imaging device for producing images from electron-hole producing radiation comprising: A. at least one solid state radiation detection unit comprising 1) a wafer comprised of doped single crystal silicon, 2) a plurality of complementary metal oxide semiconductor pixel circuits incorporated into said single crystal silicon to form an array, defining an array of pixel circuits, each of said semiconductor pixel circuits defining a pixel and comprising: a) a charge collecting pixel electrode, b) a pixel capacitor electrically connected to said charge collecting electrode so as to store charges collected by said charge collecting electrode, c) a charge measuring transistor means comprising at least one transistor for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of a photoconductive electrically insulating material covering said array of pixel circuits, said insulating material being photoconductive on exposure to said electron-hole producing radiation, 4) a surface electrode layer comprised of electrically conducting material deposited on said radiation absorbing layer, said electrode layer being at least partially transparent to said radiation, and 5) a high voltage source means for establishing an electrical field across said radiation absorbing layer and between said surface electrode layer and said charge collecting electrodes; B. a pixel charge measurement means for making said measurements of charges stored on each of said pixel capacitors via said measuring transistor means, C. a data acquisition means for acquiring and storing data derived from said charge measurements, D. a computer means for computing at least one image from said data.
Claim 2
Dependent Claim
254 words
An imaging device for producing images from electron-hole producing radiation comprising: A. at least one solid state radiation detection unit comprising 1) a wafer comprised of doped single crystal silicon, 2) a plurality of complementary metal oxide semiconductor pixel circuits incorporated into said single crystal silicon to form an array, defining an array of pixel circuits, each of said semiconductor pixel circuits defining a pixel and comprising: a) a charge collecting pixel electrode, b) a pixel capacitor electrically connected to said charge collecting electrode so as to store charges collected by said charge collecting electrode, c) a charge measuring transistor means comprising at least one transistor for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of a photoconductive electrically insulating material covering said array of pixel circuits, said insulating material being photoconductive on exposure to said electron-hole producing radiation, 4) a surface electrode layer comprised of electrically conducting material deposited on said radiation absorbing layer, said electrode layer being at least partially transparent to said radiation, and 5) a high voltage source means for establishing an electrical field across said radiation absorbing layer and between said surface electrode layer and said charge collecting electrodes; B. a pixel charge measurement means for making said measurements of charges stored on each of said pixel capacitors via said measuring transistor means, C. a data acquisition means for acquiring and storing data derived from said charge measurements, D. a computer means for computing at least one image from said data.
Claim 3
Dependent Claim
15 words
An imaging device as in claim 1 wherein said electron-hole producing radiation comprises x-ray radiation.
Claim 4
Dependent Claim
15 words
An imaging device as in claim 1 wherein said electron-hole producing radiation comprises ultraviolet radiation.
Claim 5
Dependent Claim
15 words
An imaging device as in claim 1 wherein said electron-hole producing radiation comprises particle radiation.
Claim 6
Dependent Claim
17 words
An imaging device as in claim 1 and further comprising a monitor for display of said image.
Claim 7
Dependent Claim
16 words
An imaging device as in claim 1 and further comprising a printer for printing said image.
Claim 8
Dependent Claim
26 words
An imaging device as in claim 1 wherein each pixel capacitor is comprised of an insulating oxide layer sandwiched between two heavily doped polycrystalline silicon layers.
Claim 9
Dependent Claim
15 words
An imaging device as in claim 7 wherein said oxide layer is SiO 2 glass.
Claim 10
Dependent Claim
17 words
An imaging device as in claim 1 wherein each charge collecting pixel electrode is comprised of aluminum.
Claim 11
Dependent Claim
33 words
An imaging device as in claim 1 wherein each measuring transistor means comprises at least two field effect transistors arranged in an electrical circuit so as to permit non-destructive measurement of said charge.
Claim 12
Dependent Claim
24 words
An imaging device as in claim 10 wherein said at least two field effect transistors comprise a source follower transistor and a selection transistor.
Claim 13
Dependent Claim
34 words
An imaging device as in claim 11 wherein each pixel capacitor defines two parallel plates and each source follower transistor defines a gate and one of said plates is electrically connected to said gate.
Claim 14
Dependent Claim
28 words
An imaging device as in claim 12 wherein said each of said semiconductor pixel circuits also comprises a reset transistor means for resetting each of said pixel circuits.
Claim 15
Dependent Claim
24 words
An imaging device as in claim 13 wherein each reset transistor means comprises an electrical circuit for shorting the associated pixel capacitor to ground.
Claim 16
Dependent Claim
19 words
An imaging device as in claim 14 wherein each reset transistor means comprises a reverse back biased reset transistor.
Claim 17
Dependent Claim
16 words
An imaging device as in claim 13 wherein said photoconductive electrically insulating material comprises amorphous selenium.
Claim 18
Dependent Claim
15 words
An imaging device as in claim 16 wherein said selenium is deposited as a film.
Claim 19
Dependent Claim
13 words
An imaging device as in claim 17 wherein said film is vapor deposited.
Claim 20
Dependent Claim
14 words
An imaging device as in claim 18 wherein said selenium is alloyed with arsenic.
Claim 21
Dependent Claim
14 words
An imaging device as in claim 19 wherein said surface electrode layer comprises silver.
Claim 22
Dependent Claim
33 words
An imaging device as in claim 19 wherein said high voltage source is arranged to produce an electric field gradient in said radiation absorbing layer of between 2 and 20 volts per micron.
Claim 23
Dependent Claim
34 words
An imaging device as in claim 21 wherein said charge collecting pixel electrodes are separated from said surface electrode layer by a thickness of at least 10 microns of said photoconductive electrically insulating material.
Claim 24
Dependent Claim
49 words
An imaging device as in claim 22 wherein said array is arranged to form rows and columns and said pixel charge measurement means comprises a sample and hold circuit at each column with a shift register for selection of rows and a separate shift register for selection of columns.
Claim 25
Dependent Claim
18 words
An imaging device as in claim 23 wherein said data acquisition means comprises an analog to digital converter.
Claim 26
Dependent Claim
16 words
An imaging device as in claim 1 wherein said wafer is doped to create n-type silicon.
Claim 27
Dependent Claim
16 words
An imaging device as in claim 1 wherein said wafer is doped to create p-type silicon.
Claim 28
Dependent Claim
34 words
An imaging device as in claim 1 wherein said high voltage source means is electrically arranged so as to provide positive voltage at said surface electrode layer with respect to said charge collecting electrodes.
Claim 29
Dependent Claim
35 words
An imaging device as in claim 1 wherein said high voltage source means is electrically arranged so as to provide a negative voltage at said surface electrode layer with respect to said charge collecting electrodes.
Claim 30
Dependent Claim
20 words
An imaging device as in claim 1 wherein said at least one detection unit is a plurality of detection units.
Claim 31
Dependent Claim
24 words
An imaging device as in claim 29 wherein said plurality of detection units comprises at least one row of at least four detection units.
Claim 32
Dependent Claim
23 words
An imaging device as in claim 30 wherein said at least one row is at least three rows arranged parallel to each other.
Claim 33
Dependent Claim
16 words
An imaging device as in claim 31 wherein said at least three rows is three rows.
Claim 34
Dependent Claim
301 words
An imaging device for producing images of a target irradiated with electron-hole producing radiation comprising: A. A radiation source means for producing a beam of said electron-hole producing radiation, said beam defining a beam path, B. a target positioning means for positioning said target in said beam path, C. at least one solid state radiation detection unit positioned in said beam path downstream of said target, said each comprising: 1) a wafer comprised of doped single crystal silicon, 2) a plurality of complementary metal oxide semiconductor pixel circuits incorporated into said single crystal silicon to form an array, defining an array of pixel circuits, each of said semiconductor pixel circuits defining a pixel and comprising: a) a charge collecting pixel electrode, b) a pixel capacitor electrically connected to said charge collecting electrode so as to store charges collected by said charge collecting electrode, c) a charge measuring transistor means comprising at least one transistor for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of an electrical insulating material covering said array of pixel circuits, said insulating material being photoconductive on exposure to said electron-hole producing radiation, 4) a surface electrode layer comprised of electrically conducting material deposited on said radiation absorbing layer, said electrode layer being at least partially transparent to said radiation, and 5) a high voltage source means for establishing an electrical field across said radiation absorbing layer and between said surface electrode layer and said charge collecting electrodes; D. a pixel charge measurement means for making said measurements of charges stored on each of said pixel capacitors via said measuring transistor means, E. a data acquisition means for acquiring and storing data derived from said charge measurements, F. a computer means for computing images of said target from said data.
Claim 35
Dependent Claim
301 words
An imaging device for producing images of a target irradiated with electron-hole producing radiation comprising: A. A radiation source means for producing a beam of said electron-hole producing radiation, said beam defining a beam path, B. a target positioning means for positioning said target in said beam path, C. at least one solid state radiation detection unit positioned in said beam path downstream of said target, said each comprising: 1) a wafer comprised of doped single crystal silicon, 2) a plurality of complementary metal oxide semiconductor pixel circuits incorporated into said single crystal silicon to form an array, defining an array of pixel circuits, each of said semiconductor pixel circuits defining a pixel and comprising: a) a charge collecting pixel electrode, b) a pixel capacitor electrically connected to said charge collecting electrode so as to store charges collected by said charge collecting electrode, c) a charge measuring transistor means comprising at least one transistor for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of an electrical insulating material covering said array of pixel circuits, said insulating material being photoconductive on exposure to said electron-hole producing radiation, 4) a surface electrode layer comprised of electrically conducting material deposited on said radiation absorbing layer, said electrode layer being at least partially transparent to said radiation, and 5) a high voltage source means for establishing an electrical field across said radiation absorbing layer and between said surface electrode layer and said charge collecting electrodes; D. a pixel charge measurement means for making said measurements of charges stored on each of said pixel capacitors via said measuring transistor means, E. a data acquisition means for acquiring and storing data derived from said charge measurements, F. a computer means for computing images of said target from said data.
Claim 36
Dependent Claim
14 words
An imaging device as in claim 33 wherein said electron-hole producing radiation comprises x-radiation.
Claim 37
Dependent Claim
32 words
An imaging device as in claim 34 wherein said at least one detection unit is a plurality of detection units arranged in at least one row of at least four detection units.
Claim 38
Dependent Claim
27 words
An imaging device as in claim 35 and further comprising a positioning means for moving said at least one row of detection units relative to said target.
Claim 39
Dependent Claim
21 words
An imaging device as in claim 36 and further comprising an anti-scatter grid placed between said target and said detection units.
Claim 40
Dependent Claim
19 words
An imaging device as in claim 37 wherein said anti-scatter grid is fixed with respect to said detection units.
Claim 41
Dependent Claim
36 words
An imaging device as in claim 38 wherein said computer means comprises software to generate a composite image of at least a portion of said target from a plurality of images of portions of said target.
Claim 42
Dependent Claim
22 words
An imaging device as in claim 33 and further comprising an x-ray dose limiting means for limiting x-ray dose to said target.
Claim 43
Dependent Claim
20 words
An imaging device as in claim 40 wherein said dose limiting means comprises a means for collecting pre-exposure x-ray data.
Claim 44
Dependent Claim
24 words
An imaging device as in claim 41 and further comprising spectrum selection means for selecting an x-ray spectrum based on said pre-exposure x-ray data.
Claim 45
Dependent Claim
35 words
An imaging device as in claim 33 wherein said source, said target positioning means and said at least one detection unit are configured so as to image at least a portion of a human body.
Claim 46
Dependent Claim
18 words
An imaging device as in claim 43 wherein said imaging device is utilized to image the female breast.
Claim 47
Dependent Claim
29 words
An imaging device as in claim 33 wherein said source, said target positioning means and said at least one detection unit are configured to image an electronic circuit board.
Claim 48
Dependent Claim
30 words
An imaging device as in claim 33 wherein said source, said target positioning means and said at least one detection unit are configured to provide an x-ray computed tomography device.
Claim 49
Dependent Claim
17 words
An imaging device as in claim 1 wherein said photoconductive material comprises amorphous selenium doped with tellerium.
Claim 50
Dependent Claim
14 words
An imaging device as in claim 47 wherein said electromagnetic radiation comprises visible radiation.
Claim 51
Dependent Claim
14 words
An imaging device as in claim 47 wherein said electromagnetic radiation comprises infrared radiation.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-06-18 | 1999-12-18 | 2000-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-18 | 2003-12-18 | 2004-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-18 | 2007-12-18 | 2008-06-18 | $7700.00 | Window Closed / Lapsed |