Imaging device

Claim 2

An imaging device for producing images from electron-hole producing radiation comprising: A. at least one solid state radiation detection unit comprising: 1) a substrate comprised of a doped crystalline semiconductor material, 2) a plurality of metal oxide semiconductor pixel circuits incorporated into and on said substrate 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 defined at least in part by said charge collecting electrode for storing charges collected by said charge collecting electrode, c) a charge measuring circuit comprising a single transistor amplifier for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of an electrically insulating photoconductive material covering said array of pixel circuits, said 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 connectable to a voltage source 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 circuit for measuring charges stored on each of said pixel capacitors via said measuring circuits, and outputting pixel data indicative of such charges, wherein said pixel data contains information defining an image.

Claim 3

An imaging device as in claim 1 wherein said substrate is comprised of doped single crystal silicon.

Claim 4

An imaging device as in claim 2 wherein said substrate is a wafer.

Claim 5

An imaging device as in claim 2 wherein each of said pixel capacitors is comprised of an insulating oxide layer sandwiched between two heavily doped polycrystalline silicon layers.

Claim 6

An imaging device as in claim 4 wherein said oxide layer is SiO 2 glass.

Claim 7

An imaging device as in claim 2 wherein said single crystal silicon substrate is doped to create n-type silicon.

Claim 8

An imaging device as in claim 2 wherein said single crystal silicon substrate is doped to create p-type silicon.

Claim 9

An imaging device as in claim 1 wherein said substrate is comprised of silicon on an electrical insulator.

Claim 10

An imaging device as in claim 8 wherein said insulator is comprised of silicon oxide or sapphire.

Claim 11

An imaging device as in claim 1 wherein said substrate is comprised of aluminum gallium arsenide.

Claim 12

An imaging device as in claim 1 wherein said substrate is comprised of indium gallium arsenide.

Claim 13

An imaging device as in claim 1 wherein said metal oxide semiconductor pixel circuits are complimentary metal oxide semiconductor pixel circuits.

Claim 14

An imaging device as in claim 1 wherein said metal oxide semiconductor pixel circuits are n-channel metal oxide semiconductor pixel circuits.

Claim 15

An imaging device as in claim 1 wherein said metal oxide semiconductor pixel circuits are p-channel metal oxide semiconductor pixel circuits.

Claim 16

An imaging device as in claim 1 wherein said electron-hole producing radiation comprises x-ray radiation.

Claim 17

An imaging device as in claim 1 wherein said electron-hole producing radiation comprises ultraviolet radiation.

Claim 18

An imaging device as in claim 1 wherein said electron-hole producing radiation comprises visible light.

Claim 19

An imaging device as in claim 1 wherein said electron-hole producing radiation comprises particle radiation.

Claim 20

An imaging device as in claim 1 and further comprising data acquisition system for acquiring and storing said pixel data and a monitor for display of said image.

Claim 21

An imaging device as in claim 1 and further comprising data acquisition system for acquiring and storing said pixel data and a printer for printing said image.

Claim 22

An imaging device as in claim 1 wherein each charge collecting pixel electrode is comprised of aluminum.

Claim 23

An imaging device as in claim 1 wherein each charge measuring circuit further comprises a second field effect transistor, coupled to the single transistor amplifier, and arranged in an electrical circuit so as to permit non-destructive measurement of said charge.

Claim 24

An imaging device as in claim 22 wherein said single transistor amplifier comprises a source follower transistor and said second field effect transistor comprises a selection transistor.

Claim 25

An imaging device as in claim 23 wherein each pixel capacitor defines two parallel plates and said source follower transistor defines a gate and one of said plates is electrically connected to said gate.

Claim 26

An imaging device as in claim 24 wherein said each of said metal oxide semiconductor pixel circuits also comprises a reset transistor means for resetting each of said pixel circuits.

Claim 27

An imaging device as in claim 25 wherein each of said reset transistor means comprises an electrical circuit for shorting the associated pixel capacitor to ground.

Claim 28

An imaging device as in claim 26 wherein each reset transistor means comprises a back biased reset transistor.

Claim 29

An imaging device as in claim 1 wherein said photoconductive material comprises amorphous selenium.

Claim 30

An imaging device as in claim 28 wherein said selenium is deposited as a film.

Claim 31

An imaging device as in claim 29 wherein said film is vapor deposited.

Claim 32

An imaging device as in claim 30 wherein said selenium is alloyed with arsenic.

Claim 33

An imaging device as in claim 1 wherein said surface electrode layer is silver, indium tin oxide, gold, platinum, or a conducting polymer.

Claim 34

An imaging device as in claim 1 further including a voltage source, wherein said voltage source is arranged to produce an electric field in said radiation absorbing layer of between 2 and 20 volts per micron.

Claim 35

An imaging device as in claim 1 wherein said photoconductive material is comprised of at least two layers of photoconductive material.

Claim 36

An imaging device as in claim 34 wherein said at least two layers define a photodiode.

Claim 37

An imaging device as in claim 35 wherein said photodiode comprises a p-n junction.

Claim 38

An imaging device as in claim 35 wherein said photodiode comprises a p-i-n junction.

Claim 39

An imaging device as in claim 35 wherein said photodiode comprises a Schottky junction.

Claim 40

An imaging device as in claim 1 wherein said charge collecting pixel electrodes are separated from said surface electrode layer by a thickness of at least 10 microns of said photoconductive material.

Claim 41

An imaging device as in claim 1 wherein said array is arranged to form rows and columns and said pixel charge measurement circuit 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 42

An imaging device as in claim 40 further including a data acquisition system for acquiring and storing said pixel data, wherein said data acquisition system comprises an analog to digital converter.

Claim 43

An imaging device as in claim 1 further including a voltage source, wherein said voltage source is electrically arranged so as to provide positive voltage at said surface electrode layer with respect to said charge collecting electrodes.

Claim 44

An imaging device as in claim 1 further including a voltage source, wherein said voltage source is electrically arranged so as to provide a negative voltage at said surface electrode layer with respect to said charge collecting electrodes.

Claim 45

An imaging device as in claim 1 wherein said at least one detection unit is a plurality of detection units.

Claim 46

An imaging device as in claim 44 wherein said plurality of detection units comprises at least one row of at least four detection units.

Claim 47

An imaging device as in claim 45 wherein said at least one row is at least three rows arranged parallel to each other.

Claim 48

An imaging device as in claim 1 and further comprising a computer for computing images from said pixel data.

Claim 49

An imaging device as in claim 1 wherein said imaging device is installed as an element of a bone densitometry system.

Claim 50

An imaging device as in claim 48 and further comprising a computer programmed with an algorithm for determining bone density based on said pixel data.

Claim 51

An imaging device as in claim 49 and further comprising a density standard element positioned in the path of said electron-hole producing radiation.

Claim 52

An imaging device as in claim 50 wherein said pixel data, used for determination of bone density, comprises at least two sets of data, each set corresponding to radiation at a selected x-ray energy.

Claim 53

An imaging device for producing images of a target irradiated with electron-hole producing radiation comprising: A. radiation source producing a beam of said electron-hole producing radiation directed at said target, said beam defining a beam path, B. at least one solid state radiation detection unit positioned in said beam path downstream of said target, said unit comprising: 1) a substrate comprised of doped single crystal silicon, 2) a plurality of complementary metal oxide semiconductor pixel circuits incorporated into and on 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 defined at least in part by said charge collecting electrode for storing charges collected by said charge collecting electrode, c) a charge measuring circuit comprising a single transistor amplifier for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of an electrically insulating photoconductive material covering said array of pixel circuits, said 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) voltage source establishing an electrical field across said radiation absorbing layer and between said surface electrode layer and said charge collecting electrodes; C. a pixel charge measurement circuit for making measurements of charges stored on each of said pixel capacitors via said measuring circuits, and outputting pixel data indicative of such charges, D. a data acquisition system for acquiring and storing said pixel data, E. a computer for computing images of said target from said pixel data.

Claim 54

An imaging device for producing images of a target irradiated with electron-hole producing radiation comprising: A. radiation source producing a beam of said electron-hole producing radiation directed at said target, said beam defining a beam path, B. at least one solid state radiation detection unit positioned in said beam path downstream of said target, said unit comprising: 1) a substrate comprised of doped single crystal silicon, 2) a plurality of complementary metal oxide semiconductor pixel circuits incorporated into and on 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 defined at least in part by said charge collecting electrode for storing charges collected by said charge collecting electrode, c) a charge measuring circuit comprising a single transistor amplifier for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of an electrically insulating photoconductive material covering said array of pixel circuits, said 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) voltage source establishing an electrical field across said radiation absorbing layer and between said surface electrode layer and said charge collecting electrodes; C. a pixel charge measurement circuit for making measurements of charges stored on each of said pixel capacitors via said measuring circuits, and outputting pixel data indicative of such charges, D. a data acquisition system for acquiring and storing said pixel data, E. a computer for computing images of said target from said pixel data.

Claim 55

An imaging device as in claim 52 wherein said electron-hole producing radiation comprises x-ray radiation.

Claim 56

An imaging device as in claim 53 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 57

An imaging device as in claim 54 and further comprising a positioning means for moving said at least one row of detection units relative to said target.

Claim 58

An imaging device as in claim 55 and further comprising an anti-scatter grid placed between said target and said detection units.

Claim 59

An imaging device as in claim 56 wherein said anti-scatter grid is fixed with respect to said detection units.

Claim 60

An imaging device as in claim 55 wherein said computer 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 61

An imaging device as in claim 55 wherein said source, said positioning means and said at least one detection unit are configured so as to image at least a portion of a human body.

Claim 62

An imaging device as in claim 59 wherein said imaging device is utilized to image the female breast.

Claim 63

An imaging device as in claim 55 wherein said computer is programmed with an algorithm for blending pixel values to produce seamless images.

Claim 64

An imaging device as in claim 53 wherein said at least one detection unit is a plurality of detection units arranged in a plurality of rows and a plurality of columns, and further comprising a positioning means for moving said detection units relative to said target in order to acquire a plurality of overlapping images of portions of said target.

Claim 65

An imaging device as in claim 62 wherein said positioning means moves the detections units diagonally.

Claim 66

An imaging device as in claim 62 wherein said computer comprises software to generate a composite image of at least a portion of said target from a plurality of overlapping images of portions of said target.

Claim 67

An imaging device as in claim 62 wherein said computer comprises software to cause the positioning means to acquire a first image of a portion of said target, move said detection units relative to said target, acquire at least a second, overlapping image of a portion of said target, and generate a composite image of at least a portion of said target from the overlapping acquired images.

Claim 68

An imaging device as in claim 65 wherein each said image is acquired at a low x-ray dosage such that the combined x-ray dosage of all images is within a medically acceptable limit.

Claim 69

An imaging device as in claim 52 and further comprising an x-ray dose limiting means for limiting x-ray dose to said target.

Claim 70

An imaging device as in claim 67 wherein said dose limiting means comprises a means for collecting pre-exposure x-ray data.

Claim 71

An imaging device as in claim 68 and further comprising spectrum selection means for selecting an x-ray spectrum based on said pre-exposure x-ray data.

Claim 72

An imaging device as in claim 52 wherein said source, and said at least one detection unit are configured to image an electronic circuit board.

Claim 73

An imaging device as in claim 52 wherein said source, and said at least one detection unit are configured to provide an x-ray computed tomography device.

Claim 74

An imaging device as in claim 52 wherein said photoconductive material comprises amorphous selenium doped with tellurium.

Claim 75

An imaging device as in claim 72 wherein said electron-hole producing radiation comprises visible radiation.

Claim 76

An imaging device as in claim 72 wherein said electromagnetic radiation comprises infrared radiation.

Claim 77

An imaging device as in claim 52 wherein said substrate is a wafer.

Claim 78

An imaging device as in claim 52 wherein each of said pixel circuits comprises a reset switch and a reset line.

Claim 79

An imaging device as in claim 76 wherein each of said pixel circuits comprises an isolation means to isolate said circuits from said reset line.

Claim 80

An imaging device as in claim 52 wherein each of said plurality of pixel circuits comprises a second pixel capacitor connected to said charge collecting pixel electrode.

Claim 81

An imaging device as in claim 52 wherein said device is configured to make chest x-ray images.

Claim 82

An imaging device as in claim 52 wherein said device is configured to image integrated circuit boards.

Claim 83

An imaging device as in claim 52 wherein said devices is configured to make tomographic images.

Claim 84

An imaging device for producing images from electron-hole producing radiation comprising: A. at least one solid state radiation detection unit comprising: 1) a substrate comprised of a doped crystalline semiconductor material, 2) a plurality of metal oxide semiconductor pixel circuits incorporated into and on said substrate 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 defined at least in part by said charge collecting electrode for storing charges collected by said charge collecting electrode, c) a charge measuring circuit comprising a single transistor amplifier for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of at least two sublayers of an electrically insulating photoconductive material covering said array of pixel circuits, said at least two sublayers being photoconductive on exposure to said electron-hole producing radiation, said at least two sublayers forming a semiconductor junction, 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, B. a pixel charge measurement circuit for measuring charges stored on each of said pixel capacitors via said measuring circuits, and outputting pixel data indicative of such charges, wherein said pixel data contains information defining an image.

Claim 85

An imaging device for producing images from electron-hole producing radiation comprising: A. at least one solid state radiation detection unit comprising: 1) a substrate comprised of a doped crystalline semiconductor material, 2) a plurality of metal oxide semiconductor pixel circuits incorporated into and on said substrate 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 defined at least in part by said charge collecting electrode for storing charges collected by said charge collecting electrode, c) a charge measuring circuit comprising a single transistor amplifier for permitting a measurement of charge stored on said pixel capacitor, 3) a radiation absorbing layer comprised of at least two sublayers of an electrically insulating photoconductive material covering said array of pixel circuits, said at least two sublayers being photoconductive on exposure to said electron-hole producing radiation, said at least two sublayers forming a semiconductor junction, 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, B. a pixel charge measurement circuit for measuring charges stored on each of said pixel capacitors via said measuring circuits, and outputting pixel data indicative of such charges, wherein said pixel data contains information defining an image.

Claim 86

An imaging device as in claim 82 wherein said semiconductor junction is a p-n junction.

Claim 87

An imaging device as in claim 82 wherein said semiconductor junction is a p-i-n junction.