US5912942A — X-ray detection system using active pixel sensors

Claim 1

Independent Claim 39 words

An x-ray detector comprising: a scintillator that converts an invisible-radiant-energy image into a visible-light image; and a sensor array that converts the visible-light image into an electrical signal, said sensor array comprising a plurality of CMOS active pixel sensors.

Claim 2

Dependent Claim 39 words

An x-ray detector comprising: a scintillator that converts an invisible-radiant-energy image into a visible-light image; and a sensor array that converts the visible-light image into an electrical signal, said sensor array comprising a plurality of CMOS active pixel sensors.

Claim 3

Dependent Claim 28 words

An x-ray detector according to claim 1, wherein said active pixel sensors and circuitry for reading out said active pixel sensors are monolithically formed on a semiconductor substrate.

Claim 4

Dependent Claim 42 words

An x-ray detector according to claim 2, wherein each active pixel sensor in said plurality comprises: a photogate electrode; a transfer gate electrode; a reset electrode; and a semiconductor channel underlying said photogate electrode, said transfer gate electrode and said reset electrode.

Claim 5

Dependent Claim 24 words

An x-ray detector according to claim 3, wherein said semiconductor channel is formed in a shallow well on the top of said semiconductor substrate.

Claim 6

Dependent Claim 15 words

An x-ray detector according to claim 4, wherein the shallow well is an n-type well.

Claim 7

Dependent Claim 15 words

An x-ray detector according to claim 4, wherein the shallow well is a p-type well.

Claim 8

Dependent Claim 17 words

An x-ray detector according to claim 4, wherein the shallow well is less than 5μ in thickness.

Claim 9

Dependent Claim 18 words

An x-ray detector according to claim 7, wherein the shallow well is between 1.5μ and 2μ in thickness.

Claim 10

Dependent Claim 45 words

An x-ray detector according to claim 2, wherein each active pixel sensor in said plurality comprises: a transfer gate electrode; a reset electrode; and a semiconductor channel underlying said transfer gate electrode and said reset electrode, and including a photodiode formed by a p-n junction.

Claim 11

Dependent Claim 24 words

An x-ray detector according to claim 9, wherein said semiconductor channel is formed in a shallow well on the top of said semiconductor substrate.

Claim 12

Dependent Claim 15 words

An x-ray detector according to claim 10, wherein the shallow well is an n-type well.

Claim 13

Dependent Claim 17 words

An x-ray detector according to claim 10, wherein the shallow well is less than 5μ in thickness.

Claim 14

Dependent Claim 18 words

An x-ray detector according to claim 12, wherein the shallow well is between 1.5μ and 2μ in thickness.

Claim 15

Dependent Claim 36 words

An x-ray detector according to claim 1, wherein said scintillator comprises a material selected from the group consisting of gadolinium oxysulphate, thallium-doped cesium iodide, cadmium telluride, cadmium sulfide, calcium tungstate, zinc sulfide and zinc cadmium sulfide.

Claim 16

Dependent Claim 13 words

An x-ray detector according to claim 1, wherein said scintillator comprises scintillating glass.

Claim 17

Dependent Claim 14 words

An x-ray detector according to claim 1, wherein said scintillator comprises scintillating optical fibers.

Claim 18

Dependent Claim 20 words

An x-ray detector according to claim 1, further comprising a fiber optic faceplate between said scintillator and said sensor array.

Claim 19

Dependent Claim 19 words

An x-ray detector according to claim 1, wherein said sensor array further comprises at least one event trigger diode.

Claim 20

Independent Claim 80 words

A method of reading out data from an x-ray detector, the x-ray detector comprising a scintillator that converts an invisible-radiant-energy image into a visible-light image and a sensor array signal, the sensor array comprising a plurality of CMOS active pixel sensors, said method comprising the steps of: (a) continuously reading out frames of data from the x-ray detector; and (b) determining whether the x-ray detector was exposed to x-rays by examining each frame of data read out in step (a).

Claim 21

Independent Claim 80 words

A method of reading out data from an x-ray detector, the x-ray detector comprising a scintillator that converts an invisible-radiant-energy image into a visible-light image and a sensor array signal, the sensor array comprising a plurality of CMOS active pixel sensors, said method comprising the steps of: (a) continuously reading out frames of data from the x-ray detector; and (b) determining whether the x-ray detector was exposed to x-rays by examining each frame of data read out in step (a).

Claim 22

Independent Claim 299 words

A method of reading out data from an x-ray detector, the x-ray detector comprising a scintillator that converts an invisible-radiant-energy image into a visible-light image and a sensor array that converts the visible light image into an electrical signal, the sensor array comprising a plurality of CMOS active pixel sensors, said method comprising the steps of: (a) intializing the x-ray detector; (b) reading out a frame of data from the x-ray detector upon initialization; (c) storing the frame of data read out in step (b); (d) reading out a next frame of data from the x-ray detector; (e) comparing the frame of data read out in step (d) to the frame of data stored in step (c); (f) discarding the frame of data read out in step (d) and returning to step (d) if the frame of data read out in step (d) is substantially the same as the frame of data stored in step (c); (g) storing the frame of data read out in step (d) if the frame of data read out in step (d) is not substantially the same as the frame of data stored in step (c); (h) reading out a next frame of data from the x-ray detector; (i) storing the frame of data read out in step (h); (j) reading out a next frame of data from the x-ray detector; (k) storing the frame of data read out in step (i); (l) subtracting the frame of data stored in step (k) from the frame of data stored in step (g) to obtain a first corrected frame; (m) subtracting the frame of data stored in step (k) from the frame of data stored in step (i) to obtain a second corrected frame; and (n) summing the first corrected frame and the second corrected frame.

Claim 23

Independent Claim 299 words

A method of reading out data from an x-ray detector, the x-ray detector comprising a scintillator that converts an invisible-radiant-energy image into a visible-light image and a sensor array that converts the visible light image into an electrical signal, the sensor array comprising a plurality of CMOS active pixel sensors, said method comprising the steps of: (a) intializing the x-ray detector; (b) reading out a frame of data from the x-ray detector upon initialization; (c) storing the frame of data read out in step (b); (d) reading out a next frame of data from the x-ray detector; (e) comparing the frame of data read out in step (d) to the frame of data stored in step (c); (f) discarding the frame of data read out in step (d) and returning to step (d) if the frame of data read out in step (d) is substantially the same as the frame of data stored in step (c); (g) storing the frame of data read out in step (d) if the frame of data read out in step (d) is not substantially the same as the frame of data stored in step (c); (h) reading out a next frame of data from the x-ray detector; (i) storing the frame of data read out in step (h); (j) reading out a next frame of data from the x-ray detector; (k) storing the frame of data read out in step (i); (l) subtracting the frame of data stored in step (k) from the frame of data stored in step (g) to obtain a first corrected frame; (m) subtracting the frame of data stored in step (k) from the frame of data stored in step (i) to obtain a second corrected frame; and (n) summing the first corrected frame and the second corrected frame.

Claim 24

Independent Claim 254 words

A method for reading out data from an x-ray detector, comprising: (a) intializing the x-ray detector; (b) reading out a frame of data from the x-ray detector upon initialization; (c) storing the frame of data read out in step (b); (d) reading out a next frame of data from the x-ray detector; (e) comparing the frame of data read out in step (d) to the frame of data stored in step (c); (f) discarding the frame of data read out in step (d) and returning to step (d) if the frame of data read out in step (d) is substantially the same as the frame of data stored in step (c); (g) storing the frame of data read out in step (d) if the frame of data read out in step (d) is not substantially the same as the frame of data stored in step (c); (h) reading out a next frame of data from the x-ray detector; (i) storing the frame of data read out in step (h); (j) reading out a next frame of data from the x-ray detector; (k) storing the frame of data read out in step (j); (l) subtracting the frame of data stored in step (k) from the frame of data stored in step (g) to obtain a first corrected frame; (m) subtracting the frame of data stored in step (k) from the frame of data stored in step (i) to obtain a second corrected frame; and (n) summing the first corrected frame and the second corrected frame.

Claim 25

Independent Claim 254 words

A method for reading out data from an x-ray detector, comprising: (a) intializing the x-ray detector; (b) reading out a frame of data from the x-ray detector upon initialization; (c) storing the frame of data read out in step (b); (d) reading out a next frame of data from the x-ray detector; (e) comparing the frame of data read out in step (d) to the frame of data stored in step (c); (f) discarding the frame of data read out in step (d) and returning to step (d) if the frame of data read out in step (d) is substantially the same as the frame of data stored in step (c); (g) storing the frame of data read out in step (d) if the frame of data read out in step (d) is not substantially the same as the frame of data stored in step (c); (h) reading out a next frame of data from the x-ray detector; (i) storing the frame of data read out in step (h); (j) reading out a next frame of data from the x-ray detector; (k) storing the frame of data read out in step (j); (l) subtracting the frame of data stored in step (k) from the frame of data stored in step (g) to obtain a first corrected frame; (m) subtracting the frame of data stored in step (k) from the frame of data stored in step (i) to obtain a second corrected frame; and (n) summing the first corrected frame and the second corrected frame.

Claim 26

Dependent Claim 38 words

An x-ray detector comprising: scintillating means for converting an invisible-radiant-energy image into a visible-light image; and converting means for converting the visible-light image into an electrical signal, said conversion means comprising a plurality of CMOS active pixel sensors.

Claim 27

Dependent Claim 38 words

An x-ray detector comprising: scintillating means for converting an invisible-radiant-energy image into a visible-light image; and converting means for converting the visible-light image into an electrical signal, said conversion means comprising a plurality of CMOS active pixel sensors.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2002-06-14	2002-12-14	2003-06-15	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2006-06-14	2006-12-14	2007-06-15	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2010-06-14	2010-12-14	2011-06-15	$7700.00	Window Closed / Lapsed

X-ray detection system using active pixel sensors

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