Method and apparatus for acquiring an X-ray image using a solid state device

Claim 1

In an image capture element including a dielectric substrate layer having a top surface and a bottom surface, a plurality of transistors arrayed adjacent the top surface of said dielectric layer, a plurality of charge storage capacitors also arrayed adjacent the top surface of said dielectric layer, each capacitor having a conductive inner microplate connected to at least one of said transistors, said inner microplate having a top surface opposite said dielectric layer, means disposed adjacent the top surface of said dielectric layer for electronically activating said transistors and individually accessing each of said capacitors, a photoconductive layer disposed over said transistors and said means for activating and accessing, and a top conducting layer disposed over said photoconductive layer opposite said dielectric layer, the improvement comprising a plurality of charge barrier layers disposed adjacent, respectively, the top surface of each of said inner microplates, and a barrier dielectric layer disposed between and coextensive with said photoconductive layer and said top conducting layer.

Claim 14

A method for capturing a radiogram on an image capture element comprising: a dielectric substrate layer having a top surface and a bottom surface; a plurality of transistors arrayed adjacent the top surface of said dielectric layer; a plurality of charge storage capacitors also arrayed adjacent the top surface of said dielectric layer, each capacitor having a conductive inner microplate connected to at least one of said transistors, each inner microplate having a top surface opposite said dielectric layer, each capacitor also having a conductive outer microplate disposed on the top surface of said dielectric layer, dielectric material disposed over said outer microplate, said inner microplate being disposed over said dielectric material opposite said outer microplate; means disposed adjacent the top surface of said dielectric layer for electronically activating said transistors and individually accessing each of said capacitors, said means for activating and accessing including a plurality of discrete conductive address lines extending along the transistors and being connected, respectively, to gates of adjacent transistors, and a plurality of discrete conductive sense lines extending along the transistors in a direction across the address lines and being connected, respectively, to drain regions of adjacent transistors; charge amplifying means connected, respectively, to said sense lines for converting electrical charge in said capacitors into analog signals; a photoconductive layer disposed over said transistors and said means for activating and accessing; a top conducting layer disposed over said photoconductive layer opposite said dielectric layer; a plurality of charge barrier layers disposed adjacent, respectively, the top surface of each of said inner microplates; and a barrier dielectric layer disposed between and coextensive with said photoconductive layer and said top conducting layer, the method comprising: (a) bringing all address lines to a first bias value, connecting said inner microplates to electrical ground potential, and setting said charge storage capacitors to a no-signal level; (b) applying a positive operating voltage to the top conducting layer while maintaining said outer microplates at electrical ground potential; (c) removing said first bias value from all address lines so that said charge storage capacitors are capable of accumulating electrical charges; (d) exposing the photoconductive layer to imagewise modulated radiation, causing electrical charges to be generated within the photoconductive layer at a density proportional to the amount of radiation; (e) stopping the radiation and disconnecting the initial positive operating voltage applied to the top conducting layer, effectively creating a distribution of electrical charges within the image capture element; (f) applying a signal sequentially through the plurality of address lines to the transistors, so as to allow the charges collected in the capacitors to flow from the capacitors into the plurality of sense lines; and (g) activating the charge amplifying means to accumulate the charges from each charge storage capacitor, this cumulative value later being digitized and stored in memory 1.

Claim 15

A method for capturing a radiogram on an image capture element comprising: a dielectric substrate layer having a top surface and a bottom surface; a plurality of transistors arrayed adjacent the top surface of said dielectric layer; a plurality of charge storage capacitors also arrayed adjacent the top surface of said dielectric layer, each capacitor having a conductive inner microplate connected to at least one of said transistors, each inner microplate having a top surface opposite said dielectric layer, each capacitor also having a conductive outer microplate disposed on the top surface of said dielectric layer, dielectric material disposed over said outer microplate, said inner microplate being disposed over said dielectric material opposite said outer microplate; means disposed adjacent the top surface of said dielectric layer for electronically activating said transistors and individually accessing each of said capacitors, said means for activating and accessing including a plurality of discrete conductive address lines extending along the transistors and being connected, respectively, to gates of adjacent transistors, and a plurality of discrete conductive sense lines extending along the transistors in a direction across the address lines and being connected, respectively, to drain regions of adjacent transistors; charge amplifying means connected, respectively, to said sense lines for converting electrical charge in said capacitors into analog signals; a photoconductive layer disposed over said transistors and said means for activating and accessing; a top conducting layer disposed over said photoconductive layer opposite said dielectric layer; a plurality of charge barrier layers disposed adjacent, respectively, the top surface of each of said inner microplates; and a barrier dielectric layer disposed between and coextensive with said photoconductive layer and said top conducting layer, the method comprising: (a) bringing all address lines to a first bias value, connecting said inner microplates to electrical ground potential, and setting said charge storage capacitors to a no-signal level; (b) applying a positive operating voltage to the top conducting layer while maintaining said outer microplates at electrical ground potential; (c) removing said first bias value from all address lines so that said charge storage capacitors are capable of accumulating electrical charges; (d) exposing the photoconductive layer to imagewise modulated radiation, causing electrical charges to be generated within the photoconductive layer at a density proportional to the amount of radiation; (e) stopping the radiation and disconnecting the initial positive operating voltage applied to the top conducting layer, effectively creating a distribution of electrical charges within the image capture element; (f) applying a signal sequentially through the plurality of address lines to the transistors, so as to allow the charges collected in the capacitors to flow from the capacitors into the plurality of sense lines; and (g) activating the charge amplifying means to accumulate the charges from each charge storage capacitor, this cumulative value later being digitized and stored in memory 1.