摘要:
A light block material disposed over the photosensitive region of a switching device (e.g., TFT) of a radiation imager is disclosed. The light block material prevents optical photons emitted from a scintillator from passing into the switching device and being absorbed. Cross-talk and noise in the imager are thereby reduced. Also, non-linear pixel response and spurious signals passing to readout electronics are avoided. Optionally, opaque caps comprising the same light block material may be included in the imager structure. The caps cover contact vias filled with a common electrode and located in the contact finger region of the imager. The integrity of the filled vias is thereby maintained during subsequent processing. Also disclosed is a radiation imager containing these structures.
摘要:
A radiation imager includes a photosensor array that is coupled to a scintillator so as to detect optical photons generated when incident radiation is absorbed in the scintillator. The imager includes an optical crosstalk attenuator that is optically coupled to a first surface of the scintillator (that is, the surface opposite the photosensor). The optical crosstalk attenuator includes an optical absorption material that is disposed so as to inhibit reflection of optical photons incident on the scintillator first surface back into the scintillator along selected crosstalk reflection paths. The crosstalk reflection paths are those paths oriented such that optical photons passing along such paths would be incident upon photosensor array pixels that are outside of a selected focal area corresponding to the absorption point in the scintillator. The imager further may include an optical screen layer that is optically coupled to the scintillator second surface so as to be disposed between the scintillator and the photosensor array. The optical screen layer is made of a substantially transparent material selected to have a critical index of refraction so as to cause preferential reflection of optical photons that are incident on the screen layer to reduce optical crosstalk.
摘要:
An imager array includes a substrate with a plurality of superimposed layers of electrically conductive and active components. Sets of scan and data lines are electrically insulated from one another and also from a common electrode and active array components by dielectric material. Protection of the active components against static charge potential includes resistive means between the common electrode and a ground ring conductor around the array elements and in particular a thin film transistor circuit with a parallel pair of opposite polarity diode connected field effect transistors to safely drain the static charge during subsequent fabrication, test and standby period of the imager, while remaining in circuit during imager operation. Further electrostatic charge protection is provided to the array by an protective apparatus adapted to support the radiation imager while electrically contacting its ground ring to facilitate handling and processing while protecting against electrostatic charge damage during fabrication and testing, and enabling the positioning and bonding of the flexible external connections to the contact pads of the imager. Provision is made to enable heat and pressure for thermode bonding through the fixture to the contact pads while the imager is secured within the fixture.
摘要:
A solid-state imager with back-side irradiation. The present invention provides a solid-state imager that includes a substantially radiation transparent substrate adapted to receive incident radiation. The radiation travels through the substrate and a pixelated array of photosensitive elements to a scintillator material, which absorbs the radiation. The pixelated array of photosensitive elements receives light photons and measures the amount of light generated by radiation interactions with the scintillator material. With this imager, there is less spreading and blurring and thus a better quality image. In another embodiment, there is a substantially transparent material disposed between the pixelated array of photosensitive elements and the scintillator material. The substantially transparent material absorbs and substantially blocks electrons from entering the active regions of the pixelated array of photosensitive elements. This enables the imager to perform for a longer period of time according to its specifications.
摘要:
A method for fabricating an imaging array includes forming a first dielectric barrier, forming a light block element on the first dielectric barrier, wherein the light block element is at least coextensive with a gate, and forming a second dielectric barrier on the first dielectric barrier and the light block element such that the light block element is encapsulated between the first dielectric barrier and the second dielectric barrier.
摘要:
A radiation detector includes a top gate thin film transistor (TFT) including a source electrode, a drain electrode, a gate electrode, a first dielectric layer, and a second dielectric layer, wherein the second dielectric layer is extending over a surface of the first dielectric layer. The radiation detector also includes a capacitor that includes at least two electrodes and a dielectric layer. The capacitor dielectric layer is formed unitarily with the TFT second dielectric layer.
摘要:
In one aspect of the invention a method for processing a fluoroscopic image is provided. The method includes scanning an object with an imaging system including at least one radiation source and at least one detector array, acquiring a plurality of dark images to generate a baseline image, acquiring a plurality of lag images subsequent to the baseline image, determining a plurality of parameters of a power law using at least one lag image and at least one baseline image, and performing a log—log extrapolation of the power law including the determined parameters.
摘要:
A fiber optic scintillator includes, for example, a first plurality of radiation absorbing elements comprising a scintillating material for converting radiation into light and a second plurality of radiation absorbing elements interspersed among the first plurality of radiation absorbing elements. The first plurality of radiation absorbing elements has a first radiation absorption efficiency. The second plurality of radiation absorbing elements has a second radiation absorption efficiency and an effective atomic number greater than about 50. The second radiation absorption efficiency is greater than said first radiation absorption efficiency. A scintillator forming method provides a bundle of the second plurality of radiation absorbing elements interspersed among the first plurality of radiation absorbing elements by drawing the bundle, The drawn bundle is cut into a plurality of sections. The plurality of sections are assembled to form the scintillator having an array of parallel first and second radiation absorbing elements.
摘要:
Storage capacitor design for a solid state imager. The imager includes several pixels disposed on a substrate in an imaging array pattern. Each pixel includes a photosensor coupled to a thin film switching transistor. Several scan lines are disposed at a first level with respect to the substrate along a first axis and several data lines are disposed at a second level along a second axis of the imaging array. Several data lines disposed at a second level with respect to the substrate along a second axis of the imaging array pattern. Each pixel comprises a storage capacitor coupled parallel to the photosensor, the storage capacitor comprising a storage capacitor electrode and a capacitor common electrode.
摘要:
A method for monitoring the quality of a manufacturing process for making detector panels that have a plurality of pixels in a two-dimensional array includes, in each detector panel, manufacturing a set of baseline pixels and a set of test pixels. Each test pixel has an electrical component having a geometric dimension varied by an amount sufficient to introduce a measurable variation in a test that measures parameters of pixels that are dependent upon the varied dimension. The method further includes performing the test on the set of baseline pixels and the set of varied pixels, analyzing the results of the test, and adjusting parameters of the manufacturing process in accordance with the analysis.