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US 7,688,947 B2Granted
Method for reducing sensitivity modulation and lag in electronic imagers
AssigneeVarian Medical Systems, Inc.
InventorsIvan Petrov Mollov, Carlo Alberto Tognina, Roberto Totaro
Life of this patent
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Abstract
A method for reducing gain and lag signals associated with trapped charges is described. Data is collected from a detector. A forward bias voltage is temporarily applied to the detector between collecting the data.
Claims35
A method, comprising:
- collecting data from a detector, the detector connected to a pixel Thin Film Transistor (TFT) and a reset TFT in series;
- applying a forward bias voltage to the detector between collecting data while closing the pixel TFT and the reset TFT;
- opening the pixel TFT and the reset TFT and applying a reverse bias voltage to the detector;
- and
- resetting the detector by closing the pixel TFT and the reset TFT for a predetermined amount of time for one or more cycle while applying the reverse bias voltage to the detector.
2 more elements
A detector comprising:
- a photosensor circuit having a photodiode connected to a pixel TFT and a reset TFT in series;
- and
- a switch coupled to the photosensor circuit,
- wherein the switch is coupled to a first voltage source to forward bias the photodiode, and is coupled to a second voltage source to reverse bias the photodiode.
1 more element
An imaging system comprising:
- a source of radiation;
- a detector for sensing radiation from the source and generating data representative of the radiation, the detector comprising a photodiode coupled to a pixel TFT and a reset TFT in parallel;
- and
- a processor coupled to the detector and configured to switch a voltage applied to the detector between a first voltage source to forward bias the photodiode, and coupled to a second voltage source to reverse bias the photodiode, and to reset the detector by closing the pixel TFT and the reset TFT for a predetermined amount of time for one or more cycle while applying the second voltage source to the detector.
1 more element
Dependencies are inferred from the claim text.