Method for temperature compensation of an image dectector
First Claim
1. A method for temperature compensation of an image detector comprising photosensitive spots (O1 to O6, R1 to R9), these being sensitive to ambient temperature, each connected to a row conductor (Y1 to Y3) and a column conductor (W1, W2, Z1 to Z3), each of the photosensitive spots being connected via one of its conductors to a read circuit (30a, 30b), characterized in that the photosensitive spots are divided into detecting photosensitive spots (R1 to R9), intended to be exposed to light information corresponding to the image to be detected, the read circuits (30b) associated with these photosensitive spots each delivering a measurement voltage representative of the image to be detected, and into blind photosensitive spots (O1 to O6) protected from the light information, the read circuits (30a) associated with these blind photosensitive spots each delivering a dark voltage serving for temperature compensation, and in that it consists, during detection of an image, in picking up the dark voltages, then in generating an average correction value from the dark voltages coming from one or more detected images and in using the average correction value to generate a correction voltage (VDR) to be applied, during detection of a subsequent image, to the read circuits (30b) associated with the detecting photosensitive spots (R1 to R9) so that they deliver a measurement voltage made substantially independent of temperature.
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Abstract
This is a method for temperature compensation of an image detector comprising photosensitive spots (O1 to O6, R1 to R9), these being sensitive to ambient temperature, each connected to a row conductor (Y1 to Y3) and a column conductor (W1, W2, Z1 to Z3). Each of the photosensitive spots is connected via one of its conductors to a read circuit (30a, 30b). The photosensitive spots are divided into detecting photosensitive spots (R1 to R9), intended to be exposed to light information corresponding to the image to be detected, the read circuits (30b) associated with these photosensitive spots each delivering a measurement voltage representative of the image to be detected, and into blind photosensitive spots (O1 to O6) protected from the light information, the read circuits (30a) associated with these blind photosensitive spots each delivering a dark voltage serving for temperature compensation. During detection of an image, the method consists in picking up the dark voltages, then in generating an average correction value from the dark voltages coming from one or more detected images and in using the average correction value to generate a correction voltage (VDR) to be applied, during detection of a subsequent image, to the read circuits (30b) associated with the detecting photosensitive spots (R1 to R9) so that they deliver a measurement voltage made substantially independent of temperature.
Application in particular to radiological image detectors.
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Citations
14 Claims
- 1. A method for temperature compensation of an image detector comprising photosensitive spots (O1 to O6, R1 to R9), these being sensitive to ambient temperature, each connected to a row conductor (Y1 to Y3) and a column conductor (W1, W2, Z1 to Z3), each of the photosensitive spots being connected via one of its conductors to a read circuit (30a, 30b), characterized in that the photosensitive spots are divided into detecting photosensitive spots (R1 to R9), intended to be exposed to light information corresponding to the image to be detected, the read circuits (30b) associated with these photosensitive spots each delivering a measurement voltage representative of the image to be detected, and into blind photosensitive spots (O1 to O6) protected from the light information, the read circuits (30a) associated with these blind photosensitive spots each delivering a dark voltage serving for temperature compensation, and in that it consists, during detection of an image, in picking up the dark voltages, then in generating an average correction value from the dark voltages coming from one or more detected images and in using the average correction value to generate a correction voltage (VDR) to be applied, during detection of a subsequent image, to the read circuits (30b) associated with the detecting photosensitive spots (R1 to R9) so that they deliver a measurement voltage made substantially independent of temperature.
- 7. A temperature-compensated image detector comprising photosensitive spots (O1 to O6, R1 to R9), each connected to a row conductor (Y1 to Y3) and a column conductor (W1, W2, Z1 to Z3), each photosensitive spot being connected via one of its conductors to a read circuit (30a, 30b), characterized in that the photosensitive spots are divided into detecting photosensitive spots (R1, R9), intended to be exposed to light information corresponding to the image to be detected, the read circuits (30b) associated with these photosensitive spots each delivering a measurement voltage representative of the image to be detected, and into blind photosensitive spots (O1 to O6) protected from the light information, the read circuits (30a) associated with these blind photosensitive spots each delivering a dark voltage used for temperature compensation and in that it comprises means for picking up the dark voltages during detection of an image and for generating an average correction value from the dark voltages picked up coming from one or more detected images and means for generating, from the average correction value, a correction voltage (VDR) intended to be applied to the read circuits (30b) associated with the detecting photosensitive spots, during detection of a compensated subsequent image, so that the detecting photosensitive spots (R1 to R9) deliver a measurement voltage made approximately independent of temperature.
Specification