Method for determining and correcting the stability of response of a semi-conductor matrix detector
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorsFrancis GLASSER, Loïck VERGER
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Abstract
Techniques for controlling a stability of response of a semi-conductor matrix imager composed of pixels, including a first phase of characterizing the stability of the pixels and a second phase of correcting the signals arising from the pixels during the measurements. The pixels are classed into stable pixels and unstable pixels according to a predetermined criterion, the unstable pixels being associated individually with a stable pixel whose characteristics serve as base for correcting signals arising from the unstable pixels.
Claims9
A method of controlling a stability of response of a semi-conductor matrix imager comprising a plurality of pixels, the method comprising:
- a first phase of characterizing the stability, the first phase comprising:
- irradiating the pixels with a gauge radiation that is constant over time for a first predetermined duration;
- storing signals delivered by each pixel at regular time intervals for the first predetermined duration;
- determining, for each pixel, an amplitude distribution of the signals delivered by each pixel;
- characterizing each distribution with a statistical indicator representative of a dispersion of the distribution;
- and
- classifying each pixel, on the basis the indicator for the pixel, into one of at least two categories of pixels, each category being representative of the stability of the temporal response of the pixels, the first category representing stable pixels, and the second category representing unstable pixels;
- and
- a second phase of correcting the stability, the second phase comprising:
- associating each unstable pixel with one or more stable pixels according to a predetermined criterion;
- irradiating the pixels with a radiation to be characterized for a second predetermined duration;
- storing signals delivered by each pixel for at least one time interval during the said second predetermined duration;
- and
- correcting a signal generated by each unstable pixel as a function of a signal or signals generated by the stable pixels associated with the said unstable pixel.
A matrix imager comprising:
- a semi-conducting active detection surface comprising a plurality of pixels;
- means for storing and processing signals arising from the pixels of the active detection surface, wherein
- the pixels are distributed into at least two categories, the first category representing stable pixels, the second category representing unstable pixels;
- each unstable pixel is associated with a stable pixel according to a predetermined criterion;
- and
- the signals arising from each unstable pixel are transmitted with at least one correction coefficient dependent on the signal of the stable pixel associated with the unstable pixel.
Dependencies are inferred from the claim text.