METHOD AND SYSTEM OF AUTOMATICALLY DETERMINING WHEN X-RAY RADIATION HAS BEEN RECEIVED AT A SENSOR
A system and method for automatic detection of x-rays at an x-ray sensor. A source emits x-ray radiation towards an x-ray sensor, and the x-ray sensor automatically detects the x-ray radiation. The x-ray sensor automatically detects x-ray radiation by evaluating a time series and determining that a voltage threshold is crossed a certain amount of time earlier than the average time it takes the voltage threshold to be crossed from dark current and other noise.
1 . A method of automatically detecting x-ray radiation with an x-ray sensor, the x-ray sensor having a pixel array, the method comprising:
adaptively resetting the pixel array based on a dark current; and
determining that x-ray radiation has been received at at least a portion of the pixel array when a trigger threshold is passed.
2 . The method of claim 1 , wherein adaptively resetting the pixel array based on the dark current includes determining an elapsed time between a reset of the pixel array and a determination that the trigger threshold has been crossed due to the dark current.
3 . The method of claim 1 , wherein the dark current indicates a temperature of the x-ray sensor.
4 . The method of claim 3 , further comprising generating an error condition if the temperature of the x-ray sensor indicated by the dark current exceeds a predetermined level.
5 . The method of claim 1 , wherein the trigger threshold comprises a predetermined voltage level, and wherein a predetermined amount of charge stored on the at least a portion of the pixel array causes a voltage potential at a diode to drop below the trigger threshold.
6 . The method of claim 1 , further comprising:
determining that x-ray radiation is no longer being received, and
reducing an integration time for a subsequent x-ray radiation exposure based on a duration of the x-ray radiation received at the at least a portion of the pixel array.
7 . An x-ray sensor that automatically detects receipt of x-rays, the x-ray sensor including a processor and a pixel array, the processor configured to:
adaptively reset the pixel array based on a dark current;
determine that x-ray radiation has been received at at least a portion of the pixel array based on passing a trigger threshold; and
after determining that x-ray radiation has been received, output data from the pixel array to be used to generate an x-ray image.
8 . The x-ray sensor of claim 7 , wherein adaptively resetting the pixel array based on the dark current includes determining an elapsed time between a reset of the pixel array and a determination that the trigger threshold has been crossed due to the dark current.
9 . The x-ray sensor of claim 7 , wherein the trigger threshold comprises a predetermined voltage level, and wherein a predetermined amount of charge stored on the at least a portion of the pixel array causes a voltage potential at a diode to drop below the trigger threshold.
10 . The x-ray sensor of claim 7 , wherein the processor is further configured to
determine that x-ray radiation is no longer being received, and
reduce an integration time for a subsequent x-ray radiation exposure based on a duration of the x-ray radiation received at the at least a portion of the pixel array.
11 . The x-ray sensor of claim 7 , wherein the dark current indicates a temperature of the x-ray sensor.
12 . The x-ray sensor of claim 11 , wherein the processor is further configured to generate an error condition if the temperature of the x-ray sensor indicated by the dark current exceeds a predetermined level.