Imaging array for multiple frame capture

A radiographic imaging apparatus for capturing x-ray images of an object comprising:

• a) a radiation source to direct radiation, at a first wavelength, toward an object;
• b) a scintillation screen to receive radiation directed through the object and generate excited light having a second wavelength;
• and
• c) an imaging array, optically coupled to the scintillation screen and comprising a plurality of pixel sites, each pixel site comprising:
• (i) at least one photosensing element to provide a variable signal in response to incident radiation;
• and
• (ii) a plurality of frame storage circuits electrically coupled to the photosensing element, wherein each frame storage circuit comprises:
• (1) a charge storage element to store a signal provided by the photosensing element;
• (2) a first switching element disposed to switch an electrode of the photosensing element to the at least one frame storage circuit;
• and
• (3) a second switching element disposed to switch the at least one charge storage element from a first electrode connected to the charge storage element to a second electrode;
• d) a single signal readout element comprising a data line extending between more than one pixel site, the data line to directly connect from the second electrode of each of the second switching elements of the plurality of frame storage circuits to a single sensing circuit for the more than one pixel site, the single sensing circuit displaced from the imaging array,
• wherein each of the frame storage circuits is used to reset the at least one photosensing element to a potential of the data line by enabling the first switching element and the second switching element for a reset period before the signal provided by the photosensing element is stored by a corresponding charge storage element.

A method for operating a radiographic imaging apparatus for capturing a plurality of x-ray images of an object comprising:

• a) providing an array of photosensing elements, wherein each photosensing element provides a variable signal in response to incident radiation;
• b) providing a scintillation screen for receiving incident radiation at a first wavelength and responding by emitting excited radiation at a second wavelength;
• c) storing a first signal in a first charge storage element, for at least some of the photosensing elements in the array, wherein the first signal results from incident radiation directed to the scintillation screen, representing a first image signal thereby;
• d) storing a second signal in a second charge storage element at said at least some of the photosensing elements in the array, wherein the second signal results from incident radiation directed to the scintillation screen, representing a second different image signal thereby;
• e) storing a third signal in a third charge storage element at said at least some of the photosensing elements in the array, wherein the third signal results from incident radiation directed to the scintillation screen, representing a third different image signal thereby;
• f) reading out the first image signal to a first data line extending beyond the array of photosensing elements to a first sensing circuit displaced from the array of photosensing elements;
• g) sensing the first image signal from the first data line with the first sensing circuit displaced from the array of photosensing elements;
• h) reading out the second image signal to the first data line;
• i) sensing the second image signal from the first data line with the first sensing circuit
• j) reading out the third image signal to the first data line;
• and
• k) sensing the third image signal from the first data line with the first sensing circuit.

A method for operating a radiographic imaging apparatus for obtaining an x-ray image comprising:

• a) providing an array of pixel sites including photosensing elements, wherein each photosensing element provides a variable signal in response to incident radiation;
• b) providing a scintillation screen for receiving incident radiation at a first wavelength and responding by emitting excited radiation at a second wavelength;
• c) storing a first signal in a first charge storage element, for at least some of the photosensing elements in the array, wherein the first signal of photosensing elements in the array is obtained without incident radiation directed to the scintillation screen, representing a dark state signal thereby;
• d) storing a second signal in a second charge storage element, for at least some of the photosensing elements in the array, wherein the second signal results from incident radiation directed to the scintillation screen, representing first image signal thereby;
• e) reading out the dark state signal to a connected single sensing circuit displaced from the array of photosensing elements;
• f) reading out the first image signal to the first data line;
• and
• g) conditioning the first image signal according to the dark state signal, for at least some of the photosensing elements in the array, thereby compensating for dark state effect.

A method for operating a radiographic imaging apparatus for capturing a plurality of x-ray images of an object comprising:

• providing an array of photosensing elements, wherein each photosensing element provides a variable signal in response to incident radiation;
• providing a scintillation screen for receiving incident radiation at a first band of wavelengths and responding by emitting excited radiation at a second band of wavelengths;
• resetting a plurality of photosensing elements to a data line potential before a first exposure by turning on both a-first switching elements and second switching elements, where the first switching elements are connected in series between a˜a first data line and a-first charge storage elements, where the second switching elements are connected in series between the first charge storage elements and said each of the plurality of photosensing elements;
• turning off the first switching elements upon sensing the start of the first exposure;
• storing a first signal in the first charge storage elements for at least some of the photosensing elements in the array, wherein the first signal results from incident radiation directed to the scintillation screen during the first exposure, representing a first image signal;
• resetting a plurality of photosensing elements to the data line potential before a second exposure by turning on both a-third switching elements and fourth switching elements, where the third switching elements are connected in series between the first data line and a-second charge storage elements, where the fourth switching elements are connected in series between the second charge storage elements each of the plurality of photosensing elements;
• storing a second signal in the second charge storage element for said at least some of the of photosensing elements in the array, wherein the second signal results from incident radiation directed to the scintillation screen during the second exposure, representing a second image signal;
• reading out the first image signal to the first data line extending beyond the array of photosensing elements to a first sensing circuit displaced from the array of photosensing elements;
• sensing the first image signal from the first data line with the first sensing circuit displaced from the array of photosensing elements;
• reading out the second image signal to the first data line;
• and
• sensing the second image signal from the first data line with the first sensing circuit.