High resolution storage phosphor x-ray imaging device

Abstract

A high resolution x-ray imaging device based on a storage phosphor layer. The storage phosphor layer is sandwiched between two arrays of electrodes. In one embodiment of the device, the arrays are orthogonal arrays of linear electrodes, one of the arrays being transparent to the phosphorescence emitted by the storage phosphor. To read a pixel of a latent image stored in the storage phosphor layer, a voltage difference is established between two crossed electrodes that exceeds the threshold voltage of the storage phosphor material. The emitted light is detected by a device such as a CCD array that has coarser resolution than the crossed electrode array: the resolution of the imaging device of the present invention is the electrode width. Preferably, the electrodes are addressed for activation by optical scanning of photoconductive strips adjacent and perpendicular to the electrodes. Also preferably, the electrodes are addressed in interleaved subsets, each with as many electrode intersections as there are pixels in the CCD array, to create subimages which are interleaved to provide a final image having a resolution finer than the resolution of the CCD array. In another embodiment of the device, one array is a single electrode and the other array includes several electrodes. A subimage of the latent image is read by establishing a voltage difference between the single electrode and one of the several electrodes that exceeds the threshold voltage. The emitted light is detected by a CCD array with the resolution of the CCD array. The several subimages are assembled to provide a final image having a resolution finer than the resolution of the CCD array.