Analogic Corporation

Alexander T Botka

Sorin Marcovici

Ben Tuval

Evan Colton

An X-ray detector used in CT scanner systems includes a 2-D array of scintillator elements coupled to an improved 2-D array of photo-detectors. When coupled together, each scintillator element aligns with a detection side of a corresponding photo-detector. The photo-detector array includes an insulating substrate which houses and secures the photodiodes in a predetermined alignment with the scintillator elements. The insulating substrate is comprised of a bottom piece and a top piece, wherein the bottom piece has circuit paths formed in a mounting surface thereof. The top piece has a top and a bottom surface, includes photo-detector holes for insertion of the photo-detectors, and has a thickness which is greater than the height of the photo-detectors. Additionally, the top piece includes plated conductive holes which extend from the top surface to conductive pads on the bottom surface and conductive paths formed at the top surface which electrically couple the conductive holes to the photo-detector. The top and bottom pieces are coupled together and then the photo-detectors are countersunk within the photo-detector holes, leaving a detection side of each photo-detector exposed. The detection side of each photo-detector is electrically coupled to a corresponding pair of conductive holes, which creates an electrical path from the detection side of the photo-detector to the circuit path of the bottom piece. The array of scintillator elements, including an alignment grid, is then coupled to the photo-detector array to form a 2-D X-ray detector.

Two-dimensional X-ray detector array for CT applications

A coplanar photodiode construction is disclosed having particular utility in X-ray detection applications in which alternating P-doped and N-doped regions, separated by undoped material, are located in relatively shallow depth under and along the surface between the photodiode and an associated X-ray scintillating crystal.

Coplanar X-ray photodiode assemblies

A D/A converter for converting a digital signal having a number of bits to an analog signal. The converter is fabricated in an integrated circuit digital array including a register for storing the particular number of bits, a buffer circuit for receiving those bits from the register, and an analog current switching network. The analog current switching network includes a number of current switching circuits, each of which provides the proper current output in response to the delivery of an associated bit from the buffer circuit. Each current switching circuit includes an emitter coupled switch circuit having two pluralities of parallel connected transistor cells with the bases of one of the plurality of transistor cells connected with the buffer circuit and the bases of the other of the plurality of transistor cells connected with the current switching circuit. The current switching circuit includes a first transistor cell with its emitter connected to the base of the other of the plurality of transistor cells in the emitter coupled switch circuit. A voltage summing network responsive to the current output from the analog current switching network provides voltages representative of the bit presented by the associated buffer circuit.

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Underhill, VT, United States of America

Alexander T Botka