Flying spot scanner having arbitrarily shaped field size
First Claim
1. In a flying spot X-ray scanning system of the type comprising means defining a region in which a body to be examined by X-rays may be located, detector means located adjacent one side of said region, X-ray generating means located adjacent the other side of said region for producing a pencil beam of X-rays which is adapted to repeatedly scan along a line through said region and across said detector means, and translation means for effecting relative motion between said X-ray generating means and the body to be examined in a direction transverse to said line during said repeated scans thereby to produce a rectangular X-ray scan field which has one dimension defined by the said scanning of said pencil beam along said line and a transverse dimension defined by said translation means, the improvement wherein said X-ray generating means comprises a grid-controlled X-ray tube, signal generating means coupled to the grid of said X-ray tube for providing a signal which controls the emission of X-rays from said tube, and control means coupled to said signal generating means for selectively varying the time at which said signal commences thereby to control the position of said X-ray scan field relative to said region.
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Accused Products
Abstract
A flying spot X-ray scanning system includes a grid controlled X-ray tube and associated collimators for producing a pencil beam of X-rays which is adapted to repeatedly scan along a line through a body to be examined and across an associated detector. The grid of the X-ray tube is energized by a train of rectangularly shaped pulses, and separate control means are provided for selectively varying the commencement of each such pulse thereby to determine the position of the scan field relative to the body being examined, and for selectively varying the duration of each pulse thereby to control the width of the scan field. The X-ray tube, collimators, and detector are adapted to be moved as a unit in a direction transverse to the scan line of the pencil beam, and a further control is provided for selectively varying the extent of this transverse movement thereby to control the longitudinal dimension of the scan field.
88 Citations
16 Claims
- 1. In a flying spot X-ray scanning system of the type comprising means defining a region in which a body to be examined by X-rays may be located, detector means located adjacent one side of said region, X-ray generating means located adjacent the other side of said region for producing a pencil beam of X-rays which is adapted to repeatedly scan along a line through said region and across said detector means, and translation means for effecting relative motion between said X-ray generating means and the body to be examined in a direction transverse to said line during said repeated scans thereby to produce a rectangular X-ray scan field which has one dimension defined by the said scanning of said pencil beam along said line and a transverse dimension defined by said translation means, the improvement wherein said X-ray generating means comprises a grid-controlled X-ray tube, signal generating means coupled to the grid of said X-ray tube for providing a signal which controls the emission of X-rays from said tube, and control means coupled to said signal generating means for selectively varying the time at which said signal commences thereby to control the position of said X-ray scan field relative to said region.
- 9. A flying spot X-ray scanning system comprising an X-ray source adapted to emit X-rays, collimator means positioned to intercept said emitted X-rays and operative to produce a pencil beam of X-rays which repetitively scans along a first line, means for moving said X-ray source and said collimator means along a second line transverse to said first line during the scanning of said pencil beam, first control means for selectively varying the time at which said X-ray source commences its emission of X-rays relative to the beginning of each of said scans, second control means for selectively varying the duration of said emission of X-rays subsequent to the commencement of said emission, and third control means for selectively varying the extent to which said X-ray source and collimator means are moved along said second line, whereby said first, second and third control means jointly define the position and dimensions of the X-ray scan field which is generated by said flying spot scanning system.
- 13. In a flying spot X-ray scanning system of the type comprising means defining a region in which a body to be examined by X-rays may be located, detector means located adjacent one side of said region, X-ray generating means located adjacent the other side of said region for producing a pencil beam of X-rays which is adapted to repeatedly scan along a line through said region and across said detector means, and translation means for effecting relative motion between said X-ray generating means and the body to be examined in a direction transverse to said line during said repeated scans thereby to produce a rectangular X-ray scan field which has one dimension defined by the said scanning of said pencil beam along said line and a transverse dimension defined by said translation means, the improvement wherein said X-ray generating means comprising a grid-controlled X-ray tube, signal generating means coupled to the grid of said X-ray tube for providing a signal which controls the emission of X-rays from said tube, and control means coupled to said signal generating means for selectively varying the duration of said signal thereby to control the width of said X-ray scan field.
Specification