Adjustable collimator

Claim 2

In an X-ray device having a source of X-rays positioned to direct a beam of X-rays along a path toward a subject and an Xray stimulated device having a target area positioned to intercept X-rays passing through the subject, the improvement of an adjustable collimator disposed within the path of X-rays passing between the source and the object, the collimator comprising: a plurality of web structures disposed across the path of the beam of X-rays, each of said web structures including upper and lower apertured web reaches which extend transversely across the X-ray beam path; each of said upper and lower web reaches including material substantially opaque to X-rays with the material adjacent the aperture of each reach in part delineating the perimeter of an opening therebetween for the passage of X-rays; and, web structure support means for supporting said web reaches for movement such that translation of one reach of one of said web structures in one direction is accompanied by translation of the other reach of said one web structure in the opposite direction; whereby the perimeter delineating material in said reaches may be selectively moved relatively to adjust the perimeter of the opening and thereby to adjust the transverse dimension of the beam of X-rays transmitted to the object.

Claim 3

The X-ray device of claim 1 wherein said plurality of shutter web structures comprises first and second web structures each comprising an endless apertured loop, the loop of said first web structure being interleaved with the loop of said second web structure.

Claim 4

The X-ray device of claim 2 wherein said means for supporting said web reaches comprises: A first set of elongate rollers adapted to support said uppEr and lower web reaches of said first web structures; a second set of elongate rollers adapted to support said upper and lower web reaches of said second web structure; each of said sets of rollers including a pair of rollers disposed on opposite sides of the X-ray beam; said first set of rollers having parallel axes of rotation which extend in a plane substantially perpendicular to the X-ray beam; and, said second set of rollers having parallel axes of rotation which extend in a plane substantially perpendicular to the X-ray beam and substantially perpendicular to said axes of rotation of said first set of rollers.

Claim 5

The X-ray device of claim 3 wherein each of said first and second web structures comprises a pair of spaced connected webs forming a loop reaved respectively around said first and second sets of support rollers.

Claim 6

The device of claim 1 wherein each of said web structures comprises a pair of spaced webs of X-ray opaque material and connecting elements connecting said webs together to form a loop.

Claim 7

The device of claim 5 wherein each of said webs is comprised of a sheet of vinyl material impregnated with lead particles in sufficient density to make said vinyl material opaque to X-radiation.

Claim 8

The device of claim 5 wherein there are four such connecting elements each connecting one corner of a web to one corner of the other web, whereby said loop is comprised of two webs connected together by said chains with the chains disposed substantially along edges of said loop and whereby said webs have ends which provide said perimeter delineating of said opening.

Claim 9

The device of claim 1 wherein one reach of said web structure is disposed between the reaches of the other web structure whereby the web structures are interleaved.

Claim 10

In an X-ray device having a source of X-rays positioned to direct a beam of X-rays toward a subject, and an X-ray stimulated device having a target area positioned to intercept X-rays passing through the subject, the improvement of an adjustable collimator disposed within the path of X-rays passing between the source and the subject, the collimator comprising: a first pair of elongate rollers disposed on opposite sides of the beam of X-rays and having parallel axes of rotation which extend in a plane substantially perpendicular to the direction of said beam of X-rays; a second pair of elongate rollers disposed on opposite sides of the beam of X-rays and having parallel axes of rotation which extend in a plane substantially perpendicular to the direction of the beam of X-rays and substantially perpendicular to said axes of said first pair of rollers; a first flexible web structure reaved around said first pair of rollers so as to dispose upper and lower web reaches within the path of the beam of X-rays in planes which are substantially perpendicular to the direction of the beam of X-ray, said upper and lower web reaches having a space therebetween for passage of X-rays; a second continuous flexible web structure reaved around said second pair of rollers so as to dispose upper and lower web reaches within the path of the beam of X-rays in planes which are substantially perpendicular to the direction of the beam of X-rays, said upper and lower web reaches having a space therebetween for passage of X-rays; each of said upper and lower web reaches comprising a material which is substantially impermeable to X-rays; said upper and lower reaches of each of said web structures being movable toward and away from each other to selectively vary the space therebetween to control the cross-sectional size of the X-ray beam transmitted to the subject.

Claim 11

In an X-ray device having a source of X-rays positioned to direct a beam of X-rays toward a subject, and an X-ray stimulated device having a target area positioned to intercept X-rays passing through the subject, the improvement of an adjustable collimator disposed within the path of X-rays passing between the source and the subject, the collimator comprising: a first pair of elongate rollers disposed on opposite sides of the beam of X-rays and having parallel axes of rotation which extend in a plane substantially perpendicular to the direction of said beam of X-rays; a second pair of elongate rollers disposed on opposite sides of the beam of X-rays and having parallel axes of rotation which extend in a plane substantially perpendicular to the direction of the beam of X-rays and substantially perpendicular to said axes of said first pair of rollers; a first flexible web structure reaved around said first pair of rollers so as to dispose upper and lower web reaches within the path of the beam of X-rays in planes which are substantially perpendicular to the direction of the beam of X-ray, said upper and lower web reaches having a space therebetween for passage of X-rays; a second continuous flexible web structure reaved around said second pair of rollers so as to dispose upper and lower web reaches within the path of the beam of X-rays in planes which are substantially perpendicular to the direction of the beam of X-rays, said upper and lower web reaches having a space therebetween for passage of X-rays; each of said upper and lower web reaches comprising a material which is substantially impermeable to X-rays; said upper and lower reaches of each of said web structures being movable toward and away from each other to selectively vary the space therebetween to control the cross-sectional size of the X-ray beam transmitted to the subject.