A focus collimator press for collimators for gamma ray cameras, comprising a pivot arm of fixed length mounted on a travelling pivot which is movable in the plane of a spaced apart work table surface in a direction toward and away from the work table. A press plate is carried at the opposite end of the fixed length pivot arm, and is maintained in registration with the same portion of the work table for pressing engagement with each undulating radiation opaque strip as it is added to the top of a collimator stack in process by movement of the travelling pivot inward toward the work table. This enables the press plate to maintain its relative position above the collimator stack and at the same time the angle of the press plate changes, becoming less acute in relation to the work table as the travelling pivot moves inwardly toward the work table. The fixed length of the pivot arm is substantially equal to the focal point of the converging apertures formed by each pair of undulating strips stacked together. Thus, the focal point of each aperture row falls substantially on the axis of the travelling pivot, and since it moves in the plane of the work table surface the focal point of each aperture row is directed to lie in the same common plane. When one of two collimator stacks made in this way is rotated 180 degrees and the two bonded together along their respective first strips, all focal points of every aperture row lie on the central axis of the completed collimator.
A Platz-Heinzelmann collimator is produced by introducing strips of material between the dies of a die press, heating the material to below its extrusion temperature, applying pressure, removing the strips and adhesively securing them together. The collimator may be of the focussing type.
A method for manufacturing single focus and cone beam collimators with precisely focused focal line or focal point. The method includes the steps of: forming a collimator body by using a metal casting process; measuring a displacement of a focal position of the collimator body with respect to an intended focal position; determining an adjustment size to minimize the measured displacement; adjusting the focal position of the collimator body by changing a physical size of peripheral regions of the collimator body according to the determined adjustment size. In this method, the physical size of peripheral regions of the collimator body can be changed either by cutting or attaching peripheral adjustment portions. Also, the physical size of peripheral regions of the collimator body can be changed to tilt an optical axis of the collimator body. The method should preferably be applied to segments of the collimator body separately.
