GAMMA IMAGING DEVICES

摘要

1365048 Scintillation camera PICKER CORP 6 July 1973 [10 July 1972] 32268/73 Addition to 1344804 Heading H4F A transparent disc 321 or 32111 provided between a scintillator (20, Fig. 2, not shown) and a plurality of phototubes (35) has its face facing the phototubes covered with a reflective coating (51, Fig. 3, not shown) except where this face is optically coupled to the phototubes, as in Specification 1,344,804. The opposite face of the disc is also formed with reflective masks as in that Specification, but to increase the linearity and uniformity of the device the masks on this face are altered to be, e.g. as shown in Fig. 6, masks 611, 621 being aligned with respective phototubes. In an alternative embodiment (Fig. 5, not shown) legs 75 are provided between all the spokes 631, 74 of masks 621. In a further embodiment the masks are formed as in Fig. 7, with the length of spokes 6311 of the masks 81 being equal to the radius of the associated phototube input face. Alternatively all the masks may be formed of equal-length spokes radiating from a central annular hub, with the spokes being the same length as spokes 85 in Fig. 7 which are the same length as those used in Specification 1,344,804 but with all but the central mask having a larger central aperture than in that Specification.