Patent Number: 053965345
Section: abstract

A shutter mechanism for collimating x-rays uses a frame to define an opening with two opposing interior edges. An elongated flexible band extends in sliding engagement about at least a portion of the periphery of the frame opening. A first shutter member made of an x-ray opaque material has a first end attached to the flexible band along the first interior edge of the frame. Similarly, a second shutter member made of an x-ray opaque material has a first end attached to the flexible band along the second interior edge of the frame. A drive means, such as a stepper motor, translates the flexible band relative to the frame to control the positions of the shutter members and the shutter aperture. In the preferred embodiment, the interior edges of the frame also include tracks that slidably engage the opposing edges of the shutter members for support. Two or more of these frame assemblies can be stacked in a rotated orientation about a common axis to provide two-dimensional control of the size of the shutter aperture.