An apparatus and method for computed radiography includes a rotating laser as
a pumping source for delivering light, without the use of a rotating mirror, successively
to ends of each of a plurality of optical fibers arranged in an arc. Opposite ends
of the optical fibers are arranged in a linear array to a previously-exposed computed
radiography plate having a latent X-ray image formed thereon. The plate is moved
with respect to the fibers. Light emitted from the radiographic medium due to excitation
by the pumping light travels through a light guide to an optical receiver where
an image signal responsive to the light intensity of the emitted light is generated.
The image signal is sent to a processor to generate an image representative of
the latent X-ray. An erasing of the latent x-ray image may be accomplished in the
same machine apparatus that generates the representative image. Preferably, multiple
erasure operations are performed with a relaxation period, e.g., three to ten seconds
between successive erasing operations. The laser is accurately positioned by an
adjustment mechanism in an axial direction to focus the laser light on receiving
optical fiber ends and in a radial direction to align the rotational axis substantially
coaxially to the axis of the arc for the optical fibers. Electrical power is delivered
through a brush and contact to leads in a rotating drive shaft for the rotating
laser. The preferred light guide comprises an inlet positioned to receive phosphorescent
light from the imaging plate and rearward and forward reflective surfaces for reflecting
incoming light back and forth within the light guide that was not directly aligned
for travel along a straight line path directly to the light collector, e.g., a
photomultiplier tube. A substantial portion of this reflected light will eventually
travel forwardly along a path of travel to hit the photomultiplier tube.
