Radiographic phosphor panel having improved speed and sharpness

DETAILED DESCRIPTION The present invention provides a radiographic phosphor panel comprising a phosphor layer adjacent to a polymeric multi-layer reflector that exhibits a different level of reflectance of light depending upon the angle of light incidence that is greater than 0 and up to and including 90 degrees, and on the opposing side of the reflector, a light absorbing substrate.
Still further, this invention provides a radiographic imaging assembly comprising at least one radiographic phosphor panel described above that is arranged in association with a photosensitive recording material, such as a silver halide radiographic film.
The present invention provides a number of advantages.
It provides a radiographic phosphor panel (or fluorescent intensifying screen) that provides both increased photographic speed and sharpness in imaged photosensitive recording materials.
These and other advantages of the invention are accomplished by the use of specific polymeric multi-layer reflectors (generally as the support) in the radiographic phosphor panel with a phosphor layer on one side and a light absorbing substrate on the opposite side of the support.
However, unlike the invention described in U.
S.
Ser.
No.
09/883,801, noted above, not just any polymeric multi-layer reflector can be used in the practice of this invention.
The required polymeric multi-layer reflectors exhibit a different level of reflectance of light (that is different % reflectance of light) depending upon the angle of light incidence of between 0 and up to and including 90 degrees to the plane of the reflector.
Thus, an essential feature of the present invention is the use of polymeric multi-layer reflectors that reflect most light striking them at "high incident angles" and transmit and absorb most light striking them at "low incident angles".
This low incident angle light is generally absorbed by the light absorbing substrate on the opposite side of the reflector from the phosphor layer in order to provide optimal function of the panel