| 摘要 |
<p>View box apparatus is provided for illuminating a film (20) containing a medical diagnostic image for radiologic observation and study. A light source (40) is contained within the view box, at one end thereof, and a transparent plate (48) is positioned at the other end for supporting the imaging film (20). A panel of material (46) is positioned in the box between the light source (40) and the transparent plate (48) to diffuse light from the source, and one or more layers of a microprism film (50) is positioned between the diffuser panel (46) and the imaging film (20). The microprism film (50) reflects light rays which are incident thereon at an angle less than a critical angle back into the view box, so that such light rays do not pass through the microprism film (50) to illuminate the imaging film (20). Light rays incident upon the microprism film (50) which are greater than the critical angle are refracted by the microprism film to provide light for illuminating the imaging film (20) having a solid angle which is much less than the solid angle of light from the diffuser (46). Accordingly, the microprism film (50) serves to substantially reduce scatter, and thereby significantly improves resolution and contrast for an observer of the imaging film. <IMAGE></p> |
