Light density scale imaging apparatus and method for using same

Abstract

Apparatus for exposing film, such as X-ray film, in a cassette with light of predetermined intensity from a light density scale, and a method of using such apparatus and the developed film. The apparatus is provided with an energizable luminescent element which cooperates with an indicia bearing member provided with predetermined indicia and adapted to be inserted into imaging relation with respect to the luminescent element. A light density scale preferably formed of plural areas or strips of different densities is provided either on the luminescent element or on the indicia bearing member. When for example an X-ray film cassette is properly loaded onto the apparatus, the luminescent element is energized so as to expose the X-ray film simultaneously to the predetermined indicia and to light of different predetermined intensities as transmitted through the light density scale. Prior to or subsequent to this light imaging operation, the X-ray film in the cassette is exposed to an X-ray image of a subject. Then, the exposed X-ray film is developed to form a viewable image of the subject, the predetermined indicia and the light density scale. The brightness of the respective strips of the developed light density scale is measured, and the measured values are compared to other developed X-ray films to determine which of the developed films has a brightness that differs from a measured average value, such as may be caused by an undesired variation in the film developing operation, the film characteristics, etc.