Functions

Sensitivity of an X-Ray film to direct X-Ray photons is very low. The efficiency of X-Ray film to absorb X-Ray photons is only 1%. 99% of X-Ray photons are wasted. Intensifying screen has a greater efficiency to absorb X-Ray photons and convert them into ultraviolet light or visible light. Screen reduces exposure time and X-Ray dose. Screen reduces kinetic unsharpness. Cassette provides lightproof enclosure for an X-Ray film, which is sandwiched between a pair of screen. Cassette provides contact between film and screen required for a sharp image by expelling out air trapped between film and screen.

Absorption, Conversion & Emission