Noise of CRT display systems

This paper is an attempt to correlate CRT noise (measured physically) with contrast sensitivity obtained from the detection of square-wave patterns presented to human observers on a CRT. It presents the results of both physical and psychophysical evaluations of the noise of high resolution CRTs at a luminescence level of 65 ft-L. Temporal as well as spatial noise was physically measured with the aid of a photomultiplier-based evaluation system. Human contrast sensitivity was determined physchophysically using square-wave patterns of frequencies ranging from 0.47 lp/deg to 14.9 lp/deg. Even though the set of data is not very extensive, the results indicate a correlation between physical and psychophysical evaluation: for the luminance levels under consideration, the detection of human observers seems to be limited by the spatial noise (phosphor granularity); the temporal noise plays a role only at low luminance levels.