Definitions and Analysis of The Contrast of The E-book Reader

In order to evaluate the display quality of E-book reader reasonably,The different definitions of the contrast for three commonly used light source D65,D50 and A were discussed: the contrast of the spectral behavior of is defined as reflectance contrast Cρ,which only related to the measurement of the material itself;The contrast of reflectance contrast of the materials and receiving characteristics of human eyes is defined as Cv(visual contrast) which related to the measurement of both the reflective material and the receiving characteristics of the human eyes;the brightness contrast is defined as CL measuring spectral behavior of the material itself and the receiving characteristics of the human eyes,while measuring the spectral characteristics of luminous efficiency.Through the testing analysis of chosen E-book reader products for experiments,the correlations between different contrasts could be assessed.The experimental results show that under the commonly used light source,the CL and Cv are applicable to assess the relative contrast,taking the light source and the human eye's spectral luminous efficiency characteristics into account,while the CL is more adaptive and applicable to assess the absolute contrast.