• Journal of Information Display
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• 제11권2호
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• pp.39-44
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• 2010

The time dependences of the luminance properties of 55-inch CCFL and LED backlights and 32-inch FFL backlights with LCD panels were investigated during the warm-up time from the cold start. The long-term luminance maintenance curve of a standard CCFL was examined in a time window up to 5000 hours. These two time dependences are important characteristics from the viewpoint of initial picture quality and lifetime reliability, respectively. Empirical equations were suggested for the analysis of the time dependence of these luminance data. These approaches are expected to be helpful in predicting the luminance properties of backlights based on the luminance data obtained in a limited time window.

• Journal of Information Display
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• 제12권4호
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• pp.167-171
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• 2011

The angular distribution of the luminance on each optical component of 40-inch light-emitting diode backlight was measured and studied, using the optical-simulation method. Several scattering functions were investigated as the reflection distribution function of the scattering dots printed on the bottom surface of the light guide plate (LGP). It was found that both the diffuse Lambertian and near-specular Gaussian scattering functions were necessary for the successful reproduction of the experimental angular distribution of the luminance. The optimization of the scattering parameters included in these scattering functions led to almost the same luminance distribution as that obtained from the experiment. This approach may be an effective way of indirectly estimating the reflection distribution function of the scattering dots of the LGP, which cannot be made accessible through any other experimental method.