In one method, the permeabilities are obtained by correcting the geometric factor derived from combining the FRA analysis and buildup analysis. The light source is provided adjacent to the light guide plate. The thermomelting plastic material is identical to or compatible with a plastic material of the plastic batch to which the packaging and the additive are to be added. The first power voltage supply unit applies a voltage of the first power in response to the first and second driving signals. A set of polarizers is disposed above and below the liquid crystal display panel.