Polarizing plates grading method

摘要

The present invention relates to a polarizing plates grading method. First, providing a polarizing plate, and choosing a first measurement range A₁ on the polarizing plate; then conducting an initial measurement of the polarizing plate by putting the polarizing plate under X₁° C. for Y₁ hours, then measure the first measurement range to obtain the maximum chromatic value Z_1max (NIT,cd/m), and the minimum chromatic value Z_1min, and then subtracting the minimum value from the maximum value to obtain the net chromatic difference value W₁, thus W₁=Z_1mas-Z_1min; subsequently, conducting the temperature change measurement on the polarizing plate by putting the polarizing plate under X₂° C. for Y₂ hours (X₂<>X₁); then conducting the recovery measurement on the polarizing plate by putting the polarizing plate under X₃° C. for Y₃ hours, then measuring first measurement range to obtain the maximum chromatic value Z_3max and the minimum chromatic value Z_3min, and by subtracting the minimum chromatic value from the maximum chromatic value to obtain the net chromatic difference value W₃, and thus W₃=Z_3max-Z_3min; and finally obtaining the polarizing plate grading index Q by dividing the value obtained from subtracting the net chromatic difference value W₁ obtained in the initial measurement step from the net chromatic difference value W₃ obtained in the recovery measurement step , by the net chromatic difference value W₁ to get Q=(W₃-W₁)/(W₁), so as to grade the polarizing plates.