Optical characteristic evaluation method and optical characteristic evaluation system

An optical characteristic evaluation system which evaluates unevenness of an optical characteristic in an optical film based on analysis of a polarized state of light transmitting through an optical film as an evaluation target and an analyzer, the optical characteristic evaluation system comprising:

• a hardware processor which is configured to,
• measure a phase difference and an orientation angle in the optical film in a plurality of positions;
• and
• quantify and evaluate the unevenness of the optical characteristic based on a parameter of a vector of output light calculated by the following formula 1 using a vector showing a polarized state of input light and a matrix showing a polarizing characteristic of at least the optical film and the analyzer,
• wherein,
• F2=M×F1, formula 1:
• F1:
• Stokes vector of input light
• F2:
• Stokes vector of output light
• M:
• Mueller matrix of the optical film as the evaluation target and the analyzer,
• wherein the unevenness of the optical characteristic is evaluated based on the analysis of the polarized state of the light transmitting the optical film through at least the following steps (1) to (8), wherein,
• step (1):
• selecting a plurality of measured regions in a predetermined square area in the optical film as the evaluation target and measuring the phase difference and the orientation angle for each pixel in a predetermined size included in the measured region,
• step (2):
• showing and setting the polarized state of the input light with a Stokes vector,
• step (3):
• setting the Mueller matrix of the analyzer,
• step (4):
• setting the Mueller matrix of the optical film for each pixel,
• step (5):
• calculating the Stokes vector of the output light using the above formula for each pixel,
• step (6):
• showing a parameter regarding an optical intensity in the Stokes vector of the output light for each pixel with gradation in a predetermined number of bits,
• step (7):
• setting a threshold in the gradation representation and showing by binarization,
• step (8):
• making an index of display irregularity using a result shown by binarization.