OPTICAL CHARACTERISTIC EVALUATION METHOD AND OPTICAL CHARACTERISTIC EVALUATION SYSTEM

• US 20200132551A1
• Filed: 10/15/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: Konica Minolta Inc.
• Original Assignee: Konica Minolta Inc.
• Inventors: MASUDA, Osamu, HIRABAYASHI, Kazuhiko, TANAKA, Hirofumi, NAKASHIMA, Koji
• Granted Patent: US 10,883,880 B2
• Time in Patent Office: Days
• CPC Class Codes: G01J 4/04 Polarimeters using electric detection means G01J4/02 takes precedence
• CPC Class Codes: G01M 11/02 Testing optical properties
• CPC Class Codes: G01M 11/0214 Details of devices holding the object to be tested
• CPC Class Codes: G01M 11/336 by measuring polarization mode dispersion [PMD]
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/23 Bi-refringence
• CPC Class Codes: G01N 21/8422 Investigating thin films, e.g. matrix isolation method
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 5/3066 involving the reflection of light at a particular angle of incidence, e.g. Brewster's angle
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence

Abstract

An optical characteristic evaluation method evaluates unevenness of an optical characteristic in an optical film based on analysis of a polarized state of light transmitting through an optical film and an analyzer. The method includes the following, measuring a phase difference and an orientation angle in a plurality of positions; and quantifying and evaluating the unevenness of the optical characteristic based on a parameter of a vector of output light calculated by a formula 1 using a vector showing a polarized state of input light and a matrix showing a polarizing characteristic of the optical film and the analyzer. The formula 1 is as follows, formula 1: F2=M×F1, F1: Stokes vector or Jones vector of input light, F2: Stokes vector or Jones vector of output light, M: Mueller matrix or Jones matrix of the optical film as the evaluation target and the analyzer.

Claims

1. An optical characteristic evaluation method 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 method comprising:

measuring a phase difference and an orientation angle in the optical film in a plurality of positions; and

quantifying and evaluating 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 or Jones vector of input light

F2;

Stokes vector or Jones vector of output light

M;

Mueller matrix or Jones matrix of the optical film as the evaluation target and the analyzer.

2. The optical characteristic evaluation method according to claim 1, wherein the parameter of the vector of the output light is calculated by the following formula 2, wherein,

F2=f1×

f2×

F1  

 

formula 2

f1;

Mueller matrix or Jones matrix of the optical film as the evaluation target

f2;

Mueller matrix or Jones matrix of the analyzer.

3. The optical characteristic evaluation method according to claim 1, wherein the polarized state of the input light is shown with the Stokes vector and the polarizing characteristic of the optical film and the analyzer is shown with the Mueller matrix.

4. The optical characteristic evaluation method according to claim 3, 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.

5. The optical characteristic evaluation method according to claim 4, wherein calculating is performed by setting conditions to satisfy the following formula 3 when the orientation angle of the optical film is θ

1 and the transmission axis direction of the analyzer is θ

2,

wherein,

|θ

1−

θ

2|≤

10°

 

 

formula 3

θ

1≠

θ

2.

6. The optical characteristic evaluation method according to claim 4, wherein calculating is performed by setting conditions to satisfy the following formula 4 when the orientation angle of the optical film is θ

1 and the transmission axis direction of the analyzer is θ

2,

wherein,

|θ

1−

θ

2|≤

2°

 

 

formula 4

θ

1≠

θ

2.

7. 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 or Jones vector of input light

F2;

Stokes vector or Jones vector of output light

M;

Mueller matrix or Jones matrix of the optical film as the evaluation target and the analyzer.