Device for testing optical properties and method for testing optical properties

Abstract

The present application relates to a device for testing optical properties and a method for testing optical properties using the same. The device of the present application has inexpensive manufacturing and maintenance costs, is capable of testing a wide range of plane directional phase differences, and provides the method for testing optical properties with improved identification efficiency of the phase retardation axis.

Claims

1. A device for testing optical properties of a quarter-wave film comprising a light source that emits non-polarized light, a lower polarizer, a first quarter-wave film, a second quarter-wave film, an upper polarizer and a color detecting part in sequence; wherein, the optical property to be tested is a phase retardation axis of the second quarter-wave film, the method comprises: a step of fixing a phase retardation axis of said first quarter-wave film and an absorption axis of the lower polarizer so as to form an angle of 45 degree or 135 degree, wherein said second quarter-wave film has a plane directional phase difference known as the same value as that of said first quarter-wave film; and a step of rotating said second quarter-wave film horizontally and determining that when the color of the light excluding wavelength of light corresponding to four times the plane directional phase difference of said second quarter-wave film is detected in said color detecting part, the phase retardation axis of said second quarter-wave film is parallel to the phase retardation axis of said first quarter-wave film.

2. The device according to claim 1, wherein said light source emits said un-polarized light to said lower polarizer side.

3. The device according to claim 1, wherein said lower polarizer and upper polarizer are disposed so that their absorption axes are parallel to each other.

4. The device according to claim 1, wherein said first quarter-wave film or second quarter-wave film has a plane directional phase difference of 90 nm to 200 nm.

5. The device according to claim 1, wherein said first quarter-wave film or second quarter-wave film has the same plane directional phase difference to each other.

6. The device according to claim 1, wherein color of a light transmitting said upper polarizer is detected by said color detecting part to test the optical property of the quarter-wave film.

7. The device according to claim 6, wherein the device evaluates the optical property when the color of the light excluding wavelength of light corresponding to four times a plane directional phase difference of said first quarter-wave film or second quarter-wave film is detected by said color detecting part.

8. The device according to claim 1, wherein the optical property to be tested through said device is a phase retardation axis of the second quarter-wave film having a plane directional phase difference of a known value.

9. The device according to claim 8, wherein the phase retardation axis of said second quarter-wave film is tested by horizontally rotating said second quarter-wave film in a state fixed such that an absorption axis of the lower polarizer and a phase retardation axis of the first quarter-wave film form an angle of 45 or 135.

10. The device according to claim 9, wherein when color of a light excluding wavelength of light corresponding to four times the plane directional phase difference of said second quarter-wave film is detected in said color detecting part, it is determined that the phase retardation axis of said second quarter-wave film is parallel to the phase retardation axis of the first quarter-wave film.

11. The device according to claim 1, wherein a plane directional phase difference and a phase retardation axis of said first quarter-wave film have known values.

12. The device according to claim 1, wherein the optical property to be tested through said device is plane directional phase differences of the first quarter-wave film and the second quarter-wave film each having a phase retardation axis of a known value.

13. The device according to claim 12, wherein said plane directional phase difference is tested in a state disposed such that the phase retardation axes of said first quarter-wave film and said second quarter-wave film are fixed parallel to each other and said phase retardation axes form an angle of 45 or 135 with an absorption axis of the lower polarizer or the upper polarizer.

14. The device according to claim 13, wherein a wavelength value corresponding to times the wavelength of light excluded from the wavelength of light detected in said color detecting part is determined as plane directional phase differences of the first quarter-wave film and the second quarter-wave film.

15. A method for testing optical properties comprising: a step of sequentially forming a light source that emits un-polarized light, a lower polarizer, a first quarter-wave film, a second quarter-wave film, an upper polarizer and a color detecting part, and emitting un-polarized light from said light source to said lower polarizer side to transmit said upper polarizer; and a step of detecting color of light transmitting said upper polarizer in the color detecting part and testing the optical properties of the quarter-wave film; wherein, the optical property to be tested is a phase retardation axis of the second quarter-wave film, the method comprises: a step of fixing a phase retardation axis of said first quarter-wave film and an absorption axis of the lower polarizer so as to form an angle of 45 degree or 135 degree, wherein said second quarter-wave film has a plane directional phase difference known as the same value as that of said first quarter-wave film; and a step of rotating said second quarter-wave film horizontally and determining that when the color of the light excluding wavelength of light corresponding to four times the plane directional phase difference of said second quarter-wave film is detected in said color detecting part, the phase retardation axis of said second quarter-wave film is parallel to the phase retardation axis of said first quarter-wave film.

16. The method for testing according to claim 15, wherein the optical property to be tested is plane directional phase differences of the first quarter-wave film and the second quarter-wave film, the method comprises: a step of fixing phase retardation axes of said first quarter-wave film and said second quarter-wave film to be parallel to each other, wherein said first quarter-wave film and said second quarter-wave film each has a phase retardation axis of a known value, and disposing said phase retardation axes so as to form an angle of 45 or 135 with an absorption axis of the lower polarizer or the upper polarizer; and a step of determining a wavelength value corresponding to times wavelength of light excluded from a light detected in said color detecting part as plane directional phase differences of the first quarter-wave film and the second quarter-wave film.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIGS. 1 and 2 are views showing exemplary device for testing optical properties.

MODE FOR INVENTION

(2) Hereinafter, the present application will be described in more detail by way of examples according to the present application and comparative examples not complying with the present application, but the scope of the present application is not limited by the following examples.

EXAMPLES

Manufacture of Device for Testing Optical Properties

(3) A light source (W lamp, shimadzu) emitting non-polarized light, a lower polarizer (PVA, Kuraray) having an absorption axis in one direction (shown as a first quarter-wave film (cycloolefin polymer (COP), Zeon), a second quarter-wave film (triacetylcellulose (TAC), Fuji) coated with liquid crystals (MUSK), an upper polarizer (PVA, Kuraray) in which an absorption axis is parallel to the lower polarizer and a color detecting part (Detector CA 210, Konica Minolta) were disposed sequentially to manufacture a device for testing optical properties.

Phase Retardation Axis Test

(4) Samples 1, 2 and 3, in which plane directional phase differences and phase retardation axes were known, were prepared as the first quarter-wave film. The plane directional phase differences of Samples 1, 2, and 3 were 90 nm, 125 nm, or 200 nm, respectively, and the phase retardation axes of Samples 1, 2, and 3 were disposed to form 45 with the absorption axis of the lower polarizer.

(5) Samples 4, 5 and 6, in which only the plane directional phase difference values were known and phase retardation axes were unknown, were prepared as the second quarter-wave film. The plane direction phase differences of Samples 4, 5 and 6 are 90 nm, 125 nm or 200 nm, respectively.

(6) Subsequently, Sample 1 was disposed on the lower polarizer and fixed, and then Sample 4 was disposed between Sample 1 and the upper polarizer in an unattached state. Next, while rotating Sample 4 at a speed of 0.1 m/s, un-polarized light was emitted from the light source to sequentially transmit the lower polarizer, Sample 1, Sample 4 and the upper polarizer. When the color of the light detected in the color detecting part was detected as the color except for the wavelength of light corresponding to four times the plane directional phase differences of Sample 1 and Sample 4, it was determined that the phase retardation axis of Sample 4 is parallel to the phase retardation axis of Sample 1.

(7) The phase retardation axis of Sample 4 was evaluated by testing the angle formed by the phase retardation axis of Sample 4 with the lower polarizer or the upper polarizer, and the results were shown in Table 1 below.

(8) The phase retardation axis test was performed using Samples 2 and 5 instead of Samples 1 and 4 and the phase retardation axis test was also performed using Samples 3 and 6 instead of Samples 1 and 4, and the results were shown in Table 1 below.

(9) TABLE-US-00001 TABLE 1 Sample Sample Sample 1 2 3 Plane directional phase difference of 90 125 200 the first quarter-wave film (nm) Angle formed by the absorption axis of 45 the lower polarizer or the upper polarizer with the phase retardation axis of the first quarter-wave film () Sample Sample Sample 4 5 6 Plane directional phase difference of 90 125 200 the second quarter-wave film (nm) Color detected in the color detecting part yellow magenta Cyan Angle formed by the absorption axis of 45 the lower polarizer or the upper polarizer with the phase retardation axis of the second quarter-wave film ()

(10) As shown in Table 1, by confirming that when a color excluding the wavelength region of light corresponding to four times the plane directional phase difference of the first quarter-wave film or the second quarter-wave film is detected in the color detecting part, the phase retardation axes of the first quarter-wave film and the second quarter-wave film are parallel and the angle formed by the absorption axis of the lower polarizer or the upper polarizer with the phase retardation axis of the second quarter-wave film is 45, the phase retardation axis of the second quarter-wave film can be easily tested at low cost without precise test as well.

Plane Directional Phase Difference Test

(11) Samples 7, 8 and 9, in which plane directional phase differences were unknown and only the phase retardation axes were known, were prepared as the first quarter-wave film. Samples 10, 11 and 12, which were the same as Samples 7, 8 and 9, were prepared as the second quarter-wave film. The phase retardation axes of Samples 7, 8, 9, 10, 11 and 12 were disposed to form 45 with the absorption axis of the lower polarizer. Although the plane directional phase differences of the first quarter-wave film and the second quarter-wave film have been unknown, Sample 7 and Sample 10 have the same plane directional phase difference value, Sample 8 and Sample 11 have the same plane directional phase difference value, and Sample 9 and Sample 12 have the same plane directional phase difference value.

(12) Next, in a state where the phase retardation axes of Sample 7 and Sample 10 were fixed to be parallel to each other, Sample 7 and Sample 10 were disposed between the lower polarizer and the upper polarizer in an unattached state, and un-polarized light was emitted from the light source to transmit the lower polarizer, Sample 7, Sample 10 and the upper polarizer sequentially. The wavelength corresponding to times the wavelength of the light excluded from the wavelength of the light detected in the color detecting part was determined as the plane direction phase difference of Sample 7 or Sample 10, evaluated and the results were shown in Table 2 below.

(13) The plane directional phase difference test was performed using Samples 8 and 11 instead of Samples 7 and 10 and the plane directional phase difference test was also performed using Samples 9 and 12 instead of Samples 7 and 10, and the results were shown in Table 2 below.

(14) TABLE-US-00002 TABLE 2 Sample Sample Sample 7 8 9 Angle formed by the phase retardation axis 45 of the first quarter-wave film with the absorption axis of the lower polarizer () Sample Sample Sample 10 11 12 Angle formed by the phase retardation axis 45 of the second quarter-wave film with the absorption axis of the lower polarizer () Color detected in the color detecting part yellow magenta Cyan Plane directional phase difference of the 90 125 200 first quarter-wave film or the second quarter-wave film (nm)

(15) As shown in Table 2, it can be confirmed that when the phase retardation axis of the first quarter-wave film or the second quarter-wave film forms 45 with the absorption axis of the lower polarizer or the upper polarizer, in the case that the color detected in the color detecting part is yellow, the plane directional phase difference of the first quarter-wave film or the second quarter-wave film is 90 nm; in the case that the color detected in the color detecting part is magenta, the plane directional phase difference of the first quarter-wave film or the second quarter-wave film is 125 nm; and in the case that the color detected in the color detecting part is cyan, the plane directional phase difference of the first quarter-wave film or the second quarter-wave film is 200 nm, and thus it is possible to test a wide range of plane directional phase differences of the first quarter-wave film or the second quarter-wave film through the device for testing optical properties.

COMPARATIVE EXAMPLES

Manufacture of Device for Testing Optical Properties

(16) A second quarter-wave film (triacetylcellulose (TAC), Fuji) was disposed in an equipment (Axoscan, Axometrics) composed of a polarized light source generating part continuously generating a polarized light source from right circularly polarized light to left circularly polarized light and a testing part to manufacture a device for testing optical properties.

Phase Retardation Axis Test and Plane Directional Phase Difference Test

(17) Samples 13, 14 and 15, in which the plane directional phase differences and phase retardation axes were unknown, were prepared as the second quarter-wave film.

(18) Next, Sample 13 was disposed between the polarized light source generating part and the testing part so that the direction in which the polarized light source passed and the plane direction of Sample 13 were perpendicular to each other, and then the polarized light source emitted from the polarized light source generating part passed through Sample 13, which was intended to test the phase retardation axis and the plane directional phase difference, and was continuously emitted from the testing part, where it was tested how much the phases of the continuously emitted polarized light sources were retarded with respect to the axis of a certain direction, and the results were shown in Table 3 below.

(19) The phase retardation axis test and the plane directional phase difference test were performed using Sample 14 instead of Sample 13 and the phase retardation axis test and the plane directional phase difference test were also performed using Sample 15 instead of Sample 13, and the results were shown in Table 3 below.

(20) TABLE-US-00003 TABLE 3 Sample Sample Sample 13 14 15 Angle formed by the phase retardation axis 45 45 135 of the second quarter-wave film with the direction in which the polarized light source generated from the polarized light source generating part passes () Plane directional phase difference of the 125 125 127 second quarter-wave film (nm)

(21) As shown in Table 3, by measuring the phase retardation axes and the plane directional phase differences of the second quarter-wave film using the equipment composed of the polarizing light source generating part continuously generating the polarized light source from the right circularly polarized light to the left circularly polarized light, and the testing part, the expensive device manufacturing and maintenance costs have been consumed.

(22) Also, in the case of using the device for testing optical properties of the above comparative example, it may be troublesome to perform calibration by using a standard sample (a sample in which an optical axis is fixed between two sheets of glass) to know an optical axis at a specific wavelength in advance, and in the absence of the standard sample, there may be a problem that the optical property of the second quarter-wave film cannot be measured.

EXPLANATION OF REFERENCE NUMERALS

(23) 101: lower polarizer

(24) 102: upper polarizer

(25) 103: first quarter-wave film

(26) 104: second quarter-wave film

(27) 105: light source

(28) 106: color detecting part

(29) R: red

(30) G: green

(31) B: blue

(32) C: cyan

(33) M: magenta

(34) Y: yellow