JP2014055866A - Diffusion haze value measuring method and measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide diffusion haze measuring method and measuring device in which a value representing a ratio of diffusion transmission light at an arbitrary angle in all light ray transmitted light is determined as a diffusion haze value, a diffusion haze value of a specimen can be measured, and a distribution of the diffusion transmission light for each angle can be examined.SOLUTION: Light beams from a light source are made into a parallel luminous flux to be radiated on a specimen, and an optical receiver is moved around an intersection of a radiation plane of the radiated luminous flux and an optical axis so that it takes an arbitrary angle with respect to the optical axis, whereby diffusion transmission light for each angle is measured.

Description

  The present invention relates to a diffusion haze value measuring method and measuring apparatus, and more particularly to a diffusion haze value measuring method and measuring apparatus capable of obtaining the ratio of diffuse transmitted light at an arbitrary angle with respect to the total light transmitted through a transparent substance.

  One of the apparatuses for measuring diffused transmission light of transparent materials such as transparent plastics is defined by JIS K 7136 and JIS K 7361.

  Conventionally, as a method for measuring the haze value (cloudiness value) of a transparent substance, an integrating sphere device is used to measure the total light transmittance and diffuse transmittance for each wavelength of the transparent body, and “(diffuse transmittance / total There is a scattered light measurement method for obtaining a haze value for each wavelength based on the formula of “light transmittance” × 100 ”. (Patent Document 1)

  In addition, during the measurement process, a haze standard plate to which the haze value and the true value of the total light transmittance are assigned is measured, a correction coefficient for the total light transmittance and the diffuse transmittance is obtained, and the haze used for the calculation of the sample measurement. There are value measuring methods and devices. (Patent Document 2)

JP 2002-310902 A Japanese Patent No. 3341212

  Conventionally, in the measurement of the haze value, there has been nothing to obtain by directly measuring diffuse transmitted light for each angle. Further, in the measurement, the diffuse transmission light is also obtained by removing the parallel light transmission light from the total light transmission light transmitted through the sample. The conventional haze value represents the ratio of diffusely transmitted light in the total light transmitted light.

  Incidentally, in recent years, the directivity of light after passing through a sample has become one of the important factors in evaluating the diffusivity and uniformity of a backlight diffusion plate of a liquid crystal display. However, as described above, conventionally, there is no method and apparatus for measuring haze values based on the directivity of light, and it is impossible to measure the angular characteristics of diffusely transmitted light and to measure the angular dependence of light irradiation on a sample. It was.

  In order to solve the above-mentioned problem, the present invention has a conventional haze value representing a ratio of diffusely transmitted light in all light transmitted light, but at an arbitrary angle in all light transmitted light. Diffusion haze value measurement method and measurement capable of measuring the diffusion haze value of a sample and determining the distribution of the diffuse transmitted light for each angle of the sample, with the value representing the ratio of diffuse transmitted light as the diffusion haze value The object is to realize the device.

  In order to achieve the above object, the diffusion haze value measuring method of the present invention irradiates a sample with light from a light source as a parallel light beam, and emits a light beam that has passed through the sample and an optical axis. The diffused transmitted light at each angle is measured by moving the light receiver so as to take an arbitrary angle with respect to the optical axis, centering on the intersection. Thereby, it is possible to investigate the distribution of diffuse transmitted light for each angle of the sample.

  In a further embodiment of the method for measuring the diffusion haze value, the sample is arbitrarily rotated about the optical axis.

  In a further embodiment of the diffusion haze value measuring method, a diaphragm equipped with a linear interference filter is used.

  In a further embodiment of the diffusion haze value measuring method, a wavelength selective filter is used.

  In a further embodiment of the diffusion haze value measuring method, the light receiver is arbitrarily moved in the contact / separation direction with respect to the intersection.

  In a further embodiment of the diffusion haze value measuring method, a light beam size variable means and a light receiving area variable means are used.

  In a further embodiment of the method for measuring the diffusion haze value, the sample is inclined perpendicularly to the optical axis or at an arbitrary angle.

  The diffusion haze value measuring apparatus of the present invention is characterized in that the diffusion haze value of the sample is measured by the above-described diffusion haze value measurement method. Thereby, it is possible to investigate the distribution of diffuse transmitted light for each angle of the sample.

  With the diffusion haze value measuring method and measuring apparatus of the present invention, a value representing the ratio of diffuse transmitted light at an arbitrary angle in all light transmitted light is defined as a diffusion haze value, and the diffusion haze value of the sample is measured. The distribution of diffuse transmitted light for each angle can be examined.

Also, by using a diaphragm equipped with a linear interference filter, it is possible to continuously read the diffuse haze value for each wavelength, and by measuring the diffuse haze value at an arbitrary wavelength, diffuse transmission depending on the wavelength The situation can also be measured for samples with different light distributions.

  Alternatively, the diffusion haze value can be obtained by using a wavelength selection filter instead of the linear interference filter at an arbitrary wavelength.

FIG. 1 is a plan configuration diagram of the diffusion haze value measuring apparatus according to the first embodiment. FIG. 2 is a plan configuration diagram of the diffusion haze value measuring apparatus according to the second embodiment. FIG. 3 is a plan configuration diagram of a diffusion haze value measuring apparatus using a linear interference filter in the third embodiment. FIG. 4 is a plan configuration diagram of a diffusion haze value measuring apparatus using a wavelength selection filter in the third embodiment. FIG. 5 is a diagram showing the distribution of the diffused transmission light of the sample for each angle, which diffuses evenly with 450 nm light and collects and diffuses with 600 nm light in Example 3. (A) is a figure which shows distribution for every angle of 450-nm uniform diffused transmitted light. (B) is a figure which shows distribution for every angle of 600-nm condensing diffuse transmission light. FIG. 6 is a diagram in which the distribution of the diffuse transmission light of the sample measured with light of 450 nm and 600 nm in Example 3 for each angle is combined. FIG. 7 is a diagram illustrating a method for calculating a standard haze value from the distribution of diffuse transmitted light in the third embodiment. FIG. 8 is a plan configuration diagram of the diffusion haze value measuring apparatus according to the fourth embodiment. FIG. 9 is a plan configuration diagram of the diffusion haze value measuring apparatus according to the fifth embodiment. FIG. 10 is a plan configuration diagram of the diffusion haze value measuring apparatus according to the sixth embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a diffusion haze value measuring apparatus for realizing the diffusion haze value measuring method of the present invention. The diffuse haze value measuring apparatus 1 includes a light source 2, a condenser lens 3, a diaphragm 4, a collimator lens 5, an iris diaphragm 6, and a light receiving unit 7. The light receiving unit 7 includes a light receiver 8 and an angle variable means 9.

  The light from the light source 2 is converted into a parallel light beam by the condenser lens 3, the diaphragm 4 and the collimator lens 5, and is narrowed by the iris diaphragm 6 so that the cross section of the parallel light beam has an arbitrary diameter. The light beam L focused by the iris diaphragm 6 passes through the sample 11 and is received by the light receiving element 10 of the light receiver 8. In this example, the sample 11 formed in a plate shape with a transparent material was used. However, the sample 11 is not limited to the plate shape, and an unmolded sample or a cell can be used to obtain liquid or It is also possible to measure a granular sample.

  The angle varying means 9 allows the light receiver 8 to move to an arbitrary angle θ around the intersection 14 between the light beam emitting surface 12 through which the light beam L passes through the sample 11 and the light is emitted and the optical axis 13. . The angle θ is an angle formed by a straight line connecting the intersection 14 to the center of the light receiving surface of the light receiving element 10 and the optical axis 13. The angle varying means 9 is movable on the inner peripheral surface 16 while being held by the hemispherical holding body 15 arranged around the intersection 14 and the inner peripheral surface 16 of the holding body 15 which is equidistant from the intersection 14. It is comprised with the moving tool 17. FIG. That is, the light receiving element 10 of the light receiver 8 moves so as to be equidistant r with respect to the intersection 14. The diffuser light transmitted through the sample 11 is measured three-dimensionally by moving the light receiver 8 to an arbitrary angle θ by the moving tool 17.

  As described above, the diffuse haze value measuring apparatus 1 has a conventional haze value representing the ratio of diffuse transmitted light in the total light transmitted light, whereas the diffuse haze value is an arbitrary value in the total light transmitted light. A value representing the ratio of diffusely transmitted light at the angle can be obtained. Thereby, the diffusion haze value measuring apparatus 1 can realize a measuring apparatus capable of evaluating a transparent substance having direction dependency like a backlight diffusion plate of a liquid crystal display in more detail.

  FIG. 2 shows a second embodiment. The light receiving portion 7a of the diffusion haze value measuring apparatus 1 is held by a semicircular holding body 15a and an inner peripheral surface 16a of the holding body 15a that is equidistant from the intersection point 14, and is movable on the inner peripheral surface 16a. The angle variable means 9a comprised by these is provided. That is, the light receiving element 10 of the light receiving unit 7 moves so as to be equidistant r with respect to the intersection 14. In the angle variable means 9a of the light receiving portion 7a, the movement of the light receiver 8 by the moving tool 17 is set on a semicircle, and the sample rotating means 18 is provided so that the sample 11 can be arbitrarily rotated around the optical axis. The diffusely transmitted light transmitted through the sample 11 is measured three-dimensionally by a combination of the movement of the light receiver 8 and the rotation of the sample 11. Alternatively, it is also possible to measure the diffusely transmitted light transmitted through the sample 11 two-dimensionally by fixing the sample 11 and moving the light receiver 8 from 0 ° to 90 ° or from 0 ° to −90 °.

  3 and 4 show the third embodiment. A linear interference filter 19 is disposed on the diaphragm 4 of the diffuse haze value measuring apparatus 1 shown in the first embodiment (FIG. 3), or the wavelength between the collimator lens 5 and the iris diaphragm 6 of the diffuse haze value measuring apparatus 1 is set. By disposing the selection filter 20 (FIG. 4), it is possible to measure a diffusion haze value of an arbitrary wavelength. In the present embodiment, the position of the wavelength selection filter 20 is the position of FIG. 4, but is not limited to this position, and can be installed at an arbitrary position on the optical path. When the linear interference filter 19 is arranged as shown in FIG. 3, the diffusion haze value for each continuous or intermittent wavelength is measured by changing the transmittance of the wavelength of light from the light source by the linear interference filter 19. be able to. Further, by arranging the wavelength selection filter 20 as shown in FIG. 4, by selectively measuring the wavelength, for example, 450 nm light is evenly diffused (FIG. 5A), but 600 nm light is condensed. It is possible to measure the distribution (FIG. 6) of the diffusely transmitted light of each sample 11 having different diffusion angle characteristics depending on the wavelength, such as diffusion (FIG. 5B). As a result, it is possible to measure the situation of the sample whose diffusion angular characteristics are different depending on the wavelength.

  Note that the diffusion haze value measuring apparatus 1 uses a filter whose light receiving sensitivity satisfies the visual sensitivity Vλ (Y) as the wavelength selection filter 20, and measures diffuse transmitted light and parallel transmitted light as shown in FIG. Thus, the conventional haze value can be calculated.

  FIG. 8 shows a fourth embodiment. The light receiving unit 7b of the diffusion haze value measuring apparatus 1 according to the fourth embodiment includes a distance variable unit 21 that can move the light receiver 8 in the contact / separation direction with respect to the intersection 14. The distance variable means 21 includes a support portion 22 installed on the moving tool 17 of the angle variable means 9 and an adjustment portion 23. The light receiver 8 is attached to the adjustment portion 23, and the light receiver 8 is connected to the intersection 14 by the adjustment portion 23. It is possible to move in the contact and separation direction. The diffuse haze value measuring apparatus 1 moves the light receiver 8 in the contact / separation direction by the distance varying means 21 with respect to the intersection point 14, and measures the diffusely transmitted light transmitted through the sample 11 by the light receiver 8.

  The light after passing through the sample 11 may become weak depending on the measurement position at the light receiver 8, and there is a problem that accuracy is deteriorated because the amount of received light is small. Therefore, in the diffusion haze value measuring apparatus 1 according to the fourth embodiment, the light receiver 8 can be moved in the contact / separation direction with respect to the sample 11 by the distance varying means 21. 8 can be brought closer to the sample 11 side, and the measurement accuracy can be improved.

  FIG. 9 shows the fifth embodiment. The diffusion haze value measuring apparatus 1 according to the fifth embodiment includes a light beam dimension varying unit 24 that can change a light beam diameter, which is a cross-sectional dimension of a light beam incident on the sample 11, to an arbitrary size, and a front surface of the light receiving element 10. , And a light receiving area variable means 25 that can change a region where the light receiving element 10 is irradiated with light. The light beam dimension changing means 24 is a frame-like opening / closing adjustment mechanism 27 arranged on the surface 26 side where light enters the sample 11 and an opening / closing tool capable of opening / closing the opening 28 formed in the opening / closing adjustment mechanism 27 to an arbitrary size. 29, and the beam diameter can be changed by adjusting the opening size of the opening 28 by opening / closing the opening / closing tool 29. Further, the light receiving area variable means 25 includes an adjusting mechanism 30 disposed on the front surface of the light receiving element 10 and an opening / closing tool 32 capable of opening and closing an opening 31 formed in the adjusting mechanism 30 to an arbitrary size. Corresponding to the change of the beam diameter by the means 24, the area where the light hits the light receiving element 10 can be changed. The diffusion haze value measuring apparatus 1 changes the diameter of the light beam incident on the sample 11 by the light beam size varying means 24 and measures the diffuse transmitted light that has passed through the sample 11 by the light receiver 8.

  In the conventional haze value measurement, since the size of the light beam diameter with respect to the opening diameter of the integrating sphere is defined, there is no degree of freedom to change the diameter of the light beam incident on the sample 11. The diffusion haze value measuring apparatus 1 according to the fifth embodiment can measure by changing the beam diameter according to the size of the sample 11 and can also measure a small sample. Further, by changing the beam diameter, the diameter of the parallel-line transmitted light after passing through the sample also changes at the same time, but this is dealt with by changing the area where the light receiving element 10 is irradiated by the light receiving area variable means 25.

  FIG. 10 shows a sixth embodiment. The diffusion haze value measuring apparatus 1 according to the sixth embodiment includes sample angle changing means 33 that can change the sample 11 to an arbitrary angle φ with respect to the optical axis 13. The sample angle changing means 33 includes a partially spherical annular frame 34 disposed so as to surround the outer periphery of the sample 11, and an inner peripheral surface 35 centered on the optical axis 13 held by the inner peripheral surface 35 of the frame 34. The movable tool 36 is movable on the top, the outer periphery of the sample 11 is attached to the movable tool 36, and the angle φ of the sample 11 can be arbitrarily changed by the movable tool 36. In the diffuse haze value measuring apparatus 1, the sample 11 is tilted at an angle φ with respect to the optical axis 13 by the sample angle changing means 33, and the diffuse transmitted light transmitted through the sample 11 is measured by the light receiver 8.

  Since the diffuser haze value measuring apparatus 1 of the sixth embodiment measures diffused transmitted light by moving the light receiver 8 without using an integrating sphere, it is not possible with the existing integrating sphere haze measuring method. The haze value due to incidence can be measured. In the measurement method of the diffusion haze value measuring apparatus 1, the measurement can be performed by making the sample 11 orthogonal to the optical axis 13 or by inclining the arrangement of the sample 11.

  The diffusion haze value measuring apparatus of the present invention can be applied to the evaluation of a transparent material having direction dependency of radiated light such as a backlight diffusion plate.

DESCRIPTION OF SYMBOLS 1 Diffuse haze value measuring apparatus 2 Light source 3 Condensing lens 4 Aperture 5 Collimator lens 6 Iris diaphragm 7, 7a, 7b Light receiving part 8 Light receiver 9, 9a Angle variable means 10 Light receiving element 11 Sample 12 Light flux emitting surface 13 Optical axis 14 Intersection DESCRIPTION OF SYMBOLS 15, 15a Holding body 16, 16a Inner peripheral surface 17 Moving tool 18 Sample rotation means 19 Linear interference filter 20 Wavelength selection filter 21 Distance variable means 22 Support part 23 Adjustment part 24 Light beam dimension variable means 25 Light-receiving area variable means 26 Light incidence 27 Opening / closing adjustment mechanism 28 Opening portion 29 Opening / closing tool 30 Adjustment mechanism 31 Opening portion 32 Opening / closing tool 33 Sample angle changing means 34 Frame body 35 Inner peripheral surface 36 Moving tool

Claims (8)

  The sample is irradiated with light from a light source as a parallel light beam, and the light receiver is emitted at an arbitrary angle with respect to the optical axis around the intersection of the light beam emission surface from which the light beam transmitted through the sample is emitted and the optical axis. The diffuse haze value measuring method is characterized in that the diffused transmitted light at each angle is measured by moving the light beam so as to take an angle.   2. The diffusion haze value measuring method according to claim 1, wherein the sample is arbitrarily rotated around the optical axis.   The diffusion haze value measuring method according to claim 1 or 2, wherein a diaphragm equipped with a linear interference filter is used.   3. The diffusion haze value measuring method according to claim 1, wherein a wavelength selection filter is used.   The method for measuring a diffusion haze value according to any one of claims 1 to 4, wherein the light receiver is arbitrarily moved in a contact / separation direction with respect to the intersection.   6. The diffusion haze value measuring method according to any one of claims 1 to 5, wherein a light beam dimension varying unit and a light receiving area varying unit are used.   The diffusion haze value measuring method according to any one of claims 1 to 6, wherein the sample is inclined perpendicularly to the optical axis or at an arbitrary angle.   A diffusion haze value measuring apparatus that realizes the diffusion haze value measuring method according to claim 1.

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