JP2013053919A - Haze value measuring apparatus and haze value measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To find a haze value without detecting transmitted light.SOLUTION: A haze value measuring apparatus includes: a light source 31 for emitting measurement light; an irradiation optical system 33 for emitting parallel light flux obtained by collimating the measurement light emitted from the light source 31 to a measurement sample 1; a detection optical system 40 for detecting the light quantity of reflected light reflected from the measurement sample 1 irradiated with the measurement light emitted from the irradiation optical system 33; and arithmetic means 71 for calculating a haze value of the measurement sample 1 on the basis of a regular reflection optical component and a diffuse reflection optical component included in the reflected light detected by the detection optical system 40.

Description

  The present invention relates to a haze value measuring apparatus and a haze value measuring method for measuring a haze value of a measurement sample made of a translucent material.

Conventionally, a haze value is known as an index value indicating the degree of cloudiness of a translucent material such as glass or optical crystal. This haze value is defined by the following mathematical formula (1) in JIS Z7105. The greater the cloudiness of the translucent material, the greater the scattering inside the material when the test piece is irradiated with parallel light, and the diffuse transmitted light with respect to the parallel transmitted light (regularly transmitted light) transmitted through the test piece. As a result, the haze value increases.

  The method for measuring the haze value is defined in JIS K7105 and JIS K7136. In measuring the haze value, a measuring device 100 using an integrating sphere as shown in FIG. 5 is used (for example, Patent Documents 1 and 2).

  As shown in FIG. 5, the conventional haze value measuring apparatus 100 includes a light source 131, an irradiation optical system 133 that emits light emitted from the light source 131 into parallel light and emits the light toward the measurement sample 101, and the measurement sample 101. The integrating sphere 140 into which the transmitted light that has passed through is introduced, and a photodetector 153 that detects the transmitted light introduced into the integrating sphere 140. There are two types of transmitted light that are transmitted through the measurement sample 101 and introduced into the integrating sphere 140: regular transmitted light and diffuse transmitted light. In this haze value measuring apparatus 100, it is possible to switch the one arranged in the optical path of the regular transmitted light in the integrating sphere 140 to either the standard white plate 141 or the light trap 142. When the plate 141 is disposed, the total light transmitted light amount can be detected by the light detector 153, and when the light trap 142 is disposed, the diffuse transmitted light amount can be detected by the light detector 153. The above-described haze value is calculated from the total light transmitted light amount and the diffuse transmitted light amount detected using the haze value measuring apparatus 100.

JP 2001-356092 A JP 2007-57534 A

  By the way, since the conventionally proposed method for measuring the haze value is to detect the transmitted light obtained by irradiating the measurement sample 101 with the measurement light and measure the haze value, the light source 131 and the irradiation optical system 133 are used. Therefore, the measurement sample 101 must be arranged between the integrating sphere 140 and the photodetector 153. For this reason, in the conventional method for measuring the haze value, various parts such as the light source 131, the photodetector 153, the integrating sphere 140, and the like must be arranged on both sides of the measurement sample 101. In addition, the degree of freedom of the layout of the measuring apparatus 100 is limited.

  Accordingly, the present invention has been devised in view of the above-described problems, and the object of the present invention is to provide a haze value measuring apparatus and a haze that can determine a haze value without detecting transmitted light. It is to provide a value measuring method.

  In order to solve the above-described problems, the present inventor has invented the following haze value measuring apparatus and haze value measuring method after intensive studies.

  A haze value measuring apparatus according to a first invention is a haze value measuring apparatus for measuring a haze value of a measurement sample made of a translucent material. A light source that emits measurement light, and a measurement light emitted from the light source. An irradiation optical system that emits a parallel light beam toward the measurement sample, and a detection optical system that detects the amount of reflected light from the measurement sample by the measurement light emitted from the irradiation optical system and outputs a signal; And an arithmetic means for calculating a haze value of the measurement sample based on a regular reflection light component and a diffuse reflection light component included in an output signal from the detection optical system.

  According to a second aspect of the present invention, in the first aspect of the invention, the calculation means calculates the diffuse transmittance and parallel light transmittance of the measurement sample based on the specular reflection light component and the diffuse reflection light component. The haze value of the measurement sample is calculated based on the calculated diffuse transmittance and parallel light transmittance.

  In the haze value measuring apparatus according to a third aspect of the present invention, in the first aspect or the second aspect, the detection optical system condenses the diffuse reflected light from the measurement sample by the measurement light emitted from the irradiation optical system. , A condenser that allows the specularly reflected light from the measurement sample to pass through, a first photodetector that detects the amount of diffusely reflected light collected by the condenser, and a specular reflection that has passed through the condenser It has the 2nd photodetector which detects the light quantity of light, It is characterized by the above-mentioned.

  In a haze value measuring apparatus according to a fourth invention, in the first invention or the second invention, the detection optical system collects diffusely reflected light from the measurement sample by measurement light emitted from the irradiation optical system. A condenser that allows the specularly reflected light from the measurement sample to pass through; a photodetector that detects the light collected by the condenser; and the specularly reflected light that has passed through the condenser. And a shutter that opens and closes an optical path leading to the condenser in the regular reflection light optical system.

  The haze value measuring apparatus according to a fifth aspect of the present invention is the haze value measuring apparatus according to the third or fourth aspect of the invention, wherein the concentrator causes the measurement light emitted from the irradiation optical system to be incident on the inside and the specular reflection from the measurement sample. An integrating sphere having an entrance / exit opening for emitting light to the outside and a sample opening for guiding the measurement light incident inside from the entrance / exit opening to the measurement sample is provided.

  According to a sixth aspect of the present invention, in the fifth aspect of the invention, the concentrator further includes a collimating lens disposed so as to close the sample opening of the integrating sphere, and the irradiation optical system includes the The measurement light is emitted toward the collimating lens so that the measurement light is emitted as a parallel light beam by the collimating lens toward the measurement sample disposed outside the integrating sphere.

  A haze value measurement method according to a seventh invention is a haze value measurement method for measuring a haze value of a measurement sample made of a translucent material, in which a measurement light having a parallel luminous flux is emitted toward the measurement sample, A signal is output by detecting the amount of reflected light from the measurement sample by the emitted measurement light, and the haze of the measurement sample is based on the diffuse reflected light component and the regular reflected light component included in the output signal output. A value is calculated.

  The haze value measurement method according to an eighth invention is the sixth invention, wherein the diffuse transmittance and parallel light transmittance of the measurement sample are calculated based on the specular reflection light component and the diffuse reflection light component, and the calculated diffusion The haze value of the measurement sample is calculated based on the transmittance and the parallel light transmittance.

  According to 1st invention-8th invention, when measuring the haze value of a measurement sample, it becomes possible to obtain | require a haze value from the reflected light obtained by irradiating a measurement light to a measurement sample. For this reason, in order to measure the haze value of the measurement sample, it is only necessary to arrange various components such as a light source and a light detector on one side of the measurement sample, so that the entire measurement apparatus can be reduced in size. In addition, it is possible to improve the degree of freedom of the layout of the measuring apparatus.

  In particular, according to the fourth invention, by opening and closing the shutter, it is possible to obtain each of the regular reflection light component and the diffuse reflection light component of the reflected light even when only one photodetector is used, Even in such a case, the haze value can be measured.

  Further, according to the sixth aspect of the invention, since the collimating lens disposed so as to close the sample opening of the integrating sphere as the condenser is configured to emit the parallel light beam to the measurement sample, the regular reflection from the measurement sample is performed. It becomes possible to guide diffused reflected light together with light into an integrating sphere as a condenser. Thereby, it becomes possible to measure a haze value accurately, without making a haze value measuring device contact a measurement sample.

It is a figure which shows typically the behavior in the interface between translucent material and external space, and the inside of translucent material about the incident light which injects into the surface of translucent material. It is a figure which shows typically the behavior of the non-scattering light which repeats regular reflection in the inside of a translucent material, when incident light is entered inside the translucent material. It is a schematic diagram which shows the outline | summary of the haze value measuring apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows the outline | summary of the haze value measuring apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows the outline | summary of the conventional measuring apparatus of a haze value.

  Hereinafter, embodiments for carrying out a haze value measuring apparatus and a haze value measuring method to which the present invention is applied will be described in detail with reference to the drawings.

  First, the basic concept of the present invention will be described.

  In the present invention, when determining the haze value of a translucent material to be measured, the measurement sample is irradiated with light rather than detecting the transmitted light from the measurement sample obtained by irradiating the measurement sample with light. The reflected light from the measurement sample obtained in this way is detected, and the haze value is calculated based on the detection result.

  In the first place, in order to obtain the haze value of the translucent material, as shown in the above formula (1), the diffuse transmittance and the parallel light transmittance when the translucent material to be measured is irradiated with light are calculated. Need to ask. Conventionally, in order to obtain the diffuse transmittance and the parallel light transmittance, the detected value of the light amount of the transmitted light from the measurement sample is used. On the other hand, in this invention, in order to obtain | require the diffuse transmittance and parallel light transmittance of this measurement sample, it is supposed that the detected value of the light quantity about the reflected light from a measurement sample is used. And in this invention, in order to calculate a transmitted light component from the reflected light component calculated | required as the detected value, and to obtain a haze value from the calculation result, it is assumed that a new physical model as described below is used. Yes.

  Consider how the incident light incident on the surface of the translucent material behaves at the interface between the translucent material and the external space or inside the translucent material. As shown in FIG. 1, a part of the incident light incident on the surface 1a of the translucent material 1 is specularly reflected on the surface 1a of the translucent material 1 and is emitted to the outside as reflected light. It penetrates into the inside of the optical material 1. The light that has entered the inside of the translucent material 1 is affected by scattering by the scatterers in the translucent material 1 and light absorption in the translucent material, and the surface of the translucent material 1. While repeating regular reflection on 1a and the back surface 1b, a part is emitted as reflected light from the front surface 1a of the translucent material 1 and the rest is emitted as transmitted light from the back surface 1b of the translucent material 1 to the outside. . In the following description, it is assumed that the effect of light absorption in the translucent material 1 is sufficiently small to be negligible and there is no light absorption in the external space.

  As the reflected light, when the incident light is incident on the surface 1a of the translucent material 1, the surface regular reflected light that is specularly reflected on the surface 1a, and the translucency after the regular reflection in the translucent material 1 are repeated. Backside specularly reflected light emitted outward from the surface 1a of the material 1 and diffusely reflected light emitted outwardly from the surface 1a of the translucent material 1 after being scattered due to the influence of scatterers in the translucent material 1 There is. Hereinafter, the front surface regular reflection light and the back surface regular reflection light are collectively referred to as regular reflection light.

  Further, as the transmitted light, regular transmitted light that is emitted outside from the back surface 1 b of the light transmissive material 1 without being scattered in the light transmissive material 1, and light transmitted after being scattered in the light transmissive material 1. And diffused and transmitted light emitted from the back surface 1b of the conductive material 1 to the outside.

Here, with respect to the scattered light scattered by the influence of the scatterer in the translucent material 1, the scattered light scattered from the front surface 1a to the back surface 1b of the translucent material 1 is used as the forward scattered light, and the translucent property is obtained. the scattered light scattered towards the surface 1a of the material 1 of the rear surface 1b as backscattered light, light scattering index for each of the incident light (%) S _front, and S _back, the amount of incident light when the I ₀ The scattered light rate S _all of the total scattered light scattered by the scatterer in the translucent material 1 is expressed by the following formula (11). As described above, the influence of light absorption in the translucent material 1 is negligible.
I ₀ × S _all = I ₀ × S _front + I ₀ × S _back (11)

Here, the ratio of the light amount of the regular transmitted light to the light amount of the incident light (hereinafter referred to as parallel light transmittance) when it is assumed that there is no scattering in the light transmissive material 1 is T _{spe (S = 0)} , and the incident light. The ratio of the amount of specularly reflected light to the amount of light (hereinafter referred to as regular reflectance) is R _{spe (S = 0)} , the parallel light transmittance of the translucent material 1 with scattering is T _spe , and the regular reflectance is Let R _spe . Then, the total value of I ₀ × (T _{spe (S = 0)} + R _{spe (S = 0)} ) is scattered inside the translucent material 1 after incident light enters the translucent material 1. Represents the total amount of non-scattered light emitted outside, that is, the amount of incident light, and the total value of I ₀ × (T _spe + R _spe ) is _calculated from the amount of incident light. This represents the total amount of non-scattered light after the amount of all scattered light has been lost due to internal scattering, and these relationships are expressed by the following equation (12).
I ₀ × (T _{spe (S = 0)} + R _{spe (S = 0)} ) −I ₀ × (T _spe + R _spe ) = I ₀ × S _all (12)

Here, assuming that the amount of incident light I ₀ is 1, T _{spe (S = 0)} + R _{spe (S = 0)} in the above equation (12) is represented by 1, and (T _spe + R _spe ) is (T _spe + R _spe ) / (T _{spe (S = 0)} + R _{spe (S = 0)} ). Further, since the values of T _{spe (S = 0)} and T _spe are small enough to be ignored with respect to the value of S _all , (T _spe + R _spe ) / (T _{spe (S = 0)} + R _{spe (S = 0)} ) can be expressed as R _spe / R _{spe (S = 0)} . Then, the above-mentioned formula (12) is expressed by the following formula (2).

  Next, when the incident light incident perpendicularly to the surface 1 a of the translucent material 1 repeats regular reflection inside the translucent material 1, the non-transmission in the translucent material 1 is not detected. Consider the behavior of scattered light. In the following, for this non-scattered light, the light that travels from the front surface 1a side to the back surface 1b side of the translucent material 1 is referred to as front non-scattered light, and the light that travels from the back surface 1b side to the front surface 1a side This will be described as scattered light.

The _value of I ₀ × (T _{spe (S = 0)} −T _spe ) in the above equation (12) affects the second decimal place of the haze value (%) that is the limit resolution of the conventional haze value measuring apparatus 100. Since it is a numerical value that affects the value, it can be ignored. Then, the following equation (13) is approximately derived by combining the above equation (11) and equation (12).
S _front = R _{spe (S = 0)} −R _spe −S _back (13)

Further, the following equation (14) is derived by combining some of the terms on both sides of the above equation (12) and combining the above equation (11).
T _spe = T _{spe (S = 0)} + R _{spe (S = 0)} -R _spe -S _back -S _front (14)

Then, the following equation (3) is derived from the above equations (13) and (14).
T _spe = T _{spe (S = 0)} (3)

Next, a method for approximately _calculating R _{spe (S = 0)} and T _{spe (S = 0)} included in the above-described equations (2) and (3) will be described.

  FIG. 2 is a diagram schematically illustrating the behavior of non-scattered light that repeats regular reflection inside the translucent material 1 when incident light enters the translucent material 1. 2 shows a state in which incident light is incident from a direction inclined with respect to the surface 1a of the translucent material 1 for ease of explanation. It is assumed that incident light is incident from a direction orthogonal to the surface 1a.

The non-scattering light L _{f1 traveling} straight in the translucent material 1 after the incident light is incident is non-scattering light L _f1 , and the non-scattering light L _f1 is non-scattering straight after the back surface 1 b of the translucent material 1 is regularly reflected. The scattered light is referred to as non-scattered light L _b1 , and the non-scattered light L _b1 that travels straight after the regular reflection of the surface 1a of the translucent material 1 is referred to as non-scattered light L _f2 . In the following, when n is a natural number of 1 or more, the non-scattered light L _fn is the non-scattered light L that travels straight through the light-transmissive material 1 after the regular reflection of the back surface 1b of the light-transmissive material 1. and _bn, the unscattered light L _bn is the surface 1a of the translucent material 1 regularly reflected by straight translucent material 1 after the non-scattered light non-scattering light L _{f (n + 1).} Further, the light that the non-scattered light L _fn has passed through the back surface 1b of the translucent material 1 without specular reflection is referred to as transmitted light T _n , and the non-scattered light L _bn is specularly reflected on the surface 1a of the translucent material 1. the light that has passed without the reflected light R _n. Further, the scattered light generated when the non-scattered light L _fn is scattered is S _(2n−1), and the scattered light generated when the non-scattered light L _bn is scattered is the scattered light S _2n .

In this model, when the thickness of the translucent material 1 is d (mm), it is assumed that the scatterer 1c is at the center position d / 2 of the translucent material 1 in the thickness direction. It is assumed that scattering in the translucent material 1 is generated by the body 1c. Further, it is assumed that the amount of incident light I ₀ is 1.

The amount of the non-scattered light L _f1 immediately after the non-scattered light L _f1 enters the inside from the surface 1a of the translucent material 1 is L _f1a , immediately before the light passes through the translucent material 1 and enters the scatterer 1c. unscattered light quantity of L _f1b of L _f1, light amount L _f1c of unscattered light L _f1 immediately after it enters the scatterer 1c passes through the scatterer 1c, scatterers 1c of a translucent material 1 of the back surface 1b of The amount of the non-scattered light L _f1 just before passing through and reflecting and transmitting the back surface 1b is L _f1d, and the reflectance of the translucent material 1 is R (%). Then, the light quantity L _f1a is expressed by the following equation (21). The light quantity L _f1b is expressed by the following equation (22) from Lambert-Beer's law. Further, the light quantity L _f1c is expressed by the following equation (23) when the scattered light rate is S (−). The light quantity L _f1d is expressed by the following equation (24) from Lambert-Beer's law.

Α is an absorption coefficient (m ⁻¹ ) of the light-transmitting material. When the extinction coefficient of the light-transmitting material is κ (−) and the wavelength of incident light is λ (m), the following formula ( 51).

Next, the amount of the non-scattered light L _b1 immediately after the non-scattered light L _f1 is specularly reflected by the back surface 1 _b of the light-transmissive material 1 is L _b1a , and the non-scattered light L _b1 is transmitted through the light-transmissive material 1. light amount L _b1b of unscattered light L _b1 immediately before entering the scatterer 1c, and amount of non-scattered light L _b1 immediately after it enters the scatterer 1c passes through the scatterer 1c L _B1c, from scatterers 1c Te _Let L _b1d be the amount of non-scattered light L _b1 immediately before passing through the surface 1a of the translucent material 1 and reflecting and transmitting the surface 1a. Then, the light quantity L _b1a is expressed by the following equation (25). The light quantity L _b1b is expressed by the following equation (26) from Lambert-Beer's law. The light quantity L _b1c is expressed by the following equation (27). The light quantity L _b1d is expressed by the following equation (28) from Lambert-Beer's law.

Further, when the light quantity of the non-scattered light L _f2 immediately after the non-scattered light L _b1 is specularly reflected by the surface 1a of the translucent material 1 is L _f2a , the light quantity L _f2a is expressed by the following equation (29). .

Further, when the amount of the reflected light R _n and Rq _n, amount Rq ₁ of the reflected light R ₁ is represented by the following equation (30). Further, Rq ₂ of the reflected light R _2, Rq ₃ of the reflected light R ₃ has the formula (31) below, respectively represented by (32). The light _amounts L _b2d , L _f3a , L _b3d , and L _f4a in the equations (31) and (32) are obtained by the same procedure as that for expressing the equations (21) to (28), and the light _amounts L _{f2a to} L _f2d and the light _amounts. L _{b2a to} L _b2d , light _amounts L _{f3a to} L _f3d , light _amounts L _{b3a to} L _b3d , and light amount L _f4a are obtained.

From these equations (30) - (32), the light quantity Rq _n of the reflected light R _n is the first term and Rq _1, a common ratio (1-S) equal to ^{2 × R 2 × e -2 α} d It can be considered as the nth term in the ratio sequence.

Here, the first term a _1, geometric series of geometric progression a _n of geometric ratio r, when -1 <r <1, is known to be represented by the formula (40) below.

Then, the sum of the light amounts Rq ₁ , Rq ₂ ,..., Rq _n ,..., Rq∞ of the reflected light R _n , that is, the light amount R back surface of the back regular reflection light is obtained by the following equation (41). Will be.

Further, since the reflected light of incident light, that is, the light amount R surface of the front regular reflection light is represented by R, the total value of the front reflection light and the back reflection light, that is, the regular reflection light amount R _spe is Is represented by the following equation (42).

Further, when the amount of transmitted light T _n and Tq _n, amount Tq ₁ of the transmitted light T ₁ is expressed by the following equation (33). Amount Tq _2, light amount Tq ₃ of the transmitted light T ₃ of the transmitted light T ₂ are, the following equation (34), respectively represented by (35).

From these equations (33) - (35), the light amount Tq _n of the transmitted light T _n is the first term and Tq _1, a common ratio (1-S) equal to ^{2 × R 2 × e -2 α} d It can be considered as the nth term in the ratio sequence. Then, the sum of the light amounts Tq ₁ , Tq ₂ ,..., Tq _n ,..., Tq∞ of the transmitted light T _n , that is, the light amount T _spe of the regular transmitted light is expressed by the following equation (43). Will be.

From the above, the above equation (2) is expressed by the following equation (4) when R _{spe (S = 0)} is obtained from the above equation (42).

Further, the above equation (3) is expressed by the following equation (5) when T _{spe (S = 0)} is obtained from the above equation (43).

Here, the specular reflection components of the front scattered light S _front and the back scattered light S _{back on} the _front surface 1a and the back surface 1b of the light transmissive material 1 are about R times the light intensity of each of the forward scattered light and the back scattered light. Become. Here, since the reflectance R of the measurement sample 1 that is the measurement target of the haze value is smaller than about 10%, the specular reflection components of the front scattered light _Sfront and the backscattered light _Sback affect the measurement of the haze value. There is no size. Therefore, if these specular reflection components can be ignored, S _front represents the ratio of the amount of diffuse transmitted light to the amount of incident light (hereinafter referred to as diffuse transmittance), and S _back represents the amount of incident light. This represents the ratio of the amount of diffusely reflected light (hereinafter referred to as diffuse reflectance).

Then, in formulas (4) and (5), assuming that the reflectance R, thickness d, and absorption coefficient α of the translucent material 1 are known, the regular reflectance R _spe of the translucent material 1 and the diffuse reflection If the rate S _back is known, it is possible to calculate the parallel light transmittance T _spe and the diffuse transmittance S _front from the above equations (4) and (5). Since the regular reflectance R _spe and the diffuse reflectance S _back can be obtained from the detected value of the light amount of the regular reflection light and the diffuse reflection light of the translucent material 1 as will be described later, the light amount of the reflected light. _Is detected, the parallel light transmittance T _spe and the diffuse transmittance S _front are calculated, and the haze value can be calculated from the above-described equation (1) based on the calculation result.

  Next, an embodiment of a haze value measuring apparatus and a haze value measuring method according to the present invention will be described.

  The measurement sample 1 to which the present invention is applied is made of a translucent material having translucency such as glass or optical crystal. The measurement sample 1 is a material having translucency in the visible range. Although the shape of the measurement sample 1 is not particularly limited, for example, the measurement sample 1 is a plate shape, a belt shape, a film shape, or the like.

  As shown in FIG. 3, the haze value measuring device 3 according to the first embodiment emits the measurement light emitted from the light source 31 and the measurement light emitted from the light source 31 toward the measurement sample 1 as a parallel light flux. Irradiation optical system 33, detection optical system 40 that detects the amount of reflected light from the measurement light emitted from the irradiation optical system 33 to the measurement sample 1, and arithmetic means that performs arithmetic processing based on an output signal from the detection optical system 40 As a data analysis device 71.

  As the light source 31, for example, a white light source such as a halogen lamp, or a laser light source such as a laser diode is used. As the light source 31, a light source having a continuous spectrum in the visible range is used. In the first embodiment, a white light source is used as the light source 31, and white light is emitted as measurement light.

  In the first embodiment, the irradiation optical system 33 is disposed in the optical path of the collimating lens 35 that emits the measurement light emitted from the light source 31 as a parallel light flux, and the measurement light emitted as the parallel light flux from the collimating lens 35. And a beam splitter 36. The measurement light emitted from the collimator lens 35 as a parallel light beam passes through the beam splitter 36 and is guided to the measurement sample 1. In the first embodiment, this measurement light is guided to the measurement sample 1 through an entrance / exit opening 41a provided in an integrating sphere as a condenser 41 described later. The irradiation optical system 33 is configured to emit measurement light having substantially the same optical axis with respect to the normal direction of the surface 1 a of the measurement sample 1.

  In the first embodiment, the detection optical system 40 collects diffuse reflection light from the measurement sample 1 by the measurement light emitted from the irradiation optical system 33 and emits specular reflection light from the measurement sample 1 to the outside. The first light detector 53 that detects the amount of diffusely reflected light collected by the light collector 41, and the first light detector that detects the amount of regular reflected light emitted from the light collector 41. 2 photo detectors 63. Further, the detection optical system 40 further includes a regular reflection optical system 80 for guiding the regular reflection light emitted from the condenser 41 to the second photodetector 63 in the first embodiment.

  In the first embodiment, the concentrator 41 is illustrated as having an integrating sphere 42. However, the concentrator 41 collects the diffusely reflected light from the measurement sample 1 and sends the specularly reflected light to the outside. The specific configuration is not particularly limited as long as injection is possible.

  The integrating sphere 42 is formed into a hollow sphere, and its inner wall surface is made of a material having high reflectivity and excellent diffusibility. The inner wall surface of the integrating sphere 42 is provided, for example, by coating with a white substance typified by barium sulfate. Thus, by repeatedly reflecting the diffuse reflected light from the measurement sample 1 on the inner wall surface of the integrating sphere, it becomes possible to spatially integrate the diffuse reflected light and irradiate the entire inner wall surface as uniform light.

  In the first embodiment, the integrating sphere 42 is a measurement sample that includes an incident / exit opening 42a for allowing measurement light emitted from the irradiation optical system 33 to enter the inside, and the measurement light incident inside from the incident / exit opening 42a. And a sample opening 42 b for leading to 1. In addition, the integrating sphere 42 is provided with a detection opening 42 c for guiding the diffuse reflected light repeatedly reflected on the inner wall surface of the integrating sphere 42 to the first photodetector 53. The specularly reflected light from the measurement sample 1 is emitted from the entrance / exit opening 42a. In the first embodiment, the measurement sample 1 is provided so as to block the sample opening 42b with the surface 1a. The measurement sample 1 is fixed to the sample opening 42b by a sample holder (not shown).

  An incident end of an optical fiber 46 is connected to the detection opening 42 c, and an output end of the optical fiber 46 is connected to the first spectroscopic analyzer 50. The light beam guided from the detection opening 42c to the first spectroscopic analysis device 50 through the optical fiber 46 is split by the first spectroscope 51 provided in the first spectroscopic analysis device 50 and then the first spectroscopic analysis. A spectral spectrum which is a light amount for each wavelength spectrally separated by the first photodetector 53 provided in the apparatus 50 is detected.

  In the first embodiment, the regular reflection light optical system 80 includes a beam splitter 36 for reflecting regular reflection light emitted from the entrance / exit opening 42 a of the integrating sphere 42 as the condenser 41, and the beam splitter 36. A condensing lens 81 for condensing the reflected regular reflection light and an optical fiber 83 for guiding the light beam collected by the condensing lens 81 to the second spectroscopic analyzer 60 are provided. The light beam guided to the second spectroscopic analysis device 60 through the optical fiber 83 of the specular reflection optical system 80 is split by the second spectroscope 61 provided in the second spectroscopic analysis device 60, and then the second spectroscopic light. A spectral spectrum that is the amount of light for each wavelength dispersed by the second photodetector 63 provided in the spectroscopic analyzer 60 is detected.

  The amount of light detected by the first photodetector 53 and the second photodetector 63 is converted into an electrical signal and then output to the data analysis device 71 as spectral spectrum data such as diffuse transmitted light from the measurement sample 1. The first spectroscope 51 and the second spectroscope 61 are composed of, for example, a diffraction grating, a prism, a spectral filter, etc., and the first photo detector 53 and the second photo detector 63 are, for example, photodiodes. , Line sensors and the like.

  The data analysis device 71 is configured as a computer having a keyboard, mouse, CPU, ROM, RAM, display, printer, and the like. The data analysis device 71 functions as a device that acquires information about the haze value of the measurement sample 1 by performing data analysis on the spectral data acquired by the first spectral analysis device 50 and the second spectral analysis device 60. To do.

  Next, the haze value measuring method according to the first embodiment will be described together with the operation of the haze value measuring apparatus 1 according to the first embodiment. The following steps are performed, for example, when the data analysis device 71 executes a program stored in advance in a ROM or the like of the data analysis device 71.

First, in step S1, initial parameters necessary for executing the haze value measuring method are set. As described above, in order to calculate the transmitted light component from the detected value of the reflected light component of the measurement sample 1, in addition to the physical properties such as the reflectance R, thickness d, absorption coefficient α, etc. of the measurement sample 1, the amount of incident light I It is necessary to obtain ₀ in advance. For this reason, at least these numerical values are set as initial parameters. As the initial parameters, those stored in advance in the data analysis device 71 or those input by an operator operating the data analysis device 71 are used. The physical properties of the measurement sample 1 serving as initial parameters are set according to the measurement sample 1, and a known value or a value obtained through experiments is set.

An example of a method for measuring the amount of incident light I _{0 as} an initial parameter will be described. First, the sample opening 42 b of the integrating sphere 42 as the condenser 41 is closed with a standard white plate instead of the measurement sample 1. Then, the first light detector 53 detects the light amount L _sw of the diffuse reflected light when the measurement light is emitted from the light source 31 and the measurement light is emitted to the standard white plate. Since the light applied to the standard white plate is completely diffusely reflected, the detected light amount L _sw becomes the incident light amount I ₀ .

Further, when there is an optical path that reflects a light beam such as the beam splitter 36 in the optical path, such as the regular reflection optical system 80, it is necessary to consider a reduction in the amount of light due to the reflection. For this reason, the sample opening 42b of the integrating sphere 42 as the condenser 41 is closed with a mirror instead of the measurement sample 1, and the amount L _rm of the specular reflection light when the measurement light is emitted to the mirror is detected by the second light. This is detected by the device 63. Here, the sample opening 42 b is closed with the measurement sample 1, and when the measurement light is emitted to the measurement sample 1, the amount of specular reflection light detected by the second photodetector 63 is L _rs , and the specular reflection optical system is used. When the reflectance of the entire system 80 is R _all , these relationships are expressed by the following formula (61).

By arranging the above formula (61), the following formula (6) is derived. Here, if the light amount L _rm of specular reflection light when the sample opening 42b is blocked with a mirror and the reflectance M of the mirror are known, the reflectivity R _all of the specular reflection optical system 80 is determined. First, the regular reflectance R _spe is obtained from the light amount L _rs of the regular reflection light when the sample opening 42 b is closed with the measurement sample 1. For this reason, in step S1, the light quantity L _rm of specular reflection light and the mirror reflectance M when the sample opening 42b is closed with a mirror are set as initial parameters.

Next, in step S2, the surface 1a of the measurement sample 1 is disposed so as to block the sample opening 42b of the integrating sphere 42 as the condenser 41, and in this state, the measurement light is emitted from the light source 31 and irradiated. The measurement light is converted into a parallel light beam by the optical system 33 and emitted toward the measurement sample 1. The detection optical system 40 detects the amount of reflected light from the measurement sample 1 by the measurement light. In the first embodiment, the first photodetector 53 detects the amount of diffuse reflected light L _ss of the measurement sample 1 and the second photodetector 63 detects the amount of regular reflected light L _rs of the measurement sample 1. To do. The light amounts L _ss and L _rs detected by the detection optical system 40 are output to the data analysis device 71 after being converted into electric signals.

Next, in step S <b> 3, the haze value of the measurement sample 1 is calculated based on the regular reflection light component and the diffuse reflection light component included in the reflected light detected by the detection optical system 40. In the first embodiment, the light amount L _rs of specular reflection light detected by the second photodetector 63 is used as the specular reflection light component, and the light amount of diffuse reflection light detected by the first light detector 53 as the diffuse reflection light component. L _ss is used. In calculating the haze value, in the first embodiment, the regular reflectance R _spe of the measurement sample 1 is obtained by substituting the light amount L _rs of the regular reflected light into the equation (6). Further, the diffuse reflectance S _back is obtained by dividing the light quantity L _ss of the diffuse reflected light by the light quantity I ₀ of the incident light. Then, the diffuse reflectance S _front and the parallel light transmittance T _spe are obtained by substituting the obtained regular reflectance R _spe and diffuse reflectance S _back into the equations (4) and (5). Then, the haze value of the measurement sample 1 is calculated by substituting the obtained diffuse transmittance and parallel light transmittance into the formula (1).

At this time, in JIS K7136, the haze value is measured in consideration of the visibility, and therefore the haze value in consideration of the visibility is also calculated in the first embodiment. Specifically, the diffuse transmittance and the parallel light transmittance for each wavelength obtained using the equations (4) and (5) are S (λ) _front and T (λ) _spe , and the photopic standard ratio When the visibility curve is V (λ), a haze value considering the visibility is calculated based on the following formula (1) ′ as an alternative to the above formula (1).

  Next, in step S4, the haze value calculated in the previous step S3 is recorded or output by a printer or the like as necessary.

  According to the haze value measuring device 3 and the haze value measuring method according to the first embodiment described above, when measuring the haze value of the measurement sample 1, the haze is measured from the reflected light obtained by irradiating the measurement sample 1 with the measurement light. The value can be obtained. For this reason, in order to measure the haze value of the measurement sample 1, it is only necessary to arrange various components such as the light source 31 and the photodetector 53 on one side of the measurement sample 1. In addition, the degree of freedom in the layout of the measuring device 3 can be improved.

  Next, a haze value measuring apparatus according to the second embodiment will be described. In addition, about the component same as the component mentioned above, the description below is abbreviate | omitted by attaching | subjecting the same code | symbol.

  The haze value measuring device 3 according to the second embodiment is different from the haze value measuring device 3 according to the first embodiment in the configuration of the irradiation optical system 33, the condenser 41, the position of the measurement sample 1, and the detection optical system 40. ing.

  In the second embodiment, the irradiation optical system 33 includes an optical path between the first collimating lens 35 and the condenser 41 in addition to the collimating lens 35 (hereinafter referred to as the first collimating lens 35) and the beam splitter 36. Is further provided with a condensing lens 37.

  The condensing lens 37 is disposed so that its focal point is located in the entrance / exit opening 42 a of the integrating sphere 42. As a result, the measurement light as a parallel light beam emitted from the first collimating lens 35 is condensed on the entrance / exit opening 42a to be a focal point.

  In the second embodiment, the condenser 41 further includes a second collimating lens 43 disposed so as to close the sample opening 42 b of the integrating sphere 42. In the second embodiment, the integrating sphere 42 has a distance approximately equal to the diameter of the integrating sphere 42 from the entrance / exit opening 42a to the sample opening 42b.

  As the second collimating lens 43, a lens whose focal length substantially matches the diameter of the integrating sphere 42 is used. As a result, the measurement light collected by the condenser lens 37 with the entrance / exit light opening 42a of the integrating sphere 42 as a focal point is emitted toward the measurement sample 1 as a parallel light flux. As described above, the irradiation optical system 33 emits the measurement light toward the second collimating lens 43 so that the measurement light is emitted as a parallel light flux by the second collimating lens 43 toward the measurement sample 1. It is configured. The second collimating lens 43 is fixed by a holder (not shown).

  The measurement sample 1 is disposed outside the integrating sphere 1 in the second embodiment. For example, the measurement sample 1 is fixed by a holder (not shown), or is placed in a stationary state on a placement surface such as a horizontal surface.

  The specularly reflected light from the measurement sample 1 by the measurement light emitted from the second collimating lens 43 is guided in the reverse direction along the optical path from the condensing lens 37 of the irradiation optical system 33 to the second collimating lens 43, and the condensing lens. 37 is emitted as a parallel light flux. Further, most of the diffuse reflection light from the measurement sample 1 by the measurement light is guided into the integrating sphere 42 through the second collimating lens 43.

  In the second embodiment, in addition to the integrating sphere 42 as the condenser 41, the detection optical system 40 collects the specularly reflected light emitted from the condenser 41 through an optical path different from that of the irradiation optical system 33. The regular reflection light optical system 80 which injects | emits 41, and the shutter 85 which opens and closes the optical path to the collector 41 in the regular reflection optical system 80 is provided.

  The integrating sphere 42 as the condenser 41 is used to allow the regular reflected light emitted from the regular reflected light optical system 80 to enter inside, in addition to the entrance / exit opening 42a, the sample opening 42b, and the detection opening 42c. A specularly reflected light opening 42d is further provided.

  In the second embodiment, the regular reflection light optical system 80 further includes a plurality of mirrors 87 for reflecting the regular reflection light reflected by the beam splitter 36 in addition to the beam splitter 36. The specularly reflected light reflected from the plurality of mirrors 87 is guided into the integrating sphere 42 through the specularly reflecting light opening 42d of the integrating sphere 42 as the condenser 41.

  The shutter 85 is configured to be opened and closed by manual control or electrical control. The specularly reflected light emitted from the specularly reflected light optical system 80 enters the integrating sphere 42 as the condenser 41 by opening the shutter 85, and the condenser 41 by closing the shutter 85. Therefore, the light is not incident on the integrating sphere 42. Thus, when the shutter 85 is open, both the regular reflection light component and the diffuse reflection light component are detected as reflected light by the first light detector 53, and when the shutter 85 is closed, the light is reflected by the first light detector 53. Only diffuse reflected light components are detected as light.

  Next, the haze value measuring method according to the second embodiment will be described together with the operation of the haze value measuring apparatus 1 according to the second embodiment. In addition, the description below is abbreviate | omitted about the point which is common in the haze value measuring method which concerns on 1st Embodiment.

At the time of measuring the amount of incident light I ₀ as the initial parameter set in step S1, a standard white plate is disposed as a substitute for the measurement sample 1 at the position where the measurement sample 1 is disposed. Then, the first light detector 53 detects the light quantity L _sw of the diffuse reflected light when the standard white plate is irradiated with the measurement light. The detected light quantity L _sw of the diffuse reflected light does not include the diffuse reflected light beam reflected from the standard white plate to the outside of the second collimating lens 43, but even when the measurement light is emitted to the measurement sample 1. Is not included in the same manner, and in the second embodiment, the detected light amount is set as the amount of incident light I ₀ .

In consideration of a decrease in the amount of light due to reflection by the regular reflection light optical system 80, a mirror is disposed as an alternative to the measurement sample 1 at the position where the measurement sample 1 is disposed, as in the first embodiment. . Then, the first light detector 53 detects the light amount L _rm of the specular reflection light when the measurement light is emitted to the mirror with the shutter 85 opened. Here, the amount of light detected by the first photodetector 53 when the measurement sample 1 is arranged and the shutter 85 is opened as shown in FIG. and _rsa, in the state in which the shutter 85 is closed, the amount of light detected by the first photodetector 53 when emitting the measuring light to the measurement sample 1 and L _rsb. Then, these relationships are expressed by the following formula (71).

By arranging the above formula (71), the following formula (7) is derived. Similarly to the first embodiment, if the amount L _rm of specular reflection light when the measurement light is emitted to the mirror and the reflectance M of the mirror are set, the first light is emitted when the measurement light is emitted to the measurement sample 1. The regular reflectance R _spe is obtained from the light _amounts L _rsa and L _rsb detected by the detector 53. Accordingly, in step S1, the light quantity L _rm of specular reflection light and the mirror reflectance M when the measurement light is emitted to the mirror are set as initial parameters.

Next, in step S <b> 2, the measurement light is emitted from the light source 31, and the measurement light is emitted as a parallel light beam toward the measurement sample 1 by the irradiation optical system 33, and the first photodetector 53 of the detection optical system 40. The amount of reflected light from the measurement sample 1 by the measurement light is detected. In the second embodiment, the first light detector 53 detects the amount of reflected light L _rsa when the shutter 85 is opened and the amount of reflected light L _rsb when the shutter 85 is closed. The light amount L _rsa includes both the regular reflection light component and the diffuse reflection light component, and the light amount L _rsb includes only the diffuse reflection light component.

Next, in step S3, the light amounts L _rsb and L _rsa output from the first photodetector 53 to the data analysis device 71, that is, based on the specular reflection light component and the diffuse reflection light component included in the reflection light. Calculate the haze value. In the second embodiment, in calculating the haze value, the amount of reflected light L _rsa when the shutter 85 is opened and the amount of reflected light L _rsb when the shutter 85 is closed are _expressed by Equation (7). By substituting into, regular reflectance R _spe is obtained. Further, the diffuse reflectance S _back is obtained by dividing the light amount L _rsb when the shutter 85 is closed by the light amount I ₀ of the incident light. Then, the diffuse reflectance S _front and the parallel light transmittance T _spe are obtained by substituting the obtained regular reflectance R _spe and diffuse reflectance S _back into the equations (4) and (5). Then, the haze value of the measurement sample 1 is calculated by substituting the obtained diffuse transmittance S _front and parallel light transmittance T _spe into equation (1).

  According to the haze value measuring apparatus 3 and the haze value measuring method according to the second embodiment described above, by opening and closing the shutter 85, the specularly reflected light component of the reflected light can be obtained even when only one photodetector 53 is used. Each of the diffuse reflected light components can be obtained, and even in such a case, the haze value can be measured. Further, since the parallel light beam is emitted to the measurement sample 1 by the second collimating lens 38 disposed so as to block the sample opening 41b of the integrating sphere as the condenser 41, the regular reflection from the measurement sample 1 is performed. It becomes possible to guide diffused reflected light together with light into an integrating sphere as the condenser 41 effectively. This makes it possible to accurately measure the haze value without bringing the haze value measuring device 3 into contact with the measurement sample 1.

  As mentioned above, although the example of embodiment of this invention was demonstrated in detail, all the embodiment mentioned above showed only the example of actualization in implementing this invention, and these are the technical aspects of this invention. The range should not be construed as limiting.

  Hereinafter, the effects of the present invention will be further described with reference to examples.

  In Example 1, the haze value of the measurement sample 1 was actually measured using the haze value measuring device 3 according to the first embodiment as shown in FIG. 3 and the conventional haze value measuring device 100 as shown in FIG. It was decided to compare the haze values in each case. Hereinafter, the case where the haze value is determined using the haze value measuring device 3 according to the first embodiment is referred to as an invention example, and the case where the haze value is determined using the conventional haze value measuring device 10 is referred to as a comparative example.

As the measurement sample 1, a float glass having a plate thickness d of 2.75 (mm), an absorption coefficient α of 0.005038 (mm ⁻¹ ), and a reflectance R of 4.1270 (%) is used. Further, monochromatic light having a wavelength of 555 (nm) is emitted from the light source 31.

As a result, in the case of the invention example, a value of 0.1457% as the diffuse reflectance S _back and a value of 7.7955% as the regular reflectance R _spe are calculated, and 0.2031 as the diffuse transmittance S _front is calculated from this calculation result. %, A parallel light transmittance T _spe of 90.8019% was calculated, and from this calculation result, a haze value of 0.223% was obtained. On the other hand, in the case of the comparative example, a value of 0.25% was obtained as the haze value. As described above, even in the case of each of the invention example and the comparative example, only the value of the second decimal place is slightly different with respect to the haze value, and even when the haze value is obtained by applying the present invention, it is almost the same as the conventional one. It was confirmed that the haze value was obtained.

1 Measurement sample (translucent material)
DESCRIPTION OF SYMBOLS 1a Front surface 1b Back surface 1c Scattering body 3 Haze value measuring apparatus 31 Light source 33 Irradiation optical system 35 Collimating lens (1st collimating lens)
36 Beam splitter 37 Condensing lens 40 Detection optical system 41 Condenser 42 Integrating sphere 42a Entrance / exit opening 42b Sample opening 42c Detection opening 42d Regular reflection light opening 43 Second collimating lens 46 Optical fiber 50 First spectroscopic analysis Device 51 first spectroscope 53 first photo detector 60 second spectroscopic analysis device 61 second spectroscope 63 second photo detector 71 data analysis device 80 specular reflection optical system 81 condensing lens 83 optical fiber 85 shutter 87 mirror

Claims (8)

In a haze value measuring device for measuring a haze value of a measurement sample made of a translucent material,
A light source that emits measurement light;
An irradiation optical system that emits the measurement light emitted from the light source as a parallel luminous flux and emits the measurement light toward the measurement sample;
A detection optical system for detecting the amount of reflected light from the measurement sample by the measurement light emitted from the irradiation optical system;
A haze value measuring apparatus comprising: an arithmetic unit that calculates a haze value of the measurement sample based on a regular reflection light component and a diffuse reflection light component included in reflected light detected by the detection optical system. The calculation means calculates a diffuse transmittance and a parallel light transmittance of the measurement sample based on the specular reflection light component and the diffuse reflection light component, and the measurement based on the calculated diffuse transmittance and parallel light transmittance. The haze value measuring apparatus according to claim 1, wherein the haze value of the sample is calculated. The detection optical system condenses diffuse reflection light from the measurement sample by the measurement light emitted from the irradiation optical system, and a condenser that emits specular reflection light from the measurement sample to the outside; and A first photodetector that detects the amount of diffusely reflected light collected by the condenser, and a second photodetector that detects the amount of specularly reflected light emitted from the condenser. The haze value measuring device according to claim 1 or 2. The detection optical system condenses diffuse reflection light from the measurement sample by the measurement light emitted from the irradiation optical system, and a condenser that emits specular reflection light from the measurement sample to the outside; and A specularly reflected light optical system for emitting specularly reflected light emitted from the condenser through another optical path to the condenser, a photodetector for detecting the light collected by the condenser, and the regular reflection The haze value measuring device according to claim 1, further comprising: a shutter that opens and closes an optical path to the condenser in the optical optical system. The concentrator causes the measurement light emitted from the irradiation optical system to enter the inside, and includes an entrance / exit opening for emitting the specularly reflected light from the measurement sample to the outside, and the entrance / exit opening The haze value measuring device according to claim 3 or 4, further comprising an integrating sphere having a sample opening for guiding the measurement light incident inside to the measurement sample. The condenser further includes a collimating lens disposed so as to close the sample opening of the integrating sphere,
The irradiation optical system emits the measurement light toward the collimating lens so that the measurement light is emitted as a parallel light flux by the collimating lens toward the measurement sample disposed outside the integrating sphere. The haze value measuring apparatus according to claim 5, wherein In the haze value measurement method for measuring the haze value of a measurement sample made of a translucent material,
Injecting measurement light into a parallel light beam toward the measurement sample,
Detect the amount of reflected light from the measurement sample by the emitted measurement light,
A haze value measurement method, comprising: calculating a haze value of the measurement sample based on a diffuse reflection light component and a regular reflection light component included in the detected reflected light. The diffuse transmittance and parallel light transmittance of the measurement sample are calculated based on the regular reflection light component and the diffuse reflection light component, and the haze value of the measurement sample is calculated based on the calculated diffuse transmittance and parallel light transmittance. The haze value measuring method according to claim 7, wherein the haze value is calculated.

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