JP4617436B2 - Optical property measuring method of fluorescent sample and optical property measuring apparatus using the same - Google Patents

Description

  The present invention relates to a method for measuring optical characteristics of a fluorescent sample for measuring spectral characteristics of a measurement sample accompanied by a fluorescent phenomenon, and an optical characteristic measuring apparatus using the same.

  In recent years, many papers and fibers produced have been fluorescently whitened with fluorescent whitening agents, and the whiteness (brightness) and color cannot be evaluated ignoring the influence of fluorescence. Therefore, there is a demand for improvement in colorimetry technology for the paper and fibers in consideration of the influence of fluorescence.

  In general, the visual optical characteristics of a reflected sample are relative to white, that is, illuminated and received under the same conditions of the radiated light from the reflected sample illuminated and received under a certain illumination / light reception condition. It is represented by “total spectral radiance factor (B (λ))”, which is a ratio for each wavelength λ with respect to light emitted from a perfect diffuse reflector.

By the way, although fluorescence is self-luminous, it is a light source color. However, in the above-mentioned fluorescent whitened sample, that is, a sample containing a fluorescent material (hereinafter referred to as a fluorescent sample), the fluorescence is superimposed on the reflected light and observed as an object color. . That is, since the radiated light from the fluorescent sample is given as the sum of the reflected light (reflected light component) and the fluorescent light (fluorescent component) from the fluorescent sample, the total spectral radiance factor B (λ) of the fluorescent sample is Similar to the above, the reflection spectroscopy which is the ratio of the reflected light from the fluorescent sample received and received under a certain illumination / light receiving condition and the fluorescence emitted from the completely diffuse reflector illuminated and received under the same condition. It is given as the sum of the radiance factor R (λ) and the fluorescence spectral radiance factor F (λ). This is shown by the following formula (1).
B (λ) = R (λ) + F (λ) (1)

  However, since the perfect diffuse reflector does not emit fluorescence and its reflectance does not depend on the wavelength of the illumination light, the total spectral radiance factor B (λ), the reflected spectral radiance factor, except for the proportionality constant. R (λ) and fluorescence spectral radiance factor F (λ) are expressed as a ratio of emitted light having a wavelength λ, reflected light, and fluorescence to illumination light having the same wavelength, respectively. The purpose of the color measurement is to obtain a measurement value according to visual observation. In the case of a fluorescent sample that is perceived as an object color, what should be obtained is the total spectral radiance factor B (λ), and this B (λ) From which the color value is derived.

  As illumination light for colorimetry, D65 (daylight) or A (white light source), or D50, D75, F11, C, etc. whose spectral distribution (spectral intensity) is defined by the CIE (International Commission on Illumination) Standard illumination light is used (standard illumination light D65 is usually used for fluorescent samples). The excitation / fluorescence characteristics of a fluorescent sample (fluorescent substance) illuminated by illumination light are excited by excitation light (incident light) of wavelength μ that illuminates the fluorescent sample surface with unit intensity, that is, single wavelength light having unit energy. This is described by matrix data representing the intensity of fluorescence at a wavelength λ, Bispectral Luminescent Radiance Factor F (μ, λ).

The matrix data is, for example, the three-dimensional data shown in FIG. 7, and a cross section (for example, a cross section of λ = 550 nm) along a specific fluorescence wavelength λ indicates excitation efficiency for each wavelength of excitation light that excites fluorescence of wavelength λ. The cross section along the excitation wavelength μ (for example, a cross section of μ = 450 nm) represents the spectral intensity of fluorescence excited by 450 nm illumination light. From this, it can be said that the fluorescence phenomenon is a phenomenon accompanied by wavelength conversion from the wavelength μ to the wavelength λ. Therefore, the fluorescence spectral radiance factor F (λ) of the fluorescent sample having the bispectral fluorescence radiance factor F (μ, λ) illuminated with the illumination light I having the spectral distribution I (μ) is different from the proportionality constant. Then, it is calculated | required by the following formula | equation (2).
F (λ) = ∫F (μ, λ) · I (μ) dμ / I (λ) (2)
That is, F (λ) is given by the ratio of the convolution integral of the spectral distribution I (μ) of the illumination light I and the two-spectral fluorescence radiance factor F (μ, λ) and I (λ). I (λ) is equivalent to the reflected light from the perfect diffuse reflector (surface) except for the proportionality constant. In the equations, the symbols “•”, “/”, and “∫” indicate multiplication, division, and integration, respectively (and so on).

  As the above equation (2) shows, the fluorescence spectral radiance factor F (λ) depends on the spectral distribution I (μ) of the illumination light I, so that the fluorescence spectral radiance factor F (λ) and itself The total spectral radiance factor B (λ) which is the sum of the reflected spectral radiance factor R (λ) independent of the spectral distribution I (μ) of the illumination light I also depends on the spectral distribution I (μ). That is, the total spectral radiance factor B (λ) measured and the color value derived therefrom differ depending on the difference in illumination light with respect to the fluorescent sample.

  Therefore, in the evaluation of the optical characteristics of the fluorescent sample, the spectral distribution of the illumination light (hereinafter, the illumination light used for evaluating the optical characteristics such as F (λ) and B (λ) is referred to as evaluation illumination light) is specified. In actual measurement, it is necessary to match the spectral distribution of the illumination light of the measuring device with this specific illumination light for evaluation. However, it is very difficult to match the specific evaluation illumination light, that is, to realize illumination light having the same spectral distribution as the standard illumination light (D65, C, etc.) generally used as the evaluation illumination light. It is.

Therefore, as another method, a two-spectral fluorescence radiance factor F (μ, λ) or a two-spectral radiance factor B (μ, λ) is obtained, and this F (μ, λ) or B (μ, λ) From the numerical distribution I (λ) of the evaluation illumination light given numerically, the fluorescent spectral radiance factor F (λ) or the total spectral radiance factor B (λ) is numerically calculated using the above equation (2). There is a way to ask. However, this bispectral radiance factor B (μ, λ) is similar to the above-mentioned two-spectral fluorescent radiance factor F (μ, λ). Matrix data representing the intensity of the total radiated light having the wavelength λ given as the sum of the fluorescence and reflected light, and the total spectral radiance factor B (λ) is illuminated as shown in the following equation (2-1) It is given by the ratio between the convolution integral of the spectral distribution I (μ) of the light I and the two spectral radiance factor B (μ, λ) and I (λ).
B (λ) = ∫B (μ, λ) · I (μ) dμ / I (λ) (2-1)

  However, the measurement of the two-spectral fluorescence radiance factor F (μ, λ) and the two-spectrum radiance factor B (μ, λ) is provided with both the illumination and the light-receiving system, two spectroscopy means, which takes a large amount of measurement time. It is not practical because it requires a measuring instrument (double monochromator). For example, the following two simple methods are mainly used for quality control of fluorescent whitening paper as a representative fluorescent sample. .

<Measurement method of Gaertner-Grisser>
For example, as shown in the optical characteristic measuring apparatus 600 of FIG. 9, a fluorescent sample 601 is disposed in the sample opening 603 of the integrating sphere 602. A light beam 605 from a light source 604 having a sufficient intensity in the ultraviolet region (UV region) such as a xenon lamp enters the integrating sphere 602 through the light source opening. An ultraviolet cut filter 606 is inserted into the light beam 605 for a predetermined length. Since the ultraviolet component is removed from the portion of the light beam 605 that has passed through the ultraviolet cut filter 606, the intensity of the ultraviolet region (excitation region) relative to the visible region of the illumination light can be adjusted by adjusting the degree of insertion of the ultraviolet cut filter 606. The relative ratio (relative ultraviolet intensity) is adjusted. The luminous flux that has passed through the ultraviolet cut filter 606 and the luminous flux that has not passed through are each diffused and reflected by reflection inside the integrating sphere 602 and are combined to diffusely illuminate the fluorescent sample 601. Then, a component (radiated light component 607) of the sample radiated light from the fluorescent sample 601 obtained by illumination with the synthesized illumination light is incident on the radiated light spectroscopic unit 608, and the radiated light component A spectral distribution Sx (λ) of 607 is measured. On the other hand, a light beam 609 having substantially the same spectral distribution as that of the illumination light is incident on the reference optical fiber 610, further enters the illumination light spectroscopic unit 611 through the reference optical fiber 610, and the spectral distribution Mx ( λ) is measured. Based on the measurement information of Sx (λ) and Mx (λ), the total spectral radiance factor Bx (λ) is obtained by the arithmetic control unit 612 (see, for example, FIG. 4 of Patent Document 1).

  The calibration of the relative ultraviolet intensity has excitation / fluorescence characteristics (bispectral fluorescence radiance factor) similar to the fluorescence sample 601, and the color value (for example, CIE whiteness WI) when illuminated with illumination light for evaluation is used. Using a known fluorescence reference sample, the fluorescence reference sample is disposed in the sample opening 603, the total spectral radiance factor B (λ) is measured, and calculated from the total spectral radiance factor B (λ). This is done by adjusting the degree of insertion of the ultraviolet cut filter 606 so that the obtained whiteness WI matches the known whiteness WIs.

  However, the Gaertner-Grisser method is not only mechanically complicated and has a problem in reliability, but also the adjustment of the insertion degree of the ultraviolet cut filter 606 until the whiteness WI matches the known whiteness WIs. Complicated calibration work that repeats measurement is required. Since the degree of freedom is “1”, two or more color values such as whiteness WI and chromaticity Tint are calibrated simultaneously, or the total spectral radiance factor B (λ) itself is known. In principle, it is impossible to perform calibration that matches the total spectral radiance factor Bs (λ) when illuminated with light.

<Method of Patent Document 1>
In the Gaertner-Grisser measurement method, the illumination light is synthesized in accordance with the degree of insertion of the ultraviolet cut filter 606, and as a result, the total spectral radiance factor B (λ) is synthesized. Is the same as the Gaertner-Grisser measurement method and has a degree of freedom of "1", but first, numerically synthesizes the total spectral radiance factor B (λ), and synthesizes the illumination light that gives it as a result. It differs in that it does. More specifically, for example, as shown in an optical characteristic measuring apparatus 700 in FIG. 10, a first illumination unit 704 that outputs a light beam 703 having ultraviolet intensity and a light beam 705 having no ultraviolet intensity are output to an integrating sphere 702. A second illuminating unit 706, a radiated light spectroscopic unit 709 for measuring the spectral distribution of radiated light (radiated light component 708) from the fluorescent sample 701 disposed in the sample opening 707, and a luminous flux 710 of the illuminating light at that time An illumination light spectroscopic unit 712 that measures a spectral distribution via an optical fiber 711 and a calculation control unit 713 are provided. The fluorescent sample 701 is illuminated by the first and second illumination units 704 and 706, and the spectral distributions Sx1 (λ) and Sx2 (λ) of the emitted light from the sample and the spectral distribution Mx1 of the illumination light at that time (Λ) and Mx2 (λ) are measured, and the first and second illumination units 704 and 706 for the fluorescent sample 701 are measured from these Sx1 (λ) and Sx2 (λ) and Mx1 (λ) and Mx2 (λ). The total spectral radiance factors Bx1 (λ) and Bx2 (λ) are obtained. The total spectral radiance factors Bx1 (λ) and Bx2 (λ) are set in advance for each wavelength and stored as shown in the following equation (3). The combined spectral radiance factor Bxc (λ) is obtained by linear combination using a weighting factor), and this Bxc (λ) is illuminated with the evaluation illumination light. The total spectral radiance factor is 701.
Bxc (λ) = W (λ) · Bx1 (λ) + (1−W (λ)) · Bx2 (λ) (3)

  However, the weight W (λ) has an excitation / fluorescence characteristic approximate to that of the fluorescent sample 701, and the total spectral radiance factor Bs (λ) when illuminated with the evaluation illumination light is known. Is set using. That is, the weights W (λ) are the spectral radiance rates B1 (λ) and B2 (λ) measured by illuminating the fluorescence reference sample with the first and second illumination units 704 and 706 by the weights W (λ). The values of W (λ) · B1 (λ) + (1−W (λ)) · B2 (λ) obtained by linear combination are made equal to the known total spectral radiance factor Bs (λ). Are numerically obtained for each wavelength (see, for example, FIG. 1 of Patent Document 1).

This method corresponds to performing the calibration of the relative ultraviolet intensity by the above-described Gaertner-Grisser measurement method numerically for each wavelength using the total spectral radiance factor B (λ) as a parameter. Therefore, since the total spectral radiance factor B (λ) is calibrated, all the color values calculated therefrom are calibrated. In addition, it solves many of the drawbacks of the Gaertner-Grisser measurement method, such as eliminating the need for mechanically moving parts during measurement and complicated adjustment of the degree of ultraviolet cut filter insertion, but it requires a fluorescent reference sample. Since there is no change, measurement is performed on the fluorescent sample after calibration of the relative ultraviolet intensity using the fluorescent reference sample, and therefore a measurement error occurs if there is a difference in spectral distribution between illumination light at the time of calibration and measurement. Such a problem still exists.
JP-A-8-313349

  As described above, a fluorescence reference sample is required even with a simple method such as the method of Patent Document 1 or the measurement method of Gaertner-Grisser, but this fluorescence reference sample is an excitation / fluorescence approximate to the sample to be measured. Since the same fluorescent whitening agent is used with the same material as the sample such as paper and fiber because of the necessity to have characteristics, the change over time is unavoidable, and frequent renewal or management with respect to change over time is required. In addition, errors due to changes in the spectral distribution of illumination light (long-term or short-term changes) in the measurement apparatus cannot be avoided, and frequent calibration work is required to suppress the influence of the change over time. For these reasons, it is required not to use a fluorescence reference sample for the measurement, or to eliminate the need for complicated calibration work using it.

  By the way, when measuring the optical properties of fluorescent whitened paper, it is often necessary to measure the optical properties without the influence of fluorescence. Regarding the removal of the influence of this fluorescence, conventionally, the ultraviolet cut filter is used to remove the ultraviolet region of the illumination light and suppress the excitation of the fluorescence. In this case, in order to sufficiently suppress the excitation of the fluorescence, the cut-off wavelength needs to be about 440 nm, but this makes it impossible to measure the total spectral radiance factor in the short wavelength band to be evaluated, There is a problem that the accuracy of the color value calculated based on the total spectral radiance factor is lowered.

  The present invention has been made in view of the above circumstances, and eliminates the influence of fluorescence without using a filter that suppresses excitation of fluorescence, thereby generating a wavelength range in which the total spectral radiance factor cannot be measured in the visible range. It is an object of the present invention to provide a method for measuring optical properties of a fluorescent sample and an optical property measuring apparatus using the same, which can accurately obtain the total spectral radiance factor.

The method for measuring optical properties of a fluorescent sample according to claim 1 of the present invention is a method for measuring optical properties of a fluorescent sample, and has a spectral distribution different from the bispectral fluorescence radiance factor F (μ, λ) that approximates the sample. The first and second actual illumination lights I1 and I2 have spectral distributions I1 (λ) and I2 (λ), and the actual measurement totals of the samples illuminated by the first and second actual illumination lights I1 and I2, respectively. From the spectral radiance factors Bx1 (λ) and Bx2 (λ), the reflected spectral radiance factor Rx (λ) of the sample from which the influence of fluorescence has been removed is calculated in the following first and second steps. A method for measuring optical properties of a fluorescent sample.
First step: The first spectral fluorescence radiance factor F (μ, λ) and the spectral distributions I1 (λ), I2 (λ) of the first and second actual illumination lights I1, I2 And the theoretical fluorescence spectral radiance factor F1 (λ) = ∫F (μ, λ) · I1 (μ) dμ / I1 (λ) and F2 (λ) of the sample by the second actual illumination lights I1 and I2 = ∫F (μ, λ) · I2 (μ) dμ / I2 (λ) is calculated.
Second step: Rx (λ) is the reflected spectral radiance factor of the sample, and the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) are the reflected spectral radiance factor Rx (λ), F1 (λ) · K (λ) and F2 (λ) · K (λ) by multiplication of the theoretical fluorescence spectral radiance factors F1 (λ), F2 (λ) and K (λ) The reflection simultaneous radiance factor Rx (λ) is calculated by solving the following simultaneous equations. Bx1 (λ) = Rx (λ) + F1 (λ) · K (λ), Bx2 (λ) = Rx (λ) + F2 (λ) · K (λ). However, K (λ) is a constant specific to the sample indicating the ratio between the theoretical fluorescence spectral radiance factors F1 (λ) and F2 (λ) calculated as described above and the actual fluorescent spectral radiance factor of the sample.

  According to the above configuration, the spectral distributions I1 (λ) and I2 (2) of the first and second real illumination lights I1 and I2 having different spectral distributions from the bispectral fluorescence radiance factor F (μ, λ) that approximates the sample. λ) and the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample illuminated by the first and second actual illumination lights I1 and I2, respectively, Since the reflected spectral radiance factor Rx (λ) is calculated in the first and second steps, a wavelength region in which the total spectral radiance factor cannot be measured is obtained without using a filter or the like that suppresses excitation light. Without occurrence, the total spectral radiance factor from which the influence of fluorescence has been removed can be obtained with high accuracy, and a reduction in the accuracy of the color value obtained from the total spectral radiance factor can be prevented.

  An optical property measuring apparatus for a fluorescent sample according to claim 2 of the present invention is an optical characteristic measuring apparatus for a fluorescent sample, and illuminates the sample with first and second actual illumination lights I1 and I2 having different spectral distributions. First and second illuminating means, radiated light spectroscopic means for measuring the spectral distribution of the radiated light from the sample, and illuminating light for measuring the spectral distribution of the first and second actual illuminating lights I1 and I2. Spectroscopic means, storage means for storing information of a dual spectral fluorescence radiance factor F (μ, λ) approximating the sample, and the first and second illumination means are individually turned on, and the emitted light spectroscopic means And the measured total spectral radiance factor Bx1 (λ), Bx2 (λ) of the sample for each of the first and second actual illumination lights I1 and I2 based on the information obtained by the measurement by the illumination light spectroscopic means, Spectral distribution I1 of the first and second actual illumination lights I1 and I2 ( λ) and I2 (λ) are calculated, and the influence of fluorescence is removed based on the calculated information and the information of the two-spectral fluorescence radiance factor F (μ, λ) stored in the storage means. And a calculation control means for calculating a reflection spectral radiance factor Rx (λ) of the sample.

  According to the above configuration, the sample is illuminated by the first and second real illumination lights I1 and I2 having different spectral distributions by the first and second illumination means, and the spectral distribution of the radiated light from the sample is emitted by the synchrotron radiation means. Is measured, the spectral distribution of the first and second actual illumination lights I1 and I2 is measured by the illumination light spectroscopic means, and the information of the two-spectral fluorescence radiance factor F (μ, λ) that approximates the sample is obtained by the storage means. Remembered. Then, the first and second illuminating means are individually turned on by the arithmetic control means, and the first and second actual illuminations are based on information obtained by measurement by the radiated light spectroscopic means and the illuminating light spectroscopic means. The measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample for the light I1 and I2, respectively, and the spectral distributions I1 (λ) and I2 (λ) of the first and second actual illumination lights I1 and I2 And the reflected spectral radiance factor of the sample from which the influence of fluorescence has been removed based on the calculated information and the information of the two-spectral fluorescence radiance factor F (μ, λ) stored in the storage means. Since Rx (λ) is calculated, the total spectral radiance without the influence of fluorescence is eliminated without using a filter or the like that suppresses the excitation light, and therefore without generating a wavelength range in which the total spectral radiance factor cannot be measured. Rate can be determined accurately, The reduced accuracy of the color values obtained from the light emitting luminance factor can be prevented.

  The optical property measuring apparatus for a fluorescent sample according to claim 3 is the optical sample measuring apparatus according to claim 2, wherein the first and second actual illumination lights I1 and I2 exceed the measurement range of the illumination light spectroscopic means at least in a short wavelength region. It is characterized by having no intensity in the wavelength range. According to this configuration, the first and second actual illumination lights I1 and I2 are assumed to have no intensity in the wavelength range exceeding the measurement range of the illumination light spectroscopic means at least in the short wavelength range. In the calculation by the control means, the spectral intensity in the wavelength region related to the excitation and fluorescence of the first and second actual illumination light can be grasped without any omission (which is handled by the calculation process), thereby the theoretical of each illumination light. Since the fluorescence spectral radiance factor can be accurately obtained, the total spectral radiance factor from which the influence of fluorescence has been removed can be accurately obtained.

  According to the first aspect of the present invention, the spectral distribution I1 (λ) of the first and second actual illumination lights I1 and I2 having different spectral distributions from the bispectral fluorescence radiance factor F (μ, λ) that approximates the sample. ), I2 (λ) and the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the samples illuminated by the first and second actual illumination lights I1 and I2, respectively, to influence the fluorescence. Since the reflected spectral radiance factor Rx (λ) of the removed sample is calculated in the first and second steps, the total spectral radiance factor cannot be measured without using a filter or the like that suppresses excitation light. Therefore, it is possible to accurately obtain the total spectral radiance factor from which the influence of fluorescence is removed without causing a wavelength range, and it is possible to prevent a reduction in accuracy of the color value obtained from the total spectral radiance factor.

  According to the second aspect of the invention, the sample is illuminated by the first and second actual illumination lights I1 and I2 having different spectral distributions by the first and second illumination means, and the radiation from the sample is emitted by the synchrotron radiation means. The spectral distribution of the light is measured, the spectral distribution of the first and second actual illumination lights I1 and I2 is measured by the illumination light spectroscopic means, and the two-spectral fluorescence radiance factor F (μ, λ) that approximates the sample by the storage means. ) Information is stored. Then, the first and second illuminating means are individually turned on by the arithmetic control means, and the first and second actual illuminations are based on information obtained by measurement by the radiated light spectroscopic means and the illuminating light spectroscopic means. The measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample for the light I1 and I2, respectively, and the spectral distributions I1 (λ) and I2 (λ) of the first and second actual illumination lights I1 and I2 And the reflected spectral radiance factor of the sample from which the influence of fluorescence has been removed based on the calculated information and the information of the two-spectral fluorescence radiance factor F (μ, λ) stored in the storage means. Since Rx (λ) is calculated, the total spectral radiance without the influence of fluorescence is eliminated without using a filter or the like that suppresses the excitation light, and therefore without generating a wavelength range in which the total spectral radiance factor cannot be measured. Rate can be determined accurately, The reduced accuracy of the color values obtained from the light emitting luminance factor can be prevented.

  According to the third aspect of the present invention, the first and second actual illumination lights I1 and I2 have no intensity in a wavelength range exceeding the measurement range of the illumination light spectroscopic means at least in a short wavelength range. Therefore, in the calculation by the calculation control means, the spectral intensity in the wavelength region related to the excitation and fluorescence of the first and second actual illumination lights can be grasped without omission (handled by the calculation process), thereby each illumination light. Therefore, it is possible to accurately obtain the total spectral radiance factor from which the influence of fluorescence is removed.

(Description of the basic technique of the optical property measuring method according to the present invention)
First, the basic technology of the method for measuring the total spectral radiance factor of a fluorescent sample from which the influence of fluorescence according to the present invention has been removed will be described with an example of a specific apparatus.

  FIG. 2 is a schematic configuration diagram showing an example of an optical property measuring apparatus for a fluorescent sample using the basic technique. As shown in FIG. 2, the optical characteristic measurement apparatus 10 includes a sample 1 to be measured, a first illumination unit 2, a second illumination unit 3, a reference surface unit 4, a light receiving unit 5, a two-channel spectroscopic unit 6, and a control unit 7. Configured. The sample 1 to be measured is a sample to be measured which is made of a fiber or paper product containing a fluorescent material. The sample 1 to be measured is arranged at a predetermined measurement position. The first illumination unit 2 illuminates the sample 1 to be measured, and includes an incandescent lamp 21 as a light source, and a first drive circuit 22 for driving the incandescent lamp 21 to light (for example, pulse lighting). Prepare. Similar to the first illumination unit 2, the second illumination unit 3 illuminates the sample 1 to be measured, and drives the ultraviolet LED 31 as a light source (ultraviolet light source) that outputs a light beam in the ultraviolet region and the ultraviolet LED 31. And a second drive circuit 32 for lighting (for example, pulse lighting). Note that the light source of the second illumination unit 3 is not limited to the ultraviolet LED 31, and any light source such as a xenon flash lamp may be used as long as a light beam in the ultraviolet region can be output.

  The reference surface portion 4 has a reference surface (reflection surface) composed of a white diffusing surface, and is disposed in the vicinity of the measurement area of the sample 1 to be measured. The light receiving unit 5 (light receiving system) is composed of an optical lens (or a lens group), and in the radiated light of the sample 1 to be measured and the reflected light from the reference surface unit 4 illuminated by the first and second illuminating units 2 and 3. While receiving the component in the normal direction, the received light beam is incident on a two-channel spectroscopic unit 6 described later.

  The two-channel spectroscopic unit 6 performs spectroscopic measurement on the incident light from the light receiving unit 5. The two-channel spectroscopic unit 6 includes a first incident slit 61 and a second incident slit 62. Radiated light from the sample 1 to be measured illuminated by illumination light LA or illumination light LB, which will be described later, is incident on the first incident slit 61, while the reference surface portion 4 (illuminated by this illumination light LA or illumination light LB) ( The reflected light from the reference surface enters the second incident slit 62. The two-channel spectroscopic unit 6 performs spectroscopic measurement on the sample radiation incident on the first incident slit 61, outputs spectral distribution data of the sample radiation as the first channel output, and enters the second incident slit 62. The reference surface reflected light (reference light), that is, the illumination light LA or the illumination light LB described later, is subjected to spectroscopic measurement, and the spectral distribution data of the illumination light is output as the second channel output. Thus, the two-channel spectroscopic unit 6 functions as a synchrotron radiation spectroscopic unit and an illumination light spectroscopic unit.

  The control unit 7 includes a ROM (Read Only Memory) that stores each control program, a RAM (Random Access Memory) that stores data for arithmetic processing and control processing, and a CPU that reads and executes the control program from the ROM (Central processing unit) and the like, and controls the operation of the entire optical characteristic measuring apparatus 10. Specifically, drive control related to the lighting operation of the first and second illumination units 2 and 3 and the light reception / spectral operation of the two-channel spectroscopic unit 6 is performed, or based on information (spectral information) from the two-channel spectroscopic unit 6. Thus, various calculation processes relating to the calculation of the total spectral radiance factor for the sample 1 to be measured and the calibration of the relative spectral sensitivity are executed. These various calculation functions of the control unit 7 will be described in detail later.

  In the optical characteristic measuring apparatus 10 including such units, when the control unit 7 drives, that is, drives the incandescent lamp 21 via the first drive circuit 22, the incandescent lamp 21 causes the sample 1 to be measured to be measured. Illuminate with a light beam 23 (at an incident angle) from a direction of about 45 ° with respect to the normal line of the measurement sample 1. Similarly, when the control unit 7 drives the second drive circuit 32 to light the ultraviolet LED 31, the ultraviolet LED 31 directs the measured sample 1 in a direction closer to the normal line than the 45 ° (indicated by the symbol α). Illuminate with the light flux 33 from the direction of the incident angle.

  Here, in this embodiment, the 1st illumination part 2 shall be the illumination part A, and what combined the 1st illumination part 2 and the 2nd illumination part 3 shall be expressed as the illumination part B. The illumination light LA from the illumination unit A that uses only the incandescent lamp 21 (incandescent light source) as a light source has almost no intensity in the excitation region (ultraviolet region), while the illumination unit uses the incandescent lamp 21 and the ultraviolet LED 31 as light sources. The B illumination light LB, that is, the illumination light LB when the incandescent lamp 21 and the ultraviolet LED 31 are simultaneously turned on has sufficient intensity in the excitation region. The illuminators A and B both have an incandescent light source and have an intensity in the visible range, and the excitation intensity can be relativized by the intensity of each wavelength in the visible range. The luminance factor can be obtained (in the measurement using illumination light having no spectral intensity in the visible range, the above relativity calculation cannot be performed, and the fluorescence spectral radiance factor and the total spectral radiance factor cannot be obtained. ).

  Of the radiated light from the sample 1 to be measured illuminated by the illumination light LA or the illumination light LB, a component in a substantially normal direction is incident on the first incident slit 61 of the two-channel spectroscopic unit 6 by the light receiving unit 5 and spectrally separated. The measured spectral distribution Sx1 (λ) or Sx2 (λ) is output to the controller 7 as the first channel output. On the other hand, the reference surface portion 4 arranged in the vicinity of the measurement area of the sample 1 to be measured is illuminated with the illumination light LA or the illumination light LB simultaneously with the sample surface of the sample 1 to be measured. Of the reflected light from the reference surface, a component in a substantially normal direction is incident on the second incident slit 62 of the two-channel spectroscopic unit 6 by the light receiving unit 5 and spectroscopically measured, and the spectral distribution is output as the second channel output. Mx1 (λ) or Mx2 (λ) is output to the control unit 7.

  The center wavelength of the ultraviolet LED 31 in the second illumination unit 3 is about 375 nm, and as shown in the spectral distribution diagram of the incandescent light source and the ultraviolet LED in FIG. 8 (reference A is the spectral distribution of the incandescent light source, and L is the ultraviolet LED). ), The central wavelength 301 of the ultraviolet LED 31 is located in the vicinity of the peak of the spectral excitation efficiency (relative spectral excitation efficiency) 302 of a general fluorescent whitening agent. Spectral excitation efficiency refers to the excitation efficiency for each wavelength of the excitation light that excites fluorescence of wavelength λ, and the fluorescence intensity of wavelength λ excited by the illumination light (integrated excitation) by convolution with the spectral distribution of illumination light. ) Is required. In addition, the graph shown with the code | symbol 303 has shown the fluorescence spectral distribution (relative fluorescence spectral distribution) of the said fluorescent whitening agent.

  Further, since the technique of the present invention needs to grasp the spectral distribution of the illumination light, the two-channel spectroscopic unit 6 covers a wavelength range of about 360 nm to 740 nm including the wavelength range of the emitted light from the ultraviolet LED 31. (A spectrum in this wavelength range is possible). The illumination unit B using the incandescent lamp 21 and the ultraviolet LED 31 as a light source does not cause a triplet effect that becomes a problem when it illuminates a fluorescent material with a strong short pulse light (which causes a loss of compatibility with visual observation). Emits light in the flash time. The triplet effect can be roughly explained. Illumination light having a short emission time and high excitation energy causes a transition between the S (Singlet) level and the T (Triplet) level in the electronic state of the molecule. (Usually, the probability of transition between the S level and the T level is very low), and this refers to the excitation (absorption) phenomenon that occurs.

  The optical system in the optical characteristic measuring apparatus 10 has a 45/0 geometry (reflection characteristic measuring geometry 45 ° / 0 °) by combining (arranging) the first illumination unit 2 and the light receiving unit 5 as described above. Is configured. The purpose of such geometry is to control the specularly reflected light from the sample 1 to be measured, but the specularly reflected light from the second illuminating unit 3 having no distribution in the visible range does not affect the colorimetry. Therefore, the second illumination unit 3 can be arbitrarily arranged without being restricted by geometry.

  Here, the detail of each function part in the control part 7 is demonstrated. As shown in FIG. 2, the control unit 7 includes a CPU 70, a spectral data memory 71, an evaluation illumination light data memory 72, a dual spectral data memory 73, a coefficient memory 74, and the like. The CPU 70 performs calculations related to the drive control of the first and second illumination units 2 and 3 and the two-channel spectroscopic unit 6, or calculations related to calculation of the total spectral radiance factor and relative spectral sensitivity calibration for the sample 1 to be measured. It is the said central processing unit (CPU) which performs various arithmetic processing. The spectral data memory 71 stores spectral distribution data of the radiated light and the illumination light that are spectrally measured by the two-channel spectroscopic unit 6 and transmitted from the two-channel spectroscopic unit 6. The evaluation illumination light data memory 72 stores spectral distribution data of evaluation illumination light given in advance. The bispectral data memory 73 stores preliminarily obtained bispectral fluorescence radiance factor data approximate to the sample 1 (fluorescent sample) to be measured.

  The coefficient memory 74 is a sensitivity calibration coefficient for calibrating the relative spectral sensitivity of the two-channel spectroscopic unit 6, and a spectral distribution of reflected light from the reference surface unit 4 (hereinafter referred to as reference surface reflected light). Hereinafter, the conversion coefficient to be converted into the spectral distribution of the sample surface illumination light) and the spectral distribution of the radiated light from the measured sample 1 (hereinafter referred to as the sample radiated light) and the reference surface reflected light, Coefficient data such as a calibration coefficient for obtaining the total spectral radiance factor is stored.

  The control unit 7 stores the spectral distribution data of the radiated light and the illumination light, the spectral distribution data of the illumination for evaluation, the two-fluorescence spectral radiance factor data, the sensitivity calibration coefficient, the conversion coefficient, and the calibration coefficient stored in each memory unit. Based on the data, measurement control (arithmetic processing) for the following (A) is performed.

(A) Total spectral radiance factor when illuminated with evaluation illumination light <Calculation method>
Generally, in order to obtain the spectral radiance factor of the fluorescent sample when illuminated with a certain evaluation illumination light Is, the fluorescent sample has the same spectral distribution as that of the two-spectrometer measuring instrument or the evaluation illumination light Is. Although a measuring instrument with illumination light must be used, in this embodiment as well, the same fluorescence spectrum as that of the specific evaluation illumination light is used for a fluorescent sample having excitation / fluorescence characteristics approximating a specific dual spectral fluorescence radiance factor. The virtual illumination light that gives the radiance factor is numerically synthesized. That is, the spectral distribution of the evaluation illumination light Is and the numerically synthesized illumination light (hereinafter referred to as synthesized illumination light) Ic is F (μ, λ), where the bispectral fluorescence radiance factor of the fluorescent sample is F (μ, λ). Assuming that Is (λ) and Ic (λ), respectively, from the above equation (2), the fluorescence spectral radiance factor F (λ) (= ∫F (μ, λ) · I (μ) dμ / I by each illumination light. The combined illumination light Ic in which (λ)) is expressed by the following equation (5) is obtained by combining two illumination lights I1 and I2 having different spectral distributions, particularly the relative intensities of the excitation region and the fluorescence region. However, the spectral distribution I (λ) is equivalent to the reflected light from the perfect diffuse reflector (surface) except for the proportionality constant as described above.
∫F (μ, λ) · Is (μ) dμ / Is (λ) = ∫F (μ, λ) · Ic (μ) dμ / Ic (λ) (5)

In the synthesis by the weighted linear combination of the illumination lights I1 and I2, if the weight of the linear combination set for each wavelength is W (λ) and 1-W (λ), the spectral distribution Ic ( λ) is expressed by the following formula (6) using the spectral distributions I1 (λ) and I2 (λ) of the illumination lights I1 and I2.
Ic (λ) = W (λ) · I1 (λ) + (1−W (λ)) · I2 (λ) (6)

Thereby, the fluorescence spectral radiance factor Fc (λ) by the synthetic illumination light Ic is expressed by the following equation (7):
Fc (λ) = ∫F (μ, λ) · Ic (μ) dμ / Ic (λ) = ∫F (μ, λ) · [W (λ) · I1 (μ) + (1−W (λ) ) · I2 (μ)] dμ / [W (λ) · I1 (λ) + (1−W (λ)) · I2 (λ)] (7)

Therefore, the above equation (5) can be rewritten as the following equation (8).
∫F (μ, λ) · Is (μ) dμ / Is (λ) = ∫F (μ, λ) · [W (λ) · I1 (μ) + (1−W (λ)) · I2 (μ ] Dμ / [W (λ) · I1 (λ) + (1−W (λ)) · I2 (λ)] (8)

Then, the weight W (λ) is calculated from the above equation (8), that is, the bispectral fluorescence radiance factor F (μ, λ) of the equation (8) and the spectral distribution Is (λ) = Is of the evaluation illumination light Is. (Μ) is given in advance as numerical data (set and stored), while spectral distributions I1 (λ) and I2 (λ) of illumination light (actual illumination light) I1 and I2 are obtained by actual measurement. Specifically, the weight W (λ) is calculated only by calculation processing (specifically, I1 (λ) and I2 (λ) are obtained by conversion from the actually measured spectral distribution of the reference surface reflected light). Then, using this weight W (λ), a fluorescent sample having a bispectral fluorescence radiance factor F (μ, λ) approximate to the bispectral fluorescence radiance factor used in the calculation is applied with the same illumination light Is for evaluation. The total spectral radiance factor Bxs (λ) when illuminated is calculated. That is, the spectral distributions Sx1 (λ) and Sx2 (λ) of the sample surface radiation when the fluorescent sample is illuminated with the illumination lights I1 and I2, and the spectral distributions I1 (λ) and I2 (λ) of the illumination lights I1 and I2 And Sxc (λ) and Ic (λ) given by the following equations (9) and (10) that are combined by linear combination with weights W (λ) and (1-W (λ)), respectively:
Sxc (λ) = W (λ) · Sx1 (λ) + (1−W (λ)) · Sx2 (λ) (9)
Ic (λ) = W (λ) · I1 (λ) + (1−W (λ)) · I2 (λ) (10)
(Where Sxc (λ) is the spectral distribution of the radiated light of the sample when illuminated by the synthesized illumination light Ic, and Ic (λ) is the synthesized illumination light synthesized by weighted linear combination of the illumination lights I1 and I2. The spectral distribution of Ic is shown.)
Based on the calibration constant C (λ), the total spectral radiance factor Bs (λ) is obtained by the following equation (11).
Bs (λ) = C (λ) · Sc (λ) / Ic (λ) (11)

By the way, each calculation process described above is performed by assuming that the illumination lights I1 and I2 both have an intensity in the visible range as in the present invention (specifically, for example, the illumination light I1 is converted into the illumination light LA and the illumination light). It is possible to simplify the light I2 as illumination light LB). That is, assuming illumination lights I1 (μ) / I1 (λ) and I2 (μ) / I2 (λ) in which the illumination lights I1 and I2 are relativized by the intensity at the wavelength λ in the visible range, I1 _λ (μ ), I2 _λ (μ) (I1 _λ (μ) = I1 (μ) / I1 (λ), I2 _λ (μ) = I2 (μ) / I2 (λ), so that I1 _λ (λ) = I2 _λ (λ) = 1). As a result, a different light source is assumed for each wavelength λ in the visible range. In this case, the denominator of the right side of the above equation (8) is [W (λ) · I1 _λ (λ) + (1−W (λ)) · I2 _λ (λ)], and the value is always “1”. Become. Therefore, the equation (7) is rewritten as shown in the following equation (12), and the fluorescence spectral radiance factor Fc (λ) by the combined illumination light Ic is linear of the fluorescence spectrum radiance factor by the illumination lights I1 and I2. It will be represented by a bond.
∫F (μ, λ) · Ic (μ) dμ / Ic (λ) = W (λ) ∫F (μ, λ) · I1 _λ (μ) dμ + (1−W (λ)) · ∫F ( μ, λ) · I2 _λ (μ) dμ = W (λ) · ∫F (μ, λ) · I1 (μ) dμ / I1 (λ) + (1−W (λ)) · ∫F (μ, λ) · I2 (μ) dμ / I2 (λ) (12)

Thereby, the said Formula (5) can be rewritten to the following formula | equation (13).
∫F (μ, λ) · Is (μ) dμ / Is (λ) = W (λ) ∫F (μ, λ) · I1 (μ) dμ / I1 (λ) + (1−W (λ) ) · ∫F (μ, λ) · I2 (μ) dμ / I2 (λ) (13)

Note that the equation (12) shows that the fluorescence spectral radiance factor Fc (λ) is two virtual illumination lights having different intensities at the wavelength λ and “1” for each wavelength λ, I1 _λ (μ) = I1 (Μ) / I1 (λ) and I2 _λ (μ) = I2 (μ) / I2 (λ) are added with weights W (λ) and 1-W (λ), and the following expression (12 ′) is obtained. It is shown that it can be obtained by different synthetic illumination light Ic (μ) for each wavelength λ in the visible range.
Ic (μ) = W (λ) · I1 (μ) / I1 (λ) + (1−W (λ)) · I2 (μ) / I2 (λ) (12 ′)

  Similarly to the case where the weight W (λ) is obtained from the equation (8) in the above, the equation (13) also includes the bispectral fluorescence radiance factor F (μ, λ) of the fluorescent sample and the evaluation illumination light Is. If the spectral distribution Is (λ) and the spectral distributions I1 (λ) and I2 (λ) of the two illumination lights I1 and I2 are given, the weight W (λ) can be obtained only by arithmetic processing.

  In the conventional method (Patent Document 1), since the spectral distributions I1 (λ) and I2 (λ) of the actual illumination lights I1 and I2 are unknown, the integration of the right side of the equation (13) is performed on the fluorescence reference sample. It can be considered that it is replaced with the actual measurement of the total spectral radiance factor.

In this way, W (λ) calculated from the equation (13) is applied to a fluorescent sample having a bispectral fluorescence radiance factor F (μ, λ) approximate to that used in the calculation. The fluorescence spectral radiance factor Fxc (λ) of the fluorescent sample by the synthetic illumination light Ic is used as the fluorescent spectral radiance factor Fx1 (λ), Fx2 (λ) of the sample by the illumination light I1, I2 (illumination light LA, LB). ) (Refer to equation (14) below).
Fxc (λ) = W (λ) · Fx1 (λ) + (1−W (λ)) · Fx2 (λ) (14)

Further, the same weight W (λ) as above is also applied to the total spectral radiance factor Bxc (λ), which is the sum of the fluorescent spectral radiance factor Fxc (λ) and the reflected spectral radiance factor Rxc (λ) independent of illumination light. ) Can be obtained by linear combination of the total spectral radiance factors Bx1 (λ) and Bx2 (λ) obtained by actually measuring the fluorescent sample with the illumination lights I1 and I2 (hereinafter, expression (15)). reference).
Bxc (λ) = W (λ) · Bx1 (λ) + (1−W (λ)) · Bx2 (λ) (15)

  In the above description, the weight W (λ) is obtained by the equation (8) or the equation (13) by giving the two-spectral fluorescence radiance factor F (μ, λ). From the equation (1), Fc (λ) = Fs. If (λ), Bc (λ) = Bs (λ), so F (μ, λ) in equation (8) or equation (13) is replaced with the bispectral radiance factor B (μ, λ), The weight W (λ) can be obtained in the same manner as described above.

By the way, two types of calibration are required prior to the measurement of the optical characteristics of the fluorescent sample. These calibrations are described below.
<1. Calibration of relative spectral sensitivity of spectroscopic means>
As described above, in the method of the present embodiment, it is necessary to grasp the spectral distribution of the actual illumination light of the measuring instrument. For this reason, the synchrotron radiation spectroscopic means (here, the two-channel spectroscopic unit 6) is preliminarily used at the time of manufacture. Calibration of relative spectral sensitivity is performed. First, the wavelength calibration of the synchrotron radiation means is performed by a known method, and a sensitivity calibration coefficient G is obtained from an output Sa (λ) obtained by making a light beam from a light source having a known spectral distribution A (λ) such as an A light source incident. (Λ) is obtained (see equation (16) below).
G (λ) = A (λ) / Sa (λ) (16)

<2. White calibration>
In the white calibration performed prior to the measurement (in the previous stage), the white calibration plates having the reflection spectral radiance factor Rw (λ) are known and have no fluorescence characteristics are used as the illumination lights I1 and I2 (the illumination lights LA and The spectral distributions Sw1 (λ) and Sw2 (λ) of the sample radiation (radiated light from the white calibration plate) and the reference surface reflected light (reflected light from the reference surface section 4) when illuminated with the illumination light LB) From the spectral distributions Mw1 (λ) and Mw2 (λ), the following two types of coefficients shown in <1> and <2> are obtained.

  <1> Conversion coefficients D1 (λ) and D2 (λ) for converting the spectral distributions Mx1 (λ) and Mx2 (λ) of the reference surface reflected light into the spectral distributions I1 (λ) and I2 (λ).

In this case, when a white calibration plate having a known reflection spectral radiance factor Rw (λ) is illuminated with illumination light I1 and I2, the spectral distributions Sw1 (λ), Sw2 (λ) of the sample surface reflection light, and From the spectral distributions Mw1 (λ) and Mw2 (λ) of the reference surface reflected light and the sensitivity calibration coefficient G (λ) shown in the above equation (16), the following equations (17) and (18) are used. Conversion coefficients D1 (λ) and D2 (λ) for converting the spectral distributions Mx1 (λ) and Mx2 (λ) of the reference surface reflected light into the spectral distributions I1 (λ) and I2 (λ) of the sample surface illumination light are obtained. .
D1 (λ) = [G (λ) · Sw1 (λ)] / [Mw1 (λ) · Rw (λ)] (17)
D2 (λ) = [G (λ) · Sw2 (λ)] / [Mw2 (λ) · Rw (λ)] (18)

As a result, when the spectral distribution of the reference surface reflected light is Mx1 (λ) and Mx2 (λ) when measuring the fluorescent sample, the spectral distributions I1 (λ) and I2 (λ) of the sample surface illumination light are Using the coefficients D1 (λ) and D2 (λ), the following equations (19) and (20) are used.
I1 (λ) = D1 (λ) · Mx1 (λ) (19)
I2 (λ) = D2 (λ) · Mx2 (λ) (20)

  <2> At the time of measurement, fluorescence is obtained from the spectral distributions Sx1 (λ) and Sx2 (λ) of the sample radiation illuminated with the illumination lights I1 and I2 and the spectral distributions Mx1 (λ) and Mx2 (λ) of the reference surface reflected light. Calibration coefficients C1 (λ) and C2 (λ) for obtaining the total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample.

In this case, the known reflection spectral radiance factor Rw (λ) in <1> above and the spectral distributions Sw1 (λ), Sw2 () of the sample surface reflected light when the white calibration plate is illuminated with the illumination light I1 and I2. Calibration coefficients C1 (λ) and C2 (λ) are obtained from the following equations (21) and (22) from λ) and the spectral distributions Mw1 (λ) and Mw2 (λ) of the reference surface reflected light.
C1 (λ) = Rw (λ) / [Sw1 (λ) / Mw1 (λ)] (21)
C2 (λ) = Rw (λ) / [Sw2 (λ) / Mw2 (λ)] (22)

Thereby, at the time of fluorescent sample measurement, the spectral distributions of the sample surface radiated light and the reference surface reflected light illuminated with the illumination light I1 and I2 are Sx1 (λ), Sx2 (λ), Mx1 (λ), Mx2 (λ ), The total spectral radiance factors Bx1 (λ) and Bx2 (λ) on the sample surface can be obtained by the following equations (23) and (24).
Bx1 (λ) = C1 (λ) · Sx1 (λ) / Mx1 (λ) (23)
Bx2 (λ) = C2 (λ) · Sx2 (λ) / Mx2 (λ) (24)

In addition, it can also be said that the measurement principle of the total spectral radiance factor when illuminated with the above-described evaluation illumination light is summarized as follows.
a1. The spectral characteristic of the fluorescence emitted from the fluorescent sample illuminated with arbitrary illumination light is determined by the spectral distribution of the illumination light and the two-spectrum fluorescent radiance factor of the sample (see equation (2)).
a2. Therefore, if the spectral distribution of the illumination light is known, the total spectral radiance factor of a virtual fluorescence reference sample having a known two-spectrum fluorescence radiance factor can be calculated and replaced with an actual fluorescence reference sample.
a3. The method of Patent Document 1 described above is applied to a virtual fluorescence reference sample.
a4. The spectral distribution of the illumination light for evaluation is given as data in advance, and the spectral distribution of the illumination light (actual illumination light) of the measuring device is obtained by actual measurement.

<Measurement procedure of total spectral radiance factor of fluorescent sample>
As a measurement procedure of the total spectral radiance factor of the fluorescent sample by the optical property measuring apparatus 10, after the white calibration shown in the flow of FIG. 3 performed in advance, the total spectral radiance factor is measured along the flow shown in FIG. Do. FIG. 3 is a flowchart illustrating an example of an operation relating to white calibration. First, the control unit 7 applies the first illuminating unit 2 (with respect to a white calibration plate disposed in the measurement aperture, that is, a white calibration plate having a known reflection spectral radiance factor Rw (λ) and having no fluorescence characteristics. The incandescent lamp 21) is turned on and illuminated by the illumination light LA (illumination light I1) (step S1). Then, the two-channel spectroscopic unit 6 (radiated light spectroscopic means) splits the sample reflected light by the illumination light LA (in this case, the sample radiated light with respect to the white calibration plate having no fluorescence characteristic, and thus becomes the sample reflected light). The distribution Sw1 (λ) is measured, the spectral distribution Mw1 (λ) of the reference surface reflected light of the illumination light LA is measured, and the spectral distribution information of the Sw1 (λ) and Mw1 (λ) is stored in the spectral data memory 71. (Step S2).

  Subsequently, the control unit 7 lights the second lighting unit 3 (ultraviolet LED 31) while maintaining the lighting of the first lighting unit 2 in step S1. As a result, the first and second lighting units are turned on. The sample 1 to be measured is illuminated with the illumination light LB (illumination light I2) by 2 and 3 (step S3), and the spectral distribution Sw2 of the sample reflected light by the illumination light LB is obtained by the two-channel spectroscopic unit 6 as in step S2. (Λ) is measured, the spectral distribution Mw2 (λ) of the reference surface reflected light of the illumination light LB is measured, and the spectral distribution information of these Sw2 (λ) and Mw2 (λ) is stored in the spectral data memory 71 ( Step S4). And the 1st and 2nd illumination parts 2 and 3 are light-extinguished (step S5).

  Then, the spectral distributions Sw1 (λ) and Sw2 (λ) of the sample-surface reflected light obtained in steps S2 and S4, the spectral distributions Mw1 (λ) and Mw2 (λ) of the reference-surface reflected light, and the above equation (16) ), The spectral distributions Mx1 (λ) and Mx2 (λ) of the reference surface reflected light at the time of measurement are obtained from the sample surface illumination light by the above-described equations (17) and (18). Conversion coefficients D1 (λ) and D2 (λ) for conversion into spectral distributions I1 (λ) and I2 (λ) are calculated (step S6).

  Further, the spectral distributions Sw1 (λ) and Sw2 (λ) of the sample surface reflected light obtained in steps S2 and S4, the spectral distributions Mw1 (λ) and Mw2 (λ) of the reference surface reflected light, and the known reflection spectroscopy. From the luminance rate Rw (λ), the calibration coefficients C1 (λ) and C2 (λ) are calculated by the above formulas (21) and (22) (step S7). The conversion coefficients D1 (λ) and D2 (λ) calculated in step S6 and the calibration coefficients C1 (λ) and C2 (λ) calculated in step S7 are stored in a predetermined storage unit, for example, the coefficient memory 74. (Step S8).

  FIG. 4 is a flowchart showing an example of an operation related to the measurement of the total spectral radiance factor of the fluorescent sample by the optical property measuring apparatus 10. First, the evaluation illumination light Is is selected prior to measurement. That is, the control unit 7 reads out the spectral distribution data Is (λ) (that is, the spectral distribution Is (μ)) of the evaluation illumination light Is to be selected from the evaluation illumination light data memory 72 (step S11). Subsequently, the type (kind) of the sample 1 to be measured is selected. That is, the control unit 7 (CPU 70) reads out data of the two-spectral fluorescence radiance factor F (μ, λ) of the type approximate to the sample to be measured from the two-spectral data memory 73 (step S12). Next, the control unit 7 turns on the first illumination unit 2 (incandescent lamp 21) and illuminates the sample 1 to be measured disposed in the measurement opening with the illumination light LA (illumination light I1) (step S13). ). Then, the spectral distribution Sx1 (λ) of the sample radiated light by the illumination light LA is measured by the two-channel spectroscopic unit 6 (radiated light spectroscopic means), and the spectral distribution Mx1 (λ) of the reference surface reflected light of the illumination light LA. And the spectral distribution information of these Sx1 (λ) and Mx1 (λ) is stored in the spectral data memory 71 (step S14).

  Subsequently, the control unit 7 lights the second illumination unit 3 (ultraviolet LED 31) while maintaining the lighting of the first illumination unit 2 in step S13, and the first and second illumination units 2, 3 are turned on. The sample 1 to be measured is illuminated with the illumination light LB (illumination light I2) by (Step S15), and the spectral distribution Sx2 (λ) of the sample radiation light by the illumination light LB is obtained by the two-channel spectroscopic unit 6 as in Step S14. And the spectral distribution Mx2 (λ) of the reference surface reflected light of the illumination light LB is measured, and the spectral distribution information of these Sx2 (λ) and Mx2 (λ) is stored in the spectral data memory 71 (step S16). . And the 1st and 2nd illumination parts 2 and 3 are light-extinguished (step S17).

Next, the control unit 7 calculates the following equation (25) from the spectral distribution data Is (λ) = Is (μ) and the two-spectral fluorescence radiance factor F (μ, λ) read in steps S11 and S12, respectively. ) To calculate the fluorescence spectral radiance factor Fs (λ) by the evaluation illumination light (step S18).
Fs (λ) = ∫F (μ, λ) · Is (μ) dμ / Is (λ) (25)

Then, according to the above equations (19) and (20), the spectral distributions Mx1 (λ) and Mx2 (λ) of the reference surface reflected light of the illumination light LA and LB are converted into the sample surface illumination light (illumination light LA and LB), respectively. To spectral distributions I1 (λ) and I2 (λ) (step S19), and spectral distributions I1 (λ) and I2 (λ) obtained by the conversion (that is, spectral distributions I1 (μ) and I2 (μ)). ) And the two-spectral fluorescence radiance factor F (μ, λ), the fluorescence spectral radiance factor F1 (λ) by the illumination light LA, LB (illumination light I1, I2) by the following equations (26), (27): , F2 (λ) is calculated (step S20).
F1 (λ) = ∫F (μ, λ) · I1 (μ) dμ / I1 (λ) (26)
F2 (λ) = ∫F (μ, λ) · I2 (μ) dμ / I2 (λ) (27)

Next, the following equation (28) based on the calculated fluorescence spectral radiance factors F1 (λ) and F2 (λ) and the fluorescent spectral radiance factor Fs (λ) obtained in step S18 is solved for each wavelength. Thus, the weight W (λ) is obtained (step S21).
W (λ) · F1 (λ) + (1−W (λ)) · F2 (λ) = Fs (λ) (28)
Then, from the Mx1 (λ) and Mx2 (λ) stored in the steps S14 and S16 and the Sx1 (λ) and Sx2 (λ), the illumination light is obtained using the above-described equations (23) and (24). The total spectral radiance factors Bx1 (λ) and Bx2 (λ) by LA and LB are calculated (step S22), the calculated Bx1 (λ) and Bx2 (λ), and the weight W ( From (λ), the total spectral radiance factor Bxs (λ) by the illumination light for evaluation is calculated by the following equation (29) (step S23).
Bxs (λ) = W (λ) · Bx1 (λ) + (1−W (λ)) · Bx2 (λ) (29)

(Measurement of total spectral radiance factor without the influence of fluorescence)
A method and apparatus for measuring the optical properties of a fluorescent sample according to the present invention based on the above-described measurement method will be described below. FIG. 1 is a schematic configuration diagram showing an example of an optical property measuring apparatus for a fluorescent sample according to the present invention. As shown in FIG. 1, the optical property measuring apparatus 100 includes a sample to be measured 110, a first illumination unit 120, a second illumination unit 130, an integrating sphere 140, a light receiving unit 150, a two-channel spectroscopic unit 160, and a control unit 170. Configured. The sample to be measured 110 is a sample to be measured, which is made of a fiber or paper product containing a fluorescent material. The sample 110 to be measured is disposed in the sample opening 141 of the integrating sphere 140. The first illumination unit 120 illuminates the sample 110 to be measured, and is disposed on the integrating sphere 140, here on the side of the integrating sphere 140. The first illumination unit 120 drives the xenon flash 121 (having sufficient energy in the ultraviolet region) as a light source that outputs a light beam in the visible-ultraviolet region, and drives the xenon flash 121 to light (for example, pulse lighting). The first drive circuit 122 is provided.

  Similar to the first illumination unit 120, the second illumination unit 130 illuminates the sample 110 to be measured, and is provided side by side with the first illumination unit 120 on the side of the integrating sphere 140. Similarly to the first illumination unit 120, the first illumination unit 130 also has a xenon flash 131 as a light source that outputs a light beam in the visible-ultraviolet region, and a second for driving and lighting the xenon flash 131 (for example, pulse lighting). And a drive circuit 132. The first and second illumination units 120 and 130 send the light beams of the xenon flashes 121 and 131 into the integrating sphere 140 through the first filter 123 and the second filter 133, respectively. Note that the light sources of the first and second illumination units 120 and 130 are not limited to the xenon flash, and any light source may be used as long as a light beam in the visible region and the ultraviolet region can be output.

  By the way, in the description of the basic technology, the illumination light LA when only the first illumination unit 2 is turned on is used as the illumination light I1, while the first illumination unit 2 and the second illumination are used as the illumination light I2. In this embodiment, the first and second illumination units 120 and 130 form the illumination lights I1 and I2, respectively, although the illumination light LB when both the units 3 are turned on is used. That is, the illumination light when only the first illumination unit 120 (xenon flash 121) is turned on is the illumination light I1, and the illumination light when only the second illumination unit 130 (xenon flash 131) is turned on is the illumination light I2. And In order to distinguish from the above description, the illumination light I1 here is appropriately referred to as illumination light HA, and the illumination light I2 is appropriately referred to as illumination light HB.

  The integrating sphere 140 is a spherical body having an inner wall coated with a white paint having high diffusion and light reflectance, and multiple diffusely reflects light incident on the sphere. Further, the integrating sphere 140 includes a reference surface portion 142 corresponding to the reference surface portion 4 shown in FIG. The reference surface portion 142 is configured by a part of the inner wall of the integrating sphere 140 and is disposed near the sample to be measured 110 (near the measurement region). The light receiving unit 150 (light receiving system) includes an optical lens (or a lens group), and emits light emitted from the sample 110 to be measured illuminated by the first and second illumination units 120 and 130 or reflected light from the reference surface unit 142. In addition to receiving a component in a substantially normal direction, the received light beam is also incident on a two-channel spectroscopic unit 160 described later.

  The two-channel spectroscopic unit 160 performs spectroscopic measurement on the incident light from the light receiving unit 150, and functions as a radiated light spectroscopic unit and an illumination light spectroscopic unit, like the two-channel spectroscopic unit 6. The two-channel spectroscopic unit 160 includes a first incident slit 161 and a second incident slit 162, and radiated light from the sample 110 to be measured illuminated by the illumination light HA or the illumination light HB (hereinafter, sample surface radiated light). Is incident on the first incident slit 161, while reflected light from the reference surface portion 142 illuminated by the illumination light HA or the illumination light HB (hereinafter referred to as reference surface reflected light) is incident on the second incident slit 162. To do. The two-channel spectroscopic unit 160 performs spectroscopic measurement on the sample radiation incident on the first incident slit 161, outputs spectral distribution data of the sample radiation as the first channel output, and enters the second incident slit 162. Spectral measurement is performed on the reference surface reflected light, and spectral distribution data of the reference surface reflected light is output as the second channel output. The optical system in the optical characteristic measuring apparatus 100 forms a d / 0 geometry by the arrangement of the integrating sphere 140 and the light receiving unit 150 as described above.

  The control unit 170 is responsible for overall operation control of the optical characteristic measuring apparatus 100, similar to the control unit 7. For example, the lighting operation of the first and second illumination units 120 and 130 and the light reception / reception of the two-channel spectroscopic unit 160. Performs drive control related to the spectroscopic operation, and executes various arithmetic processes related to calculation of the total spectral radiance factor, etc., from which the influence of fluorescence on the sample 110 to be measured is removed based on information (spectral information) from the two-channel spectroscopic unit 160 To do. The control unit 170 includes a CPU 171, a spectral data memory 172, an evaluation illumination light data memory 173, a dual spectral data memory 174, a coefficient memory 175, and the like.

  The CPU 171 performs processing related to the drive control of the first and second illumination units 120 and 130 and the two-channel spectroscopic unit 160, or computation related to calculation of the total spectral radiance factor from which the influence of the fluorescence on the measured sample 110 has been removed. A central processing unit (CPU) that performs various types of arithmetic processing. The spectroscopic data memory 172 stores spectroscopic distribution data of the sample surface radiation light and the reference surface reflection light that is split by the two-channel spectroscopic unit 160 and transmitted from the two-channel spectroscopic unit 160. The evaluation illumination light data memory 173 stores spectral distribution data of evaluation illumination light given in advance. The bispectral data memory 174 stores bispectral fluorescence radiance factor data approximate to the sample 110 (fluorescent sample) obtained in advance. The coefficient memory 175 converts the sensitivity calibration coefficient for calibrating the relative spectral sensitivity of the two-channel spectroscopic unit 160 and the spectral distribution of the reference surface reflected light into the spectral distribution of illumination light for the sample 110 to be measured (hereinafter referred to as sample surface illumination light). Coefficient data such as a calibration coefficient for obtaining the total spectral radiance factor of the sample 110 to be measured is stored from the conversion coefficient to be converted and the spectral distribution of the sample radiation light and the reference surface reflection light.

  The light beams 124 and 134 sent from the first and second illumination lights 120 and 130 are diffusely multiplexed and reflected within the integrating sphere 140 to illuminate the sample 110 to be measured in the sample opening 141 as diffused lights 125 and 135, respectively. To do. Since the first filter 123 blocks the light beam of “355” nm and the second filter 133 does not exceed “395” nm, the relative ultraviolet intensities of the illumination lights HA and HB (illumination lights I1 and I2) are greatly different. In the measurement method of the present invention, since it is necessary to grasp the spectral distributions I1 (λ) and I2 (λ) of the actual illumination lights HA and HB, the measurement range of the two-channel spectroscopic unit 160 is adjusted to a wavelength of 350 nm to 740 nm. The illumination lights HA and HB have an intensity of a wavelength of 355 nm or more.

  When the control unit 170 drives the xenon flash 121 via the first drive circuit 122, the first illumination unit 120 diffusely illuminates the sample 110 to be measured with a light beam (illumination light HA) of 355 nm or more. Similarly, when the control unit 170 drives the xenon flash 131 via the second drive circuit 132, the second illumination unit 130 diffusely illuminates the sample 110 to be measured with a light beam (illumination light HB) of 395 nm or more. Of the radiated light from the sample 110 to be measured illuminated by the first or second illuminating unit 120, 130, the component 1101 in the normal direction passes through the opening 143 of the integrating sphere 140, and the two-channel spectroscopic unit 160 is received by the light receiving unit 150. Is incident on the first incident slit 161 and subjected to spectroscopic measurement, and the spectral distribution Sx1 (λ) or Sx2 (λ) is output to the control unit 170 as the first channel output.

  At the same time, the component 1421 in the substantially normal direction in the reflected light from the reference surface portion 142 in the vicinity of the measurement area of the sample 110 to be measured is incident on the second incident slit 162 of the two-channel spectroscopic unit 160 by the light receiving unit 150 and is spectroscopically measured. The spectral distribution Mx1 (λ) or Mx2 (λ) of the reference surface reflected light with respect to the illumination light HA, HB (I1, I2) is output to the control unit 170 as the second channel output.

  The control unit 170 stores the first and second channel output data from the two-channel spectroscopic unit 160 and the respective memories of the control unit 170 as in the case of the optical property measuring apparatus 10 (control unit 7) shown in FIG. The total spectral radiance factor (reflected spectral radiance factor) from which the influence of fluorescence is removed is calculated using the obtained data. However, in this embodiment, using these data, the total spectral radiance factor of the fluorescent sample illuminated with the evaluation illumination light and the total spectral radiance factor (reflection spectral radiance factor) from which the influence of the fluorescence is removed And calculate.

<Calculation method>
As shown in the above equation (1), the total spectral radiance factor Bx (λ) obtained by actual measurement of the sample x is given by the sum of the reflected spectral radiance factor Rx (λ) and the fluorescent spectral radiance factor Fx (λ). It is done. While the reflected spectral radiance factor Rx (λ) does not depend on the illumination light, the fluorescent spectral radiance factor Fx (λ) depends on the spectral distribution of the illumination light. The theoretical fluorescence spectral radiance factor F (λ) calculated by the above equation (2) from the bispectral fluorescence radiance factor F (μ, λ) approximating x and the spectral distribution I (μ) of the illumination light. It is considered to be proportional and can be expressed by the following equation (30).
Bx (λ) = Rx (λ) + F (λ) · K (λ) (30)
However, K (λ) is approximate to the theoretical fluorescence spectral radiance factor F (λ) calculated above and the two-spectral fluorescence radiance factor F (μ, λ) used to calculate F (λ). The ratio of the measurement sample having the two-spectrum fluorescence radiance factor to the actual fluorescence spectrum radiance factor Fx (λ), which is a constant inherent to the sample. This K (λ) can be said to be a proportional constant inherent to the sample for associating (associating) the theoretical fluorescence spectral radiance factor with the actual fluorescence spectral radiance factor of the sample.

Therefore, the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) when the sample is illuminated with two actual illumination lights I1 and I2 having different spectral distributions are expressed by the following equations (31) and (32). Using the calculated theoretical fluorescence spectral radiance factors F1 (λ) and F2 (λ),
F1 (λ) = ∫F (μ, λ) · I1 (μ) dμ / I1 (λ) (31)
F2 (λ) = ∫F (μ, λ) · I2 (μ) dμ / I2 (λ) (32)
It is represented by the following formulas (33) and (34).
Bx1 (λ) = Rx (λ) + F1 (λ) · K (λ) (33)
Bx2 (λ) = Rx (λ) + F2 (λ) · K (λ) (34)

  Therefore, by solving the above equations (33) and (34) for each wavelength as simultaneous equations with Rx (λ) and K (λ) as unknowns, the reflected spectral radiation corresponding to the total spectral radiance factor from which the influence of fluorescence has been removed. A luminance rate Rx (λ) is obtained.

In addition, it can also be said that the measuring method of the total spectral radiance factor which removed the influence of the above-mentioned fluorescence is summarized as follows.
b1. Reflected spectral radiance as the sum of the reflected spectral radiance factor and the fluorescent spectral radiance factor of the fluorescent sample illuminated with two illumination lights having different spectral distributions (see equation (1)). The ratio (total spectral radiance ratio excluding the influence of fluorescence) is obtained.
b2. The fluorescence spectral radiance factor for each illumination light is proportional to the theoretical fluorescence spectral radiance factor calculated from the spectral distribution of each illumination light and the two spectral fluorescence radiance factor approximated to the sample.

<Measurement procedure of the total spectral radiance factor without the influence of fluorescence>
FIG. 5 is a flowchart showing an example of an operation related to the measurement of the total spectral radiance factor from which the influence of fluorescence is removed. First, the evaluation illumination light Is is selected prior to measurement. That is, the control unit 170 reads out the spectral distribution data Is (λ) (that is, the spectral distribution Is (μ)) of the evaluation illumination light Is to be selected from the evaluation illumination light data memory 173 (step S31). Subsequently, the type (kind) of the sample 110 to be measured is selected. That is, the control unit 170 (CPU 171) reads data of the selected type of two-spectral fluorescence radiance factor F (μ, λ) from the two-spectral data memory 174 (step S32). Next, the control unit 170 pulse-lights the first illumination unit 120 (xenon flash 121) with respect to the sample 110 to be measured disposed in the sample opening 141 of the integrating sphere 140, and the illumination light HA (illumination light I1). ) (Step S33). At the time of light emission (illumination) in step S33, the spectral distribution Sx1 (λ) of the sample surface radiation light by the illumination light HA is measured by the two-channel spectroscopic unit 160 (radiation light spectroscopy means), and the reference surface of the illumination light HA The spectral distribution Mx1 (λ) of the reflected light is measured, and the spectral distribution information of Sx1 (λ) and Mx1 (λ) is stored in the spectral data memory 172 (step S34).

  Subsequently, the control unit 170 pulses the second illumination unit 130 (xenon flash 131) and illuminates the sample 110 to be measured with the illumination light HB (illumination light I2) from the second illumination unit 130 (step S35). As in the case of the first illumination unit 120, the two-channel spectroscopic unit 160 measures the spectral distribution Sx2 (λ) of the sample surface radiation by the illumination light HB, and the spectrum of the reference surface reflected light of the illumination light LB. The distribution Mx2 (λ) is measured, and the spectral distribution information of these Sx2 (λ) and Mx2 (λ) is stored in the spectral data memory 172 (step S36).

  Next, by performing the same processing as steps S18 to S23 of the flowchart shown in FIG. 4, the spectral distributions I1 (λ) and I2 (λ) of the illumination lights HA and HB (illumination lights I1 and I2), The total spectral radiance factors Bx1 (λ) and Bx2 (λ) for each illumination light are calculated and stored in the spectral data memory 172, and the total spectral radiance factor Bxs (λ) by the evaluation illumination light is calculated from these pieces of information. In the process, the spectral distributions I1 (λ) and I2 (λ) and the read two-spectral fluorescence radiance factor F (μ, λ) are calculated according to the above equations (31) and (32). The calculated theoretical fluorescent spectral radiance factors F1 (λ) and F2 (λ) are stored in the spectral data memory 172 (step S37). The above equation (33) using the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) calculated in the steps S36 and S37 and the theoretical fluorescent spectral radiance factors F1 (λ) and F2 (λ). ) And (34) are solved for each wavelength, and the reflection spectral radiance factor Rx (λ) corresponding to the total spectral radiance factor from which the influence of fluorescence is removed is obtained (step S38).

  As described above, the optical property of the fluorescent sample is measured by the optical property measuring method of the present invention and the optical property measuring apparatus using the method, that is, the total spectral radiance factor and the fluorescence when illuminated with the evaluation illumination light. Although the total spectral radiance factor from which the influence is removed is measured, it can be said that the measurement method and the measurement apparatus bring about the effects summarized below.

  That is, in the present invention, by grasping the spectral distribution of the illumination light, the conventionally used fluorescence standard sample can be replaced with bifluorescence spectral radiance factor data approximate to the sample, and therefore c1. The error due to the time-dependent change of the fluorescence reference sample is replaced with the error due to the time-dependent change of the illumination light spectroscopic means. c2. There is no error due to differences between fluorescent reference samples. c3. It is not necessary to update the fluorescence standard sample to suppress the influence of the change in the fluorescence reference sample over time, and the management, labor and cost associated with this can be reduced. c4. Conventionally, the synthesis of illumination light for calibration of relative ultraviolet intensity is numerically performed at the time of measurement, so that prior calibration work is not required. c5. Since the illumination light is synthesized based on the illumination light at the time of measurement, there is no error due to a change in the illumination light. c6. Pre-store one or more spectroscopic fluorescence radiance factors or spectroscopic radiance factor data and one or more spectral distributions of evaluation illumination light that can be measured before production or before shipping to the measurement site. In general, the spectral radiance factor of the fluorescent sample can be easily obtained simply by selecting them at the measurement site. c7. Bispectral fluorescence radiance factor or bispectral radiance factor data can be added and updated as appropriate over the Internet (Web). c8. It is possible to simultaneously obtain the total spectral radiance factor of the fluorescent sample illuminated with the evaluation illumination light for the same fluorescent sample and the total spectral radiance factor from which the influence of fluorescence is removed. c9. In the measurement of the total spectral radiance factor from which the influence of fluorescence is removed, a fluorescence suppression filter or the like is not necessary. c10. A wavelength range in which the total spectral radiance factor cannot be measured does not occur, and the accuracy of the color value obtained from the total spectral radiance factor does not decrease.

  As described above, according to the optical characteristic measuring method of the present invention, the first and second actual illumination lights I1 and I2 having different spectral distributions from the two-spectral fluorescence radiance factor F (μ, λ) that approximates the sample. Measured total spectral radiance factor Bx1 (λ) of the sample illuminated by each of the spectral distributions I1 (λ) and I2 (λ) and the first and second actual illumination lights I1 and I2 (illumination lights HA and HB) , Bx2 (λ), the reflection spectral radiance factor Rx (λ) of the sample from which the influence of fluorescence is removed is calculated by the following first and second steps, that is,

First step: The first spectral fluorescence radiance factor F (μ, λ) and the spectral distributions I1 (λ), I2 (λ) of the first and second actual illumination lights I1, I2 And the theoretical fluorescence spectral radiance factor F1 (λ) = ∫F (μ, λ) · I1 (μ) dμ / I1 (λ) and F2 (λ) of the sample by the second actual illumination lights I1 and I2 = ∫F (μ, λ) · I2 (μ) dμ / I2 (λ) is calculated.
Second step: Rx (λ) is the reflected spectral radiance factor of the sample, and the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) are the reflected spectral radiance factor Rx (λ), F1 (λ) · K (λ) and F2 (λ) · K (λ) by multiplication of the theoretical fluorescence spectral radiance factors F1 (λ), F2 (λ) and K (λ) The following simultaneous equations are solved for each wavelength to calculate the reflection spectral radiance factor Rx (λ). Bx1 (λ) = Rx (λ) + F1 (λ) · K (λ), Bx2 (λ) = Rx (λ) + F2 (λ) · K (λ). However, K (λ) is a constant specific to the sample indicating the ratio between the theoretical fluorescence spectral radiance factors F1 (λ) and F2 (λ) calculated above and the measured fluorescence spectral radiance factor of the sample.

  Thus, the spectral distributions I1 (λ) and I2 (λ) of the first and second actual illumination lights I1 and I2 having different spectral distributions from the two-spectral fluorescence radiance factor F (μ, λ) that approximates the sample. And the reflection spectroscopy of the sample from which the influence of fluorescence is removed from the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample illuminated by the first and second actual illumination lights I1 and I2, respectively. Since the radiance factor Rx (λ) is calculated in the first and second steps described above, a wavelength range in which the total spectral radiance factor cannot be measured is generated without using a filter or the like that suppresses excitation light. In addition, the total spectral radiance factor from which the influence of fluorescence has been removed can be obtained with high accuracy, and a reduction in the accuracy of the color value obtained from the total spectral radiance factor can be prevented.

  Further, according to the optical characteristic measuring apparatus 100 of the present invention, the sample is obtained by the first and second actual illumination lights I1 and I2 having different spectral distributions depending on the first and second illumination means (first illumination units 120 and 130). Is illuminated, the spectral distribution of the radiated light from the sample is measured by the radiated light spectroscopic means (two-channel spectroscopic section 160), and the first and second actual illumination lights I1 are measured by the illuminating light spectroscopic means (two-channel spectroscopic section 160). , The spectral distribution of I2 is measured, and information on the two-spectral fluorescence radiance factor F (μ, λ) approximating the sample is stored by the storage means (two-spectral data memory 174). Then, the first and second illuminating means are individually turned on by the arithmetic control means (control unit 170), and the first and second illuminating means are measured based on the information obtained by the measurement by the radiated light spectroscopic means and the illuminating light spectroscopic means. The measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample for the second actual illumination lights I1 and I2, respectively, and the spectral distribution I1 (λ) of the first and second actual illumination lights I1 and I2 , I2 (λ) is calculated, and based on the calculated information and the information of the two-spectral fluorescence radiance factor F (μ, λ) stored in the storage means, Since the reflected spectral radiance factor Rx (λ) is calculated, the influence of fluorescence is eliminated without using a filter or the like that suppresses excitation light, and therefore without generating a wavelength range in which the total spectral radiance factor cannot be measured. Accurately calculate the total spectral radiance factor It is possible, the accuracy decreases color values obtained from the total spectral radiance factor can be prevented.

  Further, since the first and second actual illumination lights I1 and I2 have no intensity in the wavelength range exceeding the measurement range of the illumination light spectroscopic means at least in the short wavelength range, The spectral intensity in the wavelength range related to the excitation and fluorescence of the first and second actual illumination light can be grasped without any omission (calculation processing), so that the theoretical fluorescence spectral radiance of each illumination light can be obtained. Since the rate can be accurately obtained, it is possible to accurately obtain the total spectral radiance rate from which the influence of fluorescence is removed.

In addition, this invention can take the following aspects.
(1) In the above-described embodiment, two actual illumination lights of the illumination lights HA and HB are used, but two or more actual illumination lights may be used. In this case, a weight for synthesizing the illumination light is given for each illumination light (however, the sum of the weights is “1”).

  (2) The illumination lights HA and HB may be obtained by sequentially inserting two filters having different spectral transmission characteristics (including through) into the light flux from one light source.

  (3) A plurality of bispectral fluorescent radiance rate data approximate to fluorescent whitening products that may be evaluated are stored in advance in the bispectral data memories 73 and 174, and necessary data is obtained from these data prior to measurement. It may be configured to select and use data. In this case, the control units 7 and 170 obtain and output the total spectral radiance factor of the measurement sample from which the influence of fluorescence has been removed and the color value based on this based on the selected two-spectrum fluorescent radiance factor data. To do.

  (4) For example, as shown in Patent Document 1, a conventional measurement method (apparatus) for synthesizing illumination light that gives the same total spectral radiance factor as that of evaluation illumination light using a fluorescence reference sample, If the spectral distribution of the illumination lights HA and HB (illumination lights LA and LB) can be grasped, the method of the present invention can be applied by giving an approximate two-spectral fluorescence radiance factor to the sample to be measured. This case will be described. FIG. 6 is a schematic configuration diagram showing an example of an optical characteristic measuring apparatus when the method of the present invention is applied to a conventional measuring method. As shown in the optical characteristic measuring apparatus 200 in FIG. 1, the measuring apparatus for measuring a fluorescent sample usually includes an information processing apparatus such as a PC (personal computer) 210. The PC 210 controls the illumination unit (first and second illumination units 230 and 240) and the spectroscopic unit (spectral unit 250) via the control unit 220, and receives the spectral distribution of the illumination light and the sample surface radiation light, Based on this information, the illumination light is synthesized and the total spectral radiance factor of the sample is obtained. In the conventional measuring apparatus, since it is impossible to obtain the spectral distribution of the entire wavelength region involved in the excitation and fluorescence of the actual illumination light, it is necessary to separately provide a spectral distribution measurement means for measuring the spectral distribution of the illumination light. The spectral distribution measuring unit 201 is provided corresponding to the above. Prior to the measurement, the spectral distribution measuring unit 201 is disposed in the sample opening (opening 271 described later), and the spectral distribution of the illumination lights HA and HB based on the illumination of the first and second illumination units 230 and 240 is obtained. Measure. The spectral distribution information of the actually measured illumination lights HA and HB is sent to the PC 210. Then, in the PC 210, the theoretical distribution procedure of the actual illumination light and the information of the two-spectral fluorescence radiance factor stored in advance as numerical data in the PC 210 are theoretically performed in the same procedure as in the above-described embodiment. Fluorescence spectral radiance factor is obtained and illumination light is synthesized, and the total spectral radiance factor of the sample when illuminated with evaluation illumination light, and the total spectral radiance factor of the sample from which the influence of fluorescence is removed (reflected spectral radiation) Brightness factor) and the like.

  Note that the control unit 220, the first illumination unit 230, the second illumination unit 240, the spectroscopic unit 250, the light receiving unit 260, and the integrating sphere 270 shown in the optical property measurement apparatus 200 of FIG. 100 control unit 170, first illumination unit 120, second illumination unit 130, two-channel spectroscopic unit 160, light receiving unit 150, and integrating sphere 140. However, the light sources 231 and 241 of the first illumination unit 230 and the second illumination unit 240 are both xenon flash light sources having sufficient energy in the ultraviolet region, and the ultraviolet cut filter 243 is provided only in the second illumination unit 240. ing. The first and second incident slits 251 and 252 of the spectroscopic unit 250 correspond to the first incident slit 161 and the second incident slit 162 of the two-channel spectroscopic unit 160, respectively. Reference numerals 232 and 242 denote drive circuits for lighting the light sources 231 and 241. The integrating sphere 270 includes an opening 271 serving as a sample opening, and a reference surface portion 272 that is a part of the inner wall of the integrating sphere 270 corresponding to the reference surface portion 142 illustrated in FIG.

  By the way, the spectral distribution measurement unit 201 of the illumination light needs to have at least a relative spectral sensitivity calibrated, and the entire wavelength region related to excitation and fluorescence (for example, about 300 nm to 600 nm in the case of a fluorescent whitening sample). Wavelength range) must be covered. With this measurement method, the fluorescence reference sample lacking in stability can be replaced with the spectral distribution measurement unit 201 of the illumination light (the spectral distribution measurement unit 201 is used instead of the fluorescence reference sample), and the excitation light suppression filter Therefore, it is possible to obtain the total spectral radiance factor without the influence of fluorescence without generating a wavelength range where the total spectral radiance factor cannot be measured, but the synthesis of illumination light and theoretical fluorescence It is necessary to calculate the spectral radiance factor prior to measurement, and as a result, it becomes impossible to eliminate errors due to variations in illumination light.

  (5) In the above embodiment, the constant K (λ) specific to the sample indicating the ratio between the calculated theoretical fluorescent spectral radiance factor and the actual fluorescent spectral radiance factor of the sample is obtained for each wavelength. If the wavelength dependence of this ratio is not large, the above constant may be obtained as K independent of wavelength.

It is a schematic block diagram which shows an example of the optical property measuring apparatus of the fluorescence sample which concerns on this invention. It is a schematic block diagram which shows an example of the optical characteristic measuring apparatus of the fluorescence sample in a principle description. It is a flowchart which shows an example of the operation | movement regarding white calibration. It is a flowchart which shows an example of the operation | movement regarding the measurement of the total spectral radiance factor of the fluorescence sample by an optical characteristic measuring apparatus. It is a flowchart which shows an example of the operation | movement regarding the measurement of the total spectral radiance factor which removed the influence of fluorescence. It is a schematic block diagram which shows an example of the optical characteristic measuring apparatus at the time of applying the method of this invention to the conventional measuring method. It is a graph which shows an example of the intensity | strength matrix of a bispectral fluorescence radiance factor. It is a graph which shows the spectral distribution of an incandescent light source and ultraviolet LED. It is a schematic block diagram which shows the conventional optical characteristic measuring apparatus. It is a schematic block diagram which shows the conventional optical characteristic measuring apparatus.

Explanation of symbols

100 Optical property measuring device 110 Sample to be measured (fluorescent sample, sample)
120 1st illumination part (1st illumination means)
121 Xenon flash 122 First drive circuit 130 Second illumination section (second illumination means)
131 Xenon Flash 132 Second Drive Circuit 142 Reference Surface Part 150 Light Receiving Part 160 Two-Channel Spectroscopic Part (Radiated Light Spectroscopic Means, Illuminating Light Spectroscopic Means)
161 1st entrance slit 162 2nd entrance slit 170 Control part (calculation control means)
171 CPU
172 Spectral data memory 173 Illumination light data memory for evaluation 174 Dual spectral data memory (storage means)
175 coefficient memory

Claims (3)

A method for measuring optical properties of a fluorescent sample,
Bispectral fluorescence radiance factor F (μ, λ) approximating the sample,
Spectral distributions I1 (λ) and I2 (λ) of the first and second actual illumination lights I1 and I2 having different spectral distributions;
From the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample illuminated by each of the first and second actual illumination lights I1 and I2,
A method for measuring optical properties of a fluorescent sample, characterized in that the reflection spectral radiance factor Rx (λ) of the sample from which the influence of fluorescence has been removed is calculated in the following first and second steps.
First step: The first spectral fluorescence radiance factor F (μ, λ) and the spectral distributions I1 (λ), I2 (λ) of the first and second actual illumination lights I1, I2 And the theoretical fluorescence spectral radiance factor F1 (λ) = ∫F (μ, λ) · I1 (μ) dμ / I1 (λ) and F2 (λ) of the sample by the second actual illumination lights I1 and I2 = ∫F (μ, λ) · I2 (μ) dμ / I2 (λ) is calculated.
Second step: Rx (λ) is the reflected spectral radiance factor of the sample, and the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) are the reflected spectral radiance factor Rx (λ), F1 (λ) · K (λ) and F2 (λ) · K (λ) by multiplication of the theoretical fluorescence spectral radiance factors F1 (λ), F2 (λ) and K (λ) The reflection simultaneous radiance factor Rx (λ) is calculated by solving the following simultaneous equations.
Bx1 (λ) = Rx (λ) + F1 (λ) · K (λ),
Bx2 (λ) = Rx (λ) + F2 (λ) · K (λ)
However, K (λ) is a constant specific to the sample indicating the ratio between the theoretical fluorescence spectral radiance factors F1 (λ) and F2 (λ) calculated as described above and the actual fluorescent spectral radiance factor of the sample. An apparatus for measuring optical properties of a fluorescent sample,
First and second illumination means for illuminating the sample with first and second actual illumination lights I1 and I2 having different spectral distributions;
Synchrotron radiation means for measuring the spectral distribution of synchrotron radiation from the sample;
Illumination light spectroscopic means for measuring a spectral distribution of the first and second actual illumination lights I1 and I2,
Storage means for storing information of a dual spectral fluorescence radiance factor F (μ, λ) approximating the sample;
The first and second illumination means are individually turned on, and the first and second actual illumination lights I1 and I2 are respectively measured based on the information obtained by measurement using the synchrotron radiation spectroscopic means and the illumination light spectroscopic means. Calculate the measured total spectral radiance factors Bx1 (λ) and Bx2 (λ) of the sample and the spectral distributions I1 (λ) and I2 (λ) of the first and second actual illumination lights I1 and I2. Based on the calculated information and information on the bispectral fluorescence radiance factor F (μ, λ) stored in the storage means, the reflected spectral radiance factor Rx (λ) of the sample from which the influence of fluorescence has been removed is obtained. An optical characteristic measuring apparatus for a fluorescent sample, comprising: an arithmetic control means for calculating.   3. The fluorescence according to claim 2, wherein the first and second actual illumination lights I1 and I2 have no intensity in a wavelength range exceeding a measurement range of the illumination light spectroscopic means at least in a short wavelength range. A device for measuring optical properties of samples.

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