JP5609377B2 - measuring device - Google Patents

Description

  The present invention relates to a technique for measuring optical characteristics of a fluorescent whitening sample, in particular, spectral characteristics such as a total spectral emissivity coefficient by ambient light.

  A fluorescent whitening paper including a fluorescent whitening material that improves the whiteness by absorbing the ultraviolet component of illumination light and emitting light in the blue region is widely used for printing paper and the like. The visual reflection characteristics of a fluorescent whitening sample such as fluorescent whitening paper is the ratio of the emitted light from a sample illuminated under a certain condition to the emitted light from a perfect diffuse reflector illuminated under the same condition by wavelength. It is expressed by a certain spectral emissivity coefficient B (λ).

  The emitted light of the fluorescent sample is represented by the sum of reflected light and fluorescence. The total spectral emissivity coefficient B (λ) is also a reflected spectral emissivity coefficient (spectral reflectivity) that is a ratio of reflected light and fluorescence from the sample to wavelength of emitted light from a perfect diffuse reflector illuminated under the same conditions. It is also referred to as a coefficient.) Expressed by the sum of R (λ) and fluorescence spectral emissivity coefficient F (λ), and expressed by equation (1).

B (λ) = R (λ) + F (λ) (1)
Since the perfect diffuse reflector does not emit fluorescence and its reflectance does not depend on the wavelength, the total spectral emissivity coefficient B (λ), the reflected spectral emissivity coefficient R (λ), and the fluorescence, apart from the proportionality constant The spectral emissivity coefficient F (λ) is represented by the ratio of the emitted light, reflected light, and fluorescence of the sample to the illumination light for each wavelength.

(Optical characteristics of fluorescent sample)
The excitation characteristics and fluorescence characteristics of a fluorescent material are the ratio of the fluorescence of wavelength λ emitted from a fluorescent sample illuminated with illumination light of wavelength μ to the emitted light from a perfect diffuse reflector illuminated under the same conditions. It is described by a spectral luminescent emissivity factor F (μ, λ). The fluorescence spectral emissivity coefficient F (λ) of the fluorescent sample having the bispectral fluorescence emissivity coefficient F (μ, λ) illuminated with the illumination light having the spectral distribution I (μ) can be expressed by the following equation (2) ).

F (λ) = ∫F (μ, λ) · I (μ) dμ / I (λ) (2)
The bispectral fluorescence emissivity coefficient (bispectral characteristic) is measured with a bispectro fluorimeter.

  As Equation (2) shows, the fluorescence spectral emissivity coefficient F (λ) of the fluorescent sample depends on the spectral distribution I (μ) of the illumination light. The total spectral emissivity coefficient B (λ), which is the sum of the fluorescent spectral emissivity coefficient F (λ) and the reflected spectral emissivity coefficient R (λ) independent of the spectral distribution I (μ) of the illumination light, is also the illumination light. Depending on the spectral distribution I (μ).

  Therefore, it is necessary to specify the spectral distribution I (μ) of the illumination light for evaluation for evaluating the fluorescent sample. Even in the measurement, it is necessary to match the relative spectral distribution of the illumination light of the measuring instrument with the relative spectral distribution of the evaluation illumination light. Even when a standard illuminant such as D50 is used as the evaluation illumination light, Even when actual illumination light such as a light booth is used to obtain a correlation with visual evaluation, it is difficult for the measuring device to irradiate illumination light having the same relative spectral distribution as the evaluation illumination light.

  On the other hand, the fluorescence spectral emissivity coefficient F (λ) is obtained by the equation (2) from the spectral distribution I (μ) of the illumination light and the two-spectral fluorescence emissivity coefficient F (μ, λ) of the sample. ), The total spectral emissivity coefficient B (λ) can be obtained, but it is not practical because the dual spectrofluorometer is complicated and expensive, and it takes a long time to measure.

(Methods of Patent Documents 1 and 2)
As methods for practically replacing these, the methods of Patent Documents 1 and 2 have been proposed. In this method, the fluorescent whitening sample x is illuminated with a first illumination light having an intensity in the ultraviolet region and a second illumination light having no intensity in the ultraviolet region, and the first and second all-lights by each illumination light are illuminated. Spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) are obtained. Then, the obtained first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) are set and stored in advance as shown in Expression (3), and have a value for each wavelength. Weighted linear combination at (λ). Then, a combined total spectral emissivity coefficient Bc (λ) that approximates the total spectral emissivity coefficient B (λ) of the fluorescent whitening sample x illuminated with the evaluation illumination light is obtained.

Bc (λ) = W (λ) · Bx1 (λ) + (1−W (λ)) · Bx2 (λ) (3)
The weighting factor W (λ) is set as follows. First, a fluorescent reference sample s is prepared which has excitation characteristics and fluorescent characteristics that are similar to the fluorescent whitening sample x and has a known reference total spectral emissivity coefficient Bs (λ) when illuminated with evaluation illumination light. Then, the fluorescence reference sample s is illuminated with the first and second illumination lights to measure the first and second total spectral emissivity coefficients Bs1 (λ) and Bs2 (λ). Then, W (λ) · Bs1 (λ) + (1−W (λ)) · Bs2 (λ), which is a linear combination of the first and second total spectral emissivity coefficients Bs1 (λ) and Bs2 (λ), is obtained. The weight coefficient W (λ) is set for each wavelength so as to be equal to the reference total spectral emissivity coefficient Bs (λ).

(Optical characteristics of printing surface on fluorescent white paper)
Samples printed on fluorescent white paper are also affected by fluorescence. The fluorescent light reaches the fluorescent whitened paper as it is in the portion not covered with ink, and the excitation light corresponding to the spectral transmittance of the ink reaches the fluorescent whitened paper in the portion covered with ink. Therefore, the two spectral characteristics (spectral excitation efficiency and fluorescence spectral intensity) in the evaluation region depend on not only the two spectral characteristics of the fluorescent whitening paper but also the spectral transmission characteristics of the ink and the ink area ratio. In normal color printing, the fluorescent whitening paper is covered with each primary ink (Y, M, C, K) and their overlap (YM, MC, CY, YMC). It depends on the spectral transmission characteristics and area ratio of the inks and their overlap, that is, the printing color.

(Method of Patent Document 3)
In this method, the known bispectral characteristics of fluorescent white paper, the spectral transmittance of each primary ink, and each primary ink estimated from the total spectral emissivity coefficient of illumination light with no intensity in the ultraviolet region and their overlap. From the area ratio, effective two spectral characteristics in the evaluation area are estimated. Further, a method for estimating effective two spectral characteristics in the evaluation region from each primary ink and their overlap, the known two spectral characteristics of the non-printed surface, and the estimated area ratio is also shown.

JP-A-8-313349 JP 11-118603 A JP 2006-292510 A

  However, in the methods of Patent Documents 1 and 2, in order to price the reference total spectral emissivity coefficient Bs (λ), the two spectral characteristics of the fluorescence reference sample and the spectral distribution including the excitation range of the illumination light are required. Become. Further, it takes a long measurement time to measure the bispectral characteristics. In addition, measurement of the spectral emissivity coefficient under ambient light requires a spectral radiance meter having a measurement range in the ultraviolet region up to at least 300 nm of ambient light. Therefore, the methods of Patent Documents 1 and 2 are not practical.

  In addition, neither of the methods disclosed in Patent Documents 1 and 2 considers the printing color dependence of the two spectral characteristics, and an error occurs when applied to a printing surface on fluorescent white paper. Moreover, the method of patent document 3 also requires the measurement by an expensive measuring device, and its practicality is low.

  The object of the present invention is to provide a measuring device that can measure the spectral characteristics of the fluorescent whitening sample such as the total spectral emissivity coefficient under the ambient light with practical and high accuracy without using an expensive measuring instrument. There is to do.

(1) A measuring apparatus according to the present invention uses a measurement sample composed of a fluorescent whitening sample as ambient light as illumination light in a light booth for measuring the measurement sample and having an arbitrary spectral distribution. A measuring apparatus for measuring spectral characteristics when illuminated, an illumination unit for illuminating the measurement sample with first and second illumination lights having different relative ultraviolet intensities, and receiving radiation from the measurement sample for spectroscopy A light receiving unit for measuring the distribution, and illuminating the measurement sample with the first and second illumination light, and measuring the emitted light from the fluorescent whitening sample with the light receiving unit, the first and second spectral distributions are obtained. The first and second spectral characteristics of the measurement sample are obtained from the obtained first and second spectral distributions, and the obtained first and second spectral characteristics are weighted by a weighting factor having a value for each wavelength. Linearly coupled, and the measurement sample was illuminated with ambient light And an arithmetic unit for obtaining the composite spectral characteristic of Kino the measurement sample, wherein the calculating unit calculates the weight coefficient by the following first to third steps.

  1st process: The said non-fluorescence reference | standard by measuring in the said light-receiving part the radiation light from the non-fluorescence reference sample illuminated with environmental light, and the radiation light from the fluorescence reference | standard sample similar to the said measurement sample. Obtaining the spectral distribution of the radiated light of the sample and the spectral distribution of the radiated light of the fluorescent reference sample, and obtaining the spectral distribution of the radiated light of the non-fluorescent reference sample and the spectral distribution of the radiated light of the fluorescent reference sample, The reference spectral characteristic of the fluorescent reference sample is obtained from the known reference spectral characteristic of the non-fluorescent reference sample.

  Second step: illuminating the fluorescence reference sample with the first and second illumination light, and measuring the radiation light from the fluorescence reference sample with the light receiving unit to obtain and obtain the first and second spectral distributions The first and second spectral characteristics of the fluorescence reference sample are obtained from the first and second spectral distributions.

  Third step: The weight coefficient is obtained and stored so that the weighted linear combination of the first and second spectral characteristics matches the reference spectral characteristic.

  According to this configuration, the non-fluorescence reference sample is illuminated with the ambient light, and the fluorescence reference sample having two spectral characteristics similar to the measurement sample made of the fluorescent whitening sample is illuminated with the ambient light and the first and second illumination lights. As a result, the reference spectral characteristic and the first and second spectral characteristics of the fluorescence reference sample are obtained, and the weighting coefficient is calculated. Then, using this weighting factor, the first and second spectral characteristics of the measurement sample are weighted linearly combined, and the combined spectral characteristic when the measurement sample is illuminated with ambient light is calculated. Therefore, even when the two spectral characteristics of the measurement sample and the spectral distribution of ambient light are unknown, the spectral characteristics when the measurement sample is illuminated with ambient light can be measured. As a result, the spectral characteristics of the fluorescent whitening sample can be obtained practically without using an expensive dual spectrophotometer or ultraviolet-visible spectral radiance meter. Moreover, since the synthetic | combination spectral characteristic is calculated | required using the weighting coefficient obtained by the process 1-the process 3, the spectral characteristic of a measurement sample can be calculated | required with high precision. The “fluorescence reference sample having two spectral characteristics similar to the measurement sample” includes not only the case where the measurement sample and the two spectral characteristics are similar, but also the case where the measurement sample and the two spectral characteristics are the same. Further, the spectral characteristics include a total spectral emissivity coefficient. The bispectral characteristics include a bispectral fluorescence emissivity coefficient.

  (2) The first illumination light preferably has no intensity in the ultraviolet region, and the second illumination light preferably has an intensity in the ultraviolet region.

  According to this configuration, since the first illumination light does not have an intensity in the ultraviolet region and the second illumination light has an intensity in the ultraviolet region, the first spectral characteristic hardly receives the contribution of fluorescence. It is no longer affected by changes in the spectral distribution of light. Therefore, it is possible to simplify the correction of the error in the combined spectral characteristic that occurs when the spectral distribution of the first and second illumination light changes.

  (3) The synthetic spectral characteristic is a synthetic total spectral emissivity coefficient, the first and second spectral characteristics are first and second total spectral emissivity coefficients, and the reference spectral characteristic is a reference total spectral characteristic. An emissivity coefficient is preferred.

  According to this configuration, since the combined total spectral emissivity coefficient is finally calculated, various color values can be derived immediately from the measurement result.

  (4) The second illumination light has intensity only in an ultraviolet region, the combined spectral characteristic is a combined total spectral emissivity coefficient, the first spectral characteristic is a reflected spectral emissivity coefficient, The two spectral characteristics are preferably spectral fluorescence characteristics.

  According to this configuration, the second illumination light can be realized by, for example, radiated light of UVLED (ultraviolet light emitting diode), and the correction of the error of the combined total spectral emissivity coefficient that occurs when the spectral distribution of the second illumination light changes. It can be simplified.

  (5) The calculation unit may calculate an error in the reference spectral characteristic due to a difference in geometry between the illumination of the ambient light and the illumination of the first and second illumination lights in a wavelength region that does not cause fluorescence. Preferably, the weighting coefficient is obtained by correcting the difference between the reference spectral characteristic and the first spectral characteristic or the second spectral characteristic, and using the corrected reference spectral characteristic.

  According to this configuration, even if the geometry of the measuring device when illuminated with ambient light is different from the geometry of the measuring device when illuminated with the first and second illumination lights, the weighting factor is reduced by suppressing the influence thereof. Can be sought. Therefore, the synthetic spectral characteristics of the measurement sample can be obtained with high accuracy.

  (6) The calculation unit stores the spectral distribution of the second illumination light when the weighting factor is set as a reference spectral distribution, and the spectral distribution of the second illumination light and the reference spectral distribution when measuring the measurement sample. Based on the above, the second total spectral emissivity coefficient of the measurement sample by the second illumination light at the time of setting the weighting factor is estimated, and the combined total spectral radiation is calculated using the estimated second total spectral emissivity coefficient It is preferable to determine the rate coefficient.

  According to this configuration, the second total spectral emissivity coefficient of the measurement sample when illuminated with the second illumination light at the time of setting the weighting factor is estimated, and the combined total spectral emissivity is calculated using the second total spectral emissivity coefficient. A coefficient is required. Therefore, even if the spectral distribution of the second illumination light at the time of measurement of the measurement sample changes from the spectral distribution at the time of setting the weighting factor, the total spectral emissivity coefficient of the measurement sample is accurately obtained using the existing weighting factor. be able to. This configuration is particularly effective when a white LED or UV LED whose spectral distribution is likely to change due to a temperature rise due to driving is used as the light source of the first and second illumination light.

  (7) The calculation unit sets the reference spectral distribution to I02 (λ), the first and second total spectral emissivity coefficients to Bx1 (λ), Bx2 (λ), and the second illumination light at the time of measurement. When the spectral distribution is I2 (λ), it is preferable to estimate the second total spectral emissivity coefficient Bx02 (λ) of the measurement sample by the second illumination light at the time of setting the weighting coefficient as follows.

Bx02 (λ) = Bx1 (λ) + c · Fx2 (λ) · d (λ)
However,
Fx2 (λ) = Bx2 (λ) −Bx1 (λ)
c = ∫I02 (μ) dμ / ∫I2 (μ) dμ
d (λ) = I2 (λ) / I02 (λ)
According to this configuration, it is possible to accurately estimate the second total spectral emissivity coefficient when the measurement sample is illuminated with the second illumination light when the weighting coefficient is set.

  (8) The calculation unit stores the first and second total spectral emissivity coefficients of the fluorescence reference sample at the time of setting the weighting factor, and calculates a spectral distribution of the second illumination light at the time of setting the weighting factor. The measurement is performed based on the first and second total spectral emissivity coefficients stored as the reference spectral distribution, the spectral distribution of the second illumination light at the time of measurement of the measurement sample, and the reference spectral distribution. Estimating the second total spectral emissivity coefficient when the fluorescence reference sample is illuminated with the second illumination light of the time, resetting the weighting coefficient using the estimated second total spectral emissivity coefficient, It is preferable to obtain the combined total spectral emissivity coefficient using the set weight coefficient.

  According to this configuration, every time the measurement sample is measured, the weighting coefficient corresponding to the spectral distribution of the second illumination light can be set, and the total spectral emissivity coefficient of the measurement sample can be obtained with high accuracy.

  (9) The calculation unit sets the reference spectral distribution to I02 (λ), and sets the first and second total spectral emissivity coefficients at the time of setting the weighting coefficient to Br01 (λ), Br02 (λ), and the measurement time If the spectral distribution of the second illumination light is I2 (λ), the second total spectral emissivity coefficient Br2 (λ) of the fluorescence reference sample by the second illumination light at the time of the measurement may be estimated as follows. preferable.

Br2 (λ) = Br01 (λ) + c · Fr02 (λ) · d (λ)
However,
Fr02 (λ) = Br02 (λ) −Br01 (λ)
c = ∫I2 (μ) dμ / ∫I02 (μ) dμ
d (λ) = I02 (λ) / I2 (λ)
According to this configuration, it is possible to accurately estimate the second total spectral emissivity coefficient when the fluorescence reference sample is illuminated with the second illumination light at the time of measurement.

  (10) The calculation unit stores the spectral distribution of the second illumination light when the weighting factor is set as a reference spectral distribution, and the spectral distribution of the second illumination light and the reference spectral distribution when measuring the measurement sample. Based on the above, it is preferable to estimate a fluorescence spectral characteristic of the measurement sample by the second illumination light at the time of setting the weighting coefficient, and obtain the combined total spectral emissivity coefficient using the estimated spectral fluorescence characteristic.

  According to this configuration, even if the spectral distribution of the second illumination light at the time of measurement changes from the spectral distribution at the time of setting the weighting factor, the spectral total emissivity coefficient of the measurement sample can be obtained with high accuracy.

  (11) When the reference spectral distribution is I02 (λ), the fluorescence spectral characteristic at the time of measurement is Fx2 (λ), and the spectral distribution of the second illumination light at the time of measurement is I2 (λ), It is preferable that the fluorescence spectral characteristic Fx02 (λ) by the second illumination light at the time of setting the weighting factor is estimated as follows.

Fx02 (λ) = c · Fx2 (λ)
However,
c = ∫I02 (μ) dμ / ∫I2 (μ) dμ
According to this configuration, it is possible to accurately estimate the spectral fluorescence characteristics when the measurement sample is illuminated with the second illumination light when the weighting factor is set.

  (12) The calculation unit stores the reflection spectral emissivity coefficient of the fluorescence reference sample at the time of setting the weighting factor and the spectral fluorescence characteristic, and the spectrum of the second illumination light at the time of setting the weighting factor. The distribution is stored as a reference spectral distribution, and based on the stored spectral fluorescence characteristics, the spectral distribution of the second illumination light at the time of measurement of the measurement sample, and the reference spectral distribution, the second at the time of measurement. Estimating the spectral fluorescence characteristic when the fluorescence reference sample is illuminated with illumination light, resetting the weighting factor using the estimated spectral fluorescent property, and using the reset weighting factor, the combined total spectral emission It is preferable to determine the rate coefficient.

  According to this configuration, every time the measurement sample is measured, the weighting coefficient corresponding to the spectral distribution of the second illumination light at the time of measurement can be set, and the combined total spectral emissivity coefficient of the measurement sample can be obtained with high accuracy.

  (13) The calculation unit sets the reference spectral distribution to I02 (λ), the fluorescence spectral characteristic at the time of setting the weighting factor to Fr02 (λ), and the spectral distribution of the second illumination light at the time of measurement to I2 (λ). Then, it is preferable to estimate the spectral fluorescence characteristic Fr2 (λ) by the second illumination light at the time of measurement by the following.

Fr2 (λ) = c · Fr02 (λ)
However,
c = ∫I2 (μ) dμ / ∫I02 (μ) dμ
According to this configuration, it is possible to accurately estimate the spectral fluorescence characteristic of the fluorescence reference sample by the second illumination light during measurement of the measurement sample.

  (14) It is preferable that the fluorescent whitening sample is a printing surface printed on a fluorescent whitening paper, and the fluorescent reference sample is the fluorescent whitening paper.

  According to this configuration, when the wavelength dependence of the spectral transmittance of the ink in the excitation region is negligible, the spectral characteristics of the printing surface on the fluorescent white paper and the color characteristics derived from it can be practically and highly accurate. Can be measured.

  (15) The fluorescent whitening sample is a printing surface printed on a fluorescent whitening paper, and the fluorescent reference sample has the fluorescent whitening paper and one or more primary inks printed on the fluorescent whitening paper. A printed surface with an area ratio of 100% and a printed surface with an area ratio of 100% on which the primary ink is printed on the fluorescent whitening paper, and the calculation unit calculates the weight for each of the fluorescent reference samples. The coefficient is obtained and stored, and the spectral fluorescence characteristics of each of the fluorescence reference samples are stored, and the area of the element corresponding to each fluorescence reference sample from the first or second spectral characteristics of the measurement sample The fluorescence contribution ratio of each fluorescence reference sample is calculated from each estimated area ratio and the stored spectral fluorescence characteristics, and each calculated fluorescence contribution ratio and the stored weighting factor are calculated. And the above measurement Calculating the effective weighting coefficients of the sample, it is preferable to obtain the composite spectral characteristics of the measurement sample using the calculated weighting factor.

  According to this configuration, even when the wavelength dependence of the spectral transmittance of the ink in the excitation region cannot be ignored, the spectral characteristics under the ambient light of the printing surface on the fluorescent white paper and the color characteristics derived therefrom are obtained. It can be measured practically and with high accuracy.

(16) a weighting factor of n of the fluorescent reference sample W _{n (lambda),} the spectral fluorescence characteristics Fr2 n _(lambda), the area ratio of the fluorescent reference sample When S _n, the effective weighting factors We (λ) is preferably obtained as follows.

We (λ) = Σ _n C _n (λ) · W _n (λ)
However,
C _n (λ) = S _n · Fr2 _n (λ) / Σ _n (S _n · Fr2 _n (λ))
According to this configuration, it is possible to practically and accurately measure the spectral characteristics of the printing surface on the fluorescent white paper under ambient light and the color characteristics derived therefrom.

  (17) Either the first or second illumination light is illumination light having no intensity in the excitation wavelength range, and it is preferable to obtain each area ratio from the total spectral emissivity coefficient of the illumination light.

  According to this configuration, the area ratio can be obtained without the influence of fluorescence in one measurement, and the spectral characteristics of the printing surface on the fluorescent whitening paper and the color characteristics derived therefrom can be measured with high accuracy.

  (18) The light receiving unit is an objective optical system including an objective lens and an entrance aperture provided in the vicinity of the focal point of the objective lens, and a component parallel to the optical axis of the objective optical system of sample radiation light It is preferable to provide an objective optical system that converges on the incident aperture.

  According to this configuration, since only the component parallel to the optical axis of the objective optical system is received, the size of the measurement area can be increased even when the distance between the sample surface illuminated by the ambient light and the optical system is increased. Can be suppressed.

  (19) When the sample is irradiated with the ambient light to measure the emitted light, the sample holder further includes a setting holding base for holding the main body of the measuring device, and the setting holding base is configured to perform the measurement using the environmental light. It is preferable to guide to the objective optical system without blocking the illumination to the area and without blocking the radiated light from the measurement area.

  According to this configuration, it is possible to illuminate the non-fluorescence reference sample and the fluorescence reference sample with substantially the same illumination light as in the visual observation, and obtain a synthetic spectral characteristic of the measurement sample having a correlation with the case where the measurement sample is visually observed. be able to.

  (20) It is preferable that the setting holding table holds the main body portion so that the main body portion does not intersect a normal line passing through an outer edge of the measurement area.

  According to this configuration, it is possible to substantially prevent the illumination of the measurement area by ambient light.

  (21) It is preferable that the setting holding base includes a sample base plate on which the sample is arranged, and a holding base plate that is coupled to the sample base plate in a V shape and holds the main body.

  According to this configuration, the main body of the measurement apparatus can be moved away from the sample so that the illumination light from the measurement area is incident on the objective optical system without substantially blocking the illumination of the ambient light.

  (22) The sample base plate includes a sample placement portion on which the sample is placed, a non-fluorescence reference sample placed on the sample placement portion, and a slit that guides the sample onto the non-fluorescence reference sample. It is preferable.

  According to this configuration, the non-fluorescent reference sample and the fluorescent reference sample can be easily exchanged without changing the illumination conditions with ambient light.

  (23) The holding base plate includes a light shielding cylinder that guides the radiated light from the measurement region to the objective optical system and suppresses the radiated light from other than the measurement region to enter the objective optical system. It is preferable.

  According to this configuration, noise due to radiated light from outside the measurement area can be suppressed.

  (24) The setting holding table is preferably black.

  According to this configuration, an error due to a change in the relative spectral distribution of the illumination light of the sample from the relative spectral distribution of the ambient light due to the mixing of reflected light from the setting holding base is suppressed, and also due to the radiated light from outside the measurement area. Noise can be suppressed.

  According to the present invention, spectral characteristics such as the total spectral emissivity coefficient of the fluorescent whitening sample under ambient light can be measured practically and with high accuracy without using an expensive measuring device.

The external appearance block diagram in the case of illuminating a sample with the 1st, 2nd illumination light in the measuring apparatus by embodiment of this invention is shown. The external appearance block diagram at the time of the non-measurement of the measuring apparatus by embodiment of this invention is shown. It is the graph which showed the relative spectral distribution of the 1st, 2nd illumination part, the vertical axis | shaft shows the relative intensity and the horizontal axis shows the wavelength. The external appearance block diagram of the measuring apparatus in the case of illuminating a non-fluorescence reference sample and a fluorescence reference sample with environmental light is shown. It is the graph which showed the error resulting from the difference in the geometry of the standard total spectral emissivity coefficient obtained by illuminating with ambient light and the first and second total spectral emissivity coefficients. It is the figure which showed the modification of the holding stand for settings. It is a flowchart which shows the procedure at the time of white calibration. It is a flowchart which shows the measurement procedure of a sample. It is a flowchart which shows the setting procedure of a weighting coefficient.

  FIG. 1 shows an external configuration diagram when a sample is illuminated with first and second illumination light in the measuring apparatus according to the embodiment of the present invention. The measuring apparatus shown in FIG. 1 includes a main body 10 covered with a housing 11 and a measurement holding base 20 that holds the main body 10. The main body 10 includes a first illumination unit 12 using an incandescent lamp as a light source, a second illumination unit 13 using a UV LED (ultraviolet light emitting diode) as a light source, an objective lens 14, a light receiving unit 15, a CPU, a ROM, And a control processing unit 16 composed of a microcomputer such as a RAM. Hereinafter, in FIGS. 1, 2, 4, and 6, the left side is described as front and the right side is described as rear.

  The control processing unit 16 controls the drive circuit 12a to turn on the first illumination unit 12. The drive circuit 12 a turns on and off the first illumination unit 12 based on the control from the control processing unit 16. The 1st illumination part 12 illuminates the measurement sample 1 with the light beam 12b from the direction of 45 degrees with respect to the normal line.

  Similarly, the control processing unit 16 controls the drive circuit 13a to turn on the second illumination unit 13. The drive circuit 13 a turns on and off the second illumination unit 13 based on the control of the control processing unit 16. The 2nd illumination part 13 illuminates the measurement sample 1 with the light beam 13b from the direction of 45 degrees with respect to the normal line. The normal components 1 a, 2 a, 3 a of the reflected light of the measurement sample 1, the non-fluorescence reference sample 2, and the fluorescence reference sample 3 are incident on the light receiving unit 15 through the objective lens 14. That is, this measuring device is a measuring device having a 45 °: 0 ° geometry.

  When the measurement sample 1 is measured, the main body 10 is mounted on the measurement holding base 20. The measurement holding base 20 includes a sample opening 21 a that includes and defines a measurement area D <b> 1 of the measurement sample 1. The measurement sample 1 in the sample opening 21 a is illuminated by the light beams 12 b and 13 b, and a component parallel to the optical axis of the objective lens 14 of the radiated light of the measurement sample 1 is guided to the incident opening 15 a near the focal point of the objective lens 14. . Therefore, the measurement area D1 is defined by the effective diameter of the objective lens 14.

  The measurement holding base 20 includes a sample base plate 21 placed on the measurement sample 1 and a measurement device base plate 22 to which the housing 11 is attached.

  FIG. 2 shows an external configuration diagram of the measuring apparatus according to the embodiment of the present invention when not measuring. As shown in FIG. 2, the sample base plate 21 and the measuring device base plate 22 are coupled so as to be rotatable about an axis 20a. The user first views the measurement sample 1 from the sample opening 21a in the state shown in FIG. 2 with the measurement apparatus base plate 22 raised, and the sample base plate 21 is positioned so that the objective lens 14 is positioned above the sample opening 21a. And the measuring apparatus base plate 22 is closed and the main-body part 10 is positioned. Thereby, the measuring apparatus is in the state shown in FIG. Subsequently, when the measurement apparatus is activated, the control processing unit 16 first drives the drive circuit 12a to turn on the first illumination unit 12, and illuminates the measurement sample 1 with the light beam 12b.

  The normal component 1a of the radiated light from the illuminated measurement sample 1 is converged and incident on the incident aperture 15a of the light receiving unit 15 by the objective lens 14, and the first when the measurement sample 1 is illuminated with the first illumination light. The spectral distribution Ex1 (λ) is taken into the control processing unit 16.

  Subsequently, the control processing unit 16 drives the drive circuit 13 a to turn on the second illumination unit 13 and illuminates the measurement sample 1 with the second illumination light from both the first illumination unit 12 and the second illumination unit 13. Then, the second spectral distribution Ex2 (λ) of the radiated light of the illuminated measurement sample 1 is captured.

  FIG. 3 is a graph showing the relative spectral distribution of the first and second illuminators 12 and 13, where the vertical axis indicates relative intensity and the horizontal axis indicates wavelength. Graphs G1, G2, and G3 show relative spectral distributions of a light source composed of an incandescent lamp, a UVLED, and a white LED and a purple LED (PLED) that can be replaced by the incandescent lamp, respectively.

  As shown in the graph G1, the incandescent lamp has a low relative intensity in the ultraviolet region. For this reason, the first illumination light, which is the illumination light from the first illumination unit 12 composed of an incandescent lamp, has a low relative ultraviolet intensity. Further, as shown in the graph G2, the illumination light of the UVLED has a relative intensity in the ultraviolet region. Therefore, the second illumination light I2 composed of the illumination light from the incandescent lamp and the illumination light from the UVLED has a high relative ultraviolet intensity. As shown in the graph G3, the light source composed of the white LED and the PLED has two peaks around 450 nm and around 600 nm, and has no intensity in the ultraviolet region.

  In the white calibration phase prior to measurement of the measurement sample 1, the measurement of the non-fluorescence reference sample 2 is performed in the same manner as the measurement sample 1. That is, as shown in FIG. 1, first, the non-fluorescent reference sample 2 is illuminated with the first illumination light, and the first spectral distribution Ew1 (λ) of the emitted light from the non-fluorescent reference sample 2 is measured by the light receiving unit 15. The data is captured and stored by the control processing unit 16. Subsequently, the non-fluorescent reference sample is illuminated with the second illumination light, and the second spectral distribution Ew2 (λ) of the radiated light from the non-fluorescent reference sample 2 is measured by the light receiving unit 15 and captured by the control processing unit 16. Remembered.

  In the measurement phase of the measurement sample 1, the control processing unit 16 stores the first and second spectral distributions Ex1 (λ) and Ex2 (λ) of the measurement sample 1 and stores them at the time of white calibration. From the first and second spectral distributions Ew1 (λ) and Ew2 (λ) of the sample 2 and the known spectral reflectance coefficient Rw (λ) of the non-fluorescent reference sample 2, the first and second totals of the measurement sample 1 are obtained. Spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) are obtained.

  Specifically, the control processing unit 16 obtains the first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) using Expression (4).

Bx1 (λ) = Rw (λ) · Ex1 (λ) / Ew1 (λ)
Bx2 (λ) = Rw (λ) · Ex2 (λ) / Ew2 (λ) (4)
As known in the art, when fluctuations in the spectral distributions I1 (λ) and I2 (λ) of the first and second illumination lights become a problem when measuring the non-fluorescent reference sample 2 and when measuring the measurement sample 1. The spectral distribution E (λ) of the radiated light from each sample may be replaced with E (λ) / I (λ) normalized by the spectral distribution I (λ) of the illumination light at that time.

  As shown in Expression (5), the control processing unit 16 weights the first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) with a weight coefficient W (λ) stored in advance. A combined total spectral emissivity coefficient Bc (λ) that approximates the total spectral emissivity coefficient of the measurement sample 1 when linearly coupled and the measurement sample 1 is illuminated with ambient light is obtained.

Bc (λ) = W (λ) · Bx1 (λ) + (1−W (λ)) · Bx2 (λ) (5)
(Weighting factor setting)
In the weighting factor setting phase, the fluorescent reference sample 3 whose two spectral characteristics approximate the measurement sample 1 and the non-fluorescent reference sample 2 are illuminated with the specific ambient light 4, and the weighting factor W (λ) is obtained.

  As the specific ambient light 4, for example, a specific light booth is used. That is, the fluorescence reference sample 3 and the non-fluorescence reference sample 2 are installed in the light booth, and the weight coefficient W (λ) is obtained. This will be specifically described below.

  First, the main body 10 is mounted on the setting holder 30 and placed in the light booth. FIG. 4 shows an external configuration diagram of the measuring apparatus when the non-fluorescent reference sample 2 and the fluorescent reference sample 3 are illuminated with the ambient light 4. The setting holder 30 shown in FIG. 4 holds the main body 10 when the non-fluorescent reference sample 2 and the fluorescent reference sample 3 are illuminated with the ambient light 4 to measure the emitted light. Hereinafter, when the non-fluorescence reference sample 2 and the fluorescence reference sample 3 are not particularly distinguished, they are referred to as reference samples 2 and 3.

  Here, the setting holder 30 guides the objective lens 14 without substantially blocking the illumination of the measurement area D1 by the ambient light 4 and without blocking the radiation from the measurement area D1.

  Specifically, the setting holding base 30 includes a sample base plate 31 placed on the upper surface of the reference samples 2 and 3 and a measurement apparatus base plate 32 to which the main body 10 is attached. The sample base plate 31 and the measurement device base plate 32 are coupled in a V shape in a side view so that the main body 10 attached to the measurement device base plate 32 does not intersect the normal D2 passing through the outer edge of the measurement area D1. Has been.

  The sample base plate 31 is provided with a sample opening 31a that defines a measurement area D1. The measuring apparatus base plate 32 is provided with a light receiving opening 32a and a light shielding cylinder 32b.

  The light shielding cylinder 32b guides the radiated light from the measurement region D1 to the objective lens 14, and suppresses the radiated light from other than the measurement region D1 from entering the objective lens 14. Specifically, the light shielding cylinder 32 b has a bottomless cylindrical shape, and is attached to the lower surface of the measurement apparatus base plate 32 so that the central axis is orthogonal to the measurement apparatus base plate 32. The light receiving opening 32a is formed in the measuring apparatus base plate 32 in order to communicate the light shielding cylinder 32b.

  In the main body 10 attached to the measuring apparatus base plate 32, the optical axis of the objective lens 14 passes through the center of the light receiving opening 32a and the light shielding cylinder 32b and passes through the center of the sample opening 31a. In this state, when the reference samples 2 and 3 are arranged below the sample opening 31a, the reference samples 2 and 3 are illuminated with the ambient light 4 through the sample opening 31a.

  An incident aperture 15 a of the light receiving unit 15 is located at the focal position of the objective lens 14. Therefore, components 2c and 3c of the radiated light of the reference samples 2 and 3 parallel to the optical axis of the objective lens 14 are converged and incident on the incident aperture 15a, and the spectral distribution is measured.

  Next, the measurement of the reference samples 2 and 3 will be described. First, the non-fluorescent reference sample 2 is arranged under the sample opening 31a, the measurement device is activated, and the spectral distribution of the emitted light from the non-fluorescent reference sample 2 illuminated with the light booth illumination light (environment light 4). Ewe (λ) is measured by the light receiving unit 15. The measured spectral distribution Ewe (λ) is captured and stored in the control processing unit 16.

  Subsequently, the fluorescence reference sample 3 is arranged, the measurement device is started, and the spectral distribution Ere (λ) of the emitted light from the fluorescence reference sample illuminated with the same illumination light (environment light 4) is measured by the light receiving unit 15. Is done. The measured spectral distribution Ere (λ) is captured and stored in the control processing unit 16.

  The control processing unit 16 uses the expression (6) to calculate the ambient light from the acquired spectral distributions Ewe (λ) and Ere (λ) and the known spectral reflectance coefficient Rw (λ) of the non-fluorescent reference sample 2. 4, the reference total spectral emissivity coefficient Bre (λ) of the fluorescence reference sample 3 when the fluorescence reference sample 3 is illuminated is obtained and stored.

Bre (λ) = Rw (λ) · Ere (λ) / Ewe (λ) (6)
Subsequently, as shown in FIGS. 1 and 2, the main body 10 is mounted on the measurement holding base 20, and the fluorescence reference sample 3 is the first and second illumination lights in the same manner as the measurement of the measurement sample 1 described above. Illuminated, the first and second total spectral emissivity coefficients Br1 (λ), Br2 (λ) are measured by the light receiving unit 15 and stored in the control processing unit 16. After these measurements, the control processing unit 16 determines that the weighted linear combination of the first total spectral emissivity coefficient Br1 (λ) and the second total spectral emissivity coefficient Br2 (λ) is a reference total spectral emissivity coefficient. A weighting coefficient W (λ) having a value for each wavelength is obtained and stored so as to match Bre (λ), that is, so as to satisfy Expression (7).

Bre (λ) = W (λ) · Br1 (λ) + (1−W (λ)) · Br2 (λ) (7)
Here, the control processing unit 16 may change λ with a predetermined resolution, and calculate W (λ) by solving equation (7) each time λ is changed. Thereby, a weighting coefficient W (λ) having a value for each wavelength is obtained.

  When measuring a fluorescent whitening sample (measurement sample 1) having two spectral characteristics similar to those of the fluorescence reference sample 3, this weighting factor W (λ) is substituted into equation (5). Then, the first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) of the measurement sample 1 are obtained, and the obtained first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) are obtained. Linear combination is performed using a weight coefficient W (λ). Thereby, at the time of measurement of the measurement sample 1, the synthetic total spectral emissivity coefficient Bc (λ) when the measurement sample 1 is illuminated with the same ambient light 4 as at the time of setting the weighting coefficient can be obtained.

(Method using spectral fluorescence characteristics)
In the measurement apparatus described above, the illumination light of the incandescent lamp that contains almost no ultraviolet component was used as the first illumination light, and the first total spectral emissivity coefficient Bx1 (λ) was obtained. Further, the illumination light from the incandescent lamp and the illumination light from the UVLED were used as the second illumination light, and the second total spectral emissivity coefficient B2x (λ) was obtained. Then, using Equation (5), the first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) are linearly combined with the weighting coefficient W (λ), and the combined total spectral emissivity coefficient Bc (λ ) Was requested.

  However, the measurement apparatus is not limited to this, and the following method may be employed. That is, an ultraviolet cut filter or the like is attached to the first illumination unit 12, and the measurement sample 1 is illuminated using the illumination light whose ultraviolet component is suppressed as the first illumination light, and the reflected spectral emissivity coefficient Rx1 (λ) is received by the light receiving unit 15. Measured at, and taken into the control processing unit 16. Further, the second illumination light is illumination light only of UVLED, that is, only the illumination light of the second illumination unit 13 is used as the second illumination light, and the measurement sample 1 is illuminated and the spectral fluorescence characteristic Fx2 (λ) is measured by the light receiving unit 15. To the control processing unit 16. Then, as shown in the equation (8), the reflection spectral emissivity coefficient Rx1 (λ) and the spectral fluorescence characteristic Fx2 (λ) are weighted by the weighting coefficient W (λ) and linearly combined, and the combined total spectral emissivity is obtained. A coefficient Bc (λ) is obtained.

  In this case, the spectral fluorescence characteristic Fx2 (λ) is treated as a fluorescence spectral emissivity coefficient for virtual illumination light having no wavelength dependency and intensity of 1 in the fluorescence region.

Bc (λ) = Rx1 (λ) + W (λ) · Fx2 (λ) (8)
Here, the weighting factor W (λ) in the equation (8) is set using the same method as that described in the above item (setting of the weighting factor).

  That is, the main body 10 is placed on the setting holding base 30 shown in FIG. 4, and the non-fluorescence reference sample 2 and the fluorescence reference sample 3 are sequentially illuminated with the ambient light 4, and the spectral distributions Ewe (λ), Ere ( λ) are measured sequentially.

  Subsequently, a reference total spectral emissivity coefficient Bre (λ) of the fluorescence reference sample 3 is obtained using Expression (6). Subsequently, as shown in FIGS. 1 and 2, the main body 10 is mounted on the measurement holding base 20, and the fluorescence reference sample 3 is illuminated with the first illumination light in which the ultraviolet component is suppressed, so that the reflected spectral emissivity coefficient is obtained. Rr1 (λ) is measured. Subsequently, the fluorescence reference sample 3 is illuminated with the second illumination light composed only of the illumination light of the UVLED, and the spectral fluorescence characteristic Fr2 (λ) is measured.

  Subsequently, the reference total spectral emissivity coefficient Bre (λ), the reflected spectral emissivity coefficient Rr1 (λ), and the spectral fluorescence characteristic Fr2 (λ) are substituted into the equation (8) ′, and the weighting coefficient W (λ) is set. Ask.

Bre (λ) = Rr1 (λ) + W (λ) · Fr2 (λ) (8) ′
In order to prevent the measurement apparatus base plate 32 including the main body 10 and the light shielding cylinder 32b from blocking the illumination light reaching the measurement area D1 at least from the normal direction, as shown in FIG. It is placed on the measurement device base plate 32 at a predetermined distance from the measurement area D1. Thereby, the objective lens 14 receives the radiated light of the reference samples 2 and 3 from a direction inclined by a predetermined angle with respect to the direction of the normal line D2.

  In this case, the distance between the measurement area D1 and the main body 10 is increased. However, the objective lens 14 causes a light beam substantially parallel to the optical axis to enter the incident aperture 15a. Therefore, the measurement region D1 is defined by the effective diameter of the objective lens 14, and is prevented from expanding due to separation.

  Incidence of radiated light from outside the measurement area D1 to the incident slit 15a is suppressed by the light shielding cylinder 32b. However, the suppression by the light shielding cylinder 32b may not be sufficient. In this case, a black cavity having almost no reflection is disposed under the sample opening 31a, and the spectral distribution Ese (λ) of stray light is measured. Then, the spectral distributions Ewe (λ) and Ere (λ) may be corrected by subtracting the spectral distribution Ese (λ) from each of the spectral distributions Ewe (λ) and Ere (λ).

  Since the measuring device base plate 32 including the light shielding cylinder 32b is in the vicinity of the sample opening 31a, the light reflected from the reference samples 2 and 3 and its periphery is reflected by the measuring device base plate 32 and the like, and the reference samples 2 and 3 are removed. There is a risk of indirect lighting. If the indirect illumination light has a relative spectral distribution different from that of the ambient light 4, the reference samples 2 and 3 may not be illuminated with illumination light having the same relative spectral distribution as that of the ambient light 4. In this case, an error occurs in the weight coefficient W (λ).

  In the present embodiment, the measuring apparatus base plate 32 including the light shielding cylinder 32b is black. Thereby, the measurement apparatus base plate 32 including the light shielding cylinder 32b has low reflectance and low wavelength dependency, and an error in the weighting factor W (λ) can be suppressed.

(Correction of geometry difference)
The illumination by the normal ambient light 4 is incomplete diffuse illumination, and the 45 °: 0 ° geometry, which is the geometry of the measuring device when illuminated by the first and second illumination lights, and the illumination by the ambient light 4 Errors due to differences from the geometry of the measuring device are inevitable.

  FIG. 5 shows the difference in geometry between the reference total spectral emissivity coefficient Bre (λ) obtained by illumination with ambient light 4 and the first and second total spectral emissivity coefficients Br1 (λ) and Br2 (λ). It is the graph which showed the error resulting from. In FIG. 5, the vertical axis indicates the total spectral emissivity coefficient, and the horizontal axis indicates the wavelength.

  In FIG. 5, Bre indicates the reference total spectral emissivity coefficient Bre (λ) under the ambient light 4 of the fluorescence reference sample 3, and Br1 and Br2 indicate the first and second total spectral emissivity coefficients Br1 (λ) and Br2 ( λ).

  The reference total spectral emissivity coefficient Bre (λ) is uniformly higher than the first and second total spectral emissivity coefficients Br1 (λ) and Br2 (λ) in a wavelength region of 600 nm or more without fluorescence, and an error occurs. It can be seen that This error is caused by the contribution of specularly reflected light due to the difference in geometry. That is, the ambient light 4 close to the diffuse illumination causes such an error because the regular reflection light received by the objective lens 14 becomes larger than the regular reflection light of the first and second illumination lights.

  This error can be corrected as follows based on the fact that the reflectance of regular reflection has a small wavelength dependency. That is, the average value Br_ave of the difference ΔBr (λ) between the reference total spectral emissivity coefficient Bre (λ) in the wavelength region of 600 nm or more and the first total spectral emissivity coefficient Br1 (λ) is obtained. Then, the reference total spectral emissivity coefficient Bre ′ (λ) is obtained by subtracting the average value Br_ave from the reference total spectral emissivity coefficient Bre (λ). Thereby, an error included in the reference total spectral emissivity coefficient Bre (λ) can be removed. Then, the weight coefficient W (λ) may be obtained by substituting the spectral emissivity coefficient Bre ′ (λ) into the left side of Expression (7).

  The average value Br_ave can be obtained as follows. That is, in the wavelength region of 600 nm or more, each time the wavelength is changed with a predetermined resolution, the difference ΔBr (λ) = reference total spectral emissivity coefficient Bre (λ) −first total spectral emissivity coefficient Br1 ( λ). Then, an average value of the difference ΔBr (λ) is obtained. This average value is Br_ave.

  In the above description, the average value Br_ave is obtained by using the reference total spectral emissivity coefficient Bre (λ) and the first total spectral emissivity coefficient Br1 (λ), and Bre ′ (λ) is obtained. Instead of the 1 total spectral emissivity coefficient Br1 (λ), the average value Br_ave may be obtained using the second total spectral emissivity coefficient Br2 (λ), and Bre ′ (λ) may be obtained.

  FIG. 6 is a view showing a modified example of the setting holding base 30. In this modification, a reference sample base plate 2 b to which a non-fluorescent reference sample 2 is attached is attached to the sample base plate 31 of the setting holding base 30.

  When the reference sample base plate 2b is mounted on the sample base plate 31, the non-fluorescent reference sample 2 faces the sample opening 31a. Further, a step is provided on the lower surface of the sample base plate 31, and the thickness of the sample base plate 31 from the sample opening 31a to the front is thinner than the thickness to the rear.

  Thereby, a slit 31b is formed between the lower surface of the sample base plate 31 and the upper surface of the reference sample base plate 2b.

  First, the setting holder 30 is placed on the upper side of the reference sample base plate 2b, the ambient light 4 is irradiated onto the non-fluorescent reference sample 2, and the spectral distribution Ewe (λ) of the radiated light from the non-fluorescent reference sample 2 is obtained. Measured by the light receiving unit 15 and taken into the control processing unit 16.

  Subsequently, the fluorescence reference sample 3 made of fluorescent white paper is inserted from the front of the slit 31b, the ambient light 4 is irradiated to the fluorescence reference sample 3, and the spectral distribution Ire (λ) of the emitted light from the fluorescence reference sample 3 is received. Measured by the unit 15 and taken in by the control processing unit 16.

  In the example of FIG. 6, the upper surface of the non-fluorescent reference sample 2 is slightly lower than the upper surface of the reference sample base plate 2b so that the non-fluorescent reference sample 2 is not contaminated by the insertion of the fluorescent reference sample 3. In this case, the surface positions of the non-fluorescent reference sample 2 and the fluorescent reference sample 3 are deviated from each other. It is small compared to the distance between 14. Therefore, the influence of this deviation can be ignored.

(Flow chart of basic process)
FIG. 7 is a flowchart showing a procedure for white calibration. First, as shown in FIG. 2, the main body 10 is attached to the measurement holding base 20 (step S1). Next, the non-fluorescent reference sample 2 is disposed in the sample opening 21a, the sample base plate 21 and the measurement device base plate 22 are closed, and the lower surface of the housing 11 is brought into contact with the sample base plate 21, so that the first illumination unit 12 is turned on, and the non-fluorescent reference sample 2 is illuminated with the first illumination light having almost no ultraviolet component (step S2).

  Next, the normal component 2a of the emitted light of the non-fluorescent reference sample 2 illuminated with the first illumination light is received by the light receiving unit 15 via the objective lens 14, and the normal component 2a of the emitted light is received by the light receiving unit 15. The first spectral distribution Ew1 (λ) is measured and stored by the control processing unit 16 (step S3).

  Next, in a state where the lighting of the first illumination unit 12 is maintained, the second illumination unit 13 is turned on, and the non-fluorescent reference sample 2 is illuminated with the second illumination light having an ultraviolet component (step S4).

  Next, the normal component 2a of the radiated light of the non-fluorescent reference sample 2 illuminated with the second illumination light is received by the light receiving unit 15 through the objective lens 14, and the second spectral distribution Ew2 (λ) is received by the light receiving unit 15. Is measured and stored by the control processing unit 16 (step S5). Next, the 1st, 2nd illumination parts 12 and 13 are light-extinguished (step S6).

  FIG. 8 is a flowchart showing the measurement procedure of the measurement sample 1. First, the main body 10 is attached to the measurement holding base 20 (step S11). Next, white calibration shown in steps S2 to S6 in FIG. 7 is performed. Specifically, the non-fluorescent reference sample 2 is sequentially illuminated with the first and second illumination lights, and the control processing unit 16 causes the first and second spectral distributions Ew1 (λ) of the emitted light of the non-fluorescent reference sample 2 to be emitted. , Ew2 (λ) are sequentially measured, and the first and second spectral distributions Ew1 (λ) and Ew2 (λ) are sequentially stored (step S12).

  Next, the measurement sample 1 is arranged in the sample opening 21a, the first illumination unit 12 is turned on, and the measurement sample 1 is illuminated with the first illumination light having almost no ultraviolet component (step S13).

  Next, the normal component 1a of the radiated light of the measurement sample 1 illuminated with the first illumination light is received by the light receiving unit 15 through the objective lens 14, and the first spectral distribution Ex1 (λ) is received by the light receiving unit 15. Measured and stored by the control processing unit 16 (step S14).

  Next, in a state in which the lighting of the first illumination unit 12 is maintained, the second illumination unit 13 is turned on, and the measurement sample 1 is illuminated with the second illumination light having an ultraviolet component (step S15).

  Next, the normal component 1a of the radiated light of the measurement sample 1 illuminated with the second illumination light is received by the light receiving unit 15 through the objective lens 14, and the spectral distribution Ex2 (λ) is measured by the light receiving unit 15. It is stored by the control processing unit 16 (step S16).

  Next, the 1st, 2nd illumination parts 12 and 13 are light-extinguished (step S17). Next, the control processing unit 16 stores the first and second spectral distributions Ex1 (λ) and Ex2 (λ) of the stored measurement sample 1 and the first and second spectral distributions Ew1 ( λ), Ew2 (λ) and the known spectral reflectance coefficient Rw (λ) are substituted into equation (4), and the first and second total spectral emissivity coefficients Bx1 (λ), Bx2 ( (λ) is obtained (step S18).

  Next, the control processing unit 16 substitutes the first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) and the stored weighting coefficient W (λ) into the equation (5). Then, a synthetic total spectral emissivity coefficient Bc (λ) that approximates the total spectral emissivity coefficient when the measurement sample 1 is illuminated with the ambient light 4 is obtained (step S19).

  FIG. 9 is a flowchart showing a procedure for setting the weighting factor W (λ). First, the main body 10 is attached to the setting holding base 30, and the non-fluorescent reference sample 2 under the sample opening 31a is illuminated with the ambient light 4 (step S31).

  Next, a component 2 c of the radiated light of the non-fluorescent reference sample 2 illuminated with the ambient light 4 is received by the light receiving unit 15 via the objective lens 14 and is spectrally distributed by the light receiving unit 15. Ewe (λ) is measured and stored by the control processing unit 16 (step S32).

  Next, the fluorescence reference sample 3 which is a fluorescent whitening paper is inserted into the slit 31b, and the spectral distribution Ere (λ) of the fluorescence reference sample 3 illuminated with the ambient light 4 is measured by the light receiving unit 15 (step S33).

  Next, the control processing unit 16 transmits the spectral distribution Ere (λ) of the fluorescent reference sample 3, the spectral distribution Ewe (λ) of the stored non-fluorescent reference sample 2, and the known spectral reflectance coefficient Rw (λ). Are substituted into the equation (6), and the reference total spectral emissivity coefficient Bre (λ) when the fluorescent reference sample 3 is illuminated with the ambient light 4 is obtained and stored (step S34).

  Next, the main body 10 is removed from the setting holding base 30 and attached to the measurement holding base 20 (step S35). Next, white calibration in steps S2 to S6 in FIG. 7 is performed, and the first and second spectral distributions Ew1 (λ) and Ew2 (λ) of the normal component 2a of the radiated light of the non-fluorescent reference sample 2 are received by the light receiving unit. 15 and stored by the control processing unit 16 (step S36).

  Next, the fluorescence reference sample 3 is disposed in the sample opening 21a, the first illumination unit 12 is turned on, and the fluorescence reference sample 3 is illuminated with the first illumination light having almost no ultraviolet component (step S37).

  Next, the spectral distribution Er1 (λ) of the normal component 3a of the emitted light of the fluorescence reference sample 3 illuminated with the first illumination light is measured by the light receiving unit 15 and stored in the control processing unit 16 (step S38). .

  Next, in a state in which the lighting of the first illumination unit 12 is maintained, the second illumination unit 13 is turned on, and the fluorescence reference sample 3 is illuminated with the second illumination light having an ultraviolet component (step S39).

  Next, the normal component 3a of the emitted light of the fluorescence reference sample 3 illuminated with the second illumination light is received by the light receiving unit 15 through the objective lens 14, and the spectral distribution Er2 (λ) is measured by the light receiving unit 15. Is stored in the control processing unit 16 (step S40). Next, the 1st, 2nd illumination parts 12 and 13 are light-extinguished (step S41).

  Next, the control processing unit 16 stores the spectral distributions Er1 (λ) and Er2 (λ) of the stored normal component 3a of the emitted light of the fluorescent reference sample 3 and the normal of the emitted light of the non-fluorescent reference sample 2. The first and second spectral distributions Ew1 (λ) and Ew2 (λ) of the line segment 2a and the known spectral reflectance coefficient Rw (λ) are substituted into the equation (4), and the first and second spectral reference samples 3 Second total spectral emissivity coefficients Br1 (λ) and Br2 (λ) are obtained (step S42).

  Next, the control processing unit 16 includes the first and second total spectral emissivity coefficients Br1 (λ) and Br2 (λ) of the fluorescence reference sample 3, and the stored reference total spectral emissivity coefficient Bre (λ). Is substituted into equation (7) to obtain and save the weighting factor W (λ) (step S43).

(Correction of errors due to fluctuations in the spectral distribution of illumination light)
The weighting factor W (λ) set in the measurement of the reference samples 2 and 3 can be applied on the premise that the spectral distribution of the first and second illumination light has not changed since the setting of the weighting factor. However, even if the spectral distributions of the first and second illumination lights change between when measuring the measurement sample 1 and when setting the weighting factor, the measurement sample is illuminated when the first and second illumination lights are set when the weighting factor is set. If the first and second total spectral emissivity coefficients Bx01 (λ) and Bx02 (λ) are estimated, the combined total spectral emissivity coefficient Bc (λ) is obtained by applying the weighting coefficient W (λ). Can do.

  Therefore, the control processing unit 16 stores the spectral distribution I02 (λ) of the second illumination light when the weighting factor is set, and the spectral distribution I2 (λ) of the second illumination light when the measurement sample 1 is measured. Based on the spectral distribution I02 (λ) of the second illumination light at the time of setting the weighting factor, the second total spectral emissivity coefficient Bx02 (λ) by the second illumination light at the time of setting the weighting factor is estimated. (2) The combined total spectral emissivity coefficient Bc (λ) is obtained using the total spectral emissivity coefficient Bx02 (λ).

  The first total spectral emissivity coefficient Bx01 (λ) can be regarded as a reflected spectral emissivity coefficient because the ultraviolet component of the first illumination light is relatively small and the contribution of fluorescence is small. Since it is not affected by the change in the spectral distribution of the illumination light, Bx01 (λ) = Bx1 (λ) can be obtained.

  On the other hand, the second total spectral emissivity coefficient Bx02 (λ) changes to Bx2 (λ) because the ultraviolet component of the second illumination light is relatively large and has a contribution of fluorescence that cannot be ignored. The spectral emissivity coefficient Bx02 (λ) can be estimated as shown below.

  As shown in equation (1), the total spectral emissivity coefficient B (λ) is the sum of the reflected spectral emissivity coefficient R (λ) and the fluorescent spectral emissivity coefficient F (λ) (B (λ) = R (Λ) + F (λ)). Since only the fluorescence spectral emissivity coefficient F (λ) depends on the spectral distribution of the second illumination light, the fluorescence spectral emissivity coefficient Fx2 (λ) of the measurement sample 1 will be considered.

  From the above, Fx2 (λ) is expressed by equation (9).

Fx2 (λ) = Bx2 (λ) −Bx1 (λ) (9)
At the same time, Fx2 (λ) can be expressed by equation (2) ′ from equation (2).

Fx2 (λ) = ∫Fx (μ, λ) · I2 (μ) dμ / I2 (λ) (2) ′
Regarding the change of the fluorescence spectral emissivity coefficient Fx2 (λ) due to the change of the spectral distribution I2 (μ) of the second illumination light, the change of the excitation area by the UVLED (second illumination unit 13) and the incandescent lamp (first illumination unit 12). ) And consider the change in fluorescence range.

  Assuming that the wavelength dependency of excitation efficiency in the emission wavelength region of the UVLED is small, as shown in the equation (2) ′, the fluorescence spectral emissivity coefficient Fx2 (λ) has a shape due to a change in the excitation region of the UVLED radiation light. The intensity changes in proportion to the area ∫I2 (μ) dμ.

  In the present embodiment, a UVLED having a center wavelength of 375 nm and a temperature dependency of the center wavelength as small as about 0.05 nm / ° C. is employed. A general fluorescent brightener has a small wavelength dependency of excitation efficiency in the vicinity of 375 nm. Therefore, when the emission characteristics of the UVLED change, the fluorescence spectral emissivity coefficient Fx2 (λ) has an area ∫I2 (μ ) Changes in proportion to dμ.

  On the other hand, when the incandescent lamp radiation changes in the fluorescent region, as shown in the equation (2) ′, I2 (λ) exists in the denominator outside the integral, so the fluorescence spectral emissivity coefficient Fx2 (λ) is It changes in proportion to 1 / I2 (λ), resulting in a wavelength-dependent change.

  Therefore, if the spectral distribution of the second illumination light changes from I02 (λ) to I2 (λ) and the fluorescence spectral emissivity coefficient changes from Fx02 (λ) to Fx2 (λ), the fluorescence spectral radiation before the change The rate coefficient Fx02 (λ) is obtained by the equation (10).

Fx02 (λ) = c · Fx2 (λ) · d (λ) (10)
c = ∫I02 (μ) dμ / ∫I2 (μ) dμ
d (λ) = I2 (λ) / I02 (λ)
Bx1 (λ) that approximates the reflected spectral emissivity coefficient R (λ) is added to the fluorescent spectral emissivity coefficient Fx02 (λ) obtained by Expression (10) (Expression (11)). Accordingly, it is possible to estimate the second total spectral emissivity coefficient Bx02 (λ) when the measurement sample 1 is illuminated with the second illumination light when the weighting coefficient is set.

Bx02 (λ) = Bx1 (λ) + Fx02 (λ) (11)
Then, the second total spectral emissivity coefficient Bx02 (λ) obtained by Expression (11) is substituted into Bx2 (λ) of Expression (5), and the stored weighting coefficient W (λ) is expressed by Expression (5). ) To obtain the combined total spectral emissivity coefficient Bc (λ). As a result, it is possible to suppress an error in the combined total spectral emissivity coefficient Bc (λ) that occurs due to fluctuations in the spectral distribution of the first and second illumination light since the setting of the weighting coefficient.

(Alternative method 1 for correcting errors due to fluctuations in the spectral distribution of illumination light)
As another method 1 for correcting an error due to fluctuations in the spectral distribution of the first and second illumination light, the control processing unit 16 may employ the following processing.

  That is, the first and second total spectral emissivity coefficients Br01 (λ) and Br02 (λ) of the fluorescence reference sample 3 when the weighting factor is set are stored, and the spectral distribution of the second illumination light when the weighting factor is set. I02 (λ) is stored.

  The stored first and second total spectral emissivity coefficients Br01 (λ) and Br02 (λ), and the spectral distribution I2 (λ) of the second illumination light at the time of measurement of the measurement sample 1 are stored. Based on the spectral distribution I02 (λ) of the second illumination light that has been measured, the second total spectral emissivity coefficient Br2 (λ) when the fluorescence reference sample 3 is measured with the second illumination light when the measurement sample 1 is measured. ).

  Then, the weighting coefficient W (λ) is reset using the estimated second total spectral emissivity coefficient Br2 (λ), and the combined total spectral emissivity coefficient Bc (λ) using the reset weighting coefficient W (λ). )

  Specifically, the control processing unit 16 executes the following processing. From the first and second total spectral emissivity coefficients Br01 (λ) and Br02 (λ) of the fluorescence reference sample 3 used at the time of setting the weighting coefficient, the fluorescent spectral emissivity coefficient Fr02 at the time of setting the weighting coefficient using Expression (12) Find (λ).

Fr02 (λ) = Br02 (λ) −Br01 (λ) (12)
Then, the fluorescence spectral emissivity coefficient Fr2 (λ) when the fluorescence reference sample 3 is illuminated with the second illumination light having the same spectral distribution as that at the time of measurement of the measurement sample 1 is obtained by Expression (13).

Fr2 (λ) = c · Fr02 (λ) · d (λ) (13)
c = ∫I2 (μ) dμ / ∫I02 (μ) dμ
d (λ) = I02 (λ) / I2 (λ)
Then, the fluorescence spectral emissivity coefficient Fr2 (λ) obtained by the equation (13) is added to the stored first total spectral emissivity coefficient Br01 (λ) as shown in the equation (14), and the second The total spectral emissivity coefficient Br2 (λ) is obtained. Accordingly, it is possible to estimate the second total spectral emissivity coefficient Br2 (λ) when the fluorescence reference sample 3 is illuminated with the second illumination light at the time of measurement of the measurement sample 1.

Br2 (λ) = Br01 (λ) + Fr2 (λ) (14)
Here, since the first and second total spectral emissivity coefficients at the time of setting the weighting coefficient are expressed as Br01 (λ) and Br02 (λ), the equation (7) is represented by Bre (λ) = W (λ) · Br01 ( λ) + (1−W (λ)) · Br02 (λ).

  Then, the second total spectral emissivity coefficient Br2 (λ) obtained by Expression (14) is substituted into the second total spectral emissivity coefficient Br02 (λ) of Expression (7). Further, the stored Br01 (λ) is substituted for the first total spectral emissivity coefficient Br01 (λ) that is not affected by the fluctuation of the spectral distribution of the first illumination light.

  Also, Bre (λ) measured under the ambient light 4 and stored at the time of setting the weighting coefficient is substituted for Bre (λ) in the equation (7). Thereby, the weighting coefficient W (λ) is reset.

  Then, the measurement sample 1 is measured to obtain the first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ), and the weighting factor W (λ) and the first weighting factor reset in Equation (5) are calculated. Substituting the second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ), the combined total spectral emissivity coefficient Bc (λ) is obtained.

(Another method 2 for correcting errors due to fluctuations in the spectral distribution of illumination light)
Alternative method 2 is a method in which the method described in the column of (Error correction due to variation in spectral distribution of illumination light) is applied to the method of Expression (8). That is, the spectral fluorescence characteristic Fx02 (λ) when the measurement sample 1 is irradiated with the second illumination light at the time of setting the weighting factor is estimated, and the estimated spectral fluorescence characteristic Fx02 (λ) is calculated as Fx2 (λ) in Expression (8). To obtain the combined total spectral emissivity coefficient Bc (λ).

  Specifically, the control processing unit 16 stores the spectral distribution I02 (λ) of the second illumination light when the weighting factor is set. Then, the spectral fluorescence characteristic Fx2 (λ) obtained by illuminating the measurement sample 1 with the second illumination light, the spectral distribution I2 (λ) of the second illumination light when the measurement sample 1 is measured, and the spectral distribution I02 (λ ) To estimate the spectral fluorescence characteristic Fx02 (λ) by the second illumination light when the weighting factor is set. Then, a combined total spectral emissivity coefficient Bc (λ) is obtained using the estimated spectral fluorescence characteristic Fx02 (λ).

  Here, the control processing unit 16 estimates the spectral fluorescence characteristic Fx02 (λ) using Expression (15).

Fx02 (λ) = c · Fx2 (λ) (15)
c = ∫I02 (μ) dμ / ∫I2 (μ) dμ
Then, the control processing unit 16 substitutes the spectral fluorescence characteristic Fx02 (λ) obtained by Expression (15) into Fx2 (λ) of Expression (8), and illuminates the measurement sample 1 with the first illumination light. The obtained reflection spectral emissivity coefficient Rx1 (λ) and weighting coefficient W (λ) are substituted into Equation (8) to obtain the combined total spectral emissivity coefficient Bc (λ). As a result, even if the spectral distribution of the second illumination light changes between when the weighting factor is set and when the measurement sample 1 is measured, the existing weighting factor W (λ) is used so that errors due to this change are suppressed. Thus, the combined total spectral emissivity coefficient Bc (λ) can be obtained.

(Alternative method 3 for correcting errors due to fluctuations in the spectral distribution of illumination light)
Alternative method 3 is a method in which the method described in the column of (Alternative method 1 of correcting error due to variation in spectral distribution of illumination light) is applied to the method of equation (8).

  Specifically, the control processing unit 16 stores the reflected spectral emissivity coefficient Rr01 (λ) and the spectral fluorescence characteristic Fr02 (λ) when the weighting factor is set, and the second illumination when the weighting factor is set. The spectral distribution I02 (λ) of light is stored. Then, the stored spectral fluorescence characteristic Fr02 (λ), the spectral distribution I02 (λ) of the second illumination light when the weighting factor is set, and the spectral distribution I2 (2 of the second illumination light when measuring the measurement sample 1) Based on λ), the spectral fluorescence characteristic Fr2 (λ) when the fluorescence reference sample 3 is illuminated with the second illumination light during measurement of the measurement sample 1 is estimated. Then, the weight coefficient W (λ) is reset using the estimated spectral fluorescence characteristic Fr2 (λ), and the combined total spectral emissivity coefficient Bc (λ) is obtained using the reset weight coefficient W (λ).

  Here, the control processing unit 16 estimates the spectral fluorescence characteristic Fr2 (λ) using the equation (16).

Fr2 (λ) = c · Fr02 (λ) (16)
c = ∫I2 (μ) dμ / ∫I02 (μ) dμ
Since the reflection spectral emissivity coefficient and the spectral fluorescence characteristic at the time of setting the weighting coefficient are expressed as Rr01 (λ) and Fr02 (λ), the equation (8) ′ is represented by Bre (λ) = Rr01 (λ) + W (λ) · It is expressed as Fr02 (λ).

  Then, the spectral fluorescence characteristic Fr2 (λ) obtained by the equation (16) is substituted for Fr02 (λ) of the equation (8) ′, and the stored reflection spectral emissivity coefficient Rr01 and the weighting coefficient are set. The weighting coefficient W (λ) is reset by substituting the reference total spectral emissivity coefficient Bre (λ) into the equation (8) ′.

  Then, the reset weight coefficient W (λ), the reflection spectral emissivity coefficient Rx1 (λ) obtained by illuminating the first illumination light on the measurement sample 1, and the second illumination light obtained by illuminating the measurement sample 1 were obtained. By substituting the spectral fluorescence characteristic Fx2 (λ) into the equation (8), the combined total spectral emissivity coefficient Bc (λ) is obtained.

  Since these correction methods are based on the premise that the ultraviolet component of the first illumination light is relatively small, it is effective to arrange an ultraviolet cut filter in front of the first illumination unit 12. The change in the spectral distribution of the second illumination light can be monitored by a reference optical system and a spectroscope (not shown), but the UVLED is disclosed in Japanese Patent Laid-Open No. 2008-298579. It can also be estimated from a change in forward voltage when driven at a constant current.

  When the light source of the first illumination unit 12 is a white LED or a white LED + PLED shown by the graph G3 in FIG. 3, similarly, a spectral distribution change is estimated from a forward voltage change of each LED driven by a constant current. can do.

(Total spectral emissivity coefficient of printed surface on fluorescent white paper)
Since the printed surface of the fluorescent white paper is covered with ink, the excitation characteristics and fluorescent characteristics of the printed surface are not only the excitation characteristics and fluorescent characteristics of the fluorescent white paper, but also the primary inks (Y, M, C, K). And the primary ink overlap (YM, MC, CY, YMC) spectral transmission characteristics and area ratio, that is, color. Hereinafter, each primary ink and at least any two of the primary inks are described as extended primary ink.

  When the first illumination light does not contain an ultraviolet component and the first total spectral emissivity coefficient Bx1 (λ) is considered to be the reflected spectral emissivity coefficient, the control processing unit 16 uses the following to measure the measurement sample on which the ink has been printed. An effective weight coefficient We (λ) of 1 is obtained, and a combined total spectral emissivity coefficient Bc (λ) of the measurement sample 1 is obtained.

First, a FWA treated paper with 9 areas, the first area and the non-printing area, the remaining 8 regions, respectively, different extensions primary ink was printed at 100% of the area ratio, nine fluorescent reference sample R _n (N = 0 to 8, R0 is a non-printing area of fluorescent white paper). Next, the weighting factors W _n (λ) for the nine types of fluorescence reference samples R _n are obtained using the method described in the section (Setting of weighting factors). At the same time, from the first and second total spectral emissivity coefficients Br1 _n (λ) and Br2 _n (λ) obtained by illuminating nine types of fluorescence reference samples R _n with the first and second illumination lights, respectively. , The fluorescence spectral emissivity coefficient Fr2 _n (λ) is obtained using equation (17) and stored.

Fr2 _n (λ) = Br2 _n (λ) −Br1 _n (λ) (17)
In the measurement phase of the measurement sample 1, the first and second total spectral emissivity coefficients Bx1 (λ) and Bx2 (λ) of the measurement sample 1 are obtained. Then, from the first total spectral emissivity coefficient Bx1 (λ) to which the fluorescence of the printing surface does not contribute, the area ratio S _{n of} each extended primary ink P _n using a known method such as the Neugebauer equation or the Eule-Nielsen equation. Is estimated. Instead of the first total spectral radiance factor Bx1 (lambda), the area ratio S _n may be estimated using a second total spectral radiance factor Bx2 (lambda).

Contribution of the fluorescence from the printed surface of each extended primary ink P _n occupying the fluorescence from the printing surface, the area ratio S _n estimated, proportional to the product of the fluorescence spectral radiance factor Fr2 _n that has been stored , The fluorescence contribution ratio C _n (λ) is given by equation (18). For simplicity, it is assumed here that the first and second illumination lights during measurement do not change.

C _n (λ) = S _n · Fr2 _n (λ) / Σ _n (S _n · Fr2 _n (λ)) (18)
The substantial weighting coefficient We (λ) of the printed surface of the measurement sample 1 is given by Equation (19) using the fluorescence contribution rate C _n (λ).

We (λ) = Σ _n (C _n (λ) · W _n (λ)) (19)
That is, in the measurement of the total spectral emissivity coefficient of the measurement sample 1 on which the printing surface is printed with ink, the weight coefficient W _n (λ) of the plurality of fluorescent reference samples R _n obtained in advance and each sample are obtained. Based on the fluorescence contribution rate C _n (λ) that depends on the area ratio S _n , the weight coefficient We (λ) is obtained. Then, the obtained weight coefficient We (λ) is substituted into the equation (5), and the combined total spectral emissivity coefficient Bc (λ) is obtained.

In the above was nine fluorescent reference sample R _n, but is not limited thereto. That is, since the K (black) ink and the Y (yellow) ink hardly transmit the ultraviolet component of the illumination light, the extended primary ink P _n (Y, K, YM, CY, YMC including at least one of Y and K) is used. ) Fluorescence from the printed part is negligible. Sufficiently Therefore, usually, the non-printing area on the optically brightened paper, and M, C, by preparing four kinds of fluorescent reference sample R _n of the print zone to expand the primary ink P _n is printed at an area ratio of 100% MC It is. In this case, the fluorescence spectral emissivity coefficient Fr2 _n (λ) of the ignored fluorescence reference sample R _n may be set to Fr2 _n (λ) = 0.

  The total spectral emissivity coefficient of a printed sample under ambient light can be measured by the same method using the aforementioned spectral fluorescence characteristics.

  In the above description, the fluorescence spectral emissivity coefficient is adopted as an example of the spectral fluorescence characteristic. However, the present invention is not limited to this, and the fluorescence spectral intensity may be adopted.

DESCRIPTION OF SYMBOLS 1 Measurement sample 2 Non-fluorescence reference sample 3 Fluorescence reference sample 4 Ambient light 10 Main body part 12 First illumination part 13 Second illumination part 16 Control processing part (calculation part)
Bx1 (λ) First total spectral emissivity coefficient Bx2 (λ) Second total spectral emissivity coefficient Bc (λ) Composite total spectral emissivity coefficient C _n (λ) Fluorescence contribution ratio D1 Measurement area P _n Extended primary ink R ( λ) Reflective spectral emissivity coefficient R _n Fluorescence reference sample Rw (λ) Spectral reflectance coefficient Rx1 (λ) of non-fluorescent reference sample Reflected spectral emissivity coefficient S _n Area ratio W (λ) Weight coefficient

Claims (24)

Measurement to measure the spectral characteristics of a measurement sample consisting of a fluorescent whitening sample when illuminated with ambient light as illumination light in a light booth for measuring the measurement sample and having an arbitrary spectral distribution A device,
An illumination unit that illuminates the measurement sample with first and second illumination lights having different relative ultraviolet intensities;
A light receiving unit that receives the radiated light from the measurement sample and measures a spectral distribution;
The first and second spectral distributions are obtained by illuminating the measurement sample with the first and second illumination light, and measuring the emitted light from the fluorescent whitening sample with the light receiving unit, and obtaining the first The first and second spectral characteristics of the measurement sample are obtained from the second spectral distribution, the obtained first and second spectral characteristics are linearly combined with a weighting factor having a value for each wavelength, and the measurement sample is obtained. A calculation unit for obtaining a synthetic spectral characteristic of the measurement sample when illuminated with ambient light,
The said calculating part is a measuring apparatus which calculates | requires the said weighting coefficient in the following 1st-3rd processes.
1st process: The said non-fluorescence reference | standard by measuring in the said light-receiving part the radiation light from the non-fluorescence reference sample illuminated with environmental light, and the radiation light from the fluorescence reference | standard sample similar to the said measurement sample. Obtaining the spectral distribution of the radiated light of the sample and the spectral distribution of the radiated light of the fluorescent reference sample, and obtaining the spectral distribution of the radiated light of the non-fluorescent reference sample and the spectral distribution of the radiated light of the fluorescent reference sample, The reference spectral characteristic of the fluorescent reference sample is obtained from the known reference spectral characteristic of the non-fluorescent reference sample.
Second step: illuminating the fluorescence reference sample with the first and second illumination light, and measuring the radiation light from the fluorescence reference sample with the light receiving unit to obtain and obtain the first and second spectral distributions The first and second spectral characteristics of the fluorescence reference sample are obtained from the first and second spectral distributions.
Third step: The weight coefficient is obtained and stored so that the weighted linear combination of the first and second spectral characteristics matches the reference spectral characteristic. The first illumination light has no intensity in the ultraviolet region,
The measuring apparatus according to claim 1, wherein the second illumination light has an intensity in an ultraviolet region. The synthetic spectral characteristic is a synthetic total spectral emissivity coefficient,
The first and second spectral characteristics are first and second total spectral emissivity coefficients,
The measuring apparatus according to claim 1, wherein the reference spectral characteristic is a reference total spectral emissivity coefficient. The second illumination light has intensity only in the ultraviolet region,
The synthetic spectral characteristic is a synthetic total spectral emissivity coefficient,
The first spectral characteristic is a reflection spectral emissivity coefficient;
The measuring apparatus according to claim 2, wherein the second spectral characteristic is a spectral fluorescence characteristic.   The arithmetic unit may calculate the reference spectral characteristic error due to a geometric difference between the illumination of the ambient light and the illumination of the first and second illumination lights in the wavelength region where no fluorescence occurs. The measuring apparatus according to claim 1, wherein the weighting factor is obtained by correcting the difference between a spectral characteristic and the first spectral characteristic or the second spectral characteristic and using the corrected reference spectral characteristic.   The calculation unit stores a spectral distribution of the second illumination light when the weighting factor is set as a reference spectral distribution, and is based on the spectral distribution of the second illumination light and the reference spectral distribution when measuring the measurement sample. Then, a second total spectral emissivity coefficient of the measurement sample by the second illumination light at the time of setting the weighting factor is estimated, and the combined total spectral emissivity coefficient is calculated using the estimated second total spectral emissivity coefficient. The measuring device according to claim 3 to be obtained. The calculation unit sets the reference spectral distribution to I02 (λ), the first and second total spectral emissivity coefficients to Bx1 (λ), Bx2 (λ), and the spectral distribution of the second illumination light at the time of measurement. The measurement apparatus according to claim 6, wherein I2 (λ) is used to estimate a second total spectral emissivity coefficient Bx02 (λ) of the measurement sample by the second illumination light when the weighting factor is set as follows.
Bx02 (λ) = Bx1 (λ) + c · Fx2 (λ) · d (λ)
However,
Fx2 (λ) = Bx2 (λ) −Bx1 (λ)
c = ∫I02 (μ) dμ / ∫I2 (μ) dμ
d (λ) = I2 (λ) / I02 (λ)   The calculation unit stores the first and second total spectral emissivity coefficients of the fluorescence reference sample when the weighting factor is set, and sets a spectral distribution of the second illumination light when the weighting factor is set as a reference spectral distribution And the first and second total spectral emissivity coefficients, the spectral distribution of the second illumination light at the time of measurement of the measurement sample, and the reference spectral distribution at the time of the measurement. Estimating the second total spectral emissivity coefficient when the fluorescence reference sample is illuminated with two illumination lights, resetting the weighting coefficient using the estimated second total spectral emissivity coefficient, and resetting the weight The measuring apparatus according to claim 3, wherein the combined total spectral emissivity coefficient is obtained using a coefficient. The calculation unit sets the reference spectral distribution to I02 (λ), sets the first and second total spectral emissivity coefficients at the time of setting the weighting factor to Br01 (λ), Br02 (λ), and the first spectral distribution at the time of measurement. The second total spectral emissivity coefficient Br2 (λ) of the fluorescence reference sample by the second illumination light at the time of measurement is estimated as follows, assuming that the spectral distribution of the two illumination lights is I2 (λ). measuring device.
Br2 (λ) = Br01 (λ) + c · Fr02 (λ) · d (λ)
However,
Fr02 (λ) = Br02 (λ) −Br01 (λ)
c = ∫I2 (μ) dμ / ∫I02 (μ) dμ
d (λ) = I02 (λ) / I2 (λ)   The calculation unit stores a spectral distribution of the second illumination light when the weighting factor is set as a reference spectral distribution, and is based on the spectral distribution of the second illumination light and the reference spectral distribution when measuring the measurement sample. 5. The measuring apparatus according to claim 4, wherein a spectral fluorescence characteristic of the measurement sample by the second illumination light when the weighting factor is set is estimated, and the combined total spectral emissivity coefficient is obtained using the estimated spectral fluorescence characteristic. . When the reference spectral distribution is I02 (λ), the spectral fluorescence characteristic at the time of measurement is Fx2 (λ), and the spectral distribution of the second illumination light at the time of measurement is I2 (λ), the calculation unit The measurement apparatus according to claim 10, wherein the spectral fluorescence characteristic Fx02 (λ) due to the second illumination light at the time of setting is estimated as follows.
Fx02 (λ) = c · Fx2 (λ)
However,
c = ∫I02 (μ) dμ / ∫I2 (μ) dμ   The calculation unit stores the reflection spectral emissivity coefficient of the fluorescence reference sample at the time of setting the weighting factor and the spectral fluorescence characteristic, and uses the spectral distribution of the second illumination light at the time of setting the weighting factor as a reference. Based on the stored spectral fluorescence characteristics stored as a spectral distribution, the spectral distribution of the second illumination light at the time of measurement of the measurement sample, and the reference spectral distribution, the second illumination light at the time of measurement Estimating the spectral fluorescence characteristic when the fluorescent reference sample is illuminated, resetting the weighting factor using the estimated spectral fluorescent property, and using the reset weighting factor to calculate the combined total spectral emissivity coefficient The measuring device according to claim 4 to be obtained. When the reference spectral distribution is I02 (λ), the spectral fluorescence characteristic at the time of setting the weighting factor is Fr02 (λ), and the spectral distribution of the second illumination light at the time of measurement is I2 (λ), The measuring apparatus according to claim 12, wherein the spectral fluorescence characteristic Fr2 (λ) due to the second illumination light at the time of the measurement is estimated by the following.
Fr2 (λ) = c · Fr02 (λ)
However,
c = ∫I2 (μ) dμ / ∫I02 (μ) dμ The fluorescent whitening sample is a printing surface printed on fluorescent whitening paper,
The measurement apparatus according to claim 1, wherein the fluorescent reference sample is the fluorescent whitening paper. The fluorescent whitening sample is a printing surface printed on fluorescent whitening paper,
The fluorescent reference sample is
The fluorescent whitening paper;
A printing surface with an area ratio of 100% on which one or more primary inks are printed on the fluorescent whitening paper;
A printing surface with an area ratio of 100% printed by overlapping the primary ink on the fluorescent whitening paper,
The calculation unit obtains and stores the weighting factor for each of the fluorescence reference samples, stores the spectral fluorescence characteristics for each of the fluorescence reference samples, and stores the first spectral characteristics of the measurement sample. Alternatively, the area ratio of the element corresponding to each fluorescence reference sample is estimated from the second spectral characteristics, and the fluorescence contribution ratio of each fluorescence reference sample is calculated from each estimated area ratio and the stored spectral fluorescence characteristics. An effective weighting factor of the measurement sample is calculated from each calculated fluorescence contribution rate and the stored weighting factor, and a synthetic spectral characteristic of the measurement sample is obtained using the calculated weighting factor. The measuring apparatus in any one of -13. Assuming that the weight coefficient of the n fluorescence reference samples is Wn (λ), the spectral fluorescence characteristic is Fr2n (λ), and the area ratio of the fluorescence reference sample is Sn, the effective weight coefficient We (λ) is The measuring device according to claim 15, which is obtained by:
We (λ) = ΣnCn (λ) · Wn (λ)
However,
Cn (λ) = Sn · Fr2n (λ) / Σn (Sn · Fr2n (λ)) Either of the first and second illumination light is illumination light having no intensity in the excitation wavelength region,
The measuring device according to claim 15 or 16, wherein each area ratio is obtained from a total spectral emissivity coefficient by the illumination light. The light receiving unit is
An objective optical system including an objective lens and an incident aperture provided in the vicinity of the focal point of the objective lens, the objective optical for converging a component parallel to the optical axis of the objective optical system of sample radiation light on the incident aperture The measuring device according to claim 1, comprising a system. When measuring the emitted light by irradiating the sample with the ambient light, further comprising a setting holder for holding the main body of the measuring device,
The measurement apparatus according to claim 18, wherein the setting holding table guides to the objective optical system without blocking illumination of the measurement area by the ambient light and without blocking radiation light from the measurement area.   The measurement apparatus according to claim 19, wherein the setting holding base holds the main body portion so that the main body portion does not intersect a normal line passing through an outer edge of the measurement area. The setting holder is
A sample base plate on which the sample is disposed;
21. The measuring apparatus according to claim 19 or 20, comprising a holding base plate that is coupled to the sample base plate in a V shape and holds the main body.   The said sample base plate is equipped with the sample arrangement | positioning part by which the said sample is mounted, the non-fluorescence reference sample arrange | positioned at the said sample arrangement | positioning part, and the slit which guides the said sample on the said non-fluorescence reference sample. The measuring device described.   The said holding base plate is equipped with the light shielding cylinder which guides the radiated light from the said measurement area to the said objective optical system, and suppresses that the radiated light from other than the said measurement area enters into the said objective optical system. Or the measuring apparatus of 22.   The measuring apparatus according to any one of claims 19 to 23, wherein the setting holding table is black.

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