Optical measurement method and processing device

Abstract

The present invention provides an optical measurement method and a processing apparatus. The optical measurement method includes the following steps: obtaining a first detection result of a first standard lamp to which a value of spectral irradiance for a first wavelength range is assigned; obtaining a second detection result of a second standard lamp to which a value of spectral irradiance for a second wavelength range that at least partially overlaps with the first wavelength range is assigned; calculating a correction value of a calibration coefficient for wavelengths in a wavelength range where the first wavelength range and the second wavelength range overlap; determining a third calibration coefficient based on at least the first calibration coefficient and the correction value; obtaining a third detection result of a third standard lamp; and assigning a value of spectral radiant quantity or radiant quantity to the third standard lamp based on the third detection result and the third calibration coefficient.

Description

Technical Field

[0001] The present invention relates to an optical measurement method capable of expanding the measurable wavelength range and a processing apparatus applicable to the optical measurement method. Background Art

[0002] Light sources that generate light having wavelengths outside the visible region, such as the ultraviolet region and the infrared region, are used in various fields. For example, mercury lamps, deuterium lamps, UV-LEDs, etc. that irradiate light in the ultraviolet region are used for sterilization or disinfection, chemical analysis, resin curing, etc.

[0003] In order to evaluate such a light source that generates light having wavelengths outside the visible region, it is necessary to prepare a standard lamp (standard device) corresponding to the wavelengths generated by the light source.

[0004] As disclosed in Kenichi Kinoshita, "Investigation and Research on the Method for Realizing Photometric / Radiometric Standards Based on the Responsivity of Detectors," March 2008, NMIJ Measurement Standards Report Vol. 7, No. 1, <URL:https: / / unit.aist.go.jp / nmij / public / report / bulletin / Vol7 / 1 / V7N1P41.pdf>, in Japan, the national metrology standard group managed by the National Metrology Institute of Japan (NMIJ) has the highest level in terms of the assignment of values of light radiation quantities. When assigning values to photometric quantities such as luminous intensity and illuminance, a standard lamp provided by NMIJ (or the Electrical Metrology Institute of Japan) is used. Calibration service providers use a standard lamp calibrated by NMIJ (or the Electrical Metrology Institute of Japan) to calibrate equipment for general users such as illuminometers, incandescent lamps, and fluorescent lamps.

[0005] As described in "Classification related to the registration of requirements for JCSS technology: Name of classification of optical calibration methods: Photometric standard lamps, etc. (Classification related to the registration of requirements for JCSS technology: Name of classification of optical calibration methods: Photometric standard lamps, etc. (10th edition))", May 26, 2017, National Institute of Technology and Evaluation, <URL:https: / / www.nite.go.jp / data / 000001491.pdf>, for the spectral irradiance standard lamps proposed by calibration service providers, spectral irradiance for each wavelength in the calibration range of 200 [nm] or more and 400 [nm] or less is given by a specific standard device, and spectral irradiance for each wavelength in the calibration range of 250 [nm] or more and 2500 [nm] or less is given by a specific secondary standard device.

[0006] In addition, for the photometric standard lamps and total luminous flux standard lamps proposed by calibration service providers, photometric measurement values or total luminous flux measurement values corresponding to the specified voltage or specified distribution temperature are given on the premise of the visible region with a wavelength range of 360 [nm] to 830 [nm].

[0007] As described in "Regarding the implementation of calibration, etc. using a specific standard device (spectral total radiant flux)", February 16, 2016, the First Committee on Metrological Standards of the Metrology Council in 2017, <URL:https: / / www.meti.go.jp / shingikai / keiryogyoseishin / keiryo_hyojun / pdf / h29_01_s01_00.pdf>, in the calibration range of 250 [nm] or more and 2500 [nm] or less, a halogen lamp is used as the light source to be calibrated for spectral irradiance, and in the calibration range of less than 250 [nm], a deuterium lamp is used as the light source to be calibrated. Among them, the calibration range of the deuterium lamp is set to 200 [nm] or more and 400 [nm] or less.

[0008] As described above, regarding the standard lamps traceable to the national standard covering the ultraviolet to infrared regions, currently there are only two types: (1) spectral irradiance standard lamps (deuterium lamps) applicable to the calibration range of 200 [nm] or more and 400 [nm] or less, and (2) spectral irradiance standard lamps (halogen lamps) applicable to the calibration range of 250 [nm] or more and 2500 [nm] or less. The physical quantity for which values have been given for these standard lamps is spectral irradiance (as the unit, for example, it is [W / m 2 / nm] or [μW / cm 2 / nm]).

[0009] As standard lamps whose values are physical quantities other than spectral irradiance, there are total luminous flux standard lamps whose values are total luminous flux and photometric standard lamps whose values are luminance, etc.

[0010] Photometric quantities such as luminous flux and luminance are calculated by multiplying the corresponding spectral radiant quantity (for example, spectral irradiance, spectral radiant flux, and / or spectral radiant intensity) by the standard relative visibility V(λ). Here, the wavelength range defining V(λ) is the visible region from 360 [nm] to 830 [nm]. Therefore, the calculated luminous flux and luminance are also for the visible region, and it is impossible to calculate the radiant quantities in the ultraviolet region (wavelength below 360 [nm]) and the infrared region (wavelength above 830 [nm]).

[0011] Therefore, in the ultraviolet region (wavelength below 360 [nm]) or the infrared region (wavelength above 830 [nm]), to measure radiant quantities such as radiant flux, it is necessary to calibrate the measuring device by using a spectral irradiance standard lamp (deuterium lamp or halogen lamp) to ensure national standard traceability.

[0012] As an example, as disclosed in "Realization of Efficiency Improvement in Total Luminous Flux Measurement of LEDs - Development of Total Luminous Flux LED Calibration Device Based on a New Method -", May 2009, Tokyo Metropolitan Industrial Technology Research Institute (Tokyo Metropolitan Industrial Technology Research Center) TIRI News, May 2009 issue, <URL:https: / / www.iri-tokyo.jp / uploaded / attachment / 2602.pdf>, a method of calibrating the device by arranging a spectral irradiance standard lamp outside the integrating sphere was proposed.

[0013] However, the above-mentioned disclosed calibration method is difficult to improve the calibration accuracy because it uses an integrating sphere. SUMMARY OF THE INVENTION

[0014] An object of the present invention is to provide an optical measurement method, etc. for measuring the spectral radiant quantity and radiant quantity of a sample even within the wavelength range where there is no national standard traceable standard lamp whose value is a physical quantity other than spectral irradiance.

[0015] An optical measurement method according to an aspect of the present invention includes the following steps: turning on a first standard lamp to which a value of spectral irradiance for a first wavelength range has been assigned, and obtaining a first detection result output from a spectrophotometer, the spectrophotometer being arranged at a first distance from the first standard lamp to which the value of spectral irradiance has been assigned; turning on a second standard lamp to which a value of spectral irradiance for a second wavelength range that repeats at least a part of the wavelength range of the first wavelength range has been assigned, and obtaining a second detection result output from the spectrophotometer, the spectrophotometer being arranged at the first distance from the second standard lamp; calculating a first calibration coefficient based on the first detection result and the value of spectral irradiance assigned to the first standard lamp; calculating a second calibration coefficient based on the second detection result and the value of spectral irradiance assigned to the second standard lamp; calculating a correction value of a calibration coefficient for a wavelength in a wavelength range where the first wavelength range and the second wavelength range repeat, based on the first calibration coefficient and the second calibration coefficient; determining a third calibration coefficient based on at least the first calibration coefficient and the correction value; turning on a third standard lamp, and obtaining a third detection result output from a spectrophotometer arranged at a predetermined distance from the third standard lamp; and assigning a value of spectral radiant quantity or radiant quantity to the third standard lamp based on the third detection result and the third calibration coefficient.

[0016] Alternatively, the step of determining the third calibration coefficient may include the following steps: determining a correction target interval for which a correction value is to be determined in a wavelength range where the first wavelength range and the second wavelength range repeat; and determining a correction value for each wavelength included in the correction target interval.

[0017] Alternatively, the step of determining the correction target interval may include the following steps: searching for an interval in which the deviation amount between the value of the first calibration coefficient and the value of the second calibration coefficient is the smallest.

[0018] Alternatively, the step of determining a correction value for each wavelength included in the correction target interval may include the following steps: assigning respective weights corresponding to each wavelength to the value of the first calibration coefficient and the value of the second calibration coefficient for each wavelength included in the correction target interval, thereby determining a corresponding correction value.

[0019] The optical measurement method further includes the following steps: obtaining a third detection result output from the spectrophotometer based on the third standard lamp; obtaining a fourth detection result output from the spectrophotometer based on an arbitrary sample; and obtaining a second irradiance of the sample based on the ratio of the third detection result and the fourth detection result and the value of the first irradiance assigned to the third standard lamp.

[0020] The third detection result may also be the illuminance generated on the inner wall of the integrating sphere when the light from the third standard lamp is incident on the integrating sphere, and the fourth detection result may also be the illuminance generated on the inner wall of the integrating sphere when the light from the sample is incident on the integrating sphere.

[0021] The first wavelength range may also include the ultraviolet region, and the second wavelength range may also include the visible region.

[0022] The processing device according to another aspect of the present invention includes a first calibration coefficient calculation unit that calculates a first calibration coefficient based on a first detection result related to a first standard lamp to which a value of spectral irradiance for the first wavelength range has been assigned, and the value of spectral irradiance assigned to the first standard lamp. The first detection result is obtained by turning on the first standard lamp and using a spectrophotometer arranged at a first distance from the first standard lamp where the value of spectral irradiance is assigned. The processing device includes a second calibration coefficient calculation unit that calculates a second calibration coefficient based on a second detection result related to a second standard lamp to which a value of spectral irradiance for a second wavelength range that at least partially overlaps with the first wavelength range has been assigned, and the value of spectral irradiance assigned to the second standard lamp. The second detection result is obtained by turning on the second standard lamp and using a spectrophotometer arranged at the first distance from the second standard lamp. The processing device includes: a correction value calculation unit that calculates a correction value of the calibration coefficient related to the wavelength of the wavelength range where the first wavelength range and the second wavelength range overlap, based on the first calibration coefficient and the second calibration coefficient; a third calibration coefficient determination unit that determines a third calibration coefficient based on at least the first calibration coefficient and the correction value; and a photometric quantity determination unit that determines the value of the spectral radiant quantity or radiant quantity assigned to the third standard lamp, based on the third detection result related to the third standard lamp and the third calibration coefficient. The third detection result is obtained by using a spectrophotometer arranged at a predetermined distance from the third standard lamp.

[0023] According to an aspect of the present invention, even for a wavelength range for which a national standard-traceable standard lamp assigned a physical quantity value other than spectral irradiance is not provided, it is possible to measure the spectral radiant quantity and radiant quantity of a sample.

[0024] Based on the following detailed description of the present invention that can be understood in conjunction with the accompanying drawings, the above objects, features, aspects, and advantages of the present invention, as well as other objects, features, aspects, and advantages, will become clear. Description of the Drawings

[0025] Figure 1 It is a flowchart of a processing procedure showing the measurement process of the optical measurement method of the present embodiment.

[0026] Figure 2 This is a diagram for explaining the determination process of the calibration coefficient in the optical measurement method of the present embodiment.

[0027] Figure 3 This is a cross-sectional view showing a structural example of the light receiving head of the measurement system used in the optical measurement method of the present embodiment.

[0028] Figure 4 This is a diagram for explaining the calculation method of the calibration coefficient in the optical measurement method of the present embodiment.

[0029] Figure 5 This is a diagram for explaining the assignment of the values of the spectral radiant flux and the total radiant flux for the secondary standard lamp in the optical measurement method of the present embodiment.

[0030] Figure 6 This is a diagram for explaining the measurement of the spectral radiant flux of the sample in the optical measurement method of the present embodiment.

[0031] Figure 7 This shows in more detail Figure 6 a diagram of the internal structure of the third measurement system shown in

[0032] Figure 8 This is a diagram showing an example of the spectrum of the light generated by the spectral irradiance standard lamp used in the optical measurement method of the present embodiment.

[0033] Figure 9 This is Figure 8 a diagram obtained by magnifying an example of the spectrum shown in

[0034] Figure 10 This is a diagram showing an example of the uncertainty generated in the spectral irradiance standard lamp used in the optical measurement method of the present embodiment.

[0035] Figure 11 This is a diagram for explaining the influence of stray light generated in the spectral irradiance standard lamp used in the optical measurement method of the present embodiment.

[0036] Figure 12 This is a diagram showing an example of the calibration coefficient calculated using the spectral irradiance standard lamp used in the optical measurement method of the present embodiment.

[0037] Figure 13 This is a diagram for explaining the process of determining the wavelength range of the joint in the optical measurement method of the present embodiment.

[0038] Figure 14 This is a diagram showing an example of the process of determining the wavelength range of the joint in the optical measurement method of the present embodiment.

[0039] Figure 15 This is a diagram for explaining the process of combining calibration coefficients in the optical measurement method of this embodiment.

[0040] Figure 16 This is a diagram for explaining an example of the process of combining calibration coefficients in the optical measurement method of this embodiment.

[0041] Figure 17 This shows Figure 1 a more detailed flowchart of step S18.

[0042] Figure 18 This is a diagram showing an example of the combined calibration coefficient C(λ) in the optical measurement method of this embodiment.

[0043] Figure 19 This is a schematic diagram showing an example of the hardware structure of the processing device for implementing the optical measurement method of this embodiment.

[0044] Explanation of Reference Numerals

[0045] 2: Ultraviolet standard lamp; 4: Visible standard lamp; 6: Secondary standard lamp; 8: Sample; 10: First measurement system; 12: Optical table; 14: Support member; 16, 18: Base members; 20: Second measurement system; 22: Goniometer; 24: First rotation axis; 26: Holding member; 28: Second rotation axis; 30: Third measurement system; 32: Integrator; 34: Sample window; 36: Photometric window; 37: Light shield; 38: Calibration light source; 50: Spectrophotometer; 60: Light receiving head; 62: Aperture; 64: Diffusion plate; 66: Optical axis; 68: Optical fiber; 100: Processing device; 102: Processor; 104: Main memory; 106: Input unit; 108: Display unit; 110: Storage device; 112: Operating system; 114: Measurement program; 116: Measurement result; 118: Set parameters; 120: Communication interface; 122: Network interface; 124: Media drive; 126: Recording medium; AX1, AX2: Rotation axes. Detailed Embodiments

[0046] Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated.

[0047] <A. Solution>

[0048] As described above, since there is no total radiant flux standard lamp provided outside the visible region, it is difficult to evaluate the total radiant flux of a sample by comparative measurement using a total luminous flux standard lamp by methods such as the spherical luminous flux method.

[0049] Therefore, in an embodiment of the present invention, there is provided a spectral radiant flux standard lamp that outputs a wavelength range of a standard lamp for which a national standard traceable value of a physical quantity other than spectral irradiance has not been given, and an embodiment of the present invention provides a method capable of ensuring national standard traceability and using the spectral radiant flux standard lamp to evaluate the total radiant flux of a sample. Hereinafter, a spectral radiant flux standard lamp that generates light in the ultraviolet region (for example, 220 [nm] to 340 [nm]) will be mainly described.

[0050] In addition, as an example, the case of measuring spectral radiant flux or total radiant flux will be described.

[0051] <B. Outline of Measurement Process>

[0052] First, an outline of the measurement process of the optical measurement method of the present embodiment will be described.

[0053] Figure 1 It is a flowchart showing the processing procedure of the measurement process of the optical measurement method of the present embodiment. Figure 1 The steps involved in the arithmetic processing in the steps shown can also be executed by a processing device as described later.

[0054] Refer to Figure 1 , first, a determination process of the calibration coefficient of the measurement system is carried out (step S1).

[0055] Specifically, a first measurement system including an optical bench, a light receiving head, and a spectrophotometer (or a spectro-irradiance meter) is constructed (step S11).

[0056] Next, a spectral irradiance standard lamp (deuterium lamp) applicable to a calibration range of 200 [nm] or more and 400 [nm] or less (hereinafter, also referred to as "ultraviolet standard lamp".) is installed, and the optical axis of the ultraviolet standard lamp and the light receiving head is adjusted (step S12). In this state, the ultraviolet standard lamp is lit for aging (step S13). After aging, a first detection result output from the spectrophotometer when the ultraviolet standard lamp is lit is obtained (step S14).

[0057] In addition, a spectral irradiance standard lamp (halogen lamp) applicable to a calibration range of 250 [nm] or more and 2500 [nm] or less (hereinafter, also referred to as "visible standard lamp".) is installed, and the optical axis of the visible standard lamp and the light receiving head is adjusted (step S15). In this state, the visible standard lamp is lit for aging (step S16). After aging, a second detection result output from the spectrophotometer when the visible standard lamp is lit is obtained (step S17).

[0058] Using the first detection result obtained in step S14, the second detection result obtained in step S17, and the spectral irradiance values assigned to the ultraviolet standard lamp and the visible standard lamp, determine the calibration coefficient C(λ) of the constructed first measurement system (step S18).

[0059] In addition, the execution order of the processes of steps S12 to S14 and the processes of steps S15 to S17 can be any order.

[0060] Next, perform a process of assigning values of spectral radiant flux and / or total radiant flux to a spectral radiant flux standard lamp (hereinafter also referred to as the "secondary standard lamp") (step S2). Since the secondary standard lamp has been assigned values for the ultraviolet region, the secondary standard lamp can also be referred to as an ultraviolet spectral radiant flux standard lamp.

[0061] Specifically, construct a second measurement system including an optical bench, a goniometer, a light receiving head, and a spectrophotometer (step S21). Next, install the secondary standard lamp on the second measurement system (step S22). In this state, light up the secondary standard lamp for aging (step S23). Use the second measurement system to perform a photometric measurement of the secondary standard lamp to measure the spectral radiant flux of the secondary standard lamp (step S24). Assign the measured value of the spectral radiant flux to the secondary standard lamp. In addition, for the secondary standard lamp, a value of the total radiant flux can be assigned instead of the value of the spectral radiant flux, or in addition to the value of the spectral radiant flux, a value of the total radiant flux can also be assigned.

[0062] Finally, use the third measurement system to perform a measurement of the spectral radiant flux and / or total radiant flux of the sample (step S3).

[0063] Specifically, construct a third measurement system including an integrator (step S31). Next, install the secondary standard lamp on the sample window of the integrator (step S32). In this state, light up the secondary standard lamp for aging (step S33). After aging, obtain the detection result output from the spectrophotometer when the secondary standard lamp is lit as a reference value (step S34).

[0064] Next, remove the secondary standard lamp from the sample window of the integrator, and install the sample to be measured on the sample window of the integrator (step S35). In this state, light up the sample for aging (step S36). After aging, obtain the detection result output from the spectrophotometer when the sample is lit (step S37). Based on the reference value obtained in step S34 and the detection result obtained in step S37, calculate the spectral radiant flux of the sample (step S38). In addition, the total radiant flux may be calculated instead of the spectral radiant flux, or the total radiant flux may be calculated in addition to the spectral radiant flux. Then, a series of processes end.

[0065] In addition, the processes of steps S36 to S38 may be repeated the number of times corresponding to the number of samples. Also, the order of implementation of the processes of steps S32 to S34 and the processes of steps S35 to S37 may be any order.

[0066] <C. Determination Process of Calibration Coefficient (Step S1)>

[0067] First, the determination process of the calibration coefficient (step S1) will be described.

[0068] Figure 2 is a diagram for explaining the determination process of the calibration coefficient in the optical measurement method of the present embodiment. As Figure 2 in (A) and Figure 2 in (B) show, in the determination process of the calibration coefficient (step S1), the first measurement system 10 is used to determine the calibration coefficient C(λ) for the spectrophotometer 50 and the optical head 60.

[0069] The first measurement system 10 is a device based on the optical bench 12, and the optical head 60 is arranged at a specified position by the support member 14 arranged on the optical bench 12. The optical bench 12 is a jig for fixing the standard lamp and the optical head 60. The optical head 60 is optically connected to the spectrophotometer 50 via the optical fiber 68.

[0070] The measurement wavelength range of the spectrophotometer 50 includes at least the ultraviolet region. The optical fiber 68 is made of a material (such as quartz, etc.) that is transmissive at least in the ultraviolet region, and guides the light incident from one end via the optical head 60 to the spectrophotometer 50.

[0071] Figure 3 is a cross-sectional view showing a structural example of the optical head of the measurement system used in the optical measurement method of the present embodiment. The optical head 60 has a structure suitable for measuring irradiance. Specifically, referring to Figure 3, the optical head 60 includes a diaphragm 62 and a diffuser plate 64 disposed on the optical axis 66 passing through the connection position of the optical fiber 68. The light passing through the diaphragm 62 is diffused on the diffuser plate 64 and then enters the spectrophotometer 50 via the optical fiber 68.

[0072] In Figure 2 the state shown in (A) of, at a position facing the optical head 60, the ultraviolet standard lamp 2 is disposed by the base member 16 disposed on the optical table 12. The positions of the support member 14 and the base member 16 are adjusted so that the ultraviolet standard lamp 2 and the optical head 60 are disposed on the same optical axis. In addition, the distance between the ultraviolet standard lamp 2 and the optical head 60 is adjusted to a standard distance R1 (usually 500 [mm]) determined in advance for the calibration of the ultraviolet standard lamp 2. In Figure 2 the state shown in (A) of, the detection result output from the spectrophotometer 50 when the ultraviolet standard lamp 2 is lit is obtained as the first detection result.

[0073] In this way, the following process is implemented: the ultraviolet standard lamp 2 (the first standard lamp) having a spectral irradiance value given for a calibration range (the first wavelength range) of 200 nm or more and 400 nm or less is lit, and the first detection result output from the spectrophotometer 50 is obtained, and the spectrophotometer 50 is disposed at a position separated from the ultraviolet standard lamp 2 by a standard distance R1 (the first distance) given the spectral irradiance value. Here, the first wavelength range includes the ultraviolet region.

[0074] On the other hand, in Figure 2 the state shown in (B) of, at a position facing the optical head 60, the visible standard lamp 4 is disposed by the base member 18 disposed on the optical table 12. The positions of the support member 14 and the base member 18 are adjusted so that the visible standard lamp 4 and the optical head 60 are disposed on the same optical axis. In addition, the distance between the visible standard lamp 4 and the optical head 60 is adjusted to a standard distance R1 (usually 500 [mm]) determined in advance for the calibration of the visible standard lamp 4. In Figure 2 the state shown in (B) of, the detection result output from the spectrophotometer 50 when the visible standard lamp 4 is lit is obtained as the second detection result.

[0075] Thus, the following processing is performed: The visible standard lamp 4 (second standard lamp) having a spectral irradiance value assigned to a calibration range of 250 [nm] or more and 2500 [nm] or less (a second wavelength range in which at least a part of the wavelength range overlaps with the first wavelength range) is lit, and a second detection result output from the spectrophotometer 50 is obtained. The spectrophotometer 50 is arranged at a standard distance R1 (first distance) from the visible standard lamp 4 at which the spectral irradiance value is assigned. Here, the second wavelength range includes the visible region.

[0076] In addition, the detection result per unit time (Sig-Dark) after dark correction is output from the spectrophotometer 50.

[0077] Based on the detection result output from the spectrophotometer 50 when the ultraviolet standard lamp 2 is lit, the calibration coefficient C UV (λ) for the ultraviolet standard lamp 2 is calculated. That is, the processing of calculating the calibration coefficient C UV (λ) (first calibration coefficient) based on the first detection result and the spectral irradiance value assigned to the ultraviolet standard lamp 2 (first standard lamp) is performed.

[0078] Similarly, based on the detection result output from the spectrophotometer 50 when the visible standard lamp 4 is lit, the calibration coefficient C VIS (λ) for the visible standard lamp 4 is calculated. That is, the processing of calculating the calibration coefficient C VIS (λ) (second calibration coefficient) based on the second detection result and the spectral irradiance value assigned to the visible standard lamp 4 (second standard lamp) is performed.

[0079] Figure 4 is a diagram for explaining a method of calculating a calibration coefficient in the optical measurement method of the present embodiment. Figure 4 An example of the detection result of the spectrophotometer 50 is shown in (A) of Figure 4 In (B) of Figure 4 an example of the verification value for the standard lamp used in the measurement shown in (A) of Figure 4 is shown. An example of the calibration coefficient calculated based on the detection result of the spectrophotometer 50 and the corresponding verification value is shown in (C) of

[0080] Calculate Figure 4 the ratio (for each wavelength) of the detection result of the spectrophotometer 50 measured in (A) of Figure 4 to the verification value for the corresponding standard lamp shown in (B) of

[0081] as the calibration coefficient C(λ). The calculated calibration coefficient C(λ) includes values for each wavelength.UV (λ) and calibration coefficient C VIS (λ), where the calibration coefficient C UV (λ) is a calibration coefficient calculated using a spectral irradiance standard lamp (deuterium lamp) (ultraviolet standard lamp 2) applicable to a calibration range of more than 200 nm and less than 400 nm. The calibration coefficient C VIS (λ) is a calibration coefficient calculated using a spectral irradiance standard lamp (halogen lamp) (visible standard lamp 4) applicable to a calibration range of more than 250 nm and less than 2500 nm.

[0082] By synthesizing these two calibration coefficients, the calibration coefficient C(λ) of the measurement system of the present embodiment is determined. In addition, the calibration coefficient C UV (λ) calculated using the ultraviolet standard lamp 2 and the calibration coefficient C VIS (λ) calculated using the visible standard lamp 4 are used to determine a calibration coefficient C(λ).

[0083] <D. Assignment of spectral radiant flux and total radiant flux values to the secondary standard lamp (step S2)>

[0084] Next, the assignment of spectral radiant flux and total radiant flux values to the secondary standard lamp (step S2) will be described.

[0085] Figure 5 is a diagram for explaining the assignment of spectral radiant flux and total radiant flux values to the secondary standard lamp in the optical measurement method of the present embodiment. As Figure 5 shown, in the assignment of spectral radiant flux and total radiant flux values to the secondary standard lamp (step S2), the second measurement system 20 is used.

[0086] The second measurement system 20 is a system obtained by changing a part of the structure of the Figure 2 shown first measurement system 10, and a secondary standard lamp 6 is arranged instead of the standard lamp (ultraviolet standard lamp 2 or visible standard lamp 4). Since the optical head 60, the optical fiber 68, and the spectrophotometer 50 are the same as those used in the first measurement system 10, the calibration coefficient C(λ) determined in the above calibration coefficient determination process (step S1) can be directly utilized.

[0087] The secondary standard lamp 6 can be arranged at an arbitrary facing position relative to the optical head 60 through the goniometer 22 arranged on the optical bench 12.

[0088] More specifically, the goniometric stage 22 includes: a first rotation axis 24 that can rotate along the rotation axis AX1; a holding member 26 supported by the first rotation axis 24; and a second rotation axis 28 provided on the holding member 26 and capable of rotating along the rotation axis AX2 (orthogonal to the rotation axis AX1). The secondary standard lamp 6 is connected to the second rotation axis 28. Therefore, the secondary standard lamp 6 can rotate relative to the optical head 60 along the rotation axis AX1 and the rotation axis AX2, respectively. Regardless of the rotation state, the measurement distance R2 between the optical head 60 and the secondary standard lamp 6 remains fixed. That is, the goniometric stage 22 is a mechanism that rotates the secondary standard lamp 6 independently along two rotation axes while keeping the distance to the optical head 60 fixed.

[0089] Thus, the following process is implemented: the secondary standard lamp 6 (the third standard lamp) is lit, and the detection result (the third detection result) output from the spectrophotometer 50 is acquired, and the spectrophotometer 50 is disposed at a position where the measurement distance is a predetermined distance R2 from the secondary standard lamp 6.

[0090] The spectral radiant flux Φ ST (λ) of the secondary standard lamp 6 is measured using the detection result obtained in this way. The measurement process and measurement method, etc. of the spectral radiant flux Φ ST (λ) of the secondary standard lamp 6 will be described.

[0091] In a state where the secondary standard lamp 6 and the optical head 60 are in an arbitrary relative relationship (the angle θ of the rotation axis AX1, the angle ) of the rotation axis AX2), the detection result (the signal intensity per unit time after dark correction) of the spectrophotometer 50 is set as

[0092] Using the calibration coefficient C(λ) determined in the above-described calibration coefficient determination process (step S1), the spectral irradiance of the secondary standard lamp 6 is expressed as in the following formula (1).

[0093] Since there is an inverse square law E = I / r 2 between the irradiance E [W / m 2 and the radiant intensity I [W / sr], the spectral radiant intensity [W / sr / nm] of the secondary standard lamp 6 is as shown in the following formula (2).

[0094]

[0095] By the spectral radiant intensity of the secondary standard lamp 6 Integrating over all solid angles makes it possible to calculate the spectral radiant flux Φ ST (λ) [W / nm] of the secondary standard lamp 6. That is, the spectral radiant flux Φ ST (λ) of the secondary standard lamp 6 is as shown in the following equation (3).

[0096]

[0097] As described above, while successively changing the position of the secondary standard lamp 6 relative to the light receiving head 60 using the goniometer 22 of the second measurement system 20, the values obtained by successively multiplying the detection results (Sig - Dark) successively output from the spectrophotometer 50 by the reciprocal of the calibration coefficient C(λ) and the square value of the measurement distance R2 are successively accumulated. Thus, the spectral radiant flux ΦST(λ) of the secondary standard lamp 6 can be calculated.

[0098] In addition, the movement amount (change amount of position) of the secondary standard lamp 6 relative to the light receiving head 60 can be appropriately set according to the field of view of the light receiving head 60.

[0099] Furthermore, by integrating the spectral radiant flux Φ ST (λ) of the secondary standard lamp 6 with respect to the wavelength λ, the total radiant flux Φ ST of the secondary standard lamp 6 can be calculated.

[0100] Through the above processing, the assignment of the values of the spectral radiant flux Φ ST (λ) and the total radiant flux Φ ST for the secondary standard lamp 6 is completed.

[0101] Thus, the following processing is performed: Based on the detection results (third detection results) output from the spectrophotometer when the secondary standard lamp 6 (third standard lamp) is lit, and the calibration coefficient C(λ) (third calibration coefficient), the spectral radiant flux Φ ST (λ) and the total radiant flux Φ ST values are assigned to the secondary standard lamp 6.

[0102] <E. Measurement of the Spectral Radiant Flux of the Sample (Step S3)>

[0103] Next, the measurement of the spectral radiant flux of the sample (step S3) will be described.

[0104] Figure 6 is a diagram for explaining the measurement of the spectral radiant flux of the sample in the optical measurement method of the present embodiment. Figure 7 is a diagram showing more details of Figure 6 the internal structure of the third measurement system 30 shown.

[0105] As Figure 6As shown, in the measurement of the spectral radiant flux of the sample (step S3), the third measurement system 30 is used.

[0106] The third measurement system 30 functions as a total radiant flux measurement device (spherical photometer), and includes an integrator 32, a light receiving head 60, and a spectrophotometer 50 optically connected to the light receiving head 60 via an optical fiber 68. In Figure 6 this case, as an example, the measurement of the spectral radiant flux of the sample 8 is shown.

[0107] More specifically, in the third measurement system 30, the spectral radiant flux and / or total radiant flux of the sample 8 is measured by a comparison measurement with a secondary standard lamp 6 given values of spectral radiant flux and / or total radiant flux.

[0108] A white diffuse reflection material such as barium sulfate (BaSO 4 ) or Spectralon (registered trademark) (PTFE) is coated on the inner wall of the integrator 32. The light incident on the integrator 32 or the light generated inside the integrator 32 or incident on the inside becomes a state of uniformly illuminating the inner wall of the integrator 32 after being multiply reflected on the inner wall of the integrator 32. In such a state, the average irradiance of the inner wall of the integrator 32 is proportional to the total radiant flux of the incident light.

[0109] A photometric window 36 embedded with a transmissive diffuser plate or the like is provided on a part of the inner wall of the integrator 32. The light receiving head 60 is installed on the photometric window 36, and by observing the irradiance of the inner wall of the integrator 32, a measurement result proportional to the spectral radiant flux or total radiant flux of the light source can be obtained.

[0110] In addition, as the integrator 32, either a spherical integrator as Figure 6 shown or a hemispherical integrator with a mirror surface can be used.

[0111] As Figure 7 shown, a light shielding plate 37 can also be provided inside the integrator 32 so that the light incident from the sample window 34 does not directly enter the photometric window 36.

[0112] In addition, a correction light source 38 for correcting self-absorption can also be provided. The correction light source 38 is used to determine a self-absorption correction coefficient α for correcting the influence caused by the absorption of light by the components existing inside the integrator 32.

[0113] As described above, in step S2, values of spectral radiant flux and / or total radiant flux were assigned to the secondary standard lamp 6, which is a UV spectral radiant flux standard lamp. In the third measurement system 30, the spectral radiant flux and / or total radiant flux of the sample 8 was calculated by comparing and measuring the secondary standard lamp 6 with the sample 8.

[0114] If the value of the total radiant flux assigned to the secondary standard lamp 6 is set as Φ ST and the detection result of the spectrophotometer 50 when the secondary standard lamp 6 is lit is set as S ST and the detection result of the spectrophotometer 50 when the sample 8 is lit is set as S SMP , then the total radiant flux Φ SMP of the sample 8 is as shown in the following equation (4).

[0115] Φ SMP = α × S SMP / S ST × Φ ST …(4)

[0116] When the shape of the secondary standard lamp 6 is substantially the same as the shape of the sample 8, the self-absorption correction coefficient α≈1 can also be regarded as.

[0117] Or, if considering the detection results for each wavelength (each channel), the spectral radiant flux Φ SMP (λ) of the sample 8 is as shown in the following equation (5).

[0118] Φ SMP (λ) = α × S SMP (λ) / S ST (λ) × Φ ST (λ)…(5)

[0119] As Figure 6 shown in (A) of ST , the secondary standard lamp 6 was installed in the sample window 34 of the integrator 32, and the detection result S of the spectrophotometer 50 when the secondary standard lamp 6 was lit was obtained.

[0120] In this way, the process of obtaining the irradiance generated by the secondary standard lamp 6 (the third standard lamp) was implemented. The obtained irradiance is the irradiance generated on the inner wall of the integrator 32 after the light from the secondary standard lamp 6 (the third standard lamp) is incident on the integrator 32. Figure 6 Similarly, as SMPIn this way, a process of obtaining the irradiance generated by an arbitrary sample 8 is implemented. The obtained irradiance is the irradiance generated on the inner wall of the integrator 32 after the light from the sample 8 is incident on the integrator 32.

[0121] Using the obtained detection result S ST and the detection result S SMP , and the spectral radiant flux Φ ST (λ) or the total radiant flux Φ ST value assigned to the secondary standard lamp 6, to calculate the spectral radiant flux Φ SMP (λ) or the total radiant flux Φ SMP of the sample 8. In this way, the following process is implemented: based on the detection result S ST obtained for the secondary standard lamp 6 SMP and the detection result S ST obtained for the sample 8 ST ratio, and the spectral radiant flux Φ SMP (λ) or the total radiant flux Φ SMP value assigned to the secondary standard lamp 6, to obtain the spectral radiant flux Φ SMP

[0122] (λ) or the total radiant flux Φ (λ) or the total radiant flux Φ SMP value of the sample 8.

[0123] In addition, it is known that the reflectivity of the diffuse reflection material (such as barium sulfate, Spectralon) coated on the inner wall of the integrator 32 gradually decreases with the passage of time. Therefore, it is preferable that there is as little time gap as possible between the process of obtaining the detection result S ST of the spectrophotometer 50 when the secondary standard lamp 6 is lit and the process of obtaining the detection result S SMP of the spectrophotometer 50 when the sample 8 is lit. Therefore, it is preferable to regularly implement the process of obtaining the detection result S ST as a reference value.

[0124] <F. Determination process of calibration coefficient C(λ)>

[0125] Next, the process of determining the calibration coefficient C(λ) in the process of determining the calibration coefficient (step S1) will be described in detail (step S18).

[0126] (f1: Overall process)

[0127] Figure 8 is a diagram showing an example of the spectrum of the radiation generated by the spectral irradiance standard lamp used in the optical measurement method of the present embodiment. In Figure 8In this case, the intensities of the radiations generated by the respective standard lamps are shown in a standardized state.

[0128] Refer to Figure 8 . The ultraviolet standard lamp 2 generates radiation having a wavelength range of approximately 200 [nm] to 400 [nm]. On the other hand, the visible standard lamp 4 generates radiation having a wavelength range of approximately 250 [nm] or more.

[0129] Figure 9 is a diagram obtained by magnifying an example of the spectrum shown in Figure 8 . Refer to Figure 9 . The range of 250 [nm] to 400 [nm] is the wavelength range where the radiation generated by the ultraviolet standard lamp 2 and the radiation generated by the visible standard lamp 4 overlap.

[0130] In the optical measurement method of the present embodiment, from the viewpoints of (1) uncertainty and (2) error caused by stray light, the calibration coefficient C UV (λ) calculated using the ultraviolet standard lamp 2 and the calibration coefficient C VIS (λ) calculated using the visible standard lamp 4 are joined to synthesize the calibration coefficient C(λ). First, each viewpoint will be described.

[0131] Figure 10 is a diagram showing an example of the uncertainty generated by the spectral irradiance standard lamp used in the optical measurement method of the present embodiment. Refer to Figure 10 . The uncertainty of the ultraviolet standard lamp 2 is relatively large compared to the uncertainty of the visible standard lamp 4. That is, it is considered that the accuracy of the calibration coefficient C UV (λ) calculated using the ultraviolet standard lamp 2 is lower than the accuracy of the calibration coefficient C VIS (λ) calculated using the visible standard lamp 4.

[0132] Therefore, it is also considered preferable to use the calibration coefficient C UV (λ) in the wavelength range below the boundary with the lower limit wavelength of 250 [nm] of the visible standard lamp 4, and to use the calibration coefficient C VIS (λ) in the wavelength range above the boundary. However, near the lower limit wavelength of the visible standard lamp 4, the influence of the error caused by the stray light that may be generated inside the spectrophotometer 50 is large.

[0133] Figure 11 is a diagram for explaining the influence of the stray light generated by the spectral irradiance standard lamp used in the optical measurement method of the present embodiment. In Figure 11 (A), the stray light generated by the ultraviolet standard lamp 2 is shown, and in Figure 11 (B), the stray light generated by the visible standard lamp 4 is shown.

[0134] As shown Figure 11 in (A) of FIG. 2, regarding the radiation generated by the ultraviolet standard lamp 2, the shorter the wavelength side, the higher the intensity, and the influence of stray light relatively becomes smaller. As a result, it can be considered that the value of the calibration coefficient C UV (λ) on the shorter wavelength side is more accurate.

[0135] On the contrary, as shown Figure 11 in (B) of FIG. 2, regarding the radiation generated by the visible standard lamp 4, the shorter the wavelength side, the lower the intensity, and the influence of stray light relatively becomes larger. As a result, it can be considered that the value of the calibration coefficient C VIS (λ) on the shorter wavelength side is less accurate.

[0136] Figure 12 FIG. 3 is a diagram showing an example of the calibration coefficient calculated using the spectral irradiance standard lamp used in the optical measurement method of the present embodiment. In Figure 12 FIG. 3, an example of the calibration coefficient C UV (λ) calculated using the ultraviolet standard lamp 2 and the calibration coefficient C VIS (λ) calculated using the visible standard lamp 4 are shown.

[0137] It can be seen that regarding the calibration coefficient C VIS (λ) calculated using the visible standard lamp 4 among these calibration coefficients, the calibration coefficient changes rapidly on the wavelength side shorter than 350 [nm]. Such a rapid change in the calibration coefficient is considered to be caused by the influence of stray light that may be generated inside the spectrophotometer 50. According to Figure 12 the calculation example of the calibration coefficient shown in FIG. 3, it can be said that the range before the lower limit wavelength 250 [nm] of the visible standard lamp 4 cannot be used for calibration.

[0138] Based on the above research, regarding the calibration coefficient C(λ) in the wavelength range (for example, 250 [nm] to 400 [nm]) where the light generated by the ultraviolet standard lamp 2 and the light generated by the visible standard lamp 4 overlap as shown in Figure 9 FIG. 3, it is preferable to appropriately join the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ).

[0139] As a basic idea when joining the calibration coefficients, for example, within the range where the calibration coefficient C VIS (λ) calculated using the visible standard lamp 4 with a small uncertainty can be practically applied, the calibration coefficient C VIS(λ) is used as the calibration coefficient C(λ). In addition, for wavelengths from the lower limit wavelength (e.g., 200 nm) where there is no verification value of the visible standard lamp 4 to the wavelength at which the calibration coefficient C UV (λ) calculated using the ultraviolet standard lamp 2 and the calibration coefficient C VIS (λ) show approximate values (hereinafter, also referred to as the "junction wavelength range"). The calibration coefficient C UV (λ) is mainly used.

[0140] In this way, in order to join the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ) to determine the calibration coefficient C(λ), the following two processes are required.

[0141] (1) Search process for the junction wavelength range where the calibration coefficients are the same or approximate

[0142] (2) Arithmetic process for joining the calibration coefficients

[0143] These processes will be described in detail below.

[0144] (f2: Search process for the wavelength range where the calibration coefficients are the same or approximate (junction wavelength range))

[0145] The junction wavelength range corresponds to the correction target interval for determining the correction value of the calibration coefficient in the wavelength range where the wavelength range of the ultraviolet standard lamp 2 overlaps with the wavelength range of the visible standard lamp 4. The search process for the junction wavelength range is a process of determining the correction target interval for determining the correction value of the calibration coefficient.

[0146] Preferably, the junction wavelength range is not determined by visual observation by the user, but the numerical search is performed according to a specified algorithm. In particular, the width of the junction wavelength range varies according to the specifications of the standard lamp and the spectrophotometer used. In the case of determination by visual observation by the user, the deviation of each user is large.

[0147] Figure 13 is a diagram for explaining the process of determining the junction wavelength range in the optical measurement method of the present embodiment. Refer to Figure 13 , it is preferable to evaluate the calibration coefficient C UV (λ) calculated using the ultraviolet standard lamp 2 and the calibration coefficient C VIS (λ) for the junction wavelength range where they are the same or approximate through an interval including a plurality of consecutive calibration coefficients.

[0148] For example, when only through the calibration coefficient C UV (λ) and the calibration coefficient C VISWhen evaluating a single intersection point of (λ), in the case where there are multiple intersection points, it is not possible to appropriately determine the junction wavelength range. Therefore, for the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ) intersect at multiple points, as Figure 13 shown, it is preferable to perform the evaluation through an interval that includes multiple consecutive calibration coefficients.

[0149] In Figure 13 the example shown, the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ) intersect at three points. An example is shown where the evaluation is performed through a total of three points including the two adjacent points centered on each intersection point. By evaluating the differences (such as root mean square and sum of squares) of the calibration coefficients of three consecutive points, it is determined which interval is appropriate.

[0150] In Figure 13 the example shown, it is determined that the interval including the middle intersection point is appropriate, and this interval is determined as the junction wavelength range.

[0151] More specifically, the consistency of the calibration coefficient can also be evaluated according to the root mean square (RMS: Root Mean Square) shown in the following equation (6).

[0152]

[0153] S UV (λ): The detection value of the spectrophotometer when the ultraviolet standard lamp is lit

[0154] R UV (λ): The verification value for the ultraviolet standard lamp

[0155] C UV (λ) = S UV (λ) / R UV (λ): The calibration coefficient for the ultraviolet standard lamp

[0156] S VIS (λ): The detection value of the spectrophotometer when the visible light standard lamp is lit

[0157] R VIS (λ): The verification value for the visible light standard lamp

[0158] C VIS (λ) = S VIS (λ) / R VIS (λ): The calibration coefficient for the visible light standard lamp

[0159] ΔC(λ i) = C UV (λ i ) / C VIS (λ i ) - 1: Deviation amount of calibration coefficient for wavelength λi

[0160] In the above formula (6), assuming the range length of (2N + 1) consecutive points centered on the wavelength λ i calculate the calibration coefficient C at each point UV (λ) and the difference (deviation amount) between the calibration coefficient C VIS (λ), and calculate the root mean square ΔC of the differences within the wavelength range of the calculation object RMS (λ i ) as the coefficient deviation amount. Change the wavelength λ UV (λ) within the overlapping range of the calibration coefficient C VIS (λ) and the calibration coefficient C i , and also change the adjacent length N within a specified range. Then, the combination of the wavelength λ RMS (λ i : N) with the smallest coefficient deviation amount and the adjacent length N is determined as the junction wavelength range. That is, the junction wavelength range is determined as the range including N points on the short - wavelength side and the long - wavelength side respectively centered on the wavelength λ K . K

[0161] In addition, calculate the deviation amount of the calibration coefficient at the wavelength λ UV (λ) based on the ratio of the calibration coefficient C VIS (λ) to the calibration coefficient C i (λ), but it is also possible to calculate the deviation amount of the calibration coefficient at the wavelength λ VIS (λ) based on the ratio of the calibration coefficient C UV (λ) to the calibration coefficient C i (λ), or it can simply be the difference between the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ).

[0162] In this way, the process of determining the junction wavelength range includes the process of searching for the interval with the smallest deviation amount between the value of the calibration coefficient C UV (λ) and the value of the calibration coefficient C VIS (λ).

[0163] Figure 14 is a diagram showing an example of the process of determining the junction wavelength range in the optical measurement method of this embodiment. In Figure 14 the example shown, for the wavelength λ K , the coefficient deviation amount ΔC RMS (λ​i : N). In this example, the coefficient deviation amount ΔC RMS (λ i : N) takes the minimum value when the adjacent length N = 1, and thus the adjacent length N = 1 is determined. Then, the interval including three points centered on the wavelength λ K is determined as the joint wavelength range.

[0164] In this way, in the search process for the joint wavelength range, the coefficient deviation amount ΔC RMS (λ i : N) is calculated for each adjacent length N (N = 1, 2,...), and the calculated coefficient deviation amount ΔC RMS (λ i : N) with the minimum value is determined. Based on the wavelength λ RMS (λ i : N) at which the coefficient deviation amount ΔC K : N) takes the minimum value and the adjacent length N, the joint wavelength range is determined.

[0165] Through the search process described above, the joint wavelength range can be determined. In addition, the joint wavelength range generally refers to a range including multiple wavelengths, but it can also include the case of including only one wavelength. In this case, typically, the calibration coefficient C UV (λ) and the intersection point of the calibration coefficient C VIS (λ) correspond to the joint wavelength range.

[0166] (f3: The arithmetic processing for joining the calibration coefficients)

[0167] Next, the arithmetic processing for joining the calibration coefficients within the determined joint wavelength range is described. The arithmetic processing for joining the calibration coefficients is equivalent to the process of determining the correction value of the calibration coefficient for each wavelength included in the joint wavelength range (the correction target interval for which the correction value of the calibration coefficient should be determined).

[0168] Figure 15 is a diagram for explaining the process of joining the calibration coefficients in the optical measurement method of this embodiment. Referring to Figure 15 , even within the joint wavelength range, there is a deviation between the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ). That is, at each wavelength, the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ) do not exactly match.

[0169] Therefore, in order to determine the calibration coefficient for each wavelength, it is preferable to apply a certain interpolation process. In this interpolation process, it is preferable to maintain the continuity with the calibration coefficients at adjacent wavelengths as much as possible.

[0170] Figure 16 FIG. is a diagram showing an example of a process of joining calibration coefficients in the optical measurement method of the present embodiment. Refer to Figure 16 , within the joint wavelength range, by weighting the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ) respectively according to the wavelength, the calibration coefficient C(λ) is determined.

[0171] More specifically, the shorter the wavelength side, the greater the weight given to the calibration coefficient C UV (λ), on the other hand, the longer the wavelength side, the greater the weight given to the calibration coefficient C VIS (λ). The weight given can also be set as a weight corresponding to the distance (wavelength difference) from the center wavelength of the joint wavelength range, i.e., the wavelength λ K . More specifically, for example, the correction value of the calibration coefficient at the wavelength λ i when determining the calibration coefficient C(λ) can be calculated according to the weighting calculation shown in the following formula (7).

[0172]

[0173] λ K : Center wavelength of the joint wavelength range

[0174] λ K-N : Lower limit wavelength of the joint wavelength range

[0175] λ K+N : Upper limit wavelength of the joint wavelength range

[0176] C UV (λ): Calibration coefficient for the ultraviolet standard lamp

[0177] C VIS (λ): Calibration coefficient for the visible light standard lamp

[0178] As described above, the following process is performed: Based on the calibration coefficient C UV (λ) (first calibration coefficient) and the calibration coefficient C VIS (λ) (second calibration coefficient), the correction value of the calibration coefficient for the wavelength within the wavelength range where the calibration range (first wavelength range) of the ultraviolet standard lamp 2 and the calibration range (second wavelength range) of the visible light standard lamp 4 overlap is calculated. More specifically, by calculating for each wavelength included in the joint wavelength range (correction target interval) the calibration coefficient CUV The value of (λ) and the calibration coefficient C VIS The value of (λ) assigns respective weights corresponding to each wavelength to determine the correction value of the corresponding calibration coefficient.

[0179] Through this arithmetic processing of joining the calibration coefficients, the calibration coefficient C(λ within the wavelength range of the joint can be determined. i )

[0180] (f4: Processing procedure)

[0181] Next, the processing for determining the calibration coefficient C(λ) will be described.

[0182] Figure 17 is a flowchart showing Figure 1 a more detailed processing procedure of step S18. Refer to Figure 17 , and based on the first detection result obtained for the ultraviolet standard lamp 2 and the value of the spectral irradiance assigned to the ultraviolet standard lamp 2, calculate the calibration coefficient C UV (λ) (step S181). Similarly, based on the second detection result obtained for the visible standard lamp 4 and the value of the spectral irradiance assigned to the visible standard lamp 4, calculate the calibration coefficient C VIS (λ) (step S182).

[0183] For the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ), search for the combination of the coefficient deviation amount ΔC RMS (λ i : N) with the smallest wavelength λ K and the adjacent length N (step S183). Based on the wavelength λ K and the adjacent length N found in step S183, determine the joint wavelength range (step S184).

[0184] For each wavelength included in the joint wavelength range determined in step S184, based on the calibration coefficient C UV (λ) and the calibration coefficient C VIS (λ), calculate the correction value of the calibration coefficient through weighted arithmetic (step S185).

[0185] For wavelengths shorter than the joint wavelength range, adopt the corresponding calibration coefficient of the calibration coefficient C UV (λ), for the joint wavelength range, adopt the correction value of the calibration coefficient calculated in step S185, and for wavelengths longer than the joint wavelength range, adopt the calibration coefficient C VISThe corresponding calibration coefficient of (λ), thereby determining the calibration coefficient C(λ) (step S186).

[0186] In addition, it may also be the case that when the joint wavelength range is set to a range including 400 [nm], the calibration coefficient C is not necessarily required. VIS The corresponding calibration coefficient of (λ). Therefore, at least based on the calibration coefficient C UV (λ) (the first calibration coefficient) and the correction value of the calibration coefficient included in the joint wavelength range to determine the calibration coefficient C(λ).

[0187] (f5. Synthesis result)

[0188] Figure 18 is a diagram showing an example of the calibration coefficient C(λ) synthesized in the optical measurement method of the present embodiment. Refer to Figure 18 It can be seen that by synthesizing the calibration coefficient C(λ) based on a plurality of calibration coefficients, a more accurate calibration coefficient can be determined.

[0189] <G. Processing device>

[0190] A part of the optical measurement method of the present embodiment may also be executed by a processing device connected to the spectrophotometer 50.

[0191] Figure 19 is a schematic diagram showing a hardware structure example of the processing device 100 for implementing the optical measurement method of the present embodiment. Refer to Figure 19 , the processing device 100 includes a processor 102, a main memory 104, an input unit 106, a display unit 108, a storage device 110, a communication interface 120, a network interface 122, and a medium drive 124.

[0192] Typically, the processor 102 is an arithmetic processing unit such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and is used to read one or more programs stored in the storage device 110 into the main memory 104 for execution. The main memory 104 is a volatile memory such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory), and functions as a working memory required for the processor 102 to execute programs.

[0193] The input unit 106 includes a keyboard, a mouse, etc., and is used to receive operations from the user. The display unit 108 outputs the execution results and the like obtained by the processor 102 executing programs to the user.

[0194] The storage device 110 includes non-volatile memories such as a hard disk and a flash memory, and is used to store various programs and data. More specifically, the storage device 110 holds an operating system 112 (OS: Operating System), a measurement program 114, measurement results 116, and setting parameters 118.

[0195] The operating system 112 provides an environment for the processor 102 to execute programs. By executing the measurement program 114 with the processor 102, the optical measurement method of the present embodiment and the like are realized. The measurement results 116 include the spectral radiant flux Φ SMP (λ) and / or the measurement results of the total radiant flux Φ SMP The setting parameters 118 include the verification values of the ultraviolet standard lamp 2, the verification values of the visible standard lamp 4, the values of the spectral radiant flux Φ ST (λ) given to the secondary standard lamp 6, the detection results (reference values) output from the spectrophotometer 50 when the secondary standard lamp 6 is lit, and the like.

[0196] The communication interface 120 relays data transmission between the processing device 100 and the spectrophotometer 50. The network interface 122 relays data transmission between the processing device 100 and an external server device.

[0197] The medium drive 124 reads necessary data from a recording medium 126 (such as an optical disc, etc.) storing programs executed by the processor 102, and stores them in the storage device 110. In addition, the measurement program 114 and the like executed in the processing device 100 can be installed via the recording medium 126 or downloaded from the server device via the network interface 122.

[0198] The measurement program 114 can also execute processing by calling necessary modules in program modules provided as part of the operating system 112 at a specified timing in a specified sequence. In such a case, the measurement program 114 that does not include this module is also within the technical scope of the present invention. The measurement program 114 can also be provided by being incorporated into a part of other programs.

[0199] In addition, all or part of the functions provided by executing the measurement program 114 with the processor 102 of the processing device 100 can also be realized by dedicated hardware. Additionally, Figure 19 Part or all of the processing performed by the processing device 100 shown can be incorporated into the spectrophotometer 50.

[0200] <H. Modification Example>

[0201] In the above embodiment, as an example, the spectral radiant flux Φ is described.SMP (λ) and the total radiant flux Φ SMP , but not limited thereto.

[0202] In the above-described embodiment, an example of using a combination of an ultraviolet standard lamp and a visible standard lamp each given a spectral irradiance value has been described. However, it is not limited thereto, and an infrared standard lamp and a visible standard lamp may be used in combination.

[0203] <I. Summary>

[0204] According to this embodiment, a secondary standard lamp is given a value using a spectral irradiance standard lamp traceable to a national standard (deuterium lamp: ultraviolet standard lamp 2) and a spectral irradiance standard lamp (halogen lamp: visible standard lamp 4), and the secondary standard lamp given the value is compared and measured with a sample. By doing only this, even in a wavelength range where a national standard traceable standard lamp given a physical quantity value other than spectral irradiance is not provided, the spectral radiant quantity and radiant quantity of the sample can be measured.

[0205] According to this embodiment, compared with the method of calibrating the device by arranging a spectral irradiance standard lamp outside the integrating sphere as disclosed in Non-Patent Document 4, the overall operation process is less, and skilled techniques are not required. Therefore, according to this embodiment, high-precision measurement can be more easily and quickly achieved, and necessary calibration can be performed more frequently, so that the measurement accuracy can be improved.

[0206] The embodiments of the present invention have been described, but it should be considered that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is represented by the claims, and also includes all modifications within the meaning and scope equivalent to the claims.

Claims

1. An optical measurement method, comprising the following steps: Turn on a first standard lamp that has been given a value of spectral irradiance for a first wavelength range, and obtain a first detection result output from a spectrophotometer, the spectrophotometer being arranged at a first distance from the first standard lamp where the value of spectral irradiance has been given; Turn on a second standard lamp that has been given a value of spectral irradiance for a second wavelength range that at least partially overlaps with the first wavelength range, and obtain a second detection result output from the spectrophotometer, the spectrophotometer being arranged at the first distance from the second standard lamp; Calculate a first calibration coefficient based on the first detection result and the value of spectral irradiance given to the first standard lamp; Calculate a second calibration coefficient based on the second detection result and the value of spectral irradiance given to the second standard lamp; Calculate a correction value for the calibration coefficient of the wavelength in the wavelength range where the first wavelength range and the second wavelength range overlap based on the first calibration coefficient and the second calibration coefficient; Determine a third calibration coefficient based on at least the first calibration coefficient and the correction value; Turn on a third standard lamp, and obtain a third detection result output from the spectrophotometer arranged at a specified distance from the third standard lamp; and Based on the third detection result and the third calibration coefficient, assign a value of spectral radiant quantity or radiant quantity to the third standard lamp.

2. The optical measurement method according to claim 1, wherein the step of determining the third calibration coefficient includes the following steps: Determine a correction target interval for which the correction value is to be determined in the wavelength range where the first wavelength range and the second wavelength range overlap; and Determine the correction value for each wavelength included in the correction target interval.

3. The optical measurement method according to claim 2, wherein the step of determining the correction target interval includes the following steps: Search for an interval where the deviation between the value of the first calibration coefficient and the value of the second calibration coefficient is the smallest.

4. The optical measurement method according to claim 2, wherein the step of determining the correction value for each wavelength included in the correction target interval includes the following steps: Assign respective weights corresponding to each wavelength to the value of the first calibration coefficient and the value of the second calibration coefficient for each wavelength included in the correction target interval, thereby determining the corresponding correction value.

5. The optical measurement method according to any one of claims 1 to 4, wherein it further includes the following steps: Obtain a third detection result output from the spectrophotometer based on the third standard lamp; Obtain a fourth detection result output from the spectrophotometer based on an arbitrary sample; and Based on the ratio of the third detection result to the fourth detection result and the value of the first irradiance given to the third standard lamp, obtain the second irradiance of the sample.

6. The optical measurement method according to claim 5, wherein The third detection result is the illuminance generated on the inner wall of the integrator after the light from the third standard lamp is incident on the integrator. The fourth detection result is the illuminance generated on the inner wall of the integrator after the light from the sample is incident on the integrator.

7. The optical measurement method according to any one of claims 1 to 4, wherein, the first wavelength range includes the ultraviolet region, the second wavelength range includes the visible region.

8. A processing device, comprising: a first calibration coefficient calculation unit that calculates a first calibration coefficient based on a first detection result related to a first standard lamp to which a spectral irradiance value for a first wavelength range has been assigned, and the spectral irradiance value assigned to the first standard lamp, wherein, the first detection result is the result obtained by turning on the first standard lamp and using a spectrophotometer arranged at a first distance from the first standard lamp where the spectral irradiance value has been assigned; a second calibration coefficient calculation unit that calculates a second calibration coefficient based on a second detection result related to a second standard lamp to which a spectral irradiance value for a second wavelength range that repeats at least a part of the wavelength range of the first wavelength range has been assigned, and the spectral irradiance value assigned to the second standard lamp, wherein the second detection result is the result obtained by turning on the second standard lamp and using the spectrophotometer arranged at the first distance from the second standard lamp; a correction value calculation unit that calculates a correction value of the calibration coefficient related to the wavelength of the wavelength range that repeats the first wavelength range and the second wavelength range based on the first calibration coefficient and the second calibration coefficient; a third calibration coefficient determination unit that determines a third calibration coefficient based at least on the first calibration coefficient and the correction value; and a measured light quantity determination unit that determines the value of the spectral radiant quantity or radiant quantity assigned to the third standard lamp based on a third detection result related to the third standard lamp and the third calibration coefficient, wherein the third detection result is the result obtained by using the spectrophotometer arranged at a predetermined distance from the third standard lamp.

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