JP2014081275A - Correction method for spectral sensitivity characteristic of light metering device and light metering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a correction method for a spectral sensitivity characteristic of a light metering device and the light metering device that can more accurately correct the spectral sensitivity characteristic of the light metering device even when employing a light source having a relatively large variation in a peak wavelength of a light emission spectrum, for example, a light source attaining a prescribed light emission color by combining an excitation light source such as a white LED and the like and a phosphor as a reference light source.SOLUTION: The correction method is configured to acquire each light emission spectrum data on a plurality of reference light sources by using a reference measuring device, calculate a correction coefficient by statistical processing such as a calculation of an average value of a plurality of correction coefficient base values calculated by using the plurality of pieces of acquired light emission spectrum data, calculate a correction coefficient by selecting a representative value from the plurality of correction coefficient base values or calculate a correction coefficient by using specific light emission spectrum data selected from the plurality of pieces of acquired light emission spectrum data.

Description

  The present invention relates to a method for correcting spectral sensitivity characteristics of a photometric device for measuring the light emission of a light source to be measured to determine the characteristics of the light source to be measured, and the photometric device.

  Conventionally, for example, a measurement target light source is measured by measuring light emission (measurement light) of a measurement target light source such as a fluorescent lamp, a light bulb, an LED (light emitting diode) illumination, an LED element, an LD (laser diode) element, or an LCD (liquid crystal display). Various photometric devices for obtaining characteristics such as chromaticity, illuminance, color rendering properties, wavelength, and power have been proposed.

  Among them, there are a plurality of photosensors with different spectral sensitivity characteristics, and the output of each photosensor is weighted using a weighting coefficient that is set in advance so that the spectral sensitivity characteristics of the photometric device become the predetermined spectral sensitivity characteristics. There is a photometric device that integrates and calculates the characteristics of the light source to be measured based on the result (Patent Document 1).

  In such a photometric device, for example, the spectral sensitivity characteristics of the photometric device are approximated to color matching functions x (λ), y (λ), and z (λ) defined by the International Commission on Illumination (abbreviated as CIE). Based on the color matching functions x (λ), y (λ), and z (λ) using the light reception signal of each photosensor and each weighting factor in advance, a weighting coefficient for weighting the light reception signal of the photosensor is obtained. Tristimulus values X, Y, and Z can be calculated to determine the characteristics of the light source to be measured.

  However, the spectral sensitivity characteristics of such a photometric device may change over time due to changes over time in the spectral sensitivity characteristics of each optical sensor. In addition, in order to reduce the difference in spectral sensitivity characteristics between the user's reference measuring instrument and each photometric device, the spectral sensitivity characteristics of each photometric device must be matched to the spectral sensitivity characteristics of the user's standard measuring instrument. May be performed. The difference in spectral sensitivity characteristics between the reference measuring instrument owned by the user and each photometric device is the difference between the reference measuring instrument used by the photometric device manufacturer for calibration of the photometric device and the reference measuring instrument owned by the user. This is caused by a difference in spectral sensitivity characteristics between the two.

  On the other hand, Patent Document 2 discloses a method for easily correcting the spectral sensitivity characteristic of a photometric device. That is, first, a reference measuring instrument held by a user, such as a high-precision spectrophotometer as a reference, and a photometric device to be corrected And measured under substantially the same conditions. Next, from the measured value of the emission spectrum of the reference light source by the reference measuring instrument (for example, every 5 nm in the wavelength range of 380 nm to 780 nm) and the spectral sensitivity characteristic of each photosensor stored in the photometric device, the reference A predicted value of the output of each optical sensor when the light emission of the light source is measured by the photometric device is calculated. Next, for each optical sensor, “predicted value ÷ measured value” is calculated as a correction coefficient from the predicted value and the actual measured value of the output of each optical sensor when the light emission of the reference light source is measured by the photometric device. To do.

  Then, for example, the correction coefficient obtained for each photosensor is used as the weighting coefficient for approximating the spectral sensitivity characteristic of the photometric device to the color matching functions x (λ), y (λ), z (λ). By multiplying, the spectral sensitivity characteristic of the photometric device can be matched with the spectral sensitivity characteristic of the reference measuring device. As a result, it is possible to reduce the influence of the spectral sensitivity characteristics of the photometric devices due to changes over time and the difference in the spectral sensitivity characteristics of the photometric devices with respect to the reference measuring instrument.

JP 2002-13981 A JP 2011-107114 A

  The method of Patent Document 2 obtains a correction coefficient by measuring light emission of a specific reference light source with a reference measuring instrument and each photometric device.

  However, according to the study by the present inventors, this method may not sufficiently reduce the influence of the change in spectral sensitivity characteristics of each photometric device over time and the difference in spectral sensitivity characteristics of each photometric device with respect to a reference measuring instrument. I understood. For example, when white LED is used as a reference light source in a production site of white LED used as a light source for illumination.

  Some white LEDs emit white light by combining a blue LED as an excitation light source and a yellow phosphor (or a green phosphor or a red phosphor) as a phosphor. Such white LEDs have a relatively large variation in emission color (emission spectrum) during production. One of the causes is that the peak wavelength of the blue LED varies.

  However, white LED production sites sometimes employ white LEDs as a reference light source for matching the spectral sensitivity characteristics of each photometric device with the spectral sensitivity characteristics of a reference measuring device. In this case, when the correction coefficient is obtained using the light emission of the specific white LED selected as the reference light source, the peak wavelength of the blue LED is different between the white LED used as the reference light source and each white LED produced. In some cases, it is impossible to accurately determine the characteristics of the individual white LEDs.

The above-described problems are caused by, for example, a light source that does not have a peak in the measurement wavelength range (such as a standard illuminant A specified in JIS Z8720) as a reference light source, or a relatively broad emission spectrum that has a peak wavelength in the measurement wavelength range. When a light source indicating JIS Z8720 standard illuminant D ₆₅ or auxiliary illuminant C is used, it is unlikely to occur. However, in a light source that achieves a predetermined emission color by a combination of an excitation light source and a phosphor, such as a white LED, the excitation light source generates light in a relatively narrow wavelength range, so the emission spectrum is steep. It becomes. Therefore, the shift of the peak wavelength of the excitation light source may greatly affect the correction coefficient calculated using the light source as a reference light source. As a result, even if characteristics such as tristimulus values can be accurately obtained for individual light sources having the same peak wavelength of excitation light as the reference light source used to calculate the correction coefficient, the reference light source It may not be possible to accurately determine individual light sources having different peak wavelengths.

  Accordingly, an object of the present invention is to use a light source having a relatively large variation in peak wavelength of the emission spectrum, for example, a light source that realizes a predetermined emission color by combining an excitation light source such as a white LED and a phosphor as a reference light source. It is an object to provide a method for correcting a spectral sensitivity characteristic of a photometric device and a photometric device that can correct the spectral sensitivity property of the photometric device with higher accuracy.

  The above object is achieved by a method for correcting spectral sensitivity characteristics of a photometric device and a photometric device according to the present invention. In summary, according to the first aspect of the present invention, each of the optical sensors of the photometric device having a plurality of optical sensors having different spectral sensitivity characteristics and measuring the light emission of the measurement target light source to obtain the characteristics of the measurement target light source. A method for correcting the spectral sensitivity characteristic of a photometric device by correcting the spectral sensitivity characteristic of the photometric device, and acquiring emission spectrum data of each of a plurality of reference light sources using a reference measuring device Based on the above, there is provided a method for correcting the spectral sensitivity characteristic of a photometric device, wherein each correction coefficient for correcting the spectral sensitivity characteristic of each photosensor is set when determining the characteristic of the light source to be measured. .

  According to an embodiment of the first aspect of the present invention, the emission spectrum data of each of the plurality of reference light sources is acquired using the reference measuring device, and the plurality of corrections obtained using the acquired plurality of emission spectrum data. A correction coefficient is obtained by statistical processing such as obtaining an average value of coefficient base values, or a correction coefficient is obtained by selecting a representative value from the plurality of correction coefficient base values. According to another embodiment of the first aspect of the present invention, the correction coefficient is obtained using specific emission spectrum data selected from a plurality of acquired emission spectrum data.

  According to a second aspect of the present invention, there is provided a photometric device that has a plurality of photosensors having different spectral sensitivity characteristics and obtains the characteristics of the light source to be measured by measuring the light emission of the light source to be measured. A storage unit that stores a correction coefficient for correcting the spectral sensitivity characteristic of the photometric device, and the storage unit includes emission spectra of a plurality of reference light sources by a reference measuring device. A photometric device is provided in which a correction coefficient set based on acquiring data is stored.

  According to one embodiment of the second aspect of the present invention, the storage unit stores a correction coefficient set by the spectral sensitivity characteristic correction method of the photometric device of the first aspect of the present invention.

  According to the present invention, a light source that has a relatively large variation in the peak wavelength of the emission spectrum, for example, a light source that realizes a predetermined emission color by combining an excitation light source such as a white LED and a phosphor is used as a reference light source. Even so, the spectral sensitivity characteristic of the photometric device can be corrected with higher accuracy.

It is a block diagram which shows the electric constitution of the photometry apparatus which concerns on one Example of this invention. It is a schematic block diagram of the detection part of the photometry apparatus which concerns on one Example of this invention. It is a figure which shows an example of the relative spectral sensitivity characteristic of each photosensor of the photometry apparatus which concerns on one Example of this invention. It is a figure which shows a color matching function. It is a figure which shows the approximate color matching function as an example of the spectral sensitivity characteristic of a photometry apparatus. It is a figure which shows the other example of the spectral sensitivity characteristic of a photometry apparatus. It is a figure which shows an example of the emission spectrum of white LED. It is a figure for demonstrating the shift | offset | difference of the measured value at the time of measuring light emission of white LED from which the peak wavelength of excitation light differs from a reference light source. It is a figure for demonstrating the shift | offset | difference of the measured value at the time of measuring light emission of white LED from which the peak wavelength of excitation light differs from a reference light source. It is a flowchart which shows the schematic procedure of the 1st Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a figure which shows the effect of the 1st Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a flowchart which shows the schematic procedure of the 2nd Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a figure which shows the effect of the 2nd Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a flowchart which shows the schematic procedure of the 3rd Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a figure which shows the relationship between the gravity center wavelength of the excitation light of white LED, and the gravity center position of the optical sensor of a photometry apparatus. It is a figure which shows the effect of the 3rd Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a figure which shows the relationship between the peak wavelength of the excitation light of white LED, and the peak position of the optical sensor of a photometry apparatus. It is a figure which shows the effect of the 4th Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a flowchart which shows the schematic procedure of the 5th Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a figure which shows the effect of the 5th Example of the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention. It is a block diagram for demonstrating the example of the system configuration which embodies the correction method of the spectral sensitivity characteristic of the photometry apparatus which concerns on this invention.

  Hereinafter, a method for correcting spectral sensitivity characteristics of a photometric device and a photometric device according to the present invention will be described in more detail with reference to the drawings.

Example 1
1. First, a photometric device according to an embodiment of the present invention will be described. FIG. 1 is a block diagram showing an electrical configuration of the photometric device 1 of the present embodiment, and FIG. 2 is a schematic configuration diagram of the detection unit 10 of the photometric device 1 of the present embodiment.

  The photometric device 1 includes a detection unit 10 and a measurement unit 100. The detection unit 10 includes a housing (casing) 12, and an optical sensor unit 11 is installed inside the housing 12. The housing 12 is provided with an incident portion opening 13 through which light from the light source to be measured (light to be measured) enters. In addition, a diffusion plate 14 is installed in the entrance opening 13.

  The optical sensor unit 11 disposed inside the casing 12 has a plurality of optical sensors SE (SE1, SE2, SE3,...) In order to detect light incident from the incident part opening 13 and diffused by the diffusion plate 14. SEn-2, SEn-1, SEn) (n is a natural number of 2 or more; the same shall apply hereinafter). Each optical sensor SE includes an optical filter f (f1, f2, f3,... Fn-2, fn-1, fn) as a spectroscopic unit and a light receiving element (photoelectric conversion element) PD (PD1, PD2, PD3). ,... PDn-2, PDn-1, PDn). In the present embodiment, each optical filter f is composed of a bandpass filter that transmits light of different wavelength regions, and each light receiving element PD receives light that has passed through each optical filter f and corresponds to the amount of light received. It is composed of a silicon photodiode that outputs an electrical signal (light reception signal). Thereby, each optical sensor SE has a certain limited sensitivity wavelength region.

  That is, as shown in FIG. 3A, each optical sensor SE (SE1, SE2, SE3,... SEn-2, SEn-1, SEn) has a different spectral sensitivity characteristic S (λ) (S1 ( λ), S2 (λ), S3 (λ),... Sn-2 (λ), Sn-1 (λ), Sn (λ)).

  Note that the spectral sensitivity characteristic S (λ) of each optical sensor SE is determined for each optical sensor SE using a wavelength variable monochromatic light source or the like after the optical sensor SE is incorporated into the photometric device 1 when the photometric device 1 is manufactured. It can be determined by measuring. The spectral sensitivity characteristic S (λ) of each photosensor SE is stored in the ROM 105 described later. In the present embodiment, storing the spectral sensitivity characteristic S (λ) of each optical sensor SE in the ROM 105 in this way is called calibration of the photometric device 1.

  As described above, a plurality of optical sensors SE (SE1, SE2, SE3,... SEn-2, SEn-1, SEn) are used to detect a predetermined detection wavelength region of the optical sensor unit 11, that is, the photometric device 1, for example, A detection wavelength region of 380 nm to 720 nm is configured.

  The light reception signals output from the plurality of optical sensors SE (SE1, SE2, SE3,... SEn-2, SEn-1, SEn) of the detection unit 10 are transmitted to the measurement unit 100 as current signals.

  The measurement unit 100 includes an I / V conversion amplifier 101 that converts a light reception signal transmitted as a current signal from each optical sensor SE of the detection unit 10 into a voltage signal, and a light reception converted into a voltage signal by the I / V conversion amplifier 101. An A / D converter 102 that converts a signal into a digital value (digital signal) and a CPU 103 that serves as a control unit that receives a light reception signal converted into a digital value by the A / D converter 102 are included. The measurement unit 100 includes a RAM 104 and a ROM 105 as storage means. Further, the measurement unit 100 includes a display unit 106 that displays various information such as a result of processing the light reception signal received by the CPU 103.

  The CPU 103 controls the operation of each part of the photometric device 1 according to a control program stored in the ROM 105. The ROM 105 stores a control program used by the CPU 103 (including spectral sensitivity characteristics of each optical sensor SE, data such as weighting coefficients and correction coefficients described later), and the like. The RAM 104 temporarily stores a control program, measured value data, and the like as necessary.

  The CPU 103 stores the light reception signal of each optical sensor SE transmitted from the A / D converter 102 in the RAM 104. Then, the CPU 103 weights and adds the light reception signals of the optical sensors SE using the light reception signals of the optical sensors SE stored in the RAM 104 and a predetermined weighting coefficient stored in the ROM 105. The weighting coefficient is obtained in advance and stored in the ROM 105 so that the spectral sensitivity characteristic of the photometric device 1 becomes a predetermined spectral sensitivity characteristic corresponding to the spectral sensitivity characteristic S (λ) of each optical sensor SE. As a result, the sum of the light reception signals of the respective optical sensors SE represents the characteristics of the light source to be measured based on the predetermined spectral sensitivity characteristics in the predetermined detection wavelength region of the photometric device 1.

  For example, the CPU 103 sets each light sensor SE so as to approximate the light reception signal stored in the RAM 104 and the spectral sensitivity characteristics of the photometric device 1 to the color matching functions x (λ), y (λ), z (λ). In order to weight the received light signals, the received light signals of the respective optical sensors SE are weighted and added using a weighting coefficient obtained in advance and stored in the ROM 105. Then, the CPU 103 approximates the color matching functions x ′ (λ), y approximated to the color matching functions x (λ), y (λ), z (z) from the sum of the received light signals of the respective optical sensors SE. Tristimulus values X, Y, Z based on '(λ), z' (λ) can be calculated.

  FIG. 4 shows the color matching functions x (λ), y (λ), and z (λ). FIG. 5 shows color matching functions x (λ), y (λ), z (λ) and approximate color matching functions x ′ (λ), y ′ (λ), z ′ ( λ).

The approximate color matching functions x ′ (λ), y ′ (λ), and z ′ (λ) can be expressed by the following equations.
x ′ (λ) = a1 × S1 (λ) + a2 × S2 (λ) +... + an × Sn (λ)
y ′ (λ) = b1 × S1 (λ) + b2 × S2 (λ) +... + bn × Sn (λ)
z ′ (λ) = c1 × S1 (λ) + c2 × S2 (λ) +... + cn × Sn (λ)
Here, a1 to an, b1 to bn, and c1 to cn are weighting coefficients stored in the ROM 105.

  Based on the tristimulus values X, Y, and Z obtained as described above, the CPU 103 calculates an index (measurement value) for determining the characteristics of the light source to be measured such as chromaticity, illuminance, and color rendering properties. be able to.

  The step of obtaining the approximate color matching function and the step of obtaining the tristimulus values from the approximate color matching function are described in, for example, the above-mentioned Patent Document 1 and are well known to those skilled in the art. Description is omitted.

  Further, as understood from the above, by adding the spectral sensitivity characteristic S (λ) of each optical sensor SE by weighting using a preset weighting coefficient, the arbitrary spectral sensitivity characteristic of the photometric device 1 can be obtained. Can be obtained. For example, the spectral sensitivity characteristics of the photometric device 1 after adding the spectral sensitivity characteristics of the optical sensors SE can be made substantially linear in a predetermined detection wavelength region.

That is, the spectral sensitivity characteristic SΣ (λ) of the photometric device 1 after the addition is
SΣ (λ) = k1 · S1 (λ) + k2 · S2 (λ) +... + KnSn (λ)
It is represented by k1 to kn are weighting coefficients. As shown in FIG. 6, the spectral sensitivity characteristic SΣ (λ) of the photometric device 1 after the summation can be substantially linear, for example, flat (flat) as shown in FIG. Thus, as described above, not only the weighting coefficient for approximating the spectral sensitivity characteristic of the photometric device 1 to the color matching functions x (λ), y (λ), z (λ), but also, for example, of the photometric device 1 Other weighting coefficients such as a weighting coefficient for making the spectral sensitivity characteristic substantially linear in a predetermined detection wavelength region can also be stored in the ROM 105 and used as desired.

  In the present embodiment, the optical sensor unit 11 includes 16 optical sensors SE. FIG. 3B shows spectral sensitivity characteristics S1 (λ), S2 (λ),... S16 (λ) (n = 16) of each optical sensor SE in the present embodiment.

  That is, according to the present embodiment, the optical sensor unit 11 having 16 optical sensors SE has 16 light receiving peaks having peaks at a pitch of 20 nm in a wavelength range of 380 nm to 720 nm as shown in FIG. Output a signal.

  Note that the number of the optical sensors SE is not limited to 16, but may be other numbers (more or less than 16) if desired.

  Here, in this embodiment, the diffusion plate 14 is fixed to the incident part opening 13 so as to cover the entire area of the incident part opening 13 of the casing 12. As the diffusion plate 14, an opal type diffusion plate (trade name: manufactured by Sigma Koki Co., Ltd.) is preferably used. Even when the incident angle of the light under test is changed, the diffuser plate 14 can suppress the change in the light amount distribution on each optical sensor SE and perform more accurate measurement.

2. Principle of Correction of Spectral Sensitivity Characteristics of Photometric Device As described above, the spectral sensitivity characteristics of the photometric device 1 change over time due to changes in the spectral sensitivity characteristics of the respective optical sensors SE caused by changes in sensitivity of the respective light receiving elements PD. Furthermore, the spectral sensitivity characteristics at the time of calibration may change (deteriorate). Further, for example, in order to reduce a difference in spectral sensitivity characteristics between a reference measuring instrument owned by a user and a plurality of photometry devices 1 used in a plurality of production lines in a production site of a light source for illumination. In addition, the spectral sensitivity characteristic of each photometric device 1 may be matched with the spectral sensitivity characteristic of a reference measuring instrument owned by the user.

  Therefore, the photometric device 1 of the present embodiment is provided with a correction function based on the following principle as disclosed in Patent Document 2 described above.

  First, a reference light source is selected, and light emission of the selected reference light source is measured using a reference measuring instrument such as a high-precision spectrophotometer to obtain an emission spectrum (emission spectrum data) of the reference light source. Here, an incandescent bulb (corresponding to JIS Z8720 predetermined standard illuminant A) is selected as the reference light source. FIG. 3A shows an emission spectrum (emission spectrum data) P (λ) of an incandescent bulb as the reference light source.

Next, the light emission spectrum P (λ) of the reference light source and each photosensor SE (SE1, SE2, SE3,... SEn-2) during calibration of the photometric device 1 stored in the ROM 105 of the photometric device 1 Using the spectral sensitivity characteristics S (λ) (S1 (λ), S2 (λ),... Sn (λ)) of SEn-1, SEn), the light emission of the reference light source was measured by the photometric device 1. The predicted value (“predicted value data”) of the output of each optical sensor SE (SE1, SE2,... SEn) in each case is calculated by the following equation.
SE1 output (prediction) = P (λ1) × S1 (λ1) + P (λ2) × S1 (λ2) + ・ ・ ・ + P (λn) × S1 (λn)
Output of SE2 (prediction) = P (λ1) × S2 (λ1) + P (λ2) × S2 (λ2) + ・ ・ ・ + P (λn) × S2 (λn)
...
SEn output (prediction) = P (λ1) × Sn (λ1) + P (λ2) × Sn (λ2) + ・ ・ ・ + P (λn) × Sn (λn)

Next, the light emission of the reference light source is measured (actually measured) using the photometric device 1, and the current spectral sensitivity characteristics S ′ (λ) (S1 ′ (λ), S2 ′ (λ),... Sn ′ ( λ)), the measured value (“actual value data”) of the output of each optical sensor SE (SE1, SE2,... SEn) is acquired. The measured value of the output of each photosensor SE is as follows when expressed using the emission spectrum P (λ) of the reference light source and the current spectral sensitivity characteristic S ′ (λ).
SE1 output (measurement) = P (λ1) × S1 '(λ1) + P (λ2) × S1' (λ2) + ... + P (λn) × S1 '(λn)
SE2 output (measurement) = P (λ1) × S2 '(λ1) + P (λ2) × S2' (λ2) + ... + P (λn) × S2 '(λn)
...
SEn output (measurement) = P (λ1) × Sn '(λ1) + P (λ2) × Sn' (λ2) + ... + P (λn) × Sn '(λn)

Then, the ratio of the output (predicted) value of each optical sensor SE calculated as described above to the measured (actually measured) output (measured) value of each optical sensor SE is calculated by the following equation. , Correction coefficients B1, B2,... Bn.
B1 = SE1 output (prediction) / SE1 output (measurement)
B2 = SE2 output (prediction) / SE2 output (measurement)
...
Bn = SEn output (prediction) / SEn output (measurement)

  The above correction coefficients B1, B2,... Bn are the ratio of the change in the spectral sensitivity characteristic of each photosensor SE of each photometric device 1, or the difference in the spectral sensitivity characteristic of each photometric device 1 with respect to the spectral sensitivity characteristic of the reference measuring device. Determined by the ratio of These correction coefficients B1, B2,... Bn are stored in the ROM 105 of the photometric device 1 as correction values (correction data) for reducing these fluctuations and differences. The correction coefficients B1, B2,... Bn are used when measuring the characteristics of the light source to be measured in order to reduce the error factors due to the above-described fluctuations and differences.

For example, the approximate color matching functions x ′ (λ), y ′ (λ), and z ′ (λ) for obtaining tristimulus values X, Y, and Z at the time of calibration of the photometric device 1 are as follows: It is expressed by a formula.
x ′ (λ) = a1 × S1 (λ) + a2 × S2 (λ) +... + an × Sn (λ)
y ′ (λ) = b1 × S1 (λ) + b2 × S2 (λ) +... + bn × Sn (λ)
z ′ (λ) = c1 × S1 (λ) + c2 × S2 (λ) +... + cn × Sn (λ)

When the spectral sensitivity characteristic of the photometric device 1 is corrected using the correction coefficient, the weighting coefficient is further multiplied by correction coefficients B1 to Bn stored in the ROM 105. As a result, the correction coefficients B1 to Bn are multiplied by the spectral sensitivity characteristics of the respective optical sensors SE. In this case, the approximate color matching functions x ′ (λ), y ′ (λ), and z ′ (λ) are expressed by the following equations.
x ′ (λ) = B1 × a1 × S1 (λ) + B2 × a2 × S2 (λ) +... + Bn × an × Sn (λ)
y ′ (λ) = B1 × b1 × S1 (λ) + B2 × b2 × S2 (λ) +... + Bn × bn × Sn (λ)
z ′ (λ) = B1 × c1 × S1 (λ) + B2 × c2 × S2 (λ) +... + Bn × cn × Sn (λ)

  As described above, the correction coefficients B1 to Bn are stored in the ROM 105 of the apparatus, and the weighting coefficients a1 to an, b1 to bn, and c1 to cn are multiplied by the correction coefficients to correct the spectral sensitivity characteristics of the respective optical sensors SE. Thus, the spectral sensitivity characteristic of the photometric device 1 can be corrected using the reference measuring instrument as a reference.

3. Problems when using white LEDs as a reference light source As described above, white LED is used as a reference light source for matching the spectral sensitivity characteristics of each photometric device 1 with the spectral sensitivity characteristics of a reference measuring instrument at the production site of white LEDs. There are things to do. FIG. 7 shows an example of an emission spectrum of a white LED that includes a blue LED as an excitation light source and a yellow phosphor as a phosphor, and realizes white light emission as a predetermined emission color. In the illustrated example, the peak wavelength of the excitation light is 450 nm.

  However, as described above, white LEDs have a relatively large variation in emission spectrum, and one of the causes is considered to be a variation in peak wavelength of excitation light. Therefore, for example, when the peak wavelength of the excitation light varies in the wavelength range of 440 nm to 460 nm, the spectral sensitivity of the photometric device 1 is determined according to the principle of correction described above using a white LED having a peak wavelength of the excitation light of 450 nm as a reference light source. When the characteristics are corrected, when the peak wavelength of the excitation light of each white LED as the measurement target light source is shifted from 450 nm, the characteristics of the individual white LED may not be accurately obtained.

  FIG. 8 and FIG. 9 assume a case where white LEDs having excitation light peak wavelengths of 440 nm and 450 nm are used as reference light sources, and light emission of white LEDs having excitation light peak wavelengths different from the reference light source is measured. The result of having calculated | required the difference of the predicted value which estimated the measured value from the emission spectrum of white LED by calculation, and the theoretical value of the chromaticity value calculated | required from the emission spectrum of white LED is shown.

  For example, for FIG. 8, first, for a specific photometric device 1, a correction coefficient was determined when a white LED having a peak wavelength of excitation light of 440 nm was used as a reference light source as a specific reference light source. Then, using this correction coefficient, the chromaticity coordinates x, y when the measured values are predicted by calculation from the respective emission spectra of the white LEDs having different peak wavelengths of the excitation light every 1 nm in the wavelength range of 440 nm to 460 nm are obtained. This was obtained and used as the “predicted value”. Further, chromaticity coordinates x and y obtained by calculation from emission spectra and color matching functions of individual white LEDs having different peak wavelengths of the excitation light were defined as “theoretical values”. Further, “predicted value−theoretical value” of the chromaticity coordinate x is defined as the chromaticity deviation Δx, and “predicted value−theoretical value” of the chromaticity coordinate y is defined as the chromaticity deviation Δy. The vertical axis represents chromaticity deviations Δx and Δy, and the horizontal axis represents the peak wavelength of excitation light (blue region). FIG. 9 is a plot of chromaticity deviations Δx and Δy obtained when the peak wavelength of excitation light of a white LED as a specific reference light source is 450 nm in the same manner as described above (however, in the case of FIG. 9). Used white LEDs having different excitation light peak wavelengths every 1 nm in a wavelength range of 430 nm to 470 nm.

  As can be seen from FIGS. 8 and 9, when the peak wavelength of the excitation light is the same between the white LED selected as the reference light source and the individual white LED, the characteristics of the individual white LED can be accurately obtained. However, if they are different, the characteristics of the individual white LEDs may not be accurately obtained with the desired accuracy. As the deviation of the peak wavelength of the excitation light between the white LED selected as the reference light source and each of the white LEDs increases, the deviation (error) of the measured value tends to increase. As described above, since the excitation light source of the white LED generates light in a relatively narrow wavelength range, the emission spectrum becomes steep, and the deviation of the peak wavelength of the excitation light source is calculated using the light source as a reference light source. One of the causes is considered to have a large influence on the correction coefficient.

  For example, it is desirable that each photometric device 1 used for a sorting / sorting machine or the like at a production site of white LEDs has a smaller difference in measured values than a reference measuring device. Therefore, there is a demand for a more accurate method for obtaining the correction coefficient for correcting the spectral sensitivity characteristics of each photometric device 1.

  Therefore, in the present invention, emission spectrum data of each of a plurality of reference light sources is acquired using a reference measuring instrument such as a high-precision spectroscopic measuring instrument. Then, a correction coefficient is obtained by a statistical process such as obtaining an average value of a plurality of correction coefficient basic values obtained using a plurality of acquired emission spectrum data, or a representative value is selected from the plurality of correction coefficient basic values. Thus, the correction coefficient can be obtained. Alternatively, the correction coefficient can be obtained using specific emission spectrum data selected from a plurality of acquired emission spectrum data. That is, in the present invention, the spectral sensitivity characteristic of each photosensor SE is corrected when obtaining the characteristics of the light source to be measured based on obtaining the emission spectrum data of each of the plurality of reference light sources using the reference measuring device. Set each correction factor. Hereinafter, further detailed description will be given with reference to specific examples.

FIG. 10 is a flowchart showing a schematic procedure of a method for correcting the spectral sensitivity characteristic of the photometric device 1 in the present embodiment. In the present embodiment, the method for correcting the spectral sensitivity characteristic of the photometric device 1 includes the following steps.
(A) Step of obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device (S101)
(B) Predicting the output of each optical sensor SE when the light emission of each of the plurality of reference light sources is measured by the photometric device 1 from the emission spectrum data of each of the plurality of reference light sources and the spectral sensitivity characteristics of each optical sensor SE. Step of calculating value data (S102)
(C) A step of measuring the light emission of each of the plurality of reference light sources using the photometric device 1 and obtaining the actual measurement data of the output of each optical sensor SE (S103)
(D) Each correction coefficient basic value for obtaining a correction coefficient for correcting the spectral sensitivity characteristic of each optical sensor SE from the predicted value data and the actually measured value data is associated with each of the plurality of reference light sources. Step of calculating (S104)
(E) A step of obtaining each correction coefficient for correcting the spectral sensitivity characteristic of each optical sensor SE from the correction coefficient basic value calculated corresponding to each of the plurality of reference light sources (S105).
(F) The step of setting the correction coefficient obtained corresponding to each optical sensor SE as the respective correction coefficient for correcting the spectral sensitivity characteristic of each optical sensor SE when determining the characteristics of the light source to be measured (S106). )

  In the step (a), the reference measuring instrument is, for example, a high-precision spectroscopic measuring instrument that serves as a reference held by an operator who performs the correction (for example, a user of the photometric device 1 such as a white LED manufacturer). is there. The reference measuring device need not be calibrated in a strict sense in comparison with other spectroscopic measuring devices, and can be arbitrarily selected by the operator. As a reference measuring instrument, in general, any spectroscopic measuring instrument (spectrometer) having sufficient spectral resolution of about 0.4 nm to 0.8 nm in a wavelength range of 380 nm to 780 nm and capable of acquiring emission spectrum data as digital data. , A spectrophotometer) can be preferably used. In the step (a), the reference light source realizes a predetermined emission color by combining a light source having a relatively large variation in the peak wavelength of the emission spectrum, for example, an excitation light source such as a white LED and a phosphor. It may be a light source. The number of reference light sources can be arbitrarily selected according to the complexity of operation and the desired correction accuracy. According to the study by the present inventors, for example, when the reference light source is a white LED, even if the number of reference light sources is ten, the correction accuracy may be sufficiently improved, while considering the complexity of the operation, The number of reference light sources is preferably 500 or less, more preferably 200 or less, and typically 100. Here, for example, in the case of using a light source that realizes a predetermined emission color by combining an excitation light source such as a white LED and a phosphor as a reference light source, after grasping the range of variations in the peak wavelength of the excitation light It is preferable to use a plurality of reference light sources so that the peak wavelength of the excitation light is appropriately distributed within the range. However, in general, good results can also be obtained by randomly extracting the same type of light source as the individual light source to be measured (the same product as the white LED actually produced at the production site) and using it as multiple reference light sources. It is done.

  In the step (b), according to the principle of correction described above, each reference light source spectral data of each reference light source and spectral sensitivity characteristics of each photosensor SE at the time of calibration of the photometric device 1 to be corrected are used. Predicted value data of the output of each optical sensor SE when the light emission of the light source is measured by the photometric device 1 is calculated.

  In step (c), the photometry device 1 to be corrected measures the light emission of each reference light source under substantially the same conditions as in step (a), and obtains actual measurement data. Here, substantially the same conditions are such that conditions for causing each reference light source to emit light, conditions for detecting light from each reference light source by the light detection unit, and the like can be allowed depending on the desired correction accuracy. The same conditions may be used. Those skilled in the art can appropriately set conditions according to a conventional method.

  In the step (d), the correction coefficient basic value corresponding to each of the individual reference light sources is calculated in the manner of calculating the correction coefficient according to the above-described correction principle. Here, the correction coefficient basic value is a basis for obtaining a correction coefficient to be finally adopted based on the correction coefficient basic value. However, each correction coefficient basic value itself is the same as the correction coefficient in accordance with the principle of correction described above. It is required. Here, a group of correction coefficients (corresponding to B1, B2,... Bn described above) corresponding to each optical sensor SE of the photometric device 1 to be corrected is also referred to as a “correction coefficient set”. A group of correction coefficient basic values corresponding to each of the optical sensors SE of the photometric device 1 to be corrected (corresponding to the above-described B1, B2,... Bn) is also referred to as a “correction coefficient basic value set”. For example, when 100 reference light sources are used, 100 sets of correction coefficient basic value sets B1, B2,... Bn are calculated in the step (d).

In the step (e), in this embodiment, an average value (arithmetic average value in this embodiment) of correction coefficient basic values calculated corresponding to each of a plurality of reference light sources is calculated, and the average value is measured. When obtaining the characteristics of the target light source, the correction coefficients for correcting the spectral sensitivity characteristics of the respective optical sensors SE are used. That is, for example, when 100 reference light sources are used, average values of correction coefficient basic values B1, B2,... Bn for each photosensor SE of 100 sets of correction coefficient basic value sets are obtained (100). B1 average value B1 _ave, 100 B2 average B2 _ave of the, an average value Bn _ave of ... 100 Bn), the average value of the correction coefficient base value corresponding to each of the optical sensors SE (B1 _ave , B2 _ave ,... Bn _ave ) as a correction coefficient set.

  In the step (f), the correction coefficient set is stored in the ROM 105 of the photometric device 1 or read out to the RAM 104 for use in measuring the light emission of each measurement target light source in the photometric device 1 to be corrected. Then, set the correction coefficient set.

  FIG. 11 shows a result of obtaining chromaticity deviations Δx and Δy similar to those in FIG. 8 when the correction method of the present embodiment is used. That is, 100 white LEDs appropriately distributed in the range of the peak wavelength of the excitation light within the range of 440 nm to 460 nm are randomly extracted and used, and the average value of the correction coefficient base value is calculated according to the present embodiment to correct the correction coefficient. Asked. Then, using this correction coefficient, the chromaticity coordinates x, y when the measured values are predicted by calculation from the respective emission spectra of the white LEDs having different peak wavelengths of the excitation light every 1 nm in the wavelength range of 440 nm to 460 nm are obtained. This was obtained and used as the “predicted value”. Further, “theoretical values” of the chromaticity coordinates x and y were obtained in the same manner as in FIG.

  From FIG. 11, it can be seen that the chromaticity deviations Δx and Δy can be made smaller than in the case of FIG. 8 by obtaining the correction coefficient according to the present embodiment. In particular, it can be seen that the error of the measured value of the photometric device 1 relative to the reference measuring instrument is further reduced as the light source has a peak wavelength of excitation light closer to 450 nm. This is presumably because the error of the measured value can be minimized most in the vicinity of the median value of the peak wavelength distribution of the excitation light because the correction coefficient is obtained from the average value.

  As described above, according to this embodiment, even when a light source such as a white LED having a relatively large variation in the peak wavelength of the emission spectrum is used as a reference light source, the spectral sensitivity characteristics of the photometric device can be corrected with higher accuracy. For example, it is possible to reduce an error (chromaticity error or the like) of a measurement value of the photometric device with respect to the reference measuring device.

  In this embodiment, the average value of the correction coefficient basic value is calculated to obtain the correction coefficient. However, a specific correction coefficient basic value set is selected from a plurality of correction coefficient basic value sets, and the correction coefficient is calculated. It is good also as a set. In this case, in the step (e), the specific correction coefficient basic value set is typically selected so as to minimize the error so as to reduce the error of the measurement value of the photometric device 1 with respect to the reference measuring device. be able to. For example, based on the result showing the same error as in FIG. 11 when each correction coefficient basic value set is used, the error of the measurement value of the photometric device 1 with respect to the reference measuring device is confirmed, and the correction coefficient basic value is selected. be able to. As described above, in the step (e), the correction coefficient basic value calculated corresponding to the specific reference light source is selected as the representative value from the correction coefficient basic values calculated corresponding to each of the plurality of reference light sources. The representative value can be used as each correction coefficient for correcting the spectral sensitivity characteristic of each optical sensor SE when obtaining the characteristic of the light source to be measured.

  In addition, as a statistical process for obtaining a correction coefficient from a correction coefficient basic value, a process for obtaining a median value, a mode value, and the like in addition to a process for obtaining an arithmetic mean value. In the present invention, the average value is a concept including an arithmetic average value, a median value, a mode value, and the like.

Example 2
Next, another embodiment according to the present invention will be described. Elements having the same functions and configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 12 is a flowchart showing a schematic procedure of a method for correcting the spectral sensitivity characteristic of the photometric device 1 in the present embodiment. In the present embodiment, the method for correcting the spectral sensitivity characteristic of the photometric device 1 includes the following steps.
(A) Step of obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device (S201)
(B) A step of selecting specific emission spectrum data from a plurality of emission spectrum data corresponding to each of a plurality of reference light sources (S202).
(C) From the specific emission spectrum data and the spectral sensitivity characteristics of each photosensor SE, the photometric device 1 measures the emission of a specific reference light source corresponding to the specific emission spectrum data. Step of calculating output predicted value data (S203)
(D) A step of measuring the light emission of the specific reference light source using the photometric device 1 and acquiring the actual measurement data of the output of each optical sensor SE (S204)
(E) A step of calculating respective correction coefficients for correcting the spectral sensitivity characteristics of the respective optical sensors SE from the predicted value data and the actually measured value data (S205).
(F) The step of setting the correction coefficient calculated corresponding to each optical sensor SE as the respective correction coefficient for correcting the spectral sensitivity characteristic of each optical sensor SE when obtaining the characteristics of the light source to be measured (S206). )

  The step (a) is the same as the step (a) in the first embodiment.

  In the step (b), the error is typically minimized so that the error of the measured value of the photometric device 1 with respect to the reference measuring instrument is reduced by the correction coefficient obtained based on the specific emission spectrum. You can choose. For example, when using a light source that realizes a predetermined emission color by combining an excitation light source such as a white LED and a phosphor as a reference light source, the peak wavelength distribution of the excitation light is obtained from a plurality of emission spectrum data. Then, emission spectrum data in which the peak wavelength of the excitation light shows a median value in the above distribution is selected. That is, a light source whose excitation light peak wavelength exhibits a median value in the above distribution is selected as a specific reference light source.

  In the step (c), according to the correction principle described above, the specific emission spectrum data is used, and the specific emission spectrum is obtained using the spectral sensitivity characteristic of each photosensor SE when the photometric device 1 to be corrected is calibrated. The predicted value data of the output of each optical sensor SE when the light emission of a specific reference light source corresponding to the data is measured by the photometric device 1 is calculated.

  In the step (d), the photometric device 1 to be corrected measures the light emission of the specific reference light source corresponding to the specific emission spectrum data under substantially the same conditions as the step (a), and the measured value Get the data.

  In the step (e), a correction coefficient set (corresponding to the aforementioned B1, B2,... Bn) corresponding to the specific reference light source is calculated in the manner of calculating the correction coefficient according to the correction principle described above.

  The step (f) is the same as the step (f) in the first embodiment.

  FIG. 13 shows a result of obtaining chromaticity deviations Δx and Δy similar to those in FIG. 8 when the correction method of the present embodiment is used. That is, from 100 white LEDs in which the peak wavelength of excitation light is appropriately distributed within the range of 440 nm to 460 nm, white LEDs whose peak wavelength of excitation light shows the median value of the above distribution (450 nm in the example of FIG. 13). A specific reference light source was selected and used to determine the correction coefficient according to this embodiment. Then, using this correction coefficient, the chromaticity coordinates x, y when the measured values are predicted by calculation from the respective emission spectra of the white LEDs having different peak wavelengths of the excitation light every 1 nm in the wavelength range of 440 nm to 460 nm are obtained. This was obtained and used as the “predicted value”. Further, “theoretical values” of the chromaticity coordinates x and y were obtained in the same manner as in FIG.

  From FIG. 13, it can be seen that the chromaticity deviations Δx and Δy can be made smaller than in the case of FIG. 8 by obtaining the correction coefficient according to the present embodiment. In particular, it can be seen that the error of the measured value of the photometric device 1 relative to the reference measuring instrument is further reduced as the light source has a peak wavelength of the excitation light closer to the peak wavelength (450 nm) of the excitation light of a specific reference light source.

  As described above, according to this embodiment, it is possible to obtain the same effects as those of the first embodiment. In this embodiment, since a specific reference light source is selected from a plurality of emission spectrum data and the correction coefficient is calculated only for the specific reference light source, simplification of the operation can be expected.

Example 3
Next, another embodiment according to the present invention will be described. Elements having the same functions and configurations as those of the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 14 is a flowchart showing a schematic procedure of a method for correcting the spectral sensitivity characteristic of the photometric device 1 in the present embodiment. In the present embodiment, the method for correcting the spectral sensitivity characteristic of the photometric device 1 includes the following steps.
(A) Step of obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device (S301)
(B) Predicting the output of each optical sensor SE when the light emission of each of the plurality of reference light sources is measured by the photometric device 1 from the emission spectrum data of each of the plurality of reference light sources and the spectral sensitivity characteristics of each optical sensor SE. Step of calculating value data (S302)
(C) A step of measuring the light emission of each of the plurality of reference light sources using the photometric device 1 and acquiring the actual measurement value data of the output of each optical sensor SE (S303)
(D) Each correction coefficient basic value for obtaining a correction coefficient for correcting the spectral sensitivity characteristic of each optical sensor SE from the predicted value data and the actually measured value data is associated with each of the plurality of reference light sources. Step of calculating (S304)
(E) Classifying a plurality of reference light sources into a plurality of sections based on a plurality of emission spectrum data corresponding to each of the plurality of reference light sources (S305).
(F) A step of obtaining each correction coefficient for correcting the spectral sensitivity characteristic of each photosensor SE from the correction coefficient basic value calculated corresponding to each of the plurality of reference light sources belonging to the section for each section. (S306)
(G) The light emission of a specific measurement target light source is measured using the photometric device 1 to obtain measurement value data of the output of each optical sensor SE, and based on the measurement value data, the specific measurement target light source is a reference Selecting a category to which a reference light source to be assigned belongs (S307)
(H) From the correction coefficient obtained corresponding to each optical sensor SE for each category, the correction factor corresponding to the selected category is used to determine the characteristics of the specific measurement target light source. Setting as respective correction coefficients for correcting the spectral sensitivity characteristics (S308)

  Steps (a) to (d) are the same as steps (a) to (d) in Example 1.

  In the step (e), the plurality of reference light sources are classified into at least two sections. That is, as can be seen from the results of FIGS. 11 and 13 described in the first and second embodiments, the closer the emission spectrum of the measurement target light source is to the emission spectrum of the reference light source, the more the measurement of the photometry device 1 with respect to the reference measurement device. The value error is small. Therefore, a plurality of reference light sources are classified into a plurality of sections based on the emission spectrum data, and correction coefficients corresponding to the respective sections are obtained using a plurality of reference light sources belonging to each section. Then, when measuring the measurement target light source, a correction coefficient obtained corresponding to a category to which a plurality of reference light sources indicating emission spectrum data that is more approximate to the emission spectrum data of the measurement target light source belongs is used. Thereby, the error of the measured value of the photometry apparatus 1 with respect to a reference | standard measuring device can be made smaller at the time of measurement of a measuring object light source.

  In the present embodiment, in the step (e), the plurality of reference light sources are classified into a plurality of sections based on information relating to the barycentric wavelength in the specific wavelength region of each of the plurality of reference light sources obtained from the emission spectrum data. Classify. For example, when using a light source that realizes a predetermined emission color by combining an excitation light source such as a white LED and a phosphor as a reference light source, a plurality of reference light sources are selected based on the barycentric wavelength of the emission spectrum of the excitation light. Classify into multiple categories. The reason for paying attention to the emission spectrum of the excitation light is that, as described above, the deviation of the emission spectrum of the excitation light has a great influence on the calculated correction coefficient. The reason why the light emission spectrum is divided based on the center-of-gravity wavelength is that, even when the light emission spectrum is asymmetric, it can be expected to easily absorb the influence of the deviation of the light emission spectrum on the correction coefficient. For example, when a white LED is used as a reference light source, a centroid wavelength is obtained by limiting the specific wavelength region to a wavelength region of 380 nm to 500 nm, which is a wavelength region of a blue LED, and a plurality of categories are determined based on the centroid wavelength. Categorize it belongs to. Here, the number of sections can be arbitrarily selected according to the complexity of the operation and the desired correction accuracy. For example, when classifying into two categories, the category is classified into a first category in which the value of the centroid wavelength is less than a specific threshold centroid wavelength value and a second category that is greater than or equal to the threshold centroid wavelength value. . In addition, when classifying into three categories, the first category in which the value of the centroid wavelength is less than the value of the specific first threshold centroid wavelength, and a value greater than or equal to the first threshold centroid wavelength value The second division is less than the threshold centroid wavelength value of 2, and the third division is greater than or equal to the second threshold centroid wavelength value. Similarly, it is possible to classify into four or more sections. According to the study by the present inventors, for example, when the reference light source is a white LED, even if the number of sections is two, the correction accuracy may be sufficiently improved. The number is preferably 10 or less, more preferably 5 or less. The number of reference light sources for each category can be arbitrarily selected according to the complexity of operation and desired correction accuracy. The number of reference light sources for each section can be the same as the number of reference light sources as a whole described in the first embodiment, but preferably 50 or less in consideration of the complexity of operation. , More preferably 20 or less, typically 10. Further, the number of reference light sources may be the same or different for each section, but is preferably the same from the viewpoint of making the correction accuracy in each section the same. In the present embodiment, it is assumed that the classification is made into two sections, a first section having a centroid wavelength of less than 450 nm and a second section having a centroid wavelength of 450 nm or more.

Here, the method of obtaining the centroid wavelength from the emission spectrum data itself is well known to those skilled in the art, and detailed description thereof is omitted. However, when the emission spectrum is P (λ) and the centroid wavelength is λg, the centroid wavelength is It can be obtained from the following equation.
λg = ∫λP (λ) dλ / ∫P (λ) dλ

In the step (f), a correction coefficient set is obtained from the correction coefficient base value calculated in the step (d) for each category classified in the step (e). The method for obtaining the correction coefficient set for each section is the same as the step (e) in the first embodiment. In the present embodiment, in the step (f), an average value of correction coefficient basic values calculated corresponding to each of a plurality of reference light sources belonging to each category is calculated, and the average value is used as a characteristic of the light source to be measured. When obtaining, each correction coefficient for correcting the spectral sensitivity characteristic of each optical sensor SE is used. That is, for each section, a group of average values (B1 _ave , B2 _ave ,... Bn _ave ) of correction coefficient basic values corresponding to each of the optical sensors SE is set as a correction coefficient set.

  In step (g), it is determined whether each measurement target light source approximates the emission spectrum of a reference light source belonging to which of a plurality of sections. In this embodiment, as described above, the plurality of reference light sources are classified based on the barycentric wavelength in a specific wavelength region. Therefore, also for each measurement target light source, roughly, based on the barycentric wavelength in the specific wavelength region, it is approximated to the emission spectrum of the reference light source belonging to which category, that is, the category to which the reference light source to be a reference belongs It is necessary to select. As described above, in this embodiment, in the step (g), the specific measurement target light source is obtained based on the information on the centroid wavelength in the specific wavelength region of the light emission of the specific measurement target light source, which is obtained from the measurement value data. Selects a category to which a reference light source to be used as a reference.

  Note that the photometric device 1 has a relatively coarse spectral resolution. For example, the photometric device 1 of the present embodiment splits the visible light region into 16 divisions (16CH (channels)). For this reason, the center-of-gravity wavelength cannot be obtained from the measurement result obtained by the photometric device 1 as it is obtained from the emission spectrum data obtained by a highly accurate spectrophotometer. However, as the information related to the centroid wavelength in a specific wavelength region, the centroid position (centroid CH) corresponding to the centroid wavelength obtained from the measurement result by the reference measuring device can be obtained. For example, when a light source that realizes a predetermined light emission color by combining an excitation light source such as a white LED and a phosphor as a reference light source, the barycentric position in the wavelength region of the excitation light is obtained. For example, when a white LED is used as a reference light source, the output of the photosensor SE in the sensitivity region corresponding to the wavelength region of the blue LED of the measurement target light source as the specific wavelength region is 380 nm to 500 nm (in this embodiment, 1CH, The center of gravity position is obtained by limiting to 2CH, 3CH, 4CH, 5CH).

Here, the position of the center of gravity can be obtained from the following equation when the output of the optical sensor SE is P (n), n is the CH number, and the center of gravity position (center of gravity CH) is Ng.
Ng = ∫nP (n) dn / ∫P (n) dn

  In this method, a virtual channel obtained by interpolating between the channel positions of the optical sensor SE with sufficient accuracy so that it can be determined whether each measurement target light source has an emission spectrum that approximates to which reference light source belongs to which category. The position of the center of gravity can be obtained as a position (indicated by a decimal point).

  FIG. 15 shows the center of gravity of the white LED in the wavelength region of 380 nm to 500 nm obtained from the emission spectrum data obtained by the reference measuring instrument and the center of gravity obtained from the output of the photosensor SE of 1CH to 5CH of the photometric device 1. The correlation with the position is shown. From FIG. 15, it can be seen that there is a correlation between the centroid wavelength and the centroid position, and based on the output of the photometric device 1, it is possible to determine the classification to which the reference light source to which each measurement target light source should be based. In the present embodiment, as described above, the plurality of reference light sources are classified into two sections, the first section having a centroid wavelength of less than 450 nm and the second section having a centroid wavelength of 450 nm or more. Correspondingly, the reference light source to be used as the reference belongs to the first section for the measurement target light source whose center of gravity is less than 3.0 CH, and the second classification for the measurement target light source of 3.0 CH or more. Select as a segment.

  In the step (h), a correction coefficient set for a corresponding section is read out from the correction coefficient set for each section stored in the ROM 105 of the photometric device 1 to the RAM 104 for use in light emission measurement of each light source to be measured. By doing so, a correction coefficient set is set.

  FIG. 16 shows the result of obtaining chromaticity deviations Δx and Δy similar to those in FIG. 9 when the correction method of this embodiment is used. In other words, 100 white LEDs having an appropriate distribution of the center of gravity wavelength of excitation light within a range of 430 nm to 470 nm are randomly extracted and used, and a white LED whose center of gravity wavelength of excitation light is less than 450 nm (first category) Then, for each of the white LEDs (second category) having a centroid wavelength of the excitation light of 450 nm or more, the average value of the correction coefficient basic values was calculated according to this example to obtain the correction coefficient. Then, the chromaticity coordinates x and y when the measured values are predicted by calculation from the respective emission spectra of the white LEDs having different centroid wavelengths of the excitation light every 1 nm in the wavelength range of 430 nm to 470 nm are used as the correction coefficients for the corresponding categories. This was determined as “predicted value”. Further, “theoretical values” of the chromaticity coordinates x and y were obtained in the same manner as in FIG.

  From FIG. 16, it can be seen that the chromaticity deviations Δx and Δy can be made smaller than in the case of FIG. 9 by obtaining the correction coefficient according to the present embodiment. In particular, when the centroid wavelength of the excitation light is less than 450 nm (first section), the light source whose centroid wavelength of the excitation light is closer to about 439 nm is excited when the centroid wavelength of the excitation light is 450 nm or more (second section). It can be seen that the error of the measured value of the photometric device 1 with respect to the reference measuring instrument is further reduced as the light source has a light barycenter wavelength closer to about 462 nm. This is presumably because the error of the measured value can be minimized most in the vicinity of the median value of the distribution of the barycentric wavelength of the excitation light in each section because the correction coefficient for each section is obtained from the average value.

  As described above, according to this embodiment, it is possible to obtain the same effects as those of the first embodiment. In this embodiment, more accurate measurement is possible by subdividing a plurality of reference light sources into a plurality of sections.

  In the present embodiment, the correction coefficient is calculated by calculating the average value of the correction coefficient basic value for each category, but a specific correction coefficient basic value set is selected from a plurality of correction coefficient basic value sets for each category. A correction coefficient set for each section may be selected. In this case, in the step (f), the specific correction coefficient basic value set for each section is typically set to minimize the error so as to reduce the error of the measurement value of the photometric device 1 with respect to the reference measuring device. Can be selected. For example, based on the result showing the same error as in FIG. 16 when using each correction coefficient basic value set, the error of the measurement value of the photometric device 1 with respect to the reference measuring device is confirmed, and the correction coefficient basic value is selected. be able to. Thus, in the step (f), the correction coefficient basic value calculated corresponding to the specific reference light source is calculated from the correction coefficient basic value calculated corresponding to each of the plurality of reference light sources belonging to each category. It can be selected as a representative value, and the representative value can be used as each correction coefficient for correcting the spectral sensitivity characteristic of each photosensor SE when obtaining the characteristics of the light source to be measured.

Example 4
Next, another embodiment according to the present invention will be described. Elements having functions and configurations similar to those of the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  The present embodiment is generally different from the third embodiment in that a plurality of reference light sources are classified into a plurality of sections based on the peak wavelength instead of the barycentric wavelength in the third embodiment. In the present embodiment, the method for correcting the spectral sensitivity characteristic of the photometric device 1 has the same steps as the steps (a) to (h) in the embodiment 3 described with reference to FIG.

  However, in the present embodiment, in the step (e), a plurality of reference light sources are converted into a plurality of reference light sources based on information related to the peak wavelength in a specific wavelength region of each of the plurality of reference light sources obtained from the emission spectrum data. Classify into categories. For example, when a light source that realizes a predetermined emission color by combining an excitation light source such as a white LED and a phosphor as a reference light source is used, a plurality of reference light sources are selected based on the peak wavelength of the emission spectrum of the excitation light. Classify into multiple categories. In the case where the emission spectrum is substantially symmetrical, even if the emission spectrum is divided based on the peak wavelength of the emission spectrum, the influence of the deviation of the emission spectrum on the correction coefficient can be sufficiently reduced. For example, when a white LED is used as a reference light source, the peak wavelength is obtained by limiting the wavelength range of 380 nm to 500 nm, which is the wavelength range of the blue LED, as the specific wavelength range, and is divided into a plurality of categories based on the peak wavelength. Classify. In the present embodiment, it is classified into two sections, a first section having a peak wavelength of less than 450 nm and a second section having a peak wavelength of 450 nm or more.

  In the present embodiment, in the step (g), the specific measurement target light source is obtained based on the information on the peak wavelength in the specific wavelength region of the light emission of the specific measurement target light source, which is obtained from the measurement value data. Selects a category to which a reference light source to be used as a reference.

  As in the case of the center-of-gravity wavelength in the third embodiment, the peak wavelength cannot be obtained from the measurement result obtained by the photometric device 1 as obtained from the emission spectrum data acquired by the highly accurate spectrophotometer. However, the peak position (peak CH) corresponding to the peak wavelength obtained from the measurement result by the reference measuring device can be obtained as information relating to the peak wavelength in the specific wavelength region. For example, when using a light source that realizes a predetermined emission color by combining an excitation light source such as a white LED and a phosphor as a reference light source, the peak position in the wavelength region of the excitation light is obtained. For example, when a white LED is used as a reference light source, the output of the photosensor SE in the sensitivity region corresponding to the wavelength region of the blue LED of the measurement target light source as the specific wavelength region is 380 nm to 500 nm (in this embodiment, 1CH, The peak position is obtained by limiting to 2CH, 3CH, 4CH, 5CH).

  Here, the peak position can be obtained by Lagrange interpolation from the output of each optical sensor SE. Lagrangian interpolation itself is well known to those skilled in the art and will not be described in detail, but here, roughly, the CH numbers obtained by interpolation are 1.0, 1.1, 1.2,. .9, 5.0 and up to one digit after the decimal point, the output of the optical sensor SE of each CH number is obtained by Lagrange interpolation, and the CH number of the peak is obtained. In this method, a virtual channel obtained by interpolating between the channel positions of the optical sensor SE with sufficient accuracy so that it can be determined whether each measurement target light source has an emission spectrum that approximates to which reference light source belongs to which category. The peak position can be obtained as a position (indicated by a decimal point).

  FIG. 17 is obtained by Lagrange interpolation from the peak wavelength in the wavelength region of 380 nm to 500 nm of the white LED obtained from the emission spectrum data obtained by the reference measuring instrument and the output of the photosensor SE of 1CH to 5CH of the photometric device 1. The correlation with the peak position is shown. From FIG. 17, it can be seen that there is a correlation between the peak wavelength and the peak position, and based on the output of the photometric device 1, it is possible to determine the classification to which the reference light source to which each measurement target light source should be based. In the present embodiment, as described above, the plurality of reference light sources are classified into two sections, the first section having a peak wavelength of less than 450 nm and the second section having a peak wavelength of 450 nm or more. Correspondingly, the reference light source to be used as the reference belongs to the first section for the measurement target light source having a peak position of less than 3.0 CH, and the second classification for the measurement target light source of 3.0 CH or more. Select as a segment.

  FIG. 18 shows a result of obtaining chromaticity deviations Δx and Δy similar to those in FIG. 9 when the correction method of the present embodiment is used. In other words, 100 white LEDs having a peak wavelength of excitation light appropriately distributed within a range of 430 nm to 470 nm are randomly extracted and used, and a white LED having a peak wavelength of excitation light of less than 450 nm (first category) Then, for each of the white LEDs (second category) having a peak wavelength of excitation light of 450 nm or more, the average value of the correction coefficient basic values was calculated according to this example to obtain the correction coefficient. Then, the chromaticity coordinates x and y when the measured values are predicted by calculation from the respective emission spectra of the white LEDs having different excitation light peak wavelengths every 1 nm in the wavelength range of 430 nm to 470 nm are used as the correction coefficients for the corresponding categories. This was determined as “predicted value”. Further, “theoretical values” of the chromaticity coordinates x and y were obtained in the same manner as in FIG.

  From FIG. 18, it can be seen that the chromaticity deviations Δx and Δy can be made smaller than in the case of FIG. 9 by obtaining the correction coefficient according to the present embodiment. In particular, when the peak wavelength of the excitation light is less than 450 nm (first category), the light source whose excitation light peak wavelength is closer to 440 nm, the excitation light when the peak wavelength of excitation light is 450 nm or more (second category). It can be seen that the error of the measured value of the photometric device 1 relative to the reference measuring instrument is further reduced as the light source has a peak wavelength closer to 462 nm. This is considered to be because the correction coefficient of each section is obtained from the average value, so that the error of the measured value can be minimized in the vicinity of the median value of the peak wavelength distribution of the excitation light in each section.

  As described above, according to this embodiment, it is possible to obtain the same effects as those of the first embodiment. In this embodiment, more accurate measurement is possible by subdividing a plurality of reference light sources into a plurality of sections.

  In the present embodiment, the average value of the correction coefficient basic value is calculated for each division to obtain the correction coefficient. However, as in the case of the third embodiment, a plurality of correction coefficient basic value sets are set for each division. A specific correction coefficient basic value set may be selected from the above, and a correction coefficient set for each section may be set.

  In this embodiment, Lagrange interpolation is used as an interpolation method for obtaining a peak position in a specific wavelength region of the light source to be measured from the measurement value of the photometric device 1, but the interpolation method is not limited to this. Other available interpolation methods such as spline interpolation can be used.

Example 5
Next, another embodiment according to the present invention will be described. Elements having the same functions and configurations as those of the first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, a plurality of reference light sources are classified into a plurality of sections as in the third embodiment, and a specific reference light source is selected from a plurality of emission spectrum data for each section as in the second embodiment. The correction coefficient is calculated only for the specific reference light source.

FIG. 19 is a flowchart showing a schematic procedure of a method for correcting the spectral sensitivity characteristic of the photometric device 1 in the present embodiment. In the present embodiment, the method for correcting the spectral sensitivity characteristic of the photometric device 1 includes the following steps.
(A) Step of obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device (S501)
(B) A step of classifying the plurality of reference light sources into a plurality of sections based on a plurality of emission spectrum data corresponding to each of the plurality of reference light sources (S502).
(C) For each category, a step of selecting specific emission spectrum data from a plurality of emission spectrum data corresponding to each of a plurality of reference light sources belonging to the category (S503).
(D) For each section, each light emission of the specific reference light source corresponding to the specific emission spectrum data is measured by the photometry device 1 from the specific emission spectrum data and the spectral sensitivity characteristics of each optical sensor SE. Step of calculating predicted value data of output of optical sensor SE (S504)
(E) A step of measuring the light emission of the specific reference light source by using the photometric device 1 and obtaining the actual measurement value data of the output of each optical sensor SE for each category (S505).
(F) For each category, a step of calculating each correction coefficient for correcting the spectral sensitivity characteristic of each photosensor SE from the predicted value data and the actually measured value data (S506).
(G) The light emission of a specific measurement target light source is measured using the photometric device 1 to obtain measurement value data of the output of each optical sensor SE, and based on the measurement value data, the specific measurement target light source is a reference Selecting a category to which a reference light source to be assigned belongs (S507)
(H) From the correction coefficient calculated corresponding to each of the photosensors SE for each section, the correction coefficient corresponding to the selected section is used to determine the characteristics of the specific light source to be measured. Setting as respective correction coefficients for correcting the spectral sensitivity characteristics (S508)

  The step (a) is the same as the step (a) in the second embodiment.

  The step (b) is the same as the step (e) in the third embodiment. However, in the present embodiment, the plurality of reference light sources are classified into more sections (for example, every 10 nm of the center of gravity wavelength) than in the third embodiment. For example, it is classified into a first category having a center-of-gravity wavelength of 430 nm or more and less than 440 nm, a second category of 440 nm or more and less than 450 nm, a third category of 450 nm or more and less than 460 nm, and a fourth category of 450 nm or more and less than 470 nm. can do.

  In the step (c), specific emission spectrum data, that is, a specific reference light source is selected for each section in the same manner as the step (b) in the second embodiment. For example, the emission spectrum data indicating the median value of the distribution in the wavelength range of each section, that is, the reference light source is selected.

  In the step (d), predicted value data is calculated for each category in the same manner as the step (c) in the second embodiment.

  In the step (e), the measured value data is calculated for each category in the same manner as the step (d) in the second embodiment.

  In the step (f), the correction coefficient is calculated for each section in the same manner as the step (e) in the second embodiment.

  In the step (g), the category is selected as in the step (g) in the third embodiment.

  In the step (h), the correction coefficient is set for the selected section in the same manner as the step (f) in the second embodiment.

  FIG. 20 shows a result of obtaining chromaticity deviations Δx and Δy similar to those in FIG. 9 when the correction method of the present embodiment is used. That is, a reference light source is selected for every 10 nm of the center of gravity wavelength of the excitation light from 100 white LEDs in which the center of gravity wavelength of the excitation light is appropriately distributed within the range of 430 nm to 470 nm, and is used to correct the correction coefficient according to the present embodiment. I asked for each. Then, the chromaticity coordinates x and y when the measured values are predicted by calculation from the respective emission spectra of the white LEDs having different centroid wavelengths of the excitation light every 1 nm in the wavelength range of 430 nm to 470 nm are used as the correction coefficients for the corresponding categories. This was determined as “predicted value”. Further, “theoretical values” of the chromaticity coordinates x and y were obtained in the same manner as in FIG.

  From FIG. 20, it can be seen that the chromaticity deviations Δx and Δy can be made smaller than in the case of FIG. 9 by obtaining the correction coefficient according to the present embodiment. It can also be seen that the chromaticity deviations Δx and Δy can be further reduced by increasing the number of reference light source sections.

  As described above, according to this embodiment, it is possible to obtain the same effects as those of the first embodiment. In this embodiment, more accurate measurement is possible by subdividing a plurality of reference light sources into a plurality of sections. Further, in this embodiment, since a specific reference light source is selected from a plurality of emission spectrum data for each section and the correction coefficient is calculated only for the specific reference light source, the operation can be simplified.

  In the present embodiment, a plurality of reference light sources are classified into a plurality of sections based on the barycentric wavelength of the excitation light as in the third embodiment. However, as in the fourth embodiment, the reference light sources are classified based on the peak wavelength of the excitation light. May be.

Example 6
Next, another embodiment according to the present invention will be described. Elements having the same functions and configurations as those of the first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, several examples of a system configuration that embodies the method for correcting the spectral sensitivity characteristic of the photometric device 1 according to the present invention will be described.

  As an example, as shown in FIG. 21A, the above-described system can be configured by the photometric device 1 shown in FIG. The photometric device 1 and the reference measuring device 2 can be connected so as to be able to communicate with each other by wire or wirelessly, or can exchange data via a removable (removable, movable) recording medium. In this case, the CPU 103 of the photometric device 1 receives the emission spectrum data acquired by the reference measuring device 2 that is a highly accurate spectroscopic measuring device or the like, and this emission spectrum data is stored in the RAM 104 or the ROM 105 of the photometric device 1. Is done. The RAM 104 of the photometric device 1 stores a light reception signal (actual measurement value data) by the optical sensor SE, and the ROM 105 of the photometric device 1 stores spectral sensitivity characteristics, weighting factors, and correction coefficient basic values of the optical sensors SE. , Correction coefficients, predicted value data, and the like are stored. In addition, the CPU 103 performs calculations such as a correction coefficient basic value and a correction coefficient, sets a correction coefficient used when measuring the measurement target light source, and selects a category to which the reference light source to which the measurement target light source should belong. In FIG. 1, a part of the measurement unit 100, for example, the CPU 103, the RAM 104, the ROM 105, and the like may be separated from the other parts, and the two may be wired or wirelessly communicable. In that case, the photometric device 1 is constituted by both of them.

  Thus, for example, the RAM 104 or the ROM 105 of the photometric device 1 functions as an emission spectrum data storage unit. For example, the RAM 104 of the photometric device 1 functions as an actual measurement value data storage unit. Further, for example, the ROM 1035 of the photometric device 1 functions as a spectral sensitivity measurement storage unit, a weighting coefficient storage unit, a correction coefficient basic value storage unit, a correction coefficient storage unit, and a predicted value data storage unit of each optical sensor SE. For example, the CPU 105 of the photometric device 1 functions as a predicted value data calculation unit, a correction coefficient basic value calculation unit, a correction coefficient calculation unit, a correction coefficient setting unit, a classification selection unit, and the like.

  As another example, as shown in FIG. 21B, the above system can be configured by the photometric device 1 shown in FIG. 1, the reference measuring instrument 2, and an external host device 3 such as a personal computer. it can. The photometric device 1 and the external host device 3, the reference measuring device 2 and the external host device 3 are connected to each other so that they can communicate with each other by wire or wirelessly, or can exchange data via a removable recording medium. Can do. The external host device 3 has a CPU as control means and a RAM and ROM as storage means. Therefore, all or part of the functions of the CPU 103, RAM 104, and ROM 105 of the photometric device 1 in the mode of FIG. 21A can be achieved by the CPU, RAM, and ROM of the external host device 3. For example, the process until the correction coefficient is obtained is executed by the external host device 3, and this correction coefficient is finally stored in the ROM 105 of the photometric device 1 and set as a correction coefficient used when measuring the measurement target light source. . In this case, the photometric device according to the present invention can be considered to be configured to include the photometric device 1 and the external host device 3 shown in FIG.

  As described above, a system that embodies the method for correcting the spectral sensitivity characteristics of the photometric device 1 in each of the above-described embodiments as in this embodiment can be configured, and the effects of the above-described embodiments can be obtained.

  Although the present invention has been described with reference to specific embodiments, the present invention is not limited to the above-described embodiments. For example, the reference light source is not limited to a light source including an excitation light source and a phosphor, and may be a fluorescent lamp, a light bulb, an LED (light emitting diode) illumination, an LED element, an LD (laser diode) element, as desired. It may be any light source such as an LCD (Liquid Crystal Display).

DESCRIPTION OF SYMBOLS 1 Photometry apparatus 10 Detection part 11 Optical sensor part 12 Casing (housing | casing)
100 Measuring unit 103 CPU
104 RAM
105 ROM
PD photo detector SE photo sensor

Claims (17)

A photometric device having a plurality of photosensors having different spectral sensitivity characteristics, and measuring the light emission of the measurement target light source to obtain the characteristics of the measurement target light source, correcting the spectral sensitivity characteristics of each of the photosensors to obtain the spectrum of the photometry device A method for correcting spectral sensitivity characteristics of a photometric device that corrects sensitivity characteristics,
Based on acquiring emission spectrum data of each of a plurality of reference light sources using a reference measuring device, each correction coefficient for correcting the spectral sensitivity characteristics of each of the photosensors when determining the characteristics of the light source to be measured is set. A method for correcting spectral sensitivity characteristics of a photometric device.   Using the acquired plurality of emission spectrum data, a plurality of correction coefficient basic values for obtaining the correction coefficient are obtained, statistical processing of the plurality of correction coefficient basic values, or representative values from the plurality of correction coefficient basic values are obtained. 2. The spectral sensitivity of the photometric device according to claim 1, wherein the correction coefficient is obtained by selection, or the correction coefficient is obtained by using specific emission spectrum data selected from the acquired plurality of emission spectrum data. Correction method for characteristics. Obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device;
From the emission spectrum data of each of the plurality of reference light sources and the spectral sensitivity characteristics of each of the photosensors, the predicted value of the output of each of the photosensors when the light emission of each of the plurality of reference light sources is measured by the photometric device. Calculating the data;
Measuring the light emission of each of the plurality of reference light sources using the photometric device to obtain measured value data of the output of each of the optical sensors;
Respective correction coefficient basic values for obtaining correction coefficients for correcting the spectral sensitivity characteristics of the photosensors from the predicted value data and the actual measurement value data, corresponding to each of the plurality of reference light sources. A calculating step;
Obtaining each correction coefficient for correcting the spectral sensitivity characteristic of each photosensor from the correction coefficient basic value calculated corresponding to each of the plurality of reference light sources;
Setting the correction coefficient determined corresponding to each of the photosensors as the correction coefficient for correcting the spectral sensitivity characteristics of the photosensors when determining the characteristics of the light source to be measured;
The method for correcting spectral sensitivity characteristics of a photometric device according to claim 1, wherein:   In the step of obtaining the correction coefficient, an average value of the correction coefficient basic values calculated corresponding to each of the plurality of reference light sources is calculated, and each light is calculated when determining the characteristic of the light source to be measured. 4. The method for correcting spectral sensitivity characteristics of a photometric device according to claim 3, wherein each of the correction coefficients for correcting spectral sensitivity characteristics of the sensor is used.   In the step of obtaining the correction coefficient, the correction coefficient basic value calculated corresponding to a specific reference light source is selected as a representative value from the correction coefficient basic value calculated corresponding to each of the plurality of reference light sources. 4. The spectral sensitivity characteristic of the photometric device according to claim 3, wherein the representative value is used as the correction coefficient for correcting the spectral sensitivity characteristic of each of the photosensors when the characteristic of the light source to be measured is obtained. Correction method.   The method for correcting spectral sensitivity characteristics of a photometric device according to claim 1, wherein the reference light source is a light source that includes an excitation light source and a phosphor and realizes a predetermined emission color. . Obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device;
Selecting specific emission spectrum data from the plurality of emission spectrum data corresponding to each of the plurality of reference light sources;
Prediction of the output of each photosensor when the photometric device measures the emission of a specific reference light source corresponding to the specific emission spectrum data from the specific emission spectrum data and the spectral sensitivity characteristics of each photosensor. Calculating value data;
Measuring the light emission of the specific reference light source using the photometric device to obtain the measured value data of the output of each photosensor;
Calculating each correction coefficient for correcting the spectral sensitivity characteristic of each of the photosensors from the predicted value data and the actually measured value data;
Setting the correction coefficient calculated corresponding to each of the photosensors as the correction coefficient for correcting the spectral sensitivity characteristics of the photosensors when determining the characteristics of the light source to be measured;
The method for correcting spectral sensitivity characteristics of a photometric device according to claim 1, wherein:   The reference light source is a light source that includes an excitation light source and a phosphor and realizes a predetermined emission color. In the step of selecting the specific emission spectrum data, the wavelength of each excitation light source of the plurality of emission spectrum data 8. The method for correcting spectral sensitivity characteristics of a photometric device according to claim 7, wherein emission spectrum data showing a median value in the distribution of peak wavelengths in the region is selected. Obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device;
From the emission spectrum data of each of the plurality of reference light sources and the spectral sensitivity characteristics of each of the photosensors, the predicted value of the output of each of the photosensors when the light emission of each of the plurality of reference light sources is measured by the photometric device. Calculating the data;
Measuring the light emission of each of the plurality of reference light sources using the photometric device to obtain measured value data of the output of each of the optical sensors;
Respective correction coefficient basic values for obtaining correction coefficients for correcting the spectral sensitivity characteristics of the photosensors from the predicted value data and the actual measurement value data, corresponding to each of the plurality of reference light sources. A calculating step;
Classifying the plurality of reference light sources into a plurality of categories based on a plurality of the emission spectrum data corresponding to each of the plurality of reference light sources;
Obtaining each correction coefficient for correcting the spectral sensitivity characteristic of each photosensor from the correction coefficient base value calculated corresponding to each of the plurality of reference light sources belonging to the section for each of the sections When,
The light measurement device is used to measure the light emission of a specific measurement target light source to obtain measurement value data of the output of each photosensor, and based on the measurement value data, the specific measurement target light source should be used as a reference Selecting a category to which the reference light source belongs;
The correction coefficient corresponding to the selected section is calculated from the correction coefficient determined corresponding to each of the optical sensors for each section, and the characteristics of the specific measurement target light source are determined. A step of setting each of the correction coefficients for correcting spectral sensitivity characteristics;
The method for correcting spectral sensitivity characteristics of a photometric device according to claim 1, wherein:   In the step of obtaining the correction coefficient, an average value of the correction coefficient basic values calculated corresponding to each of the plurality of reference light sources belonging to each of the categories is calculated, and the average value is used to obtain the characteristics of the light source to be measured. 10. The method for correcting spectral sensitivity characteristics of a photometric device according to claim 9, wherein the correction coefficients for correcting spectral sensitivity characteristics of the respective optical sensors are used.   In the step of obtaining the correction coefficient, the correction coefficient basic value calculated corresponding to a specific reference light source is calculated from the correction coefficient basic value calculated corresponding to each of the plurality of reference light sources belonging to each of the categories. 10. The photometric device according to claim 9, wherein the photometric device is selected as a representative value, and the representative value is used as the correction coefficient for correcting the spectral sensitivity characteristic of each of the photosensors when the characteristic of the light source to be measured is obtained. Correction method of spectral sensitivity characteristics. Obtaining emission spectrum data of each of a plurality of reference light sources using a reference measuring device;
Classifying the plurality of reference light sources into a plurality of categories based on a plurality of the emission spectrum data corresponding to each of the plurality of reference light sources;
Selecting specific emission spectrum data from the plurality of emission spectrum data corresponding to each of a plurality of reference light sources belonging to the classification for each of the classifications;
For each of the sections, each light when the light emission of the specific reference light source corresponding to the specific emission spectrum data is measured by the photometric device from the specific emission spectrum data and the spectral sensitivity characteristics of the photosensors. Calculating predicted value data of the output of the sensor;
For each of the sections, measuring the light emission of the specific reference light source using the photometric device to obtain measured value data of the output of each photosensor;
Calculating each correction coefficient for correcting the spectral sensitivity characteristic of each photosensor from the predicted value data and the measured value data for each of the categories;
The light measurement device is used to measure the light emission of a specific measurement target light source to obtain measurement value data of the output of each photosensor, and based on the measurement value data, the specific measurement target light source should be used as a reference Selecting a category to which the reference light source belongs;
From the correction coefficient calculated corresponding to each of the photosensors for each category, the correction factor corresponding to the selected category is used to determine the characteristics of the specific light source to be measured. A step of setting each of the correction coefficients for correcting spectral sensitivity characteristics;
The method for correcting spectral sensitivity characteristics of a photometric device according to claim 1, wherein:   In the step of classifying into the plurality of sections, the plurality of reference light sources are classified into a plurality of sections on the basis of information relating to the centroid wavelength in a specific wavelength region of each of the plurality of reference light sources obtained from the emission spectrum data. And in the step of selecting the category, the specific measurement target light source is obtained from the measurement value data on the basis of information related to the centroid wavelength in a specific wavelength region of light emission of the specific measurement target light source. The method for correcting the spectral sensitivity characteristic of a photometric device according to any one of claims 9 to 12, wherein a category to which a reference light source to be a reference belongs is selected.   In the step of classifying into the plurality of sections, the plurality of reference light sources are classified into a plurality of sections on the basis of information relating to peak wavelengths in specific wavelength regions of light emission of the plurality of reference light sources obtained from the emission spectrum data. And in the step of selecting the category, the specific measurement target light source is obtained from the measurement value data on the basis of information relating to a peak wavelength in a specific wavelength region of light emission of the specific measurement target light source. The method for correcting the spectral sensitivity characteristic of a photometric device according to any one of claims 9 to 12, wherein a category to which a reference light source to be a reference belongs is selected.   15. The reference light source is a light source that includes an excitation light source and a phosphor and realizes a predetermined emission color, and the specific wavelength region is a wavelength region of the excitation light source. Correction method for spectral sensitivity characteristics of photometric devices. A photometric device having a plurality of photosensors having different spectral sensitivity characteristics and measuring the light emission of the measurement target light source to obtain the characteristics of the measurement target light source,
A storage unit for storing a correction coefficient for correcting the spectral sensitivity characteristic of each photosensor by correcting the spectral sensitivity characteristic of each photosensor;
The storage unit stores a correction coefficient set based on acquiring emission spectrum data of each of a plurality of reference light sources by a reference measuring device.   The photometry according to claim 16, wherein the storage unit stores a correction coefficient set by the method for correcting the spectral sensitivity characteristic of the photometry device according to any one of claims 1 to 15. apparatus.

Images