JP5585722B2 - Reflection characteristic measuring device - Google Patents

Description

  The present invention relates to a reflection characteristic measuring apparatus that illuminates a sample with illumination light from a white LED and measures the reflection characteristic of the sample, and in particular, scans a plurality of arranged samples and continuously measures the reflection characteristic. It relates to a possible reflection characteristic measurement technique.

  A reflection characteristic measuring apparatus for measuring the reflection characteristic of a sample is known. In this reflection characteristic measuring apparatus, a white light emitting diode (also referred to as a white LED) having advantages such as high efficiency and long life can be adopted as a light source of illumination light. However, the spectral distribution of the illumination light emitted from the white LED varies depending on the temperature of the white LED. Therefore, in order to correct the variation in the spectral distribution of the illumination light, a reference system for observing the variation in the spectral distribution of the illumination light is required. However, if a reference system having an optical system and a spectroscopic unit is provided separately from the optical system and spectroscopic unit for measuring the reflection characteristics of a sample, the reflection characteristic measuring device becomes complicated, the manufacturing cost increases, and resources Incurs a waste of money.

  In view of this, a reflection characteristic measuring apparatus capable of accurately correcting fluctuations in illumination light based on reference light information highly correlated with illumination light irradiated on the surface of the sample has been proposed (for example, Patent Document 1). etc). In this apparatus, since the optical path change for taking in the reference light is performed by inserting the optical path changing means into the reference surface, the configuration becomes simple and the cost can be reduced. Also, based on the spectral distribution of the illumination light estimated by interpolation of the spectral distribution of the illumination light acquired before and after the measurement of the color sample, and the spectral distribution of the reflected light or transmitted light from the color sample, A spectral characteristic measurement system for specifying spectral characteristics has been proposed (for example, Patent Document 2).

  Here, the reflection characteristic measuring apparatus of Patent Document 1 will be briefly described.

  As shown in FIG. 19, in the reflection characteristic measuring apparatus of Patent Document 1, when the light beam 102a emitted from the white LED 102 is irradiated onto the surface 101 of the sample under the control of the light source control unit 102d, the traveling direction of the light beam 102a Forms 45 ° with respect to the normal of the surface 101 of the sample. At this time, of the reflected light generated on the surface 101 of the sample, the reflected light 101 a traveling in the normal direction of the surface 101 of the sample is incident on the spectroscopic unit 109 through the objective lens 106 and the reflecting mirror 107. Then, the spectral distribution of the reflected light 101 a is measured by the spectroscopic unit 109, and a signal indicating the measurement result is sent to the control processing unit 110.

  A glass plate 104 is provided between the white LED 102 and the surface 101 of the sample, which is substantially orthogonal to the normal line of the surface 101 of the sample. Furthermore, a diffusion plate chopper 105 that is intermittently inserted in an optical path through which the light beam 101a passes along a plane that is plane-symmetric with the surface 101 of the sample with respect to the glass plate 104 is provided. As shown in FIG. 19 and FIG. 20, the diffuser plate chopper 105 has a diffuser blade 105a in the optical path through which the light beam 101a passes due to rotation around the rotation shaft 105f using the motor 105e under the control of the motor controller 105d. Is inserted intermittently.

  Thus, the reflected light on the surface 101 of the sample is incident on the spectroscopic unit 109 when the diffuser blade 105a is not inserted in the optical path through which the light beam 101a passes. On the other hand, when the diffusing plate blade 105a is inserted in the optical path through which the light beam 101a passes, a part of the light beam 102a is reflected on the surface of the glass plate 104 together with the reflected light on the surface 101 of the sample to the diffusing plate blade 105a. Incident. At this time, light that passes through the diffusion plate blade 105 a and is emitted in the normal direction of the upper surface of the diffusion plate blade 105 a enters the spectroscopic unit 109 through the objective lens 106 and the reflecting mirror 107.

  Then, the control processing unit 110 obtains the spectral distribution of the illumination light emitted from the white LED 102 based on the spectral distribution measured by the spectroscopic unit 109 when the diffusion plate blade 105a is inserted and not inserted.

  In such a reflection characteristic measuring apparatus of Patent Document 1, a diffusion plate chopper 105, a motor 105e, and the like are required, but separately from the optical system and the spectroscopic unit for measuring the reflection characteristic of the sample, the optical system and the spectroscopic unit It is not necessary to provide a reference system having For this reason, it is possible to realize a highly accurate measurement of the reflection characteristic of the sample by correcting the fluctuation of the spectral distribution of the illumination light without complicating the reflection characteristic measuring apparatus, increasing the manufacturing cost, and not wasting resources. .

  Next, the spectral characteristic measurement system of Patent Document 2 will be briefly described.

  As shown in FIG. 21, in the spectral characteristic measurement system of Patent Document 2, the measurement unit 210 of the spectral characteristic measuring device 230 is scanned along the color sample sheet 201 in which a plurality of color samples are arranged, The reflection characteristics are continuously measured. Similarly to the spectral characteristic measurement apparatus of Patent Document 1, the measurement unit 210 is controlled by the drive circuit 206 so that the traveling direction of the illumination light emitted from the white LED 202 forms 45 ° with respect to the normal line of the surface 201 of the sample. Further, the color sample sheet 201 is illuminated by the illumination light. At this time, the reflected light traveling in the normal direction of the surface of the color sample sheet 201 out of the reflected light in the color sample sheet 201 is incident on the polychromator 204 through the objective lens 208. The spectral distribution information of the reflected light is obtained by the polychromator 204 and the signal processing circuit 207, and the spectral distribution information is sent to the control unit 205.

  Here, as shown in FIG. 22, the white LED 202 is driven with a constant current If by the drive circuit 206. The drive circuit 206 includes a forward voltage detection circuit 206a. The forward voltage Vf in the white LED 202 when the spectral characteristics of each color sample are measured by the forward voltage detection circuit 206a is measured, and information indicating the forward voltage Vf is obtained. Is sent to the control unit 205.

  A white calibration plate 220 having a known spectral reflection characteristic is disposed at the start end of the scanning range of the measurement unit 210. In the spectral characteristic measurement device 230, the scanning unit 213, the conveyance control circuit 214, and the like are controlled by the control unit 205. Thus, each time the measurement unit 210 is scanned, the spectral distribution of the reflected light of the white calibration plate 220 is measured. In the control unit 205, information indicating the spectral distribution of the reflected light of the white calibration plate 220 and the forward voltage Vf of the white LED 202 when measuring the spectral characteristics of each color sample is transmitted via the control unit 205 to the data processing device 240. Is output.

  As described above, the spectral distribution of the illumination light emitted from the white LED 202 varies depending on the temperature of the white LED 202. And there exists a relation peculiar to the element as shown in FIG. 23 between the forward voltage Vf in the white LED 202 driven by a constant current and the temperature of the white LED 202. For this reason, a fixed relationship can be established between the spectral distribution of the illumination light emitted from the white LED 202 and the forward voltage Vf.

  Therefore, the spectral distribution and forward voltage Vf of the reflected light generated on the white calibration plate 220 measured before and after the scanning of the measurement unit 210 by the data processing device 240, the known spectral reflection characteristics, and the reflection generated in each color sample. Based on the forward voltage Vf at the time of measuring the spectral distribution of light, the spectral distribution of the illumination light at the time of measurement related to each color sample is estimated by interpolation using the forward voltage Vf as a parameter.

  Accordingly, a reference system including the optical system and the spectroscopic unit may not be provided separately from the optical system and the spectroscopic unit for measuring the reflection characteristics of the sample. As a result, highly accurate measurement of the reflection characteristic of the sample can be realized by correcting the variation in the spectral distribution of the illumination light without complicating the reflection characteristic measurement device, increasing the manufacturing cost, and wasting resources. .

JP 2007-225312 A International Publication No. 2009/119367

  However, in the reflection characteristic measuring apparatus of Patent Document 1, assuming that the reflection characteristics of a plurality of samples are continuously measured, the diffusion plate chopper 105 must be intermittently inserted during measurement of each sample. It takes a long time.

  Further, in the spectral characteristic measurement system of Patent Document 2, the white calibration plate 220 must be disposed at the start end of the scanning range of the measurement unit 210, resulting in an increase in the size of the system. Furthermore, it is not a dedicated system limited to an application in which the measurement unit 210 is scanned and the reflection characteristics of a plurality of color samples are continuously measured, and the system is too large when measuring the reflection characteristics of individual samples. And a problem that takes a long time for measurement.

  The present invention has been made in view of the above problems, and various aspects of the reflection characteristics of a sample can be measured quickly and accurately with a simple configuration regardless of fluctuations in the spectral distribution of illumination light. The purpose is to provide the technology to obtain.

In order to solve the above-described problem, a reflection characteristic measuring apparatus according to a first aspect includes a semiconductor light emitting element that emits illumination light by constant current driving, and a detection unit that detects a forward voltage of the semiconductor light emitting element. And the reflected light generated by reflecting the illumination light on the surface of the sample and the illumination light are mixed at a first ratio to output a first mixed light, and the reflected light and the illumination light are The mixing unit that outputs the second mixed light by mixing at a second ratio different from the first ratio, and the first reflected light and the illumination light that are generated when the illumination light is reflected from the surface of the first sample are mixed. The first spectral distribution of the first mixed light is measured by the first light reception of the first mixed light output by being mixed at the first ratio in the unit, and the first reflected light and the illumination light are The second output by mixing at the second ratio in the mixing unit. A second spectral distribution related to the second mixed light is measured by the second light reception of the combined light, and the second reflected light and the illumination light generated by reflecting the illumination light on the surface of the second sample are the mixing unit. The third spectral distribution of the first mixed light is measured by the third light reception of the first mixed light output by being mixed at the first ratio, and the second reflected light and the illumination light are A measurement unit that measures a fourth spectral distribution related to the second mixed light by a fourth light reception of the second mixed light output by being mixed at the second ratio in the mixing unit, and detected by the detection unit A calculation unit that calculates a spectral reflectance coefficient of a third sample irradiated with the illumination light when a fifth forward voltage is applied to the semiconductor element, and the detection unit is configured by the measurement unit. The first order of the semiconductor light emitting elements when the first light reception is performed. A second forward voltage of the semiconductor light emitting element is detected when the second light reception is performed by the measurement unit, and a second forward voltage of the semiconductor light emitting element is detected when the third light reception is performed by the measurement unit. 3 forward voltages are detected, and when the fourth light reception is performed by the measurement unit, the fourth forward voltage of the semiconductor light emitting element is detected, and the arithmetic unit detects the first to fourth forward voltages and the first To derive a linear function approximately representing the spectral distribution of the illumination light having the forward voltage as an independent variable based on the fourth spectral distribution, and applying the fifth forward voltage to the linear function, The estimated spectral distribution of the illumination light when the fifth forward voltage is detected by the detection unit is calculated, the spectral reflectance coefficient is calculated using the estimated spectral distribution, and the linear function is the forward voltage. Is Vf, the wave of the spectral distribution of the illumination light A linear function having a relationship of I (λ) = p _λ × Vf + q _{λ when} the intensity at the long λ is I (λ) and the coefficients and constants specific to the wavelength λ are p _λ and q _λ The arithmetic unit has an intensity at the wavelength λ of the first spectral distribution I ₁ (λ), an intensity at the wavelength λ of the second spectral distribution I ₂ (λ), and the third spectral distribution. Of the first spectral distribution is I ₃ (λ), the intensity of the fourth spectral distribution at the wavelength λ is I ₄ (λ), and the reflectance of the first sample with respect to light of the wavelength λ is R. ₁ (λ), the reflectance of the second sample with respect to light of the wavelength λ is R ₂ (λ), the first forward voltage is Vf ₁ , the second forward voltage is Vf ₂ , and the third forward voltage is Vf. _3, the fourth forward voltage Vf _4, wherein the reflection characteristic measuring apparatus _{lambda-specific} coefficient a to the wavelength lambda be specific to, b _lambda, c _lambda and tables If the four numerical values p _λ , q _λ , R ₁ (λ), R ₂ (λ) are unknown numbers , the formula [I] I ₁ (λ) = {p _λ × Vf ₁ + q _λ } × { R ₁ (λ) + a _λ }, formula [II] I ₂ (λ) = {p _λ × Vf ₂ + q _λ } × {b _λ × R ₁ (λ) + c _λ }, formula [III] I ₃ (λ ) = { _Pλ × Vf ₃ + q _λ } × {R ₂ (λ) + a _λ }, and the formula [IV] I ₄ (λ) = {p _λ × Vf ₄ + q _λ } × {b _λ × R ₂ ( by solving the simultaneous equations consisting _λ) + c λ} for each of the wavelength lambda, the numerical p _lambda, we derive the linear function for each of the wavelength lambda seeking q _lambda.

The reflection characteristic measurement apparatus according to the second aspect is the reflection characteristic measurement apparatus according to the first aspect, wherein the measurement unit causes the third reflection to occur when the illumination light is reflected from the surface of the third sample. Measuring the fifth spectral distribution related to the first mixed light by the fifth light reception related to the first mixed light output by mixing the light and the illumination light at the first ratio in the mixing unit; The detection unit detects the fifth forward voltage of the semiconductor light emitting element when the measurement unit performs the fifth light reception, and the calculation unit detects the intensity at the wavelength λ of the fifth spectral distribution. Is expressed as I ₅ (λ), the fifth forward voltage is Vf ₅ , and the reflectance of the third sample with respect to light of the wavelength λ is R ₃ (λ), the numerical values p _λ and q _λ are used. According to the formula [V] I ₅ (λ) = {p _λ × Vf ₅ + q _λ } × {R ₃ (λ) + a _λ } Thus, the spectral reflectance coefficient is calculated by obtaining the reflectance R ₃ (λ) for each wavelength λ.

A reflection characteristic measurement device according to a third aspect is the reflection characteristic measurement device according to the first or second aspect, wherein the measurement unit continuously measures a spectral distribution related to reflected light of a plurality of samples. The first sample is a sample whose spectral distribution is first measured by the measurement unit of the plurality of samples, and the second sample is finally spectrally analyzed by the measurement unit of the plurality of samples. The sample whose distribution is to be measured.

A reflection characteristic measurement device according to a fourth aspect is the reflection characteristic measurement device according to any one of the first to third aspects, wherein the measurement unit maintains radiation of the illumination light by the semiconductor light emitting element. Thus, the illumination light is irradiated to the first reference sample whose reflectance with respect to the light of the wavelength λ is R _W (λ) in a period in which the forward voltage of the semiconductor light emitting element becomes a constant voltage with time. In this case, the reflected light generated when the illumination light is reflected by the surface of the first reference sample and the illumination light are output by being mixed at the first ratio in the mixing unit. The first reference spectral distribution is measured by receiving the mixed light, and the reflected light generated when the illumination light is reflected by the surface of the first reference sample and the illumination light are the second ratio in the mixing unit. 2nd output by mixing with The second reference spectral distribution by receiving the focus light to measure, when the illumination light reflectance in the second reference sample is a R _{d (λ)} for light of the wavelength lambda is irradiated, the illumination By receiving the first mixed light that is output as a result of the light reflected from the surface of the second reference sample and the illumination light being mixed at the first ratio in the mixing unit, the first mixed light is received. The three-spectral spectral distribution is measured, and the reflected light generated when the illumination light is reflected by the surface of the second reference sample and the illumination light are mixed and mixed at the second ratio in the mixing unit. A fourth reference spectral distribution is measured by receiving the second mixed light, and the calculation unit has an intensity at the wavelength λ of the first reference spectral distribution I _1W (λ), and the second reference spectral distribution. Of which the intensity at the wavelength λ is I _2W (λ), the third group The intensity at the wavelength λ of the quasi-spectral distribution is I _1d (λ), the intensity at the wavelength λ of the fourth reference spectral distribution is I _2d (λ), and the forward voltage of the semiconductor light emitting element is the constant voltage. When the intensity at the wavelength λ in the spectral distribution of the illumination light is expressed as I ₀ (λ), the coefficients a _λ , b _λ , c _λ and the intensity I ₀ (λ) are Formula [VI] I _1W (λ) = I ₀ (λ) × {R _W (λ) + a _λ }, which is an unknown number, Formula [VII] I _2W (λ) = I ₀ (λ) × {b _λ × R _W (λ) + c _λ ), formula [VIII] I _1d (λ) = I ₀ (λ) × {R _d (λ) + a _λ }, and formula [IX] I _2d (λ) = I ₀ (λ) The coefficients a _λ , b _λ , and c _λ are obtained by solving simultaneous equations consisting of × {b _λ × R _d (λ) + c _λ } for each wavelength λ.

With the reflection characteristic measuring apparatus according to any one of the first to fourth aspects, measurement of various aspects relating to the reflection characteristics of the sample can be performed with high accuracy and speed with a simple configuration regardless of fluctuations in the spectral distribution of the illumination light. Can be done.

According to the reflection characteristic measuring apparatus according to the first aspect, the spectral distributions of the first and second mixed lights having different mixing ratios for the two samples are measured, so that the spectral distribution of the illumination light is approximately shown. A linear function of voltage is derived. For this reason, even if the spectral distribution measurement for a plurality of samples is continuously performed at high speed, the spectral distribution of the illumination light at the time of measuring each sample can be estimated by the forward voltage detected at the time of measuring each sample. .

According to the reflection characteristic measuring apparatus according to the second aspect, the spectral reflectance coefficient of the third sample can be obtained by a simple calculation.

According to the reflection characteristic measuring apparatus according to the third aspect, when performing continuous measurement on a plurality of samples, the spectral distributions of the first and second mixed lights for the first and last samples, and those Since a large difference may occur in the forward voltage corresponding to, the estimation accuracy of the spectral distribution of the illumination light during measurement of each sample can be improved. Further, for example, during continuous measurement, only the spectral distribution of the first mixed light is measured, thereby enabling higher-speed continuous measurement.

According to the reflection characteristic measuring apparatus according to the fourth aspect, for example, after the forward voltage is stabilized by driving the semiconductor light emitting element at the time of manufacturing the apparatus, the first and second mixed lights are related to the two reference samples. By measuring the respective spectral distributions, the coefficients a _λ , b _λ , and c _{λ that} are specific to the reflection characteristic measuring apparatus and specific to the wavelength λ can be easily obtained.

FIG. 1 is a schematic diagram illustrating a schematic configuration of a reflection characteristic measuring apparatus according to an embodiment. FIG. 2 is a schematic diagram illustrating a schematic configuration of a reflection characteristic measuring apparatus according to an embodiment. FIG. 3 is a diagram illustrating an arrangement mode of a plurality of samples in the sample arrangement sheet. FIG. 4 is a block diagram showing one configuration of the control calculation unit. FIG. 5 is a block diagram showing a functional configuration realized by the control calculation unit. FIG. 6 is a diagram for explaining a method of obtaining the coefficients a _λ , b _λ , and c _λ . FIG. 7 is a flowchart illustrating the operation flow of continuous measurement. FIG. 8 is a flowchart illustrating an operation flow of individual measurement. FIG. 9 is a flowchart showing an operation flow for _obtaining the coefficients a _λ , b _λ , and c _λ . FIG. 10 is a flowchart showing an operation flow for _obtaining the coefficients a _λ , b _λ , and c _λ . FIG. 11 is a diagram illustrating spectral characteristics of illumination light according to two types of LEDs. FIG. 12 is a schematic diagram illustrating a schematic configuration of a reflection characteristic measuring apparatus according to a first modification. FIG. 13 is a schematic diagram illustrating a schematic configuration of a reflection characteristic measuring apparatus according to a first modification. FIG. 14 is a schematic diagram for explaining the configuration and operation of the diffusing member according to the first modification. FIG. 15 is a schematic diagram for explaining the configuration and operation of the diffusing member according to the first modification. FIG. 16 is a schematic view illustrating a part of a diffusing member according to a modification. FIG. 17 is a schematic view illustrating a part of the diffusing member according to a modification. FIG. 18 is a schematic view illustrating the configuration according to a modification. FIG. 19 is a schematic view illustrating the configuration of a reflection characteristic measuring apparatus according to Patent Document 1. FIG. 20 is a diagram illustrating the configuration of the diffusion plate chopper according to Patent Document 1. FIG. 21 is a schematic view illustrating the configuration of a spectral characteristic measurement system according to Patent Document 2. FIG. 22 is a schematic diagram showing a configuration of a white LED. FIG. 23 is a diagram illustrating the temperature dependence of the light emission characteristics of the white LED.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, parts having the same configuration and function are denoted by the same reference numerals, and redundant description is omitted in the following description. Further, the drawings are schematically shown, and the sizes, positional relationships, and the like of various structures in the drawings are not accurately illustrated.

<(1) Configuration of reflection characteristic measuring apparatus>
<(1-1) Schematic configuration of reflection characteristic measuring apparatus>
FIG. 1 is a schematic diagram illustrating a schematic configuration of a reflection characteristic measuring apparatus 1 according to an embodiment. FIG. 2 is a diagram of the optical unit 40 and its periphery in the reflection characteristic measuring apparatus 1 as viewed from the right side of FIG. In FIG. 1 and FIG. 2, the optical path and the traveling direction related to the light flux are indicated by thick broken arrows.

  The reflection characteristic measuring apparatus 1 includes a measuring device 30 and a control calculation unit 10, and can measure a spectral reflectance coefficient of a sample placed at the measurement position Pm1. Specifically, in the reflection characteristic measuring apparatus 1, as shown in FIG. 3, a plurality of samples Sm1 to Smn (n is an integer of 2 or more) having different reflection characteristics arranged on the sample arrangement sheet SA1 are measuring devices 30. The spectral reflectance coefficient of each of the samples Sm1 to Smn can be measured by scanning. In addition, the reflection characteristic measuring apparatus 1 can also measure the spectral reflectance coefficient of the individual sample SA2.

  The measuring device 30 includes the illumination unit 2, the optical unit 40, the spectroscope 9, and a drive control circuit 52.

  The illumination unit 2 includes a light source unit 21 and a light emission control circuit 22.

  The light source unit 21 is a light emitting element using a semiconductor (also referred to as a semiconductor light emitting element), and emits illumination light under the control of the light emission control circuit 22. The illumination light may be white light, for example, and the white light only needs to include a wide range of visible light in a wavelength band of 400 to 700 nm. That is, the light source unit 21 may be a white LED.

Light emission control circuit 22 is a circuit for realizing the driving for emitting the illumination light L _W from the light source unit 21 by supplying a constant current to the light source unit 21 (also referred to as constant current driving). Further, the light emission control circuit 22 detects a forward voltage Vf applied to the light source unit 21 when the illumination light _LW is emitted from the light source unit 21 in accordance with the control of the control calculation unit 10. It has the composition as.

  The optical unit 40 includes a plurality of reflection units 3, partial reflection units 4, a light diffusion member 5, a lens unit 6, a reflection mirror 7, and a light guide unit 8.

The plurality of reflecting portions 3 are arranged in an annular shape around an axis Px1 connecting the light source portion 21 and the measurement position Pm1. The distance between each reflecting portion 3 and the axis Px1 is substantially constant, and the plurality of reflecting portions 3 are arranged so as to be symmetric (also referred to as axial symmetry) with respect to the axis Px1. Each reflection part 3, may be a reflecting mirror for reflecting illumination light L _W emitted from the light source unit 21.

Partially reflecting portion 4 (an intermediate surface of the front and rear two surfaces, also referred to as a first entrance surface) incidence surface illumination light L _W is incident of the illumination light L _W of the reflected by the plurality of reflection portions 3 A portion (eg, about 10% of each wavelength component) is reflected, and the remaining portion (eg, about 90% of each wavelength component) is transmitted. Specifically, the partially reflecting portion 4 is, for example, may be a glass plate, along with some is reflected to generate a reflected light L _WR with the illumination light L _W is irradiated by transmitting remaining portion Transmitted light _LWT is generated. In other words, partially reflecting portion 4 is a mirror for branching the light of the illumination light L _W into two rays of reflected light L _WR and the transmitted light L _WT (also referred to as partial reflection mirror). More specifically, the partially reflecting portion 4, each wavelength component of the illumination light L _W is branched into a component of the transmitted light L _WT and components of the reflected light L _WR.

Transmitted light _{L WT} is irradiated onto the sample (also referred to as the measurement sample) disposed in measured position Pm1 of samples Sm1~Smn and sample SA2. At this time, the transmitted light _LWT is irradiated onto the surface of the sample to be measured along a virtual plane that forms an angle θ with respect to the surface of the sample to be measured, and reflected light is generated on the surface of the sample to be measured. The angle θ may be about 45 °, for example. The reflected light generated here includes light (also referred to as sample reflected light) _LRN that travels along the normal of the surface of the sample to be measured.

From another perspective, the light source unit 21 (here, the axial Px1) normal to any surface of the measured sample emits illumination light L _W in the direction of approximately 45 ° to. The illumination light _LW is reflected by the plurality of reflecting portions 3 and transmitted along a second imaginary plane that is inclined by about 45 ° with respect to the normal of the surface of the sample to be measured (here, the axis Px1). L _WT is irradiated on the surface of the sample to be measured, normal Px1 direction component L _RN of reflected light generated in the sample to be measured is received via the lens 6 and the reflector 7. Accordingly, the illumination unit 2 and the optical unit 40 form a 45 ° c: 0 ° geometry recommended by various standards related to the measurement of the spectral characteristics of the printing surface. In addition, about 45 degrees should just be 40 degrees or more and 50 degrees or less.

  The light diffusing member 5 has a light diffusing portion that diffuses transmitted light in all directions. When a light diffusing plate is employed as the light diffusing member 5, substantially the entire surface of the light diffusing plate functions as a light diffusing portion. The light diffusing member 5 is fixed to, for example, a rod-shaped arm portion 53 that is connected substantially perpendicularly to the rotation shaft 51r of the rotation driving unit 51. The rotation drive unit 51 may be, for example, a rotary solenoid, and rotates the rotation shaft 51r under the control of the drive control circuit 52 according to the control signal from the control calculation unit 10.

  And the rotation drive part 51 can work | function as a state change part which selectively sets the state of the light-diffusion member 5 to a 1st state and a 2nd state by rotation of the rotating shaft 51r. Here, the first state is a state in which the light diffusing unit is retracted from the optical path from the surface of the sample to be measured to the spectroscope 9 via the lens unit 6 and the reflecting mirror 7. The second state is a state in which the light diffusion member 5 is disposed on the optical path from the surface of the sample to be measured to the spectroscope 9 via the lens unit 6 and the reflecting mirror 7.

  In FIG. 1, the position of the outer edge of the light diffusing member 5 (also referred to as the retracted position) when the light diffusing member 5 is set to the first state is drawn with a solid line, and the light diffusing member 5 is set to the second state. The position of the outer edge of the light diffusing member 5 (also referred to as an intrusion position) is depicted by a broken line.

Here, when the light diffusing member 5 is set to the second state, the first incident surface of the partial reflection portion 4 is used as a reference, and the surface of the sample to be measured and the sample to be measured among the light diffusing members 5 are used. The surface (also referred to as a second incident surface) facing the surface of the surface has a plane symmetry relationship. In this case, the second incident surface, and the sample reflected light L _RN generated at the surface of the measured sample, and the reflected light L _WR caused by the first incident surface of the partially reflecting portion 4 is irradiated.

Due to the plane symmetry, the reflected light L _WR irradiated to the light diffusing member 5 and the transmitted light L _WT irradiated to the sample to be measured have the same incident angle and degree of convergence. In other words, the reflected light L _WR irradiated to the light diffusing member 5 well represents the transmitted light L _WT irradiated to the sample to be measured. Thus, the light beam which approximates the light flux incident on the surface of the measured sample is incident on the light diffusing member 5, is the portion of the sample reflected light L _RN illumination light L _W from the surface of the sample to be measured The reflected light _LWR can be easily mixed.

Therefore, when the light diffusing member 5 is set to the first state, the first mixed light L _M1 mainly including the sample reflected light _LRN is incident on the lens unit 6. On the other hand, when the light diffusing member 5 is set to the second state, the light diffusing member 5 is generated on the sample reflected light _LRN generated on the surface of the sample to be measured and on the first incident surface of the partial reflecting portion 4. The second mixed light L _M2 mainly mixed with the reflected light L _WR is emitted to the lens unit 6.

Accordingly, the first mixed light L _M1 becomes light in which the sample reflected light L _RN and the reflected light L _WR that is part of the illumination light L _W are mixed at the first ratio, and the second mixed light L _M2 is the sample The reflected light L _RN and the reflected light L _WR that is a part of the illumination light L _W are light mixed at a second ratio different from the first ratio. Therefore, the partial reflection unit 4, the light diffusing member 5, and the rotation driving unit 51 function as a mixing unit that selectively outputs the first mixed light L _M1 and the second mixed light L _M2 . Thus, if the partial reflection part 4, the light-diffusion member 5, and the rotation drive part 51 comprise a mixing part, the enlargement of the reflection characteristic measuring apparatus 1 and the increase in manufacturing cost will be suppressed, but a mixing ratio will differ. The first and second mixed lights L _M1 and L _M2 can be generated.

The lens unit 6 converges the first mixed light L _M1 and the second mixed light L _M2 output from the mixing unit. The reflecting mirror 7 changes the direction of the light by totally reflecting the light emitted from the lens unit 6. The light guide 8 guides the convergent light reflected by the reflecting mirror 7 to the spectroscope 9. The light guide unit 8 may be an optical fiber, for example.

The spectroscope 9 is a measurement unit that measures a spectral intensity distribution (hereinafter, abbreviated as a spectral distribution) of light guided by the light guide unit 8. The spectroscope 9 may be a polychromator or the like, for example. The spectroscope 9, when the light diffusing member 5 is set to the first state is mainly the first mixed light L _M1 containing the sample reflected light L _RN is received, the light diffusing member 5 to the second state If it is set, the second mixed light L _M2 to the reflected light L _WR and the sample reflected light L _RN are mixed mainly is received.

The control calculation unit 10 controls the entire reflection characteristic measuring apparatus 1. Further, the control calculation unit 10, to estimate the spectral distribution of the illumination light L _W by the approximate function using the forward voltage Vf, regardless of variations in the spectral distribution of the illumination light L _W, a simple structure, to be measured Measurement of reflection characteristics on the surface of the sample is performed quickly with high accuracy.

<(1-2) Configuration of Control Operation Unit>
FIG. 4 is a block diagram showing a configuration of the control calculation unit 10 included in the reflection characteristic measuring apparatus 1 according to the present embodiment.

  The control calculation unit 10 has a function of, for example, a personal computer (personal computer). The control calculation unit 10 includes an operation unit 11, a display unit 12, an interface (I / F) unit 13, a storage unit 14, an input / output (I / O) unit 15, and a control unit 16.

  The operation unit 11 includes, for example, a mouse and a keyboard. The display unit 12 includes, for example, a liquid crystal display. The I / F unit 13 is connected to the spectroscope 9, the light emission control circuit 22, and the drive control circuit 52 so as to be able to transmit and receive signals. The storage unit 14 has, for example, a hard disk or the like, and stores a program P1 and various information for realizing various operations in the control calculation unit 10. The I / O unit 15 includes, for example, a disk drive, can receive a storage medium 17 such as an optical disk, and can exchange data with the control unit 16.

  The control unit 16 includes a CPU 16 a that functions as a processor and a memory 16 b that can temporarily store information, and controls each unit of the control calculation unit 10. Further, in the control unit 16, various functions, various information processing, and the like are realized by reading and executing the program P1 in the storage unit 14. Data temporarily generated in this information processing is appropriately stored in the memory 16b or the like. Note that the control unit 16 can store the program stored in the storage medium 17 in the storage unit 14 or the like via the I / O unit 15.

  FIG. 5 is a block diagram illustrating a functional configuration related to the measurement of reflection characteristics realized by the control calculation unit 10. The functional configuration includes a coefficient calculation unit 161, an approximate function derivation unit 162, a spectral distribution estimation unit 163, a spectral reflectance coefficient calculation unit 164, a drive control unit 165, a lighting control unit 166, and a voltage detection control unit 167. included. With these functional configurations, the measurement of reflection characteristics related to the surface of the sample described below is realized.

<(2) Measuring method of reflection characteristics on sample surface>
<(2-1) Measuring method of reflection characteristics for plural samples>
In the reflection characteristic measuring apparatus 1, when the spectral reflectance coefficient of each sample Sm1 to Smn is measured while the plurality of samples Sm1 to Smn are scanned by the measuring device 30, for example, the spectral reflectance coefficient in the order of the samples Sm1 to Smn. Are measured continuously. Prior to the start of this continuous measurement (also referred to as continuous measurement), the light diffusing member 5 is set to the second state in which it is disposed at the entry position. In the following, the wavelength of light is represented by the symbol λ.

In the continuous measurement, first, a sample Sm1 having a spectral reflectance coefficient R ₁ (λ) is placed at the measurement position Pm1. Then, according to the control signal from the lighting control unit 166 included in the control calculation unit 10, the light source unit 21 is turned on by constant current driving under the control of the light emission control circuit 22. At this time, in a state where the light diffusing member 5 is set to the second state, by the spectroscope 9, second mixed light L _M2 according to the sample Sm1 is received, the spectral distribution I according to the second mixed light L _{M2 2-1} (λ) is measured. Further, the forward voltage _{Vf 2-1} second mixed light _{L M2} according to the sample Sm1 spectroscopically 9 is applied to the light source unit 21 when it is received is detected by the light emission control circuit 22, that order voltage Vf _{2 -1} is sent to the control calculation unit 10. The detection of each forward voltage Vf by the light emission control circuit 22 is performed according to the control of the voltage detection control unit 167.

Next, the light diffusion member 5 is moved to the retracted position under the control of the drive control circuit 52 in accordance with a control signal from the drive control unit 165 included in the control calculation unit 10. Then, in a state where the light diffusing member 5 is set to the first state, the spectroscope 9 receives the first mixed light L _M1 related to the sample Sm1, and the spectral distribution I ₁₋ related to the first mixed light L _{M1. 1} (λ) is measured. Further, when the spectroscope 9 receives the first mixed light L _M1 related to the sample Sm1, the forward voltage Vf _1-1 applied to the light source unit 21 is measured by the light emission control circuit 22, and the forward voltage Vf is measured. Information indicating _1-1 is sent to the control calculation unit 10.

Next, with the light diffusing member 5 held in the first state, the first mixed light L relating to the sample Smi (i = 2 to n) whose spectral reflectance coefficient is R _i (λ) is obtained by the spectroscope 9. _M1 is sequentially received, and the spectral distribution I _1-i (λ) related to the first mixed light L _M1 is measured in order. Further, the forward voltage Vf _1-i applied to the light source unit 21 when the first mixed light L _M1 related to the sample Smi (i = 2 to n) is received by the spectroscope 9 is generated by the light emission control circuit 22. Information that indicates the respective forward voltages Vf _{1 -i} is sent to the control calculation unit 10.

Next, the light diffusion member 5 is moved to the intrusion position by the control of the drive control circuit 52 in accordance with a control signal from the drive control unit 165 included in the control calculation unit 10. Then, in a state where the light diffusing member 5 is set to the second state, by the spectroscope 9, second mixed light L _M2 according to the sample Smn is received, the spectral distribution I ₂ according to the second mixed light L _{M2 -N} (λ) is measured. Further, the forward voltage Vf _2-n in which the second mixed light L _M2 according to the sample Smn is applied to the light source unit 21 when it is received is determined by the light emission control circuit 22 by the spectroscope 9, that order voltage Vf ₂ Information indicating _-n is sent to the control calculation unit 10.

  Thereafter, the light source unit 21 is turned off under the control of the light emission control circuit 22 in accordance with a control signal from the lighting control unit 166 included in the control calculation unit 10.

Spectral distributions I _2-1 (λ), I _1-1 (λ) to I _1-n (λ), I _2-n (λ) and forward voltages Vf _2-1 , Vf ₁ thus obtained. _{Based on −1 to} Vf _1−n and Vf _2−n , the spectral reflectance coefficient relating to each of the samples Sm 1 to Smn is calculated in the control calculation unit 10. Hereinafter, the calculation method of the spectral reflectance coefficient concerning each sample Sm1-Smn is demonstrated.

Intensity of the illumination light L _W at the wavelength lambda I (lambda) of the formula (1) a linear function of the forward voltage Vf and independent variables represented by (hereinafter, also referred to as approximation function) can be approximately expressed by.

I (λ) = p _λ × Vf + q _λ (1).

Note that p _λ and q _λ are specific coefficients and constants for the wavelength λ.

Here, the spectral distributions I _1-1 (λ), I _2-1 (λ), I _{1 -n} (λ), and I _{2 -n} (λ) are expressed by using the linear function represented by the equation (1). Approximately expressed by equations (2) to (5).

I _1-1 (λ) = (p _λ × Vf _1-1 + q _λ ) × {R ₁ (λ) + a _λ } (2)
I _2-1 (λ) = (p _λ × Vf _2-1 + q _λ ) × {b _λ × R ₁ (λ) + c _λ } (3)
I _1-n (λ) = (p _λ × Vf _1−n + q _λ ) × {R _n (λ) + a _λ } (4)
_{I 2-n (λ) =} (p λ × Vf 2-n + q λ) × {b λ × R n (λ) + c λ} ··· (5).

Wherein the first parentheses in the right side of each equation in the equation (2) to (5) shows the intensity I (lambda) of the illumination light L _W at each wavelength lambda. In the expressions in the second parentheses on the right side in the expressions (2) to (5), the first term including the spectral reflectance coefficients R ₁ (λ) and R _n (λ) distribution _{I 1-1 (λ), I 2-1} (λ), I 1-n (λ), with respect to _{I 2-n (λ),} the degree illumination light _{L W} contributes as a sample reflected light _{L RN} Show. In the expression in the second parenthesis, the second term includes the spectral distributions I _1-1 (λ), I _2-1 (λ), I _1-n (λ), I _2-n ( The degree to which the illumination light L _W contributes as the reflected light L _WR with respect to λ).

Illumination light L _W degree contributes as degree of contribution and the illumination light L _W reflected light L _WR as a sample reflected light L _RN is disposed in the case and a retracted position where the light diffusing member 5 is disposed for entry position It differs depending on the case. Here, in a case where the light diffusing member 5 is disposed in the retracted position, the coefficients illumination light L _W determines the degree contributes as a sample reflected light L _RN is the one, as the illumination light L _W reflected light L _WR The coefficient for each wavelength λ that determines the degree of contribution is a _λ . In the case where the light diffusing member 5 is disposed in penetration position, the coefficient of each wavelength lambda of the illumination light L _W determines the degree contributes as a sample reflected light L _RN is a b _lambda, the illumination light L _W is reflected The coefficient for each wavelength λ that determines the degree of contribution as the light L _WR is c _λ . The wavelength dependence of the coefficients a _λ and c _λ is very small.

Incidentally, the coefficient a _λ, b λ, c λ, a unique factor for each measuring unit 30, obtained by the coefficient calculation unit 161 in the manufacturing or the like, for example, shows the coefficient a _λ, b λ, c λ The inherent coefficient information 142 is stored in the storage unit 14.

Among the expressions (2) to (5), the spectral distributions I _1-1 (λ), I _2-1 (λ), I _1-n (λ), I _2-n (λ), and the forward voltage Vf _{1 −1} , Vf ₂₋₁ , Vf _1−n , Vf _2−n are obtained by actual measurement. For this reason, the equations (2) to (5) are simultaneous for each of the wavelengths λ, with the coefficient p _λ , the constant q _λ , and the reflectance coefficients R ₁ (λ) and R _n (λ) as unknowns. It can be solved as an equation.

In the control calculation unit 10, the approximate function deriving unit 162 reads out information related to the expressions (2) to (5) from the relational expression information 141 stored in the storage unit 14 and stores the information in the storage unit 14. Information indicating the coefficients a _λ , b _λ , and c _λ is read from the intrinsic coefficient information 142. Next, the approximate function deriving unit 162 calculates the coefficients a _λ , b _λ , c _λ , and the spectral distributions I _1-1 (λ), I _2-1 (λ), I _1-n (λ ), I _2-n (λ) and forward voltages Vf _1-1 , Vf _2-1 , Vf _{1 -n} and Vf _{2 -n} are applied to the equations (2) to (5). Then, the approximate function deriving unit 162 solves the equations (2) to (5) for each wavelength λ, whereby the coefficient p _λ and the constant q _λ can be calculated.

That is, in the approximate function deriving unit 162, the spectral distributions I _1-1 (λ), I _2-1 (λ), I _1-n (λ), I _2-n (λ) and the forward voltage Vf _1-1 , vf _2-1, based _vf 1-n, to the _{vf 2-n,} the approximation function of equation (1) is derived. Approximate function information 143 indicating this approximate function is appropriately stored in the storage unit 14.

As described above, the coefficient p _λ and the constant q _λ are determined by the spectral distribution of the first and second mixed lights L _M1 and L _M2 measured for a small number of samples and the forward voltage Vf of the light source unit 21 at the time of light reception. Can be determined and an approximate function can be easily derived.

Next, used the coefficient a _lambda coefficient p is calculated by the approximation function deriving unit 162 _lambda and the constant q _lambda is first mixed light according to the sample reflected light _{L RN} sample Smi (i = 1~n) For the spectral distribution I _1-i (λ) of L _M1 , a formula (6) similar to the formula (2) can be established.

I _1-i (λ) = (p _λ × Vf _1−i + q _λ ) × {R _i (λ) + a _λ } (6)
Wherein first portion in parentheses of the right side of (6) is a portion corresponding to the approximation function of Equation (1), the spectral of the illumination light L _W is irradiated onto the sample Smi (i = 1 to n) The distribution is shown approximately. Of the first term on the right side of the equation (6), the coefficient p _λ and the constant q _λ calculated by the approximate function deriving unit 162 are known. Therefore, the spectral distribution estimation unit 163, the first term of the right side of the expression (6), the light emission control forward voltage Vf _1-i obtained in the actual measurement by the circuit 22 is applied, the forward voltage Vf ₁ by the light emission control circuit 22 spectral distribution of the illumination light L _W during the detection of _-i (also referred to as the estimated spectral distribution) can be calculated.

Note that the spectral distribution estimation unit 163 reads, for example, information related to the expression (6) from the relational expression information 141, and applies the coefficient p _λ , constant q _λ , and forward voltage Vf _1-i obtained by actual measurement and calculation. doing, it calculates the estimated spectral distribution of the illumination light L _W during the detection of the forward voltage Vf _1-i.

Further, the spectral reflectance coefficient calculation unit 164 reads information indicating the coefficient a _λ from the intrinsic coefficient information 142 and applies it to the equation (6). Furthermore, the spectral distribution I _1-i (λ obtained by actual measurement with the spectroscope 9 is calculated by the spectral reflectance coefficient calculation unit 164 into the equation (6) including the first term on the right side indicating the estimated spectral distribution for each wavelength λ. ) Is applied to calculate the reflectance coefficient R _i (λ) of each sample Smi (i = 1 to n). That is, the spectral reflectance coefficient R _i (λ) of each sample Smi (i = 1 to n) is calculated. Note that the spectral reflectance coefficients R ₁ (λ) and R _n (λ) of the samples Sm1 and Smn are obtained by solving the formulas (2) to (5) for each wavelength λ by the spectral reflectance coefficient calculation unit 164. It may be calculated by Information indicating the spectral reflectance coefficients R ₁ (λ) to R _n (λ) of the samples Sm _{1 to} Smn calculated here is stored in the calculation result information 144 in the storage unit 14.

As described above, in the continuous measurement for a plurality of samples Sm1 to Smn, the first and second mixed lights L _M1 and L _{M having} different mixing ratios for two samples Sm1 and Smn among the plurality of samples Sm1 to Smn. The spectral distribution of _M2 is measured. Thus, the primary function of the forward voltage Vf showing the spectral distribution of the illumination light L _W to approximately can be determined. For this reason, even if the measurement of the spectral distribution of the plurality of samples Sm1 to Smn is continuously performed at high speed, the forward voltage Vf1 _-i detected at the time of measuring each sample Smi (i = 1 to n) is used. spectral distribution of the illumination light L _W during measurement of each sample Smi can be estimated. Then, the spectral reflectance coefficient R _i (λ) of each sample Smi can be obtained by a simple calculation using the estimated spectral distribution.

Further, the spectral distributions I _1-1 (λ), I _2-1 (λ), I _1-n (λ) of the first and second mixed lights L _M1 and L _M2 for the first and last samples Sm1 and Smn. , I _2-n (λ) and the corresponding forward voltages Vf _1-1 (λ), Vf _2-1 (λ), Vf _1-n (λ), Vf _2-n (λ), Large differences can occur. For this reason, the independence of Formula (2)-(5) is ensured. As a result, can estimate the accuracy of the spectral distribution of the illumination light L _W is increased at the time of measurement intended for each sample Smi (i = 1~n).

<(2-2) Measurement of reflection characteristics for individual samples>
The spectral reflectance coefficient measurement (also referred to as individual measurement) for the individual sample SA2 in the reflection characteristic measuring apparatus 1 is based on the above-described continuous measurement for the plurality of samples Sm1 to Smn, and the number of samples n. May be changed to 1. In this case, the spectral reflectance coefficient R _n (λ) becomes the spectral reflectance coefficient R ₁ (λ), the expressions (2) and (4) match, and the individual samples SA2 and Sm1 match.

Therefore, in the individual measurement, for example, the light diffusing member 5 is sequentially set to the second state, the first state, and the second state. In this case, first, when the light diffusing member 5 is set to the second state, by the spectroscope 9, second mixed light L _M2 according to the individual sample SA2 is received, the second mixed light L _M2 The spectral distribution I _2-1 (λ) is measured. Then, when the light diffusing member 5 is set to the first state, by the spectroscope 9, first mixed light L _M1 according to individual sample SA2 is received, according to the first mixed light L _M1 Spectroscopy The distribution I _1-1 (λ) is measured. Further, when the light diffusing member 5 is set to the second state, by the spectroscope 9, second mixed light L _M2 according to the individual sample SA2 is received again, according to the second mixed light L _M2 Spectroscopy The distribution I _2-1-2 (λ) is measured again.

In parallel with these measurements, firstly, the spectrometer during the first reception of the second mixed light L _M2 according to the individual specimen SmA by 9, the forward voltage is applied to the light source unit 21 by the light emission control circuit 22 Vf _{2 -1} is detected, and information indicating the forward voltage Vf _2-1 is sent to the control calculation unit 10. Next, when the spectroscope 9 receives the first mixed light L _M1 related to the individual sample SmA, the forward voltage Vf _1-1 applied to the light source unit 21 is detected by the light emission control circuit 22, and the forward voltage Vf is detected. Information indicating _1-1 is sent to the control calculation unit 10. Furthermore, during the second reception of the second mixed light _{L M2} according to the individual specimen SmA by the spectroscope 9, the forward voltage _{Vf 2-1-2} being applied to the light source unit 21 is detected by the light emission control circuit 22, Information indicating the forward voltage Vf _2-1-2 is sent to the control calculation unit 10.

Here, the spectral distribution I _2-1 (λ) is approximately represented by Expression (3) using the forward voltage Vf _2-1 and the linear function represented by Expression (1). Further, the spectral distribution I _1-1 (λ) is approximately represented by Expression (2) using the forward voltage Vf _1-1 and a linear function represented by Expression (1). Further, the spectral distribution I _2-1-2 (λ) is obtained by using a forward voltage Vf _2-1-2 (λ) and a linear function represented by the expression (1), and an expression ( It is shown approximately by 7).

I _2-1-2 (λ) = (p _λ × Vf _2-1-2 + q _λ ) × {b _λ × R ₁ (λ) + c _λ } (7).

Here, in equation (2), in one eye expressions in parentheses on the right side, the spectral distribution I of the illumination light L _W at the time when the forward voltage Vf _1-1 is detected (lambda), the forward voltage Vf _{1 −1} , the coefficient p _λ and the constant q _λ are approximately indicated. In other words, Equation (2) is a first relational expression showing the relationship between the spectral distribution I of the illumination light L _W and (lambda) and the spectral distribution I _{1-1 (lambda).} Further, in Formula (3), in first expression in parentheses on the right side, the spectral distribution I of the illumination light L _W at the time when the forward voltage Vf _2-1 is detected (lambda), the forward voltage Vf _2- It is approximately represented by ₁ and the coefficient p _lambda a constant q _lambda. That is, Equation (3) is a second relational expression showing the relationship between the spectral distribution I of the illumination light L _W and (lambda) and the spectral distribution I _{2-1 (lambda).} Furthermore, in Formula (7), in one eye expressions in parentheses on the right side, the spectral distribution I of the illumination light L _W at the time of the forward voltage Vf _2-1-2 is detected (lambda), the forward voltage Vf It is approximately represented by the _2-1-2 and coefficient p _lambda a constant q _lambda. That is, equation (7) is a third relational expression showing the relationship between the spectral distribution I of the illumination light L _W and (lambda) and the spectral distribution I _{2-1-2 (lambda).}

Of the equations (2), (3), and (7), the spectral distributions I _1-1 (λ), I _2-1 (λ), I _2-1-2 (λ), and the forward voltage Vf _{1 −1} , Vf _2-1 , Vf _2-1-2 are obtained by actual measurement. For this reason, the equations (2), (3), and (7) are expressed as simultaneous equations with three numerical values of the coefficient p _λ , the constant q _λ , and the reflectance coefficient R ₁ (λ) as unknowns for each wavelength λ. It is possible to solve.

Specifically, in the control calculation unit 10, for example, the spectral reflectance coefficient calculation unit 164 reads information related to the equations (2), (3), and (7) from the relational expression information 141 in the storage unit 14. Then, information indicating the coefficients a _λ , b _λ , and c _λ is read from the specific coefficient information 142 in the storage unit 14. Next, spectral distributions I _1-1 (λ), I _2-1 (λ), I _2-1-2 (λ), and forward voltage Vf _1-1 obtained by the spectral reflectance coefficient calculation unit 164 are measured. , Vf _2-1 , Vf _2-1-2 , and coefficients a _λ , b _λ , and c _λ are applied to equations (2), (3), and (7). Then, the spectral reflectance coefficient calculation unit 164 solves the equations (2), (3), and (7) for each wavelength λ, thereby calculating the spectral reflectance coefficient R ₁ (λ) of the sample SmA. . That is, the spectral reflectance coefficient R ₁ (λ) of the sample SmA is calculated based on the first to third relational expressions expressed by the expressions (2), (3), and (7). Information indicating the spectral reflectance coefficient R ₁ (λ) of the sample SmA calculated here is stored in the calculation result information 144 in the storage unit 14.

As described above, in the individual measurement intended for individual sample SA2, even without measurement is made using a reference sample, the spectral distribution of the illumination light L _W during measurement of individual sample SA2 can be estimated. Thus, regardless of the variation of the spectral distribution of the illumination light L _W, reflection characteristics of the individual sample SA2 can be measured easily with high accuracy.

Here, when the light diffusing member 5 is set in the order of the second state, the first state, and the second state, and the light diffusing member 5 is set in each state, the spectral distribution I _2-1 ( λ), I _1-1 (λ), I _2-1-2 (λ) are measured and forward voltages Vf _2-1 , Vf _1-1 , Vf _2-1-2 are detected. However, the mode of three times of measurement and three times of detection is not limited to this.

For example, when the light diffusion member 5 is set in the order of the first state, the second state, and the second state, and the light diffusion member 5 is set in each state, the spectral distribution I _1-1 (λ), I _2-1 (λ), I _2-1-2 (λ) may be measured, and the forward voltages Vf _1-1 , Vf _2-1 , Vf _2-1-2 may be detected. For example, when the light diffusing member 5 is set in the order of the second state, the second state, and the first state, and the light diffusing member 5 is set in each state, the spectral distribution I _2-1 (λ ), I _2-1-2 (λ), I _1-1 (λ) may be measured, and the forward voltages Vf _2-1 , Vf _2-1-2 , and Vf _1-1 may be detected.

However, if the light diffusing member 5 is set twice after the second state, the forward voltage Vf _2-1 detected when the light diffusing member 5 is set to the second state for the first time; The difference from the forward voltage Vf _2-1-2 detected when the light diffusing member 5 is set to the second state for the second time can be reduced. Therefore, if the light diffusing member 5 is not set twice following the second state, the independence of the expressions (2), (3), and (7) is further secured, and the spectral reflectance coefficient R ₁ (λ) The calculation accuracy of can be improved.

Further, when the light diffusing member 5 is set in the order of the first state, the second state, and the first state, and the light diffusing member 5 is set in each state, the spectroscope 9 uses the spectral distribution I _1-1. (λ), I _2-1 (λ), I _1-1-2 (λ) are measured, and the light emission control circuit 22 detects the forward voltages Vf _1-1 , Vf _2-1 , Vf _1-1-2. May be.

In this case, for example, Expressions (2), (3), and (7-1) are obtained by changing three numerical values of a coefficient p _λ , a constant q _λ , and a reflectance coefficient R ₁ (λ) for each wavelength λ to an unknown Can be solved as simultaneous equations. Equation (7-1) uses the forward voltage Vf _1-1-2 (λ) and the linear function represented by Equation (1) to approximate the spectral distribution I _1-1-2 (λ). It is a formula which shows.

I _1-1-2 (λ) = (p _λ × Vf _1-1-2 + q _λ ) × {R ₁ (λ) + a _λ } (7-1).

Therefore, in the control calculation unit 10, for example, the spectral reflectance coefficient calculation unit 164 solves the equations (2), (3), and (7-1) for each wavelength λ so that the spectral reflectance coefficient R ₁ ( λ) can be calculated. In other words, the spectral reflectance coefficient calculation unit 164 performs spectral distributions I _1-1 (λ), I _2-1 (λ), I _1-1-2 (λ) and forward voltages Vf _1-1 (λ), Vf. _{Based on the} three relational expressions (2), (3), and (7-1) to which _2-1 (λ) and Vf _1-1-2 (λ) are applied, the spectral reflectance coefficient R of the sample SmA. ₁ (λ) is calculated.

For example, when the light diffusion member 5 is set in the order of the second state, the first state, and the first state, and the light diffusion member 5 is set in each state, the spectral distribution I _2-1 (λ ), I _1-1 (λ), I _1-1-2 (λ) may be measured, and the forward voltages Vf _2-1 , Vf _1-1 , and Vf _1-1-2 may be detected. For example, when the light diffusing member 5 is set in the order of the first state, the first state, and the second state, and the light diffusing member 5 is set in each state, the spectral distribution I _1-1 (λ ), I _1-1-2 (λ), I _2-1 (λ) may be measured, and the forward voltages Vf _1-1 , Vf _1-1-2 , Vf _2-1 may be detected.

However, if the light diffusing member 5 is set twice after the first state, the forward voltage Vf _1-1 detected when the light diffusing member 5 is set to the first state for the first time; The difference from the forward voltage Vf _1-1-2 detected when the light diffusing member 5 is set to the first state for the second time can be reduced. Therefore, if the light diffusing member 5 is not set twice following the first state, the independence of the expressions (2), (3), and (7-1) is further secured, and the spectral reflectance coefficient R ₁ ( The calculation accuracy of λ) can be improved.

By the way, in the individual measurement operation for the individual sample SA2, the forward voltage Vf ₁₋ detected when the light diffusion member 5 is set in the order of the first state, the second state, and the first state. ₁ , Vf _2-1 , Vf _1-1-2 may be almost the same. In this case, for example, the forward voltage Vf _1-1 detected when the light diffusion member 5 is set to the first state for the first time, and the light diffusion member 5 is set to the second state for the first time. The difference from the forward voltage Vf _1-1-2 detected at this time may be equal to or less than a predetermined threshold value Vt.

In this case, the spectral distribution of the illumination light _{L W} at the time of detection of the forward voltage _{Vf 1-1} until the detection of the forward voltage _{Vf 1-1-2} can be regarded as a constant. Specifically, equation (2), (3) a function showing approximately the spectral distribution of the illumination light _{L W} of the _{(p λ × Vf 1-1 + q} λ) and (p _lambda × _{Vf 2- 1} + q _λ ) can be considered to exhibit a constant spectral distribution I ₀ (λ). That is, the expressions (2) and (3) are obtained by replacing (p _λ × Vf _1-1 + q _λ ) and (p _λ × Vf _2-1 + q _λ ) with a constant spectral distribution I ₀ (λ). (2-1) and (3-1) may be used.

I _1-1 (λ) = I ₀ (λ) × {R ₁ (λ) + a _λ } (2-1)
I _2-1 (λ) = I ₀ (λ) × {b _λ × R ₁ (λ) + c _λ } (3-1).

Expressions (2-1) and (3-1) can be solved as simultaneous equations with the intensity I ₀ (λ) and the reflectance coefficient R ₁ (λ) as unknowns for each wavelength λ. Therefore, in the control calculation unit 10, the spectral reflectance coefficient R ₁ (λ) is calculated by solving the expressions (2-1) and (3-1) for each wavelength λ by the spectral reflectance coefficient calculation unit 164. Can be done. That is, the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2 can be calculated based on the spectral distributions I _1-1 (λ), I _2-1 (λ).

Note that (p _λ × Vf _2-1 + q _λ ) and (p _λ × Vf _1-1-2 + q _λ ) in formulas (3) and (7-1) are replaced with a constant spectral distribution I ₀ (λ). Equations (3-2) and (7-2) are solved as simultaneous equations with the spectral distribution I ₀ (λ) and the spectral reflectance coefficient R ₁ (λ) as unknowns for each wavelength λ, and the spectral reflectance is calculated. The coefficient R ₁ (λ) may be calculated. That is, the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2 may be calculated based on the spectral distributions I _2-1 (λ) and I _1-1-2 (λ).

I _2-1 (λ) = I ₀ (λ) × {b _λ × R ₁ (λ) + c _λ } (3-2)
I _1-1-2 (λ) = I ₀ (λ) × {R ₁ (λ) + a _λ } (7-2).

Further, in the individual measurement operation for the individual sample SA2, the forward voltage Vf ₂₋ detected when the light diffusion member 5 is set in the order of the second state, the first state, and the second state. ₁ , Vf _1-1 , Vf _2-1-2 may be almost the same. In this case, for example, the forward voltage Vf _2-1 detected when the light diffusing member 5 is set to the second state for the first time and the light diffusing member 5 are set to the second state for the second time. The difference from the forward voltage Vf _2-1-2 detected at this time may be equal to or less than a predetermined threshold value Vt.

In this case, the spectral distribution of the illumination light _{L W} at the time of detection of the forward voltage _{Vf 2-1} until the detection of the forward voltage _{Vf 2-1-2} can be regarded as a constant. Specifically, equation (2), (3) a function showing approximately the spectral distribution of the illumination light _{L W} of the _{(p λ × Vf 1-1 + q} λ) and (p _lambda × _{Vf 2- 1} + q _λ ) can be considered to exhibit a constant spectral distribution I ₀ (λ). That is, the expressions (2) and (3) are obtained by replacing (p _λ × Vf _1-1 + q _λ ) and (p _λ × Vf _2-1 + q _λ ) with a constant spectral distribution I ₀ (λ). (2-3) and (3-3) may be used.

I _1-1 (λ) = I ₀ (λ) × {R ₁ (λ) + a _λ } (2-3)
I _2-1 (λ) = I ₀ (λ) × {b _λ × R ₁ (λ) + c _λ } (3-3).

Expressions (2-3) and (3-3) can be solved as simultaneous equations with the intensity I ₀ (λ) and the reflectance coefficient R ₁ (λ) as unknowns for each wavelength λ. Therefore, in the control calculation unit 10, the spectral reflectance coefficient R ₁ (λ) is calculated by solving the equations (2-3) and (3-3) for each wavelength λ by the spectral reflectance coefficient calculation unit 164. Can be done. That is, the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2 can be calculated based on the spectral distributions I _1-1 (λ), I _2-1 (λ).

It should be noted that the equations (2) and (7) in which (p _λ × Vf _1-1 + q _λ ) and (p _λ × Vf _2-1-2 + q _λ ) are replaced with a constant spectral distribution I ₀ (λ) (2-4) and (7-4) are solved for each wavelength λ as a simultaneous equation with the intensity I ₀ (λ) and the reflectance coefficient R ₁ (λ) as unknowns, and the spectral reflectance coefficient R ₁ ( λ) may be calculated. That is, the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2 may be calculated based on the spectral distributions I _1-1 (λ) and I _2-1-2 (λ).

I _1-1 (λ) = I ₀ × {R ₁ (λ) + a _λ } (2-4)
I _2-1-2 (λ) = I ₀ × {b _λ × R ₁ (λ) + c _λ } (7-4).

If the configuration in which the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2 is calculated by the simultaneous equations consisting of the two formulas as described above is adopted, even when there is almost no change in the forward voltage Vf, it is possible to achieve a high accuracy. The reflection characteristics of the sample SA2 can be measured.

<(2-3) Determining Coefficients a _λ , b _λ , c _λ >
The coefficients a _λ , b _λ , and c _λ can be obtained by the following method, for example, when the reflection characteristic measuring apparatus 1 is manufactured. Here, a white plate or a white tile having a known spectral reflectance coefficient R _W (λ) is employed as the first reference sample, and light having a known spectral reflectance coefficient R _d (λ) as the second reference sample. A trap, a black plate, a black tile, or the like may be employed. The first and second reference samples may be achromatic samples having low wavelength dependency of the spectral reflectance coefficients R _W (λ) and R _d (λ), but the first reference sample and the second reference sample may be used. If the spectral reflectance coefficients R _W (λ) and R _d (λ) are significantly different from the sample, the calculation accuracy of the coefficients a _λ , b _λ , and c _λ can be improved.

  When the light source unit 21 emits light by constant current driving, for example, as shown in FIG. 6, the forward voltage Vf applied to the light source unit 21 can simply decrease with time.

Here, at time T4, the light diffusing member 5 together with the second reference sample is placed in the measurement position Pm1 disposed in the insertion position, the second mixed light L _M2 according to a second reference sample by the spectroscope 9 is received Assuming that In this case, the time T4, the spectral distribution _{I 2d} of the second mixed light _{L M2 (λ)} is measured according to a second reference sample by spectroscopic 9, the forward voltage _{Vf 2d} of the light source unit 21 by the light emission control circuit 22 is detected Is done.

At the time before and after time T4, the first reference sample is disposed at the measurement position Pm1 and the light diffusion member 5 is disposed at the retracted position. The spectroscope 9 causes the first mixed light L related to the first reference sample to be measured. _M1 is received. At a time before time T4 (for example, time T1), the spectroscope 9 measures the spectral distribution I _1W-1 (λ) of the first mixed light L _M1 related to the first reference sample, and the light emission control circuit 22 Thus, the forward voltage Vf _1W-1 of the light source unit 21 is detected. On the other hand, at the time after time T4 (for example, time T5), the spectroscope 9 measures the spectral distribution I _1W-2 (λ) of the first mixed light L _M1 related to the first reference sample, and the light emission control circuit 22 Thus, the forward voltage Vf _1W-2 of the light source unit 21 is detected.

At the time before and after the time T4, the first reference sample is arranged at the measurement position Pm1 and the light diffusion member 5 is arranged at the intrusion position. The spectroscope 9 causes the second mixed light L related to the first reference sample to be measured. _M2 is received. Then, prior to the time of the time T4 (for example, time T2) in the spectral distribution _{I 2W-1} of the second mixed light _{L M2 (λ)} is measured according to the first reference sample by spectroscopic 9, the light emission control circuit 22 Thus, the forward voltage Vf _2W-1 of the light source unit 21 is detected. On the other hand, time after time T4 (e.g., time T6) in the spectral distribution _{I 2W-2} of the second mixed light _{L M2 (λ)} is measured according to the first reference sample by spectroscopic 9, the light emission control circuit 22 Thus, the forward voltage Vf _2W-2 of the light source unit 21 is detected.

Further, at a time before and after the time T4, the second reference sample is arranged at the measurement position Pm1 and the light diffusing member 5 is arranged at the retracted position. The spectroscope 9 causes the first mixed light L related to the second reference sample to be measured. _M1 is received. At a time before time T4 (for example, time T3), the spectroscope 9 measures the spectral distribution I _1d-1 (λ) of the first mixed light L _M1 related to the second reference sample, and the light emission control circuit 22 Thus, the forward voltage Vf _1d-1 of the light source unit 21 is detected. On the other hand, at the time after time T4 (for example, time T7), the spectroscope 9 measures the spectral distribution I _1d-2 (λ) of the first mixed light L _M1 related to the second reference sample, and the light emission control circuit 22 Thus, the forward voltage Vf _1d-2 of the light source unit 21 is detected.

In such a case, if the forward voltage Vf _{2d at} time T4 is the reference forward voltage, the spectral distribution I _{1W of} the first mixed light L _M1 related to the first reference sample at times T1 and T5 before and after time T4. ₋₁ (λ) and I _1W−2 (λ) are measured. Therefore, forward voltages Vf _1W−1 , Vf _2d , Vf _{1W−2 at} times T1, T4, T5, and spectral distributions I _1W-1 (λ), I _1W-2 (λ) at times T1, T5 The spectral distribution I _1W (λ) of the first mixed light L _M1 related to the first reference sample at time T4 can be calculated by the linear approximation formula (8) based on the above. Here, the spectral distribution I _1W (λ) can be calculated by interpolation. This spectral distribution I _1W (λ) is measured by the spectroscope 9 when the first reference sample is placed at the measurement position Pm1 and the light diffusion member 5 is placed at the retracted position at time T4. the spectral distribution of the first mixed light L _M1 of the first reference sample to be predicted.

_{I 1W (λ) = {I} 1W-1 (λ) × (V 1W-2 -Vf 2d) + I 1W-2 (λ) × (Vf 2d -Vf 1W-1)} / (Vf 1W-2 -Vf _1W-1 ) (8).

Further, before and after the time T2, T6 of time T4, the spectral distribution _{I 2W-1} of the second mixed light _{L M2} according to a first reference sample _{(λ), I 2W-2} (λ) is measured. Therefore, forward voltages Vf _2W−1 , Vf _2d , Vf _2W−2 at times T2, T4, T6, and spectral distributions I _2W-1 (λ), I _2W-2 (λ) at times T2, T6 by linear approximation (9) based on the spectral distribution I _2W of the second mixed light L _M2 according to a first reference sample at time T4 _(lambda) can be calculated. Here, the spectral distribution I _2W (λ) can be calculated by interpolation. This spectral distribution I _2W (λ) is measured by the spectroscope 9 when the first reference sample is disposed at the measurement position Pm1 and the light diffusion member 5 is disposed at the intrusion position at time T4. the spectral distribution of the second mixed light L _M2 of the first reference sample to be predicted.

I _2W (λ) = {I _2W−1 (λ) × (V _2W−2 −Vf _2d ) + I _2W−2 (λ) × (Vf _2d −Vf _2W−1 )} / (Vf _2W−2 −Vf _2W-1 ) (9).

In addition, at times T3 and T7 before and after time T4, the spectral distributions I _1d-1 (λ) and I _1d-2 (λ) of the first mixed light L _M1 related to the second reference sample are measured, respectively. Therefore, forward voltages Vf _1d−1 , Vf _2d , Vf _1d−2 at times T 3, T 4, and T 7 and spectral distributions I _1d−1 (λ), I _1d−2 (λ) at times T 3, T 7 and The spectral distribution I _1d (λ) of the first mixed light L _M1 related to the second reference sample at time T4 can be calculated by the linear approximation formula (10) based on the above. Here, the spectral distribution I _1d (λ) can be calculated by interpolation. The spectral distribution I _1d (λ) is measured by the spectroscope 9 when the second reference sample is placed at the measurement position Pm1 and the light diffusion member 5 is placed at the retracted position at time T4. the spectral distribution of the first mixed light L _M1 of the second reference sample to be predicted.

I _1d (λ) = {I _1d−1 (λ) × (V _1d−2 −Vf _2d ) + I _1d−2 (λ) × (Vf _2d −Vf _1d−1 )} / (Vf _1d−2 −Vf _1d-1 ) (10).

Here, similarly to the equations (2) to (5), the linear function represented by the equation (1) is used, and the forward voltage Vf _2d and the spectral reflectance coefficients R _W and R _{d at the} time T4 are further used. Thus, the spectral distributions I _1W (λ), I _2W (λ), I _1d (λ), and I _2d (λ) at time T4 are approximately expressed by the equations (11) to (14). In the formulas (11) to (14), since the constant forward voltage _{Vf 2d} is employed, illumination light _{L W} spectral distribution _{(p λ × Vf 2d + q} λ) constant spectral distribution _{I 0} of (lambda ) May be substituted.

I _{1 W} (λ) = (p _λ × Vf _2d + q _λ ) × {R _W (λ) + a _λ } = I ₀ (λ) × {R _W (λ) + a _λ } (11)
I _{2 W} (λ) = (p _λ × Vf _2d + q _λ ) × {b _λ × R _W (λ) + c _λ } = I ₀ (λ) × {b _λ × R _W (λ) + c _λ }. (12)
I _1d (λ) = (p _λ × Vf _2d + q _λ ) × {R _d (λ) + a _λ } = I ₀ (λ) × {R _d (λ) + a _λ } (13)
I _2d (λ) = (p _λ × Vf _2d + q _λ ) × {b _λ × R _d (λ) + c _λ } = I ₀ (λ) × {b _λ × R _d (λ) + c _λ }. (14).

These four equations (11) to (14) can be solved as simultaneous equations in which four numerical values of the intensity I ₀ (λ) and the coefficients a _λ , b _λ , and c _λ are unknown for each wavelength λ. .

In the control calculation unit 10, the coefficient calculation unit 161 calculates the spectral distributions I _1W (λ), I _2W (λ), and I _1d (λ) based on the equations (8) to (10). Further, the coefficient calculation unit 161 reads the information of the four formulas (11) to (14) from the relational expression information 141 in the storage unit 14, and the spectral distribution I _1W (λ obtained by actual measurement and calculation in the four formulas. ), I _2W (λ), I _1d (λ), I _2d (λ) are applied. Then, the coefficients a _λ , b _λ , and c _λ can be calculated by solving the equations (11) to (14) for each wavelength λ by the coefficient calculation unit 161. Here, the specific coefficient information 142 indicating the calculated coefficients a _λ , b _λ , and c _λ is stored in the storage unit 14, for example.

Here, the spectral distribution I _2d (λ) is obtained by actual measurement, but the present invention is not limited to this. For example, the time T4 in spectral distribution _{I 2d} (lambda) is not measured, before and after the time of the time T4, the spectral distribution _{I 2d-1} of the second mixed light _{L M2} according to a second reference sample _{(lambda), I 2d -2} (λ) may be measured, and the spectral distribution I _2d (λ) may be calculated by so-called interpolation calculation. In this case, the forward voltage _{Vf 2d} at time T4, the spectral distribution _{I 2d-1 (λ)} and the forward voltage _{Vf 2d-1} at the time of measurement, the spectral distribution _{I 2d-2 (λ)} forward when a measurement voltage of _{Vf 2d-2} Then, the spectral distribution I _2d (λ) can be calculated by the linear approximation formula (15) based on the spectral distributions I _2d-1 (λ) and I _2d-2 (λ).

I _2d (λ) = {I _2d−1 (λ) × (V _2d−2 −Vf _2d ) + I _2d−2 (λ) × (Vf _2d −Vf _2d−1 )} / (Vf _2d−2 −Vf _2d-1 ) (15).

In this way, all of the spectral distributions I _1W (λ), I _2W (λ), I _1d (λ), and I _2d (λ) may be calculated by interpolation. Also, any one of the spectral distributions I _1W (λ), I _2W (λ), I _1d (λ), and I _2d (λ) is obtained by actual measurement, and the other spectral distributions are interpolated or extrapolated. It may be calculated by calculation.

<(3) Operation of reflection characteristic measuring apparatus>
<(3-1) Operation flow of continuous measurement>
FIG. 7 is a flowchart illustrating the operation flow of continuous measurement in the reflection characteristic measuring apparatus 1. This operation flow can be executed under the control of the control calculation unit 10. For example, in the state where the sample arrangement sheet SA1 is arranged in the reflection characteristic measuring apparatus 1, this operation flow is started according to the operation of the operation unit 11 by the operator, and the process proceeds to step S1. In addition, when this operation | movement flow is started, the light-diffusion member 5 is arrange | positioned at the penetration | invasion position.

  In step S1, the measuring device 30 is arranged on the top sample Sm1 in the sample arrangement sheet SA1 by the control calculation unit 10.

  In step S <b> 2, the light source unit 21 is turned on by constant current driving under the control of the lighting control unit 166.

In step S3, the second mixed light _{L M2} is received according to the sample Sm1 spectroscopically 9, spectral distribution _{I 2-1} (lambda) is measured according to the second mixed light _{L M2.} Further, the light emission control circuit 22, a second mixed light L _M2 order is applied to the light source unit 21 when it is received voltage Vf _2-1 are measured according to the sample Sm1 spectroscopically 9. At this time, information indicating the spectral distribution I _2-1 (λ) and the forward voltage Vf _2-1 is sent to the control calculation unit 10.

  In step S <b> 4, the light diffusion member 5 is moved and placed at the retracted position under the control of the drive control unit 165.

  In step S <b> 5, scanning for n samples Sm <b> 1 to Smn is started by the control calculation unit 10.

In step S6, the first mixed light _{L M1} according to the sample Sm1~Smn is received sequentially by the spectroscope 9, spectral distribution _{I 1-1} according to the first mixed light _{L M1 (λ) ~I 1-} n (λ ) Are measured in order. Further, the forward voltage Vf _{1-1 to} Vf _{1 -n} applied to the light source unit 21 when the spectroscope 9 receives the first mixed light L _M1 related to the samples Sm1 to Smn by the light emission control circuit 22. Are measured in order. At this time, information indicating the spectral distributions I _1-1 (λ) to I _1-n (λ) and the forward voltages Vf _{1-1 to} Vf _1-n is sent to the control calculation unit 10.

  In step S <b> 7, the scan for n samples Sm <b> 1 to Smn is ended by the control calculation unit 10.

  In step S <b> 8, the light diffusion member 5 is moved and placed at the entry position under the control of the drive control unit 165.

In step S9, the spectroscope 9 receives the second mixed light L _M2 related to the sample Smn, and the spectral distribution I _2-n (λ) related to the second mixed light L _M2 is measured. Further, the light emission control circuit 22, a forward voltage Vf _2-n that is applied to the light source unit 21 when the second mixed light L _M2 according to the sample Smn is received is measured by the spectroscope 9. At this time, information indicating the spectral distribution I _2-n (λ) and the forward voltage Vf _2-n is sent to the control calculation unit 10.

  In step S <b> 10, the light source unit 21 is turned off under the control of the lighting control unit 166.

In step S11, the approximate function deriving unit 162 derives an approximate function using the forward voltage Vf. At this time, the spectral distributions I _1-1 (λ), I _2-1 (λ), I _1-n (λ), I _2-n obtained in steps S3, S6, and S9 by the approximate function deriving unit 162. (λ), forward voltages Vf _1-1 (λ), Vf _2-1 (λ), Vf _1-n (λ), Vf _2-n (λ), and coefficients a _λ , b _λ , c _λ are 4 This applies to equations (2) to (5). Then, the approximate function deriving unit 162 solves the equations (2) to (5) for each wavelength λ, thereby calculating the coefficient p _λ and the constant q _λ .

In step S12, the spectral distribution estimation unit 163 calculates the coefficient p _λ and the constant q _λ calculated in step S11 and the forward voltage Vf _1-i (i = _{1 to} n) detected in step S6 in the equation (6). in applied that, estimated spectral distribution of the illumination light L _W during the detection of the forward voltage Vf _1-i is calculated. Further, the coefficient a _λ is applied to the equation (6) by the spectral reflectance coefficient calculation unit 164, and the spectral distribution I _1-i (λ) measured in step S6 is applied for each wavelength λ, and the sample Sm1. The reflectance coefficients R ₁ (λ) to R _n (λ) of ˜Smn are calculated. That is, the spectral reflectance coefficients R ₁ (λ) to R _n (λ) of the samples Sm1 to Smn are calculated.

In step S13, information indicating the spectral reflectance coefficients R ₁ (λ) to R _n (λ) of the samples Sm1 to Smn calculated in step S12 is calculated in the storage unit 14 by the spectral reflectance coefficient calculating unit 164. The result information 144 is stored. At this time, information indicating the spectral reflectance coefficients R ₁ (λ) to R _n (λ) may be visually output to the display unit 12.

<(3-2) Individual measurement operation flow>
FIG. 8 is a flowchart illustrating an operation flow of individual measurement in the reflection characteristic measuring apparatus 1. This operation flow can be executed under the control of the control calculation unit 10. For example, in the state where the individual sample SA2 is arranged in the reflection characteristic measuring apparatus 1, this operation flow is started in accordance with the operation of the operation unit 11 by the operator, and the process proceeds to step S21. In addition, when this operation | movement flow is started, the light-diffusion member 5 is arrange | positioned at the penetration | invasion position.

  In step S21, the measuring device 30 is arranged on the individual sample SA2 by the operator, and the flow from step S22 is started by the operation of the operation unit 11.

  In step S <b> 22, the light source unit 21 is turned on by constant current driving under the control of the lighting control unit 166.

In step S23, the second mixed light _{L M2} is received according to the individual sample SA2 spectroscopically 9, spectral distribution _{I 2-1} (lambda) is measured according to the second mixed light _{L M2.} Further, the light emission control circuit 22, the forward voltage Vf _2-1 which is applied to the light source unit 21 is measured when the second mixed light L _M2 according to the individual sample SA2 is received by the spectroscope 9. At this time, information indicating the spectral distribution I _2-1 (λ) and the forward voltage Vf _2-1 is sent to the control calculation unit 10.

  In step S24, the light diffusing member 5 is moved and placed at the retracted position under the control of the drive control unit 165.

In step S25, the spectroscope 9 receives the first mixed light L _M1 related to the individual sample SA2, and the spectral distribution I _1-1 (λ) related to the first mixed light L _M1 is measured. The light emission control circuit 22 measures the forward voltage Vf _1-1 applied to the light source unit 21 when the spectroscope 9 receives the first mixed light L _M1 related to the individual sample SA2. At this time, information indicating the spectral distribution I _1-1 (λ) and the forward voltage Vf _1-1 is sent to the control calculation unit 10.

  In step S <b> 26, the light diffusion member 5 is moved and placed at the entry position under the control of the drive control unit 165.

In step S27, the spectroscope 9 receives the second mixed light L _M2 related to the individual sample SA2 again, and the spectral distribution I _2-1-2 (λ) related to the second mixed light L _M2 is measured. Further, the light emission control circuit 22, the forward voltage Vf _2-1-2 being applied to the light source unit 21 is measured when the second mixed light L _M2 is received again according to the individual sample SA2 spectroscopically 9 The At this time, information indicating the spectral distribution I _2-1-2 (λ) and the forward voltage Vf _2-1-2 is sent to the control calculation unit 10.

  In step S <b> 28, the light source unit 21 is turned off under the control of the lighting control unit 166.

In step S29, the difference between the forward voltage Vf _2-1 detected in step S23 and the forward voltage Vf _2-1-2 detected in step S27, that is, the amount of change in the forward voltage Vf is calculated by the control calculation unit 10. It is determined whether or not the threshold value Vt is exceeded. If the change amount of the forward voltage Vf exceeds the threshold value Vt, the process proceeds to step S30. If the change amount of the forward voltage Vf is equal to or less than the threshold value Vt, the process proceeds to step S31.

In step S30, the spectral reflectance coefficient calculation unit 164 calculates the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2. Specifically, the spectral distributions I _2-1 (λ), I _1-1 (λ), I _2-1-2 (λ) and the forward voltage Vf _2-1 obtained in steps S23, S25, and S27, Vf _1-1 , Vf _2-1-2 and coefficients a _λ , b _λ , and c _λ are applied to the three formulas (2), (3), and (7), and for each wavelength λ, the formula (2) , (3), (7) are solved. Thereby, the spectral reflectance coefficient R ₁ (λ) is calculated.

In step S31, the spectral reflectance coefficient calculation unit 164 calculates the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2. Specifically, for example, equations (2-1) and (3-1) are solved for each wavelength λ. Thereby, the spectral reflectance coefficient R ₁ (λ) is calculated.

In step S32, information indicating the spectral reflectance coefficient R ₁ (λ) of the individual sample SA2 calculated in step S30 or step S31 by the spectral reflectance coefficient calculating section 164 is calculated result information 144 in the storage section 14. Is remembered. At this time, information indicating the spectral reflectance coefficient R ₁ (λ) may be visually output to the display unit 12.

<(3-3) Operation Flow for Determining Coefficients a _λ , b _λ , c _λ >
FIG. 9 and FIG. 10 are flowcharts illustrating an operation flow relating to the determination of the coefficients a _λ , b _λ , and c _{λ in} the reflection characteristic measuring apparatus 1. This operation flow can be executed under the control of the control calculation unit 10. For example, this operation flow is started in accordance with the operation of the operation unit 11 by the operator, and the process proceeds to step S41. When the operation flow is started, the light diffusing member 5 is disposed at the retracted position.

  In step S <b> 41, the light source unit 21 is turned on by constant current driving under the control of the lighting control unit 166.

In step S42, the measuring device 30 is placed on a white plate as a first reference sample whose spectral reflectance coefficient R _W (λ) is known.

In step S43, the spectroscope 9 receives the first mixed light L _M1 related to the white plate, and the spectral distribution I _1W-1 (λ) related to the first mixed light L _M1 is measured. The light emission control circuit 22 measures the forward voltage Vf _1W-1 applied to the light source unit 21 when the spectroscope 9 receives the first mixed light L _M1 related to the white plate. At this time, information indicating the spectral distribution I _1W-1 (λ) and the forward voltage Vf _1W-1 is sent to the control calculation unit 10.

  In step S44, the light diffusing member 5 is moved and placed at the entry position under the control of the drive control unit 165.

In step S45, the second mixed light _{L M2} according to the white plate is received by the spectroscope 9, spectral distribution _{I 2W-1 (λ)} is measured according to the second mixed light _{L M2.} Further, the light emission control circuit 22, the forward voltage Vf _2W-1 of the second mixed light L _M2 according to the white plate is applied to the light source unit 21 when it is received is measured by the spectroscope 9. At this time, information indicating the spectral distribution I _2W-1 (λ) and the forward voltage Vf _2W-1 is sent to the control calculation unit 10.

In step S46, the measuring device 30 is placed in an optical trap as a second reference sample whose spectral reflectance coefficient R _d (λ) is known.

  In step S <b> 47, the light diffusing member 5 is moved and placed at the retracted position under the control of the drive control unit 165.

In step S48, the spectroscope 9 receives the first mixed light L _M1 related to the optical trap, and the spectral distribution I _1d-1 (λ) related to the first mixed light L _M1 is measured. The light emission control circuit 22 measures the forward voltage Vf _1d-1 applied to the light source unit 21 when the spectroscope 9 receives the first mixed light L _M1 related to the optical trap. At this time, information indicating the spectral distribution I _1d-1 (λ) and the forward voltage Vf _1d-1 is sent to the control calculation unit 10.

  In step S49, the light diffusion member 5 is moved and placed at the entry position under the control of the drive control unit 165.

In step S50, the spectroscope 9 receives the second mixed light L _M2 related to the optical trap, and the spectral distribution I _2d (λ) related to the second mixed light L _M2 is measured. Further, the light emission control circuit 22, the forward voltage Vf _2d of the second mixed light L _M2 according to the light trap is applied to the light source unit 21 when it is received is measured by the spectroscope 9. At this time, information indicating the spectral distribution I _2d (λ) and the forward voltage Vf _2d is sent to the control calculation unit 10.

In step S51, the measuring device 30 is placed on a white plate as a first reference sample whose spectral reflectance coefficient R _W (λ) is known.

  In step S <b> 52 of FIG. 10, the light diffusion member 5 is moved and placed at the retracted position under the control of the drive control unit 165.

In step S53, the spectroscope 9 receives the first mixed light L _M1 related to the white plate, and the spectral distribution I _1W-2 (λ) related to the first mixed light L _M1 is measured. Further, the light emission control circuit 22, the forward voltage Vf _1W-2 in which the first mixed light L _M1 according to the white plate is applied to the light source unit 21 when it is received is measured by the spectroscope 9. At this time, information indicating the spectral distribution I _1W-2 (λ) and the forward voltage Vf _1W-2 is sent to the control calculation unit 10.

  In step S54, the light diffusing member 5 is moved and placed at the entry position under the control of the drive control unit 165.

In step S55, the second mixed light _{L M2} according to the white plate is received by the spectroscope 9, spectral distribution _{I 2W-2 (λ)} is measured according to the second mixed light _{L M2.} Further, the light emission control circuit 22, the forward voltage Vf _2W-2 in which the second mixed light L _M2 according to the white plate is applied to the light source unit 21 when it is received is measured by the spectroscope 9. At this time, information indicating the spectral distribution I _2W-2 (λ) and the forward voltage Vf _2W-2 is sent to the control calculation unit 10.

In step S56, the measuring device 30 is placed in an optical trap as a second reference sample whose spectral reflectance coefficient R _d (λ) is known.

  In step S57, the light diffusing member 5 is moved and placed at the retracted position under the control of the drive control unit 165.

In step S58, the spectroscope 9 receives the first mixed light L _M1 related to the optical trap, and the spectral distribution I _1d-2 (λ) related to the first mixed light L _M1 is measured. The light emission control circuit 22 measures the forward voltage Vf _1d-2 applied to the light source unit 21 when the spectroscope 9 receives the first mixed light L _M1 related to the optical trap. At this time, information indicating the spectral distribution I _1d-2 (λ) and the forward voltage Vf _1d-2 is sent to the control calculation unit 10.

  In step S <b> 59, the light source unit 21 is turned off under the control of the lighting control unit 166.

In step S60, the spectral distributions I _1W (λ), I _2W (λ), and I _1d (λ) corresponding to the forward voltage Vf _2d as the reference forward voltage obtained in step S50 are calculated by the coefficient calculation unit 161 using the formula ( ₁ ). It is calculated by the calculation of interpolation based on 8) to (10).

In step S61, the coefficient calculation unit 161 calculates the coefficients a _λ , b _λ , and c _λ using the simultaneous equations of the four formulas (11) to (14).

In step S62, the coefficient calculation unit 161 stores the specific coefficient information 142 indicating the coefficients a _λ , b _λ , and c _λ calculated in step S61 in the storage unit 14.

<(4) Summary of one embodiment>
As described above, approximate the reflection characteristic measuring apparatus 1 according to an embodiment, the light source unit 21 is caused major changes in the spectral distribution of the illumination light L _W is emitted by the temperature rise immediately after the lighting, using the forward voltage Vf spectral distribution of the illumination light L _W corresponding to the measurement of the sample is estimated by the function. Therefore, even if either of the continuous measurement and individual measurement, it is not necessary to measure the reference sample such white plate or the like to estimate the spectral distribution of the illumination light L _W. Therefore, regardless of the spectral distribution change of the illumination light L _W, with a simple configuration, measurement of the various aspects of the reflection characteristic of the sample can be quickly performed with high accuracy.

<(5) Modification>
It should be noted that the present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, when the light source unit 21 emits light with constant current drive, the forward voltage Vf applied to the light source unit 21 over time is simply as shown in FIG. In the case of decreasing, the method for _obtaining the coefficients a _λ , b _λ , and c _λ has been shown, but the present invention is not limited to this.

For example, by radiation of the illumination light L _W by the light source unit 21 is a predetermined time (e.g. 10 minutes) maintaining the forward voltage Vf applied to the light source unit 21, regardless of the time, substantially without little change A period of constant voltage occurs. During this period, the spectroscope 9 measures the spectral distribution I _1W (λ) of the first mixed light L _M1 and the spectral distribution I _2W (λ) of the second mixed light L _M2 for the first reference sample, and the second reference. Even if the spectral distribution I _1d (λ) of the first mixed light L _M1 and the spectral distribution I _2d (λ) of the second mixed light L _M2 are measured for the sample, the coefficients a _λ , b _λ , and c _λ are calculated. good.

Specifically, in the state where the forward voltage Vf of the light source unit 21 is stable, since the spectral distribution of the illumination light L _W given by formula (1) is not changed, to be a constant spectral distribution I _{0 (lambda)} it can. In this case, the spectral distributions I _1W (λ), I _2W (λ), I _1d (λ), and I _2d (λ) are approximately expressed by equations (16) to (19).

I _1W = (p _λ × Vf + q _λ ) × {R _W (λ) + a _λ } = I ₀ (λ) × {R _W (λ) + a _λ } (16)
I _2W = (p _λ × Vf + q _λ ) × {b _λ × R _W (λ) + c _λ } = I ₀ (λ) × {b _λ × R _W (λ) + c _λ } (17)
I _1d = (p _λ × Vf + q _λ ) × {R _d (λ) + a _λ } = I ₀ (λ) × {R _d (λ) + a _λ } (18)
I _2d = (p _λ × Vf + q _λ ) × {b _λ × R _d (λ) + c _λ } = I ₀ (λ) × {b _λ × R _d (λ) + c _λ } (19).

These four equations (16) to (19) can be solved as simultaneous equations with four numerical values of spectral distribution I ₀ (λ) and coefficients a _λ , b _λ , and c _λ as unknowns for each wavelength λ. is there.

In the control calculation unit 10, the coefficient calculation unit 161 reads the information of the four expressions (16) to (19) from the relational expression information 141 in the storage unit 14, and the spectral distribution I obtained by actual measurement in the four expressions. _1W (λ), I _2W (λ), I _1d (λ), I _2d (λ) and known spectral reflectance coefficients R _W , R _d are applied. The coefficients a _λ , b _λ , and c _λ can be calculated by solving the equations (16) to (19) for each wavelength λ. Here, the calculated coefficients a _λ , b _λ , and c _λ are stored in the storage unit 14 as the specific coefficient information 142, for example.

According to such a configuration, the coefficient a _lambda, b _lambda, for measuring the number and amount of calculation for obtaining the c _lambda is reduced, the coefficient a _λ, b _λ, c _λ can be obtained easily.

  In the above embodiment, a white LED is used as the light source unit 21. However, the present invention is not limited to this. For example, a combination of two or more types of LEDs having different spectral distributions of emitted light is used. May be.

Specifically, for example, as the light source unit 21, a white LED that emits white light having a distribution of relative intensity with respect to the wavelength indicated by the curve _CW in FIG. 11, and a relative intensity with respect to the wavelength indicated by the curve CP in FIG. A combination of violet LEDs that emit violet light having the following distribution may be employed. More specifically, for example, a white LED emits white light with blue emission and yellow fluorescence excited by blue emission, and a purple LED has a wavelength range of 400 to 450 nm where the white light has almost no intensity. An example of emitting violet light having intensity is given.

  If the said structure is employ | adopted, the raise of the manufacturing cost of an apparatus will be avoided as much as possible, and the spectral reflection characteristic of each sample can be measured rapidly and highly accurately about all the wavelength bands which concern on visible light.

When the above configuration is adopted, the coefficients a _λ , b _λ , and c _λ for each LED may be obtained by measurement in which each LED is individually turned on by the same method as in the above embodiment.

In the continuous measurement, for example, a coefficient p _λ , a constant q _λ , and a spectrum for each LED are obtained by measuring each color LED individually for the samples Rm1 and Rmn and using the equations (2) to (5). The reflectance coefficients R ₁ (λ) and R _n (λ) may be calculated. Then, an estimated spectral distribution of each color light at the time of measurement of each sample Rmi (i = 1 to n) is calculated for each LED based on the formula (1), and the sum of the estimated spectral distributions of each color light is calculated by the formula (6). It may be applied in the first parenthesis on the right side of. At this time, the spectral distribution I _1-i (λ) of the first mixed light L _M1 related to each sample Rmi measured while the two-color LEDs are turned on is applied to the left side of the equation (6), so that the wavelength λ The spectral reflectance coefficient R _i (λ) related to the sample Rmi can be calculated every time.

Further, in the individual measurement, for example, the coefficient p _λ , for each LED is obtained by measuring each LED individually for each sample RmA and using the equations (2), (3), and (7). The constant q _λ and the spectral reflectance coefficient R ₁ (λ) may be calculated. Then, for each LED, the estimated spectral distribution of each color light at the time of measurement of the sample RmA is calculated based on the formula (1), and the sum of the estimated spectral distributions of the respective color lights is the first on the right side of the formula (2). The spectral reflectance coefficient R ₁ (λ) of the individual sample RmA is calculated by applying the sum of the spectral distributions of the first mixed light L _M1 by each color light to the left side of the formula (2). It should be done.

In the above embodiment, in the continuous measurement, the first sample Rm1 and the nth sample Rmn among the plurality of samples Rm1 to Rmn are targeted, and the light diffusion member 5 is disposed at the intrusion position. while spectral distribution _{I 2-1} of the second mixed light _{L M2 (lambda),} but _{I 2-n} (λ) is measured, not limited to this. For example, instead of the spectral distributions I _2-1 (λ) and I _2-n (λ), any two x-th and y-th samples Rmx and Rmy out of the plurality of samples Rm1 to Rmn are targeted. Thus, the spectral distributions I _2-x (λ) and I _2-y (λ) of the second mixed light L _M1 may be measured while the light diffusing member 5 is disposed at the entry position.

With this configuration, the primary function of the illumination light _{L W} spectral distribution _{I 1-i} forward voltage shows approximately a (λ) _{Vf 1-i} of the time of measurement of the reflection characteristic of each sample Rmi (i = 1~n) Can be determined. For this reason, even when the spectral distributions I _1-1 (λ) to I _1-n (λ) of the plurality of samples Rm1 to Rmn are continuously measured at high speed, they are detected at the time of measuring each sample Rmi. that the forward voltage _{Vf 1-i} by the spectral distribution of the illumination light _{L W} during measurement of each sample Rmi _{I 1-1} (λ) can be estimated.

  In the above embodiment, a diffusion plate is used as the light diffusing member 5, but the present invention is not limited to this. For example, a polymer dispersed liquid crystal (PDLC) may be employed as the light diffusing member 5. The polymer-dispersed liquid crystal element performs a function similar to that of a diffusion plate when the application of voltage is stopped, and functions like a glass capable of transmitting light when a voltage is applied. Therefore, when a polymer dispersion type liquid crystal element is employed as the light diffusing member 5, the rotation driving unit 51, the rotating shaft 51r, the rod-shaped arm portion 53, and the like for moving the light diffusing member 5 are not necessary. For this reason, size reduction of an apparatus and reduction of manufacturing cost can be achieved.

  In the above-described embodiment, substantially the entire light diffusing member 5 is configured by a diffusing plate, and the light diffusing member 5 is moved into the intrusion position and the retracted position by the rotation drive unit 51, the rotation shaft 51r, and the rod-shaped arm portion 53. However, this is not a limitation. For example, a part of the light diffusing member 5 is composed of a light diffusing unit that diffuses light, and the spectroscope 9 is changed from the surface of the sample to be measured via the lens unit 6 and the reflecting mirror 7 by changing the posture of the light diffusing member 5. Even if the state of the light diffusing member is selectively set between the first state where the light diffusing part is retracted from the optical path leading to the second state where the light diffusing part is disposed on the optical path good.

  Specifically, as shown in FIGS. 12 and 13, in the reflection characteristic measuring apparatus 1 according to the above embodiment, the light diffusing member 5 is replaced with the light diffusing member 5 </ b> A, and the rotation driving unit 51 and the rotating shaft are replaced. The reflection characteristic measuring apparatus 1A according to the first modification in which the 51r and the rod-shaped arm portion 53 are replaced with the rotation drive unit 51A and the rotation shaft 51rA may be employed. Note that, by these replacements, the measuring device 30 is replaced with the measuring device 30A.

  For example, as illustrated in FIGS. 12 to 14, the light diffusion member 5 </ b> A is fixed with respect to the rotation shaft 51 r </ i> A of the rotation drive unit 51 </ b> A, for example. The rotation drive unit 51A may be, for example, a stepping motor or the like, and rotates the rotation shaft 51rA by the control by the drive control circuit 52 according to the control signal from the control calculation unit 10.

  Specifically, the light diffusing member 5A is a transparent rectangular parallelepiped member, and passes through the center of two surfaces parallel to the extending direction of the optical path from the surface of the sample to be measured to the reflecting mirror 7 by the rotation driving unit 51A. It rotates about the axis Ar1. In the light diffusion member 5A, one of the four surfaces through which the axis Ar1 does not pass is a diffusion surface 5d, and the other three surfaces are smooth surfaces 5t. The diffusion surface 5d functions as a light diffusion unit that diffuses incident light. As shown in FIGS. 14 and 15, the light diffusion member 5A is rotated by ± 90 °, and the first state where the smooth surface 5t faces the surface of the sample to be measured and the diffusion surface 5d It is selectively set to the opposing second state.

  More specifically, FIG. 14 shows a first state of the light diffusion member 5A in which the smooth surface 5t faces the surface of the sample to be measured. In this first state, the diffusing surface 5d as the light diffusing unit is retracted from the optical path from the surface of the sample to be measured to the spectroscope 9 via the lens unit 6 and the reflecting mirror 7. FIG. 15 shows a second state of the light diffusion member 5A in which the diffusion surface 5d faces the surface of the sample to be measured.

  In the above configuration, a configuration in which the light diffusing member 5A rotates around the axis Ar1 passing through the center thereof is employed. For this reason, the rotational moment required to rotate the light diffusing member 5A is determined so that the light diffusing member 5 is moved into the intrusion position and the retracted position by the rotation driving portion 51, the rotation shaft 51r, and the rod-shaped arm portion 53 in the one embodiment. Significantly less than the rotational moment required to move between the two.

  Therefore, a small motor with low torque may be applied to the rotation drive unit 51A. Through the downsizing of the rotation drive unit 51A, the reflection characteristic measuring device 1A can be reduced in size, manufacturing cost, and power consumption. And so on.

  In the configuration of the above embodiment, the light diffusing member 5 is completely retracted from the optical path from the surface of the sample to be measured to the spectroscope 9 through the lens unit 6 and the reflecting mirror 7, whereas this modification In the configuration according to the example, the diffusing surface 5d that is a part of the light diffusing member 5A may be retracted from the optical path. For this reason, downsizing of the reflection characteristic measuring apparatus 1A can be achieved through downsizing of the measuring instrument 30A.

  By the way, other aspects may be employed for the light diffusing member 5A and the axis Ar1 that is the center of rotation of the light diffusing member 5A.

  For example, FIG. 16 shows an example in which the light diffusion member 5B and the axis Ar2 are employed instead of the light diffusion member 5A and the axis Ar1. Similar to the light diffusing member 5A, the light diffusing member 5B is a transparent rectangular parallelepiped member, and has one surface that is a diffusing surface 5d and five surfaces that are smooth surfaces 5t. Further, the light diffusing member 5B passes through the midpoint Pc1 of the first side obliquely above the light diffusing member 5B and the midpoint Pc2 opposite to the first side and obliquely below the second side of the light diffusing member 5B. It rotates around the axis Ar2. The light diffusing member 5B is rotated by ± 180 ° about the axis Ar2, and the diffusion surface 5d is in the first state where the smooth surface 5t faces the surface of the sample to be measured and the surface of the sample to be measured. Are selectively set to the opposite second state.

  FIG. 17 shows an example in which the light diffusion member 5C and the axis Ar3 are employed instead of the light diffusion member 5A and the axis Ar1. Similarly to the light diffusion member 5A, the light diffusion member 5C is a transparent rectangular parallelepiped member, and has one surface that is a diffusion surface 5d and five surfaces that are smooth surfaces 5t. The light diffusing member 5C has an axis Ar3 passing through the first corner Pc3 obliquely above the light diffusing member 5C and the second corner Pc4 facing the first corner Pc3 and obliquely below the light diffusing member 5C. Rotate around. The light diffusing member 5C is rotated by ± 120 ° about the axis Ar2, and the diffusion surface 5d is in the first state where the smooth surface 5t faces the surface of the sample to be measured and the surface of the sample to be measured. Are selectively set to the opposite second state.

  In the light diffusing member 5B, the axis Ar2 serving as the center of rotation forms 45 ° with respect to the extending direction of the optical path from the surface of the sample to be measured to the reflecting mirror 7. In the light diffusing member 5C, the axis Ar3 serving as the center of rotation forms 54.7 ° with respect to the extending direction of the optical path from the surface of the sample to be measured to the reflecting mirror 7. For this reason, it becomes possible to arrange | position the rotation drive part 51A and rotating shaft 51rA which rotate the light-diffusion member 5B and the light-diffusion member 5C so that it may not interfere with the some reflection part 3. FIG.

  In FIG. 18, the light diffusing member 5B is fixed to the rotation shaft 51rA at a midpoint Pc1 obliquely above the light diffusing member 5B, and the light diffusing member 5B is configured to be rotatable by the rotation driving unit 51A. An example configuration is shown.

In the above-described embodiment, the transmitted light _LWT is transmitted along the imaginary plane inclined by 40 to 50 ° with respect to the normal line (here, the axis Px1) of the surface of the sample to be measured. However, the present invention is not limited to this. For example, instead of 40 to 50 °, other angles around it may be adopted.

  It goes without saying that all or a part of each of the above-described embodiment and various modifications can be appropriately combined within a consistent range.

DESCRIPTION OF SYMBOLS 1,1A Reflection characteristic measuring apparatus 2 Illumination part 3 Reflection part 4 Partial reflection part 5, 5A-5C Light-diffusion member 5d Diffusion surface 5t Smooth surface 9 Spectrometer 10 Control calculating part 14 Storage part 16 Control part 21 Light source part 22 Light emission control Circuit 30, 30A Measuring instrument 40 Optical unit 51, 51A Rotation drive unit 52 Drive control circuit 161 Coefficient calculation unit 162 Approximate function deriving unit 163 Spectral distribution estimation unit 164 Spectral reflectance coefficient calculation unit 165 Drive control unit 166 Lighting control unit 167 Voltage Detection control unit

Claims (4)

A lighting unit having a semiconductor light emitting element that emits illumination light by constant current driving, and a detection unit that detects a forward voltage of the semiconductor light emitting element;
The reflected light generated by reflecting the illumination light on the surface of the sample and the illumination light are mixed at a first ratio to output a first mixed light, and the reflected light and the illumination light are converted to the first ratio. Are mixed at a different second ratio and output a second mixed light; and
The first light reception of the first mixed light that is output by mixing the first reflected light and the illumination light generated by reflecting the illumination light on the surface of the first sample at the first ratio in the mixing unit. The first spectral distribution of the first mixed light is measured by the first mixed light, and the first reflected light and the illumination light are mixed at the second ratio in the mixing unit at the second ratio. The second spectral distribution of the second mixed light is measured by two light receptions, and the second reflected light and the illumination light generated by reflecting the illumination light on the surface of the second sample are the first light in the mixing unit. The third spectral distribution of the first mixed light is measured by the third light reception of the first mixed light output by being mixed at a ratio, and the second reflected light and the illumination light are For the fourth light reception of the second mixed light output by mixing at the second ratio A measuring unit for measuring a fourth spectral distribution of the second mixed light I,
A calculation unit that calculates a spectral reflectance coefficient of a third sample irradiated with the illumination light when a fifth forward voltage detected by the detection unit is applied to the semiconductor element;
The detection unit is
A first forward voltage of the semiconductor light emitting element is detected when the first light reception is performed by the measurement unit, and a second forward voltage of the semiconductor light emitting element is detected when the second light reception is performed by the measurement unit. The third forward voltage of the semiconductor light emitting element is detected when the third light reception is performed by the measurement unit, and the fourth forward voltage of the semiconductor light emitting element is detected when the fourth light reception is performed by the measurement unit. Detect
The computing unit is
Based on the first to fourth forward voltages and the first to fourth spectral distributions, a linear function approximately representing the spectral distribution of the illumination light having the forward voltage as an independent variable is derived, and the fifth By applying a forward voltage to the linear function, an estimated spectral distribution of the illumination light when the fifth forward voltage is detected by the detection unit is calculated, and the spectral reflectance coefficient is calculated using the estimated spectral distribution is calculated,
The linear function is
When the forward voltage is Vf, the intensity at a wavelength λ of the spectral distribution of the illumination light is I (λ), and the coefficients and constants specific to the wavelength λ are p _λ and q _λ , I (λ) = P _λ × Vf + q _λ is a linear function,
The computing unit is
The intensity at the wavelength λ of the first spectral distribution is I ₁ (λ), the intensity at the wavelength λ of the second spectral distribution is I ₂ (λ), and the wavelength of the third spectral distribution. The intensity at λ is I ₃ (λ), the intensity of the fourth spectral distribution at the wavelength λ is I ₄ (λ), and the reflectance of the first sample with respect to light of the wavelength λ is R ₁ (λ), The reflectance of the second sample with respect to light of the wavelength λ is R ₂ (λ), the first forward voltage is Vf ₁ , the second forward voltage is Vf ₂ , the third forward voltage is Vf ₃ , the fourth When the forward voltage is Vf ₄ and the coefficients peculiar to the reflection characteristic measuring apparatus and the wavelengths λ are expressed as a _λ , b _λ , and c _λ , four numerical values p _λ , q _λ , R ₁ By solving the simultaneous equations consisting of the following equations [I] to [IV] where (λ) and R ₂ (λ) are unknown numbers, the numerical values p _λ and q _λ And calculating the linear function for each wavelength λ .
[I] I ₁ (λ) = {p _λ × Vf ₁ + q _λ } × {R ₁ (λ) + a _λ }
[II] I ₂ (λ) = {p _λ × Vf ₂ + q _λ } × {b _λ × R ₁ (λ) + c _λ }
[III] I ₃ (λ) = {p _λ × Vf ₃ + q _λ } × {R ₂ (λ) + a _λ }
[IV] I ₄ (λ) = {p _λ × Vf ₄ + q _λ } × {b _λ × R ₂ (λ) + c _λ } The reflection characteristic measuring apparatus according to claim 1,
The measurement unit is
The third reflected light that is output by mixing the third reflected light generated when the illumination light is reflected by the surface of the third sample and the illumination light at the first ratio in the mixing unit. Measuring the fifth spectral distribution of the first mixed light by five light receptions;
The detection unit is
Detecting the fifth forward voltage of the semiconductor light emitting element when the fifth light reception is performed by the measurement unit;
The computing unit is
Of the fifth spectral distribution, the intensity at the wavelength λ is I ₅ (λ), the fifth forward voltage is Vf ₅ , and the reflectance of the third sample with respect to light of the wavelength λ is R ₃ (λ). when the numerical value p _lambda, the lower q _lambda is used formula [V], in the determining the reflectivity R _{3 (lambda)} for each of the wavelength lambda, that you calculate the spectral reflectance factor Characteristic reflection characteristic measuring device.
[V] I ₅ (λ) = {p _λ × Vf ₅ + q _λ } × {R ₃ (λ) + a _λ } The reflection characteristic measuring apparatus according to claim 1 or 2,
The measurement unit is
Continuously measure the spectral distribution related to the reflected light of multiple samples,
The first sample is
The sample in which the spectral distribution is first measured by the measurement unit of the plurality of samples,
The second sample is
The reflection characteristic measuring apparatus , wherein the spectral distribution is finally measured by the measuring unit among the plurality of samples . The reflection characteristic measuring apparatus according to any one of claims 1 to 3, wherein
The measurement unit is
In the period in which the forward voltage of the semiconductor light emitting element is constant over time by maintaining the radiation of the illumination light by the semiconductor light emitting element, the reflectance with respect to the light of the wavelength λ is R _W (λ) When the illumination light is irradiated on the first reference sample, the reflected light generated by the illumination light being reflected by the surface of the first reference sample and the illumination light are mixed in the first mixing portion. The first reference spectral distribution is measured by receiving the first mixed light that is output by being mixed at a ratio, and the reflected light generated when the illumination light is reflected by the surface of the first reference sample and the reflected light The second reference spectral distribution is measured by receiving the second mixed light output by mixing the illumination light with the second ratio in the mixing unit, and the reflectance with respect to the light of the wavelength λ is R _d. Illuminate the second reference sample (λ) When the illumination light is irradiated, the reflected light generated by the reflection of the illumination light on the surface of the second reference sample and the illumination light are output by being mixed at the first ratio in the mixing unit. The third reference spectral distribution is measured by receiving the first mixed light, and the reflected light and the illumination light generated by reflecting the illumination light on the surface of the second reference sample are The fourth reference spectral distribution is measured by receiving the second mixed light output by being mixed at the second ratio,
The computing unit is
The intensity at the wavelength λ of the first reference spectral distribution is I _1W (λ), the intensity at the wavelength λ of the second reference spectral distribution is I _2W (λ), out of the third reference spectral distribution When the intensity at the wavelength λ is I _1d (λ), the intensity at the wavelength λ of the fourth reference spectral distribution is I _2d (λ), and the forward voltage of the semiconductor light emitting element is the constant voltage. When the intensity at the wavelength λ of the spectral distribution of the illumination light is expressed as I ₀ (λ), the coefficients a _λ , b _λ , c _λ and the intensity I ₀ (λ) are unknown. [VI] by solving ~ the simultaneous equations consisting of [IX] in each of the wavelength lambda, the coefficient a _λ, b _λ, the reflection characteristic measuring apparatus according to claim Rukoto seek c _lambda.
[VI] I _1W (λ) = I ₀ (λ) × {R _W (λ) + a _λ }
[VII] I _2W (λ) = I ₀ (λ) × {b _λ × R _W (λ) + c _λ )
[VIII] I _1d (λ) = I ₀ (λ) × {R _d (λ) + a _λ }
[IX] I _2d (λ) = I ₀ (λ) × {b _λ × R _d (λ) + c _λ }

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