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WO2015151802A1 - Dispositif de mesure spectroscopique - Google Patents

Dispositif de mesure spectroscopique Download PDF

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Publication number
WO2015151802A1
WO2015151802A1 PCT/JP2015/057878 JP2015057878W WO2015151802A1 WO 2015151802 A1 WO2015151802 A1 WO 2015151802A1 JP 2015057878 W JP2015057878 W JP 2015057878W WO 2015151802 A1 WO2015151802 A1 WO 2015151802A1
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WIPO (PCT)
Prior art keywords
light
wavelength
unit
spectroscopic
period
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English (en)
Japanese (ja)
Inventor
森谷　直司
裕也 酒井
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Shimadzu Corp
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Shimadzu Corp
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
    • G01J3/0224—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using polarising or depolarising elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
    • G01J3/0218—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using optical fibers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
    • G01J3/0229—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G01J3/06—Scanning arrangements arrangements for order-selection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/12—Generating the spectrum; Monochromators
    • G01J3/1256—Generating the spectrum; Monochromators using acousto-optic tunable filter
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/28—Investigating the spectrum
    • G01J3/2803—Investigating the spectrum using photoelectric array detector
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/28—Investigating the spectrum
    • G01J3/42—Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/28—Investigating the spectrum
    • G01J3/42—Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry
    • G01J3/433—Modulation spectrometry; Derivative spectrometry
    • G01J3/4338—Frequency modulated spectrometry

Definitions

  • the present invention relates to a spectrometer.
  • the present invention relates to a spectroscopic measurement apparatus that can be suitably used when measuring light absorption by a sample.
  • a spectroscopic measurement device is one of the devices used for qualitative and quantitative determination of substances contained in a sample. For example, when measuring the concentration of a target component contained in a sample gas using a spectroscopic measurement device, the sample gas is irradiated with light emitted from a light source, and the light transmitted through the sample gas is detected by a light detection unit. To do. The signal from the light detection unit is output to the data processing unit to create an absorption spectrum. Then, the concentration of the target component is determined based on the peak area and intensity of the target component on the absorption spectrum.
  • WMS wavelength modulation spectroscopy
  • a light source that can change the wavelength by changing the magnitude and temperature of the current supplied from the outside is used.
  • Such light sources include, for example, a distributed feedback (DFB) laser light source, but have a narrow wavelength range of oscillating light.
  • DFB distributed feedback
  • Patent Document 3 describes that the wavelength range of laser light is from sub nm to several nm. Therefore, there is a problem that WMS using a DFB laser capable of high-speed modulation cannot perform spectroscopic measurement for a broad absorption peak such as a solid substance.
  • the problem to be solved by the present invention is to provide a spectroscopic measurement apparatus capable of performing spectroscopic measurement with high sensitivity in a wide wavelength range.
  • the spectroscopic measurement device which has been made to solve the above problems, a) a light source that emits irradiation light having a wavelength width; b) a light detection unit for detecting measurement light emitted from the light source and interacting with the sample; c) from an irradiation light side spectroscope that transmits light of a specific wavelength of the irradiation light, a measurement light side spectroscope that transmits light of a specific wavelength of the measurement light, or from a light detection unit
  • a wavelength selection unit including a specific wavelength signal generation unit for outputting a detection signal of light of a wavelength; d) a modulation controller that changes the specific wavelength by superimposing a modulation component that changes in a second period shorter than the first period on a wavelength that changes in the first period; e) a synchronization detection signal generation unit that generates a synchronization detection signal from an output signal output from the photodetector, using a frequency that is a positive integer multiple of
  • the spectroscopic measurement apparatus is broadly embodied in three modes. Each aspect corresponds to a configuration in which the wavelength selection unit is an irradiation light side spectroscope, a configuration in which the wavelength selection unit is a measurement light side spectroscope, and a configuration in which a specific wavelength signal generation unit is provided.
  • the first aspect of the spectrometer is: A light source that emits irradiation light having a wavelength width; A spectroscopic unit that selectively transmits light having a wavelength corresponding to a value of a supplied current or voltage among the irradiation light; and A photodetector for detecting the measurement light after passing through the spectroscopic unit and interacting with the sample; A drive signal supply unit that supplies a current or voltage obtained by superimposing a modulation component that changes in a cycle shorter than the current or voltage that periodically repeats a change in continuous value to the spectroscopic unit; A synchronization detection signal generation unit that generates a synchronization detection signal from an output signal output from the photodetector, using a frequency that is a positive integer multiple of the frequency of the modulation component as a reference frequency; It is characterized by providing.
  • Examples of the spectroscopic unit include various types of monochromators described in Non-Patent Documents 2 to 4 (acousto-optic filter type monochromators, Fourier interference type monochromators, MEMS applied Hadamard transform type monochromators, etc. ) Can be used.
  • the integer multiple is typically twice.
  • a waveform obtained by second-order differentiation of the absorption spectrum is obtained as the synchronization detection signal, but the present invention is not limited to this.
  • this multiple is increased, a waveform obtained by multi-order differentiation of the absorption spectrum is obtained, so that a broad spectrum can be sharpened.
  • the spectroscopic measurement device uses a spectroscopic unit whose wavelength to be monochromatic changes according to the value of the supplied current or voltage, and for the spectroscopic unit, a continuous value (the sharpened spectrum is sufficiently resolved). Supply a current or voltage that superimposes a modulation component that changes in a shorter cycle than the current or voltage that periodically changes the wavelength to be monochromatic as much as possible. To do. In this configuration, since various types of light sources that emit light having a wavelength width can be used as the light source, spectroscopic measurement can be performed with high sensitivity in a wide wavelength range.
  • the drive signal supply unit described above is not limited to supplying current or voltage directly to the spectrometer, but indirectly supplies current or voltage to the spectrometer (inside the spectrometer). It is also possible to use a digital signal or the like that can be converted into a current or voltage.
  • the output signal from the photodetector is synchronously detected at a frequency that is an integer multiple of the frequency f (for example, 2f), the influence of noise generated in a low frequency band such as electrical noise generated in the light receiving circuit is eliminated. Can do.
  • the coherent laser light emitted from the light source may be reflected on the surface by an optical element or the like disposed on the optical path from the light source to the detector to generate an interference beat. is there. When such an interference beat occurs, noise is superimposed on the detection signal.
  • the spectroscopic measurement apparatus of the first aspect does not use a laser light source, it is not affected by noise caused by the occurrence of an interference beat.
  • the second aspect of the spectrometer is: A light source that emits irradiation light having a wavelength width; A spectroscopic unit that selectively transmits light having a wavelength according to a value of a supplied current or voltage, among measurement light that is emitted from the light source and interacts with a sample; A photodetector for detecting measurement light that has passed through the spectroscopic unit; A drive signal supply unit that supplies a current or voltage obtained by superimposing a modulation component that changes in a cycle shorter than the current or voltage that periodically repeats a change in continuous value to the spectroscopic unit; A synchronization detection signal generation unit that generates a synchronization detection signal from an output signal output from the photodetector, using a frequency that is a positive integer multiple of the frequency of the modulation component as a reference frequency; It is characterized by providing.
  • the spectroscopic measurement device has a configuration in which only the place where the spectroscopic measurement device according to the first aspect and the spectroscopic unit are arranged is changed, and the same effect as the spectroscopic measurement device according to the first aspect can be obtained. it can.
  • a third aspect of the spectroscopic measurement apparatus includes a light source that emits irradiation light having a wavelength width, and a spectroscopic detection unit that detects the measurement light emitted from the light source and interacting with the sample by wavelength separation. And a signal processing unit that generates a detection signal from an output signal output for each wavelength from the spectroscopic detection unit, the timing at which the signal processing unit reads the output signal and the readout at the timing Data defining the relationship between wavelengths, and reading wavelength data in which a modulation component that changes at a predetermined period is superimposed on a reading center wavelength within the range of the wavelength of the light detected by the spectroscopic detection unit.
  • Read wavelength data generation unit for sequentially changing the wavelength to create, A modulation output signal generation unit that generates a modulation output signal by reading an output signal having a wavelength defined by the read wavelength data from the output signal at a cycle shorter than the cycle, A synchronization detection signal generation unit configured to generate a synchronization detection signal from the modulation output signal using a frequency which is a positive integer multiple of the frequency of the modulation component as a reference frequency.
  • the read wavelength when reading a signal output for each wavelength from the spectroscopic detector, the read wavelength is modulated at a predetermined frequency and the read wavelength is changed in order to read wavelength data. Is generated. Then, an output signal having a wavelength defined by the read wavelength data is read out from signals output from the spectroscopic detection unit, and a modulated output signal is generated. As a result, a modulation signal similar to the output signal output from the photodetector is obtained in the spectroscopic measurement devices of the first and second aspects.
  • a synchronization detection signal is generated from the modulation output signal using a frequency that is a positive integer multiple of the frequency of the modulation component as a reference frequency. That is, the first and second spectroscopic measurement apparatuses and the third spectroscopic measurement apparatus have different components to be subjected to wavelength modulation, but the frequency modulation frequency of the modulation component is determined from the output signal subjected to wavelength modulation. Based on the common technical idea of acquiring a synchronization detection signal using an integer multiple frequency as a reference frequency, the same effect as described above can be obtained.
  • the spectroscopic measurement device of each aspect according to the present invention it is possible to perform spectroscopic measurement with high sensitivity in a wide wavelength range.
  • FIG. 2 is a main part configuration diagram of the spectroscopic measurement apparatus according to the first embodiment.
  • FIG. 3 is a diagram for explaining a drive signal in the spectroscopic measurement apparatus according to the first embodiment.
  • FIG. 3 is a diagram for explaining an output signal from a photodetector in the spectrometer according to the first embodiment.
  • FIG. 3 is a diagram for explaining a synchronization detection signal in the spectroscopic measurement apparatus according to the first embodiment.
  • FIG. 3 is a main part configuration diagram of a spectrometer according to a second embodiment.
  • FIG. 5 is a main part configuration diagram of a spectrometer according to a third embodiment.
  • FIG. 10 is a diagram for explaining generation of readout wavelength data in the spectroscopic measurement apparatus according to the third embodiment.
  • FIG. 6 is a main part configuration diagram of a film thickness measuring apparatus according to a fourth embodiment. The figure which shows the change of the wavelength in the spectroscopy part of the film thickness measuring apparatus of Example 4.
  • FIG. 1 shows the main configuration of the spectroscopic measurement apparatus of Example 1.
  • the spectroscopic measurement device 1 includes a light source 11 that emits irradiation light having a wavelength width, a sample cell 12 in which a sample gas is sealed, and a first polarizer that passes light of a linearly polarized light component among light that has passed through the sample cell 12.
  • acousto-optic filter type spectroscope 14 light of a linearly polarized light component (a component in a direction orthogonal to the polarization direction of the light that has passed through first polarizer 13) out of the light that has passed through spectroscope 14
  • a second polarizer 15 that passes through, a beam dump 16 that absorbs light that has passed through the spectroscope 14 without changing its traveling direction, and light detection that detects measurement light of a wavelength selected by the spectroscope 14.
  • the acoustooptic filter type spectroscope 14 generates an acoustic wave by applying a high frequency voltage to the piezoelectric element 141 located at the input end thereof, and propagates it in the crystal inside the spectroscope 14.
  • This is a spectroscope that emits light by changing the traveling direction and polarization direction of linearly polarized light having a specific wavelength.
  • the entity of the control unit 19 is a personal computer, which includes a storage unit 191 and functionally includes a drive signal generation unit 192 and a synchronization detection signal generation unit 193.
  • An input unit 194 and a display unit 195 are connected to the control unit 19.
  • the first period, the second period, the range of values that change in the first period, and the amplitude of the modulation component that changes in the second period are preset by the user and stored in the storage unit 191.
  • a drive signal is generated by the drive signal generation unit 192 based on the parameters. That is, in this embodiment, the drive signal generation unit 192 and the voltage application unit 18 cooperate to function as the drive signal supply unit of the present invention.
  • Irradiation light having a wavelength width emitted from the light source 11 is absorbed by the sample gas in the sample cell 12 and then enters the first polarizer 13 as measurement light.
  • the linearly polarized measurement light that has passed through the first polarizer 13 enters the spectroscope 14.
  • light having a specific wavelength determined by the value of the voltage applied to the spectroscope 14 from the outside is diffracted to change the traveling direction, and in a plane orthogonal to the traveling direction.
  • the polarization direction changes by 90 degrees and is emitted.
  • light of other wavelengths in the measurement light travels straight without being diffracted by the spectroscope 14, and part of the light passes through the second polarizer 15 and is absorbed by the beam dump 16.
  • the photodetector 17 When the light passing through the sample gas is detected by modulating the wavelength passing through the spectroscope 14, the photodetector 17 outputs a signal on which the modulation component of the frequency f is superimposed as shown in FIG.
  • the synchronization detection signal generation unit 193 generates a synchronization detection signal from the output signal from the photodetector 17 using the frequency 2f that is twice the frequency f described above as a reference frequency, creates a waveform thereof, and displays the waveform on the display unit 195. To do.
  • An example of the synchronization detection signal is shown in FIG.
  • a waveform obtained by secondarily differentiating the absorption spectrum in real time without performing an arithmetic process such as differentiating the output signal is obtained.
  • the reference frequency for synchronous detection may be a positive integer multiple of the frequency of the modulation component, and the N-th derivative is obtained by setting the frequency Nf N times (N is a positive integer) as the reference frequency. Waveform can be obtained.
  • the measurement object is a gas sealed in the sample cell 12, but the measurement object is not limited to this, and a flow cell is arranged instead of the sample cell 12, and light absorption by the gas flowing through the inside is measured. It can also be targeted. Further, the measurement target of the spectroscopic measurement apparatus 1 may be a solid or a liquid.
  • the principal part structure of the spectrometer 2 of Example 2 is shown in FIG.
  • the spectroscopic measurement device 2 passes through a light source 21 that emits irradiation light having a wavelength width, a first polarizer 23 that passes light of a linearly polarized light component in the irradiation light, an acousto-optic filter type spectroscope 24, and a spectroscope 24.
  • the traveling direction does not change in the second polarizer 25 and the spectroscope 24 that transmit the light of the linearly polarized light component (the component in the direction orthogonal to the polarization direction of the light that has passed through the first polarizer 23) of the light that has been transmitted.
  • a beam dump 26 that absorbs the light that has passed, a sample cell 22 that is disposed at a position where light having a predetermined wavelength that has passed through the spectrometer 24 is irradiated, a photodetector 27 that detects the light that has passed through the sample cell 22, and a spectrometer
  • a voltage applying unit 28 for applying a high-frequency voltage to 24 and a control unit 29 are provided.
  • the substance of the control unit 29 is a personal computer, which includes a storage unit 291 and functionally includes a drive signal generation unit 292 and a synchronization detection signal generation unit 293. Further, an input unit 294 and a display unit 295 are connected to the control unit 29.
  • the spectroscopic measurement apparatus 1 has a configuration in which the measurement light after passing through the sample cell 12 is incident on the spectroscope 14 and is modulated.
  • the light source 21 is used in the spectroscopic measurement apparatus 2 according to the second embodiment.
  • the sample cell 22 is irradiated with monochromatic light that is incident on the spectroscope 24 and is wavelength-modulated. That is, the arrangement of the sample cell and the spectroscope (and the polarizer) is different between the spectroscopic measurement apparatus 1 of the first embodiment and the spectroscopic measurement apparatus 2 of the second embodiment.
  • the drive signal generation unit 292 changes the voltage to a voltage whose value continuously changes in the first period (second period ( A drive signal on which the frequency f) modulation component is superimposed is generated and transmitted to the voltage application unit 28, and the drive voltage is applied from the voltage application unit 28 to the piezoelectric element 241 of the spectroscope 24.
  • the synchronization detection signal generation unit 293 generates a synchronization detection signal from the output signal from the photodetector 27 using the frequency Nf N times the frequency f as a reference frequency, and displays the waveform created from the signal as the display unit 295. To display.
  • Nf N the frequency Nf N times the frequency f as a reference frequency
  • the principal part structure of the spectrometer 3 of Example 3 is shown in FIG.
  • the spectroscopic measurement device 3 includes a light source 31 that emits irradiation light having a wavelength width, a sample cell 32, a photodetector 37 that detects light that has passed through the sample cell 32, and a control unit 39.
  • the entity of the control unit 39 is a personal computer, which includes a storage unit 391 and functionally includes a readout wavelength data generation unit 392, a modulation output signal generation unit 393, and a synchronization detection signal generation unit 394.
  • An input unit 395 and a display unit 396 are connected to the control unit 39.
  • Irradiation light having a wavelength width emitted from the light source 31 is absorbed by the sample gas in the sample cell 32 and then enters the spectroscope 34 as measurement light.
  • the measurement light is wavelength-separated by the spectroscope 34 and enters the photodetector 37.
  • a general diffraction grating or the like can be used as the spectroscope 34 of this embodiment.
  • the photodetector 37 is an array detector in which n detection elements are arranged in a one-dimensional or two-dimensional array, and simultaneously detects measurement light after wavelength separation by the spectroscope 34 and outputs a signal. Signals SP ( ⁇ 0 ) to SP ( ⁇ n ⁇ 1 ) corresponding to the wavelength range are output from the 1st to nth detection elements, respectively.
  • a wavelength range in which the user performs wavelength modulation described later range set as a readout center wavelength
  • ⁇ s to ⁇ s + m ⁇ 1 range set as a readout center wavelength
  • s and m are natural numbers
  • s + m ⁇ 1 are natural numbers equal to or less than n ⁇ 1
  • a wavelength modulation width d ⁇ a periodic division number M of a sine wave for performing wavelength modulation
  • the read wavelength data generation unit 392 generates wavelength data used for modulation based on the parameters set by the user (see FIG. 7).
  • the lower part of FIG. 7 is an enlarged view of one period of wavelength data.
  • L integer from 0 to (kM-1).
  • the following readout wavelength data string in which k ⁇ M wavelengths are defined for each readout center wavelength is generated. ⁇ s + ⁇ 0, ⁇ s + ⁇ 1, ..., ⁇ s + ⁇ kM-1, ⁇ s + 1 + ⁇ 0, ⁇ s + 1 + ⁇ 1, ..., ⁇ s + m-1 + ⁇ 0, ..., ⁇ s + m-1 + ⁇ kM-1
  • the modulation output signal generation unit 393 reads out output data from the photodetector 37 corresponding to the wavelength specified in the readout wavelength data sequence, and generates a modulation spectrum data sequence. At this time, if the wavelength specified in the read wavelength data string and the wavelength detected by each detection element of the photodetector 37 do not match, the output data from the photodetector 37 obtained discretely is stored. In this way, continuous output data for the wavelength axis is generated. As a result, a modulated output signal as shown in FIG. 3 is obtained.
  • the generation of the continuous output data described above can be performed by a method such as linear interpolation or spline interpolation.
  • the synchronization detection signal generation unit 394 When the modulation output signal is obtained, the synchronization detection signal generation unit 394 generates a synchronization detection signal from the modulation output signal with a period (2N ⁇ L) / M corresponding to a frequency N times the modulation frequency f of the read wavelength data as a reference frequency.
  • N 2N ⁇ L
  • N may be a natural number and may be a value other than 2.
  • the waveform which carried out N-order differentiation of the absorption spectrum can be acquired in real time similarly to Examples 1 and 2.
  • any of the spectroscopic measurement apparatuses described in Examples 1 to 3 above can use various light sources that emit light having a wavelength width.
  • a laser light source as in WMS
  • a synchronous detection signal can be obtained in real time without performing an operation such as differentiation on the output signal obtained from the photodetector.
  • the synchronization detection signal is generated from the output signal modulated in the high frequency band, it is not affected by noise in the low frequency band such as electrical noise in the light receiving circuit.
  • the configuration example in the case of measuring the light absorption by the target component in the sample gas has been described.
  • the measurement target of the spectrometer according to the present invention may be a solid or a liquid.
  • a spectroscopic measurement device having the same configuration as described above for measurement of coating film thickness in a coating device, measurement of a component ratio in a blender, measurement of moisture content and particle size in a granulation device, measurement of reactivity in a chemical synthesis device, etc. Can be used.
  • Such a spectroscopic measurement apparatus is useful, for example, for monitoring a powder sample in a preparation apparatus or analyzing a sample component in preparation research.
  • FIG. 8 shows an apparatus for manufacturing a granular pharmaceutical product by coating a plurality of components in a predetermined order and thickness (hereinafter referred to as “coating apparatus”). An example used as the measuring device 7 is shown.
  • irradiation light from the white light source 71 is introduced into the incident side optical fiber 711, transported to the coating device 720, collected by the incident side lens 712, and then provided on the lower surface of the coating device 720.
  • the sample 721 being coated is irradiated from the window 722 thus formed. Reflected light from the sample 721 is extracted from the window portion 722, introduced into the incident end of the emission side optical fiber 781 by the emission side first lens 782, and transported to the detection optical system.
  • the detection optical system includes an exit-side second lens 783 that condenses the measurement light emitted from the exit-side optical fiber 781, and only linearly polarized light of the measurement light collected by the exit-side second lens 783.
  • a first polarizer 73 that passes through, an acousto-optic filter type spectroscope 74 that changes the traveling direction and polarization direction of linearly polarized light having a specific wavelength, and the light that has passed through the spectroscope 74,
  • a second polarizer (cross-polarizer) 75 that passes only a linearly polarized component in a direction orthogonal to the light that has passed through the first polarizer 73, and the light that has passed through the spectroscope 74 without changing the traveling direction.
  • a beam dump 76 to be absorbed a photodetector 77 that receives light of a specific wavelength whose traveling direction and polarization direction have changed in the spectroscope 74, a voltage application section 78 that applies a high-frequency voltage to the spectroscope 74, and a control section 79.
  • the reflected light from the sample 721 is not only the light reflected by the surface of the sample 721, but also enters the sample 721, passes through the coating layer and is reflected at the interface between the coating layer and its lower layer, and then coated again.
  • Light that passes through the layer and exits from the sample 721 (referred to as “internally reflected light”) is included. Therefore, the intensity of reflected light is measured in advance for a standard sample coated with a plurality of predetermined film thicknesses with the same components as the actual sample, and film thickness correspondence data that associates the reflected light intensity with the film thickness is obtained. By comparing the synchronous detection signal generated using the reflected light from the film with the film thickness correspondence data, the coating thickness of the actual sample can be measured in real time.
  • the entity of the control unit 79 is a personal computer, and in addition to having a storage unit 791, functionally, a drive signal generation unit 792, a measurement execution unit 793, a synchronization detection signal generation unit 794, a synchronization detection signal processing unit 795, and a film A thickness determining unit 796 is provided.
  • an input unit 797 and a display unit 798 are connected to the control unit 79.
  • the storage unit 791 has, for each of one or more components coated on the sample 721, a signal proportional to the absorption wavelength characteristic of the component and the amount of light absorption at the absorption wavelength of the absorption spectrum of the component (for example, the thickness correspondence data indicating the relationship between the ratio of the thickness of the second derivative waveform data) and the ratio of the average reflected light intensity for one second period to be described later and the film thickness is stored.
  • the drive signal generation unit 792 reads the absorption wavelength of the component from the storage unit 791, and the spectrometer 74 A drive signal is generated such that a specific wavelength changes around the absorption wavelength.
  • the drive signal is obtained by superimposing a modulation component that changes in a second period shorter than the first period on waveform data whose value changes continuously in the first period. It is.
  • the measurement execution unit 793 controls the operation of the voltage application unit 78 based on the drive signal, and applies a voltage to the piezoelectric element 741 of the spectrometer 74. .
  • an output signal from the photodetector 77 is acquired.
  • the synchronization detection signal generation unit 794 generates a synchronization detection signal from the output signal of the photodetector 77 using a frequency (2f) twice the frequency (f) of the second period as a reference frequency, and generates a second-order differential waveform. Generate data.
  • the average reflection intensity data for the frequency (f) integer period of the second period is generated.
  • the secondary differential waveform data and the average reflection intensity will be described.
  • the orders of the two waveform data such as a combination of the tertiary differential waveform data and the average reflection intensity can be determined as appropriate.
  • the synchronization detection signal processing unit 795 obtains a secondary differential value (the height of the secondary differential waveform at the absorption wavelength of the measurement component) from the secondary differential waveform data, and calculates a ratio with the average reflection intensity data.
  • the film thickness determining unit 796 determines the film thickness by comparing the ratio value with the film thickness correspondence data stored in the storage unit 791 and displays the film thickness on the display unit 798.
  • the position of the sample and the properties and shape of the surface tend to change over time.
  • the detection intensity of the measurement light may change even though the film thickness of the sample has not changed.
  • second derivative waveform data and average reflection intensity data are generated from the output signal of the photodetector at the same time. Since the multiple signals generated in this way include fluctuations in the intensity of transmitted light and reflected light that accompany temporal changes in the state of the sample, the transmitted light can be obtained by determining their ratio.
  • accurate measurement results can be obtained by removing fluctuations in the intensity of reflected light.
  • the sample in this example is a granular sample. However, even in the case of a liquid sample or a solid sample of another shape, the sample can be configured as in this example to change the state of the sample to be measured over time. Accurate measurement results can be obtained by eliminating the influence.
  • Examples 1 to 4 are all examples, and can be appropriately changed in accordance with the gist of the present invention.
  • the first polarizers 13, 23, 73 and the second polarizers 15, 25, 75 are used. However, these are not essential components, and zero-order light (acousto-optic filter) is used.
  • a beam blocker that physically blocks the light whose traveling direction does not substantially change by the spectroscopes 14, 24, and 74 may be used.
  • a configuration in which an acousto-optic filter type spectroscope and a polarizer are combined is used as a spectroscope.
  • Other spectroscopes can be used as long as the spectroscope can change the wavelength of light to be transmitted.
  • FIG. 8A shows the configuration of a MEMS mirror type spectroscope 43 which is an example of such a spectroscope.
  • the spectroscope 43 includes an entrance slit 431, a first concave mirror 432, a MEMS mirror 433, a diffraction grating 434, a second concave mirror 435, and an exit slit 436, and changes the magnitude of the voltage supplied from the outside, thereby changing the MEMS.
  • the angle of light incident on the mirror 433 can be changed, and the wavelength of the light passing through the exit slit 436 can be changed.
  • FIG. 8A shows the configuration of a MEMS mirror type spectroscope 43 which is an example of such a spectroscope.
  • the spectroscope 43 includes an entrance slit 431, a first concave mirror 432, a MEMS mirror 433, a diffraction grating 434, a second concave mirror 435, and an exit slit 436,
  • an exit slit scanning diffraction that includes an entrance slit 531, a concave diffraction grating 532, and an exit slit 533, and can move the exit slit 533 by supplying a drive signal from the outside.
  • a grating-type spectrometer (ScanningScangratingPDmonochromator) 53 As shown in FIG. 8C, a grating-type spectrometer (ScanningScangratingPDmonochromator) 53, a PDA63grating polychromator 63 having an entrance slit 631, a concave holographic diffraction grating 632, and a PDA 633, etc.
  • Various configurations can be used.
  • Reading wavelength data generation unit 393 Modulation output signal generation unit 710 ... White light source 711 ... Incoming side optical fiber 712 ... Incoming side lens 720 ... Coating device 721 ... Sample 722 ... Window 7 1 ... emission-side optical fiber 782 ... exit-side first lens 783 ... exit-side second lens 793 ... measurement execution section 795 ... synchronization detection signal processing unit 796 ... film thickness calculating unit

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  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

L'invention concerne un dispositif de mesure spectroscopique caractérisé en ce qu'il est pourvu d'une source de lumière (11) pour émettre une lumière d'irradiation ayant une plage de longueurs d'onde; une unité de division de lumière (14) pour sélectivement permettre à la lumière parmi la lumière d'irradiation ayant une longueur d'onde correspondant à la valeur d'un courant fourni ou d'une tension fournie de passer; un détecteur de lumière (17) pour détecter la lumière de mesure qui est passée à travers l'unité de division de lumière (14) et a interagi avec un échantillon; une unité de délivrance de signal d'attaque (18, 192) pour fournir, à l'unité de division de lumière (14), un courant ou une tension ayant une valeur à variation continue et répétition périodique et une composante de modulation superposée à celle-ci qui varie à une période plus courte que celle de la valeur; et une unité de génération de signaux de détection de synchronisation (193) pour générer, à partir du signal de sortie délivré en sortie par le détecteur de lumière, un signal de détection de synchronisation ayant une fréquence de référence qui est un nombre entier positif multiple de la fréquence de la composante de modulation.
PCT/JP2015/057878 2014-03-31 2015-03-17 Dispositif de mesure spectroscopique Ceased WO2015151802A1 (fr)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6163129U (fr) * 1984-09-29 1986-04-28
JPS61266926A (ja) * 1985-05-21 1986-11-26 ヘリゲ・ゲゼルシヤフト・ミツト・ベシユレンクタ・ハフトウング 微分分光計
JPS62135737A (ja) * 1985-12-10 1987-06-18 Anritsu Corp 波長変調型微分分光計
JPH06341901A (ja) * 1993-05-31 1994-12-13 Anelva Corp 波長変調分光器
JP2010038875A (ja) * 2008-08-08 2010-02-18 Fuji Electric Systems Co Ltd ガス分析装置
JP2012026830A (ja) * 2010-07-22 2012-02-09 Shimadzu Corp ガス濃度測定装置
JP2012132443A (ja) * 2010-12-17 2012-07-12 General Electric Co <Ge> ガス燃料混合物の当量比の実時間測定のためのシステムおよび方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6163129U (fr) * 1984-09-29 1986-04-28
JPS61266926A (ja) * 1985-05-21 1986-11-26 ヘリゲ・ゲゼルシヤフト・ミツト・ベシユレンクタ・ハフトウング 微分分光計
JPS62135737A (ja) * 1985-12-10 1987-06-18 Anritsu Corp 波長変調型微分分光計
JPH06341901A (ja) * 1993-05-31 1994-12-13 Anelva Corp 波長変調分光器
JP2010038875A (ja) * 2008-08-08 2010-02-18 Fuji Electric Systems Co Ltd ガス分析装置
JP2012026830A (ja) * 2010-07-22 2012-02-09 Shimadzu Corp ガス濃度測定装置
JP2012132443A (ja) * 2010-12-17 2012-07-12 General Electric Co <Ge> ガス燃料混合物の当量比の実時間測定のためのシステムおよび方法

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