JP2015031606A - Spectrometry device and spectrometry method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectrometry device and a spectrometry method capable of correcting spectroscopic shift with high accuracy.SOLUTION: The spectrometry device can switch between a spectrometry mode in which spectrometry of an object A to be measured is performed using a spectral element and a spectral shift correction mode in which a spectral shift from the initial state of spectral characteristic of the spectral element is corrected and execute the selected mode. The spectral element is a variable etalon 30 capable of changing the wavelength of light to be selectively transmitted from incident light. During the spectral shift correction mode, the spectral shift of the variable etalon is corrected using light of first order passing through the variable etalon; during the spectrometry mode, spectrometry is performed using light of second order, higher in order than the first order, having had the spectral shift corrected and passing through the variable etalon.

Description

  The present invention relates to a spectroscopic measurement apparatus and a spectroscopic measurement method for performing spectroscopic measurement of an object to be measured.

  2. Description of the Related Art Conventionally, a spectroscopic measurement apparatus having a configuration capable of executing a spectroscopic measurement mode for performing spectroscopic measurement of an object to be measured and a spectroscopic shift correction mode for correcting a spectroscopic shift from an initial state of spectroscopic characteristics has been proposed ( For example, Patent Document 1). In the spectroscopic measurement apparatus described in Patent Document 1, spectroscopic measurement is performed in a measurement wavelength region of 380 nm to 780 nm using a light source having a spectrum including a bright line in the spectroscopic measurement mode, and in the spectroscopic shift correction mode, the measurement wavelength is measured. The spectral shift amount is calculated using the bright line included in the region.

JP 2007-192747 A

  However, in the conventional technique, since the spectral measurement in the spectral measurement mode and the detection of the spectral shift amount in the spectral shift correction mode are performed using light in the same wavelength range, There is a problem that the detection accuracy is low and the spectral shift cannot be corrected with high accuracy. For this reason, there is a problem that the spectroscopic measurement cannot be performed with high accuracy. In addition, the conventional spectroscopic measurement apparatus is desired to be reduced in size, cost, resource saving, processing speed, usability, and the like.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) In one aspect of the present invention, a spectroscopic measurement mode for performing spectroscopic measurement of a measurement object using a spectroscopic element, a spectroscopic shift correction mode for correcting a spectroscopic shift from an initial state of spectroscopic characteristics of the spectroscopic element, Is a spectroscopic measurement apparatus capable of executing In this spectroscopic measurement device, the spectroscopic element is a variable etalon that can change the wavelength of light that is selectively transmitted from incident light, and the first-order light that passes through the variable etalon in the spectral shift correction mode. The second order light having a higher order than the first order is transmitted through the variable etalon in which the spectral shift is corrected in the spectroscopic measurement mode. Perform spectroscopy using.
According to the spectroscopic measurement apparatus of this aspect, the second order light having a higher order can increase the spectral accuracy compared to the case where the first order light having a lower order is used. The spectral shift of the variable etalon is corrected using the first order light with a low and the second order light is used in the spectroscopic measurement mode to perform the spectroscopic measurement, thereby improving the spectroscopic accuracy in the spectroscopic measurement. There is an effect that can be.

(2) The spectroscopic measurement apparatus according to the above aspect includes a light source that emits light having a spectrum including one or more emission lines, and in the first wavelength range corresponding to the second-order light in the spectroscopic measurement mode. A second wavelength range in which the wavelength of the transmitted light of the variable etalon is changed, corresponds to the light of the first order, and includes a specific wavelength of the one or more bright lines in the spectral shift correction mode. In the configuration, the wavelength of the transmitted light of the variable etalon may be changed. In the spectroscopic measurement apparatus of this embodiment, the spectral shift can be detected with high accuracy by using the bright line of light from a light source that emits light having a spectrum including one or more bright lines. As a result, the spectral shift can be corrected with high accuracy.

(3) In the spectroscopic measurement device of the above aspect, the light source is a xenon lamp, and the emission line of the specific wavelength is at least one of a plurality of emission lines included in the xenon lamp between 800 nm and 1100 nm. It is good also as a certain structure. In the spectroscopic measurement apparatus of this embodiment, since the strong emission line of the xenon lamp can be used in the spectroscopic measurement mode, the detection accuracy of the spectroscopic shift can be further increased.

(4) The spectroscopic measurement apparatus according to the above aspect includes a light source and a bandpass filter that selectively passes light in a predetermined wavelength region from light emitted from the light source, and in the spectroscopic measurement mode, the second The wavelength of the transmitted light of the variable etalon is changed in a first wavelength range corresponding to the light of the first order, and in the spectral shift correction mode, corresponding to the light of the first order and the predetermined wavelength range It is good also as a structure which changes the wavelength of the transmitted light of the said variable etalon in the 2nd wavelength range containing. In the spectroscopic measurement apparatus of this embodiment, since the spectral shift can be corrected using a light source having no emission line, the versatility of the light source is excellent and the apparatus can be made inexpensive.

(5) In the spectroscopic measurement device of the above aspect, a wavelength filter that interposes selection of light used in each of the spectroscopic measurement mode and the spectroscopic measurement mode on an optical path of incident light or transmitted light of the variable etalon It is good also as a structure performed by. In the spectroscopic measurement device of this embodiment, it is possible to reliably select the light used in each of the spectroscopic measurement mode and the spectroscopic measurement mode.

(6) In the spectroscopic measurement apparatus of the above aspect, the light used in each of the spectroscopic measurement mode and the spectroscopic measurement mode is selected by a dichroic mirror disposed in the light emission direction of the variable etalon. It is good. In the spectroscopic measurement device of this embodiment, it is possible to reliably select the light to be used in each of the spectroscopic measurement mode and the spectroscopic measurement mode, and since the device configuration is simple, it is possible to reduce the size and durability. Improvements can be made.

(7) Another embodiment of the present invention includes a spectroscopic measurement mode for performing spectroscopic measurement of an object to be measured using a spectroscopic element, and a spectroscopic shift correction mode for correcting a spectroscopic shift from the initial state of the spectroscopic characteristics of the spectroscopic element. The spectroscopic measurement method can perform the above. The spectroscopic element is a variable etalon that can change the wavelength of light selectively transmitted from incident light. In the spectroscopic measurement method, the spectral shift of the variable etalon is corrected using light of the first order that passes through the variable etalon in the spectral shift correction mode, and the spectral shift is corrected in the spectroscopic measurement mode. Spectroscopy is performed using light of a second order that is higher than the first order and passes through the variable etalon. This spectroscopic measurement method has an effect that the spectroscopic accuracy in spectroscopic measurement can be increased as in the spectroscopic measurement apparatus of the present invention.

  Furthermore, the present invention can be realized in various forms other than those described above, for example, a form as a computer program that realizes each step included in the spectroscopic measurement method as a function, a recording in which the computer program or the computer program is recorded. It can be realized in the form of a medium or the like.

It is a schematic block diagram which shows the spectrometer as 1st Embodiment of this invention. It is a graph which shows the transmission characteristic of the light in a 1st and 2nd filter. It is a flowchart which shows the spectroscopic measurement mode process routine performed with CPU of a control apparatus. It is explanatory drawing which shows an example of the drive table for spectrometry. It is a graph which shows the transmission characteristic of the light in an etalon. It is a flowchart which shows the spectral shift correction mode processing routine performed with CPU. It is explanatory drawing which shows an example of the drive table for spectral shift correction | amendment. It is a graph which shows an example of the spectral characteristic of a xenon lamp. It is explanatory drawing which shows the correction image by the process of step S320. It is a schematic block diagram which shows the spectrometry apparatus as 2nd Embodiment of this invention. It is a graph which shows the transmission / reflection characteristic of a dichroic mirror. It is a graph which shows an example of the spectral characteristic of an incandescent lamp. It is a graph which shows the transmission characteristic of the light of the band pass filter used in 3rd Embodiment of this invention. It is a schematic block diagram which shows the spectrometry apparatus as 4th Embodiment of this invention. It is a graph which shows the transmission characteristic of the light of the band pass filter used in 4th Embodiment. It is a schematic block diagram which shows the spectrometry apparatus as 5th Embodiment of this invention. It is a graph which shows the permeation | transmission characteristic of the light of the band pass filter used in 5th Embodiment.

Embodiments of the present invention will be described below.
A. First embodiment:
A-1. Overall configuration:
FIG. 1 is a schematic configuration diagram showing a spectroscopic measurement apparatus as a first embodiment of the present invention. The spectroscopic measurement device 10 can selectively execute a normal spectroscopic measurement, that is, a spectroscopic measurement mode for performing spectroscopic measurement of the measurement target A, and a spectroscopic shift correction mode for correcting a spectroscopic shift from the initial state of spectroscopic characteristics. It has become.

  The spectrometer 10 includes a light source device 20, an etalon 30, a light receiving sensor 40, a filter switching device 50, and a control device 100. The light source device 20 includes a light source control unit 60, the etalon 30 includes an etalon drive control unit 70, the light receiving sensor 40 includes a light reception sensor control unit 80, and the filter switching device 50 includes a filter switching drive control unit 90. Connected. A control device 100 is electrically connected to each control unit 60-90.

  The light source device 20 includes a light source 22 and a plurality of lenses 24 (only one is shown in the figure), and irradiates the measurement target A with white light. The light source 22 is a light source that emits continuous spectrum light including a plurality of bright lines, and is, for example, a xenon lamp. The light source controller 60 controls the on / off of the light source 22 and the irradiation amount. The measurement target A is set when the spectroscopic measurement mode is executed. On the other hand, when the spectroscopic shift correction mode is executed, the white plate B is replaced with the measurement target A. , Set at the same position as the measurement object A. In this embodiment, the measurement object A or the white plate B is set by the operator's hand. In addition, it is good also as a structure which replaces with a thing by hand and sets automatically with a machine.

  The etalon 30 is a Fabry-Perot filter that selects and emits light having a specific wavelength from incident light. For example, as disclosed in Japanese Patent Application Laid-Open No. 2011-191492, a detailed configuration is such that a pair of reflective films are opposed to each other and a gap (interval) is formed between the reflective films. By changing the wavelength, the wavelength of outgoing light to be transmitted can be changed. That is, the etalon 30 is an air gap type variable etalon. The etalon drive control unit 70 applies a drive voltage (drive signal) to the etalon 30, and the gap dimension is determined according to the magnitude of the drive voltage. As a result, the etalon 30 receives the reflected light from the measurement object A or the white plate B and emits (transmits) light having the wavelength set by the etalon drive control unit 70.

  The light receiving sensor 40 converts light intensity (light quantity) into an electric signal, and for example, a CCD image sensor can be used. The light receiving sensor 40 receives the emitted light from the etalon 30 and measures the amount of the emitted light. The sensitivity of the light receiving sensor 40 is controlled by the light receiving sensor control unit 80.

  The filter switching device 50 includes a first filter 52, a second filter 54, and a motor 56, and the first and second filters are provided in the optical path from the measurement target A (or white plate B) to the etalon 30. Either of 52 and 54 can be switched by the motor 56. The switching can be performed by controlling the motor 56 by the filter switching drive control unit 90.

  The first filter 52 is used when the spectroscopic measurement mode is executed, and the second filter 54 is used when the spectroscopic shift correction mode is executed. That is, according to the filter switching device 50, the first filter 52 is interposed in the optical path from the measurement target A to the etalon 30 in the spectroscopic measurement mode, and the optical path from the white plate B to the etalon 30 in the spectral shift correction mode. A second filter 54 is interposed.

  FIG. 2 is a graph showing light transmission characteristics in the first and second filters 52 and 54. In this graph, the vertical axis indicates the light transmittance (= pass rate), and the horizontal axis indicates the wavelength of light. The first filter 52 passes light having a wavelength of 720 nm or less, and the second filter 54 passes light having a wavelength of 740 nm or more. That is, the first and second filters 52 and 54 are wavelength filters, that is, wavelength cut filters. In the spectroscopic measurement mode, the first filter 52 is used as described above, so that light having a wavelength of 720 nm or less (visible light) is transmitted to the etalon 30. On the other hand, in the spectral shift correction mode, the second filter 54 is used as described above, so that light having a wavelength of 740 nm or more (light in a range including at least near infrared light) is sent to the etalon 30. The boundary values such as 720 nm and 740 nm are examples, and can be changed to other values. The boundary value of the first filter 52 may be any value as long as it selects a range including the wavelength range of the light irradiated to the measuring object A for spectroscopy in the spectroscopic measurement mode. The boundary value of the filter 54 may be any value as long as it selects a bright line to be described later.

  The control device 100 includes a CPU 110 that performs various processes and controls by executing a computer program (hereinafter simply referred to as “program”), a memory 120 that is a data saving location, and a hard disk drive that stores programs and data. This is a well-known device having 130 or the like. The hard disk drive 130 includes a reference drive table TL0, a spectral measurement drive table TL1, and a spectral shift correction drive table TL2. The spectroscopic measurement drive table TL1 is a drive table of the etalon 30 used in spectroscopic measurement in the spectroscopic measurement mode. The spectral measurement drive table TL1 is subjected to a correction process for correcting the spectral shift from the initial state of the etalon 30 in the spectral shift correction mode, and the reference drive table TL0 is an initial stage where the correction process is not performed. This corresponds to a spectroscopic measurement drive table in a state (for example, a state at the time of factory shipment). Details of the tables TL0 to TL2 will be described later. The CPU 110 functions as the spectral shift correction unit 112. The spectral shift correction unit 112 will also be described later. The control device 100 can be realized by a discrete electronic circuit instead of a configuration including a CPU, a memory, a hard disk drive, and the like.

  The spectroscopic measurement apparatus 10 includes a spectroscopic measurement execution button 92 for starting execution of the spectroscopic measurement mode and a spectroscopic shift correction execution button 94 for starting execution of the spectroscopic shift correction mode. Both execution buttons 92 and 94 are operated by an operator. Both execution buttons 92 and 94 are electrically connected to the control device 100, and when pressed by an operator, an on command for starting execution of the spectroscopic measurement mode or an on command for starting execution of the spectroscopic shift correction mode. Is output to the control device 100.

A-2. Processing in spectroscopic mode:
FIG. 3 is a flowchart showing a spectroscopic measurement mode processing routine executed by the CPU 110 of the control device 100. The spectroscopic measurement mode processing routine is started when the spectroscopic measurement execution button 92 is pressed by the operator and an ON command is received from the spectroscopic measurement execution button 92. Prior to pressing the spectroscopic measurement execution button 92, the operator sets the measurement object A to a predetermined position, that is, a position that receives light from the light source device 20 and reflects the light in the direction of the etalon 30. Further, it is assumed that the filter switching device 50 is operated in advance so that the first filter 52 is interposed in the optical path from the measurement target A to the etalon 30.

  In FIG. 3, when the process is started, the CPU 110 first reads the spectroscopic measurement drive table TL1 from the hard disk drive 130 and stores it in the memory 120 (step S110).

  FIG. 4 is an explanatory diagram showing an example of the spectroscopic measurement drive table TL1. As shown in the figure, the spectroscopic measurement drive table TL1 includes n records composed of three items C1, C2, and C3 of “No.”, “Transmission peak wavelength”, and “Drive voltage”. n is an integer greater than or equal to 1 and is 9 in the illustrated example. The item “No.” C1 stores one or more integers 1 to 9 indicating the order of records. The item “transmission peak wavelength” C2 stores a wavelength to be transmitted through the etalon 30, that is, transmission peak wavelengths λ0 to λ8. The item “drive voltage” C3 stores drive voltages v0 to v8 necessary for obtaining the transmission peak wavelengths λ0 to λ8 in the etalon 30. In the present embodiment, the transmission peak wavelengths λ0 to λ8 are 700, 660, 620, 580, 540, 500, 460, 420, and 380 nm, and there are nine stages from 700 nm to 380 nm every 40 nm. The drive voltages v0 to v8 are sequentially updated in a spectral shift correction mode that will be described later.

  Returning to FIG. 3, after executing step S110, CPU 110 sets initial value 1 to variable i indicating the number of times of measurement (step S120). The variable i is an integer of 1 or more. Next, the CPU 110 reads the i-th record corresponding to the variable i from the spectroscopic measurement drive table TL1 (step S130). Subsequently, the CPU 110 outputs a drive control signal to the etalon drive control unit 70, thereby driving the etalon 30 according to the drive voltage included in the i-th record read in step S130. The process is executed (step S140).

  FIG. 5 is a graph showing light transmission characteristics in the etalon 30. In this graph, the vertical axis indicates the light transmittance, and the horizontal axis indicates the wavelength of the light. The graph shows a case where the etalon 30 is driven in accordance with the eighth record of the spectroscopic measurement drive table TL1, and peaks with high transmittance are generated around the wavelength of 420 nm and around the wavelength of 840 nm. This peak at a wavelength of 420 nm is a secondary peak of the transmission characteristic in the gap dimension adjusted by the driving voltage v7 stored in the eighth record, and the peak at a wavelength of 840 nm is adjusted by the driving voltage v7. It is a primary peak of transmission characteristics in the gap size. That is, the drive voltage stored in the item C3 of the spectroscopic measurement drive table TL1 is a voltage value that determines the gap dimension so that the transmission peak wavelength stored in the item C2 is generated as the secondary peak of the etalon 30. When the etalon 30 is driven according to the driving voltage, a secondary peak of the transmission peak wavelength stored in the item C2 and a primary peak having a lower order than the secondary peak are generated. In the spectroscopic measurement device 10 of the present embodiment, the light incident on the etalon 30 in the spectroscopic measurement mode is limited to a wavelength region of 720 nm or less by the first filter 52, so that in fact, the light is incident on the primary peak side from the etalon 30. Light with a wavelength of 840 nm is not emitted. That is, according to the spectroscopic measurement apparatus 10 of the present embodiment, the etalon 30 performs spectroscopy using only secondary light.

The orders such as “first order” and “second order” are orders (positive integers) of interference light in the Fabry-Perot interference system as the etalon 30, and light passing through the etalon 30 as shown in the following expression (1). The wavelength λ differs depending on the order n.
λ = 2 × d / n (1)
Here, d is a gap dimension. This is the case where the incident angle = 0 degrees and the refractive index = 1. As can be seen from Equation (1), when focusing on the primary light (n = 1), the wavelength λ of the transmitted light is twice the gap dimension d. When focusing on secondary light (n = 2), the wavelength λ of the transmitted light is equal to the gap dimension d.

  Returning to FIG. 3, simultaneously with the process of step S <b> 140, the CPU 110 outputs a control signal to the light receiving sensor control unit 80 to cause the light receiving sensor 40 to measure the amount of light transmitted through the etalon 30 and perform spectroscopic measurement ( Step S150). Thereafter, the CPU 110 increments the variable i by the value 1 (step S160), and determines whether or not the variable i exceeds n, which is the number of records in the spectroscopic measurement drive table TL1 (step S170). Here, when it is determined that it does not exceed, the CPU 110 returns the process to step S130 and repeatedly executes the processes of steps S130 to S170. By repeating this, the measurement target light, which is the light reflected by the measurement target A, can be dispersed into nine stages of wavelengths from 700 nm to 380 nm every 40 nm, and the amount of light of each of the divided wavelengths can be measured. As described above, this spectroscopy is performed using the secondary light by the etalon 30. Since the first filter 52 is interposed on the optical path to the etalon 30, no primary light is emitted from the etalon 30. The range from 700 nm to 380 nm corresponds to the “first wavelength range” described in the “Summary of Invention” column. If it is determined in step S170 that the variable i exceeds n, the spectroscopic measurement mode processing routine is terminated.

A-3. Spectral shift correction mode processing:
FIG. 6 is a flowchart showing a spectral shift correction mode processing routine executed by the CPU 110. This spectral shift correction mode processing routine is started when the spectral shift correction execution button 94 is pressed by the operator and an ON command is received from the spectral shift correction execution button 94. Before the operator depresses the spectral shift correction execution button 94, the white plate B receives the light from the light source device 20 and reflects the light in the direction of the etalon 30. Set to. This spectral shift correction mode processing routine corresponds to the spectral shift correction unit 112 (FIG. 1).

  In FIG. 6, when the process is started, the CPU 110 first causes the filter switching drive control unit 90 to perform switching from the first filter 52 to the second filter 54 (step S210). Next, the CPU 110 reads the spectral shift correction drive table TL2 from the hard disk drive 130 and stores it in the memory 120 (step S220).

  FIG. 7 is an explanatory diagram showing an example of the spectral shift correction drive table TL2. As shown in the figure, the spectral shift correction drive table TL2 has three items C11, C12, “No.”, “Transmission peak wavelength”, and “Drive voltage”, similarly to the spectral measurement drive table TL1 of FIG. A record constituted by C13 is provided. The number of records m is an integer greater than or equal to 1 and is 11 in the illustrated example. In the item “C12 of transmission peak wavelength”, the wavelength range around the peak portion of the bright line included in the light of the light source 22 is stored.

  FIG. 8 is a graph showing an example of spectral characteristics of a xenon lamp that is the light source 22. In this graph, the vertical axis indicates the relative intensity (%) of light, and the horizontal axis indicates the wavelength (nm) of light. As shown in the graph, the light emitted from the xenon lamp is a continuous spectrum including light of a wide wavelength from ultraviolet to infrared, and several strong emission lines exist in the range from 800 nm to 1100 nm. In particular, there is a maximum bright line at the wavelength λp of 850 nm, that is, the brightest line. Therefore, in the item C12 of “transmission peak wavelength” in the spectral shift correction drive table TL2 of FIG. 7, the wavelength of 850 nm (= λp), which is the peak portion of the maximum emission line, is set to the middle, and 870, 866 on the long side. , 862, 858, and 854 nm, and wavelengths of 846, 842, 838, 834, and 830 nm are stored on the short side. That is, the transmission peak wavelengths stored in the item C12 of the spectral shift correction drive table TL2 are eleven levels every 4 nm from 870 nm to 830 nm. The drive voltage stored in the item C13 of the spectral shift correction drive table TL2 is a voltage value that determines the gap size so that the transmission peak wavelength stored in the item C11 is generated as the primary peak of the etalon 30.

  Returning to FIG. 6, after the execution of step S220, the reference drive table TL0 is read from the hard disk drive 130 and stored in the memory 120 (step S230). As described above, the reference drive table TL0 is a spectroscopic measurement drive table in an initial state, and has the same format as the spectroscopic measurement drive table TL1 in FIG.

  After execution of step S230, CPU 110 sets initial value 1 to variable j indicating the number of measurements (step S240). The variable j is an integer of 1 or more. Next, the CPU 110 reads the j-th record corresponding to the variable j from the spectral shift correction drive table TL2 (step S250). Subsequently, the CPU 110 outputs a drive control signal to the etalon drive controller 70, thereby driving the etalon 30 according to the drive voltage included in the jth record read in step S250. The process is executed (step S260). Then, the CPU 110 outputs a control signal to the light receiving sensor control unit 80 to cause the light receiving sensor 40 to measure the amount of light transmitted through the etalon 30 and perform spectroscopic measurement (step S270).

  Thereafter, the CPU 110 increments the variable j by a value 1 (step S280), and determines whether or not the variable j exceeds m, which is the number of records in the spectral shift correction drive table TL2 (step S290). Here, when it is determined that it does not exceed, the CPU 110 returns the process to step S250 and repeatedly executes the processes of steps S250 to S290. By repeating this, the shift detection light, which is the light reflected by the white plate B, is dispersed into 11 steps of wavelengths every 4 nm from 870 nm to 830 nm, and the amount of light of each of the divided wavelengths can be measured. Spectroscopy in the spectral shift correction mode is performed by using the primary light by the etalon 30 as described above. Since the second filter 54 is interposed on the optical path to the etalon 30, no secondary light is emitted from the etalon 30. The range from 870 nm to 830 nm corresponds to the “second wavelength range” described in the “Summary of the invention” column. When it is determined in step S290 that the variable j has exceeded m, the CPU 110 advances the process to step S300.

  In step S300, the CPU 110 selects the maximum light amount of each wavelength obtained in step S270, and obtains the drive voltage VA in step S260 when the maximum light amount is obtained. Instead of simply selecting the maximum light amount, the driving voltage VA may be obtained by fitting to a Gaussian function. This drive voltage VA is the wavelength of the maximum bright line included in the light emitted from the light source 22 in the etalon 30 when the spectral shift correction mode processing routine is executed (hereinafter simply referred to as “correction execution time”) (in this embodiment, 850 nm) is a driving voltage required for transmission.

Since the spectral characteristics of the etalon 30 change from an initial state (for example, a state at the time of factory shipment) due to deterioration or the like, the drive voltage VA required to transmit each wavelength at the time of correction execution changes from the initial state. For this reason, the driving voltage VA required to transmit the wavelength of 850 nm is also a value shifted from the driving voltage VA0 required to transmit the wavelength of 850 nm in the initial state (hereinafter referred to as “reference driving voltage”) VA0. Yes. Therefore, in the subsequent step S310, the CPU 110 detects the spectral shift by comparing the drive voltage VA obtained in step S300 with the reference drive voltage VA0 and obtaining the voltage shift amount ΔV according to the following equation (2). ing. It is assumed that the reference drive voltage VA0 is obtained in advance by experiments and simulations and stored in the hard disk drive 130 in advance.
ΔV = VA−VA0 (2)

  Subsequently, the CPU 110 performs a process of correcting the spectroscopic measurement drive table TL1 using the reference drive table TL0 read in step S230 and the voltage shift amount ΔV obtained in step S310 (step S320). Specifically, the reference drive table TL0 (the same format as in FIG. 4) is copied as the spectroscopic measurement drive table, and the voltage shift is performed with respect to each value of the item C3 of the “drive voltage” of the spectroscopic measurement drive table obtained by copying A new spectroscopic measurement drive table is created by adding the amount ΔV. This new spectroscopic measurement drive table is overwritten in the memory 120 as the spectroscopic measurement drive table TL1. In the spectroscopic measurement mode, the etalon 30 is driven using the latest spectroscopic measurement drive table TL1.

  FIG. 9 is an explanatory diagram showing a correction image by the process of step S320. FIG. 9A is for explaining the spectral shift occurring in the etalon 30, and FIG. 9B is for explaining the correction of the spectroscopic measurement drive table TL1. When the spectral characteristics of the etalon 30 are spectrally shifted from the initial state, as shown in FIG. 9A, the value of the transmission wavelength with respect to the driving voltage is shifted from the position of the solid line in the initial state to the position of the one-dot chain line at the time of observation. To do. That is, a wavelength shift occurs. For this reason, the drive voltage that transmits the wavelength of the maximum emission line is shifted from VA0 by ΔV to VA. Therefore, as shown in the graph of FIG. 9B, the driving voltage VB corresponding to the wavelength target value is shifted by ΔV from the solid line position value VB0 in the initial state to the one-dot chain line position. The process of shifting this voltage is the correction process of the spectroscopic measurement drive table TL1 in step S320. Thereby, the spectral shift from the initial state of the etalon 30 can be corrected.

  Returning to FIG. 6, after execution of step S320, the CPU 110 causes the filter switching drive control unit 90 to perform switching from the second filter 54 to the first filter 52 (step S210). As a result, the filter interposed in the optical path switched to the second filter 54 at the start of the spectroscopic measurement mode processing routine is returned to the first filter 52. Thereafter, the CPU 110 ends the spectroscopic measurement mode processing routine.

A-4. effect:
As described above, according to the spectroscopic measurement device 10 of the present embodiment described in detail, in the spectral shift correction mode, when the primary light transmitted through the etalon 30 is used and the wavelength shift is adjusted with an accuracy of every 4 nm, In the spectroscopic measurement mode, the wavelength can be adjusted at 2 nm, which is half of 4 nm, by using secondary light. For this reason, the spectral accuracy in spectroscopic measurement can be improved. In addition, in the spectral shift correction mode, since the spectral shift is detected using the strongest emission line emitted from the xenon lamp as the light source 22, the detection can be performed with high accuracy, and the spectral shift can be corrected. Can be made highly accurate.

  In the present embodiment, the first filter 52 or the second filter 54 is configured to be interposed in the optical path from the measurement target A (or white plate B) to the etalon 30, but instead of this, an etalon is used. It is good also as a structure interposed in the optical path from 30 to the light receiving sensor 40. With this configuration, the same effects as those of the first embodiment can be obtained. Further, in the present embodiment, the second wavelength range is a range from 870 nm to 830 nm including 850 nm which is the peak portion of the maximum emission line, but instead, in the range from 800 nm to 1100 nm in the xenon lamp. It can also be set as a range including a bright line other than the maximum bright line among a plurality of bright lines included.

B. Second embodiment:
FIG. 10 is a schematic configuration diagram showing a spectroscopic measurement apparatus 210 as a second embodiment of the present invention. Compared with the spectroscopic measurement apparatus 10 in the first embodiment, the spectroscopic measurement apparatus 210 is different in the method of switching the order of the light used between the spectroscopic measurement mode and the spectroscopic measurement mode. The configuration is the same as that of the spectrometer 10 in the first embodiment. That is, in the spectroscopic measurement device 10 of the first embodiment, the order of the light used is switched between the spectroscopic measurement mode and the spectroscopic measurement mode by switching the filter by the filter switching device 50 (FIG. 1). On the other hand, in the spectroscopic measurement device 210 of this embodiment, the dichroic mirror 220 is provided on the optical path between the etalon 30 and the light receiving sensor 40 without providing the filter switching device 50. The switching is performed. In the second embodiment, the same constituent elements as those in the first embodiment are denoted by the same reference numerals in FIG. 10 as those in FIG.

  FIG. 11 is a graph showing the transmission / reflection characteristics of the dichroic mirror 220. As shown in this graph, the dichroic mirror 220 transmits light having a wavelength of 720 nm or less and reflects light having a wavelength of 740 nm or more. By placing the dichroic mirror 220 having such characteristics on the optical path between the etalon 30 and the light receiving sensor 40, the light to be measured is light to be measured by the light receiving sensor 40 (hereinafter referred to as “first light receiving sensor 40”). Is incident, and shift detection light, which is near-infrared light, is incident on the second light receiving sensor 230 provided in the reflection direction of the dichroic mirror 220. The first and second light receiving sensors 40 and 230 can measure both visible light and near infrared light. With such a configuration, in the spectroscopic measurement mode, spectroscopic measurement can be performed from the measurement result of the first light receiving sensor 40, and in the spectroscopic shift correction mode, the spectral shift can be corrected from the measurement result of the second light receiving sensor 230. it can.

  According to the spectroscopic measurement apparatus 210 of the second embodiment configured as described above, the spectral accuracy in spectroscopic measurement can be increased as in the spectroscopic measurement apparatus 10 of the first embodiment. In addition, the detection accuracy of the spectral shift can be increased, and the spectral shift can be corrected with high accuracy. Further, since the spectroscopic measurement device 210 does not include a movable part like the filter switching device 50, the durability of the device is high.

  As a modification of the second embodiment, the first light receiving sensor 40 can observe only visible light, and the second light receiving sensor 230 can observe only near infrared light. Further, the transmission / reflection characteristics of the dichroic mirror 220 can be changed to a configuration in which transmission and reflection are reversed in FIG. In this case, spectroscopic measurement is performed using visible light measured by the second light receiving sensor 230 in the spectroscopic measurement mode, and near infrared light measured by the first light receiving sensor 40 is used in the spectroscopic shift correction mode. Thus, the spectral shift may be corrected.

C. Third embodiment:
A third embodiment of the present invention will be described. The spectroscopic measurement device of the third embodiment is different from the spectroscopic measurement device 10 (FIG. 1) of the first embodiment in the type of the light source 22 provided in the light source device 20 and the second filter provided in the filter switching device 50. 54 is different, and the other configuration is the same as the configuration of the spectroscopic measurement apparatus 10 in the first embodiment. In the first embodiment, the light source 22 is a light source that emits light having a continuous spectrum including a plurality of bright lines. On the other hand, in this embodiment, the light source emits light having a continuous spectrum that does not include bright lines. A light source was used. Examples of this type of light source include incandescent bulbs and halogen lamps.

  FIG. 12 is a graph showing an example of the spectral characteristics of an incandescent bulb. As shown in this graph, in the spectral characteristics of the incandescent lamp, the specific energy gradually increases as the wavelength increases. This continuous spectrum does not include emission lines.

  In the first embodiment, the second filter 54 is a wavelength filter (see FIG. 2) that passes light having a wavelength of 740 nm or more. On the other hand, in the present embodiment, the second filter is a bandpass. A band pass filter was designed to have the characteristics shown in FIG. 13 as a filter. That is, as shown in FIG. 13, the band-pass filter as the second filter has a characteristic of transmitting only light in the wavelength region near 850 nm. In other words, in the first embodiment, the peak light of 850 nm used in the spectral shift correction mode is obtained from the bright line included in the light of the light source, whereas in this embodiment, the light source and the band pass filter are used. Trying to get.

  According to the spectroscopic measurement device of the third embodiment configured as described above, the spectroscopic accuracy in spectroscopic measurement can be increased as in the spectroscopic measurement device 10 of the first embodiment. In the spectral shift correction mode, light having a long wavelength is used by using primary light, but light having a long wavelength has high light intensity as can be seen from FIG. Can be accurately detected, and the spectral shift can be corrected with high accuracy. Furthermore, since the spectroscopic measurement apparatus of the third embodiment is configured to generate 850 nm peak light with a light source having no emission line and a bandpass filter, the versatility of the light source is high and the apparatus can be made inexpensive. .

  In the present embodiment, the first filter or the second filter (bandpass filter) is configured to be interposed in the optical path from the measurement target A (or white plate B) to the etalon 30. Alternatively, the optical path from the etalon 30 to the light receiving sensor 40 may be interposed. With this configuration, the same effect as that of the third embodiment can be obtained.

D. Fourth embodiment:
FIG. 14 is a schematic configuration diagram showing a spectroscopic measurement apparatus 410 as a fourth embodiment of the present invention. The spectroscopic measurement device 410 is different from the spectroscopic measurement device 210 (FIG. 10) in the second embodiment in that the light source 422 provided in the light source device 420 does not have a bright line, and the measurement target A or white plate B The difference is that a band pass filter 440 is provided on the optical path from to etalon 30, and the other configuration is the same as the configuration of the spectrometer 210 of the second embodiment. In addition, in 4th Embodiment, about the component same as 2nd Embodiment, the same code | symbol as FIG. 10 is attached | subjected in FIG. 14, and the description is abbreviate | omitted.

  The light source 422 is the same as the light source of the third embodiment, and is, for example, a halogen or an incandescent bulb. The band pass filter 440 is designed to have the characteristics shown in FIG. That is, as shown in FIG. 15, the band-pass filter 440 has a characteristic of transmitting light having a wavelength of 720 nm or less and light having a wavelength region near 850 nm. The spectroscopic measurement device 410 of the fourth embodiment having such a configuration uses the dichroic mirror 220 as a method for switching the order of light used between the spectroscopic measurement mode and the spectroscopic measurement mode. It can be said that the method of obtaining the peak light of 850 nm used in the spectral shift correction mode is based on the light source and the band pass filter.

  Therefore, according to the spectroscopic measurement device 410 of the fourth embodiment, the spectral accuracy in spectroscopic measurement can be increased as in the spectroscopic measurement devices 10 and 210 of the first and second embodiments. In addition, the detection accuracy of the spectral shift can be increased, and the spectral shift can be corrected with high accuracy. Further, since the spectroscopic measurement apparatus 410 does not include a movable part like the filter switching apparatus 50, the apparatus can be downsized and the durability can be improved. In addition, since the light source having no bright line and the bandpass filter generate peak light of 850 nm, the versatility of the light source is high and the apparatus can be made inexpensive.

  In the present embodiment, the band pass filter 440 is configured to be interposed in the optical path from the measurement target A (or white plate B) to the etalon 30. It is good also as a structure interposed in an optical path. Even with this configuration, the same effects as in the fourth embodiment can be obtained.

E. Fifth embodiment:
FIG. 16 is a schematic configuration diagram showing a spectroscopic measurement apparatus 510 as a fifth embodiment of the present invention. The spectroscopic measurement device 510 differs from the spectroscopic measurement device 410 in the fourth embodiment in the position of the bandpass filter. That is, in the spectroscopic measurement apparatus 410 (FIG. 14) of the fourth embodiment, the band pass filter 440 is provided on the optical path from the measurement target A or the white plate B to the etalon 30, but this embodiment is replaced with this. In the spectroscopic measurement device 510 of the embodiment, a band pass filter 520 is provided between the dichroic mirror 220 and the second light receiving sensor 230. The band pass filter 520 is designed to have the characteristics shown in FIG. That is, as shown in FIG. 17, the band-pass filter 440 has a configuration that transmits only light in a wavelength region near 850 nm. According to the spectroscopic measurement device 510 of the fifth embodiment having such a configuration, the same effects as those of the spectroscopic measurement device 410 of the fourth embodiment can be obtained.

F. Variation:
The present invention is not limited to the first to fifth embodiments and the modifications thereof, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible. is there.

・ Modification 1:
In the first and second embodiments, one bright line is used in the spectral shift correction mode, but instead, a configuration using a plurality of bright lines in the spectral shift correction mode may be used. Specifically, for example, a voltage shift amount ΔV is obtained from each of two (or three, four, etc.) bright lines included in a range from 800 nm to 1100 nm to obtain a plurality of voltage shifts. The spectral shift is detected by interpolating the amount ΔV. According to this configuration, the shift amount of the spectral shift can be detected with higher accuracy. Similarly, in the third to fifth embodiments, the light source may be a light source that does not have a bright line, and a band-pass filter that passes through a plurality of wavelength ranges may be used.

Modification 2
In the first and third embodiments, a xenon lamp is used as a light source that emits continuous spectrum light including a plurality of bright lines. However, instead of this, another light source such as a xenon flash lamp may be used. Good. Furthermore, instead of a light source that emits continuous spectrum light including a plurality of emission lines, a light source that emits light of a continuous spectrum including one emission line may be used.

・ Modification 3:
In each of the above-described embodiments and modifications, an air gap etalon that changes the gap dimension by electrostatic attraction is used as the variable etalon. Instead, the piezoelectric effect (electrostrictive effect), electromagnetic force, and pneumatic pressure are used. A variable etalon that changes the gap size using pressure or the like can be used. In short, any variable etalon that can change the wavelength of light selectively transmitted from incident light can be used.

-Modification 4:
In each of the above-described embodiments and modifications, in the spectral shift correction mode, the first-order light (corresponding to the “first order” described in the “Summary of Invention”) that transmits the etalon is used to perform spectroscopy. The shift is corrected, and in the spectroscopic measurement mode, the second-order (corresponding to the “second order” described in the “Summary of Invention” column) is used for the spectroscopic analysis. The secondary light may be used in the spectral shift correction mode, and the tertiary light may be used in the spectral measurement mode. In short, any configuration can be used as long as it uses light having a higher order than the order of light used in the spectral shift correction mode in the spectroscopic measurement mode.

-Modification 5:
In each of the above-described embodiments and modifications, the spectral shift is corrected using the primary light transmitted through the etalon in the spectral shift correction mode, and the secondary light is used in the spectroscopic measurement mode to perform spectroscopy. However, instead of this, it is possible to use a configuration in which primary light is used in the spectral shift correction mode and primary light and secondary light are used in the spectroscopic measurement mode. Specifically, for example, in the spectral shift correction mode, primary light having eleven steps of wavelengths every 4 nm from 870 nm to 830 nm is used as in the above-described embodiments, and in the spectral measurement mode, 700 nm, 660 nm, and 620 nm. And the secondary light of 580 nm, 540 nm, 500 nm, 460 nm, 420 nm, and 380 nm. In short, in the spectroscopic measurement mode, a configuration may be used in which a plurality of orders of light including at least orders of light higher than the orders of light used in the spectroscopic shift correction mode are used.

Modification 6:
In the embodiment and each modified example, the function realized by software may be realized by hardware.

  It should be noted that elements other than those described in the independent claims among the constituent elements in each of the above-described embodiments and modifications are additional elements and can be omitted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Spectrometer 20 ... Light source device 22 ... Light source 24 ... Lens 30 ... Etalon 40 ... Light receiving sensor 50 ... Filter switching device 52 ... 1st filter 54 ... 2nd filter 56 ... Motor 60 ... Light source control part 70 ... Etalon Drive control unit 80 ... Light receiving sensor control unit 90 ... Filter switching drive control unit 92 ... Spectral measurement execution button 94 ... Spectral shift correction execution button 100 ... Control device 110 ... CPU
DESCRIPTION OF SYMBOLS 112 ... Spectral shift correction | amendment part 120 ... Memory 130 ... Hard disk drive 210 ... Spectroscopic measuring device 220 ... Dichroic mirror 230 ... 2nd light reception sensor 410 ... Spectroscopic measuring device 420 ... Light source device 422 ... Light source 440 ... Band pass filter 510 ... Spectroscopic measurement Device 520 ... Band pass filter A ... Measurement object B ... White plate TL0 ... Reference drive table TL1 ... Spectral measurement drive table TL2 ... Spectral shift correction drive table

Claims (7)

A spectroscopic measurement apparatus capable of executing a spectroscopic measurement mode for performing spectroscopic measurement of a measurement object using a spectroscopic element and a spectroscopic shift correction mode for correcting a spectroscopic shift from an initial state of spectroscopic characteristics of the spectroscopic element. ,
The spectroscopic element is a variable etalon that can change the wavelength of light selectively transmitted from incident light,
The spectral shift of the variable etalon is corrected using light of the first order that passes through the variable etalon during the spectral shift correction mode, and the variable etalon with the spectral shift corrected is corrected during the spectral measurement mode. A spectroscopic measurement apparatus that performs spectroscopy using light of a second order that is higher in order than the first order. The spectroscopic measurement apparatus according to claim 1,
Comprising a light source that emits light of a spectrum including one or more emission lines;
In the spectral measurement mode, the wavelength of the transmitted light of the variable etalon is changed in a first wavelength range corresponding to the second order light, and the first order light is supported in the spectral shift correction mode. And the wavelength of transmitted light of the variable etalon is changed in a second wavelength range including an emission line having a specific wavelength among the one or more emission lines. The spectroscopic measurement device according to claim 2,
The light source is a xenon lamp;
The spectroscopic measurement apparatus, wherein the emission line having the specific wavelength is at least one of a plurality of emission lines included between 800 nm and 1100 nm of the xenon lamp. The spectroscopic measurement apparatus according to claim 1,
A light source;
A band-pass filter that selectively passes light in a predetermined wavelength region from light emitted from the light source,
In the spectral measurement mode, the wavelength of the transmitted light of the variable etalon is changed in a first wavelength range corresponding to the second order light, and the first order light is supported in the spectral shift correction mode. And a spectral measurement device that changes the wavelength of the transmitted light of the variable etalon in a second wavelength range including the predetermined wavelength range. The spectroscopic measurement apparatus according to any one of claims 1 to 4,
A spectroscopic measurement apparatus that selects light to be used in each of the spectroscopic measurement mode and the spectroscopic measurement mode by using a wavelength filter interposed on an optical path of incident light or transmitted light of the variable etalon. The spectroscopic measurement apparatus according to any one of claims 1 to 4,
A spectroscopic measurement apparatus that selects light to be used in each of the spectroscopic measurement mode and the spectroscopic measurement mode by using a dichroic mirror arranged in the light emission direction of the variable etalon. A spectroscopic measurement method capable of executing a spectroscopic measurement mode for performing spectroscopic measurement of a measurement object using a spectroscopic element and a spectroscopic shift correction mode for correcting a spectroscopic shift from an initial state of spectroscopic characteristics of the spectroscopic element. ,
The spectroscopic element is a variable etalon that can change the wavelength of light selectively transmitted from incident light,
The spectral shift of the variable etalon is corrected using light of the first order that passes through the variable etalon during the spectral shift correction mode, and the variable etalon with the spectral shift corrected is corrected during the spectral measurement mode. A spectroscopic measurement method for performing spectroscopy using light of a second order that is higher in order than the first order.

Images