JP2017223515A - Spectrometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectrometer capable of obtaining satisfactory detection sensitivity with a small configuration at small cost.SOLUTION: There is provided a spectrometer (10), which includes: an electromagnetic wave source (11) that irradiates a measurement object with a first electromagnetic wave; and a detection part (13) including a spectral sensor constituted of an optical filter and a detector, which detects a second electromagnetic wave returning from the measurement object irradiated with the first electromagnetic wave, and which has a detection sensitivity to a part of a wavelength region of the first electromagnetic wave.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a spectroscopic measuring apparatus suitable for a measuring apparatus for fluorescence emitted from a measuring object.

  One method of measuring physical properties is to use measurement of fluorescence emitted from a substance by irradiating the substance with excitation light. In recent years, fluorescence has been used as various markers, and is often used for specifying the position of cancer or virus in a living body and checking for the presence or absence of viruses in food. In addition, tissue in the living body or food itself may emit fluorescent light, and the type of fat can be specified by this fluorescence.

  However, since fluorescence is weak light, in order to measure and analyze fluorescence, it is necessary to ensure a sufficient amount of light or to perform sufficiently sensitive measurement. In the following patent documents, apparatuses for detecting weak fluorescence with high sensitivity are disclosed.

  Patent Document 1 discloses a medical diagnostic apparatus that can detect weak fluorescence by irradiating white light for observation and laser light that is excitation light for acquiring a fluorescent image in a time-sharing manner. Yes. Patent Document 2 discloses a detector that enables highly sensitive fluorescence measurement by allowing only light having a wavelength to be detected to enter a spectroscopic sensor by using a light shielding plate provided on a cell of the fluorescence detection element. Has been.

JP 59-040869 (published March 6, 1984) JP 2011-017658 A (published January 27, 2011)

  However, in order to realize an excitation light emitting element for obtaining a high light amount or a detector capable of detecting with high sensitivity, a large or expensive light emitting element and a detector are required, which increases the size of the measuring device or increases the cost. Accompanying

  The excitation light-emitting element used in Patent Document 1 needs to use a large and expensive gas laser such as an excimer laser in order to obtain a sufficiently high excitation intensity. Further, in Patent Document 2, since a light shielding plate is provided on the element, the light shielded element space is wasted and the apparatus becomes large.

  The present invention has been made in view of the above-described problems, and an object thereof is to realize a spectroscopic measurement apparatus that can obtain good detection sensitivity even with a small and inexpensive configuration.

  In order to solve the above problems, a spectroscopic measurement device according to one embodiment of the present invention includes an electromagnetic wave source and a detection unit, and the electromagnetic wave source irradiates a measurement object with a first electromagnetic wave, and the detection unit includes: , Comprising an optical filter and a detector, detecting a second electromagnetic wave returning from the measurement object irradiated with the first electromagnetic wave, from a wavelength longer than the shortest wavelength of the first electromagnetic wave, from a longest wavelength of the first electromagnetic wave It has a detection sensitivity for a wavelength range up to a long wavelength.

  According to one embodiment of the present invention, by efficiently detecting only a wavelength necessary for detection, there is an effect that a small and inexpensive spectroscopic measurement device having good detection sensitivity can be realized.

It is a block diagram of the spectrometer which concerns on Embodiment 1 of this invention. It is a top view of the detection part which concerns on Embodiment 1 of this invention, and a perspective view which shows a part of spectral sensor. It is the graph which showed the relationship of the intensity | strength of the emitted light of the electromagnetic wave source which concerns on Embodiment 1 of this invention, the detection sensitivity of a detection part, and a wavelength. It is a top view of the detection part which concerns on the modification of Embodiment 1 of this invention. It is the graph which showed the relationship between the intensity | strength of the emitted light of the electromagnetic wave source which concerns on the modification of Embodiment 1 of this invention, the detection sensitivity of a detection part, and a wavelength. It is a block diagram of the spectrometer which concerns on Embodiment 2 of this invention. It is the graph which showed the relationship between the intensity | strength of the emitted light of the electromagnetic wave source which concerns on Embodiment 2 of this invention, the intensity | strength of return light, and the detection sensitivity of a detection part, and a wavelength. It is the graph which showed the time change of the drive current of the light emitting element of the electromagnetic wave source which concerns on Embodiment 2 of this invention, and the detection signal of a spectroscopic sensor. It is a block diagram of the spectrometer which concerns on Embodiment 3 of this invention. It is the graph which showed the relationship of the intensity | strength of the emitted light of the electromagnetic wave source which concerns on Embodiment 1 of this invention, the detection sensitivity of a detection part, and a wavelength.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. However, the configuration described in this embodiment is merely an illustrative example, and is not intended to limit the scope of the present invention only to that unless otherwise specified. In the drawings described below, components having the same function are denoted by the same reference numerals, and repeated description thereof is omitted.

<Spectroscopic measurement device>
FIG. 1 is a block diagram showing a configuration of a spectroscopic measurement apparatus according to this embodiment.

  The spectroscopic measurement apparatus 10 according to this embodiment irradiates a certain measurement target with emitted light (first electromagnetic wave) from an electromagnetic wave source, and detects return light (second electromagnetic wave) from the measurement target with respect to the emitted light. Thus, it is used for the spectroscopic measurement of the measurement object 1 (detection object). The arrows represent the emitted light emitted from the electromagnetic wave source and the return light from the measurement object. Here, the return light may be detected not only in the reflection direction as shown in FIG. 1 but also in the transmission direction or another direction. As shown in FIG. 1, the spectroscopic measurement apparatus 10 includes an electromagnetic wave source 11, a detection unit 13, and a calculation unit 17.

  The electromagnetic wave source 11 includes a light emitting element 12 that is a light source for emitting outgoing light to the measuring object 1 outside the spectrometer 10. The light emitting element 12 is a light source having a wavelength component suitable for the spectroscopic measurement of the measurement target 1, and for example, a light emitting diode can be preferably used, but is not limited thereto.

  Next, a fluorescence measurement method for the measurement object 1 using the spectrometer 10 will be described. First, as an excitation process, emitted light is emitted from the electromagnetic wave source 11 toward the measurement object 1 through a window (not shown) provided on the outer wall of the spectrometer 10. The measurement object 1 is a substance that emits fluorescence, scattered light, and the like in response to light irradiation. Through the excitation process, return light including fluorescence, scattered light, reflected outgoing light, and the like is generated from the measurement target 1. As a detection step, at least a part of the return light is detected by the detection unit 13 through a window (not shown) provided on the outer wall of the spectroscopic measurement device 10, whereby return light including fluorescence and scattered light can be measured.

  In the above description, the electromagnetic wave source 11 and the detection unit 13 are described as being integrated as the spectroscopic measurement device 10, but each may be configured to be installed separately.

  The detection unit 13 has a function of detecting at least a part of the return light returning from the measurement object 1 irradiated with the emitted light, converting it into an electrical signal, and outputting the electrical signal to the calculation unit 17. Based on the received electrical signal, the calculation unit 17 calculates the intensity of the electromagnetic wave incident on the detection unit 13 for each wavelength. From this calculation result, the physical property of the measuring object 1 can be estimated. In addition, although the calculation part 17 has mentioned the structure formed in the inside of the spectrometer 10 in this embodiment, it is not restricted to this. For example, the spectroscopic measurement device 10 may include an electromagnetic wave source 11 and a detection unit 13, and the calculation unit 17 may be an external device connected to the spectroscopic measurement device 10.

<Detector>
Next, the detection part of this embodiment is demonstrated using FIG.

  FIG. 2 is a schematic diagram showing the configuration of the detection unit 13, where FIG. 2A is a top view of the detection unit 13, and FIG. 2B is a part of the spectroscopic sensor 13 a provided in the detection unit 13. It is the expanded perspective view.

  As shown in FIG. 2A, the detection unit 13 includes at least one spectroscopic sensor that is different for each wavelength band. In FIG. 2A, spectral sensors 13a and 13b are shown as an example. As shown in FIG. 2B, the spectroscopic sensor 13 a includes an optical filter 14 and a detector 16. The spectroscopic sensor 13a detects return light returning from the measurement object 1 irradiated with the emitted light, and a wavelength range from a wavelength longer than the shortest wavelength of the emitted light to a wavelength longer than the longest wavelength of the emitted light. Has detection sensitivity. The optical filter 14 has a periodic structure that transmits return light having at least some wavelengths among the return light. As an example, the optical filter 14 has a plurality of holes 15 two-dimensionally formed with a predetermined period. The spectroscopic sensors 13 a and 13 b are connected so that signals can be transmitted to the calculation unit 17.

  In the present embodiment, the optical filter 14 is a plasmon filter as an example. The plasmon filter is a metal thin film having a hole array formed with a period of several hundred nanometers as the periodic structure, and transmits only electromagnetic waves near a specific wavelength band by surface plasmon resonance only in a specific wavelength band. It is an optical filter. Since the optical filter 14 is formed immediately above the detector 16 (on the light incident side), the spectroscopic sensor 13a can detect only an electromagnetic wave having a specific wavelength band that passes through the optical filter 14 out of the return light. .

  One of the differences between the spectroscopic sensors 13a and 13b is that the periodic structures of the hole arrays of the optical filters provided on the respective detectors are different. Thereby, the wavelength bands of electromagnetic waves that can be detected by the spectral sensors 13a and 13b are different from each other. Further, in the spectral sensors 13a and 13b, the number of holes 15 provided in each optical filter is also different.

  In the plasmon filter, since the transmittance of a specific wavelength band depends on the number of hole arrays to be formed, it can be seen that the plasmon filters of the spectroscopic sensors 13a and 13b have different transmittance heights in a specific wavelength band. However, in the periodic structure of the optical filter 14, the length of the period corresponds to about half of the wavelength. Therefore, when it is desired to detect an electromagnetic wave having a long wavelength, the area becomes large even if the number of hole arrays is the same. Except for the differences described above, the spectroscopic sensors 13a and 13b have the same configuration and function. Note that the detection sensitivity of the spectroscopic sensors 13 a and 13 b in a specific wavelength band depends on the product of the transmittance of the optical filter 14 and the detection sensitivity of the detector 16.

  The light incident on the detection unit 13 is detected by the spectroscopic sensors 13a and 13b, and signals are respectively generated. For this reason, the detection sensitivity of the entire detection unit 13 can be considered as the sum of the detection sensitivities of the spectroscopic sensors 13a and 13b.

  In the present embodiment, the detection unit 13 includes a spectroscopic sensor including a plurality of optical filters 14 that transmit electromagnetic waves in different wavelength ranges and a plurality of detectors 16 provided for each of the plurality of optical filters 14. It has, but is not limited to this. For example, a spectroscopic sensor in which an optical filter 14 in which a hole array having a plurality of types of periods is formed on one detector 16 may be provided. In this case, if the detector 16 can separately detect the periodic structure of the optical filter 14, spectroscopic measurement is possible.

  In addition, in the present embodiment, the detection unit 13 includes a spectroscopic sensor including the optical filter 14 formed as a metal film on the detector 16, but is not limited thereto. For example, the optical filter 14 can be an appropriately replaceable cartridge that is attached to the detector 16. As a result, the optical filter 14 mounted on the detector 16 can be replaced depending on the wavelength range to be detected.

  For example, the optical filter 14 of the spectral sensor 13b in FIG. 2A can be used by replacing it with an optical filter 14 having the same periodic structure as the optical filter 14 of the spectral sensor 13a. By doing so, it is possible to realize the detection unit 13 that can detect return light in a plurality of wavelength regions using only the detector 16 of the spectroscopic sensor 13b. Therefore, it contributes to the downsizing of the detection unit 13 and the downsizing of the spectrometer 10.

  In this case, when the filter is replaced as described above, the optical filter 14 having the same periodic structure as the optical filter 14 of the spectral sensor 13a occupies the area of the optical filter 14 of the spectral sensor 13b. It becomes wider than the area of the optical filter 14 of the spectroscopic sensor 13a when 14 is not replaced. For this reason, the number of detection elements for detecting the return light transmitted through the optical filter 14 of the spectroscopic sensor 13a is increased, and the detection sensitivity is improved. Therefore, even if the voltage applied to the light emitting element 12 and the detector 16 is lowered, the same detection sensitivity as that of the spectroscopic sensor 13a can be obtained, which contributes to reduction of power consumption.

The detection unit 13 has been described as a configuration including only the spectral sensor 13a and the spectral sensor 13b illustrated in FIG. 2, but may include a spectral sensor corresponding to another wavelength range. For example, the detection sensitivity shown in FIG. 3 may be obtained by providing a plurality of spectroscopic sensors having detection sensitivity peaks at wavelengths between λ2 and λ3. A plurality of spectroscopic sensors that have detection sensitivity peaks at wavelengths of λ2 or less and λ3 or more may be provided. Which spectral sensor has a peak at which wavelength may be determined from the wavelength dependence of the detection sensitivity of each spectral sensor and the detection sensitivity spectrum required of the spectroscopic measurement device.
<Intensity of outgoing light and sensitivity of detector>
FIG. 3 is a graph showing the intensity of the emitted light emitted from the electromagnetic wave source 11 to the measuring object 1 and the detection sensitivity of the detection unit 13. The solid line in the graph indicates the relationship between the wavelength and intensity of the emitted light, the horizontal axis indicates the wavelength of the emitted light, and the vertical axis indicates the intensity. The broken line in the graph shows the relationship between the wavelength of the return light incident on the detector 13 and the height of the detection sensitivity, the horizontal axis indicates the wavelength of the incident light, and the vertical axis indicates the detection sensitivity of the electromagnetic wave at each wavelength.

  In FIG. 3, λ1 is the peak wavelength of the emitted light from the light emitting element 12, and λ3 is the peak wavelength of the fluorescence and scattered light of the measuring object 1 with respect to the emitted light from the light emitting element 12. λ2 is a wavelength at the bottom of the longer wavelength side of the emitted light from the light emitting element 12, that is, a wavelength longer than λ1 and shorter than the longest wavelength of the emitted light. The scattered light targeted for detection in the present invention is scattered light having a wavelength different from the wavelength of the emitted light, and corresponds to, for example, Raman scattered light (inelastic scattered light). The Raman scattered light includes Stokes light having a wavelength longer than that of the outgoing light and anti-Stokes light having a wavelength shorter than that of the outgoing light. The example shown in FIG. 3 is applicable to Stokes light. However, the spectrometer 10 according to the present embodiment may target anti-Stokes light. Further, as a configuration for detecting Stokes light and anti-Stokes light, several types of periodic structures (detection elements) in the range of λ1 ± Δλ may be provided.

  In the detection unit 13 of the present embodiment, the periodic structures of the optical filters 14 formed in the spectroscopic sensor 13a and the spectroscopic sensor 13b are designed to have high detection sensitivity near λ2 and λ3, respectively. Here, the spectroscopic sensor 13a has high detection sensitivity with respect to electromagnetic waves with wavelengths near λ2, but does not have detection sensitivity with respect to electromagnetic waves with other wavelengths. Similarly, the spectroscopic sensor 13b has high detection sensitivity with respect to electromagnetic waves having a wavelength near λ3, but does not have detection sensitivity with respect to electromagnetic waves with other wavelengths.

  Since the detection sensitivity of the detection unit 13 is the sum of the detection sensitivities of the spectroscopic sensors 13a and 13b, as shown in FIG. 3, the detection unit 13 can detect electromagnetic waves from wavelengths near λ2 to wavelengths near λ3. , Has high detection sensitivity. However, it does not have detection sensitivity for electromagnetic waves on the shorter wavelength side near λ2 and on the longer wavelength side near λ3.

  In particular, on the short wavelength side, the detection unit 13 does not have detection sensitivity for electromagnetic waves having a wavelength shorter than λ1. This is because the detection unit 13 does not include a spectroscopic sensor having an optical filter that transmits an electromagnetic wave having a wavelength shorter than λ1.

  Since the detection unit 13 has detection sensitivity as shown in FIG. 3, the detection unit 13 not only detects fluorescence and scattered light among the return light from the measurement target 1 that has received the light emitted from the electromagnetic wave source 11. A part of the emitted light reflected by the measuring object 1 can also be detected. However, the reflected outgoing light detected by the detection unit 13 is only an electromagnetic wave having a lower wavelength in the wavelength range of the outgoing light, and the peak wavelength λ1 of the outgoing light is not particularly detected.

  Thus, since the detection unit 13 includes the spectroscopic sensor having the optical filter 14 corresponding only to the wavelength range to be detected, the area of the optical filter 14 corresponding to the unnecessary wavelength range can be removed, and the size is reduced. Further, the area of the optical filter 14 corresponding to the wavelength band for which the detection sensitivity is desired to be increased can be increased by the amount of the removed area.

<Saturation of detector>
In general, the fluorescence and scattered light generated from the measurement object 1 are often very weak. For this reason, in order to obtain a stronger signal necessary for the analysis, it is necessary to increase the intensity of the emitted light irradiated to the measuring object 1 to increase the intensity of the fluorescence and scattered light, or to increase the sensitivity of the detector 16. . The intensity of the emitted light can be increased by improving the voltage applied to the electromagnetic wave source 11, that is, the light emitting element 12. Further, the sensitivity of the detector 16 can be increased by improving the voltage applied to the detector 16.

  However, when a large number of photons are incident on the detection element of the detector 16 per unit time, the detector 16 causes the above-described saturation, which causes a problem that the detection operation cannot be performed correctly or the detection element is damaged.

  When the voltage applied to the electromagnetic wave source 11 is increased, not only the fluorescence and scattered light but also the detection intensity of the outgoing light reflected by the measurement object 1 is increased. The reflected outgoing light is generally stronger than fluorescence and scattered light, so when the intensity of the reflected outgoing light increases, the number of photons incident on the spectroscopic sensor corresponding to the wavelength of the reflected light increases significantly, Saturation of the detector 16 is likely to occur. If the voltage applied to the detector 16 is in a range that does not cause saturation, the sensitivity of the detection unit 13 that detects other wavelength ranges is reduced, and weak fluorescence and scattered light cannot be detected. Further, when the voltage applied to the detector 16 is increased, the detection element becomes sensitive and the upper limit of the allowable number of photons per unit time is lowered, so that saturation is likely to occur similarly.

<Effect of this embodiment>
The detection unit 13 of the spectroscopic measurement apparatus 10 according to the present embodiment has higher detection sensitivity for electromagnetic waves on the longer wavelength side than the wavelength range of light emitted from the electromagnetic wave source 11. For this reason, it has a high detection sensitivity with respect to the fluorescence and scattered light which have arisen from the measuring object 1 which received the emitted light and have a wavelength longer than the wavelength of the emitted light.

  The detection unit 13 has detection sensitivity for a wavelength range from a wavelength longer than the shortest wavelength of the emitted light to a wavelength longer than the longest wavelength of the emitted light. That is, the detection unit 13 does not have detection sensitivity with respect to a part of the wavelength range of light emitted from the electromagnetic wave source 11 (near the shortest wavelength). For this reason, even if the outgoing light reflected by the measuring object 1 enters the detection unit 13 without changing its wavelength, the detection unit 13 does not detect a part of the reflected outgoing light. Saturation is less likely to occur. In particular, the detection unit 13 does not detect the electromagnetic wave having the peak wavelength (λ1) of the reflected outgoing light. That is, since the electromagnetic wave having the strongest wavelength in the emitted light is not detected, the saturation of the detector 16 is less likely to occur.

  Thereby, the voltage applied to the electromagnetic wave source 11 or the detector 16 can be increased, and the detection sensitivity of the detection unit 13 with respect to fluorescence and scattered light can be further increased. From this, the spectroscopic measurement apparatus 10 does not employ an expensive and large light source such as a strong gas laser as the electromagnetic wave source 11, but adopts a low-priced and small light source such as a low-intensity light emitting diode. Good detection sensitivity for fluorescence and scattered light.

  In addition, the detection unit 13 of the present embodiment uses the optical filter 14 as means for extracting only the necessary wavelength from the incident return light. Therefore, since it is not necessary to directly shield the detection element of the detector 16 in order to extract only the necessary wavelength, all the detection elements of the detector 16 can be used efficiently, and the detector 16 can be made small. Good detection sensitivity can be obtained. From this, since the detection part 13 can be reduced in size, it leads to size reduction of the spectroscopic measurement apparatus 10 whole.

  The detection unit 13 preferably has detection sensitivity at a wavelength shorter than the longest wavelength of the light emitted from the electromagnetic wave source 11. In particular, it has detection sensitivity with respect to an electromagnetic wave in a wavelength region having a low intensity in the wavelength range of emitted light, in other words, in a wavelength region corresponding to the skirt in the intensity distribution with respect to the wavelength. This means that the detection unit 13 can detect a part of the outgoing light reflected by the measurement object 1. For this reason, as long as the measurement object 1 is irradiated with the emitted light from the electromagnetic wave source 11 and the detection operation is performed correctly, the detection unit 13 is always emitted even if no fluorescence and scattered light are generated from the measurement object 1. The detection signal based on the incident light is generated. Therefore, when electromagnetic waves in the wavelength range of fluorescence and scattered light are not detected, the detection unit 13 detects whether there is no generation of fluorescence and scattered light from the measurement object 1 or whether the detection unit 13 is not detecting. It can be easily determined from the presence or absence of a signal.

  In addition, when the measurement is performed a plurality of times, it is necessary to normalize and analyze the obtained fluorescence and scattered light data with reference to the intensity of the emitted light irradiated to the measurement object 1. Since the detection unit 13 can detect a part of the emitted light, the intensity of the electromagnetic wave can be used for data normalization. Therefore, analysis of fluorescence and scattered light data is facilitated.

[Modification]
A modification of the present embodiment will be described below with reference to FIGS. 4 and 5. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals and description thereof is omitted.

<Modification of detection unit>
The detection unit 13 ′ according to this modification can be used by replacing the detection unit 13 of the spectroscopic measurement apparatus 10 of the previous embodiment. The operation method of the spectroscopic measurement apparatus 10 using the detection unit 13 ′ as the detection unit is the same as when the detection unit 13 is used. Here, the case where the detection unit 13 of the spectroscopic measurement apparatus 10 of the previous embodiment is used in place of the detection unit 13 ′ will be described.

  FIG. 4 is a top view of the detection unit 13 ′ of the spectroscopic measurement apparatus according to this modification. The detection unit 13 ′ also has detection sensitivity at λ <b> 1 that is the peak wavelength of the emitted light. FIG. 4 shows, as an example, spectral sensors 13c, 13d, and 13e each including an optical filter 14 and a detector 16 corresponding to λ1 and the same λ2 and λ3 as the detection unit 13.

  Compared with the spectral sensors 13a and 13b corresponding to λ2 and λ3 in the previous embodiment, the periodic structures of the spectral sensors 13d and 13e corresponding to λ2 and λ3 in the present modification are equal to the spectral sensors 13a and 13b, respectively. However, since the light receiving area of the spectroscopic sensor 13d is smaller than the light receiving area of the spectroscopic sensor 13a, it can be seen that the spectroscopic sensor 13d has lower detection sensitivity in the corresponding detection wavelength region than the spectroscopic sensor 13a. Furthermore, compared with the detection unit 13, the detection unit 13 ′ has a spectral sensor corresponding to λ1 in which an optical filter 14 having a shorter period than the periodic structure of the optical filter 14 of the spectral sensors 13a and 13b is formed. 13c is added. Except for the above differences, the spectroscopic sensors 13c, 13d, and 13e have the same configuration and function as the spectroscopic sensors 13a and 13b of the previous embodiment.

  In this modification, the detection unit 13 ′ has been described as a configuration including only the spectral sensors 13 c, 13 d, and 13 e illustrated in FIG. 4, but a spectral sensor corresponding to another wavelength range may be provided. For example, a plurality of spectroscopic sensors having detection sensitivity peaks at wavelengths between λ1 and λ2 and between λ2 and λ3 may be provided so as to achieve detection sensitivity as shown in FIG. A plurality of spectroscopic sensors having a detection sensitivity peak at a wavelength of λ3 or more may be provided.

<Detection sensitivity to peak wavelength>
FIG. 5 is a graph showing the intensity of the emitted light emitted from the electromagnetic wave source 11 to the measuring object 1 and the detection sensitivity of the detection unit 13 ′. The solid line in the graph indicates the relationship between the wavelength and intensity of the emitted light, the horizontal axis indicates the wavelength of the emitted light, and the vertical axis indicates the intensity. The broken line in the graph shows the relationship between the wavelength of the return light incident on the detector 13 'and the height of the detection sensitivity, the horizontal axis indicates the wavelength of the incident light, and the vertical axis indicates the detection sensitivity of the electromagnetic wave at each wavelength. .

  In FIG. 5, λ1 is the peak wavelength of the emitted light. The optical filter 14 formed in the spectroscopic sensor 13c is designed so that the peak wavelength of the transmitted electromagnetic wave is λ1. Further, λ2 and λ3 represent peak wavelengths of electromagnetic waves that pass through the optical filter 14 formed in the spectral sensors 13d and 13e, respectively. λ2 is longer than λ1 and is included in the emission wavelength region of the electromagnetic wave source 11. In addition, λ3 is longer than λ2, and is included in the wavelength range of fluorescence and scattered light from the measurement object 1.

  The detection unit 13 ′ has a spectroscopic sensor 13 c that can detect an electromagnetic wave having a wavelength of λ1. However, since the detector 16 of the spectroscopic sensor 13c has fewer detection elements than the detectors 16 of the spectroscopic sensors 13a and 13b, the detection sensitivity of the spectroscopic sensor 13c is also low. For this reason, the detection sensitivity of the detection unit 13 ′ shown in FIG. 5 is slightly higher than the detection sensitivity of the detection unit 13 of FIG. However, the detection unit 13 ′ has detection sensitivity at a wavelength longer than the shortest wavelength in the wavelength range of the emitted light.

  The detection sensitivity of the detection unit 13 ′ shown in FIG. 5 is different from the detection sensitivity of the detection unit 13 of FIG. 3 because the spectral sensors 13c, 13d, and 13e corresponding to the respective wavelengths included in the detection unit 13 ′. This is because the number of detection elements and the wavelength dependence of the sensitivity of the detector 16 are different.

  As described above, the detection unit 13 ′ can detect an electromagnetic wave from a wavelength longer than the shortest wavelength in the wavelength range of the emitted light to a wavelength exceeding λ3, which is a wavelength longer than the longest wavelength in the wavelength range of the emitted light. It is. However, the detection unit 13 ′ has high detection sensitivity for wavelengths longer than the wavelength range of the emitted light.

  The detection unit 13 ′ of the present modification has high detection sensitivity for electromagnetic waves on the longer wavelength side than the wavelength range of the light emitted from the electromagnetic wave source 11. For this reason, it has the high detection sensitivity with respect to the fluorescence and scattered light which were produced from the measuring object 1 which received the emitted light and have a wavelength higher than the wavelength of the emitted light.

  Further, the detection unit 13 ′ does not have high detection sensitivity in the wavelength range of light emitted from the electromagnetic wave source 11, and does not have detection sensitivity at all for some wavelength ranges. In particular, the detection unit 13 ′ has detection sensitivity with respect to the peak wavelength of light emitted from the electromagnetic wave source 11, but the detection sensitivity is very low. That is, the detection unit 13 ′ has higher detection sensitivity for a longer wavelength than the longest wavelength of the emission wavelength region of the electromagnetic wave source 11 than the detection sensitivity for the emission wavelength region of the electromagnetic wave source 11. For this reason, even if the outgoing light reflected from the measurement object 1 without changing the wavelength is incident on the detection unit 13 ′, saturation of the detector 16 is less likely to occur for the same reason as in the previous embodiment.

  Furthermore, as described above, the detection unit 13 ′ has detection sensitivity with respect to the peak wavelength of the emitted light from the electromagnetic wave source 11, and therefore detects the intensity of the reflected light with the peak wavelength of the emitted light. Can do. For this reason, it is possible to efficiently detect both reflected light and fluorescence when it is desired to examine the surface state and the internal state of the measuring object 1 together.

  Similarly to the previous embodiment, the detection unit 13 ′ detects a low-intensity wavelength region of the outgoing light from the electromagnetic wave source 11, in other words, an electromagnetic wave in a wavelength region corresponding to the base in the intensity distribution with respect to the wavelength. And has detection sensitivity. For this reason, the detection result of the reflected outgoing light can be used for confirmation of detection operation and normalization of detection data.

  How long the detection sensitivity of the detectors 13 and 13 'is longer than the shortest wavelength of the emitted light may be determined as follows, for example.

  The detection sensitivity in the range from the shortest wavelength of the emitted light to the wavelength of the fluorescence or scattered light to be detected is dλ, and the return light intensity detected by the detection unit 13 is Iλ, and the wavelength of the fluorescence or scattered light to be detected is detected. If the sensitivity is d and the intensity of the fluorescence or scattered light to be detected is I, the fluorescence or scattered light to be detected can be sufficiently detected if d × I is equal to or greater than dλ × Iλ.

  On the other hand, in order to use dλ × Iλ for normalization of detection intensity, a certain level of signal intensity is required. For example, the detection current of the detection unit 13 corresponding to dλ × Iλ is several times the dark current. It only has to be above.

  Since these conditions depend on the detection sensitivity, that is, the number (area) of the hole array of the optical filter 14 corresponding to the wavelength λ, it is necessary to consider the size of the detection unit 13.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

<Electromagnetic wave source having two light emitting elements>
FIG. 6 is a block diagram showing the configuration of the spectrometer according to the present embodiment.

  The spectroscopic measurement device 20 according to the present embodiment is different from the spectroscopic measurement device 10 of the previous embodiment in that an electromagnetic wave source 21 having two light emitting elements is provided instead of the electromagnetic wave source 11. Repeated description of other similar configurations and functions is omitted.

  The electromagnetic wave source 21 is a light source for irradiating the measuring object 1 outside the spectroscopic measurement apparatus 20 with emitted light, and the light emitting element 22a (first light emitting element) and the light emitting element 22b (second light emitting element). Have The wavelength range (first emission wavelength range) of the emitted light (first emission light) emitted from the light emitting element 22a is different from the wavelength range (second emission wavelength range) of the emission light (second emission light) emitted from 22b. ing. Here, the fact that the wavelength ranges are different means that they do not match each other, and the wavelength ranges of the emitted light may partially overlap. The electromagnetic wave source 21 can cause the light emitting elements 22a and 22b to individually emit light, and can emit outgoing light from only one or both of the light emitting elements.

  Next, a fluorescence measurement method for the measurement object 1 using the spectrometer 20 will be described. First, as an excitation process, emitted light from at least one of the light emitting element 22a or the light emitting element 22b is emitted from the electromagnetic wave source 21 toward the measurement object 1 through a window (not shown) provided on the outer wall of the spectrometer 20. To do. The measurement object 1 is a substance that emits fluorescence, scattered light, and the like in response to light irradiation. Through the excitation process, return light including fluorescence, scattered light, reflected outgoing light, and the like is generated from the measurement target 1. As a detection step, at least a part of the return light is detected by the detection unit 13 through a window (not shown) provided on the outer wall of the spectroscopic measurement device 20, whereby return light including fluorescence and scattered light can be measured.

  In the present embodiment, a light source having a relatively narrow emission wavelength range such as a blue light emitting diode as the light emitting element 22a and a light source having a wide emission wavelength range such as a white light emitting diode as the light emitting element 22b are taken as an example. However, the present invention is not limited to this as long as the light emitting wavelength regions of the two light emitting elements are different.

<Intensity of two outgoing lights and sensitivity of detection part>
FIG. 7 is a graph showing the intensity of the outgoing light emitted from the electromagnetic wave source 21 to the measuring object 1, the intensity of the returning light from the measuring object 1, and the detection sensitivity of the detection unit 13. FIG. 7A is a graph showing the relationship between the intensity of the emitted light from the light emitting element 22a and the intensity and wavelength of the return light with respect to the emitted light. The solid line represents the emitted light, and the broken line represents the returned light. FIG. 7B is a graph showing the relationship between the intensity of the emitted light from the light emitting element 22b and the intensity and wavelength of the return light with respect to the emitted light. The solid line represents the emitted light and the broken line represents the returned light. (C) of FIG. 7 is a graph which shows the relationship between the detection sensitivity of the detection part 13 of this embodiment, and a wavelength.

  In FIG. 7, λ1 is a peak wavelength of the emitted light from the light emitting element 22a, and λ2 is a peak generated by adding the intensities of fluorescence and scattered light with the peak wavelengths of the emitted light from the light emitting elements 22a and 22b as excitation light. The wavelength, λ3, is the peak wavelength of fluorescence and scattered light using excitation light with light having a wavelength on the longer wavelength side of the light emitted from the light emitting element 22b. Note that the fluorescence and scattered light with respect to the light emitted from the light emitting element 22a have no intensity at the wavelength of λ3.

  In the detection unit 13 of the present embodiment, the periodic structure of the optical filter 14 is designed so as to have high detection sensitivity near λ2 and λ3. The detection sensitivity of the detection unit 13 is a detection sensitivity range from a wavelength longer than the shortest wavelength in the wavelength range of the emitted light from the light emitting element 22a to a wavelength longer than the longest wavelength in the wavelength range of the emitted light from the light emitting element 22a. There are two detection sensitivity ranges, a detection sensitivity range from a wavelength longer than the shortest wavelength in the wavelength range of the emitted light of the light emitting element 22b to a wavelength longer than the longest wavelength of the wavelength range of the emitted light of the light emitting element 22b. doing.

  In the detection sensitivity region on the low wavelength side, the detection unit 13 has high detection sensitivity at λ2, but does not have detection sensitivity in a part of the wavelength region of the emitted light of the light emitting element 22a. For this reason, the saturation of the detector 16 is less likely to occur for the same reason as described above, and the voltage applied to the electromagnetic wave source 21 and the detector 16 can be increased, so that the fluorescence and scattered light corresponding to the wavelength of λ2 can be increased. Good detection sensitivity.

  In the detection sensitivity region on the long wavelength side, the detection unit 13 has high detection sensitivity at λ3, but does not have detection sensitivity in a part of the wavelength region of the emitted light of the light emitting element 22b. For this reason, the saturation of the detector 16 is less likely to occur for the same reason as described above, and the voltage applied to the electromagnetic wave source 21 and the detector 16 can be increased, so that the fluorescence and scattered light corresponding to the wavelength of λ3 can be increased. Good detection sensitivity.

  In particular, when the wavelength range of the emitted light is wide like the light emitting element 22b, various types of fluorescence of the measuring object 1 can be excited, while the wavelength range of the emitting light and the fluorescence wavelength from the measuring object 1 overlap, and the light emitting element 22b. When the voltage applied to is increased, it becomes difficult to detect the fluorescence from the measurement target 1, but the number of spectral sensors (area of the optical filter 14) is changed according to the wavelength band of the detection sensitivity of the detection unit 13 as in this embodiment. Thus, the electromagnetic wave source 21 includes a plurality of light emitting elements 22 having different wavelength ranges, so that a desired wavelength can be detected with high sensitivity as described below. Further, when there are light emitting elements having emission wavelength ranges that overlap each other, a light emitting element having only an emission wavelength range that excites the fluorescence wavelength that overlaps the wavelength range of emitted light may be prepared. Thereby, the fluorescence wavelength which overlaps with the wavelength range of emitted light can be detected with high sensitivity.

  As described above, the spectroscopic measurement apparatus 20 according to the present embodiment can perform spectroscopic measurement with a good detection sensitivity even for a plurality of fluorescence and scattered light having different wavelength ranges.

<Multiple fluorescence measurement method>
Hereinafter, a spectroscopic measurement method for a plurality of fluorescence and scattered light having different wavelength ranges will be described in detail with reference to FIG.

  FIG. 8 is a graph showing temporal changes of the drive currents of the light emitting elements 22a and 22b of the electromagnetic wave source 21 and the detection signals of the spectroscopic sensor in the present embodiment.

  8A to 8E show the drive current that flows through the light emitting elements 22a and 22b when only the light emitting element 22a or only the light emitting element 22b is caused to emit light alternately in the electromagnetic wave source 21, and the detection unit 13. It shows how the detection signal output from the spectroscopic sensor changes with time. 8A and 8B are the drive currents of the light emitting element 22a and the light emitting element 22b, respectively, and FIGS. 8C and 8E are the detection signals of λ1 to λ3 in the spectroscopic sensor of the detection unit 13, respectively. It is a graph showing each time change.

  When only the light emitting element 22a emits light, fluorescence and scattered light corresponding to λ2 are generated, so that a detection signal of λ2 is detected as shown in FIG. 8D. At this time, as shown in FIG. 8E, the detection signal of λ3 is not generated. On the other hand, when only the light emitting element 22b emits light, fluorescence and scattered light corresponding to λ2 and λ3 are generated, so that detection signals of λ2 and λ3 are detected as shown in FIGS. Has been.

  At this time, the light emitting element 22a and the light emitting element 22b have different light emission intensities, and the intensity of the emitted light from the light emitting element 22b is lower. However, when the light emitting element 22b emits light, reflected light of λ2 is also detected. Therefore, the detection signal of λ2 when only the light emitting element 22b emits light is higher than the detection signal of λ2 when only the light emitting element 22a emits light. As described above, by alternately causing the light emitting elements 22a and 22b to emit light, the detection signals of λ2 and λ3 can be obtained while being changed with time.

  Thus, when only the light emitting element 22a or only the light emitting element 22b is made to emit light alternately, the light emission time of each light emitting element can be shortened as much as possible, leading to a reduction in power consumption and a reduction in deterioration of the light emitting element. It leads to doing. For example, when a blue light emitting diode is used as the light emitting element 22a and a white light emitting diode in which a phosphor excited by blue light is sealed in a resin is used as the light emitting element 22b, when measuring only the fluorescence emitted from the blue light emitting diode, Since only the light emitting diode needs to emit light, the deterioration of the resin of the white light emitting diode is reduced, and the lifetime of the white light emitting diode can be extended.

  Next, (f) to (j) in FIG. 8 show driving currents flowing through the light emitting elements 22a and 22b and detection when the light emitting element 22a is blinked in the electromagnetic wave source 21 while the light emitting element 22b emits light. It shows how the signal changes over time. 8 (f) and 8 (g) are drive currents of the light emitting element 22a and the light emitting element 22b, respectively, and FIGS. 8 (h) to 8 (j) are detection signals of λ1 to λ3 in the spectroscopic sensor of the detection unit 13, respectively. It is a graph showing each time change.

  Since the light emitting element 22b always emits light, fluorescence and scattered light corresponding to λ3 are always generated. Therefore, as shown in (j) of FIG. 8, the detection signal of λ3 is detected constantly regardless of time. In addition to this, when the light emitting element 22a further emits light, fluorescence and scattered light corresponding to λ2 are generated, so that the detection signal of λ2 is strongly detected as shown in FIG. At this time, since the two light emitting elements emit light at the same time, the detection signal of λ2 becomes stronger than when only the light emitting element 22a emits light. In this manner, the detection signal of λ2 can be acquired while continuing to check the detection signal of λ3.

  As described above, when the light emitting element 22a is blinked while the light emitting element 22b is caused to emit light, when both the light emitting elements emit light, the intensity of the emitted light can be increased, so that the detection signal becomes stronger, The S / N ratio is improved.

  In the present embodiment, the measurement method is not limited to always causing the light emitting element 22b to emit light, and the light emitting element 22b may emit light intermittently as long as the light emitting elements 22a and 22b emit light simultaneously at least once. Good.

  As described above, the detection unit 13 of the present embodiment can perform good detection on fluorescence and scattered light in a plurality of different wavelength ranges. For this reason, the spectroscopic measurement device 20 can analyze, for example, the state of the surface of the measurement target from components other than the fluorescence including reflected light and the state inside the measurement target from the components of the fluorescence at a time.

  For example, the return light of λ2 when the light emitting element 22a is irradiated on the measuring object 1 and the light returned from the light emitting element 22b when the measuring object 1 is irradiated may be compared. When the measurement target 1 is irradiated with the light emitting element 22a, only fluorescence components are detected. When the light emission element 22b is irradiated with the measurement target 1, fluorescence and reflected light components are detected. By comparing, the fluorescence and reflected light components can be separated and analyzed. As described above, since there is an overlapping portion and a non-overlapping portion in the wavelength range of light emission of the light emitting element 22a and the light emitting element 22b, various analyzes on the measurement object 1 are possible.

  In the present embodiment, when a white light emitting diode in which a blue light emitting diode is used as the light emitting element 22a and a white light emitting diode in which a phosphor excited by blue light is encapsulated in a resin is used, the spectrum that excites the fluorescence of the white light emitting diode. It is preferable to use a blue light emitting diode having the same component as the light emitting element 22a. With the above-described configuration, the spectrum of the blue light that is the excitation source to be measured does not change regardless of whether the two light emitting elements emit light alternately or simultaneously, so that the fluorescence detection result can be easily analyzed.

  For example, a semiconductor laser may be employed as the light emitting element 22a of the present embodiment. In this case, since the intensity can be made stronger than that of the light emitting diode, the fluorescence and scattered light to be measured can be made stronger.

[Embodiment 3]
The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

<An electromagnetic wave source having three or more light emitting elements>
FIG. 9 is a block diagram showing the configuration of the spectroscopic measurement apparatus according to this embodiment.

  The spectroscopic measurement device 30 according to the present embodiment is different from the spectroscopic measurement devices 10 and 20 of the previous embodiment in that an electromagnetic wave source 31 having three light emitting elements is provided instead of the electromagnetic wave sources 11 and 21. is there. Repeated description of other similar configurations and functions is omitted.

  The electromagnetic wave source 31 includes light emitting elements 32 a, 32 b, and 32 c that are light sources for emitting outgoing light to the measurement object 1 outside the spectroscopic measurement device 30. The wavelength ranges of the emitted light emitted from the light emitting elements 32a, 32b, and 32c are different from each other. In addition, the light emission wavelength regions of at least two of these light emitting devices have wavelength regions that do not overlap each other. The electromagnetic wave source 31 can individually emit these light emitting elements, and can emit outgoing light from at least one light emitting element.

  The electromagnetic wave source 31 emits outgoing light toward the measuring object 1 from a window (not shown) provided on the outer wall of the spectrometer 30. In addition, the said window may be provided with two or more for every light emitting element, and only one may be provided as a common window.

  In the present embodiment, the configuration in which the electromagnetic wave source 31 includes three light emitting elements is described. However, the configuration is not limited thereto, and the electromagnetic wave source 31 may include four or more light emitting elements. The spectroscopic measurement method using the spectroscopic measurement device 30 is not different from the case where the spectroscopic measurement device 20 is used.

<Intensity of three outgoing lights and sensitivity of detection part>
FIG. 10 is a graph showing the intensity of outgoing light emitted from the electromagnetic wave source 31 to the measuring object 1 and the detection sensitivity of the detection unit 13. FIG. 10A shows the intensity of the emitted light and the detection sensitivity of the detector 13 when a light source having a relatively narrow emission wavelength region such as the light emitting element 12 is used for the light emitting elements 32a, 32b, and 32c. It is a graph which shows a relationship, A solid line represents the emitted light and a broken line represents the detection sensitivity of the detection part 13. FIG. FIG. 10B is a graph showing the relationship between the intensity of emitted light and the detection sensitivity of the detection unit 13 when the light emitting element 32a is a light source having a relatively wide emission wavelength range such as the light emitting element 22b. The solid line represents the emitted light, and the broken line represents the detection sensitivity of the detection unit 13.

  As can be seen from FIGS. 10A and 10B, in the present embodiment, the detection unit 13 is designed to have detection sensitivity at positions in the detection ranges 1 to 3 that are different from each other and do not overlap. .

  FIG. 10A shows an example in which a light source having a relatively narrow emission wavelength region such as the light emitting element 12 is used for the light emitting elements 32a, 32b, and 32c. As shown in FIG. 10A, the light emitting elements 32a, 32b, and 32c have different emission wavelength ranges that do not overlap each other.

  At this time, the detection range 1 is shorter than the shortest wavelength of the light emitted from the light emitting element 32b from a part of the light emission wavelength region of the light emitting element 32a, that is, the wavelength between the shortest wavelength and the longest wavelength of the light emitted from the light emitting element 32a. In wavelength. For this reason, in the detection range 1, out of the return light from the measurement target 1, a part of the reflected light emitted from the light emitting element 32a and at least a part of the fluorescence and scattered light from the measurement target 1 with respect to the output light are detected. Is done. In addition, the reflected light emitted from the light emitting element 32b is not detected.

  Similarly, the detection range 2 is a wavelength shorter than the shortest wavelength of the light emitted from the light emitting element 32c, from the wavelength between the shortest wavelength and the longest wavelength of the light emitted from the light emitting element 32b. For this reason, in the detection range 2, of the return light from the measurement target 1, a part of the reflected light emitted from the light emitting element 32b and at least a part of the fluorescence and scattered light from the measurement target 1 with respect to the output light are detected. Is done. In addition, the reflected light emitted from the light emitting element 32c is not detected.

  The detection range 3 is on the long wavelength side from the wavelength between the shortest wavelength and the longest wavelength of the light emitted from the light emitting element 32c. For this reason, in the detection range 3, of the return light from the measurement object 1, a part of the reflected light emitted from the light emitting element 32c and at least a part of the fluorescence and scattered light from the measurement object 1 with respect to the emitted light are detected. Is done.

  Therefore, the detection unit 13 of the present embodiment detects only the return light with respect to the emitted light from one light emitting element in each detection range. That is, each detection range and the light emitting element can be associated with each other one to one. Furthermore, since the peak range of the light emitting element 32 is not included in the detection range, the detection unit 13 that is less likely to generate saturation can be realized as described above. Thereby, the spectroscopic measurement apparatus 30 can measure fluorescence and scattered light in a plurality of wavelength ranges at a time with good detection sensitivity.

  In FIG. 10B, a light source having a relatively narrow emission wavelength range such as the light emitting element 12 is used for the light emitting elements 32b and 32c, and a light source having a relatively wide emission wavelength range such as the light emitting element 22b is used for the light emitting element 32a. An example of using is shown. As shown in FIG. 10B, the light emitting elements 32a and 32b and the light emitting element 32c have different emission wavelength ranges that do not overlap with each other, but the light emitting element 32a and the light emitting element 32b have different emission wavelength ranges. Some overlap.

  At this time, the detection range 1 is in the wavelength region from the wavelength between the shortest wavelength and the longest wavelength of the emitted light of the light emitting element 32b to the long wavelength side. For this reason, in the detection range 1, out of the return light from the measurement target 1, a part of the reflected light emitted from the light emitting element 32b and at least a part of the fluorescence and scattered light from the measurement target 1 with respect to the output light are detected. Is done.

  Similarly, the detection range 2 is in a wavelength range from a wavelength between the shortest wavelength and the longest wavelength of the light emitted from the light emitting element 32a to a wavelength shorter than the shortest wavelength of the light emitted from the light emitting element 32c. For this reason, in the detection range 2, of the return light from the measurement target 1, a part of the reflected light emitted from the light emitting element 32a and at least a part of the fluorescence and scattered light from the measurement target 1 with respect to the output light are detected. Is done. In addition, the reflected light emitted from the light emitting element 32c is not detected.

  The detection range 3 is in the wavelength region from the wavelength between the shortest wavelength and the longest wavelength of the light emitted from the light emitting element 32c to the long wavelength side. For this reason, in the detection range 3, of the return light from the measurement object 1, a part of the reflected light emitted from the light emitting element 32c and at least a part of the fluorescence and scattered light from the measurement object 1 with respect to the emitted light are detected. Is done.

  Therefore, in the detection ranges 2 and 3, the detection unit 13 of the present embodiment detects only the return light with respect to the emitted light from one light emitting element. That is, each detection range and the light emitting element can be associated with each other one to one. Further, the detection unit 13 does not detect the outgoing light on the long wavelength side among the plurality of outgoing lights in each detection range. Also in the detection range 1, only a part of the reflected light emitted from the light emitting element 32b is detected. For this reason, similarly to the reason described above, it is possible to realize the detection unit 13 in which saturation is less likely to occur. Thereby, the spectroscopic measurement apparatus 30 can measure fluorescence and scattered light in a plurality of wavelength ranges at a time with good detection sensitivity.

  At this time, the measurement may be performed by alternately emitting light from the light emitting element 32b and at least one of the light emitting elements 32a or 32c. In this case, the light emission time of each light emitting element can be shortened as much as possible, leading to a reduction in power consumption and a reduction in deterioration of the light emitting element. Alternatively, measurement may be performed by blinking the light emitting element 32b while at least one of the light emitting elements 32a or 32c is caused to emit light. In this case, since the intensity of the emitted light can be increased, the detection signal becomes stronger and the S / N ratio is improved.

  As mentioned above, although several embodiment was illustrated and demonstrated, you may combine the structure demonstrated in these embodiment. Also, the wavelength range and detection range of the emitted light may be combined with those described in some embodiments.

[Summary]
The spectroscopic measurement apparatus according to the first aspect of the present invention includes an electromagnetic wave source and a detection unit, the electromagnetic wave source irradiates a first electromagnetic wave on a measurement target, and the detection unit includes an optical filter and a detector. At least one spectroscopic sensor is provided, the second electromagnetic wave returning from the measurement object irradiated with the first electromagnetic wave is detected, and the wavelength longer than the shortest wavelength of the first electromagnetic wave is longer than the longest wavelength of the first electromagnetic wave. It has detection sensitivity for a wavelength range up to a wavelength.

  According to the above configuration, since the spectroscopic sensor of the detection unit includes the optical filter, a detection unit including the spectroscopic sensor that detects an electromagnetic wave only in the vicinity of a necessary wavelength without directly shielding the detection element can be realized. Thereby, it leads to size reduction of a detection part.

  Moreover, the wavelength of the 2nd electromagnetic wave which a detection part can detect is longer than the shortest wavelength of a 1st electromagnetic wave. Accordingly, the detection sensitivity of the detection unit is set so as not to detect a part of the first electromagnetic wave reflected from the detection target without changing the wavelength. As a result, even if the first electromagnetic wave reflected by the detection target or the like is incident on the detection unit, saturation of the detector of the spectroscopic sensor provided in the detection unit is difficult to occur, so the voltage applied to the electromagnetic wave source and the detection unit It becomes easy to raise. For this reason, since it becomes easy to obtain detection sensitivity even if it employ | adopts an electromagnetic wave source with weak intensity | strength, it leads to the price reduction and size reduction of an electromagnetic wave source.

  “To a wavelength longer than the longest wavelength of the first electromagnetic wave” means that the detection unit can detect the second electromagnetic wave having a peak wavelength longer than the longest wavelength of the first electromagnetic wave. The second electromagnetic wave returning from the measurement object includes an electromagnetic wave such as fluorescence emitted from the measurement object excited by the first electromagnetic wave, or scattered light scattered by the measurement object. The peak wavelength of such fluorescence or scattered light is longer than the peak wavelength of the first electromagnetic wave.

  In the spectrometer according to aspect 2 of the present invention, in the aspect 1, the detection unit may have detection sensitivity at a wavelength shorter than the longest wavelength of the first electromagnetic wave.

  In general, the intensity of the second electromagnetic wave depends on the intensity of the first electromagnetic wave irradiated to the measurement object. For this reason, when the second electromagnetic wave is measured a plurality of times, in order to compare a plurality of measurement results, it is necessary to normalize the intensity of the second electromagnetic wave with reference to the intensity of the first electromagnetic wave. According to said structure, since a detection part can detect at least one part of the electromagnetic wave of the wavelength range of a 1st electromagnetic wave, it standardizes a measurement result using the detection result of the wavelength range of a 1st electromagnetic wave. This makes it easy to analyze the measurement results.

  Further, according to the above configuration, when the second electromagnetic wave is not detected, whether the second electromagnetic wave is not generated from the measurement object or whether the detection unit is not performing the detection operation in the first place. It can be easily determined from the presence or absence of detection of electromagnetic waves in the wavelength region.

  In the spectrometer according to aspect 3 of the present invention, in the above aspect 1 or 2, the detection unit is longer than the longest wavelength in the emission wavelength range of the electromagnetic wave source, rather than the detection sensitivity of the electromagnetic wave source in the emission wavelength range. The detection sensitivity with respect to the wavelength may be higher.

  In the above configuration, the second electromagnetic wave may include the first electromagnetic wave reflected by the measurement target. When the reflected first electromagnetic wave enters the detection unit, in particular, when the first electromagnetic wave having the peak wavelength enters the detection unit, the detector of the spectroscopic sensor provided in the detection unit is likely to cause saturation.

  According to said structure, since the sensitivity with respect to a 1st electromagnetic wave can be lowered | hung, even if the 1st electromagnetic wave of a peak wavelength injects into a detection part, the influence of the 1st electromagnetic wave of a peak wavelength can be reduced. For this reason, it becomes easy to raise the applied voltage of an electromagnetic wave source and a detector, and it leads to the improvement of the detection sensitivity of a 2nd electromagnetic wave.

  The spectroscopic measurement device according to aspect 4 of the present invention is the aspect 1 to 3, wherein the optical filter may have a periodic structure that transmits electromagnetic waves having at least some wavelengths among the second electromagnetic waves.

  According to said structure, the detection part can detect the electromagnetic wave which permeate | transmits an optical filter among 2nd electromagnetic waves. That is, the optical filter does not need to disperse the optical path of the second electromagnetic wave, and can sort the second electromagnetic wave incident on the optical filter along the same optical path into an electromagnetic wave to be detected and an electromagnetic wave to be excluded. Therefore, the optical filter according to the present invention can be downsized as compared with the optical filter that needs to disperse the optical path of the second electromagnetic wave, and thus the detection unit can be downsized.

  The spectroscopic measurement device according to aspect 5 of the present invention is the aspect 1 to 4, in which the electromagnetic wave source includes a plurality of light emitting elements having different emission wavelength ranges, and the spectroscopic sensor emits electromagnetic waves in different wavelength ranges. You may consist of the some optical filter which permeate | transmits, and a detector.

  According to the above configuration, it becomes possible to detect return light (corresponding to the second electromagnetic wave) with respect to outgoing light (corresponding to the first electromagnetic wave) of a plurality of wavelengths, so that the response of the measurement object to each outgoing light is measured in detail can do. Thereby, for example, the characteristic of the reflected light corresponding to the light emitted from one light emitting element is measured, and the characteristic of the fluorescence emitted when the measurement object is excited by the light emitted from the other light emitting element is measured. It is possible to realize a spectroscopic measurement apparatus capable of various measurements.

  In the spectroscopic measurement device according to aspect 6 of the present invention, in the aspect 5, each emission wavelength region of at least two light emitting elements among the plurality of light emitting elements has a wavelength region that does not overlap with each other, and the detection unit May include the above-described wavelength regions that do not overlap with each other, and may have detection sensitivity that does not overlap with the emission wavelength region on the longer wavelength side among the emission wavelength regions of the at least two light-emitting elements.

  According to said structure, each light emission wavelength range of a some light emitting element can be made to respond | correspond one by one with each detection wavelength range of a detection part which does not mutually overlap. Furthermore, since the detection unit does not detect electromagnetic waves in the wavelength region on the longer wavelength side among the light emission wavelength regions of the plurality of light emitting elements in each detection wavelength region, it is possible to realize a spectroscopic measurement device that is less likely to generate saturation.

  The spectrometric measurement device according to aspect 7 of the present invention is the aspect 5, wherein at least two light emitting elements among the plurality of light emitting elements have light emission wavelength ranges that overlap each other, and the detection unit includes the overlap. It may have detection sensitivity for a wavelength range longer than the wavelength between the shortest wavelength and the longest wavelength of the emission wavelength range on the short wavelength side of the emission wavelength range.

  According to the above configuration, since there are a plurality of light emitting elements having light emission wavelength ranges that overlap each other, the intensity of excitation light of fluorescence or scattered light can be increased by the amount of the plurality of light emitting elements. In particular, when the wavelength range of the emitted light of one light emitting element is wide, various types of fluorescence can be excited while the wavelength range of the emitted light overlaps with the fluorescence wavelength from the measured object. When the voltage applied to is increased, it becomes difficult to detect fluorescence from the measurement target. However, when there is a light emitting element having an emission wavelength range that overlaps with each other as in this embodiment, a light emitting element having an emission wavelength range of only a wavelength portion that excites a fluorescence wavelength that overlaps with the wavelength range of the emitted light. By preparing, the fluorescence wavelength which overlaps with the wavelength range of the emitted light can be detected with high sensitivity.

  The fluorescence measurement method according to Aspect 8 of the present invention is a fluorescence measurement method using the spectroscopic measurement apparatus according to Aspects 1 to 7, and an excitation step of irradiating the measurement object with the first electromagnetic wave from the electromagnetic wave source; And a detection step of detecting return light from the measurement object generated through the excitation step by the detection unit.

  According to the above method, it is possible to measure the return light including the light emitted when the measurement target is excited and the light reflected by the measurement target using a small and inexpensive device. Of the return light, the light emitted by excitation is useful for examining the internal state of the measurement target, and the reflected light is useful for examining the state of the surface of the measurement target.

  A fluorescence measurement method according to Aspect 9 of the present invention is a fluorescence measurement method using the spectroscopic measurement device according to Aspects 5 to 7, wherein the first emission wavelength as the emission wavelength region among the plurality of light emitting elements. An excitation step of irradiating the measurement object with emitted light from at least one of a first light emitting element having a wavelength range and a second light emitting element having a second emission wavelength range different from the first emission wavelength range, and the excitation step And a detecting step of detecting return light generated from the measurement object by the detection unit.

  According to said structure, the return light from the measuring object with respect to several emitted light can be measured using a small and cheap apparatus.

  The fluorescence measurement method according to aspect 10 of the present invention is the fluorescence measurement method according to aspect 9 described above, wherein in the excitation step, irradiation of the first emitted light from the first light emitting element and irradiation of the second emitted light from the second light emitting element are performed. And may be performed alternately.

  According to said structure, since irradiation of 1st emitted light and irradiation of 2nd emitted light are not performed simultaneously, the time when a voltage is applied to each light emitting element is shortened. For this reason, the power consumption of each light emitting element can be suppressed low. Moreover, since the light emission time of each light emitting element is shortened, deterioration of each light emitting element can be prevented and the lifetime can be extended.

  The fluorescence measurement method according to aspect 11 of the present invention is the fluorescence measurement method according to aspect 9 or 10 described above, wherein in the excitation step, irradiation of the first emitted light from the first light emitting element and second emitted light from the second light emitting element are performed. Irradiation may be performed at least at the same time.

  According to the above configuration, since the measurement object is irradiated with a plurality of outgoing lights at the same time, the outgoing light intensity is increased and the detection signal is increased, so that the S / N ratio is improved and the detection sensitivity is improved.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

DESCRIPTION OF SYMBOLS 1 Measurement object 10,20,30 Spectrometer 11,21,31 Electromagnetic wave source 12,22a, 22b, 32a, 32b, 32c Light emitting element 13 Detection part 14 Optical filter 15 Hall 16 Detector 17 Calculation part

Claims (5)

An electromagnetic wave source and a detection unit;
The electromagnetic wave source irradiates the measurement object with the first electromagnetic wave,
The detection unit includes at least one spectroscopic sensor including an optical filter and a detector, detects a second electromagnetic wave returning from the measurement object irradiated with the first electromagnetic wave, and detects the second electromagnetic wave from the shortest wavelength of the first electromagnetic wave. A spectroscopic measurement device having a detection sensitivity for a wavelength range from a long wavelength to a wavelength longer than the longest wavelength of the first electromagnetic wave.   The spectroscopic measurement apparatus according to claim 1, wherein the detection unit has detection sensitivity at a wavelength shorter than a longest wavelength of the first electromagnetic wave.   The detection part according to claim 1 or 2, wherein the detection unit has a detection sensitivity for a long wavelength higher than a longest wavelength in a light emission wavelength range of the electromagnetic wave source than a detection sensitivity for the light emission wavelength range of the electromagnetic wave source. The spectroscopic measurement apparatus described.   The said optical filter has a periodic structure which permeate | transmits the electromagnetic wave of at least one part wavelength among said 2nd electromagnetic waves, The spectrometer of any one of Claim 1 to 3 characterized by the above-mentioned. The electromagnetic wave source comprises a plurality of light emitting elements having emission wavelength ranges different from each other,
The spectroscopic measurement apparatus according to claim 1, wherein the spectroscopic sensor includes a plurality of optical filters that transmit electromagnetic waves in different wavelength ranges and a detector.

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