Spectroscopic measurement device

Abstract

A spectrometric device according to an aspect of the present invention includes: a frame constituting an outer cover; a base plate fixed to the frame with a prescribed interval above a bottom surface of the frame; a spectrometric section including a diffraction grating, a detection section, and an optical system, and fixed to an optical system base plate, the diffraction grating dispersing wavelengths of a light to be measured, the detection section detecting the light dispersed in wavelength by the diffraction grating, and the optical system guiding the light to be measured to the diffraction grating and / or guiding the light dispersed in wavelength by the diffraction grating to the detection section; a plurality of vibration absorbing sections having a vibration absorbing effect and fixed to the optical system base plate with respect to the base plate; and an electrical circuit section including at least an electrical circuit receiving an output based on the detection section, and disposed in a space between the bottom surface and the base plate. Thus, a spectrometric device having excellent vibration resistance, impact resistance, and a small size and a high space saving property can be provided.

Description

TECHNICAL FIELD

[0001] The present application relates to a spectrometer. BACKGROUND

[0002] As one of the spectrometers, a multi-channel spectrometer disclosed in Non-Patent Literature 1 or the like is known. The general multi-channel spectrometer includes a light-splitting section that wavelength-disperses measured light inputted through an optical fiber or the like, and a detection section such as a linear sensor that detects the wavelength-dispersed light over a prescribed wavelength range at substantially the same time (hereinafter, the light-splitting section and the detection section will be collectively referred to as "light-splitting / detection section"). In the multi-channel spectrometer disclosed in Non-Patent Literature 1, as the light-splitting section, a Czerny-Turner type spectrometer using a diffraction grating is used. Such a multi-channel spectrometer is mainly used to measure a spectrum of luminescence, absorption, reflection, or the like at substantially real time.

[0003] In the multi-channel spectrometer, in order to improve performance such as wavelength accuracy or wavelength resolution, it is necessary to use a linear sensor having a small pixel size as the detection section, or to lengthen an optical path length of the wavelength-dispersed light from the diffraction grating to the linear sensor. In the case where such a structure for improving performance is adopted, a slight variation or deviation in relative positional relationship of optical elements due to thermal expansion or vibration or the like becomes a factor of accuracy degradation.

[0004] In the apparatus described in Patent Literature 1, in order to prevent vibration generated in a power transformer arranged in a frame of the apparatus from being transmitted to the light-splitting / detection section via the frame, a vibration-proof material such as a silicon polymer is arranged between a bottom panel that is a part of the frame and an optical system base that mounts optical parts in the frame. By the vibration-proof material, vibration is prevented from being transmitted from the frame to the optical system base. Further, in the apparatus, an electrical system member such as an electrical circuit that processes a signal detected by the detection section is arranged in the frame in a horizontal direction apart from the optical system base, and a partition wall is arranged standing between the two. By the partition wall, heat generated by the electrical system member is prevented from being transmitted to the optical system base.

[0005] [Related Art Documents]

[0006] [Patent Literature]

[0007] Patent Literature 1: Japanese Patent Laid-Open No. 11-264764

[0008] [Non-Patent Literature]

[0009] Non-Patent Literature 1: "PMA-12 Multi-Channel Spectrometer Series", [online], [retrieved on February 3, 2020], Hamamatsu Photonics K.K., the Internet <URL: https: / / www.hamamatsu.com / resources / pdf / sys / SDSS0008J_PMA12.pdf> SUMMARY

[0010] [Problems to be Solved by the Invention]

[0011] However, in the device described in Patent Literature 1, only relatively small vibrations such as vibrations caused by a power transformer are considered. For example, at the time of assembly or conveyance of the device, a large external force can sometimes be applied to the frame body, but in the device, external forces such as large vibrations or impacts applied from the outside to the frame body are not addressed, and in the spectrometric detection section, the positional relationship of the optical elements can deviate, or in the worst case, breakage can occur. Moreover, in general, if such a large external force is to be addressed, there is a problem that the size of the device becomes large and a large installation area is required.

[0012] The present application was made to solve such a problem, and its main object is to provide a spectrometric measurement device that has high resistance to vibrations or impacts from the outside, is small in size, and is space-saving.

[0013] [Means for Solving the Problems]

[0014] A spectrometric measurement device according to an aspect of the present application, which was made to solve the above-described problem, includes:

[0015] a frame body that constitutes an outer housing;

[0016] a base plate that is fixed to the frame body with a prescribed interval above a bottom panel of the frame body;

[0017] a spectrometric detection section that includes a diffraction grating that wavelength-disperses measured light, a detection section that detects light that has been wavelength-dispersed by the diffraction grating, and an optical system that guides measured light to the diffraction grating and / or guides wavelength-dispersed light generated by the diffraction grating to the detection section, and that is fixed to the optical system base plate;

[0018] a plurality of vibration-absorbing sections that have a vibration-absorbing effect and that fix the optical system base plate to the base plate; and

[0019] an electrical circuit section that includes an electrical circuit that receives an output based on the detection section, and that is disposed in a space between the bottom panel and the base plate.

[0020] Here, the vibration absorbing portion can include, for example, a rubber nut and a bolt.

[0021] [Effects of Invention]

[0022] In the spectrometric apparatus of the aspect of the present application, when an impact is applied to the frame from the outside, for example, the impact is transmitted to the base plate via the connecting portion of the frame and the base plate. Also, in the process of the force being transmitted from the base plate to the optical system base plate through the plurality of vibration absorbing portions, the force is absorbed by the vibration absorbing portions. In this way, the base plate has a buffering effect in the path of the external force, and thus, compared to the conventional apparatus, the transmission of the force from the outside to the spectrometric detection portion can be greatly suppressed.

[0023] That is, in the spectrometric apparatus of the aspect of the present application, the spectrometric detection portion and the environment outside the frame are sufficiently separated, and the spectrometric detection portion is less likely to be affected by the external environment. Thus, in the spectrometric apparatus of the aspect of the present application, for example, even if a large external force is applied to the frame at the time of assembly or transportation of the apparatus, the positions of the optical elements in the spectrometric detection portion can be prevented from deviating. Also, even if a vibration is applied to the apparatus from the outside during the execution of the spectrometry, the precision of the measurement result can be suppressed from decreasing. Furthermore, even if a thermal stress is generated in the frame due to a temperature change in the external environment or heat generation of the members arranged inside the frame, the influence thereof can hardly reach the spectrometric detection portion, and thus, the precision of the measurement result can be suppressed from decreasing.

[0024] Also, in the spectrometric apparatus of the aspect of the present application, as the vibration absorbing portion, a member such as a rubber nut, which is inexpensive and suitable for the fixation of members to each other, can be used, and thus, the mechanical strength of the installation of the spectrometric detection portion can be easily ensured. Also, in the spectrometric apparatus of the aspect of the present application, the base plate functions as a member for reinforcing the frame, and thus, the strength of the frame itself can be improved, and the resistance to the impact such as a drop can be improved. Furthermore, in the spectrometric apparatus of the aspect of the present application, a structure in which the electrical circuit portion and the spectrometric detection portion are stacked vertically is adopted, and thus, the installation area of the apparatus can be reduced. Furthermore, in the spectrometric apparatus of the aspect of the present application, the base plate prevents the heat generated in the electrical circuit portion from being transmitted to the optical system base plate. Thus, the decrease in the analysis precision due to the thermal expansion of the optical system base plate or the optical elements themselves can be alleviated. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic longitudinal sectional view of a multi-channel spectrometer as an embodiment of the present application.

[0026] Figure 2is an optical path structure diagram centered on the light-splitting detection section in the multichannel optical splitter of the present embodiment.

[0027] [Explanation of symbols]

[0028] 1: frame

[0029] 1a: bottom panel

[0030] 2: rubber feet

[0031] 3: base plate

[0032] 4: lower space

[0033] 5: electrical circuit section

[0034] 6: light-splitting detection section

[0035] 60: optical fiber

[0036] 61: entrance optical system

[0037] 62: optical splitter

[0038] 620: entrance slit

[0039] 621: first concave mirror

[0040] 622: diffraction grating

[0041] 623: second concave mirror

[0042] 63: detector

[0043] 64: motor

[0044] 7: anti-vibration fixing section

[0045] 8: support

[0046] 9: optical input connector DETAILED DESCRIPTION

[0047] Hereinafter, a multichannel optical splitter as an embodiment of the spectrometric device of the present application will be described with reference to the accompanying drawings.

[0048] Figure 1 is a schematic longitudinal sectional view of the multichannel optical splitter of the present embodiment.

[0049] The multichannel spectrometer has a frame 1 of a substantially rectangular box shape constituting an outer package. A plurality of (e.g., six) rubber feet 2 are attached to the lower surface of a bottom panel 1a that is a part of the frame 1. Inside the frame 1, a base plate 3 is attached at a prescribed distance from the bottom panel 1a and substantially parallel to the bottom panel 1a by screws (not shown) or the like, and the inside of the frame 1 is divided into upper and lower spaces by the base plate 3. Above the base plate 3, a spectrometer detection unit 6 is attached via a plurality of vibration-proof fixing portions 7 having a function of absorbing vibration. That is, the spectrometer detection unit 6 is provided in the upper space inside the frame 1. On the other hand, in the lower space 4 between the bottom panel 1a and the base plate 3, an electrical circuit unit 5 is disposed, which includes an electrical circuit substrate on which various electrical circuit components are mounted, or a power transformer or the like.

[0050] In this example, the vibration-proof fixing portions 7 each include a rubber nut and a bolt. By inserting the rubber nut into a hole provided in the base plate 3 and screwing the bolt inserted into a hole provided in an optical system base plate of the spectrometer detection unit 6 into the screw hole of the rubber nut, the optical system base plate is fixed with respect to the base plate 3. Furthermore, at the attachment positions of the plurality of vibration-proof fixing portions 7, a support 8 that supports the base plate 3 with respect to the bottom panel 1a is provided. That is, the peripheral edge portion of the base plate 3 is fixed with respect to the inner side of the side surface of the frame 1, and is supported from the lower side by the plurality of supports 8. In this example, the vibration-proof fixing portions 7 are provided at three positions, two of the four corners in a rectangular shape in plan view and one position that is a vertex of a substantially isosceles triangle with respect to the two corners. However, as will be described later, the number of vibration-proof fixing portions 7 is not limited thereto.

[0051] Figure 2 is a diagram of an optical path structure centered on the spectrometer detection unit 6 in Figure 1 . The spectrometer detection unit 6 is for measuring the wavelength distribution, i.e., the spectrum, of the light intensity of the measured light, and includes an optical input connector 9 for connecting an external optical fiber for input of the measured light, an optical fiber 60 for guiding the measured light, an incident optical system 61, a spectrometer 62, and a detector 63. As shown in Figure 1 , the optical input connector 9 is separate from the frame 1, and external force or vibration applied to the frame 1 is prevented from being transmitted to the spectrometer detection unit 6 via the optical input connector 9.

[0052] The spectrometer 62 is a Czerny-Turner type spectrometer including an entrance slit 620, a first concave mirror 621, a diffraction grating 622, and a second concave mirror 623. The diffraction grating 622 is rotatable by a motor 64 within a prescribed angle range. The detector 63 is a linear sensor such as a charge coupled device (CCD) linear sensor in which a plurality of light receiving elements are disposed in the wavelength dispersion direction of the diffraction grating 622.

[0053] In the spectrometer 6, the beam splitter 62 and the detector 63 are mounted on the upper surface of the optical system base plate, and the motor 64 that drives the diffraction grating 622 to rotate is mounted on the lower surface of the optical system base plate as shown in FIG. 6. In the base plate 3, an opening having a diameter that is one circle larger than the outer diameter of the motor 64 is provided, and the position of the optical system base plate is determined so that the motor 64 is inserted into the opening. Figure 1

[0054] The operation when measuring the spectrum of light in a wide wavelength range in the multichannel beam splitter of the present embodiment will be described.

[0055] A fiber for inputting the light to be measured is connected to the light input connector 9, and the light to be measured such as laser light is introduced into the apparatus through the fiber. The light to be measured is guided by the fiber 60, and is introduced into the beam splitter 62 through the entrance optical system 61 and the entrance slit 620. In the beam splitter 62, the light to be measured is irradiated onto the first concave mirror 621, and is reflected to advance toward the diffraction surface of the diffraction grating 622. The light to be measured at this time is substantially parallel light.

[0056] The light to be measured that is irradiated onto the diffraction surface of the diffraction grating 622 is wavelength-dispersed, and is sent to the second concave mirror 623. The wavelength-dispersed light that is irradiated onto the second concave mirror 623 is respectively condensed and reflected, and reaches each light-receiving element of the detector 63. In the prescribed wavelength range λ1 to λ2, light of each different wavelength reaches each light-receiving element of the detector 63. The plurality of light-receiving elements respectively output detection signals corresponding to the intensity of the light incident thereon. The detection signals correspond to the spectrum of light in the wavelength range λ1 to λ2.

[0057] When the detection signals in the prescribed wavelength range are obtained in a state where the position (angle) of the diffraction grating 622 is fixed, the control section and the drive circuit included in the electrical circuit section 5 operate the motor 64 to rotate the diffraction grating 622 by a prescribed angle. Then, the angle of the diffraction surface of the diffraction grating 622 with respect to the light to be measured from the first concave mirror 621 changes, and the wavelength range of the wavelength-dispersed light sent from the diffraction grating 622 to the second concave mirror 623 changes. Therefore, in the detector 63, detection signals of light in a wavelength range (for example, λ2 to λ3) different from the wavelength range λ1 to λ2 are obtained.

[0058] In this way, the acquisition of the detection signals obtained by the detector 63 is repeatedly performed while the diffraction grating 622 is rotated by a prescribed angle step by step. Thus, information indicating the spectrum of light in a wide range of wavelengths can be obtained. At the time of acquisition of the detection signals in the detector 63 (at the time of exposure), the position of the diffraction grating 622 is fixed, that is, at the time of acquisition of the detection signals, the motor 64 has stopped, and therefore the influence of vibration due to rotation of the motor 64 does not exist in the detection signals.​

[0059] If a large impact is applied to the frame 1 at the time of assembly of the apparatus or at the time of conveyance or the like, or if the relative positional relationship of the optical elements contained in the spectrometric detection section 6 is shifted due to vibration or thermal stress applied at the time of measurement or the like, a wavelength error or the like can sometimes occur. In contrast, the multichannel spectrometer of the present embodiment adopts the countermeasure described below.

[0060] For example, when an external force such as an impact or vibration is applied to the apparatus from the outside, the frame 1 vibrates, and the bottom panel 1a also vibrates. Therefore, the electrical circuit section 5 fixed to the bottom panel 1a also vibrates. On the other hand, the spectrometric detection section 6 is fixed to the base plate 3 only by the vibration-proof fixing sections 7, and the vibration of the base plate 3 is absorbed by the vibration-proof fixing sections 7, specifically, by the rubber of the rubber nuts. Furthermore, the vibration of the frame 1 is temporarily transmitted to the base plate 3 via the connecting portions of the frame 1 and the base plate 3, and further transmitted from the base plate 3 to the vibration-proof fixing sections 7. In this way, the vibration is attenuated to some extent in the course of the vibration propagation. Therefore, the vibration can be effectively absorbed by the vibration-proof fixing sections 7, and the vibration transmitted to the spectrometric detection section 6 can be suppressed. Thus, the shift in the relative positional relationship of the optical elements due to the external force can be avoided.

[0061] On the other hand, the electrical circuit section 5 generates heat at the time of measurement, and therefore the temperature of the base plate 3 also rises to cause thermal expansion. The change in the distance between the plurality of vibration-proof fixing sections 7 due to the thermal expansion of the base plate 3 is also absorbed by the vibration-proof fixing sections 7, and hardly affects the spectrometric detection section 6. Furthermore, the base plate 3 functions as a partition wall that separates the electrical circuit section 5 from the optical system base plate, and has an effect of blocking heat to some extent. Therefore, the temperature rise of the optical system base plate itself due to the heat from the electrical circuit section 5 can be suppressed. Thus, the shift in the relative positional relationship of the optical elements due to the thermal expansion can also be avoided.

[0062] Furthermore, the plurality of support columns 8 provided between the bottom panel 1a and the base plate 3 have the following effects.

[0063] The spectrometric detection section 6 is fixed to the base plate 3 by the plurality of vibration-proof fixing sections 7, and the weight of the spectrometric detection section 6 is relatively large. Therefore, for example, when a large impact is applied due to dropping of the apparatus or the like, the load caused by the spectrometric detection section 6 is concentrated on the vibration-proof fixing sections 7, and the base plate 3 is easily deformed.

[0064] On the other hand, in the multichannel spectrometer of the embodiment, the support post 8 is disposed on substantially the same line as the anti-vibration fixing portion 7, that is, on substantially the same axis as the anti-vibration fixing portion 7. Since the support post 8 is thus disposed, when a large load caused by the impact on the spectrometric portion 6 is applied to the base plate 3 from the anti-vibration fixing portion 7, the load is quickly received by the support post 8 directly below. Therefore, the degree of deformation of the base plate 3 can be greatly reduced compared with the case where the support post 8 is not provided, and compared with the case where the support post 8 is provided at a position not on the same axis as the anti-vibration fixing portion 7. Further, at the position of the support post 8, the interval between the base plate 3 and the bottom plate la is limited by the support post 8, and thus the deformation of the bottom plate la when an impact is applied is also suppressed.

[0065] Thus, in the multichannel spectrometer of the embodiment, even in the case where a large impact is applied, the deformation of the frame 1 or the base plate 3 can be suppressed, and the failure or damage of the device can be reduced.

[0066] Further, in the embodiment, the support post 8 is disposed on the same axis as the anti-vibration fixing portion 7, but the positional relationship between the anti-vibration fixing portion 7 and the support post 8 can not be entirely on the same axis. Specifically, as long as the support post receives a large load applied to the base plate 3 from the anti-vibration fixing portion 7, it is sufficient, for example, that the contact portion of the anti-vibration fixing portion 7 and the contact portion of the support post 8 with the base plate 3 partially overlap when viewed from the upper surface. Thus, the support post 8 can be regarded as being substantially disposed on the same axis as the anti-vibration fixing portion 7. Further, in the embodiment, the support post 8 can be appropriately added at a position where there is no anti-vibration fixing portion 7.

[0067] Further, in the embodiment, three anti-vibration fixing portions 7 are provided, but the number of anti-vibration fixing portions 7 is not limited thereto, and the positions where the anti-vibration fixing portions 7 are provided can be appropriately determined. Here, a rubber nut is used as the anti-vibration fixing portion 7, but in general, the anti-vibration characteristics (forced vibration frequency-support load) of the rubber nut are specified, and the anti-vibration characteristics differ depending on the material or size of the rubber nut. Therefore, it is desirable to determine the number of anti-vibration fixing portions 7 in accordance with the anti-vibration characteristics of the rubber nut used, so that the load applied to one rubber nut becomes appropriate.

[0068] Further, the embodiment is one example of the present application, and it should be clear that even if appropriately modified, corrected, or added within the scope of the gist of the present application, it is included in the claims of the present application.

[0069] For example, the embodiment is a multichannel spectrometer, but the present application can of course be applied to a spectrometric device of various structures or modes other than this.

[0070] [Various Modes]

[0071] Those skilled in the art will appreciate that the exemplary embodiments described are specific examples of the following aspects.

[0072] (First) An aspect of the spectrometric apparatus of the present application includes:

[0073] a frame body constituting an exterior;

[0074] a base plate fixed to the frame body with a prescribed interval above the bottom panel of the frame body;

[0075] a spectrometric detection section including a diffraction grating that wavelength-disperses the measured light, a detection section that detects the light that has been wavelength-dispersed by the diffraction grating, and an optical system that guides the measured light to the diffraction grating and / or guides the wavelength-dispersed light produced by the diffraction grating to the detection section, and fixed to the optical system base plate;

[0076] a plurality of vibration-absorbing sections that have a vibration-absorbing effect and fix the optical system base plate to the base plate; and

[0077] an electrical circuit section including an electrical circuit that receives an output based on the detection section, and disposed in the space between the bottom panel and the base plate.

[0078] The spectrometric apparatus according to the first aspect can prevent positional deviation of each optical element in the spectrometric detection section, and the like, even if a large external force is applied to the frame body, for example, at the time of assembly of the apparatus. Also, even if vibration is applied to the apparatus from the outside during execution of the spectrometry, the precision of the measurement result can be suppressed from decreasing. Furthermore, even if thermal stress is generated in the frame body due to temperature changes in the external environment or heat generation of the members disposed inside the frame body, and the like, the influence thereof can hardly reach the spectrometric detection section, and thus the precision of the measurement result can be suppressed from decreasing.

[0079] Also, the spectrometric apparatus according to the first aspect functions as a member that reinforces the frame body, and thus the strength of the frame body itself can be improved, and the resistance to impact such as dropping can be improved. Furthermore, since the electrical circuit section and the spectrometric detection section are stacked in the up-down direction, the installation area of the apparatus can be reduced. Furthermore, the base plate prevents heat generated in the electrical circuit section from being transmitted to the optical system base plate. Thus, the decrease in the analysis precision due to thermal expansion of the optical system base plate or the optical elements themselves can be alleviated.

[0080] (Second) In the spectrometric apparatus according to the first aspect, the vibration-absorbing sections can include rubber nuts and bolts.

[0081] According to the spectrometric apparatus of the second aspect, as the vibration absorbing portion, for example, a rubber nut or the like, which is inexpensive and suitable for fixing of members to each other, can be used, and thus it is easy to ensure the mechanical strength of mounting of the light detecting portion.

[0082] (Third aspect) The spectrometric apparatus according to the first or second aspect can further include a support disposed between the bottom panel and the base panel in the same axis as the vibration absorbing portion for each of the plurality of vibration absorbing portions.

[0083] Here, the "same axis" means that, in a plan view, the contact portion of the vibration absorbing portion with the base panel and the contact portion of the support with the base panel partially overlap.

[0084] In the spectrometric apparatus of the third aspect, for example, when a large impact such as a fall of the apparatus is applied to the apparatus, the load caused by the light detecting portion, which is concentrated from the vibration absorbing portion to the base panel, is received by the support. Thus, deformation of the base panel and the bottom panel can both be suppressed, and thus it is possible to reduce occurrence of damage or malfunction of the apparatus.

[0085] (Fourth aspect) In the spectrometric apparatus according to any one of the first to third aspects, the diffraction grating can be rotatable freely within a prescribed angle range, and the electric circuit portion can include a motor for rotating the diffraction grating.

[0086] According to the spectrometric apparatus of the fourth aspect, by rotating the diffraction grating, it is possible to achieve measurement of a spectrum over a wide range of wavelength.

Claims

1. A spectrophotometer, comprising: The frame constitutes the outer casing; A base plate is fixed relative to the frame, within the frame and above the bottom panel of the frame, at a predetermined interval from the bottom panel; The spectroscopic detection unit includes a diffraction grating, a detection unit, and an optical system. The diffraction grating, the detection unit, and the optical system are fixed relative to a base plate of the optical system. The diffraction grating performs wavelength dispersion on the light to be measured. The detection unit detects the light that has undergone wavelength dispersion using the diffraction grating. The optical system guides the light to be measured to the diffraction grating and / or guides the wavelength-dispersed light generated by the diffraction grating to the detection unit. Multiple vibration-absorbing parts have a vibration-absorbing function and fix the optical system base plate relative to the base plate; A support column, for each of the plurality of vibration absorbing parts, is coaxially disposed between the bottom panel and the base plate, wherein the lower end of the support column abuts against the bottom panel and the upper end of the support column abuts against the base plate. as well as The electrical circuit section includes electrical circuitry for receiving outputs based on the detection section and is disposed within the space between the bottom panel and the base plate.

2. The spectrophotometer according to claim 1, wherein the vibration absorption part comprises a rubber nut and a bolt.

3. The spectrophotometer according to claim 1, wherein the diffraction grating is rotatable within a specified angular range in the wavelength dispersion direction, and the electrical circuit includes a motor for rotating the diffraction grating.

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