Spectrophotometer

Abstract

A spectroscopic measurement device according to an aspect of the present invention comprises: a housing (1) forming an exterior; a base plate (3) that is fixed to the housing at a predetermined interval above a bottom plate (1a) of the housing in the housing; a spectroscopic detection unit (6) which includes a diffraction grating that disperses the wavelength of light to be measured, a detection unit that detects the light of which the wavelength is dispersed by the diffraction grating, and an optical system that introduces, to the diffraction grating, the light to be measured and / or guides, to the detection unit, the light of which the wavelength is dispersed by the diffraction grating, and in which the diffraction grating, the detection unit, and the optical system are fixed to an optical system base plate (6a); a plurality of vibration absorption units (7) that fix the optical system base plate to the base plate while having a vibration absorption action; and an electric circuit unit (5) that includes at least an electric circuit for receiving output from the detection unit and is disposed in a space between the bottom plate and the base plate. Accordingly, provided is a spectroscopic measurement device that has excellent vibration resistance and impact resistance and has a small size, thereby achieving excellent space saving.

Description

Technical Field

[0001] The present invention relates to a spectroscopic measurement device.

Background Art

[0002] As one of spectroscopic measurement devices, a multi-channel spectroscope disclosed in Non-Patent Document 1 or the like is known. A general multi-channel spectroscope includes a spectroscopic unit that disperses measurement light input through an optical fiber or the like in terms of wavelength, and a detection unit such as a linear sensor that detects wavelength-dispersed light over a predetermined wavelength range substantially simultaneously (hereinafter, the spectroscopic unit and the detection unit are collectively referred to as a "spectroscopic detection unit"). In the multi-channel spectroscope disclosed in Non-Patent Document 1, a Czerny-Turner type spectroscope using a diffraction grating is used as the spectroscopic unit. Such a multi-channel spectroscope is mainly used for measuring spectra such as emission, absorption, and reflection substantially in real time.

[0003] In order to improve performance such as wavelength accuracy and wavelength resolution in the above multi-channel spectroscope, it is necessary to use a linear sensor with a small pixel size as the detection unit, or to increase the optical path length of wavelength-dispersed light from the diffraction grating to the linear sensor. When a configuration for improving such performance is adopted, slight fluctuations or displacements in the relative positional relationship of optical elements due to thermal expansion, vibration, or the like become factors causing a decrease in accuracy.

[0004] In the device described in Patent Document 1, in order to prevent vibration generated by a power transformer disposed in the housing of the device from being transmitted to the spectroscopic detection unit through the housing, a vibration-proof material such as a silicon-based polymer is provided between a bottom plate that is a part of the housing and an optical system base installed in the housing to which optical components are attached. This vibration-proof material prevents vibration from being transmitted from the housing to the optical system base. Further, in the above device, an electrical system member such as an electric circuit that processes a signal detected by the detection unit and the optical system base are installed horizontally separated from each other in the housing, and a partition is erected between the two. This partition prevents heat generated by the electrical system member from being transmitted to the optical system base.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the device described in Patent Document 1, only relatively small vibrations such as those caused by the power transformer are considered. For example, when assembling or transporting the device, a large external force may be applied to the housing. However, the above device does not cope with external forces such as large vibrations and impacts applied to the housing from the outside, and there is a risk that the positional relationship of the optical elements may shift in the spectroscopic detection unit, or in the worst case, damage may occur. Also, generally, if an attempt is made to cope with such large external forces, there is a problem that the size of the device increases and a large installation area is required.

[0008] The present invention has been made to solve such problems, and its main object is to provide a spectroscopic measurement device that has high resistance to external vibrations and impacts and is small in size and space-saving.

Means for Solving the Problems

[0009] One aspect of the spectroscopic measurement device according to the present invention made to solve the above problems is a housing forming an exterior, Inside the housing, a base plate fixed to the housing with a predetermined distance from the bottom plate of the housing above the bottom plate of the housing, a diffraction grating that wavelength-disperses the light to be measured, a detection unit that detects the light wavelength-dispersed by the diffraction grating, and an optical system that introduces the light to be measured into the diffraction grating and / or guides the wavelength-dispersed light by the diffraction grating to the detection unit, and a spectroscopic detection unit formed by fixing them to an optical system base plate, a plurality of vibration absorption parts that fix the optical system base plate to the base plate while having a vibration absorption effect, including an electric circuit that receives the output from the detection unit, and an electric circuit unit disposed in the space between the bottom plate and the base plate, is provided.

[0010] Here, the vibration absorption part can include, for example, a washer nut and a bolt.

Advantages of the Invention

[0011] In the spectroscopic measurement device according to the above aspect of the present invention, for example, when an impact is applied to the housing from the outside, the impact is transmitted to the base plate through the connection part between the housing and the base plate. Then, in the process of the force being transmitted from the base plate to the optical system base plate through the plurality of vibration absorption parts, the force is absorbed by the vibration absorption parts. Since the base plate has a buffering effect in the path where the external force propagates in this way, compared with the above conventional device, it is possible to greatly suppress the transmission of the external force to the spectroscopic detection unit.

[0012] That is, in the spectroscopic measurement device of the above aspect according to the present invention, the spectroscopic detection unit and the environment outside the housing are sufficiently separated, and the spectroscopic detection unit is hardly affected by the external environment. Thereby, according to the spectroscopic measurement device of the above aspect according to the present invention, even when a large external force is applied to the housing during, for example, assembly or transportation of the device, displacement of each optical element in the spectroscopic detection unit can be prevented. Further, even when vibration is applied to the device from the outside during the execution of spectroscopic measurement, a decrease in the accuracy of the measurement result can be suppressed. Furthermore, even when thermal stress is generated in the housing due to a temperature change in the external environment or heat generation of a member disposed inside the housing, the influence hardly reaches the spectroscopic detection unit, and a decrease in the accuracy of the measurement result can be suppressed.

[0013] Also, in the spectroscopic measurement device of the above aspect according to the present invention, since a member such as a welnut, which is inexpensive and suitable for fixing members to each other, can be used as the vibration absorption unit, it is easy to ensure the mechanical strength of the attachment of the spectroscopic detection unit. Further, in the spectroscopic measurement device of the above aspect according to the present invention, since the base plate functions as a member for reinforcing the housing, the strength of the housing itself can also be increased, and the resistance to impacts such as dropping can be improved. Furthermore, in the spectroscopic measurement device of the above aspect according to the present invention, since the electric circuit unit and the spectroscopic detection unit are stacked vertically, the installation area of the device can be reduced. Furthermore, in the spectroscopic measurement device of the above aspect according to the present invention, the base plate prevents the heat generated in the electric circuit unit from being transmitted to the optical system base plate. Thereby, a decrease in analysis accuracy due to thermal expansion of the optical system base plate and the optical element itself can also be reduced.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0015] Hereinafter, a multi-channel spectrometer, which is an embodiment of the spectroscopic measurement apparatus according to the present invention, will be described with reference to the accompanying drawings.

[0016] FIG. 1 is a schematic longitudinal sectional view of the multi-channel spectrometer of the present embodiment. This multi-channel spectrometer has a substantially rectangular parallelepiped box-shaped housing 1 that forms an exterior. A plurality (for example, six) of rubber feet 2 are attached to the lower surface of a bottom plate 1a that is a part of the housing 1. Inside the housing 1, a base plate 3 is attached by screws (not shown) or the like at a predetermined distance from the bottom plate 1a and substantially parallel to the bottom plate 1a. The internal space of the housing 1 is partitioned vertically by this base plate 3. On the base plate 3, a spectroscopic detection unit 6 is attached via a plurality of vibration-absorbing anti-vibration fixing parts 7. That is, the spectroscopic detection unit 6 is provided in the upper space inside the housing 1. On the other hand, in the lower space 4 between the bottom plate 1a and the base plate 3, an electric circuit unit 5 including an electric circuit board on which various electric circuit components are mounted, a power transformer, and the like is arranged.

[0017] In this example, each of the anti-vibration fixing parts 7 is composed of a welnut and a bolt. The optical system base plate 6a is fixed to the base plate 3 by inserting a welnut into a hole provided in the base plate 3 and screwing a bolt inserted through a hole provided in the optical system base plate 6a of the spectroscopic detection unit 6 into the screw hole of the welnut and tightening it. Further, at the attachment positions of the plurality of anti-vibration fixing parts 7, support columns 8 that support the base plate 3 with respect to the bottom plate 1a are provided respectively. That is, the base plate 3 is fixed at its peripheral portion to the inner side of the side surface of the housing 1 and is supported from below by a plurality of support columns 8. In this example, the anti-vibration fixing parts 7 are provided at a total of three positions, namely, two of the four rectangular corners in a top view and one position that is the apex of a substantially isosceles triangle with respect to the two corners. However, as will be described later, the number of the anti-vibration fixing parts 7 is not limited to this.

[0018] Figure 2 is an optical path configuration diagram centered on the spectroscopic detection unit 6 in Figure 1. This spectroscopic detection unit 6 measures the wavelength distribution of the light intensity of the light to be measured, that is, the optical spectrum, and includes an optical input connector 9 to which an external optical fiber for the light to be measured is connected, an optical fiber 60 that guides the light to be measured, an incident optical system 61, a spectroscope 62, and a detector 63. As shown in Figure 1, the optical input connector 9 is independent of the housing 1, and it is avoided that external force or vibration applied to the housing 1 is transmitted to the spectroscopic detection unit 6 through the optical input connector 9.

[0019] The spectroscope 62 is a Czerny-Turner type spectroscope and includes 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 within a predetermined angular range by a motor 64. The detector 63 is a linear sensor, for example, a CCD linear sensor, in which a large number of light receiving elements are arranged in the wavelength dispersion direction by the diffraction grating 622.

[0020] In the spectroscopic detection unit 6, the spectroscope 62 and the detector 63 are attached to the upper surface of the optical system base plate 6a, and the motor 64 that rotationally drives the diffraction grating 622 is attached to the lower surface of the optical system base plate 6a as shown in Figure 1. The base plate 3 is provided with an opening having a diameter slightly larger than the outer diameter of the motor 64, and the position of the optical system base plate 6a is determined so that the motor 64 is inserted through the opening.

[0021] The operation when measuring the optical spectrum in a wide wavelength range in the multi-channel spectroscope of this embodiment will be briefly described. An optical fiber for inputting the light to be measured is connected to the optical input connector 9, and the light to be measured such as laser light is introduced into this device through the optical fiber. The light to be measured is guided by the optical fiber 60 and introduced into the spectroscope 62 through the incident optical system 61 and the entrance slit 620. In the spectroscope 62, the light to be measured hits the first concave mirror 621 and is reflected and travels toward the diffraction surface of the diffraction grating 622. The light to be measured at this time is almost parallel light.

[0022] The light to be measured that hits the diffraction surface of the diffraction grating 622 is wavelength-dispersed and sent to the second concave mirror 623. The wavelength-dispersed light that hits the second concave mirror 623 is reflected while being converged respectively and reaches each light-receiving element of the detector 63. Light of different wavelengths within a predetermined wavelength range λ1 to λ2 reaches each light-receiving element of the detector 63. The plurality of light-receiving elements output detection signals corresponding to the intensity of the incident light respectively. This detection signal corresponds to the spectrum of the light in the wavelength range λ1 to λ2.

[0023] When a detection signal in a predetermined wavelength range is obtained with the position (angle) of the diffraction grating 622 fixed, the control unit and the drive circuit included in the electric circuit unit 5 operate the motor 64 to rotate the diffraction grating 622 by a predetermined angle. Then, the angle of the diffraction surface of the diffraction grating 622 with respect to the light to be measured coming 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. For this reason, a detection signal for light in a wavelength range (for example, λ2 to λ3) different from the above wavelength range λ1 to λ2 is obtained by the detector 63.

[0024] In this way, while rotating the diffraction grating 622 step by step by a predetermined angle, the acquisition of the detection signal obtained by the detector 63 is repeated. Thereby, information representing the spectrum of light in a wide wavelength range can be obtained. When acquiring the detection signal by the detector 63 (during exposure), the position of the diffraction grating 622 is fixed, that is, the motor 64 is stopped when acquiring the detection signal, so the detection signal is not affected by the vibration caused by the rotation of the motor 64.

[0025] When a large impact is applied to the housing 1 during the assembly process or transportation of the device, or when vibration, thermal stress, etc. applied during measurement cause the relative positional relationship of the optical elements included in the spectroscopic detection unit 6 to fluctuate or shift, it may cause a wavelength error or the like. In contrast, the following measures are taken in the multi-channel spectroscope of this embodiment.

[0026] For example, when an external force such as impact or vibration is applied to the present device from the outside, the housing 1 vibrates, and the bottom plate 1a also vibrates. Therefore, the electric circuit unit 5 fixed on the bottom plate 1a also vibrates. On the other hand, the spectroscopic detection unit 6 is fixed to the base plate 3 only by the anti-vibration fixing unit 7, and the vibration of the base plate 3 is absorbed by the anti-vibration fixing unit 7, specifically, the rubber of the well nut. Also, the vibration of the housing 1 is once transmitted to the base plate 3 through the connection part between the housing 1 and the base plate 3, and further transmitted from the base plate 3 to the anti-vibration fixing unit 7. In this way, the vibration attenuates to a certain extent during the process of vibration propagation. Therefore, the vibration is effectively absorbed by the anti-vibration fixing unit 7, and the vibration transmitted to the spectroscopic detection unit 6 can be suppressed. Thereby, the fluctuation and deviation of the relative positional relationship of the optical elements due to the external force can be avoided.

[0027] On the other hand, since the electric circuit unit 5 generates heat during measurement, the temperature of the base plate 3 also rises and thermal expansion occurs. The change in the distance between the plurality of anti-vibration fixing units 7 due to the thermal expansion of the base plate 3 is also absorbed by the anti-vibration fixing unit 7, and hardly affects the spectroscopic detection unit 6. Furthermore, the base plate 3 functions as a partition wall separating the electric circuit unit 5 and the optical system base plate 6a, and has an effect of shielding heat to a certain extent. Therefore, the temperature rise of the optical system base plate 6a itself due to the heat from the electric circuit unit 5 can be suppressed. Thereby, the deviation of the relative positional relationship of the optical elements due to thermal expansion can also be avoided.

[0028] Also, the plurality of support columns 8 provided between the bottom plate 1a and the base plate 3 have the following functions. The spectroscopic detection unit 6 is fixed to the base plate 3 by a plurality of anti-vibration fixing units 7, and the spectroscopic detection unit 6 is relatively heavy. Therefore, for example, when a large impact is applied by dropping the present device, the load by the spectroscopic detection unit 6 is intensively applied to the anti-vibration fixing unit 7, and the base plate 3 is easily deformed.

[0029] On the other hand, in the multi-channel spectrometer of this embodiment, the support column 8 is arranged substantially in a straight line with the vibration-proof fixing portion 7, that is, substantially coaxially with the vibration-proof fixing portion 7. Since the support column 8 is arranged in this way, when a large load from the vibration-proof fixing portion 7 is applied to the base plate 3 by the spectroscopic detection portion 6 due to an impact, the load is promptly received by the support column 8 directly below. Therefore, not only when the support column 8 is not provided, but also when compared with the case where the support column 8 is provided at a position non-coaxial with the vibration-proof fixing portion 7, the degree of deformation of the base plate 3 can be significantly reduced. Further, at the position where the support column 8 is present, the distance between the base plate 3 and the bottom plate 1a is regulated by the support column 8, so the deformation of the bottom plate 1a when an impact is applied is also suppressed.

[0030] In this way, in the multi-channel spectrometer of this embodiment, even when a large impact is applied, the deformation of the housing 1 and the base plate 3 is suppressed, and malfunctions and damages of the device can be reduced.

[0031] In the above embodiment, the support column 8 is arranged coaxially with the vibration-proof fixing portion 7. However, the positional relationship between the vibration-proof fixing portion 7 and the support column 8 does not have to be completely coaxial. Specifically, since it is only necessary for the support column to receive the load when a large load is applied from the vibration-proof fixing portion 7 to the base plate 3, for example, in the state seen from above, if a part of the contact portion between the vibration-proof fixing portion 7 and the base plate 3 and the contact portion between the support column 8 and the base plate 3 overlap, it can be regarded that the support column 8 is arranged substantially coaxially with the vibration-proof fixing portion 7. Further, the support column 8 can be appropriately added also at a position where the vibration-proof fixing portion 7 is not present in the above embodiment.

[0032] Also, in the above embodiment, three vibration-proof fixing portions 7 are arranged. However, the number of the vibration-proof fixing portions 7 is not limited to this, and the position where the vibration-proof fixing portion 7 is provided can also be determined appropriately. Here, a wing nut is used as the vibration-proof fixing portion 7. Generally, the vibration-proof characteristics (forced vibration frequency - support load) are defined for the wing nut, and the vibration-proof characteristics vary depending on its material, size, etc. Therefore, it is desirable to determine the number of the vibration-proof fixing portions 7 so that the load applied to one wing nut becomes appropriate based on the vibration-proof characteristics of the wing nut used.

[0033] Further, the above-described embodiment is an example of the present invention, and it is obvious that even if appropriate modifications, corrections, or additions are made within the scope of the gist of the present invention, they are included in the scope of the claims of the present application.

[0034] For example, although the above-described embodiment is a multi-channel spectroscope, it goes without saying that the present invention can be applied to spectroscopic measurement devices with various other configurations and methods.

[0035] [Various aspects] Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following aspects.

[0036] (Item 1) One aspect of the spectroscopic measurement device according to the present invention is a housing forming an exterior, a base plate that is inside the housing, has a predetermined interval from the bottom plate of the housing, and is fixed to the housing, a diffraction grating that wavelength-disperses the light to be measured, a detection unit that detects the light wavelength-dispersed by the diffraction grating, and an optical system that introduces the light to be measured to the diffraction grating and / or guides the wavelength-dispersed light by the diffraction grating to the detection unit, and a spectroscopic detection unit formed by fixing them to an optical system base plate, a plurality of vibration absorption parts that fix the optical system base plate to the base plate while having a vibration absorption effect, including an electric circuit that receives the output from the detection unit, and an electric circuit unit disposed in the space between the bottom plate and the base plate, and is provided with.

[0037] According to the spectroscopic measurement apparatus described in the first aspect, even when a large external force is applied to the housing, for example, during the assembly of the apparatus, it is possible to prevent displacement of each optical element in the spectroscopic detection unit. Also, even when vibration is applied to the apparatus from the outside during the execution of spectroscopic measurement, it is possible to suppress a decrease in the accuracy of the measurement result. Furthermore, even when thermal stress is generated in the housing due to a change in temperature of the external environment or heat generation of a member disposed inside the housing, the influence is less likely to reach the spectroscopic detection unit, and it is possible to suppress a decrease in the accuracy of the measurement result.

[0038] Also, according to the spectroscopic measurement apparatus described in the first aspect, since the base plate functions as a member for reinforcing the housing, the strength of the housing itself can be increased, and the resistance to impacts such as dropping can be improved. Furthermore, since the electric circuit unit and the spectroscopic detection unit are stacked vertically, the installation area of the apparatus can be reduced. Furthermore, the base plate prevents the heat generated in the electric circuit unit from being transmitted to the optical system base plate. Thereby, it is also possible to reduce a decrease in analysis accuracy due to thermal expansion of the optical system base plate and the optical elements themselves.

[0039] (Second aspect) In the spectroscopic measurement apparatus according to the first aspect, the vibration absorption unit may include a wing nut and a bolt.

[0040] According to the spectroscopic measurement apparatus described in the second aspect, since inexpensive wing nuts or the like, which are suitable for fixing members to each other, are used as the vibration absorption unit, it is easy to ensure the mechanical strength of the attachment of the spectroscopic detection unit.

[0041] (Third aspect) The spectroscopic measurement apparatus according to the first or second aspect may further include a support column disposed between the bottom plate and the base plate, coaxially with each of the plurality of vibration absorption units.

[0042] Here, "coaxially" means that in a top view state, a part of the contact portion between the vibration absorption unit and the base plate and a part of the contact portion between the support column and the base plate overlap.

[0043] In the spectroscopic measurement apparatus according to the third aspect, when a large impact is applied to the apparatus, such as the apparatus falling, the column receives the load applied intensively to the spectroscopic detection unit from the vibration absorption unit onto the base plate. Thereby, deformation of both the base plate and the bottom plate can be suppressed, and occurrence of breakage or failure of the apparatus can be reduced.

[0044] (Item 4) In the spectroscopic measurement apparatus according to any one of Items 1 to 3, the diffraction grating is rotatable within a predetermined angular range, and the electric circuit unit may include a motor for rotating the diffraction grating.

[0045] According to the spectroscopic measurement apparatus according to Item 4, by rotating the diffraction grating, it is possible to measure spectra over a wide wavelength range.

Explanation of Signs

[0046] 1... Housing 1a... Bottom plate 2... Rubber feet 3... Base plate 4... Lower space 5... Electric circuit unit 6... Spectroscopic detection unit 60... Optical fiber 61... Incident optical system 62... Spectrometer 620... Incident slit 621... First concave mirror 622... Diffraction grating 623... Second concave mirror 63... Detector 64... Motor 6a... Optical system base plate 7... Vibration-proof fixing part 8... Column 9... Optical input connector

Claims

1. A housing forming an exterior, a base plate within the housing, fixed to the housing with a predetermined interval above the bottom plate of the housing, a diffraction grating that wavelength-disperses the light to be measured, a detection unit that detects the light wavelength-dispersed by the diffraction grating, and an optical system that introduces the light to be measured into the diffraction grating and / or guides the wavelength-dispersed light by the diffraction grating to the detection unit, wherein the diffraction grating, the detection unit, and the optical system are fixed to an optical system base plate to form a spectroscopic detection unit, a plurality of vibration absorption parts that fix the optical system base plate to the base plate while having a vibration absorption effect, for each of the plurality of vibration absorption parts, a support column arranged between the bottom plate and the base plate so that the lower end abuts against the bottom plate and the upper end abuts against the base plate coaxially with the vibration absorption part, including an electric circuit that receives the output from the detection unit, and an electric circuit unit arranged in the space between the bottom plate and the base plate, A spectroscopic measurement device comprising the above.

2. The spectroscopic measurement device according to claim 1, wherein the vibration absorption part includes a nut and a bolt.

3. The spectroscopic measurement device according to claim 1, wherein the diffraction grating is rotatable within a predetermined angular range in the wavelength dispersion direction, and the electric circuit unit includes a motor for rotating the diffraction grating.

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