JP2020085799A - Optical device - Google Patents

Abstract

To suppress influence of heat in a small-sized spectrometry unit.SOLUTION: An optical device includes: a light source for irradiating an object with light; a spectroscope for dispersing reflection light from the object; a housing for housing the light source and the spectroscope; a light source fixing member for fixing the light source to an inner surface of the housing; and a spectroscope fixing member for fixing the spectroscope to the inner surface of the housing. The light source, through the light source fixing member, includes a gap to a first inner surface of the housing to which the light source fixing member is fixed, and is fixed to the first inner surface. The spectroscope, through the spectroscope fixing member, includes a gap to a second inner surface of the housing to which the spectroscope fixing member is fixed, and is fixed to the second inner surface.SELECTED DRAWING: Figure 4

Description

The present invention relates to optical devices.

A spectroscope is an optical device that disperses light into various wavelengths such as UV (Ultra Violet), visible light, near infrared light, and infrared light for spectroscopic analysis and the like. In recent years, the need for on-site spectroscopic analysis not only indoors but also outdoors has increased, and the spectroscopic analysis unit has been downsized in order to be applied to various applications.

As a small spectroscopic analysis unit, a concave diffraction grating that is a spectroscopic element having a light dispersion function and a light condensing function, an array sensor of photodiodes such as Si and InGaAs, an LED (Light Emitted Diode) of a desired wavelength band, and A device including a light source such as a halogen lamp is known.

In the case of a small spectroscopic analysis unit, it is necessary to dispose a light source, a detector, and the like in close proximity, and heat generation of the light source may affect the spectroscopic spectrum acquired. On the other hand, there is disclosed a spectroscopic analysis unit in which a housing is provided in an optical path that guides light from an object to be measured to a semiconductor spectroscopic sensor with a condensing lens (for example, see Patent Document 1).

However, since the spectroscopic analysis unit of Patent Document 1 includes the condenser lens, the spectroscopic analysis unit may be upsized.

The present invention has been made in view of the above points, and an object thereof is to suppress the influence of heat in a small spectroscopic analysis unit.

An optical device according to an aspect of the disclosed technology includes a light source that irradiates an object with light, a spectroscope that disperses reflected light from the object, a housing that houses the light source and the spectroscope, and A light source fixing member that fixes a light source to an inner surface of the housing; and a spectroscope fixing member that fixes the spectroscope to an inner surface of the housing, wherein the light source includes the light source fixing member. The light source fixing member includes a void portion between the light source fixing member and the first inner surface of the housing, and the light source fixing member is fixed to the first inner surface. The spectroscope is fixed to the spectroscope fixing member via the spectroscope fixing member. Is fixed to the second inner surface including a space between the second inner surface of the housing and the second inner surface.

According to the embodiments of the present invention, it is possible to suppress the influence of heat in a small spectroscopic analysis unit.

It is a figure explaining the basic principle of the spectroscopy by the spectrometer concerning an embodiment. It is a figure explaining an example of composition of a flexible region concerning an embodiment, (a) is a side view of a flexible region, and (b) is a top view of a flexible region. It is a figure which shows an example of a structure of the spectrometer which concerns on embodiment, (a) is sectional drawing, (b) is a perspective view. It is a figure which shows an example of a structure of the spectroscopic analysis unit which concerns on 1st Embodiment, (a) is sectional drawing, (b) is the figure which looked at the spectroscopic analysis unit from the direction of the arrow A of (a). Yes, (c) is a diagram of the spectroscopic analysis unit viewed from the direction of arrow B in (a). It is a block diagram which shows an example of the hardware constitutions of the process part which concerns on 1st Embodiment. It is a figure which shows an example of the component which the process part which concerns on 1st Embodiment has by a functional block. It is a figure explaining the fixed position to the inner surface of the housing|casing of a light source fixing member and a spectrometer fixing member. It is a figure explaining an example of composition of a spectrum analysis unit concerning a 2nd embodiment. It is a figure explaining an example of the detection signal by a movable photodetector when rotating the reflection part of a movable part periodically. It is a figure which shows an example of the component which the process part which concerns on 2nd Embodiment has by a functional block.

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be denoted by the same reference numerals, and duplicate description may be omitted.

In the embodiment, a spectroscopic analysis unit will be described as an example of an optical device.

It should be noted that although a solid arrow may indicate the direction in each drawing, the X, Y, and Z directions common to each drawing are shown.

<Basic principle of spectroscopy according to the embodiment>
First, the basic principle of spectroscopy according to the embodiment will be described. FIG. 1 is a diagram illustrating a basic principle of spectroscopy by the spectroscope 100 according to the embodiment.

As shown in FIG. 1, the spectroscope 100 has an entrance slit 1, a concave diffraction grating 2, a movable portion 3, and an exit slit 4. A light ray 40 indicated by a dotted line in the drawing indicates a light ray which enters the spectroscope 100 through the entrance slit 1, propagates, and then exits the spectroscope 100 through the exit slit 4.

The entrance slit 1 is a thin rectangular opening for allowing the light to be separated into the inside of the spectroscope 100, and is a rectangular through hole formed in a plate-shaped metal base made of nickel or the like. is there. The width of the entrance slit 1 in the lateral direction is, for example, several tens to several hundreds μm.

However, the material of the base material is not limited to metal, and may be resin or the like. The entrance slit 1 is not limited to the rectangular opening, and may be a circular opening pinhole or the like.

The light that has entered the spectroscope 100 from the entrance slit 1 enters the concave diffraction grating 2 as divergent light.

The concave diffraction grating 2 is an optical element in which fine lines with equal intervals are formed on the surface of a metal concave mirror. The concave diffraction grating 2 has both the light dispersion function of the diffraction grating and the reflection/condensation function of the concave mirror. The concave diffraction grating 2 diffracts and disperses the incident light, and condenses the dispersed light toward the movable portion 3. Here, light dispersion refers to a phenomenon in which incident light is separated separately for each wavelength.

The base material of the concave diffraction grating 2 is not limited to metal, but may be semiconductor, glass, resin or the like. Further, the fine line formed on the concave diffraction grating 2 may be directly formed on the base material, or may be formed on a layer such as a thin resin provided on the base material.

On the other hand, the movable portion 3 is a MEMS (Micro Electro Mechanical System) mirror in which a reflecting portion 7 having a reflecting surface is integrally formed with an elastic beam portion.

Here, FIG. 2 is a diagram illustrating an example of the configuration of the movable section 3, (a) is a side view of the movable section 3, and (b) is a plan view of the movable section 3.

In the movable portion 3, the reflecting portion 7 is rotatably supported by the substrate 6 via the elastic beam portion 8. The elastic beam portion 8 has a function of a torsion spring, and a driving force is applied from a driving portion (not shown) such as piezoelectric driving, electrostatic driving, or electromagnetic driving to move the reflecting portion 7 to the broken line A- in FIG. 2A is rotated about the axis of A′ in the direction of the one-dot chain line arrow. The rotation is an example of “driving”.

By forming the driving unit of the reflecting unit 7 monolithically on the substrate 6, the reflecting unit 7 can be rotated without using an external driving unit such as a motor, and the movable unit 3 can be downsized.

The material of the substrate 6 is not particularly limited, but is, for example, Si (silicon) or glass. The use of a semiconductor material such as Si for the substrate 6 enables highly precise microfabrication by semiconductor manufacturing technology.

Returning to FIG. 1, the movable portion 3 reflects the dispersed light from the concave diffraction grating 2 toward the exit slit 4. The angle of reflection of the reflected light by the movable portion 3 can be changed by rotating the reflecting portion 7.

The exit slit 4 is a narrow rectangular opening arranged at the image forming position of the dispersed light by the concave diffraction grating 2, and causes the dispersed light by the concave diffraction grating 2 to be emitted to the outside of the spectroscope 100.

Here, the dispersed light from the concave diffraction grating 2 has its image forming position laterally displaced (shifted) according to the wavelength. Therefore, the wavelength of the light passing through the exit slit 4 can be changed by changing the reflection angle at the reflecting portion 7, and thus the light of a desired wavelength of the dispersed light can be selectively emitted from the spectroscope 100. Can be emitted.

The light emitted from the spectroscope 100 is detected by a photodetector such as a Si photodiode, and spectral analysis or the like is performed. The material and shape of the exit slit 4 are the same as those of the entrance slit 1.

By the way, the Rowland circle 5 shown by the broken line in FIG. 1 is a circle having a radius of curvature of the concave surface of the concave diffraction grating 2 as its diameter. The concave diffraction grating 2 is circumscribed on the Rowland circle 5. In other words, the concave diffraction grating 2 is arranged so that the concave surface forms a part of the Rowland circle 5. However, since the radius of curvature of the concave surface of the concave diffraction grating 2 and the diameter of the Rowland circle are the same, the concave surface of the concave diffraction grating 2 and the Rowland circle intersect at only one point in a complete arrangement by the Roland circle (Fig. 1). reference).

By letting light enter the inside of the spectroscope 100 via the entrance slit 1 arranged on the circumference, all the light of each wavelength of the dispersed light by the concave diffraction grating 2 is combined on the circumference of the Rowland circle. Can be made to image.

Further, in the embodiment, since the reflection part 7 of the movable part 3 is rotated to selectively emit the light of the desired wavelength from the emission slit 4, the light of the wavelength corresponding to the rotation of the reflection part 7 is emitted from the emission slit. The exit slit 4 and the movable portion 3 are arranged appropriately so as to pass through 4.

Such arrangement can be determined in advance by optical simulation or the like. Although FIG. 1 shows an example in which the exit slit 4 is arranged at a position deviated from the Rowland circle 5, the exit slit 4 may be arranged on the Rowland circle 5 according to the result of optical simulation or the like. ..

<Structure of spectrometer according to embodiment>
Next, FIG. 3 is a diagram showing an example of the configuration of the spectroscope 100 according to the embodiment, (a) is a cross-sectional view of the spectroscope 100, and (b) is a perspective view of the spectroscope 100. It should be noted that elements having the same functions as those of the constituent elements described with reference to FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and duplicate description will be omitted.

As shown in FIG. 3, the spectroscope 100 has a frame 9 which is a hollow prism having a polygonal cross section. The material of the frame 9 is not particularly limited, but is resin, metal, ceramic or the like. Here, the frame 9 is an example of a “support frame”.

Rectangular openings 9a to 9d for communicating the outside of the frame 9 with the hollow portion are formed at predetermined positions on the surface forming the frame 9.

The entrance slit 1 is arranged at the position of the opening 9a. The light passing through the entrance slit 1 enters the hollow portion of the frame 9 through the opening 9a and propagates toward the opening 9b. The opening 9a is an example of the "third opening".

The entrance slit 1 is fixed to the outer surface of the frame 9. This fixing method may be fixing with an adhesive or fixing by fitting or screwing. This point is the same in the method of fixing the optical element arranged in each aperture described below.

Next, the concave diffraction grating 2 is arranged at the position of the opening 9b, and the concave diffraction grating 2 is fixed to the outer surface of the frame 9. The light that has entered the opening 9 a passes through the opening 9 b and enters the concave diffraction grating 2. The concave diffraction grating 2 diffracts and disperses the incident light to collect the dispersed light toward the opening 9c. The opening 9b is an example of the "first opening".

Next, the movable portion 3 is arranged at the position of the opening 9c, and the movable portion 3 is fixed to the outer surface of the frame 9. The dispersed light from the concave diffraction grating 2 passes through the opening 9c and enters the reflecting section 7 of the movable section 3. The opening 9c is an example of the "second opening".

The light that has entered the reflecting portion 7 of the movable portion 3 is reflected by the reflecting portion 7 toward the opening 9d. Here, the reflecting portion 7 of the movable portion 3 rotates in the direction of the one-dot chain line arrow in FIG. 3A, but since the reflecting portion 7 rotates in the area of the opening 9c of the frame 9, during the rotation. The reflector 7 does not come into contact with the frame 9.

The exit slit 4 is arranged at the position of the opening 9d, and the exit slit 4 is fixed to the outer surface of the frame 9. The light reflected by the reflector 7 passes through the opening 9d and is emitted to the outside of the frame 9 through the emission slit 4. The opening 9d is an example of the "fourth opening".

In the embodiment, the position is adjusted so that the entrance slit 1 is arranged on the Rowland circle 5, and the opening 9a is formed. Further, the position is adjusted so that the concave surface of the concave diffraction grating 2 forms a part of the circumference of the Rowland circle 5, and the opening 9b is formed. By arranging in this way, it is possible to easily adjust the position and inclination of the members such as the entrance slit 1 and the concave diffraction grating 2 fixed to the frame 9.

Further, in the embodiment, the frame 9 having a polygonal cross section is used, and the straight line portion connecting the adjacent vertices of the polygon is continuously connected. In other words, each surface of the frame 9 for fixing members such as the concave diffraction grating 2 and the movable portion 3 is integrally formed. With this configuration, the deformation of the base material such as the frame 9 can be suppressed.

Further, in the embodiment, each member is arranged and fixed on the outer surface of the frame 9. Therefore, a device such as a chip mounter used for surface-mounting electronic components on a printed circuit board can be used for mounting members such as the concave diffraction grating 2 and the movable portion 3.

By using a device such as a chip mounter, the mounted members can be aligned with high accuracy. Further, it is possible to suppress individual differences in each manufactured spectroscope. It is desirable that each surface on which the member is arranged is provided with a tilt correction portion such as an abutting portion or an alignment mark in order to prevent the member from tilting during mounting.

Further, in the embodiment, members such as the concave diffraction grating 2 and the movable portion 3 are not mounted on the primary mounting substrate (carrier member) such as a printed circuit board but are directly mounted on the frame 9. As a result, it is possible to prevent the primary mounting boards from interfering with each other and restricting the close arrangement of the members, and also preventing the miniaturization of the spectroscope from being restricted.

As a comparative example according to the embodiment, a spectroscope may be configured by arranging each member so as to form a frame with a primary mounting board, but in this case, the primary mounting board is accurately arranged. Things will be difficult. Further, since the configuration is such that different substrates are combined, the rigidity is lowered, deformation is generated, and the stability of the spectroscope is impaired.

On the other hand, according to the embodiment, since each member is mounted on the frame 9, each member can be arranged with high accuracy, and the spectroscope can be improved in accuracy. Further, the stability of the spectroscope can be ensured by increasing the rigidity of the spectroscope.

As described above, in the embodiment, it is possible to arrange the optical elements close to each other with good alignment accuracy, and to realize a small spectroscope with high accuracy.

[First Embodiment]
Next, the spectroscopic analysis unit according to the first embodiment will be described. The same components as those in the above-described embodiment may be designated by the same reference numerals and the description thereof may be omitted.

<Structure of the spectroscopic analysis unit according to the first embodiment>
FIG. 4 is a diagram illustrating an example of the configuration of the spectroscopic analysis unit 300 according to the present embodiment, and (a) is a cross-sectional view of the spectroscopic analysis unit 300. Further, (b) is a diagram of the spectroscopic analysis unit 300 viewed from the direction of arrow A in (a), and (c) is a diagram of the spectroscopic analysis unit 300 viewed from the direction of arrow B in (a). 4B and 4C are views seen from the directions of arrows A and B when the portion indicated by the broken line of the spectroscopic analysis unit 300 in FIG. 4A is cut.

The spectroscopic analysis unit 300 has a housing 50 having a window 51, and the housing 50 houses the light source 20, the light source fixing member 21, the spectroscopic unit 200, and the spectroscope fixing member 201. There is.

The light source 20 is a light source that irradiates the target of the spectroscopic analysis outside the housing 50 with light through the window 51, and includes a halogen lamp, an LED, and the like. As the light source 20, a light source that irradiates an object with light in an appropriate wavelength band is selected.

The spectroscopic unit 200 includes the outer frame 10, the spectroscope 100, the spectroscopic detector 14, and the processing unit 15, and reflects the light emitted from the light source 20 from the object outside the housing 50. This is a functional unit for performing spectroscopic analysis by allowing light to enter through the window 51.

As shown in FIG. 4, the outer frame 10 is a prism having a polygonal cross section and a hollow portion 11 inside. A spectroscope 100 is arranged in the hollow portion 11 of the outer frame 10.

As described above, the spectroscope 100 has the entrance slit 1, the concave diffraction grating 2, the movable portion 3, the exit slit 4, and the frame 9. The hollow portion 11 is formed with a surface facing each of the outer surfaces of the frame 9.

Since both side surfaces of the outer frame 10 in the Y direction of FIG. 4 are open, it is possible to insert and fix the spectroscope 100 into the hollow portion 11 from the opened side surfaces.

In the outer frame 10, a taper hole 12 that communicates the outside of the outer frame 10 with the hollow portion 11 is formed on the surface of the spectroscope 100 arranged in the hollow portion 11 that faces the entrance slit 1. The light that enters the spectroscopic unit 200 through the window 51 passes through the tapered hole 12 and is guided to the entrance slit 1.

The taper hole 12 has a taper angle of θ, and the taper angle determines the viewing angle of light incident on the spectroscope 100. The taper hole 12 is formed with a taper angle corresponding to a viewing angle required for the spectroscope 100.

Further, in the outer frame 10, a communication hole 13 for communicating the outside of the outer frame 10 and the hollow portion 11 is formed on the surface of the outer frame 10 that faces the emission slit 4 of the spectroscope 100 arranged in the hollow portion 11. A spectroscopic detector 14 is inserted and fixed in the communication hole 13. The light emitted from the emission slit 4 of the spectroscope 100 enters the spectroscopic detector 14.

The spectroscopic detector 14 may be a Si light receiving element, a Ge (germanium) light receiving element, an InGaAs (indium gallium arsenide) light receiving element, or the like.

The spectral detector 14 is a single-pixel light receiving element. Further, a plurality of detectors such as a Si light receiving element and a Ge light receiving element may be arranged in parallel in a plane facing the emission slit 4. The spectroscopic detector 14 outputs an electric signal according to the received light intensity, and the output electric signal is input to the processing unit 15.

Here, when the entrance slit 1 is arranged on the Rowland circle 5 and the concave surface of the concave diffraction grating 2 is arranged so as to form part of the circumference of the Rowland circle 5, the wavelengths dispersed by the concave diffraction grating 2 are arranged. All the light for each image is formed on the circumference of the Rowland circle 5. Since the image forming position of light shifts laterally for each wavelength, an array type light receiving element such as a line sensor is required to receive the dispersed light for each wavelength at once.

Although a light receiving element such as Ge or InGaAs can be obtained at a relatively low cost as long as it is a light receiving element having a single pixel, it becomes very expensive when it becomes an array type light receiving element. As described above, the arrangement using the Roland circle 5 has the merit of facilitating the arrangement and adjustment of the optical element such as the concave diffraction grating, but has the demerit of requiring an expensive light receiving element and photodetector. ..

In the present embodiment, the reflection angle of the reflecting section 7 of the movable section 3 is changed to selectively emit light of a desired wavelength from the spectroscope 100 among the light dispersed by the concave diffraction grating 2. Therefore, it is possible to receive the light of each wavelength dispersed by the light receiving element of a single pixel without using the array type light receiving element, and it is possible to obtain a spectrum.

As described above, in the present embodiment, the arrangement using the support frame facilitates the arrangement and adjustment of the optical element such as the concave diffraction grating. Further, the movable portion 3 allows the spectroscope to be inexpensively configured by using the light receiving element of a single pixel. In addition, spectroscopic analysis is performed in a wide wavelength band from light in a short wavelength band of about 300 nm where the Si light receiving element has a light receiving sensitivity to light in a long wavelength band of about 2000 nm where a Ge light receiving element or an InGaAs light receiving element has a light receiving sensitivity. be able to.

Further, it is possible to irradiate various spectral analysis objects with light in an appropriate wavelength band from the light source 20, which is suitable for on-site spectroscopic analysis such as outdoors.

<Configuration of processing unit according to the first embodiment>
The processing unit 15 has a function of performing a calculation for obtaining a spectrum based on the input electric signal and controlling the rotation of the reflecting unit 7 of the movable unit 3 in order to selectively emit light having a desired wavelength. Equipped with.

FIG. 5 is a block diagram showing an example of the hardware configuration of the processing unit 15 according to this embodiment.

The processing unit 15 includes a CPU (Central Processing Unit) 151, a ROM (Read Only Memory) 152, and a RAM (Random Access Memory) 153. Further, the processing unit 15 includes an NVRAM (Non Volatile Memory) 154, an output I/F (Inter/Face) 155, an A/D (Analog/Digital) conversion circuit 156, a reflection drive circuit 157, and a light source drive circuit 158. Have and. These are connected to each other via a system bus 159.

The CPU 151 centrally controls the operation of the processing unit 15. Further, the CPU 151 executes a process of calculating a spectral spectrum based on the electric signal output from the spectral detector 14.

The CPU 151 executes a program stored in the ROM 152 or the like by using the RAM 153 as a work area (work area) to execute the above-described processing and realize various functions described below. Note that some or all of the functions of the CPU 151 may be realized by hardware such as ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array) that is a wired logic.

The NVRAM 154 is a non-volatile memory that stores the input electric signal data, the calculation result of the spectral spectrum, and the like. The output I/F 155 is an interface for connecting to an external device such as a PC (Personal Computer) or a video device.

The A/D conversion circuit 156 is an electric circuit that is electrically connected to the spectroscopic detector 14, receives an analog electric signal output from the spectroscopic detector 14, and converts the analog electric signal into a digital signal.

The reflection driving circuit 157 is an electric circuit that is electrically connected to the movable portion 3 and outputs a voltage or a current indicating the rotation angle of the reflecting portion 7 to the movable portion 3. The reflecting portion 7 of the movable portion 3 is rotated by a predetermined angle according to the voltage or the current input from the reflection driving circuit 157.

The light source drive circuit 158 is an electric circuit that is electrically connected to the light source 20 and outputs a voltage or current indicating the light intensity of the irradiation light to the light source 20. The light source 20 emits light of a predetermined intensity according to the voltage or current input from the light source drive circuit 158.

Next, FIG. 6 is a diagram showing functional blocks of an example of the constituent elements of the processing unit 15 according to the present embodiment. The functional blocks illustrated in FIG. 6 are conceptual and do not necessarily have to be physically configured as illustrated. All or a part of each functional block may be functionally or physically dispersed or combined in arbitrary units.

The processing unit 15 includes an A/D conversion unit 161, a spectrum acquisition unit 162, a storage unit 163, an output unit 164, a drive control unit 165, a reflection drive unit 166, and a light source drive unit 167. There is.

The A/D conversion unit 161 is realized by the A/D conversion circuit 156 and the like, converts the analog electric signal output from the spectroscopic detector 14 into a digital signal, and outputs the digital signal to the spectrum acquisition unit 162, the storage unit 163, and the like.

The spectrum acquisition unit 162 is realized by the CPU 151 and the like, and calculates the spectrum of the light incident on the spectroscope 100 based on the digital signal output by the A/D conversion unit 161. Since a known calculation method can be used in this embodiment, description thereof will be omitted here. The calculation result is output to the storage unit 163, the output unit 164, and the like.

The storage unit 163 is realized by the NVRAM 154 or the like, stores the spectral information such as the spectral spectrum acquired by the spectrum acquisition unit 162 and the digital signal data output from the A/D conversion unit 161, and outputs them in response to a request. To 164.

The output unit 164 is realized by the output I/F 155 and the like, and outputs spectral information such as a spectral spectrum acquired by the spectrum acquisition unit 162 and digital signal data output by the A/D conversion unit 161 to a PC (Personal Computer) or video equipment. Etc. to an external device.

The drive control unit 165 is realized by the CPU 151 or the like and outputs a control signal to control the reflection drive unit 166 and the light source drive unit 167.

The reflection drive unit 166 is realized by the reflection drive circuit 157 or the like, outputs a voltage or a current to the movable unit 3 according to a control signal, and rotates the reflection unit 7 so as to obtain a desired reflection angle.

The light source driving unit 167 is realized by the light source driving circuit 158 or the like, outputs a voltage or a current to the light source 20 according to the control signal, and drives the light source 20 so that a desired intensity of irradiation light can be obtained.

The processing unit 15 may be provided inside the housing 50 or outside the housing 50.

<Structures of Light Source Support Member and Spectral Support Member>
Next, the configurations of the light source support member and the spectroscopic section support member will be described with reference to FIGS. 4 and 7.

In FIG. 4, the light source fixing member 21 is a columnar member having a bent portion, and the surface 21 a at one end is fixed to the inner surface 52 on the positive Z direction side of the housing 50. Further, the light source 20 is inserted and fixed in an insertion portion provided on the other end surface of the light source fixing member 21. The inner surface of the housing 50 to which the light source fixing member 21 is fixed is not limited to the inner surface 52 on the positive Z direction side, and may be any surface. Further, the fixing can be performed by adhesion, screwing or the like.

As shown in FIG. 4A, since the light source fixing member 21 has a bent portion, a gap is formed between the inner surface 52 to which the light source fixing member 21 is fixed and the light source 20 fixed to the light source fixing member 21. The part 21b is formed. That is, the light source 20 is fixed to the inner surface 52 through the light source fixing member 21 including the void portion 21b between the light source 20 and the inner surface 52 of the housing 50 to which the light source fixing member 21 is fixed. The inner surface 52 is an example of the “first inner surface”.

On the other hand, the spectrometer fixing member 201 is also a columnar member having a bent portion, and the surface 201 a at one end is fixed to the inner surface 53 of the housing 50 on the negative Y direction side. Further, the spectroscopic unit 200 including the spectroscope 100 is fixed to the other surface 201b of the spectroscope fixing member 201. The spectroscope fixing member 201 fixes the spectroscope 100 via the spectroscopic unit 200.

The inner surface of the housing 50 to which the spectrometer fixing member 201 is fixed is not limited to the negative Y-direction side inner surface 53, and may be any surface. Further, similarly to the above, the fixing can be performed by adhesion, screwing, or the like.

As shown in FIG. 4C, the spectroscope fixing member 201 has a bent portion, so that the inner surface 53 to which the spectroscope fixing member 201 is fixed and the spectroscope 100 fixed to the spectroscope fixing member 201. A space 201c is formed between them. That is, the spectroscope 100 is fixed to the inner surface 53 through the spectroscope fixing member 201, including the void portion 201c between the spectroscope fixing member 201 and the inner surface 53 of the housing 50 to which the spectroscope fixing member 201 is fixed. The inner surface 53 is an example of the “second inner surface”.

Here, when the spectroscope and the light source are housed in the same housing, the heat generated by the light source is transferred to the spectroscope through the housing, and the concave diffraction grating, the movable part, the frame, etc. are thermally deformed, thereby improving the spectral analysis accuracy. It may decrease.

It may be possible to increase the distance between the spectroscope and the light source to suppress heat transfer in order to prevent deterioration of the accuracy of the spectroscopic analysis. There is. Further, as the distance between the spectroscope and the light source is lengthened, a light guide optical system is required in the optical path from the light source to the object and the optical path from the object to the spectroscope. A decrease in the amount of light due to multiple reflection may reduce the accuracy of spectral analysis.

On the other hand, in the present embodiment, the gap 21b is included between the inner surface 52 of the housing 50, the light source 20 is fixed to the inner surface 52, and the void 201c is included between the inner surface 53 of the housing 50 and The spectroscope 100 is fixed to the inner surface 53. Since a space is included between the housing and the inner surface, the heat transfer path between the light source 20 and the spectroscope 100 can be lengthened to increase the thermal resistance. Thereby, it is possible to suppress the heat generated in the light source 20 from being transferred to the spectroscope 100. Further, since the distance between the spectroscope 100 and the light source 20 is not increased, the spectroscopic analysis unit does not become large, and the spectroscopic analysis accuracy does not deteriorate due to a decrease in the amount of light due to multiple reflection in the light guide optical system. ..

Thus, in a small-sized spectroscopic analysis unit, the influence of heat on spectroscopic analysis can be suppressed, and spectroscopic analysis accuracy can be ensured.

On the other hand, the light source fixing member 21 and the spectroscope fixing member 201 may be fixed to the inner surface of the housing 50 at positions symmetrical with respect to the space center of the housing 50. Here, the space center means the center position of the cube forming the housing 50.

FIG. 7 is a diagram for explaining the fixing positions of the light source fixing member 21 and the spectroscope fixing member 201 to the inner surface of the housing 50.

In FIG. 7, the space center 54 indicates the space center of the housing 50. The fixed position 55a shows an example of a position where the surface 21a at one end of the light source fixing member 21 is fixed to the inner surface of the housing 50, and the fixed position 55b is such that the surface 201a at one end of the spectrometer fixing member 201 is the housing 50. An example of a position fixed to the inner surface is shown. The fixed position 55a and the fixed position 55b are positions symmetrical with respect to the space center 54.

The fixed position 56a shows another example of the position where the surface 21a at one end of the light source fixing member 21 is fixed to the inner surface of the housing 50, and the fixed position 56b is such that the surface 201a at one end of the spectrometer fixing member 201 is a casing. The other example of the position fixed to the inner surface of the body 50 is shown. The fixed position 56a and the fixed position 56b are also symmetrical positions with respect to the space center 54.

In this way, by fixing the light source fixing member 21 and the spectrometer fixing member 201 to the inner surface of the housing 50 at a position symmetrical with respect to the space center of the housing 50, the heat generating housing 50 of the light source 20 is interposed. The spectroscope 100 can be arranged at the most distant position in the heat transfer path. As a result, it is possible to further suppress the heat generated by the light source 20 from being transferred to the spectroscope 100 and ensure the accuracy of spectroscopic analysis.

[Second Embodiment]
Next, the spectroscopic analysis unit according to the second embodiment will be described with reference to FIG. The description of the same components as those of the above-described embodiment will be omitted.

FIG. 8 is a diagram illustrating an example of the configuration of the spectroscopic analysis unit 300a according to the present embodiment. The spectroscopic analysis unit 300a includes a light source fixing member 23 in which a light source light guide hole 22A is formed, and a spectroscopic unit 200a including an outer frame 10a in which a movable portion light guide hole 22B and a detector fixing hole 16 are formed. There is.

The light source light guide hole 22A is a hole formed in the light source fixing member 23 to communicate the insertion portion of the light source fixing member 23 and the outside of the light source fixing member 23, and a part of the light emitted from the light source 20 is split into a spectroscopic unit. It is a hole that guides light toward 200a.

The movable portion light guide hole 22B is a hole that is formed in the outer frame 10a and connects the hollow portion 11 and the outside of the outer frame 10a to each other. Light from the light source 20 that has passed through the light source light guide hole 22A is moved by the movable portion 3a. This is a hole for guiding light to the reflection part 7 of The movable portion light guide hole 22B allows the light from the light source 20 that has passed through the light source light guide hole 22A to be incident on the surface (rear surface) opposite to the surface on which the dispersed light from the concave diffraction grating 2 of the reflection portion 7 is incident. To guide the light.

Here, the light guide portion 22 configured by the light source light guide hole 22A and the movable portion light guide hole 22B is an example of “a light guide portion that guides a part of the light emitted from the light source to the movable portion”. ..

On the other hand, the detector fixing hole 16 is a hole that is formed in the outer frame 10a and connects the hollow portion 11 and the outside of the outer frame 10a, and is a hole into which the movable photodetector 17 is inserted and fixed. The light passing through the light source light guide hole 22A and reflected by the reflecting portion 7 passes through the detector fixing hole 16 and is incident on the movable photodetector 17, and the movable photodetector 17 detects the incident light.

As long as the movable photodetector 17 can detect the light reflected on the back surface of the reflecting portion 7, the back surface of the reflecting portion 7 does not necessarily have to be formed with a reflecting surface such as aluminum.

The movable photodetector 17 is a photodetector such as a PD (photodiode) and outputs a detection signal indicating the intensity of the received light. The movable photodetector 17 is electrically connected to the processing unit 15a, and the detection signal from the movable photodetector 17 is input to the processing unit 15a.

When the reflecting portion 7 is rotated periodically, the light reflected from the back surface of the reflecting portion 7 of the light from the light source 20 is scanned in the rotating direction, and the light intensity is changed at the moment when the light passes through the movable photodetector 17. The detection signal shown is obtained.

Here, FIG. 9 is a diagram illustrating an example of a detection signal by the movable photodetector 17 when the reflecting portion 7 of the movable portion 3 is periodically rotated. The horizontal axis of FIG. 9 represents time and the vertical axis represents the detection signal from the movable photodetector 17.

Since the reflecting portion 7 periodically reciprocates (swings or oscillates), the scanning light passes through the movable photodetector 17 twice in the forward and backward directions with one cycle of rotation. At time T1 in FIG. 9, the two signals detected at the time interval Td are signals when the scanning light passes on the movable photodetector 17 in the forward and backward movements of the rotation of the reflecting section 7. Of the two signals, the outgoing signal is the first signal and the returning signal is the second signal.

At time T2, in the next cycle, two detection signals are obtained when the scanning light passes over the movable photodetector 17 in the forward and backward directions of the rotation of the reflecting section 7. Here, the time interval Ts is a time interval from the return signal of the first cycle to the forward signal of the second cycle.

In this example, since the scanning light is set so as to pass over the movable photodetector 17 when the reflecting portion 7 is rotated near the maximum amplitude, the time interval Td is relative to the rotation cycle T. It's getting shorter. However, the present invention is not limited to this, and the timing at which the scanning light passes on the movable photodetector 17 with respect to the rotation of the reflecting portion 7 may be arbitrarily adjusted depending on the position where the detector fixing hole 16 is provided. Good.

If the reflection unit 7 is not rotated in a constant cycle, the scanning of the dispersed light by the concave diffraction grating 2 may become unstable, and the accuracy of the spectroscopic analysis may decrease.

Therefore, in the present embodiment, in the detection signal shown in FIG. 9, the rotation of the reflecting section 7 is controlled based on the detection signal so that at least one of the time interval Td and the time interval Ts becomes a constant time interval. ..

Next, FIG. 10 is a diagram showing functional blocks of an example of components included in the processing unit 15a according to the present embodiment.

The processing unit 15a has an A/D conversion unit 161a and a drive control unit 165a.

The A/D conversion unit 161a A/D converts the detection signal of the spectroscopic detector 14 and outputs it to the spectrum acquisition unit 162, and A/D converts the detection signal of the movable photodetector 17 to drive control unit 165a. Output to.

The drive control unit 165a controls the rotation of the reflection unit 7 via the reflection drive unit 166 based on the A/D converted detection signal of the movable photodetector 17. Here, the drive control unit 165a is an example of a “control unit”.

The control by the drive control unit 165a is a control that changes the rotation angle of the reflection unit 7 by increasing or decreasing the current or the voltage applied from the reflection drive unit 166 to the movable unit 3. The drive control unit 165a may control the current or voltage applied to the movable unit 3 in real time based on the detection signal of the movable photodetector 17 while the reflecting unit 7 is rotating. Alternatively, for the purpose of calibrating the rotation cycle of the reflection unit 7, the drive control unit 165a applies a current to the movable unit 3 based on the detection signal of the movable photodetector 17 before operating the spectroscopic analysis unit 300a. Alternatively, the voltage may be adjusted.

As described above, in the present embodiment, the rotation of the reflection section 7 is detected, and the processing section 15a controls the reflection section 7 to rotate at a constant cycle based on the detection signal. This makes it possible to ensure the accuracy of the spectral analysis.

Further, in the present embodiment, a light guide section for guiding a part of the light emitted from the light source 20 to the reflecting section 7 of the movable section 3 is provided, and the reflected light from the reflecting section 7 is detected by the movable photodetector 17. Then, the rotation of the reflector 7 is detected. Since a light source for detecting the rotation of the reflecting portion 7 is not added separately, the accuracy of the spectroscopic analysis can be ensured without increasing the size of the spectroscopic analysis unit 300a and increasing the cost.

Further, in this embodiment, a part of the light emitted from the light source 20 is guided so as to be incident on the surface (rear surface) of the reflecting portion 7 opposite to the surface on which the dispersed light by the concave diffraction grating 2 is incident. Since the incident surface of the dispersed light by the concave diffraction grating 2 is not used, the rotation of the reflection section 7 can be detected with a simple configuration and with the light source 20 and the spectroscopic section 200a arranged close to each other.

A slit member such as a rectangular slit may be provided in the optical path between the light source 20 and the movable portion 3. By passing through the slit member, the light from the light source 20 can be shaped into a desired shape, which can reduce the rounding of the detection signal by the movable photodetector 17.

Although an example according to the embodiment of the present invention has been described above, the present invention is not limited to such a specific embodiment, and various modifications are possible within the scope of the gist of the present invention described in the claims. Can be modified and changed.

1 entrance slit 2 concave diffraction grating (an example of diffraction grating)
3 Moving part 4 Emitting slit 5 Roland circle 6 Substrate 7 Reflecting part 8 Elastic beam part 9 Frame 9a Opening (an example of the third opening)
9b opening (an example of the first opening)
9c opening (an example of the second opening)
9d opening (an example of the fourth opening)
10 Outer Frame 11 Hollow Part 12 Tapered Hole 13 Communication Hole 14 Spectral Detector 15, 15a Processing Section 16 Detector Fixing Hole 17 Movable Photodetector 20 Light Source 21, 23 Light Source Fixing Member 22 Light Guide 22A Light Source Light Guide Hole 22B Movable Inner light guide hole 52 inner surface (an example of a first inner surface)
53 Inner surface (an example of second inner surface)
100 spectroscope 162 spectrum acquisition unit 165 drive control unit 165a drive control unit (an example of control unit)
166 Reflection driving unit 167 Light source driving unit 200, 200a Spectroscopic unit 201 Spectroscope fixing member 300, 300a Spectroscopic analysis unit (an example of an optical device)

JP, 2008-025495, A

Claims (8)

A light source that irradiates the object with light,
A spectroscope for separating the reflected light from the object,
A housing containing the light source and the spectroscope;
A light source fixing member for fixing the light source to the inner surface of the housing,
A spectroscope fixing member for fixing the spectroscope to the inner surface of the housing,
The light source includes a space between the light source fixing member and the first inner surface of the housing to which the light source fixing member is fixed, and is fixed to the first inner surface,
The spectroscope includes an air gap between the spectroscope fixing member and the second inner surface of the housing to which the spectroscope fixing member is fixed, and is fixed to the second inner surface. .. A spectroscopic detector for detecting light dispersed by the spectroscope,
The optical device according to claim 1, further comprising: an output unit configured to output the spectral information acquired based on the detection signal of the spectral detector. The optical device according to claim 1, wherein the light source fixing member and the spectroscope fixing member are members each including a bent portion. 4. The light source fixing member and the spectroscope fixing member are fixed to the inner surface of the housing at positions symmetrical with respect to the space center of the housing. Optical device. The spectroscope is
A hollow support frame with at least four openings;
A diffraction grating arranged at the position of the first aperture,
A movable portion which is arranged at the position of the second opening and which reflects the dispersed light by the diffraction grating by the reflecting portion in a variable reflection angle;
A third opening for allowing light to enter the support frame;
The optical device according to any one of claims 1 to 4, further comprising: a fourth opening that allows the light reflected by the reflector to be emitted to the outside of the support frame. The optical device according to claim 1, wherein the diffraction grating is a concave diffraction grating. A light guide section for guiding a part of the light emitted from the light source to the reflection section,
A movable photodetector that detects light reflected by the reflection part of light guided by the light guide part,
The optical device according to any one of claims 1 to 6, further comprising: a control unit that controls driving of the reflection unit based on a detection signal of the movable photodetector. The optical device according to claim 7, wherein the light guide section guides a part of the light emitted from the light source to a surface of the reflection section opposite to a surface thereof on which the dispersed light is reflected.

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