JP3203149B2 - Emitter / receiver for spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting / receiving device for a spectroscopic analyzer, and more particularly, to an irradiation unit for irradiating a sample with a measuring light beam and a light receiving unit for receiving reflected light from the sample. .

[0002]

2. Description of the Related Art Conventionally, in such a light emitting / receiving device for a spectrometer, one of an irradiation optical fiber and a light receiving optical fiber is formed in a ring at least at a tip portion, and the other is close to the inside thereof. It is formed in a coaxial portion located so that the tip end surface of the irradiation optical fiber functions as an irradiation portion and the tip end surface of the light receiving optical fiber functions as a light receiving portion. By forming the coaxial part close to the outer annular optical fiber and the optical fiber located inside, the thickness of the coaxial part is reduced and the coaxial part is provided with flexibility, which improves operability. It was excellent.

[0003]

However, in the conventional light emitting / receiving device for a spectroscopic analyzer, the irradiating section and the light receiving section are close to each other. Only the surface reflection light reflected on the surface of the sample could be received, and the diffuse reflection light diffusely reflected inside the sample could not be received. Therefore, the components inside the sample could not be analyzed. By the way, it is supposed that the coaxial portion is formed by widening the interval between the outer annular optical fiber and the optical fiber located inside the outer coaxial portion. Since the operability is reduced, the operability is deteriorated, which is not practical.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a light emitting / receiving device for a spectroscopic analyzer capable of receiving diffuse reflected light from a sample and having excellent operability. To provide.

[0005]

According to a first aspect of the present invention, there is provided an irradiating section for irradiating a sample with a measuring light beam and receiving reflected light from the sample. A light-receiving unit, in the irradiation direction of the irradiation unit,
One is formed in an annular shape, and a detection unit provided in a state where the other is located inside is provided, and in the detection unit, an irradiation optical fiber for guiding a measurement light beam from a light source to the irradiation unit,
A light-receiving optical fiber for guiding light received by the light-receiving unit is connected, and the detection unit includes, at a distal end thereof, the irradiation unit and the light-receiving unit at an interval, the detection unit including the irradiation unit and the light-receiving unit. The one located on the outer side is characterized in that the outer diameter of the tip is formed to be larger than the optical fiber connected to it.

A second characteristic configuration is that one of the irradiation optical fiber and the light receiving optical fiber is formed in a ring shape, and the other is formed coaxially in which the other is located.

A third characteristic configuration is that one of the irradiating portion and the light receiving portion which is located on the outside has an optical path whose diameter becomes smaller as approaching the fiber connection portion on the base end side. is there.

[0008] A fourth characteristic configuration is that the irradiating section is located inside,
The detection unit is configured such that the light receiving unit is located outside, and the irradiation unit includes an optical path having a smaller diameter as approaching the fiber connection unit on the base end side.

A fifth characteristic configuration is that the optical path is formed by inserting an optical path forming optical fiber into the detecting section.

A sixth characteristic configuration is that the distal end of the detection section is formed in a concave curved shape in which the center is the deepest.

[0011]

The operation of the first characteristic configuration is as follows. The detecting unit connected to the irradiation optical fiber and the light receiving optical fiber is the outer one of the irradiation unit and the light receiving unit, and the outer diameter of the tip is larger than the optical fiber connected to it. It is formed in. Therefore, even if the coaxial portion of the irradiation optical fiber and the light receiving optical fiber, which is the connection portion with the detection portion, is formed by making the outer annular optical fiber and the optical fiber located inside thereof close to each other, the detection can be performed. The part can be provided with an irradiating part and a light receiving part at an end thereof at an interval.

According to the second characteristic configuration, one coaxial probe in which an irradiation optical fiber and a light receiving optical fiber are formed coaxially is connected to the detection unit.

The operation of the third characteristic configuration is as follows. The light path provided on the outer one of the irradiation unit and the light receiving unit has a smaller diameter as it approaches the fiber connection unit on the base end side. If the diameter of the fiber connection portion on the proximal end side of the optical path is, for example, the same or substantially the same as the outer diameter of the optical fiber connected to it, the outer one of the irradiation portion and the light receiving portion is determined. Although the outer diameter of the distal end portion is formed larger than the optical fiber connected to the distal end portion, the connection configuration between the detecting section, the irradiation optical fiber, and the light receiving optical fiber is simplified.

The operation of the fourth characteristic configuration is as follows. A measuring light beam is irradiated to the sample from the irradiation unit located inside, and the diffuse reflection light diffusely reflected from the sample is received by the light receiving unit located outside the irradiation unit. Light can be received. Therefore, it is possible to reduce the light amount of the measuring light beam irradiated on the sample. Further, since the measurement light beam is applied to the sample from an optical path having a larger diameter at the tip, the irradiation area of the measurement light beam to the sample is increased.

According to the fifth characteristic configuration, since the light path is formed simply by inserting the optical path forming optical fiber into the detecting portion, for example, the inner peripheral surface of the cylindrical body reflects light. By finishing the mirror as much as possible, the light path can be formed more easily than forming the light path, and as a result, the detector can be easily manufactured.
Further, if the optical fiber for forming the optical path is held in a state where the optical path is formed with resin, the detecting section itself can be manufactured by resin molding, so that the detecting section can be more easily manufactured. can do.

According to the sixth characteristic configuration, since the tip of the detection section has a concave curved surface, even if the outer shape of the sample to be analyzed such as apples or oranges has a convex curved surface, the detection section has a curved surface. Since the periphery of the tip can be brought into close contact with the surface of the sample over the entire circumference, it is possible to suppress diffused reflected light from the sample from escaping to the outside and receive light efficiently.

[0017]

According to the first characteristic configuration, the coaxial portion of the irradiation optical fiber and the light receiving optical fiber is formed by bringing the outer annular optical fiber and the optical fiber located inside thereof into close proximity. Accordingly, while the thickness of the coaxial portion is reduced and the coaxial portion is provided with flexibility, the irradiating portion and the light receiving portion can be provided at an interval at the distal end portion of the detecting portion. As a result, it has become possible to provide a light emitting / receiving device for a spectroscopic analyzer that is capable of receiving diffuse reflected light from a sample and has excellent operability.

According to the second characteristic configuration, since only one coaxial probe is connected to the detection unit, the operability can be further improved.

According to the third characteristic configuration, the connection structure between the detection unit and the irradiation optical fiber and the light receiving optical fiber can be simplified, so that the present invention can be implemented at low cost. Became.

According to the fourth characteristic configuration, it is possible to reduce the amount of the measuring light beam irradiated on the sample, and
The synergistic effect with the fact that the irradiation area of the measurement light beam to the sample can be made large can suppress the influence of heat on the sample as much as possible.

According to the fifth characteristic configuration, since the detector can be easily manufactured, the present invention can be implemented at a lower cost.

According to the sixth characteristic configuration, diffuse reflection light from the sample can be efficiently received regardless of the external shape of the sample.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a light emitting and receiving device for a spectroscopic analyzer for analyzing components contained in fruits and vegetables will be described below with reference to FIGS. FIG.
As shown in FIG. 1, the spectroscopic analyzer includes a light source unit 1 and a light emitting / receiving device M that irradiates a sample S with a measurement light beam from the light source unit 1 and receives diffuse reflected light from the sample S. A spectroscopy unit 7 for obtaining a spectrum of the diffuse reflection light received by the apparatus M, a signal processing unit 8 for calculating the amount of components contained in the sample S based on the spectrum obtained by the spectroscopy unit 7, The output unit 9 that outputs the calculation result of the processing unit 8 is configured as a main component. Emitter / receiver M
Is an irradiation optical fiber 2 for guiding a measurement light beam from the light source unit 1, an irradiation unit 3 for irradiating the sample S with the measurement light beam guided by the irradiation optical fiber 2, and diffuse reflection light from the sample S. A sample contact adapter 5 as a detection unit having a light receiving unit 4 for receiving light; and a light receiving optical fiber 6 for guiding the light received by the light receiving unit 4 to the spectroscopic unit 7.

As shown in FIG. 1, a light source unit 1 includes a tungsten-halogen lamp 11 as a light source that emits infrared light as a measuring light beam, and a measuring light beam from the tungsten-halogen lamp 11 into a parallel light beam. It is constituted by a lens 12 to be molded.

As shown in FIG. 1, the irradiating optical fiber 2 and the receiving optical fiber 6 are the incident end of the measuring light beam in the irradiating optical fiber 2 and the emitting end of the diffusely reflected light in the receiving optical fiber 6. The portion excluding the portion is formed on the coaxial probe P in which the irradiation optical fiber 2 is located inside the annular light receiving optical fiber 6. As shown in FIGS. 2 and 3, the light receiving optical fiber 6
And the circular end surface of the irradiation optical fiber 2 are flush with each other.

Next, the sample contact adapter 5 will be described with reference to FIGS. The sample contact adapter 5 includes an outer cylinder 51, an inner cylinder 52 coaxially located inside the outer cylinder 51 at a distance from the outer cylinder 51,
A connecting member 53 for connecting the outer cylinder 51 and the inner cylinder 52,
Attachment cylinder 5 fixed to one end of outer cylinder 51 so as to fit externally
4 and a screw 55 screwed into the mounting cylinder 54. Then, the sample contact adapter 5 is connected to the coaxial probe P by externally fitting the mounting cylinder 54 to the coaxial probe P and tightening the screw 55. vice versa,
When removing the sample contact adapter 5 from the coaxial probe P, the screw 55 may be loosened.

The inner cylindrical body 52 is formed in a truncated conical shape in which the inner diameter and the outer diameter of the cylinder become smaller as approaching the fiber connection portion on the base end side, and the thickness of the peripheral wall becomes smaller as approaching the coaxial probe P. It is formed so that it becomes. Furthermore, the inner cylinder 5
In the fiber connection portion on the base end side, the inner diameter is substantially the same as the diameter of the circular distal end surface of the irradiation optical fiber 2, and the thickness of the peripheral wall is equal to the distal end surface of the irradiation optical fiber 2 and the light receiving light. The distance from the distal end surface of the fiber 6 is substantially the same.
The thickness d of the peripheral wall at the distal end of the inner cylinder 52 is set to 20 mm. The inner peripheral surface and the outer peripheral surface of the inner cylindrical body 52 are finished to mirror surfaces capable of reflecting light. The outer cylinder body 51 is formed in a truncated cone shape in which the inner diameter and the outer diameter of the cylinder become smaller as they approach the fiber connection portion on the base end side. Further, the outer cylinder 51
In the fiber connection portion on the base end side, the inner diameter is made substantially the same as the outer diameter of the annular distal end surface of the optical fiber 6 for light reception. The inner peripheral surface of the outer cylinder 51 is finished to a mirror surface capable of reflecting light.

That is, the shape of the opening of the fiber connection portion on the proximal end side of the inner cylindrical body 52 becomes substantially the same as the shape of the distal end surface of the irradiation optical fiber 2, and the shape of the opening of the inner cylindrical body 52 is the same as that of the inner cylindrical body 52. The shape of the annular opening formed by the base end of the cylindrical body 51 is substantially the same as the shape of the annular distal end surface of the light-receiving optical fiber 6. When the sample contact adapter 5 is connected to the distal end of the coaxial probe P, the opening of the inner cylindrical body 52 is located in a state facing the distal end surface of the irradiation optical fiber 2, and the inner cylindrical body 52 and the outer cylindrical body The opening formed in the optical fiber 51 is positioned so as to face the distal end surface of the light receiving optical fiber 6. Further, the distal end portion of the sample contact adapter 5 is formed in a concave curved shape in which the central portion is the deepest.

Then, the tip of the sample contact adapter 5 is brought into contact with the sample S, and the tungsten-halogen lamp 11
Lights up. Then, the measuring light beam is applied to the irradiation optical fiber 2.
The light enters the inner cylindrical body 52 from the front end surface thereof, passes through the inner cylindrical body 52, and emerges from the front end opening of the inner cylindrical body 52 to the sample S. Then, the diffusely reflected light from the sample S is
2 enters the space between the inner cylinder 52 and the outer cylinder 51 from an annular opening formed by the tip of the second cylinder and the tip of the outer cylinder 51, passes through the space, and From the opening formed by the base end of the cylinder 52 and the base end of the outer cylinder 51,
The light is emitted to the distal end surface of the light receiving optical fiber 6.

Therefore, by configuring the sample contact adapter 5 as described above, the inner space of the inner cylindrical body 52 is made smaller in the optical path L1 as the closer to the fiber connection portion on the base end side.
, And the space between the inner cylindrical body 52 and the outer cylindrical body 51 is configured to function as an optical path L2 having a smaller diameter as approaching the fiber connection portion on the base end side. The irradiating section 3 is constituted by an optical path L1, and the light receiving section 4 is constituted by an optical path L2. The sample contact adapter 5 is configured to irradiate the sample S with a measurement light beam, and
A light receiving unit 4 for receiving diffusely reflected light from the sample S is provided in a state where the light receiving unit 4 is formed in a ring shape and the irradiation unit 3 is located inside the light receiving unit 4 when viewed in the irradiation direction of the irradiation unit 3. I have. In addition, the sample contact adapter 5 has an irradiation unit 3 and a light receiving unit 4 at a distal end thereof at an interval of 20 mm, and the light receiving unit 4 located outside of the irradiation unit 3 and the light receiving unit 4 has The outer diameter of the tip is formed larger than the light receiving optical fiber 6 connected to the tip.

Next, the spectroscopic section 7 will be described with reference to FIG. The spectroscopy unit 7 includes a reflecting mirror 71 that reflects the diffusely reflected light guided by the light receiving optical fiber 6, and a reflecting mirror 7.
A concave diffraction grating 72 that spectrally reflects the diffusely reflected light reflected by 1 and an array-type light receiving element 73 that detects the light flux intensity for each wavelength spectrally reflected by the concave diffraction grating 72 are provided. The array-type light receiving element 73 receives diffusely reflected light spectrally reflected by the concave diffraction grating 72 at the same time for each wavelength, and converts and outputs the signal for each wavelength. Reflecting mirror 71, concave diffraction grating 72, and array type light receiving element 73
Is an aluminum dark box 74 that shields external light.
The diffused reflected light guided by the light receiving optical fiber 6 is configured to be guided into the dark box 74 through an incident hole 75 formed in the dark box 74. R in the drawing indicates an optical path from the light source unit 1 to the array type light receiving element 73. However, the optical path R in the coaxial probe P is not shown.

Next, the signal processing unit 8 will be described. The signal processing unit 8 is configured using a microcomputer. The signal processing unit 8 includes an array type light receiving element 73
Processing the output signal from
The second derivative in the wavelength region of the absorbance spectrum is obtained, and the amount of the component contained in the sample S is calculated based on the second derivative. Absorbance is the amount of light emitted from the light source (reference light amount)
Is defined as I and the amount of transmitted light is defined as T, and is defined as Log (I / T). The signal processing unit 8 calculates the component amount included in the sample S based on the multiple regression analysis using the following equation (hereinafter, referred to as a component amount calculation equation). Y = K ₀ + K ₁ × A (λ ₁ ) + K ₂ × A (λ ₂ ) + K ₃
× A (λ ₃ ) where Y: component amount K ₀ , K ₁ , K ₂ , K ₃ …; coefficient A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) ……; Wavelength λ
Derivative of absorbance spectrum at

The signal processing section 8 includes a sample S
For each component, calculate the amount of component
The component amount calculation formula is set. That is, the above component amount calculation
In the formula, for each fruit and vegetable variety, specify for each ingredient
Coefficient K₀, K₁, K_Two, K _Three……, wavelength λ₁, Λ_Two,
λ_Three…… is set. Then, the signal processing unit 8
Vegetables and varieties set in analysis condition setting section (not shown)
Each component is calculated using a specific component amount calculation formula for each component according to
Calculate the component amount of the minute.

[Another Embodiment] Next, another embodiment will be described. In the above embodiment, the sample contact adapter 5 includes the irradiation unit 3 and the light receiving unit 4 in a state where the irradiation unit 3 is located inside the annular light receiving unit 4 when viewed in the irradiation direction of the irradiation unit 3. Although the case where it is configured as shown above is exemplified,
Instead of this, when viewed in the irradiation direction of the irradiation unit 3, the light receiving unit 4 may be provided in a state where the light receiving unit 4 is located inside the annular irradiation unit 3. In this case, the coaxial probe P is formed coaxially so that the irradiation optical fiber 2 is annular and the light receiving optical fiber 6 is located inside. The irradiation optical fiber 2 and the light receiving optical fiber 6 are formed in a coaxial shape in which the light receiving optical fiber 6 is annular and the irradiation optical fiber 2 is located inside only the connection portion with the sample contact adapter 5, Other parts may be configured separately. The distal end of the sample contact adapter 5 can be formed in a flat shape or various shapes suitable for the outer shape of the fruits and vegetables to be analyzed, in addition to the concave shape as in the above embodiment. The distance d between the light receiving section 4 and the irradiating section 3 at the tip of the sample contact adapter 5 is set to 20 mm in the above embodiment, but if it is 20 mm or more, the diffused reflected light from the sample S can be received. Therefore, if the distance d is 20 mm or more, various changes can be made. As shown in FIGS. 6 and 7, in the coaxial probe P, the irradiation optical fiber 2 located inside the annular light receiving optical fiber 6 has a rectangular cross section (a surface orthogonal to the axis). It may be formed. In this case, as shown in FIGS. 6 and 8, in the inner cylindrical body 52 of the sample contact adapter 5, the shape of the opening of the fiber connection portion on the base end side is substantially the same as the shape of the distal end surface of the irradiation optical fiber 2. Is formed to have a rectangular shape. As shown in FIGS. 9 and 10, the light paths L1, L2
Is an optical fiber 1 for forming an optical path in a sample contact adapter 5.
It may be formed by inserting 0. Note that, in this case, the sample contact adapter 5 is an optical fiber 1 for forming an optical path.
The resin 56 is formed by molding the resin 56 in a state where 0 is kept and held. Further, in another embodiment shown in FIGS. 9 and 10, the outer light path L2 is made to function as the irradiation unit 3,
The inner light path L1 may function as the light receiving unit 4. As shown in FIG. 11, the outer light path L <b> 2 includes a plurality of unit light paths L <b> 2 a having an arc-shaped cross section (a surface orthogonal to the irradiation direction of the irradiation unit 3) when viewed in the irradiation direction of the irradiation unit 3. It may be arranged in a ring shape. As shown in FIG. 12, the outer light path L2 has a unit light path L2b having a circular cross section (a plane orthogonal to the irradiation direction of the irradiation unit 3).
May be arranged annularly in the irradiation direction of the irradiation unit 3. Although not shown, each of the plurality of unit optical paths L2a may be in a state of being continuously connected to each other in a ring at the fiber connection portion on the base end side, or may be separated from each other. Similarly, each of the plurality of unit light paths L2b may be in a state of being continuously connected in a ring shape or separated from each other at the fiber connection portion on the base end side. In another embodiment shown in FIGS. 11 and 12,
The outer light path L2 may function as the irradiation unit 3 and the inner light path L1 may function as the light receiving unit 4.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a block diagram of a spectroscopic analyzer.

FIG. 2 is a cross-sectional view of the sample contact adapter taken along a plane along the axial direction.

FIG. 3 is a view taken in the direction of the arrow II in FIG. 2;

FIG. 4 is a view as viewed from the direction of the arrow in FIG. 2;

FIG. 5 is a view as viewed from the direction indicated by the arrows in FIG. 2;

FIG. 6 is a cross-sectional view of a sample contact adapter according to another embodiment, taken along a plane along the axial direction.

FIG. 7 is a view as seen from the direction of the arrows in FIG. 6;

FIG. 8 is a view taken in the direction of an arrow E in FIG. 6;

FIG. 9 is a cross-sectional view of a sample contact adapter in another example taken along a plane along the axial center direction.

FIG. 10 is a view taken in the direction of an arrow in FIG. 9;

FIG. 11 is a front view of an irradiation unit of a sample contact adapter according to another embodiment.

FIG. 12 is a front view of an irradiation unit of a sample contact adapter according to another embodiment.

[Explanation of symbols]

 2 irradiating optical fiber 3 irradiating unit 4 light receiving unit 5 detecting unit 6 light receiving optical fiber 10 optical fiber for forming optical path 11 light source L1, L2 optical path

──────────────────────────────────────────────────続 き Continuing on the front page (72) Ryogo Yamauchi 1-1-1, Hama, Amagasaki-shi, Hyogo Prefecture Inside Kubota Technology Development Laboratory Co., Ltd. (72) Shinya Morimoto 1-1-1, Hama, Amagasaki-shi, Hyogo Prefecture Inside the Kubota Technology Development Laboratory Co., Ltd. (72) Inventor Susumu Kaminaka 1-1-1, Hama, Amagasaki-shi, Hyogo Prefecture Inside the Kubota Technology Development Laboratory Co., Ltd. (56) References JP-A-58-33153 (JP, A) JP-A-6-160272 (JP, A) JP-A-57-190254 (JP, A) JP-A-1-165936 (JP, A) JP-A-5-288674 (JP, A) (JP, U) US Patent 4,379,225 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 G01J 3/00- 3/52

Claims (6)

(57) [Claims] 1. An irradiation unit (3) for irradiating a sample with a measuring light beam and a light receiving unit (4) for receiving reflected light from the sample, when viewed in an irradiation direction of the irradiation unit (3).
A detector (5) is provided, one of which is formed in an annular shape and the other is positioned inside the detector. The detector (5) is provided with a measuring light beam from a light source (11). An irradiation optical fiber (2) for guiding to 3) and a light receiving optical fiber (6) for guiding the light received by the light receiving section (4) are connected. An irradiating section (3) and the light receiving section (4) are provided at an interval, and the outer one of the irradiating section (3) and the light receiving section (4) is located outside its tip. A light emitting / receiving device for a spectroscopic analyzer having a diameter larger than the optical fibers (2) and (6) connected thereto. 2. The optical fiber for irradiation (2) and the optical fiber for light reception (6), one of which is formed in an annular shape, and the other of which is formed coaxially in which the other is located. Light emitting and receiving device for spectroscopic analyzers. 3. The irradiation section (3) and the light receiving section (4).
3. The light-emitting / receiving device for a spectroscopic analyzer according to claim 1, wherein an outer one of the light-emitting and light-emitting devices has an optical path (L2) whose diameter becomes smaller as approaching the fiber connection portion on the proximal end side. 4. The detection section (5) is configured such that the irradiation section (3) is located inside and the light receiving section (4) is located outside, and the irradiation section (3) is located on the proximal side. 4. The light emitting and receiving device for a spectroscopic analyzer according to claim 3, further comprising an optical path (L1) having a smaller diameter as approaching the fiber connection portion. 5. The optical path (L1), (L2) according to claim 3 or 4, wherein the optical path forming optical fiber (10) is inserted into the detection section (5). Light emitting and receiving device for spectrometer. 6. A tip portion of the detection portion (5) is formed in a concave curved surface with a center portion being deepest.
6. The light emitting and receiving device for a spectroscopic analyzer according to 3, 4, or 5.