JP3324341B2 - Spectroscopic analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectroscopic analyzer and, more particularly , to a spectroscopic analyzer for measuring the amount of components in plant leaves.

[0002]

Conventionally, contained in the leaves, component amount involved in growth, there was no simple device capable of measuring for example nitrogen amount directly. As an alternative to this, the amount of nitrogen can be estimated by comparing the leaf color with the color chart (color scale), or by irradiating the target leaf with light and determining the amount of red light and infrared light from the transmitted light. chlorophyll content in the leaves by or measured (chlorophyll) were measured, was estimated nitrogen content from the chlorophyll amount. Then, a week to determine fertilization commensurate with <br/> growing season with nitrogen amount estimated here. In particular , as seen in rice cultivation, the time and amount of fertilization determined based on the estimated amount of nitrogen are important points for ensuring the yield of cereals and preventing the rice from falling down. .

On the other hand, the method of comparing the leaf color of rice with the color chart requires not only experience, but also that the visible leaf color is affected by the weather and the position of sunlight, or that a part of the plant In many cases, the result of the judgment differs depending on whether the user looks at the image, and also depending on the observation angle. However, it is also a fact that the utilization rate is high because the measurement method is simple and the color chart used is inexpensive.

A chlorophyll measuring device has been developed as an alternative to this color chart. The measurement principle of a typical chlorophyll meter is
As shown in FIG. 3, a light source 51 is attached to a leaf 50 to be measured.
The transmitted light is measured by a dichroic mirror 52, and the transmitted light is affected by a chlorophyll component related to chlorophyll (light receiving element 5).
Infrared region which is not affected by the quantity of transmitted light 3) (light receiving element 5
4) the amount of transmitted light was measured for by determining the light amount difference is estimated chlorophyll concentration per unit area in a non-destructive. However , in practice, the nitrogen concentration is estimated on the assumption that the chlorophyll concentration and the nitrogen concentration are in a proportional relationship, and is used to determine the amount of fertilization to a plant.

The applicant of the present invention has proposed a leaf component amount measuring apparatus for simply measuring the nitrogen content of a plant, as disclosed in Japanese Patent Application No. Hei 6-165.
Already proposed by No. 871. In this regard, FIG.
This will be described in detail with reference to FIG. FIG. 4 shows an optical measuring unit 60 which is a main component of a leaf component amount measuring apparatus, and is provided with a light emitting means 62 for irradiating a measured leaf 61 with near-infrared light having an arbitrary wavelength . The light emitting means 62 includes a near-infrared light emitting element 63 composed of a light emitting diode or the like and a narrow band filter 64 through which only near infrared light of an arbitrary wavelength passes.
Then, the leaf 61 to be measured is sandwiched two-dimensionally so that near-infrared light is uniformly irradiated on the leaf surface of the leaf 61 to be measured, and transmitted light and reflected light from the sandwiched leaf 61 to be measured are measured. Holding means 66 having measurement windows 65A and 65B for opening
A, 66B are provided. The measuring window 65B of the leaf holding means 66B and the light emitting means 62 are optically connected by an integrating sphere 67. In other words, the light-emitting unit 62 is Yes and fixed to the integrating sphere 67 to scattered by irradiating illumination light inside the integrating sphere 67, further wherein the measuring window 65B in the integrating sphere 67
And an opening 70 on the other side of which a reflection light receiving means 69 made of a silicon photodiode is fixed.

[0006]the aboveDescribes the operation of the leaf component measurement device
And the near-infrared light emitted from the light emitting means 62,Integrating sphere 6
Scattered within 7handIrradiation from the measurement window 65B to the surface of the leaf 61 to be measured
Is done.on the other hand, The light reflected by the measured leaf 61 is,Integrating sphere 6
Scattered within 7handThe light is received by the reflection light receiving means 69.Further
Of the near-infrared light applied to the leaf 61 to be measured
The object is fixed to the leaf holding means 66 on the measurement window 65A side.
TosiliconTransmitted light receiving means 71 composed of a photodiode
ByIt is received as transmitted light.

[0007]

In the use of the integrating sphere 67 in the above configuration, in order to increase the light amount of the light source and to increase the number of wavelengths to be used for measurement in order to secure the measurement accuracy, it is necessary to use the following method. There is an advantage that the light of the wavelength can be evenly applied to the leaf to be measured regardless of the light emission position. However, the integrating sphere 67 has a process in which a spherical surface is formed inside, and the spherical surface is matte-finished and then plated with gold to finish the process.

[0008] In view of the above problems, the present invention provides an integrating sphere.
Correspondingly low cost and without a required, moreover, the variation of light quantity and technical problem of providing a <br/> had spectroscopic measuring device Do things be affected the measurement accuracy as compared to the integrating sphere.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a light source section for irradiating near-infrared light of an arbitrary wavelength to an object to be measured, and receiving transmitted light or reflected light from the object to be measured. Light amount detection means, and while calculating the absorbance of the measured object from the transmitted light amount or reflected light amount obtained from the light amount detection means,
A component amount estimation formula is determined by the absorbance obtained when the object to be measured whose component amount is known is irradiated with the near-infrared light and the known component amount, and the component amount estimation formula and the absorbance of the object to be measured are determined. an arithmetic means and spectroscopic measurement apparatus comprising a for calculating a component quantity of the object to be measured by the, the light source unit may include a light source comprising a plurality of light emitting elements, a hollow portion conical inside A cone-diffusion cylinder provided with a scattering plate through which the bottom of the conical hollow portion is opened , an opening communicating with the outside at the apex is provided, and a light-diffusing and transmitting plate is provided on the conical bottom of the conical hollow portion; a light emitting device for a light-emitting element appropriate emission is made, said conical dispersion drum irradiates the measurement object from the opening of the apex of the cone dispersion drum is transmitted through the scattering plate of the conical bottom portion of the light which the light emitting element is generated makes position so, Toi
Take technical measures.

Preferably, the plurality of light emitting elements are provided on a circumference centered on a conical axis of the conical diffusion cylinder.

[0011]

According to the spectroscopic measurement apparatus of the present invention, near-infrared light having an arbitrary wavelength relating to the components of the object is irradiated on the object, and the transmitted or reflected light of the object is received. The respective light amounts are obtained, and the absorbance of the measured object at the wavelength is obtained from the respective light amounts. Then, the obtained absorbance is substituted into a component amount estimating equation of a predetermined object to be measured, and the component amount is directly nondestructively calculated.
The component amount estimation formula is calculated by multiple regression analysis based on the absorbance when irradiating near-infrared light of a specific wavelength to the DUT whose component amount is known, and the actual component amount of the DUT whose component amount is known. It was done.

The light source unit for irradiating the object to be measured with near-infrared light emits light from a plurality of light emitting elements in the light source unit toward the object to be measured. Light emitted from the plurality of light emitting elements is:
The light having a specific wavelength in the near infrared region is incident on the scattering plate by a narrow band filter or the like. Within the thickness of the scattering plate, light is repeatedly diffused and transmitted, and the light is diffused and loses directivity. The light lost directivity emitted from the scattering plate is then incident on the internal conical dispersion drum, inside the conical dispersion drum,
Light is further reflected and diffused in the space surrounded by the conical diffusion cylinder and the scattering plate, and is incident on the light quantity detection means from the opening at the vertex. At this time, the light is reflected and diffused one or more times by the conical diffuser which is inclined in a conical manner and reaches the light amount detecting means from the opening. The object to be measured can be uniformly irradiated.

[0013] Further, since the plurality of light emitting elements are provided on a circumference centered on the conical axis of the conical diffusion cylinder, a plurality of light emitting elements used for measurement are provided in order to secure measurement accuracy. In addition, the distance between each light-emitting element having a different wavelength and the conical axis of the conical diffusion cylinder becomes equal, so that the light from any light-emitting element can be evenly applied to the measured object.

[0014]

Suitable examples EXAMPLES The present invention, by irradiating near infrared light to the leaves, as an example spectroscopic measurement apparatus to measure calculating nitrogen or the like is a component obtained from the absorbance and the absorbance explain. Those shown in FIG. 1 is a side sectional view of a spectroscopic measurement apparatus 1 main portion of the portable. In FIG. 1, the book
The light source unit 3 is provided in the body 2, and a photodiode 5 as a light amount detection unit 4 is provided above the light source unit 3. The light source unit 3 includes a plurality of LEDs 6 which are light-emitting elements having different wavelength peaks on the same circumference, and the LEDs 6 are provided with narrow-band filters 7 having different wavelength bands. Wavelength band is 600nm ~ 1100n
At m, a narrow-band filter 7 of an arbitrary specific wavelength related to a component to be obtained is selected from this wavelength band. Each LE
Emitting light of D6 is a light of a specific wavelength by the narrow band filter 7, light enters the permeable scattering plate 8. The scattering plate 8 is provided perpendicular to the optical axis so that the light beam of each LED 6 is incident substantially perpendicularly, and is formed in a circular ground glass shape. The scattering plate 8, LED 6 side or are formed frosted surface to either the object to be measured 9 side. Also, polished surfaces may be formed on both the LED 6 side and the DUT 9 side. When light enters the scattering plate 8, the diffusion plate 8
Within this thickness, light diffuses and loses directivity. The light emerging from the scattering plate 8 then enters the conical diffusion cylinder 10.
The conical diffusion cylinder 10 has a hollow conical shape, and the diffusion plate 8 is fixed to the bottom, and light emitted from the scattering plate 8
In toward bored an opening 12 at the top so as to collect light, one <br/> or to form an inner wall the scattering wall 11. The scattering wall 11
Is preferably formed of , for example, pure aluminum, or aluminum may be subjected to a satin finish. In the conical diffusion cylinder 10, the light exits from the opening 12 while repeatedly reflecting and diffusing light in the space surrounded by the scattering wall 11 and the scattering plate 8, and enters the light quantity detection means 4 via the transparent glass plate 13. . The light amount detection means 4 is arranged at an arbitrary interval from the light source unit 3,
More specifically , the light source unit 3 is fixed to the transparent glass plate 13 with an interval at which the leaf 9 to be measured can be inserted.

An upper cover 14 is provided on the outer periphery of the upper part of the light quantity detecting means 4.
The arm 15 extending from the upper lid 14 is pivotally supported by a fulcrum 16. Furthermore, the upper cover 14
A push button 17 for pushing up the arm 15 is provided, and the coil spring 1 is urged in a direction opposite to the push button 17.
8 is provided. A switch 19 for detecting that the push button 17 has been pressed down is provided on the main body 2 facing the push button 17 with the arm 15 interposed therebetween .

Next, based on FIG.
Will be described. The transmitted light amount of the sample leaf 9 to be measured detected by the measuring unit including the light source unit 3 and the light amount detecting means 4 is converted into an analog signal by the photodiode 5 and communicated to the analog board 20. The light source unit 3 is provided with a light emitting device 21 of the LED 6. A / D from analog to digital signal in analog board 20
Conversion or V / F conversion from voltage to frequency. Converted signal, via the I / O board 22, is input to the CPU board 23 including the operation of the arithmetic and control unit. The I / O board 22, measurement results, calculation results or the liquid crystal display device for displaying an operation instruction LCD 24, a keyboard 25 for inputting and operation of the initial data, RS232C connection port 26 for inputting and outputting external device and data And a switch. These CPU board 23 and I
The / O board 22 is connected to supply power from a power supply board 27. The printer 29 is connected to the CPU board 23 via the printer I / F board 28.

The spectroscopic analyzer 1 thus constructed
The operation of will be described below. First, when a reference sample having a known component amount is inserted into the spectroscopic measurement apparatus 1 and measured, the CPU board 23 determines the absorbance of the reference sample when irradiating near-infrared light and the actual component amount of the reference sample. Is used to calculate a component amount estimation formula. And
This is stored in the CPU board 23 having the function of a storage device.

Next, when a reference sample is taken out from the spectroscopic analyzer 1 and the sample leaf 9 is inserted and the power is turned on, a light emission signal is sent from the CPU board 23 to the light source unit 3 via the light emitting device 21. Then, light is emitted from the plurality of LEDs 6 in the light source unit 3 toward the sample leaf 9 to be measured. The light emitted from each LED 6 is converted into light having a specific wavelength in the near-infrared region by the narrow band filter 7 and is incident on the scattering plate 8 through which the light is transmitted. Within the thickness of the scattering plate 8, light is repeatedly diffused and transmitted, and the light is diffused and loses directivity. The light that has lost the directivity from the scattering plate 4 then enters the conical diffusion cylinder 10. The in conical dispersion drum 10, a space surrounded by the scattering wall 11 and a scattering plate 8 is the light incident from the transparent glass plate 13 while repeating reflection and diffuse further in the light quantity detecting section 4. At this time, the light incident into the conical diffusion cylinder 10 is transmitted once by the conical-inclined diffusion wall 11.
Since or arrives from the opening 12 a plurality of times reflected and diffused by the light quantity detecting section 4, without reducing the quantity of light of the light source is uniformly irradiated to the measured sample leaves 9 to the same extent as the integrating sphere.

When light is applied to the sample leaf 9 to be measured,
The transmitted light or the reflected light is received by the photodiode 5, photodetection signals are communicated to the analog board 20 for A / D conversion. The analog board 20 performs A / D conversion, and then inputs the signal to the CPU board 23 including the operation of the arithmetic and control unit via the I / O board 22. CP
In U board 23, it is as is also the transmittance of light from the transmitted light or reflected light of the measurement sample leaves 9 to calculate the absorbance.

[0020] In this manner, the calculated absorbance of the measured sample leaves 9, absorbance is substituted into previously stored the component amount estimation formula, component amounts are finally workers seeking of calculation Is done.

In some cases, the CPU board 23 is provided with a light source lighting routine in which the LEDs 6 are turned on for a certain period of time at regular intervals. In this light source lighting routine, each LED 6 having a different wavelength peak is turned on, and the amount of transmitted light of the sample leaf 9 to be measured is measured for each wavelength. Thus, the better the accuracy of measurement of the transmitted light amount of the measurement sample leaves 9, the measurement accuracy of the absorbance of the sample leaves the measurement is improved to further.

[0022]

As described above, according to the spectroscopic measurement apparatus of the present invention, the light source section has a light source including a plurality of light emitting elements and a conical hollow portion inside , and the conical hollow portion. A conical diffusion cylinder provided with an opening communicating with the outside at the apex by opening the bottom of the cone , and a scattering plate through which light is transmitted while diffusing at the conical bottom of the conical hollow portion, and the light emitting element is appropriately disposed. Since the light-emitting device emits light, the conical diffusion cylinder is positioned so that light from the light-emitting element is transmitted through the scattering plate at the bottom of the cone and illuminates the device under test from the opening at the top of the conical diffusion cylinder. When light is incident on the scattering plate, the light is diffused within the thickness of the scattering plate and loses directivity. Further, when light is incident on the conical diffusion cylinder, the light is diffused by the conical diffusion cylinder that is inclined in a conical shape. once or multiple times reflected and diffused by the light amount detection from the opening Since reaching the unit, without reducing the quantity of light of the light source, uniformly and it is possible to irradiate light to the object to be measured to the same degree as the integrating sphere. Then, machining of the spherical surface in the case of manufacturing the integrating sphere is simplified, and it can be manufactured at lower cost than using the integrating sphere.

Further, the plurality of light emitting elements, so is provided on a circumference around the cone axis of said conical dispersion drum, to ensure measurement accuracy, provided a plurality of light emitting elements used in the measurement In this case, the distance between each light-emitting element having a different wavelength and the conical axis of the conical diffusion cylinder became equal, so that the light of any light-emitting element could be evenly applied to the object to be measured.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a spectroscopic analyzer of the present invention.

FIG. 2 is a block diagram of a spectroscopic analyzer.

FIG. 3 is a schematic view showing a conventional representative chlorophyll meter.

FIG. 4 is an optical measuring section of a conventional component amount measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spectroscopic analysis measuring device 2 Main body 3 Light source part 4 Light quantity detection means 5 Photodiode 6 LED 7 Narrow band filter 8 Scattering plate 9 DUT 10 Conical diffusion cylinder 11 Scattering wall 12 Opening 13 Transparent glass plate 14 Upper lid 15 Arm 16 Support point 17 push button 18 coilSpring  19 Switch 20 Analog Board 21 Light Emitting Device 22 I / O Board 23 CPU Board 24 Liquid Crystal Display LCD 25 Keyboard 26 Connection Port 27 Power Board 28 I / F Board 29 Printer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 G01J 3/00-3/52 Practical file ( (PATOLIS) Patent file (PATOLIS)

Claims (2)

(57) [Claims] 1. A light source unit for irradiating an object with near-infrared light of an arbitrary wavelength, a light amount detecting unit for receiving transmitted light or reflected light from the object, and a transmitted light amount obtained from the light amount detecting unit Or while calculating the absorbance of the measured object from the reflected light amount, the component amount estimation formula by the absorbance and the known component amount obtained when irradiating the near-infrared light to the object whose component amount is known in advance determined, a molded amount estimation formula and said calculating means for calculating a component of the object to be measured by the absorbance of the measured object, spectroscopic measurement apparatus consisting of, said light source unit includes a plurality of light emitting elements A light source, having a conical hollow portion inside, opening the bottom of the conical hollow portion, providing an opening at the apex communicating with the outside, and diffusing light to the conical bottom portion of the conical hollow portion. A conical diffusion cylinder provided with a scattering plate that transmits while A light emitting device that appropriately emits light from the light emitting element, wherein the conical diffusion cylinder irradiates the object to be measured from the opening at the apex of the conical diffusion cylinder by transmitting light generated by the light emitting element through a scattering plate at the bottom of the cone. Spectroscopic analysis measuring device characterized by being positioned as follows. 2. The spectroscopic analyzer according to claim 1, wherein the plurality of light emitting elements are provided on a circumference centered on a conical axis of the conical diffusion cylinder.