JPH03160344A - Device for measuring constitutions of vegetable and fruit - Google Patents

Abstract

PURPOSE:To enable instantaneous and highly precise measurement of constituents by near- infrared rays by dispercing a reflected light into spectral lights of a number of wavelength bands and by converting them into electric signals by a detector array wherein a plurality of detecting elements are arranged. CONSTITUTION:A measuring head unit 1 having a light-projecting device 1a inside irradiates vegetable 2 and a reflected light therefrom is made to enter a spectroscope 10 through an optical fiber 3. A diffraction grating 22 provided in the spectroscope 10 disperses the light into a plurality of spectral lights of different wavelengths and the light of each wavelength band enters each of detecting elements of a detector array 11 and is subjected to photoelectric conversion. An electric signal therefrom is inputted to an arithmetic unit 24 together with an electric signal of a reference light which is made to enter a light-sensing element 7 through the other optical fiber 3a and subjected to photoelectric conversion, and thereby a constituent of vegetable 2 is measured. Since the reflected light from the vegetable 2 is dispersed into spectral lights of a number of wavelength bands and the light of each wavelength band is converted into the electric signal by the detector array 11 made up of a number of detecting elements in this way, the constituents of the vegetable 2 can be measured instantaneously and highly precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a fruit and vegetable component measuring device for use in fruit sorting machines and the like.

[Conventional technology]

Conventional fruit sorting machines, etc., are used to measure the content of fruits and vegetables by indirectly estimating the components based on the shape of the fruits or vegetables, or by measuring the concentration of chlorophyll using light with a wavelength of 685 nm. However, there were methods to indirectly determine ripeness and sugar content. Furthermore, as a conventional measurement of content components, a diffraction grating type analyzer has been used. This analyzer is a device that sends light through a rotating diffraction grating from a slit, and sequentially extracts the separated light from a slit on the opposite side. When this device is used, the contents of fruits and vegetables can be directly and quickly detected. For example, it is difficult to measure several fruits and vegetables per second.

[Problems that the invention helps solve]

In the conventional measurement of content components of fruits and vegetables, etc., rather than rotating the diffraction grating, stopping it when dispersing each wavelength, and rotating it when dispersing the next wavelength, the method repeats rotation and braking. However, the measurement time was long, and the accuracy was poor because the measurement results were affected by changes in the light source, temperature, environment, etc.

The present invention provides an apparatus that can instantly, accurately, and non-destructively measure the contents of fruits and vegetables using near-infrared rays.

[Means to solve the problem]

The fruit and vegetable component measuring device of the present invention has a measuring head section which has a light projecting section and a condensing lens inside and is applied to the fruit or vegetables whose content components are to be measured, and one optical fiber to which one end of the measuring head section K is connected. A spectrometer has a diffraction grating that inputs reflected light from fruits and vegetables from the other end and separates it into multiple lights with different wavelengths, and a multiple spectrometer that each receives light with different wavelength bands separated by the same spectrometer. a detector array in which detection elements are arranged; a light receiving element that receives reference light through a filter from the other end of the other optical fiber, one end of which is connected to the measurement head; and an electrical It is characterized by being equipped with an arithmetic unit that measures the components of fruits and vegetables by inputting eight signals.

[Effect]

In the above, when the fruit and vegetable κ measurement part is applied to the fruit and vegetables whose content components are to be measured, and the light emitting part provided inside the fruit emits light, it is diffusely reflected inside the fruit and the fruit, and the reflected light is passed through the condensing lens. The light is focused and illuminates one end of the light 71.

The reflected light irradiated onto one end of the same light beam 77 passes through the optical fiber and enters the spectroscope from the other end. Inside the spectrometer, the reflected light is split into multiple lights with different wavelengths, and the light in each wavelength band is transmitted to each detection element of the detector array, depending on the intensity of the light for each wavelength. is converted into an electrical signal.

In addition, reference light enters the light receiving element from the measurement head section through the other light beam 71 and the filter, and is converted into an electrical signal. The respective electrical signals output from the detector array and the light receiving element are input to the calculation section,
The calculation unit calculates the absorption rate for each wavelength band of light, and uses the absorption rate to calculate the concentration of components of fruits and vegetables.

According to the above, when it comes to conventional equipment, only one piece is required? A song that makes it easier to instantly and accurately measure the components of fruits and vegetables, which used to take minutes of measurement time.

〔Example〕

An embodiment of the present invention is shown in Figs. 1 to 4. An embodiment of the present invention shown in Figs. , an optical fiber 3 having one end connected to the same measuring head part 1 and a fiber end 5 at the other end, a spectrometer having a mirror 23 and a diffraction grating 22, into which reflected light from fruits and vegetables 20 enters from the fiber end 5 of the same optical fiber 3. 10, a detector array 11 in which 100 or more detection elements (made of germanium or lead sulfide, for example) are arranged, each receiving light in different wavelength bands separated by the spectrometer 10 and converting it into an electrical signal; The detector array 11 is a current amplifier 12 and a differential calculation processor 1.
3, an output terminal 14 connected to the electric wire κ through 3, an optical fiber 3m with one end connected to the measuring head 1 and the other end 4, and a fiber end 4 of the same optical fiber 3a.
A light-receiving element 7 receives light through a visible light filter 6, an output terminal 9 to which the light-receiving element 7 is connected by an electric wire via a current amplifier 8, and an arithmetic unit to which the output terminals 9 and 14 are connected. It is equipped with 24.

The measuring head section 11 is connected to a fruit or vegetable 2 as shown in FIG.
A rubber disturbance light shield 20 is provided at the contact portion with the
Inside, there is a 7-door 17 whose inner surface is gold-plated to allow light reflected by the fruits and vegetables 2 to enter therein, a rubber light shield 16 disposed at one end of the hood 17 that comes into contact with the fruits and vegetables 2, and other parts of the hood 17. A condensing lens 15 disposed at the end, a fiber end 18 of the optical fiber 3 which receives reflected light from the fruits and vegetables 2 through the condensing lens 15 and is disposed as shown in FIG. A light projecting device 1a is provided on the outside as shown in FIG. 4K.

Above! ? The near-infrared rays emitted from the projector 1a to the fruits and vegetables 2 are diffusely reflected inside the fruits and vegetables 2, and the light is reflected by the 7-door 17 whose inner surface is gold-plated, and then collected by the condenser lens 15. 7-eyeper end 18K can be applied.

The light hitting the fiber end 1B passes through the optical fiber 3 and reaches the fiber end 5, and from the fiber end 5 to the υ spectrometer 10.
Inside the spectrometer 10, the light reflected by the mirror 23 is separated into a plurality of different wavelength bands by the diffraction grating 22K. The light separated by the diffraction grating 22K is transmitted to a detector array 11 installed at the exit of the spectrometer 10.
More than 100 detection elements constituting the detector array 14 receive light in different wavelength bands and convert it into electrical signals.

After the electric signal is amplified by the current amplifier 12,
In order to clarify the change in the amount of light depending on the wavelength, it is differentiated by a differential calculation processor 13 and outputted from an output terminal 14.

Additionally, a reference light for correcting changes in the output of the light source, changes in the position of fruits and vegetables, etc. is taken out from the measuring head section 11 through an optical fiber 3a, and is passed through a visible light filter 6 through fiber terminals 4 and b. The light is guided to the light receiving element 7 and subjected to photoelectric conversion.

The photoelectrically converted electrical signal is amplified by the current amplifier 8 and guided to the output terminal 9.The electrical signal A2B outputted from the output terminals 14 and 9, respectively, is
is input.

In the arithmetic unit 24, the absorption coefficient α is calculated for each wavelength band using the following formula: absorption coefficient α=jnA/B.
The components of fruits and vegetables and their concentrations Cx can be determined from the absorption coefficient α for each wavelength band.

Next, the results of tests conducted using the apparatus of this example will be explained. Using the apparatus of this example, 600 nm
As a result of determining the relationship between the sugar content and absorbance of peaches for the wavelength at 2500nmt, in the case of 1784nrn, the sugar content calculated from the absorbance has a multiple correlation coefficient with an error of 0.50φ sugar content compared to the sugar content measured with the Brlx meter. was 0.95. 1. As a result of testing other wavelengths highly correlated with sugar content, 1148 nm, 900 nm and 845 nm
Since similar results were obtained for these wavelengths, it was found that m degrees can be measured with high accuracy by using the absorption rate of light at these wavelengths. The time required to measure the sugar content was 0.1 seconds per piece. Regarding the above test results, in the case of the conventional method in which the diffraction grating is rotated, the diffraction grating is rotated for each wavelength to perform spectroscopy, so for example, 600
If you perform spectroscopy every 2 nm from 1900 nm to 2500 nm, you will have to repeat the operation of moving and stopping the diffraction grating for 1900/2 = 950 wavelengths, and the time it takes to move and stop is about 0.1 seconds.
The actual measurement time is 0. Since it takes about 1 second and 0.19 seconds for one wavelength κ, it usually takes about 3 minutes.

In addition, in the case of conventional devices, wavelength reproducibility is poor because it is necessary to move and stop the diffraction grating, and as a result, the sugar content calculated from the absorbance has an error of 1.0% from the sugar content measured with a Brix meter. The sugar content and correlation coefficient were 0.8. As a result of the above, the reflected light from fruits and vegetables is separated into light in many wavelength bands and converted into electrical signals by a detector array consisting of many detection elements for each wavelength band, so it takes 3 minutes for each fruit to measure with conventional equipment. Component measurement of fruits and vegetables, which previously required a time-consuming process, can now be carried out instantaneously and with high precision.Another embodiment of the present invention is shown in FIG.

The present embodiment shown in FIG. 5 is an improved version of the measuring head section 1 of the above-mentioned embodiment shown in FIG. The light is applied to the fruits and vegetables 2 from the end of the χ fiber 21 passing through the condenser lens 15. The light diffusely reflected inside the fruits and vegetables 2 is collected by a condenser lens 15 and a condenser lens 19,
applied to the fiber end 18. The light passing through the fiber end 18 and the optical fiber 3 is guided to the reference optical fiber end 4 and the seven-eyeper end 5 on the spectrometer side.

In the case of this embodiment, since the light projecting device 1 is provided outside the measurement head section, it can be made more compact than the measurement head section shown in FIG. The device is CH, , CH, ,OH
, NH, and other functional groups, it can also be applied to the component analysis of foods other than fruits and vegetables that contain these functional groups.

〔Effect of the invention〕

In the fruit and vegetable component measuring device of the present invention, a measuring head section having a light projecting section inside irradiates the fruit and vegetable K light, and transmits the reflected light to a spectrometer via an optical fiber. The diffraction grating splits the light into multiple lights with different wavelengths, and the light in each wavelength band enters each detection element κ of the detector array and is photoelectrically converted, and the electrical signal is converted together with the electrical signal of the photoelectrically converted reference light. By inputting the information to the arithmetic unit, it is now possible to instantaneously and accurately measure the components of fruits and vegetables, which took three minutes per piece using conventional devices.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of one embodiment of the present invention, Fig. 2 is an explanatory diagram of the measuring head section of the above embodiment, and Fig. 3 is I-1 in Fig. 2.
4 is a view taken along the IV-ff arrow in FIG. 2, and FIG. 5 is an explanatory view of another embodiment of the present invention. l...Measurement hood part, la...Light emitter, 2...
・Fruits and vegetables, 3, 3a... Optical fiber, 4... Fiber end, 5... Fiber end, 6... Visible light filter, 7... Light receiving element, 8... Current amplifier, 9.
... Output terminal, 10... Spectrometer, 11-... Detector array, 12... Current amplifier, 13... Differential calculation processor, 14... Output terminal, 15... Condenser lens, 16...Rubber light shield, 17...
Hood, 18...Fiber end, 19. One converging lens,
20...Rubber disturbance light shield, 21...-L77 fiber, 22...Diffraction grating, 23...
...Mirror 24...Arithmetic section.

Claims (1)

[Claims] A measuring head section has a light projecting section and a condensing lens inside and is applied to the fruits and vegetables whose content components are to be measured.One end of the measuring head section is connected to the other end of one optical fiber, and the reflected light from the fruits and vegetables is input into the measuring head section. A spectrometer has a diffraction grating that separates light into multiple light beams with different wavelength bands, and a detector array has multiple detection elements each receiving the light beams with different wavelength bands separated by the spectrometer. , a light-receiving element that receives reference light from the other end of the other optical fiber, one end of which is connected to the measurement head section through a filter; A component measuring device for fruits and vegetables, characterized by comprising a calculating section for measuring.