JPH0518924A - Method and sensor for judging ripening degree of fruit and the like - Google Patents

Abstract

PURPOSE:To detect ripening degree readily without damaging a fruit by measuring the change in conductivity or dielectric constant of the fruit and the like with a ripening-degree judging sensor, and judging the ripening degree of the content. CONSTITUTION:The head of a ripening-degree judging sensor S is brought close to or into contact with the surface of the exodermis of a fruit A. When an operating switch 24 is turned ON, a high-frequency electromagnetic field is applied on an exciting electrode 16 from a high-frequency oscillator 19. The electromagnetic wave oscillated in the electrode 16 is received with a receiving detecting coil 17. The result is displayed on a DC voltmeter 23 through a high-frequency detecting diode 22. Thus, a resonance peak is observed in a certain frequency. Namely, the resonance peak in a certain frequency is associated with conductivity. The resonance peak in a certain frequency is associated with dielectric constant. Therefore, the judging sensor S can detect the ripening degree by setting the frequency based on whether the inside of the fruit is conductive or inductive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the ripening degree of fruits and the like and a ripening degree determining sensor which can easily detect the ripening degree by detecting changes in the state of various fruits and the like.

[0002]

2. Description of the Related Art Conventionally, the above-mentioned determination of the ripening degree of fruits and the like has been performed by a visual method, a sense of smell, and a tactile sense of the color, fragrance, softness, etc. (sensory test), and component analysis of sugar content, etc. There is a component analysis method for quantitatively measuring using a device or the like.

[0003]

However, in the method of sizing, the criteria are ambiguous, and there are many uncertain factors such as the experience of the judge, the sharpness of the sense, and the value standard.

On the other hand, the component analysis method is not suitable for fieldwork because it requires the destruction of fruits or the like as a sample and is expensive or requires a component analysis device.

An object of the present invention is to provide a method for judging the ripening degree of fruits and the like which can solve the above-mentioned problems.

[0006]

Means for Solving the Problems The present invention is characterized in that the ripening degree of a content is determined by measuring a change in the electric conductivity or the dielectric constant of the fruit or the like with a ripening degree determination sensor, and ripening of the fruit or the like is characterized. It relates to a method of determining the degree.

Further, according to the present invention, the maturity determination sensor is provided with an exciting electrode connected to a high frequency oscillator, and a receiving detecting coil insulated from the exciting electrode and receiving an electromagnetic wave oscillated from the exciting electrode. The change in the state of fruits and the like around the receiving detection coil is detected as a change in the electric conductivity and permittivity by a change in the resonance voltage or resonance frequency induced in the receiving detection coil. Also has features.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

First, referring to FIGS. 1 to 3, the structure of a sensor S for determining the ripening degree of fruits and the like according to the present invention will be described.

As shown in the figure, the shield container 11 is composed of a shield container body 12 and an insulator cover 13. The shield container body 12 is made of aluminum and has a diameter of 40
One end is closed by about mm, and an insulating cover 13 is attached to the open end side of the shield container body 12 via a packing 14.

An insulating plate 15 is provided inside the shield container 11 on the side of the insulating cover 13, and a disk-shaped excitation electrode 16 having a thickness of about 0.5 mm is provided inside the insulating plate 15. As is apparent from FIG. 3, a planar spiral receiving detection coil 17 is provided on the plate 15 on the side of the insulator cover 13.

That is, the excitation electrode 16 and the reception detection coil
The sensor head consisting of 17 is placed in a non-contact state with a fruit A such as a mandarin orange (see FIG. 4).

A high frequency oscillator 19 using a dry battery 18 as a power source is built in the shield container 11, and one output terminal of this high frequency oscillator 19 is connected to an excitation electrode 16 by a lead wire 20 and the other output terminal ( (Ground terminal) is shield net 21
It is connected to the. The reception detection coil 17 is connected to a DC voltmeter 23 via a high frequency detection diode 22.
Further, 24 is an operation switch provided on the top of the shield container body 12.

Next, a method of determining the ripening degree of the fruit A by the ripening degree determination sensor S having the above structure will be described with reference to FIG.

Now, the sensor head of the maturity determination sensor S is brought closer to or in contact with the surface of the outer skin a of the fruit A.

Next, by turning on the operation switch 24, the high frequency oscillator 19 excites a high frequency electromagnetic field.
A resonance peak can be observed at a certain frequency by applying the electromagnetic wave oscillating from the exciting electrode 16 to the receiving detecting coil 17 and applying the electromagnetic wave to the exciting electrode 16. Figure 5 shows the measurement results.
Shown in.

In FIG. 5, the frequency F ₁ is related to the electric conductivity, and the peak increases as the electric conductivity increases. The resonance peak at frequency F ₂ is related to the dielectric constant, and the peak also increases as the dielectric constant increases.

Therefore, when the inside b of the fruit A is electrically conductive, it is set near the frequency F ₁ , and when the inside b is dielectric, it is set near the frequency F ₂ . The corruption determination sensor S can easily detect the degree of maturity inside.

As described above, in this embodiment, the excitation electrode 16
Since the fruit can be disposed outside the fruit A, even if the inside of the fruit A cannot be visually observed, the ripening degree can be expressed by a current value or a voltage value, so that the decay determination can be easily and accurately performed. Further, since the sensor head of the ripening degree determination sensor S may simply be applied to the fruit A, the measurement can be easily performed and the fruit or the like is not damaged. Further, since the maturity determination sensor S is substantially composed of only the high frequency oscillator 19, the excitation electrode 16 and the reception detection coil 17, it can be manufactured inexpensively and in a small size.

[0020]

[Effect] As described above, in the present invention, the state of the ripening degree of the fruit or the like is determined by measuring the change in the electric conductivity or the dielectric constant inside the fruit or the like by the ripening degree determination sensor. Further, the maturity determination sensor, the excitation electrode connected to the high-frequency oscillator, and is insulated from the excitation electrode,
It is composed of a receiving detection coil that receives electromagnetic waves oscillated from the excitation electrode, and changes in internal properties of fruits and the like that surround the receiving detection coil are induced in the receiving detection coil as changes in electrical conductivity and dielectric constant. It is configured so as to be detected by a change in resonance voltage or resonance frequency.

Therefore, since the excitation electrode can be arranged outside the fruit or the like, even if the inside of the fruit or the like cannot be visually inspected, the ripening degree is expressed by the current value or the voltage value, so that it can be rotted easily and accurately. A decision can be made. Further, since the sensor head may be simply applied to the fruit or the like, the measurement can be easily performed and the fruit or the like is not damaged. Further, since the maturity determination sensor is substantially composed of only the high frequency oscillator, the excitation electrode and the reception detection coil, it can be manufactured inexpensively and in a small size.

[Brief description of drawings]

FIG. 1 is a perspective view of a sensor for determining maturity of fruits and the like.

FIG. 2 is an explanatory diagram of an internal structure of the maturity level determination sensor.

3 is a view taken along line I-I of FIG.

FIG. 4 is an explanatory view of a usage state of the sensor for determining the maturity of fruits and the like according to the present invention.

FIG. 5 is a graph showing the relationship between the resonance voltage and the resonance frequency of fruits and the like.

[Explanation of symbols]

A fruit S Maturity judgment sensor 16 Excitation electrode 17 Receiver detection coil 19 high frequency oscillator

Claims (3)

[Claims] 1. A method for determining the ripening degree of fruits or the like, which comprises measuring a change in the electric conductivity or the dielectric constant of the fruits or the like with a ripening degree determination sensor to determine the ripening degree of the contents. 2. The maturity determination sensor comprises an excitation electrode connected to a high-frequency oscillator, and a reception detection coil insulated from the excitation electrode and receiving an electromagnetic wave oscillated by the excitation electrode for reception. A change in the state of fruits or the like forming the periphery of the detection coil for use is detected as a change in the electric conductivity or the dielectric constant by a change in the resonance voltage or the resonance frequency induced in the reception detection coil. 1. A method for judging the ripening degree of fruits and the like according to 1. 3. An excitation electrode connected to a high-frequency oscillator, and a reception detection coil insulated from the excitation electrode and receiving an electromagnetic wave oscillated from the excitation electrode,
A fruit characterized by being configured to detect a change in the state of a fruit or the like around the receiving detection coil as a change in electric conductivity or dielectric constant by a resonance voltage or a change in resonance frequency induced in the receiving detection coil. A sensor for determining the maturity level of the product.