JPH11337480A - Apparatus and method for measuring quality in fruits and vegetables - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of overvoltage in such a case that fruits and vegetables are not present between a floodlight projector and a photodetector in an apparatus for measuring quality in fruits and vegetables in a non- destructive manner by using light. SOLUTION: In an internal quality measuring apparatus, the presence and absence of fruits and vegetables between a floodlight projector and a photodetector are judged from the intensity of detected near infrared rays and, when fruits and vegetables are judged to be absent, predetermined reference voltage of the same level as that at a time of the shading of light is sent to an amplifying circuit by a voltage signal changeover circuit 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to oranges, melons,
The present invention relates to a device for non-destructively measuring the quality such as internal sugar content of fruits and vegetables such as watermelon, and more particularly to the prevention of the occurrence of overvoltage in an evaluator system generated when measuring the internal quality of many fruits and vegetables in a continuous transport state. .

[0002]

2. Description of the Related Art Generally, the evaluation of the internal quality of fruits and vegetables at the time of shipment has been carried out mainly by visual inspection of a skilled inspector. In addition, certain kinds of fruits and vegetables have a problem that if they are harvested or shipped in a ripe state, the taste at the time of sale is reduced, the flesh is pulverized, and the like.
For this reason, the fruits and vegetables are harvested in an unripe state, then ripened by leaving them at a constant temperature, and shipped after being made suitable for edible use. Completion of the maturation was visually judged by a skilled inspector or the like. However, there is no clear standard for the judgment of the internal quality as described above, and it is difficult to make an accurate judgment.

On the other hand, when near-infrared light is projected on fruits and vegetables,
Since components such as carbohydrates in fruits and vegetables absorb light of a specific wavelength, it is possible to know the internal quality such as sugar content of fruits and vegetables by analyzing the transmitted light transmitted through the fruits and vegetables. There is known a method of non-destructively determining the internal quality of fruits and vegetables using transmitted light.

[0004] Specifically, FIG. 3 shows an example of a schematic diagram of a device for measuring the internal quality of fruits and vegetables. In FIG. 3, a plurality of subjects 5 are continuously measured while the subjects 5, which are fruits and vegetables, are conveyed on a conveyor 10 such as a conveyor. First, the presence of the subject 5 is confirmed by the position sensor 11 on the transport means. Next, a predetermined position A on the transporting means 10
In this case, the light source 1 irradiates the subject 5 with light having a predetermined frequency range (hereinafter referred to as near-infrared light). The irradiated light is transmitted to the outside of the subject 5 after near-infrared light having a predetermined wavelength is absorbed by a saccharide or the like existing in the subject 5. The transmitted near-infrared light is measured by the light receiving element 2, and the transmitted light obtained by the measurement is analyzed by the signal processing device 12, so that the internal quality of the subject 5 can be known.

[0005]

However, in general, the above-described evaluation in the process of sorting fruits and vegetables must be performed in a state where the subject is transported by a transport system such as a belt conveyor. In this case, the subject 5 is placed on the belt conveyor.
Are randomly arranged and the analysis time allowed for each individual subject is very short. Under such measurement conditions, it is effective for the light source 1 to continuously emit near-infrared light to shorten the measurement time.

However, in this case, a state occurs in which the subject 5 is not between the light source 1 and the light receiving element 2 during transportation, and the light receiving element 2 directly receives near-infrared light. As a result, the baseline of the measured value of the signal processing device 12 connected to the light receiving element 2 (a reference value for measurement) fluctuates or the signal processing device 1 is caused by the occurrence of an excessive voltage.
2 causes a problem such as deterioration of the signal processing capability itself due to a rise in the temperature of the internal circuit.

According to the present invention, the subject 5 includes the light source 1 and the light receiving element 2.
In consideration of the above-mentioned problem in a state that is not in between, the initial setting of the signal processing apparatus 12 may be shifted in this state, or the temperature of the internal circuit of the signal processing apparatus 12 may increase due to the generation of an excessive voltage. Eliminate the deterioration of signal processing capability itself,
It is an object of the present invention to provide an internal quality measuring device that enables accurate internal quality measurement even in a state in which a subject is transported.

[0008]

In order to solve the above-mentioned problems, an apparatus for measuring the internal quality of fruits and vegetables according to the present invention comprises a conveying means for conveying fruits and vegetables in a predetermined direction, and a sensor for confirming the presence of the fruits and vegetables being conveyed. A light projecting means for projecting light having a predetermined frequency range to the fruits and vegetables, a light receiving means for receiving the light transmitted through the fruits and vegetables, and calculating intensity data according to the transmitted light received by the light receiving means. A fruit and vegetable internal quality nondestructive measurement device having a light reception signal processing circuit and an internal quality calculation circuit that calculates the internal quality of the fruit or vegetable using the intensity data, wherein the light reception signal processing circuit further converts the transmitted light into a voltage signal. A signal conversion circuit, a comparator circuit for comparing whether the voltage signal is greater than a predetermined voltage value, and a voltage signal to the amplifier circuit when the voltage signal is smaller than the predetermined voltage value. A voltage signal switching circuit that sends a predetermined reference voltage to the amplifier circuit when the voltage signal is larger than a predetermined voltage value; an amplifier circuit that amplifies the voltage signal; and a calculation circuit that calculates intensity data from the amplified voltage signal. It is characterized by having.

[0009]

As described above, in the light receiving signal processing circuit, the transmitted light is converted into a voltage signal by the signal conversion circuit, and the voltage signal is amplified by the amplifier circuit and used for calculating intensity data. Here, when there is a fruit or vegetable between the light emitting means and the light receiving means, the voltage signal is determined by the comparison circuit to be smaller than the predetermined voltage value, and the voltage signal is sent to the amplifier circuit as it is to calculate the intensity data. Used for

When there is no fruit or vegetable between the light projecting means and the light receiving means, the voltage signal is determined to be larger than a predetermined voltage value, and a predetermined reference voltage is sent to the amplifier circuit by the voltage signal switching circuit. . As described above, generation of an excessive voltage in the light receiving signal processing circuit can be eliminated, and deviation of the initial set value and deterioration of the signal processing ability can be prevented.

Further, by comparing a voltage signal when there is no fruit or vegetable between the light emitting means and the light receiving means and a predetermined voltage value, initial setting of the light receiving means is performed for each measurement, or inspection of the light emitting means is performed. Is also good. Initial setting of each variable at the time of calculating intensity data or each variable at the time of calculating internal quality by CPU etc. by a predetermined reference voltage sent to the amplifier circuit when there is no fruit or vegetable between the light emitting means and the light receiving means May be performed.

In order to obtain a more accurate measurement result of the internal quality, the transmitted light is divided into a predetermined number of frequency regions, and a corresponding light receiving signal processing circuit is provided for each of the divided frequency regions. A plurality of light receiving signal processing circuits may simultaneously calculate intensity data. In that case, each light receiving signal processing circuit may have the above-described comparator circuit or the like, or only the light receiving signal processing circuit corresponding to a specific frequency region may have a comparator circuit or the like.

[0013]

FIG. 1 is a block diagram showing a signal processing according to an embodiment of the present invention, and FIG. 2 is a block diagram including a comparator circuit. Conveying means 10, position sensor 11, light source 1, photodiode 2, signal processing device 12, and near-infrared light (light having a predetermined frequency range) emitted from light source 1 to subject 5
Since there is no difference from the prior art until the transmitted light is transmitted from the non-sample 5 and the transmitted light is received by the photodiode 2, the description is omitted here. Hereinafter, a signal processing routine after the transmitted light is received by the photodiode 2 in the present embodiment will be described.

The split optical spectrum is converted to a current by the photodiode 2, and the current is further converted to a voltage signal having the voltage value V 1 by the current-voltage conversion amplifier 22. As shown in FIG. 2, the comparator circuit 31 compares the voltage value V1 with the voltage value V2 applied from the comparison voltage generation circuit 32.

Here, when the subject 5 is not in front of the photodiode 2 and near-infrared light is received by the photodiode 2 as it is, a very large current is generated in the photodiode 2 and further a current-voltage conversion is performed. The signal is converted by the amplifier 22 into a voltage signal having an excessive voltage value V1. The comparator circuit 31 compares the voltage value V1 with the voltage value V2, determines that V1 ≧ V2, and outputs a voltage signal applied to the gain amplifier 23 by the voltage signal switching circuit 33 to the reference voltage generation circuit 34 in a light-shielded state. Is switched to a voltage signal having a voltage Vd equal to the voltage generated in the above.

When the subject 5 is in front of the photodiode 2 and near-infrared light is received by the photodiode 2 as transmitted light, the comparator circuit 31 a
It is determined that <V2, and the voltage signal having the voltage value of V1 is applied to the gain amplifier 23 as it is. The above operation is performed when the subject 5 is transported, so that an excessive voltage is not generated by the gain amplifier 23, and the deviation of the initial set value at the time of calculating the intensity data and the deterioration of the evaluation capability of the evaluation machine system. Can be prevented.

After the voltage value is amplified by the gain amplifier 23, the noise component is cut by the low-pass filter 24, and the frequency is converted by the voltage-frequency converter 25. Thereafter, the frequency is counted by the counter 26 during a predetermined integration time t. The counted frequency is input to the CPU 27 as intensity data D = f × t of the transmitted light received by the photodiode 2.

The intensity data input to the CPU 25 is converted into internal quality data by performing a predetermined operation.
These are displayed as images on a CRT or the like. In addition, the image display may be a format in which only the suitability of shipment of the non-sample 5 is displayed based on, for example, a predetermined sugar content or the like. Further, only the suitability data is output without performing the image display, and connected to the measuring apparatus. The sorting of the non-sample 5 may be performed in the transfer device.

[0019]

According to the present invention, when there is no fruit or vegetable between the light projecting means and the light receiving means, a predetermined reference voltage having the same level as that at the time of shading is sent to the amplifier circuit by the voltage signal switching circuit. This makes it possible to eliminate the occurrence of excessive voltage in the evaluation system even when the near-infrared light is continuously emitted and the internal quality of fruits and vegetables is evaluated intermittently. And the deterioration of the evaluation ability can be prevented.

[Brief description of the drawings]

FIG. 1 is a signal processing block diagram according to an embodiment of the present invention.

FIG. 2 is a block diagram related to a comparator circuit according to the embodiment of the present invention;

FIG. 3 is a diagram showing a schematic configuration of a method for measuring the internal quality of fruits and vegetables using near-infrared light;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light source 2 light receiving element 5 non-sample 10 transport means 11 position sensor 12 signal processing device 22 current-voltage conversion amplifier 23 gain amplifier 24 low-pass filter 25 voltage-frequency converter 26 counter 27 CPU 31 comparator circuit 32 comparison voltage generation circuit 33 voltage signal switching Circuit 34 Reference voltage generation circuit

Claims (2)

[Claims] 1. A conveying means for conveying fruits and vegetables in a predetermined direction, a sensor for confirming the presence of the fruits and vegetables during conveyance, and a light projecting means for projecting light having a predetermined frequency range to the fruits and vegetables. A light-receiving unit that receives light transmitted through the fruit and vegetable, a light-receiving signal processing circuit that calculates intensity data using the transmitted light received by the light-receiving unit, and an internal quality of the fruit and vegetable using the intensity data. In the fruit and vegetable internal quality measurement device having an internal quality calculation circuit that calculates, the light reception signal processing circuit, a signal conversion circuit that converts the transmitted light into a voltage signal, an amplification circuit that amplifies the voltage signal, A calculating circuit for calculating intensity data from the amplified voltage signal; and the light receiving signal processing circuit further comprising: a comparing circuit for comparing whether the voltage signal is larger than a predetermined voltage value; A voltage signal switching circuit that sends the voltage signal to the amplifier circuit when the voltage signal is smaller than a predetermined voltage value and sends a predetermined reference voltage to the amplifier circuit when the voltage signal is larger than the predetermined voltage value. An apparatus for measuring the internal quality of fruits and vegetables, characterized in that: 2. In a state where the fruits and vegetables are transported on the transporting means, the presence of the fruits and vegetables is confirmed by a position sensor. Projecting light having a predetermined frequency range, and receiving light transmitted through the fruits and vegetables by light receiving means,
The received transmitted light is calculated as intensity data corresponding to the transmitted light by a received light signal processing circuit, and an internal quality calculation circuit calculates an internal quality of the vegetable using the intensity data. In the light receiving signal processing circuit, the transmitted light is converted into a voltage signal by a signal conversion circuit, and the voltage signal is amplified by an amplifier circuit and used for calculating intensity data. Before being amplified by the amplifier circuit, whether or not the voltage signal is larger than a predetermined voltage value is compared by a comparison circuit.If the voltage signal is smaller than a predetermined voltage value, the voltage signal is sent to the amplifier circuit, When the voltage signal is larger than a predetermined voltage value, a predetermined reference voltage is sent to the amplification circuit by a voltage signal switching circuit, wherein the inside quality of the fruits and vegetables is measured. Method.