JPS63293450A - Quality sorting method for citrus fruit - Google Patents

Abstract

PURPOSE:To sort defects which are hardly discriminated from appearances with high accuracy by forming an image of the gap pattern of a center part surrounded with the bunch of citrus fruit whose quality is to be inspected. CONSTITUTION:When a tangerine 30 which is carried in comes to right below an X-ray irradiated part, an X ray is transmitted through the tangerine 30. A transmitted X-ray image is obtained by this X-ray transmission, but this transmitted X-ray image differs in features with the quality state of the tange rine 30. Namely, the shape of the gap pattern nearby the center axis of the tangerine 20 which is given a mechanical shock and surrounded with a bunch of tangerines form a star shape whose border is sharp unless the mechanical shock is applied. When the border is no sharp, on the other hand the gap pattern of the star shape, etc., is deformed. For the purpose, the shape of the gap pat tern is analyzed to select a tangerine 30 having a latent rotting factor. Then, the tangerine 30 which is decided as a defective is fallen to beside a rubber belt 10 by a defective discharge part 28.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for quality selection of citrus fruits, and more particularly to a method for quality selection of citrus fruits that automatically screens out defects that cannot be identified from the appearance.

[Conventional technology]

Traditionally, citrus fruits, such as mandarin oranges, are classified into three types of quality: good and poor quality.In addition to visual inspection, the mandarin oranges are screened for defects such as deterioration, damage from pests, and damage that can be identified from their appearance, as well as their surface color, i.e. , depending on the degree of coloration of the fruit surface.
The fruits are classified into eight ranks, ranging in color from deep green to deep red.

[Problem that the invention seeks to solve]

However, there is no suitable inspection method for identifying defects that cannot be identified from their appearance, such as latent defects in mandarin oranges that have been subjected to excessive shock and have a poor shelf life and are easily perishable.
It could not be tested and was overlooked.

The purpose of the present invention was made in view of the above-mentioned state of the prior art, and it is an object of the present invention to provide a method for selecting the quality of citrus fruits, which allows defects that cannot be identified from appearance to be automatically selected with high accuracy.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention is characterized by imaging the void pattern in the center surrounded by clusters of citrus fruits to be inspected for quality, and sorting out whether the citrus fruits are good or bad based on the shape.

[Effect]

According to the above method, the shape of the void pattern in the center of the citrus fruit differs depending on the presence or absence of mechanical impact, and this shape can be imaged by transmitting X-rays or ultrasonic waves, so by processing the image, it is possible to distinguish between good and defective products. Sorting can be done automatically.

〔Example〕 Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a front view showing an inspection apparatus suitable for applying the present invention.

An endless rubber belt 10 is connected to a roller 1 in order to carry in a workpiece.
2a and 12b. An X-ray generator 14 that generates soft X-rays is disposed above a predetermined position on the horizontal portion of the endless rubber belt 10, and an imaging section is installed facing the X-ray generator 14 and with the rubber belt 10 interposed therebetween. 16 are arranged. Additionally, a lead glass window 18 is provided between the X-ray generator 14 and the rubber belt 10 to prevent X-rays from leaking outside.
is provided, and an X-ray generation power source 20 is installed adjacent to the X-ray generator 14.

The endless rubber belt 10 is rotationally driven using a roller 12b as a driving roller, and rotational force is transmitted to the roller 12b from a continuously variable transmission 22 via a belt 24.

A motor (not shown) is connected to the continuously variable transmission 22 as a drive source.

X-ray generator 14, imaging unit 16, lead glass window 18, power supply 2
0, the continuously variable transmission 22, and the like are housed in a shielding box 26 to prevent workers and the like from being exposed to X-rays. Further, each of the X-ray generator and the imaging section 16 is shielded.

2 to 4 show specific examples of the imaging unit 16, each of which is an imaging body that captures a transmitted X-ray image obtained when citrus fruits 30 are irradiated with X-rays (Xray).
This uses a T camera 32, a II camera 34, and a photodiode array 36.

In the configuration shown in FIG. 2, a transmitted X-ray image is formed into a visible image on a fixed imaging panel 38, and this is transmitted to the SI via a total reflection mirror 40.
An image is taken by a T camera 32. Further, in the configuration shown in FIG. 4, after imaging is performed by the photodiode array 36 via the scintillator 42,
After amplification and distribution processing, the signal processing circuit 46 performs selection/judgment.

In the above configuration, the mandarin oranges and the like to be inspected are carried in while being placed on the rubber bell 10 in the direction of the arrow in FIG. When the carried mandarin oranges reach directly below the X-ray irradiation section as shown in FIG. 4, for example, the X-rays pass through the mandarin oranges 30. A transmission X-ray image is obtained by this X-ray transmission, and characteristic differences occur in this transmission X-ray image depending on the quality state of the mandarin orange 300.

In other words, when a tangerine is subjected to a mechanical shock, its internal structural feature is that the shape of the void pattern near the central axis of the tangerine surrounded by the tangerine clusters is similar to that of the border when the tangerine is not subjected to a mechanical shock. However, the boundaries are not clear and the star-like or star-shaped void pattern is distorted, resulting in a random void pattern.

This example is schematically shown in the transmission X-ray images shown in FIGS. 5 and 6. FIG. 5 shows the case when mechanical shock is applied, and FIG. 6 shows the case when no mechanical shock is applied. Therefore, by analyzing the shape of this void pattern, mandarin oranges with potential spoilage factors can be selected. As a shape analysis means, for example, a pattern matching method using a feature evaluation function method in which the value obtained by dividing the area of the void pattern by the circumferential length, the circularity, etc., is taken as the vf minute amount can be adopted. The roundness δ is calculated by the following formula. For example, for a good mandarin orange (one that has not been subjected to mechanical shock), δ = 2
If it is about 5.9, defective mandarin oranges (those that have been subjected to mechanical shock) will have a value of about 13.8, and can be easily identified.

Mandarin oranges 30 determined to be good products based on the circumference length move straight in the direction of movement of the rubber belt 10 and sent to the next process, while mandarin oranges 30 determined to be defective products are removed from the rubber belt 1 by the defective product discharge section 28
00 is brushed off to the side.

In addition, the external dimensions of the inspection device body are 3,700 yen in width x
It is approximately 1800 mm in height x 1000 mm in depth, and has a total weight of approximately 1000 kg.

Further, the specifications of the X-ray generator 14 include, for example, a tube voltage of 40 KV.
, a tube current of 4 mA, and an irradiation time of 0.1 seconds are used. The X-ray image obtained thereby can be directly captured with a high-sensitivity X-ray television.

Further, in the imaging system according to the embodiment, the soft X-ray method was mentioned, but this may also be a method for processing tomographic images of an ultrasonic sensor. In this case, an ultrasonic sensor is placed at a position where the mandarin orange is sandwiched between the mandarin oranges on the central axis of the mandarin orange, and while the mandarin orange or the sensor is moved, the transmitted ultrasound image is sampled and analyzed. What is necessary is to measure the shape of the void pattern near the central axis of the mandarin orange.

〔Effect of the invention〕

As is clear from the above, according to the present invention, it is possible to sort out mandarin oranges that contain spoilage factors, which were difficult to detect by conventional visual inspection, and to perform high-speed, high-performance mandarin quality inspection that can be achieved online. equipment can be provided.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a quality inspection apparatus suitable for applying the method of the present invention, and FIGS. 2 to 4 are photographing section 1 shown in FIG. 1.
6, and FIGS. 5 and 6, which are diagrams illustrating three examples, are transmission X images with and without mechanical impact. 10... endless commbell), 12a, 12b...
Roller, 14... X-ray generator, 16... Photographing unit, 18... Lead glass window, 20... X-ray generation power source, 32... SIT camera, 34... II camera, 36...Photodiode array. Applicant Hitachi Plant Construction Co., Ltd. 1st edition Figure 2 Figure 3 Figure 4 12, 12b-+Cola, 20-X! r
*-$14 IM,, 14---Xai, 32-
51 ]] hme y16 --- Feathers and the City 3
4-TI Noamera, 36--7 Oto 4゛Iode Array.

Claims (3)

[Claims] (1) A method for quality sorting citrus fruits, which comprises imaging the void pattern in the center surrounded by clusters of citrus fruits to be inspected for quality, and sorting out whether the citrus fruits are good or bad based on the shape. (2) The imaging and sorting means irradiates soft X-rays from above the central axis of the citrus fruit, and analyzes the transmitted image to determine the void pattern near the central axis of the tangerine surrounded by bunches of tangerines. The method for selecting quality of citrus fruits according to claim 1, which comprises measuring the shape. (3) The imaging and sorting means arranges an ultrasonic sensor on the central axis of the citrus fruit at a position where the mandarin orange is sandwiched, and samples the transmitted ultrasound image while moving the mandarin fruit or the sensor. , the method for quality sorting citrus fruit according to claim 1, characterized in that the shape of the void pattern near the central axis of the tangerine surrounded by the tangerine clusters is measured by analyzing this.