JPH01105140A - How to grade citrus fruits - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a post-selection method for citrus fruits, and more particularly to a post-selection method for citrus fruits, which sorts citrus fruits according to their sugar content or acidity.

[Prior art]

Citrus fruits are graded based on size, shape, discoloration, or damage such as scratches, cracks, and cracks before being shipped.

FIG. 5 is a perspective view of a conventional tangerine grading device. As shown in FIG. 5, a sorting conveyor 73 is provided on the sorting table 71, and the mandarin oranges 75 moving on the sorting conveyor 73 are sent to rotary drums 77, 77, . . . . The rotary drum 77 has holes of size S to 2L depending on the type of drum, and the mandarin oranges 75 pass through the holes of the drum 77 and are sorted into sizes S to 2L depending on their size.

The mandarin oranges 75 that have passed through the drum 77 are packed in boxes through hoppers 79, 79, . . . of sizes S to 2L.

An automatic weigher 81 is installed at the boxing position, and when a predetermined weight is reached, the weight is transferred to a slat conveyor 83. The boxed mandarin oranges 75 on the slat conveyor 83 pass through a vibrator device 85 and are shipped.

Inspection of the mandarin oranges 75 for discoloration is carried out by visual inspection, and the inspector selects the discolored and defective mandarin oranges on the sorting conveyor 73. Normally, each line requires several dozen inspectors, and they screen dozens of tangerines 75 as defective per minute.

However, with this sorting method, it takes a lot of manual labor to grade the discolored and defective parts of the mandarin oranges 75, and if the mandarin oranges 75 are dropped into the rotary drum 77, there is a problem that the mandarin oranges 75 will be damaged. A method of automatically sorting mandarin oranges 75 by detecting their size and discoloration defects using a two-dimensional image processing method using a camera or the like has been considered.

[Problem that the invention seeks to solve]

However, these conventional tangerine classification methods are based on direct appearance such as size and poor discoloration, and are not based on the original sweetness (sugar content) and sourness (acidity) of mandarin oranges. Not done. Therefore, there is a need for a method for classifying citrus fruits based on the sugar content and acidity, which are the inherent qualities of tangerines.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a method for laterally sorting citrus fruits, which allows for laterally sorting citrus fruits based on the sugar content and acidity, which are the original qualities of citrus fruits.

[Means for solving problems]

In order to achieve the above object, the present invention photographs citrus fruits,
The number of oil spores or the size of oil spores per unit area of the epidermis of the citrus fruit is measured based on the photographed images, and based on the measured values, the citrus fruits are classified according to their sugar content or acidity. Special feature: mold.

[Effect]

According to the method for classifying citrus fruits according to the present invention, a citrus fruit is photographed, and the number or size of oil spores per unit area of the epidermis of the citrus fruit is measured based on the photographed image. It is also known that the smaller and more oil spores in citrus fruit, the higher the sugar content and acidity of the citrus fruit, and the larger and fewer oil spores, the lower the sugar content and acidity. There is a unique correlation between pore size and the sugar and acidity of citrus fruits.

Therefore, the sugar content and acidity of citrus fruits can be easily measured from the measured value of the number of oil sacs or their size based on the accumulated experimental data of the above correlation, and the sugar content and acidity of citrus fruits can be easily determined based on the measured sugar content and acidity. Can be done.

〔Example〕

Preferred embodiments of the method for separating citrus fruits according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a side view of a sorting and inspection apparatus in which the method for sorting citrus fruits according to the present invention is used. As shown in FIGS. 1 to 3, the mandarin oranges are transported to the conveyor 14 of the inspection device
The paper is transported from the left to the right at a transport speed of 49 m/min. Color shutter television cameras 16.16 are installed on both sides of the conveyor 14, and the television cameras 16.16 are used to monitor the mandarin oranges 1 moving on the conveyor 14.
0 is being photographed. Further, a background plate 18 is arranged at the photographing position of each television camera 16, and the background plate 18 has a color complementary to the color of the oil spores 10A formed on the epidermis of the mandarin orange 10.

The color shutter television camera 16 continuously photographs the transported mandarin oranges 10, and uses a shutter function to capture the images at a cycle of 1760 seconds. Also, the timing of capturing the video is determined by the timing sensor 21.
The timing sensor 21.21 detects the position of the mandarin oranges 10 on the conveyor 14.

The captured color video signal is output to the processing device 24, and the processing device 24 converts the color video signal into primary color signals (R, G, B signals) and a luminance signal (Y
Only the color of the oil spores 10A of the tangerine 10 determined by the synthesis ratio of the signal) is extracted (Kuromatsuki one-way method). Next, a continuous binary image of the oil sac 10A of the mandarin orange is created based on this extracted image. The processing device 24 measures the number of oil spores per unit area of the oil spores 12A on the tangerine skin and their size using this binary image.

Also, the number and size of oil spores 10A in tangerine 10 are as follows.
It is known that there is a correlation between sugar content and acidity of 0. This correlation shows that when the number of oil spores is large or when the oil spores are small, the sugar content and acidity tend to be high, and when the number of oil spores is small or the oil spores are large, the sugar content and acidity tend to be low. Therefore, the processing device 24 stores a memory of a correlation table between the sugar content and acidity of the mandarin orange 10 and the number and size of the oil spores 10Δ, and the sugar content and acidity of the mandarin orange are determined based on the number and size of the measured oil spores of the mandarin orange 10. can be measured. For this reason, 10 oranges is 1 oil! ! ! The sugar content and acidity are measured from the IOA measurement values, and the products are classified into grades based on the measured values. Based on this grade classification data, the processing device 2
4 outputs a control signal to a subsequent fruit sorting conveyor (not shown), and the fruit sorting conveyor sorts the mandarin oranges 10 into grades based on the sugar content and acidity based on this control signal.

According to the citrus fruit grading method configured as described above,
The oranges 10 are continuously photographed by a color television camera 16. The color video signal from the color television camera 16 is processed by the processing device 24, and the oil spore 1 of the mandarin orange 10 is processed.
Extract the color of only 0A, and based on this extracted image, orange 10
The number and size of oil sacs 10A per unit area in the epidermis are measured. In this case, the background plate 18 is the oil spore 1
Since the color of 0A and complementary color are applied, oil sac 10
A is clearly photographed.

Furthermore, due to the correlation between the oil spores of the mandarin orange, sugar content, and acidity, the sugar content and acidity of the mandarin orange 10 can be measured based on the number and size of oil spores 10A per unit area in the epidermis. . For this reason, it is possible to classify oils into grades based on the number of oil Ha 10 A or the measured value of their size.
You can grade the sugar content and acidity of 10 mandarin oranges.

Although the color shutter television camera 16 was used in the above embodiment, the invention is not limited to this, but a two-dimensional black and white shutter television camera and a selective transmission filter may be used to photograph and extract the 100 mandarin oranges and the oil spores 10A for measurement. . Alternatively, instead of the color shutter television camera 16, a one-dimensional image sensor and a selection filter may be used to photograph the oil sac 10A of the mandarin orange 10, and the size and size of the oil 11a 10A may be measured.

The oil spores 10A measured in this manner can be reliably graded based on sugar content and acidity, similar to the color shutter television camera 16.

Furthermore, the oil spores of Tangerine 10 contain carcinoid pigments and have selective absorption characteristics in the ultraviolet region. Therefore, instead of the color television camera 16, a camera sensitive to the ultraviolet region and a selective transmission filter that transmits only the selective absorption wavelength of the carcinoid pigment are used to capture the oil spores 10 from the epidermis of 100 mandarin oranges.
Only A may be photographed and extracted.

〔Effect of the invention〕

As explained above, according to the method for grading citrus fruits according to the present invention, the sugar content and acidity of citrus fruits can be measured by photographing the oil spores of citrus fruits and measuring the number or size of the oil spores. It is possible to grade the quality of citrus fruits based on sugar content and acidity.

[Brief explanation of the drawing]

Fig. 1 is a side view of a sorting inspection device using the citrus fruit grading method according to the present invention, Fig. 2 is a plan view of Fig. 1, and Fig. 3 is a cross section taken along the line ■-■ of Fig. 2. 4 is a diagram showing the skin surface of a mandarin orange, and FIG. 5 is a perspective view of a conventional citrus sorting device. 10... Tangerine, 14... Conveyor, 16
...Color shutter television camera, 24...Processing device. Applicant Hitachi Plant Construction Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] A citrus fruit is photographed, the number of oil spores per unit area of the epidermis of the citrus fruit or the size of the oil spores is measured based on the photographed image, and the citrus fruit is graded based on the sugar content or acidity of the citrus fruit based on the measured values. A citrus fruit grading method characterized by sorting.