JP3109728B2 - Apple internal quality inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, apple ripeness, on internal quality inspection apparatus of apple for inspecting the internal quality such as freshness and internal defects.

[0002]

2. Description of the Related Art Conventionally, in the inspection of apples , the degree of maturity of the apples is determined mainly based on the size, weight, appearance shape and color of the apples obtained at the time of harvest, and the grades are determined. Was. However, in the apple, what it is difficult to determine in appearance such as shape and color the internal quality of maturity, such as multi
No. In general, apples with a red skin color are considered ripe and good, but the red color of the skin and the maturity are irrelevant. In other words, apples, even when immature, are colored red when forcibly exposed to sunlight. Also, even among the ripe apples, those in the shade of the leaves have a low degree of red coloring. In particular, yellow-green or yellow parts remain around the tops of apples (portions with flowers), so such apples may be treated as immature, even though they are ripe. There are many.

[0003] Usually, apples that are ripe on a tree are preferred as seasonal apples. For this reason, there is a case where an apple taken at a time other than the season is shipped in the same state as the apple taken at the time of the season by using a technique of preserving the freshness for a long time while maintaining the freshness by controlling the temperature and the atmosphere gas. However, in the inspection of an apple to which such a technique has been applied, even if the freshness of the apple decreases during storage and an internal defect occurs, the state of the apple cannot be determined from the appearance.

In particular, as shown in FIGS. 3 and 4, a certain kind of ripe apple is such that the periphery of the fruit core 107 of the apple 100 becomes a vascular bundle 108 (a bundle of tubes through which water and sugar pass). The so-called "honey-contained state" spreads along the transparent honey-containing portion 200, and emits a unique fragrance and taste, and is preferred as a luxury product. Such quantitative determination of the nectar-containing portion 200 of the apple 100 is performed by cutting the extracted sample and visually inspecting it. The classification of the tightness state by this visual inspection is classified as shown in the following table. In addition, grades 2 and 3 are good and the commercial value is high as a tightly packed product. Grade 5 is a so-called overripe state and has a poor freshness life.

[0005]

However, when such a tightly packed apple is stored for a long period of time as described above, the part of the pulp 107 and the whole pulp 109 turn brown (browning) during storage, and the flavor and taste are reduced. It has the defect of falling. In addition, even apples that do not contain nectar, when stored for a long time, may turn brown like apples with nectar. The browned apples cannot be distinguished only by their appearance, and may be overlooked in the sampling inspection.

[0007] By the way, when apples are immature, the inside is hard and the water content is low, so that the light is scattered and the light transmittance is low. However, as the apples ripen, the water content in the pulp increases and the transparency increases. It has the property of increasing light transmittance. In recent years, a technology for performing non-destructive internal inspection of apples utilizing such properties of apples has been disclosed. For example,
"Non-destructive measurement of honey symptom of apple fruit by single wavelength light transmission" (Hiroyuki Fukuda, Fruit Tree Trial Report, C15 P41-47)
Ministry of Agriculture, Forestry and Fisheries 1988), "Non-destructive measurement method of fruit sugar content by near infrared transmission spectrum" (JP-A-6-18615)
No. 9). In addition, although the inspection target is not apple,
As a similar technique, “Development of a portable pineapple ripeness determination device” (Akira Hirata, Food Distribution Technology Vol.23 N)
o. 11 P61-64).

[0008] The "non-destructive measurement of bee symptom of apple fruit by single-wavelength light transmission" is based on the fact that water-immersed tissue transmits light well and is not affected by temperature. This is a technique that transmits a single wavelength of 810 nm and can measure the degree of honey generation based on the absorbance. In addition, the “Non-destructive measurement method of sugar content of fruits by near-infrared transmission spectrum” detects the absorbance of wavelengths related to the size of apples and some specific wavelengths related to sugar components, and determines the sweetness of apples. It is a technique that can measure the degree. Furthermore, the “Development of a portable pineapple ripeness determination device” is to determine the ripeness of pineapple and internal obstacles by transmission of natural light, measure the surrounding brightness, and determine the determination value based on the measured value. This is a technology that can correct

[0009] However, the technique of "non-destructive measurement of honey symptom of apple fruit by single wavelength light transmission" can effectively measure fresh apples immediately after harvest. On the other hand, the total amount of transmitted light was very small for apples that had undergone internal browning due to long-term storage, and accurate identification was difficult.

Further, when any of the above-mentioned techniques is applied to the determination of apples containing honey, there is a problem in that even apples in the same state of honey produce differences depending on the color of the peel. That is, as shown in FIG. 5, even in the same apple containing honey, the light transmittance of an apple having a yellow or yellow-green peel is larger than that of an apple having a red peel. If the technique is not considered, a large determination error occurs. Furthermore, fruits generally have a shape close to a sphere, but are not always uniform, and have a directivity in light transmittance. Therefore, unless the measurement direction of the light transmission amount is determined according to the shape of the fruit,
It could not be measured accurately.

Therefore, the present applicant has previously disclosed in Japanese Patent Laid-Open No.
No. 1290, “Inner quality inspection method and device for apple”
Discloses a technology that can accurately and nondestructively determine the internal quality of apples over a wide range from a ripe state with nectar to a browned one without being affected by the color of apple peel. . In this method, the wavelength of light is determined by measuring the transmittance of visible light of 620 nm to 1100 nm, which is not affected by the color of apple peel, from near-infrared light, and a halogen incandescent lamp is used as a light source. Further, in order to reduce a discrimination error due to work environment illumination light or extraneous light (ambient light), a light-shielding member such as a black sponge is provided around the photodetector, and is used by being brought into contact at the time of inspection.

[0012]

However, in the prior art, since a halogen light bulb is used as a light source, it is necessary to flash the halogen light bulb each time each apple is inspected.
This is because, when the halogen bulb is continuously turned on, when the apple is missing from the inspection position, the lamp light directly strikes the photodetector, and the photodetector cannot be properly distinguished due to deterioration or damage. As a result, the response speed during inspection decreases,
This has been an obstacle to high-speed automatic discrimination.

In order to reduce a discrimination error due to ambient light, a light receiver having a light-shielding member that comes into contact with the apple at the time of inspection is used. Therefore, the light receiver is moved from the standby position to the inspection position at the time of inspection of each apple by the movable mechanism. , And after each apple is inspected, it is necessary to move the apple from the inspection position to the standby position, which also hinders speeding up of automatic discrimination. Further, for the purpose of minimizing the discrimination error due to ambient light as much as possible, it is necessary to darken the work lighting,
The working environment was bad.

The present invention has been made in view of such circumstances, and focuses on the fact that the emission time of pulse light is extremely short, and measures the height of a pulse current based on the brightness of ambient light. The purpose of the present invention is to provide an apparatus for inspecting the internal quality of apples , which can speed up automatic discrimination by inspecting the internal quality of apples based on the measured values.
You.

Incidentally, if the size (ball size) of an apple or the like to be inspected varies, an error may occur in the inspection result. That is, when measuring the degree of light scattering attenuation due to the increase and decrease of air bubbles in the pulp accompanying the progress of apple maturity and the decrease in freshness, the light scattering attenuation changes exponentially depending on the thickness through which it passes. Therefore, an error may occur in the measured value depending on the size (ball size) of the apple. In particular, when apples are put directly into the inspection device without sorting from the orchard or storage, their diameter is about 7
There is a mixture of small balls of 0 mm to large balls of about 110 mm. Therefore, the amount of nectar in Odama is determined to be small,
Kodama may be over-determined.

Therefore, in particular, the present invention relates to the size of an apple,
In other words, to reduce the measurement error due to the size of the apple,
Aiming to provide an internal quality inspection device for apples that enables more accurate inspection by performing internal quality inspection of apples while correcting the measured value according to the size of apples
I have.

In addition, the internal quality inspection of the apple is performed by light or X.
Techniques for controlling the detection sensitivity by the size of a ball in a method of transmitting light such as a line include, for example, “Optical Measurement Method and Apparatus” (Japanese Patent Laid-Open No. 7-229840) or “watermelon cavity using X-rays”. Inspection equipment ”(Hideaki Homma,
Food distribution technology, Vol. 18 No. 7).

Here, "Optical measurement method and its apparatus"
When the sugar content of citrus fruits is measured with an infrared spectrophotometer, the size of a sample is measured for the purpose of improving the measurement accuracy and the accumulation time of the amount of transmitted light to be analyzed is changed. Specifically, in order to analyze transmitted light for tangerines having a size of 60 mm to 75 mm, 50 ms to 15 mm is used.
The accumulation time of 0 ms is changed, and the light source continuously emits light for that time. And as a light source,
Halogen lamps are preferred.

However, since the amount of transmitted light in an apple is only about one-fifth that of a tangerine, if this technique is applied to an apple, the accumulation time will need to be five times more. Therefore, it is considered difficult to apply this technology to the internal quality inspection of apples during continuous high-speed running. Also, this technique does not correct the measured values.

"A watermelon cavity inspection device using X-rays"
Measures the size of the sample and changes the intensity of the irradiated X-rays in order to inspect the internal cavity of the watermelon with X-ray fluoroscopic images, and tries to obtain a clear image regardless of the size of the sample Things. Specifically, the operation of changing the generated energy of X-rays based on the result of measuring the size of the watermelon requires a considerable amount of time, so the size of the watermelon is measured one minute before the X-ray irradiation. The operation of changing the generated energy is performed during a moving time of 0.9 seconds, and X-ray irradiation is performed during 0.1 seconds when the watermelon is stopped. This technique changes the energy of X-rays to obtain a suitable image for the size of the watermelon, and corrects an index indicating the size of the cavity, that is, the measured value is changed according to the ball size. It does not compensate.

[0021]

Means for Solving the Problems] To achieve the above object, the internal quality inspecting device of apple according to a first aspect of the present invention, a signal from the lamp control device, for projecting pulsed light apple in the test position A light source unit, a light receiving unit provided on the optical axis of the light source unit, and having a light sensor that detects a pulse light transmitted through the apple and outputs a detection pulse signal; and an amplifier that amplifies a signal from the light receiving unit. And compares the level of the detection pulse signal amplified by the amplifier with a predetermined determination level, and outputs a signal relating to the grade of the apple , the degree of internal browning, freshness, etc. based on the determination result. And the diameter of the apple
At the same time, the diameter of the apple increases by 5 mm from the standard size.
To output a 1.2 times correction coefficient as a correction signal.
Size measuring means and the correction signal from this size measuring means.
Correction based on the transmitted light level detected by the
And a correction unit .

[0022] According to a second aspect of the invention, Hayashi of claim 1, wherein
In the apple internal quality inspection device, the size measuring means outputs a signal for lighting preparation to the lamp control device together with the correction signal.

According to a third aspect of the present invention, there is provided the first or second aspect of the present invention.
In the apple internal quality inspection device, the size measuring means is:
The configuration includes one photo switch for detecting the front end of the apple and a plurality of photo switches arranged side by side in the transport direction of the apple for detecting the rear end.

[0024] A fourth aspect of the present invention, the internal quality inspecting device apple of claim 3, wherein the size measurement means, the correction coefficient corresponding the signal from the photo switches logically determine the size of the apple It is configured to include a generated logic circuit.

The invention according to claim 5 is the invention according to claims 1 to 4.
In the apple internal quality inspection device described in
The amplifier is configured to have a unit for adjusting the amplification conversion rate .

[0026]

Embodiments of the present invention will be described below with reference to the drawings. First, the basic principle of the present invention will be described with reference to FIGS. Immature apple 10
In the case of 0, the moisture contained in the cells of the flesh 109 is small and the air bubbles are large. For this reason, light has many scattering reflections, and the flesh has a white color. However, as the maturity increases, the water content of the cells of the pulp 109 increases, filling the cells, and the bubbles inside the cells disappear. Then, as the maturity further advances, a state in which water overflows between the cells of the flesh 109, that is, a state in which light passes through the honey is obtained. As a result, the pulp 109 becomes transparent, and scattering and reflection of light are eliminated.

In order to observe the inside of the apple 100 in a state with honey (for example, grade 3 with honey), as shown in FIG. 3, the apple 100 is cut in the vertical direction from the handle 101 to the top 103, and As shown in FIG. 4, the central part of the apple 100 was cut in the lateral direction. As a result, as shown in FIG. 4, the nectar-containing portion 200 spreads in an island shape around the ten vascular bundles 108 surrounding the fruit core 107 where the seed 105 is located.
A pattern was formed in which 0 petals were arranged radially. In addition, as shown in FIG. 3, the tightly packed portion 200 was spread inside the flesh 109 along the vascular bundle 108 from the stalk 101 to the top 103.

That is, the honey-containing portion 200 serves as a light guide having high transparency, thereby facilitating the passage of light in the vertical direction of the apple 100. In addition, nectar part 2 with 10 petal patterns
00 was not necessarily of uniform size and was observed to be significantly biased.

The fruit pattern 101 of the apple 100 with the honey
2 was peeled off from the peripheral portion 102 of the fruit crest 103 and the peripheral portion 104 of the fruit crest 103, and the transmittance of the light radiated on the fruit crest peripheral portion 104 and transmitted through the fruit handle peripheral portion 102 was measured. As shown in the figure, the light transmittance is approximately 5 × 1
0 ^-5 , and the specific gravity of the pulp at this time is approximately 0.95 g
/ Cm ³ .

Next, when the apple containing honey is stored for a long period of time, the freshness is reduced, and browning eventually occurs. When this state was observed, the moisture of the flesh 109 was gradually lost, and the state with honey disappeared in a few months. Furthermore, when the storage was continued, water was lost, bubbles in the cells increased, the scattering and reflection of light increased, and the amount of transmitted light decreased significantly. The light transmittance of only the flesh 109 in the state without honey is about 2 × 10 ^{−6 to} 5 × 10 ⁻⁷ as shown in FIG. Light transmittance decreased.

In some apples, the cells are necrotic from the portion that was in the nectar state, leading to brownish internal browning, which eventually spreads over the entire flesh 109.
In addition, even when the pulp 109 is not in a honey state, it loses freshness due to long-term storage, and the whole pulp 109 may turn brown.
The light transmittance of the flesh 109 browned in this way is further reduced as compared with the apple without honey, and as shown in FIG.
× 10 ^-9 to 1 × 10 ^-11 . The pulp specific gravity at this time was 0.65 to 0.75 g / cm ³ . The relationship between the pulp quality and the light transmittance is shown in the table below.

果 果 果 果 果 光 光 光 光 光 光 光 光 光 光等 Grade with honey 3.5 × 10 ^-5 Non-honey containing ordinary product 2 × 10 ^-6 〜5 × 10 ^-7 Inside browning 5 × 10 ^-9 〜1 × 10 ^-11 ───── ──── ─────────────

As described above, it was found that the light transmittance of the apple 100 greatly differs depending on the nectar state, the nectar state, and the browning state, and the state can be accurately determined by irradiating light in the vertical direction. .

Next, the results of observation on the color of the peel of apple 100 will be described. The characteristic of the difference in transmitting light in the range from visible light to near-infrared light through the pericarp 110 is, for example, a curve as shown in FIG. That is, in the yellow pericarp part which is immature or fully matured but not exposed to sunlight, its characteristic gradually rises from the wavelength of 400 nm toward the longer wavelength side, and has a gentle peak at about 620 nm on the way to about 800 nm. The above became constant (the thin line in FIG. 5).

On the other hand, in the characteristic curve of the pericarp that has become sufficiently red when exposed to sunlight (thick line in FIG. 5), the transmittance of light having a wavelength of 600 nm or less is 5%, which is extremely low. The characteristic curve shows a gradually higher light transmittance from around 600 nm toward the longer wavelength side, and from 800 nm to 11 nm.
In the range of 00 nm, the light transmittance was 40%, which was almost equal to the light transmittance of the yellow-green pericarp.

That is, when light is irradiated in the vertical direction of the apple 100, the light passes through the pericarp 110 twice, so that the light transmittance becomes 40% × 40%.
It has been found that when light having a wavelength of about m or more is irradiated, the internal state of the apple can be accurately determined without being affected by the color of the peel.

Irradiation light having a wavelength range of 1100 nm or more may be used as long as no difference is observed between the yellow-green to yellow sample and the bright red sample. However, in general, in the wavelength region of 1200 nm or more, since the light is absorbed by various components of the chemical functional groups, the light transmittance changes and the apple-honey state and the browning state of the apple 100 can be accurately determined. Cannot be determined.

An inspection method using the apparatus for inspecting the internal quality of apple 100 according to the present invention will be described based on the above observation results. As shown in FIG. 6, when the apple 100 on the sample stage A having a light passage window A ₁ is detected by the position sensor B, Xe light source section D the detection signal via the lamp control unit C (Xenon ) It is output to a flash discharge lamp (hereinafter referred to as “flash lamp”) E. As a result, the flash lamp E emits the pulse light P, and the pulse light P is converged by the reflecting mirror (not shown) and the lens system (not shown), and passes through the inside of the apple 100 on the sample table A. .

The pulse light p transmitted through the apple 100 is
In the light receiving portion (detection portion) F, the semiconductor light sensor H detects the pulse light in the wavelength range in which the transmittance changes little due to the color of the pericarp. The photocurrent a corresponding to the pulsed light detected by the optical sensor H is amplified by the photocurrent amplifier G to a degree sufficient for comparing and judging the grade of the honey, and furthermore, the short-time pulse in a specific range is further amplified by the frequency filter J. Only pass through.

Here, the emission time t of the pulse light of the flash lamp E is 1 as shown in FIGS. 7A and 7B.
0 ^-5 following minute time. On the other hand, ambient light noise is almost static, and even a discharge lamp such as a fluorescent lamp or a mercury lamp is lit at a commercial frequency of 50 Hz or 60 Hz. B)
As shown in the figure, the change is very gradual at 10 ^-2 seconds compared to the emission time of the flash lamp E. That is, since there is a difference of three digits in the light emission time between the two, if a frequency filter that passes a photocurrent with a pulse time of about 10 ⁻⁴ seconds or less is provided in the photocurrent amplifier G, the photocurrent due to ambient light noise Can no longer pass through the photocurrent amplifier G, so that measurement errors due to ambient light noise are basically eliminated.

Further, as shown in FIG. 8, the emission wavelength spectrum of the flash lamp E has a strong radiation distribution in the near-infrared range from 800 nm to 1100 nm in addition to visible light, and thus selectively transmits pulsed light in this wavelength range. Sharing an optical filter is very advantageous for implementing the present invention.

The discriminator I measures the height of the photocurrent pulse, compares the measured level with a preset discrimination level and discriminates the discrimination result (discrimination result according to the grade of honey). Is output to a sorting mechanism (not shown).

If necessary, the transmission amount of the pulsed light when the internal quality of the apple is at least one of immature, ripe or degraded is compared with a previously determined reference value. Thus, the state of the internal quality of the apple as the inspection object is determined.

The present invention has been made based on such a principle, and in order to achieve the above object , the apparatus for inspecting the internal quality of apple according to the first embodiment of the present invention emits pulsed light to the apple. It is incident on the apex or peduncle and detects the intensity or brightness of the transmitted light from the peduncle or peduncle or side of the apple. Depending on the detection level, the grade of the apple and the browning of the apple are detected. The degree, freshness, and the like are determined.

FIG . 1 is a block diagram showing an internal apple quality inspection apparatus according to an embodiment of the present invention . In the figure,
The internal quality inspection device has a light source unit 1, a light receiving unit 2, an amplifying unit 3, a determining unit 4, and a display unit 5.

The light source unit 1 includes a housing 10 that opens inward and outward on the upper surface, and a flash lamp 12 and a condensing optical system 14 housed in the housing 10. The opening 10 a of the housing 10 is provided with a pulse light L
In order to make the irradiation area constant, a hole having a diameter of about 50 mm is formed.

The flash lamp 12 is constituted by a light source for irradiating the apple 100 on the sample table 15 with pulsed light L containing a large amount of near infrared rays. Flash lamp 12
Is turned on by a photoelectric type position sensor 16 installed on a fixed portion of a conveyor (not shown) interposed between the light source unit 1 and the light receiving unit 2 and a lamp control device 17 connected to the position sensor 16. Done by That is, when the position sensor 16 detects that the apple 100 placed on the sample stage 15 has reached a predetermined position (inspection position), the detection signal is flashed via the lamp control device 17. This is performed by outputting to the lamp 12.

As shown in FIG. 8, the emission spectrum of the flash lamp 12 has a substantially uniform continuous wavelength distribution including several line spectra in a range from ultraviolet light of 400 nm to near infrared light of 800 nm including a visible light region. Therefore, it is often used as simulated sunlight. However, the near-infrared region from 800 nm to 1100 nm has a light emission distribution including many line spectra that is much stronger than the visible light region. However, this spectrum need not be a continuous spectrum in practicing the present invention,
The shape of the spectrum does not matter whether it is a continuous wavelength or a single wavelength, as long as it contains a sufficient light emission amount and a wavelength in a necessary range.

The condensing optical system 14 includes the flash lamp 12
A condenser mirror 14a disposed above the flash lamp 12 and a reflecting mirror 14a disposed below the
The pulse light L emitted from the flash lamp 12 is converged and efficiently taken out of the housing 10.

The sample table 15 is provided on a transport conveyor (not shown).
And has a circular shape with a diameter of 150 mm, and is formed in a dish shape in order to stably mount the apple 100. In the center of the sample table 15,
A stop hole 15a having a diameter of about 50 mm for passing the pulse light L emitted from the flash lamp 12 is provided.

On the mounting surface side of the sample table 15, a thickness of 1 mm
A light-shielding member 11 made of a black rubber sheet or the like which is flexible and has no light transmission is attached so as not to damage the apple 100 as an object to be inspected. The light-shielding member 11 of the sample stage 15 has a stop hole 11a communicating with the stop hole 15a to make the beam of light projected on the apple 100 a constant area, and the opening periphery of the stop hole 11a and the surface of the apple 100 are in flexible contact. To prevent useless light leakage.

When the position sensor 16 detects the apple 100 placed on the sample table 15 due to the light source section 1 having the above-described configuration, the lamp control device 17
Operates to supply a power supply voltage to the flash lamp 12. As a result, the flash lamp 12 emits pulsed light, and the pulsed light is condensed by the condensing optical system 14, transmitted through the opening 10a, and projected on the apple 100.

The signal T ₁ output from the position sensor 16 is not only a signal for lighting the flash lamp 12 but also a signal level after amplifying a pulse current detected by the optical sensor as described later. It is also used as a synchronization signal for comparing and discriminating with a reference level.

On the other hand, the light receiving section 2 is provided on the optical axis OP of the light source section 1 and has a dark box 2a which opens inward and outward on the lower surface, an optical sensor 20 housed in the dark box 2a, and a short wavelength cutoff. And a filter 21. The opening 2A of the dark box 2a has a diameter of about 50 mm corresponding to the opening 10a.
Are formed.

The optical sensor 20 is a silicon photodiode having a light receiving area of 1 cm ² and has a function of detecting the transmitted pulse light L ₁ and outputting a current detection pulse signal S 1 to the amplifier 3. As shown in FIG. 9, the sensitivity characteristic of this optical sensor 20 is 1100 nm from near visible light to near infrared light.
And has a gentle peak at 800 nm of red light.

That is, the optical sensor 20 combines the transmitted pulse light L of the apple 100 with the flash lamp 12.
A silicon photodiode having an optimum sensitivity characteristic for measuring ₁ is used.

The short wavelength cutoff filter 21 has a cutoff wavelength of 6
It is composed of a long-pass filter R65 optical filter of 50 nm, housed in the dark box 2a, and disposed on the flash lamp side of the optical sensor 20. As shown in FIG. 8, the long wavelength filter R65 is used as the short wavelength cutoff filter 21 because the emission wavelength distribution of the flash lamp 12 includes a wide range of visible light, and the yellow or orange
Since the wavelength of 50 nm or less is also strong, the wavelength range in which the transmittance of the pulse light L greatly changes depending on the color of the peel of the apple 100 is removed.

It should be noted that the short wavelength cutoff filter 21 is
However, in order to reduce a decrease in accuracy due to leakage of extraneous light such as a work environment illumination lamp, the light source may be provided in the dark box 2a of the light receiving unit 2 as in the present embodiment. preferable.

The amplifying unit 3 has a current-voltage conversion amplifier 3a and a voltage amplifier 3b, and amplifies the detection pulse signal S1 detected by the optical sensor 20 to a size that allows comparison of the grade of apple 100 with honey. Then, it is configured to be able to output to the determination unit 4. The amplification degree of the amplification unit 3 is configured to be adjustable to a predetermined size.

For example, a flash lamp 12 having a light emission intensity of “1 J (joule)” and an apple 1 having a grade of “3” containing honey
00, the detection pulse signal S by the optical sensor 20
1 is 30 μA, the current-voltage conversion amplifier 3a sets the voltage to 0.3 V, and the voltage amplifier 3b sets the voltage to 1 V.
It is amplified to 0 times 3V.

In addition, since the internal browning test requires measuring two to three orders of magnitude less light intensity than the honey containing test, the amplifier for browning detection has a higher amplification than the honey containing amplifier. It is necessary to prepare an amplifier. However, since the test for honey is performed immediately after harvesting and the test for browning is performed at the time of shipment of long-term storage products, the test time is different. Therefore, since both tests are not performed at the same time, two amplifiers, one for the test with honey and the one for the browning test, are not required. In the present embodiment, the circuit constant of one amplifier is switched by a switch. The two types of amplification conversion rates are obtained.

The amplifying section 3 has a low-frequency cutoff filter (high-pass filter) 3c interposed between the amplifiers 3a and 3b.
It is included. The low-frequency cutoff filter 3c is configured to allow a steep pulse current to pass therethrough and cut off noise due to slowly changing ambient light noise. Cutoff frequency f _c of the low-frequency cutoff filter 3c is a pulse time width t _w it is desired to pass, when the period of the fluctuations of the ambient light noise and _{T W, t w "τ"} T W ··· (1) selecting _{τ = 1 / 2πf c ··· (} 2), it is possible to remove unwanted noise without disturbing the waveform of the pulse current of the detection pulse signal L _1.

[0063] The low-frequency cutoff filter 3c of this embodiment, the time width of the pulse current of the detection pulse signal L _1, since the period of the fluctuation of the ambient light noise is a difference of even 3 orders of magnitude,
Considering that no sharp cut-off characteristics are necessary, the simplest CR
A single-stage low-frequency cutoff filter is used. In this case, the capacitance C and the resistance R are 50 nF and 10 k, respectively.
Assuming that the time constant of one CR type is τ , the time constant τ of the low frequency cutoff filter 3c is 5 from the relational expression of τ = CR (3)
× 10 ^-4 seconds. As a result, the base due to extraneous natural light
It has been found that not only the rise of the slope but also the pulsation of the signal due to the blinking of a fluorescent lamp or the like is not recognized, and the waveform of the pulse current does not collapse.

It is to be noted that an alarm is issued to the output side of the current-voltage conversion amplifier 3a of the amplifiers 3a and 3b in accordance with the intensity of the photocurrent level due to ambient light noise such as direct sunlight, for example, for example, display. Alarm device 6 is connected. This is because the light current level of the detection pulse signal S1 detected by the optical sensor 20, because it may exceed the normal operating range of the amplifier 3.

The discriminating unit 4 includes, for example, four numerical comparators (not shown), each of which is connected in parallel with each other, and these numerical comparators are set in advance by the discriminating level value V0 of the setting unit 41. , V1, V2, V3 (V0 <V1 <V2
It operates based on <V3) and is classified according to, for example, the grade of apple 100 (without honey, small with honey, medium with honey, large with honey). Here, the sorting is performed by a sorting mechanism including a sound generator and the like, and the sorting mechanism is driven to be delayed in synchronization with the movement of the sample table 15 transported by a transport conveyor (not shown). In addition to the classification of the grades, it is also possible to determine that the measured level value larger than a certain level value is “good” and that the smaller level value is “bad”.

An analog-to-digital converter 7 for digitizing the amplified detection pulse signal S2 is connected to the input side of the discrimination section 4. Input terminal 7 of analog-digital converter 7
a is connected to a voltage amplifier 3b via an integrating circuit 8,
A position sensor 16 is connected via a delay circuit 9 to a timing input terminal 7b for performing analog-digital conversion.

The digitization by the analog-to-digital converter 7 is performed by the integration circuit 8 because the time width of the amplified detection pulse signal S2 is short.
This is performed after the integrated value of is set to the peak hold state. The timing of this digitization is determined by the amplified detection pulse signal S
To as when 2 is securely passed, is performed with a delay by time approximately the width of the amplified detection pulse signal S2 output signal T ₁ of the from the position sensor 16 by the delay circuit 9 as the output signal T _2.

It should be noted that a sensitivity adjustment comprising a variable resistor is provided between the integrating circuit 8 and the voltage amplifier 3b in order to correct a sensitivity difference generated for each device due to aging of the flash lamp 12 and a difference in performance of each part. A vessel (not shown) is provided.

The display unit 5 has an analog-digital converter 7
And is configured to display a digitized value of the voltage indicated by the amplified detection pulse signal S2.

The numerical comparator, the current-to-voltage conversion amplifier 3a, the voltage amplifier 3b, etc. of the discriminating section 4 are composed of ordinary operational amplifiers, integrated circuits such as A / D converters and digital comparators, resistors and capacitors. And so on. However, the present invention is not limited to this, and can be configured by using a commercially available microcurrent amplifier and voltage comparator or a sequence control device, or by performing software processing using analog and digital external input / output units of a computer. Of course.

Although an example in which a differential filter is used as the low-frequency cutoff filter 3c in order to remove noise due to ambient light noise has been described, the present invention is not limited to this, and may be performed by performing software processing. be able to. For example, the height of the pulse current alone can be obtained by continuously digitizing and temporarily storing the pulse current and the vicinity thereof, and measuring the difference between the value immediately before the rise of the pulse current and the peak value of the pulse current. .

Although a flash lamp was used as the light source, the present invention is not limited to this, and other types of light sources may be used as long as they generate pulsed light having a wavelength suitable for the apple 100 as an object to be inspected. It is practical. For example, a semiconductor laser or a light emitting diode driven by a pulse current may be used. When a semiconductor laser and a light emitting diode are driven by a pulsed current, a current several tens of times larger than that when a continuous current is supplied can be tolerated. It is possible to obtain a light quantity of the order. In particular, if the material composition is GaAs,
Light emitting diodes and laser diodes such as GaAlAs and InGaAs have light emitting wavelengths of 670 nm to 1060 n.
m, which is suitable for determining the internal quality of apples.

Next, an example of classification work using the internal quality inspection apparatus of this embodiment will be described. First, the classification operation of apples 100 with honey immediately after harvest will be described. As shown in FIG. 1, the apple 100 was placed on the sample stand 15
The sample table 15 is moved to the inspection position by a transport conveyor (not shown), and the fruit portion of the apple 100 faces the light receiving unit 2. Then, the apple 100 is detected by the position sensor 16.

As a result, the lamp control device 17 operates, a constant pulse current is supplied to the flash lamp 12, and the flash lamp 12 emits light. As a result, the pulse light L is condensed on the opening 10a and is incident on the top of the apple 100. As described above, the incident side of the pulse light L is set to the top of the apple 100 because, when the apple 100 is incident from the fruit handle or the lateral direction, the transmittance of the pulse light L is large in the apple 100 where the honey-containing portion is largely biased. This is because a difference of as much as twice appears depending on the circumferential direction of 100, which is not preferable in terms of measurement.
In parallel with the above operation, the output signal from the position sensor 16 is delayed by the time width of the pulse current (detected pulse signal) by the delay circuit 9 and is input to the analog-digital converter 7, and the discriminator 4 operates.

The pulse light L incident on the top of the apple 100 passes through the honey-containing portion of the apple 100 and emerges as transmitted pulse light L1 from the fruit handle side. The transmitted pulse light L is filtered by the short-wavelength cutoff filter 21 and has a wavelength 650 that is not affected by the color of the peel of the apple 100.
Transmitted pulse light ~1100nm L ₁ Nomigahikari sensor 2
Reaches 0.

[0076] the current value of the detected pulse signal S1 indicating a has been the intensity of the transmitted pulsed light L ₁ detected by the optical sensor 20 is very small, the detection pulse signal S1 is a current-voltage conversion amplifier 3 amplifier 3a Is amplified and converted by the voltage amplifier 3
At b, the voltage is further amplified to a predetermined voltage. For example,
In the apple 100 containing the third-grade honey, the detection pulse signal S1 from the optical sensor 20 has a current value of only 30 μA, but is amplified to 0.3 V by the current-voltage conversion amplifier 3a.
Thereafter, the voltage is amplified to 3 V by the voltage amplifier 3b. As a result, the amplified detection pulse signal S having a magnitude sufficient for the subsequent measurement is obtained.
2 is digitized by the analog-digital converter 7 and then sent to the discriminating unit 4.

The voltage amplified by the amplifier 3 and the grade of the apple 100 have a correlation. That is, as described in the above principle, since the transmittance of the pulsed light L corresponds to the size of the honey-containing moiety, transmitted pulsed light L ₁ of the strength corresponding to the grade is detected by the optical sensor 20, amplifying section This is because the signal is amplified by 3. In fact, when a large number of sample apples 100 were measured and then cut and classified with nectar, the linear relationship between the class and the measured voltage was obtained. Therefore, the amplified detection pulse signal S2 indirectly indicates the grade of the apple 100 with honey.

The amplified detection pulse signal S 2 amplified by the amplifying unit 3 is digitized by the analog-to-digital converter 7 and then input to the discriminating unit 4, where the voltage is compared by each numerical comparator of the discriminating unit 4. For example, when the apple 100 is of the second grade, the voltage of the amplified detection pulse signal is equal to the reference voltage V
Since it is equal to or more than 1 and less than V2, a control signal is output from a predetermined numerical comparator.

When this control signal is input to a sorting mechanism (not shown), the operator can easily know that the apple 100 being measured is of the second grade (with honey). . In this way, the operator can determine the grade of the apple 100 that is currently being measured by the sorting mechanism (not shown).

Incidentally, for immature products, generally, apple 10
Since the color of the peel is green to yellowish-green, it can be determined by the conventional visual inspection. However, according to the apparatus of the present embodiment, the immature product can be determined without looking at the color of the peel. can do. By the way, since the immature product has little moisture of the pulp, the transmittance of the pulse light L is low, and it is equivalent to a long-term storage of a normal product not containing honey.

Next, the operation of detecting the browning state of apple 100 after long-term storage will be described. In this browning detection work, the circuit constant of the amplification unit 3 is switched in advance by a switch,
In accordance with V0 to V3 of the numerical comparators of the discriminating unit 4, the amplification factor of the amplifying unit 3 is set to be larger than that at the time of the inspection with honey.

In this state, it is possible to carry out the work of determining the internal browning in the same manner as the inspection of the apple 100 containing honey. That is, depending on the degree of browning of the apple 100, since the strength of the transmitted pulse light L ₁ is changed, becomes the voltage value of the amplified detection pulse signal S2 from the amplifier 3 is according to the degree of browning size, the amplified The detection pulse signal is compared and determined by each numerical comparator of the determination unit 4 as described above, and a determination signal corresponding to the degree of browning is output to a sorting mechanism (not shown). In addition, the apple 100, which does not reach browning but has a reduced freshness, loses more water than the normal product, and the transmittance of the pulse light L is reduced. The degree can be compared and determined.

The verification as to whether or not the present apparatus made a normal determination was performed using a spherical dummy 50 having a diameter of 8 cm and having a light transmittance adjusted to be equal to that of a product containing moderate honey.
The dummy 50 is formed by combining two hemispheres 50a and 50b made of milky white polyethylene resin into flat spheres,
A diaphragm sheet 51 for determining light transmittance was used between both mating surfaces 50A and 50B. The aperture sheet 51 is formed of a black sheet having a size equal to the diameter of a sphere, and has a central aperture having an aperture hole 51a having an inner diameter of 2 cm.
By adjusting the inner diameter of the throttle hole 51a, the grade containing honey was adjusted to about "3". The adjustment of the detection sensitivity was performed by adjusting the amplification degree of the amplification unit 3 so as to have a value designated as the dummy.

Next, a case where correction is performed according to the size of an apple ball
Will be described. The basic principle of the above-described internal quality inspection measures the degree of light scattering attenuation due to the increase and decrease of bubbles in the pulp accompanying the progress of apple maturity and the decrease in freshness. It changes exponentially according to the size of the apple through which light passes.

Next, the relationship between the ball size and the correction coefficient will be described. Since it is difficult to test the relationship between the ball size and the correction coefficient in an actual apple, it looks white with countless fine bubbles like the apple pulp, and the light transmission amount is equivalent to that of an apple with almost medium honey. A simulated test was performed using styrene foam spheres having a cushioning material. Since the actual size of the apple is in the range of 75 mm to 110 mm in the diameter of the equator, the relationship of the light transmittance was examined using styrene foam spheres at intervals of 5 mm in that range. Since the density of Styrofoam varies depending on the location, in order to eliminate the effect, first make a single large sphere and measure the light transmittance, then cut the entire sphere evenly with a knife and reduce the diameter by 5 mm Shrink and re-measure,
The measurement was repeated while gradually reducing the diameter. The results are as shown in the table below.

Simulation of Ball Size Correction Using Styrofoam Balls Ball Size (mm) Light Transmission Attenuation Rate Correction Factor 75 18.4 1.00 80 15.2 1.21 1.20 85 12.8 1.19 1.44 90 10.7 1.20 1.73 95 8.9 1.20 2.07 100 7.3 1.22 2.49 105 6.0 1.21 2.98

As described above, the light attenuation becomes an exponential function that becomes about 1 / 1.2 every time the ball size increases by 5 mm. Therefore, it was found that it is sufficient to correct the measured value to about 1.2 times each time the diameter increases by 5 mm based on the ball size of 75 mm, and to apply the correction coefficient in the above table to each ball size. .

Since there is no universal criterion for determining whether or not this correction coefficient is appropriate, it was left to the visual judgment of several experienced apple-producing farmers. Prepare a large number of apples that seem to be different in the size of the ball and the honey, and first measure the unmeasured apples at the equator to hear the degree of honey that it should indicate. The measurement was repeated again by bonding the balls divided by, and giving an appropriate correction coefficient so as to show a value equivalent to the visual judgment. As a result, it almost coincided with the correction coefficient obtained by the simulation test. Therefore, it was found that the correction from the apple without honey to the apple with excessive honey should be corrected with this correction coefficient.

An implementation based on such a premise
The form will be described. FIG. 11 is a block diagram showing the inspection apparatus of this embodiment . As shown in the figure, the test
The inspection device has a configuration in which a ball size (size) measuring device 30 and a correction unit 40 are added to the inspection device . That is, the ball size measuring device 30 is disposed slightly before the light transmitting portion (the light source portion 1 and the light receiving portion 2) on the transport path of the apple 10, and the measured value is measured based on the measurement signal from the ball size measuring device 30. The correction unit 40 for correction is connected between the analog-digital converter 7 and the discrimination unit 4.

FIG. 12 is a plan view of the ball size measuring device. As shown in the figure, the ball size measuring device 30 has a large number of fiber type photoswitch groups 30-1 to 30-3 having a light emitter and a light receiver.
It consists of 0-8 and has a diameter of 90 which is the average size of an apple
The center ball of mm is placed at a height equivalent to the equator when placed on the sample stand with the handle facing upwards, with the tips of the emitter and receiver fibers facing each other at an interval that does not interfere with the passage of apples I have. As the apple is transported, the light of each photo switch is blocked by the apple, and when the foremost photo switch is activated, the ball size is measured according to which photo switch is applied to the rear end.

More specifically, the ball size measuring device 30 is composed of nine sets of photo switches, and the photo switch 30-0 detects the front end of the apple, and detects the rear end by 30-1 to 30-8.
The respective intervals are such that the photo switches 30-1 to 30-8 are arranged at intervals of 5 mm from 75 mm to 110 mm with reference to the photo switch 30-0. A coefficient is generated.

In the inspection apparatus of the present embodiment, since the ball size measurement of the apple 100 is performed before the light transmission is measured, a location along the transport path slightly upstream of the light source unit 1 and the light receiving unit 2 is measured. Are located in Photo switch 30-
0 is a light source unit in order to provide a sufficient time margin to give the correction unit 40 a ball size correction coefficient before the center of the 70 mm diameter apple considered to be the minimum ball size moves to the optical axis. It is arranged at a position 20 mm upstream of the transport path from one optical axis. That is, there is a margin of about 15 mm until the optical window of the sample table 15 coincides with the optical axis. The distance during which the apple 100 travels this distance is set to 200 pieces per minute at an upper limit speed at which the apple 100 can be conveyed and ejected without damaging the apple 100.
If it is conveyed at an interval of mm, it takes about 30 ms. This time is a time sufficient to provide the correction unit 40 with the ball size correction coefficient.

The photo switch 30-0 also serves to prepare the flash lamp 12 for lighting. That is, the flash lamp 12 is turned on when the photo switch 30-0 detects the apple 100 and the photo switch 31 detects coincidence between the optical axes of the sample stage and the light source. Therefore, the flash lamp 12 is not turned on when the apple 100 is not placed on the sample table 15, and the strong light is prevented from directly irradiating the sensor and being damaged.

When the sample table 15 on which the apple 100 is placed coincides with the optical axis, the flash lamp 12 is turned on. Thus, when the light sensor 20 detects the light transmitted through the apple 100, the amplification unit 3 amplifies the photocurrent, extracts the pulse component due to the light of the flash lamp, and detects the peak height of the pulse by the integration circuit 8. . In this manner, measurement without error due to ambient light is performed in the same manner as in the first embodiment.

On the other hand, since the measurement of the ball size of the apple 100 has already been completed at this time, the logic circuit 32 of the ball size measuring device 30 adds the paragraph number [ [0086] The ball size correction coefficient as shown in [0086] is given to the correction unit 40. As a result, the measured value of the pulse light is corrected based on the ball size correction coefficient, and the corrected value is determined by the determination unit 4.
Is compared with the discrimination level value set in the table.

Up to the integration circuit 8, analog processing is performed by using the analog operational amplifier 3. Ball size correction, display, setting, and comparison discrimination thereafter are digitally processed by using digital logic circuits. I have. The signal that has determined the degree of honey is sent to a sorting mechanism (not shown), as in the first embodiment, and is sorted and discharged according to the degree of honey.

According to this internal quality inspection apparatus , the measured value is corrected based on the size of the apple, so that the measurement discrimination with few errors can be performed. In other words, it is necessary to correct the judgment of the quality of apples based only on their appearance color and shape, and to rescue those that are ripe even if they have poor coloring as normal non-defective products.
In addition, by performing the ball size correction of the apple 100 , the measurement discrimination with higher accuracy is enabled.

In addition, due to the high precision of the measurement, it is possible to remove an obstacle called "core mold" which is difficult to determine in the conventional apparatus. The "core mold" is a mold that has developed inside a cavity called a "room" around the seed, and the interior wall has turned dark brown. This apple with a core mold is a defective product even though it has ripe honey.

In the above embodiment, the present invention has been described with reference to the determination of the inclusion of apples in the honey. Needless to say, internal browning rarely occurring in apples stored for a long time can be determined with higher accuracy. Further, the relationship between the progress of ripeness and the specific gravity of the pulp is very similar to that of apples, and can be applied to the determination of ripeness of melons that are almost spherical in shape than apples .

In this embodiment, the place where the correction coefficient is given is before the final stage of display and comparison judgment. However, the present invention is not limited to this, and the amplification, pulse extraction, integration, display and comparison determination are performed from the optical sensor. It can be done at any of the stages.

The ball size measuring device 30 can perform stepless correction by scanning with a linear CCD sensor or a laser beam instead of a group of optical fiber type photoswitches. If it is an electromagnetic non-contact measurement method, it is possible to cope with the inspection during high-speed continuous running.

[0102]

According to the present invention as described in the foregoing, by measuring the intensity of the pulse light transmitted through the apples, Hayashi
Since the grade, internal browning, freshness, etc. of the apple can be easily and non-destructively determined without being affected by the color of the apple peel, the classification operation can be performed accurately and efficiently. Special
The intensity of the pulse light detected according to the size of the apple.
Corrects measurement errors due to apple size
More accurate internal quality inspection
Was.

That is, the apple is cut or damaged.
Apples can be used from outside, regardless of the size of the apple
Classes can be inspected. So, for example,
Despite being a high-quality apple, the conventional appearance inspection only
Apples that have been determined to be out of grade can be rescued.
It can also contribute to the production of apples with excellent internal quality.
So, not only is it possible to classify, etc.,
The effect is that it can greatly contribute to the improvement of the agricultural economy.
There is fruit.

Further , since there is no need to move the light receiving unit by a movable mechanism for light shielding in the apple quality inspection as in the prior art, the response speed at the time of inspection can be increased, and the speed of automatic discrimination can be increased. Can be. In addition, since a light source that emits pulsed light is used as the light source, the risk of erroneous determination due to ambient light noise is extremely small, so that the work can be performed with bright lighting, and a favorable work environment can be obtained. it can.

[0105] In addition, the seeds of the core of the fruit
Of core mold with mold in the cavity around the
Higher accuracy of discrimination can be realized in order to discriminate
You.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an internal apple quality inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between specific gravity of apple pulp and light transmittance.

FIG. 3 is a longitudinal sectional view of an apple.

FIG. 4 is a cross-sectional view of an apple.

FIG. 5 is a diagram showing the relationship between the color of apple peel and light transmittance.

FIG. 6 is a block diagram shown to explain the principle of the present invention.

FIGS. 7A and 7B are diagrams for explaining a pulse current from which an ambient light noise current has been removed by a low frequency cutoff filter; FIGS.

FIG. 8 is a diagram showing an emission spectrum of a flash lamp.

FIG. 9 is a diagram illustrating the spectral sensitivity of an optical sensor.

FIG. 10 is a front view showing a dummy used for a discrimination test of the internal quality of an apple.

FIG. 11 is a block diagram illustrating an internal quality inspection device for an apple according to an embodiment of the present invention that performs ball size correction .

FIG. 12 is a schematic plan view of a size measuring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Light source part 2 Light receiving part 3 Amplifier 4 Judgment part 7 Analog-digital converter 8 Integrating circuit 9 Delay circuit 12 Flash lamp 15 Sample stand 16 Position sensor 20 Optical sensor 30 Size (ball size) measuring device 40 Correction part 100 Apple L pulse light L ₁ transmitted pulse light S1 detection pulse signal S2 amplified detection pulse signal

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI G01N 33/02 G01N 33/02 (56) References JP-A-4-104041 (JP, A) JP-A-61-11190 (JP) JP-A-4-84740 (JP, A) JP-A-4-83148 (JP, A) JP-A-6-300680 (JP, A) JP-A-8-101121 (JP, A)

Claims (5)

(57) [Claims] 1. A light source for projecting pulse light to an apple at an inspection position in response to a signal from a lamp control device, and a pulse light provided on an optical axis of the light source and transmitted through the apple. A light receiving unit having an optical sensor for outputting a pulse signal; an amplifying unit for amplifying a signal from the light receiving unit ; and comparing and determining a level of the detection pulse signal amplified by the amplifying unit and a predetermined determination level. Based on the result of this determination, a determination unit that outputs a signal relating to the grade of the apple , the degree of internal browning, freshness, etc., and measures the diameter of the apple, and the diameter of the apple is a large standard.
A correction factor of 1.2 times every 5 mm
Size measuring means for output as a signal, and the above-mentioned reception based on a correction signal from the size measuring means.
A correction unit for correcting the transmitted light level detected by the optical unit.
An apple internal quality inspection device characterized by being provided . Wherein said size measuring means, said with the correction signal, apple internal quality inspecting device according to claim 1, wherein characterized in that outputs a signal for lighting prepare the lamp control device. Wherein said size measuring means, claim that is characterized by comprising a plurality of photo switch group are arranged in parallel in the conveying direction of the apple for detecting a single photo switch and the rear end for detecting the front end of the apple 3. The apple internal quality inspection device according to 1 or 2 . Wherein said size measuring means, and characterized in that it comprises a logic circuit for generating the <br/> correction coefficient corresponding to the signal from the photo switches logically determine the size of the apple claims Item 3. The apple internal quality inspection device according to Item 3 . 5. An amplifier according to claim 1, wherein said amplifier adjusts an amplification conversion rate.
The method according to any one of claims 1 to 4, further comprising a step.
Apple internal quality inspection device as described.