JPH0410581B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting split grains of grains, and in particular, irradiates each particle of split grains with oblique light and measures the amount of light that diffusely passes through each grain. The present invention relates to a method for detecting split grains of grains, which determines the quality of grains.

A method of optically detecting defective grains of granular materials such as grains is widely used.

For example, brown rice contains defective grains such as dead rice, immature rice, colored rice, and split rice.

Split rice is a type of damaged grain, and most of the grains have cracks that are perpendicular to the longitudinal axis of the brown rice.Therefore, when this is irradiated with oblique light, light and dark areas are created along the cracks. Conventionally, the method used was to detect these brightnesses with the naked eye and count the number of them. However, since this method is a visual inspection, there are individual differences, and it is time consuming and troublesome.

A method has also been proposed in which defective rice is detected by shining an oblique light beam on brown rice, converting the amount of transmitted light into an electrical signal, and comparing it with a predetermined value. Since the amount of transmitted light changes accordingly, various problems remain to be solved before it can be put into practical use.

The applicant is Japanese Patent Application No. 57-114679, Japanese Patent Application No. 59-5940
proposed an electro-optical method for detecting defective grains that solves the above-mentioned drawbacks.

In other words, one particle of granules is irradiated with oblique light,
In the method of detecting defective particles by measuring the amount of diffusely transmitted light, a distribution curve of the amount of transmitted light is determined along the reference axis direction of this single particle, and the slope of the curve at each point on the distribution curve is determined. A method for detecting defective grains of granules is proposed, which compares the slope with a predetermined value to determine whether the particles are good or bad.

According to the above-mentioned Japanese Patent Application No. 57-114679, a received light amount measuring device is used to irradiate one particle of granular material with an oblique light beam and measure the amount of diffused transmitted light. In a received light amount measuring device having first and second slits and a light receiving element provided behind the second slit, a lens optical device is provided between the second slit and the light receiving element, and the lens optical device is provided between the second slit and the light receiving element. A light receiving amount measuring device is provided which is configured to form a surface image of a single particle to be measured on a light receiving surface of a light receiving element.

The present invention proposes an improved method for detecting split rice proposed in Japanese Patent Application No. 57-114679, ie, a method for more reliably detecting split rice.

In other words, in the configuration of the measuring device proposed in Japanese Patent Application No. 57-114679, it was discovered that the distribution of the amount of diffused transmitted light of the split grains irradiated with oblique light has a small peak near the presence of cracks. It is based on That is, since there is a small peak in the transmitted light amount distribution, the slope of the transmitted light amount distribution curve temporarily becomes negative in the latter half of this small peak portion, and then rapidly rises toward a high positive value.
Therefore, if the slope of the transmitted light amount distribution curve temporarily takes a negative value and then takes a high positive value, it can be reliably determined that the grain is a split grain.

That is, according to the present invention, there is provided a method for identifying split grains in grains. Specifically, a single grain of grain is irradiated with an oblique light beam, and the amount of diffused transmitted light is measured to detect split grains. The method includes a step of obtaining a transmitted light amount distribution curve for one grain of grain along its reference axis direction, a step of obtaining a gradient of the distribution curve, and a step of obtaining a gradient of the distribution curve when the gradient shows a negative value and then a positive value higher than a predetermined value. In the case shown in FIG.

The invention will be explained in detail below in the form of embodiments together with the accompanying drawings.

In FIG. 1 and FIG. 2, which is a cross-sectional view taken along the - line in _FIG . One grain of brown rice P in position
is transferred, and the amount of light that has diffused and passed through each grain of brown rice P is measured by a transmitted light amount measuring device 5. The defective grain detection device with a turntable 2 was developed in 1983.
Described in No. 71974. The light beam that has passed through one grain of brown rice (hereinafter referred to as a particle) is the first one directly above the particle P.
Passing through the second slit 7 behind the slit 6,
The light reaches the light-receiving surface of the light-receiving element 11 via an optical device 10 having lenses 8 and 9. The first and second slits 6, 7 both extend in a direction parallel to the paper plane of FIG. 1 and are arranged in alignment with each other. The optical device 10 includes a lens 8, a
9 is in focus. This optical device 10
Therefore, the weak transmitted light can be reliably detected by
It is possible to accurately measure the amount of light transmitted to one surface.

Note that the motor 1 and the turntable 2 are rotated at a constant speed, so that the particles P in the holes 12 provided at the periphery of the turntable 2 are transported on the transparent plate 3 at a constant speed. Note that the longitudinal axis of the brown rice particles P is oriented in the tangential direction of the circumference drawn by the center of the hole 12. In other words, the direction perpendicular to the plane of the drawing,
Alternatively, the longitudinal axis of the particles P is oriented in a direction perpendicular to the direction in which the slits 6, 7 extend. The hole 12 of the turntable 2 is located relatively far from its center of rotation, so that the slits 6, 7 are considered almost perpendicular to the longitudinal axis of the particles. That is, the particles 1 are scanned by the slits 6 and 7 as shown in FIG.

As is clear from FIG. 2, a continuous recess 12a is provided at the lower rear of each hole, and this is intended to ensure that the entire particle P is irradiated with the oblique light beam from the light source 4. It is something. In other words, the rear part of the particle P is difficult to be irradiated with oblique light.
As is clear from the figure, this problem is solved by providing the recess 12a.

The parallel light beam L ₀ is incident on the lower surface of the transparent plate 3 at an angle of incidence of 90 degrees or less, preferably at an angle of incidence of 30 degrees, and the particle P
is diffusely transmitted and ejected from the upper surface of particle P,
The light beam having a component perpendicular to the surface of the transparent plate 3 is captured by the slits 6 and 7, and the amount of received light is measured.

The particles P transferred on the transparent plate 3 pass through the slits 6,
7, the amount of received light measuring device 5 is controlled so that the amount of light received by the light receiving element 11 is measured every Δt=t/n. n
If is made sufficiently large, the amount of transmitted light of the particle P is measured for every Δl=l/n as shown in FIG. 4, where the total length of the particle P is l.

The results of an experiment to measure the amount of light transmitted through a single grain of brown rice using the above device are shown below.

Experiment 1 A photodiode was used as the light receiving element 11, and a light source lamp with a wavelength of 600 nm to 700 nm was used as the light source 4. Under these conditions, the amount of transmitted light I of the sized grain of brown rice was measured, and the distribution of the amount of transmitted light in the reference axis direction, that is, the longitudinal axis direction, of the brown rice was determined. The transmitted light amount distribution is as shown in FIG. Further, when the difference ΔI in the amount of transmitted light obtained every Δt=2 m sec is determined, the result is as shown in FIG. That is, the differential coefficient distribution with respect to the distribution curve of FIG. 5 becomes approximately as shown in FIG. 6.

Experiment 2 Under the same conditions as Experiment 1, the transmitted light amount I of the split rice was measured, and the transmitted light amount distribution and the transmitted light amount distribution were determined as shown in FIGS. 7 and 8.

As is clear from a comparison of FIG. 5 and FIG. 7, in the case of split rice, the transmitted light amount distribution curve has a continuous small peak followed by a large peak. The slope of this transmitted light amount distribution curve is the difference in transmitted light amount during an infinitesimal time (ΔI)
Figure 8 shows the results obtained as follows. That is, in the case of split rice, the transmitted light amount difference (ΔI) first shows a negative value, and then shows a large positive value.

Therefore, when the slope of the transmitted light amount distribution curve shows a negative value and then shows a positive value of a predetermined value or more,
A method for detecting split rice that determines that it is split rice is proposed. FIG. 9 is a flowchart of this method of detecting split rice, and the detection procedure is automatically executed by a microcomputer.

Note that in FIGS. 5 and 7, the portion of the distribution curve below the dotted line is not the actual light transmitted through a single grain of brown rice, but is optical noise due to the influence of light reflection and the like. Therefore, in measuring the amount of transmitted light according to the present invention, the amount of light I measured by the light receiving element 11 is shown in FIGS.
Detection of split rice is started when the threshold value T _th shown in the figure is reached.

FIG. 9 shows an example of a flowchart of the method for detecting split rice of the present invention, which is automatically performed using a logic operation circuit for determining defective grains using a microcomputer. The logical operation circuit for determining split rice using a microcomputer can be constructed in a wide variety of ways using known means based on the flowchart shown in FIG. do not.

In FIG. 9, in step _S1 , variables j, k,
The initial value of m is set to "0". In FIG. 9, variable j indicates the number of grains measured. That is, it shows how many brown rice particles P have been measured at present, and after the measurement is completed, it shows the total number of samples. Further, the variable k is the number of split rice, and the variable m is the number of grained rice.

Next, in step _S2 , the initial value of yet another variable I is set to "0". Since the variable I gives the amount of transmitted light, it is used to determine the difference in amount of transmitted light ΔI, and the variable i means the number of measurements in that case.

In step _S3 , the measured amount of light received from the light receiving element 11 Ii
is input. At the same time, input the current time Tc. The current time Tc can be easily obtained, for example, by counting clock pulses with a counter.

In step _S4 , the amount of received light Ii is compared with the threshold value _Ith , and if it is less than the threshold value _Ith , this indicates that one grain of brown rice has not yet been measured.
Return to step _S3 and repeat the procedure. Amount of light received
If Ii is greater than or equal to the threshold, the light amount difference ΔI is calculated in step _S5 .

Next, in step _S6 , it is determined whether the transmitted light amount difference ΔI is positive or negative. If the transmitted light amount ΔI is positive, the measured light amount Ii and the current time Tc are stored for the next calculation.

If the transmitted light amount difference ΔI is negative, the process jumps to step _R1 and starts the split rice discrimination procedure. First, newly input the amount of transmitted light Ii and current time Tc, compare the amount of transmitted light Ii with the threshold value I _th , and if it is greater than or equal to the threshold value I _th ,
Calculate the elapsed time ΔT and check whether the elapsed time ΔT exceeds a predetermined elapsed time (Δt). If the predetermined time Δt has elapsed, the inputs Ii and Tc are considered valid, and the transmitted light amount difference ΔI is calculated. Next, it is determined whether the transmitted light amount difference ΔI is greater than or equal to a positive predetermined value A, and if the transmitted light amount difference ΔI is less than the predetermined value A, the transmitted light amount Ii and time Tc input in step _R7 are used for the next calculation. After memorizing the information, return to step (R ₁ ) and repeat the split rice determination method.

At step R ₆ , the transmitted light amount difference (ΔI) is set to the predetermined value (A)
If it is larger, it is determined that it is split rice, and the step is taken.
Increase the number of split rice by 1 with R ₆₁ and step (Y ₁ )
The number j of measured brown rice is increased by one, and then in step _Y2 it is determined whether the number 3 of measured brown rice has reached a predetermined number 3. If the predetermined number J has not been reached, the process returns to step _S2 to inspect the next grain of brown rice (P), and the same procedure is repeated.

If the transmitted light amount difference ΔI is not negative in step S ₆ , the transmitted light amount Ii and time Tc inputted for the next calculation are memorized in step S ₇ , and the process jumps to step X ₁ to newly calculate the transmitted light amount Ii and Input _the current time Tc, calculate the elapsed time ΔT in step X ₂ , check whether the predetermined time Δt has elapsed in _step Similarly, the procedure is repeated.

Note that the split rice determination procedure from step _R1 to step _R7 is repeated, and the determination is made in step _R6 .
Before the transmitted light amount difference ΔI exceeds the predetermined value A,
If the amount of transmitted light Ii input in step R ₂ becomes less than the threshold value I _th , the brown rice particles to be measured are considered to be brown rice that is not grained rice, and the process jumps to step R ₂₁ where the number of grained rice m is reduced to one. To increase. However, if there are damaged grains in the brown rice that are not grain-split rice, the variable m does not mean the number of grain-sized rice, and it becomes brown rice that is not grain-split rice. A method for detecting damaged rice that is not split rice is described in detail in the aforementioned Japanese Patent Application No. 114679/1983. Next, jump from step R ₂₁ to step Y ₁ , add one brown rice number j to be measured, and then judge in step Y ₂ whether this number j of brown rice to be measured has reached a predetermined value J, and set it to the predetermined value. If J has been reached, the number _j of brown rice to be measured, the number of grain-sized rice, the number m of brown rice that is not split rice, and the number k of split rice are output at step Y 4, and at the same time, the number k of split rice is output in step Y ₄ . The contamination rate is calculated,
Output the result in step _Y5 .

A block diagram of an apparatus embodying the apparatus of the present invention for carrying out the above method for detecting split rice is shown in Fig. 10.
Illustrated in the figure.

Although the method for detecting split rice of the present invention has been described in the form of an example, the present invention is not limited to the form of the above-mentioned example, but can be variously modified within the scope of the claims. For example, in the above embodiment, for each input of the transmitted light amount Ii, split rice is determined based on the transmitted light amount difference ΔI, but after calculating the transmitted light amount difference ΔI from the input transmitted light amount Ii, this is calculated as one grain of brown rice. about,
It is also possible to memorize the information moment by moment and perform batch processing to determine whether the rice is split into shells or not.

In addition, in the above embodiments, the present invention was explained with respect to split rice in brown rice, but the above-mentioned light transmission characteristics also show similar tendencies to other grains, such as paddy, and therefore, the present invention It is thought that the method for determining shell-split grains can be similarly applied.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically illustrating an electro-optical detection device for defective grains in a cross-sectional view. FIG. 2 is a diagram illustrating a cross-sectional view taken along the - line in FIG. 1. Figures 3 and 4
The figure is a diagram illustrating a method for detecting the amount of light transmitted by a single particle. Figures 5 to 8 show the distribution of the amount of transmitted light and the difference distribution of the amount of transmitted light for each particle, which were obtained experimentally. A graph showing the experimental results of split rice. FIG. 9 is a flowchart showing the method for detecting split rice of the present invention. FIG. 10 is a block diagram of an apparatus for carrying out the procedure of FIG. 9. DESCRIPTION OF SYMBOLS 1...Motor, 2...Turntable, 3...Translucent plate, 4...Light source, 5...Transmitted light amount measuring device, 6...First
slit, 7... second slit, 8, 9... lens,
10... Lens optical device, 11... Light receiving element, 12...
Hole, P...measurement particle, _L0 ...parallel light beam, 12a...recess.

Claims (1)

[Scope of Claims] 1. A method for detecting split grains in grains, in which a single grain of grain is irradiated with an oblique light beam, and the amount of diffused transmitted light is measured to detect split grains in grains, comprising: a step of obtaining a transmitted light amount distribution curve for one grain along its reference direction; a step of determining the slope of the transmitted light amount distribution curve; , a step of determining that one grain of grain is a split grain.