JP2001347231A - Method for distinguishing color of unpolished rice and unpolished rice color distinguishing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable sorting out colored grains from feeded unpolished rice grains, by using a conventional color distinguishing apparatus for unpolished rice, equipped with light sensors at a forward and a rear positions of the apparatus, respectively. SOLUTION: A signal ratio between a red signal and a green signal is calculated using an arithmetic circuit 30, based on the quantity of light of a green signal light receiving sensor 7 which receives a diffused light of a green wavelength region from a feedstock unpolished rice and the quantity of light of a red signal light receiving sensor 8 which receives a diffused light of a red wavelength region from the feedstock unpolished rice. Next, the signals are compared to a specified value using a first comparison circuit 31 which compares the specified value for classifying the signal ratio calculated by the arithmetic circuit 30 as a 'green unripened grain' category and the other category to the signal ratio and classifies the comparison results as either of these categories and outputs a signal under either of the categories, a second comparison circuit 32 which compares a signal of the green wavelength region to the specified value and outputs the signal when it exceeds the specified value and a third comparison circuit 33 which compares a signal of the red wavelength region to the specified value and outputs the signal when it exceeds the specified value. In addition, no signal indicating the green unripened grain category which is obtained by the first comparison circuit 30 is output and an exclusion signal is output from a distinguishing circuit 34 by either of the output signals from the second comparison circuit 32 and the third comparison circuit 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sorting apparatus for removing, from brown rice after grain selection, brown rice other than blue immature rice having a particle size close to that of regular brown rice from raw brown rice, the grain having a red wavelength range. Detects the color and the grain color in the green wavelength range, discriminates between unregulated blue rice and blue immature rice with a grain size close to that of regular brown rice and other grains, The present invention relates to a brown rice color sorter that excludes (sorts) non-blue immature rice.

[0002]

2. Description of the Related Art When sorting kernels by color, as shown in FIG. 6, received light is identified by color components preferably separated into three wavelengths. Therefore, sensors for three wavelengths were required. Usually, when sorting beans, the light received is color-separated as described above, and the raw beans are discriminated as good or defective.
In the case of milled barley, one specific wavelength is used to identify colored grains. For example, a light receiving sensor provided with a green filter is disposed before and after a moving grain, and the light receiving amount of the light receiving sensor is often discriminated based on the amount of light received, that is, light and dark. However, when it comes to the identification of brown rice, the grades of grains contained in the raw materials are various, such as regular brown rice, unripe green rice, dead blue rice, and damaged grains. In this case, 2
It is preferable that the reflected light of the grain is separated into colors using up to 3 wavelengths for selection, but the conditioned brown rice and the blue immature rice whose blue color disappears after milling are regarded as good products, and other grades of grain are used. There is no color sorter for brown rice that sorts as defective.

A discriminating device called a granular article position discriminating device different from a general color sorter discriminates brown rice into a plurality of qualities, sorts the brown rice for each grace, and displays the discrimination result.
Although there is an apparatus for discriminating brown rice for each grade and sorting for each grade, this apparatus is not an apparatus for discriminating a large amount of brown rice at a high speed and sorting grains of unnecessary grade.

[0004] In order to sort brown rice obtained by removing dried rice grains with a known huller, a known grain sorter that sorts according to the size of a mesh, that is, the grain size of brown rice, is generally used. It is a target. The non-defective brown rice obtained by using this grain sorter includes regular brown rice (sized) having a particle size of a predetermined particle size or more, immature green, dead blue rice, and damaged grains. In the quality inspection of the brown rice thus selected, the grade is determined by the content of grains other than the regulated brown rice, such as unripe green, dead blue rice, and damaged grains. When the mesh size of the grain sorter is increased to increase the grade, the mixing ratio of grains other than the brown rice is reduced, and the grade is increased, but the yield is significantly reduced.

[0005] In the determination of the grade, if the mixture of unripe blue grains into the polished rice does not exceed the predetermined range, the grade will not be lowered by the mixing of the unripe blue grains. I want to improve the yield by leaving immature grains. Blue immature grains have a blue surface color before milling, but when milled, they become no different from regular brown rice. Therefore, we want to remove the grains and damaged grains that become colored grains even after milling, and realize sorting that leaves blue immature grains.However, with a conventional grain sorting machine, it is not possible to sort by only the particle size as described above. It is.

Further, in the conventional color sorter, sorting is performed depending on the amount of light of one specific wavelength received from the grain, that is, the lightness and darkness of the grain, so that brown rice including unripe green grains, dead blue rice, and damaged grains is sorted out. It is difficult to use at least two wavelengths, for example, a green wavelength and a red wavelength, as in a granular article position determination device.

However, as shown in FIG. 7, at the green wavelength, the difference between the damaged grain and the blue immature grain is very small, so that it is difficult to set a threshold value. If both grains are excluded and a threshold value is provided between the regular brown rice and the damaged grains at the red wavelength, the immature blue grains are eliminated together with the damaged grains and the dead blue rice. Therefore, it is not possible to select only the damaged grain (colored grain) or the blue dead rice alone in both the green wavelength and the red wavelength.

The granular article position discriminating apparatus discriminates a plurality of qualities based on an R / G ratio of a red wavelength light amount and a green wavelength light amount obtained by receiving reflected light of brown rice and a transmitted / reflected light ratio (R + G) / T. However, since light-receiving elements for measuring the amount of reflected light and the amount of transmitted light are required for each of the green wavelength and the red wavelength, a large number of elements are required. Will be.

[0009] When the brown rice obtained by hulling is grain-sorted,
The above-mentioned grains containing brown rice and the grains commonly called "recycled rice" are sorted. In order to obtain polished rice, or to obtain brown rice as a raw material for confectionery. For this sorting, a specific gravity sorter equipped with an oscillating sorter plate is used, but because of the difference in specific gravity, kernels of the same specific gravity are sorted regardless of quality, so to speak.
Since there is no other suitable device, it is common to use a specific gravity sorter. However, it is a matter of course that the graded brown rice is improved by the fact that the sorted kernels contain a large amount of necessary brown rice and the number of unnecessary damage grains is small, and the development of a sorting machine with high sorting accuracy is desired. I have.

[0010]

In view of the above, it is an object of the present invention to provide a brown rice color sorting apparatus for sorting out defective products using brown rice as a raw material. In particular, select the damaged grains that can become colored grains after milling from the non-defective brown rice after grain sorting, reduce the grade as low as possible, and increase the mixing ratio of regular brown rice and blue immature grains to improve the quality grade of brown rice The purpose of the present invention is to provide a brown rice color sorting device that can provide a color sorting device that can improve the color and that can be sorted with the conventional simple configuration provided with one light receiving sensor at each of the front and rear. is there.

The brown rice used as a raw material may be a defective rice side after grain sorting, that is, brown rice on a so-called “milled rice” side. Using the milled rice as a raw material, unregulated brown rice and green immature grains are extracted from the milled rice. Of brown rice color sorter that can be used for the purpose.

[0012]

In order to solve the above problems, a green signal receiving process for receiving diffused light in a green wavelength range from raw brown rice and a red signal receiving process for receiving diffused light in a red wavelength range from raw brown rice are provided. Process, from the green signal obtained in the green signal receiving process and the red signal obtained in the red signal receiving process,
A calculating step of calculating the signal ratio of the red signal / green signal, and comparing the signal ratio with a predetermined value for classifying the signal ratio calculated in the calculating step into a blue immature grain division and the other. A first comparing step of dividing the signal into one and outputting a signal in one of the sections; and a second comparing step of comparing a signal in the green wavelength range with a predetermined value and outputting a signal when the signal exceeds a predetermined value. And a third comparison step of comparing the signal in the red wavelength range with a predetermined value and outputting a signal when the signal exceeds the predetermined value, and there is no signal indicating the blue immature grain division obtained in the first comparison step, and An exclusion signal output step of outputting an exclusion signal based on an output signal of either the second comparison step or the third comparison step.

A red / green signal calculated from a green signal obtained by receiving diffused light in the green wavelength range from raw brown rice and a red signal obtained by receiving diffused light in the red wavelength range from raw brown rice. Corresponding to the ratio, if the signal ratio is, for example, 1.0 or less, it is determined that the grain has a strong blue color, for example, a green immature grain, or dead blue rice. If the signal ratio is 1.3 or more, it is known as a discriminating technique of a conventional granular article position discriminating apparatus to discriminate a grain having a strong red color, for example, a damaged grain.

In the present application, in the first comparison step, the threshold value for comparing the signal ratio is set to a threshold value for dividing the green immature grains and the other grains, for example, a signal ratio of 1.0. The threshold value is set, the signal is first classified into two sections according to the signal ratio, and a discrimination signal is output in one of the blue immature grain section and the other section.

At the same time, in the second comparison step, a threshold value for comparing a green signal obtained by receiving diffused light in the green wavelength range from the raw brown rice is set as a threshold value for simply comparing the brightness of the green signal. Then, for example, a threshold is set so that a signal is output when the signal is a green signal of a predetermined brightness or less (darkness exceeding the predetermined brightness). Here, when a signal is output, it is determined as a colored particle.

Further, at the same time as the second comparison step, the threshold value for comparing the red signal obtained by receiving the diffused light in the red wavelength range from the raw brown rice is used as the threshold value for simply comparing the brightness of the red signal. For example, a threshold value is set so that a signal is output when the signal is a red signal of a predetermined brightness or less (darkness exceeding the predetermined brightness). Here, when a signal is output, it is determined as a colored particle.

In the rejection signal output step, the rejection signal is output if there is no signal indicating the blue immature grain classification from the first comparison step and either the second comparison step or the third comparison step signal has been output. Things. That is, in the first comparison step, the signal ratio is determined to be the value of the green immature grain division, and no exclusion signal is output when a signal indicating the green immature grain division is output.

In the first comparison step, if it is determined that the signal ratio is not the value of the green immature grain classification, and if a signal indicating the green immature grain classification is not output, it is determined whether the signal is regular brown rice or colored grains. The determination is made based on the output signals of the second comparison step and the third comparison step. In other words, if there is a dark signal exceeding the threshold value in green in the second comparison step or red in the third comparison step, it is treated as a signal of a colored grain. If the signal indicating the blue immature grain classification is not output and the signal is output from any of the second comparison process and the third comparison process, the elimination signal is output.

According to the above method, the signal receiving process required for the discrimination may include a green signal receiving process and a red signal receiving process. More specifically, as the configuration of the device, it is sufficient that one light receiving sensor in the green wavelength region and one light receiving sensor in the red wavelength region are provided. In other words, in the color sorting device that receives the diffused light of the grains by the conventional light receiving sensors in the green wavelength range arranged in a pair of front and rear, and sorts the colored grains in the white rice by the brightness of the received grain diffused light, By replacing one of the light receiving sensors with a light receiving sensor in the red wavelength range and adding the above-described arithmetic circuit and discriminating circuit, the color selection device of the present application can be realized. Therefore, remodeling is possible by using the conventional white rice color sorter as it is.

As a result, the conventional apparatus which has been discarded by replacing the color sorting apparatus can be effectively reused.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An outline of a brown rice color sorting apparatus according to the present invention will be described with reference to FIG. Fig. 1 Brown rice color sorting device 1
FIG. 2 is a sectional side view of a main part schematically showing a main part and an internal structure thereof. A brown rice supply unit 4 composed of a vibrating feeder device 2 and a tank unit 3 is provided at an upper part, and a chute 5 on an inclined plate for transferring brown rice supplied from the vibrating feeder device 2 to a predetermined locus. The light is supplied to the next optical detection unit 6.

The next optical detection unit 6 is configured by arranging a front optical detection unit 6a and a rear optical detection unit 6b substantially symmetrically about the locus of the fall of brown rice discharged from the chute 5. Each of the optical detectors 6a and 6b includes, for example, S before and after a viewpoint O set on the locus of brown rice falling.
Visible light receiving portions 7 and 8 each having a light receiving sensor composed of an i (silicon) sensor element are provided corresponding to the width direction of the chute 5. And corresponding background plates 12 and 13. The visible light receiving units 7 and 8 may be configured by a wide-angle camera equipped with a well-known condenser lens.

A sorting unit (exclusion means) 15 is disposed below the optical detection unit 6 along the direction of the brown rice drop, and the sorting unit 15 is provided with an air nozzle 16 for injecting air to the locus of brown rice falling.
And a solenoid valve 17 for supplying air to the air nozzle 16. A plurality of these are provided in the width direction of the chute 5.
The air from the air compressor 18 is supplied to the electromagnetic valve 17, and the electromagnetic valve 17 serves as a drive circuit 17 that discharges air to the air nozzle 16 in response to a rejection signal output from a control device 20 described later.

The light receiving units 7 and 8 are connected to a drive circuit 17 via a control device 20 described later. The brown rice signals received by the light receiving units 7 and 8 are processed by the control device 20 to detect damaged grains. Then, the control device 20 outputs an exclusion signal to the corresponding drive circuit 17. The driving circuit 17 is driven by receiving the rejection signal from the control device 20 and supplies air to the air nozzle 16 connected to the driving circuit 20, and the damaged particles are eliminated from the locus of brown rice by the air jetted from the air nozzle 16. Is discharged out of the machine through the defective product discharge port 25. Brown rice that is not removed is discharged out of the machine from the refined product discharge port 26 along the original rice grain trajectory.

The light receiving section 7 is provided with a band pass filter in the green wavelength range and receives the light quantity in the green wavelength range. The light receiving section 8 is provided with a band pass filter in the red wavelength range and controls the light quantity in the red wavelength range. It receives light.

The control device 20 will be described with reference to FIGS. FIG. 2 is a block diagram of the control device 20 and a circuit related thereto. The light receiving signal obtained by receiving the diffused light of the brown rice by the light receiving unit 7 is amplified by the amplifier 38, and the diffused light of the brown rice is received by the light receiving unit 8. The received light signals are amplified by the amplifier 39 and input to the control device 20 respectively. In the control device 20, the light receiving signals of the light receiving units 7 and 8 are calculated by the operation determining circuit 2
1 and outputs an exclusion signal to the delay circuit 22 when the arithmetic discrimination circuit 21 detects a signal of a grain to be eliminated,
An exclusion signal is output to the drive circuit 17 via the delay circuit 22.

The operation determining circuit 21 will be described with reference to FIG. The operation determination circuit 21 includes an operation circuit 30 to which light receiving signals of the light receiving units 7 and 8 are input, a first comparison circuit 31 to which an operation value signal of the operation circuit 30 is input, and a light receiving signal of the light receiving unit 7. The second comparison circuit 32 to be input, the third comparison circuit 33 to which the light receiving signal of the light receiving unit 8 is input, and the signals of the first comparison circuit 31, the second comparison circuit 32, and the third comparison circuit 33 are input. A determination circuit 34;

The light receiving signal (light amount) of the light receiving portion 7 in the green wavelength range and the light receiving signal (light amount) of the red light wavelength region of the light receiving portion 8 are input to the calculating circuit 30 of the calculation determining circuit 21. That is, the light receiving units 7 and 8 receive the diffused light of the brown rice flowing down from the same viewpoint in the brown rice downflow locus, and the light receiving unit 7 filters the light in the green wavelength range by the band-pass filters provided in each of the light receiving units. The light receiving unit 8 receives the light and outputs a light amount value, and the light receiving unit 8 receives the light in the red wavelength range and outputs the light amount value. The light amount value signal thus obtained is input to the arithmetic circuit 30. The input signal is input to the arithmetic circuit 30

[Mathematical formula-see original document] An operation is performed with red light amount / green wavelength light amount = C (calculated value).

The operation value calculated by the operation circuit 30 is input to the first comparison circuit 31. In the first comparison circuit, the calculated value is compared with a predetermined value preset in the reference value circuit 35,
If the calculated value exceeds a predetermined value, a signal is output from the first comparison circuit 31 to the determination circuit 34. Here, the predetermined value preset in the reference value circuit 35 is a value set in order to distinguish between blue immature grains and other grains, and is, for example, (red light amount value / If the value of the (green light amount) ratio is borrowed, C = 1.0 in FIG. 4 is set as the predetermined value. That is, if the calculated value exceeds 1.0, a signal is output from the first comparison circuit 31 to the determination circuit 34.
That is, a signal is output which is not a green immature grain but a kernel other than a blue immature grain. If the calculated value is 1.0 or less, no signal is output from the first comparison circuit 31 to the determination circuit 34 as blue immature grains. The predetermined value of the first comparison circuit 31 is determined so that appropriate division can be performed, and is not limited to the value used in this example.

The light amount in the green wavelength range received by the light receiving section 7 is also input to the second comparison circuit 32. Second comparison circuit 3
At 2, the light amount value is compared with a predetermined value set in advance in the reference value circuit 36. If the light amount value exceeds the predetermined value, the second
A signal is output from the comparison circuit 32 to the determination circuit 34. The case where the light amount value received by the light receiving unit 7 exceeds a predetermined value preset in the reference value circuit 36 is, for example, if the predetermined value is set to a darker side of light and dark, it is darker than the predetermined value. If it is a signal (light amount value), a signal is output from the second comparison circuit 32 to the determination circuit 34. The predetermined value sets a standard for brown rice sorting and should be changed as appropriate so that appropriate sorting can be performed.

The light amount in the red wavelength range received by the light receiving section 8 is also input to the third comparison circuit 33. Third comparison circuit 3
In 3, the light amount value is compared with a predetermined value preset in the reference value circuit 37. If the light amount value exceeds the predetermined value, the third
A signal is output from the comparison circuit 33 to the determination circuit 34. The case where the light amount value received by the light receiving unit 8 exceeds the predetermined value preset in the reference value circuit 37 means that, for example, if the predetermined value is set on the dark side of light and dark, it is darker than the predetermined value. If it is a signal (light amount value), a signal is output from the third comparison circuit 33 to the determination circuit 34. The predetermined value sets a standard for brown rice sorting and should be changed as appropriate so that appropriate sorting can be performed.

Here, the predetermined value will be described. Based on the brightness of the background plates 12 and 13, if the brown rice looks brighter than the background plate, the brown rice is shifted to a side brighter than the reference signal (the signal when the brown rice is not flowing). A waveform corresponding to the brightness of the brown rice is output. If the brown rice looks darker than the background plate, a waveform corresponding to the darkness of the brown rice is output to a darker side than the reference signal.
The predetermined value set in the reference value circuit is a reference for comparing the height of the waveform, and a signal is output from the comparison circuit when the height of the waveform is larger than the predetermined value.

An example of the determination circuit 34 will be described with reference to a block diagram shown in FIG. The second comparison circuit 32 and the third comparison circuit 33 are connected to an OR circuit 40, and the OR circuit 40 and the first comparison circuit 31 are connected to an AND circuit 41. With this circuit, the output signal of the first comparison circuit 31 and the second comparison circuit 3
The output signal of either the second or third comparison circuit 33 is AN
An exclusion signal is output from the AND circuit 41 by being input to the D circuit 41. That is, the first comparison circuit 31
Is determined by the second comparator 32 to be a signal darker than a predetermined value, or is determined by the third comparator 33 to be red. When it is determined that the light amount of the wavelength band light receiving unit is a signal darker than a predetermined value, the target brown rice which has obtained the diffused light in the light receiving units 7 and 8 is determined as a damaged grain or a colored grain, and an exclusion signal is output. .

When the first comparison circuit 31 determines that the grains are of the blue immature grain classification, the second comparison circuit 32 determines that the light amount of the green wavelength region light receiving section is a signal darker than a predetermined value. Alternatively, even when the third comparison circuit 33 determines that the light amount of the red wavelength region light receiving unit is a signal darker than a predetermined value, the AND circuit 41 does not output the exclusion signal. That is, if the first comparison circuit 31 determines that the operation value of the operation circuit 30 is a value of the blue immature grain classification, no exclusion signal is output, and the operation value of the operation circuit 30 is a value other than the blue immature grain classification. If there is, the second comparison circuit 3
2 and the value of the third comparison circuit 33 are adopted, and the second comparison circuit 3
If there is an output from either the second comparison circuit 33 or the third comparison circuit 33, a signal for eliminating the brown rice is output.

[0035]

EFFECTS OF THE INVENTION Brown rice is obtained by selecting damaged grains that can become colored grains after milling from non-defective brown rice after grain sorting, minimizing the grade of lowering grades as much as possible, and increasing the mixing ratio of regular brown rice and blue immature grains. The present invention has provided a color sorter capable of improving the quality grade of the brown rice, and has provided a brown rice color sorter capable of sorting with a conventional simple configuration having one light receiving sensor at each of the front and rear.

The brown rice used as a raw material may be a defective product after grain sorting, that is, brown rice on a so-called "milled rice" side. Using the milled rice as a raw material, unregulated brown rice and green immature grains are extracted from the milled rice. Can also be used for

[Brief description of the drawings]

FIG. 1 is a side sectional view of a main part of a color sorting device of the present invention.

FIG. 2 is a signal processing block diagram of the present invention.

FIG. 3 is a block diagram illustrating an operation determination circuit.

FIG. 4 is a diagram showing grain quality classified by an R / G spectral ratio and a reflected / transmitted light ratio.

FIG. 5 is a block diagram showing a discrimination circuit.

FIG. 6 is a diagram showing color components when a grain is color-sorted into three wavelengths.

FIG. 7 is a diagram showing a detected light amount with respect to a wavelength for each brown rice grade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brown rice color sorter 2 Vibration feeder device 3 Tank unit 4 Brown rice supply unit 5 Chute 6 Optical detection unit 7 Visible light receiving unit 8 Visible light receiving unit 9 Fluorescent lamp for lighting 10 Fluorescent lamp for lighting 12 Background plate 13 Background plate 15 Sorting Unit 16 Air nozzle 17 Solenoid valve (drive circuit) 18 Air compressor 20 Control device 21 Calculation discrimination circuit 22 Delay circuit 25 Defective product discharge port 26 Clean product discharge port 30 Calculation circuit 31 First comparison circuit 32 Second comparison circuit 33 Third comparison Circuit 34 Discrimination circuit 35 Reference value circuit 36 Reference value circuit 37 Reference value circuit 38 Amplifier 39 Amplifier 40 OR circuit 41 AND circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G051 AA04 AB20 BA01 BA08 CA03 CB05 2G059 AA10 BB09 CC20 DD12 EE02 EE11 GG03 HH02 JJ02 KK03 MM01 3F079 AC17 BA06 CA32 CB25 CB32 CB35 CB36 CC03 DA06 EA11

Claims (3)

[Claims] 1. A green signal receiving process for receiving diffused light in the green wavelength range from raw brown rice, a red signal receiving process for receiving diffused light in the red wavelength range from raw brown rice, and a green signal obtained in the green signal receiving process And calculating the signal ratio of the red signal / green signal from the red signal obtained in the process of receiving the red signal and the red signal, and a predetermined value for classifying the signal ratio calculated in the calculating process into the blue immature grain classification and the others. A first comparison step of comparing the signal ratio with the signal ratio and outputting a signal in one of the sections, and comparing the signal in the green wavelength range with a predetermined value to obtain a signal. A second comparing step of outputting a signal when the signal exceeds a predetermined value, a third comparing step of comparing a signal in the red wavelength range with a predetermined value and outputting a signal when the signal exceeds a predetermined value, and a first comparing step. No signal indicating the resulting green immature grain classification A rejection signal output step of outputting a rejection signal by one of the output signal of the second comparison step or the third comparison step One,
A brown rice color sorting method, comprising: 2. Irradiation means for irradiating light to the transferred or flowing raw brown rice, a green light receiving sensor for receiving diffused light in the green wavelength range from the raw brown rice, and receiving diffused light in the red wavelength range from the raw brown rice. A light receiving means having a red light receiving sensor to perform the processing, a light receiving signal of the green light receiving sensor and a light receiving signal of the red light receiving sensor being inputted, and a calculating means for calculating a signal ratio of the red signal / green signal, and a calculated signal ratio Is input, a predetermined value for classifying the signal ratio into the green immature grain class and the other class is compared with the signal ratio, and the signal ratio is classified into any one, and a signal is output in one of the classes. A comparison unit, a second comparison unit that receives a light reception signal of the green light reception sensor, compares the light reception signal of the green light reception sensor with a predetermined value, and outputs a signal when the light reception signal exceeds a predetermined value; Received light signal A third comparing unit that compares a light receiving signal of the red light receiving sensor with a predetermined value and outputs a signal when the light receiving signal exceeds the predetermined value; a first comparing unit and a second comparing unit And the output signal of the third comparison unit is input, and there is no signal indicating the blue immature grain classification from the first comparison unit, and the exclusion signal is output according to the input of either the second comparison unit or the third comparison unit. A brown rice color sorting apparatus, comprising: means for receiving an output signal of the discriminating unit, and an exclusion means for eliminating grains by the input signal. 3. The brown rice color sorting apparatus according to claim 2, wherein one green light receiving sensor and one red light receiving sensor are arranged at symmetrical positions with respect to the movement locus of the raw brown rice.