JPH0233095B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for determining grain quality of polished rice, and particularly to a method for optically measuring and determining grain quality of polished rice. Polished rice has quality standards established under the Agricultural Products Inspection Act, and is graded according to these standards. Among the quality items for grading, upper limits are set for the mixing ratio (mixing rate) for two items: powdery grains and colored grains. In order to distinguish between regular grains, powdery grains, and colored grains during milling, it has been proposed to irradiate the rice with light, measure the transmittance, and make the discrimination based on the transmittance. For example, there are methods described in Japanese Patent Application Laid-open No. 54-78191, Japanese Patent Application Laid-Open No. 54-78190, and the like. However, no method has yet been proposed that specifically and accurately makes these distinctions by referring to the wavelength characteristics of the irradiating light beam. The present invention proposes a method for accurately and concretely determining grain size, powdery grains, and colored grains during rice milling based on the measurement of light transmittance. According to the present invention, a predetermined amount of polished rice is processed one grain at a time.
The first wavelength λ ₁ and the second wavelength in the wavelength range from 400 nm to 850 nm
When irradiated with a light beam of wavelength λ ₂ (λ ₁ ≠ λ ₂ ), the transmittance of one grain of polished rice is the first transmittance T ₁ for the first wavelength λ ₁ and the transmittance T ₂ for the second wavelength λ ₂ . Measure the first and second
This paper proposes a method for determining the grain quality of a single grain of polished rice based on the transmittances T ₁ and T ₂ and the correlation between these two transmittances. When _a substance is irradiated with light, the transmittance _T is T=
It can be stopped by I _t /I ₀ . The inventor of the present application focused on the fact that the transmittance T of sized grains, powdery grains, and colored grains during rice milling uniquely changes the characteristics of each grain along with the wavelength λ of the irradiation light, and this property change causes sized grains, powdery grains, and colored grains. We devised a method to distinguish between textured grains and colored grains. In particular, we focused on the fact that this characteristic change is significantly different for regular grains, powdery grains, and colored grains in the region where the wavelength λ of light is λ > 400 nm, and we irradiated each grain of polished rice with light in this wavelength range. This paper proposes that the grain quality of milled rice can be determined based on changes in the characteristics of light transmittance. FIG. 1 shows the characteristics of light transmittance T of regular grains, powdery grains, and colored grains with respect to light wavelengths λ of approximately 400 nm to 850 nm. As is clear from FIG. 1, it is understood that the transmittance of defective grains, including regular grains, colored grains, powdery grains, etc., is clearly significantly different in the wavelength range from 400 nm to 850 nm. However, there is no significant difference in transmittance values between powdery grains and colored grains, which are defective grains, in the wavelength range from 400 nm to 850 nm. However, it is clear that the slopes of the characteristic curves are different in this wavelength range. In view of the above, it can be seen that regular grains and defective grains can be distinguished from the transmittance value, and powdery grains and colored grains among the defective grains can be distinguished by the difference in the gradient of transmittance. For example, the first wavelength is λ ₁ =800nm, and the second wavelength is
Find the values on each characteristic curve at λ ₂ = 600 nm, that is, the transmittances T ₁ and T ₂ , and find the transmittance difference ΔT = T ₁ − _{T 2} , and calculate the transmission from the characteristic curve at wavelength λ ₁ = 800 nm. rate
FIG. 2 shows how the transmittance difference ΔT is distributed with respect to T ₁ . From Figure 2, the transmittance difference ΔT between powdery grains and colored grains is distributed vertically as ΔT = ΔT′ _t (ΔT′ _t is the threshold transmittance difference, see Table 1). I can understand. (Specifically, ΔT′ _t =0.005). In addition, the transmittance T of defective grains consisting of powdery grains and colored grains and regular grains is distributed on the left and right as T = T _t (T _t is the threshold transmittance, see Table 1). It is also concretely clear. However, it has been found through experiments that the transmittance T of the colored grains is almost equal to that of the regular grains, and the difference only in transmittance difference ΔT is as shown by the dotted line in FIG. However, there are very few materials that exhibit such a difference in transmittance. Considering the conditions for distinguishing sized grains, powdery grains, and colored grains from Figure 2, we find that (a) sized grains are in area A T>T _t ΔT>ΔT _t (b) Colored grains are outside areas A and B In other words, when T < T _t , ΔT > _ΔT ' t When T > T _t , ΔT _t > ΔT >ΔT' _t (c) Powdery grains are in region B, where T < T _t ΔT <ΔT' . If the above is expressed as a logical formula for areas A and B, it will be as follows: Regular grain: A, Colored grain: ・=+ Powdery quality: B. From the above conditions, it is understood that it is possible to determine the grain quality of a single grain of polished rice by logical judgment. However, as mentioned above, the distribution of colored grains as shown by the dotted line in Figure 2 is extremely rare and can be ignored, so in reality, colored grains are distributed under the condition of T<T _t ΔT>ΔT′ _t . It's okay to judge. Therefore, for one grain of polished rice, if its transmittance T is T > T _t , it is determined to be grain size, and if T < T _t , it is determined to be a defective grain, and then the transmittance difference ΔT is examined carefully. >ΔT', it is determined to be a colored grain, and if ΔT<ΔT', it is determined to be a powdery grain. The present invention will be specifically described in detail below with reference to the embodiment shown in FIG. FIG. 3 shows a schematic diagram of the present invention, in which one polished rice grain 1 is held in an opening 3 of a light-shielding transfer plate (hereinafter referred to as a "shade plate") 2, moves in the direction of the arrow, and emits light. Light beams of wavelengths λ ₂ and λ ₁ are irradiated from elements 4 and 6. The light receiving elements 5 and 7 receive the light that has passed through each polished rice grain 1. The transmittance is for light emitting elements 4 and 6.
It is calculated as the ratio of the amount of light rays of The value is proportional to the transmittance. The amount of received light is photoelectrically converted by light receiving elements 5 and 7, amplified by amplifiers 8 and 12, and valid signal discriminators 9 and 13 determine whether it is a valid signal. If it is a valid signal, it is converted from an analog quantity to a digital quantity by A-D converters 10 and 14, and is held in buffer registers 11 and 15. The calculator 16 inputs the contents of the buffer registers 11 and 15 and calculates the quality of one grain of milled rice, the sorted grains in a predetermined amount of milled rice, the defective grains, and the mixing rate of powdery grains and colored grains among the defective grains. Then, the output device 17 outputs the value. The above operation of the computer 16 is shown in the flowchart of FIG. In FIG. 4, the variables are as shown in the table below. At the start of measurement, in step _S1 , the number of milled rice grains N, the rectification number N _o , the number of defective grains N _a , and the number of powdery grains are determined.
Set N _p and the number of colored particles N _c to zero.
Transmittance T _{1 (} λ ₁ =
The transmittance at 800 nm light is read, and in step _S3 it is compared whether _T1 is greater or less than the threshold transmittance _Tt . If T ₁ > T _t , it is determined that the grain is sized and goes to step S ₂₀ .
Add the number “1” to the grain size number N _o . and step
Add "1" to S ₉ and the number of grains of polished rice N. In step _S10 , it is determined whether the number of grains N of polished rice is less than a predetermined number of grains _Nnax , and

[Table] If the measured grain number N _nax or less, the process returns to step _S2 and the operation is repeated for the next grain of polished rice. If T ₁ ≦T _t in step S ₃ , the number “1” is added to the number of defective grains N _a in step S ₄ . Further, the process proceeds to step _S5 , where the transmittance T ₂ (transmittance for a light beam of λ ₂ =600 nm) of the buffer register 15 is read, and the transmittance difference ΔT is calculated at step _S6 . Further, the process proceeds to step _S7 , where the transmittance difference ΔT is compared with the threshold transmittance difference ΔT′ _t . If the transmittance difference ΔT is ΔT>ΔT' _t , it is determined that the colored grains are among the defective grains, and the process goes to step _S30 , where the number of colored grains _Nc is set to "1".
Add. Further, if the transmittance difference ΔT is ΔT≦ΔT′ _t , it is determined that the particles are powdery particles, and the process proceeds to step _S8 , where the number “1” is added to the number N _p of powdery particles. After the processing in step S ₃₀ or step S ₈ , proceed to step S ₉ , where the number "1" is added to the number N of grains of polished rice, and proceed to step S ₁₀ , where the number N of grains of polished rice is equal to the predetermined measured grain number N. It is determined whether it is less than or equal to _nax , and if it is less than or equal to a predetermined number N _nax , the process returns to step _S2 . If the number of milled rice grains N is the predetermined measured grain number _Nnax , proceed to step _S11 .
Calculate the mixed grain ratio n, defective grain mix rate a, powdery grain mix rate p, and colored grain mix rate c during rice milling, and step
In _S12 , the results are outputted by an output device 17 such as a line printer. The above operation of the calculator 16 is such that the measured transmittances T ₁ and T ₂ of each grain of polished rice are sequentially changed for each process of steps S ₂ to S ₁₀ including steps S ₂₀ and S ₃₀ , which are one calculation cycle. It is assumed that the information is stored in the front registers 11 and 15. calculator 1
There are various ways to read the transmittances T ₁ and T ₂ of No. 6, and all of them can be done by known means. The reading of the transmittances T ₁ and T ₂ of the transmittance measurement calculator 16 for each grain of polished rice must be synchronized. Although the present invention has been described in the form of examples, the present invention is not limited to the above-mentioned examples, and can be variously modified within the scope of the claims. For example, in the above embodiment, the judgment is made based on the transmittance difference ΔT between the two light wavelengths λ ₁ and λ ₂ , but it is also within the scope of the present invention to make the judgment based on the relationship of the light transmittance ratio α=T ₂ /T ₁ . It is.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the change characteristics of the light transmittance of polished rice with respect to the light wavelength. FIG. 2 is a diagram showing the distribution in relation to the transmittance at a light wavelength of 800 nm and the transmittance difference between the same transmittance and the transmittance at a light wavelength of 600 nm. FIG. 3 shows a schematic diagram of an embodiment of an apparatus for carrying out the method of the invention. FIG. 4 is a flowchart of the apparatus shown in FIG. 3. 1...One grain of polished rice, 2...Shading plate, 3...Opening,
4, 6... Light emitting element, 5, 7... Light receiving element.

Claims (1)

[Scope of Claims] 1. A method of irradiating each grain of polished rice with light to determine grain size and quality of defective grains including powdery grains and colored grains, (a) irradiating each grain of the polished rice with light at 400 nm. The first wavelength λ ₁ in the wavelength range of 850 nm is irradiated from
( _{b) Comparing the first transmittance T 1 and} a predetermined threshold transmittance T _t to determine whether the milled rice grain is a regular grain or a defective grain. (c) If one grain of the polished rice is determined to be a defective grain, further irradiation with a second wavelength λ ₂ (λ ₁ ≠ λ ₂ ) in the wavelength range of 400 nm to 850 nm, and Transmittance T ₂
(d) calculating a transmittance difference ΔT between the first transmittance T ₁ and the second transmittance T _2; and (e) calculating the transmittance difference ΔT by a predetermined threshold transmittance difference. △
A method for determining the grain quality of polished rice, comprising: comparing T _t ′ to determine whether one grain of the polished rice is a colored grain or a powdery grain among defective grains. 2. The method according to claim 1, wherein the first wavelength λ ₁ is 800 nm and the second wavelength λ ₂ is 600 nm. 3. In a method of irradiating each grain of polished rice with light to determine grain size and defective grains including powdery grains and colored grains, (a) each grain of polished rice is irradiated with light in the wavelength range from 400 nm to 850 nm. The first wavelength λ ₁ of the milled rice grains is irradiated with the first wavelength λ 1 of
(b) comparing _{the transmittance T 1 and} a predetermined threshold transmittance T _t to determine whether one grain of the milled rice is a regular grain or a defective grain; (c) If one grain of the milled rice is determined to be a defective grain, it is further irradiated with a second wavelength λ ₂ (λ ₁ ≠ λ ₂ ) in the wavelength range of 400 nm to 850 nm, and a second transmission is performed. rate T ₂
(d) calculating a transmittance ratio α between the first transmittance T ₁ and the second transmittance T ₂ ; (e) the first transmittance T ₁ and the second transmittance T 2 . comparing the transmittance ratio α with the rate T ₂ with a predetermined threshold transmittance ratio α _t to determine whether the classified defective grains of the milled rice are colored grains or powdery grains; A method for determining grain quality of milled rice having the following. 4. The method according to claim 3, wherein the first wavelength λ ₁ is 800 nm and the second wavelength λ ₂ is 600 nm.