Food inspection device

Abstract

To provide a food inspection device capable of accurately determining the acceptability of a food product provided with an ingredient-containing part.SOLUTION: A food inspection device 2 inspects an onigiri 1 (food product) in which an ingredient-containing part 1a is set. The food inspection device comprises: an inspection region storage unit which stores an inspection region set within a range of the ingredient-containing part 1a of a model onigiri 1; a model spectrum storage unit which stores a model spectrum generated on the basis of the transmitted near-infrared light which has passed through the inspection region of the model onigiri 1 conveyed by conveying means 3; an inspection spectrum generation unit which generates an inspection spectrum from transmitted near-infrared light which has passed through the inspection region of an onigiri 1 to be inspected that is conveyed by the conveying means 3; and a determination unit which determines whether the onigiri 1 to be inspected is acceptable by comparing the inspection spectrum with the model spectrum. Since the inspection spectrum is generated on the basis of transmitted near-infrared light which has passed through the inspection region set in the ingredient-containing part 1a, it is possible to accurately determine the acceptability of the ingredient.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a food inspection device, and more particularly to a food inspection device that irradiates near-infrared light onto food and measures the near-infrared light that has passed through the food to determine whether the food is good or bad. [Background technology]

[0002] Conventionally, a food inspection device is known that includes a conveying means for conveying food, an irradiating means for irradiating near-infrared light onto the food being conveyed by the conveying means, and a light-receiving means for measuring the transmitted near-infrared light that has passed through the food, and that determines whether the food is good or bad based on a spectrum created based on the received transmitted near-infrared light (Patent Document 1). In the above-mentioned Patent Document 1, it is possible to detect whether or not the entire bread is filled with cream based on near-infrared light transmitted through the bread filled with cream. In addition, in Patent Document 2, near-infrared light transmitted through food is measured and compared with reference data prepared in advance, thereby identifying a plurality of foods. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-101966 [Patent Document 2] Patent No. 6296883 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the above-mentioned foods include, for example, rice balls and manju, which have ingredient storage sections in which ingredients are stored in required areas, and there is a demand for determining whether such ingredient storage sections are good or bad. In this case, the food inspection devices of Patent Documents 1 and 2 irradiate the entire food with near-infrared light to determine whether it is good or bad, so the transmitted near-infrared light that has passed through parts other than the ingredient storage section is also subject to the pass / fail determination, which reduces the inspection accuracy for the ingredient storage section. In view of the above problems, the present invention provides a food inspection device that can accurately inspect the ingredient container of a food product. [Means for solving the problem]

[0005] That is, the food inspection device according to the invention of claim 1 is a food inspection device comprising a conveying means for conveying food, an irradiating means for irradiating near-infrared light onto the food conveyed by the conveying means, a light receiving means for receiving the transmitted near-infrared light that has passed through the food, and a control means for controlling these means, The food product has an ingredient storage section in which ingredients are stored within a required range inside, The control means is characterized by having an inspection area memory unit that stores an inspection area set within the ingredient storage section of a normal model food; a model spectrum memory unit that stores a model spectrum created based on transmitted near-infrared light that has passed through the inspection area of ​​the model food transported by the transport means; an inspection spectrum creation unit that creates an inspection spectrum from transmitted near-infrared light that has passed through the inspection area of ​​the inspected food that is the subject of inspection and transported by the transport means; and a judgment unit that compares the inspection spectrum with the model spectrum to judge whether the inspected food is good or bad. [Effects of the Invention]

[0006] According to the above invention, the inspection area setting unit sets an inspection area in the ingredient storage section of the food, and the inspection spectrum creation unit creates an inspection spectrum from the transmitted near-infrared light that has passed through the inspection area, and the model spectrum stored in the model spectrum memory unit is also created based on the transmitted near-infrared light that has passed through the ingredient storage section of a normal model food. Therefore, since both the test spectrum and the model spectrum are spectra of the portion containing ingredients and do not include spectra of the portion not containing ingredients, accurate test results for the ingredient containing portion can be obtained by comparing the test spectrum and the model spectrum. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a front view of a food inspection device according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. 2 is a diagram illustrating the configuration of a control unit. [Figure 4] Continuous spectrum of near-infrared light transmitted through rice ball. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will now be described with reference to the illustrated embodiment. Figure 1 shows a food inspection device 2 that inspects rice balls 1 as food. Near-infrared light is irradiated onto the rice balls 1 transported by a transport means 3, and the rice balls 1 are inspected based on the transmitted near-infrared light that passes through the rice balls 1. As shown in Figure 2, the rice ball 1 of this embodiment is a food product made by forming cooked rice into a triangle in a plan view, and an ingredient storage section 1a is provided in a required area approximately in the center of the inside of the rice ball to store ingredients such as kelp, sockeye salmon, salmon roe, etc. The rice that makes up the rice ball 1 may be white rice or cooked rice, and may be any shape such as triangular, round, oval, etc. Furthermore, the outside of the rice ball 1 may or may not be covered with seaweed. Furthermore, the rice ball 1 inspected in this embodiment is wrapped in wrapping paper made of resin film or the like, and this wrapping paper has a label printed with the names of the ingredients in the rice ball 1, other ingredients, expiration date, etc. attached to it, or these contents are printed directly on the wrapping paper. The wrapping paper and label are made of a material that is transmissive to near-infrared light. The food inspection device 2 of this embodiment detects whether the ingredients displayed on the wrapping paper match the ingredients placed in the rice ball 1, and also detects whether any ingredients have been left out.

[0009] The food inspection device 2 comprises a conveying means 3 for conveying the rice balls 1, an irradiation means 4 for irradiating near-infrared light onto the rice balls 1 conveyed by the conveying means 3, a light receiving means 5 for receiving the transmitted near-infrared light that has passed through the rice balls 1, a control means 6 for controlling these, and an operation panel 7 for an operator to perform the required input operations, etc. As shown in Figure 2, the conveying means 3 includes two endless belts 3A, 3A arranged in parallel along the conveying direction, and a pair of rotating rollers 3B is provided at both ends of the endless belts 3A, 3A, one of which is driven by a motor 8. When the motor 8 is driven by a command from the control means 6, the rotating roller 3B is rotated, and the two endless belts 3A, 3A are caused to circulate at a constant speed in the direction of the arrow. In addition, a gap S is formed between the endless belts 3A, 3A, and the rice ball 1 is placed in a position that is recognized as a triangle when viewed in a plane, and the ingredient storage section 1a is placed so that it straddles the gap S.

[0010] 1, the irradiation means 4 is provided above the conveying means 3, and the light receiving means 5 is provided below the irradiation means 4, sandwiching the conveying means 3. The position where the irradiation means 4 and the light receiving means 5 are provided is defined as inspection position A for the rice ball 1. The irradiation means 4 is made of a halogen lamp that emits light in a wavelength range of about 400 to 3000 nm, and is kept on at all times during inspection. Therefore, when the rice ball 1 passes through the inspection position A, near-infrared light is continuously irradiated from the irradiation means 4 toward the rice ball 1. Note that the irradiation means 4 is not limited to a halogen lamp, and a wideband LED or laser may also be used. The light receiving means 5 is equipped with a light receiving element, a near-infrared spectrometer, etc., and the near-infrared light irradiated by the irradiation means 4 passes through the rice ball 1 to become transmitted near-infrared light, which then passes through the gap S between the two endless belts 3A, 3A of the conveying means 3 to be received by the light receiving means 5.

[0011] The conveying means 3 is also provided with a position detecting means 11 for detecting the position of the rice ball 1 being conveyed. The position detection means 11 comprises a photoelectric sensor 11a provided on the transport path of the rice ball 1 and an encoder 11b provided on the rotating roller 3B, and when the photoelectric sensor 11a detects the rice ball 1, the control means 6 counts the pulse signal output by the encoder 11b, thereby detecting the position of the rice ball 1 transported by the transport means 3.

[0012] FIG. 3 shows a configuration diagram of the control means 6, to which the position detection means 11 and light receiving means 5 are connected, and required operations can be performed via the operation panel 7. The control means 6 of this embodiment is equipped with an inspection area memory unit 12 that stores the inspection area I set within the ingredient storage unit 1a of the rice ball 1, an inspection spectrum creation unit 13 that creates an inspection spectrum from transmitted near-infrared light that has passed through the inspection area I of the inspected rice ball 1, which is the object of inspection, a model spectrum memory unit 14 that stores a model spectrum created based on transmitted near-infrared light that has passed through the inspection area I of a normal model rice ball 1, and a judgment unit 15 that compares the inspection spectrum with the model spectrum and judges whether the inspected rice ball 1 is good or bad. The control means 6 can be a conventionally known computer or the like, and each component such as the inspection area storage unit 12 and the inspection spectrum creation unit 13 may be configured as a different terminal.

[0013] The inspection area storage unit 12 stores the position of the inspection area I of the inspected rice ball 1, which is set based on the dimensional data of the normal model rice ball 1. For example, if a circular ingredient storage section 1a is set at the center of a triangular rice ball 1, the center position is calculated based on the base and height of the rice ball 1, and an inspection area I narrower than the diameter of the ingredient storage section is set before and after the center position. More specifically, if the outer shape of the triangular rice ball 1 is a base of 8.5 cm and a height of 6 cm, and the ingredient storage section 1a is formed within a circle with a radius of 1.25 cm centered 2.5 cm above the center of the base, the inspection area I will be set within a range of 1 cm both in front of and behind the center. When the conveying means 3 conveys the triangular rice ball 1 with its base positioned downward as shown in Figure 2, the inspection area I is the section from the position where the front end of the rice ball 1 in the traveling direction reaches the inspection position and is conveyed a further 3.25 cm until it is conveyed 5.25 cm. With the inspection area I stored in this manner, when the rice ball 1 is transported by the transporting means 3, the rice ball 1 reaches the inspection position A between the irradiation means 4 and the light receiving means 5, and when the inspection area I approaches the inspection position A, the control means 6 causes the light receiving means 5 to receive the transmitted near-infrared light that has passed through the inspection area I of the rice ball 1 multiple times, for example, about five times, before the inspection area I passes the inspection position A.

[0014] In this embodiment, the inspection area I is set to a range slightly narrower than the ingredient-accommodating portion 1a of the rice ball 1, as shown in FIG. This is because during the manufacturing process of rice ball 1, the ingredients may become biased from the center of rice ball 1, and in that case, if inspection area I is set in the same area as ingredient storage section 1a, there is a possibility that the ingredients will fall out of inspection area I. Furthermore, the gap S between the endless belts 3A, 3A of the conveying means 3 is set to be equal to or smaller than the dimension of the inspection area I. In the case of the rice ball 1 described above, the gap S is set to be equal to or smaller than 2 cm. By setting the gap S in this manner, when the rice ball 1 passes through the inspection position, near-infrared light is prevented from passing through the parts above and below the ingredient storage section 1a that do not contain ingredients.

[0015] The inspection spectrum creation unit 13 creates a continuous waveform spectrum showing the relationship between the wavelength and absorbance of the transmitted near-infrared light as shown in Figure 4, based on the transmitted near-infrared light received by the light receiving means 5. To explain the spectrum, in FIG. 4, the horizontal axis indicates the wavelength of the transmitted near-infrared light, and the vertical axis indicates the absorbance, and in this embodiment, the wavelength of the spectrum is set in the range of 500 to 1200 nm. Figure 4 shows an example of a spectrum created based on transmitted near-infrared light that has passed through the ingredient housing section 1a of the rice ball 1, showing the spectrum of a rice ball 1 containing sockeye salmon (A) and kelp (B) in the ingredient housing section 1a, and the spectrum of a rice ball 1 without any ingredients (C). As can be seen, the shape of the spectrum differs depending on the ingredients. In this embodiment, the spectrum is created using transmitted near-infrared light that has passed through the inspection area I set within the ingredient storage section 1a. Therefore, compared to creating a spectrum by irradiating the entire rice ball 1 with near-infrared light, the spectrum does not include the parts where no ingredients are stored, making it possible to clearly obtain variations between ingredients. When creating the spectrum, the transmittance of the rice ball 1 may be measured instead of the absorbance of the rice ball 1, and a line spectrum may be used instead of a waveform spectrum for the spectral distribution.

[0016] The inspection spectrum creating unit 13 creates an inspection spectrum based on the near-infrared light transmitted through the inspected rice ball 1 as the inspection object. Specifically, as described above, while the inspection area I of the rice ball 1 to be inspected passes through the inspection position A, the light receiving means 5 receives the transmitted near-infrared light that has passed through the inspection area I set in the ingredient storage section 1a multiple times. The inspection spectrum creating unit 13 creates a spectrum for each of the transmitted near-infrared lights received by the light receiving means 5, and then averages these to create an inspection spectrum.

[0017] The model spectrum memory unit 14 stores a model spectrum created in advance for a normal model rice ball 1, i.e., a rice ball 1 in which the ingredients written on the wrapping paper match the ingredients contained in the rice ball 1 and the ingredients are contained in a normal area. The model spectrum can be created in the same way as when the inspection spectrum is created using the inspection spectrum creation unit 13 described above. Specifically, multiple model rice balls 1 containing the same ingredients are prepared in advance, and spectra are created based on the transmitted near-infrared light that has passed through the inspection area I of these model rice balls 1, and the average of the obtained spectra is stored in the model spectrum memory unit 14 as the above-mentioned model spectrum. In this example, three types of model spectra are stored: (A) sockeye salmon, (B) kelp, and (C) no ingredients, as shown in Figure 4. Note that in Figure 4, the vertical axis represents absorbance and the horizontal axis represents wavelength, but the vertical axis may represent transmittance and the horizontal axis represents wavelength. A model spectrum must be created for each ingredient, and even for the same ingredients, the spectrum obtained will differ depending on the shape of the rice ball, the type of rice, the presence or absence of seaweed, and the wrapping paper, so a separate model spectrum must be created for each product. Also, while it is possible to create a model spectrum immediately before the testing process, it is desirable to create one at least every few days or every month.

[0018] The judgment unit 15 compares the inspection spectrum of the inspected rice ball 1 measured by the inspection spectrum creation unit 13 with the model spectrum of a normal model rice ball 1 stored in the model spectrum storage unit 14, and judges whether the inspected rice ball 1 is good or bad. For example, if the ingredient of the rice ball 1 to be inspected is sockeye salmon, the determination unit 15 extracts the model spectrum of sockeye salmon shown in FIG. 4A from the model spectrum storage unit 14. On the other hand, when the light receiving means 5 receives the transmitted near-infrared light that has passed through the inspected rice ball 1 containing the sockeye salmon, the inspection spectrum creation unit 13 generates a spectrum that is similar to the spectrum of the sockeye salmon shown in (A). The judgment unit 15 then sets comparison points for approximately 100 required wavelengths for each of the model spectrum and the test spectrum, calculates the difference in absorbance at each comparison point, and calculates the sum of the differences at all the calculated comparison points. If the sum is equal to or less than a predetermined value, this means that there is little difference between the model spectrum and the test spectrum, and the determining unit 15 determines that the filling of the test rice ball 1 is sockeye salmon. In contrast, if the rice ball 1 to be inspected contains kelp or no ingredients, the inspection spectrum creation unit 13 will generate the kelp spectrum (B) or the ingredient-free spectrum (C), causing the sum of the differences at the above comparison points to exceed the predetermined value. In this case, the judgment unit 15 will determine that the rice ball 1 does not contain sockeye salmon and will judge it to be defective. In this embodiment, when comparing the model spectrum waveform and the test spectrum waveform, the comparison is made over the entire wavelength range, but it is also possible to set a wavelength range in advance where there is a clear difference and make the comparison within that wavelength range.

[0019] A method for inspecting rice balls 1 using food inspection device 2 having the above configuration will be described below. First, in the rice ball manufacturing process, rice balls 1 containing required ingredients are made automatically, semi-automatically, or manually by an operator. Thereafter, the rice ball 1 is wrapped in wrapping paper, and a label bearing information about the ingredients contained therein is attached to the wrapping paper. In the rice ball manufacturing process, a predetermined number of rice balls 1 containing the same ingredients are manufactured, and the rice balls 1 manufactured in this manner with the same ingredients are inspected by the food inspection device 2 as inspected rice balls 1.

[0020] The operator inputs the ingredients on the operation panel 7 that are the same as those written on the wrapping paper of the rice ball 1 to be inspected, and the control means 6 instructs a supply means (not shown) located upstream of the conveying means 3 to start supplying the rice ball 1 to be inspected. For example, if the wrapping paper of the rice ball 1 shows sockeye salmon as an ingredient, the operator selects sockeye salmon as an ingredient on the operation panel 7, which causes the control means 6 to read out the model spectrum of sockeye salmon from the model spectrum memory unit 14.

[0021] The supply means supplies the rice balls 1 to be inspected to the conveying means 3 at predetermined intervals, and at this time, the rice balls 1 are placed so that a triangle is visible when viewed in a plane as shown in Figure 2, and so that the ingredient storage section 1a spans the gap S between the endless belts 3A, 3A. When the rice ball 1 to be inspected that has been conveyed by the conveying means 3 is detected by the photoelectric sensor 11a that constitutes the position detecting means 11, the position of the rice ball 1 to be inspected thereafter is recognized by the encoder 11b. When the inspection area I of the rice ball 1 to be inspected reaches the inspection position A where the irradiating means 4 and the light receiving means 5 are provided, the control means 6 commands the light receiving means 5 to receive light.

[0022] While the inspection area I of the rice ball 1 to be inspected passes through the inspection position A, the near-infrared light irradiated by the irradiation means 4 passes through the ingredient storage section 1a of the rice ball 1 to be inspected, and the light receiving means 5 receives the transmitted near-infrared light that has passed through the rice ball 1 to be inspected multiple times. When the light receiving means 5 receives the transmitted near-infrared light in this manner, the inspection spectrum creating section 13 creates an inspection spectrum from the transmitted near-infrared light received multiple times. Next, the judgment section 15 compares the inspection spectrum created by the inspection spectrum creation section 13 with the model spectrum stored in the model spectrum storage section 14, and judges whether the inspected rice ball 1 is good or bad.

[0023] As described above, the judgment unit 15 judges whether the rice ball 1 to be inspected is good or bad based on the difference between the inspection spectrum and the model spectrum, and if the difference is less than a predetermined value, the judgment unit 15 judges the rice ball 1 to be inspected as good, and if the difference exceeds the predetermined value, it judges the rice ball 1 to be defective. Defective products can be detected, for example, when ingredients are placed incorrectly or forgotten in a rice ball manufacturing device, or when a label is attached incorrectly to the wrapping paper.In addition, if ingredients are placed far outside the required ingredient storage section 1a, they can also be detected as defective. Then, the rice balls 1 that are determined to be defective are rejected by a rejection means (not shown) provided downstream of the conveyance means 3. Once inspection of the rice ball 1 containing sockeye salmon has been completed in this way, if inspection of a rice ball 1 containing another ingredient such as kelp is to be continued, the operator simply inputs kelp as an ingredient into the operation panel 7 and supplies the rice ball 1 with kelp as an ingredient on the label to the supply means. In this embodiment, it is possible to inspect so-called salted rice balls, which do not contain any ingredients in the ingredient-containing section 1a. In other words, since the ingredient in the ingredient-containing section 1a is white rice, if a model spectrum without ingredients, such as that shown in Figure 4(C), is created, it is possible to determine whether such salted rice balls 1 are good or bad.

[0024] As described above, according to the food inspection device 2, an inspection area I is set in the ingredient storage section 1a of the rice ball 1, and an inspection spectrum is created from the transmitted near-infrared light that has passed through the inspection area I, thereby enabling accurate inspection to be performed using the spectrum that has passed through the ingredients in the ingredient storage section 1a. On the other hand, if the entire rice ball 1 is used as the inspection area, the transmitted near-infrared light that has passed through the portion consisting only of white rice other than the ingredient storage section 1a will also be received by the light receiving means 5, and a spectrum will be created that includes this transmitted near-infrared light that has passed through the white rice, resulting in a problem of reduced inspection accuracy. Furthermore, in this embodiment, the above model spectrum can be created using the actual model rice ball 1, and it is only necessary to compare the inspection spectrum of the rice ball to be inspected with one model spectrum. Therefore, complicated operations of the food inspection device 2 are not required, and fine adjustments can also be simplified.

[0025] In the above embodiment, if the ingredients are automatically recognized by image recognition of the label attached to the wrapping paper, it is possible to determine whether the ingredients match for each rice ball 1 to be inspected, even if rice balls 1 containing different ingredients are supplied randomly. Furthermore, in this embodiment, only the near-infrared light transmitted through the inspection area I is measured, but the entire area of ​​the rice ball 1 may also be measured. By measuring the entire area, it is possible to detect the presence of ingredients in areas where no ingredients should be present. However, even when measuring the entire area, it is sufficient to make a pass / fail judgment based on the transmitted near-infrared light that has transmitted through the inspection area I, as in the above embodiment. Furthermore, in the food inspection device 2 of this embodiment, the irradiation means 4 and the light receiving means 5 are not limited to a configuration in which they are placed above and below the conveying means 3, but can also be placed on one side and the other side of the rice ball 1 depending on the shape and conveying form of the rice ball 1. As for food, instead of the rice ball 1, it is possible to inspect any food that contains ingredients in a predetermined position, such as a Chinese steamed bun or a steamed bun. [Explanation of symbols]

[0026] 1 Onigiri (food) 1a Ingredients storage section 2 Food inspection equipment 3 Transportation means 4 Irradiation means 5 Light receiving means 6 Control means 11 Position detection means 12 inspection area setting unit 13 inspection spectrum creation unit 14 Model spectrum storage unit 15 Determination unit A Inspection position I Inspection area

Claims

1. A food inspection device comprising: a conveying means for conveying food; an irradiating means for irradiating near-infrared light onto the food conveyed by the conveying means; a light receiving means for receiving near-infrared light transmitted through the food; and a control means for controlling these means, The food product has an ingredient storage section in which ingredients are stored within a required range inside, The food inspection device is characterized in that the control means comprises an inspection area memory unit that stores an inspection area set within the range of the ingredient storage unit of a normal model food, a model spectrum memory unit that stores a model spectrum created based on transmitted near-infrared light that has passed through the inspection area of ​​the model food transported by the transport means, an inspection spectrum creation unit that creates an inspection spectrum from transmitted near-infrared light that has passed through the inspection area of ​​the inspected food that is the subject of inspection and transported by the transport means, and a judgment unit that compares the inspection spectrum with the model spectrum to judge whether the inspected food is good or bad.

2. The food is a rice ball, and the ingredient storage section is provided in the center of the rice ball, The model spectrum storage unit stores a model spectrum of a rice ball containing ingredients made of required ingredients, 2. The food inspection device according to claim 1, wherein the determination unit determines whether the required ingredients are contained in the rice ball to be inspected by comparing the inspection spectrum with the model spectrum.

3. The food is a rice ball, and the ingredient storage section is provided in the center of the rice ball, the model spectrum storage unit stores a model spectrum of a rice ball in which no ingredient is accommodated in the ingredient accommodation unit, 2. The food inspection device according to claim 1, wherein the determination unit determines whether or not the rice ball to be inspected contains any ingredients by comparing the inspection spectrum with the model spectrum.

4. The model spectrum and the test spectrum are continuous waveform spectra that show the relationship between wavelength and the intensity of absorbance or transmittance of transmitted near-infrared light, 2. The food inspection device according to claim 1, wherein the judgment unit compares the waveform spectra of the model spectrum and the inspection spectrum to judge whether the food is good or bad.

5. When comparing the waveform spectra of the model spectrum and the test spectrum, the determination unit sets comparison points at a plurality of wavelengths constituting the waveform spectrum, and calculates a sum of differences in absorbance at these comparison points; 5. The food inspection device according to claim 4, wherein the food to be inspected is determined to be normal when the total sum is equal to or less than a predetermined value.

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