Hair inspection device

Abstract

To provide a hair inspection device capable of detecting hair adhering to the surface of jelly-like food.SOLUTION: A hair inspection device comprises: a conveyor that transports plastic containers in which jelly-like food is filled in an unsealed state before sealing; dome-shaped illumination tool means that has an inner reflective surface, a window for imaging formed at a top portion, and LEDs that can emit near-infrared light of multiple bands therein, and irradiates the plastic container with near-infrared light of the predetermined band; a near-infrared camera that receives reflected light of near-infrared light from the jelly-like food in the plastic container and captures an image; foreign matter detection means that analyzes the image captured by the near-infrared camera and extracts hair adhering to the surface of the jelly-like food; and a sorting device that is provided at an end portion in the conveying direction of the conveyor, and discharges the plastic container in which hair has been detected by the foreign matter detection means onto a defective product table separate from a non-defective product table.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hair inspection device, and more particularly to a hair inspection device that can detect and remove hairs adhering to the surface of a jelly-like food filled in a plastic container. [Background technology]

[0002] For example, a hair stuck to coffee jelly is difficult to distinguish visually because there is no contrast between the two. Even with a color sorter, it is difficult to distinguish because they are both the same brown color.

[0003] Patent Document 1 shows a fruit and vegetable inspection device that uses near-infrared light. Near-infrared images are obtained by irradiating mandarin oranges with near-infrared light, and fluorescent images are obtained by irradiating them with ultraviolet light, and the device detects damaged areas of the mandarin oranges that are difficult to see. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-59775 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a hair inspection device that can detect hairs adhering to the surface of jelly-like food. [Means for solving the problem]

[0006] The hair inspection device according to the present invention is characterized by comprising: a conveyor that transports plastic containers filled with jelly-like food and without a seal before sealing; a dome-shaped lighting device means having a reflective surface on the inner surface, a window for imaging at the top, and LEDs inside that are capable of emitting near-infrared light in multiple bands, and that irradiates the plastic container with the near-infrared light of the set band; a near-infrared camera that receives the near-infrared light reflected from the jelly-like food in the plastic container and takes an image; a foreign object detection means that analyzes the image taken by the near-infrared camera and extracts hair adhering to the surface of the jelly-like food; and a sorting device that is provided at the end of the conveyor in the transport direction and that ejects plastic containers in which hair has been detected by the foreign object detection means to a defective product table separate from a non-defective product table.

[0007] The near-infrared band set for the dome-shaped lighting means is selected from the range of 1450 nm to 1650 nm by conducting a test using a jelly-like food product to which hair has been attached in advance.

[0008] The sorting device is characterized by comprising a sorting plate with a receiving portion for sorting the plastic containers, and a rotating shaft for rotating the sorting plate, the rotating shaft sliding in a direction perpendicular to the conveyor. [Effects of the Invention]

[0009] The hair inspection device of the present invention comprises a conveyor that transports plastic containers filled with jelly-like food but without a pre-sealing seal, a dome-shaped lighting device that irradiates a set band of near-infrared light toward the plastic containers, and a foreign object detection device that analyzes images taken with a near-infrared camera to extract hair on the surface of the jelly-like food. Since hair and jelly-like food have different moisture contents and pixel contrasts (shades), near-infrared imaging makes it easy to distinguish hair. Furthermore, plastic containers with hair stuck to the jelly-like food are ejected by a sorting device to a defective product table separate from the non-defective product table, so the conveyor does not need to be stopped when a hair is detected, facilitating post-processing.

[0010] The near-infrared band set for the dome-shaped lighting device means is 1450nm to 1650nm, where the contrast between hair and jelly-like food is prominent. Therefore, by knowing in advance the grayscale value, which is the shade of the hair pixels, it is possible to identify the hair pixels on the surface of the jelly-like food.

[0011] The sorting device is provided with a sorting plate with a receiving part for sorting plastic containers and a rotary shaft for rotating the sorting plate, and is configured so that the rotary shaft slides in a direction perpendicular to the conveyor, so that plastic containers without hair can be discharged onto a normal table and plastic containers with hair attached can be discharged onto a foreign object table. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a configuration diagram of a hair inspection device according to the present invention. [Figure 2] FIG. 2 is a diagram showing the internal configuration of a dome-shaped lighting means. [Figure 3] FIG. 10 is a diagram showing an LED provided in the dome-shaped lighting means. [Figure 4] FIG. [Figure 5] FIG. 10 is a diagram illustrating the operation of the sorting device. [Figure 6] This is an image of coffee jelly in a plastic container. [Figure 7] This is an image of coffee jelly in a plastic container. [Figure 8] This is an image of coffee jelly in a plastic container. [Figure 9] This is an image of coffee jelly in a plastic container. [Figure 10] 10 is a flowchart showing a procedure for capturing images of a plastic container of coffee jelly with hair attached thereto using different near-infrared bands to determine the grayscale value of the hair in advance. [Figure 11]10 is an operational flowchart for inspecting coffee jelly filled in a plastic container using a hair inspection device. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, the hair inspection device according to the present invention will be described in detail with reference to the drawings.

[0014] FIG. 1 is a configuration diagram of a hair inspection device 100 according to the present invention. The hair inspection device 100 includes a conveyor 3 that conveys plastic containers 1 filled with coffee jelly 2, a jelly-like food, without a pre-sealing seal. The plastic containers 1 are, for example, approximately 8 cm in height and approximately 8 cm in diameter at the top. The conveyor 3 can feed, for example, 100 containers per minute, and transports them at regular intervals. Near-infrared light is irradiated from a dome-shaped lighting device means 4 toward the plastic containers 1 filled with coffee jelly 2, and an image is taken by a near-infrared camera 6.

[0015] The dome-shaped lighting device means 4 is equipped with multiple LED light sources with different bands to emit near-infrared light in multiple bands (wavelengths). During operation, LED light sources with preset near-infrared light bands are used. The near-infrared camera 6 is an area camera with, for example, 640 pixels x 512 pixels. It receives and captures near-infrared light reflected from the coffee jelly 2 in the plastic container 1. The near-infrared camera 6 is sensitive to a wavelength range of, for example, 700 nm to 1700 nm. The dome-shaped lighting device means 4 is powered by a power source 5. The image captured by the near-infrared camera 6 is sent to the foreign object detection means 7 for analysis. A PC can be used as the foreign object detection means 7. The foreign object detection means 7 uses image processing to inspect the captured image for hair adhering to the surface of the coffee jelly 2.

[0016] As shown in Figure 1, a sorting device 25 is provided at the end of the conveyor 3 in the conveying direction. Plastic containers 1 in which a hair 30 is detected by the foreign object detection means 7 are discharged onto a defective product table 9. Plastic containers 1 in which no hair 30 is detected are discharged onto a non-defective product table 8. The plastic containers 1 are pushed out by a partition plate 19 towards either the non-defective product table 8 or the defective product table 9.

[0017] 2 is a diagram showing the internal configuration of the dome-shaped lighting means 4. The dome-shaped lighting means 4 has a reflective surface formed on the inner surface and an imaging window 4a formed at the top. A near-infrared LED 10 capable of emitting near-infrared light in multiple bands is disposed inside.

[0018] 3 is a diagram showing the LEDs 10 provided in the dome-shaped lighting means 4. The LEDs 10 consist of eight types to emit light in multiple bands: LEDs 10 in the 850 nm band, LEDs 10 in the 9400 nm band, LEDs 10 in the 1050 nm band, LEDs 10 in the 1200 nm band, LEDs 10 in the 1300 nm band, LEDs 10 in the 1450 nm band, LEDs 10 in the 1550 nm band, and LEDs 10 in the 1650 nm band. Each LED is powered by the power supply 5, and can be turned on or off by turning switches SW1 to SW8 on or off.

[0019] 4 is a perspective view of the sorting device 25. The sorting device 25 includes a sorting plate 19 with receiving portions 19a that sort the plastic containers 1, and a rotating shaft 20 that rotates the sorting plate 19. The rotating shaft 20 slides in a direction perpendicular to the conveyor 3. The sliding mechanism can be realized by, for example, a rack and pinion.

[0020] FIG. 5 illustrates the operation of the sorting device 25. FIG. 5(A) shows the operation of the sorting board 19 discharging a plastic container 1 onto the defective product table 9. In FIG. 5(a), the sorting board 19 is tilted to the right, in its initial state. The board is tilted to the right when it is determined that the next plastic container 1 will be discharged onto the defective product table 9. When a plastic container 1 is transported by the conveyor 3, the plastic container 1 is received by the receiving portion 19a, and the rotating shaft 20 is slid leftward by the slide mechanism 21. At the same time, the sorting board 19 rotates counterclockwise. This rotation is achieved by an extension (not shown) of the sorting board 19 extending on the opposite side of the rotating shaft 20 and abutting against a stopper. When the rotating shaft 20 is slid leftward by the slide mechanism 21, the plastic container 1 moves toward the defective product table 9, as shown in FIG. 5(b). When the rotating shaft 20 is further slid, the plastic container 1 is pushed out onto the defective product table 9, as shown in FIG. 5(c).

[0021] FIG. 5(B) shows the operation of the sorting board 19 to eject a plastic container 1 onto the non-defective product table 8. At the stage (a), the sorting board 19 is tilted to the left, in its initial state. The board is tilted to the left when it is determined that the next plastic container 1 will be ejected onto the non-defective product table 8. When a plastic container 1 is transported by the conveyor 3, the plastic container 1 is received by the receiving portion 19a, and the sliding mechanism 21 slides the rotating shaft 20 to the right. At the same time, the sorting board 19 rotates clockwise. This rotation is achieved by an extension (not shown) of the sorting board 19 extending on the opposite side of the rotating shaft 20 and abutting against a stopper. When the rotating shaft 20 is further slid to the right, the plastic container 1 moves toward the non-defective product table 8, as shown in (b). When the rotating shaft 20 is further slid, the plastic container 1 is pushed out onto the non-defective product table 8, as shown in (c).

[0022] 6 to 9 are images of coffee jelly 2 in a plastic container 1. A hair 30 was placed on the surface of the coffee jelly 2. In images captured using near-infrared light bands of 850 nm, 940 nm, and 1050 nm, both the coffee jelly 2 and the hair 30 appear gray. The grayscale values of the pixels indicate gray. The water content of the hair 30 is approximately 10% by weight, while the water content of the coffee jelly 2 is approximately 80 to 90% by weight. The circular shadow in the center is the shadow of the window 4a at the top of the dome-shaped lighting means 4 cast on the surface of the coffee jelly 2. In images captured using near-infrared light bands of 1200 nm, as shown in FIG. 7, the coffee jelly 2 appears slightly dark due to the absorption of near-infrared light by the coffee jelly 2.

[0023] As shown in Figure 8, the image captured in the 1300 nm near-infrared band appears slightly white, but the image captured in the 1450 nm near-infrared band appears dark because the moisture in the coffee jelly 2 absorbs the near-infrared light. As shown in Figure 9, the images captured in the 1550 nm and 1650 nm near-infrared bands appear even darker. The image of hair 30 is gray even in the 1450 nm near-infrared band, and appears dark in the images captured in the 1550 nm and 1650 nm near-infrared bands, but is whiter than coffee jelly 2. In this way, coffee jelly 2 appears dark from around the 1450 nm band, while hair 30 does not appear very dark, resulting in a difference in density in the image and making the pixels of hair 30 distinguishable from the pixels of coffee jelly 2. Coffee jelly has a high water content of 80-90%, and its absorption of near-infrared light increases around 1450 nm, but hair has a water content of around 10%, so it is still gray at 1450 nm.

[0024] Figure 10 is a flowchart showing the procedure for capturing images of a plastic container 1 of coffee jelly 2 with a hair 30 attached thereto using different near-infrared bands to determine the grayscale value of the hair 30 in advance. From the images of each band, a band is selected that has a large difference between the grayscale value of the hair 30 and the grayscale value of the coffee jelly 2, i.e., a large difference in shading. For example, the 1450 nm band is selected. During the actual test, the switch SW6 of the dome-shaped lighting means 4 is turned on, an image is captured using the 1450 nm band, and the foreign object detection means 7 inspects the image to see if the previously determined grayscale value of the hair 30 is present.

[0025] FIG. 11 is an operational flowchart when coffee jelly 2 filled in a plastic container 1 is inspected by the hair inspection device 100. As an example, a near-infrared light band of 1450 nm is selected. As shown in S54, all pixels of the captured image are analyzed. For example, the total number of pixels is 327,680 pixels (= 640 pixels × 512 pixels) for inspection. When an area of 100 mm × 100 mm is imaged, one pixel is approximately 0.03 mm. 2 (=100mm x 100mm ÷ 327,680 pixels). A hair 30 that is 20mm long and 0.1mm thick has an area of 2mm 2 Therefore, a total of 66 pixels of the specified gray color are detected. If the specified number of pixels of hair 30 are found as shown in S58, the plastic container 1 is sent to the defective product table 9 as shown in S60. If no pixels of hair 30 are found, the plastic container 1 is sent to the non-defective product table 8 as shown in S59.

[0026] In this example, the 1450 nm band of near-infrared light was selected, the dome-shaped lighting unit 4 was set to the 1450 nm band, and the image captured at 1450 nm was inspected for pixels that match the gray color of hair. Two dome-shaped lighting units 4 may be installed on the conveyor 3, one dome-shaped lighting unit 4 set to the 1450 nm band and the other dome-shaped lighting unit 4 set to the 1650 nm band, and the image captured at 1650 nm may be inspected for pixels that match the gray color of hair. Since the gray color of hair is confirmed using two bands, a more reliable determination can be made. While the example has been described using coffee jelly, it is not limited to this, and the example can also be applied to puddings and jelly-like foods such as yogurt filled in a plastic container. [Industrial Applicability]

[0027] The present invention is suitable as a hair inspection device that can detect and remove hair adhering to the surface of a jelly-like food filled in a plastic container. [Explanation of symbols]

[0028] 1 plastic container 1a Rim of cup 2. Coffee Jelly 3 Conveyor 4 Dome-shaped lighting means 4a Window 5 Power supply (for lighting) 6. Near-infrared camera 7 Foreign object detection means (PC) 8 Good table (no hair) 9. Defective table (with hair) 10 LEDs (near-infrared light source) 19 Sorting Board 19a Receiving part 20 Rotating shaft 21 Slide mechanism 25 Sorting device 30 Hair 31 Window shadow (of a dome-type lighting device) 100 Hair Inspection Device SW1~SW8 Band (wavelength) switching switches

Claims

1. a conveyor for transporting plastic containers filled with jelly-like food and without a seal before sealing; a dome-shaped lighting device having a reflective surface formed on the inner surface, an imaging window formed on the top, and an LED disposed inside capable of emitting near-infrared light in a plurality of bands, for irradiating near-infrared light in a preset band toward the plastic container; a near-infrared camera that receives and captures near-infrared light reflected from the jelly-like food in the plastic container; a foreign object detection means for analyzing the image captured by the near-infrared camera and recognizing the image as hair when a predetermined number of pixels with a grayscale value corresponding to a pre-specified hair are detected; a sorting device that is provided at an end of the conveyor in the conveying direction and that discharges the plastic container in which hair has been detected by the foreign object detection means onto a defective product table separate from a non-defective product table; A hair inspection device comprising:

2. The hair inspection device according to claim 1, wherein the near-infrared band set for the dome-shaped lighting means is selected from the range of 1450 nm to 1650 nm by conducting a test using a jelly-like food to which hair has been attached in advance.

3. The hair inspection device according to claim 1, characterized in that the sorting device comprises a sorting plate with a receiving portion for sorting the plastic containers, and a rotating shaft for rotating the sorting plate, the rotating shaft sliding in a direction perpendicular to the conveyor.

Images