Inspection device and inspection method

Abstract

To provide an inspection device with which it is possible to reliably discriminate pass or fail of a product that is heat seal packaged.SOLUTION: Provided is an inspection device for inspecting a product that is heat seal packaged. The inspection device comprises: an infrared camera that captures an image of the product; an acquisition unit that acquires a thermography image of the product having been captured by the infrared camera; a first determination unit that determines a center position of the product in the thermography image; a second determination unit that sets a plurality of line segments extending from the center position to an outer circumference of the product in the thermography image, and determines a plurality of inspection regions on the basis of the line segments; a detection unit that detects a peak temperature in the inspection region; a first assessment unit that assesses whether or not the peak temperature is within a prescribed range; and a second assessment unit that assesses whether or not the number or the percentage of the inspection regions whose peak temperatures are assessed to be within the prescribed range by the first assessment unit is greater than or equal to a threshold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inspection device and an inspection method for inspecting heat-sealed packaged products. [Background technology]

[0002] An inspection device is known that uses thermographic images taken with an infrared camera to inspect products packaged by placing food or the like in a container and heat-sealing a lid to the opening of the container for defective heat-sealing of the product (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-307505 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned inspection device detects the minimum temperature of the heat-sealed portion of a product and determines whether the heat-sealed portion is defective based on whether the detected temperature is within a predetermined temperature range. However, it is difficult to set the temperature detection area only to the heat-sealed portion, and the temperature detection area is sometimes set to include the vicinity of the heat-sealed portion, which creates problems such as determining whether the heat-sealed portion is defective by detecting the temperature near the heat-sealed portion. Furthermore, when detecting the maximum temperature of the heat-sealed portion of a product and determining whether the heat-sealed portion is defective based on whether the detected temperature is within a predetermined temperature range, the minimum temperature of the heat-sealed portion within the temperature detection area is not detected, which could result in overlooking defective heat-sealed portions.

[0005] An object of the present invention is to provide an inspection device and an inspection method that can reliably determine whether a heat-sealed packaged product is good or bad. [Means for solving the problem]

[0006] The inspection device of the present invention is an inspection device for inspecting heat-sealed packaged products, and is characterized by comprising an infrared camera that photographs the product, an acquisition unit that acquires a thermographic image of the product photographed by the infrared camera, a first determination unit that determines the center position of the product in the thermographic image, a second determination unit that sets multiple line segments extending from the center position toward the outer periphery of the product in the thermographic image and determines multiple inspection areas based on the line segments, a detection unit that detects the peak temperature within the inspection area, a first discrimination unit that determines whether the peak temperature is within a predetermined range, and a second discrimination unit that determines whether the number or percentage of the inspection areas whose peak temperature is determined by the first discrimination unit to be within the predetermined range is equal to or greater than a threshold value.

[0007] The inspection device of the present invention is also characterized in that the inspection area is a predetermined area including on the line segment or in the vicinity of the line segment.

[0008] The inspection device of the present invention is also characterized in that the inspection area is an area between the adjacent line segments.

[0009] The inspection device of the present invention is characterized in that the inspection area is an area between a position that is a first distance away from the center position and a second distance that is further away than the first distance.

[0010] In addition, the inspection device of the present invention is characterized in that the first determination unit further comprises a first setting unit that sets a first straight line within the thermographic image, and a first detection unit that detects a first temperature point that has the highest temperature on the first straight line and a second temperature point that has the highest temperature on the first straight line that is a predetermined distance or more away from the first temperature point, and the midpoint between the first temperature point and the second temperature point is set as the central position.

[0011] In addition, the inspection device of the present invention is characterized in that the first determination unit further comprises a first setting unit that sets a first straight line within the thermographic image, a first detection unit that detects a first temperature point on the first straight line that is the highest temperature and a second temperature point on the first straight line that is a predetermined distance or more away from the first temperature point, a second setting unit that sets a second straight line that is perpendicular to the first straight line within the thermographic image, and a second detection unit that detects a third temperature point on the second straight line that is the highest temperature and a fourth temperature point on the second straight line that is a predetermined distance or more away from the third temperature point, and determines the center position based on the midpoint of the first temperature point and the second temperature point and the midpoint of the third temperature point and the fourth temperature point.

[0012] The inspection device of the present invention is also characterized in that the first setting unit sets two parallel first lines, the first detection unit detects the first temperature point and the second temperature point on each of the first lines, and the first determination unit rotates the thermographic image so that a first line segment connecting one of the first temperature points and the closest of the other first temperature point and the other second temperature point is parallel to a first reference line segment used to correct the rotation direction of the thermographic image.

[0013] The inspection device of the present invention is also characterized in that the second setting unit sets two parallel second lines, the second detection unit detects the third temperature point and the fourth temperature point on each of the second lines, and the first determination unit rotates the thermographic image so that a second line segment connecting one of the third temperature points and the other of the closer third temperature point and the other of the closer fourth temperature point is parallel to a second reference line segment used to correct the rotation direction of the thermographic image.

[0014] The inspection device of the present invention is also characterized in that the first setting unit sets two parallel first lines, the first detection unit detects the first temperature point and the second temperature point on each of the first lines, and the first determination unit rotates the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a line perpendicular to the first lines.

[0015] The inspection device of the present invention is also characterized in that the second setting unit sets two parallel second lines, the second detection unit detects the third temperature point and the fourth temperature point on each of the second lines, and the first determination unit rotates the thermographic image so that a second line segment connecting one of the third temperature points and the other of the closer third temperature point and the other of the closer fourth temperature point is parallel to the first line.

[0016] The inspection device of the present invention is an inspection device for inspecting heat-sealed packaged products, and includes an infrared camera that photographs the product, an acquisition unit that acquires a thermographic image of the product photographed by the infrared camera, and a first determination unit that determines the center position of the product in the thermographic image, wherein the first determination unit includes a first setting unit that sets two parallel first lines in the thermographic image, a first detection unit that detects a first temperature point with the highest temperature on each of the first lines and a second temperature point with the highest temperature on each of the first lines that is a predetermined distance or more away from the first temperature point, a second setting unit that sets two parallel second lines that are perpendicular to the first lines in the thermographic image, a third temperature point with the highest temperature on each of the second lines, and and a second detection unit that detects a fourth temperature point that has the highest temperature on the second line and is at least a predetermined distance away from the third temperature point, and the center position is determined based on the midpoint between the first temperature point and the second temperature point and the midpoint between the third temperature point and the fourth temperature point, the thermographic image is rotated so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a first reference line segment used for correction in the rotation direction of the thermographic image, and the thermographic image is rotated so that a second line segment connecting one of the third temperature points and the nearest one of the other third temperature point and the other fourth temperature point is parallel to a second reference line segment used for correction in the rotation direction of the thermographic image.

[0017] The inspection device of the present invention is an inspection device for inspecting heat-sealed packaged products, and includes an infrared camera that photographs the product, an acquisition unit that acquires a thermographic image of the product photographed by the infrared camera, and a first determination unit that determines the center position of the product in the thermographic image, wherein the first determination unit includes a first setting unit that sets two parallel first lines in the thermographic image, a first detection unit that detects a first temperature point with the highest temperature on each of the first lines and a second temperature point with the highest temperature on each of the first lines that is a predetermined distance or more away from the first temperature points, and a second setting unit that sets two parallel second lines that are perpendicular to the first lines in the thermographic image. and a second detection unit that detects a third temperature point that is the highest on each of the second straight lines, and a fourth temperature point that is the highest on the second straight lines that is a predetermined distance or more away from the third temperature point, wherein the center position is determined based on the midpoint between the first temperature point and the second temperature point and the midpoint between the third temperature point and the fourth temperature point, the thermographic image is rotated so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to the second straight line, and the thermographic image is rotated so that a second line segment connecting one of the third temperature points and the nearest one of the other third temperature point and the other fourth temperature point is parallel to the first straight line.

[0018] The inspection method of the present invention is an inspection method for inspecting heat-sealed packaged products, and is characterized by including: a photographing step of photographing the product with an infrared camera; an acquisition step of acquiring a thermographic image of the product photographed by the infrared camera; a first determination step of determining the center position of the product in the thermographic image; a second determination step of setting a plurality of line segments extending from the center position toward the outer periphery of the product in the thermographic image and determining a plurality of inspection areas based on the line segments; a detection step of detecting a peak temperature within the inspection area; a first determination step of determining whether the peak temperature is within a predetermined range; and a second determination step of determining whether the number or proportion of the inspection areas whose peak temperatures are determined to be within the predetermined range in the first determination step is equal to or greater than a threshold value.

[0019] The inspection method of the present invention is characterized in that the second determining step determines a predetermined area including on the line segment or in the vicinity of the line segment as the inspection area.

[0020] The inspection method of the present invention is characterized in that the second determining step determines an area between adjacent line segments as the inspection area.

[0021] The inspection method of the present invention is also characterized in that the second determination step determines the inspection area to be an area between a position that is a first distance away from the center position and a second distance that is further away than the first distance.

[0022] In addition, the inspection method of the present invention is characterized in that the first determination step further includes a first setting step of setting a first straight line within the thermographic image, and a first detection step of detecting a first temperature point on the first straight line that has the highest temperature, and a second temperature point on the first straight line that is a predetermined distance or more away from the first temperature point, and the midpoint between the first temperature point and the second temperature point is set as the central position.

[0023] In addition, the inspection method of the present invention further includes a first determination step of setting a first straight line within the thermographic image, a first detection step of detecting a first temperature point on the first straight line that is the highest temperature, and a second temperature point on the first straight line that is a predetermined distance or more away from the first temperature point, a second setting step of setting a second straight line perpendicular to the first straight line within the thermographic image, and a second detection step of detecting a third temperature point on the second straight line that is the highest temperature, and a fourth temperature point on the second straight line that is a predetermined distance or more away from the third temperature point, and is characterized in that the center position is determined based on the midpoint between the first temperature point and the second temperature point and the midpoint between the third temperature point and the fourth temperature point.

[0024] Furthermore, the inspection method of the present invention is characterized in that the first setting step sets two parallel first lines, the first detection step detects the first temperature point and the second temperature point on each of the first lines, and the first determination step rotates the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a first reference line segment used to correct the rotation direction of the thermographic image.

[0025] Furthermore, the inspection method of the present invention is characterized in that the second setting step sets two parallel second lines, the second detection step detects the third temperature point and the fourth temperature point on each of the second lines, and the first determination step rotates the thermographic image so that a second line segment connecting one of the third temperature points and the other of the closer third temperature point and the other of the closer fourth temperature point is parallel to a second reference line segment used to correct the rotation direction of the thermographic image.

[0026] Furthermore, the inspection method of the present invention is characterized in that the first setting step sets two parallel first lines, the first detection step detects the first temperature point and the second temperature point on each of the first lines, and the first determination step rotates the thermographic image so that a first line segment connecting one of the first temperature points and the other of the first temperature point and the other of the second temperature point, whichever is closer, is parallel to a line perpendicular to the first lines.

[0027] Furthermore, the inspection method of the present invention is characterized in that the second setting step sets two parallel second lines, the second detection step detects the third temperature point and the fourth temperature point on each of the second lines, and the first determination step rotates the thermographic image so that a second line segment connecting one of the third temperature points and the other of the closer third temperature point and the other of the closer fourth temperature point is parallel to the first line. [Effects of the Invention]

[0028] According to the present invention, it is possible to provide an inspection device and an inspection method that can reliably determine whether a heat-sealed packaged product is good or bad. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a block diagram showing a system configuration of an inspection device according to an embodiment; [Figure 2] 10 is a flowchart for explaining an inspection method for inspecting a product using the inspection device according to the embodiment. [Figure 3] 10A and 10B are diagrams showing thermographic images within an inspection frame according to an embodiment. [Figure 4] 10A and 10B are diagrams showing thermographic images within an inspection frame according to an embodiment. [Figure 5] 10A and 10B are diagrams showing thermographic images within an inspection frame according to an embodiment. [Figure 6] 10A and 10B are diagrams showing thermographic images within an inspection frame according to an embodiment. [Figure 7] 10A and 10B are diagrams showing thermographic images within an inspection frame according to an embodiment. [Figure 8] 10 is a flowchart for explaining a method for determining whether a product is good or bad according to an embodiment. [Figure 9] 10A and 10B are diagrams showing thermographic images within an inspection frame according to an embodiment. [Figure 10] FIG. 10 is a diagram showing a thermographic image within an inspection frame according to another embodiment. [Figure 11] FIG. 10 is a diagram showing a thermographic image within an inspection frame according to another embodiment. [Figure 12] FIG. 10 is a diagram showing a thermographic image within an inspection frame according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] An inspection device according to an embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing the system configuration of the inspection device according to the embodiment. The inspection device 2 according to this embodiment is a device for inspecting heat-sealed packaged products for defective sealing, and as shown in FIG. 1, includes a control unit 4 that controls each unit of the inspection device 2. An infrared camera 6 and a memory unit 8 are connected to the control unit 4. The infrared camera 6 photographs the product to be inspected by the inspection device 2. In this embodiment, the product is a container with an oval opening containing food or the like, with a lid double-heat sealed over the opening. The infrared camera 6 photographs the product 26 (see FIGS. 3 to 7 and 9) conveyed by a belt conveyor or the like from above. The memory unit 8 stores programs executed by the control unit 4 and values ​​required for executing the programs.

[0031] 1, the control unit 4 includes a thermographic image acquisition unit 10, a line segment / straight line setting unit 12, a temperature detection unit 14, a center position determination unit 16, an inspection area determination unit 18, a first discrimination unit 20, and a second discrimination unit 22. The thermographic image acquisition unit 10 acquires a thermographic image of a product 26 photographed by an infrared camera 6.

[0032] The line and line setting unit 12 sets the line segments and lines required for the inspection of the product 26 by the inspection device 2 in the thermographic images 24a to 24d within the inspection frame 28 (see FIGS. 3 to 7). Note that in FIGS. 3 to 7, the orientations of the line segments and lines set in the thermographic images 24a to 24d within the inspection frame 28 will be described with the X-axis (horizontal axis) representing the longitudinal direction of the rectangular inspection frame 28 and the Y-axis (vertical axis) representing the lateral direction. When the center position determining unit 16 determines the center position of the product 26, the line and line setting unit 12 sets, for example, a first line LX parallel to the X-axis of the inspection frame 28 and passing through the center C of the inspection frame 28 (thermographic image 24a) shown in FIG. 3 within the thermographic image 24a. The second line LY is perpendicular to the first line LX, i.e., is parallel to the Y-axis of the inspection frame 28 and passes through the center C of the inspection frame 28 (thermographic image 24a). Furthermore, when the center position determination unit 16 determines the center position of the product 26, the line and segment setting unit 12 sets, for example, two first lines LX1 and LX2 parallel to the X axis of the inspection frame 28 shown in FIG. 6, two second lines LY1 and LY2 perpendicular to the first lines LX1 and LX2, i.e., parallel to the Y axis of the inspection frame 28, and line segments L1, L2, L3, and L4 shown in FIG. 6 within the thermographic image 24c. Line segment L1 is a line segment connecting the first temperature points T11 and T12 detected by temperature detection unit 14, line segment L2 is a line segment connecting the second temperature points T21 and T22 detected by temperature detection unit 14, line segment L3 is a line segment connecting the third temperature points T31 and T32 detected by temperature detection unit 14, and line segment L4 is a line segment connecting the fourth temperature points T41 and T42 detected by temperature detection unit 14.

[0033] The temperature detection unit 14 detects the temperature of the product 26, which is necessary for the inspection of the product 26 by the inspection device 2. For example, when the center position determination unit 16 determines the center position of the product 26, the temperature detection unit 14 detects the temperature of the product 26 on the first lines LX, LX1, and LX2 shown in Figures 3 and 6, and outputs first temperature points T1, T11, and T12 and second temperature points T2, T21, and T22 that indicate high temperatures on the first lines LX, LX1, and LX2. Note that the first temperature points T1, T11, and T12 have the highest temperatures on the first lines LX, LX1, and LX2, and the second temperature points T2, T21, and T22 have the highest temperatures on the first lines LX, LX1, and LX2 that are a predetermined distance or more away from the first temperature points T1, T11, and T12. Since the product 26 is double heat-sealed, the predetermined distance is set in advance and stored in the memory unit 8 so that two points on the first straight line LX that are close to each other are output as the two highest temperature points, and two points sandwiching the center position of the product 26 are output.

[0034] Similarly, when the center position determination unit 16 determines the center position of the product 26, the temperature detection unit 14 detects the temperature of the product 26 on the second lines LY, LY1, and LY2 shown in Figures 3 and 6, and outputs third temperature points T3, T31, and T32 and fourth temperature points T4, T41, and T42, which indicate high temperatures on the second lines LY, LY1, and LY2. The third temperature points T3, T31, and T32 are the highest on the second lines LY, LY1, and LY2, and the fourth temperature points T4, T41, and T42 are the highest on the second lines LY, LY1, and LY2 that are a predetermined distance or more away from the fourth temperature points T4, T41, and T42. Furthermore, when the first discrimination unit 20 discriminates for sealing defects on the product 26 within each inspection area, the temperature detection unit 14 detects peak temperatures TP1 to TPn of the product 26 on the lines LR1 to LRn shown in Figure 9.

[0035] The center position determination unit 16 determines the center position of the product 26 in the thermographic image 24a based on the midpoint CX and midpoint CY shown in Figure 3. The midpoint CX is the midpoint of the line segment connecting the first temperature point T1 and the second temperature point, and the midpoint CY is the midpoint of the line segment connecting the third temperature point T3 and the fourth temperature point T4. The center position determination unit 16 corrects the image within the inspection frame 28 from thermographic image 24a to thermographic image 24b shown in Figure 4 by moving the thermographic image 24a in the X direction so that the X coordinate of the midpoint CX shown in Figure 3 is the same as the X coordinate of the center C of the inspection frame 28 (thermographic image 24a). The center position determination unit 16 also corrects the image within the inspection frame 28 from thermographic image 24b to thermographic image 24c shown in Figure 5 by moving the thermographic image 24b in the Y direction so that the Y coordinate of the midpoint CY shown in Figure 4 is the same as the Y coordinate of the center C of the inspection frame 28 (thermographic image 24b). The center position determination unit 16 also corrects the rotation direction (tilt) of the product 26 in the thermographic image 24c. That is, the center position determination unit 16 corrects the image within the inspection frame 28 from thermographic image 24c to 24d by rotating the thermographic image 24c so that each of the line segments L1 to L4 shown in Fig. 6 is parallel to each of the reference line segments LC1 to LC4 shown in Fig. 7, i.e., so that the tilt of line segments L1 and L2 is the same as the tilt of reference line segments LC1 and LC2, and so that the tilt of line segments L3 and L4 is the same as the tilt of reference line segments LC3 and LC4. Note that the tilt of the thermographic image 24c may be corrected using at least one of the reference line segments LC1 to LC4 (line segments L1 to L4). For example, the image within the inspection frame 28 may be corrected from thermographic image 24c to 24d by using only reference line segment LC4 and line segment L4 and rotating thermographic image 24c so that line segment L4 is parallel to reference line segment LC4, i.e., so that the inclination of line segment L4 is the same as the inclination of reference line segment LC4.

[0036] Reference line segments LC1 and LC2 are set in advance as first reference line segments used for correction of the thermographic image in the rotation direction based on an image that does not require correction, and are stored in the storage unit 8. Similarly, reference line segments LC3 and LC4 are set in advance as second reference line segments used for correction of the thermographic image in the rotation direction, and are stored in the storage unit 8.

[0037] The inspection area determination unit 18 sets a plurality of line segments LR1 to LRn (see FIG. 9 ) extending radially outward from the center position of the product 26 (center C of the thermographic image 24d) in the thermographic image 24d within the inspection frame 28, the center position of which has been determined by the center position determination unit 16. Note that n is an arbitrary natural number and can be set appropriately. The inspection area determination unit 18 determines and stores the line segments LR1 to LRn in advance for each type of product and / or each type of infrared camera. The inspection area determination unit 18 also determines and stores a plurality of inspection areas in advance for each type of product and / or each type of infrared camera based on the plurality of line segments LR1, LR2 to LRn. In the inspection device 2 according to this embodiment, the inspection areas are located on the respective line segments LR1, LR2 to LRn, i.e., the first inspection area is located on the line segment LR1, the second inspection area is located on the line segment LR2, and so on, and the nth inspection area is located on the line segment LRn.

[0038] First determination unit 20 determines whether peak temperatures TP1 to TPn detected by temperature detection unit 16 are within a predetermined range. The predetermined range is set in advance as a temperature range within which it can be determined that the lid of product 26 is securely heat-sealed, and is stored in memory unit 8.

[0039] The second discriminator 22 determines whether the percentage of the inspection areas in which the first discriminator 20 determined that the peak temperatures TP1 to TPn are within the predetermined range is equal to or greater than a threshold value. In this embodiment, the threshold value is preset to 100% and stored in the memory 8. The threshold value can also be set to a percentage less than 100%. The second discriminator 22 determines whether all of the peak temperatures TP1 to TPn are within the predetermined range. If the second discriminator 22 determines that all of the peak temperatures TP1 to TPn are within the predetermined range, it is determined that there are no defects in the heat-sealed portions of the product 26, i.e., the product 26 is a non-defective product. On the other hand, if the second discriminator 22 determines that even one of the peak temperatures TP1 to TPn is not within the predetermined range, it is determined that there is a defect in the heat-sealed portions of the product 26, i.e., the product 26 is a defective product.

[0040] Next, with reference to the drawings, an inspection method for inspecting whether or not there is a seal defect in a heat-sealed packaged product 26 using the inspection device 2 according to this embodiment will be described. Fig. 2 is a flowchart for explaining the process executed by the control unit 4 of the inspection device 2 to inspect the heat-sealed portion of the product 26.

[0041] First, the control unit 4 outputs a control signal to the infrared camera 6, and the infrared camera 6 photographs the product 26, which has been heat-sealed and transported by a belt conveyor or the like, from above so that the heat-sealed portion of the product 26 can be confirmed (step S10). Next, the thermographic image acquisition unit 10 of the control unit 4 acquires the thermographic image of the product 26 photographed by the infrared camera 6 in step S10 (step S11).

[0042] Next, the control unit 4 determines whether a center position correction mode for correcting the center position of the product 26 is enabled or disabled (step S12). If it is determined in step S12 that the center position correction mode is enabled (step S12, Yes), the control unit 4 proceeds to processing in step S13. On the other hand, if it is determined in step S12 that the center position correction mode is disabled (step S12, No), the control unit 4 sets the center C of the thermographic image 24 as the center position of the product 26, and proceeds to processing in step S17.

[0043] If it is determined in step S12 that the center position correction mode is enabled (step S12, Yes), the center position determination unit 16 of the control unit 4 determines the center position of the product 26 in the thermographic image 24a. Specifically, the line segment / straight line setting unit 12 of the control unit 4 first sets a first line LX and a second line LY shown in FIG. 3 with respect to the thermographic image 24a within the inspection frame 28 (step S13). As shown in FIG. 3, the first line LX is a line parallel to the X-axis direction and passes through the center C of the thermographic image 24a. As shown in FIG. 3, the second line LY is a line parallel to the Y-axis direction and passes through the center C of the thermographic image 24a.

[0044] Next, the temperature detection unit 14 of the control unit 4 detects the first temperature point T1, the second temperature point T2, the third temperature point T3, and the fourth temperature point T4 shown in Fig. 3 (step S14). Specifically, as shown in Fig. 3, the temperature detection unit 14 detects the first temperature point T1, which is the highest temperature point on the first line LX, and detects the second temperature point T2, which is the highest temperature point on the first line LX that is a predetermined distance or more away from the first temperature point T1. Similarly, as shown in Fig. 3, the temperature detection unit 14 detects the third temperature point T3, which is the highest temperature point on the second line LY, and detects the fourth temperature point T4, which is the highest temperature point on the second line LY that is a predetermined distance or more away from the third temperature point T3.

[0045] Next, the center position determination unit 16 determines the midpoint CX between the first temperature point T1 and the second temperature point T2 detected by the temperature detection unit 14 as the center position of the product 26 in the X-axis direction, and calculates the deviation from the center C in the X-axis direction. Similarly, the center position determination unit 16 determines the midpoint CY between the third temperature point T3 and the fourth temperature point T4 detected by the temperature detection unit 14 as the center position of the product 26 in the Y-axis direction, and calculates the deviation from the center C in the Y-axis direction. As shown in FIG. 4, the center position determination unit 16 corrects the position of the thermographic image 24a in the X-axis direction by moving it by the calculated amount of deviation in the X-axis direction (including the case where this amount is zero) so that the X-coordinate of the midpoint CX is the same as the X-coordinate of the center C (step S16). The thermographic image 24a within the search frame 28 is moved in the X-axis direction in step S16 and corrected to thermographic image 24b.

[0046] 5, the center position determination unit 16 corrects the position of the thermographic image 24b in the Y-axis direction by moving it by the calculated amount of deviation in the Y-axis direction (including 0) so that the Y-coordinate of the midpoint CY is the same as the Y-coordinate of the center C (step S16). The thermographic image 24b within the search frame 28 is moved in the Y direction in step S16 and corrected to thermographic image 24c.

[0047] Next, the control unit 4 determines whether the tilt correction mode for correcting the tilt of the product 26 is enabled or disabled (step S17). If it is determined in step S17 that the tilt correction mode is enabled (step S17, Yes), the control unit 4 proceeds to the process of step S18. On the other hand, if it is determined in step S17 that the tilt correction mode is disabled (step S17, No), the control unit 4 proceeds to the process of step S22.

[0048] If it is determined in step S17 that the tilt correction mode is enabled (step S17, Yes), the line segment / straight line setting unit 12 of the control unit 4 sets first straight lines LX1, LX2 and second straight lines LY1, LY2 shown in FIG. 6 with respect to the thermography image 24c within the inspection frame 28 (step S18). As shown in FIG. 6, the first straight lines LX1 and LX2 are straight lines parallel to the X-axis direction and have different Y coordinates. As shown in FIG. 6, the second straight lines LY1, LY2 are straight lines parallel to the Y-axis direction and have different X coordinates.

[0049] Next, the temperature detection unit 14 of the control unit 4 detects first temperature points T11 and T12, second temperature points T21 and T22, third temperature points T31 and T32, and fourth temperature points T41 and T42 shown in Fig. 6 (step S19). Specifically, as shown in Fig. 6, the temperature detection unit 14 detects the first temperature point T11, which has the highest temperature, on the first line LX1, and detects the second temperature point T21, which has the highest temperature, on the first line LX1 that is a predetermined distance or more away from the first temperature point T11. Similarly, as shown in Fig. 6, the temperature detection unit 14 detects the first temperature point T12, which has the highest temperature, on the first line LX2, and detects the second temperature point T22, which has the highest temperature, on the first line LX2 that is a predetermined distance or more away from the first temperature point T12.

[0050] 6, the temperature detection unit 14 detects a third temperature point T31 having the highest temperature on the second line LY1, and detects a fourth temperature point T41 having the highest temperature on the second line LY1 that is a predetermined distance or more away from the third temperature point T31. Similarly, as shown in FIG. 6, the temperature detection unit 14 detects a third temperature point T32 having the highest temperature on the second line LY2, and detects a fourth temperature point T42 having the highest temperature on the second line LY2 that is a predetermined distance or more away from the third temperature point T32.

[0051] Next, the center position determination unit 16 compares the slope of the line segment L1 connecting the first temperature points T11 and T12 detected by the temperature detection unit 14 with the slope of the reference line segment LC1 (see FIG. 7) used for correction of the thermographic image in the rotational direction. Similarly, the center position determination unit 16 compares the slope of the line segment L2 connecting the second temperature points T21 and T22 detected by the temperature detection unit 14 with the slope of the reference line segment LC2 (see FIG. 7) used for correction of the thermographic image in the rotational direction. Furthermore, the center position determination unit 16 compares the slope of the line segment L3 connecting the third temperature points T31 and T32 detected by the temperature detection unit 14 with the slope of the reference line segment LC3 (see FIG. 7) used for correction of the thermographic image in the rotational direction. Similarly, the center position determination unit 16 compares the slope of the line segment L4 connecting the fourth temperature points T41 and T42 detected by the temperature detection unit 14 with the slope of the reference line segment LC4 (see Figure 7) used for correction in the rotational direction of the thermographic image.

[0052] 7, the center position determining unit 16 rotates the thermography image 24c within the inspection frame 28 by the amount of deviation from the slope of the reference line segments LC1 to LC4 (including the case where this deviation is 0) so that each of the line segments L1 to L4 is parallel to each of the reference line segments LC1 to LC4, that is, so that the slope of the line segments L1 to L4 is the same as the slope of the reference line segments LC1 to LC4 (step S21). The thermography image 24c within the search frame 28 is rotated clockwise in (step S21) and corrected to thermography image 24b.

[0053] Next, the control unit 4 determines whether the product 26 is good or bad (step S22). FIG. 8 is a flowchart for explaining a method for determining whether the product 26 is good or bad. First, the control unit 4 reads the inspection areas for the product 26 and the infrared camera 6 from the inspection areas that have been determined and stored in advance by the inspection area determination unit 18 for each type of product and / or each type of infrared camera (step S30). That is, the control unit 4 sets n line segments LR1, LR2...LRn shown in FIG. 9 in the thermography image 24d within the inspection frame 28. As shown in FIG. 9, the n line segments LR1, LR2...LRn are line segments that extend radially from the center position of the product 26 toward the periphery. The inspection areas are on each of the line segments LR1, LR2...LRn.

[0054] Next, the temperature detection unit 14 of the control unit 4 detects the peak temperature in the inspection area (step S31). Specifically, as shown in FIG. 9, the temperature detection unit 14 detects the highest peak temperature TP1 in the first inspection area, which has the inspection area on the line segment LR1. Then, the first discrimination unit 20 of the control unit 4 determines whether the peak temperature TP1 detected in step S31 is within a predetermined range (step S32). The predetermined range is set in advance and stored in the storage unit 8. The control unit 4 temporarily stores the discrimination result by the first discrimination unit 20 in the storage unit 8. If the first discrimination unit 20 has not made discrimination for all the inspection areas, that is, if the first discrimination unit 20 has not made discrimination for the last inspection area (the nth inspection area) (step S33, No), the control unit 4 returns to the process of step S31 and repeats the processes of steps S31 to S33. That is, next, in the second inspection area, whose inspection area is on line segment LR2, the highest peak temperature TP2 is detected and determined whether it is within the specified range; then, in the third inspection area, whose inspection area is on line segment LR3, the highest peak temperature TP3 is detected and determined whether it is within the specified range; then, in the fourth inspection area, whose inspection area is on line segment LR4, the highest peak temperature TP4 is detected and determined whether it is within the specified range; peak temperatures are detected in all inspection areas in a clockwise direction and determined whether they are within the specified range; ... and finally, in the nth inspection area, whose inspection area is on line segment LRn, the highest peak temperature TPn is detected and determined whether it is within the specified range.

[0055] After the first discriminator 20 has discriminated all of the inspection areas (Step S33, Yes), the second discriminator 22 of the control unit 4 discriminates whether the percentage of the discrimination results by the first discriminator 20 is equal to or greater than a threshold value (Step S34). Specifically, if the threshold value is 100%, the second discriminator 22 discriminates whether the percentage of peak temperatures discriminated to be within the predetermined range by the first discriminator 20 is 100%, i.e., whether all peak temperatures TP1 to TPn are within the predetermined range. If the second discriminator 22 discriminates that the percentage of peak temperatures discriminated to be within the predetermined range is equal to or greater than the threshold value, the control unit 4 determines that there is no defect in the heat-sealed portion of the product 26. On the other hand, if the second discriminator 22 discriminates that the percentage of peak temperatures discriminated to be within the predetermined range is not equal to or greater than the threshold value, or is lower than the threshold value, the control unit 4 determines that there is a defect in the heat-sealed portion of the product 26.

[0056] According to the inspection device 2 and inspection method of this embodiment, the center position of the product 26 is determined, multiple line segments extending radially from the center position are set, and the quality of the heat-sealed portion of the product 26 is judged by a line profile that detects the peak temperature on each line segment. Therefore, it is possible to reliably judge the quality of the heat-sealed packaged product 26 without overlooking any defects in the heat-sealed portion.

[0057] While this embodiment has been described with reference to an example in which the inspection area is on line segments LR1-LRn, the inspection area may also be a predetermined area including the vicinity of line segments LR1-LRn, or a region with a certain width. Furthermore, the inspection area may be an area between adjacent line segments, such as the hatched area A1 between line segments LR1 and LR2, the dotted area A2 between line segments LR3 and LR4, etc., as shown in FIG. 10 . The inspection area may also be an area between a position a first distance away from the center position of the product 26 and a second distance further away than the first distance. For example, as shown in FIG. 11(A), the inspection area may be on line segment LRn' between position P, which is a first distance D1 away from center position C, and a second distance D2. Furthermore, as shown in FIG. 11(B), the inspection area may also be an area A(n-1)' between line segments LR(n-1) and LRn, which is a hatched area between a position a first distance D1 away from center position C and a second distance D2. Although only line segment LRn' is shown in Figure 11(A) and only area A(n-1)' is shown in Figure 11(B), it goes without saying that the inspection area is between a position that is a first distance away from the center position of product 26 and a second distance that is further away than the first distance, and areas other than line segment LRn' and area A(n-1)' are also included in the inspection area.

[0058] In this embodiment, the case where it is determined whether the ratio of the inspection areas whose peak temperatures TP1 to TPn are determined to be within the predetermined range is equal to or greater than a threshold value has been described as an example, but it may also be determined whether the number of inspection areas whose peak temperatures TP1 to TPn are determined to be within the predetermined range is equal to or greater than a threshold value. In this case, the threshold value is preset to a number equal to or less than the number n of inspection areas and is stored in the storage unit 8.

[0059] Furthermore, in this embodiment, the line segment L1 is a line segment connecting the first temperature points T11 and T12, but for example, as shown in Figure 12, if the line segment connecting the first temperature point T11 and the second temperature point T22 is shorter than the line segment connecting the first temperature points T11 and T12, the line segment connecting the first temperature point T11 and the second temperature point T22 is defined as the line segment L1. Similarly, if the line segment connecting the second temperature point T21 and the first temperature point T12 is shorter than the line segment connecting the second temperature point T21 and T22, the line segment connecting the second temperature point T21 and the first temperature point T12 is designated as line segment L2 (see Figure 12), if the line segment connecting the third temperature point T31 and the fourth temperature point T42 is shorter than the line segment connecting the third temperature point T31 and T32, the line segment connecting the third temperature point T31 and the fourth temperature point T42 is designated as line segment L3 (see Figure 12), and if the line segment connecting the fourth temperature point T41 and the third temperature point T32 is shorter than the line segment connecting the fourth temperature point T41 and T42, the line segment connecting the fourth temperature point T41 and the third temperature point T32 is designated as line segment L4 (see Figure 12).

[0060] In addition, in this embodiment, correction of the center position of the product 26 and correction by rotation are performed, but when photographing the product 26 with the infrared camera 6, by supplying the photographing position and the rotation direction of the product 26 to be constant, if correction is not necessary, either or both of the correction of the center position and correction by rotation can be omitted.

[0061] Furthermore, when correcting the center position and correcting by rotation, an image that has already been corrected or does not require correction is prepared in advance, and the amount of correction for the center position and rotation can be calculated and corrected by using the difference from that image. Note that the center C (FIGS. 3 to 5) in this case is not the center of the inspection frame 28, but the center point determined from the image that has already been corrected or does not require correction.

[0062] Furthermore, in this embodiment, the first straight line LX and the second straight line LY are set, and both the deviation in the X-axis direction and the deviation in the Y-axis direction are corrected. However, if, for example, deviation in the Y-axis direction or the X-axis direction does not occur due to the characteristics of the device or product, it is also possible to set only the first straight line LX or only the second straight line and correct only the deviation in the X-axis direction or only the deviation in the Y-axis direction.

[0063] Furthermore, in this embodiment, the thermographic image 24c is rotated based on the comparison between the slopes of the line segments L1-L4 and the slopes of the reference line segments LC1-LC4, but the thermographic image 24c may also be rotated so that the line segments L1 and L2 are parallel to a line perpendicular to the first lines LX1 and LX2. Similarly, the thermographic image 24c may also be rotated so that the line segments L3 and L4 are parallel to a line perpendicular to the second lines LY1 and LY2.

[0064] Furthermore, in this embodiment, four reference line segments LC1 to LC4 and four line segments L1 to L4 are set, and the inclination is corrected based on these reference line segments LC1 to LC4 and line segments L1 to L4, but it is also possible to set only one reference line segment and line segment, for example, reference line segment LC4 and line segment L4, and correct the inclination based on reference line segment LC4 and line segment L4. [Explanation of symbols]

[0065] 2...inspection device, 4...control unit, 6...infrared camera, 8...memory unit, 10...thermographic image acquisition unit, 12...line segment / straight line setting unit, 14...temperature detection unit, 16...center position determination unit, 18...inspection area determination unit, 20...first discrimination unit, 22...second discrimination unit.

Claims

1. An inspection device for inspecting heat-sealed packaged products, comprising: an infrared camera that photographs the product; an acquisition unit that acquires a thermographic image of the product captured by the infrared camera; a first determination unit that determines a center position of the product in the thermographic image; a second determination unit that sets a plurality of line segments extending from the center position toward the outer periphery of the product in the thermographic image and determines a plurality of inspection areas based on the line segments; a detector for detecting a peak temperature within the inspection area; a first determination unit that determines whether the peak temperature is within a predetermined range; a second determination unit that determines whether or not the number or ratio of the inspection areas in which the peak temperature is determined to be within the predetermined range by the first determination unit is equal to or greater than a threshold value; The first determination unit a first setting unit that sets a first line within the thermographic image; a first detection unit that detects a first temperature point on the first straight line that has the highest temperature, and a second temperature point on the first straight line that is a predetermined distance or more away from the first temperature point and has the highest temperature; a second setting unit that sets a second line that is perpendicular to the first line in the thermographic image; a second detection unit that detects a third temperature point on the second straight line that has the highest temperature, and a fourth temperature point on the second straight line that is a predetermined distance or more away from the third temperature point and has the highest temperature, An inspection device that determines the center position based on the midpoint between the first temperature point and the second temperature point and the midpoint between the third temperature point and the fourth temperature point.

2. the first setting unit sets two parallel first straight lines; the first detection unit detects the first temperature point and the second temperature point on each of the first straight lines, The inspection device described in claim 1, wherein the first determination unit rotates the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a first reference line segment used to correct the rotation direction of the thermographic image.

3. the second setting unit sets two second straight lines that are parallel to each other, the second detection unit detects the third temperature point and the fourth temperature point on each of the second straight lines, The inspection device described in claim 2, wherein the first determination unit rotates the thermographic image so that a second line segment connecting one of the third temperature points and the closer of the other third temperature point and the other fourth temperature point is parallel to a second reference line segment used to correct the rotation direction of the thermographic image.

4. the first setting unit sets two parallel first straight lines; the first detection unit detects the first temperature point and the second temperature point on each of the first straight lines, The inspection device described in claim 1, wherein the first determination unit rotates the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a line perpendicular to the first line.

5. the second setting unit sets two second straight lines that are parallel to each other, the second detection unit detects the third temperature point and the fourth temperature point on each of the second straight lines, The inspection device described in claim 4, wherein the first determination unit rotates the thermographic image so that a second line segment connecting one of the third temperature points and the closer of the other third temperature point and the other fourth temperature point is parallel to the first line.

6. 6. The inspection device according to claim 1, wherein the inspection area is a predetermined area including on the line segment or in the vicinity of the line segment.

7. 6. The inspection device according to claim 1, wherein the inspection area is an area between adjacent line segments.

8. 8. The inspection device according to claim 1, wherein the inspection area is an area between a position that is a first distance away from the center position and a second distance that is further away than the first distance.

9. An inspection device for inspecting heat-sealed packaged products, comprising: an infrared camera that photographs the product; an acquisition unit that acquires a thermographic image of the product captured by the infrared camera; a first determination unit that determines a center position of the product in the thermographic image; The first determination unit a first setting unit that sets two parallel first lines in the thermographic image; a first detection unit that detects a first temperature point on each of the first straight lines that has the highest temperature, and a second temperature point on each of the first straight lines that is a predetermined distance or more away from the first temperature point and has the highest temperature; a second setting unit that sets two second lines that are parallel and perpendicular to the first line in the thermographic image; a second detection unit that detects a third temperature point that is the highest temperature on each of the second straight lines and a fourth temperature point that is the highest temperature on the second straight lines that is a predetermined distance or more away from the third temperature point; determining the center position based on a midpoint between the first temperature point and the second temperature point and a midpoint between the third temperature point and the fourth temperature point; rotating the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a first reference line segment used for correction of the rotation direction of the thermographic image; An inspection device that rotates the thermographic image so that a second line segment connecting one of the third temperature points and the closest of the other third temperature point and the other fourth temperature point is parallel to a second reference line segment used to correct the rotation direction of the thermographic image.

10. An inspection device for inspecting heat-sealed packaged products, comprising: an infrared camera that photographs the product; an acquisition unit that acquires a thermographic image of the product captured by the infrared camera; a first determination unit that determines a center position of the product in the thermographic image; The first determination unit a first setting unit that sets two parallel first lines in the thermographic image; a first detection unit that detects a first temperature point on each of the first straight lines that has the highest temperature, and a second temperature point on each of the first straight lines that is a predetermined distance or more away from the first temperature point and has the highest temperature; a second setting unit that sets two second lines that are parallel and perpendicular to the first line in the thermographic image; a second detection unit that detects a third temperature point that is the highest temperature on each of the second straight lines and a fourth temperature point that is the highest temperature on the second straight lines that is a predetermined distance or more away from the third temperature point; determining the center position based on a midpoint between the first temperature point and the second temperature point and a midpoint between the third temperature point and the fourth temperature point; rotating the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to the second line; An inspection device that rotates the thermographic image so that a second line segment connecting one of the third temperature points and the nearest one of the other third temperature point and the other fourth temperature point is parallel to the first line.

11. 1. A method for inspecting a heat-sealed packaged product, comprising: an imaging step of imaging the product with an infrared camera; an acquisition step of acquiring a thermographic image of the product taken by the infrared camera; a first determining step of determining a center position of the product in the thermographic image; a second determination step of setting a plurality of line segments extending from the center position toward the outer periphery of the product in the thermographic image and determining a plurality of inspection areas based on the line segments; detecting a peak temperature within the test area; a first determination step of determining whether the peak temperature is within a predetermined range; a second determination step of determining whether or not the number or proportion of the inspection areas in which the peak temperature is determined to be within the predetermined range in the first determination step is equal to or greater than a threshold value; The first determination step includes: a first setting step of setting a first straight line within the thermographic image; a first detection step of detecting a first temperature point on the first straight line that has the highest temperature, and a second temperature point on the first straight line that is a predetermined distance or more away from the first temperature point and has the highest temperature; a second setting step of setting a second line in the thermographic image that is perpendicular to the first line; a second detection step of detecting a third temperature point on the second straight line that has the highest temperature, and a fourth temperature point on the second straight line that is a predetermined distance or more away from the third temperature point and has the highest temperature, An inspection method in which the center position is determined based on a midpoint between the first temperature point and the second temperature point and a midpoint between the third temperature point and the fourth temperature point.

12. the first setting step includes setting two parallel first straight lines; the first detection step detects the first temperature point and the second temperature point on each of the first straight lines; The inspection method described in claim 11, wherein the first determination step rotates the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a first reference line segment used to correct the rotation direction of the thermographic image.

13. the second setting step includes setting two second straight lines that are parallel to each other; the second detecting step detects the third temperature point and the fourth temperature point on each of the second straight lines, The inspection method described in claim 12, wherein the first determination step rotates the thermographic image so that a second line segment connecting one of the third temperature points and the closer of the other third temperature point and the other fourth temperature point is parallel to a second reference line segment used to correct the rotation direction of the thermographic image.

14. the first setting step includes setting two parallel first straight lines; the first detection step detects the first temperature point and the second temperature point on each of the first straight lines; The inspection method according to claim 11, wherein the first determination step rotates the thermographic image so that a first line segment connecting one of the first temperature points and the nearest one of the other first temperature point and the other second temperature point is parallel to a line perpendicular to the first line.

15. the second setting step includes setting two second straight lines that are parallel to each other; the second detecting step detects the third temperature point and the fourth temperature point on each of the second straight lines, The inspection method according to claim 14, wherein the first determination step rotates the thermographic image so that a second line segment connecting one of the third temperature points and the nearest one of the other third temperature point and the other fourth temperature point is parallel to the first line.

16. 16. The inspection method according to claim 11, wherein the second determination step determines a predetermined area including on the line segment or in the vicinity of the line segment as the inspection area.

17. 16. The inspection method according to claim 11, wherein the second determination step determines an area between adjacent line segments as the inspection area.

18. An inspection method according to any one of claims 13 to 17, wherein the second determination step determines the inspection area to be an area between a position that is a first distance away from the center position and a second distance that is further away than the first distance.

Images