Patent Description:
An inspection apparatus for inspecting a sealing portion of a package including a content such as food is known. The content is packed inside the package by sealing the sealing portion of the package. Specifically, the inspection apparatus checks whether the sealing portion is correctly sealed or not. In other words, the inspection apparatus performs a pass-or-fail determination for the package.

In <CIT>, an inspection apparatus for the package is disclosed. The inspection apparatus emits light to the package all the time during inspection, detects the package when the package reaches the predetermined position of the inspection apparatus, and acquires an image of the package after a predetermined time.

In addition to the pass-or-fail determination, the inspection apparatus may accurately discriminate a type of defects from the other types of defects when the package fails. A manufacturer or an inspector of the package can take measures against the fundamental cause of the defect and eliminate the defect.

In view of the above circumstances, embodiments of the present invention aim at providing an inspection apparatus and an inspection method that determine whether the package is pass or fail and discriminate a certain type of defects of the package from the other types of defects when the package is fail without additional time to determine (identify) a type of defects.

<CIT> discloses an apparatus for monitoring and detecting thermal sealing defects includes a thermal imager, a controller, and an output device.

"<NPL> ET AL discloses a case study where an automated non-invasive and non-destructive quality control system was designed to assess the quality of the seals of bottles containing pesticide. In this case study, the integrity of the seals is evaluated using an artificial neural network based on images of the seals processed with computer vision techniques.

<CIT> discloses a light source unit that is configured to alternately and repetitively irradiate an object under inspection with light from a region of a light-emitting region and light from the region and other regions thereof at an interval of a frame acquisition period of a line sensor. The line sensor <NUM> is configured to receive light emitted from the light source unit and transmitted through the object under inspection in synchronization with irradiation timing of the light source unit, and generate a detection signal based on a volume of transmission of received light. Linear light source images and surface light source images are separately generated from detection information that is based on the detection signal from the line sensor to obtain two kinds of transmission images, which are used to identify a seal area of a seal section of the object under inspection and determine the presence or absence of anomaly in the seal area.

According to embodiments of the present invention, the inspection apparatus and the inspection method determine whether the sealing portion of the package is pass or fail and discriminate between types of defects of the package without additional time to discriminate between the types of the defect.

Hereinafter, embodiments of an inspection apparatus and an inspection method will be described in detail with reference to the accompanying drawings.

<FIG> is a diagram of a configuration example of the inspection apparatus <NUM> according to the embodiment, and <FIG> is a diagram of an example of a package <NUM> inspected by the inspection apparatus <NUM>. The inspection apparatus <NUM> checks whether the package <NUM> is properly sealed or not, and rejects the package <NUM> found to be an anomaly from the production line.

The package <NUM> will be described. As illustrated in <FIG>, the package <NUM>, which is a bag-shaped package material <NUM>, contains , e.g., food such as curry or soup (the contents of the package <NUM>). In the package <NUM> in <FIG>, the bag-shaped opening is sealed by bonding the packaging materials <NUM> to each other.

For the package material <NUM> of the package <NUM>, a single-layer plastic film, a single-layer plastic film having a surface treatment, or a plastic film laminated with multiple single-layer films is used. Examples of the surface treatment include coating for adding moisture proof or vapor deposition of aluminum, silica, or alumina for adding gas barrier properties.

Further, as the package material <NUM> of the package <NUM>, a film laminated with an aluminum foil 51b (<FIG>) on the plastic film described above is used. The package material <NUM> laminated with the aluminum foil 51b is used in applications involving higher gas barrier properties and moisture proof properties. In particular, the package material <NUM> laminated with an aluminum foil 51b is a packaging container for pre-packaged food, retort food, a sealed pouch, or a retort pouch.

<FIG> is a diagram of a configuration example of the packaging material <NUM>. A packaging material <NUM> illustrated in <FIG> is a configuration example of the packaging material <NUM> for a retort pouch. In the package material <NUM> in <FIG>, a polyester film 51a, an aluminum foil 51b, and a non-oriented polypropylene (CPP) film 51c are laminated in this order from the surface of the package material <NUM>. A film laminated with an aluminum foil or an aluminum deposition film as in the package material <NUM> in <FIG> has poor visual transparency, and a content packed inside the package material <NUM> is visually hard to be seen.

The package <NUM> illustrated in <FIG> has a bag-shaped opening in which the package materials <NUM> are facing each other. The bag-shaped opening is sealed by bonding the packaging materials <NUM> to each other, which is referred to a sealing portion <NUM>. The sealing portion <NUM> is bonded by heat sealing in which a heated bar is pressed against a portion to be sealed, that is, thermocompression bonding or an ultrasonic sealing in which a portion to be sealed is melted and bonded by ultrasonic vibration and pressurization.

Herein, a manufacturing process of the package <NUM> will be briefly described. The package <NUM> is manufactured by filling contents (e.g., food such as curry or soup) into a package material <NUM>, which is bag-shaped, by a filling means (e.g., filling machine) and sealing the sealing portion <NUM> of the package material <NUM>.

In such a manufacturing process, the inspection apparatus <NUM> inspects the package <NUM> sealed at the sealing portion <NUM> in order to make sure that the package <NUM> is tightly sealed and the content does not leak (i.e., seal inspection). In the seal inspection, the inspection apparatus <NUM> determines whether the sealing portion <NUM> has a normal state or an anomaly state (i.e., defect). The anomaly state is, for example, trapping, pinhole, through-hole, wrinkle, and tunnel. Specifically, the trapping is a defect in which the contents are trapped in the sealing portion <NUM>, the pinhole or the through-hole is a defect in which a hole is formed in the sealing portion <NUM>, the wrinkle is a defect in which a crease appears when the sealing portion <NUM> is folded or crushed, and the tunnel is a defect in which a passage through which the contents may leak to the outside is formed in the sealing portion <NUM>.

The inspection apparatus <NUM> will be described in detail. As illustrated in <FIG>, the inspection apparatus <NUM> includes a conveyor unit <NUM>, an image acquisition device <NUM>, and a controller device <NUM>.

The image acquisition device <NUM> includes a light emitting unit <NUM> (light emitter) disposed below the conveyor unit <NUM> and a light receiving unit <NUM> (light receiver) disposed above the conveyor unit <NUM>.

The conveyor unit <NUM> includes a first conveyor part <NUM> and a second conveyor part <NUM>. The first conveyor part <NUM> and the second conveyor part <NUM> convey the package <NUM> on an endless belt by rotationally driving the endless belt. The first conveyor part <NUM> is disposed on the upstream side in the conveying direction X of the package <NUM> with respect to the arrangement position of the image acquisition device <NUM>. The second conveyor part <NUM> is disposed on the downstream side in the conveying direction X of the package <NUM> with respect to the arrangement position of the image acquisition device3. The conveyor unit <NUM> has a gap O between the first conveyor part <NUM> and the second conveyor part <NUM>. The gap O is also a space between the light emitting unit <NUM> and the light receiving unit <NUM>. The distance, which is the gap O, between the first conveyor part <NUM> and the second conveyor part <NUM> is a distance that does not affect the conveyance of the package <NUM> from the first conveyor part <NUM> to the second conveyor part <NUM>. Since the conveyor unit <NUM> has the configuration described above, the conveyor unit <NUM> conveys the package <NUM> through the space between the light emitting unit <NUM> and the light receiving unit <NUM>.

The image acquisition device <NUM> acquires two-dimensional thermal information on the sealing portion <NUM> of the package <NUM> conveyed by the conveyor unit <NUM> as an image.

The light emitting unit <NUM> two-dimensionally emits light to the entire sealing portion <NUM> of the package <NUM> conveyed by the conveyor unit <NUM>. The light emitting unit <NUM> may emit light to the package <NUM> being conveyed by the conveyor unit <NUM> at the gap O between the first conveyor part <NUM> and the second conveyor part <NUM> or may emit light to the package <NUM> temporarily being stopped on the conveyor unit <NUM>.

The light receiving unit <NUM> two-dimensionally receives thermal radiation from the entire sealing portion <NUM> of the package <NUM>. The thermal radiation is caused by the light emitting unit <NUM>'s emitting light to the sealing portion <NUM>.

The controller device <NUM> will be described. The controller device <NUM> entirely controls the inspection apparatus <NUM>. <FIG> is a block diagram of a hardware of the controller device <NUM>. As illustrated in <FIG>, the controller device <NUM> includes a central processing unit (CPU) <NUM>, a read only memory (ROM) <NUM>, a random access memory (RAM) <NUM>, and a hard disk drive <NUM> (HDD). The controller device <NUM> controls each unit of the conveyor unit <NUM> and the image acquisition device <NUM> to drive using the RAM <NUM> as a working memory in accordance with a program stored in the RAM <NUM> or the HDD <NUM> in advance. As the controller device <NUM>, for example, a personal computer (e.g., desktop, notebook computer or laptop computer) can be used.

The program executed by the controller device <NUM> according to the present embodiment may be provided by recorded in a computer-readable recording medium such as a compact disc read-only memory (CD-ROM), a flexible disk (FD), a compact disc recordable (CD-R), and a digital versatile disc (DVD) as a file of an installable format or an executable format.

Further, the program executed by the controller device <NUM> according to the present embodiment may be stored in a computer connected to a network such as the Internet and provided by downloaded through the network. The program executed by the controller device <NUM> according to the present embodiment may be provided or distributed through a network such as the Internet.

The controller device <NUM> determines whether the sealing portion <NUM> of the package <NUM> is in a normal state or an anomaly state (i.e., defect) based on the two-dimensional image acquired by the image acquisition device <NUM>.

The function of the controller device <NUM> will be described. <FIG> is a functional block diagram of the controller device <NUM>. As illustrated in <FIG>, when the CPU <NUM> works in accordance with the program, the controller device <NUM> works as a controller <NUM>, a two-dimensional image acquisition unit <NUM>, and a defect discrimination unit <NUM>.

The controller <NUM> controls light emission of the light emitting unit <NUM> and light reception of the light receiving unit <NUM> of the image acquisition device <NUM>. The controller <NUM> controls the first conveyor part <NUM> and the second conveyor part <NUM> of the conveyor unit <NUM> to drive.

The two-dimensional image acquisition unit <NUM> acquires two-dimensional thermal information on the sealing portion <NUM> of the package <NUM> from thermal radiation information two-dimensionally received by the light receiving unit <NUM> as an image. The two-dimensional image acquisition unit <NUM> converts the light information into the thermal information and acquires a thermal image. The two-dimensional image acquisition unit <NUM> is also referred to as thermography (thermal image). The two-dimensional image acquisition unit <NUM> may be provided in an infrared camera in which the light receiving unit <NUM> is an uncooled microbolometer.

The light emitting unit <NUM> and the light receiving unit <NUM> will be described in detail. As described above, the aluminum vapor deposition film or a film laminated with an aluminum foil is used in the package material <NUM> of the package <NUM>, and at least aluminum is included in the package material <NUM> of the package <NUM>. Thus, the light emitting unit <NUM> of the inspection apparatus <NUM> according to the present embodiment emits light to one side of the sealing portion <NUM> of the package <NUM>, in which the light has a wavelength that at least aluminum absorbs. The aluminum foil 51b (<FIG>) of the package material <NUM> absorbs the light emitted from the light emitting unit <NUM> and converts optical energy of the light into thermal energy. Heat generated in the aluminum foil 51b of the package material <NUM> is conducted between the surfaces of each layer and through each layer and reaches the surface of the package material <NUM>. The package material <NUM> radiates light due to thermal radiation from the surface. The light radiation is emitted as a spectrum based on the Planck's law and is received by the light receiving unit <NUM>. The light receiving unit <NUM> two-dimensionally receives information on the thermal radiation.

<FIG> is a graph of the absorptance of aluminum; Aluminum has an absorbance spectrum illustrated in <FIG>. As illustrated in <FIG>, aluminum effectively absorbs light at the peak of the absorbance of near infrared light of <NUM> to <NUM> in wavelength. In addition, aluminum has a high absorbance for ultraviolet light (<NUM> or shorter in wavelength) and visible light (<NUM> to <NUM> in wavelength). The absorbance of aluminum decreases at a wavelength of <NUM> or longer. Preferably, the light emitting unit <NUM> emits at least one of ultraviolet light, visible light, or near infrared light. A halogen lamp capable of emitting light including at least ultraviolet light, visible light, or near infrared light can be applied to the light emitting unit <NUM> of the present embodiment. In general, a halogen lamp can emit light having a wavelength longer than a wavelength of visible light and has a very broad emission spectrum. Depending on the temperature of the halogen lamp, the halogen lamp includes a large amount of light (e.g., <NUM>% or larger) having a wavelength longer than a wavelength of the near infrared light.

The light emitting unit <NUM> is not limited to a halogen lamp, and a xenon lamp capable of emitting ultraviolet light, visible light, or near infrared light may be applied. In general, the xenon lamp has a broad emission spectrum over ultraviolet light, visible light, and near infrared light, and has multiple sharp emission spectra in the near infrared light. The xenon lamp includes little light having a wavelength longer than near infrared (e.g., <NUM>% or smaller). Such light having a wavelength longer than the wavelength of the near infrared light is also referred to as a heat ray and heats surrounding members, which affects downsizing of the apparatus and selection of components. Preferably, the light emitting unit <NUM> excludes light having a wavelength longer than near infrared wavelengths.

A near infrared light emitting diode (LED) or a near infrared laser having a peak wavelength in a near infrared wavelengths may be applied to the light emitting unit <NUM>. Since the peak wavelength of the emission spectrum of the near infrared light emitting diode or the near infrared laser is substantially the same as the peak wavelength of the absorption spectrum of aluminum, light energy can be converted into thermal energy with high efficiency. The near infrared LED or the near infrared laser generally has a longer life than a life of a halogen lamp or a xenon lamp and has an advantage in a longer replacement cycle when used in the inspection apparatus <NUM> that continuously operates.

The light emitting unit <NUM> may be continuously turned on (i.e., direct current (DC) light emission) or intermittently turned on (i.e., pulse light emission). However, in terms of life, preferably, the light emitting unit <NUM> can be intermittently turned on at about <NUM> to <NUM>. Specifically, the light emitting unit <NUM> is a laser, an LED, or a xenon lamp.

When continuously turned on (i.e., DC light emission), the light emitting unit <NUM> may be provided with an intermittent emission means (e.g., shutter) between the light emitting unit <NUM> and the package <NUM> so as to intermittently emit light to the package <NUM>.

In the present embodiment, an increase in the surface temperature of the sealing portion <NUM> may be about several degrees of Celsius to <NUM>. Depending on the cost of light source and size, a high-power light source may be used to further raise temperature. When the ambient temperature around the inspection apparatus <NUM> is about <NUM> to <NUM>, the surface temperature of the seal portion is about <NUM> to <NUM> in absolute temperature. (<NUM> is <NUM>. When the ambient temperature is about <NUM> to <NUM>, it is about <NUM> to <NUM>. In consideration of the surface temperature of the sealing portion, it is about <NUM> to <NUM>) According to the Planck's law, the thermal radiation corresponding to <NUM> has wavelengths of about <NUM> or longer. Thus, the light emitted from the sealing portion <NUM> of the package <NUM> caused by thermal radiation has a wavelength of about <NUM> or longer according to the Planck's law. Thus, the light receiving unit <NUM> receives the light having a wavelength of <NUM> or longer.

As described above, since the wavelength of the light emitted from the light emitting unit <NUM> and the wavelength of the thermal radiation received by the light receiving unit <NUM> are different from each other (i.e., wavelength difference), the light receiving unit <NUM> does not receive the light emitted from the light emitting unit <NUM>. Thus, the wavelength difference does not generate noise to the light receiving unit <NUM>, and the light receiving unit <NUM> receives a signal having a higher quality.

In the transmission spectrum of the atmosphere, there are wavelength bands referred to as an atmospheric window in which the transmittance of the atmosphere is higher. When the inspection is performed in the atmosphere, it is preferable to use such wavelength bands. The wavelength bands are, for example, middle wavelength infrared radiation (MWIR) having a wavelength band of <NUM> to <NUM> and long wavelength infrared radiation (LWIR) having a wavelength band of <NUM> to <NUM>.

In addition, since the thermal radiation spectrum of about <NUM> has a peak at about <NUM> in wavelength, it is preferable to use the atmospheric window of LWIR in order to achieve a higher sensitive measurement.

Thus, in the present embodiment, an infrared light receiving element that receives the LWIR is used as the light receiving unit <NUM>. The infrared light receiving element includes a cooling infrared light receiving element cooled to extremely low temperature to achieve higher sensitivity and an uncooled infrared light receiving element operable at room temperature. In the present embodiment, the uncooled infrared light receiving element is used as the light receiving unit <NUM> because it is practically low cost.

The light emitting unit <NUM> may be a point light source, a line light source, or an area light source as long as these light sources two-dimensionally emits light to the entire sealing portion <NUM>.

The light emitting unit <NUM> and the light receiving unit <NUM> will be described in detail. As described above, the light receiving unit <NUM> is an area light receiving element that receives thermal radiation from the entire sealing portion <NUM> due to the light emission to the sealing portion <NUM>. <FIG> is a diagram of a configuration of the light receiving unit <NUM>. As illustrated in <FIG>, the light receiving unit <NUM> has a rectangular shape and includes a large number of pixels. In the light receiving unit <NUM>, a readout direction in which a signal is output from each pixel is the direction of the shorter side of the rectangular shape (i.e., a direction in which the number of pixels is small). A row of pixels arranged in a direction orthogonal to the readout direction is referred to as a line.

<FIG> is a timing chart of a typical sequential readout of the light receiving unit. The light receiving unit <NUM> is an area light receiving unit such as a complementary metal-oxide-semiconductor (CMOS) image sensor. Typically, the CMOS readout circuitry is built in the light receiving unit <NUM>. Herein, a typical sequential readout will be briefly described. However, the readout is not limited to the description below.

In the timing chart illustrated in <FIG>, the vertical axis represents each line where the readout direction is from the first line to Nth line (i.e., line <NUM> to line N). The horizontal axis represents time, which is divided by frames. Each line includes an exposure time and an readout time which have predetermined periods. Herein, the exposure time is a period of time for charge accumulation in the pixel, when light is emitted to the pixel. As illustrated in <FIG>, each line has a delay (time lag) in starting the exposure time within the Pth frame. Each exposure time sequentially starts from the 1st line to the Nth line. After the readout time of the Nth line in Pth frame is finished, the exposure time of the 1st line in the (P+<NUM>)th frame starts.

<FIG> is a timing chart of a sequential readout of a light receiving unit as a comparative example. In the comparative example illustrated in <FIG>, the light emitting unit emits light (i.e., light emission) for a certain period of time, for example, about <NUM> millisecond (ms), around the middle of the Pth frame (i.e., during the exposure time of a certain line). As a result, in a two-dimensional image acquired in the Pth frame, a lower half part of the two-dimensional image is overexposed (i.e., with uneven exposure to laser irradiation). Such a two-dimensional image with the uneven exposure is a poor-quality image and is not used for a package inspection. Thus, two-dimensional images of (P-<NUM>)th frame and (P+<NUM>)th frame are used before and after the light emission (or light irradiation). However, one frame (i.e., Pth frame) is unusable (i.e., frame missing). If the package has a time change during the inspection, the frame missing may decrease the accuracy of the inspection.

As illustrated in <FIG>, when the light emitting unit emits light in the middle of the Pth frame, some lines are exposed to and some lines are unexposed to the light and the two-dimensional image has the uneven exposure. In the present embodiment, as illustrated in <FIG>, the light receiving unit <NUM> may have a limited region to acquire a two-dimensional image, and the remaining region of the light receiving unit <NUM> is referred to as a non-limited region. In the present embodiment, as illustrated in <FIG>, the limited region of the light receiving unit <NUM> limits the lines along the readout direction. These lines are not exposed to the light during these exposure times. Although the light receiving unit <NUM> outputs signals from all the lines (i.e., the 1st line to the Nth line) including all the pixels, the two-dimensional image acquisition unit <NUM> limits the signals as information. Since the signals output from the lines of the non-limited region are not used as information in the following processing, the light emission to the non-limited region during the exposure times of the lines does not cause any troubles. Preferably, the limited region is set around the center portion of the light receiving unit <NUM> in view of an optical performance of a lens used in the inspection apparatus.

As described above, the light receiving unit <NUM> has a rectangular shape. Each line outputs a signal, and the readout direction is along the shorter side including less pixels of the rectangular shape. In the present embodiment, the signals to be output from the limited region along the readout direction is used. Thus, in order to increase the spatial resolution of the two-dimensional image, preferably, the directions of the shorter side of light receiving unit <NUM> and the shorter side of the sealing portion <NUM> are matched.

<FIG> is a timing chart of a sequential readout in which the light emitting unit emits light during the exposure times of the lines of the non-limited region of the light receiving unit <NUM>. In <FIG>, the limited region of the light receiving unit <NUM> is limited to the first line to the nth line (i.e., line <NUM> to n). As illustrated in <FIG>, the light emitting unit starts emitting light at the end of the exposure time of the line of the limited region in the Pth frame and ends emitting the light at the start of the exposure time of the line of the limited region in the (P+<NUM>)th frame. In the present embodiment, a two-dimensional image before the light emission is acquired from the limited region in the Pth frame and a two-dimensional image after the light emission is acquired from the limited region in the (P+<NUM>)th frame. Thus, two-dimensional images having a higher quality are acquired without missing any frames.

<FIG> is another timing chart of a sequential readout in which the light emitting unit emits light during the exposure times of the lines of the non-limited region of the light receiving unit <NUM>. As illustrated in <FIG>, a two-dimensional image before the light emission of is acquired from the limited region in the Pth frame and a two-dimensional image after the light emission is also acquired from the limited region in the (P+q) frame. Since a two-dimensional image before the light emission is acquired and the light emission starts within the Pth frame only, a higher-quality two-dimensional image is acquired without wasting time in inspection.

The limited region is not limited to the line <NUM> to n and may be, for example, the line n to N. In such a case, the light emitting unit starts emitting light at the end of the exposure time of the line of the limited region in the Pth frame and ends emitting light at the start of the exposure time of the line of the limited region in the (P+<NUM>)th frame.

The light exposure time in the light emitting unit <NUM> will be described in detail. <FIG> is a timing chart in which the light emitting unit <NUM> emits light for a certain period of time (i.e., light exposure time). As illustrated in <FIG>, the light emitting unit <NUM> starts to emit light after the end of the exposure time of the line of the limited region in the Pth frame and ends to emit light before the start of the exposure time of the line of the limited region in the (P+<NUM>)th frame (i.e., light exposure time).

<FIG> is another timing chart in which the light emitting unit <NUM> emits light for a certain period of time (i.e., light exposure time). As illustrated in <FIG>, the light emitting unit <NUM> may start to emit light after the end of the exposure time of the line of the limited region in the Pth frame and end to emit the light in the middle of the exposure time of the line of the non-limited region in the (P+<NUM>)th frame.

When a two-dimensional image of the package <NUM> being conveyed by the conveyor unit <NUM> is acquired using the light receiving unit <NUM> having the sequential readout for each line having a time delay in the exposure time, the image is distorted. Preferably, the package <NUM> is being temporarily stopped for a certain period of time on the conveyor unit <NUM>, the light emitting unit <NUM> emits light to the package <NUM>, and the light receiving unit <NUM> receives thermal radiation (i.e., light reception) from the package between the Pth frame and the (P+<NUM>) frame.

The package <NUM> is stopped on the conveyor unit <NUM> of the inspection apparatus <NUM> is stopped (i.e., stopping configuration). The stopping configuration will be described. Specifically, the conveyor unit <NUM> stops the package <NUM> by applying the stopping configuration described below.

The controller <NUM> of the controller device <NUM> (<FIG>) controls the first conveyor part <NUM> to convey the packages <NUM> at the speed V1. The speed V1 is also referred to as a constant speed V. The controller <NUM> of the controller device <NUM> (<FIG>) controls the second conveyor part <NUM> to convey the packages <NUM> at the speed V2. The speed V2 is varied from <NUM> to V. In addition, the friction coefficient µ1 of the belt surface of the first conveyor part <NUM> that conveys the package <NUM> and the friction coefficient µ2 of the belt surface of the second conveyor part <NUM> that conveys the package <NUM> are different from each other, and µ1 is smaller than µ2 (i.e., µ1 < µ2).

As illustrated in <FIG>, the conveyor unit <NUM> includes a position-and-angle aligner <NUM> in the first conveyor part <NUM>. As a simple example, the position-and-angle aligner <NUM> is configured by a guide part made of aluminum. The package <NUM> conveyed on the first conveyor part <NUM> has a certain range of positional variation with respect to an orthogonal direction of the conveying direction (i.e., initial position of the package). The position-and-angle aligner <NUM> is a guide part to align the initial position of the package <NUM> being conveyed on the first conveyor part <NUM> to a predetermined position. The initial position is displaced in a direction orthogonal to the conveying direction. The package <NUM> conveyed on the first conveyor part <NUM> also has a certain range of angle variation with respect to an orthogonal direction of the conveying direction (i.e., initial angle of the package). The position-and-angle aligner <NUM> is the guide part for aligning the initial angle of the package <NUM> being conveyed on the first conveyor part <NUM> to a predetermined angle. The initial angle is tilted with respect to the direction orthogonal to the conveying direction. The position-and-angle aligner <NUM> is not limited to the guide part made of aluminum, and existing techniques may be used.

The package <NUM> is conveyed on the first conveyor part <NUM> at a constant speed V, and the position and the angle of the package are aligned in the direction orthogonal to the conveyor direction by the position-and-angle aligner <NUM>. The position-and-angle aligner <NUM> aligns the package <NUM> to be substantially parallel to the conveying direction and the direction orthogonal to the conveying direction. The friction coefficient µ1 of the belt of the first conveyor part <NUM> is set such that the package <NUM> slides in the direction orthogonal to the conveying direction according to the position-and-angle aligner <NUM> while being conveyed on the belt of the first conveyor part <NUM> in the conveying direction.

The package <NUM> in which the position and the angle are aligned by the position-and-angle aligner <NUM> is conveyed from the first conveyor part <NUM> to the second conveyor part <NUM>. The first conveyor part <NUM> and the second conveyor part <NUM> are arranged having a predetermined gap O therebetween. When the package <NUM> conveys to the second conveyor part <NUM>, the second conveyor part <NUM> decreases the conveying speed of the package <NUM> from V to <NUM> and stops. The package <NUM> being conveyed at the speed V2 stops with little slide on the belt of the second conveyor part <NUM>. The friction coefficient µ2 of the belt of the second conveyor part <NUM> is set such that slide of the package <NUM> due to decreasing the speed is unlikely to occur.

Thus, the position and the angle of the package <NUM> in the direction orthogonal to the conveyor direction is aligned by the position-and-angle aligner <NUM>, and the speed of the belt of the second conveyor part <NUM> having the friction coefficient µ2 larger than µ1 is decreased from V to <NUM>. The package <NUM> stops. As described above, the package <NUM> being conveyed is temporarily stopped, and a two-dimensional image is acquired by the light receiving unit <NUM> while the package <NUM> is being stopped. Thus, blurring or image distortion that occurs at the time of acquiring the image does not occur. In addition, the influence of a temperature change due to convection during conveying is reduced.

As described above, the position of the package <NUM> in the direction orthogonal to the conveying direction is aligned by the position-and-angle aligner <NUM>. The stop position of the package <NUM> in the conveying direction is determined by controlling the second conveyor part <NUM> to decrease the speed of conveying and stop. When the package <NUM> slides on the belt of the second conveyor part <NUM> due to inertia, the controller <NUM> (<FIG>) of the controller device <NUM> controls the second conveyor part <NUM> to decrease the speed of conveying the package <NUM> including the amount of the slide. Thus, the conveyor unit <NUM> enables the sealing portion <NUM> to set a position within in the field of view of the light receiving unit <NUM> in the conveying direction and the direction orthogonal to the conveying direction. When the position of the package <NUM> is determined with higher accuracy, there is an advantage in reducing the image size by trimming a region of a two-dimensional image acquired by the light receiving unit <NUM> as thermal information.

When the package <NUM> has a substantially rectangular parallelepiped shape, a two-dimensional image in which the sides of the package <NUM> and the sides of the light receiving unit <NUM> are substantially parallel to each other is acquired. In such a case, trimming image processing of the two-dimensional image of the package <NUM> is easy to perform.

The second conveyor part <NUM> increases the conveyor speed of the package <NUM> from <NUM> to V and keeps the conveying speed of the package <NUM> at the constant speed V.

As illustrated in <FIG>, the conveyor unit <NUM> may include a positioning part <NUM> to determine a stop position of the package <NUM> in the conveying direction in the second conveyor part <NUM>. As described above, when the package <NUM> conveyed to the second conveyor part <NUM>, the controller device <NUM> controls the second conveyor part <NUM> to decrease the conveying speed of the package <NUM> from V to <NUM> and stop. Since the positioning part <NUM> is disposed on the second conveyor part <NUM> and the top of the package <NUM> touches the positioning part <NUM>, the conveyor unit <NUM> accurately determines the position of the package <NUM> to be stopped.

As a simple example, the positioning part <NUM> is a stopper made of aluminum. The position and the angle of the package <NUM> are aligned in the direction orthogonal to the conveying direction of the package <NUM> by the position-and-angle aligner <NUM>. The package <NUM> having a substantially rectangular parallelepiped shape is stopped by touching the top side of the packaged <NUM> substantially parallel to a part of the positioning part <NUM> orthogonal to the conveying direction.

Specifically, the controller <NUM> of the controller device <NUM> (<FIG>) controls the positioning part <NUM> to lower a plate portion of the positioning part <NUM> on the belt of the second conveyor part <NUM> in accordance with a timing in which the second conveyor part <NUM> decreases the conveying speed and stops. The controller <NUM> of the controller device <NUM> (<FIG>) controls the positioning part <NUM> to lift the plate portion of the positioning part <NUM> and restart conveying the package <NUM> after the light emission by the light emitting unit <NUM> and the light reception by the light receiving unit <NUM>.

When the package <NUM> has a circular shape, the positioning part <NUM> may have an arc-shaped stopper corresponding to the shape of the package <NUM>. The positioning part <NUM> is not limited thereto, and existing technique may be used.

Light emission of the light emitting unit <NUM> will be described. <FIG> is a diagram of a point light source to emit light on the package being stopped. As illustrated in <FIG>, the point light source emits the light to the sealing portion <NUM> in a point shape. As illustrated in <FIG>, when emitting the light to the package <NUM> being stopped, the light emitting unit <NUM> two-dimensionally emits the light by the point light source through an optical system that two-dimensionally scans the sealing portion <NUM>. <FIG> is a diagram of a line light source to emit light on the package being stopped. As illustrated in <FIG> and <FIG>, the line light source emits the light to the sealing portion <NUM> in a line shape. The line light source may be composed of the point light sources arranged in one row or multiple rows or may form a line-shaped emission pattern through an optical system using the point light sources. As illustrated in <FIG>, when emitting the light to the package <NUM> being stopped, the light emitting unit <NUM> two-dimensionally emits the light to the package <NUM> by a line light source slightly longer than the lateral width of the sealing portion <NUM> through an optical system that one-dimensionally scans the sealing portion <NUM>.

<FIG> is a diagram of an area light source to emit light on the package being stopped. As illustrated in <FIG>, the area light source emits the light to the sealing portion <NUM> in an area shape as one shot. The area light source may be composed of the point light sources arranged vertically and horizontally, the line light sources arranged in a row, or these light sources are combined with an optical system to form an area shaped emitting pattern. Thus, in the area light source the point light sources are arrayed in vertical and horizontal directions. As illustrated in <FIG>, when emitting the light to the package <NUM> being stopped, the light emitting unit <NUM> using the area light source emits the light to the package <NUM> by one shot.

The light receiving unit <NUM> will be described. On the other hand, the light receiving unit <NUM> may be any one of the point light receiving element, the line light receiving element, and the area light receiving element as long as these light receiving elements two-dimensionally receive thermal radiation from the entire sealing portion <NUM> upon the light emission to the sealing portion <NUM>. A microbolometer may be applied to the area light receiving element.

<FIG> is a diagram of an area light receiving element to receive thermal radiation from the package being stopped; As illustrated in <FIG>, when the light receiving unit <NUM> receives the thermal radiation from the package <NUM> being stopped, the light receiving unit <NUM> receives the thermal radiation form the sealing portion <NUM> with the area light receiving element as one shot.

As described above, there are various modifications for the light emitting unit <NUM> that emits light to the entire sealing portion <NUM> and the light receiving unit <NUM> that receives thermal radiation from the entire sealing portion <NUM>. In the present embodiment, the light emitting unit <NUM> is an area light source, and the light receiving unit <NUM> is an area light receiving element. As described above, by combining the area light source and the area light receiving element, the light can be emitted to the entire sealing portion <NUM> as one shot and the thermal radiation from the entire sealing portion <NUM> can be received as one shot, even when the package <NUM> is being conveyed or stopped. Further, in the case of using an area light source in which the point light sources (e.g., LEDs) are arranged vertically and horizontally and an area light receiving element, an optical system for one- or two-dimensional scanning (i.e., a movable component) may be excluded, and a higher-quality image can be acquired without being affected by vibration of the movable component.

The positional relation between the light emitting unit <NUM> and the light receiving unit <NUM> (i.e., arrangement or layout) will be described in detail.

As described above, the light receiving unit <NUM> does not directly receive the light emitted from the light emitting unit <NUM> and the light transmitted through the sealing portion <NUM> of the package material <NUM> or the light reflected from the sealing portion <NUM>. The light receiving unit <NUM> receives light emitted from the surface of the package material <NUM> as the thermal radiation generated by the light emitted from the light emitting unit <NUM>. The light emitting unit <NUM> and the light receiving unit <NUM> are not limited to an arrangement based on transmission of the light or regular reflection of the light. Thus, the latitude in the layout of the light emitting unit <NUM> and the light receiving unit <NUM> is increased.

<FIG> is a diagram of a first layout of the light emitting unit <NUM> and the light receiving unit <NUM> as an example. In the example illustrated in <FIG>, the light receiving unit <NUM> is installed with an optical axis tilted with respect to the light emitting unit <NUM> and the sealing portion <NUM> of the package material <NUM> having the surfaces substantially parallel to the conveying direction X. By titling the optical axis of the light receiving unit <NUM> with respect to the sealing portion <NUM> of the package material <NUM>, the reflection (the reflection image) of the light receiving unit <NUM> itself can be prevented.

Specifically, as illustrated in <FIG>, the package <NUM> has a bloated portion to pack the contents inside the package material <NUM>. The package <NUM> has a slope portion <NUM>. The sealing portion <NUM> is substantially parallel to the conveying direction X, but the slope portion <NUM> is tilted with respect to the conveying direction X. In <FIG>, the light receiving unit <NUM> is installed with the optical axis tilted in the same manner as the slope portion <NUM>.

<FIG> is a diagram of a second layout of the light emitting unit <NUM> and the light receiving unit <NUM> as an example. In the example illustrated in <FIG>, under a condition that there is no influence of reflection of the light receiving unit <NUM> itself, the light receiving unit <NUM> may be disposed at a position orthogonal to the sealing portion <NUM> which is a surface substantially parallel to the conveying direction X without being tilted.

<FIG> is a diagram of a third layout of the light emitting unit <NUM> and the light receiving unit <NUM> as an example. In the example illustrated in <FIG>, in addition to the second layout of <FIG>, the light emitting unit <NUM> is installed with its optical axis tilted with respect to the sealing portion <NUM> of the package material <NUM> and the light receiving unit <NUM> which are surfaces substantially parallel to the conveying direction X.

The defect discrimination unit <NUM> will be described. The defect discrimination unit <NUM> determines whether the package <NUM> is pass or fail. <FIG> is a tree diagram of classification of defects of the package <NUM> (i.e., package defect). As illustrated in <FIG>, the defects of the package <NUM> are roughly classified into several types such as appearance defect, sealing portion defects, foreign substance, and weight fail. Each defect of the package <NUM> is inspected through a dedicated inspection apparatus or through visual inspection by an inspector.

<FIG> is a tree diagram of classification of defects of sealing portion <NUM> (i.e., sealing portion defect). As illustrated in <FIG>, the sealing portion defect of the sealing portion <NUM> of the package <NUM> is further classified into a middle classification and a small classification based on occurrence factors or features thereof. The sealing portion defect of the sealing portion <NUM> of the package <NUM> is classified into a middle classification including a surface defect, an inner surface defect, a shape fail, and a region fail. Further, the middle classification is classified into a small classification. The small classification of the sealing portion defect includes pinhole, discoloration, trapping, tunnel, wrinkle, bending, short seal width, and seal displacement. In the present embodiment, the types of the defects of the sealing portion <NUM> of the package <NUM> are the small classification.

As described above, when the sealing portion <NUM> of the package <NUM> has the anomaly state, the heat capacity of the anomaly state of the sealing portion <NUM> changes with respect to normal state. For example, when a content or a portion of the content of the package <NUM> is trapped in the sealing portion <NUM> (i.e., trapping), the trapping is a defect in which the content is trapped between the packaging materials (i.e., one package material <NUM> and the opposite packaging material <NUM>). Thus, a new layer is generated by the content trapped in the sealing portion <NUM>, and heat transfer slows. A tunnel is a defect in which a passage through which the content leaks to the outside of the package is formed in the sealing portion <NUM>. Since there is an air layer between one packaging material <NUM> and the opposite package material <NUM>, heat transmission slows due to high thermal resistance of air. When the sealing portion <NUM> of the package <NUM> is in an anomaly state as described above, it takes time for heat to reach the surface of the sealing portion <NUM> and the time delays, so that a temperature distribution occurs on the surface. Thus, the defect discrimination unit <NUM> can determine that the two-dimensional image is in an anomaly state, that is, not acceptable, based on the temperature distribution generated in the two-dimensional image having the thermal information.

The defect discrimination unit <NUM> determines whether the sealing portion <NUM> of the package <NUM> is in a normal state or in an anomaly state (i.e., determination of pass or fail) based on the two-dimensional image having the thermal information. The defect discrimination unit <NUM> applies various conventional image processing on the two-dimensional image in order to reveal an anomaly state. The image processing will be described below.

The pass-or-fail determination of the sealing portion <NUM> in the defect discrimination unit <NUM> will be described.

<FIG> is a graph of a change over time t of the surface temperature between a position in a normal state and a position in an anomaly state illustrated in <FIG> is a two-dimensional image related to the pass-or-fail determination of the sealing portion <NUM> as an specific example. In <FIG>, as an example of the anomaly state, an air layer is in the sealing portion <NUM>. The anomaly state described above also occurs in the tunnel, or the trapping of the content including air.

In the example illustrated in <FIG>, light is emitted from the light emitting unit <NUM> to one side of the sealing portion <NUM> including aluminum and having the normal state and the anomaly state at time <NUM>, and the temperature distribution of the surface at the other side of the sealing portion <NUM> is acquired at certain time. The time <NUM> is the time when the light emitting unit <NUM> emits light to the sealing portion <NUM>.

The two-dimensional image in <FIG> is an image acquired at time A in <FIG>. The image in <FIG> is a monochrome image in which a white portion indicates higher temperature and a grey portion indicates a lower temperature. As illustrated in <FIG>, the position in which the anomaly state (i.e., defect) occurs due to the air layer in the sealing portion <NUM> is darker than the surroundings.

In the example of <FIG>, the temperature of the normal state reaches the peak temperature at time T. Although the time T varies depending on the type and thickness of the package material <NUM>, it is about several hundred ms to <NUM> second (s or sec) or less. By contrast, as illustrated in <FIG>, the position of the anomaly state (defect) reaches the peak temperature after the time T, and the peak temperature of the normal state and the anormal state are almost the same. From <FIG>, when the time t is larger than <NUM> and smaller than T (i.e., <NUM> < t < T), the temperature is higher in the normal state than in the anomaly state. The normal state and the anomaly state have almost the same peak temperature over time, and the temperature difference becomes smaller after passing the peak temperature.

As described above, when the air layer is present in the seal portion <NUM> as illustrated in <FIG>, the thermal resistance of the sealing portion <NUM> in which the air layer is present increases. As a result, heat transfer slows. The time varying of the surface temperature of the sealing portion <NUM> is different between the normal state and the anomaly state, and a large temperature difference capable of detecting is generated at a certain time. The defect discrimination unit <NUM> detects an anomaly state by acquiring the two-dimensional image at this time.

Depending on the anomaly state, the thermal resistance may become smaller, and the temperature of the anomaly state may become higher than the surrounding temperature. In such a case, the anormal state of the sealing portion <NUM> can be detected by inspecting the difference between the normal state and the anomaly state.

<FIG> is a tree diagram of a relation between modules (i.e., image processing modules), image processing algorithms, and sealing defects. As illustrated in <FIG>, there are multiple image processing modules (i.e., modules), multiple types of defects of the sealing portion <NUM> of the package <NUM>, and multiple image processing algorithms. A certain image processing algorithm suitably discriminates a certain type of sealing defect from other types of sealing defects to identify a type of sealing defect. As illustrated in <FIG>, an image processing algorithm includes multiple image processing modules (i.e., modules) to suitably discriminate a certain type of sealing defect from other types of sealing defects. In other words, an image processing algorithm more suitably discriminates a certain type of sealing defect from other types of sealing defects by combining multiple image processing modules.

For example, the image processing algorithm (<NUM>) to discriminate the sealing defect (<NUM>) from other types of sealing defects (<NUM>) to (<NUM>) will be described (<FIG>). The defect discrimination unit <NUM> includes an image processing algorithm (<NUM>) to discriminate the sealing defect (<NUM>) from other types of sealing defects (<NUM>) to (<NUM>). The image processing algorithm (<NUM>) includes an image processing module A (module A), an image processing module a (module a), and an image processing module m (module m), and sequentially processes these image processing modules. The defect discrimination unit <NUM> inputs the two-dimensional image data set α into the module A as first image processing. Each module applies various image processing such as rotational deformation processing, averaging processing, and edge extraction processing.

In <FIG>, the image processing algorithm (<NUM>) discriminates the sealing defect (<NUM>) and the sealing defect (<NUM>) from the other types of sealing defects based on criteria such as a difference in a threshold value with respect to the processing result. In <FIG>, the image processing algorithm (<NUM>) discriminates the sealing defect (<NUM>) and the sealing defect (<NUM>) from other types of sealing defects based on criteria with respect to the processing result. In other words, the sealing defect (<NUM>) is discriminated by different image processing algorithms (i.e., image processing algorithms (<NUM>) and (<NUM>)). Since the sealing defect (<NUM>) is discriminated from the other sealing defects by the image processing algorithm (<NUM>) and the image processing algorithm (<NUM>) at the same time, accuracy of occurrence of the sealing defect (<NUM>) increases.

As described above, the defect discrimination unit <NUM> includes multiple image processing algorithms to discriminate between sealing defects that cannot be overlooked and any one of image processing algorithms detects the sealing defect, overlook of the sealing defect is less likely to occur.

<FIG> is another tree diagram of a relation between image processing modules (modules), image processing algorithms, and sealing defects. In the example illustrated in <FIG>, there are multiple two-dimensional image data sets to be used for multiple image processing algorithms.

As described above, the light emitting unit <NUM> and the light receiving unit <NUM> work under a certain condition, and a two-dimensional image is acquired from the thermal information. As an example of a practical condition, the light emitting unit <NUM> starts to emit light having a desired power at a desired time and ends to emit the light after a desired duration time. The light receiving unit <NUM> receives thermal radiation from the sealing portion <NUM> of the package <NUM> at a desired period of time (i.e., frame rate) and the desired number of two-dimensional images in accordance with the light emission timing of the light emitting unit <NUM>. The light receiving unit <NUM> may select a desired region (i.e., size of light receiving area) for the light reception. The defect discrimination unit <NUM> acquires a two-dimensional image having two-dimensional thermal information of the sealing portion <NUM> of the package <NUM> from the thermal information received in this manner. At this time, the defect discrimination unit <NUM> may perform image processing such as adjustment of image size or image contrast.

The defect discrimination unit <NUM> generates multiple two-dimensional image data sets from the two-dimensional image acquired under a certain condition on operations of the light emitting unit and the light receiving unit (i.e., light emission-and-reception condition) described above.

The generation of multiple two-dimensional image data sets will be described. The defect discrimination unit <NUM> generates multiple two-dimensional image data sets from two-dimensional images acquired under different light emission-and-reception conditions. Herein, the different light emission-and-reception conditions are not mechanical conditions such as positional changes of the light emitting unit <NUM>, the light receiving unit <NUM>, or at least one part that constitutes the light emitting unit 31or the light receiving unit <NUM>. Thus, the different light emission-and-reception conditions are, for example, changes of set vales in a software or in circuitry (i.e., software and circuitry conditions). Specifically, the changes of set values are , a change in light emission power, a stat timing of light emission, and duration period of light emission in the light emitting unit <NUM>, or a change in a period of time (i.e., frame rate), the number of two-dimensional images to be acquired, or light receiving size in the light receiving unit <NUM>.

Since the defect discrimination unit <NUM> does not use the mechanical conditions and use the software and circuitry conditions, the defect discrimination unit <NUM> changes the conditions in a short time. As a result, the package inspection is done at a constant speed. As a result, a latitude of generating the two-dimensional image data set increases.

For example, when the defect discrimination unit <NUM> acquires three two-dimensional images (sequentially, 1st image, 2nd image, and 3rd image) under a condition in which three two-dimensional images are acquired, the defect discrimination unit <NUM> may create a two-dimensional image data set α consisting of the 2nd image and a two-dimensional image data set β consisting of the first image, the second image, and the third image (i.e., all three images). The defect discrimination unit <NUM> may perform image processing such as differential processing or processing on rate of change in the image using, for example, the three images in the two-dimensional image data set β. The two-dimensional image data set β has a different feature as compared with the two-dimensional image data set α consisting of one two-dimensional image as an input image.

In some embodiments, the controller <NUM> of the inspection apparatus <NUM> controls a light emitter to emit light and controls a light receiver to receive thermal radiation as thermal information at the same condition, and generates the multiple two-dimensional image data sets based on the thermal information acquired.

In some embodiments, the controller 401of the inspection apparatus <NUM> controls the light emitter to emit the light and controls the light receiver to receive the thermal radiation at different number of two-dimensional images, and generates the multiple two-dimensional image data sets based on the thermal information acquired.

In some embodiments, the controller <NUM> of the inspection apparatus <NUM> controls the light emitter to emit the light at different light emitting conditions and controls the light receiver to receive the thermal radiation at different light receiving conditions to acquire the thermal information, and generates the multiple two-dimensional image data sets based on the thermal information acquired.

As another example, the defect discrimination unit <NUM> may generate a two-dimensional image data set having different light receiving timings. <FIG> is a timing chart of light emission. <FIG> is a timing chart of light reception (i.e., reception of thermal radiation). <FIG> is a timing chart in which the light emitting unit <NUM> emits light to the package <NUM>. <FIG> is a timing chart in which the light receiving unit <NUM> receives thermal radiation from the package <NUM> and four images are received.

The defect discrimination unit <NUM> may generate the two-dimensional image data set α including the first two-dimensional image and the second two-dimensional image, and a two-dimensional image data set β including the third two-dimensional image and the fourth two-dimensional image. In the two-dimensional data set α, the first two-dimensional image is acquired before the light emission and the second two-dimensional image is acquired after the light emission. In the two-dimensional data set β, the third two-dimensional image and the fourth two-dimensional image are acquired after certain intervals from the light emission. Thus, these four two-dimensional images include information on different states of the package <NUM> as input images.

In an example illustrated in <FIG>, two two-dimensional images of the two-dimensional image data set α are acquired at α1 and α2 around <NUM> to <NUM> sec when the surface temperature increases, and two two-dimensional images of the two-dimensional image data set β are acquired at β1 and β2 after <NUM> sec when the surface temperature decreases. Thus, the four two-dimensional images include different thermal information such as temperature rise or drop of the sealing portion <NUM>, the defect discrimination unit <NUM> discriminates between the types of defects using different image processing algorithms.

Both the number of the two-dimensional image to be acquired and the light receiving timings may vary for the defect discrimination unit <NUM>.

As illustrated in <FIG>, the defect discrimination unit <NUM> may have multiple two-dimensional data sets to be input to each image processing algorithm. Specifically, the image processing algorithms (<NUM>) to (<NUM>) have an image processing module A (module A) as first image processing. The defect discrimination unit <NUM> inputs the two-dimensional data set α into the image processing module A. The image processing algorithms (<NUM>) to (<NUM>) have an image processing module B (module B) as the first image processing. The defect discrimination unit <NUM> inputs the two-dimensional data set β into the image processing module B. Since the two-dimensional image data set α is suitable for the image processing algorithm (<NUM>) and the two-dimensional image data set β is suitable for the image processing algorithm (<NUM>), a sealing defect is discriminated at a higher accuracy.

In some embodiments, the defect discrimination unit <NUM> may input the two-dimensional data set α into the image processing algorithm (<NUM>) and the two-dimensional data set β into the image processing algorithm (<NUM>).

The defect discrimination unit <NUM> displays a determination result (i.e., pass or fail) on the display device. In addition to the determination result, the defect discrimination unit <NUM> displays the type of sealing defect (i.e., type of defect) and a symbol or name indicating the image processing algorithm that discriminates the sealing defect when the determination result is fail.

<FIG> is an illustration of a screen of the determination result (i.e., result screen) as an example. As illustrated in <FIG>, in the upper part of the result screen, notations relating to the package <NUM> and the inspection such as a serial number, a product name, a lot number, and an inspection date and time are displayed, and FIAL is displayed when the determination result is fail. When the determination result is pass, PASS is displayed.

As illustrated in <FIG>, in the middle part of the result screen, a part of the two-dimensional image among the two-dimensional image data set, which indicates the location where the defect was detected, is displayed. For example, two sealing defects are displayed and the locations of the defects are surrounded by rectangular frames in <FIG>.

As illustrated in <FIG>, the two types of sealing defects are noted in the lower part of the result screen so that the relation between the defect and the location is clear. The names of the sealing defects are displayed in <FIG>. The image processing algorithm that discriminated the type of the sealing defect is indicated so that the relation between the type of the sealing defect and the image processing algorithm is clear. In <FIG>, the names of the image processing algorithms are displayed on the right side of the types of the sealing defects. If the name is complicated, a symbol may be used for expressing the sealing defect. In <FIG>, the sealing defect (<NUM>) was discriminated by the image processing algorithm (<NUM>) and the image processing algorithm (<NUM>). In <FIG>, the names of the two image processing algorithms are displayed in different two lines as a case where a sealing defect is discriminated by the two image processing algorithms. When a sealing defect discriminated by one image processing algorithm, the notation is one line.

Since the type of defect and the image processing algorithm that discriminated the defect is displayed on the result screen in accordance with the two-dimensional image, an inspector or a supervisor of the production line easily grasps the inspection state.

As described above, the inspection apparatus <NUM> determines whether the sealing portion <NUM> of the package <NUM> is pass or fail. Further, in the inspection apparatus <NUM>, after the package <NUM> is conveyed by the second conveyor part <NUM> of the conveyor unit <NUM>, the package <NUM> determined to be anomaly is removed from the second conveyor part <NUM> by a sorting means (e.g., rejector). By contrast, the package <NUM> determined to be a normal state is conveyed by the second conveyor part <NUM> and packed into a box by a packing means (e.g., caser) or manually.

As described above, according to the present embodiments, an inspection apparatus determines whether the sealing portion <NUM> of the package <NUM> is pass or fail and discriminates between the types of the sealing defect without an additional time for determining the type of the defect (i.e., the inspection speed is not decreased).

An inspection apparatus (<NUM>) includes: a light emitting unit (<NUM>) to emit light to a sealing portion (<NUM>) of a package (<NUM>) containing a light energy absorbing material, the light having a wavelength absorbable by the light energy absorbing material (<NUM>); a light receiving unit (<NUM>) to receive thermal radiation from the sealing portion (<NUM>) as thermal information; a controller device (<NUM>) including multiple image processing algorithms. The control device (<NUM>) acquires the thermal information on the sealing portion (<NUM>) from the light receiving unit (<NUM>) as a two-dimensional image, determines whether the sealing portion (<NUM>) is pass or fail based on the two-dimensional image acquired, and discriminates a type of a sealing defect from other types of sealing defects previously set in the multiple image processing algorithms in response to a determination that the sealing portion (<NUM>) is fail.

An inspection method includes: emitting light by a light emitting unit (<NUM>) to a sealing portion (<NUM>) of a package (<NUM>) including a light energy absorbing material, the light having a wavelength absorbed by the light energy absorbing material; receiving thermal radiation from the sealing portion (<NUM>) by a light receiving unit (<NUM>) as thermal information; acquiring the thermal information on the sealing portion (<NUM>) as a two-dimensional image based on the light receiving unit (<NUM>); determining whether the sealing portion (<NUM>) is pass or fail based on the two-dimensional image acquired; and discriminating a type of a sealing defect from other types of sealing defects previously set in multiple image processing algorithms in response to a determination that the sealing portion (<NUM>) is fail.

In the present embodiment, aluminum is used as a material that absorbs energy of light, but the material is not limited thereto, and other metals or resins may be used as long as the material absorbs energy of light (light energy) and converts into thermal energy.

In the present embodiment, a retort pouch is applied as the packaging material <NUM> of the package <NUM>, but the package material <NUM> is not limited thereto, and can be applied to various packaging materials <NUM> that packs contents and seal openings. Examples of the package material <NUM> of the package <NUM> include, for example, a lid of a yogurt container, a container for sealing a medicine tablet therein.

The inspection apparatus <NUM> according to the present embodiment may be used for in-line inspection. In mass production, multiple products are sequentially conveyed on a belt conveyor and produced through multiple processes. An inspection process is one of the multiple processes, and the inspection apparatus is installed in the vicinity of the belt conveyor to sequentially inspect the produced products. Such an inspection is referred to as in-line inspection. A typical inspection apparatus acquires an image of an area of an object (e.g., package)while conveying the object. By contrast, the inspection apparatus <NUM> according to the present embodiment acquires a higher-quality image because the inspection apparatus <NUM> temporarily stops the package when acquiring the image of an area of the object. As a result, the accuracy of the inspection is increased. Thus, the inspection apparatus <NUM> is suitable for in-line inspection.

Claim 1:
An inspection apparatus (<NUM>) comprising:
a light emitting unit (<NUM>) configured to emit light to a sealing portion (<NUM>) of a package (<NUM>) containing a light energy absorbing material, the light having a wavelength absorbable by the light energy absorbing material (<NUM>);
a light receiving unit (<NUM>) configured to receive thermal radiation from the sealing portion (<NUM>) as thermal information;
a controller device (<NUM>) including multiple image processing algorithms, the control device (<NUM>) configured to:
acquire the thermal information on the sealing portion (<NUM>) from the light receiving unit (<NUM>) as a two-dimensional image;
determine whether the sealing portion (<NUM>) is pass or fail based on the two-dimensional image acquired; and
discriminate a type of a sealing defect from other types of sealing defects previously set in the multiple image processing algorithms in response to a determination that the sealing portion (<NUM>) is fail.