Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/90—Investigating the presence of flaws or contamination in a container or its contents
  • G01N21/9018—Dirt detection in containers
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/30—Measuring arrangements characterised by the use of optical techniques for measuring roughness or irregularity of surfaces
  • G01B11/303—Measuring arrangements characterised by the use of optical techniques for measuring roughness or irregularity of surfaces using photoelectric detection means
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/47—Scattering, i.e. diffuse reflection
  • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
  • G01N21/51—Scattering, i.e. diffuse reflection within a body or fluid inside a container, e.g. in an ampoule
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/90—Investigating the presence of flaws or contamination in a container or its contents
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/93—Detection standards; Calibrating baseline adjustment, drift correction
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/94—Investigating contamination, e.g. dust
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
  • G01B11/25—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures by projecting a pattern, e.g. one or more lines, moiré fringes on the object
  • G01B11/254—Projection of a pattern, viewing through a pattern, e.g. moiré

Definitions

• the invention relates to a device for inspecting containers for impurities.
• the device comprises a radiation source, wherein the radiation source is designed to emit radiation which radiates through a container to be examined.
• the device further comprises a detection device, which is designed to detect the radiation which has been emitted by the radiation source and has transmitted through the container.
• the device also comprises an evaluation device, which is designed to evaluate the radiation detected by the detection device.
• the present invention is particularly intended for use in automatic filling plants in which the containers are transported at high speeds.
• the invention is intended for inspection of empty containers.
• empty containers are inspected for possible impurities or foreign bodies prior to filling.
• the containers are for this purpose passed through an inspection device comprising a visible light source and a semiconductor camera.
• the containers are transilluminated and inspected from different angles.
• the inspection detects brightness, color or contrast differences. Present differences are identified as contamination or contamination of the container and the container is subsequently rejected.
• segregated containers can be fed to a cleaning plant or recycled.
• optical components of the inspection device may be contaminated or have interference.
• optical components of the inspection device may mist up. Other impurities such.
• the invention is therefore based on the object of further developing an inspection device for containers in such a way that contamination of optical components of the inspection device can be detected in a simple manner.
• a device for inspecting containers for contamination which comprises a radiation source.
• the radiation source is designed to emit radiation that radiates through a container to be examined.
• the apparatus further comprises a detection device, which is designed to detect the radiation which has been emitted by the radiation source and has transmitted through the container.
• the device also has an evaluation device, which is designed to evaluate the radiation detected by the detection device.
• an identification element is arranged, which has an optical watermark.
• the optical watermark in the optical path between the radiation source and the detection device does not or only slightly influences the examination of the containers for contamination.
• the optical watermark allows verification of the optical components of the inspection device.
• the evaluation device checks the optical watermark. If the detected watermark differs significantly from the actual optical watermark in successive shots, which is located in the beam path between the radiation source and the detection device, contamination is detected by the evaluation device or interference of the optical components of the inspection device.
• the identification element comprising the optical watermark is preferably arranged between the radiation source and the container to be examined. In this way, an identification of disturbances or impurities of the optical components can be ensured, which are located between the identification element and the detection device. In addition, contamination of the container can be detected in this case, since they can lead to a disturbance of the watermark.
• the identification element which has the optical watermark
• the identification element can be arranged between the container to be examined and the detection device. This makes it possible to detect disturbances or impurities in the optical components, which are located exclusively between the identification element and the detection device. However, contamination of the container will be ignored in this way.
• multiple identification elements with different optical watermarks can be placed in the optical path between the radiation source and the detection device. These multiple identification elements can be arranged in the optical path to the optical components of the inspection device, which are to be examined for disturbances and impurities.
• the detection device may be formed as a semiconductor camera with lens and deflection mirror as a camera box.
• a cleaning of the protective glass of the semiconductor camera is possible without problems.
• a disturbance or contamination within the camera box constitutes a significant disturbance.
• a first identification element comprising a first optical watermark in the optical path can be arranged in front of the protective glass of the camera box and a second identification element comprising a second optical watermark in the optical path Way, be placed behind the protective glass of the camera box. If it is determined by the evaluation device that the second optical watermark is detected correctly by the detection device, but not the first watermark, it can be deduced that the protective glass of the camera box is contaminated or defective.
• the evaluation device can output a signal that the protective glass of the camera box is to be cleaned.
• both the first watermark as well as the Second watermark can not be detected correctly by the detection device can be closed by the evaluation of contamination or interference within the camera box.
• suitable components in the optical path between the radiation source and the detection device can be provided with identification elements and different optical watermarks, so that it is possible to determine exactly which optical component of the inspection device is dirty or disturbed by the evaluation device in the event of contamination or interference.
• the optical watermark is designed in such a way that the detection of contamination of the containers by the watermark is not or only slightly disturbed.
• the watermark is formed, for example, by fine points, lines or structures which differ from contamination of the containers.
• the watermark can not or only with difficulty be recognized by the human eye.
• the watermark can have lines or dot patterns.
• the optical watermark is defined and selected by the frequency spectrum present in the optical watermark.
• suitable frequencies within a fixed frequency band are selected in the frequency spectrum of the watermark.
• the frequency spectrum of the watermark thus generated can be transformed from the frequency domain into the spatial domain by means of a known Fourier transformation or another suitable orthogonal transformation. This results in the image in the spatial space of the optical watermark.
• This image is then applied to the identification element and placed in the optical path between the radiation source and the detection device of the inspection device. As a result, the radiation of the radiation source is impressed on the watermark.
• the recording detected by the detection device is preferably transformed from the spatial domain into the frequency domain.
• a Fourier transformation or another suitable orthogonal transformation is used.
• the evaluation device now checks whether the frequency spectrum of the optical watermark is present in the detected by the detection device recording, or whether the frequency spectrum is disturbed. If the frequency spectrum is essentially present in the recording, ie not disturbed or only slightly disturbed, the evaluation device detects that there is no interference or contamination of optical components of the inspection device and that there is no contamination of the container to be examined. If, on the other hand, the frequency spectrum of the original watermark present in the recording detected by the detection device is severely distorted or disturbed, the evaluation device detects contamination of the container to be examined.
• the evaluation device detects contamination or interference of an optical component of the inspection device. If, as described above, a plurality of different optical watermarks are used, the evaluation device further detects which of the optical components of the inspection device is affected by contamination or interference.
• the frequency spectrum of the optical watermark is chosen such that all frequencies in the frequency spectrum of the watermark can still be detected by the detection device.
• the upper limit frequency is selected so that no artifacts are generated by the optical components of the inspection device, the container to be examined and by the evaluation in the evaluation.
• the lowest frequency in the frequency spectrum of the optical watermark is chosen so that the detection of contaminants of the containers to be examined is not or only minimally disturbed.
• the frequency spectrum of the optical watermark is chosen so that the detection of contaminants from containers to be examined is not significantly disturbed, but the frequencies of the optical watermark can be detected by the detection device. If several watermarks are used at the same time, they preferably complement each other spectrally and therefore do not share any common frequencies.
• the frequency spectrum of the optical watermark is further selected such that diffuse impurities from optical components of the inspection device in the optical path between the radiation source and the detection device to a Disturb the optical watermark. This ensures that, for example, oil films, cleaning strips, fittings, etc. can be detected on optical components of the inspection device.
• the radiation source is preferably an electromagnetic radiation source, e.g. B. a radiation source for light in the visible range.
• the radiation source may further be configured to emit UV or infrared light or a combination thereof. Infrared radiation can be used advantageously in colored containers, in particular in brown glass bottles.
• the radiation source can be operated pulsed and controlled so that the radiation pulses are emitted only when a container to be examined is located in front of the radiation source.
• the radiation source can be operated continuously.
• the present invention may be used to inspect containers of any material substantially transparent to radiation from the radiation source. Particularly advantageous is the invention in containers made of glass or transparent plastics such. B. use PET. In particular, the invention is applicable to the inspection of glass bottles in the beverage industry.
• the detection device is preferably a commercially available color camera, in particular a semiconductor camera.
• a semiconductor camera in particular a semiconductor camera.
• infrared and UV cameras can be used.
• shutter cameras with short shutter speeds can be used. This is particularly advantageous when the radiation source is operated continuously.
• the invention further relates to a method for inspecting containers for contaminants, the method comprising the following method steps:
• an identification element comprising an optical watermark
• the evaluation device preferably closes by a frequency-analytical method from a change in the frequency spectrum of the watermark in the recording detected by the detection device to contamination or interference in the optical path between the radiation source and the detection device.
• the evaluation device detects contamination or interference if a significant change occurs in the frequency spectrum of the watermark.
• a recording is detected by each of the container to be examined by the detection device. If the evaluation device detects contamination or interference in a single recording in the optical path between the radiation source and the detection device, it is assumed that the container is contaminated. For example, the container may be fogged or contaminated with rust so that there is diffuse contamination of the container. If, on the other hand, a stationary disturbance or contamination by the evaluation device is detected in the case of several successive detected recordings of the detection device, the evaluation device detects contamination or interference of an optical component of the inspection device in the optical path between identification element and detection device. In this case, it is unlikely that a plurality of containers will have diffuse contaminants at the same location.
• the evaluation device preferably decomposes the recording detected by the detection device into a plurality of subregions, for B. with 64x64 or 32x32 pixels. These subsections of the total recording are in each case transformed from the evaluation device from the spatial domain into the frequency domain, and the received information spectrum of the individual sub-ranges compared with the frequency spectrum of the optical watermark.
• the original frequency pattern of the optical watermark can be observed in each subarea of the recording, whereby the original frequency pattern may be systematically distorted due to the container. Greater distortion or attenuation of the frequency spectrum compared to the original frequency spectrum of the optical watermark indicates contamination.
• a one-time detection of a distorted or disturbed frequency spectrum can be attributed to a dirty container. If, however, distorted or disturbed frequency spectra are detected by the evaluation device in consecutive recordings, contamination or interference of an optical component of the inspection device in the optical path between the radiation source and the detection device is deduced.
• FIG. 1 shows an illustrative representation of an embodiment of the inspection device according to the invention with identification element
• FIG. 1 shows a device for inspecting containers for contamination.
• the device has a radiation source 10.
• the radiation source 10 is designed to emit radiation.
• the radiation radiates through a container 12 to be examined. After the container 12 to be examined is irradiated by the radiation of the radiation source If the radiation is transmitted through a detection device 14, the recording detected by the detection device 14 is transmitted to an evaluation device 16 for further evaluation.
• an identification element 18 is arranged, wherein the identification element 18 has an optical watermark.
• various optical components 22, 24 of the inspection device may be provided. These may be protective glass panes 22 or deflecting mirrors 24.
• the radiation source 10 and the detection device 14 are to be regarded as optical components of the inspection device.
• the containers 12 to be examined as well as all optical components 10, 14, 22, 24 of the inspection device can have impurities. In the containers 12 to be examined, these impurities are detected in a known manner by the detection device 14 and detected by the evaluation device 16. In contrast, by the device according to the invention further disturbances or impurities on the optical components of the inspection device can be detected.
• the identification element 18 is provided with the optical watermark.
• the optical watermark is designed such that the detection of contaminants on the container 12 to be examined is not or hardly affected. However, if there is a disturbance or contamination in one of the optical components of the inspection device, this leads to a change of the optical watermark in the recording detected by the detection device 14. This can be determined by the evaluation device 16.
• the identification element 18 with the optical watermark is arranged between a first protective glass 22 and the radiation source 10.
• a disturbance or contamination in the protective glasses 22, the deflection mirror 24 and optical components within the detection device 14 can be detected. Disturbances or contamination within the radiation source 10 can not be determined.
• Figures 2 and 3 show different arrangements of the optical components of the inspection device.
• FIG. 2 shows a tilting of the radiation source with respect to the optical path shown in FIG.
• FIG. 3 shows a bottom inspection.
• FIG. 4 shows an embodiment in which two identification elements 18 with respective different optical watermarks are used.
• any existing interference or contamination of optical components of the inspection device can be assigned to the individual optical components.
• the evaluation device 16 evaluates the image detected by the detection device 14 in such a way that the optical watermark which has the right-hand identification element 18 shown in FIG. 4 is disturbed.
• the optical watermark which has the left identification element 18 shown in FIG. 4 will not be disturbed.
• separate identification elements with different optical watermarks can be placed in front of and / or behind these optical components.
• the identification elements 18 can be applied as films to the optical components of the identification device or introduced by other suitable measures in the optical path 20 between the radiation source 10 and the detection device 14, for example by screens.
• FIG. 5 shows an embodiment of an optical watermark in the spatial domain, see FIG. 5B and in the frequency domain, see FIG. 5A.
• the conversion of an optical watermark from the spatial domain into the frequency domain and vice versa is done by the known Fourier transform or another suitable orthogonal transformation.
• an optical watermark is selected as shown in Figs. 5A and 5B.
• a suitable frequency spectrum is generated, wherein the frequencies are selected such that the frequencies can be detected by the detection device 14 and at the same time not or not substantially disturb the detection of contaminants on the containers 12 to be examined.
• FIG. 5A shows such a selection of a suitable frequency spectrum, where 5A shows the real part and the imaginary part in the frequency spectrum of the optical watermark thus generated.
• FIG. 5B shows an enlarged partial section of this optical watermark. This optical watermark is then introduced into the optical path 20 between the radiation source 10 and the detection device 14, as shown in FIGS. 1 to 4.
• FIG. 6 shows exemplary evaluations of the recordings detected by the detection device 14.
• the evaluation device divides a recording detected by the detection device 14 into several subregions.
• FIGS. 6A and 6B respectively show the frequency spectrum of two such subregions.
• FIG. 6A shows the frequency spectrum of a partial region in which the frequency spectrum of the optical watermark which was introduced into the optical path 20 between the radiation source 10 and the detection device 14 could be substantially reconstructed. In this recording, the evaluation would therefore detect that no pollution or interference in the optical path 20 is present.
• FIG. 6B shows the frequency spectrum of a partial region in which there is a disturbance or contamination in the optical path 20. If such a disturbance or contamination is only detected during a recording, it is concluded by the evaluation device that a contaminated container 20 has been present. If, however, such a disturbance or contamination is detected at the same point in the case of a plurality of successive exposures, the evaluation device determines that there is a disturbance or contamination of one of the optical components of the inspection device. If, as described above, several identification elements 18 with different optical watermarks are used, the evaluation device 16 can also determine in this case, which optical component of the inspection device is disturbed or contaminated.

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• Physics & Mathematics (AREA)
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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
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• General Health & Medical Sciences (AREA)
• Immunology (AREA)
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• Spectroscopy & Molecular Physics (AREA)
• Engineering & Computer Science (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Analysing Materials By The Use Of Radiation (AREA)

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• 2017
  • 2017-09-07 DE DE102017008383.5A patent/DE102017008383A1/de not_active Withdrawn
• 2018
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  • 2018-09-06 WO PCT/EP2018/074067 patent/WO2019048577A1/de not_active Ceased
  • 2018-09-06 EP EP18766228.3A patent/EP3679357B1/de active Active
  • 2018-09-06 ES ES18766228T patent/ES2909299T3/es active Active
  • 2018-09-06 DK DK18766228.3T patent/DK3679357T3/da active
  • 2018-09-06 KR KR1020207008151A patent/KR102306810B1/ko active Active
  • 2018-09-06 US US16/644,366 patent/US10837917B2/en active Active
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