EP2841932A1 - Procédé et dispositif de mesure de structures de soufflage d'une vitre précontrainte - Google Patents

Procédé et dispositif de mesure de structures de soufflage d'une vitre précontrainte

Info

Publication number
EP2841932A1
EP2841932A1 EP13714948.0A EP13714948A EP2841932A1 EP 2841932 A1 EP2841932 A1 EP 2841932A1 EP 13714948 A EP13714948 A EP 13714948A EP 2841932 A1 EP2841932 A1 EP 2841932A1
Authority
EP
European Patent Office
Prior art keywords
disc
radiation source
image
detector
analysis
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP13714948.0A
Other languages
German (de)
English (en)
Inventor
Valentin SCHULZ
Lutz HERMANNS
Lars PAPE
Stephan Kremers
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Saint Gobain Glass France SAS
Compagnie de Saint Gobain SA
Original Assignee
Saint Gobain Glass France SAS
Compagnie de Saint Gobain SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Saint Gobain Glass France SAS, Compagnie de Saint Gobain SA filed Critical Saint Gobain Glass France SAS
Priority to EP13714948.0A priority Critical patent/EP2841932A1/fr
Publication of EP2841932A1 publication Critical patent/EP2841932A1/fr
Withdrawn legal-status Critical Current

Links

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
    • G01N21/8806—Specially adapted optical and illumination features
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
    • G01L1/241—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet by photoelastic stress analysis
    • 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
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/892—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the flaw, defect or object feature examined
    • G01N21/896—Optical defects in or on transparent materials, e.g. distortion, surface flaws in conveyed flat sheet or rod
    • 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
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/958—Inspecting transparent materials or objects, e.g. windscreens
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
    • G01N33/386—Glass
    • 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
    • G01N21/8806—Specially adapted optical and illumination features
    • G01N2021/8848—Polarisation of light

Definitions

  • the invention relates to a method for measuring blast structures of a prestressed disc.
  • the invention further relates to an arrangement for measuring blast structures of a prestressed disc and their use.
  • Discs are often preloaded. For this purpose, the disks are heated to a temperature above the lower expansion limit and cooled rapidly, whereby at the surface of the disk compressive stresses and in the core of the disk tensile stresses are formed. Prestressed discs have an increased thermal and mechanical load capacity compared to non-prestressed discs. If a prestressed disc breaks down under high load, fracture fragments form which, due to their shape and size, do not pose a risk of serious cuts. Prestressed disks are used as single-pane safety glass, for example as side windows or rear windows of motor vehicles.
  • the disks are typically loaded with a stream of air from a plurality of nozzles.
  • a stream of air from a plurality of nozzles.
  • the inhomogeneously distributed voltages lead to a location-dependent interaction of the disc with light striking them.
  • blowing structures In suitable conditions of light and observation, it is possible to detect structures on the pane which are often perceived as disturbing by an observer.
  • Such visible structures as a result of the biasing process are referred to as blowing structures in the context of the invention. They are also known, for example, as temper marks, "quench marks" or stress patterns.
  • the term blast structures is understood to mean all optically perceivable structures which are produced by pretreatment of the pane. The treatment does not necessarily include the application of an air stream.
  • WO 201 1 157815 A1 discloses a method for measuring blast structures. An essential part of the method described is the comparison of an optical measurement with the subjective evaluation of test discs by a group of persons. The measuring method is therefore not completely objective. In addition, a movement of the test disk relative to the analysis unit is required for the optical measurement, whereby the described method is complicated to perform.
  • the object of the present invention is to provide an improved method for measuring blast structures on a prestressed disk and a device suitable for this purpose.
  • the method is intended to provide an objective, quantitative measure of the extent of the blast structures and to be simple and reproducible.
  • the object of the present invention is achieved by a method for measuring Blas Quilten a prestressed disc, wherein at least
  • At least one analysis region of the slice is irradiated with linearly polarized light of a radiation source at an angle of incidence ⁇ ⁇ and at least one detector captures an image of at least the analysis region at an observation angle ⁇ ⁇ ,
  • the disc has a first surface and a second surface and the peripheral side edge. In the installed position, the intended viewing through the pane takes place through the first and the second surface.
  • the first surface is that surface of the disc which faces the radiation source.
  • the first surface of the disc is irradiated with the light of the radiation source. This means, in the context of the invention, that the light hits the first surface and then the second surface of the disk, which faces away from the light source, as it passes through the disk.
  • the analysis area of the disk is thus irradiated according to the invention over the first surface of the disk with the light of the radiation source.
  • prestressed disc also includes partially prestressed discs
  • a prestressed disc in the narrower sense typically has surface compressive stresses of 85 MPa to 140 MPa and tensile stresses in the core of 40 MPa to 60 MPa
  • a partially prestressed disc typically has surface compressive stresses of 24 MPa to 52 MPa.
  • an arrangement for measuring blast structures of a prestressed disc at least comprising:
  • a radiation source which irradiates at least one analysis region of the disk with linearly polarized light at an angle of incidence ⁇ ⁇ ,
  • At least one detector which takes an image at least of the analysis area at an observation angle ⁇ ⁇ and
  • an evaluation unit which receives the image, reads out a brightness course along an analysis line on the image, determines the local maxima and the local minima of the brightness curve and an intensity index l B s by the difference between a mean brightness value M max of the local maxima and a mean brightness value M min of local minima.
  • Parallel polarized radiation components are reflected on passing through a disk to a lesser extent on the surfaces of the disk than perpendicularly polarized radiation components.
  • the inhomogeneous stress distribution in the disk produced in the bias process leads to a location-dependent interaction of the light with the disk (Paul Chagnon: "Optics for People Stuck in Traffic: Stress Patterns", The Physics Teacher 32 (1994), p. 166f.
  • the location-dependent intensity of the reflected and / or transmitted light is captured by the detector in the form of an image and analyzed quantitatively in the sequence.
  • the method according to the invention for the measurement of blister structures provides an objective and reproducible quantitative measure of the extent of the blast structures, which are caused by the inhomogeneous distribution of the stresses. Since at least the entire analysis area is irradiated by the radiation source and detected by the detector, no movement of the disc is required, whereby the method is easy to perform.
  • the irradiation of the analysis area according to the invention over the pane surface has decisive advantages over the irradiation over the side edge.
  • the method of the invention is applicable to a much wider variety of panes.
  • the method is particularly applicable to discs in Motor vehicle area applicable, which are typically curved and have a ground, in particular turbid side edge. With such disks, irradiation of the analysis area over the side edge is not possible.
  • the areas where no rotation of the plane of polarization of the light occurs are stress-free areas or areas having the same principal amounts.
  • the areas where rotation of the plane of polarization occurs are the areas of unequal principal stresses, and the extent of rotation of the plane of polarization depends on the difference of the principal stresses.
  • the analysis area is an area of the pane for which the brightness curve is to be determined in the method according to the invention.
  • the analysis area is thus the smallest possible area which has to be irradiated by the light of the radiation source and from which an image has to be taken by the detector in order to be able to carry out a desired analysis of the blast structures.
  • the analysis area has a first surface that is an area of the first surface of the disk.
  • the analysis area has a second surface which is an area of the second surface of the disk.
  • the thickness of the analysis area corresponds to the thickness of the disc.
  • the analysis area according to the invention is preferably arranged in the middle of the pane.
  • the first surface of the analysis area is then located in the center of the first surface of the disk and the second surface of the analysis area is located in the center of the second surface of the disk.
  • the geometric center of the first surface of the analysis area corresponds approximately to the geometric center of the first surface of the disk and that the geometric center of the second surface of the analysis area corresponds approximately to the geometric center of the second surface of the disk.
  • the size of the analysis area is suitably chosen so that it comprises a sufficient number of blast structures, ie a sufficient number of areas with different reflectance ("light” and "dark” areas).
  • the analysis area has, for example, a length and width of 30 cm.
  • the analysis area can also be chosen significantly larger.
  • the analysis area can in principle also include the entire pane.
  • the radiation source irradiates at least the analysis area of the pane.
  • the radiation source may irradiate a larger area of the disk containing the analysis area.
  • the radiation source can, for example, irradiate the entire pane.
  • the detector records an image of at least the analysis region of the disk.
  • the detector can also take an image of a larger area of the disk containing the analysis area.
  • the light of the radiation source is linearly polarized.
  • linear polarization the direction of the oscillation of the electric field is constant.
  • the magnitude and sign of the electric field change periodically.
  • the excellent vibration direction is called a polarization direction.
  • the light of the radiation source is preferably parallel polarized (p-polarized) or predominantly p-polarized with respect to the first surface of the disk.
  • P-polarized means that the direction of polarization when the radiation hits the disk is in the plane of incidence. The plane of incidence is clamped by the incident vector and the surface normal of the disc at the point where the radiation hits the disc.
  • the particular advantage of p-polarized light is its lower reflection compared to perpendicular polarized (s-polarized) light. The p-polarized light is reflected to a lesser extent at the first surface. In regions of the disk in which a rotation of the polarization direction occurs, the perpendicularly polarized radiation component is increased, which is reflected at the second surface amplified.
  • the direction of polarization may, to a certain extent, slightly deviate from the ideal p-polarization, for example by an amount of 0 ° to 10 °.
  • the method according to the invention can also be carried out with s-polarized light or with light which contains p-polarized and s-polarized radiation components.
  • the location-dependent rotation of the polarization direction leads in these cases to a location-dependent reflectance and thus to a brightness pattern of the total of the disc reflected and / or transmitted light, which can be used for an inventive analysis of Blas Modellen.
  • the pane whose blast structures are to be measured may be flat, as is customary in particular in the field of architecture, for example in the access or window area.
  • the disc may be slightly or strongly bent in one direction or in multiple directions of the space.
  • Such curved windows occur in particular for glazing in the vehicle area.
  • Typical radii of curvature of the curved discs are in the range of about 10 cm to about 40 m. The radius of curvature need not be constant over the entire disk, there may be stronger and less curved portions in a disk.
  • the disc is preferably bent.
  • the inventive method can be advantageously applied to such curved discs.
  • the disc preferably has a ground, in particular opaque, ground side edge.
  • the entire surface of the side edge is preferably trimmed turbid.
  • the disc is in an advantageous embodiment of the invention, a vehicle window.
  • the vehicle window is preferably bent and has a dull ground edge.
  • the direction of the surface normal within the surface of the analysis area is location dependent.
  • the orientation of the plane of incidence can also be location-dependent.
  • the geometric center of the first surface of the analysis area is usefully used.
  • the radiation is considered to be p-polarized if the direction of polarization lies in the plane defined by the Incident vector and the surface normal in the middle of the first surface of the analysis area is spanned.
  • the radiation source facing first surface of the disc may be facing the detector and / or facing away from the detector. If the first surface faces the detector, the radiation reflected by the disk as a whole is detected by the detector.
  • the detector records an image of at least the first surface of the analysis area. If the first surface faces away from the detector and the second surface thus faces the detector, then the radiation transmitted through the disk is detected by the detector.
  • the detector records an image of at least the second surface of the analysis area. In both cases, the extent of the blast structures on the image can be analyzed. It is also possible to take in each case an image of a first detector and a second detector, wherein the first surface of the disk faces the first detector and faces away from the second detector.
  • the radiation source facing the first surface of the disc faces the detector.
  • the detector detects the radiation reflected from the disk.
  • Such a reflection measurement has the advantage over a transmission measurement that it can also be applied to printed discs.
  • printed discs in particular provided with a screen printing discs, are common especially in the vehicle sector.
  • the reflectance of the linearly polarized radiation is dependent on the angle of incidence of the radiation on the surface of the disc.
  • the reflectance is the ratio of reflected radiation intensity to irradiated radiation intensity.
  • the angle of incidence is the angle between the incident vector and the surface normal of the disc at the point where the radiation hits the surface of the disc.
  • the difference between the reflectance of parallel polarized radiation and the reflectance of perpendicularly polarized radiation is particularly great when the angle of incidence ⁇ ⁇ is equal to the so-called Brewster angle. For light incidence below the Brewster angle, the reflectance for p-polarized radiation is ideally zero.
  • the angle of incidence ⁇ ⁇ is location-dependent.
  • the geometric center of the first surface of the analysis area is usefully used.
  • the angle of incidence ⁇ ⁇ according to the invention is preferably measured in the middle of the first surface of the analysis area.
  • the angle of incidence ⁇ ⁇ is preferably from 20 ° to 70 °, particularly preferably from 40 ° to 65 °, very particularly preferably from 55 ° to 60 °, in particular about 57 °.
  • the difference between the reflectance of p-polarized light and the reflectance of s-polarized light is particularly large, and the brightness pattern caused by the blast structures is particularly advantageous.
  • the specified ranges for the angle of incidence ⁇ ⁇ are particularly advantageous when the light reflected from the disc is detected by the detector. If the light transmitted through the pane is detected by the detector, then the angle of incidence ⁇ ⁇ can also be, for example, from 0 ° to 20 °, preferably from 0 ° to 10 °, in particular approximately 0 °.
  • the radiation source is preferably a planar radiation source.
  • This is understood to mean a radiation source which emits light via a radiating surface, and which can not be regarded as a point radiation source relative to the dimensions of the pane.
  • Such an approximate point radiation source is, for example, a laser or a light bulb.
  • the emission surface of the planar radiation source can have, for example, a size of at least 0.5 m 2 or at least 1 m 2 .
  • the emission surface of the planar radiation source can in principle be bent, but in a particularly preferred embodiment it is flat. Then the propagation direction of the light is constant over the emission surface. As a result, the entire analysis region of the disk surface can advantageously be irradiated with radiation of the same propagation direction.
  • the radiation source very particularly preferably comprises at least one so-called polarization wall.
  • a polarization wall comprises at least one, typically a plurality of primary radiation sources, for example a plurality of fluorescent tubes arranged parallel to one another, behind a strongly scattering glass pane, typically an opal glass pane. At the Passing through the scattering glass is generated from the radiation of the primary radiation sources, a flat, unpolarized radiation.
  • a planar polarizing filter on the side facing away from the primary radiation sources side of the diffusing glass pane linearly polarized radiation is generated.
  • the radiation source preferably radiates radiation in the visible spectral range.
  • this is advantageous because of the simple availability of suitable radiation sources and detectors.
  • a disturbing effect of the blast structures for a viewer occurs in the context of visible light, so that the use of visible light for the quantitative measurement of Blasregalen makes sense.
  • the light of the radiation source does not have to cover the entire visible spectral range.
  • the radiation of the radiation source does not have to be limited to the visible spectral range.
  • the radiation of the radiation source may contain radiation components from other spectral regions, for example I radiation and / or UV radiation.
  • the detector preferably comprises a camera with a two-dimensional image sensor, for example a CCD sensor or an active pixel sensor (APS sensor, CMOS sensor). Due to better availability and lower cost, a camera with a CCD sensor is preferred.
  • the two-dimensional image sensor it is advantageously possible to take a picture of at least the entire analysis area. Of course, the image is taken while the disc is irradiated with light by the radiation source.
  • the detector may comprise further optical elements, for example optical filters such as gray filters or color filters.
  • the detector is preferably arranged such that the radiation reflected at the disk or transmitted through the disk is optimally detected.
  • the detector is aligned to an excellent location on the surface of the disk facing the detector. If the detector is a camera, the objective is preferably focused on the excellent location.
  • the observation angle ⁇ ⁇ is then the angle between on the one hand the connecting line between the detector and the marked spot and on the other hand the surface normal of the disk at the marked spot. As excellent Place on the surface of the disc is usefully chosen the geometric center of the surface of the analysis area, which faces the detector.
  • the observation angle ⁇ ⁇ is preferably from 20 ° to 70 °, more preferably from 40 ° to 65 °, most preferably from 55 ° to 60 °, in particular about 57 °.
  • the observation angle ⁇ ⁇ is preferably equal in magnitude to the angle of incidence ⁇ ⁇ or deviates only slightly from the angle of incidence ⁇ ⁇ , for example by an amount of 0 ° to 10 °. If the first surface of the disk faces the radiation source and the detector, the radiation source and the detector are preferably arranged opposite one another with respect to the surface normal in the geometric center of the first surface of the analysis region. Then, the reflected light can be detected particularly advantageous.
  • the radiation source facing first surface of the disc is preferably the outer surface of the disc. With outer surface while the surface of the disc is referred to, which is intended to be facing in installation position of the disc of the external environment of a space bounded by the disc. If the pane is, for example, a motor vehicle window, then the outer surface, in the installed position, faces the outer environment and faces away from the interior of the motor vehicle.
  • the image is preferably shot against a black or dark background. Then the Blas Jardin are particularly advantageous to recognize. Particularly preferred method of the invention is carried out in a darkened room, wherein the radiation source is the only light source.
  • the evaluation unit preferably comprises at least one computer with image analysis software which is suitable for reading out the brightness value of each pixel (pixel) of the image recorded by the detector.
  • the image recorded by the detector is fed to the evaluation unit according to the invention. This can be done via a direct connection between the detector and the evaluation unit, for example via a cable or a wireless connection.
  • the transmission of the image can take place automatically or be initiated by a command of the user.
  • the image can be the evaluation unit but also be supplied by other suitable means, for example via a server or a storage medium.
  • the blast structures can be seen as patterns of darker and brighter areas.
  • the disk is typically loaded with a stream of air from a plurality of parallel rows of nozzles.
  • the pattern of the darker and lighter areas is caused by the arrangement of the nozzles.
  • the lighter areas on the image are therefore typically arranged along mutually parallel lines.
  • the evaluation unit according to the invention the brightness characteristic is read out along an analysis line.
  • the analysis line is preferably chosen such that it passes through a group of bright areas arranged on the same of the lines running parallel to one another.
  • the analysis line preferably runs centrally through the bright areas.
  • the image taken by the detector can be processed in the usual way before the analysis of the brightness curve.
  • the data volume and / or the image dimensions can be reduced electronically, for example.
  • the brightness curve in the context of the invention is a plot of the determined brightness value against the position along the analysis line, which can be expressed for example by an arbitrary length scale (for example a numbering of the successive pixels).
  • the brightness progression along the analysis line shows a wave-like progression with a sequence of local maxima (center of the bright areas in the picture) and local minima (center of the dark areas in the picture).
  • the position of the local maxima and minima is identified and the respective brightness value is read out.
  • the identification of the local maxima and minima preferably takes place automatically by means of a suitable algorithm, but can also be done manually.
  • the data of the brightness curve can be smoothed before the analysis of the local maxima and minima by a suitable algorithm.
  • the analysis area is preferably selected such that the brightness profile contains at least 3 local maxima.
  • the analysis range is particularly preferably chosen such that the brightness profile is from 5 to 20, very particularly preferably from 8 to 15 local Contains maxima. This is particularly advantageous with regard to a reliable and reproducible measurement of the blowing structures on the one hand and a time-saving evaluation of the measurement on the other hand.
  • a first mean value is formed, which in the sense of the invention is referred to as the mean brightness value M max of the local maxima.
  • a second mean value is formed, which in the meaning of the invention is referred to as the brightness mean value M min of the local minima.
  • the brightness average values M max and M min are preferably obtained as an arithmetic mean. In principle, however, other averages can also be used if they appear to be appropriate to the person skilled in the art, for example the geometric mean, the harmonic mean or the quadratic mean.
  • the magnitude difference between the mean brightness value M max of the local maxima and the mean brightness value M min of the local minima is referred to in the sense of the invention as the intensity index l B s of the blowing structures.
  • the intensity index l B s is a quantitative and objective measure of the extent of the blast structures. Large values of the intensity index l B s indicate a large difference in the reflectance in the bright areas compared to the dark areas and thus on pronounced blazed structures. Small values of the intensity index l B s indicate a small difference in the reflectance in the light areas compared to the dark areas and thus less pronounced blast structures.
  • different disks can be compared quantitatively with respect to the extent of the blowing structures. Due to the objectivity and reproducibility of the method according to the invention, the measurements to be compared on different panes can also take place with a certain time interval.
  • the preferably planar radiation source is arranged vertically.
  • the surface over which the radiation of the light takes place is arranged vertically, ie at an angle of approximately 90 ° to the horizontal.
  • the blast structures can be observed particularly well when the disk is arranged at an angle to the horizontal which is at most 15 °, preferably at most 5 ° deviates from the angle of the polarization direction of the light of the radiation source to the horizontal.
  • the angle to the horizontal, in which the disc is arranged corresponds to the angle of the polarization direction of the light of the radiation source to the horizontal.
  • the angle to the horizontal, in which the disc is arranged, and the angle of the polarization direction of the light of the radiation source to the horizontal are measured in a value range of 0 ° to 90 °. If a polarization wall as a radiation source has, for example, a polarization direction which is arranged at an angle of approximately 45 ° to the horizontal, then the blast structures can be observed particularly well if the pane is at an angle of 30 ° to 60 °, preferably 40 ° is arranged to 50 ° and in particular about 45 ° to the horizontal. In the case of curved disks, for example, the tangential plane in the middle of the analysis region can be used to assess the angle to the horizontal.
  • the disc can be arranged in a suitable holder, which allows a safe and reproducible positioning of the disc.
  • the detector may be positioned on a tripod or other suitable fixture.
  • the relative arrangement of disk and detector can be done for example via ground markings.
  • the holder of the detector and the holder of the disc may alternatively be permanently connected to each other, for example on a common frame. This advantageously achieves a reproducible relative arrangement of the disk and detector that can be generated quickly and easily.
  • the reproducible relative alignment of the radiation source and the disc can be done, for example, by means of ground markings.
  • the radiation source and the holder of the disc and / or the detector can also be stably connected to each other.
  • the pane preferably contains glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass and / or soda-lime glass.
  • the thickness of the disc can vary widely and so perfectly adapted to the requirements in each case.
  • the thickness of the disc is preferably from 1, 0 mm to 25 mm and particularly preferably from 1, 4 mm to 5 mm.
  • the size of the disc can vary widely and depends on its intended use.
  • the pane has, for example, in the automotive and architectural field common areas of 200 cm 2 to 20 m 2 .
  • the disk can be largely transparent and, for example, have a total transmission of greater than 70%.
  • the disk can also be colored and / or tinted and, for example, have a total transmission of less than 50%.
  • the term total transmission refers to the method defined by ECE-43, Annex 3, ⁇ 9.1 for testing the transparency of vehicle windows.
  • the invention further includes the use of the arrangement according to the invention for the quantitative measurement of blown structures on prestressed panes, in particular for a quantitative comparison measurement of different panes.
  • the panes are preferably slices in buildings, in particular in the access or window area, in furniture and appliances, in particular electronic appliances with cooling or heating function, or in means of transport for traffic on land, in the air or on water, especially in trains , Ships and motor vehicles, such as side windows, roof windows and / or rear windows as toughened safety glass.
  • Fig. 1 is a schematic representation of the inventive arrangement for
  • FIG. 2b is a schematic representation of the image of Figure 2a
  • FIG. 3 a is a diagram of the brightness course along the analysis line in FIG. 2 a
  • FIG. 4 a is a front view of a holding device for the pane and the detector
  • FIG. 4 b is a side view of the holding device from FIGS
  • FIG. 5 shows a detailed flowchart of an embodiment of the method according to the invention for measuring bias structures of a prestressed disk.
  • Fig. 1 shows a schematic representation of the arrangement according to the invention for measuring Blas Quilten a prestressed disc 1.
  • the disc 1 is a rear window of a passenger car.
  • the disc 1 has the usual for rear windows curvature and edge grinding.
  • the pane 1 is a 3 mm thick toughened safety glass made of soda lime glass with a width of 150 cm and a height of 80 cm.
  • the disk 1 is thermally toughened and has, for example, a surface compressive stress of about 120 MPa and a tensile stress in the core of about 60 MPa. Due to the tempering process, the disc 1 has inhomogeneously distributed stresses, which lead to so-called blast structures which are optically perceptible under certain observation and light conditions as a pattern of lighter and darker areas.
  • the extent of the blowing structures can be determined quantitatively. As a result, for example, disks biased with different methods can be compared with respect to the extent of the blowing structures.
  • the inventive arrangement comprises a radiation source 2.
  • the disc 1 is bent, as is customary for rear windows.
  • the convex first surface (I) of the disc 1, which is provided in the installation position of the disc 1 as the outer surface is the Facing radiation source 2, so that the light 5 of the radiation source 2 when passing through the disc 1 first on the first surface (I) meets.
  • the radiation source 2 is a polarization wall.
  • the polarization wall comprises a plurality of parallel arranged fluorescent tubes behind an opal glass pane and a planar polarizing filter on the side facing away from the fluorescent tubes side of the opal glass pane.
  • the radiation source 2 linearly polarized white light 5 is emitted in the visible spectral range over a radiating surface with a height of 150 cm and a width of 200 cm.
  • the planar radiation source 2 By the planar radiation source 2, the entire surface (I) of the disc 1 is illuminated, less any shaded areas.
  • an analysis area 4 is completely irradiated.
  • the analysis area 4 is provided for the evaluation of the measurement of blast structures.
  • the analysis area 4 has, for example, a length and width of 30 cm and is arranged approximately in the geometric center of the pane 1.
  • the analysis area 4 has a first surface which is an area of the first surface (I) of the disk 1, the first surface of the analysis area 4 being located in the geometric center of the first surface (I) of the disk.
  • the analysis area 4 has a second surface which is an area of the second surface (II) of the disk 1, the second surface of the analysis area 4 being located in the geometric center of the second surface (I) of the disk.
  • the light 5 of the radiation source is polarized parallel with respect to the surface (I).
  • the oscillation direction of the electromagnetic waves described by the polarization vector 12 lies in the plane of incidence 1 1, which is spanned by the incident vector of the light 5 and the surface normal 10 of the surface (I).
  • Parallel polarized light is reflected less strongly on the surfaces of the pane 1 than perpendicularly polarized light. This effect is particularly pronounced when the angle of incidence ⁇ ⁇ corresponds approximately to the Brewster angle.
  • the Brewster angle for an air-glass transition is about 57 ° and the angle of incidence ⁇ ⁇ is chosen accordingly.
  • the direction of the surface normal 10 within the analysis area 4 is location-dependent.
  • the surface normal 10 in the geometric center of the first surface of the analysis region 4 is used.
  • the reflected light from the disk 1 13 has a location-dependent intensity. The reason for this are inhomogeneously distributed stresses in the disk 1 produced by the tempering process. These stresses lead to a location-dependent rotation of the polarization vector 12 as it passes through the disk 1. If the polarization vector 12 is not rotated, parallel polarization strikes the surface (II ) of the disc 1, which faces away from the radiation source 2.
  • the light 5 is only slightly reflected on both surfaces (I) and (II), and the intensity of the total light 13 reflected by the pane 1 is small. If the polarization vector 12 is rotated, the light 5 strikes the surface (II) with an increased perpendicularly polarized radiation component, which is reflected significantly more strongly than parallel polarized light. The intensity of the total reflected light from the disc 1 13 is thereby increased, the reflectance of the extent of rotation of the polarization vector 12 is dependent. As a result of the inhomogeneously distributed stresses in the disk 1, the reflected light 13 thus forms a pattern of darker and brighter areas.
  • the arrangement according to the invention further comprises a detector 3.
  • the surface (I) of the pane 1 facing the radiation source 2 also faces the detector 3.
  • the detector 3 is a camera with a CCD sensor.
  • the pattern of the location-dependent intensity of the reflected light 13 is detected by the detector 3.
  • a photograph is taken, which images at least the analysis area 4, but typically a larger area of the pane 1.
  • the camera is aligned and focused on the center of the first surface of the analysis area 4.
  • the observation angle ⁇ ⁇ is about 60 °, for example, and is thus selected near the Brewster angle.
  • the pattern of the location-dependent intensity of the re-rectified light 13 can be detected particularly well.
  • the inventive arrangement further comprises an evaluation unit 7.
  • the evaluation unit 7 is connected for example via a connecting cable 14 to the detector 3. Via the connecting cable 14, the photograph is transmitted from the detector 3 to the evaluation unit 7.
  • the evaluation unit 7 is a computer with suitable image analysis software which can read the brightness value of each pixel of the photograph.
  • FIG. 2 a shows a detail (707 ⁇ 480 pixels) of an image 6, which depicts the analysis area 4, more precisely the first surface of the analysis area 4.
  • the image 6 is a photograph and was taken by the camera as the detector 3 in the arrangement of FIG.
  • the camera as detector 3 was a Canon EOS 30D digital SLR with a Canon EF-S 18-55 mm lens.
  • the blast structures are clearly visible as a pattern of bright areas against a dark background.
  • the bright areas are arranged along mutually parallel lines.
  • the pattern results from the arrangement of the nozzles, with which the disc 1 was subjected during pretensioning with an air flow.
  • the figure further shows an analysis line 9.
  • the analysis line 9 runs along one of the lines arranged parallel to one another, along which the bright areas are arranged.
  • the analysis line 9 is chosen so that it runs approximately centrally through the bright areas.
  • the brightness profile of the image 6 along the analysis line 9 is used to quantify the blazed structures.
  • FIG. 2b shows a schematic representation of the image 6 from FIG. 2a.
  • the bright areas in front of the dark background and the analysis line 9 can be seen.
  • FIG. 3 shows a diagram of the brightness curve 8 along the analysis line 9 on the image 6 of FIG. 2a.
  • the analysis area 4 and the analysis line 9 are selected so that eleven of the bright areas are covered.
  • the generation and analysis of the brightness curve 8 takes place in the evaluation unit 7.
  • the brightness curve 8 was created by means of an image evaluation software which reads out the brightness value (RGB color space, 256 brightness levels) of each pixel along the analysis line 9.
  • the brightness curve 8 shows a wave-like profile with eleven local maxima 15 and eleven local minima 16. From the brightness values of the local maxima 15, the arithmetic mean is formed, and thus the mean brightness value M max of the local maxima 15 is determined.
  • the mean brightness value M max in the example shown is 177, the mean brightness value M min is 96.
  • the absolute difference between the mean brightness value M max and the mean brightness value M min is referred to in the context of the invention as intensity index l B s.
  • the intensity index I B s is on quantitative measure of the extent of blast structures.
  • the intensity index l B s is 81 in the example shown. The lower the value of the intensity index l B s, the lower the average brightness difference between the bright area and the dark areas on the image 6, and the more uniform the overall reflection of the pane appears.
  • comparison disks can be compared with respect to the visibility of the blowing structures.
  • the brightness curve 8 has a decreasing tendency in the example shown.
  • the reason for this is the bending of the disk 1, which leads to a location-dependent direction of the surface normal 10 within the analysis area 4.
  • the brightness mean values M max and M min nevertheless provide a meaningful intensity index l B s, by means of which comparison disks can be compared with one another, in particular if the comparison disks have an identical or similar bend. For example, discs of the same type that have been biased in different ways can be compared.
  • the measurements were carried out under identical boundary conditions on a reference disk 1.
  • the measurements provided an average for the intensity index I BS of 84 with an empirical variance of 0.5.
  • the intensity index I BS is thus a highly reproducible measure of the blast structures.
  • FIGS. 4a and 4b each show a detail of a suitable holding device 17 for the pane 1 and the detector 3.
  • the holding device 17 comprises a pane holder 18, a detector holder 24 and a positioning stop 23, which are arranged on a common frame 19.
  • the holding device 17 advantageously achieves a stable and reproducible relative arrangement of the pane 1 and the detector 3. As a result, a constant observation angle ⁇ ⁇ is ensured in a comparison measurement .
  • the frame 19 is mounted on rollers 26, with which the holding device 17 can be easily moved, for example, for orientation relative to the light source 2.
  • the positioning stop 23 allows a reproducible arrangement of the disc 1 on the disc holder 18, if in a comparison measurement different discs 1 of the same type to be examined.
  • the disc holder 18 includes a horizontal base member 20 on which a support member 22 and two holding forks 21 are arranged. The lower edge of the disc 1 is inserted into the holding forks 21 and the disc 1 is leaned against the support member 22. The arrangement of the disc 1 is permanently stable and reproducible.
  • the base member 20 is connected via two hinges 25 to the frame 19. Thereby, the disc holder 18 can be tilted and the angle between the disc 1 and the horizontal can be adjusted. The desired angle is thereby permanently adjusted by means of an angle fixing 27 arranged on the side of the support element 22 facing away from the disk 1.
  • the angle fixing 27 is, for example, a metal rail in the form of a circular arc segment whose center of the circle is arranged on the connecting line between the hinges 25.
  • the metal rail has a recess which extends parallel to the circular arc-segment-shaped edges and through which a screw connected to the Ge Mother 19 is guided. If the screw is released, the disc holder 18 can be tilted, the screw slides through the recess of the Winkelfix ist 27. In the desired position of the disc holder 18, the screw is tightened and disc holder 18 thus permanently fixed stable.
  • FIG. 5 shows a flow chart of an exemplary embodiment of the method according to the invention for measuring blast structures on a prestressed disk 1.

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Abstract

L'invention concerne un procédé de mesure de structures de soufflage d'une vitre précontrainte (1), selon lequel au moins (a) au moins une zone d'analyse (4) de la vitre (1) est irradiée par une lumière polarisée linéaire (5) d'une source de rayonnement (2), sous un angle d'incidence (θE) et, par l'intermédiaire d'au moins un détecteur (3), une image (6) d'au moins la zone d'analyse (4) est reçue sous un angle de vision (θA), (b) l'image (6) d'une unité d'évaluation (7) est transmise, et (c) au moyen de l'unité d'évaluation (7), (c1) une courbe de luminosité (8) est relevée le long d'une ligne d'analyse (9), sur l'image (6), (c2) les maxima locaux (15) et les minima locaux (16) de la courbe de luminosité (8) sont déterminés, et (c3) un indice d'intensité (IBS) est déterminé par la différence entre une valeur moyenne de luminosité (Mmax) des maxima locaux, et une valeur moyenne de luminosité (Mmin) des minima locaux.
EP13714948.0A 2012-04-23 2013-04-10 Procédé et dispositif de mesure de structures de soufflage d'une vitre précontrainte Withdrawn EP2841932A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP13714948.0A EP2841932A1 (fr) 2012-04-23 2013-04-10 Procédé et dispositif de mesure de structures de soufflage d'une vitre précontrainte

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP12165122 2012-04-23
PCT/EP2013/057469 WO2013160105A1 (fr) 2012-04-23 2013-04-10 Procédé et dispositif de mesure de structures de soufflage d'une vitre précontrainte
EP13714948.0A EP2841932A1 (fr) 2012-04-23 2013-04-10 Procédé et dispositif de mesure de structures de soufflage d'une vitre précontrainte

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EP (1) EP2841932A1 (fr)
JP (1) JP2015515631A (fr)
KR (1) KR20140132773A (fr)
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WO (1) WO2013160105A1 (fr)

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DE202013008910U1 (de) * 2013-10-07 2015-01-09 MÖLLER-WEDEL OPTICAL GmbH Vorrichtung zum Vermessen von Scheiben, insbesondere von Windschutzscheiben von Fahrzeugen
JP6290651B2 (ja) * 2014-02-27 2018-03-07 株式会社キーエンス 画像測定器
JP6278741B2 (ja) * 2014-02-27 2018-02-14 株式会社キーエンス 画像測定器
DE102016114485A1 (de) 2016-08-04 2018-02-08 Isra Surface Vision Gmbh Vorrichtung und Verfahren zur Bestimmung eines Doppelbildwinkels und/oder eines Sichtwinkels
DE102018122391A1 (de) * 2018-09-13 2020-03-19 Sikora Ag Vorrichtung und Verfahren zum Detektieren eines Gegenstandes
KR102237593B1 (ko) * 2020-03-19 2021-04-07 비전코웍 주식회사 글라스 표면 검사용 광학 장치
CN113267145B (zh) * 2021-05-12 2023-01-17 无锡先导智能装备股份有限公司 卷绕机极片入料控制方法、装置、电子设备及存储介质

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1175776B (it) * 1984-02-13 1987-07-15 Siv Soc Italiana Vetro Apparecchiatura per la misurazione automatica di tensioni in un corpo trasparente mediante luce diffusa
JPH0628659Y2 (ja) * 1988-12-19 1994-08-03 東芝硝子株式会社 光弾性測定装置
JP2600461B2 (ja) * 1990-06-18 1997-04-16 三菱電機株式会社 トルク測定方法
WO1994008229A1 (fr) * 1992-09-29 1994-04-14 The University Of Queensland Detection de defauts dans le verre
TW251350B (fr) * 1993-10-26 1995-07-11 Asahi Chemical Ind
US6067155A (en) * 1997-12-24 2000-05-23 Owens-Brockway Glass Container Inc. Optical inspection of transparent containers using infrared and polarized visible light
JPH11316195A (ja) * 1998-04-30 1999-11-16 Asahi Glass Co Ltd 透明板の表面欠陥検出装置
US5969810A (en) * 1998-05-14 1999-10-19 Owens-Brockway Glass Container Inc. Optical inspection of transparent containers using two cameras and a single light source
JP5334005B2 (ja) * 2001-04-27 2013-11-06 旭硝子株式会社 強化ガラス板
JP4679313B2 (ja) * 2005-09-14 2011-04-27 株式会社沖データ 表面平滑性測定装置
EP2282186B1 (fr) * 2009-08-05 2015-09-09 Emhart Glass S.A. Mesure de la contrainte d'un récipient en verre au moyen de fluorescence
BE1019378A3 (fr) 2010-06-17 2012-06-05 Agc Glass Europe Analyse des marques de trempe.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2013160105A1 *

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KR20140132773A (ko) 2014-11-18
JP2015515631A (ja) 2015-05-28
CN104272091A (zh) 2015-01-07
US9207186B2 (en) 2015-12-08
WO2013160105A1 (fr) 2013-10-31
US20150036120A1 (en) 2015-02-05

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