WO2016015833A1 - Détection optique de défauts - Google Patents

Détection optique de défauts Download PDF

Info

Publication number
WO2016015833A1
WO2016015833A1 PCT/EP2015/001462 EP2015001462W WO2016015833A1 WO 2016015833 A1 WO2016015833 A1 WO 2016015833A1 EP 2015001462 W EP2015001462 W EP 2015001462W WO 2016015833 A1 WO2016015833 A1 WO 2016015833A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensor
defect
detector
detector elements
pin
Prior art date
Application number
PCT/EP2015/001462
Other languages
German (de)
English (en)
Inventor
Wolfram Aumeier
Original Assignee
Brückner Maschinenbau GmbH & Co. KG
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 Brückner Maschinenbau GmbH & Co. KG filed Critical Brückner Maschinenbau GmbH & Co. KG
Publication of WO2016015833A1 publication Critical patent/WO2016015833A1/fr

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
    • G01N21/89—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
    • G01N21/894—Pinholes
    • 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
    • G01N21/8901—Optical details; Scanning details
    • 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
    • G01N21/8901—Optical details; Scanning details
    • G01N21/8903—Optical details; Scanning details using a multiple detector array

Definitions

  • the invention relates to an optical detection method for measuring defects (defects) in and on materials.
  • the measuring technology can be used to cover applications on a wide variety of moldings, but especially on material webs (polymer or metal foils, paper or textile webs), coatings and permeable or porous materials.
  • a special application of measurement technology relates to so-called separator films and membranes.
  • Defect detection systems are widely represented in the market (Schenk, OCD, ISRA, Futec, etc.).
  • a moving object is illuminated with a light source, usually an LED line source, and the re-inflected or transmitted light is detected by means of a line camera, usually a CCD or CMOS array, via a photo-optic system. If a defect occurs, there is a deviation in the gray values compared to a reference. The analysis of the measured values then takes place against faulty patterns from a teaching procedure.
  • the resolution of the conventional detection systems depends on the working width (AB) - with moving material webs such as plastic films in the transverse direction (TD) transverse to the withdrawal direction of the material web - the number and size of the Arraypixel or the number of cameras used, and in Direction of the web (MD) from the clock frequency of the array.
  • Teledyne cameras with a pixel size (pitch) of 3.5 m, 16 k pixels and a line rate of up to 140 kHz are currently available on the civil market.
  • the method is suitable for high-contrast defects and materials with different optical properties between base material and defect.
  • the material or web should not absorb or scatter too much.
  • defects greater than or equal to 50 m are measured by the method, in the experimental range the limit is currently 14 ⁇ m, the defects themselves are qualified with synchronized microscopy.
  • Small signal changes such as microholes, porosities or micro-scratches in front of a strongly transmitting or scattering background, may occur due to overloading of the array elements. can not be detected.
  • the biggest problem is the diffraction of the very small imperfections (below 50 ⁇ m), which leads to the fact that the intensity distribution of the Airy pattern decreases sharply and is no longer detectable before the background signal.
  • the image brightness is proportional to the diameter of the pinhole to the fourth power. At half the diameter, the amount of light drops four times, and the area of the diffraction disk increases fourfold. The luminous flux density is thus 16 times lower in the pixel.
  • reading devices from scanning devices (WO 2002/73 173, DE 38 50 871, DE 101 24 943) are known in which a Long contact image sensor (CIS contact image sensor) is in one or almost in contact with the material or web. Frequently, a micro-optic (GRIN, etc.) is applied between the web and the line sensor in order to facilitate or improve the adjustment and focusing.
  • CIS contact image sensor Long contact image sensor
  • GRIN, etc. micro-optic
  • the resolution in the transport direction depends on the readout rate (readout speed - line rate l_r) and the speed of the object v or the defect. Assuming that defects of 7 [ ⁇ ] are to be detected, this is possible with a read rate of 70 [kHz] (line rate - raster time approx. 14 [ ⁇ ]) up to MD speeds of 30 [m / min] ( Figure 14).
  • a defect at time t0 in the transverse or TD direction is imaged over at least one, but usually over several pixels as a gray value over the line array.
  • line rate sampling or read-out rate
  • another gray value pattern is mapped.
  • the superimposition of the pattern can detect the defect and the defect position in the machine direction and transverse direction at least as long as the read rate (line rate) is faster than the take-off speed of the web. Each pixel is thus read out at the read rate (line rate).
  • FIG. 16 a representation of the maximum resolution [pm] in the transverse direction in relation to the scanning region in [mm] is shown, specifically with regard to the four variants
  • A resolution in TD direction [ ⁇ ] with 2048 [pixel] camera
  • B resolution in TD direction [ ⁇ ] with 4096 [pixel] camera
  • C resolution in TD direction [ ⁇ ] with 8192 [pixel] camera
  • D Resolution in TD direction [ ⁇ ] with 16384 [pixel] camera
  • the pitch size ie the distance measure
  • a particular work area ABa is mapped onto a single sensor Rr. Many of these individual detectors Rr are then lined up along the working width (AB) in succession or overlapping. For example, several defects within ABa occur at the same time, then the signal height increases correspondingly at the Rr.
  • the carrier material that is to say the material web
  • the defect detection largely depends on the sensitivity of the sensor.
  • the background signal is amplified or detected in addition to the defect signal, so that the signal is difficult to separate from the background.
  • the simplest arrangement is when the object, in particular a web, is transparent only for defects, or reflect only the defects in light or dark field arrangement. Then there is a good contrast ratio and the detection limit is determined by the size and properties of the defect, the withdrawal speed and the bandwidth of the detection.
  • the material or material web is, for example, an aluminum foil or a light-permeable material web coated with aluminum, then, for example, visible light is absorbed.
  • Defects in the form of, for example, micro-holes can then theoretically be detected up to the resolution limit of the light used.
  • the practical problem is to distinguish the low signal of the microhole (pinhole) from the noise signal. If the difference is large enough, the pinhole signal can be clearly distinguished by mathematical methods. However, if diffraction or scattering occurs at the defect, no differentiation is possible, even if the irradiated intensity is greatly increased.
  • the main problem with prior art line systems is that the Airy pattern is mapped onto many cells, and thus from noise and background. background signal can no longer be distinguished.
  • the geometric image of the defect on the detector via a focus optics which collects the entire room light and contributes to the noise signal or background signal.
  • FIG. 17 reproduces a background / noise signal RS (not proportional to its size), and at a measuring point a defect point signal DS which only slightly protrudes, which is shown again separately in FIG.
  • the invention is based on a system and a method for the measurement of defects in order to: increase the bandwidth BW of the sensor in the MD drawing direction of the material web, and thus to increase the take-off speed;
  • the defect scans the beam waist (2w0) of a focused line laser L.
  • This convolution together with the high bandwidth of the scanning sensor and the knowledge of the take-off speed, gives a signal which makes it possible to draw conclusions about the type of defect, the shape and size.
  • a referencing of the measurement signal relative to the background signal during operation is possible.
  • a referencing is made, for example, with respect to a defect-free object 1 in a certain range.
  • This background signal is then electronically referenced. If the optical properties of the substrate change during operation, the actual defect signal can not be detected.
  • FIG. 1 shows a schematic plan view with respect to a measuring arrangement provided in the context of the invention for detecting defect locations in a moving object, in the form of a material web in the embodiment shown;
  • FIG. 2 shows a representation of the exemplary embodiment according to FIG. 1 along the direction of the arrow 9 in FIG. 1 (omitting the rollers provided below the material web);
  • FIG. 3 shows a detail of a plan view of the exemplary embodiment according to FIG. 1 in an enlarged representation
  • FIG. 4 shows a schematic plan view of a sensor arrangement, for example using a plurality of photodiodes, which also serve to detect the background and / or scattered light signal to achieve on this basis a better result with respect to a received defect signal;
  • FIG. 5a a first schematic representation with respect to FIG
  • FIG. 5b shows a second schematic representation with respect to FIG
  • FIG. 6 shows a double-row measuring arrangement with a multiplicity of PIN photodiodes
  • FIG. 7 shows a schematic measuring arrangement in side view parallel to the object path plane
  • FIG. 8a shows a schematic enlarged fragmentary cross-sectional view parallel to the object plane, using a diaphragm device
  • FIG. 8b shows a partially plan view of the exemplary embodiment according to FIG. 8a
  • Figure 9 a schematic arrangement of obliquely
  • FIG. 10 a schematic representation with regard to the relationships and results with an inclined detector and / or sensor elements
  • FIG. 11 a representation similar to FIG. 10 with respect to a modified measurement situation
  • FIG. 12 shows a further illustration similar to FIG. 11 with regard to a further modification
  • FIG. 13 is a schematic representation of a measurement and evaluation setup using evaluation electronics
  • FIG. 14 a graph relating to the resolution in the direction of movement of the object to be examined
  • FIG. 15 shows a schematic representation of how a defect point to be examined is displaced on a moving object in order to clarify the limit values with regard to the expected defect position signal
  • FIG. 16 shows a further diagram with regard to the resolution in the transverse direction relative to the scan area.
  • FIG. 17 a partial representation of the to be determined
  • a material web 1 for example in the form of a plastic film 1
  • another object 1 is moved through a device in the direction of the withdrawal direction MD
  • MD The draw direction
  • MD Machinery Direction
  • a material web 1 in the form of a plastic film 1 "runs over two rolls 3a arranged offset from one another in the withdrawal direction MD and 3b, whose axes of rotation 3'a and 3'b are oriented transversely and in particular perpendicular to the withdrawal direction MD.
  • MD Machinery Direction
  • the withdrawal direction is abbreviated as TD by a corresponding arrow or vector MD and the transverse direction (transverse direction) extending therefrom.
  • the thickness direction th is perpendicular to the plane and thus perpendicular to the plane E of the material web 1, wherein the perpendicular to the plane extending thickness vector th is shown in Figure 1 as a circle.
  • the thickness direction is referred to as abb abbreviated.
  • One or more light sources L for example LED row elements, line lasers
  • sensor elements S are positioned above or below the material web 1 in a transmission or reflection arrangement (light or dark field arrangement) across the transverse direction TD of the material web 1. The same applies of course to other moldings, if they are to be examined accordingly.
  • FIG. 2 shows a side view of the arrangement according to the arrow illustration 9 in FIG. 1, that is to say a representation parallel to the material web plane E.
  • a light source L which may consist of one or more units, is applied to the material web 1, for example in the form of a plastic film 1 "in transmission or reflection, with both, collinear, in waveguide configuration or in dark field configuration.
  • the lightwave L along the working width (preferably in the TD direction) consists of one or more individual light sources LI stacked along the AB. It can also be seen from FIG. 3 that the light source drawn there works in the form of a laser with a laser line length Llength. In other words, a plurality of such light sources and in particular lasers must be positioned side by side, ie offset transversely relative to one another, in order to cover and check the entire web width. With regard to the light sources and in particular of the laser, L or line light source L is also used to this extent by a transverse or TD light source.
  • a detection device In the transmission or reflection direction or in a dark field arrangement is also a detection device, which is also referred to below as a sensor or sensor device S.
  • This sensor device can consist of one or more units Ss, which detects the light emitted by the TD light source L and transmitted or reflected by the material web 1. in principle It is possible to reference the light emitted by the laser and the transmitted light against each other, or to an additional light source.
  • the assignment of the defect in the direction of rotation via a timing and / or sensor, which detects the MD movement of the object 1.
  • a timing and / or sensor which detects the MD movement of the object 1.
  • MD position detecting device MD-E operating in the drawing direction MD, for example in the form of a marking system, the position, i. the location or location of the detected defect or defect is detected and / or marked.
  • corresponding beam traps can be used, so that background and / or scattered radiation should be absorbed as far as possible.
  • a laser LI radiates in the normal vector of the TD-MD plane E on an object 1, and the transmitted light strikes a sensor or detector element SEs, which should consist in the imaginary experiment of five individual photodiodes PIN_A.
  • the axis of the laser should define the optical axis OA, which hits the center of the active surface SE_AF of the PIN_An.
  • a) Assuming the static case in which exactly one defect, for example a microhole 7 (pinhole), is imaged symmetrically in the middle of the active surface SE_AF of a PIN_A, in an otherwise opaque object 1. For larger defects 7, the diffraction can be neglected, and the sensor receives the light passing through the material web 1 or reflected light. So this PIN sees the max.
  • Intensity of the beam source passing through the pinhole or the intensity maximum of the diffraction is low because, for example, visible light is absorbed and the remainder of the laser radiation does not pass through the object.
  • the defect detection then largely depends on the sensitivity of the sensor.
  • the defect site 7 Due to the Airy relationship, the defect site 7 is subject to strong diffraction, the intensity returns to the fourth power of the decreasing half radius each, and the transmitted light experiences a broad spatial intensity distribution at an Airy angle AW.
  • the intensity at the PIN_An decreases sharply while the intensity of the surrounding PIN increases. Especially if the active areas of the PIN are close to each other, like eg Row arrays is the case. The farther the sensor element is from the object, the stronger the effect becomes. a) To make this simple static case detectable, the following methods can be used:
  • the distance could be reduced
  • the evaluation routine thus detects an increased signal at the two PINs compared to the other.
  • the spatial resolution in TD is determined by the size of the active area of the single sensor (e.g., the PIN or pixels). If, for example, two defects are imaged on the active area of the PIN_An, then its signal height simply increases and simulates a major defect. Remedy here creates the inventive skew of the sensors, as explained in the discussion of the dynamic cases. c) detection of a defect in the direction of withdrawal or withdrawal MD
  • a partial region of the film of the working width ABa parallel to the transverse extension TD is irradiated with a line laser of length Llength and the beam waist 2w0 in the focal plane E. If the edge of a defect enters the focus region at the speed v at the time t0 (as shown in FIG. 5a for the case of a small-sized defect location (small microhole 7 '), then the corresponding sensor element SE should provide a signal. The signal should then be detected until the defect has completely left the focus area again.
  • DP is the diameter of a detected defect 7, for example in the form of a microhole 7 1
  • v represents the relative direction of movement of the object relative to the line laser.
  • the size of the defect is then determined via the half-width of the detector signal, a mathematical deconvolution and a calibration pattern for sensor adjustment.
  • the sensor usually only responds within the beam waist 2w0, therefore it is necessary here to work with calibration patterns in a first setting (FIG. 5a). If, on the other hand, one assumes that a larger defect 7 is present with a larger micro hole 7 '(as shown in FIG. 5b), then the signal duration, the half width and also the signal height are correspondingly longer, since in this exemplary embodiment more light is propagated hits the sensor. The corresponding relationships are shown in FIG. 5b with respect to FIG. 102.
  • a thin layer 7 'of the same size is present as a defect 7, then the signal level decreases in this case because less light is transmitted.
  • a receiver signal 101 which is lower in intensity is obtained, as shown in FIG. 5b.
  • Suitable calibration patterns and teaching methods can be used to determine the type of defect, the defect size and the defect shape. e) several defects in MD and TD direction If there are several defects on a line parallel to MD, e.g. goes through OA, then the defects can be distinguished by the timing.
  • the signal can no longer be detected. So it is e.g. According to the prior art, it is possible to change the wavelength of the light source so that it meets an absorption band of the object 1, or other physical properties, e.g. Polarization properties of the object 1 exploited.
  • the intensity decreases with the fourth power of the decreasing half radius and the continuous light experiences a broad spatial intensity Airy distribution.
  • the intensity along the optical axis OA thus continues to decrease with respect to the background signal. If the intensity of the laser source also fluctuates, the signal is no longer detectable.
  • the background signal is at least from a further PIN photodiode, e.g. PIN_An + l added in the vicinity of PIN_An.
  • the referencing of at least two detector elements is used by a balancing circuit.
  • a balancing circuit As already mentioned, laser fluctuations are compensated by balanced photodiodes (Hobbs), although the principle has not hitherto been used for the detection of defect sites. With the principle circuit according to the prior art for a so-called. Balanced detection (Balanced or auto-balanced photo-diode detection), it is then possible to better resolve the defect signal from the background signal and the partial diffraction intensity. The closer the individual detection elements are to each other, the better the effect will be. In principle, both discrete photoelements such as arrays, photodiodes, CIS, etc., and position sensitive photosensitive devices (PSD position sensitive devices) with multi-channel resolution can be used.
  • PSD position sensitive photosensitive devices position sensitive photosensitive devices
  • a defect is detected at the photodiode PIN_An, then one receives, depending on the bias of the PIN, eg a positive signal.
  • the photodiode PIN_An + l detects the background signal, and returns a negative signal if this PIN is driven in reverse polarity as the PIN_An. So if there is no defect, then see the photodiodes PIN_An, n + l the same background signal, the difference between the two signals is zero. If the difference signal of PIN_An and PIN_An + l is used in a balanced detection, then even the smallest differential signals can be detected.
  • all PINs with the highest possible bandwidth are queried in parallel.
  • the evaluation routine thus detects an increased signal at the two PINs compared to the other.
  • PIN_Reference it is also possible to set a PIN_Reference. Since the individual sensor elements are arranged stacked over the AB, at least one PIN for the overlap is provided. So you see the same signal as the leading PIN, but later.
  • One of the main problems in the detection of small defects is the high background signal of the transmitting or reflecting or scattering object.
  • the aim is thus to keep the background signal as low as possible in order to be able to resolve the defect signal.
  • small defects with systems that operate at a relatively slow sampling rate can no longer detect the defects.
  • a focused line laser is selected with a laser waist, on the one hand gives a small background signal to the sensor elements, but on the other hand is still wide enough to allow the folding of the defect with the laser waist within the bandwidth of the sensor.
  • the sensor element SE S is brought close to the underside of the object, and there is a diaphragm with an opening in the order of the laser waist 2w0, attached (see Fig. 8a and 8b).
  • suitable imaging optics can also be interposed.
  • the diaphragm can be provided with an opening in the order of magnitude which corresponds at least to the laser waist 2w0.
  • each sensor sub-element e.g. of PIN_An and PIN_An + l with high bandwidth, and simultaneous difference formation of at least two PIN.
  • the difference takes place between see two series-connected PIN, which are each supplied with reverse bias (reverse biased).
  • the size of the active surface of the detector element or the optional focus optics is chosen so that at least the focus width of the light source can be imaged thereon. This can be ensured by suitable measures such as blinds.
  • the area of the active surface should be selected so that as little stray light or diffracted light strikes the active surface, in order to avoid overloading of the sensors or to reduce a high background signal.
  • each detector element Rr, r e N with its maximum bandwidth BW and not with the line rate (line rate) l_r read (as was previously possible only in the prior art).
  • the defect scans the focus or beam waist.
  • the mean diameter of the defect can be determined.
  • FIG. 7 shows a light source LI which radiates onto the object 1 via a focus optics FO in , so that the beam or focus waist 2w0 lies near or ideally in the object plane E, that is to say in the case of a material web 1 'in the plane E of this material web 1 ', because in this object plane E are the defect points 7 to be detected, in particular in the form of microholes 7'.
  • coherent light sources LI whose power can be regulated and which can optionally be used in pulse mode.
  • line lasers of the beam length Llength with a low coherence angle and a uniform intensity profile are used.
  • a material web 1 'in the form of a plastic film 1 "only a small position variation (ie variations perpendicular to the object plane E) executes or can run, can additionally guide and stabilization units SLTin, out above and below the object be provided, which is preferred
  • the guide and stabilization units which may be provided only on one or both sides of the material web plane E, may additionally be designed as jet traps in order to reduce the ambient light and / or the light conducted through the object ,
  • the object should be able to be guided through these sandwich-type guiding and stabilizing units without generating any friction or damage.
  • the receiver units SE and / or the optional focus optics units FOou on the receiver side are to be placed as close as possible to the rear side of the object 1 to be examined (material web 1 ') after the actual object 1. This is to prevent that the Airy area widens greatly and the intensity of the subsurface is no longer separate.
  • the corresponding optics and / or sensor units are preferably integrated in the stabilization device and an optionally provided light trap, as can be seen in detail in FIG.
  • an optional imaging optic FOLG can therefore also be provided on the receiver side below the material web 1 'to be examined, which can also comprise, for example, photoconductive elements (GRIN, Selfoc, etc.).
  • one or more receiver-side optional optical devices PFS can also be provided, for example diaphragms, polarization devices, filters, devices for reducing light scattering, etc.
  • the mentioned receiver units SE are provided, into which the light emitted by the light generator, in particular in the form of a laser, is received, for example by the frequently mentioned photodiodes, which are arranged on the same optical axis (-line) as the light sources.
  • a detection device could come into play, which comprises a plurality of juxtaposed photodiodes PIN in a row extending in the transverse direction TD, as shown for example with reference to FIG. 6 (FIG Variant with two adjacent rows of sensor elements SE in the form of photodiodes PIN_A, PIN_C etc. is shown).
  • a further laser-side optional device PFOin is provided below in the beam direction of the focus optics FOin, for example in the form of a polarizer, a filter, etc.
  • an optional beam splitter SGU is inserted into the beam path downstream of the laser LI which, for example, can consist of a deflection or prism device, a scanning unit, etc., whereby the laser beam is split.
  • the laser LI which, for example, can consist of a deflection or prism device, a scanning unit, etc.
  • the entire illustrated transmitter-side optical device FOin, PFOin as well as the receiver-side optical device FOLG, PFS are also designed so that the same conditions exist for both laser beam phenomena LEI and LE2. Accordingly, two rows of sensors SEn and SEm are arranged side by side, which form the sensor device.
  • the optional dual laser plane option is chosen to minimize the cost of the laser source and to ensure overlap of the active areas with the discrete design of the sensor elements SE (single PIN arrangement and non-integrated array design).
  • a line laser LI with a small beam waist (2w0) and a line length of the same intensity (beam convergence ⁇ 1 °) is used.
  • the intensity profile is imaged onto the object 1 by the focus optics FOin. If discrete sensors such as PIN photodiodes, CIS sensors (contact image sensor based on CMOS technology), CMOS sensor, CCD sensors etc.
  • edge or bandpass filters can be used.
  • any polarization properties that can be implemented with appropriate optics. Such a procedure is known in the art and shown in detail in the prior art.
  • the active area should e.g. are reduced in size by a diaphragm (denoted by the general designation FOLG in FIGS. 7, 8a and 8b), since the scattered light increases the background signal. This is reproduced, for example, in a representation parallel to a film plane E in FIG. 8 a and in an extractive plan view in FIG. 8 b.
  • FOLG diaphragm
  • this component can also be omitted.
  • an array adjustment device is often required to hit the focus line.
  • the zeroing with an ND filter PFS can be carried out, for example, at the active area of the PIN_An.
  • optics also filters and / or polarization optics can be provided on single or all active surfaces.
  • PIN photodiodes directly under the object 1, it is possible to route the signal via optical fibers to the receiver.
  • state-of-the-art optics such as fiber optics, GRIN, collection and magnification optics, etc. are used.
  • the individual detector elements SEs, s e N are staggered overlapping to cover the entire working width AB. For most applications, it is sufficient to know the location of the defect for the respective active area of a sensor within the sensor element. Consists e.g. a sensor element SEs of 10 PIN with respective active lengths of 2 mm, then in practice this TD resolution of 2 mm is sufficient for the quality control.
  • the sensor elements SE can be inclined, as shown in an extractable plan view with reference to Figure 9 and in a graph according to Figure 11.
  • X (t n ) is detected in sequence About one Encoder in the MD direction and the temporal discrimination of the TD location of the defect 7 can be determined (with all suitable measures for the exact position determination of a defect in the direction of MD MD of the object 1, ie in the pull direction MD of the material web 1 shown here are "suitable in this respect reference is also made to known methods and apparatuses for this purpose) (FIG. 10).
  • PIN_An is referenced to PIN_An + l or to PIN_Referenzj.
  • sensor elements with a long active area for example PSD, elongate PIN or light-guiding elements
  • a larger signal height results when several defects strike at time t x .
  • the spatial resolution is then obtained by a second sensor element, which then also serves as a reference element for the background signal. From the illustration according to FIG. 12, the corresponding conditions can be taken.
  • FIG. 13 A possible structure for the data acquisition is shown in FIG.
  • This electronic evaluation device AE which can be seen in FIG. 13, comprises various functional and / or subassemblies, as shown schematically in FIG. 13 in their structural interconnection and arrangement.
  • the photodiodes are preferably operated reverse-biased.
  • the difference is formed by two PINs (variants: cathode of PIN_An and the anode of PIN_Cn, K of PIN_An and A of PIN_An + l, K of PIN_An and A of PIN_Reference, etc.), and a transimpedance amplifier (TIA) fed.
  • TIA transimpedance amplifier
  • one PIN of the row n is for safety's sake ever matched with a PIN of row m. If these two PIN photodiodes give e.g. serve as referencing for the other PIN photodiodes.
  • a multiplexer can interconnect a single PIN against each other or with respect to a reference sample.
  • FIG. 13 shows an example of the electronic evaluation device, in which - as shown with reference to FIG. 6 - the optionally provided second laser measuring line m is provided in addition to the actual laser measuring line n. Therefore, the electronic evaluation device shown in Figure 13 is quasi also shown in its double structure, namely with a respective device DSP with associated multiplexer and an analog / digital converter A / D and a device FPGA for the parallel processing of the signals including the aforementioned FIFO - cache. If the optional second laser measurement line m in FIG. 6 or in FIG. 13 were omitted, the structure would be halved to that extent. However, of course, a computer must always be provided to control and evaluate the entire device.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

L'invention concerne un système amélioré de détection de points défectueux (7, 7') sur un objet (1), en particulier de défauts (7) sous la forme de microtrous (7') dans une bande de matériau (1') ou un film (1"), présentant entre autres les caractéristiques suivantes : le système comprend au moins une source de lumière primaire (L, L1) permettant de produire un faisceau lumineux, un dispositif de détection et/ou de capteurs muni d'éléments de détection ou d'éléments capteurs (SE s, SE), et un dispositif d'évaluation (AE) permettant d'évaluer le point défectueux (7) ; le système muni du dispositif d'évaluation (AE) comprend un circuit d'équilibrage pour les éléments de détection ou les éléments capteurs (SE s, SE), de sorte qu'un signal équilibré permettant l'évaluation des points défectueux est produit par la formation d'une différence entre un signal de mesure produit par un élément de détection ou un élément capteur (SE s, SE) et au moins un signal de mesure produit par un élément de détection ou un élément capteur (SE s, SE) adjacent ou référencé.
PCT/EP2015/001462 2014-07-29 2015-07-16 Détection optique de défauts WO2016015833A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102014011268.3 2014-07-29
DE102014011268.3A DE102014011268A1 (de) 2014-07-29 2014-07-29 Optische Fehlstellendetektion

Publications (1)

Publication Number Publication Date
WO2016015833A1 true WO2016015833A1 (fr) 2016-02-04

Family

ID=53673888

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2015/001462 WO2016015833A1 (fr) 2014-07-29 2015-07-16 Détection optique de défauts

Country Status (2)

Country Link
DE (1) DE102014011268A1 (fr)
WO (1) WO2016015833A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110779934A (zh) * 2019-08-28 2020-02-11 深圳市灿锐科技有限公司 检测平面透明工件上灰尘和划痕的光学模块

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102020006637A1 (de) 2020-10-29 2022-05-05 Siempelkamp Maschinen- Und Anlagenbau Gmbh Verfahren zur Überwachung eines Stahlbandes in einer kontinuierlichen Presse auf Materialanhaftungen und kontinuierliche Presse

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH477691A (de) * 1965-09-23 1969-08-31 Nash & Harrison Ltd Verfahren und Einrichtung zur Feststellung von Fehlern in Flachmaterial
US4431309A (en) * 1980-01-07 1984-02-14 Erwin Sick Gmbh/Optik-Elektronik Monitoring apparatus
US4728800A (en) * 1985-04-24 1988-03-01 Young Engineering, Inc. Apparatus and method for detecting defects in a moving web
US6934029B1 (en) * 2002-04-22 2005-08-23 Eugene Matzan Dual laser web defect scanner
DE69923120T2 (de) * 1998-07-21 2006-04-06 Toshiba Engineering Corp., Kawasaki Vorrichtung und Verfahren zum Feststellen von hellen oder dunklen Flecken
US20070057208A1 (en) * 2003-07-14 2007-03-15 Rolf Joss Method and device for monitoring a moving fabric web
DE102012110793A1 (de) * 2012-11-09 2014-05-15 R.A.M. Realtime Application Measurement Gmbh Vorrichtung und Verfahren zur Abbildung eines bahnförmigen Materials
DE102012024359A1 (de) * 2012-12-13 2014-06-18 Tichawa IP GmbH Sensoranordnung zur zeilenweisen optischen Abtastung

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3755674A (en) * 1972-03-09 1973-08-28 Columbia Res Corp Method of detecting pinhole defects in sheet material
US3700909A (en) * 1972-03-09 1972-10-24 Columbia Research Corp Method for detecting pinhole defects in foil material
JPH01181374A (ja) 1988-01-14 1989-07-19 Sony Corp 密着型イメージセンサー
NO914574L (no) * 1991-11-22 1993-05-24 Elkem Technology Fremgangsmaate for detektering av pin-hull i strengestoeptemetallemne
DE4302137C2 (de) * 1993-01-27 1999-09-02 Micro Perforation Engineering Verfahren und Vorrichtung zur optischen Porositätsmessung an einer laufenden Bahn
JP3372193B2 (ja) * 1997-08-20 2003-01-27 日本たばこ産業株式会社 シガレット製造装置
WO2002073173A2 (fr) 2001-01-29 2002-09-19 Kla-Tencor, Inc. Systeme et procedes d'inspection de surfaces de specimen
DE10124943A1 (de) 2001-05-21 2002-12-05 Nikolaus Tichawa Sensormodul und Detektoranordnung zur zeilenweisen optischen Abtastung eines bewegten Objektes
US6895811B2 (en) * 2001-12-14 2005-05-24 Shawmut Corporation Detection of small holes in laminates
DE10251610A1 (de) 2002-11-06 2004-05-27 Werner Grosse Verfahren und Vorrichtung zur optischen Porositätsmessung und Positionsbestimmung von Perforation mit einem Dual-Sensorsystem
US7224447B2 (en) 2004-03-08 2007-05-29 Philip Morris Usa Inc. System and method for measuring the permeability of a material
US7200982B2 (en) 2004-07-01 2007-04-10 Briggs & Stratton Corporation Blade slippage apparatus
DE102007006525B4 (de) * 2007-02-06 2009-05-14 Basler Ag Verfahren und Vorrichtung zur Detektierung von Defekten

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH477691A (de) * 1965-09-23 1969-08-31 Nash & Harrison Ltd Verfahren und Einrichtung zur Feststellung von Fehlern in Flachmaterial
US4431309A (en) * 1980-01-07 1984-02-14 Erwin Sick Gmbh/Optik-Elektronik Monitoring apparatus
US4728800A (en) * 1985-04-24 1988-03-01 Young Engineering, Inc. Apparatus and method for detecting defects in a moving web
DE69923120T2 (de) * 1998-07-21 2006-04-06 Toshiba Engineering Corp., Kawasaki Vorrichtung und Verfahren zum Feststellen von hellen oder dunklen Flecken
US6934029B1 (en) * 2002-04-22 2005-08-23 Eugene Matzan Dual laser web defect scanner
US20070057208A1 (en) * 2003-07-14 2007-03-15 Rolf Joss Method and device for monitoring a moving fabric web
DE102012110793A1 (de) * 2012-11-09 2014-05-15 R.A.M. Realtime Application Measurement Gmbh Vorrichtung und Verfahren zur Abbildung eines bahnförmigen Materials
DE102012024359A1 (de) * 2012-12-13 2014-06-18 Tichawa IP GmbH Sensoranordnung zur zeilenweisen optischen Abtastung

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110779934A (zh) * 2019-08-28 2020-02-11 深圳市灿锐科技有限公司 检测平面透明工件上灰尘和划痕的光学模块

Also Published As

Publication number Publication date
DE102014011268A1 (de) 2016-02-04

Similar Documents

Publication Publication Date Title
DE19960653B4 (de) Verfahren und Vorrichtung für die Detektion oder Lagebestimmung von Kanten
DE2260090C3 (de) Photoelektrische Einrichtung zur Bestimmung der Rauhigkeit bzw. Glätte diffusstreuender Oberflächen
DE2256736C3 (de) Meßanordnung zur automatischen Prüfung der Oberflächenbeschaffenheit und Ebenheit einer Werkstückoberfläche
DE102010005962B4 (de) Verfahren zur Bestimmung der statischen und/oder dynamischen Lichtstreuung
EP3443297A1 (fr) Dispositif de mesure térahertz pour la mesure d'objets à contrôler et procédé de mesure térahertz
DE112015004550T5 (de) Tdi-sensor in einem dunkelfeld-system
DE102009000528B4 (de) Inspektionsvorrichtung und -verfahren für die optische Untersuchung von Objektoberflächen, insbesondere von Waferoberflächen
EP3324203A1 (fr) Module de télémétrie laser présentant une analyse de polarisation
EP2002208A1 (fr) Dispositif de mesure optique de distances et son procédé de fonctionnement
EP0052813A2 (fr) Procédé pour l'examen d'une bande réfléchissante ou transparente en mouvement et dispositif pour la mise en oeuvre de ce procédé
DE102011076611A1 (de) System zum detektieren eines pinhole vonbrennstoffzellenstapelteilen
DE102012104874B4 (de) Optisches Messsystem mit Polarisationskompensation, sowie entsprechendes Verfahren
EP0811146A1 (fr) Dispositif et procede permettant de mesurer la position du bord de bandes ou de feuilles
EP2144052A1 (fr) Procédé et dispositif de détection et de classification de défauts
WO2016015833A1 (fr) Détection optique de défauts
WO2010127872A1 (fr) Dispositif et procédé pour la mesure de lumière diffusée à résolution angulaire
DE3544871C2 (fr)
EP2434311B1 (fr) Procédé de surveillance optique d'un domaine de surveillance et senseur lumineux à réflexion
DE3917571C2 (fr)
DE19816359A1 (de) Fasersensor zum Erkennen von Oberflächenstrukturen
EP3324149B1 (fr) Procédé et dispositif de détermination des modifications de surface des composants optiquement transparents
EP2831570A1 (fr) Procédé pour la détection de couches enterrées
DE4229349C2 (de) Verfahren und Anordnung zur Messung der optischen Oberflächengüte von spiegelnden Materialien und der optischen Güte transparenter Materialien
DE102015105128A1 (de) Verfahren und Vorrichtung zur Messung des Glanzgrads und/oder der Mattheit von Gegenständen
EP0052812A2 (fr) Procédé pour la détection des déviations d'un signal, utilisant un amplificateur différentiel intégrateur

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15738839

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15738839

Country of ref document: EP

Kind code of ref document: A1