[go: up one dir, main page]

WO1991011703A1 - Appareil detecteur - Google Patents

Appareil detecteur Download PDF

Info

Publication number
WO1991011703A1
WO1991011703A1 PCT/GB1990/002032 GB9002032W WO9111703A1 WO 1991011703 A1 WO1991011703 A1 WO 1991011703A1 GB 9002032 W GB9002032 W GB 9002032W WO 9111703 A1 WO9111703 A1 WO 9111703A1
Authority
WO
WIPO (PCT)
Prior art keywords
raman
light
sample
filter
source
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.)
Ceased
Application number
PCT/GB1990/002032
Other languages
English (en)
Inventor
Robin Bratchley
David Neville Batchelder
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.)
De la Rue International Ltd
De la Rue Holdings Ltd
Original Assignee
Thomas De la Rue and Co Ltd
De la Rue Co PLC
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 Thomas De la Rue and Co Ltd, De la Rue Co PLC filed Critical Thomas De la Rue and Co Ltd
Publication of WO1991011703A1 publication Critical patent/WO1991011703A1/fr
Priority to GB9214031A priority Critical patent/GB2256923B/en
Anticipated expiration legal-status Critical
Ceased 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
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/65—Raman scattering
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
    • G07D7/06—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using wave or particle radiation
    • G07D7/12—Visible light, infrared or ultraviolet radiation
    • G07D7/1205—Testing spectral properties
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
    • G07D7/06—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using wave or particle radiation
    • G07D7/12—Visible light, infrared or ultraviolet radiation
    • G07D7/121—Apparatus characterised by sensor details

Definitions

  • This invention relates to apparatus suitable for detecting resonance Raman scattering.
  • the apparatus is particularly useful for the authentication of appropriately marked security documents, for example in banknote-sorting equipment.
  • a security printer is able to select a variety of measures to prevent counterfeiting and forgery and to allow authentication. Any one document will include a range of them, and the choice of those that are actually included in any one document or part of a document presents a daunting obstacle to wrong-doers.
  • Raman spectra of chemical compounds have been used for many years as a means of identification.
  • Raman spectra arise when laser light incident upon a sample of the material is scattered: the scattered light includes light of the laser wavelength plus, at much lower intensity, light of additional wavelengths which are characteristic of the compound.
  • the additional light appears at frequencies which are shifted from that of the laser beam by amounts equal to the frequencies of collective vibrations of the atoms in the compound. These frequencies are determined by the masses of the atoms comprising the material and the forces which hold them together.
  • the Raman spectrum is often used as its fingerprint. In this way, the compound may be identified in various conditions, for example as a crystal, in solution, as a powder and in mixtures with other compounds.
  • Resonance Raman scattering occurs when the wavelength of the incident laser beam is equal to, i.e. in resonance with, that of an optical absorption band in the material.
  • the electrons responsible for the absorption are often located on a subset of atoms in the compound known as the chromophore.
  • the Raman scattered light which is frequency shifted by the collective vibrations of atoms in the chromophore will be greatly enhanced in intensity.
  • conventional Raman scattering spectroscopy provides information complementary to that obtained from infra-red absorption spectroscopy.
  • Raman spectroscopy has usually only been used when infra-red spectroscopy is incapable of providing required information.
  • conventional Raman spectroscopy requires lasers of high power (about 100-200 mw) and a sophisticated, sensitive spectrometer requiring cooled photomultipliers.
  • the commercial application of such apparatus has historically been limited, owing to its high cost and large size.
  • Raman-active compounds are known, for example polydiacetylenes. Polydiacetylenes have a conjugated polymer backbone. Raman-active compounds, for the purposes of this specification, exhibit Resonance Raman activity or other Raman activity of similar intensity.
  • US-A-4586819 discloses a "laser Raman microprobe" that separates a laser beam reflected by a sample and Raman-scattered light generated by the sample, using a filter that transmits or reflects light in a predetermined wavelength region. All light transmitted at the Raman-scattering wavelength is subjected, via a single monochromator, to spectroanalysis.
  • Patent Abstracts of Japan (1988) £(265) 399 discloses apparatus adapted to eliminate the influence of fluorescence when detecting wavelength-modulated Raman-scattered light.
  • the apparatus involves a mechanically-complex oscillating slit arrangement which oscillates at a rate slower than the wavelength-modulated incident radiation.
  • the novel apparatus can be used to analyse security documents for the presence of a Raman-active compound, e.g. compounds and security documents of the types described and claimed in a copending International Application filed in the name of The De La Rue Company pic et aj., having the same filing date, and entitled "Ink Compositions and Components Thereof". Description of the Invention
  • the light source preferably provides intense monochromatic light, and is preferably a laser, and can be a relatively inexpensive, low-power laser such as a HeNe laser. As is conventional, it may be combined with a filter which removes spurious laser radiation so that monochromatic light, e.g. at a wavelength of 632.8 nm, is passed.
  • the source and/or the detector may be solid-state devices, so that the apparatus can be compact.
  • the selective transmission means is preferably a filter which, at the wavelength of the monochromatic source, allows the incoming beam to be reflected onto the sample and that portion of the beam scattered by the sample in the direction of the filter to be transmitted through it, to allow detection of the Raman-scattered light.
  • light is incident on the sample at 90°, and scattered radiation can be processed along the same axis.
  • the source light may be incident on the sample at another angle, and the scattered light may be processed along a different path from incidence.
  • the scattered radiation- processing devices may be on the opposite side of the sample from the source.
  • the selective filter in apparatus may also be of a known type, as may be the detector.
  • a plurality of detectors may bd" used, e.g. to distinguish Raman scattering and fluorescence, but a single device may be employed, e.g. if the apparatus is to detect a known Raman-active compound for its presence on a security document.
  • the apparatus additionally comprises means adapted to split the transmitted Raman-scattered light and transmitted light of a neighbouring wavelength, detection means for each of the split radiations, and means for comparing the two beams.
  • a conventional beam-splitter which splits the transmitted light along two paths is associated with filters in each path, one filter passing essentially only Raman-scattered light and the other excluding Raman light and passing longer (or shorter) wavelength light just clear of the Raman band. The filtered beams are compared, for the purposes of analysis.
  • novel apparatus In order that the novel apparatus should be particularly useful for the authentication of security documents, it should be able to discriminate between Raman and other emissions of the same wavelength.
  • the Stokes-type Raman scattering will usually be measured, as that signal will be at lower energy and longer wavelength, although it is possible to measure the anti-Stokes Raman scatter.
  • the fluorescence from a sample can be measured in the same geometric arrangement as the Raman scatter.
  • the fluorescence band will however be broad and smooth, unlike the Raman spikes.
  • the novel apparatus can distinguish the two components. In use, the signal at the Raman frequency is measured and so also is a neighbouring background signal immediately beside the Raman spike. By subtraction, the value of the Raman spike is obtained, and this can be used for authentication. Possibly there may be some other scattering components in the neighbouring background apart from fluorescence, but it is unlikely that they will have spikes at the measured Raman wavelength.
  • the discrimination can be achieved in a number of ways.
  • a tunable filter is employed in a "static" detector for use with stationary authenticatable items. Two neighbouring readings from the sample are made, with the filter respectively tuned on and just off the Raman peak, to distinguish the true Raman component.
  • a pair of filtered detectors can be employed, one measuring the Raman signal and the other the background.
  • Narrow band-pass filters, monochromators or tunable filters may be used.
  • a fixed arrangement of this type could be used in a "dynamic" detector where, say, banknotes have to be checked quickly.
  • Such equipment can allow the authentication of documents moving at speeds of up to 10 metres per second.
  • modulating the sourc intensity can be used to provide comparative signals. Th benefit of modulation is that the background illuminatio components can be removed, so allowing the system to b used in less dark conditions.
  • the two wavelengths measured can be determined from knowledge of the Raman spectrum of the authenticatabl working material. At one wavelength, there should b substantially no Raman scattering by comparison with th scattering at the other wavelength.
  • Figures 1 to 4 are each schematic representations o different embodiments of apparatus according to th invention.
  • Figure 5 shows the spectral characteristics of selective filter suitable for use in the invention
  • Figures 6A, 6B, 7 and 8 show various resonance Rama spectra; and Figure 9 is an oscilloscope trace.
  • the laser light is then deflected by filter F2 throug 90° so that it passes through a microscope objective 0, b which it is focused on the sample S to be authenticated Some of the light which is scattered by the sample is the collected by the microscope objective 0 and returns in t direction from which the laser beam came.
  • the speci features of filter F2 come into effect to segregate t Raman-scattered light from the much more intens elastically-scattered light which has the same waveleng as the laser light. While the light of wavelength 632.8 nm is again deflected through 90°, back towards the mirror M and the laser L, the Raman-scattered light (plus any fluorescence present) at longer wavelength passes straight through. While it is possible to use a 50:50 beam-splitter instead of filter F2, it is preferred to use a filter of the type having the spectral characteristics shown in Fig. 5, as available from Omega Optical Corp., USA.
  • Figure 5 shows the relationship between the percentage transmission value and the wavelength for a selective filter suitable for use in the invention.
  • R p and R s represent the reference in the P and S planes of polarisation;
  • F p and F s represent the filter in the P and
  • the spectra indicate a substantial drop in the percentage transmission value of the incident laser wavelength of 632.8 nm. This decrease corresponds to the passage of Raman-scattered light through the filter, and the deflection through 90° of the more intense, elastically-scattered light that has the same wavelength as that of the incident laser light. Hence very little light of wavelength 632.8 nm passes through the filter.
  • Filter F3 functions to separate the scattered light into Raman emission and a neighbouring background signal. For a given source wavelength, and a particular Raman-active compound to be detected, the filter
  • F3 may be a stationary filter having a characteristic pass-band for the Raman-scattered light. This is particularly appropriate if the fluorescence is wide-band.
  • the filter F3 may be tunable, by rotation
  • Such a filter has special characteristics: when the light is perpendicular to the filter it has one characteristic pass-band; when the angle of the filter with respect to the light beam is decreased from 90°, however, the pass-band shifts to shorter wavelengths.
  • the equation which relates the wavelength of the centre of the pass-band, ⁇ c , to the angle, ⁇ , through which the filter F3 has been rotated from its position perpendicular to the light beam is:
  • ⁇ c ⁇ _»x I 1 - ( °- 47 sin / 3) /2
  • the filter F3 is suitably selected to cover the range from 701.6 nm at normal incidence to 692.2 nm at an angle of 20°. This is appropriate for Raman-scattered light on illumination of a Raman-active compound, of the type defined in the copending Application, in the vicinity of maximum absorbance, e.g. using laser light at 632 nm.
  • the filter has a tuning range for the analysis of Raman-scattered light displaced to lower energy by 1357 cm ' to 1550 cm " , in the central region of the Raman spectrum.
  • Other filters can be used to obtain optimum results with different lasers and other Raman-active materials.
  • the light which passes through filter F3 is detected by a photomultiplier PM and its associated electronics.
  • a chopper may be used to modulate the laser beam, so that phase-sensitive detection may be used. If the Raman-scattered light is sufficiently intense, however, e.g. if a polydiacetyiene is being detected, simple DC detection is also appropriate.
  • the microscope objective was an X40 with a numerical aperture of 0.65 and a working distance of only 0.7 mm.
  • a long working distance X40 objective of numerical aperture 0.4 and working distance 7 mm may be used.
  • a X10 objective with a numerical aperture of 0.25 and a working distance of 6.7 mm was also used successfully. The longer working distances are more suitable for use on banknote-sorting equipment.
  • Figure 6A is a plot of the photomultiplier output, equivalent to intensity, as a function of angle through which the filter F3 had been manually turned. At zero angle, filter F3 is perpendicular to the beam of scattered light.
  • Figure 6B is a plot of the resonance Raman spectrum taken on a conventional Raman spectrometer. The agreement between the two is very good, providing allowance is made for the lower resolution of the filter and the fact that its transmission decreases with increasing angle.
  • the intensity at the peak of the photomultiplier output corresponded to approx. 3 pW.
  • the intensity reaching the photomultiplier actually increased when the print samples containing microcrystals of polydiacetylene were investigated.
  • the maximum intensity was 5 pW, although a greater percentage of this was fluorescence than in the case of the single crystal.
  • Most of this fluorescence came from either the underlying paper or ink vehicle. In fact, for some of the samples, the presence of polydiacetylene in the ink served to reduce the amount of fluorescence output considerably.
  • the Raman and background combined signal would conveniently be measured at 1500 cm * , and the background on its own at 1400 cm " or
  • FIG. 7 shows the relative intensity of resonan Raman spectra for matching pairs of samples, one (21) usi the ink vehicle alone, and the other (20) t polydiacetylene-loaded ink vehicle. The value of 1 on th relative scale corresponds approximately to 6 pW. T spectra were taken from the chart recording of the Digit Voltmeter output made as the micrometer was driven with motor.
  • Figure 8 is a repeat spectrum of the sample in Figu 7, but taken using the X10 microscope objective.
  • the intensity has decreased by about factor of seven; this is to be expected as seven approximately equal to the ratio of the squares of t numerical apertures of the two microscope objective
  • the resolution of the spectrum is considerab improved. This is due to the fact that it is easier obtain a parallel output beam for the scattered light wi the longer focal length lens.
  • the pass-band of filter is narrowest when the incident light is plane-parallel. is clear that the reduction in intensity does not radical degrade the quality of the spectrum.
  • t filter F3 was adjusted to give peak intensity for t polydiacetylene polymer sample of Fig. 6A/6B, with pigment (see Figure 7) .
  • a 500 Hz chopper was then used modulate the laser beam.
  • the oscilloscope trace of t resulting output is shown in Figure 9.
  • the signal go negative from 0 V and reaches a maximum peak-to-pe amplitude of 4 V.
  • the 1 Megohm input impedance of t oscilloscope was the effective load resistor for t photomultiplier current.
  • the period of the signal is 2 and the signal can be seen to approach its maximum value in 1 ms.
  • the spectrum is sufficiently noise-free to judge that a measurement could satisfactorily be made in this time.
  • Resonance Raman spectra of plain and UV bright paper were compared: there was very little difference in the fluorescence output of the two papers when the HeNe laser was used for illumination.
  • a X10 (i.e. ten times magnification) microscope objective it was found that a working distance of 6.7 mm was adequate. Within ⁇ 1 mm of the value, the spectra were acceptable.
  • the X40 (0.65 numerical aperture) microscope objective collected seven times as much light, but its 0.7 mm working distance would usually require a contact head to be used.
  • a long working distance objective e.g. 7 mm working distance
  • FIG 2 is a schematic diagram of a further possible arrangement of optical components in an instrument.
  • Beam ⁇ splitter BS1 is equivalent to F2 in Figure 1, and a 50:50 beam-splitter BS2 has been added.
  • BS2 splits the transmitted light which thus takes paths P, and P 2 .
  • Fixed filters F2 and F3 have narrow (approximately 6 nm) pass bands selected so that F2 is centred on the wavelength of the main Raman band and F3 is centred at a longer wavelength just clear of that band.
  • the effect can be demonstrated by subtracting the output of one photomultiplier from the other using a differential oscilloscope.
  • the difference in signal would allow differentiation of genuine articles relative to forgeries: as the acceptable levels of variation of Raman response would be known, the circuitry would regard articles as having passed the test or failed it.
  • the signals from the two photomultipliers can be electronically processed so that an analogue or digital status signal is produced, to indicate the presence or absence of a specific Raman-active material.
  • the equipment will be calibrated so that a'pass signal is produced if the signal from photomultiplier PM2 is above the level of that from photomultiplier PMI by a predetermined amount. Otherwise a fail signal will be produced. If necessary, a marginal signal can be produced by appropriate circuitry.
  • the status signal produced from the above Raman limit test can be used to drive other circuits, e.g. a lamp or visual indicator to indicate if the document is "genuine", “false” or, if required, "marginal".
  • accept/reject mechanism in a wide range of document or currency handling equipment, e.g. money-acceptor, ticket-operated gate, bank card-reader, etc.
  • the response time of the Raman detector sufficiently fast that it can be used in document sorti and verification equipment, especially for banknote tickets, passports, cheques, travellers' cheques, etc. such cases, the genuine documents bearing the Raman-acti material and passing the test would be authenticated by t equipment.
  • the equipme could also be used to read bar codes or other types printed codes on documents which contain Raman-acti compounds such as polydiacetylenes or diamond. F example, such codes could be used to discriminate betwe different denominations of banknotes.
  • the optical path could be spli after filter F2, by inclusion of appropriat beam-splitters, filters and additional photomultipliers, s that Raman-active materials scattering' at differen wavelengths could be simultaneously detected.
  • FIG. 3 An alternative detector design for use in both stati and dynamic detection modes is shown in Fig. 3.
  • Fig. 3 shows an arrangement similar to that of Fig. 2 except that a signal generator is connected to a acousto-optic modulator AO.
  • AO acousto-optic modulator
  • the modulation frequency might be 50 Hz, but up to 100 kHz or higher is feasible for a dynami mode, depending on the monitoring speed (e.g. 1 mm line o print at 1 m/sec) .
  • Part of the output from the signa generator is also connected to a phase-sensitive detecto which also receives the output signals from photomultiplier detectors.
  • the design has the s advantage as the apparatus of Fig. 2, in that the prese of fluorescence can be eliminated.
  • the resultant sig which is free from background light interference can t be passed to a display device such as an oscillosc (shown) or other discriminator.
  • the acoustic-op modulator is modulated at a suitable frequency, e.g. KHz.
  • the modulator alternately passes light along path and P 2 .
  • P 2 In the deflected path P 2 , light is reflected f mirror M and passes through filter Fl at an angle.
  • Fil Fl is of a similar type to F3 in Fig. 1, and the wavelen of transmitted light is dependent on angle.
  • Path P 2 is the shorter wavelength in Fig. 3, i.e. path P 2 is for Raman frequency and path P, for the background (at lon wavelength) .
  • the level of AC signal produced can be used to provide a "Raman Li Test" for subsequent use with authentication reading sorting equipment.
  • An advantage of apparatus of the type shown in Fi is that effects due to the presence of fluorescence (w will be present in approximately equal amounts in P 1 and can largely be eliminated instantly.
  • a further advan of the apparatus shown in Fig. 4 over these shown in F 2 and 3 is that only one filter and one photomultipl detector are required.
  • Apparatus of the invention may be solid-state. suitable arrangement would be similar to that shown in 3, except that the plasma rejection filter Fl used in 3 is not needed.
  • operation In the solid state, operation may be in AC (modulated) or DC mode.
  • the solid-state laser can be modulated electronically (e.g. in range 10-100 MHz) and an acousto-optic coupler is not needed.
  • DC mode the operation of the instrument can be observed using an oscilloscope with differential inputs.
  • AC mode a phase-sensitive detector is employed.
  • Solid-state photodetectors are exemplified by two types: silicon photodiodes and silicon photoavalanche diodes.
  • Raman-detectable materials may be included in items and documents to be authenticated in different places.
  • the material may be located on the same side or opposite sides of the document.
  • the placing of the feature may be varied within the limits that a given detector system may allow.
  • Security document automatic sorting equipment incorporating the apparatus of the invention will generally also comprise:
  • (e) means for receiving, and optionally marking or spoiling notes which have not been identified as verified.
  • a simpler automatic feeding device would enable one manually-sorted document to be scanned at a time.
  • a device may comprise authentication apparatus of the invention and document- acceptor and document-expelling driving means and an electronic signalling means to indicate, visually, aurally or otherwise, whether a document has passed or not.
  • the apparatus of the invention is used for detec the presence of Raman-active compounds which are on or the surface of the item to be authenticated.
  • the pres of Raman-active compounds may be detected within the of such items, provided that the illuminating light substantially reach the Raman-active compound, and that resulting Raman and scattered light can be collected analysis.
  • the apparatus may be used to authenticate items of suitable kind including tagging and labelling markings, is principally intended for use with security-printed i including security-printed documents.
  • the method of the invention is applicable to analysis of any authenticatable item, of which secur printed items and security documents are examples, for presence of a Raman-active compound.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Toxicology (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Optics & Photonics (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)

Abstract

L'appareil décrit, qui peut être utilisé pour authentifier un article de valeur ou pour analyser un échantillon (S) contenant un matériau à effet Raman, comprend une source de lumière sensiblement monochrome (L), des organes (M1, F1, F2, O) servant à diriger la lumière provenant de la source sur l'échantillon, un organe (F2) servant à séparer la lumière provenant de la source du rayonnement émis et/ou diffusé par l'échantillon, un organe destiné à établir une distinction (F3) entre la lumière diffusée par effet de Raman et la lumière d'une longueur d'ondes voisine, ainsi qu'un ou plusieurs déflecteurs (PM) pour les rayonnements respectifs ainsi distingués. L'appareil permet d'établir une distinction entre la diffusion Raman et la fluorescence ambiante.
PCT/GB1990/002032 1990-02-02 1990-12-28 Appareil detecteur Ceased WO1991011703A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9214031A GB2256923B (en) 1990-02-02 1992-07-01 Detection apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB909002335A GB9002335D0 (en) 1990-02-02 1990-02-02 Detection apparatus
GB9002335.9 1990-02-02

Publications (1)

Publication Number Publication Date
WO1991011703A1 true WO1991011703A1 (fr) 1991-08-08

Family

ID=10670307

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1990/002032 Ceased WO1991011703A1 (fr) 1990-02-02 1990-12-28 Appareil detecteur

Country Status (4)

Country Link
EP (1) EP0513025A1 (fr)
CA (1) CA2075056A1 (fr)
GB (1) GB9002335D0 (fr)
WO (1) WO1991011703A1 (fr)

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5257334A (en) * 1991-09-24 1993-10-26 Seikoh Giken Co., Ltd. Ribbon type optical fiber connector
GB2274165A (en) * 1990-04-24 1994-07-13 Gersan Ets Method and apparatus for examining an object
GB2244329B (en) * 1990-04-24 1994-10-26 Gersan Ets Method and apparatus for examining an object
EP0740133A1 (fr) * 1991-11-16 1996-10-30 RENISHAW plc Illumination de l'échantillon pour appareil spectroscopique
US5623342A (en) * 1995-06-07 1997-04-22 Renishaw Plc. Raman microscope
EP0781990A1 (fr) * 1995-12-30 1997-07-02 Kyoto Dai-ichi Kagaku Co., Ltd. Dispositif de mesure de lumière diffusée
US5689333A (en) * 1988-12-22 1997-11-18 Renishaw Plc Spectroscopic apparatus and methods
EP0756169A3 (fr) * 1995-07-19 1998-02-25 Kyoto Dai-ichi Kagaku Co., Ltd. Spectromètre et appareil pour analyse automatique
WO1999009382A1 (fr) * 1997-08-13 1999-02-25 De La Rue International Limited Procedes et dispositif de detection
US6008888A (en) * 1999-03-16 1999-12-28 Wizard Of Ink & Co. Laser verification and authentication Raman spectrometer (LVARS)
WO2001038858A1 (fr) * 1999-11-29 2001-05-31 Wizard Of Ink & Co. Spectrometre raman d'authentification et de verification laser (lvars) detectant les stokes et/ou l'emission anti-stokes
WO2002065409A3 (fr) * 2001-02-12 2003-08-07 Deutsche Post Ag Procede pour controler l'affranchissement appose sur un envoi postal
US6608670B2 (en) * 1999-03-16 2003-08-19 Wizard Of Ink & Co. Laser verification and authentication raman spectrometer (LVARS) detecting the stokes and/or anti-stokes emission
WO2002061695A3 (fr) * 2001-02-02 2003-10-09 Deutsche Post Ag Procede et dispositif de controle d'un affranchissement applique sur un envoi postal
WO2003083419A1 (fr) * 2002-03-28 2003-10-09 Valtion Teknillinen Tutkimuskeskus Procede et spectrometre permettant de mesurer un spectre raman
GB2411954A (en) * 2004-03-12 2005-09-14 Ingenia Technology Ltd Determining a signature from an article to verify its authenticity
US6995839B1 (en) * 2002-10-08 2006-02-07 Shapiro Frederick W Automated Raman scanner for documents and materials
WO2007044268A1 (fr) * 2005-10-04 2007-04-19 Nu Skin International, Inc. Instrument raman permettant de mesurer des signaux faibles en présence de forte fluorescence de fond
WO2008028476A3 (fr) * 2006-09-07 2008-09-04 Bundesdruckerei Gmbh Document de sécurité et / ou de valeur à particules sers
EP2111542A2 (fr) * 2007-01-29 2009-10-28 Cambrius, Inc. Analyseur chimique pour contrôle de procédé industriel
US8179526B2 (en) 2007-01-25 2012-05-15 Renishaw Plc Spectroscopic apparatus with dispersive device for collecting sample data in synchronism with relative movement of a focus
US8305571B2 (en) 2007-05-03 2012-11-06 Renishaw Plc Spectroscopic apparatus and methods
US8892556B2 (en) 2009-11-10 2014-11-18 Ingenia Holdings Limited Optimisation
US8896885B2 (en) 2004-03-12 2014-11-25 Ingenia Holdings Limited Creating authenticatable printed articles and subsequently verifying them based on scattered light caused by surface structure
US9222043B2 (en) 2009-09-22 2015-12-29 Authentix, Inc. Dipyrromethenes and azadipyrromethenes as markers for petroleum products
US9818249B1 (en) 2002-09-04 2017-11-14 Copilot Ventures Fund Iii Llc Authentication method and system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2190761B1 (es) * 2002-01-14 2005-09-01 Brake Plus, S.L. Sistema de reconocimiento de documentos.

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60113132A (ja) * 1983-11-25 1985-06-19 Agency Of Ind Science & Technol ラマン分光測定装置
US4586819A (en) * 1982-07-09 1986-05-06 Hitachi, Ltd. Laser Raman microprobe
WO1988001730A1 (fr) * 1986-08-27 1988-03-10 The Australian National University Procede et appareil permettant de distinguer des surfaces photoluminescentes et reflechissantes dans des applications du domaine des sciences legales
EP0314312A2 (fr) * 1987-10-26 1989-05-03 De La Rue Systems Limited Méthode et dispositif de détection d'encres

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4586819A (en) * 1982-07-09 1986-05-06 Hitachi, Ltd. Laser Raman microprobe
JPS60113132A (ja) * 1983-11-25 1985-06-19 Agency Of Ind Science & Technol ラマン分光測定装置
WO1988001730A1 (fr) * 1986-08-27 1988-03-10 The Australian National University Procede et appareil permettant de distinguer des surfaces photoluminescentes et reflechissantes dans des applications du domaine des sciences legales
EP0314312A2 (fr) * 1987-10-26 1989-05-03 De La Rue Systems Limited Méthode et dispositif de détection d'encres

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Patent Abstracts of Japan, vol. 9, no. 265 (P-399)(1988), 23 October 1985; & JP-A-60113132 (KOGYO GIJUTSUIN (JAPAN) 19 June 1985 *

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5689333A (en) * 1988-12-22 1997-11-18 Renishaw Plc Spectroscopic apparatus and methods
GB2274165A (en) * 1990-04-24 1994-07-13 Gersan Ets Method and apparatus for examining an object
GB2274165B (en) * 1990-04-24 1994-10-26 Gersan Ets Method and apparatus for examining a diamond
GB2244329B (en) * 1990-04-24 1994-10-26 Gersan Ets Method and apparatus for examining an object
US5257334A (en) * 1991-09-24 1993-10-26 Seikoh Giken Co., Ltd. Ribbon type optical fiber connector
EP0740133A1 (fr) * 1991-11-16 1996-10-30 RENISHAW plc Illumination de l'échantillon pour appareil spectroscopique
US5623342A (en) * 1995-06-07 1997-04-22 Renishaw Plc. Raman microscope
EP0756169A3 (fr) * 1995-07-19 1998-02-25 Kyoto Dai-ichi Kagaku Co., Ltd. Spectromètre et appareil pour analyse automatique
US5754289A (en) * 1995-12-30 1998-05-19 Kyoto Dai-Ichi Kagaku Co., Ltd. Raman scattered light measuring apparatus
EP0781990A1 (fr) * 1995-12-30 1997-07-02 Kyoto Dai-ichi Kagaku Co., Ltd. Dispositif de mesure de lumière diffusée
WO1999009382A1 (fr) * 1997-08-13 1999-02-25 De La Rue International Limited Procedes et dispositif de detection
US6024202A (en) * 1997-08-13 2000-02-15 De La Rue International Limited Detector methods and apparatus
US6608670B2 (en) * 1999-03-16 2003-08-19 Wizard Of Ink & Co. Laser verification and authentication raman spectrometer (LVARS) detecting the stokes and/or anti-stokes emission
US6008888A (en) * 1999-03-16 1999-12-28 Wizard Of Ink & Co. Laser verification and authentication Raman spectrometer (LVARS)
WO2000055586A1 (fr) * 1999-03-16 2000-09-21 Wizard Of Ink & Co. Spectromètre raman de vérification et d'authentification laser (lvars)
US6275285B1 (en) * 1999-03-16 2001-08-14 Wizard Of Ink & Co. Laser verification and authentication Raman spectrometer (LVARS) detecting the stokes and/or anti-stokes emission
WO2001038858A1 (fr) * 1999-11-29 2001-05-31 Wizard Of Ink & Co. Spectrometre raman d'authentification et de verification laser (lvars) detectant les stokes et/ou l'emission anti-stokes
WO2002061695A3 (fr) * 2001-02-02 2003-10-09 Deutsche Post Ag Procede et dispositif de controle d'un affranchissement applique sur un envoi postal
US7529386B2 (en) 2001-02-02 2009-05-05 Deutsche Post Ag Method and device for monitoring stamps on mail
AU2002240792B2 (en) * 2001-02-02 2007-02-15 Deutsche Post Ag Method and device for monitoring stamps on mail
WO2002065409A3 (fr) * 2001-02-12 2003-08-07 Deutsche Post Ag Procede pour controler l'affranchissement appose sur un envoi postal
AU2002242605B2 (en) * 2001-02-12 2007-03-22 Deutsche Post Ag Method for monitoring prepaid stamps on mail
CN100334600C (zh) * 2001-02-12 2007-08-29 德国邮政股份公司 检查邮件上预付邮票的方法
US7646885B2 (en) 2001-02-12 2010-01-12 Deutsche Post Ag Method for monitoring prepaid postage indicia on mail
WO2003083419A1 (fr) * 2002-03-28 2003-10-09 Valtion Teknillinen Tutkimuskeskus Procede et spectrometre permettant de mesurer un spectre raman
US9818249B1 (en) 2002-09-04 2017-11-14 Copilot Ventures Fund Iii Llc Authentication method and system
US6995839B1 (en) * 2002-10-08 2006-02-07 Shapiro Frederick W Automated Raman scanner for documents and materials
US8896885B2 (en) 2004-03-12 2014-11-25 Ingenia Holdings Limited Creating authenticatable printed articles and subsequently verifying them based on scattered light caused by surface structure
GB2411954B (en) * 2004-03-12 2006-08-09 Ingenia Technology Ltd Authenticity verification methods,products and apparatuses
GB2411954A (en) * 2004-03-12 2005-09-14 Ingenia Technology Ltd Determining a signature from an article to verify its authenticity
US9019567B2 (en) 2004-03-12 2015-04-28 Ingenia Holdings Limited Methods and apparatuses for creating authenticatable printed articles and subsequently verifying them
WO2007044268A1 (fr) * 2005-10-04 2007-04-19 Nu Skin International, Inc. Instrument raman permettant de mesurer des signaux faibles en présence de forte fluorescence de fond
WO2008028476A3 (fr) * 2006-09-07 2008-09-04 Bundesdruckerei Gmbh Document de sécurité et / ou de valeur à particules sers
US8179526B2 (en) 2007-01-25 2012-05-15 Renishaw Plc Spectroscopic apparatus with dispersive device for collecting sample data in synchronism with relative movement of a focus
EP2111542A2 (fr) * 2007-01-29 2009-10-28 Cambrius, Inc. Analyseur chimique pour contrôle de procédé industriel
US8305571B2 (en) 2007-05-03 2012-11-06 Renishaw Plc Spectroscopic apparatus and methods
US9222043B2 (en) 2009-09-22 2015-12-29 Authentix, Inc. Dipyrromethenes and azadipyrromethenes as markers for petroleum products
US8892556B2 (en) 2009-11-10 2014-11-18 Ingenia Holdings Limited Optimisation

Also Published As

Publication number Publication date
CA2075056A1 (fr) 1991-08-03
GB9002335D0 (en) 1990-04-04
EP0513025A1 (fr) 1992-11-19

Similar Documents

Publication Publication Date Title
WO1991011703A1 (fr) Appareil detecteur
EP0721717B1 (fr) Procede et systeme d'authentification
US5574790A (en) Fluorescence authentication reader with coaxial optics
US7218386B2 (en) Detection of printing and coating media
US7092583B2 (en) Apparatus and method for detecting the authenticity of secured documents
KR101297702B1 (ko) 적분된 투과 및 반사 스펙트럼 응답을 이용한 개선된 위조 화폐 검출기
US5903340A (en) Optically-based methods and apparatus for performing document authentication
EP2504819B1 (fr) Appareil d'authentification pour documents de valeur en mouvement
RU2183861C2 (ru) Способ установления подлинности документа, аппарат и система для его осуществления
EP1066602B1 (fr) Procedes et appareil permettant de surveiller des articles
KR20070039953A (ko) 가치 증서를 검사하는 장치 및 방법
EP0198819B1 (fr) Appareil pour controler l'authenticite de billets de banque
GB2122743A (en) Apparatus for authenticating bank notes
US10950079B2 (en) Method and apparatus for determining the authenticity of flat objects: banknotes, documents, security labels, and related items
Wlodarski et al. Application of advanced optical methods for classification of air contaminants

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA GB US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE

WWE Wipo information: entry into national phase

Ref document number: 1991901881

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2075056

Country of ref document: CA

WWP Wipo information: published in national office

Ref document number: 1991901881

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1991901881

Country of ref document: EP