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    • 专利摘要:
    SCANNER, METHOD AND SYSTEM TO DETERMINE A LIGHT INTENSITY PROFILE OF A LUMINESCENT MATERIAL. The present invention relates to a scanner (1) that allows detecting the time-to-decline characteristics of the light emitted by a luminescent mark on an item that is transported, even at high speed, in a distribution / production line. The detection zone (10) of the light sensor (5) of the scanner (1) has an elongated shape along a path of the moving item and the responsiveness of the light sensor (5), within the wavelength range of the emitted luminescence light, it is uniform across the detection zone (10). The control unit (6) of the scanner (1) is further operable to adapt the drive current, or drive voltage, which supplies energy to the excitation light source (3) to adapt the light intensity of the light in this way. excitation delivered to the marking so that its light sensor (5) can easily measure the corresponding luminescence light response and thus accurately determine a corresponding decline time value.
    公开号:BR112013031399B1
    申请号:R112013031399-4
    申请日:2012-06-01
    公开日:2021-01-19
    发明作者:Milan Vasic；Nicola Duca
    申请人:Sicpa Holding Sa；
    IPC主号:
    专利说明:

    TECHNICAL FIELD
    The present invention relates to the field of the technique of optical devices for determining time-out characteristics of luminescence light emitted by a luminescent material. In particular, the invention relates to optical devices such as optical scanners for authenticating an item marked with a luminescent material based on the time characteristics of luminescence light decline emitted by said luminescent material. BACKGROUND OF THE INVENTION
    Luminescent materials are commonly used in security markings to be placed on documents or articles or in bulk material for documents or articles, as an authenticity feature. A luminescent material typically converts energy from excitation radiation of a given wavelength into emitted light that has a different wavelength. The luminescence emission used for authentication of a mark can be in the spectrum of UV light spectrum (200 to 400 nm), visible light (400 to 700 nm) or close to the medium infrared light (700 to 2,500 nm).
    An "upward converter" material emits radiation at a wavelength shorter than that of excitation radiation. In contrast, a "downward converter" emits radiation at a wavelength longer than that of excitation radiation. Most luminescent materials can be excited at more than one wavelength and some luminescent materials can emit simultaneously at more than one wavelength.
    Luminescence can be divided into: (i) phosphorescence, which refers to the emission of radiation delayed in an observable time after excitation radiation is removed (typically, with a declining life span of above 1 μs at about 100 s) , and (ii) fluorescence, which refers to the emission of immediate radiation upon excitation (typically, with a declining life span below 1 μs).
    Thus, a luminescent material, upon illumination with excitation light within a first wavelength range, emits luminescence light within a second wavelength range, which may differ or overlap with said first wavelength range. depending on the luminescent material used. A characteristic spectral property of a luminescent material such as its emission light intensity profile over time, or its characteristic decline time after the excitation has ceased, for example, constitutes a signature of a presence of that same material and can thus be used as an authenticity feature to detect the authenticity or falsification of a luminescent mark.
    Luminescent materials are classic ingredients of paints and safety coatings. For example, the following patents disclose luminescent substances, which may include mixtures of pigments that have distinct decline time properties and safety paper that includes such substances: EP 0 066 854 B1, US 4,451,530, US 4,452,843, US 4,451,521. The processes and devices for detecting the luminescence light and authenticity of a marked item are also well known: see, for example, US 4,598,205, or US 4,533,244, which reveal the declining behavior of sensing luminescence emissions. The luminescent coded symbols are known from US 3,473,027 and an optical reader for luminescent codes is disclosed in US 3,663,813. The patents in US 6,996,252 B2, US 7,213,757 B2 and US 7,427,030 B2 disclose the use of two luminescent materials, which have different decline time properties, to authenticate an item.
    Typically, a scanner according to the known technique for detecting time-dependent luminescence light comprises a power source, or a connection to a power source, a light source (connected to the power source) to illuminate a luminescent material with excitation light, a light sensor to measure a luminescence light intensity emitted by the luminescent material and a control unit (processor) to control the power source, light source and light sensor to acquire and store a profile intensity of the emitted luminescence light and calculate a decline time value from that intensity profile. A luminescence emission intensity profile (or intensity versus time curve) comprises successive emission values I (t1), ..., I (tn) of a luminescent material measured at consecutive times t1, ..., tn, which together form a luminescence emission curve I (t).
    The light source in such a scanner, depending on the part of the spectrum used for detecting the luminescent material, can be an incandescent lamp, typically for wavelengths between about 400 nm to about 2500 nm, used with mechanical devices or opto devices. -electronics to deliver pulsed light delivery or a flash lamp (for example, a high pressure Xenon flash lamp) or a laser or Light Emitting Diode (LED), which emits in the UV, visible or IR region, typically for wavelengths from about 250 nm to about 1 μm. The light source can be energized by a drive current (for an LED, for example) or a drive voltage (for a discharge lamp, for example).
    The light sensors or photodetectors in such a scanner can be photodiodes (single or arrays), phototransistor or photoresist circuits, linear CMOS or CCD sensors, for example.
    The scanner, in addition to its specific power module to supply the scanner with power, can also comprise a communication module, which can be a radio module for wireless communication (for Wi-Fi, for example), a display module, for example, an LCD liquid crystal display, or kinescope display, for displaying measured data or scanning parameters and a control interface for entering scanning conditions, including control switches that have multiple functions and an ON / OFF switch. .
    More normally, the time-dependent intensity curve of luminescence emission light (ie intensity profile with time) of a luminescent material is modeled by an exponential law I (t) = I0 exp (-α [t-t0 ]), in which time t is counted from the initial time t0 in which the excitation light that illuminates said material is turned on. Thus, obtaining a value corresponding to the α rate of decline constant that characterizes the luminescent material requires measurement, after the excitation has been interrupted, an emission intensity profile composed of successive emission intensity values I (t1), ..., I (tn), for a period of time. The decline time value t from the intensity profile I (t) corresponds to α-1. In commercially available scanners, a pulsed light source illuminates the luminescent material with an excitation light of a given intensity, in a first wavelength range, during an excitation time interval. After the illumination has ceased, possibly with a time delay, the light sensor starts measuring successive values of the luminescence light declining intensity in a second wavelength range for a measurement time interval and the profile corresponding luminescence intensity is stored in a memory. The operation can be repeated in order to obtain more reliable average values. Usually, it is possible to define the excitation time interval and / or the time delay in order to avoid luminescence intensity measurement values below a light sensor detection limit value or above its saturation limit value. .
    However, the variants are also known. For example, US Patent No. 6,264,107 B1 discloses the determination of a time of decline from the time required for the intensity of latent phosphorescence to be across two predetermined limits. This patent reveals a scanner that comprises a flood LED (FLED) as a light source, that is, a very intense light source. Such an intense light source is, in fact, necessary in this case to carry enough a label that comprises the luminescent material (phosphor) and that prevents the problem of low signal response.
    In another approach, US Patent No. 7,262,420 B1 discloses the execution of multiple illuminations with excitation light to obtain a single time-to-decline value: the light source is activated successively (during the same excitation time interval) and a single luminescence intensity measurement is performed after the illumination of the luminous material with the excitation light source has been switched off, but each successive measurement is performed with a different contact time delay from the time the light of excitation is switched off. However, this method is time consuming, as it requires a lighting value by measured intensity. However, in order to obtain more reliable results, this method requires repeated measurements that correspond to the same time delay.
    In order to obtain a stronger luminescence signal, some scanners allow to define the excitation time interval, in order to "charge" enough the luminescent particles in the luminescent material (that is, to excite a large number of such luminescent particles to obtain emission of more intense luminescence). However, for a better accuracy of the determined time of decline value, a plurality of valid intensity profiles is successively acquired (for example, about one hundred), these curves are then added together and an average curve is calculated. The increased precision is obtained if the signal resulting from the measured intensity is normalized and the normalized signal is used to calculate the value of time of decline. An intensity profile is valid if the intensity value of at least the first point of the intensity profile is above a detection limit of the light sensor and below its saturation limit (if the said value is too low or too high , the excitation time is increased or decreased respectively). However, a problem arises in the case where the excitation time interval is too short to allow a reliable normalization of the luminescence intensity signal, particularly for luminescent materials that include a mixture of luminescent particles of different types and of which the values Decay times are widely different (for example, particles that have the shortest decline time may not be detected by the scanner). Another problem that arises with the use of variable excitation time is that the luminescent material is not excited under the same conditions for all intensity profiles and, in the case of a material that includes a mixture of luminescent pigments that has properties of distinct decline, this can cause confusion. For example, Figures 1A and 1B illustrate a case of profiles of normalized intensity of a marking with an ink (luminescent material) including two types of luminescent pigments: pigments P1 and P2; in this example, the decline time value for P1 pigments is about 100 μs and the decline time value for P2 pigments is about 500 μs. Fig. 1A shows an excitation curve 1 that has a long excitation time interval of 100 μs and a corresponding normalized luminescence intensity profile (P1 + P2) for a luminescent paint material that is a mixture of 50% of the first P1 pigments (which have the shortest decline time or highest decline rate) and 50% of the second P2 pigments (which have the longest decline time or lowest decline rate). Fig. 1B corresponds to a luminescent ink that includes a mixture of 42% of the first pigments P1 and 58% of the second pigments P2. In this case, the excitation time was adjusted to a shorter value of 10 μs, as shown in excitation curve 2. Although the pigment concentrations in pigment mixtures P1 and P2 differ significantly from Fig. 1A to Fig. 1B , the normalized luminescence intensity profiles (P1 + P2) are very similar and can hardly be distinguished. Thus, it is not always possible, or it can be difficult, to detect a difference between two mixtures based on the luminescence intensity profiles obtained by varying the excitation time. Although the above example refers to pigments that have typical decline time values of around hundreds of microseconds, a similar conclusion remains for pigments that have much longer decline time values (a few ms or more).
    Another problem that arises with said known time-of-decline scanners is that they do not allow you to acquire a luminescence intensity profile and thus determine a corresponding time-to-decline value, or time-to-decline values and also concentrations in the case a mixture of different types of pigments, in the event that the luminescent material is moving through the scanner; particularly, in the case where the luminescent material moves quickly through the scanner on a production / distribution line. For example, in the case of items marked with a luminescent material and transported on a conductive belt of a production line that moves with a typical speed of about 200 to about 400 m / min (that is, about 3 to 6 m / s), it is clearly not possible to acquire a luminescent intensity profile I (t), even if the luminescent material has a very long decline time value of a few ms or more. Thus, the identification / authentication of said marking in motion is not possible online: for example, authentication of a luminescent marking such as a bar code or a data matrix on an item transported on a conductive belt. Consequently, secure online identification and tracking operations based on such online determination of a luminescent intensity profile are not possible, although highly desirable. SUMMARY OF THE INVENTION
    The present invention aims to provide a scanner and a method to determine an intensity profile of a luminescence emitting light of a luminescent material and a time of decline of said luminescent material that overcomes the disadvantages of the prior art mentioned above.
    The invention also relates to a system for the online identification / authentication of an item marked with a luminous material and transported on a distribution / production line, possibly at high speed, based on the characteristics of time of use. decline of this material, with the use of the specific scanner and the method of detecting the time of decline according to the invention.
    Thus, the invention allows online operations for the identification / authentication of an item marked with a luminescent material, based on the determination, from a measured intensity profile, of the time of decline of said material or, in the case of of a material that includes a mixture of luminescent particles that have different decline time characteristics, decline time values and concentrations corresponding to each type of particle in the mixture.
    According to one aspect of the invention, a scanner for determining a luminescence light intensity profile of a luminescent material that moves through said scanner along a path in a first direction, wherein said luminescent material emits said luminescence light within a second wavelength range upon illumination with an excitation light within a first wavelength range comprises: a power source; a light source connected to the power source and operable to illuminate with the said excitation light the luminescent material within a lighting area, when energized by the power source; a light sensor operable to measure an intensity of said luminescence light received from the luminescent material within a detection zone of said scanner and to deliver a corresponding luminescence intensity signal; and a control unit connected to the light sensor and operable to determine an intensity profile of said luminescence light received from luminescence intensity signals delivered by the light sensor, in which: said lighting area is in a first location along said path; said detection zone is in a second subsequent location along said path in the first direction and extends over a portion of said path; said light sensor is operable to collect luminescence light from the luminescent material during its movement along the path in the first direction through the detection zone and measure an intensity of said luminescence light collected within said second wavelength range and deliver a corresponding luminescence intensity signal; and said control unit is operable to control said power source, the light source and the light sensor and to determine said intensity profile from the luminescence intensity signal delivered by said light sensor upon receipt of the light. of luminescence emitted by said luminescent material that moves through said detection zone in the first direction, in response to illumination with said excitation light within said lighting area.
    The light source can be equipped with an optical filter to deliver excitation light within the first selected wavelength range. In addition, the light sensor can be equipped with an optical filter adapted to receive only the luminescence light that is within the second wavelength range. The respective first and second locations of the lighting zone and the detection zone can be separated or can be overlapped. This latter compact arrangement is more convenient in the case of a luminescent material that has a short decline time value and / or a slow movement of said material that passes through the scanner.
    The specific detection zone above that extends along a path in the direction of movement (that is, along a path) of the luminescent material, together with the light sensor is specifically adapted to collect luminescent light emitted while the luminous material - nescent is crossing this elongated detection zone, in fact it allows the scanner to "follow" said emitting material for a much longer period compared to a prior art scanner, even if the luminous material moves quite fast through the scanner. In fact, the typical length L of the detection zone along the direction of movement, for a given typical speed V of the luminescent material that travels through said detection zone (for example, an average speed), can be determined so that the corresponding measurement time interval Δt of the emitted luminescent intensity is sufficient to acquire a luminescent intensity profile I (t): for example, with L> V Δt.
    The above scanner according to the invention can also have its light sensor adapted so that the responsiveness (that is, the ratio between generated photocurrent, or output voltage, incident optical power), within the second wavelength range ( that is, the luminescence emission range of the luminescent material considered), of said light sensor is substantially uniform throughout the detection zone. Substantially uniform means that the responsiveness of the light sensor to a luminescence emission received from a part of the detection zone is constant or only oscillates around an average value, for example, by no more than 10% and, preferably, not more than 5%, depending on the location of that part within the detection zone. This substantial uniformity of the responsiveness of the light sensor to the detection zone allows the elimination of the contributions of the measured intensity profile I (t) corresponding to a degraded quantum yield of the light sensor for the detection of photons received from a certain region of the region. detection zone in relation to photons received from another region of the detection zone. As a consequence, the acquired intensity profile shows a variation in intensity over time that is practically unique due to the radiative de-excitation of the luminescent particles with time in the luminescent material. The reliability of the determined intensity profile is thus increased. Consequently, it is also possible to obtain a more reliable value of the time of decline from such an intensity profile. Ideally, the responsiveness should be close to the highest possible value for the luminescence wavelength range considered, but still within the linear response range of the light sensor, in order to have a high signal-to-noise ratio and sensitivity high for measurements. The spatial uniformity of the light sensor's responsiveness across the detection zone has the additional advantage of allowing very high reliable sampling rates for the acquisition of the intensity profile, so that the acquired profile I (t) approaches a curve better. "to be continued". Such a better intensity profile curve allows for more reliable interpolation, for example, in view of derivation operations or precise integration based on the curve: this is particularly useful in the case of complex luminescence signatures of a mixture of different types of luminescent particles, to extract precise concentration values and time-to-decline values from the constituents of the luminescent material.
    The scanner control unit can be further adapted to control that this responsiveness of the light sensor is, in fact, substantially uniform across the detection zone, that is, it is comprised within authorized limits around an authorized average value.
    A light sensor of a scanner according to the invention can have different configurations corresponding to the elongated detection zone mentioned above and / or substantially uniform responsiveness for said detection zone.
    The above scanner according to the invention can thus have: said light sensor which comprises a plurality of photodetectors arranged successively along said first direction, in which each photodetector is operable to measure an intensity of luminescence light received at starting from a corresponding detection area within the detection zone, within the second wavelength range and delivering a corresponding photodetector luminescence intensity signal, wherein the set of corresponding detection areas covers said detection zone; and said control unit which is operable to determine said intensity profile from the luminescence intensity signals delivered by said photodetectors upon receipt of the luminescence light emitted by said luminescent material that moves through said detection areas at the along the said route in the first direction.
    In contrast to a possible case of a "monoblock" light sensor that has, for example, a monoblock CDD array to detect the collected photons, the configuration above the light sensor corresponds to separate photodetectors that are spaced in order to collect luminescence photons from the detection zone and connected to a set of circuits so that the light sensor can measure the light intensity of a luminescent material that moves through the entire detection zone. These photodetectors can be photodiodes connected in parallel, for example. In addition, any two successive photodetectors of said plurality of photodetectors are arranged to have their respective detection areas partially overlapped so that a responsiveness of the light sensor within said second wavelength range is substantially uniform across said detection zone.
    In another configuration of the above scanner according to the invention, the light sensor may comprise a plurality of optical waveguides, wherein each waveguide has an operable entrance to collect luminescence light within said second wavelength range. of a corresponding detection area within said detection zone, in which the plurality of waveguide entries are arranged successively along said first direction and in which the set of corresponding detection areas covers said detection zone. For example, said optical waveguides can be optical fibers. Furthermore, said optical waveguides can be arranged to have their respective detection areas partially overlapped so that a responsiveness of the light sensor within said second wavelength range is substantially uniform across said detection zone. This configuration can correspond, for example, to a light sensor that has a compact CCD sensor array for capturing photons, in contrast to a light sensor that has an extended monoblock CCD sensor array, for example, by the entire length of the detection zone in order to collect the light directly from it. For example, in the case of optical waveguides that are optical fibers to collect luminescence light from an item marked with a luminescent material that is transported on a conductive belt, the roads of these optical fibers are spaced (between them along the direction movement and at a distance above the luminescent mark) and so that their acceptance cones (or numerical openings) delimit said areas of partial overlap within the detection zone.
    The light sensor may further comprise an operable focusing device for focusing the luminescence light received from the detection zone. This can help to reduce a restriction on acceptance cones for waveguide entries, for example. In addition, the light source may comprise operable focusing means for focusing the excitation light in said lighting area. In particular, said focusing means can focus the excitation light produced by a plurality of LEDs that produce the excitation light within the first wavelength range. This light source configuration allows the luminescent material to be supplied with a high excitation light intensity to better "charge" it and is also convenient for pulsating light sources.
    According to the invention, any of the above scanners can further comprise: a trigger unit operable to detect that the luminescent material is within the illumination area of the light source and deliver a corresponding trigger signal; and the control unit is further operable to control the light source to deliver the excitation light pulse to the luminescent material within the illumination area upon receiving said trigger signal from the trigger unit and controlling the light sensor to acquire the intensity profile after the lighting has ceased.
    This configuration allows to precisely synchronize the movement of the luminescent material through the illumination area of the light source and the detection zone with the luminescence intensity profile acquisition operations, that is, illumination with the light source only while the luminescent material is within the illumination area, followed by the luminescence intensity measurement with the light sensor after the illumination has ceased, while the luminescent material crosses the scanner's detection zone.
    A scanner that has its light sensor comprising a plurality of photodetectors, as described above, can be further adapted to synchronize the movement of the luminescent material through the detection zone with operations to measure the luminescent intensity so that the intensity values I ( t1), ..., I (tn) are acquired only while the luminescent material is in specific locations within the detection zone. For example, when the luminescent material is positioned in relation to a photodetector so that the irradiation of that photodetector is maximum. Consequently, the successive values I (ti) of the acquired intensity profile correspond to consecutive positions of the luminescent material in which the response of the corresponding photodetector submitted to said maximum irradiation is more reliable. In addition, the control unit can also only select the response of that same photodetector subjected to maximum irradiation as a constituent of the intensity signal measured by the light sensor when the luminescent material is in the corresponding location in the detection zone.
    Thus, the invention also relates to a scanner that has its light sensor comprising a plurality of photodetectors, as described above, in which the scanner further comprises an operable position sensor for determining a position of the luminescent material within said zone of detection and deliver a corresponding position signal; the control unit is further operable to receive a position signal from said position sensor and determine said intensity profile only from the consecutive luminescence intensity signals corresponding to the consecutive positions of the luminescent material within each of the detection areas successive intervals in which the radiation from the light sensor is maximum.
    According to the invention, in order to better detect a difference between intensity profiles of luminescent materials that include mixtures of different types of luminescent particles (ie, which have different decline time characteristics), any of the above scanners may have yet its operable power source to deliver a variable drive current or drive voltage of the light source in order to obtain more reliable luminescence intensity signals. Thus, according to the invention, define the intensity of the excitation light by means of the intensity of the drive current or the value of the drive voltage (depending on the power supply adapted to the light source), so that the luminescence signal detected is acceptable (that is, it is within the reliable operating range of the light sensor), it allows both to obtain more reliable luminescence intensities and to have the same excitation time for each luminescence intensity profile. The luminescence intensity value can be considered acceptable by the control unit if it is within a given range of luminescence intensity values. For example, in the case mentioned above of two different mixtures of luminescent pigments P1 and P2, change the excitation light flow for the same excitation time (that is, change only the respective illumination intensities at t0 for the decline curve of P1 and for the P2 decline curve) allows to discriminate, or to discriminate better, between the different concentrations directly in the normalized profiles of these mixtures. This is illustrated in Fig. 2A and 2B. Fig. 2A shows a luminescence intensity profile for the aforementioned mixture of 50% P1 pigments and 50% P2 pigments, for a constant excitation time interval of 100 μs. Fig. 2A is in fact identical to Fig. 1A. Fig. 2B shows a luminescence intensity profile for the above mentioned mixture of 42% P1 pigments and 58% P2 pigments, for the constant excitation time interval of 100 μs, but the excitation light intensity of illumination has been changed compared to the case of Fig. 2A. A difference between the normalized decline curves in Fig. 2A and Fig. 2B is now clearly visible: for example, the point of intersection between the normalized intensity profile (P1 + P2) and the horizontal line corresponding to the ordered value of 0, 2 has an abscissa value of about 280 μs in Fig. 2B and only about 250 μs in Fig. 2A. Thus, varying the excitation light intensity clearly allows you to discriminate mixtures of luminescent particles, even if those particles have widely different decline times. Thus, the invention refers to a scanner in which: said power source is still operable to deliver a driving current or variable driving voltage; said light source is further operable to produce said excitation light with an intensity that varies according to the drive current or drive voltage delivered; and said control unit is further operable to control said power supply to define a value of the drive current or a value of the drive voltage delivered to the light source so that a value of luminescence intensity corresponding to a signal of luminescence intensity delivered is within a given range of luminescence intensity values. For example, the luminescence intensity value can be above a light sensor detection limit and below a light sensor saturation limit, that is, within a reliable light sensor detection range. The range of luminescence intensity values can also ensure that a signal-to-noise ratio of measured luminescence intensity is above a threshold value and / or the light sensor does not saturate during the corresponding measurement operation. For example, depending on the measured level of luminescence intensity detected by the light sensor at the end of the lighting cycle, the control unit can adapt the intensity level of the excitation light that is blocked by the light source, by varying the driving current ( or activation voltage) delivered by the power source, so that a luminescence intensity signal delivered at the beginning of the intensity measurement cycle (that is, just after the end of the illumination by the light source) corresponds to an intensity value close to the saturation level of the light sensor, but still below the said saturation level: in this case, the measured values are highly reliable and the data extracted from the intensity profile are more accurate.
    In addition, the light sensor can also have its detection limit and saturation limit adjustable and the control unit can still be operable to adjust a value of these limits. This is particularly interesting for the detection with the light sensor of a deviation value of a signal intensity corresponding to the illumination of the luminescent material only with an ambient light (that is, without illumination through the light source) to be subtracted from the signals of intensity that constitute the intensity profile, to eliminate any disturbance corresponding to the said ambient light: in the case where the deviation value is outside the detection range of the light sensor, the control unit can further adjust the detection range of so that the deviation value is within the modified detection range. Consequently, the luminescence intensity values to be measured by the light sensor (to constitute the luminescence intensity profile) in the presence of said ambient light will be within said modified detection range then adapted to the specific real measurement conditions, even if the luminescence level is low and the resulting luminescence intensity profile will be more reliable.
    According to the invention, the light source can be further operable to deliver light for an adjustable excitation time interval and the control unit can still be operable to control said light source to define the time interval of excitation. excitement. Thus, in the case where the intensity of the activation current (or activation voltage) of the light source is at its maximum, it is, however, still possible to increase the charge of the luminescent material by increasing the excitation time.
    In addition, in the scanner according to the invention, the control unit can be further operable to control the light sensor to measure a luminescence light intensity collected with a time delay after the excitation time interval has elapsed. In addition, the control unit can also be operable to define said time delay. Thus, it is possible to better discriminate luminescent materials that have very different decline time characteristics. If necessary, the excitation time interval and / or the time delay after the end of the illumination can thus be further defined to achieve the above objective of obtaining a luminescence intensity value at the beginning of the next intensity measurement cycle. at the saturation level.
    The invention also relates to a scanner as described above, in which the control unit is still operable to determine a time-to-decline value of the luminescent material from said determined intensity profile. Many knowledgeable techniques are known to the skilled person to calculate a decline time value from an intensity profile.
    Any of the above scanners according to the invention can have its control unit still operable to authenticate said luminescent material in the case of the determined intensity profile I (t) of the luminescent material corresponds to a given luminance intensity profile of reference Iref (t) stored in a memory of the control unit, in which said profile of luminescence intensity reference is a profile of luminescence intensity of a luminescent reference material. Thus, the curve formats are used as authentication features, instead of mere intensity values of individual measurements.
    For example, in order to have an even more reliable comparison of the intensity profiles I (t) and Iref (t), each intensity profile can first be normalized and the normalized profiles are then compared. This normalization has the effect that the comparison becomes model-free and also largely independent of possible intensity deviations due to aging, alterations or dirtiness of the considered luminescent material marking. For example, both the luminescence intensity profiles I (t) and Iref (t) are scaled, so that the highest values of both profiles coincide: if the resulting normalized profiles l (t) and lref ( t) match within a given tolerance, then the luminescent material is considered to correspond to the reference luminescent material (that is, it is genuine).
    The invention also relates to a scanner that has its control unit operable to determine a time value of decline of the luminescent material from the determined intensity profile (see the previous one), in which said control unit is still operable to authenticate said luminescent material in the event that the value of time of decline of the luminescent material determined from said intensity profile corresponds to a given value of time of decline of reference stored in a memory of the control unit, in which the said reference decline time value corresponds to a decline time value of a luminescent reference material. For example, the control unit can test whether these decline time values correspond, within a given margin of error: in the case of correspondence, the luminous material is considered to be genuine. The authentication operation can, in addition to the comparison of values of determined time of decline and reference, also comprise a comparison of the measured intensity profiles I (t) and reference Iref (t) (the latter being also stored in the unit's memory. control) and / or a comparison of an additional characteristic extracted from these intensity profile curves, such as the respective concentrations in luminescent particles within the luminescent material and the luminescent reference material, as known in the art.
    Another aspect of the invention relates to a method for determining a luminescence light intensity profile of a luminescent material that moves through a scanner according to the invention along a path in a first direction, in which said luminous material emits said luminescence light from within a second wavelength range by means of illumination with an excitation light within a first wavelength range, in which said method comprises the steps of: illuminating the luminescent material that moves through the scanner in the first direction, as it crosses the scanner's lighting area, with an excitation light within the first wavelength range through the scanner's light source; according to the luminescent material, after being illuminated with the excitation light, it still moves in the first direction and enters the detection area of said scanner, measure an intensity of luminescence light emitted by said luminescent material within the second range of wavelength as it crosses the detection zone by means of said light sensor and delivers a luminescence intensity signal corresponding to the scanner control unit; determine an intensity profile from the luminescence intensity signal received by the control unit.
    The invention also relates to a method for determining an intensity profile and detecting a luminescence light decline time of a luminescent material that moves through a scanner according to the invention (as described above) over a period of time. path in a first direction, in which said luminescent material emits said luminescence light within a second wavelength range by means of illumination with an excitation light within a first wavelength range, in which said method comprises the steps of: illuminating the luminescent material that moves through the scanner in the first direction, as it crosses the scanner's illumination area, with an excitation light within the first wavelength range through the scanner's light source ; according to the luminescent material, after being illuminated with the excitation light, it still moves in the first direction and enters the detection zone of said scanner, measure an intensity of luminescence light emitted by said luminescent material within the second range of length of wave while it crosses the detection zone by means of said light sensor and delivers a luminescence intensity signal corresponding to the scanner control unit; determine an intensity profile from the luminescence intensity signal received by the control unit; and determining a value for the time of decline of the luminous material from said determined intensity profile.
    The scanner control unit can be programmed to perform the steps above the method according to the invention. The above method can further comprise a control step that a responsiveness of the light sensor within the second wavelength range is substantially uniform across the scanner's detection zone. For example, the control unit can control even if the light sensor responsiveness is within authorized limits around an authorized average value.
    In the case of a scanner according to the invention comprising a power source operable to deliver a drive current or variable drive voltage to the light source, as mentioned above, the method according to the invention may further comprise the steps of : (a) define a value of the drive current or a value of the drive voltage, delivered by the power source; (b) illuminating the luminescent material during said excitation time interval with the light source energized with said driving current value or driving voltage; (c) measuring a corresponding value of the luminescence light intensity of the luminescent material with the light sensor after said excitation time interval; (d) judge whether the said measured value of luminance intensity is acceptable, that is, it is within a given range of luminescence intensity values, and if it is acceptable, (e) store the measured value in a memory of the control unit as a corresponding point of said intensity profile; and (f) carry out steps (c) and (e) successively until the completion of said intensity profile for the measurement time interval; or, if not acceptable, (g) define a modified value of the drive current or a modified value of the drive voltage, delivered by the power source in step (a) and illuminate the luminescent material in step (b) with the source of light energized with said modified value of the drive current or drive voltage and then perform steps (c) to (f); and (h) determining a decline time value from said stored intensity profile.
    Setting the excitation light intensity by means of the drive current or drive voltage (depending on which supply is suitable for the light source), so that the de-detected luminescence signal is acceptable, allows you to measure reliable intensity profiles which correspond to the signals obtained under the same lighting conditions (that is, with the same excitation time). Thus, the above method particularly allows for much better discrimination between luminescent materials that include mixtures of luminescent particles that have distinct decline time characteristics and that differ only by their respective concentrations in said particles.
    In step (h), the stored intensity profile can be further normalized and the decline time value is then determined from the normalized intensity profile. This normalization allows for better accuracy of the determined decline time values.
    The above method, with said scanner control unit still being operable to adjust a value of said detection limit and saturation limit, can also comprise: a preliminary step of acquiring a signal of initial intensity of the light sensor, without illuminate the luminescent material with the light source, to obtain a corresponding deviation value that corresponds to an ambient light; and, in the case where said initial intensity signal is outside said detection range of the light sensor, modify the detection range by a step of setting the duct limit of detection value or said limit value of saturation, so that said initial intensity signal is within the modified detection range; then, in step (c), subtract said value of deviation from the luminescence intensity signal delivered by the light sensor to obtain said measured value of luminescence light intensity, and, in the case where the detection range was modified, in step (d), with the use of said modified detection range as the detection range of the light sensor. Thus, a possible contribution of ambient light to the luminescence light detected by the light sensor is then removed and the luminescence intensity profile obtained and the corresponding single-time decline value refer to the luminescent light by the luminescent material. Consequently, the accuracy and reliability of measurements are further increased.
    In a variant of the method according to the invention, in which the light source is operable to deliver light for an adjustable excitation time interval and the control unit is further operable to control the light source to define the time interval of excitation, in the case where, in step (d), a measured value of the luminescence light intensity is not acceptable and the corresponding value of the driving current or the corresponding value of the driving voltage is below a first limit value, then step (g) includes a preliminary step of decreasing said excitation time interval, or, in the case where, in step (d), a measured value of the luminescence light is not acceptable and the corresponding value of the intensity of the drive current or the corresponding value of the drive voltage is above a second limit value, so step (g) includes a preliminary step of increasing said excitation time interval. Thus, even if the drive current or the drive voltage is very low (that is, below said first limit value) or very high (that is, above said second limit value), it is possible to try to have a luminance signal acceptable by adjusting the excitation time interval. It is also possible to include a mere preliminary step of defining the excitation light (regardless of any condition in the drive current or drive voltage and the measured luminescence signal).
    In the above method according to the invention, in step (c), for the first point of the intensity profile corresponding to the value of the drive current or the value of the drive voltage defined in step (a), said measurement of the intensity of the luminescence light can be executed with a time delay after said excitation time interval has elapsed. In addition, the control unit can further define this time delay.
    With a scanner according to the invention that has its control unit still operable to authenticate the luminescent material based on a time of decline value determined from the emitted luminescence light, the above method for determining an intensity profile can comprise an additional step of authentication of said luminescent material in the case where the value of time of decline of the luminous material determined from said intensity profile corresponds to the given value of time of decline of reference stored in the memory of the unit control panel. For example, if the measured decline time value substantially matches the reference decline time value, the item is considered to be genuine.
    With a scanner according to the invention that has its control unit still operable to authenticate the luminescent material based on a comparison of a determined intensity profile with a reference intensity profile, as described above, the above method according to the invention comprises the additional step of: authenticating said luminescent material in the case where the value of time of decline of the luminescent material determined from said intensity profile corresponds to a given value of time of decline of reference stored in a memory of the control unit, wherein said reference decline time value corresponds to a decline time value of a reference luminescent material.
    Finally, the invention relates to a system for determining a luminescence light intensity profile of a luminescent material that moves through a scanner according to any of the above variants according to the invention over a period of time. path in a first direction on a production / distribution line, in which said luminescent material emits said luminescence light within a second wavelength range by means of illumination with an excitation light within a first wavelength range delivered by the light source of said scanner, in which said scanner is installed in said production / distribution line, in which the control unit of said scanner is programmable and includes a program which, when executed in said control unit, makes the operable control unit implements the steps of the corresponding method above to determine the intensity profile according to the invention.
    The present invention will be described more fully hereinafter with reference to the accompanying desires in which similar numerals represent similar elements throughout the different figures and in which the prominent features and features of the invention are illustrated. BRIEF DESCRIPTION OF THE DRAWINGS
    Figures 1A and 1B, respectively, show the normal decline curves of a conventional scanner with definition of excitation time and the light excitation curves for two luminescent materials corresponding to mixtures of different concentrations in luminescent ink pigments P1 and P2 that have distinct time-to-decline characteristics. Figures 2A and 2B, respectively, show the normalized decline curves of a scanner according to the invention, with constant excitation time per intensity profile and the light excitation curves for the two luminescent materials corresponding to the same mixtures as for Figures 1A and 1B. Fig. 3 is a schematic illustration of an optical block of a scanner according to the invention. Fig. 4 illustrates a lighting cycle for a light source from the scanner in Fig. 3. Fig. 5 illustrates a responsiveness curve of one of the photosensors in the light sensor of the scanner in Fig. 3. Fig. 6 illustrates a responsiveness curve of the light sensor of the scanner of Fig. 3. Fig. 7 illustrates an electrical circuit diagram of a scanner according to the invention. DETAILED DESCRIPTION
    The operation of a scanner to detect the time-to-decline characteristics of a luminescent material according to an example of a modality of the invention is illustrated with Figures 3 to 9. Scanner 1 is installed on a production line: items marked with a luminescent material 7 that emits in the near infrared (NIR), when excited with light within a shorter wavelength range (that is, said first wavelength range), are transported on a conductive belt 2 of the line at a typical speed V through the illumination area and the scanner's detection zone. As an example, this speed can be V «6 ms-1.
    The optical block of scanner 1 (see also Fig. 3) comprises a light source 3 and a light sensor 5. Light source 3 can be, for example, an LED that operates with a wavelength emitting peak Àp within the first wavelength range, for a centroid wavelength Àc and a spectral bandwidth at 50% of the maximum triggering current intensity ΔA = 45 nm (this corresponds to the first wavelength range mentioned above ). This LED is operable to produce the excitation light with an intensity that varies according to a driving current intensity Is to illuminate the marking on the item, that is, the luminescent material 7. The light source is arranged above the conductive belt 2 and has a lighting cone 17 that delimits a lighting area 8 on a surface of said conductive belt. The light sensor 5 collects the luminescence light emitted by the mark 7 inside the detection zone 10 of the scanner 1 by means of photosensors aligned along a direction of movement of the sample 7, above the conductive belt 2. Here, the light sensor light 5 comprises five identical photosensors which are photodiodes PD1 to PD5, each equipped with a focusing lens 18, operable to detect luminescence light in a second wavelength range (in the NIR range). These photodiodes are connected in parallel. The photodiodes are arranged at a distance d «6 mm from each other and at a height h« 15 mm above the conductive belt 2, as shown in Fig. 3. Each photodiode has an angle detection cone β, here β «20 ° which delimits a corresponding detection area 9 on the conductive belt 2, within the detection zone 10. The detection areas of any two closest photodiodes are superimposed and the union of the five detection areas of the photodiodes in fact constitutes the detection zone 10 from the scanner.
    The scanner 1 also comprises a power source 4, for delivering the variable intensity drive current Is to the light source 3 and a control unit 6 operable to control the power source 4, the light source 3 and the light sensor 5 in order to acquire an intensity profile I (t) of the luminescence light emitted by marking 7, from luminescence intensity signals delivered over a measurement time interval Δtm by the light sensor 5 and determine a time value decline from the acquired intensity profile I (t). The control unit 6 also receives the luminescence intensity signals from the light sensor 5 and controls the power source 4 to select an intensity value of the drive current Is delivered to the light source 3 so that a value of IL luminescence intensity corresponding to a delivered luminescence intensity signal is both above the detection limit of the light sensor 5 and below its saturation level (that is, in the reliability range). Fig. 4 illustrates an illumination cycle of the light source 3: the light source is energized with the activation current intensity Is between moments T0 and T1. Where the excitation time interval is Δtex = T1 - T0: here, Δtex = 100 μs. For light sensor 5, a time delay Δtd corresponding to (T2-T1) can be defined by the control unit and at T3 a new cycle is started, here T3-T1 = 4 ms. The measurement time interval Δtm of the light sensor thus corresponds to (T3-T2). Fig. 5 illustrates a typical responsiveness (within the second wavelength range) of any of the five photodiodes, that is, PDi, equipped with its focusing lens 18, as a function Rei (x) of an x position of a light emission sample within the detection area 9 of the photodiode, along the direction of movement of the mark 7. The responsiveness (in A / W) reaches zero close to the threshold of the detection area (corresponding to the hatched region) and reaches a maximum in the center of the detection area. Fig. 6 illustrates the responsiveness Re (x) of the light sensor 5, within the second wavelength range, as a function of an x position of a light emitting sample within the detection zone 10 of the photodiode. The distance d between the photodiodes and the height h of the photodiodes above the conductive belt are adapted so that the general responsiveness Re (x) of the light sensor, due to the resulting overlap of the detection areas (the angle β being given), from fact is substantially uniform across the detection zone 10. Here, the general responsiveness Re (x) of the light sensor 5, as a function of position x within the detection zone 10 of the scanner, along the direction of movement of the sample 7 , only oscillates by less than 5% around an average Rem value for a uniformity length L and falls below zero at the threshold of the detection zone (that is, anywhere on the uniformity region of length L). Here, Rem «0,6 A W-1. The distance d between the photodiodes and the height h of the photodiodes above the conductive belt are defined to have both L «V Δtm and an overlap of the detection areas 9 sufficient to obtain said substantial uniformity of the light sensor's Re (x) responsiveness length L. Here we have: L «5 d« 30 mm. The combination of the detection zone 10 elongated along the direction of movement of the marking 7 and the substantial uniformity of the responsiveness of the light sensor over a length L within the detection zone, allows the luminescence light to be measured from the marking accordingly. crosses the region of length L in conditions that are very similar to those of an ordinary scanner that is stationary above said marking and following it during its movement through said region. Thus, the movement of the marking is "compensated" due to the specific structure of the scanner, even if the marking is moving fast through the detection zone. Fig. 7 illustrates a circuit diagram in relation to a preferred mode of a scanner according to the invention: the control unit 6, by means of a data bus 12 and a D / A converter (not shown), controls the power source 4, that is, it defines the drive current intensity Is to energize the light source 3 and the values T0 and T1 of the lighting cycle (in order to have the desired values of Δtex). The control unit 6 further controls the light sensor 5 via the data bus 12 and a D / A converter of an ambient light bypass compensation unit 13, that is, it defines the values T2 and T3 of the cycle measurement (in order to have the desired values of Δtd and Δtm). An operational amplifier 11 connected to the light sensor 5 delivers a voltage signal corresponding to a luminescence intensity signal measured by the light sensor 5, via an A / D converter connected to the data bus 12, to the control unit 6 .
    In order to guarantee a quick return to the unsaturated state of the light sensor 5 photodiodes, said light sensor in fact acts as a current source (under illumination by the sample's luminescence light) and is always shortened, thus preventing the internal capacities of the photo diodes from being charged and making the response of the photodiodes faster.
    In fact, a diode D1 connected in parallel with a capacitor C1 and a resistor R1, lets the current flow in case of a very high voltage at the output of the operational amplifier 11, thus preventing the saturation of the operational amplifier. The diode D1 is thus arranged in the negative feedback loop of the operational amplifier 11, which allows the photodiodes of the light sensor 5 to be always shortened and thus never saturated.
    Consequently, it is possible to acquire an intensity profile much faster and measure shorter decline times.
    In addition, a resistor R2, connected directly to the output of photodiodes 5, absorbs the bypass current in order to displace a relevant part of the measured intensity signal within a reliable detection range of the A / D converter that sends the intensity signal. measured to the control unit 6 via data bus 12.
    The part of the intensity signal that is due to ambient light is thus suppressed at the output of photodiodes 5 and only the intensity signals, from which the bypass current has been removed, are sent from the operational amplifier 11 to the control unit 6 , by means of an A / D converter and through the data bus 12, to form a precise intensity profile I (t). In addition, the linearity of the luminescence light response is increased due to the fact that the photodiodes 5 operate as a current generator and the D1 diode, in the negative feedback loop of the operational amplifier 11, always functional around the same point of operation.
    Controlling the intensity of the excitation light emitted by LED 3 by means of its driving current Is intensity, according to this modality of the invention, has the advantage of producing controlled flashes of light, both in duration and in intensity format. The method is effective, since in most cases an acceptable value of Is to precisely determine the first point of the luminescence intensity profile is obtained with just three flashes (see step (g) of the method explained above).
    In a preferred embodiment of the invention, the control unit 6 is further operable to adjust the levels of detection limit and saturation limit of the light sensor 5, which constitutes a detection range of the light sensor. Thus, the sensitivity of the light sensor can be adapted to the actual conditions that prevail during the measurement of luminescence light intensity and the resulting luminescence intensity profile is more reliable.
    The operation of the scanner according to the said preferred mode of the invention is detailed as follows: in a preliminary phase, an initial intensity signal from the light sensor 5 is acquired without illuminating the luminescent material with LED 3 and without time delay ( Δtd = 0) (since the ambient light usually only oscillates around a constant value during the measurement) and an Off light intensity deviation value corresponding to the ambient light is then determined. The ambient light intensity that is usually very low, if the initial intensity signal is outside a detection range of the light sensor, the control unit 6 then modifies that detection range by adjusting the detection limit value and / or the limit value of saturation of the range, so that the initial intensity signal is now within the new detection range. Then, the operation to illuminate said luminescent material of the downconverter starts: the control unit 6 defines a value of the intensity of the driving current IS0 delivered by the power source 4; the light source 3 is then energized with this activation intensity for an excitation time interval Δtex = 100 μs, and Δtd now set at 60 μs and Δtm = 4,000 μs and illuminates the luminescent material during said 100 μs. The control unit 6 also controls the light sensor 5 to measure a corresponding value of the intensity of the luminescence light then emitted by the luminescent material immediately after the excitation time interval of 100 μs. The light sensor 5 then delivers a first signal of luminescence intensity to the control unit 6, which then subtracts the intensity deviation value from the first corresponding measured value of the luminescence light intensity and judges whether the result is acceptable (ie , is within the detection range of the light sensor 5) and if it is acceptable, the result is stored in a memory of the control unit 6 as a first corresponding point of said intensity profile; and measurements of the declining luminescence light are then performed during the measurement time interval Δtm = 4,000 μs and the corresponding results obtained as explained above constitute the measured luminescence intensity profile I (t). Said stored profile is then used by the control unit 6 to calculate a corresponding decline time value (or for comparison with a reference intensity profile).
    In the case where the mentioned result corresponding to the first measured value of the luminescence light intensity is not within the detection range (usually, this corresponds to a situation in which the first luminescence signal is above the saturation limit of the sensor. light), the control unit 6 changes the value of the driving current intensity delivered by the power source to the light source (if the first signal is too high, the driving current intensity is decreased). Then, the lighting cycle, the measurement (with offset correction) and the judgment are repeated until a luminescence intensity profile is acquired and a corresponding decline time value is calculated.
    In a variant of the invention, in the case where the first luminescence signal is above the saturation limit of the light sensor, an additional step of increasing the saturation limit value and then repeating the measurement for the first point is attempted, at the instead of changing the value of the drive current intensity, where said drive current is modified only if the additional step fails to generate a first acceptable point of the intensity profile.
    The invention is not strictly limited to the above modalities and various modifications can be made without departing from the scope of the invention as defined by the claims. For example, the light source used to deliver excitation light can be any conventional source that has a definition of drive current or, equivalently, a definition of supply voltage, to allow adaptation of the light intensity of excitation delivered by the light source according to a light intensity level detected by a light sensor by changing the drive current or supply voltage of the light source.
    The scanner decline time detection method and the decline time according to the invention can be used for any luminescence emission in the spectrum of UV light spectrum (200 to 400nm), visible light (400 to 700 nm) or light infrared close to the average (700 to 2,500 nm). A scanner according to the invention can also comprise a radio module for communication (possibly wireless), a display module for displaying the measured data or scanning parameters and a control interface for entering scanning conditions.
    The invention also relates to a use of the decline time scanner and the method of determining the intensity profile according to the invention to determine the decline time characteristics of a luminescent material and / or authenticate an item comprising a material luminescent based on its decline time characteristics; wherein said decline time characteristics are a luminescence emission intensity profile or a decline time value, or concentrations of different types of luminescent particles in said material 5 in the case where the luminescent material includes a mixture of said types of particles.
    权利要求:
    Claims (22)
    [0001]
    1. Scanner (1) to determine a profile of intensity I (t) of luminescence light of a luminescent material (7) that moves through said scanner (1) along a path in a first direction, in which the said luminescent material (7) emits said luminescence light within a second wavelength range upon illumination with an excitation light within a first wavelength range comprising: a power source (4); a light source (3) connected to the power source (4) and operable to illuminate with the said excitation light the luminescent material (7) within a lighting area (8), when energized by the power source ( 4); a light sensor (5) operable to measure an intensity of said luminescence light received from the luminescent material (7) that is within a detection zone (10) of said scanner (1) and deliver a corresponding luminescence intensity signal ; and a control unit (6) connected to the light sensor (5) and operable to determine an intensity profile I (t) of said luminescence light received from luminescence intensity signals delivered by the light sensor (5) , characterized by the fact that: said lighting area (8) is in a first place along said path; said detection zone (10) is in a second subsequent location along said path and extends over a portion of said path; said light sensor (5) is operable to collect luminescence light from the luminescent material (7) during its movement along the path in the first direction through the detection zone (10) and to measure an intensity of said collected luminescence light within said second wavelength range and delivering a corresponding luminance intensity signal, the responsiveness of said light sensor (5) within said second wavelength range being uniform throughout said detection (10); and said control unit (6) is operable to control said power source (4), the light source (3) and the light sensor (5) and determine said intensity profile I (t) from of the luminescence intensity signal delivered by said light sensor (5) upon receipt of the luminescence light emitted by said luminescent material (7) which moves through said detection zone (10) in the first direction, in response to illumination with said excitation light within said lighting area (8).
    [0002]
    2. Scanner (1) according to claim 1, characterized by the fact that said light sensor (5) comprises a plurality of photodetectors arranged successively along said first direction, in which each photodetector is operable for measure a luminescence light intensity received from a corresponding detection area (9) within the detection zone (10), within the second wavelength range and to deliver a corresponding photodetector luminescence intensity signal, in that the set of corresponding detection areas (9) covers said detection zone (10); any two successive photodetectors of said plurality of photodetectors are arranged to have their respective detection areas (9) partially overlapped so that said responsiveness of the light sensor (5) within said second wavelength range is uniform throughout said detection zone (10); and said control unit (6) is operable to determine said intensity profile I (t) from the luminescence intensity signals delivered by said photodetectors upon receipt of the luminescence light emitted by said luminescent material (7) which moves through said detection areas (9) along said path in the first direction.
    [0003]
    3. Scanner (1), according to claim 2, characterized by the fact that said photodetectors are photodiodes (5) connected in parallel.
    [0004]
    4. Scanner (1) according to claim 1, characterized by the fact that the light sensor (5) comprises a plurality of optical waveguides, in which each waveguide has an operable entrance to collect luminescence light a corresponding detection area (9) within said detection zone (10), in which the plurality of waveguide entries are arranged successively along said first direction and in which the set of detection areas (9) corresponding covers the said detection zone (10); and said optical waveguides are arranged to have their respective detection areas (9) partially overlapped so that said responsiveness of the light sensor (5) within said second wavelength range is uniform over said zone detection (10).
    [0005]
    5. Scanner (1) according to claim 4, characterized by the fact that said optical waveguides are optical fibers.
    [0006]
    6. Scanner (1) according to any one of claims 1 to 5, characterized in that said light sensor (5) further comprises a focusing device operable to focus the luminescence light received from the detection zone ( 10).
    [0007]
    7. Scanner (1) according to any one of claims 1 to 6, characterized in that said light source (3) comprises a plurality of LEDs and operable focusing means for focusing the excitation light of said LEDs in said lighting area (8).
    [0008]
    8. Scanner (1) according to any one of claims 1 to 7, characterized by the fact that it further comprises: a trigger unit operable to detect that the luminescent material (7) is within the illumination area (8) of the light source (3) and deliver a corresponding trigger signal; and where the control unit (6) is still operable to control the light source (3) to deliver the excitation light pulse to the luminous material (7) within the lighting area (8) upon receipt of the said trigger signal from the trigger unit and control the light sensor (5) to acquire the intensity profile I (t) after the lighting has ceased.
    [0009]
    9. Scanner (1) according to any one of claims 2 to 8, characterized in that the scanner (1) further comprises a position sensor operable to determine a position of the luminescent material (7) within said zone of detection (10) and deliver a corresponding position signal; the control unit (6) is further operable to receive a position signal from said position sensor and determine said intensity profile I (t) only from the consecutive luminescence intensity signals corresponding to the consecutive positions of the luminescent material ( 7) within each of the successive detection areas (9) where the irradiation of the light sensor (5) is maximum.
    [0010]
    10. Scanner (1) according to any one of claims 1 to 9, characterized by the fact that said power source (4) is operable to deliver a driving current or variable driving voltage; said light source (3) is operable to produce said excitation light with an intensity that varies according to the drive current or drive voltage delivered; and said control unit (6) is further operable to control said power source (4) to define a value of the drive current or a value of the drive voltage delivered to the light source (3) so that a value luminescence intensity IL corresponding to a luminescence intensity signal delivered is within a given range of luminescence intensity IL values.
    [0011]
    11. Scanner (1), according to claim 10, characterized by the fact that the said luminescence intensity value range IL corresponds to a detection range of the light sensor (5), in which said detection range is a range of luminescence intensity values IL between a detection limit value and a saturation limit value of the light sensor (5).
    [0012]
    12. Scanner (1) according to any one of claims 10 to 11, characterized by the fact that said range of luminescence intensity values IL further guarantees that a signal-to-noise ratio of a measured luminescence intensity is above of a limit value.
    [0013]
    13. Scanner (1) according to any one of claims 1 to 12, characterized in that said light source (3) is operable to deliver the excitation light for an adjustable excitation time interval, in which the control unit (6) is further operable to define the excitation time interval.
    [0014]
    14. Scanner (1), according to claim 13, characterized by the fact that said control unit (6) is still operable to control said light sensor (5) to measure an intensity of luminescence light collected with a time delay after said excitation time interval has elapsed.
    [0015]
    15. Scanner (1) according to any one of claims 1 to 14, characterized by the fact that said control unit (6) is still operable to determine a time-to-decline value of the luminescent material (7) from of said intensity profile I (t) determined.
    [0016]
    16. Scanner (1), according to claim 15, characterized by the fact that said control unit (6) is still operable to authenticate said luminescent material (7) in the event that the value of time of decline of the luminescent material (7) determined from said intensity profile I (t) corresponds to a given reference decline time value stored in a control unit memory (6), in which said decline time value reference corresponds to a decline time value of a reference luminescent material (7).
    [0017]
    17. Scanner (1) according to any one of claims 1 to 15, characterized by the fact that said control unit (6) is still operable to authenticate said luminescent material (7) in the case where the profile of intensity I (t) determined of the luminescent material (7) corresponds to a given profile of reference luminescence intensity stored in a memory of the control unit (6), in which the said luminescence intensity profile I (t) is a luminescence intensity profile I (t) of a luminescent reference material (7).
    [0018]
    18. Method for determining a luminescence light intensity I (t) profile of a luminescent material (7) that passes through a scanner (1), as defined in any one of claims 1 to 17, along a path in a first direction, in which said luminous material (7) emits said luminescence light within a second wavelength range upon illumination with an excitation light within a first wavelength range, said method characterized by the fact that it comprises the steps of: illuminating the luminescent material (7) that moves through the scanner (1) in the first direction, as it crosses the illumination area (8) of the scanner (1), with a excitation within the first wavelength range by means of the light source (3) of the scanner (1); as the luminescent material (7), after being illuminated with the excitation light, still moves in the first direction and enters the detection zone (10) of said scanner (1), measure an emitted luminescence light intensity by said luminescent material (7) within the second wavelength range while it crosses the detection zone (10) by means of said light sensor (5) and delivers a luminescence intensity signal corresponding to the control unit ( 6) the scanner (1); determine an intensity profile I (t) from the luminescence intensity signal received by the control unit (6).
    [0019]
    19. Method, according to claim 18, characterized by the fact that it comprises an additional step of determining a time of decline value of the luminescent material (7) from said determined intensity profile I (t).
    [0020]
    20. Method according to claim 19, characterized by the fact that said scanner (1) is a scanner (1) as defined in claim 16, which comprises the additional step of: authenticating said luminescent material (7) in in which case the time of decline of the luminescent material (7) determined from said intensity profile I (t) corresponds to a given value of time of decline of reference stored in a memory of the control unit (6), wherein said reference decline time value corresponds to a decline time value of a luminescent reference material (7).
    [0021]
    21. Method according to claim 18, characterized by the fact that said scanner (1) is a scanner (1) as defined in claim 17, which comprises the additional step of: authenticating said luminescent material (7) in case in which the intensity profile I (t) determined of the luminescent material (7) corresponds to a given profile of luminance intensity of reference I (t) stored in a memory of the control unit (6), in which said profile luminescence intensity reference I (t) is a luminescence intensity profile I (t) of a luminescent reference material (7).
    [0022]
    22. System for determining a luminescence light intensity I (t) profile of a luminescent material (7) that moves through a scanner (1), as defined in any one of claims 1 to 17, over a path in a first direction on a production / distribution line, in which said luminescent material (7) emits said luminescence light within a second wavelength range by means of illumination with an excitation light within a first wavelength range delivered by the light source (3) of said scanner (1), said scanner (1) being installed in said production / distribution line, characterized by the fact that the control unit (6) of said scanner (1) is programmable and includes a program that, when executed in said control unit (6), makes the control unit (6) operable to implement the method steps, as defined in any of claims 18 to 21.
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    同族专利:
    公开号 | 公开日
    US20160216207A1|2016-07-28|
    EP2718910B1|2015-11-18|
    AU2012266827B2|2015-11-26|
    AU2012266827A1|2014-01-09|
    ZA201309721B|2015-10-28|
    US9335211B2|2016-05-10|
    WO2012167894A1|2012-12-13|
    AR086678A1|2014-01-15|
    RU2579976C2|2016-04-10|
    CN103597522A|2014-02-19|
    CA2837988A1|2012-12-13|
    US20140097359A1|2014-04-10|
    TW201303283A|2013-01-16|
    MA35254B1|2014-07-03|
    SA112330572B1|2015-07-07|
    JP2014519130A|2014-08-07|
    MX2013014170A|2014-03-21|
    CN103597522B|2016-10-05|
    KR20140030246A|2014-03-11|
    BR112013031399A2|2016-12-06|
    RU2013157332A|2015-07-20|
    MY168878A|2018-12-04|
    US10241046B2|2019-03-26|
    EP2718910A1|2014-04-16|
    BR112013031399B8|2021-06-29|
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    法律状态:
    2018-12-11| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2020-12-08| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-01-19| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 01/06/2012, OBSERVADAS AS CONDICOES LEGAIS. |
    2021-06-01| B16C| Correction of notification of the grant [chapter 16.3 patent gazette]|Free format text: REFERENTE AO DESPACHO 16.1 PUBLICADO NA RPI 2611, QUANTO AO TITULO |
    2021-06-29| B16C| Correction of notification of the grant [chapter 16.3 patent gazette]|Free format text: REF. RPI 2611 DE 19/01/2021 QUANTO AO RELATORIO DESCRITIVO. |
    优先权:
    申请号 | 申请日 | 专利标题
    US201161493710P| true| 2011-06-06|2011-06-06|
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