EP1864113A1

EP1864113A1 - Portable detection appliance enabling elements marked by fluorescence to be detected in the field

Info

Publication number: EP1864113A1
Application number: EP06709078A
Authority: EP
Inventors: Sébastien DE LAMBERTERIE
Original assignee: Cypher Science SARL
Current assignee: Cypher Science SARL
Priority date: 2005-01-21
Filing date: 2006-01-12
Publication date: 2007-12-12
Also published as: US20090127475A1; FR2881225B1; CA2595614A1; US7795598B2; FR2881225A1; BRPI0606485A2; WO2006077304A1; CA2595614C

Abstract

The invention relates to a portable appliance for detecting fluorescent particles which are visibly excited for the authentication of products. Said appliance comprises: an excitation light source (2) provided with at least one electroluminescent diode or a laser for producing a focused light beam; a housing (1) respectively containing the light source (2) and means for electrically feeding the same; and compact optical means which can be integrated into the housing (1) or not and enable the user to instantaneously visualise the fluorescence of the marked elements excited by means of the light source (2). The appliance is used as a field detector for authenticating and tracing products having a secret identifier formed by fluorescent particles.

Description

Portable sensing device for field-detected fluorescently labeled elements

The invention relates to the field of the detection of fluorescent markers by excitation in the visible and re-emission in the visible (0.4 - 0.7 microns). The invention more particularly relates to a portable device for detecting in the field fluorescently labeled elements.

There are more and more products including optically detectable fluorescent elements, such as for example banknotes or identity documents. Inks (for example invisible), coatings or other solid or liquid products used in this type of application have a fluorescence that can be revealed by UV radiation whose spectrum is between about 0.01 μm and 0.385 μm or by radiation IR whose spectrum is between 0.76 microns and 1 mm.

It is known in the prior art, in particular from document WO 02/10295 by the same applicant, for epifluorescence detection systems for an "invisible" ink of the type comprising fluorescent molecules. This detection is generally carried out using an epifluorescence microscope comprising a light source emitting in the visible, combined with a set of filters to cause the excitation of the fluorescent molecules contained in the ink, which is self-extinguishing. determined wave and select the wavelengths of the fluorescence emission. Thus the marking elements for secretly tracing each product can be observed visually through an epifluorescence microscope with a dichroic mirror disposed between eyepiece and lens. This mirror makes it possible to reflect the radiation of a light source towards the product forming the support of the marking elements. The labeled product is disposed under the objective and can be observed visually by the eyepiece when an appropriate set of filters is used so as to pass the radiation of the fluorescent molecule used and the light source. The filters are also adapted to the surface of the labeled product; indeed it is often necessary to support the contrast between this surface and the fluorescence of the particles to be detected because of the background noise specific to the support.

The set of filters makes it possible in particular to isolate the photons from the fluorescent emission of the excitation photons emitted by the light source and reflected by the dichroic mirror. A first excitation filter is arranged between the source and the mirror and a second filter is provided between the mirror and the eyepiece to form a stop or emission filter. The excitation filter will promote the passage of specific wavelengths of the radiation from the chosen light source emitting in the visible. The stop filter passes only one or more ranges of wavelengths in the selected range between 0.4 μm and 0.7 μm. This stop filter is very important because it allows:

to prevent the passage of the transmitted waves, that is to say, not reflected by the dichroic mirror, resulting from the reflection of the light incident on the marked product and directly from the light source and ^to select the waves of emission emitted by the fluorescence.

WO 02/10295 also discloses detection systems for observing fluorescence by epifluorescence without using a microscope. These detection systems include a light source such as a 100-watt mercury vapor lamp housed in a drilled housing and equipped with a reflector for reflecting light to the bore. Such a detection system further comprises a set of filters adapted to the characteristics of the fluorescent molecule used and the light source as well as to the surface of the labeled product.

A disadvantage of this type of system is that it is still bulky, including the use of a mercury vapor lamp or other equivalent light generator (halogen / xenon), which prevents common use as a field detector . It is known from WO 2004/088387 a lighting assembly for a laboratory fluorescence microscope. This set comprises a housing connectable to a microscope carrying structure. This housing incorporates a light unit composed of a light-emitting diode (LED) and an associated optical collimator element for routing the light produced by the LED in the form of a beam (parallel) of light rays to a side window of the microscope . The disadvantage of this type of solution is that the lateral space and height remains important. It is then necessary to provide an important basic structure to support the complete apparatus. There is therefore a need for more compact tools suitable for routine detections.

A first object of the invention is to provide a small size detection device (lightweight, portable, preferably prehensile with one hand) and can operate autonomously (on battery for example) to excite and detect, exclusively in the visible, fluorescent particles used to mark a product.

A second object of the invention is to provide an apparatus for quick and easy detection in the field, as opposed to the use of laboratory equipment. The object of the invention is thus to make it easier to control the tracing or authentication of articles marked secretly.

For this purpose, the invention proposes a portable optical detection device for detecting fluorescently labeled elements on a specific marking zone, said apparatus comprising at least one light source for the excitation of particles including a fluorophore function, characterized in that the light source comprises at least one emitting element of a focused light beam consisting of a light-emitting diode or a laser, each emitter having a similar emission peak around a length of determined wave, the portable sensing apparatus comprising: a housing for respectively housing the light source, a user interface for controlling the light source and power supply means for supplying the light source, this light source being designed to emit in the visible, the housing comprising a light output oriented towards the marking area; and

integrated or non-integrated optical means in the housing, comprising a first end allowing the user to instantly detect in the visible the fluorescence of the marked elements excited in the visible through the light source, a second end opposite to the said first end and adapted to come close or flush with said marking area, a filter being provided between these two ends to eliminate at least the wavelength radiation below a predetermined threshold, said ends thus allowing the light to pass for at least less a range of visible wavelength. Said ends are separated from each other by a determined distance that may exceed 2 cm.

Thus, unlike a cumbersome laboratory assembly, the apparatus according to the invention makes it possible to group all the elements of generation of the light beam in a compact housing which integrates the optical means facilitating the visualization or which is closely associated with these optical means.

According to another feature, the light source comprises a plurality of light emitting diodes grouped adjacently in an assembly oriented in a directiQrjL-ay_ant- a component- transverse to the axis of alignment of the ends of the optical means.

According to another particularity, said member for emitting a focused light beam consists of at least one miniature xenon or halogen bulb associated with a bandwidth filter to form said light source. According to another feature, the two ends of the optical means are aligned and arranged in the housing which is of the grippable type.

According to another feature, the casing is substantially parallelepipedal, of the pocket size and comprises on the same side the user interface and said first end of the optical means.

According to another feature, the optical means comprise a longitudinal axis corresponding to a viewing axis of the fluorescently labeled elements, the distance between the ends of the optical means being between 2 and 35 cm.

According to another feature, the distance between the ends of the optical means is between 2 and 15 cm.

According to another particularity, the housing comprises a housing for receiving batteries allowing autonomous use of the apparatus, said housing comprising a longitudinal axis corresponding to the orientation of the focused light beam at the light source and transversely having a lower perimeter at 25 cm.

According to another feature, at least ten light emitting diodes are mounted in a honeycomb arrangement on a support card to form the light source.

According to another feature, the light-emitting diodes are connected to an electronic unit arranged to control the supply of the diodes.

According to another feature, the optical means are formed in a substantially cylindrical assembly adapted to align with a ring-shaped annular device provided with housings for receiving light-emitting diodes oriented towards a focusing point located on the side opposite to the optical means.

According to another feature, the housing consists of a laser emission device. 071

According to another feature, the laser emission device is of the type having a wavelength of the order of 532 nm to emit a green light beam.

According to another feature, the optical means comprise a support means provided with an arm for detachably fixing the laser emission device.

According to another feature, the first end of the optical means comprises a periphery adapted to allow the addition and / or attachment to the apparatus of a magnifying optical element which may be necessary for the user to visualize the fluorescence marked elements. Thus, poorly visible fluorescent particles can be detected, for example fluorescence microbeads with a diameter of less than 5 μm.

According to another particularity, an excitation filter (bandwidth type) is provided to refine chromatically the emission from the light source.

According to an essential aspect of the invention, the optical means comprise a filter unit including an emission filter for preventing at least the passage of visible waves coming from the emission device (s) and for letting the specific wavelengths pass through. emission of the fluorescence of the labeled elements.

According to another feature, the housing includes a longitudinal axis and at least one alignment of light emitting diodes according to this longitudinal axis ^"A further object of the invention is to provide a use of the unit cell to quickly authenticate products having an area of optically revealable marking.

This object is achieved by using the apparatus according to the invention, characterized in that said portable apparatus is used to detect fluorescent particles contained in all or part of a product to be authenticated. According to another feature, said portable apparatus is used to detect fluorescent particles contained in a marking zone associated with a product to ensure marking.

According to another particularity, the marking zone consists of an adhesion or coating compound comprising a minimal proportion of fluorescent molecules, invisible to the light of day but detectable optically by epifluorescence in a range of excitation wavelength. included in the visible.

According to another feature, the fluorescence to be detected comes from at least one wire or fiber of 3 to 20 mm in length called fibrette.

In another feature, the yarn or fibrette is associated with a security paper.

According to another particularity, the fluorescence to be detected comes from bodies of very small size whose volume is less than 0.1 mm ³ . According to another feature, the fluorescence to be detected comes from microspheres whose diameter is between 0.2 and 20 microns.

In another feature, the microspheres are associated with a security paper.

In another feature, the microspheres are dispersed in a lubricating oil or a surface treatment of metal parts.

In another feature, the apparatus is used for detecting fluorescence from microspheres signaling DNA hybridization on biochips or microarrays. Other features and advantages of the present invention will appear more clearly on reading the following description made with reference to the accompanying drawings in which:

- Figure 1 shows schematically an apparatus according to the invention for the observation by epifluorescence of a product labeled with fluorescent particles;

FIG. 2 represents an arrangement of LEDs (Light-Emitting Diode) in corona; FIG. 3 schematically represents an apparatus according to the invention provided with a laser light source;

FIG. 4 shows an example of an apparatus with light-emitting diodes in an alternative embodiment of the invention. The invention is applicable to the detection of any type of product that can be fluorescently labeled. In the following, a fluorescent particle must be understood to mean a particle which absorbs and re-emits respectively in visible wavelengths (0.4-0.7 μm).

Examples of fluorescently labeled products using a colorless ink cited in WO 02/10295 can all be authenticated by the field apparatus of the present invention. The labeled product (6) has a defined area (60) in which fluorescently labeled elements have been inserted. This marking zone (60) may comprise a coating formed by application of a liquid adhering or coating product, containing fluorescent molecules, detectable by epifluorescence. The episcopia is distinguished from the transmitted light by the fact that in the first, the excitation radiation of the observed object does not cross the latter, whereas in the transmitted light, the light source is on the other side of the observed object relative to the observer.

In what follows, reference will be made to an example for which the fluorescence of molecules results in an absorption peak at about 570 nm. It should be understood that other molecules having a different peak are to be used. Fluorescent molecules that the device must detect are for example invisible to the naked eye on the labeled product. The authentication of the product can not be done either by conventional means using, as in the field of secure inks, UV and IR radiation. Fluorescent molecules are generally present in low concentration and can be detected by epifluorescence only if, on the one hand, they are excited by a determined wavelength range of the emission spectrum of a light source and if on the other hand, the emission of fluorescence is filtered. In other cases, the particles are concentrated but very localized and can be detected by epifluorescence only by being first excited by a determined wavelength range of the emission spectrum of a light source and secondly by being observed after magnification and filtering the emission of fluorescence.

Referring to Figure 1, the apparatus according to the invention comprises a light source (2) incorporated in a housing (1) of the pocket size type and easily graspable. The device is therefore easily transportable, unlike epifluorescence microscope type equipment. Unlike light sources of the mercury vapor lamp type generally associated with an epifluorescence microscope, the light source (2) envisaged in the invention is more compact and light to allow use in the field of the device. The portable optical sensing apparatus is considerably simplified with respect to most fluorescence detection apparatuses and reliably authenticates fluorescently labeled elements on a designated marking area (60).

The light source (2) is designed to emit in the visible. According to the invention, the light source (2) comprises at least one emitting element of a focused light beam consisting of a light-emitting diode or a laser for exciting particles having the fluorophore function. For this purpose, each transmission member has a similar emission peak around a determined wavelength that is ccirïe ^ p ^^ ^"s ^ nslbïëment at the excitation wavelength of the fluorophores. In an alternative embodiment, said emitting member of a focused light beam may comprise at least one miniature bulb or xenon halogen associated with a bandpass filter to form said light source (2).

The excitation of the fluorescent molecules occurs approximately between 0.385 and 0.7 μm, which makes it possible to obtain a fluorescent emission in a range of wavelengths belonging to the range of radiation visible by the human eye. This broadcast is only for an intensity luminous excitation determined. In the embodiment of the figure

1, the light source (2) has a plurality of light-emitting diodes grouped adjacent. The set of diodes makes it possible to obtain a luminous intensity sufficient to excite the fluorophores. At least ten light emitting diodes may be mounted in a honeycomb arrangement on a support board to form the light source (2). It may also be envisaged to use a single LED type ₁ diode this diode to have specific characteristics of intensity and aperture angle to generate a brightness of at least 0.1 lumen.

The apparatus is also provided with optical means, integrated or not in the housing (1). These optical means may comprise zoom magnification means or magnification elements of the type used in a microscope. In one embodiment of the invention, the optical means perform a function of sufficient magnification to allow the detection of small particles, for example 5 microns. If the fluorescence is sufficiently intense and the light used is selective, the authentication can be done without such magnification means. These can be removed, a magnification accessory can also be associated with the optical means if necessary. As illustrated in FIG. 1, the optical means comprise for example a first end (E1) allowing the user to instantly visualize the fluorescence of the marked elements and an opposite second end (E2) able to come close to or flush with the marking (60). The ends (E1, E2) are for example aligned and pass light for at least one range of visible wavelength. The detection of the marking is carried out by direct observation of the surface of the product through the optical means, without destruction or deterioration of the surface of the product concerned. The first end (E1) of the optical means may comprise a periphery (11) adapted to allow the addition and / or attachment to the apparatus of a magnifying optical element which may be necessary for the user to visualize the fluorescence of marked elements. In particular, it is permissible with such an optical magnification element to detect (or better distinguish) small fluorescent particles.

The set of diodes illustrated in Figure 1 is oriented in a direction having a component transverse to the axis of alignment of the ends (E1, E2) of the optical means. The path of the excitation radiation (5) coming from the light source (2) for example passes through an excitation filter (F1) intended to refine the emission chromatically and is then reflected by a dichroic mirror (14). The mirror (14) reflects this radiation towards the marking area (60) formed on the support, in order to illuminate over this area (60). The labeled product is disposed under the second end and can be observed visually as represented by reference (3). The excitation filter (F1) promotes the passage of specific wavelengths of the radiation from the chosen light source emitting in the visible. These wavelengths will be determined as a function of the fluorochrome, that is to say the fluorescent material chosen to produce a fluorescent emission wavelength in the spectrum of visible radiation. The dichroic mirror (14) is adapted to the two excitation and emission wavelength spectra.

In the embodiment of FIG. 1, the housing (1) of the portable detection device is advantageously grippable and makes it possible to house not only the light source (2) but also the optical means with a suitable filter block (BF). . A user interface (10) for controlling in particular the light source (2) and power supply means for powering the light source (2) are further arranged in the housing (1). The housing (12) can receive batteries (9V PP3 or the like) for autonomous use of the device. This compact housing (1) can thus delimit the entire device which makes it easy to handle. In one embodiment of the invention, the housing (1) has a longitudinal axis corresponding to the orientation of the beam focused light at the light source (2) and has transversely a perimeter less than 25 cm. The ends (E1, E2) of the optical means are for example separated from each other by a determined distance (d, d ') of the order of a few centimeters and may exceed 2 cm (a distance of about 4 cm being sufficient) . The distance (d) may naturally be shorter for embodiments where said optical means are external to the housing including the light source (2). According to some embodiments of the invention, the optical means comprise a longitudinal axis corresponding to a viewing axis of the fluorescently labeled elements and the distance (d ') between the ends of the optical means is between 2 and 35 cm. This distance (d, d ') is for example between 2 and 15 cm. The first end (E1) may comprise a filter (F2), for example red when the excitation is carried out beyond 600 nm, the excitation filter (F1) being for example a green filter, this red filter then forming a transmission filter. This filter (F2) makes it possible in particular to isolate the photons of the fluorescent emission (4) of the excitation photons (5) emitted by the light source (2) and reflected by the mirror (14). It is then easy to visualize the fluorescence of molecules having an emission peak, for example at 605 nm. It is understood that the optical means may comprise a filter block (BF) including such a transmission filter (F2) for filtering the specific emission wavelengths of the fluorescence of the labeled elements. This allows viewing of the fluorescent particles in the marking area (60). The emission filter (F2) disposed between the two ends (E1, E2) makes it possible to eliminate at least the wavelength radiation below a determined threshold. In practice, this filter (2) thus makes it possible to filter the excitation radiations so as to let only the emission radiations into the visible of the marked elements. In alternative embodiments in which the excitation radiation is rendered monochromatic, for example by means of the first excitation filter (F1), this second filter (F2) can be eliminated. In the case of the observation by epifluorescence of fluorescence emitting in I ¹ UV (unlike the present invention), the emission filter (F2) is not necessary. Indeed, the excitation waves being very little visible, the reflection of the excitation waves does not interfere with the observation of the waves emitted from the fluorescence.

The user interface (10) may comprise at least two buttons for enabling LEDs to be lit for a simple illumination to easily position themselves on the marking area (60), or to light the diode assembly allowing exciting the fluorophores on the marking area (60). To enable these different types of ignition, the light-emitting diodes are connected to an electronic processing unit (8) arranged to control the supply of the diodes. In the example of particles having an excitation peak at 570 nm, a red light from one or more delocalized sources thus makes it possible to place on the zone (60) and a green light allows the excitation of the fluorophores. The relocated sources are arranged outside the optics but in the housing (1), for example in a position adjacent to the glass forming the second end (E2). This glass (or similar transparent element) can be anti-reflective to improve the visualization, limiting the losses due to the reflection of the excitation and emission rays.

As illustrated in FIG. 1, the casing (1) is substantially parallelepipedic, of the pocket-sized type and comprises on the same side the user interface (10) and the said first end (E1) of the optical means.

The optical means allow a determined magnification that can be a function of the size of the particles to be observed. These particles consist for example of microspheres (having a diameter that may be between 0.2 and 20 microns), for example of the type described in patent WO 01/30936 of the same applicant. The number of LEDs and the magnification of the optics depends on the size of the microspheres to be observed: a magnification objective of 10 can be provided for example to detect microspheres of the order of 10 microns. In the embodiment of the figure, the objective (not shown) may be a separate element of the housing (1), so that the housing (1) is suitable for any type fluorescent molecules when the appropriate objective is used in addition. The objective can be arranged against the second end (E2) of the optical means.

Referring to Figure 2, the optical means are formed in a substantially cylindrical assembly adapted to align with an annular device constituting said housing (1 '). In this embodiment, the body (21) of the housing (1 ') forms a ring (21) provided with housings for receiving light-emitting diodes (20) oriented towards the center of the ring. The housing of the body (1 ¹ ) can be inclined towards a lower side of the crown, while the optical means are arranged on the upper side of the ring (21).

With the arrangement of ring diodes, the diodes (LEDs) are focused at the same point in order to increase the amount of light on the marking area (60) to be observed. This arrangement makes it possible to excite the fluorophores of the marking zone or body to be observed. For microspheres of 8 to 10 μm, an X10 magnification objective can be used and the ring (21) has 4 focused LEDs. To visualize smaller microspheres, for example 5 .mu.m, it is preferable to use a system comprising 8 focused LEDs with a higher magnification objective, for example X45. The number of diodes can however vary according to the intrinsic characteristics of each diode (brightness, aperture angle, power level). Blue LEDs with an emission peak around 470 nm may be suitable for the detection of fluorescent molecules having their peak absorption at 570 nm, even if the excitation is then at 30% of its maximum. The emission spectrum of blue LEDs not exceeding

At 600 nm, excitation filter (F1) can be dispensed with using a 610 nm high pass band type emission filter. In embodiments with a ring gear (21), an excitation filter can also be envisaged, the filter (F1) then being annular (not shown) or composed of a plurality of filters each associated with one or more diodes (20). ).

The arrangement with crown or similar form (truncated cone, pyramid, etc.) allows great flexibility to be associated with optical means with a higher or lower magnification.

An embodiment of the invention will now be described more particularly with reference to FIG. 3. The housing (1 ") consists of a laser emission device (7) in the example of FIG. The pump circuit (73) of the laser emission device is adjusted to a wavelength of about 532 nm to generate a green light.A laser emission device of the type having a wavelength of the order of 532 nm may be suitable for efficiently excite molecules having an absorption peak at about 570 nm.

The optical means used with the laser emission device (7) may comprise a support means (70) having an arm (75) for removably attaching the housing (1 ") incorporating the laser light source (2). The use of a laser-type source provides a powerful illumination focused on a reduced surface (diameter less than 5 mm) and the housing (1 ") of cylindrical type containing the laser source is extremely compact reduced. The casing (1 ") then has a size comparable to a pen.This use is advantageous for observing bodies of very small size, for example microspheres having a diameter of between 0.2 and 5 μm.

The wavelength of green lasers of the type emitting at 532 nm makes it possible to excite a family of fluorescent molecules which excite around 570 nm and emit beyond 610 nm (wavelength of red). The excitation at 532 nm is certainly not optimal since the absorption peak is at 570 nm, nevertheless the light power of the lasers can compensate for the difference between the emission peak of the source and the absorption peak (in the extent to which there is recovery). Moreover, the chromatic precision of a laser emission device (7) eliminates the use of the excitation filters (F1) which are necessary when LEDs, for example green or white, are used as sources. bright. In this embodiment, the optical means may consist of a conventional lens, with or without an eyepiece and without a transmission filter. The objective may be analogous to those used as a magnifying element of a microscope. The laser emission device (7) may be of the current type having a power of less than 5 mW to comply with the safety standards. By way of nonlimiting example, the laser emission device (7) comprises a laser diode manufacturer Sony, generates a constant wave whose wavelength is 532 nm. It has a power output of 4.99 mW and a service life of about 2000 to 3000 hours. The housing (1 ") further comprises a housing for at least one battery, and for example 2 AAA type accumulators.

FIG. 4 illustrates an alternative embodiment in which the housing comprises a longitudinal axis and at least one alignment of light-emitting diodes along this longitudinal axis. A bar (B) of LEDs can be incorporated in the housing and powered by batteries or a power supply, a user interface for controlling the switching on / off of the light source thus formed. The optical means may consist of a magnifying glass device (L) with which a transmission filter (F2) is associated. The magnifying glass device or a similar magnification means can be made integral and articulated with respect to the housing. An excitation filter (not shown) may optionally be provided, for example in a position adjacent to the bar (B) of light-emitting diodes. The housing may comprise an L-shaped profile with a support part for laying the product to be authenticated and a lateral part where the light source is arranged.

It is possible thanks to the portable detection device to reveal a secure marking by exciting the fluorescent molecules directly on a fabric made from sized son. The fluorophore is previously inserted into the oil coating on the wire.

It should be understood that the invention provides an apparatus for detecting markings in various fields, for example for works of art, textiles, hollow or flat glass (by surface treatment, screen-printing, or ink-jet printing), characters and designs printed by thermal transfer, offset or gravure printing, metallic spare parts (by treatment or by use of a lubricating oil), aluminum blisters and holograms (by gravure or flexography), security papers, banknotes and tax-sealing tape. Examples of security paper include coated papers such as checks, securities, identification, labels, tax strips or other tamper resistant paper. An application of the apparatus can be envisaged in the field of molecular biology, in particular for the detection of fluorescent microspheres signaling a hybridization of DNA on biochips or microarrays. These fluorescent microspheres then serve as a marker by attachment to at least one hybrid DNA strand. For this type of application, only the hybrid DNA strands can bind to the fluorescent microspheres, for example by a biotin-streptavidin bond.

The portable optical detection device makes it easy to visualize fluorescent particles contained in all or part of a product to be authenticated, for example in a marking area (60) associated with a product. The user simply has to press a button on the interface (10) to excite the fluorescent particles. The marking zone (60) formed on the support to be observed is shown in FIG. for example consists of an adhesion or coating compound, for example invisible inks, comprising a minimum proportion of fluorescent molecules.

These molecules, for example incorporated in bodies of very small size having a volume of less than 0.1 mm ³ , in microspheres of a few microns in diameter, are invisible in daylight but optically detectable by epifluorescence in a range of length. of excitation wave included in the visible. The apparatus according to the invention therefore advantageously constitutes a terrain detector for authenticating products containing a secret marking by fluorescent particles, this detection can be carried out quickly on site without requiring the shipment of the product in a laboratory equipped with heavy equipment epifluorescence microscope type. The fluorescence to be detected may also reside in at least one wire or fibrette. The detection can thus be performed for fluorescent particles impregnating or covering at least one thread or fibrette associated with a product to ensure marking. Such a wire or fibrette is for example associated with a security paper. Alternatively, the fluorescence to be detected may be from microspheres. The patent application WO 01/30936 of the same applicant describes a specific example of microspheres having bonds with fluorescent molecules. Such fluorescent microspheres may also be associated with security paper, banknotes, sealers, polymer-based materials, or other types of support such as leather, textile, etc. Such fluorescent microspheres can also be dispersed in a lubricating oil or a surface treatment of metal parts.

It can be understood that the visualization can also be carried out through the optical means of the apparatus according to the invention, directly by the human eye (3), or by means of a device of the digital camera type, for example CCD camera (Charge Coupled Device), possibly being fixed on the side of the first end (E1) optical means so as to allow viewing of the area (60) to be observed on a screen. A photosensitive cell also allows detection through its sensitivity to photons. It can thus be envisaged a detection without visualization, a detection signal that can be translated acoustically (connection to an alarm) or by a brightness measurement.

It should be obvious to those skilled in the art that the present invention allows embodiments in many other specific forms without departing from the scope of the invention as claimed.

Claims

1. Portable optical detection device for detecting fluorescently labeled elements on a specific marking area (60), said apparatus comprising at least one light source (2) for exciting particles including a fluorophore function, the light source (2) comprising at least one emitter of a focused light beam consisting of a light-emitting diode or a laser, each emitter having a similar emission peak around a determined wavelength characterized in that it comprises: - a housing (1, 1 ', 1 ") for respectively housing the light source (2), a user interface (10) for controlling the light source and power supply means for supplying the light source (2), this light source being designed to emit in the visible, the housing (1, 1 ', 1 ") having a light output oriented towards the marking area (60); and

optical means integrated or not in the housing (1, V, V), comprising a first end (E1) allowing the user to detect instantly in the visible the fluorescence of the marked elements excited in the visible via the light source (2), a second end (E2) opposite to said first end and able to come close to or flush with said marking area (60), a filter (F2) being provided between these two ends (E1, E2 ) to eliminate at least the wavelength rays below a determined threshold, said ends (E1, E2) thus passing light for at least one visible wavelength range and being separated from each other by determined distance (d) exceeding 2 cm.

2. Apparatus according to claim 1, wherein the two ends (E1, E2) of the optical means are aligned and arranged in the housing (1, 1 ', 1 ") which is of the gripping type.

3. Apparatus according to claim 1 or 2, wherein the housing (1) is substantially parallelepiped, pocket size type and comprises on the same side the user interface (10) and said first end (E1) optical means.

4. Apparatus according to one of claims 1 to 3, wherein the optical means comprise a longitudinal axis corresponding to a viewing axis of the fluorescently labeled elements, the distance (d ¹ ) between the ends of the optical means being between 2 and 35. cm.

5. Apparatus according to one of claims 1 to 4, wherein the distance (d) between the ends (E1, E2) of the optical means is between 2 and 15 cm.

6. Apparatus according to one of claims 1 to 5, wherein the housing (1) comprises a housing (12) for receiving batteries for autonomous use of the apparatus, said housing having a longitudinal axis corresponding to the orientation of the beam focused light at the light source (2) and having transversely a perimeter less than 25 cm.

Apparatus according to one of claims 1 to 6, wherein the light source (2) comprises a plurality of light-emitting diodes grouped adjacently in an array oriented in a direction having a component transverse to the alignment axis of the electrodes. ends (E1, E2) of the optical means.

8. Apparatus according to claim 7, wherein at least ten light emitting diodes are mounted in a honeycomb arrangement on a support board to form the light source (2).

9. Apparatus according to claim 7 or 8, wherein the light emitting diodes are connected to an electronic unit (8) arranged to control the power supply of the diodes.

10. Apparatus according to one of claims 1 to 7, characterized in that the optical means are formed in a substantially cylindrical assembly adapted to align with an annular device constituting said housing (1 '), the body (21) of the housing ( 1 ') forming a ring having housings for receiving light emitting diodes oriented towards a focusing point on the opposite side of the optical means.

11. Apparatus according to one of claims 1 to 6, characterized in that said member for emitting a focused light beam consists of at least one miniature xenon or halogen bulb associated with a bandpass filter to form said light source ( 2).

12. Apparatus according to one of claims 1 to 6, characterized in that the housing (1 ") consists of a laser emission device (7).

Apparatus according to claim 12, wherein the laser emission device (7) is of the type having a wavelength of the order of 532 nm to emit a green light beam.

An apparatus according to claim 12 or 13, wherein the optical means comprises a support means (70) having an arm (75) for releasably securing the laser emission device (7).

15. Apparatus according to one of claims 1 to 14, wherein the first end (E1) of the optical means comprises a periphery (11) adapted to allow the addition and / or attachment to the apparatus of an optical element - - magnification - so that the user can better visualize the fluorescence of the marked elements.

Apparatus according to one of claims 1 to 15, wherein an excitation filter (F1) is provided to chromatically refine the emission from the light source (2).

17. Apparatus according to one of claims 1 to 15, wherein the optical means comprise a filter block (BF) including a transmission filter (F2) to prevent at least the passage of visible waves from the or transmitters and to pass the specific wavelengths of emission of the fluorescence of the marked elements.

18. Apparatus according to one of claims 1 to 5, characterized in that the housing comprises a longitudinal axis and at least one alignment of light-emitting diodes along said longitudinal axis.

19. Use of the apparatus according to one of claims 1 to 18, characterized in that said portable apparatus is for detecting fluorescent particles contained in all or part of a product to be authenticated.

The use of the apparatus according to claim 19, wherein said portable apparatus is for detecting fluorescent particles contained in a marking area (60) associated with a product for marking.

21. Use of the apparatus according to claim 19, wherein the marking zone consists of an adhesion or coating compound comprising a minimal proportion of fluorescent molecules, invisible in the light of day but optically detectable by epifluorescence in a excitation wavelength range included in the visible.

22. Use of the apparatus according to claim 19, wherein the fluorescence to be detected is from at least one wire or fiber of 3 to 20 mm in length called fibrette.

23. Use of the apparatus according to claim 22, wherein the yarn or fibretêê is associated with a security paper.

24. Use of the apparatus according to claim 19, wherein the fluorescence to be detected comes from bodies of very small size whose volume is less than 0.1 mm ³ .

25. Use of the apparatus according to claim 19, wherein the fluorescence to be detected comes from microspheres whose diameter is between 0.2 and 20 microns.

26. Use of the apparatus according to claim 25, wherein the microspheres are associated with a security paper.

27. Use of the apparatus according to claim 25, wherein the microspheres are dispersed in a lubricating oil or a surface treatment of metal parts.

28. Use of the apparatus according to claim 19, wherein the apparatus detects luminescent signals of microspheres signaling hybridization of DNA on biochips or microarrays.