Optical analysis system

Abstract

The invention relates to an optical analysis system (10), characterised in that it comprises: - at least one first light source (20); - at least one dichroic filter (40); - at least one lens (50); - at least one optical fibre (60); - at least one spectrometer connected to the optical fibre (60), wherein the first light source (20) is configured to emit a first light flux passing through at least the lens (50) in order to expose a target area on a surface of a material (80), and wherein the optical fibre (60) collects at least one second flux resulting from the reflection of the first flux off the target area or from the fluorescence of the target area following exposure by the first flux and conveys it to the spectrometer, the system (10) further comprising at least one camera (30) configured to capture an image of the test area (80).

Description

[0001] OPTICAL ANALYSIS SYSTEM

[0002] Field of invention

[0003] The invention relates to the field of analysis systems. In one aspect, the invention relates to the field of systems for detecting contaminants on a scene. More particularly, the invention relates to the field of optical systems for analyzing compounds and the field of spectroscopy.

[0004] State of the art

[0005] Devices are known in the state of the art for carrying out analyses of components present on a surface or a sample based on an analysis of the light transmitted or reflected by the sample. For example, a spectrometer can measure the components of light to give the spectrum of the analyzed light. The spectrum is a representation of the light intensity of the analyzed light as a function of the frequency or wavelength of said light. In the context of analyzing or detecting a contaminant, an intensity peak or an intensity trough at a specific wavelength can highlight the presence of said compound.

[0006] One method for measuring and detecting compounds is to perform a spectral reflectance pointing. This method consists of sending incident light radiation onto a target. This incident light radiation will be reflected by the target to generate reflected light radiation. Then, an optical analysis system is used that will include one or more lenses to collect the reflected light radiation and a spectrometer to analyze the reflected light radiation. The spectrometer thus generates a spectrum of the reflected light radiation. Then, an analysis of this spectrum will detect peaks at certain wavelengths of radiation. These peaks correspond to the presence of a specific compound on the target at the location that was illuminated by the incident radiation. Such a measurement method has the advantage of being a non-destructive method of analyzing compounds.For example, it is possible to check whether an area of ​​a manufactured part has been contaminated by a particular compound only by illuminating it with incident light radiation. In this way, the part does not suffer any deterioration due to the control. However, such a measurement method has several disadvantages. For example, it is necessary to carry out the measurement in a place with very low external light pollution to maintain the integrity of the measurements taken. Similarly, careful calibration of the optical measuring instrument is necessary to, on the one hand, properly align the line of sight of the instrument with the area illuminated by the incident radiation and, on the other hand, place the spectrometer at the correct distance from the target to obtain good focusing of the reflected radiation at the spectrometer entrance. Finally, such a measurement method does not allow covering a large area of ​​the target.Indeed, spectral pointing only allows obtaining the spectrum of a point area on a target surface. Therefore, when one wishes to obtain several measurements on a surface, it is necessary to move the measuring device and recalibrate it to obtain a spectrum for each point pointed on the analyzed surface.

[0007] It is also known from the state of the art to carry out measurements by fluorescence spectral pointing. For fluorescence imaging, the measurement point is irradiated using incident radiation. This radiation is generally radiation in the ultraviolet range. This incident radiation will excite the electrons of the molecules on the surface of the analyzed sample which will in return emit fluorescence radiation which is generally visible light. This fluorescence radiation is subsequently analyzed by spectroscopy in the same way as for reflectance spectral pointing.

[0008] Document CN113740317A discloses a method and system for positioning the position of the focal point of a laser based on a spot area.

[0009] Document US2024 / 108410A1 discloses spectral detection of optical fiber blinking.

[0010] Document US2019 / 383605A1 discloses a surface measurement using excited fluorescence.

[0011] Document FR2826461A1 discloses an autofocus system, a method and a device for optical inspection of parts incorporating such a system. Summary of the invention

[0012] An object of the invention is to overcome the disadvantages of the existing art.

[0013] To this end, the invention relates to an optical analysis system which comprises:

[0014] ■ At least one first light source,

[0015] ■ At least one dichroic plate,

[0016] ■ At least one lens,

[0017] ■ At least one optical fiber, and

[0018] ■ at least one spectrometer connected to the optical fiber.

[0019] The first light source is configured to emit a first light flux passing through at least the lens to expose a target area of ​​a surface of a material.

[0020] The optical fiber is configured to collect at least a second light flux and convey it to the spectrometer, said second flux originating from the reflection and / or fluorescence of a material of the test area following the exposure of said test area, the second light flux passing through the lens, the dichroic plate being configured to reflect at least a spectral portion of the first light flux and / or the second light flux. The spectrometer is configured to record a spectrum characteristic of the second light flux originating from a target area of ​​the scene illuminated by the second flux.

[0021] The system further comprises at least one camera configured to capture at least one image of the test area and detect a position of the target area of ​​the scene illuminated by said beam defining the first flow.

[0022] The system according to the invention therefore advantageously makes it possible to carry out measurements of spectral points in reflectance and fluorescence with the same equipment. In addition, the presence of the camera advantageously makes it possible to take an image of the test area which will allow a contextualization of the spectrum resulting from the reflectance and / or fluorescence of the test area. The camera allows in particular a detection of the target area of ​​the illuminated scene. Thus, the user of the optical analysis system obtains a complete image of the test area with an indication of the area on which the spectral pointing was carried out. Such contextualization of the spectral pointing makes it possible to know precisely on the test area the place where the spectral pointing was carried out. As a result, a mapping of the test area can be carried out.

[0023] According to one embodiment, the optical analysis system comprises a computer for generating at least one descriptor of the spectrum recorded by the spectrometer from the second light flux. The generation of the descriptor by the system according to the invention makes it possible to characterize the spectrum generated by the system. Such a descriptor advantageously makes it possible to characterize a substance to be detected on the target area.

[0024] According to one embodiment, the optical analysis system comprises at least one pointing light source configured to illuminate the target area to form a light pointer on said target area. Such a pointer advantageously makes it possible to provide light information of the area on which the spectrum measurement is carried out.

[0025] According to one embodiment, the optical fiber comprises a bifurcation from which the fiber comprises two optical paths, a first optical path linking the fiber to the spectrometer, the second optical path linking the fiber to the pointing light source, said pointing light source being arranged to emit light into said fiber, the assembly of the optical fiber and the pointing light source forming the light pointer on the target area. This arrangement advantageously makes it possible to form a light pointer on the target area. This arrangement is particularly advantageous because by passing a pointing beam directly through the fiber, the target area which is in the "field of view" of the optical fiber is directly pointed. In this way, the pointing is always precise.

[0026] According to one embodiment, the pointing light source is a monochromatic colored LED source. The monochromatism of the pointing source makes it possible to create a pointer that is easily visible to the naked eye on the target area. Similarly, such a pointer is efficiently detectable on an image of the test area, whether by viewing the image or by detection by computer means.

[0027] According to one embodiment, the optical analysis system comprises a second light source, said second light source being configured to emit a third light flux towards the target area, said light being reflected by the test area and collected by the optical fiber to perform a reflectance measurement. This arrangement advantageously makes it possible to combine a reflectance spectrum measurement using the third light source and a fluorescence spectrum measurement using the first light source. Similarly, it makes it possible, in the case where the first light source is used to measure a reflectance spectrum, to perform two reflectance measurements with different sources.

[0028] According to one embodiment, when the second light flux comes from a fluorescence of the target area by the first light flux, the system comprises a second light source, said second light source being configured to emit a third light flux towards the target area, said third light flux being chosen so as to generate a fourth light flux coming from a reflectance phenomenon of said target material surface. This arrangement makes it possible to combine the measurement of the fluorescence spectrum and the reflectance spectrum of the target area. This arrangement therefore makes it possible to obtain more information and a better characterization of the material of the target area or of the substances present on the target area.

[0029] According to one embodiment, when the second light flux comes from a reflection of the first light flux, the system comprises a third light source, said third light source being configured to emit a fifth light flux towards the target area, said fifth light flux being chosen so as to generate a sixth light flux coming from a fluorescence phenomenon of said target material surface. This arrangement makes it possible to combine a measurement of the reflectance spectrum by the first light source and a measurement of the fluorescence spectrum by the third light source. This arrangement therefore makes it possible to obtain more information and a better characterization of the material of the target area or of the substances present on the target area.

[0030] According to one embodiment, the optical analysis system comprises a computer for generating two descriptors of each of the two spectra recorded by the spectrometer(s) originating on the one hand from the second light flux and on the other hand from the fourth light flux or the sixth light flux. This arrangement advantageously makes it possible to generate descriptors allowing the analysis of the spectra obtained by the system. Such descriptors allow the characterization of the material of the target area. These descriptors also allow the detection of one or more substances present in the target area. According to one example, the substance(s) detected are contaminants.

[0031] According to one embodiment, the second light source and / or the third light source are offset relative to a main optical axis of the system. This arrangement advantageously makes it easier to place all the elements of the system in a system housing.

[0032] According to one embodiment, the optical analysis system is configured to calculate a distance between a point of said system and the test area by detecting on an image taken by said camera the area illuminated by the first light source and by triangulation calculation. This arrangement is particularly advantageous because it makes it easier to calibrate the optical system during its installation thanks to knowledge of the distance between the system and the target area. This arrangement makes it possible to adjust the optics comprising the lenses easily and quickly.

[0033] According to one embodiment, the optical system comprises at least one optical axis. The first light source, an input of the optical fiber and the lens are aligned along the optical axis. This arrangement advantageously makes it possible to control the polarity of the second light flux. This arrangement also makes it possible to produce spectra under ambient conditions, by allowing the exposure of a small area of ​​the sample to be analyzed and by only "looking" with the fiber at a small area of ​​the illuminated area.

[0034] The invention also relates to an optical analysis system which comprises:

[0035] ■ At least one first light source,

[0036] ■ At least one dichroic plate,

[0037] ■ At least one lens,

[0038] ■ At least one optical fiber,

[0039] ■ At least one spectrometer connected to the optical fiber,

[0040] The first light source being configured to emit a first light flux passing through at least the lens to expose a test area. The optical fiber is configured to collect at least a second light flux resulting from the reflection and / or fluorescence of a material of the test area following the exposure of said test area, the second light flux passing through the lens, the dichroic plate being configured to reflect at least a spectral portion of the first light flux and / or the second light flux. The device further comprises an optical axis, the first light source, an input of the optical fiber and the lens being aligned along the optical axis.

[0041] The optical analysis system according to the invention makes it possible to produce spectra in ambient conditions, by allowing the exposure of a small area of ​​the sample to be analyzed and by only "looking" with the fiber at a small area of ​​the illuminated area.

[0042] The invention also relates to an optical analysis method which comprises the steps of:

[0043] ■ Emission by at least one first light source of a first light flux passing through or being reflected by a dichroic plate passing through at least one lens to expose a test area;

[0044] ■ Fluorescence emission following exposure of the test area or reflection of the first light flux by the test area to produce a second light flux passing through the lens and passing through or being reflected by the dichroic plate, the second light flux then being collected by at least one optical fiber;

[0045] ■ Routing of the second light flux via optical fiber to a spectrometer; and

[0046] ■ Taking an image of the test area by a camera.

[0047] The method according to the invention advantageously makes it possible to carry out measurements of spectral points in reflectance and fluorescence in the same process. In addition, the presence of the camera advantageously makes it possible to take an image of the test area which will allow a contextualization of the spectrum resulting from the reflectance and / or fluorescence of the test area. The camera allows in particular a detection of the target area of ​​the illuminated scene. Thus, a user obtains a complete image of the test area with an indication of the area on which the spectral pointing was carried out. Such contextualization of the spectral pointing makes it possible to know precisely on the test area the place where the spectral pointing was carried out. As a result, a mapping of the test area can be carried out.

[0048] According to one embodiment, the image of the target area is associated with a spectrum generated by the spectrometer, the method comprising a step of detecting a surface singularity of the material on the image of the test area as well as its position within the surface. This arrangement makes it possible to detect on the image candidate points which may have a singularity to be studied by spectral pointing. Since spectral pointing only gives a spectrum for one point of the target area, it is therefore very useful to generate several points of interest on which spectral pointing will be carried out.

[0049] According to one embodiment, the surface singularity comprises a variation in texture, color, depth and / or geometry of said surface.

[0050] According to one embodiment, the method comprises a step of displaying on a screen the image of the target area and a graphical representation of the spectrum generated by the spectrometer. This arrangement allows on the one hand a contextualization of the spectrum obtained by providing the user with a contextual image of the target area, making it possible to contextualize the measurement of the reflectance and / or fluorescence spectrum. The display of the spectrum on the screen allows for analysis by the user of the spectrum obtained, in particular to determine the presence of one or more substances and / or materials on the target area.

[0051] According to one embodiment, the method comprises a step of classifying a calculated spectrum descriptor, said classification being implemented by means of a machine learning algorithm trained from a data set defining on the one hand spectrum descriptors and on the other hand surface states characteristic of a material or a contaminant. This arrangement advantageously allows the determination of a descriptor on the spectrum which allows an analysis thereof. According to one example, the descriptor comprises a wavelength of a light intensity peak on the spectrum, a spectral width of the intensity peak, a slope of the intensity peak. The classification of the descriptor by the learning algorithm advantageously makes it possible to automatically characterize a substance present in the target area, a surface state, or any singularity on the material of the target area.This arrangement makes it possible to offer a user initial spectrum analysis results.

[0052] Brief description of the figures

[0053] Other characteristics and advantages of the invention will emerge on reading the detailed description which follows, with reference to the appended figures, which illustrate:

[0054] Figure 1 represents a diagram of an optical analysis system according to a variant of the invention.

[0055] Figure 2 represents a diagram of an optical analysis system according to a second variant of the invention.

[0056] Figure 3 represents a diagram of an optical analysis system according to a third variant of the invention.

[0057] Figure 4 represents a diagram of an optical analysis system according to a fourth variant of the invention.

[0058] Figure 5 represents a diagram of an optical analysis system according to a fifth variant of the invention.

[0059] Figure 6 represents a diagram of an optical analysis system according to a sixth variant of the invention.

[0060] Figure 7 represents a first spectrum generated by the optical analysis system according to the invention.

[0061] Figure 8 represents a second spectrum generated by the optical analysis system according to the invention.

[0062] Figure 9 represents a diagram of an analysis device according to a seventh variant of the invention.

[0063] Figure 10 represents a diagram of an optical fiber comprising a bifurcation according to an embodiment of the invention.

[0064] Description of the invention

[0065] Figures 1 to 6 represent embodiments of an optical analysis system 10 according to the invention.

[0066] The optical system 10 according to the invention comprises at least one first light source 20. By first light source 20 is meant any device which is adapted to produce a first luminous flux. Such a first light source 20 may for example be a light-emitting diode (often designated by the acronyms LED or DEL). According to one embodiment, the first light source 20 is an incandescent lamp. According to one embodiment, the first light source 20 is a halogen lamp. According to one embodiment, the first light source 20 is a neon lamp. According to one embodiment, the first light source is a fluorescent tube. According to one embodiment, the first light source 20 is a fluorescent lamp or compact fluorescent lamp. The first light source is configured to emit the first luminous flux in the visible wavelength range.According to one embodiment, the first light source 20 is configured to emit the first light flux in the ultraviolet wavelength range. According to one embodiment, the first light source 20 is configured to emit the first light flux in the infrared wavelength range. According to one embodiment, the first light source 20 is configured to emit a first light flux in the infrared, visible and ultraviolet wavelength range.

[0067] The optical system 10 comprises at least one dichroic plate 40. By dichroic plate 40 is meant an optical component having properties of reflection and transmission of a luminous flux which strongly depend on the wavelength of the luminous flux in question. In other words, the dichroic plate 40 acts as a filter for an incident luminous flux, transmitting a part of this flux and reflecting another part of it, depending on the wavelengths composing said flux.

[0068] The optical system 10 comprises at least one lens 50. By lens 50 is meant a device designed to converge or diverge the light rays passing through it. According to one embodiment, the system 10 comprises at least two lenses 50 forming a doublet of lenses 50.

[0069] The optical system 10 comprises at least one optical fiber 60. By optical fiber 60 is meant a light-conducting filament. The optical fiber 60 is capable of transmitting a light flux from an input 64 to an output thereof.

[0070] The optical analysis system 10 comprises at least one optical spectrometer 70 which is connected to the optical fiber 60. By optical spectrometer is meant a device which is capable of generating a spectrum of light radiation which it analyzes.

[0071] In the optical analysis system 10, the first light source 20 emits the first light flux. The first light flux then passes through the lens 50, or through the lenses 50. The lenses 50 advantageously allow focusing of the flux in a focal plane in which a target zone Zc of a surface of a material 80 is located.

[0072] Following its exposure to the first luminous flux, a second luminous flux leaves the target zone Zc in a direction substantially opposite to the direction of the first luminous flux. The second luminous flux results from the reflection of the first flux on the target zone Zc of the surface of the material 80 and / or from the fluorescence of the material 80 following its exposure to the first luminous flux. In this way, the second luminous flux comprises a spectral composition which is characteristic of the material of the target zone Zc.

[0073] The second flux then passes through the lens 50 or lenses 50. The lenses advantageously allow the focusing of the second luminous flux at an input 64 of the optical fiber 60.

[0074] The optical fiber 60 thus transmits the second light flux to the spectrometer for analysis of said second light flux.

[0075] The dichroic plate 40 is arranged to be on the path of the first light flux and / or on the path of the second light flux. In other words, the first light flux will pass or be reflected by the dichroic plate 40 and / or the second light flux will pass and / or be reflected by the dichroic plate 40. The dichroic plate is chosen to allow at least a first spectral part of the first to pass and to reflect a second spectral part of the second flux. The advantage of using the dichroic plate 40 is to allow the first or second flux to be separated in order to filter the part of these light fluxes that interests us for the analysis by spectroscopy. For example, in the case of a fluorescence spot, it may be useful to filter the second light flux entering the optical fiber 60 to keep only the part of the flux that is included in the visible wavelengths.In this way, the measurement by the spectrometer is not polluted by the first light flux which is in the ultraviolet wavelengths or by reflection of the first flux on the target zone Zc. The optical analysis system 10 comprises at least one camera 30. The camera is placed so as to be able to capture an image of the test zone 80. The image taken by the camera therefore also includes the target zone Zc which is in the test zone 80. This image of the test zone 80 advantageously allows a contextualization of the measurement carried out by pointing at the point of the target zone Zc.

[0076] The camera 30 detects a position of the target area Zc onto which the first light flux is directed.

[0077] The optical analysis system 10 according to the invention therefore advantageously makes it possible to take a measurement, in particular for the purpose of detecting substances and materials at the target zone Zc of a test zone 80 of a material. This measurement is carried out by pointing. In addition, the invention allows a contextualization of this measurement by the image which is taken of the test zone 80. In this way, it is possible for a user to know precisely the place on the test zone 80 where the pointing was carried out, and therefore to know the location of a substance which would have been detected by the pointing.

[0078] System Configurations

[0079] We will rely here on figures 1 to 6 which present several variants of the invention all presenting different configurations of the optical analysis system 10 according to the invention.

[0080] According to one embodiment, the first light source 20 emits the first light flux towards the dichroic plate 40. The dichroic plate reflects the first light flux towards the test zone 80.

[0081] According to one embodiment, the second light flux passes through the dichroic plate 40. According to this embodiment, the dichroic plate filters the second light flux according to the frequency. Thus, a frequency portion of the second light flux is reflected by the dichroic plate 40. The other frequency portion of the second flux passes through the dichroic plate to reach an input 64 of the optical fiber 60. This arrangement allows filtration of the second light flux in order to keep wavelengths of interest for analysis by the spectrometer 70.

[0082] According to one embodiment, the optical analysis device 10 comprises at least two lenses 50. The two lenses 50 form a doublet of lenses advantageously allowing a focusing of the first luminous flux at the level of the test zone 80. Advantageously, the first luminous flux is focused at the level of the target zone Zc of the test zone 80. Thus, the zone which is exposed to the first luminous flux is an area which is preferably of small surface area. This arrangement makes it possible to obtain the spectrum corresponding to a small surface area of ​​the material tested, and therefore to have a precise localization of the results obtained.

[0083] According to one embodiment, the second light flux is focused at an input 64 of the optical fiber 60. This arrangement advantageously allows a concentration of all the light radiation coming from the target zone Zc in the optical fiber. This arrangement makes it possible to obtain a light intensity of the second light flux sufficiently high to allow an analysis of the second light flux by the spectrometer 70.

[0084] According to one embodiment, the optical analysis system 10 comprises a main optical axis 100. The input 64 of the optical fiber 60 is aligned with the main optical axis 100. According to one embodiment, the first light source 20 is offset relative to the main optical axis 100 of the system 10. According to this embodiment, the dichroic plate 40 is inclined relative to the main optical axis 100. Thus, the first light flux emitted by the first light source 20 is reflected by the dichroic plate 40 which reorients the first light flux in a manner parallel or substantially parallel to the main optical axis 100 of the optical analysis system 10. According to one embodiment, the first light flux is emitted by the first light source 20 in a manner perpendicular or substantially perpendicular to the main optical axis 100 of the system 10.According to one embodiment, the dichroic plate is oriented obliquely relative to the main optical axis 100 of the system 10. According to one embodiment, a main plane of the dichroic plate 40 forms an angle of approximately 45 degrees with the main optical axis 100 of the system 10.

[0085] According to the variant of Figure 1, the first light source 20 emits the first light flux. This first light flux is emitted substantially perpendicular to the main optical axis 100 of the optical analysis system 10. The first light flux is then reflected by the dichroic plate 40 in the direction of the lenses 50 and the test zone 80. The first light flux is then oriented in a direction substantially parallel to the main optical axis 100 of the optical device 10. This arrangement advantageously makes it possible not to disturb the measurement of the spectrum by the spectrometer. Indeed, the input 64 of the optical fiber 60 is isolated from the first light source 20 by the dichroic plate 40 which prevents at least a frequency portion of the first light flux from reaching it. The first light flux then passes through the doublet of lenses 50.This doublet of lenses 50 advantageously makes it possible to focus the first luminous flux in a precise target zone Zc of the test zone 80. When the measurement is a reflectance measurement, this makes it possible to increase the luminous intensity at the target zone Zc and therefore to increase the intensity of the second luminous flux which comes from the reflection of the first luminous flux on the target zone Zc. When the measurement is carried out in fluorescence, this makes it possible to increase the luminous intensity at the target zone Zc and therefore to increase the intensity of the second luminous flux which comes from the fluorescence of the material of the target zone Zc due to the excitation by the first luminous flux. The second luminous flux then passes through the lenses 50. It then passes through the dichroic plate 40 which will filter the second flux according to the frequency thereof.In this way, the wavelengths of interest for analysis by the spectrometer are retained, and the other wavelengths are filtered. This arrangement makes it possible in particular to carry out pointing in bright ambient conditions, especially when the test area 80 is illuminated.

[0086] Figure 2 shows a second variant of the invention.

[0087] According to one embodiment, the first light source 20 is aligned along the main optical axis 100 of the device 10. According to one embodiment, the dichroic plate 40 is perpendicular or substantially perpendicular to the main optical axis 100 of the optical system 10. According to one embodiment, the input 64 of the optical fiber 60 is aligned or substantially aligned with the main optical axis 100 of the optical device 10. According to one embodiment, the first light flux is emitted by the first light source along the main optical axis of the optical system 10. The first light flux then passes through the dichroic plate 40. The dichroic plate 40 is selected to allow the first light flux to pass through. In other words, it is transparent at least in part to the wavelengths of the first light flux. The first flux then passes through the lens(es) 50. The first flux then reaches the target zone Zc of the test zone 80.The second light flux resulting from the reflection of the first flux by the target zone Zc or by the fluorescence of said target zone Zc following the excitation thereof by the first light flux. The second light flux then passes through the lens(es) 50. The second flux is then reflected by the dichroic plate 40. Advantageously, the dichroic plate 40 is selected to reflect wavelengths of interest of the second light flux. Wavelengths of interest are understood to mean wavelengths which make it possible to highlight the presence of particular substances in the target zone by analyzing their spectrum. The second reflected light flux then reaches the input 64 of the optical fiber 60. The optical fiber 60 channels the second light flux towards the spectrometer 70.

[0088] According to one embodiment, the optical system 95 comprises at least one mask 95. By mask 95 is meant an opaque part making it possible to conceal a portion of the first light flux coming from the first light source 20. The use of the mask 95 is particularly advantageous, especially when the first light source emits the first light flux in the direction of the input 64 of the optical fiber 60. In this way, the mask 95 makes it possible to conceal the input 64 of the optical fiber 60 to prevent the first light flux from penetrating directly into the optical fiber 60. In this way, the first light flux does not disturb the spectrum measurement of the second light flux by the spectrometer 70. An example of use of the mask 95 is visible in FIG. 2 which presents the second variant of the invention. A mask 95 is also used in the variants of the invention presented in FIGS. 3, 4, 5 and 6.

[0089] In the variant of Figure 2, the mask 95 is placed between the first light source 20 and the dichroic plate 40. In this way, the mask 95 is placed as close as possible to the first light source 20.

[0090] Figure 3 shows a third variant of the invention.

[0091] According to one embodiment, the first light source 20 is arranged on the main optical axis 100 of the system 10. The first light source 20 is arranged to emit the first light flux in a direction parallel or substantially parallel to the main optical axis 100. According to one embodiment, the first light flux is emitted in a direction opposite to the test area 80. The first light flux is emitted in the direction of the dichroic plate 40. The first light flux is then reflected in the direction of the lens(es) 50 and the test area 80. The lens(es) 50 allow the first light flux to be focused at the target area Zc of the test area 80. The second light flux from the target area Zc then passes through the lens(es) 50. The second flux then passes through the dichroic plate 40. The dichroic plate 40 is configured to filter wavelengths of interest from the second light flux.The second light flux then reaches the input 64 of the optical fiber 60 to be routed to the spectrometer 70.

[0092] Figure 4 shows a fourth variant of the invention.

[0093] According to one embodiment, the first light source 20 is arranged between the lens(es) 50 and the target area Zc of the test area 80. According to this embodiment, the first light flux is emitted towards the dichroic plate 40. The first flux passes through the lens(es) 50 before reaching the dichroic plate 40. The dichroic plate 40 reflects the first light flux towards the test area 80. The first flux passes through the lens(es) 50 again. The first flux then reaches the target area Zc. The second flux from the target zone Zc then passes through the lens(es) 50 before passing through the dichroic plate 40 and reaching the input 64 of the optical fiber 60. According to one embodiment, the mask 95 is fixed directly onto the dichroic plate 40. The mask 95 obstructs a portion of the first light flux which is not reflected by the dichroic plate 40. In this way, the input 64 of the optical fiber 60 is protected from the first light flux.This arrangement makes it possible to limit disturbances in the measurement of the spectrum of the second luminous flux.

[0094] Figure 5 shows a fifth variant of the invention.

[0095] According to one embodiment, the input 64 of the optical fiber 60 is located between the lens(es) 50 and the target zone Zc along the main optical axis 100. The input 64 of the optical fiber 60 is preferably oriented towards the lens 50 and the dichroic plate 40. According to one embodiment, the first light source 20 is located at one end of the optical system 10, opposite the target zone Zc. According to one embodiment, the first light flux emitted by the first light source passes through the dichroic plate 40, the lenses 50 before reaching the target zone Zc. The second light flux from the target zone Zc passes through the lenses 50 before being, at least in part, reflected by the dichroic plate 40. Then, the second light flux passes through the lenses 50 again before reaching the input 64 of the optical fiber 60. According to one embodiment, the dichroic plate comprises the mask 95.The mask 95 is advantageously placed opposite the first light source 20. According to one embodiment, the mask 95 is aligned with the first light source and the input 64 of the optical fiber 60. This arrangement makes it possible to mask the optical fiber from the first light source 20.

[0096] Figure 6 shows a sixth variant of the optical analysis system 10 according to the invention.

[0097] According to one embodiment, the optical analysis system 10 comprises at least two light sources, the first light source 20 and a second light source 22. Advantageously, the first light source 20 is an infrared source and the second light source 22 is an ultraviolet source. This arrangement is particularly advantageous because it makes it possible to successively or simultaneously perform a fluorescence spectral pointing of the target zone Zc and a reflectance spectral pointing on the target zone Zc. Alternatively, the first light source 20 is an ultraviolet source and the second light source 22 is an infrared source. According to one embodiment, at least the first light source 20 and / or the second light source 22 emit light in the visible wavelengths.

[0098] According to one embodiment, the second light source 22 emits a third light flux. The third light flux reaches the target zone Zc of the test zone 80. According to one embodiment, the third light flux is a light flux comprising a component in the ultraviolet wavelengths. According to this embodiment, the third light flux reaches the target zone Zc in order to cause a fluorescence phenomenon of the target zone Zc. In this way, a fourth light flux is generated by the target zone Zc. The fourth flux advantageously follows the same optical path as the second light flux. Thus, the fourth light flux reaches the input 64 of the optical fiber 60 then the spectrometer 70.

[0099] According to one embodiment, the optical analysis system comprises at least two dichroic plates 40. This arrangement is particularly advantageous in the case where the system comprises two light sources 20, 22, more particularly when each emits a light flux in different wavelength ranges. According to one embodiment, at least one of the dichroic plates is inclined relative to the main optical axis 100 of the optical system 10. According to one embodiment, the second light source 22 is offset relative to the main optical axis 100 of the system 10. According to one embodiment, the second light source 22 emits a light flux. The light flux is preferably emitted perpendicularly or substantially perpendicularly to the main optical axis 100 of the optical system 10.According to one embodiment, the second dichroic plate is oriented so as to form an angle of approximately 45 degrees with the main optical axis 100 of the optical system 10. In this way, the second light source emits the light flux towards the second dichroic plate 40. The second dichroic plate reflects the light flux towards the lens(es) 50. The light flux passes through the lens(es) 50 and reaches the target zone Zc of the test zone 80. The exposure of the target zone Zc to the light flux generates a second light flux resulting from the reflection of the light flux on the target zone Zc or from the fluorescence of the target zone Zc induced by the light flux. In this way, a second spectral pointing can be carried out jointly or additionally to the first pointing following the light exposure due to the light flux of the first light source.For example, a fluorescence spectral pointing measurement can be carried out by exposure by the first light source 20 and a reflectance pointing can be carried out by exposure by the second light source 22.

[0100] According to one embodiment, the transmittance and reflectance characteristics of the dichroic plates 40 are selected to allow the desired type of measurement depending on the measurements to be carried out. According to one example, the first light source 20 is a source emitting light in the ultraviolet range and the second light source is a source emitting radiation in the infrared range. According to this example, the dichroic plate 40 which is opposite the first light source 20 is configured to transmit ultraviolet light and to reflect visible waves. According to this same example, the dichroic plate 40 which is opposite the second light source (the one which is oriented at an angle relative to the optical axis 100 of the system 10 in FIG. 6) is configured to reflect infrared waves and to transmit visible light.This configuration allows the transmission of light fluxes towards the target zone Zc and the transmission of the second light flux (in particular its component in the visible) by reflection on the dichroic plate 40 which is perpendicular to the optical axis 100 towards the input 64 of the optical fiber 60.

[0101] Contextualization

[0102] The optical analysis system 10 comprises at least one camera 30. The camera 30 is oriented so as to be able to capture an image of the test area 80. Taking the image of the test area 80 is particularly advantageous because it allows a user of the optical system 10 to contextualize the spectrum obtained by the optical system 10. According to one embodiment, the camera 30 is configured to allow detection of the target area Zc on the image taken of the test area 80. According to one embodiment, the detection of the target area Zc is carried out by detecting the illumination of the target area Zc by the first light flux. The detection of the target area Zc on the image is particularly advantageous because it makes it possible to improve the contextualization of the measurements. Indeed, the target area Zc is typically much smaller in surface area than the test area 80.Thus, precise detection of the target area Zc advantageously makes it possible to know exactly the location on the test area 80 where a particular substance has been detected on the spectrum. In this way, it is possible to map the test area 80 by carrying out several spectral pointings on several target areas Zc chosen by the user. This gives a precise mapping of the test area associated with spectra for each target area that has been selected.

[0103] According to one embodiment, the camera 30 is preferably a fluorescence imaging camera, a multispectral reflectance imaging camera or an infrared imaging camera.

[0104] According to one embodiment, the system comprises a pointing light source 26. The pointing light source 26 advantageously provides illumination on the target area Zc. This illumination allows detection of the target area by the camera 30 or by a user. According to one embodiment, the pointing light source 26 illuminates the target area Zc by forming a light spot thereon. According to one example, the pointing light source 26 is a red light source. A red color of the pointing light source allows effective detection of the target area Zc on the test area 80. According to one embodiment, the optical fiber 60 comprises a bifurcation. By bifurcation, we mean a separation of the optical fiber 60 into two strands. According to one embodiment, a first strand of optical fiber 60 leads to the spectrometer 70. According to one embodiment, a second strand of the optical fiber 60 leads to the pointing light source 26.Thus, the pointing light source 26 can emit a light flux into the optical fiber 60. The light flux emitted by the pointing light source 26 emerges through the inlet 64 of the optical fiber 60. In this way, the light flux emitted by the pointing light source 26 is projected onto the target area Zc. Advantageously, the light flux from the pointing light source 26 illuminates the “field of view” of the optical fiber 60. In other words, the light flux from the pointing light source 26 precisely illuminates the target area Zc to allow detection of the location of the target area Zc. An optical fiber arrangement 60 comprising a bifurcation is shown in FIG. 10.

[0105] According to one embodiment, the pointing light source 26 forms a pointer on the target area Zc. The formation of a pointer on the target area Zc allows easy detection of the target area Zc on the test area 80. This detection can be carried out with the naked eye by a user of the system 10. This detection can also be carried out on the image of the test area 80 taken by the camera 30. Advantageously, the pointer on the target area Zc is colored. According to one embodiment, the pointing light source 26 forms a red colored pointer on the target area. According to one embodiment, the pointing light source is a monochromatic colored LED source. This arrangement allows easier detection of the pointer on the test area 80.

[0106] According to one embodiment, the camera 30 allows detection of the pointer formed by the pointing light source on the target area Zc. According to one embodiment, an analysis of the image of the test area 80 is carried out to detect a position of the pointer on the image. This analysis of the image advantageously makes it possible to associate a position on the image with a spatial coordinate of the pointer on the test area 80.

[0107] Calibration

[0108] According to one embodiment, the optical analysis system 10 is capable of calculating the distance between the test zone 80, and more particularly the target zone Zc, and the system 10. This arrangement advantageously allows adjustment of the different lenses, or even movement of one lens 50 relative to the other to modify the focal length of the lens combination. This allows focusing of the different light fluxes at the target zone Zc and focusing of the second light flux, the fourth light flux, and / or the fifth light flux at the input 64 of the optical fiber 60. According to one embodiment, the system detects at least one point of the target zone Zc on the image taken of the test zone 80 by the camera 30. This detection can, for example, be carried out in the manner described previously in this description.Advantageously, the detection of the target zone Zc is done by detecting the area illuminated by the first light flux from the first light source 20. Alternatively or additionally, the detection of the target zone Zc is done by detecting the area illuminated by the pointing light source 26. According to one embodiment, the distance is calculated by triangulation. The camera 30 and the different elements used for the projection of the first light flux and / or the third light flux and / or projection of the pointing are fixed relative to each other. Thus, the position of the pointer and / or the first flux on the target zone Zc in the image captured by the camera 30 makes it possible to deduce, geometrically, the distance between a point of the system and the test zone 80.In other words, the pointer formed by the pointing light source or the area illuminated by the first light flux will be shifted on the image taken by the camera 30 the greater the distance between the system 10 and the test area. Measuring the distance between the system and the test area is particularly advantageous because it makes it possible to calibrate the optical system 10 by knowing precisely its distance from the test area 80.

[0109] Singularity detection

[0110] According to one embodiment, the optical analysis system 10 comprises at least one computer. By computer is meant any means capable of processing information. According to one embodiment, the image of the test area 80 captured by the camera 30 is digitized. The digitized image of the test area 80 is transmitted to the computer. According to one embodiment, the computer analyzes the digitized image and generates at least one coordinate corresponding to the position of the target area Zc on the test area 80. According to one embodiment, the detection of the position of the target area Zc is carried out by a search for contrasts on the image of the test area 80. In other words, this search for contrast makes it possible to detect an area more illuminated than the rest of the test area 80 which corresponds to the target area Zc illuminated by the pointer.

[0111] According to one embodiment, the spectrometer 70 is configured to digitize a spectrum of the light flux received by the optical fiber 60. The spectrum thus digitized can be recorded on a physical memory of the optical system 10. According to one embodiment, the digitized spectrum is sent to a remote server.

[0112] According to one embodiment, the calculator is configured to generate at least one descriptor of the spectrum of the second luminous flux. According to one example, the descriptor of the spectrum is at least one wavelength value of a peak of the spectrum. Such an example is visible in FIG. 7, which represents a spectrum generated by the spectrometer 70. The curve 110 is the spectrum. The graph comprises wavelength values ​​on the abscissa and luminous intensity values ​​on the ordinate. The curve of the spectrum comprises a peak 112. The peak 112 of the spectrum is characteristic of the presence of a particular substance at the target zone Zc. According to one embodiment, the calculator compares the wavelength value of the intensity peak with an equivalence table. The equivalence table comprises names of materials or substances associated with specific wavelengths.In this way, the calculator can return at least one name of substance present at the target area Zc using the wavelength value of the peak. According to one embodiment, a width 114 of the wavelength peak is measured on the spectrum by the calculator. According to one embodiment, the descriptor of the spectrum is the wavelength value associated with a light intensity trough of the spectrum. According to one embodiment, the spectral width of the trough in the spectrum is the descriptor.

[0113] According to one embodiment, the calculator classifies the spectrum descriptor. The classification of the descriptor is advantageously implemented by means of a machine learning algorithm. According to one embodiment, the machine learning algorithm is trained from at least one set of data defining on the one hand descriptors and on the other hand surface states of materials, and / or given material types, and / or presences of contaminants. According to one embodiment, the machine learning algorithm defines a neural network.

[0114] According to one embodiment, the computer is configured to generate at least two spectra recorded by the spectrometer. According to one embodiment, at least one of the spectra is a reflectance spectrum and at least one of the spectra is a fluorescence spectrum. Advantageously, when the system 10 comprises several light sources, the optical system 10 can simultaneously generate fluorescence and reflectance spectra of the target area Zc.

[0115] Detection of areas of interest

[0116] According to one embodiment, the camera is a camera taking images in red, green, and blue. Thus, an intensity value of each color is associated with each pixel of the image taken by the camera. According to one embodiment, a spectral pointing of reflectance or fluorescence is performed on the target zone Zc of the test zone 80. At least one descriptor of the spectrum obtained following the pointing is extracted from said spectrum. According to one example, the descriptor obtained is a distribution of wavelengths of said spectrum. According to one example, the descriptor is a wavelength value associated with a high intensity in the spectrum. According to one example, the descriptor is a value of wavelengths of low intensity in the spectrum. According to one embodiment, the calculator performs a transformation of the descriptor to extract at least one red, green, or blue intensity value.This arrangement makes it possible to provide an equivalence between the detection of a particular substance at the target area Zc by the pointer and the image taken by the camera. In other words, a similarity is made between the fluorescence and / or reflectance spectrum of the target area Zc and the intensity values ​​of red, green and blue obtained on a pixel corresponding to the target area Zc of the image taken by the camera. According to one example, a pixel ratio of a given color on the spectrum is calculated from the spectrum obtained. This ratio advantageously determines a criterion for detecting a point similar to that on which the pointer was made. According to one embodiment, the calculator determines an intensity ratio between the intensity values ​​of red, blue and green corresponding to the point of the target area Zc.

[0117] According to one embodiment, the calculator performs a search on the image taken by the camera to find points on the test area 80 which have a similarity with the target area Zc on which the pointing was carried out. According to one example, once the intensity ratio has been determined, a search is performed on the image of the test area 80 taken by the camera. This search is performed for each pixel of the test area 80. The pixels of the image comprising a ratio identical or close to that of the ratio previously determined for the target area Zc are detected on the image of the test area 80. This arrangement advantageously makes it possible to detect points of the test area 80 which have similarities with the target area Zc. In other words, this arrangement makes it possible to detect points which have a high probability of presence of the substance which was detected at the target area Zc.This arrangement therefore advantageously makes it possible to obtain a map of the locations on the test zone 80 likely to present a given substance which has been detected by a pointing at the target zone Zc. Advantageously, this map makes it possible to guide the user when he wishes to find all the points where the given substance is located. Advantageously, he can then carry out spectral pointings on the locations of the test zone 80 which have been detected in order to confirm the presence of the given substance, the spectral pointings giving more security on the detection of the given substance.

[0118] Application examples

[0119] We will now describe a particular example of application of the optical analysis system 10 according to the invention.

[0120] According to one example, the optical system 10 is used for an analysis of a work of art. In this specific example, the work of art is a graphic work, such as a painting on canvas, or a fresco. However, the system can be used on any type of work of art, such as sculptures for example. In this example, the test area 80 comprises at least one painted surface. In other words, the test area 80 comprises at least a portion of the work of art. First, a user places the optical analysis system 10 in front of the painting. The user then performs a pointing on the test area 80. The pointing comprises a measurement of a reflectance and / or fluorescence spectrum by the optical system 10. The pointing is performed on the target area Zc which is an area belonging to the test area 80, preferably on a point of interest.By point of interest, we mean a location of the test area 80 comprising degradation, underlying features and / or a restoration trace. According to one embodiment, a first image from the camera is taken of the test area 80. The first image from the camera is preferably an image by fluorescence imaging, multispectral reflectance imaging or infrared imaging. This first image makes it possible to detect areas of interest on which to perform a first spectral pointing. The areas of interest comprise areas comprising degradation, underlying features and / or a restoration trace. Then, the spectral pointing measurement will be performed on the areas of interest determined by the imaging.This arrangement makes it possible to easily select the areas on which to perform spectral pointing, much more qualitative imaging but requiring more time, which makes it difficult to make a large number of pointing measurements on the test area 80. According to one embodiment, the spectrum measured by pointing on the target area Zc is used to obtain a similarity vector allowing a search for areas of interest on which to perform spectral pointing subsequently. According to one embodiment, the similarity vector comprises at least one intensity value, preferably associated with a wavelength value. According to one embodiment, the similarity vector comprises at least one ratio of according to wavelength bands corresponding to red, blue and green. This arrangement makes it possible to convert a measurement carried out by pointing values ​​corresponding to the image taken by the camera.Thus, according to this arrangement, it is possible to search in the image taken with the camera for similarities with the measurement of the spectrum taken by pointing. As a result, a search for points of interest in the camera image is carried out. As a result, the user can reveal all locations on the image of the test area 80 which have a high similarity in optical response with the target area Zc. Thus, the user can quickly locate on the test area 80 all areas which have for example undergone restoration, degradation or on which an underlying feature is present.

[0121] According to another example, the same operating mode can be used in a manufacturing room to detect contamination on a satellite during manufacturing. In the same way, the optical analysis system 10 can be used in a semiconductor manufacturing room or in a clean room to detect impurities. According to another example, the same operating mode is used for surgical assistance. According to this embodiment, the points of interest are defined by the surgeon. For example, the location of tumor tissues can be sought by the optical analysis system 10. Thus, the surgeon can locate the presence of said tumor tissues over an entire organ.

[0122] A particular interest of the optical analysis system 10 according to the invention is that it allows non-destructive measurements to be carried out on the test area 80. As a result, a large number of applications can be determined for the optical system 10 according to the invention.

[0123] Figure 9 shows another variant of the invention.

[0124] According to one embodiment, the optical analysis system 10 comprises a housing 140. The housing 140 advantageously comprises all of the elements of the optical analysis system 10. According to one embodiment, the optical analysis system 10 comprises the first light source 20. The first light source is preferably a source emitting the first light flux in the ultraviolet wavelengths. The first light source 20 is offset relative to the main optical axis 100. By offset, it is meant that the first light source emits the first light flux in a direction which is not parallel or coincident with the main optical axis 100. According to one embodiment, the first light source 20 emits the first flux perpendicular to the main optical axis. According to one embodiment, the dichroic plate 40 is inclined relative to the main optical axis 100.This arrangement makes it possible to reflect the first luminous flux, the reflection of said flux making it aligned with the main optical axis 100. The dichroic plate 40 is selected to reflect light radiation in the ultraviolet wavelengths. The dichroic plate 40 is selected to transmit light radiation in the visible wavelengths and in the infrared wavelengths.

[0125] According to one embodiment, the optical system 10 comprises at least one optic 52. Optic 52 is understood to mean a combination of several lenses 50 forming an optical system. The optic 52 comprises the lens(es) 50. The optic 52 is located along the main optical axis 100. In this way, the first light flux passes through the optic 52. According to one embodiment, the optic 52 is controlled. Controlling the optic comprises moving at least one lens 50 along an optical axis of the optic 52. In this case, controlling the optic 52 comprises moving a lens 50 along the main optical axis 100. Controlling the optic 52 makes it possible to move the focal plane of the optic 52. In this way, the system is calibrated to allow the focusing of the first light flux and / or the second light flux at the target zone Zc.According to one embodiment, the control is manual, carried out by the user for example using a wheel. According to one embodiment, the control of the optics 52 is electronic. In this case, it is carried out using at least one electric motor actuating the movement of at least one lens 50. According to one embodiment, the electronic control of the optics 52 is controlled by the user via an interface. According to one embodiment, the control of the optics is carried out by the computer. According to one example, the computer controls the optics 52 according to the distance which has been calculated by triangulation using the camera 30, as seen previously.

[0126] The first light flux therefore passes through the optics 52 before reaching the target zone Zc. The first light flux excites the target zone Zc to generate a fluorescence phenomenon giving rise to a second light flux. The second light flux emitted by the target zone Zc passes through the optics 52 then the dichroic plate 40. The dichroic plate 40 does not reflect the second light flux because it is mainly composed of wavelengths in the visible range. Finally, the second light flux reaches the input 64 of the optical fiber 60 and then reaches the spectrometer 70.

[0127] According to one embodiment, the second light source 22 is an infrared source. This second light source emits the third light flux in the infrared wavelength range. Preferably, the second light source emits the third light flux along the main optical axis 100. The third light flux passes through the dichroic plate 40 then the optics 52, before reaching the target zone Zc. The reflection of the third light flux on the target zone gives rise to a fourth light flux. The fourth light flux then passes through the optics 52, then the dichroic plate 40. Finally, it reaches the input 64 of the optical fiber 60 then the spectrometer 70. The optical system 10 comprises the camera 30. The camera 30 is oriented towards the test zone 80. The camera 30 is oriented obliquely relative to the main optical axis 100.In this way, the camera can point to the target area Zc without being located on the main optical axis 10.

[0128] According to one embodiment, the optical system 10 comprises a third light source 24. The third light source is advantageously offset relative to the main optical axis 100. The third light source 24 is arranged opposite a second optic 5. The second optic 54 comprises an arrangement of at least two lenses which is similar to the arrangement of the first optic 52. The third light source emits a fifth light flux. According to one embodiment, the third light source emits the fifth light flux in the infrared wavelength range. According to one embodiment, the third light source emits the fifth light flux in the visible wavelength range. The third light source 24 emits the fifth light flux towards the target zone Zc. Advantageously, the fifth light flux is reflected by the target zone Zc to create a sixth light flux.The sixth light flux then passes through the optics 52, the dichroic plate 40 before reaching the input 64 of the optical fiber 60. The optical fiber 60 carries the sixth light flux to the spectrometer 70.

[0129] An arrangement as shown in the variant of Figure 9 allows a plurality of spectrum measurements to be made. The spectrum from the second light flux is acquired. The spectrum from the fourth light flux is acquired. The spectrum from the sixth light flux is acquired. Thus, such an arrangement allows a plurality of different measurements to be made at once, with a single adjustment or calibration of the system.

[0130] According to one embodiment, the first light source 20, the second light source 22 and / or the third light source 24 is an LED source. In the following paragraph, we will refer to the first light source 20, the second light source 22 and the third light source 24 interchangeably as light source. The following characteristics are all applicable to each of the three light sources, in an additional or alternative manner. The light source is advantageously wavelength-controlled. The wavelength-controlled light source is preferably carried out to adapt the light source to external conditions. The wavelength-controlled light source is also advantageously carried out to detect particular substances or materials. Thus, it is possible to favor the emission of certain wavelengths, because they make it possible to more effectively detect a given substance.According to one embodiment, the light source is amplitude controlled. The amplitude control makes it possible to adapt the amplitude of the first luminous flux, for example to carry out a measurement in conditions of significant ambient light. According to one embodiment, the system 10 comprises an ambient light sensor. According to one embodiment, the intensity control of the light source is carried out according to a data item or physical quantity from the ambient light sensor. According to one embodiment, the computer controls the intensity of the light source according to the data from the ambient light sensor. According to one embodiment, the light source comprises a set of LEDs. Advantageously, each LED is adapted to emit light in a given wavelength range.According to one embodiment, each LED of the LED assembly is arranged to emit light in a wavelength range representing a part of the wavelength range of the light source. This arrangement makes it easier to control the wavelength of the light source, since it is sufficient to solicit more or less each LED corresponding to the wavelengths that one wishes to have in the first luminous flux.

[0131] According to one embodiment, the optical analysis system 10 comprises a tripod support 120. Advantageously, the tripod support 120 makes it possible to place the optical system 10 on a tripod. In this way, the optical system 10 can be placed opposite the test area 80 to carry out the spectral measurements.

[0132] According to one embodiment, the system 10 comprises at least one screen or display. The screen is configured to display at least one spectrum obtained by the optical system 10. The display of the spectrum obtained by the spectrometer 70 allows a user to perform an analysis of said spectrum. According to one embodiment, at least one graphical representation of a descriptor is generated. According to one embodiment, the display comprises cursors. According to one embodiment, the system comprises at least one control means, for example a potentiometer, a touch screen or a button. The control means advantageously makes it possible to move a cursor on the screen. According to one embodiment, the cursor allows the user to adjust a detection threshold for areas of interest on the image taken by the camera 30.

[0133] According to one embodiment, the optical analysis system 10 comprises at least one means of connection to an external system. By connection means is meant a communication interface allowing the transmission of information to an external system. Advantageously, the connection means connects the computer to the external system. The communication means may comprise a wired connection means such as a USB connector, a wireless connection means such as a radio wave connection, a WIFI connection, a Bluetooth connection.

[0134] Nomenclature:

[0135] 10: optical analysis system

[0136] 20: first light source

[0137] 22: second light source

[0138] 24: third light source

[0139] 26: pointing light source

[0140] 30: camera

[0141] 40: dichroic plate

[0142] 50: lens

[0143] 52: optics

[0144] 54: second optic

[0145] 60: optical fiber

[0146] 62: fiber optic branch

[0147] 64: optical fiber input

[0148] 70: spectrometer

[0149] 80: test zone

[0150] Zc: target zone

[0151] 90: support

[0152] 95: mask

[0153] 100: main optical axis of the system

[0154] 110: spectrum curve

[0155] 112: peak light intensity

[0156] 114: wavelength peak width

[0157] 120: tripod mount

[0158] 130: USB ports

[0159] 140: case

Claims

CLAIMS 1. Optical analysis system (10) characterized in that it comprises: ■ At least one first light source (20), ■ At least one dichroic plate (40), ■ At least one lens (50), ■ At least one optical fiber (60), ■ At least one spectrometer (70) connected to the optical fiber (60), The first light source (20) being configured to emit a first light flux passing through at least the lens (50) to expose a target area of ​​a surface of a material (80), said material being arranged within a test area (80); The optical fiber (60) being configured to collect at least a second light flux and convey it to the spectrometer (70), said second flux originating from the reflection and fluorescence of a material of the test area (80) following the exposure of said test area (80), the second light flux passing through the lens (50), the dichroic plate (40) being configured to reflect at least a spectral portion of the first light flux and at least a spectral portion of the second light flux; the spectrometer being configured to record a spectrum characteristic of the second light flux originating from said target area of ​​a surface of a material (80) of a scene illuminated by the first flux; The system (10) further comprising at least one camera (30) configured to capture at least one image of the test area (80) and detect a position of the target area of ​​a surface of a material (80) of the scene illuminated by said beam defining the first flow.

2. Optical analysis system (10) according to any one of the preceding claims, characterized in that it comprises a calculator for generating at least one descriptor of the spectrum recorded by the spectrometer from the second light flux.

3. Optical analysis system (10) according to the preceding claim which comprises at least one pointing light source (26) configured to illuminate the target area (Zc) to form a light pointer on said target area (Zc).

4. Optical analysis system (10) according to the preceding claim in which the optical fiber (60) comprises a bifurcation (62) from which the fiber (60) comprises two optical paths, a first optical path linking the fiber to the spectrometer (70), the second optical path linking the fiber (60) to the pointing light source (26), said pointing light source (26) being arranged to emit light in said fiber (60), the assembly of the optical fiber (60) and the pointing light source (26) forming the light pointer on the target zone (Zc).

5. Optical analysis system (10) according to any one of claims 3 to 4 wherein the pointing light source (26) is a monochromatic color LED source.

6. Optical analysis system (10) according to any one of the preceding claims which comprises a second light source (22), said second light source (22) being configured to emit a third light flux towards the target area (Zc), said light being reflected by the test area and collected by the optical fiber (60) to carry out a reflectance measurement.

7. Optical analysis system (10) according to any one of the preceding claims which when the second light flux comes from a fluorescence of the target zone (Zc) by the first light flux, the system comprises a second light source (22), said second light source (22) being configured to emit a third light flux in the direction of the target zone (Zc), said third light flux being chosen so as to generate a fourth light flux coming from a reflectance phenomenon of said surface of the targeted material.

8. Optical analysis system (10) according to any one of the preceding claims which when the second light flux comes from a reflection of the first light flux, the system comprises a third light source, said third light source being configured to emit a fifth light flux towards the target zone (Zc), said fifth light flux being chosen so as to generate a sixth light flux resulting from a fluorescence phenomenon of said surface of the targeted material.

9. Optical analysis system (10) according to any one of claims 7 to 8, characterized in that it comprises a calculator for generating two descriptors of each of the two spectra recorded by the spectrometer(s) originating on the one hand from the second light flux and on the other hand from the fourth light flux or the sixth light flux.

10. Optical analysis system (10) according to any one of the preceding claims which is configured to calculate a distance between a point of said system (10) and the test area (80) by detecting on an image taken by said camera (30) the area illuminated by the first light source and / or by the pointing light source (26) and by triangulation calculation.

11. An optical analysis system (10) according to any preceding claim which comprises at least one main optical axis (100), and wherein the first light source (20), an input (64) of the optical fiber (60) and the lens (50) are aligned along the main optical axis (100).

12. Optical analysis system (10) according to the preceding claim in which the second light source (22) and / or the third light source (24) is offset relative to the main optical axis (100) of the system (10).

13. Optical analysis method characterized in that it comprises the steps of: ■ Emission by at least one first light source (20) of a first light flux of which at least one spectral part is reflected by a dichroic plate (40) and passes through at least one lens (50) to expose a test zone (80); ■ Fluorescence emission following exposure of the test area (80) and by reflection of the first light flux by the test area (80) to produce a second light flux passing through the lens (50) of which at least one spectral part is reflected by the dichroic plate and then collected by at least one optical fiber (60); ■ Routing by the optical fiber (60) of at least one spectral part of the second light flux to a spectrometer (70); and ■ Taking an image of the test area (80) by a camera (30).

14. Method according to the preceding claim in which the image of the target zone (Zc) is associated with a spectrum generated by the spectrometer (70), the method comprising a step of detecting a surface singularity of the material on the image of the test zone (80) as well as its position within the surface.

15. Method according to one of claims 13 and 14 which comprises a step of displaying on a screen the image of the target zone (Zc) and a graphic representation of the spectrum generated by the spectrometer (70).

16. Method according to any one of claims 13 to 15, characterized in that it comprises a step of classifying a calculated spectrum descriptor, said classification being implemented by means of a machine learning algorithm trained from a set of data defining on the one hand spectrum descriptors and on the other hand surface states characteristic of a material or a contaminant.

Images