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    • 专利摘要:
    A method of marking an optical article (20) coated with an interference coating comprising at least two inner (15) and outer (14) layers and reflection coefficient Re; by insolation of the inner layer (15) at a marking point (P) by means of a laser beam at a marking wavelength so as to ablate the inner layer and any layer further away from the substrate ; the ablated zone having a reflection coefficient Rm different from Re of at least 1%; The inner layer absorbs the marking wavelength more than any layer further away from the substrate. The invention also relates to an optical article coated with an interferential coating with at least two inner and outer layers, said article comprising a marking pattern formed by localized absence of layers.
    公开号:FR3054043A1
    申请号:FR1656851
    申请日:2016-07-18
    公开日:2018-01-19
    发明作者:Sebastien Maurice；Gerhard Keller；Michele Thomas
    申请人:Essilor International Compagnie Generale dOptique SA；
    IPC主号:
    专利说明:

    Holder (s): ESSILOR INTERNATIONAL (COMPAGNIE GENERALE D'OPTIQUE) Public limited company.
    Extension request (s)
    Agent (s): SANTARELLI.
    METHOD OF VISIBLE PERMANENT MARKING OF OPTICAL ARTICLE AND OPTICAL ARTICLE MARKED.
    FR 3 054 043 - A1 f5 /) Method for marking an optical article (20) coated with an interference coating comprising at least two inner (15) and outer (14) layers and of reflection coefficient Re;
    by insolation of the inner layer (15) at a marking point (P), by means of a laser beam at a marking wavelength, so as to ablate the inner layer and any layer further from the substrate ; the ablated zone having a reflection coefficient Rm different from Re by at least 1%;
    The inner layer absorbing the marking wavelength more significantly than any layer further from the substrate.
    The invention also relates to an optical article coated with an interference coating with at least two inner and outer layers, said article comprising a marking pattern formed by localized absence of layers.

    The present invention relates to the general field of visible permanent marking of optical articles, typically ophthalmic glasses, coated with a multilayer interference coating.
    It is known that ophthalmic lenses, such as spectacle lenses, are subjected to different stages of manufacture. One of these stages includes the so-called permanent marking of the ophthalmic lens on one of its faces. The permanent technical marking is formed by etching, or micro-etching, representing points or crosses and identifying a particular point (for example the optical center of the ophthalmic lens or the prism reference point for a progressive lens), or centerlines (for example to indicate the horizontal axis along which the astigmatism is corrected), or shapes limiting a particular area (for example, the near vision area or the far vision area in the case of 'a progressive lens).
    These permanent, technical or commercial markings are often made on one side, front face or rear face, of ophthalmic lenses, certain markings being able to be on the front face and others on the rear face. By "rear face" or "internal face" (generally concave) of the substrate is meant the face which, when the article is used, is closest to the wearer's eye. Conversely, by "front face" or "external face" (generally convex) of the substrate is meant the face which, when the article is used, is the farthest from the eye of the wearer.
    The most widely used methods of marking optical articles today are ink marking and laser (beam) marking.
    The ink marking has the disadvantages that it is difficult to find a permanent ink compatible with any type of ophthalmic glass surface, and that this type of marking is not only visible by an outside observer but also by the wearer of the glass. ophthalmic.
    Laser marking can be carried out by photolithography thanks to the production of a mask on the surface and localized chemical etching of the surface in the parts left free by said mask, as described for example in documents US 2004/0095645 and EP 0677764 from Jax Holdings Inc. Such a technique is long and expensive, and requires the use of complex machines.
    Laser marking can also be carried out by ablation (i.e. removal of a quantity of material) forming an etching of the surface. Thus, the marking is generally formed by a series of points called marking points (also called "spots"), each marking point being produced by one or more pulses of the laser. In this case, the marking has a visibility which depends on the depth and width of the marking points, as well as on the thickness and the nature of the ablated layer (s). This marking must also be positioned outside the field of vision of the ophthalmic lens wearer so as not to disturb his vision.
    The document US 2014/0016083 describes an improvement of the latter technique, according to which a marking can be carried out by laser beam on the convex surface of an ophthalmic lens after deposition under vacuum of a coating of thin layers of oxides. These thin layers are applied in a certain order, and are then exposed successively to the laser beam, and therefore successively ablated. The treated surface therefore has a different visibility compared to the untreated surface. This allows marking visible to an outside observer, because different colors are visible to an outside observer when exposed to white light.
    However, this ablative solution by means of a laser beam presents the major problem that the marking is not easily controllable, mainly in depth. Consequently, the marking points produced by repeating a marking step at different points belonging to the same pixel are generally not contiguous, which implies that the marking is not continuous. According to this document, a succession of multiple partial ablations in the same pixel makes it possible to avoid the problem of an engraving carried out too large (ie too much laser beam at a given location), which could lead to the unwanted effect. that a coating of the ophthalmic glass, such as an anti-reflection coating or else an anti-abrasion coating, is attacked, in part or in whole, by the laser beam.
    One of the objects of the invention is to provide a method of marking an optical article which overcomes the drawbacks of the state of the art, in particular the problems of unwanted ablation of all or part of a coating of the article. optical.
    The subject of the invention is therefore, in a first aspect, a method of marking an optical article comprising at least one step of using a marking machine on an optical article:
    The marking machine being a marking machine by electromagnetic beam, preferably by laser beam, comprising an electromagnetic source, preferably a laser source, configured to emit a beam having a determined wavelength of radiation called wavelength of marking;
    The optical article being an optical article comprising a substrate having a main face coated with an interference coating, said interference coating comprising at least two superposed layers called inner layer and outer layer, the inner layer being located between the substrate and the outer layer , the interference coating being such that it has a reflection coefficient Re in the visible range (380-780 nm);
    The use comprising the exposure of at least the inner layer at a given point called the marking point, by means of the laser beam at the marking wavelength, so as to ablate the inner layer at the marking point over at least part of its thickness, and any layer located between the electromagnetic source and the inner layer; and being such that the ablated zone has a reflection coefficient Rm in the visible range (380-780 nm), Rm being different from Re by at least 1%;
    The inner layer absorbing the marking wavelength more significantly than any layer located between the electromagnetic source and the inner layer.
    The invention also relates, in a second aspect, to an optical article comprising a substrate coated with an interference coating comprising two layers of materials superimposed, said inner layer and outer layer, the inner layer being located between the substrate and the outer layer , the interference coating being such that it has a reflection coefficient Re in the visible range (380-780 nm);
    Said article comprising a marking pattern on the surface of the interference coating, the marking pattern being formed by a plurality of substantially identical marking points, each marking point corresponding to the localized absence of the inner layer and of any layer situated between said surface and the inner layer, the ablated zone having a reflection coefficient Rm in the visible range (380-780 nm) such that Re is different from Rm by at least 1%, the marking pattern preferably being continuous. Preferably, such an optical article is obtained by the marking method according to the invention.
    The invention is described in more detail below.
    The method according to the invention therefore makes it possible to achieve, at a marking point, direct localized ablation of at least part of the inner layer and indirect of the layers located between the electromagnetic source and the inner layer.
    The invention therefore advantageously allows control of the marking process, in particular the depth of the engraving, which is very advantageous compared to the processes of the state of the art. Without wishing to be bound by any theory, the Applicant thinks that this is mainly due to the fact that the electromagnetic beam succeeds in exposing the inner layer which is made of a material very absorbent at the wavelength of the radiation compared to the other layers present.
    Indeed, according to the invention, each of the layers of material between the electromagnetic source and the inner layer is at least partially transparent to the marking wavelength, that is to say that it does not absorb at least in part at this marking wavelength. Preferably, this layer is at least semi-transparent at this marking wavelength, that is to say that it allows more than half of the energy of this marking wavelength to pass.
    Therefore, when exposed to the electromagnetic beam, this inner layer receives most of the transmitted energy and is therefore selectively degraded. Since the layers between the inner layer and the electromagnetic source are generally very thin oxide layers, the degradation or even the sublimation of the inner layer effectively separates these layers which can then be removed.
    Thus, the electromagnetic beam advantageously aims to ablate the inner layer, and indirectly allows the ablation, most often by detachment, of any layer located between the electromagnetic source and the inner layer, and therefore in particular of the outer layer. In other words, the inner layer is destroyed (partially or totally) by the bundle, the layers between the bundle and the inner layer being destroyed / removed by collateral effect of the destruction of the inner layer.
    The ablation is such that the single marking point which results therefrom generally has a substantially cylindrical shape with an axis substantially perpendicular to the surface of the inner layer farthest from the substrate before the latter is ablated.
    It should be noted that when the invention is applied to an ophthalmic lens comprising an anti-reflective coating, not only the values of intensity of reflection between the ablated zone and the non-ablated zone are different, but in an additional embodiment, the chroma, presented in an L, a *, b * system, is different between the two zones. The unbleached area can thus have a pale green residual reflection color, for example for the lens comprising a Crizal Forte® coating, with a reflection value of approximately 0.8%, and the ablated zone has a reflection color rather pale blue.
    More generally, the marking method according to the invention is advantageously such that the reflection at the marking point has a color, in saturation (hue: h *) and / or in hue (Chroma: C *), different from that of the reflection of the unbleached area.
    Thus, the contrast between the ablated zone and the non-ablated zone making it possible to observe the pattern based mainly on a difference in reflection intensity can be improved by a difference in reflection color. The optical article according to the invention is not necessarily an article with low transmittance like a solar glass. It can also be almost transparent.
    It should be noted, however, that the laser focal point is not necessarily located in the inner layer of the interference coating. It is even moreover most often outside of it, typically 1 to 2 mm outside of it, for example 2 mm above the optical article. This is for example described in patent application WO 2015/040338 of the applicant.
    By "element between A and B", unless otherwise specified, we mean that the element is located between A and B but is neither A nor B.
    By "element included in an interval from A to B" or "element from A to B" means, unless otherwise specified, that the element is located between A and B and can be A or B. By "set of elements going from A to B "means, unless otherwise specified, the set formed by A, B and any element located between A and B.
    By "insolate" is understood according to the invention to expose to an electromagnetic beam. This leads to removing material, that is to say ablating. The insolation is carried out according to the invention by means of the marking machine.
    By "unbleached area" is meant according to the invention any part of the main face which has not been exposed and therefore has not been ablated.
    By “interference coating” (also called interference filter or dichroic filter) is meant within the meaning of the invention, any coating of at least two layers whose indices and thicknesses lead to attenuation and / or amplification of the reflection coefficient d '' a surface of the optical article by an interference mechanism, constructive or destructive, over all or part of the wavelengths included in the visible, that is to say in the interval (380 nm-780 nm ). This reflection filter therefore consists of a succession of thin layers, the operating principle of which is based on the interference of successive reflections on each of the diopters encountered. Interference can, depending on the thickness of the layers and the wavelength, be constructive or destructive. The part that is not transmitted is reflected. In the case of anti-reflective coatings, the various reflections interfere to strongly attenuate. Conversely, when all reflections are in phase, we obtain mirror interference coatings with a very high reflection factor.
    An "anti-reflective coating" is defined as a coating deposited on the surface of an optical article, which improves the anti-reflective properties of the article ready for use. It reduces the reflection of light at the article-air interface over a relatively large portion of the visible spectrum.
    Anti-reflective coatings are well known in the art and specific examples are described in application US2008 / 0206470. The anti-reflective coating of the present invention may include any layer or coating of layers which improves the anti-reflective properties of the final optical article, over at least a portion of the visible spectrum, so as to increase the transmission of light and reduce the reflectance of the surface at the air-optical article interface.
    As explained above, the invention also relates to a mirror-type interference coating.
    The interference coating, whether anti-reflection coating or not, of the optical article according to the invention comprises the interference coating according to the invention as defined above.
    In particular, within the meaning of the invention, the “interference coating” does not include any anti-fouling and / or anti-fog and / or rain-proof and / or hydrophobic and / or oleophobic and / or hydrophilic coating which generally has a thickness less than or equal to 2 nm and participates only in a negligible way in attenuating or amplifying the reflection. Thus, any layer of the interference coating has an effect on the interference mechanism.
    According to the invention, "interior" refers to the side closest to the substrate and "exterior" refers to the side furthest from the substrate. Consequently, “inner layer” and “outer layer” respectively mean, unless explicitly stated otherwise, “the layer of the interference coating closest to the substrate among the layers of the interference coating” and “the layer of the interference layer most distant of the substrate among the layers of the interference coating ".
    The “outer layer” can be covered with a possible additional anti-fouling or anti-rain or anti-fog layer, or even a temporary layer intended to increase the adhesion, for example for a trimming step. , and intended to be removed for use by the optical article by an end user. Such an additional layer is usually known as a "topcoat", and does not, as explained above, belong to the interference coating within the meaning of the invention.
    By “the inner layer absorbing the marking wavelength more significantly than any layer situated between the electromagnetic source and the inner layer”, it is understood according to the invention that the absorption coefficient at the wavelength of marking of the inner layer is at least 10%, preferably at least 20%, higher than the absorption coefficient at the marking wavelength of any other layer, located between the electromagnetic source and the inner layer .
    The “absorption coefficient” represents the absorption at a wavelength of the visible spectrum, and is defined according to the invention as the ratio between the absorbance A and the optical path L (= A / L) for a beam electromagnetic of given wavelength (here in the visible range) in a given medium. This ratio is expressed in m ' 1 or cm' 1 , in particular according to ISO / CD 11551.
    By "more importantly" is meant according to the invention in a manner discernible by a person skilled in the art, to suit the aim sought by the invention.
    By “reflection coefficient” (Re or Rm according to the invention), within the meaning of the invention, is meant the rate of light reflected by the surface of an optical article, illuminated by an illuminant covering at least the whole of the visible spectrum, for example the solar illuminant or the D65 illuminant. The reflection rate is preferably measured with a ray of light incident on the surface with an angle of 2 ° or 10 °. When this is not specified, the reflection coefficient only takes into account visible light, that is to say light having a wavelength between 380 nm and 780 nm.
    The "transmission factor", or the "transmittance" T v (tau index v) corresponds to the fraction of light flux which passes through an optical article, as a function of the wavelength, illuminated by an illuminant covering at least the entire visible spectrum, for example the solar illuminant or the D65 illuminant. The factor t v corresponds to an international standardized definition (standard ISO 13966: 1998) and is measured in accordance with standard ISO 8980-3. It is defined in the wavelength range from 380 to 780 nm.
    By "transparent" is meant according to the invention not absorbing at a visible wavelength [380-700 nm], that is to say in other words, that an image observed through the product qualified as transparent is perceived without significant loss of contrast or quality.
    The inner layer is the layer of the interference coating closest to the substrate. It is located between the substrate and the outer layer of the interference coating, but is not necessarily in contact with the substrate or with the outer layer. Thus, one or more layers of one or more intermediate coatings can be arranged between the substrate and the inner layer, and between the inner layer and the outer layer. In addition, the inner layer does not necessarily completely cover the substrate although, preferably, it covers it.
    Any possible layer located between the substrate and the inner layer is at least partially transparent at the marking wavelength, that is to say that it does not absorb at least in part at this wavelength. marking. Preferably, this layer is at least semi-transparent at this marking wavelength, that is to say that it allows more than half of the energy of this marking wavelength to pass.
    Likewise, the outer layer is not necessarily in contact with the inner layer. In addition, one or more additional layers may be arranged above the outer layer, as indicated above. In other words, the outer layer is not necessarily the layer of the optical article furthest from the substrate. These additional layers are for example temporary layers used in the context of manufacturing but not intended to be present on the optical article which will be used by an end user. This can be for example, in the case of ophthalmic lenses, a coating used to allow the trimming of the lenses so that they are formed into a frame, said additional layers being removed after this shaping.
    Although the optical article according to the invention can be any article, such as a screen, a glazing, a protective glass usable in particular in the working environment, or a mirror, it is preferably an ophthalmic glass, and again better an ophthalmic lens, for glasses, or an ophthalmic lens blank such as a semi-finished optical lens, in particular a spectacle lens. The lens can be a clear, polarized, colored lens or a photochromic lens, or can be added to an active element such as an augmented reality device, an electrochromic or electrofocal device. The lens can be a lens without optical power, with an optical power, simple or complex, or even be a progressive or bi or multifocal lens.
    An optical article generally has, on the side of the outer layer furthest from the substrate, an interference coating, preferably an anti-reflection coating, as is known to those skilled in the art, so as to prevent the formation of parasitic reflections. troublesome for the wearer of the ophthalmic lens and his interlocutors. It is this interference coating which is marked by the marking process according to the invention.
    Thus, typically, an ophthalmic lens is most often provided with a mono- or multilayer anti-reflective coating, generally made of mineral material. Such an interference coating may be, without limitation, an anti-reflective coating, a reflective coating (mirror), an infrared filter or an ultraviolet filter or an interference coating functioning as an anti-reflection coating on part of the light spectrum and functioning as a partial mirror to the around one or more wavelength ranges, preferably an anti-reflective coating.
    The substrate is transparent at visible wavelengths [380-780nm], and has main front and rear faces.
    The substrate according to the invention is preferably an organic glass, for example made of thermoplastic or thermosetting plastic. Before depositing the interference coating on the possibly coated substrate, for example with at least one layer of abrasion-resistant and / or scratch-resistant coating, it is common to subject the surface of said substrate possibly coated to a physical activation treatment. -chemical, intended to increase the adhesion of interference coating.
    The interference coating according to the invention may be present on the surface of at least one of the main faces of the bare substrate, that is to say uncoated, or on at least one of the main faces of a substrate already coated with at least one functional coating layer. However, it can also be present on the surface of the two main faces of the substrate of the optical article.
    By “functional coating” is meant within the meaning of the invention at least one coating chosen from a non-exhaustive list comprising anti-scratch coatings, anti-shock coatings or coatings improving adhesion, tinted, antistatic coatings or others, films or coatings comprising a polarized function, or a photochromic function, or else the structures allowing an active function, for example electrochromic.
    As is well known, interference coatings, preferably anti-reflective coatings, are conventionally multilayer coatings usually comprising layers of high refractive index (Hl) and layers of low refractive index (BI).
    H1 layers are well known in the art. They generally include one or more mineral oxides such as, without limitation, zirconia (ZrO 2 ), titanium oxide (TiO 2 ), tantalum pentoxide (Ta 2 O 5 ), neodymium oxide (Nd2O5) , hafnium oxide (HfO 2 ), praseodymium oxide (PrTiO 3 ), La 2 O 3 , Nb 2 O 5 , Y 2 O 3 , indium oxide ln 2 O 3 or l tin oxide SnO 2 . The preferred materials are TiO 2 , Ta 2 O 5 , PrTiO 3 , ZrO 2 , SnO 2 , ln 2 O 3 and their mixtures.
    The BI layers are also well known and can comprise, without limitation, SiO 2 , MgF 2 , SrF 4 , alumina (AI 2 O 3 ) in small proportion, AIF 3 , and their mixtures, preferably SiO 2 .
    At least one of these layers can be electrically conductive. This thus makes the article optical antistatic. By "antistatic" is meant the property of not retaining and / or of not developing an appreciable electrostatic charge. An optical article is generally considered to have acceptable antistatic properties when it does not attract or fix dust and small particles after one of these surfaces has been rubbed with a suitable cloth. The electrically conductive layer can be located at different locations of interference coating, provided that the interference properties of the optical article, for example anti-reflective, are not disturbed. It must be fine enough not to alter the quasi-transparency of the interference coating. Generally, its thickness varies between 0 and 100 nm, preferably in the range of 2 to 25 nm, even more preferably in the range of 4 to 15 nm. The electrically conductive layer, which is part of the interference coating, preferably comprises a metal oxide chosen from the oxides of indium, tin, zinc and their mixtures. Tin-indium oxide (ln 2 O 3 : Sn, indium oxide doped with tin) and indium oxide (ln 2 O 3 ), as well as tin oxide SnO 2 , are preferred.
    For example, French patent application FR 2943798 of the applicant describes an optical article with antistatic and antireflective or reflective properties, comprising a substrate having at least one main surface coated with an antireflective or reflective coating, said coating comprising at least one layer electrically conductive based on tin oxide, that is to say comprising at least 30% by mass of tin oxide relative to the total mass of the electrically conductive layer. Such an optical article can advantageously be marked by the marking method according to the invention, the electrically conductive layer being particularly suitable for being the inner layer according to the invention at certain marking wavelengths.
    The interference coating may also include a sublayer (that is to say a coating of relatively large thickness), with the aim of improving the abrasion and / or scratch resistance of said coating and / or of promote its adhesion to the underlying substrate or coating. Such an undercoat, which is part of the interference coating, generally has a thickness of 100 to 200 nm. It is generally of an exclusively mineral nature, for example consisting of silica dioxide SiO 2 .
    Generally, a layer H1 has a thickness of 10 to 120 nm, and a layer B1 has a thickness of 10 to 100 nm.
    Preferably according to the invention, the total thickness of the interference coating is less than 1 μm, better less than or equal to 780 nm, even better still less than or equal to 500 nm. The total thickness of the interference coating is generally greater than 100 nm, preferably greater than 150 nm.
    The marking machine is for example as described in the patent application WO 2015/040338 of the applicant, which particularly describes the use of an Nd-YAG laser at application wavelengths from 230 to 290 nm, preferably around 266 nm.
    For example, an Nd-YAG laser can be used according to the invention, at 266 nm with pulses of 1 ns, an energy per pulse of 3 pJ and a marking point surface of 10 pm in diameter.
    This type of configuration of the marking laser advantageously makes it possible to target an SnO 2 layer and to at least partially remove the SnO 2 layer when exposed, without crossing the substrate, but also to remove, during the ablation of the part. of the SnO 2 layer, the layer or layers present above the SnO 2 layer. This will be demonstrated in the examples below.
    In the case where the interference coating is an anti-reflective coating, its reflection coefficient Re is preferably less than 1.4% and even more preferably less than 0.85%.
    The marking method according to the invention advantageously makes it possible to obtain a marking pattern which is very visible to an outside observer and little, preferably not visible, to the wearer of an optical article. In practice, 2% difference in reflection coefficient between Re and Rm (Rm-Re = 0.02) corresponds to a local increase in reflection of around 200 to 300% depending on the angle of reflection, the perceived increase of the reflection being as follows: (Rm-Re) / Re.
    In the case where the interference coating is an anti-reflective coating, the perceived increase in reflection is for example about 0.02 / 0.0085 [either (Rm-Re) / Re], or 235%.
    Preferably according to the invention, the difference between Rm and Re is, in absolute value, greater than 3%, even more preferably greater than 5% (in quantity relative to the same incident light). In general, the difference between Rm and Re is less than 50% of the reflection coefficient Re, except when the interference coating is a mirror.
    According to one embodiment, the difference between Rm and Re is, in absolute value, between 5% and 25%, preferably between 7% and 20%.
    According to one embodiment of the invention, the insolation step is followed by a cleaning step to remove all traces of the ablated layers during the insolation step.
    According to a preferred embodiment of the invention, the electromagnetic beam is emitted per pulse, and has an energy per pulse comprised in a range of 0.1 to 10 pJ, for example equal to 0.5 pJ, 1 pJ, 2 pJ or 5 pJ, preferably in the range 0.1 to 3 pJ, for example equal to 0.5 pJ, 1 pJ, 2 pJ or 3 pJ.
    Preferably, the insolation step is carried out by emission of a focused beam of pulsed ultraviolet laser radiation having at least the following parameters:
    - a radiation wavelength in the range of 200 to 400 nm, preferably 200 to 300 nm,
    - a pulse duration in the range of 0.5 to 5 ns, and
    - an energy per pulse included in a range of 0.1 to 10 pJ, preferably included in a range of 0.5 to 3 pJ, as well as, at the marking point, a beam diameter included in a range of 5 to 50 pm.
    In a preferred embodiment of the invention, when the radiation wavelength of the pulsed ultraviolet laser radiation beam performing the exposure step is in the range of 200 to 300 nm, the inner layer is base, preferably consisting essentially of tin, preferably of tin oxide, even more preferably of tin dioxide SnO 2 .
    "Based" means in the sense of the invention that the inner layer comprises at least 50%, by mass, of the compound relative to the total mass of the inner layer.
    “Essentially constituted” means within the meaning of the invention that the proportion of the compound in said inner layer is greater than or equal to one of the following values: 70%, 75%, 80%, 90%, 95%, 97%, 99%, 99.5%, 99.9%, 99.95%. Ideally, said inner layer consists of a layer of tin dioxide SnO 2 .
    The inventors have in particular noted that the layers based on tin, in particular tin oxide, in particular tin dioxide, react selectively upon illumination by means of a laser beam having a length d wave between 200 and 300 nm, when they are present in an interference coating moreover comprising only layers based on silica or zirconia. In this configuration, the layers based on silica or on zirconia are substantially transparent at the wavelength while the layers based on tin absorb energy at this wavelength in an amount sufficient to generate destruction, or even a local ablation of this layer, over at least part of its thickness.
    The inner layer may contain other constituents, in particular metal oxides, in particular electrically conductive metal oxides which are preferably transparent. It can in particular comprise titanium oxide and / or zinc oxide. Preferably, the inner layer does not contain indium, whether in the oxide form or in any other form.
    Preferably, the inner layer has a thickness in the range from 1 to 100 nm, preferably from 2 to 25 nm, even more preferably from 4 to 15 nm, the sum of the thicknesses of the inner and outer layers being from 5 to 300 nm, preferably 45 to 175 nm.
    The outer layer is generally based, preferably consisting essentially of silicon, preferably of silicon oxide, even more preferably of silicon dioxide SiO 2 .
    According to a particular embodiment of the invention, the transmission in the visible of the interference coating possibly coated and the transmission in the visible of all the layers going from the substrate to the outer layer are substantially identical. This is generally achieved by the fact that the absorbance, in the visible, is substantially identical (i.e. to 0.1 or 0.2%), whether the ablated layers are present or not. Thus, in general, the difference in the amount of light transmitted between the ablated area (ie marked area, comprising at least one marking point or even a marking pattern, produced by the marking process according to the invention) and the non-marking area ablated (or unmarked, ie not including such a marking pattern) depends mainly, in the first order, on the difference in reflection between these areas. For a clear ophthalmic lens having an anti-reflective coating, the rate of visible light transmitted is generally greater than 85%, or even 90% or even 95%. In particular, the transmission, in the visible, of the interference coating is close to (0.99-Rm), where Rm is the reflection coefficient of this coating. In this case, a difference in reflection between the two zones, of between 1% and 8%, leads to a rate of light passing through the interference coating at the level of the ablated zone of between 0.92 times and 0.99 times the rate of light passing through the coating in the unblasted area. It is this small difference that makes the marking pattern barely visible to the wearer.
    According to a preferred embodiment of the invention, at least one absorbent layer (that is to say one which at least partially absorbs visible light) is present in the interference coating of the invention, and is locally removed, directly or indirectly, during the ablation of the inner layer by the electromagnetic beam. In this case, preferably, all of the layers going from the inner layer to the outer layer have an absorption of at least 0.5% of the visible light transmitted, for example at least 1% of the transmitted light and, preferably, the absorbent layer has an absorption ("Abs") (or in other words an absorption coefficient) in the range of 0.5 to 1.5 times, preferably 0.9 to 1.1 times, the absolute value of the difference between Re and Rm. This is achieved by the parameters of the thickness and the absorption coefficient of the absorbent layer.
    The absorbent layer is a layer of the interference coating and participates in the reflection properties of the interference coating. It can be the inner layer, the outer layer or another layer positioned between these two layers.
    According to this embodiment, the rate of light transmitted through the interference coating no longer depends solely on the reflection coefficient of the interference coating, but also on the intrinsic absorption of the absorbent layer. Thus, the rate of light transmitted through the interference coating in the unblasted area, corresponds approximately to [1 - Re - Abs] with Abs representing the absorption of light by the absorbent layer. For comparison, the rate of light transmitted through the interference coating in the ablated zone, in which the absorbent layer was locally removed (directly or indirectly) during the exposure, corresponds approximately to [1 - Rm], Indeed, the absorption of the layers of the interference coating other than the absorbent layer is considered to be zero in the first order.
    Thus, the difference in reflection between the two zones remains [Re-Rm]; on the other hand, the difference in the rate of light transmitted between the two zones is then [Rm-Re-Abs],
    On the other hand, the difference in the rate of light transmitted between the ablated zone and the non-ablated zone is reduced. It is preferably between - 0.5x (Rm-Re) and 0.5x (Rm-Re), it being understood that (Rm-Re) represents the absolute value of the difference between Re and Rm. This value depends on the absorption value of the absorbent layer. In such a case, the perception in transmission of the ablated area, by the spectacle wearer, is reduced by at least half.
    In a particular case, the thickness and the absorption coefficient of the absorbent layer are determined so that the absorption of light by the absorbent layer is close to the difference in reflection and is between 0.9 and 1.1 times the absolute value of (Re-Rm). In this case, it is possible to consider that the ablated zone is invisible in transmission.
    According to one embodiment of the invention, the interference coating is an anti-reflective coating. In this case, the anti-reflective coating preferably comprises, from the surface of the substrate possibly coated towards the outside, a layer of ZrO 2 , from 5 to 40 nm thick, a layer of SiO 2 , from 10 to 55 nm d thickness, a layer of ZrO 2 , 20 to 150 nm thick, an inner layer of SnO 2 , 4 to 15 nm thick, and an outer layer of SiO 2 , 50 to 120 nm thick .
    In one embodiment of the invention, the interference coating is itself coated (on the side furthest from the substrate) with a coating of protective material, such as a rain coating, an anti-fog coating and / or an anti-fouling coating, said marking process then generally being followed in this case by a deprotection step subsequent to said marking process, said deprotection step comprising the removal of this coating of protective material.
    According to a particular embodiment according to the invention, the insolation step is carried out at as many marking points as necessary so as to locally mark a region of the main surface of the substrate of the optical article by means of multiple points marking region, said region forming a predefined pattern said marking pattern. In such a case, there is preferably a continuity between the marking points which define the region forming the marking pattern. Such a labeling region preferably comprises less than 1% in surface area of residues from the ablated layers (by direct or indirect exposure). Such a state can be obtained directly at the end of the marking process, or else require an additional brushing and removal step, accessible to a person skilled in the art. This differs notably and advantageously from the achievements of the state of the art.
    In such a case, preferably, the marking is carried out at a pitch of dimension less than or equal to the dimensions of the marking point, that is to say less than or equal to the average diameter of an area ablated at a single point of marking, so that the marking points show a partial overlap. For example, the marking pitch is between 0.5 and 1 times the marking diameter of a beam pulse when the beam emits by pulse. If the pulse is reproduced identically each time by the electromagnetic source, a particular embodiment is such that the marking pitch is equal to the marking diameter. This allows very particularly and advantageously according to the invention to be able to carry out a continuous marking process which consumes the least possible electromagnetic energy. This is particularly effective when the electromagnetic beam is emitted per pulse, and has an energy per pulse comprised in the range of 0.1 to 3 pJ, for example equal to 0.5 pJ, 1 pJ, 2 pJ or 3 pJ.
    By "step" is meant according to the invention the minimum distance between the centers of two marking points made successively.
    Preferably, only one pulse is required per marking point.
    The invention also relates to an optical article comprising a substrate having a main face coated with a multilayer interference coating, said interference coating comprising at least two layers of materials superimposed, said inner layer and outer layer, the inner layer being located between the substrate and the outer layer, said article comprising a marking pattern on the surface of the interference coating, the marking pattern being formed by a plurality of substantially identical marking points, each marking point corresponding to the localized absence of at least a portion of the thickness of the inner layer and of the whole of any layer situated between said surface and the inner layer, the marking pattern preferably being continuous.
    Preferably, such an optical article is obtained by the marking method according to the invention, in which the exposure step is repeated several times.
    The marking area is formed by a plurality of marking points, each marking point being obtained by exposure performing the ablation by electromagnetic beam of at least part of the thickness of the inner layer.
    By "at the surface of the interference coating" is meant at the surface of the interference coating if the latter is not itself coated with at least one coating layer and at the surface of the most distant coating layer on substrate if it is itself coated with at least one coating layer.
    By “continuous marking pattern” is meant according to the invention that any marking pattern is formed by multiple contiguous marking points, the pitch between two contiguous marking points being of dimension less than or equal to the smallest of the dimensions of these two marking points.
    The characteristics of the interference coating, in particular of the inner and outer layers, are as described above for the marking method according to the invention.
    Preferably, the optical article according to the invention does not absorb in the visible or absorbs little in the visible. This means, within the meaning of the present application, that its transmission factor t v in the visible, also called relative transmission factor in the visible, is greater than 90%, preferably greater than 95%, more preferably greater than 97% and even more preferably greater than 99%.
    In a particularly preferred manner, the light absorption of the optical article according to the invention is less than or equal to 1.
    Alternatively, the optical article can be a tinted lens, called a solar lens, for example having a transmission of between 5% and 50% according to its classification on the international scale for the classification of sunglasses.
    The invention will be better understood on seeing the appended drawings in which:
    - Figures 1 to 3 schematically represent a first exemplary embodiment of the marking method according to the invention, Figure 1 schematically representing in sectional plane the principle of the marking process before its realization, Figure 2 schematically representing in sectional plan the marking process in progress, and FIG. 3 schematically representing in section plan the marking process at the end of production; and
    - Figures 4 and 5 illustrate the results obtained in reflection (R) and transmission (T) for the opthalmic lens (1) obtained according to the first embodiment of Figures 1 to 3, in the area of the marking point (25 ) and in other areas of the surface of the ophthalmic lens; and
    - Figures 6 to 9 schematically represent a second embodiment of the marking method according to the invention, Figures 6 and 7 showing the ophthalmic lens before carrying out the marking process and Figures 8 and 9 showing the ophthalmic lens after carrying out the marking process, more precisely FIG. 6 representing the ophthalmic glass in an overview before carrying out the marking process, FIG. 7 representing in perspective a section of the layers present on the ophthalmic glass before carrying out the marking process , Figure 8 showing the ophthalmic lens in an overview after carrying out the marking process, and Figure 9 showing in perspective a section of the layers present on the ophthalmic lens after carrying out the marking process.
    The invention will be better understood from the examples of embodiments which follow, with reference to the accompanying drawings as indicated above. Figures 1 to 9 are explained in the examples below.
    EXAMPLES
    The following examples illustrate the invention without limiting its scope.
    In the following two exemplary embodiments, the inner layer consists of tin dioxide SnO 2 ; the outer layer consists of silica, namely either silica monoxide SiO, or silica dioxide SiO 2 ; and the electromagnetic beam is a laser beam at 266 nm (UV). The marking wavelength is therefore 266 nm.
    Example 1: marking of an ophthalmic lens consisting of a substrate, of a first chromium layer ("Cr1"). an inner layer SnO , a second absorbent chrome layer ("Cr2"). and an outer layer
    SiO
    The ophthalmic glass (1) consists of a substrate (6) on which have been successively superimposed a first layer (5) of metal (chromium, "Cr1"), an inner layer (4) of tin dioxide SnO 2 , a second layer (3) of metal (chromium, “Cr2”), or absorbent layer, and an outer layer (2) of silica monoxide SiO. The substrate (6) is here a polarized or tinted substrate comprising an anti-scratch coating of the Mithril® brand.
    Such a substrate-metal-dielectric-metal-dielectric structure is to be compared to that of glass which is etched according to the state of the art US 2004/0095645, except for the fact that, according to the invention, a layer of SnO 2 was added between the Cr1 layer and the Cr2 layer.
    The layers (2) SiO 2 / (3) Cr2 / (4) SnO 2 / (5) Cr1 are of a nature and have a thickness such that the coating which they constitute creates an interference effect increasing the reflections so as to create a mirror with reflection. This coating has an average reflection coefficient of around 12 to 15%, with higher reflection in purple.
    The layer (5) chromium Cr2 absorbing very slightly in the visible significantly reduces the overall transmission of the system, which is not a problem in the case of ophthalmic glass (1) used which is here a solar glass.
    The nature and the physical and optical characteristics of the layers are indicated in the following table:
    Layer numberfrom the substrate /Reference ofdiaper (illustration) Material of thelayer Thickness of thelayer (± 2 nm) 1 / (5) Cr 15 nm 2 / (4) SnO 2 6 nm 3 / (3) Cr 5 nm 4 / (2) SiO 65 nm
    The marking method according to the invention was carried out by means of a pulse laser emitting a beam at the wavelength 266 nm with pulses of duration 1 ns, an energy per pulse of 3 pJ and a dot surface marking approximately 10 µm in diameter.
    Figures 1 to 3 schematically illustrate this first embodiment of the marking method according to the invention. The laser beam 23 is very symbolically represented by a lightning bolt which focuses on the inner layer 4.
    Figure 1 shows schematically in sectional plan the principle of the marking process before its realization on ophthalmic glass 1. We see the substrate (6), on which was deposited the first layer (5) of chromium Cr1, on which the inner layer (4) of tin dioxide SnO 2 is superimposed, then the layer (3) of chromium Cr2, and finally the outer layer (2) of silica monoxide SiO.
    Figure 2 shows schematically in sectional view the marking process in progress by local removal of the layers (4), (3) and (2) by the electromagnetic beam (23) which insoles the inner layer (4) in SnO 2 and destroys it, causing the layers (3) and (2) to be withdrawn indirectly during the destruction of the layer (4). We can distinguish the part (24) of the layers (4), (3) and (2) being removed, which will become the marking point (25) of Figure 3. On this cutting plane, the layer (4) splits into two parts (4 ') and (4 ”), the layer (3) splits into two parts (3') and (3”) and the layer (2) splits into two parts (2 ') and (2 ”). The ophthalmic lens (T) on which the marking begins also includes the layer (5) on the substrate (6).
    Figure 3 shows schematically in sectional plan the marking process at the end of production. On this cutting plane, the layers (4), (3) and (2) have been ablated following exposure by the electromagnetic beam (23), splitting into two parts (4 ') and (4 ”) respectively , in two parts (3 ') and (3 ”) and in two parts (2') and (2”). An etched ophthalmic lens (10) is thus obtained.
    The realization thus diagrammed made it possible to carry out a point of marking (25). The repetition of the insolation step of the process of the invention makes it possible to carry out several marking points thus forming a marking pattern, such as a logo.
    Advantageously, the chromium layer (5) Cr1, comprised between the inner layer (4) and the substrate, absorbs little or very little of the light emitted at the wavelength of the laser (266 nm), which makes it practically insensitive to the electromagnetic marking beam. It is therefore not destroyed by exposure to the electromagnetic marking beam. It is therefore possible to superimpose the marking points without risk of over-etching at the level of overlap between two marking points. Consequently, the method according to the invention advantageously makes it possible to carry out continuous marking on the surface of the ophthalmic lens (1), such as a large area logo, homogeneous, without "pointillist" effect.
    Conversely, the technologies of the prior art wishing to make residue-free marking by laser ablation must achieve marking points in partial superposition which implies a larger local over-etching of two contiguous marking points relative to the rest of the pattern. , which can lead, for example, to the local ablation of at least one additional layer, here layer (5) Cr1.
    Figure 4 illustrates the results obtained in reflection (R) for the ophthalmic lens (1) obtained according to the first embodiment of Figures 1 to 3, in the ablated area of the marking point (25): R m and in the area not ablated from the surface of the ophthalmic lens (1): R e .
    We see that the interference coating (2, 3, 4, 5) is characterized by a specific reflection spectrum R e , illustrated in Figure 4, and that in the unbleached area the average reflection spectrum Ref2, which is approximately 12 to 15%, reflects slightly more in purple. It can also be seen that the layer (5) Cr1, alone, present on the scratch-resistant material, leads the lens to locally have a reflection coefficient
    Ref1 of about 33% (which is higher than Ref2), and relatively homogeneous according to the wavelengths of the visible.
    Thus, when the ophthalmic lens (1) is observed, the observer perceives an additional reflection in the area of the marking, in contrast to the reflection of the surrounding points.
    The difference in reflection coefficient between the marking point (25) and the other areas (not ablated) of the surface of the ophthalmic lens (1) is therefore approximately 18% on average, which makes it possible to form patterns by difference. reflection intensity but also hue and Chroma (respectively "hue" and "Chroma" in English) in reflection on the surface of the ophthalmic lens. There is indeed a factor up to about two and a half in the central wavelengths of the visible spectrum, between the reflection coefficient R m of the pattern formed by the ablated area of the marking point (25) and the coefficient reflecting the unblasted area of the surface of the ophthalmic lens (1).
    This variation in shade and chroma can also be achieved by means of the invention with other interference coatings than that of Example 1.
    Furthermore, as appears from the data above, the shade of the reflection and the intensity of this shade varies between the ablated area of the marking point (25) and the unblasted area of the surface of the ophthalmic lens (1). The marking point (25) has a substantially homogeneous reflection on the spectrum of visible light, which gives a substantially white reflection, or in any case with a low intensity of tint. Conversely, the unblasted area of the surface of the ophthalmic lens (1) more particularly reflects purple, giving an overall rather violet tint to the ophthalmic lens (1).
    Preferably, the absorbance A2 of the layer (3) Cr2 in the visible is such that the following equation is verified or approximated: Ref2 + A2 = Ref1. In this case, the transmission of light passing through the ophthalmic lens (1) in the ablated area of the marking point (25) is substantially identical to the transmission outside the marking, in the unblasted area of the surface of the ophthalmic lens (1 ). This allows the wearer of ophthalmic lens to practically perceive no difference or no difference in transmission at the marking point (25). It is therefore visible to an outside observer and invisible to the wearer of the ophthalmic lens (1).
    Thus, according to this exemplary embodiment, the absorbance, in the visible (380-780 nm) of the layer (3) Cr2 is such that it is equivalent to the reduction in the effectiveness of the interference coating devoid of the layers (2 ) SiO 2 , (3) Cr2, and (4) SnO 2 .
    Figure 5 shows the transmission (T) measured as a function of the wavelength, through the ophthalmic lens (1) obtained according to the first embodiment of Figures 1 to 3, in the area of the marking point (25) : T m and in the unblasted area of the surface of the ophthalmic lens (1): T e .
    We see that, during the ablation of at least part of the thickness of the inner layer (4), the layer (3) Cr2 is also removed and no longer participates, in the ablated zone of the marking point ( 25), to absorb the light. Consequently, as can be seen on the curve in Figure 5, the transmission is substantially identical for the ablated area of the marking point (25) (curve T m ) and for the unblasted area of the surface of the ophthalmic lens (1 ) (curve T e ).
    Thus, the reduction in the rate of light passing through the ophthalmic lens (1) caused by the absorption of the chromium layer (3) Cr2 in the unblasted area of the surface of the ophthalmic lens (1) is approximately equivalent to the reduction in the rate of light passing through the ophthalmic lens (1) caused by the presence of a greater reflection coefficient in the ablated area of the marking point (25).
    Different variants of this first exemplary embodiment can be envisaged, all within the reach of the skilled person. Some of these variants are explained below.
    Thus, the layer (5) Cr1 can be replaced by a coating of layers each having the property of not absorbing too much at the marking wavelength.
    Likewise, the layer (2) SiO and the layer (3) Cr2 can be replaced by another coating with similar layers.
    Finally, it is possible that the layer (3) Cr2 is not absorbent, even slightly, in the visible (380-700 nm), or is not present. This is particularly the case when the inner layer (4) is itself chosen from an absorbent material in the visible wavelength range.
    Example 2: Marking of an Ophthalmic Glass Consisting of a Substrate, a ZrO Layer, a SiO Layer, a ZrO Layer, an Inner SnO Layer, an Outer SiO Layer , a DSX layer and a temporary double layer
    The ophthalmic lens (20) consists of a substrate (21) which is a lens of index 1.5 from the company Essilor International® comprising a scratch-resistant coating of the Mithril® brand, on which is superposed an interference coating consisting of a coating comprising successively, starting from the varnish present on the substrate, a first layer (18) of zirconium oxide ZrO 2 , a first layer (17) of silica dioxide SiO 2 , a second layer (16) of zirconium dioxide ZrO 2 , a layer (15) of tin dioxide SnO 2 , or inner layer, a second layer (14) of silica dioxide SiO 2 , or outer layer, a layer (13) antifouling (hydrophobic and / or oleophobic), a layer (12) of magnesium difluoride MgF 2 with a thickness of 37 nm and a layer (11) of magnesium oxide MgO with a thickness of some nanometers.
    All of the layers (14, 15, 16, 17, 18), without taking into account the respective layers 12 and 11 MgF 2 and MgO which are temporary layers, produces an interference coating which is here an anti-reflective coating, having thicknesses layers calculated using software known to those skilled in the art (which takes into account the nature of these layers) in order to present a total reflection coefficient (Re) of less than 1%, for example 0.7 or 0 .8% depending on the samples measured.
    The nature and the physical and optical characteristics of the layers of the interference coating are indicated in the following table:
    Layer numberfrom the substrate /Reference ofdiaper (illustration) Material of thelayer Optical index oflayer Thickness of thelayer (± 3 nm) 1 / (18) ZrO 2 2.0038 30 nm 2 / (17) SiO 2 1.4741 40 nm 3 / (16) ZrO 2 2.0038 60 nm 4 / (15) SnO 2 1.8432 6 nm 5 / (14) SiO 2 1.4741 110 nm
    The implementation of the method according to the invention comes to local ablation of the outer SiO 2 layer 14, of the layers 13, 12 and 11, outside of the outer SiO 2 layer, as well as an at least partial ablation of the inner layer 15 , in SnO 2 . At this marking point (P), the value of the reflection measured in the ablated zone (Rm) is approximately 8.5%, or approximately 10 times more than Re.
    Figures 6 to 9 schematically illustrate this second embodiment of the marking method according to the invention.
    Figures 6 and 7 show the ophthalmic lens before carrying out the marking process and Figures 8 and 9 show the ophthalmic lens after carrying out the marking process.
    Figure 6 schematically shows the ophthalmic lens (20) in an overview before carrying out the marking process.
    Figure 8 shows schematically the ophthalmic lens (30) in an overview after carrying out the marking process. We see the marking or engraving (22) in the marking pattern forming the word "Essilor".
    Figure 7 shows schematically in perspective a section of the layers present on the ophthalmic lens (20), before carrying out the marking process.
    We see there the substrate (21), on which were successively deposited a layer (19) of UV filter "UL", a first layer (18) of ZrO 2 , a first layer (17) of SiO 2 , a second layer (16) of ZrO 2 , an inner layer (15) of SnO 2 , a second layer of SiO 2 , outer, (14), a layer (13) of DSX coating, a layer (12) of MgF 2 and a layer (11) of MgO.
    Figure 9 shows schematically in perspective a section of the layers present on the ophthalmic lens (20) after the completion of the marking process.
    Layers (11), (12), (13), (14) and (15) have been ablated at a marking point (P) (here represented schematically in two dimensions whereas it is in reality, as explained more before, substantially a cylinder which, by repeating the exposure step of the process of the invention, forms part of the marking (22), which has led to the production of the layers (11 '), (12' ), (13 '), (14') and (15 '). An etched ophthalmic lens (30) is thus obtained.
    In practice, at the bottom of the marking point (P), it has been observed that there is a slight marking (25) (here represented schematically in two dimensions whereas it is in reality substantially a cylinder) in the layers (16) and (17) immediately present under the layer (15). The zirconium dioxide ZrO 2 of the layer (16) and the silica dioxide SiO 2 of the layer (17) therefore slightly absorb the marking wavelength. The absorption being relatively low, as has been observed on the resulting marking, this is compatible with the performance of the marking method according to the invention because the visibility of the marking is not affected.
    EXAMPLE 3 Marking of an Ophthalmic Glass Consisting of a Substrate, an SiO 2 Underlayer, a ZrO 2 Layer, an SiO 2 Layer, a ZrO 2 Layer, an Inner Layer SnO , an outer layer SiO , a DSX layer and a temporary double layer
    Figures 6 to 9 schematically illustrate this third embodiment of the marking method according to the invention, only the nature of the layer (19) being modified compared to the second embodiment.
    The ophthalmic lens (20) consists of a substrate (21) which is a lens of index 1.5 from the company Essilor International® comprising a scratch-resistant coating of the Mithril® brand, and comprising above an interference coating successively comprising, starting from the varnish present on the substrate: a thick layer (19) of SiO 2 , a first layer (18) of zirconium oxide ZrO 2 , a first layer (17) of silica dioxide SiO 2 , a second layer (16) of zirconium dioxide ZrO 2 , a layer (15) of tin dioxide SnO 2 , or inner layer, a second layer (14) of silica dioxide SiO 2 , or outer layer, a layer (13) anti-fouling coating (hydrophobic and / or oleophobic), a layer (12) of magnesium difluoride MgF 2 with a thickness of 37 nm and a layer (11) of magnesium oxide MgO with a thickness of a few nanometers.
    All the layers (14, 15, 16, 17 and 18), without taking into account the respective layers 12 and 11 MgF 2 and MgO which are temporary layers, produces an interference coating which is here an anti-reflective coating, having thicknesses layers calculated using software known to those skilled in the art (which takes into account the nature of these layers) in order to present a total reflection coefficient of less than 1%, for example 0.7% or 0.8 % according to the samples measured.
    The nature and the physical and optical characteristics of the layers are indicated in the following table:
    Layer numberfrom the substrate /Reference ofdiaper (illustration) Material of thelayer Optical index oflayer Thickness of thelayer (± 3 nm) 1 / (19) SIO2 1.4658 150 nm 2 / (18) ZrO 2 2.0038 20 nm 3 / (17) SiO 2 1.4741 20 nm 4 / (16) ZrO 2 2.0038 100 nm 5 / (15) SnO 2 1.8432 6 nm 6 / (14) SiO 2 1.4741 75 nm
    Carrying out the method according to the invention, according to the operating conditions of Example 1 and in the same way as in Example 2, comes to create a pattern on the surface of the ophthalmic lens by local ablation of the SiO layer 2 exterior 14, layers 13, 12 and 11, exterior to the exterior layer SiO 2 14, as well as an at least partial ablation of the interior layer 15, in SnO 2 , which is the interior layer ablated by the electromagnetic beam. At this marking point (P), the value of the reflection measured in the ablated area (Rm) is close to 10%, more precisely between 9.5%, and 10.5% depending on the samples, i.e. approximately 12 times more that Re.
    权利要求:
    Claims (15)
    [1" id="c-fr-0001]
    1. Method for marking an optical article (1.20) comprising at least one step of using a marking machine on an optical article (1.20):
    The marking machine being an electromagnetic beam marking machine (23), preferably by laser beam, comprising an electromagnetic source, preferably a laser source, configured to emit a beam having a determined wavelength of radiation called length d 'marking wave;
    The optical article being an optical article (1, 20) comprising a substrate (6,21) having a main face coated with an interference coating (2,3,4,5; 14,15,16,17,18, 19), said interference coating comprising at least two superposed layers, said inner layer (4,15) and outer layer (2,14), the inner layer being located between the substrate and the outer layer, the interference coating being such that it has a reflection coefficient Re in the visible range (380-780 nm);
    The use comprising the exposure of at least the inner layer (4,15) at a given point called the marking point (25, P), by means of the laser beam at the marking wavelength, so as to ablate, at the marking point, the inner layer, over at least part of its thickness, and any layer located between the upper layer and the inner layer; and being such that the ablated zone has a reflection coefficient Rm in the visible range (380-780 nm), Rm being different from Re by at least 1%;
    The inner layer absorbing the marking wavelength more significantly than any layer located between the electromagnetic source and the inner layer.
    [2" id="c-fr-0002]
    2. Marking method according to claim 1, such that the difference between Rm and Re is, in absolute value, greater than 3%, even more preferably greater than 5%.
    [3" id="c-fr-0003]
    3. Marking method according to one of claims 1 or 2, such that the insolation step is carried out by emission of a focused beam of pulsed ultraviolet laser radiation having at least the following parameters:
    - a radiation wavelength in the range of 200 to 400 nm, preferably 200 to 300 nm, and
    - a pulse duration in the range 0.1 to 5 ns, and
    - an energy per pulse included in a range of 0.1 to 10 pJ, preferably included in a range of 0.5 to 3 pJ, as well as, at the marking point (24, P), a beam diameter included in an interval of 5 to 50 µm.
    [4" id="c-fr-0004]
    4. Marking method according to one of claims 1 to 3, such that, when the radiation wavelength of the pulsed ultraviolet laser beam carrying out the insolation step is in the range of 200 to 300 nm, the inner layer (4.15) is based, preferably consisting essentially of tin, preferably tin oxide, even more preferably tin dioxide SnO 2 .
    [5" id="c-fr-0005]
    5. Marking method according to one of claims 1 to 4, such that the inner layer (4,15) has a thickness in the range of 1 to 100 nm, preferably 2 to 25 nm, even more preferred from 4 to 15 nm, the sum of the thicknesses of the inner (4.15) and outer (2, 14) layers being from 5 to 300 nm, preferably from 45 to 175 nm.
    [6" id="c-fr-0006]
    6. Marking method according to one of claims 1 to 5, such that the interference coating (2,3,4,5) comprises at least one absorbent layer (3).
    [7" id="c-fr-0007]
    7. A marking method according to claim 6, such that all of the layers going from the inner layer to the outer layer have an absorption of at least 0.5% of the visible light transmitted and, preferably, an absorption included. in the range of 0.5 to 1.5 times, preferably 0.9 to 1.1 times, the absolute value of the difference between Re and Rm.
    [8" id="c-fr-0008]
    8. Marking method according to one of claims 1 to 7, such that the difference in the rate of light transmitted between the ablated area and the unblasted area is between - 0.5x (Rm-Re) and 0.5x ( Rm-Re), it being understood that (Rm-Re) represents the absolute value of the difference between Re and Rm.
    [9" id="c-fr-0009]
    9. Marking method according to one of claims 1 to 8, such that the interference coating is an anti-reflective coating (14,15,16,17,18) and comprises, from the surface of the substrate or a varnish present on this substrate, towards the outside, a layer (18) of ZrO 2 , 5 to 40 nm thick, a layer (17) of SiO 2 , 10 to 55 nm thick, a layer (16) of ZrO 2 , 20 to 150 nm thick, an inner layer (15) of SnO 2 , 4 to 15 nm thick, and an outer layer (14) of SiO 2 , 50 to 120 nm thick thickness.
    [10" id="c-fr-0010]
    10. Marking method according to one of claims 1 to 9, such that the interference coating is itself coated with a surface coating (13, 12, 11), such as a rain coating, an anti coating fog, an anti-fouling coating and / or at least one layer of protective material.
    [11" id="c-fr-0011]
    11. Marking method according to one of claims 1 to 10, such that the exposure step is carried out at as many marking points as necessary so as to locally mark a region of the main surface of the substrate of the article. optical by means of multiple marking points, said region forming a predefined pattern (22) said marking pattern.
    [12" id="c-fr-0012]
    12. The marking method according to claim 11, such that there is continuity between the marking points which define the region forming the marking pattern, said region preferably comprising less than 1% in surface area of residues of the ablated layers.
    [13" id="c-fr-0013]
    13. A marking method according to one of claims 11 or 12, such that the marking is carried out at a pitch of dimension less than or equal to the dimensions of the marking point.
    [14" id="c-fr-0014]
    14. A marking method according to one of claims 1 to 13, such that the reflection at the marking point has a color, in saturation and / or in hue, different from that of the reflection of the unblasted area.
    [15" id="c-fr-0015]
    15. Optical article (30) comprising a substrate (21) having a main face coated with an interference coating (14,15,16,17,18), said interference coating comprising at least two layers of superimposed materials called inner layer ( 15) and outer layer (14), the inner layer being located between the substrate and the outer layer, the interference coating being such that it has a reflection coefficient Re in the visible range (380,780 nm);
    Said article (30) comprising a marking pattern (22) on the surface of the interference coating, the marking pattern (22) being formed by a plurality of substantially identical marking points (P), each marking point corresponding to the localized absence of at least part of the layer thickness
    5 interior (15) and any layer (14, 13, 12, 11) located between said surface and the interior layer, the ablated zone having a reflection coefficient Rm in the visible range (380-780 nm) such that Re is different from Rm by at least 1%, the marking pattern (22) preferably being continuous.
    1/3
    2/3
    T
    4 Fig. 5
    o o O O O o o o o o o o o o CO CT CN LO 00 T— Ν ' o co co CT CN LO CO CO Ν ' Ν ' Ν ' LO LO LO co co co co
    780
    3/3
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    FR2990774A1|2013-11-22|Ophthalmic lens for pair of glasses for e.g. improving contrast of vision of wearer, has interferential filter whose curve of reflectivity includes angle of incidences, where parameters of incidences are defined by using specific expression
    EP3491461A1|2019-06-05|Ophthalmic lens in particular for sunglasses
    EP0409719A1|1991-01-23|Ophthalmic glass intended for binocular spectacles for protection of the eyes against harmful solar rays
    FR3108989A1|2021-10-08|Process for processing a mirrored optical article
    WO2015177447A1|2015-11-26|Method for determining colour characteristics reflected by an interference filter, method for depositing such an interference filter, and assembly formed by an interference filter and an object
    EP3815838A1|2021-05-05|Method for producing a transparent part for a vehicle
    同族专利:
    公开号 | 公开日
    US20190171034A1|2019-06-06|
    KR20190029598A|2019-03-20|
    FR3054043B1|2018-07-27|
    CN109477977A|2019-03-15|
    WO2018015650A9|2019-01-03|
    EP3485324A1|2019-05-22|
    CN109477977B|2020-11-13|
    JP2019523447A|2019-08-22|
    WO2018015650A1|2018-01-25|
    引用文献:
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    US20040095645A1|2001-01-25|2004-05-20|Jax Holdings, Inc.|Multi-layer thin film optical filter arrangement|
    US20060051501A1|2002-11-15|2006-03-09|Essilor International |Method for obtaining a mark on a low surface energy ophthalmic lens|
    US20140016083A1|2012-07-11|2014-01-16|Carl Zeiss Vision International Gmbh|Spectacle lens and method and apparatus for making the same|
    WO2015040338A1|2013-09-20|2015-03-26|Essilor International |Device and process for marking an ophthalmic lens with a pulsed laser of wavelength and energy selected per pulse|
    US20160207249A1|2013-09-20|2016-07-21|Essilor International |Device and process for marking an ophthalmic lens with a pulsed laser of wavelength and energy selected per pulse|
    US4044222A|1976-01-16|1977-08-23|Western Electric Company, Inc.|Method of forming tapered apertures in thin films with an energy beam|
    EP0677764B1|1994-04-12|2002-01-23|Jax Holdings, Inc.|An optical filter arrangement|
    FR2913116B1|2007-02-23|2009-08-28|Essilor Int|METHOD FOR MANUFACTURING OPTICAL ARTICLE COATED WITH AN ANTI-REFLECTIVE OR REFLECTIVE COATING HAVING IMPROVED ADHESION AND ABRASION RESISTANCE PROPERTIES|
    CN101533771A|2009-03-03|2009-09-16|浙江水晶光电科技股份有限公司|A laser marking method on wafer surface|
    FR2943798B1|2009-03-27|2011-05-27|Essilor Int|OPTICAL ARTICLE COATED WITH AN ANTIREFLECTIVE OR REFLECTIVE COATING COMPRISING AN ELECTRICALLY CONDUCTIVE LAYER BASED ON TIN OXIDE AND METHOD OF MANUFACTURE|
    EP3031785B1|2014-12-12|2018-10-17|Schott AG|Method for producing a glass ceramic element having a structured coating|US20210397020A1|2018-12-28|2021-12-23|Hoya Lens Thailand Ltd.|Method for manufacturing optical member and optical member|
    US11067828B2|2019-12-08|2021-07-20|Brandon T. Michaels|Eyewear lens or optical film with decorative dichromic mirror pattern having variable opacity|
    FR3108989A1|2020-04-02|2021-10-08|Bnl Eurolens|Process for processing a mirrored optical article|
    JP2022007102A|2020-06-25|2022-01-13|ホヤ レンズ タイランド リミテッド|Manufacturing method of optical member and optical member|
    CN113005939A|2021-03-18|2021-06-22|浙江宏基道安科技股份有限公司|Anti-aging road cone, manufacturing process and manufacturing equipment|
    CN113308600B|2021-05-19|2022-02-15|武汉大学|Hydrophobic coating based laser shock method|
    法律状态:
    2017-07-26| PLFP| Fee payment|Year of fee payment: 2 |
    2018-01-19| PLSC| Search report ready|Effective date: 20180119 |
    2018-07-26| PLFP| Fee payment|Year of fee payment: 3 |
    2019-07-25| PLFP| Fee payment|Year of fee payment: 4 |
    2020-07-27| PLFP| Fee payment|Year of fee payment: 5 |
    2021-07-26| PLFP| Fee payment|Year of fee payment: 6 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1656851A|FR3054043B1|2016-07-18|2016-07-18|VISIBLE PERMANENT MARKING METHOD OF OPTICAL ARTICLE AND OPTICAL ARTICLE MARK|FR1656851A| FR3054043B1|2016-07-18|2016-07-18|VISIBLE PERMANENT MARKING METHOD OF OPTICAL ARTICLE AND OPTICAL ARTICLE MARK|
    JP2019502208A| JP2019523447A|2016-07-18|2017-07-18|Method of permanent visual marking of optical products and marked optical products|
    KR1020197001694A| KR20190029598A|2016-07-18|2017-07-18|Method and marking optical article for permanent visibility marking of optical articles|
    CN201780044543.5A| CN109477977B|2016-07-18|2017-07-18|Method for permanently visually marking an optical article and marked optical article|
    EP17757788.9A| EP3485324A1|2016-07-18|2017-07-18|Method for permanent visible marking of an optical article and marked optical article|
    US16/318,249| US20190171034A1|2016-07-18|2017-07-18|Method for permanent visible marking of an optical article and marked optical article|
    PCT/FR2017/051949| WO2018015650A1|2016-07-18|2017-07-18|Method for permanent visible marking of an optical article and marked optical article|
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