Method and system for obtaining customized optical article having at least one predetermined optical property

Abstract

The invention relates to a method and a system for obtaining a customized optical article from a print carrier by thermal transfer via sublimation technique, the customized optical article having at least one predetermined optical property selected from absorbance and transmittance in the visible and / or invisible light region, the print carrier comprises a carrier and at least one ink (C, M, Y) printed on the carrier according to the inking level, the at least one ink comprising at least one sublimable dye selected from the group consisting of visible dyes, invisible dyes and mixtures thereof. The invention is particularly applicable to ophthalmic lens parts, although ophthalmic lens parts may involve any optical article to be colored and / or provided with invisible light absorbers such as IR, UV and / or blue light absorbers. The method comprises controlling the inking level of the at least one ink (C, M, Y) by using an experimentally determined variation rule of the at least one predetermined optical property that varies with the inking level of the at least one ink, to obtain said customized optical article.

Description

Technical Field

[0001] The present invention relates to a method and a system for obtaining a customized optical product having at least one predetermined optical property in the visible and / or invisible light domain by thermal transfer via sublimation technology from a carrier printed with at least one visible and / or invisible ink. The present invention is particularly applicable to ophthalmic lens parts, even if the ophthalmic lens part may involve any optical product to be colored with visible dyes and / or provided with invisible light absorbers, such as IR, UV or blue light absorbers. Background Art

[0002] In a known manner, most tinting techniques implemented recently for ophthalmic lenses may include:

[0003] - a dip tinting method, according to which the lenses are tinted by dipping into an aqueous tinting bath, and

[0004] - A coloring method by thermally transferring a colored dye from a printed paper to a lens by successive sublimation and imbibition steps, see WO 2020 / 064640 A1, page 15, lines 1-7 for an example of the disclosure of this technology, in which a mixture of three sublimable dyes is printed on a specific paper, the dyes are then transferred from the specific paper to the concave side of the lens by sublimation, and finally the lens is heated so that the dyes diffuse in the lens mass by imbibition.

[0005] The major disadvantage of tinting ophthalmic lenses by sublimation and imbibition methods is that such methods involve inherent dispersion, often requiring compensation for color variations from one pair of lenses to another during lens manufacturing by using a touch-up dip tinting step to ensure color consistency for each customer.

[0006] WO 2020 / 025595 A1 discloses a method and system for determining a lens with a customized color, the method comprising the following steps: determining a target colorimetric data set; providing access to a database comprising data representing colors; using multiple simulation modules to calculate, based on the data from the database, multiple simulated colorimetric data of a lens substrate combined with a dye mixture having a determined dye combination, composition and amount, or with a multilayer stack varying with a determined layer composition and thickness; and color matching the multiple simulated colorimetric data with the target colorimetric data set to determine one or more combinations of the lens substrate with the determined dye mixture or with the determined multilayer stack.

[0007] WO 2020 / 025595 A1 does not relate to a coloring method by sublimation and absorption from printing paper, and there is no printing paper for measuring optical parameters thereof. Summary of the invention

[0008] The object of the present invention is to provide a method for obtaining a customized optical product from a printed support by thermal transfer via the sublimation technique, the customized optical product comprising a main surface having at least one predetermined (i.e. desired) optical property chosen from absorbance and transmittance in the visible and / or invisible light domain, the printed support comprising a support and at least one ink printed on the support according to an inking level, the at least one ink comprising at least one sublimable dye chosen from visible dyes, invisible dyes and mixtures thereof, which allows to omit a retouching step for the optical product, thereby avoiding the above-mentioned final step of immersion coloring.

[0009] To this end, the method according to the invention comprises controlling the inking level of said at least one ink by using an experimentally determined variation law of said at least one predetermined optical property as a function of the inking level of said at least one ink to obtain said customized optical article.

[0010] It should be noted that the method of the invention thus allows obtaining said customized optical product simply by analyzing / modifying the printed support before implementing the sublimation step, this analysis / modification operation directly allowing the optical product finally obtained to obtain said at least one predetermined optical characteristic, without having to implement any correction step to adjust its optical characteristics. Thus, since the method of the invention thus allows compensating for variations or dispersions in the inking level on the support, there is no need for a final step of dipping a color correction plate in addition to the thermal transfer process in order to guarantee the specified optical characteristics (e.g. color and / or invisible light absorption requirements) for each customer.

[0011] Thus, by ensuring that the at least one ink is obtained at the correct inking level on the print support so as to match the target absorbance and / or transmittance value predetermined for the optical article, any final retouching step can be omitted. In other words, the customized optical article is advantageously produced solely by the inking level of the at least one ink.

[0012] As explained below, the method of the invention is applicable not only to ophthalmic lens parts, but also to any optical article which is to be tinted and / or provided with an invisible light absorber and which may not belong to the ophthalmic field.

[0013] It should also be noted that the method of the invention is generally applicable to supports that are not transparent to visible light, such as made of paper or cardboard.

[0014] It should further be noted that in the case where multiple inks are to be printed (i.e., several visible dyes and / or several invisible dyes), such inks must be printed on the carrier individually (i.e., without forming an ink mixture), and then the inking level of each ink must be controlled individually, as will be described in detail in the following examples.

[0015] According to another feature of the present invention, the variation law of the at least one predetermined optical property as a function of the inking level of the at least one ink can be determined experimentally by combining the following:

[0016] - a first experimental correlation between an optical parameter of the at least one ink on the print support and its inking level, the optical parameter of the at least one ink being selected from the group consisting of its K / S ratio of absorbance coefficient to scattering coefficient, its optical density, its colorimetric coefficients such as its colorimetric lightness L* and colorimetric coefficients a* and b*, and combinations thereof, and

[0017] - a second experimental correlation between at least one predicted optical property of said customized optical article and said optical parameter of said at least one ink, said at least one predicted optical property being selected from the maximum absorbance and minimum transmittance values ​​of said optical article and measured at at least one given wavelength in said visible and / or invisible light domain.

[0018] Preferably, the optical parameter of the at least one ink used for both the first and second experimental correlations is the K / S ratio of the absorbance coefficient K to the scattering coefficient S of the at least one printed ink, as defined by the Kubelka-Munk relation:

[0019] K / S = (1-R∞)2 / 2R∞, where R∞ represents the diffuse reflectivity of an infinitely thick layer.

[0020] Also preferably, the at least one predicted optical property of the customized optical article is its maximum absorbance value.

[0021] Advantageously, according to the above features of the present invention:

[0022] - the first experimental correlation can be approximated as a linear correlation of the type y=ax+b, where y represents an optical parameter of at least one ink on the printed support, x represents the inking level of said at least one ink, and a, b are constants representing said at least one ink, and

[0023] - The second experimental correlation can be approximated as a linear correlation of the type y=a'x+b', where y represents at least one predicted optical property of the customized optical article, x represents an optical parameter of at least one ink on the printed support, and a', b' are constants representing the at least one ink.

[0024] More preferably, the optical parameter of the at least one ink used for both the first and second experimental correlations is its K / S ratio as defined above, and the at least one predicted optical property of the customized optical article is its maximum absorbance value.

[0025] According to a preferred embodiment of the present invention, which can be combined with any of the above features, the method comprises compensating the inking level of the at least one ink with the aid of the first experimental correlation and available data of a reference optical product pre-manufactured from a similar printing support by thermal transfer, the reference optical products each comprising a main surface having at least one known optical property in the visible and / or invisible light domain that is similar to the at least one predetermined optical property, the available data of the reference optical product being generated by the first and second experimental correlations.

[0026] Specifically, the method according to this preferred embodiment may include:

[0027] - calculating a compensation coefficient based on a reference value of an optical parameter of said at least one ink and a measured value of said optical parameter, said reference value of said optical parameter being derived from said available data of said reference optical article and corresponding to said at least one predicted optical property of said customized optical article, and then

[0028] - obtaining a compensated inking level of the at least one ink from the calculated compensation coefficient.

[0029] As explained above, the optical parameter of the at least one ink used is preferably its K / S ratio as defined above, and the at least one predetermined optical property of the customized optical article is more preferably its maximum absorbance value.

[0030] It should be noted that, due to the available data of the reference optical product, such compensation of the inking level on the print support to be reprinted with the new compensated inking level therefore allows to simply and accurately obtain at least one predetermined optical property of the optical product, by taking into account both the first and second experimental correlations.

[0031] It should also be noted that said available data of the reference optical article together with the calculation of the compensation coefficients and the resulting compensated inking levels may advantageously be provided by a computer program configured to control the inking level of said at least one ink to obtain said customized optical article.

[0032] More preferably, according to the preferred embodiment of the present invention, the method comprises:

[0033] a) printing the carrier, which is opaque to visible light and is made of, for example, paper or cardboard, by means of at least one printer according to the determined inking level of the at least one ink;

[0034] b) measuring a reflectivity parameter R of the at least one ink on a printed support by reflectance spectrophotometry;

[0035] c) converting the reflectance parameter R of the at least one ink into the measured value of the optical parameter of the at least one ink by using the relationship between the reflectance parameter R and the optical parameter;

[0036] d) comparing the measured value of the optical parameter of the at least one ink obtained in c) with the reference value of the optical parameter of the at least one ink and determining the difference between the two values;

[0037] e) if the difference determined in d) is not zero, calculating a compensation coefficient, which is equal to the ratio of a reference value of an optical parameter of the at least one ink to a measured value of the optical parameter, and then obtaining a compensated inking level of the at least one ink from the calculated compensation coefficient by the cubic rule;

[0038] f) reprinting the support according to the compensated inking level of the at least one ink obtained in e);

[0039] g) optionally sequentially repeating steps b) to f), using at least one new compensated inking level of said at least one ink, until a new measured value of an optical parameter of said at least one ink is equal to a reference value of said optical parameter; and

[0040] h) thermal transfer by sublimation of at least one dye of at least one ink printed at the current or newly compensated inking level onto the optical article to be customized, and an optional fixing step, depending on the constituent material of the optical article into which the dye is sublimated, comprising fixing the sublimated dye onto the optical article, for example by an imbibition step, for example by air convection, during a sufficient time and with a sufficient temperature to irreversibly fix the dye onto the optical article, the time and temperature depending on the material of the optical article (for example, for an optical article consisting of The manufactured optical product is subjected to a temperature between 100°C and 160°C and a time period of one hour), or according to another example, the imbibition step is performed by surface irradiation (such as IR / UV laser irradiation) to obtain a major surface of the customized optical product, wherein the major surface has at least one predicted optical property that matches the at least one predetermined optical property.

[0041] Preferably, step c) is implemented by using an optical parameter which is the K / S ratio of the absorbance coefficient K to the scattering coefficient S of at least one printing ink, as defined by the Kubelka-Munk relationship: K / S=(1-R∞)2 / 2R∞.

[0042] It should be noted that steps d) and g) may alternatively be implemented by taking into account a given tolerance interval (ie each measured value is substantially equal to the corresponding reference value within this tolerance interval) when comparing:

[0043] - in step d), comparing the current or new measured value of the optical parameter with a reference value of the optical parameter, and

[0044] - In step g), a current or new measured value of an optical parameter of said at least one ink is compared with a reference value of the optical parameter.

[0045] According to another general feature of the invention, which may relate to any of the preceding features and embodiments, the method may further comprise:

[0046] The carrier is sequentially printed a plurality of times to detect inking variations over time due to the at least one printer for a given formulation of the at least one ink, and the inking level of the at least one ink is adjusted to compensate for the detected inking variations by, for example, increasing the inking level in response to a previously detected decrease in the inking level to provide at least one measured value of an optical parameter of the at least one ink and a consistent value of the resulting at least one predetermined optical property of the customized optical article.

[0047] As explained above, said at least one predetermined optical property in said visible and / or invisible light domain is preferably a maximum absorbance value of said optical article measured at at least one given wavelength in said visible and / or invisible light domain.

[0048] According to another general feature of the invention, which may be related to any of the preceding features and embodiments, the method may further comprise: bringing the new printer into conformity with the reference printer by using a correction coefficient, the correction coefficient being generated by:

[0049] (i) measured values ​​of a reflectivity parameter R of said at least one ink printed on said support by said reference printer and by said new printer with identical printing parameters,

[0050] the reflectivity parameter R measurement is converted into a measurement of an optical parameter of the at least one ink, such as the K / S ratio, to obtain a calculated equivalent inking level of the at least one ink and to determine an inking level ratio for the at least one ink, the inking level ratio being equal to the equivalent inking level calculated for the new printer / the equivalent inking level calculated for the reference printer,

[0051] The inking level ratio represents the correction factor to be applied to the printing parameters of the new printer in order to make the new printer consistent with the reference printer; or is generated by:

[0052] (ii) a measured value of the visual transmittance Tv of the custom optical article,

[0053] said at least one ink is printed on said support by said reference printer and by said new printer with said same printing parameters, and said sublimation is performed to obtain said customized optical article of said at least one ink printed by both printers,

[0054] converting the transmittance Tv measurements into absorbance A measurements and calculating the resulting ratio for the at least one ink, the absorbance ratio being equal to the absorbance derived from the transmittance measured with the new printer / the absorbance derived from the transmittance measured with the reference printer,

[0055] A straight line corresponding to the relationship between the absorbance of the at least one ink at its characteristic wavelength and the inking level is obtained, and if the two straight lines obtained for the two printers respectively have different slopes, a slope ratio is calculated, the slope ratio being equal to the slope obtained by the new printer / the slope obtained by the reference printer, the slope ratio determining the correction coefficient to be applied to the at least one ink printed by the new printer.

[0056] According to another general feature of the invention, which may relate to any of the preceding features and embodiments, the method may further comprise: monitoring the inking level of the at least one ink printed on the support by the at least one printer according to set printing parameters defining the set inking level, the monitoring comprising a measured value of a reflectivity parameter R of the at least one ink,

[0057] The reflectivity parameter R measurement is converted into a measurement of an optical parameter of the at least one ink, such as the K / S ratio, to obtain a calculated equivalent inking level of the at least one ink,

[0058] calculating an inking level ratio defining a correction factor, the inking level ratio being equal to the equivalent inking level of the at least one ink / the set inking level, and if the correction factor is outside a predetermined range of the at least one ink, such as less than 0.9 or greater than 1.1, performing at least a second printing of the at least one ink in the same manner, and determining again the corresponding correction factor of the at least one ink, and

[0059] If the correction factor of the at least one ink is still outside the range after the at least one second printing, replacing an ink cartridge of the at least one printer.

[0060] According to a first example of the present invention, the at least one predetermined optical property is that in the visible light domain, the at least one ink includes at least one primary color consisting of cyan and / or magenta and / or yellow (CMY, i.e., subtractive color model), and the primary colors are printed separately on the carrier (i.e., not mixed together thereon), and then the inking level of each primary color is controlled separately.

[0061] According to a second example of the present invention, which can be optionally combined with the above first example, the at least one predetermined optical property is in the invisible light domain, and the at least one ink comprises an invisible single-component dye selected from UV absorbers, IR absorbers and blue light absorbers for optical products (for example, for ophthalmic lenses).

[0062] According to another general feature of the invention, which may relate to any of the foregoing features, embodiments and examples, thermal transfer may include:

[0063] (i) drying the printing carrier,

[0064] (ii) transferring said at least one ink from a dry printing support by sublimation by vacuum heating onto the surface of an optical blank intended to form said customized optical article, and

[0065] (iii) fixing said at least one dye into a surface sub-layer, for example several μm thick, of said optical blank to form said major surface of said customized optical article.

[0066] The present invention also relates to a system for obtaining a customized optical product from a printed support by thermal transfer via sublimation technology, the customized optical product comprising a main surface having at least one predetermined optical property selected from absorbance and transmittance in the visible and / or invisible light domain, the printed support comprising a support and at least one ink printed on the support according to an inking level, the at least one ink comprising at least one sublimable dye selected from visible dyes, invisible dyes and mixtures thereof.

[0067] According to the present invention, the system comprises at least one printer and a computer-readable medium equipped with or coupled to the at least one printer, the computer-readable medium carrying one or more stored instruction sequences of a computer program, which are accessible to a processor and when executed by the processor cause the processor to control the inking level of the at least one ink to obtain the customized optical product by using an experimentally determined variation law of the at least one predetermined optical property as a function of the inking level of the at least one ink.

[0068] According to other features of the present invention, the system may further include a reflectance spectrophotometer configured to measure a reflectance parameter R of the at least one ink on the printed support, and

[0069] The one or more stored instruction sequences may be configured to implement the variation rule of the at least one predetermined optical property as a function of the inking level of the at least one ink, the variation rule being experimentally determined by using a combination of:

[0070] - a first experimental correlation between an optical parameter of said at least one ink on said print support and its inking level, said optical parameter being calculated from said reflectivity parameter R of said at least one ink and being selected from its K / S ratio of absorbance coefficient to scattering coefficient, its optical density, its colorimetric coefficients such as its colorimetric lightness L* and colorimetric coefficients a* and b*, and combinations thereof, and

[0071] - a second experimental correlation between at least one predicted optical property of the customized optical article and the optical parameter of the at least one ink, the at least one predicted optical property being selected from the maximum absorbance and minimum transmittance values ​​of the optical article and measured at at least one given wavelength in the visible or invisible light domain.

[0072] Still other features of the system according to the present invention:

[0073] the first experimental correlation may be a linear correlation of the type y=ax+b, where y represents an optical parameter of said at least one ink on said print support, x represents the inking level of said at least one ink, and a, b are constants, and

[0074] - The second experimental correlation may be a linear correlation of the type y=a'x+b', where y represents at least one predicted optical property of the customized optical article, x represents an optical parameter of at least one ink on the printed support, and a', b' are constants.

[0075] Still other features of the system according to the present invention:

[0076] The one or more stored instruction sequences may be configured to: compensate the inking level of the at least one ink by means of the first experimental correlation and available data of a reference optical article previously manufactured by thermal transfer from a similar print support, the available optical articles each comprising a major surface having at least one known optical property in the visible and / or invisible light domain similar to the at least one predetermined optical property, the available data of the reference optical article being generated by the first and second experimental correlations, and

[0077] The one or more stored instruction sequences are configured to:

[0078] - calculating a compensation coefficient based on a reference value of an optical parameter of said at least one ink and a measured value of said optical parameter, said reference value of said optical parameter being derived from said available data of said reference optical article and corresponding to said at least one predicted optical property of said customized optical article, and then

[0079] - obtaining a compensated inking level of the at least one ink from the calculated compensation coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 An exemplary formulation of three individual primary colors, cyan (C), magenta (M), and yellow (Y), which are printed in the method of the present invention and analyzed individually by reflectance spectrophotometry is shown;

[0081] Figure 2a to Figure 2c are three graphs showing the change in paper reflectance with the use of three separate primary colors (in Figure 2a , Figure 2b , Figure 2c The variation of wavelength (nm) of the paper printed with the M, Y, and C colors (in the figure), the inking level of each primary color is 50% (i.e., the dots per inch dpi is 2000);

[0082] Figure 3a to Figure 3c are three graphs of a first embodiment according to a first series of experiments, showing the relative humidity of the three individually printed primary colors (in Figure 3a , Figure 3b , Figure 3c (in the figure, respectively, M measured at 520 nm, Y measured at 410 nm, and C measured at 650 nm), K / S ratio changes with inking level (dpi);

[0083] Figures 4a to 4c are three graphs of this first embodiment according to a first series of experiments, showing the Figure 4a , Figure 4b , Figure 4c where M is measured at 520 nm, Y is measured at 410 nm and C is measured at 650 nm, respectively. The maximum absorbance of the lens changes with the K / S ratio of the printing paper;

[0084] Figure 5a to Figure 5c are three graphs in another example of a first series of experiments showing the relative relative humidity of the three individually printed primary colors (in Figure 5a , Figure 5b , Figure 5cIn the figure, they are M, Y, and C, respectively. The optical density varies with the inking level (the horizontal axis is expressed as the coefficient of the 2000 dpi inking level, in %).

[0085] Figures 6a to 6c are three graphs in yet another embodiment of the first series of experiments showing the relative relative humidity of the three individually printed primary colors (in Figure 6a , Figure 6b , Figure 6c , C, M, Y in the figure, respectively), the variation of colorimetric lightness L* with inking level (expressed as a coefficient of 2000 dpi for C and M, and as a coefficient of 1200 dpi for Y, in %);

[0086] Figures 7a to 7c are three graphs in yet another embodiment of the first series of experiments showing the relative relative humidity of the three individually printed primary colors (in Figure 7a , Figure 7b , Figure 7c In the figure, they are C, M, and Y, respectively), and the colorimetric coefficient a* changes with the inking level (expressed as the coefficient of 2000 dpi, in %);

[0087] Figures 8a to 8c are three graphs in yet another embodiment of the first series of experiments showing the relative relative humidity of the three individually printed primary colors (in Figure 8a , Figure 8b , Figure 8c In the figure, they are C, M, and Y, respectively), and the colorimetric coefficient b* changes with the inking level (expressed as the coefficient of 2000 dpi, in %);

[0088] Figures 9a to 9c are three graphs of the first embodiment according to a first series of experiments, showing the Figure 9a , Figure 9b , Fig.9c (in are M, Y, and C), the K / S ratio of printing paper changes with time;

[0089] Fig.10 is a graph from a second series of experiments according to the present invention involving seven formulations including constant inking levels of magenta and cyan primaries and an invisible ink consisting of a UV absorber at a variable inking level, showing the variation of paper reflectance with wavelength (nm);

[0090] Fig.11 is a graph according to the first example of the second series of experiments showing the variation of the K / S ratio measured at 410 nm as a function of the inking level (in dpi) of a UV absorber of a defined formulation, the vertical bars representing the minimum and maximum values ​​obtained from measurements made on ten printed sheets;

[0091] Fig.12 is a graph according to the first embodiment of the second series of experiments, showing the cross-sectional area at 415 nm for seven formulations on the left side of the printed paper. Variation of the light transmittance of the lens with the K / S ratio measured at 410 nm, with the vertical bars representing the minimum and maximum values ​​obtained from measurements made on ten printed papers;

[0092] Fig.13 is a graph according to the first example of this second series of experiments, which shows the K / S ratio obtained at 415 nm through The absorbance of the lens varies with the inking level (in dpi) of a defined formulation of UV absorber;

[0093] Fig.14 This second series of experiments was based on Fig.11 A graph of an example of a comparative example showing the variation of the optical density measured at 410 nm with the inking level (in dpi) of a UV absorber of a defined formulation;

[0094] Fig.15 This second series of experiments was based on Fig.11 A graph of another embodiment of the embodiment of the present invention showing the variation of the paper reflectance measured at 410nm as a function of the inking level (in dpi) of the UV absorber defining seven printing recipes; and

[0095] Fig.16 According to this second series of experiments Fig.11 A graph of the first embodiment shows the variation of the K / S ratio over time (in days) and the corresponding tolerance of the value of the K / S ratio for seven printing recipes.

[0096] Fig.17 is a screenshot of printing parameters to be changed according to another embodiment of the invention, which uses correction coefficients to bring two printers into agreement with each other, starting from the reflectivity parameters measured for the primary colors M, Y, C on paper printed by the two printers.

[0097] Fig.18 is a graph of absorption spectra versus wavelength for M, Y, and C according to another embodiment of the present invention, which uses correction factors to make two printers consistent with each other, starting with visual transmittance measurements of lenses obtained by the two printers, as Fig.17 An alternative to the embodiment of .

[0098] Fig.19a It involves Fig.18A graph of an embodiment of the invention shows the linear variation of absorbance with the inking level (dpi) of Y on each printed paper for each printer, where the absorbance values ​​are generated from the visual transmittance measurements.

[0099] Fig.19b It involves Fig.18 A graph of an embodiment of the invention shows, for each printer, the linear variation of absorbance with the inking level (dpi) of M on each printed paper, where the absorbance values ​​are generated from the visual transmittance measurements.

[0100] Fig.19c It involves Fig.18 A graph of an embodiment of the invention shows the linear variation of absorbance with the inking level (dpi) of C on each printed paper for each printer, where the absorbance values ​​are generated from the visual transmittance measurements.

[0101] Fig.20a is with Fig.18 and Fig.19b Graphs related to an embodiment of the invention show the linear variation of the corrected absorbance of a lens obtained by using a correction factor for absorbance between two printers versus the inking level (dpi) of the M primer.

[0102] Fig.20b is with Fig.18 and Fig.19a Graphs related to an embodiment of the invention show the linear variation of the corrected absorbance of the lens obtained by using a correction factor for absorbance between two printers versus the inking level (dpi) of the Y primer.

[0103] Fig.20c is with Fig.18 and Fig.19c Graphs related to an embodiment of the invention show the linear variation of the corrected absorbance of a lens obtained by using a correction factor for absorbance between two printers versus the inking level (dpi) of the C primer.

[0104] Fig.21a It is to show that the Figure 17 to Figure 20c A screenshot of optical parameter measurements of yet another embodiment of an embodiment of the invention, including reflectance of paper printed with M primary colors, which involves monitoring the inking level of the printer for the M color among M, Y, C by using a correction factor for M.

[0105] Figure 21b It shows that according to Fig.21aScreen shot of optical parameter measurements of the same embodiment of FIG. 1 including reflectance of paper printed with the Y primary color, but involving monitoring the printer's inking level for the Y color by using a correction factor for Y.

[0106] Fig.21c It shows that according to Fig.21a and Figure 21b Screen shot of optical parameter measurements of an embodiment of which include reflectance of paper printed with the C primary color, but which involves monitoring the inking level of the printer for the C color by using a correction factor for C. DETAILED DESCRIPTION

[0107] In this specification, the terms "comprise" (and any grammatical variations thereof, such as "comprises" and "comprising"), "have" (and any grammatical variations thereof, such as "has" and "having"), "contain" (and any grammatical variations thereof, such as "contains" and "containing"), and "include" (and any grammatical variations thereof, such as "includes" and "including") are open linking verbs. They are used to specify the presence of the features, integers, steps or components or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps or components or groups thereof. Therefore, a method or a step in a method that "comprises", "has", "contains" or "includes" one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more steps or elements.

[0108] Unless otherwise indicated, all numbers or expressions of quantities of ingredients, ranges, reaction conditions, etc. used herein should be understood to be modified in all cases by the term "about". Likewise, unless otherwise indicated, indications of intervals of values ​​"from X to Y" or "between X and Y" according to the present invention are intended to include values ​​of X and Y.

[0109] Visible and / or invisible light range, visible and / or invisible dyes

[0110] The "visible light domain" includes the light domain visible to the human eye, i.e., the light domain with wavelengths in the visible domain range of 380 nm to about 750 nm. This light domain includes, for example, the emission range of LED-based digital devices, between 380 nm and 500 nm, preferably between 430 nm and 470 nm, most preferably between 440 nm and 460 nm, and blue-violet radiation from 400 nm to 455 nm, which corresponds to the harmful part of blue light radiation as defined in ISO TR20772:2018 and in several peer-reviewed papers (Marie et al., Cell Death and Disease, 2020), (Marie et al., Cell Death and Disease, 2018), (Arnault, Barrau et al., 2013).

[0111] “Visible dyes” relate to dyes which absorb light in the so-called visible range.

[0112] The "invisible light region" includes light regions that are invisible to the human eye, that is, light regions outside the visible region of 380 nm to about 750 nm in wavelength. These invisible light regions include ultraviolet (UV), near infrared (NIR), and infrared (IR).

[0113] “Invisible dyes” relate to dyes which absorb light in the so-called invisible region.

[0114] Optical products:

[0115] The optical article according to the present invention comprises at least one ophthalmic lens or filter or optical glass or optical material suitable for human vision, or an optical film or patch intended to be fixed on a substrate, or a specific layer of a multilayer optical film (for example at least one ophthalmic lens), or an optical film or patch intended to be fixed on a substrate, or an optical glass, or an optical material intended to be used in an ophthalmic instrument (for example for determining the visual acuity and / or refraction of a subject), or any kind of safety equipment (including safety glass or safety walls intended to face the eyes of an individual, such as protective equipment (for example safety lenses or masks or shields)).

[0116] The optical article may be implemented as an eyewear device having a frame that at least partially surrounds one or more ophthalmic lenses. As non-limiting examples, the optical article may be a pair of glasses, sunglasses, safety goggles, sports goggles, contact lenses, intraocular implants, active lenses with amplitude modulation (such as polarized lenses) or active lenses with phase modulation (such as autofocus lenses), etc.

[0117] At least one ophthalmic lens or optical glass or optical material suitable for human vision, or an optical film or patch intended to be fixed on a substrate can provide an optical function to the user, ie the wearer of the lens.

[0118] For example, the ophthalmic lens can be a corrective lens, i.e., a spherical, cylindrical and / or under-addition power lens for ametropia users to treat myopia, hyperopia, astigmatism and / or presbyopia. The lens can have a constant power, such that the lens provides power like a single vision lens, or the lens can be a progressive lens with variable power.

[0119] The optical article of the invention may consist of any known mineral and / or organic optical material, including, in the specific case of an ophthalmic lens part to be obtained, for example, a mineral (i.e. made of mineral glass) or organic (i.e. polymer) ophthalmic substrate made of thermoplastic or thermosetting material.

[0120] Examples of ophthalmic lenses:

[0121] Among the thermoplastics suitable for ophthalmic substrates, mention may be made of (meth)acrylic (co)polymers, in particular polymethyl methacrylate (PMMA), thio(meth)acrylic (co)polymers, polyvinyl butyral (PVB), polycarbonates (PC, including homopolycarbonates, copolycarbonates and ordered copolycarbonates), polyesters such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), polycarbonate / polyester copolymers, cycloolefin copolymers such as ethylene / norbornene copolymers or ethylene / cyclopentadiene copolymers and combinations thereof, and thermoplastic ethylene / vinyl acetate copolymers.

[0122] Among the thermosetting materials suitable for ophthalmic substrates, polyurethane (PU), polythiourethane, polyol (allyl carbonate) (co)polymer, polyepoxysulfide and polyepoxide can be mentioned.Other available thermosetting materials are (co)polymers of acrylic acid type, whose refractive index is included between 1.5 and 1.65 and usually close to 1.6.These acrylic acid (co)polymers are obtained by polymerizing (meth) acrylic acid monomer blends and optionally allyl and / or vinyl aromatic monomers.(Meth)acrylate (i.e. acrylate or methacrylate) monomer can be monofunctional or multifunctional, usually with from 2 to 6 (meth)acrylate groups.These monomers can be aliphatic, cyclic, aromatic, polyalkoxylated derivatives of compounds such as bisphenols and / or with other functional groups such as epoxy, thioepoxy, hydroxyl, mercaptan, sulfide, carbonate, carbamate and / or isocyanate functional groups.

[0123] Exemplary thermoset materials for ophthalmic substrates include:

[0124] - cycloolefin copolymers, such as ethylene / norbornene or ethylene / cyclopentadiene copolymers,

[0125] - homopolymers and copolymers of allyl carbonates of linear or branched aliphatic or aromatic polyols, such as homopolymers of diethylene glycol bis(allyl carbonate),

[0126] - homopolymers and copolymers of (meth)acrylic acid and its esters, optionally derived from bisphenol A,

[0127] - homopolymers and copolymers of thio(meth)acrylic acid and its esters,

[0128] - homopolymers and copolymers optionally derived from bisphenol A or allyl esters of phthalic acid and allyl aromatic compounds such as styrene,

[0129] - copolymers of urethanes and thiourethanes,

[0130] - homopolymers and copolymers of epoxy resins, and

[0131] - Homopolymers and copolymers of sulfides, disulfides and episulfides.

[0132] Ophthalmic substrates may be obtained by polymerizing blends of the above monomers, or may even comprise blends of these polymers and (co)polymers.

[0133] Particularly recommended organic ophthalmic substrates are substrates such as:

[0134] - obtained by (co)polymerization of diethylene glycol bis(allyl carbonate) (i.e. a homopolymer or copolymer of an allyl carbonate of a linear or branched aliphatic or aromatic polyol), even more preferably such as is available from PPG Industries under the trademark The homopolymer of diethylene glycol bis(allyl carbonate) is sold under the trademark Lens sales,

[0135] - made of polythiourethane copolymers, such as the so-called "MR-7", "MR-8" sold by the Japanese company Mitsui (the resulting substrate is sold under the trademark lens sales), "MGC N19", MR-10 or "MR-1.74" lens substrates, or

[0136] - Thermoplastic substrates of the polycarbonate type.

[0137] In certain applications, it is preferred to coat the front major face of the ophthalmic substrate with one or more functional coatings prior to depositing the optional multilayer inorganic coating. These functional coatings conventionally used in optics may be, but are not limited to, an impact-resistant primer layer, an anti-wear and / or anti-scratch coating, a polarizing coating, a photochromic coating or a pigmented coating. In general, the front major face of the substrate is thus coated with an impact-resistant primer layer, an anti-wear coating and / or an anti-scratch coating, or an impact-resistant primer layer coated with an anti-wear and / or anti-scratch coating.

[0138] The multilayer inorganic coating may be deposited on an anti-wear and / or anti-scratch coating, which may be any layer conventionally used as an anti-wear and / or anti-scratch coating in the field of ophthalmic lenses. These anti-wear and / or scratch-resistant coatings are preferably hard coatings based on poly(meth)acrylates or silanes, the hard coatings generally comprising one or more mineral fillers, the mineral fillers being intended to increase the hardness and / or refractive index of the coating (once cured), and they are preferably produced by a composition comprising at least one alkoxysilane and / or one of its hydrolysates (obtained, for example, by hydrolysis with a hydrochloric acid solution) and optionally a condensation and / or curing catalyst. Coatings based on hydrolysates of epoxysilanes may be mentioned, such as those described in documents FR 2702486 (EP 0614957), US 4,211,823 and US 5,015,523.

[0139] A preferred composition for anti-wear and / or anti-scratch coatings is the one disclosed in the name of the Applicant in document FR 2 702 486. It comprises the hydrolyzate of epoxytrialkoxysilane and dialkyldialkoxysilane, silica gel and a catalytic amount of an aluminum-based curing catalyst (such as aluminum acetylacetonate), the remainder consisting essentially of solvents conventionally used to formulate such compositions.

[0140] The anti-wear and / or anti-scratch coating composition can be deposited on the main surface of the substrate by dip coating or spin coating. It is then cured using an appropriate method (preferably thermally, or under UV). The thickness of the anti-wear and / or anti-scratch coating generally varies from 2 μm to 10 μm, and preferably from 3 μm to 5 μm.

[0141] Before depositing the anti-wear and / or anti-scratch coating, it is possible to deposit a primer coating (also called a tie layer) on the substrate, which primer coating improves the impact resistance and / or adhesion of subsequent layers in the final product. This coating can be any impact-resistant primer coating conventionally used for articles made of transparent polymers.

[0142] Among the preferred primer compositions, mention may be made of compositions based on thermoplastic polyurethanes, such as those described in documents JP 63-141001 and JP 63-87223; poly(meth)acrylic primer compositions, such as those described in that US 5,015,523; compositions based on thermosetting polyurethanes, such as those described in document EP 0404111; and compositions based on poly(meth)acrylic latexes or polyurethane latexes, such as those described in documents US 5,316,791 and EP 0680492. Preferred primer compositions are compositions based on polyurethanes and compositions based on latexes, in particular polyurethane latexes optionally containing polyester units.

[0143] Primer composition blends of these latexes, particularly polyurethane latexes and poly(meth)acrylic latexes, may also be used.

[0144] Before depositing the multilayer inorganic coating on a substrate (optionally coated with, for example, an anti-wear layer), the surface of the optionally coated substrate may be subjected to a chemically or physically active treatment aimed at improving the adhesion of the coating. This pretreatment is usually carried out under vacuum. It can be a matter of bombardment with high-energy substances such as ion beams (ion pre-cleaning or IPC), corona discharge treatment, electron beam, UV treatment or plasma treatment under vacuum (usually argon or oxygen plasma). It can also be a matter of acidic or alkaline surface treatment and / or surface treatment with solvents (water or organic solvents).

[0145] The different layers of the multilayer inorganic coating and the optional primer layer are preferably deposited by vacuum deposition using one of the following techniques:

[0146] (i) evaporation, optionally assisted by an ion beam,

[0147] (ii) ion beam sputtering,

[0148] (iii) cathode sputtering, or

[0149] (iv) Plasma enhanced chemical vapor deposition.

[0150] These various techniques are described in the following books: "Thin Film Processes" and "Thin Film Processes II", Vossen and Kern, Academic Press, 1978 and 1991. A particularly preferred technique is vacuum evaporation.

[0151] Preferably, the deposition of each layer of the coating and the optional primer is performed by vacuum evaporation.

[0152] The ophthalmic lens may be made antistatic, i.e., not retaining and / or forming any appreciable electrostatic charge, by incorporating at least one electrically conductive layer into the multilayer inorganic coating. The electrically conductive layer is preferably located between two layers of the inorganic coating, and / or adjacent to a high refractive index layer of such coating. Preferably, the electrically conductive layer is located directly below the low refractive index layer and ideally forms the penultimate layer of the coating, the penultimate layer being located directly below the outermost (low refractive index, e.g., silica-based) layer of the coating.

[0153] The conductive layer must be thin enough not to change the transparency of the coating, and it is preferably made of a highly transparent conductor. In this case, its thickness preferably varies from 1 nm to 15 nm, and even better from 1 nm to 10 nm. The conductive layer preferably comprises an optionally doped metal oxide selected from indium oxide, tin oxide, zinc oxide and mixtures thereof. Indium tin oxide (In2O3:Sn for tin-doped indium oxide), aluminum-doped zinc oxide (ZnO:Al), indium oxide (In2O3) and tin oxide (SnO2) are preferred. Even more preferably, this optically transparent conductive layer is an indium tin oxide (ITO) layer or a tin oxide layer.

[0154] Ophthalmic lenses may also include supplemental features such as, but not limited to:

[0155] - a coating formed on the outer (ie exposed) surface of the multilayer inorganic coating and capable of modifying its surface properties, such as, for example, an antifouling or antifogging topcoat (topcoat);

[0156] - Specific filtering functions within the coating or integrated directly into the substrate, such as filtering for UV, blue violet (400nm to 460nm) or IR; and / or

[0157] -Polarization function.

[0158] By antifouling coating (which may typically be hydrophobic and / or oleophobic and whose thickness is generally less than or equal to 10 nm, preferably 1 nm to 10 nm, and better still 1 nm to 5 nm) mention may be made of a fluorosilane or fluorosilazane type coating which may be obtained by depositing a fluorosilane or fluorosilazane precursor, the precursor preferably comprising at least two hydrolyzable groups per molecule. The precursor fluorosilane preferably contains a fluoropolyether group and better still a perfluoropolyether group. These fluorosilanes are well known and are described in particular in documents US 5,081,192, US 5,763,061, US 6,183,872, US 5,739,639, US 5,922,787, US 6,337,235, US 6,277,485 and EP 0933377. A preferred hydrophobic and / or oleophobic coating composition is sold by Shin-Etsu Chemical under the trade name KP 801M(R). Another preferred hydrophobic and / or oleophobic coating composition is sold by Daikin Industries under the trade name OPTOOL DSX(R). It is a fluororesin containing perfluoropropylene groups.

[0159] Thus, an ophthalmic lens may, for example, comprise a substrate which is coated successively on its front main face with an impact resistant primer layer, an anti-abrasion and / or anti-scratch layer, a multilayer inorganic coating, and a hydrophobic and / or oleophobic top coating.

[0160] As for the rear main face of the substrate, it can, for example, be coated in sequence with an impact-resistant primer layer, an antiadhesive and / or antiscratch layer, an antireflective coating (preferably with low reflectivity in the UV range), and a hydrophobic and / or oleophobic coating.

[0161] As explained above, the ophthalmic lenses obtainable by the process of the invention are tinted with visible dyes derived from C, M, Y primaries and / or are provided with at least one invisible light absorber, such as IR, UV and / or blue light absorber.

[0162] Measurement of optical parameters of printed carriers and optical properties of optical products:

[0163] The optical parameters of at least one ink on the printed support may be:

[0164] - the K / S ratio of its absorbance coefficient to its scattering coefficient, as defined by the Kubelka-Munk relation K / S=(1-R∞)2 / 2R∞, where R∞ represents the reflectivity parameter R of at least one ink measured by reflectance spectrophotometry (derived from the diffuse reflectivity of an infinitely thick layer on the printed support);

[0165] - Its optical density OD, as known per se, is defined by:

[0166] OD = log 10 R, where R is the minimum value of the measured reflectivity; and / or

[0167] - its colorimetric coefficients, such as its colorimetric lightness L* and the colorimetric coefficients a* and b*, which refer to reflected light on the front side in the international colorimetric system CIE L*a*b* and are calculated between 380 nm and 780 nm, taking into account the standard illuminant D65 and the observer (angle 10°). The observer is a "standard observer" as defined in the international colorimetric system CIE L*a*b*.

[0168] For optical products, the optical properties may in particular be:

[0169] Rv (%) - visual reflectance (the average light reflectance coefficient in the visible domain calculated using the equation given in ISO 13666:1998 standard and measured according to ISO8980-4 standard, which is the weighted average of the spectral reflectance over all visible spectra between 380nm and 780nm). Regarding spectral reflectance, it is defined as the ratio of the spectral radiant flux reflected by a material to the incident spectral flux at any specified wavelength.

[0170] Rm (%) - average reflectance (average value of spectral reflectance over the wavelength range of 400 nm to 700 nm).

[0171] Tv (%) - visual transmittance (light transmittance in the visible domain calculated using the equation given in ISO 13666:1998 standard, which refers to the average relative light transmittance in the wavelength range of 380nm to 780nm, weighted according to the sensitivity of the eye at each wavelength in the range and measured under D65 lighting conditions).

[0172] Absorbance: According to ISO 13666:1998, the fraction of incident radiation that is neither reflected nor transmitted. In particular for lenses, the absorptivity is given by the ratio α i =Φ α / Φ in Characterized by, where Φα is the radiation flux absorbed between the incident surface and the exit surface of the lens, represented by Φ in -Φ ex represents, and Φ in is the radiant flux that has successfully passed through the lens. If the lens absorptivity varies with wavelength, the internal spectral absorption factor of the lens is λ It is determined in the same way for each wavelength λ of the incident light.

[0173] Examples of methods implemented according to the invention:

[0174] 1. A first series of experiments for obtaining custom ophthalmic lenses by sublimation and imbibition (see Figures 1 to 9c ),this Some custom ophthalmic lenses have a predetermined maximum absorbance in the visible light domain and are tinted with C, M and / or Y primary colors:

[0175] 1.1. First preferred embodiment (see Figures 1 to 4c ):

[0176] According to a first embodiment of this first series of experiments, in which said optical parameter of the C, M, Y inks on the printed support for said first and second experimental correlations is chosen as the K / S ratio, the method is implemented by carrying out the following successive steps:

[0177] a) The paper is printed by a "ROLAND BN20" printer according to a 50% inking level determined for each primary color C, M, Y (i.e. half of the maximum inking amount, e.g. 2000 dpi) (each primary color is printed separately, see Figure 1 );

[0178] b) Measure the reflectance parameter R (which varies with wavelength, see Figure 2a to Figure 2c three curve graphs of );

[0179] c) For each individually printed primary color C, M, Y, by using the relationship between R and K / S (K / S = (1-R)2 / 2R) Figure 2a to Figure 2c Selecting a wavelength of 520 nm for magenta, a wavelength of 410 nm for yellow, and a wavelength of 650 nm for cyan from the graph of , converting the measured reflectance parameter R into a value of the K / S ratio, thereby calculating each K / S ratio;

[0180] d) comparing, for each individually printed primary color C, M, Y, this measured value of the K / S ratio obtained in c) with reference values ​​of K / S from data of reference lenses made from the same paper by the same sublimation step and having a similar maximum absorbance, these data being available from a software storage medium coupled to the printer and resulting from said first and second experimental correlations (as hereinafter respectively referred to in Figure 3a to Figure 3c and Figures 4a to 4c ), and determining the difference between the measured value and the reference value;

[0181] e) For each individually printed primary color C, M, Y, if the difference determined in d) is not zero, calculate a compensation coefficient "CC" which is equal to the ratio of the reference value of K / S to the measured value K / S [i.e., CC = (K / S) 参考 / (K / S) 测量 ], and then obtain the compensated inking level "CIL" from the calculated compensation coefficient [e.g., for 50% current inking level of each primary color C, M, Y, CIL=CC×2000dpi] by the cubic rule;

[0182] f) reprinting the paper according to the compensated inking level of each individual process colour C, M, Y obtained in e);

[0183] g) optionally sequentially repeating steps b) to f), wherein each individual primary color C, M, Y has at least one new compensated inking level, until the new measured value of the K / S ratio of each individual primary color C, M, Y is equal to the reference value of the K / S ratio; and

[0184] h) Thermally transferring by sublimation each primary color C, M, Y printed at the current or newly compensated inking level onto the ophthalmic lenses to be customized, which thus exhibit the desired predetermined maximum absorbance.

[0185] Regarding step d) and as in Figure 3a to Figure 3c As can be seen in the Figures 1 and 2, the inventors have determined that, according to the present invention, there is indeed a proportional relationship between the K / S ratio of each individually printed primary color C, M, Y and its inking level, as demonstrated by the following:

[0186] - Figure 3a is for M at 520 nm, showing that the first experimental correlation is approximately of the type y=0.0054x-0.1275 (where R 2 =0.9981), where y represents the K / S ratio of M and x represents the inking level of M in dpi;

[0187] - Figure 3b is for Y at 410 nm, showing that the first experimental correlation is approximately of the type y=0.0046x-0.0012 (where R 2 =0.9893), where y represents the K / S ratio of Y and x represents the inking level of Y in dpi;

[0188] - Figure 3c is for C at 650 nm, showing that the first experimental correlation is approximately of the type y=0.0047x-0.1046 (where R 2 =0.9935), where y represents the K / S ratio of Y and x represents the inking level of C in dpi.

[0189] As in Figures 4a to 4c As can be seen in, the inventors have also established that There is a proportional relationship between the maximum absorbance of the lens and the K / S ratio obtained for each individually printed primary color C, M, Y, as demonstrated by:

[0190] - Figure 4aFor M, the second experimental correlation is shown to be approximately of the type y = 0.4009x + 0.0491 (where R 2 =0.9922), where y represents the maximum absorbance of M and x represents the K / S ratio measured for M at 520 nm;

[0191] - Figure 4b For Y, the second experimental correlation is shown to be approximately y = 0.7925x + 0.0472 (where R 2 =0.9868), where y represents the maximum absorbance of Y and x represents the K / S ratio measured for Y at 410 nm;

[0192] - Figure 4c For C, the second experimental correlation is shown to be approximately of the type y = 0.3558x-0.0621 (where R 2 =0.9903), where y represents the K / S ratio of C and x represents the inking level of C at 650 nm.

[0193] The inventors have therefore established that the colour of a lens (determined by its maximum absorbance) is directly related to the inking level of the or each primary colour C, M, Y on the printed paper, which inking level can be controlled by the K / S ratio to predict the maximum absorbance of the lens with the aid of a compensation coefficient applied to the current inking level of each primary colour C, M, Y.

[0194] Specifically, the compensation coefficient is calculated for each of C, M, Y based on the reference value of the K / S ratio and the measured value of the K / S ratio, and then due to the simple cubic rule, the compensated inking level is obtained for each primary color C, M, Y. The reference value of the K / S value is selected based on the first day of starting to print with C, M, Y paper.

[0195] Tables 1 and 2 below detail exemplary implementations of the method of the invention according to this first preferred embodiment according to a first series of experiments.

[0196] Table 1:

[0197]

[0198] According to the compensation coefficients calculated for each of the initially printed C, M, Y, the reflectivity R of C, M, Y is measured again by the cubic rule according to the compensated inking level CIL derived from each compensation coefficient CC (for 50% initial current inking level, CIL=CC×2000dpi), and then converted into a new K / S ratio and therefore into a new compensation coefficient as explained above, until the predicted maximum absorbance produced by the newly measured K / S ratio matches the predetermined maximum absorbance to be obtained for the custom lens by matching (i.e., being equal to) the reference K / S ratio.

[0199] Table 2:

[0200]

[0201] Once the newly calculated compensation coefficient is equal to (or almost equal to, according to a given tolerance) 1.00, which means that the newly measured K / S ratio matches the reference K / S ratio and therefore matches the predetermined maximum absorbance to be obtained for the lens, a printed paper comprising the or each primary colour C, M, Y is thermally transferred in step h) above by sublimation and then fixing the sublimated dye onto the lens blank, for example by imbibition, so that an ophthalmic lens exhibiting the desired maximum absorbance is finally obtained, due to the proper fixing of the primary colours into the (several μm thick) surface sublayer of the lens blank.

[0202] like Figures 9a to 9c As can be seen in the graph of , the variation of the K / S ratio of the printing paper for the primary colors M, Y, C over several days is shown, including the minimum and maximum tolerances of the K / S ratios, and the need to adjust (i.e., control) the inking level of the printer "ROLANDBN20" on a daily basis in order to maintain a substantially constant inking level for each primary color over several days, and thus maintain a reproducible primary color of the obtained ophthalmic lens. Specifically, once a significant decrease in the inking level of a primary color is detected, the printer is adjusted so that it prints this primary color according to a correspondingly increased inking level.

[0203] 1.2. Other examples of the first series of experiments (see Figures 5a to 8c ):

[0204] 1.2.1.According to Figure 5a to Figure 5c In another embodiment of the invention, in which the optical parameter of the M, Y, C inks on the printing paper for the first and second experimental correlations is selected as optical density, the method being implemented by carrying out the same successive steps a) to h) as presented in §1.1 above, except that steps c) to g) are implemented by using the relationship established by the inventors between the optical density of each individually printed primary color M, Y, C and its corresponding inking level on the printing paper, and between The ratio between the maximum absorbance of the lens and the optical density obtained for each printed primary color M, Y, C is calculated.

[0205] Specifically, as obtained after printing paper with M, Y, C through a "ROLAND BN20" printer Figure 5a to Figure 5c As can be seen in the figure, the inventors have established that the first experimental correlation is approximately a linear correlation of the type y=ax+b, where respectively Figure 5a , Figure 5b , Figure 5c In , y represents the optical density of M, Y, C, and x represents the coefficient of the 2000 dpi inking level of M, Y, C (in %).

[0206] 1.2.2.According to Figures 6a to 6c In another embodiment of the invention, wherein the optical parameter of the C, M, Y inks on the printing paper used for the first and second experimental correlations is selected as the colorimetric lightness L*, the method being implemented by carrying out the same successive steps a) to h) as presented in §1.1 above, except that steps c) to g) are implemented by using the relationship established by the inventors between the colorimetric lightness L* of each individually printed primary color C, M, Y and its corresponding inking level on the printing paper, and between The ratio between the maximum absorbance of the lens and the colorimetric brightness L* obtained for each printed primary color C, M, Y is calculated.

[0207] Specifically, as obtained after printing paper with C, M, Y by a "ROLAND BN20" printer Figures 6a to 6c As can be seen in the figure, the inventors have established that the first experimental correlation is approximately a linear correlation of the type y=ax+b, where respectively Figure 6a , Figure 6b , Figure 6c , y represents the colorimetric lightness L* of C, M, and Y, and x represents the coefficient (in %) of the 2000 dpi inking level of C, M and the coefficient of the 1200 dpi inking level of Y.

[0208] 1.2.3.According to Figures 7a to 7c In another embodiment of the invention, in which the optical parameter of the C, M, Y inks on the printing paper used for the first and second experimental correlations is selected as the colorimetric coefficient a*, the method being implemented by carrying out the same successive steps a) to h) as presented in §1.1 above, except that steps c) to g) are implemented by using the relationship established by the inventors between the colorimetric coefficient a* of each individually printed primary color C, M, Y and its corresponding inking level on the printing paper, and between The ratio between the maximum absorbance of the lens and the colorimetric coefficient a* obtained for each printed primary color C, M, Y is calculated.

[0209] Specifically, as obtained after printing paper with C, M, Y by a "ROLAND BN20" printer Figures 7a to 7c As can be seen in the figure, the inventors have established that the first experimental correlation is approximately a linear correlation of the type y=ax+b, where respectively Figure 7a , Figure 7b , Figure 7c y represents the colorimetric coefficient a* of C, M, Y, and x represents the coefficient of the 2000 dpi inking level of C, M, Y (in %).

[0210] 1.2.4.According to Figures 8a to 8c In another embodiment of the invention, in which the optical parameter of the C, M, Y inks on the printing paper used for the first and second experimental correlations is selected as the colorimetric coefficient b*, the method being implemented by carrying out the same successive steps a) to h) as presented in §1.1 above, except that steps c) to g) are implemented by using the relationship established by the inventors between the colorimetric coefficient b* of each individually printed primary color C, M, Y and its corresponding inking level on the printing paper, and between The ratio between the maximum absorbance of the lens and the colorimetric coefficient b* obtained for each printed primary color C, M, Y is calculated.

[0211] Specifically, as obtained after printing paper with C, M, Y by a "ROLAND BN20" printer Figures 8a to 8c As can be seen in the figure, the inventors have established that the first experimental correlation is approximately a linear correlation of the type y=ax+b, where respectively Figure 8a , Figure 8b , Figure 8c y represents the colorimetric coefficient b* of C, M, Y, and x represents the coefficient (in %) of the 2000 dpi inking level of C, M, Y.

[0212] In general, it should be noted that any kind of commercially available sublimable C, M, Y inks useful in the ophthalmic field can be used in the present invention.

[0213] 2. A second series of experiments for obtaining custom ophthalmic lenses by sublimation and imbibition (see Figures 10 to 15 ),this These custom ophthalmic lenses have a predetermined transmittance in both the visible light domain (M and C primaries) and the invisible light domain (UV absorber) and / or maximum absorbance:

[0214] Seven formulations 1-7, each including magenta (M) and cyan (C) (without yellow Y primary) at a given inking level and a commercially available UV absorber that can be used in the ophthalmic field, were printed separately by the same "ROLAND BN20" printer, as detailed in Table 3.

[0215] Table 3:

[0216] formula M primary color Y primary color UV absorbers C primary color 1 25 0 2250 58 2 25 0 2300 58 3 25 0 2350 58 4 25 0 2400 58 5 25 0 2450 58 6 25 0 2500 58 7 25 0 2550 58

[0217] 2.1. First preferred embodiment (see Figures 10 to 12 and Fig.15 ):

[0218] According to a first embodiment of this second series of experiments, in which said optical parameter of the UV invisible ink on the printed support for said first and second experimental correlations is chosen to be the K / S ratio, the method is implemented by carrying out the following successive steps:

[0219] a) Printing the paper by means of a "ROLAND BN20" printer according to the predetermined inking level of UV for the individually printed recipe;

[0220] b) The reflectance parameter R (varies with wavelength, see Fig.10 Graph of );

[0221] c) For each individually printed recipe, by using the relationship between R and K / S (K / S = (1-R)2 / 2R) by selecting Fig.10 The wavelength of 410 nm in the image is used to convert the measured reflectivity parameter R into a value of the K / S ratio, thereby calculating each K / S ratio;

[0222] d) for each individually printed formulation, comparing this measured value of the K / S ratio obtained in c) with a reference value of K / S from data of reference lenses made from the same paper by the same sublimation and dye fixation steps and having a similar minimum transmittance or maximum absorbance, these data being available from a software storage medium coupled to the printer and resulting from said first and second experimental correlations (as described below with reference to each, respectively). Figures 11 to 13 ), and determining the difference between the measured value and the reference value;

[0223] e) For each individually printed recipe, if the difference determined in d) is not zero, a compensation factor "CC" is calculated, which is equal to the ratio of the reference value of K / S to the measured value K / S [i.e., CC = (K / S) 参考 / (K / S) 测量 ], then obtain the compensated inking level "CIL" from the calculated compensation coefficient [e.g., CIL=CC×2250 dpi, for the current inking level of 2250 dpi for Formulation 1] by the cubic rule;

[0224] f) reprinting the paper according to the compensated inking level for each individual recipe obtained in e);

[0225] g) optionally sequentially repeating steps b) to f), wherein the or each individual formulation has at least one new compensated inking level, until the new measured value of the K / S ratio for each individual formulation is equal to the reference value of the K / S ratio; and

[0226] h) Thermally transferring by sublimation the dye of each formulation printed at the current or newly compensated inking level onto the ophthalmic lenses to be customized, which thus exhibit the desired predetermined maximum absorbance or minimum transmittance.

[0227] With regard to step d), the inventors have established that, according to the invention, there is indeed a proportional relationship between the K / S ratio of each individually printed formulation and the inking level of the UV absorber in the printed formulation, such as Fig.11 The first experimental correlation is approximately of the type y = 0.0011x-0.2574 (where R 2 =0.9359), where y represents the K / S ratio of M and x represents the inking level of the UV absorber in the range of 2250 dpi to 2550 dpi.

[0228] The inventors have also established that for each individually printed formulation (ie for each inking level of UV absorber) the There is a proportional relationship between the lens transmittance of the lens and the K / S ratio obtained at 410nm, such as Fig.12 As demonstrated, the figure shows that the second experimental correlation is approximately y = -30.348x + 117.08 (where R 2 =0.8993) type, where y represents the transmittance and x represents the K / S ratio.

[0229] It should be noted that Fig.11 and Fig.12 Middle, black bar ( Fig.11 Middle vertical bar, Fig.12 The middle horizontal bars) represent the minimum and maximum values ​​obtained for the K / S ratio in five measurements made on the printed paper.

[0230] Further, the inventors have established that There is a proportional relationship between the maximum absorbance of the lens and the inking level of the UV absorber that defines the printing recipe, such as Fig.13 As demonstrated, the figure shows that the second experimental correlation is approximately of the type y=0.0005x-0.6213 (where R 2 =0.9797), where y represents the maximum absorbance and x represents the inking level of the UV absorber;

[0231] In other words, the inventors have established that the absorption / transmission capacity of a lens is directly related to the inking level of the UV absorber on the printed paper, which inking level is controlled by the K / S ratio to predict the maximum absorbance or minimum transmittance of the lens with the help of a compensation factor applied to the current inking level of the or each formulation.

[0232] Specifically, the compensation coefficient is calculated based on the reference value of the K / S ratio of the UV absorber and the measured value of the K / S ratio, and then the compensated inking level for the UV absorber is obtained due to the simple cubic rule. The reference value of the K / S value is selected based on the first day of starting to print paper with the formula.

[0233] Tables 4 and 5 below detail exemplary implementations of the method of the invention according to this first preferred embodiment according to a second series of experiments.

[0234] Table 4:

[0235]

[0236] Based on the compensation coefficients calculated for the UV absorber as initially printed in each formulation, the reflectance R is measured again by the cubic rule based on the compensated inking level CIL derived from each compensation coefficient CC and then converted into a new K / S ratio and therefore into new compensation coefficients as explained above until the predicted maximum absorbance or minimum transmittance resulting from the newly measured K / S ratio matches the predetermined maximum absorbance or minimum transmittance to be obtained for the custom lens by matching (i.e., being equal to) the reference K / S ratio.

[0237] Table 5:

[0238]

[0239]

[0240] Once the newly calculated compensation coefficient is equal to (or almost equal to, according to a given tolerance) 1.00, which means that the newly measured K / S ratio matches the reference K / S ratio and therefore matches the predetermined maximum absorbance or minimum transmittance to be obtained for the customized lens, the printing paper comprising the UV absorber is thermally transferred in step h) above by sublimation and then by a fixing step (such as wicking onto the lens blank), so that an ophthalmic lens exhibiting the desired maximum absorbance or minimum transmittance is finally obtained, due to the UV absorber being appropriately fixed into the (several μm thick) surface sublayer of the lens blank.

[0241] like Fig.16As can be seen in the graph of , which shows the variation of the K / S ratio of the printed paper at 410 nm for a UV absorber over several days (at 60% of the maximum inking level, including the minimum and maximum tolerances of the K / S ratio), it is also necessary to adjust the inking level of the printer "ROLAND BN20" every day in order to maintain a substantially constant inking level of the UV absorber over several days, and therefore to maintain a reproducible absorbance or transmittance of the ophthalmic lenses obtained. In particular, as soon as a significant decrease in the inking level of the UV absorber is detected, the printer is adjusted so that it prints the UV absorber according to a correspondingly increased inking level.

[0242] In general, it should be noted that any type of commercially available sublimable UV absorber useful in the ophthalmic field may be used in the present invention.

[0243] 2.2. Other examples of the second series of experiments (see Figure 14 to Figure 15 ):

[0244] 2.2.1.According to Fig.14 A comparative example, in which the optical parameter of the UV absorber on the printing paper used for the first and second experimental correlations was chosen to be its optical density, the method of the present invention gave quite satisfactory results at low and medium inking levels of the UV absorber (between about 2250 dpi and 2450 dpi), wherein a proportional relationship between the optical density and the inking level of the UV absorber was observed, but this was not the case at higher inking levels of the UV absorber (above about 2450 dpi), in which case it was approximately a cubic function and therefore not a linear function.

[0245] 2.2.2.According to Fig.15 In other comparative examples, in which the optical parameter of the UV absorber on the printing paper used for the first and second experimental correlations was chosen to be the paper reflectivity, the method of the present invention also gave quite satisfactory results at low and medium inking levels of the UV absorber (between about 2250 dpi and 2400 dpi), in which a proportional relationship between the paper reflectivity and the inking level of the UV absorber was observed, but this was not the case at higher inking levels of the UV absorber (above about 2400 dpi), in which case it was approximated by another cubic function and therefore not a linear function.

[0246] 3. Used to obtain the C, M and / or Y primaries by using the correction factors to make the new printer consistent with the reference printer. Experiments with tinted custom ophthalmic lenses (see Figure 17 to Figure 20c ):

[0247] 3.1. Experiment using the measured value of the reflectivity parameter R of the printed paper (see Fig.17 ):

[0248] The three primary colors M, Y, and C are printed by each of the reference printer and the new printer with the same printing parameters (eg, 2000 dpi).

[0249] Reflectance measurement is carried out for each of the obtained colors M, Y, C thus printed on paper by each printer.

[0250] Due to the conversion ratio K / S detailed above, equivalent values ​​of the calculated dpi are obtained for each color M, Y, C and for each printer (e.g. 1994 dpi for M printed by the reference printer compared to 2015 dpi for M printed by the new printer).

[0251] The dpi ratio of each color M, Y, C is then determined, which is equal to the dpi of each of M, Y, C calculated for the new printer / dpi calculated for the reference printer.

[0252] This ratio represents the correction to be made to the printing parameters of the new printer in order to bring the new printer into line with the reference printer (see Fig.17 In the screenshot of , the print dpi parameter is to be changed using the "ink darkness correction factor" represented by the ratio).

[0253] 3.2 Experiment using the measured values ​​of the visual transmittance Tv of the ophthalmic lenses obtained (see Figure 18 to Figure 20c ):

[0254] The three primary colors M, Y, and C are printed by each of the reference printer and the new printer with the same printing parameters (eg, 2000 dpi).

[0255] The sublimation and imbibition processes were performed on six identical ophthalmic lenses for three colors M, Y, C printed by two printers.

[0256] Then, the transmission spectrum obtained on each of these six lenses was measured by a spectrophotometer "Cary 60".

[0257] As in Fig.18 As can be seen in , for each color M, Y, C produced by each printer, the lens transmittance Tv measurement is converted into an absorptance A measurement (by using the well-known relationship A = 2 - log Tv), which allows for better definition / discrimination (i.e. fine differentiation) of each color, since they appear in the form of absorptance peaks that are satisfactorily distinct and centered at specific wavelengths for each color, while the transmittance spectrum of each color is less distinct (i.e., it has a broad scalloped shape, rather than a peak, see Fig.18 absorbance spectrum in ).

[0258] The absorbance ratio of each color M, Y, C was calculated, which was equal to the absorbance derived from the transmittance measured with the new printer / the absorbance derived from the transmittance measured with the reference printer.

[0259] As in Figures 19a to 19c and Figures 20a to 20cAs can be seen in FIG. 20 , the straight line obtained is tracked, which corresponds to the relationship between the absorbance of each color of M, Y, and C at its characteristic wavelength and dpi (i.e., color concentration). In particular, see FIG. 20 to FIG. Fig.20c Graph of corrected lens absorbance versus dpi for individual primers for M, Y and C.

[0260] If the two straight lines obtained for the two printers have different slopes, a slope ratio is calculated, which is equal to the slope obtained by the new printer / the slope obtained by the reference printer, which determines the correction factor applied to each color M, Y, C obtained by the new printer (for example, the new printer may deliver more ink than the reference printer). In the example, the slope ratio of the new printer / reference printer is about 0.85.

[0261] Table 6 below gives exemplary correction coefficients obtained for the slope ratio of the new printer / reference printer for the three colors M, Y, C.

[0262] Table 6:

[0263]

[0264] It may be noted that both methods disclosed in §3.1 and §3.2 above appear to be reliable and produce similar results (i.e. produce substantially the same correction coefficients), even though the method of §3.2 is preferred, which uses visual transmittance Tv measurements of ophthalmic lenses in order to take into account all possible unforeseen / negative effects arising from the entire process (from the initial printing step to the sublimation and imbibition steps).

[0265] 4. Experiment for monitoring the ink level of the printer (see Figures 21a to 21c ) (rather than refilling the ink Simple traditional visual monitoring):

[0266] The three primary colors M, Y, and C are printed by the printer using the same printing parameters (eg, 2000 dpi).

[0267] The reflectance parameter R of each printed color obtained on the paper, and other optical parameters are measured.

[0268] Due to the conversion ratio K / S detailed above, simulated values ​​(ie, calculated equivalent estimated values) of the dpi for each color M, Y, C are obtained (eg, 1994 dpi for M, 2215 dpi for Y, and 1800 dpi for C).

[0269] Specifically, Table 7 below shows some exemplary simulated dpi obtained from the analyzed paper measurements using the K / S conversion ratio, compared to 2000 dpi measured by the operator for M, Y, C on the printed paper (setting print parameters).

[0270] Table 7:

[0271]

[0272] The ratio of equivalent dpi / set printing parameters (2000 dpi in this example) is calculated for each color M, Y, C. Table 8 below shows exemplary correction factors finally obtained in this way.

[0273] Table 8:

[0274]

[0275]

[0276] If the correction factor represented by the ratio defined above is less than 0.9 or greater than 1.1 (i.e., has a difference greater than ±10%) for at least one of the three primary colors M, Y, and C, a second printing of the color in question is performed and the corresponding correction factor is determined. If the correction factor in question is still outside the range of the difference of ±10% after the second printing, it is determined that the ink cartridge is replaced with another ink cartridge.

[0277] It may be noted that such a monitoring method according to the invention may advantageously be automated and may create, for at least one of the primary colors M, Y, C, an ink level alert requiring replacement of the ink cartridge.

Claims

1. A method for obtaining a customized optical product from a printed support by thermal transfer via sublimation technology, the customized optical product comprising a main surface having at least one predetermined optical property chosen from absorbance and transmittance in the visible and / or invisible light domain, the printed support comprising a support and at least one ink printed on the support according to an inking level, the at least one ink comprising at least one sublimable dye chosen from visible dyes, invisible dyes and mixtures thereof, in, The method comprises controlling the inking level of the at least one ink by using an experimentally determined variation rule of the at least one predetermined optical property as a function of the inking level of the at least one ink to obtain the customized optical article.

2. The method of claim 1, wherein: The variation pattern of the at least one predetermined optical property as a function of the inking level of the at least one ink is determined experimentally using a combination of: - a first experimental correlation between an optical parameter of the at least one ink on the print support and its inking level, the optical parameter of the at least one ink being selected from the group consisting of its K / S ratio of absorbance coefficient to scattering coefficient, its optical density, its colorimetric coefficients such as its colorimetric lightness L* and colorimetric coefficients a* and b*, and combinations thereof, and - a second experimental correlation between at least one predicted optical property of said customized optical article and said optical parameter of said at least one ink, said at least one predicted optical property being selected from the maximum absorbance and minimum transmittance values ​​of said optical article and measured at at least one given wavelength in said visible and / or invisible light domain.

3. The method of claim 2, wherein: - said first experimental correlation is a linear correlation of the type y=ax+b, wherein y represents an optical parameter of said at least one ink on said printed support, x represents the inking level of said at least one ink, and a, b are constants representing said at least one ink, and - said second experimental correlation is a linear correlation of the type y=a'x+b', wherein y represents said at least one predicted optical property of said customized optical article, x represents an optical parameter of said at least one ink on said printed support, and a', b' are constants representing said at least one ink.

4. The method according to claim 2 or 3, wherein: The method comprises compensating the inking level of the at least one ink by means of the first experimental correlation and available data of reference optical products previously manufactured by thermal transfer from similar printing supports, the reference optical products each comprising a main surface having at least one known optical property in the visible and / or invisible light domain similar to the at least one predetermined optical property, the available data of the reference optical products being generated by the first and second experimental correlations, and Wherein, the method comprises: - calculating a compensation coefficient based on a reference value of an optical parameter of said at least one ink and a measured value of said optical parameter, said reference value of said optical parameter being derived from said available data of said reference optical article and corresponding to said at least one predicted optical property of said customized optical article, and then - obtaining a compensated inking level of the at least one ink from the calculated compensation coefficient.

5. The method of claim 4, wherein: The method comprises: a) printing the carrier, which is opaque to visible light and is made of paper, for example, by means of at least one printer according to the determined inking level of the at least one ink; b) measuring a reflectivity parameter R of the at least one ink on the printed support by reflectance spectrophotometry; c) converting the reflectance parameter R of the at least one ink into the measured value of the optical parameter of the at least one ink by using the relationship between the reflectance parameter R and the optical parameter; d) comparing the measured value of the optical parameter of the at least one ink obtained in c) with the reference value of the optical parameter of the at least one ink and determining the difference between the two values; e) if the difference determined in d) is not zero, calculating a compensation coefficient, which is equal to the ratio of a reference value of an optical parameter of the at least one ink to a measured value of the optical parameter, and then obtaining a compensated inking level of the at least one ink from the calculated compensation coefficient by the cubic rule; f) reprinting the support according to the compensated inking level of the at least one ink obtained in e); g) optionally sequentially repeating steps b) to f), using at least one new compensated inking level of said at least one ink, until a new measured value of an optical parameter of said at least one ink is equal to a reference value of said optical parameter; and h) thermally transferring by sublimation at least one dye of the at least one ink printed at the current or newly compensated inking level onto the optical article to be customized to obtain a major surface of the customized optical article having the at least one predicted optical property matching the at least one predetermined optical property.

6. The method of claim 5, wherein: The method further comprises printing the carrier a plurality of times sequentially to detect inking variations over time due to the at least one printer for a given formulation of the at least one ink, and adjusting the inking level of the at least one ink to compensate for the detected inking variations by, for example, increasing the inking level in response to a previously detected decrease in the inking level to provide at least one measured value of an optical parameter of the at least one ink and a consistent value of the resulting at least one predetermined optical property of the customized optical article.

7. The method according to claim 5 or 6, wherein: The method further includes: aligning the new printer with the reference printer by using a correction factor generated by: (i) measured values ​​of a reflectivity parameter R of said at least one ink printed on said support by said reference printer and by said new printer with identical printing parameters, the reflectivity parameter R measurement is converted into a measurement of an optical parameter of the at least one ink, such as the K / S ratio, to obtain a calculated equivalent inking level of the at least one ink and to determine an inking level ratio for the at least one ink, the inking level ratio being equal to the equivalent inking level calculated for the new printer / the equivalent inking level calculated for the reference printer, The inking level ratio represents the correction factor to be applied to the printing parameters of the new printer in order to make the new printer consistent with the reference printer; or is generated by: (ii) a measured value of the visual transmittance Tv of the custom optical article, said at least one ink is printed on said support by said reference printer and by said new printer with said same printing parameters, and said sublimation is performed to obtain said customized optical article of said at least one ink printed by both printers, converting the transmittance Tv measurements into absorbance A measurements and calculating the resulting ratio for the at least one ink, the absorbance ratio being equal to the absorbance derived from the transmittance measured with the new printer / the absorbance derived from the transmittance measured with the reference printer, A straight line corresponding to the relationship between the absorbance of the at least one ink at its characteristic wavelength and the inking level is obtained, and if the two straight lines obtained for the two printers respectively have different slopes, a slope ratio is calculated, the slope ratio being equal to the slope obtained by the new printer / the slope obtained by the reference printer, the slope ratio determining the correction coefficient to be applied to the at least one ink printed by the new printer.

8. The method according to any one of claims 5 to 7, wherein: The method further comprises: monitoring the inking level of the at least one ink printed on the support by the at least one printer according to set printing parameters defining the set inking level, the monitoring comprising a measured value of a reflectivity parameter R of the at least one ink, The reflectivity parameter R measurement is converted into a measurement of an optical parameter of the at least one ink, such as the K / S ratio, to obtain a calculated equivalent inking level of the at least one ink, calculating an inking level ratio defining a correction factor, the inking level ratio being equal to the equivalent inking level of the at least one ink / the set inking level, and if the correction factor is outside a predetermined range of the at least one ink, such as less than 0.9 or greater than 1.1, performing at least a second printing of the at least one ink in the same manner, and determining again the corresponding correction factor of the at least one ink, and If the correction factor of the at least one ink is still outside the range after the at least one second printing, replacing an ink cartridge of the at least one printer.

9. A method as claimed in any one of the preceding claims, wherein: Said at least one predetermined optical property in said visible and / or invisible light domain is a maximum absorbance value of said optical article measured at at least one given wavelength in said visible and / or invisible light domain.

10. A method as claimed in any one of the preceding claims, wherein: The at least one predetermined optical property is in the visible light domain, the at least one ink comprises at least one primary color consisting of cyan and / or magenta and / or yellow (CMY), the primary colors are printed separately on the carrier, and the inking level of each primary color is controlled separately.

11. A method as claimed in any one of the preceding claims, wherein: The at least one predetermined optical property is in the invisible light domain, and the at least one ink comprises an invisible single component dye selected from UV absorbers and IR absorbers for optical articles.

12. A method as claimed in any one of the preceding claims, wherein: The thermal transfer comprises: (i) drying the printing carrier, (ii) transferring the at least one dye in the at least one ink from the dried printing support to the surface of an optical article intended to form the customized optical article by sublimation by vacuum heating, and (iii) fixing the at least one dye into a surface sub-layer of the optical article, for example several micrometers thick, to form the major surface of the customized optical article.

13. A method as claimed in any one of the preceding claims, wherein: The at least one predetermined optical property of the customized optical article is produced solely by the inking level of the at least one ink, the method being free of a finishing step such as a dip coloring step.

14. A system for obtaining a customized optical product from a printed support by thermal transfer via sublimation technology, the customized optical product comprising a main surface having at least one predetermined optical property selected from absorbance and transmittance in the visible and / or invisible light domain, the printed support comprising a support and at least one ink printed on the support according to an inking level, the at least one ink comprising at least one sublimable dye selected from visible dyes, invisible dyes and mixtures thereof, in, The system includes at least one printer and a computer-readable medium equipped or coupled to the at least one printer, the computer-readable medium carrying one or more stored instruction sequences of a computer program that are accessible to a processor and that, when executed by the processor, cause the processor to control the inking level of the at least one ink to obtain the customized optical product by using an experimentally determined variation law of the at least one predetermined optical property as a function of the inking level of the at least one ink.

15. The system of claim 14, wherein: The system further comprises a reflectance spectrophotometer configured to measure a reflectance parameter R of the at least one ink on the printed support, and The one or more stored instruction sequences are configured to implement the variation rule of the at least one predetermined optical property as the inking level of the at least one ink varies, the variation rule being experimentally determined by combining the following: - a first experimental correlation between an optical parameter of said at least one ink on said print support and its inking level, said optical parameter being calculated from said reflectivity parameter R of said at least one ink and being selected from its K / S ratio of absorbance coefficient to scattering coefficient, its optical density, its colorimetric coefficients such as its colorimetric lightness L* and colorimetric coefficients a* and b*, and combinations thereof, and - a second experimental correlation between at least one predicted optical property of the customized optical article and the optical parameter of the at least one ink, the at least one predicted optical property being selected from the maximum absorbance and minimum transmittance values ​​of the optical article and measured at at least one given wavelength in the visible or invisible light domain.

16. The system of claim 15, wherein: - said first experimental correlation is a linear correlation of the type y=ax+b, wherein y represents an optical parameter of said at least one ink on said printed support, x represents the inking level of said at least one ink, and a, b are constants, and - said second experimental correlation is a linear correlation of the type y=a'x+b', wherein y represents said at least one predicted optical property of said customized optical article, x represents an optical parameter of said at least one ink on said printed support, and a', b' are constants.

17. The system of claim 15 or 16, wherein: The one or more stored instruction sequences are configured to: compensate the inking level of the at least one ink by means of the first experimental correlation and available data of a reference optical product previously manufactured by thermal transfer from a similar print support, the available optical products each comprising a major surface having at least one known optical property in the visible and / or invisible light domain similar to the at least one predetermined optical property, the available data of the reference optical product being generated by the first and second experimental correlations, and Wherein, the one or more stored instruction sequences are configured as: - calculating a compensation coefficient based on a reference value of an optical parameter of said at least one ink and a measured value of said optical parameter, said reference value of said optical parameter being derived from available data of said reference optical article and corresponding to said at least one predicted optical property of said customized optical article, and then - obtaining a compensated inking level of the at least one ink from the calculated compensation coefficient.

Images