Methods and systems for inkjetting on optical substrates

Abstract

A method of producing a continuous optical layer or coating on a curved optical substrate, the method comprising: (a) inkjetting drops of a colorant-containing ink formulation, by means of an inkjet nozzle, onto a target surface of a curved optical surface of the optical substrate, to form a wet continuous ink layer; and (b) treating the wet continuous ink layer to produce a dried continuous ink layer on said optical surface; wherein, over the entire course of said inkjetting, said inkjetting of said drops is performed while the inkjet nozzle and the optical substrate are disposed in fixed relative position with respect to the jetting direction.

Description

[0001] METHODS AND SYSTEMS FOR INKJETTING ON OPTICAL SUBSTRATES This application draws priority from GB Patent Application No. 2501808.6, filed February 6, 2025; which application is incorporated by reference for all purposes as if fully set forth herein.

[0002] FIELD AND BACKGROUND OF THE INVENTION

[0003] The present invention relates to methods and systems for inkjetting on optical and ophthalmic substrates, such as a lens.

[0004] In various known processes, optical impediments may be appreciably exacerbated when the target surface is a curved optical surface such as an eyeglass lens, particularly, for eyeglass lenses having high SAG numbers.

[0005] The present inventors have recognized a need for improved methods and systems for digitally depositing continuous layers on optical and ophthalmic substrates, particularly at high throughputs and at high resolution.

[0006] SUMMARY OF THE INVENTION

[0007] According to some teachings of the present invention there is provided a method of producing a continuous optical layer or coating on a curved optical substrate, the method comprising: (a) inkjetting drops of a colorant-containing ink formulation, by means of an inkjet nozzle, onto a target surface of a curved, typically polymeric optical surface of the optical substrate, to form a wet continuous ink layer; and (b) treating the wet continuous ink layer to produce a dried continuous ink layer on said optical surface; wherein, over the entire course of said inkjetting, said inkjetting of said drops is performed while said inkjet nozzle and the optical substrate are disposed in fixed relative position with respect to the jetting direction; wherein:

[0008] GDmin is defined as the smallest gap distance between the inkjet nozzle and the curved optical surface during the inkjetting; GDmax is defined as the largest gap distance between the inkjet nozzle and the curved optical surface during the inkjetting; and AGDmax is the maximum gap differential defined by the subtraction of GDmin from GDmax, wherein AGDmax is within a range of 2.8mm to 12mm; wherein an average diameter of the inkjetted drops (Ddrop) is within a range of 18 to 60 micrometers (pm); and wherein a ratio of a mean volume of the inkjetted ink formulation per unit of area of the target surface in an edge portion thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surface and a perimeter thereof, is between 0.58 and 0.95 times a maximum ratio of a volume the inkjetted ink formulation per unit of area of the target surface.

[0009] Other aspects and embodiments of the present invention are provided hereinbelow.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. Throughout the drawings, like-referenced characters are used to designate like elements.

[0011] In the drawings:

[0012] Figure 1 shows a schematic cross-sectional side view of a contour-following inkjetting on a curved surface of an optical substrate in accordance with a virtual two-dimension projection of the surface;

[0013] Figure 2 shows a schematic cross-sectional side view of a fixed-position, at-a-distance inkjetting on a curved surface of an optical substrate in accordance with a virtual two-dimension projection of the surface, according to the present invention;

[0014] Figures 3A and 3B show respective schematic views of exemplary optical substrates according to embodiments of the present invention;

[0015] Figure 4 is a schematic cross-sectional view of a multi-layered ophthalmic structure, which includes an ophthalmic substrate having a colorant-containing, ophthalmic construction fixedly attached to a broad surface of the substrate;

[0016] Figure 5 shows a conceptual representation of a process for coating and finishing an optical or ophthalmic substrate using a coating system, according to embodiments of the present invention;

[0017] Figure 6A, 6B and 6C show respective block diagrams of exemplary coating systems according to embodiments of the present invention;

[0018] Figure 7A and 7B show respective conceptual representations of a process for coating an optical or ophthalmic substrate using a coating system in conjunction with a surface treatment apparatus, according to embodiments of the present invention;

[0019] Figure 8 shows a block diagram of an exemplary coating system according to embodiments of the present invention;

[0020] Figure 9 shows a block diagram of an exemplary surface treatment apparatus according to embodiments of the present invention;Figures 10A, 1OB, IOC and 11 show respective conceptual representations of processes for coating and drying an optical or ophthalmic substrate, according to embodiments of the present invention;

[0021] Figures 12A, 12B, 12C and 12D show respective schematic views of exemplary optical substrates according to embodiments of the present invention;

[0022] Figures 13 A and 13B show respective side and perspective schematic views of a virtual two-dimensional projection of a curved surface of an optical substrate according to embodiments of the present invention;

[0023] Figure 14 shows a schematic side view of drop deposition on a curved surface of an optical substrate in accordance with a virtual two-dimension projection of the surface, according to embodiments of the present invention;

[0024] Figure 15 shows a schematic top view of an optical substrate including a virtual annulus comprising an edge portion according to embodiments of the present invention;

[0025] Figure 16 shows a schematic side view of an optical substrate having a curved surface, showing certain aspects of the surface geometry according to embodiments of the present invention; and

[0026] Figures 17A-17D are images of various lens blanks coated with a colorant-containing ink formulation.

[0027] DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The principles and operation of the optical constructions according to the present invention may be better understood with reference to the drawings and the accompanying description.

[0029] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0030] The inventors have found that applying one or more optical coatings to an optical substrate involves a variety of technological hurdles. Some of these relate to optical substrates, which tend to be highly smooth, and substantially non-absorbent. Optical substrates are generally transparent, and may require a high degree of transparency from the plurality of optical coatings. Moreover, the refractive index of each coating, or of all the coatings together, may be constrained to be similar to that of the optical substrate.The optical construction or article produced must satisfy mechanical criteria such as hardness and / or scratch resistance. Each of the coatings must also be relatively inert to the other coatings in contact therewith. Moreover, since the coatings may be applied successively, at least one of the applied wet, or uncured, formulations may contact, and interact with, a previously applied coating.

[0031] The curing time of each coating or layer should be reasonable (at most minutes or hours), and the curing temperature should be sufficiently low so as not to damage the optical substrate, nor to damage any previously applied coatings.

[0032] The adhesion to the optical or ophthalmic substrate and resistance to peeling or cracking of the coating or coatings may also be crucial to obtaining a viable coated lens such as a coated ophthalmic lens. The inventors have found that such adhesion problems may markedly worsen when the hardcoat formulation contains one or more tint dyes. Without wishing to be limited by theory, the inventors believe that the presence of the tint dye at the interface of layers within an optical stack, or at the interface between the bottommost layer and the optical substrate, may appreciably compromise the bonding or attachment at such interfaces. Moreover, the inventors believe that tint dyes may exhibit an affinity for the interfacial zones, such that the concentration of a tint dye at the interface may be significant higher than the average concentration of the tint dye in the ink solids.

[0033] While inkjetting on optical substrates has been disclosed, the inventors have found that inkjetting onto highly curved optical substrates to produce continuous films poses significant challenges. These challenges become yet more appreciable for systems geared towards commercial production, as well as for systems in which the drops are inkjetted while the inkjet nozzle and the optical substrate move relative to one another in the horizontal (X-Y) plane.

[0034] It will be appreciated that for highly curved lens surfaces (e.g., base curve 4, base curve 6 or higher), the problem of uncontrolled flow becomes even more severe, particularly for large lens diameters.

[0035] Moreover, the inventors have further found that in the production of ultra-thin (e.g., having a dry thickness of at most 2pm) optical coatings, the potential for optical impediments in the finished product may be yet further pronounced. With reference now to Figures 1 and 2, Figures 1 and 2 show a lens 100 having a base curve of 8 (spherical), concave curvature on a front curved surface 104 thereof, which is oriented as the top face of lens 100. Lens 100 has a diameter D of 70mm. The SAG of front surface 104 is an extremely important parameter with respect to inkjet printing, as will be developed hereinbelow.

[0036] The SAG represents the maximum height differential between the vertex of front surface 104 and an imaginary line Lp drawn perpendicular to the vertex, and connecting the oppositeedges of lens 100.

[0037] Indeed, as used herein in the specification and in the claims section that follows, the term “SAGITTA”, or “SAG”, with reference refers to the convex or concave curvature of an optical substrate, represents the physical distance between the vertex (the highest point of the convex or concave curvature) along the curved surface of the optical substrate and the center point of a line drawn perpendicular to the curved surface from one edge of the optical substrate to the other. For spherical lenses, by way of example, the SAG may be measured, or determined according to the following established equation:

[0038]

[0039] wherein R is the radius of curvature of the optical surface and D is the diameter thereof. The term SAG number is used herein as the absolute value of the SAG (SAG number = |SAG|) so as to properly represent the challenges of concave surfaces, e.g., the inwardly-facing broad surface of a lens.

[0040] The radius of curvature of the optical surface and the base curve are related by the following equation:

[0041] R • base curve = 530,

[0042] where R is expressed in mm. Thus, the SAG of front surface 104 is readily calculated to be 10.0mm. Both Figures 1 and 2 show a multiple-nozzle inkjet printhead 110 jetting ink drops 7 onto a curved target surface of 106 of front curved surface 104. In Figure 1, the gap distance (GD) between the nozzle and the target surface, measured along the jetting direction shown as the z-axis (which is typically vertical or substantially vertical) or, is maintained constant as inkjet printhead 110 moves orthogonally to the z-axis in the x-y plane with respect to the lens-bearing stage holding lens 100). Maintaining a small, constant gap distance may advantageously provide near-deterministic jetting onto the target surface. Typically, this gap distance is about 0.5 to 1.0mm or less.

[0043] However, in order to maintain this small, constant gap distance when jetting onto a highly curved surface, a mechanism is required for making a relative movement between the nozzle and the substrate along the z axis (e.g., having a fixed z-position inkjet printhead coupled with a lens-bearing stage adapted to move along the z-axis, or having a lens-bearing stage in a fixed z-position coupled with an inkjet printhead adapted to move along the z-axis). Such a system is relatively complicated in terms of mechanical equipment, and may require appreciablymore sophisticated control. Moreover, the requirement for z-direction movement may significantly slow down the process, which in addition to compromising throughput, may deleteriously affect the optical quality (including homogeneity) of the jetted ink layer.

[0044] With specific reference to Figure 2 now, the inkjetting of the ink drops by inkjet printhead 110 is performed while the inkjet head (and nozzles) and the optical substrate are disposed in fixed relative position with respect to the z axis. However, this results in a gap distance that changes as a function of the x-y position above the target surface. For the convex surface shown in Figure 2, the minimum gap distance (GDmin) is the gap distance at middle of front curved surface 104. The maximum gap distance (GDmax) is the gap distance at the perimeter of front curved surface 104. The maximum gap differential (AGDmax) is obtained by subtracting GDmin from GDmax. Thus, when the printing target surface extends all the way to the edge of curved surface 104, the maximum gap differential equals the SAG number, in this case, 10.0mm.

[0045] This amounts to a significant hurdle. It is known that in inkjetting, various physical phenomena occurring during the droplet flying process may appreciably limit both the printing speed and the printing distance. For example, due to the effect of air resistance, droplet velocity decelerates continuously. The position where the droplet velocity reaches a zero value is the theoretical maximum printing distance, which is often termed the “throwing distance”. For this and other reasons, the throwing distance of various inkjet heads that are fundamentally suitable for optical-quality printing on optical surfaces is typically low, making such inkjet heads fundamentally unsuitable for curved optical surfaces such as curved surface 104.

[0046] While some inkjet systems have throw distances of about 10mm or more, many are fundamentally unsuitable for producing optical coatings, and in particular, continuous optical coatings, on optical surfaces. One issue is that the impact velocity at a GDmin of 0.5mm is radically different from a gap distance of 5mm or 10mm at another position (GDi) on the target surface.

[0047] This problem may be severely compounded by relative x-y movement of the printhead and the lens stage during the inkjetting. Significantly, the inventors have found that over the course of this relative x-y movement, the curved shape on the lead side of the lens substrate makes moving contact with the surrounding air (e.g., within the printing chamber) imparting an upward vector to the surrounding air and disadvantageously introducing a non-deterministic side flow into the path of the jetted drops.

[0048] This and more: even if a printing pattern could be deterministically printed onto the curved optical surface, the inventors have found that there are other hurdles to overcome. Thecurved optical surface is non-absorbent and typically smooth. Particularly in the case of continuous layers, the jetted drops, after impacting the curved surface, may flow uncontrollably towards the low areas (for concave geometries, towards the center) of the surface. For a convex optical surface, the ink may flow from the center of the lens towards the lens perimeter.

[0049] Thus, by way of example, a colorant-containing ink formulation, upon jetting onto a curved convex optical surface, may flow towards the lens perimeter, producing a relatively lightly-tinted (or “bald spot”) centroid region with respect to the annulus surrounding the inner region. In other cases, a ring that is heavily tinted may form near the lens perimeter. In yet other cases, the lens may have both a centroid bald spot as well as a heavily-tinted ring adjacent to the lens perimeter.

[0050] The inventors have discovered that these deleterious phenomena may be substantially mitigated by controlling the printing pattern on the target surface. The inventors have also discovered that these deleterious phenomena may be substantially mitigated by controlling the drop size of the jetted drops to be within a narrow range.

[0051] Methods and systems for achieving controlled flow are provided hereinbelow.

[0052] The inventive method includes inkjetting drops of an ink formulation, by means of an inkjet nozzle, onto a target surface of a curved (most typically polymeric) optical surface (e.g., on a lens such as an eyeglass lens or lens blank) of the optical substrate, to form a wet continuous ink layer. Typically, this inkjet nozzle forms a part of an inkjet head having multiple nozzles, e.g., typically having several hundred nozzles per printhead.

[0053] The inkjetting is performed with the printhead and the optical substrate being held at a large distance, in a fixed (typically stage-to-nozzle) vertical (z axis) position. This will be developed hereinbelow.

[0054] From a throughput standpoint, it would be advantageous to apply very large ink drops on such curved optical surfaces. The inventors have found, however, that large ink drops — even with precise digital application — disadvantageously detract from image resolution. Moreover, jetted ink drops tend to slip on curved optical surfaces such as curved, smooth eyeglass lens surfaces, such that uncontrolled flow of the ink drops may ensue. This problem is particularly acute in the case of low-viscosity ink drops. Such uncontrolled flow may make the ultimate positioning of the drops decidedly non-deterministic, and may ultimately result in the formation of a non-continuous or at least non-even wet layer. Typical optical impediments include uneven thickness, uneven optical density, bald spots, and rings in the wet layer and / or in the finished product.

[0055] It would be highly desirable to produce ophthalmic-quality, thin, continuous, smooth wet layers on curved lens surfaces, and without having to change the gap distance or rotate the stagewith respect to the nozzle. It would be yet further desirable for the operation of the nozzles to be agnostic or independent of surface geometry of the lens, or for all of the nozzles to have identical operating parameters.

[0056] For colored layers and coatings, it would be further desirable for the optical substrate to be free of these optical impediments, and for the optical density to be substantially even, at least as discernable by the naked eye.

[0057] In some embodiments, and most typically, the ink formulation is a colorant-containing ink formulation.

[0058] In some embodiments, the ink formulation contains contains at least one dye or tint. In some embodiments, the ink formulation contains contains at least one dye or tint, fully dissolved within the formulation.

[0059] In some embodiments, the ink formulation is devoid of photochromic pigment and tint pigment.

[0060] In some embodiments, the ink formulation may be inkjetted directly onto the surface of the lens / lens blank / optical substrate.

[0061] In some embodiments, this ink formulation may be inkjetted on top of a primer layer, e.g., the primer layer applied in the optional surface treatment.

[0062] The inkjetting of the ink formulation onto the optical / ophthalmic substrate may be performed according to a pre-determined pattern such as a pre-determined digital pattern.

[0063] As schematically provided in Figures 3 A and 3B, an inkjet device may be utilized to jet ink drops onto surfaces of different contours, including a convex lens surface (Figure 3A) and a concave lens surface (Figure 3B).

[0064] In some embodiments, the ink formulation contains at least one polymeric resin (e.g., as a film-former and binder), dissolved within the ink formulation.

[0065] In some embodiments, the ink formulation containing the dissolved polymeric resin is an organic or “solvent-based” ink formulation.

[0066] A “solvent-based” ink formulation is used herein as used in the art of ink formulations. Typically, a “solvent-based” ink formulation contains at most 2% water, by weight, and more typically, is devoid or substantially devoid of water.

[0067] Subsequently, the wet layer is treated to produce a dried continuous ink layer on the optical surface. A number of wet layers may be applied prior to drying as will be explained in greater detail below. The delicate nature of the drying treatment will also be explained below.

[0068] The treatment may include drying and / or curing to produce a dried and / or cured ink layer, and may be performed according to various drying and curing methods known to those ofskill in the art. The curing of the ink layer may advantageously be performed so as to achieve a “fully-cured” ink layer.

[0069] In some embodiments, the colorant-containing layer(s), after drying and full curing, has a thickness or an average thickness within the range of 0.25 to 8pm or 0.35 to 7pm, and more typically, within a range of 0.45 to 5pm, 0.8 to 6pm, 1.5 to 6pm, or 2.5 to 6pm.

[0070] In some embodiments, the dried colorant-containing layer has a thickness or average thickness of at least 0.6pm, at least 0.8pm, at least 1pm, at least 1.2pm, at least 1.5pm, at least 1.8pm, at least 2pm, at least 2.2pm, at least 2.5pm, at least 3pm, or at least 3.5pm.

[0071] In some embodiments, the thickness or average thickness is at most 10pm, at most 8pm, at most 7pm, at most 6pm, at most 5pm, at most 4.5pm, at most 4pm, or at most 3.6pm.

[0072] The dried continuous ink layer may be transparent or substantially transparent.

[0073] In some embodiments, the ink formulation contains at least one dissolved dye (e.g., a tint).

[0074] In some embodiments, the ink formulation is a solvent-based ink formulation (e.g., containing a dissolved colorant and a dissolved polymer (resin)).

[0075] In some embodiments, the dissolved dye is a photochromic dye.

[0076] In some embodiments, the photochromic ink formulation may comprise a resin, a photochromic dye, and a solvent system.

[0077] In some embodiments, the photochromic ink formulation may comprise a softening agent for softening the resin. Typically, the softening agent forms a single liquid phase with the solvent system, the resin, and the photochromic dye.

[0078] In some embodiments, the softening agent includes a liquid softening agent. Typically, the liquid softening agent is, includes, or consists essentially of a non-volatile liquid softening agent.

[0079] In some embodiments, the softening agent includes a solid softening agent such as a solid polymeric softening agent.

[0080] Before applying a wet ink layer to the optical surface of the optical substrate, the optical surface may be subjected to an optional pretreatment stage.

[0081] Pre-Treatment

[0082] The lens blank provided to the process may or may not have a protective hardcoat adhering thereto. Within the pretreatment stage, the lens blank / optical substrate may be subjected to surface preparation prior to the application of the wet ink layer. Such surface preparation may include washing in water or in an aqueous cleaning solution, optionally followed by drying.In embodiments, the surface preparation of the lens surface includes an etching treatment. In embodiments, the etching treatment includes laser etching.

[0083] In embodiments, the etching treatment includes chemical etching.

[0084] Before applying a colorant-containing ink formulation, the lens blank may be subjected to at least one surface treatment, e.g., an energy treatment to raise the surface energy of the optical surface.

[0085] In embodiments, this energy treatment includes a corona treatment.

[0086] In embodiments, this energy treatment includes a plasma treatment.

[0087] In embodiments, this energy treatment includes an electron beam treatment.

[0088] In embodiments, this energy treatment includes an electromagnetic (e.g., actinic) radiation treatment.

[0089] In embodiments, this energy treatment is an electrical discharge treatment.

[0090] In embodiments, the surface treatment or pre-treatment includes applying a liquid primer formulation to the exposed (lens) surface of the ophthalmic substrate to form a wet primer layer or coating. The primer may be particularly needed when the optical substrate surface is glass. The wet primer layer or coating is subsequently dried or otherwise cured, to obtain a dried primer layer or coating. Exemplary treatments include oven drying, microwave, and IR.

[0091] The drying / curing of the wet primer layer formulation may be performed by any conventional curing means for producing the cured primer layer. The curing of the wet primer layer may advantageously be performed so as to achieve a “fully-cured” primer layer.

[0092] The liquid primer formulation may be applied using various conventional technologies (each having any of various technological disadvantages), such as spin coating, slit coating, and dip coating.

[0093] In some embodiments, the primer is microvalved onto the exposed surface of the ophthalmic substrate.

[0094] In some embodiments, the primer pre-treatment is directed to facilitate wetting of the subsequently-applied ink layer with respect to the lens surface.

[0095] In some embodiments, the primer pre-treatment is directed to facilitate adherence of this layer with respect to the lens surface.

[0096] In some embodiments, the primer is a polymeric primer.

[0097] In some embodiments, the polymeric primer is in the form of a waterborne emulsion (e.g., an acrylic emulsion).

[0098] In some embodiments, the polymeric primer is in the form of an aqueous dispersion (e.g., a polyurethane dispersion).In some embodiments, the polymeric primer is, or includes, a UV-curable material such as UV curable oligomers, epoxy acrylates, polyester acrylates, and urethane acrylates.

[0099] In some embodiments, the polymeric primer is in the form of a solution (e.g., a polyurethane resin solution).

[0100] In some of these embodiments, the thickness and / or average thickness of the wet primer layer is at least 0.5pm, at least 0.8pm, at least 1pm, at least 1.5pm, at least 2pm, at least 3pm, at least 5pm, or at least 7pm.

[0101] In some of these embodiments, the thickness and / or average thickness of the wet primer layer is at most 80pm, at most 60pm, at most 40pm, and more typically, at most 25pm, at most 20 pm, or at most 15pm.

[0102] In some embodiments, the method includes effecting such an energy treatment (e.g., corona, plasma, or actinic radiation) to the top / exposed surface of the cured or fully cured primer layer.

[0103] The liquid primer formulation may be applied using various conventional technologies, such as spin coating, slit coating, and dip coating.

[0104] In some embodiments, the primer is microvalved onto the exposed surface of the ophthalmic substrate.

[0105] In some embodiments, the primer pre-treatment is directed to facilitate wetting of the subsequently-applied colorant-containing ink with respect to the lens surface.

[0106] In some embodiments, the primer pre-treatment is directed to facilitate adherence of the colorant-containing ink with respect to the lens surface.

[0107] Subsequent Layering

[0108] The inventors have found that various hardcoat formulations deposited upon the colorant containing ink layer may dissolve or otherwise attack this ink layer. However, by applying an overcoat layer on top of this colorant containing ink layer and effecting drying / curing as necessary, such attack may be inhibited or appreciably mitigated.

[0109] These steps may be repeated as desired to produce additional overcoat layers.

[0110] In some embodiments, the first overcoat layer, as a wet layer, has a thickness or an average thickness within a range of 6 to 100pm, 6 to 80pm, 6 to 60pm, or 6 to 50pm.

[0111] In some of these embodiments, this layer has a thickness or an average thickness of at least 8pm, at least 12pm, at least 20pm, at least 30pm, or at least 40pm.

[0112] In some embodiments, the first overcoat layer, as a dry layer, has a thickness or an average thickness within a range of 3 to 15pm.In some of these embodiments, this dry thickness or average thickness is at least 4pm, at least 5.5pm, or at least 6.5pm.

[0113] In some of these embodiments, this dry thickness or average thickness is at most 13.5pm, at most 12pm, at most 11pm, at most 10pm, at most 8pm, or at most 7pm.

[0114] In some embodiments, the material of the dry or fully cured overcoat layer has a Kbnig hardness of at least 80 (seconds). More typically, this Kbnig hardness is within a range of 80 to 240, 80 to 210, 80 to 180, or 80 to 160.

[0115] In some embodiments, this Kbnig hardness is at least 90, at least 100, at least 110, at least 120, or at least 130.

[0116] In some embodiments, the first overcoat layer is or contains a thermoplastic polymer. In some embodiments, the first overcoat layer is or contains a thermoset polymer.

[0117] In some embodiments, the first overcoat formulation is a polymer emulsion.

[0118] In some embodiments, the first overcoat formulation is a polymer dispersion.

[0119] In some embodiments, the first overcoat formulation is a polymer solution.

[0120] In some embodiments, the first overcoat formulation includes an acrylic polymer.

[0121] In some embodiments, the first overcoat formulation includes a polyurethane.

[0122] In some embodiments, the first overcoat formulation includes a polyvinyl ester resin such as polyvinyl butyral and polyvinylpyrrolidone vinyl acetate copolymer .

[0123] In some embodiments, the first overcoat formulation includes epoxy resin.

[0124] In some embodiments, the material of fully cured overcoat layer includes, predominantly includes, or consists of any of the above polymers.

[0125] In some embodiments, the PVB-based overcoat formulation may be a PVB-containing aqueous dispersion, for example, as disclosed in EP3587106 (e.g., Example 1 A).

[0126] In some embodiments, the method further comprises, following the drying / curing of the overcoat layer, applying a second or additional overcoat layer on top of the dried first overcoat layer.

[0127] In some embodiments, the method further comprises drying / curing the second or additional overcoat layer.

[0128] In some embodiments, the dried second or additional overcoat layer may exhibit increased hardness with respect to the dried first overcoat layer.

[0129] In some embodiments, the dried second or additional overcoat layer may exhibit a lower coefficient of linear thermal expansion (CTE) with respect to the dried first overcoat layer.

[0130] In some embodiments, the method further comprises, following the curing of the sole or final overcoat layer, applying a liquid (film-forming) hardcoat (“1sthardcoat” or “inner hardcoat”) formulation onto the exposed optical or ophthalmic surface of the optical orophthalmic substrate, to form a wet hardcoat layer. The wet layer may then be treatedto produce a dried, typically transparent hardcoat layer on the optical surface.

[0131] In some embodiments, the method includes, before the applying of the hardcoat formulation, effecting an energy treatment (e.g., any of the energy treatments described hereinabove, mutatis mutandis) to the top / exposed surface of the cured or fully-cured ink layer or overcoat layer, respectively. This may appreciably improve the adhesion between the fully-cured underlayer and the hardcoat layer.

[0132] In some embodiments, the applying of the (1st) liquid hardcoat formulation is effected by microvalving drops of the formulation onto the exposed surface of the ophthalmic substrate.

[0133] In some embodiments, the method further comprises, following curing of the 1sthardcoat layer, applying a 2ndliquid (film-forming) hardcoat (“2ndhardcoat” or “outer hardcoat”) formulation onto the exposed optical or ophthalmic surface of the optical or ophthalmic substrate, to form a wet 2ndhardcoat layer. This optional step may be followed by treating the wet layer to produce a dried, typically transparent 2ndhardcoat layer on the optical surface.

[0134] In some embodiments, the applying of the (2nd) liquid hardcoat formulation is effected by microvalving drops of the formulation onto the exposed surface of the ophthalmic substrate.

[0135] In some embodiments, the hardcoat formulation base includes one or more acrylates, methacrylates, and the like.

[0136] In some embodiments, the ophthalmic hardcoat formulation is based upon Sol-gel monomers and oligomers.

[0137] Hardcoat coating compositions are well known to those skill in the art. By way of example, thermal curable coating technologies are disclosed in various patents, including the following U.S. Patents: 4,547,397, 5,385,955, and 6,538,092, and radiation curable coatings are disclosed in U.S. Patent Nos. 4,478,876 and 5,409,965.

[0138] In some embodiments, the hardcoat layer or coating, as a wet layer, has a thickness or an average thickness within a range of 1.5 to 40pm, 2.5 to 40pm, 4 to 40pm, 6 to 40pm, 4 to 25pm, 6 to 25pm, 4 to 15pm, or 6 to 15pm.

[0139] In some embodiments, solely a single layer of hardcoat is applied to the substrate.

[0140] Following the drying / curing of the hardcoat layer, the method may include applying a liquid (film-forming) post-hardcoat formulation onto an optical or ophthalmic surface of an optical or ophthalmic substrate, to form a wet layer. This may be followed by treating the wet layer to produce a dried (fully-cured) transparent post-hardcoat layer on the optical surface. These steps have been described hereinabove in a general fashion.

[0141] Such post hardcoat layers may include at least one of the following functionalities:

[0142] • anti-wetting layer• anti -reflective layer

[0143] • super hydrophobic / anti-fog layer

[0144] • super hydrophilic / anti-fog layer

[0145] • anti-glare layer

[0146] • blue light.

[0147] It will be appreciated by those of skill in the art that these post-hardcoat formulations may be applied by microvalving or inkjetting or by conventional coating processes such as spin coating and dip coating, or PVD or CVD for the extremely thin layers.

[0148] In embodiments, a inkjet coating system comprises an ink-formulation-application station including inkjet apparatus configured to inkjet droplets of the formulation onto a target surface of an optical substrate to form a wet layer of a colorant-containing ink formulation on the target surface; a drying and / or curing station configured to dry and / or cure, on the target surface, the wet layer of the ink formulation into a dry coating; and optionally but typically, an optical-substrate transfer apparatus configured to transfer the optical substrate and the wet layer on the target surface thereof from the ink-formulation-application station to the drying and / or curing station(s).

[0149] In some embodiments, the optical-substrate transfer apparatus includes at least one of a robotic arm, a gripper, a conveyer belt, and an elevator for raising or lowering an elevation of the optical substrate and the wet layer on the target surface thereof.

[0150] In some embodiments, the microvalve coating system further comprises a controller for regulating the optical-substrate-transfer apparatus such that the transfer of the optical substrate is contingent upon a detection that the wet layer has been formed on the target surface of the optical substrate at the ink-formulation-application station.

[0151] In some embodiments, the drying and / or curing station includes at least one of a heat lamp and an oven.

[0152] In some embodiments, the drying and / or curing station includes an oven which: (i) is open when the optical substrate with the wet layer on the target surface thereof is transferred into the housing of the optical substrate with the wet layer on the target surface; and (ii) is closed, subsequent to transfer of the optical substrate to the oven, and remains closed to the ambient environment during the drying and / curing.

[0153] In some embodiments, the system further comprises a primer application station for applying droplets of primer formulation onto the target surface of the optical substrate before the optical substrate is subsequently transferred to the ink formulation-application station.

[0154] In some embodiments, the inkjet coating system further comprises a surface treatment station for increasing the surface energy of the target surface of the optical substrate before microvalve-application thereon of the primer.In some embodiments, the inkjet coating system further comprises a cleaning station for subjecting the target surface of the optical substrate, before microvalve-application thereon of the primer, to a cleaning process.

[0155] In some embodiments, the surface treatment station includes at least one of corona-treatment-apparatus and plasma-treatment apparatus.

[0156] In some embodiments, the system is devoid of any dip coating apparatus.

[0157] In some embodiments, the system is devoid of any spin coating apparatus.

[0158] The term “ophthalmic substrate”, as used herein, refers to a substrate that is used by the human eye to view therethrough. The ophthalmic substrate is a component of an ophthalmic device or system, or an ophthalmic component of such a device or system. Typically, the ophthalmic substrate is a lens, and the ophthalmic surface is a surface of the lens. Yet more typically, the lens is an eyeglass lens or lens blank.

[0159] More generally, the term “ophthalmic”, as used herein to modify a structure, such as “substrate”, “surface”, “construction”, “structure”, “device”, “arrangement”, and “system”, refers to the property of that structure that enables the human eye to view an object therethrough. While a coated lens is a typical example of an ophthalmic device, other applications will be appreciated by those of skill in the art, including, by way of example, a helmet having a transparent visor.

[0160] An ophthalmic construction may consist of, or include, an ophthalmic component of such an ophthalmic device or system.

[0161] The method may further comprise treating the wet layer to produce a dried / cured transparent layer on the optical surface.

[0162] For hardcoat formulations, the drying / curing is a chemical curing, in that polymerization and / or cross-linking is effected.

[0163] In some embodiments, the chemical drying / curing is or includes curing by actinic radiation, i.e., by electromagnetic radiation (e.g., UV radiation, electron beam, IR, and microwave) that is capable of initiating a chemical reaction.

[0164] The drying / curing of the wet layer may advantageously be performed so as to achieve a “fully cured” layer or coating. The inventors have found that partially cured layers may result in solvent attack, migration, mixing, etc. from an adjacent or subsequently-applied layer in the stack. These phenomena may appreciably detract from optical quality.

[0165] As used herein in the specification and in the claims section that follows, the terms “fully curing” and “fully cured” (e.g., of a formulation or layer) refers to at least 85% curing of the polymeric material, as determined by a Kbnig hardness test according to ASTM D4366 StandardTest Methods for Hardness of Organic Coatings by Pendulum Damping Tests. Thus, for a reference polymer sheet that is 100% completely cured, having a Konig hardness of 80, the identical material that is “fully-cured” or has undergone “full curing” would have a Konig hardness within a range of 68 (0.85*80) to 80. Thus, the “fully cured” polymeric material has a minimum hardness coefficient (CH) of at least 0.85.

[0166] Typically, the optical surface is a curved optical surface, such as a lens surface.

[0167] Typically, the optical surface is a polymeric surface, such as a polymeric lens surface. In some embodiments, the ophthalmic substrate or lens may be coated or pre-coated with a hardcoat, and the microvalving of liquid film-forming drops may be performed on or directly on top of this “precoated” hardcoat (i.e., the hardcoat that comes with / is integral to the lens blank).

[0168] In some embodiments, a primer may first be applied to this precoated hardcoat, prior to the application of any additional layer, in order to enhance adhesion of the additional layer to the substrate.

[0169] The jetting of the liquid hardcoat formulation onto the optical / ophthalmic substrate may be performed by a digital microvalving technology, according to a pre-determined pattern such as a pre-determined digital pattern.

[0170] It will be appreciated by those of skill in the art that these post-hardcoat formulations may also be applied by inkjetting or by conventional coating processes such as spin coating and dip coating.

[0171] In some embodiments, the first overcoat layer is a thermoplastic polymer.

[0172] In some embodiments, the first overcoat layer is a thermoset polymer.

[0173] In some embodiments, the first overcoat formulation is a polymer emulsion.

[0174] In some embodiments, the first overcoat formulation is a polymer dispersion.

[0175] In some embodiments, the first overcoat formulation includes an acrylic polymer.

[0176] In some embodiments, the first overcoat formulation includes polyurethane.

[0177] Figure 4 is a schematic cross-sectional view of a multi-layered optical or ophthalmic device, component or structure 400, which includes an optical or ophthalmic substrate 402 having an optical or ophthalmic construction 403 fixedly attached to a broad surface 401 of the optical or ophthalmic substrate 402. Construction 403 further includes an optional primer layer 440 disposed between broad surface 401 and colorant layer 404. The thickness of primer layer 440 is designated as Tp. Above colorant layer 404 may be disposed an overcoat layer 406, substantially as described hereinabove. The thickness of overcoat layer 406 is designated asTov. Above overcoat layer 406 may be disposed one or more hardcoat layers 420. Above hardcoat layer(s) 420, whose thickness is designated as Th, one or more post-hardcoat layers 430 may be disposed. The entire thickness of optical construction 403 is designated as Toe.

[0178] Figure 5 schematically illustrates selected steps of a process for coating an optical or ophthalmic substrate (OS) 1100, for example a lens blank, using a coating system 1300.

[0179] Examples of OS 1100 (e.g. to apply thereon one or more coating using any teaching or combination of teachings disclosed herein) include but are not limited to: (i) eyeglass lenses; (ii) Single-Vision Lenses; (iii) Multifocal Lenses; (iv) Anti-fatigue lenses (e.g. including a singlevision prescription and a boost of magnification at the bottom of the lens); (v) Progressive lenses (e.g. designed to correct for multiple viewing distances — including far, intermediate and near — in one lens); (vi) Prism Lenses; (vii) Spherical lenses; (viii) Cylindrical lenses. Other examples of OS 1110 include lenses of a virtual-reality (VR) device including but not limited to VR glasses or VR goggles.

[0180] Element 1110 schematically represents a target surface of an optical substrate 1100 to be coated so as to produce at least one dried layer, e.g. multiple dried layers stacked directly or indirectly on each other. For example, an optical substrate (OS) 1110 may correspond to optical or ophthalmic device, component or structure 400 (e.g. an uncoated version or partially uncoated version thereof). For example, the target surface 1110 may correspond to surface 401, or to any other surface of any other layer of Figure 4.

[0181] For example, the target surface 1110 may correspond to the ‘outward-facing surface’, i.e. that which will face away from the wearer of the glasses of an eyeglass lens.

[0182] Target surface 1110, before being modified by coating system 1300, may be uncoated or may be pre-coated, e.g. before ‘delivery’. In contrast, coated substrate OS 1100’ has a coated version of target surface 1110 - i.e. after a coating is applied by coating system 1300.

[0183] In embodiments, an optical coating system 1300 may be employed to provide ‘customization’ of optical articles-of-manufacturing (e.g. eyeglasses). For example, optical coating system 1300 may be deployed in a factory or in a store-front, e.g., of an optometrist. For example, optical coating system 1300 may include, or may be in communication with, a digital computer (not shown), which stores and / or includes directives for producing a customized optical article-of-manufacturing.

[0184] In one non-limiting use-case, a customer having a certain optical prescription may require one or more of, e.g. any combination of: (i) specific tint or target color - i.e. to customize her / lens to a specific color; and / or (ii) a specific physical or characteristic such as, e.g. abrasion resistance; and / or (iii) a presence or absence of photochromatic features; and / or (iv) a desired glossiness; and / or (v) a desired presence or absence of varnish.The manufacturing of the lens geometries, e.g. to satisfy a certain optical prescription and / or shape, may optionally be carried out ‘off site’ in a different location from where the coating system 1300 is deployed.

[0185] Since the possible combinations of articles-of-manufacturing could be very large such as many types of lens geometries, multiple types of ‘color features’ for coating a lens, or target colors to coat the lens, target digital pixel-patterns of lenses, etc., it may not be practical to maintain an inventory of ‘every possibility.’

[0186] Instead, it may be desirable to maintain a supply 1120 of multiple types of ‘raw material’ substrates 1100 based on lens geometry. Thus, a specific workpiece such as OS 1100 may be selected from a plurality of candidates, which can optionally be stored in a digital computer, according to specified geometric properties such as geometric properties expressed as an optical prescription. An ‘input’ OS 1100 may be selected by rejecting some candidate in favor of a ‘preferred candidate’ OS 1100 whose geometric properties best match required lens-geometry and / or refractive index and / or multi-focal directive and / or astigmatism directive and / or optical prescription data.

[0187] The coated OS 1100', such as an eyeglass blank or an eyeglass lens can be cut and / or installed into eyeglass frames in a lens-cutting and / or glasses-frame installing apparatus 1200.

[0188] OS 1100, in some embodiments, is rigid - e.g. having an average thickness (alternatively or additionally, a thickness in at least one location of OS 1100) that is at least 0.5 mm or at least 1 mm or at least 2 mm or at least 3 mm).

[0189] As will be discussed below, a coating system 1300 in various embodiments apply one or more dried layers of optionally transparent material dried layer of material or multiple dried layers onto or over surface 1110 of OS 1100.

[0190] The combination of: (A) operating parameter(s) of coating system 1300 and / or (B) physical and / or chemical properties of materials (e.g. viscosity and / or fraction of solids and / or surface-energy, employed by any implementation or embodiment of coating system 1300 may be such that the layers, i.e. dried and / or transparent layers produced on or over surface 1110 of OS 1100, have one or more specific properties.

[0191] Such properties include, but are not limited to, (i) thickness of a particular dried transparent layer or ratios between different transparent layer ratios (ii) area over which the transparent layer or a convex subportion thereof is continuous over the entirety of the area of convex subportion thereof; (iii) color and / or optical density of any dried layer; (iv) mechanical properties of any dried layer or combination of layer(s). Thus, system 1300 may be configured to manufacture on surface 1110 of OS 1100 to obtain any property or combination of properties of wet or dried layers disclosed herein.As will be discussed below, operating parameters of coating system 1300 or any one or more of its components, including components controllable, e.g., by controller 1250 (not shown in Figure 5) can include, without limitation: (i) parameters for microvalving or inkjetting drops (or, equivalently as used herein: droplets) such as, for example, drop velocity, drop-deposition frequency, drop size and / or volume, spacing between droplets, or any other operating parameter for depositing drop or droplets, drop or droplet ejection-speed, and gap-distance between a nozzle of a microvalve or inkjet device and target surface 1110; (ii) drying time or drying temperature or drying intensity or power or any other parameter related to drying of a wet layer such as, for example, oven temperature, parameters of convective and / or radiative drying such as, for example, UV intensity; (iii) relative motion between any nozzle for delivering drops or droplets and target surface 1110; (iv) properties related to treating surface 1110 of OS 1100, e.g. to obtain a desired surface-energy or an energy in a certain range; (v) selection of a formulation, or a container, cartridge or reservoir of the formulation, from a plurality of candidates and / or mixing of a formulation; and ventilation operating parameters.

[0192] In different embodiments, the term ‘apparatus’ may refer to a specific station (e.g. drying station and / or wet layer-application station for any wet layer). Thus, any reference to ‘apparatus’ may also be taken as (i.e. in embodiments of the invention) a ‘station’.

[0193] In various embodiments, the components of optical coating system 1300 are configured and / or arranged to perform any method described herein.

[0194] The resulting coated OS 1100' may include any dry layer or combination of layers or feature(s) thereof or combination(s) thereof taught with reference to Figure 4 (not all layers are required) - the layers produced and properties thereof (e.g. within the framework of Figure 4) are according to the specific elements (and their operating parameter(s) and formulation(s)) of a specific implementation of coating system 1300 - we note various versions of system 1300 are described herein.

[0195] Various examples and / or embodiments of coating systems 1300 and / or processes related to coating systems are schematically presented in Figures 6A-6C, 7A-7B, 8, 9, 10A-10C, and 11 as block diagrams and / or flow-diagrams illustrating various systems and methods according to various embodiments of the disclosure.

[0196] Figure 6A shows a block diagram of an exemplary coating system 1300A. The coating system 1300A can include any one or more (or all) of (i) a hardcoating-formulation application apparatus 1350 for applying a coating or layer of a hardcoating formulation e.g. by microvalving, (ii) hardcoat-drying and / curing apparatus 1370 for drying and / or curing a wet layer of a hardcoat formulation, (iii) selection and / or transfer apparatus 1330, and a (IV) controller 1250. The wetlayer can be ‘thin’, characterized by having a thickness of at most 100 or 90 or 75 or 50 or 25 or 20 or 15 or 10 microns.

[0197] Figure 6B shows a block diagram of another exemplary coating system 1300B. The coating system 1300B can include any one or more (or all) of (i) a inkjet-based coating apparatus 1900 for coating a surface of an optical substrate 1100, configured, for example, to coat on the surface 1110 of optical substrate 1100 by inkjetting liquid drops to form one or more thin layers of a formulation. Such a thin layer can be characterized by having a thickness, by way of example, of at most 50 or 35 or 25 or 15 or 10 or 5 microns, (ii) drying and / or curing apparatus 1910, (iii) selection and / or transfer apparatus 1330, and (iv) a controller 1250. In an example, one or more wet layers applied by inkjet-based coating apparatus 1900 are subjected to a drying and / or curing process by drying and / or curing apparatus 1910. Examples of the ‘formulations’ which can be applied by inkjet-based coating apparatus 1900 are: (i) hardcoat formulations which may be inkjetted to produce a wet layer of the hard-coating formulation, (ii) inkformulations, e.g., for tinting or photochromic and / or electrochromic ink to produce a wet layer of the ink formulation; (iii) surface-energy-increasing formulations which may be inkjetted to produce a layer of the surface-energy-increasing formulation so as to increase the surface energy of the target surface 1110 of the optical substrate 1100.

[0198] The skilled artisan will appreciate that inkjet-based coating apparatus 1900 may deliver only one such layer or may deliver a plurality of such layers such that layers are stacked on each other. For example, a first applied layer (i.e., a complete continuous layer) may be dried by the drying and / or curing apparatus 1910 before a second layer is applied directly or indirectly over the first layer.

[0199] In some embodiments, at least two and as many as four layers of ink such as colorantcontaining ink formulation(s) may be applied (layer-on-layer) prior to effecting drying in the drying station.

[0200] Significantly, the inventors have discovered that in the case of multiple inkjetted layers (particularly those produced from colorant-containing ink formulations), applying such layers without intermediate drying may result in uncontrolled flow during the printing and / or during drying. Such uncontrolled flow may disadvantageously promote non-homogeneous color density and various optical impediments. Figure 17A shows an image of such a coated lens blank, in which the inner area 1710 is markedly lighter than peripheral area 1720.

[0201] The inventors have found that intermediate curing of the wet inkjetted layer, or even drying of the wet inkjetted layer, may inhibit this uncontrolled flow. However, the inventors have further discovered that this apparent solution may actually be deleterious, producing other optical impediments. For example, after printing a new wet, continuous ink layer on top of thecured or dried continuous ink layer, and subsequent drying / curing, the coated lens tends to exhibit optical defects. Figure 17B shows an image of such a coated lens blank, in which the white arrows point to such defects. The long white arrow points to a line produced due to a missing nozzle. It must be emphasized that this artifact is unrelated to the printing method.

[0202] In any event, it is evident that both of the above-described methods: (a) applying multiple wet layers without intermediate drying; and (b) effecting intermediate drying / curing in between these layers, tend to yield defect-ridden lens coatings. However, the inventors have discovered that by effecting solely partial drying in between the application of the layers (in a manner to be described in greater detail hereinbelow), the various optical defects may be appreciably mitigated or even inhibited. Without wishing to be limited by theory, the inventors that the partial drying of the wet layer(s) is sufficient to mitigate uncontrolled flow, while the residual solvent in the partially-dried layer enables additional leveling processes to transpire and in addition, enables the next-applied wet layer in the stack to intimately contact and, to a minor extent, integrate with the layer underneath such that, after additional drying, the two layers appear to be, and behave as, a single optical layer.

[0203] Figure 17C shows an image of such a coated lens blank, in which the entire coated lens blank is substantially free of optical impediments. In particular, inner area 1730 and peripheral area 1740 exhibit the same optical density.

[0204] With reference now to Figure 6C, the exemplary coating system 1300C of Figure 6C is a specific example of coating system 1300B of Figure 6B where multiple layers are stacked on each other on upper target surface 1110 of optical substrate 1100. At least one of such layers may be produced by microvalving drops - e.g. by microvalve based coating apparatus 1920.

[0205] Reference is now made to Figure 7A. In the example of Figure 7A, an optical substrate 1100 is first treated by surface-energy-increasing apparatus 1310 to increase the surface energy of the target surface 1110 before coated by the coating system 1300A or any other coating system 1300 disclosed herein to apply one or more layers, e.g., with a hardcoating formulation.

[0206] Figure 7B is another example of a coating system where optical substrate 1100 is first treated by surface-energy-increasing apparatus, and subsequently coated by hardcoating-formulation application apparatus 1350 to apply a wet layer and / or coating of a hardcoating formulation. This wet layer and / or coating of a hardcoating formulation is subsequently dried and / or cured by hardcoat-drying and / or curing apparatus 1370, to yield coated optical substrate 1100'. The system of Figure 7B may also including (i) selection and / or transfer apparatus 1330 and / or (ii) a controller 1250.

[0207] According to embodiments, a coating system 1300 may include any one or more of the following components:One or more controllers 1250: for simplicity, only a single controller 1250 is shown in the various drawings. A controller 1250 can regulate operating parameters of any other element of a coating system 1300, including, but not exhaustively: microvalving apparatus, drying apparatus, inkjet apparatus, transfer apparatus, or any other apparatus or combination if present. The controller 1250 may be part of and / or be located in the coating system 1300 or in any of the components, and / or may be located separately and / or remotely. Controller 1250 may include any electrical and / or electronic components required to perform its function of controlling any component or combination of components.

[0208] In some embodiments of the invention, any coating system 1300 disclosed herein may include data-acquisition and / or monitoring apparatus 1430 such as, for example, imaging and / or inspection components. A controller 1250 may directly or indirectly receive data from such data-acquisition and / or monitoring apparatus 1430.

[0209] Hardcoating-formulation application apparatus 1350 microvalves drops of hardcoat formulation onto the target surface 1110 of an OS 1100 in order to produce on the surface 1110 a wet layer of hard coat formulation from the microvalved droplets of hardcoat formulation. The hardcoating apparatus 1350 can be in communication with and / or loaded with a hardcoating formulation. In any of the embodiments of the coating system, a formulation, including without limitation a hardcoating formulation, can be disposed within a cartridge or any other container or reservoir.

[0210] The hardcoating formulation employed by the hardcoating apparatus 1350 may be in accordance with any hardcoat formulation teaching disclosed herein or any combinations of the teachings. As already disclosed hereinabove, the hardcoating formulation employed by a microvalve-based apparatus, e.g., microvalving apparatus 1900, can optionally also be an ink.

[0211] In various embodiments, hardcoating apparatus 1350 may be configured and / or regulated by the controller 1250 to produce a wet layer of hardcoat formulation having specific properties. For example, the wet layer can comprise a sub-lOOp wet layer of hardcoat formulation.

[0212] In various embodiments, apparatus 1350 is configured, e.g., by controller 1250 and / or by formulation properties to perform the applying of the ink formulations as well as the drying and curing steps.

[0213] Hardcoat-drying and / or curing apparatus 1370 can be provided and configured for applying thermal energy to a wet layer of hardcoat formulation such as that produced by hardcoating apparatus 1350 and having a thickness or any other properties taught herein, to convert this wet layer in hardcoat formulation into a dried hardcoat layer having any property disclosed herein. In various embodiments, the hardcoating apparatus 1350 is configured, e.g., bythe controller 1250 and / or by formulation properties to perform the applying of the ink formulations as well as the drying and curing steps.

[0214] Selection and / or transfer apparatus 1330 for selecting and / or providing relative motion of OS 1110 relative to any apparatus and / or unit and / or station of 1300 or component thereof. This ‘relative motion’ may transport, e.g., by translation and / or rotational motion, the OS 1100 or portion thereof and / or any apparatus and / or component and / or station of the coating system 1300 relative to the OS 1100.

[0215] In different embodiments, selection and / or transfer apparatus 1330 may be controlled at least in part by the controller 1250, e.g. to achieve a directive stored in a digital computer, such as, for example a target property of hardcoating layer.

[0216] In various embodiments, selection and / or transfer apparatus 1330 may include one or more of: a robotic arm, a gripper, a conveyer belt, and an elevator for raising or lowering an elevation of the optical substrate and the wet layer on the target surface thereof.

[0217] Selection and / or transfer apparatus 1330 may be configured for such relative motion between components of coating system 1300 and / or for selecting an OS 1110 from a plurality of candidates according to a directive in computer storage and / or read by a digital computer such as, for example, an optical prescription.

[0218] Microvalve-based coating apparatus 1900 or 1920: any wet layer disclosed herein may be applied by microvalving apparatus 1900, which in embodiments can be controlled by the controllers 1250. The operating parameters of 1900 may depend on the specific layer to be formed or the formulation from which this layer is produced.

[0219] A coating system may include a single instance of inkjetting apparatus 1900 (or microvalving apparatus 1920) configured to operate in accordance with multiple sets of operating parameters depending on the wet layer to be dried / converted into a dry layer.

[0220] A ‘continuous’ dried layer is one that is continuous over an entirety of a virtual convex-region as schematically illustrated, for example, in Figure 12D, where region 1962, region 1966, and region 1968 are examples of convex regions while region 1964 is a counter-example. In examples, the area of a convex-region of target surface 1110 may be, in different embodiments, at least 0.5cm2or at least 1cm2or at least 2cm2or at least 4cm2or at least 8cm2or at least 10cm2or at least 20cm2.

[0221] The boundaries of the region are ‘virtual’ rather than physical. Thus, the term ‘convex region’ refers to the shape of these ‘virtual’ boundaries rather than to any geometric property of the physical topography of target surface 1110 of optical substrate 1100.Thus, as shown in Figures 12B and 12C, even when topographically surface 1100 is completely concave as in Figure 12C, it is possible to define thereupon, by defined / virtual boundaries, a convex-portion or convex-region within the topographically-concave surface 1100.

[0222] A thickness of a ‘thin’ dried layer is at most 20 microns or at most 15 microns or at most 10 microns or 5 microns or at most 3 microns or at most 1 micron.

[0223] Alternatively or additionally, multiple instances of 1900 or 1920 may be provided, each for drying a different wet layer of formulation and each operating according to different operating parameters.

[0224] Still referring to Figure 8, any coating system 1300 disclosed herein may include any of the following in any combination:

[0225] (i) Cleaning apparatus 1440 can be provided to treat the target surface 1110 of the optical substrate 1100, e.g., for surface-cleaning.

[0226] (ii) Additional drying and / or curing apparatus(es) 1420;

[0227] (iii) Ventilation apparatus 1450;

[0228] (iv) Housing 1442;

[0229] (v) Microvalve-based additional-layer Application Apparatus(es) 1490; and

[0230] (vi) Selection and / or transfer apparatus 1330 (e.g. for substrate and / or solvent and / or cartridge and / or other apparatus).

[0231] Figures 10A-10C and 11 schematically illustrate non-limiting examples of operating respective exemplary coating systems 1300 comprising one or more ovens for drying and / or curing a wet coating on an optical substrate 1100.

[0232] Figure 10A illustrates an exemplary operating process as follows:

[0233] (i) A first jetting (inkjet or microvalve) apparatus 1610 in communication with and / or loaded with surface-energy-increasing formulation is provided for increasing the surface energy of target surface 1110 of an optical substrate 1100 so that drops that are microvalved to the surface 1110 collectively form a wet coating of the surface-energy-increasing formulation on the target surface 1110;

[0234] (ii) A first oven 1630 is provided, to operate a drying process at a Tow’ temperature and / or short duration - i.e. for a drying process of relative Tow’ duration) in order, to dry the wet coating delivered by inkjet or microvalve apparatus 1610;

[0235] (iii) A second microvalve apparatus 1640 is provided for applying a second wet coating by microvalving drops of a second formulation - for example, a hardcoating - onto the target surface 1110 after the wet coating of the surface-energy-increasing formulation is dried by the first oven 1630; and

[0236] (iv) a second oven 1650 is provided for drying and / or curing the wet coating of the wetcoating of the second formulation.

[0237] The example of Figure 10B shows a setup comprising a single oven 1670 rather than multiple ovens. A first transfer of the optical substrate 1100 is made into the single oven 1670 for drying / curing the wet coating from the inkjet or microvalve apparatus 1. A first transfer is made out of the single oven 1670 after the first drying / curing process. A second transfer is made into the single oven 1670 to dry or cure the wet coating from second microvalve apparatus 1640.

[0238] The requisite movement of substrate 1100 may be performed at least in part by the optical-substrate transfer apparatus 1602 and at least some of the movements can be made automatically or robotically.

[0239] Figure 10C shows a third setup in which the coating (e.g. utilizing a colorant-containing ink formulation) is performed by an ink-jet apparatus 1690. The setup and process are otherwise the same as that shown in Figure 10A.

[0240] Figure 11 shows a fourth setup similar to that of Figure 7B with the addition of an inkjet apparatus 1646 and an ink-layer drying and / or curing apparatus(s) 1420.

[0241] With reference now to Figures 13A, 13B, 14, 15 and 16, Figure 13A shows a cross-sectional side view, and Figure 13B shows a top perspective view, of a virtual two-dimensional projection 1800 of a curved surface 1110 of an exemplary optical substrate 1100. In embodiments, a coating system, such as any one of the coating systems 1300 disclosed herein comprising a controller 1250, can be configured to microvalve drops with a constant density in terms of volume of formulation per unit of area of the two-dimensional projection 1800. The term ‘constant density’ as used herein can mean exactly constant, or alternatively can mean within ±10%, or within ±5%, or within ±2%, or within ±1% of a mean value of the ‘density’, i.e., the volume of formulation per unit of area of the two-dimensional projection, ratio for the entirety of two-dimensional projection. The constant density or, in the alternative, the density within one of the given ranges from the mean, can be measured in a small area of the two-dimensional projection such as, for example, any subdivision of the two-dimensional projection 1800 having an area of 5% or more of an area of the projection 1800.

[0242] The applied formulation can include any one or more of the inks and / or coating formulations disclosed herein. In some embodiments, the formulation is selected, inter alia, for physical characteristics that make the formulation suitable for being deposited on curved surfaces in the manner described here.

[0243] The term ‘configured’ in the foregoing should be understood as including ‘programmed’ and / or ‘programmable’, i.e., that the controller 1250 is so programmed or programmable to control the inkjet and microvalve apparatus accordingly.In some embodiments, the controller 1250 can be programmed or programmable to generate the two-dimensional projection 1800 and / or to calculate or select a target value and / or mean value of the ratio of the volume of formulation per unit of area of the two-dimensional projection 1800.

[0244] Application of drops 175 of the formulation by the inkjet or microvalve apparatus 1610 in a constant density vis-a-vis the two-dimensional projection is shown schematically in Figure 14, although for the sake of clarity it should be noted again that the two-dimensional projection is a virtual one. The drops 175 are actually applied to the curved surface 1100, albeit being applied in a density or, equivalently, frequency, determined by the area of the two-dimensional projection 1800. As one can understand from the schematically illustrated geometry, the surface area of the curved surface 1110 is larger than the two-dimensional projection. Furthermore, the divergence of the area of the curved surface 1110 from that of the two-dimensional projection 1800 is larger in peripheral sections of the optical substrate 1100 than in central areas for the single-vision convex lens surface shown in the non-limiting example of Figures 13A-14. As is known, the degree of divergence of the area of the curved surface 1110 from that of the two-dimensional projection 1800 can be determined by the curve geometry of the curved surface, e.g., from curve geometry parameters such as the sagitta 180 of the surface 1110, the radius in the case of a spherical curve, and so on.

[0245] In some embodiments, depositing the formulation in a manner or distribution suitable to the particular formulation and curve geometry can be accomplished without requiring the application process to take into account the curve geometry when selecting or calculating a density of the application. Moreover, in some embodiments, the application of the formulation can cover an area greater than the surface of the optical substrate without requiring the application process to take into account other geometric parameters, such as the diameter or shape of the optical substrate.

[0246] Figure 15 schematically shows an annular section 1150 at the periphery of an exemplary optical substrate 1100, which can be useful for characterizing the divergence of the area of the curved surface 1110 of the optical substrate 1100 from the corresponding area of the two-dimensional projection 1800, as well as for characterizing the reduced actual density on the actual curved surface 1110 as a function of distance from the center. In this non-limiting example, the annular section 1150 describes the area characterized by falling between 90% and 100% of the distance from a centroid of the optical substrate 1100 to the edge 1151. In an exemplary embodiment, the microvalving of the drops 175 of the formulation is controlled by the controller 1250 such that a ratio of a mean volume of formulation applied per unit of area of the curved surface 1110 in the outer annulus 1150 characterized by lying between 90% and100% of a distance from a centroid of the curved surface 1110 and the perimeter 1151, is typically between 0.6 and 0.97 or 0.6 and 0.96 or 0.6 and 0.94 times a maximum ratio of a volume of formulation applied per unit of area of the curved surface 1100.

[0247] Referring now to Figure 16, a virtual tangent line 1111 (or plane) is drawn at point (x,y) on the curved surface 1110 of the optical substrate 1110. The tangent line can be used to characterize the angle a of curved surface 1110, e.g., relative to the horizontal, and to describe the localized divergence of the area of the actual curved surface 1110 from the corresponding localized portion of the virtual two-dimensional projection 1800. In embodiments, the angle a can be between 5° and 50°, or between 10° and 40°, or between 5° and 20°, or between 20° and 50°, or within any intervening range between 5° and 50°. In embodiments, the microvalving of the drops 175 of the formulation is such that a ratio of a mean volume of formulation applied per unit of area of the curved surface 1110 at a given point on the surface 1110, is equal to a reduction factor times a maximum ratio of a volume of formulation applied per unit of area at any point on the surface 1100, said reduction factor being equal to a cosine of the acute angle a formed between (i) a plane or line 1111 that is tangent to the curved surface 1110 at said given point and (ii) a horizontal plane.

[0248] All mentions of a horizontal plane herein refer to a plane horizontal to a floor, and tangent planes or angles refer to planes or angles when the optical substrate is at rest on a horizontal surface.

[0249] As an example, an optical substrate 1100 such as a lens blank has a front surface characterized by a base curve of 6.00 diopter. The lens blank has a diameter of 60mm and a SAG number of 5.25mm. A virtual tangent line 1111 (or plane) drawn at a point on the edge of the curved surface 1110 forms an angle a of 19.9° relative to the horizontal plane. The divergence of the area of the curved surface 1110 from that of the two-dimensional projection 1800 is such that at the point on the perimeter 1151 of the curved surface 1110, the area of the curved surface 1110 is 6.3% larger than at the corresponding point on the two-dimensional projection 1800. The area of outer annulus 1150 characterized by lying between 90% and 100% of a distance from the centroid of the curved surface 1110 and the perimeter 1151 is proportionally 5.6% to 5.7% larger than the corresponding outer annulus on the two-dimensional projection 1800 than is an inner region characterized by lying between 0% and 10% of a distance from the centroid of the curved surface 1110 and the perimeter 1151 with respect to a corresponding inner region on the two-dimensional projection 1800.EXAMPLES

[0250] Reference is now made to the following examples, which together with the above description, illustrate the invention in a non-limiting fashion.

[0251] Materials

[0252] Photochromic Dyes:

[0253] • Reversacol Amazon Green (James Robinson Specialty Ingredients Ltd.): a photochromic dyestuff in powder form;

[0254] • Reversacol Midnight Gray (James Robinson Specialty Ingredients Ltd.): a photochromic dyestuff in powder form;

[0255] • Reversacol Leather Brown (James Robinson Specialty Ingredients Ltd.): a photochromic dyestuff in powder form;

[0256] • Reversacol Com Yellow (James Robinson Specialty Ingredients Ltd.): a photochromic dyestuff in powder form;

[0257] • Reversacol Ocean Blue (James Robinson Specialty Ingredients Ltd.): a photochromic dyestuff in powder form.

[0258] Thermoplastic Resins

[0259] o Pearlcoat™ DIPP 119 — Aromatic poly caprolactone copolyester-based thermoplastic polyurethane (TPU) (Lubrizol)

[0260] o Pearlbond™ 360 — Poly ether based thermoplastic polyurethane (TPU) (Lubrizol) o SETALUX® 2127 XX-60 — Thermoplastic acrylic resin having good adhesion to plastics (Allnex)

[0261] o Laropal A-81 — Thermoplastic aldehyde resin (BASF).

[0262] Primers and Overcoats

[0263] • Acrylic polymer emulsions:

[0264] o Joncryl®1532 - waterborne acrylic emulsion offering excellent adhesion to a wide variety of substrates including plastics (BASF); Primer

[0265] o Joncryl®1534 - waterborne acrylic emulsion offering excellent adhesion to a wide variety of substrates including plastics (BASF); Primer

[0266] o Joncryl®2110 - waterborne acrylic emulsion primer, styrene acrylate copolymer (BASF); Primer

[0267] o Joncryl®9530-A — waterborne acrylic emulsion self-crosslinking polymer designed for use in topcoats and primers; Overcoat

[0268] o Joncryl®617-A - waterborne acrylic polymer emulsion film forming overprintvarnish formulations (BASF); Overcoat

[0269] o SETALUX® 17-7202 — acetoacetate functional acrylic resin combined with a ketimine resin (SETALUX® 10-1440) for primer; Overcoat

[0270] o SETALUX®17-1246 — a fast-dry thermoplastic acrylic resin solution providing an excellent balance of hardness, adhesion and film toughness together with clarity and transparency; Overcoat

[0271] • PU polymer emulsions:

[0272] o ALBERDINGK® APU 10600 self-crosslinking acrylic, PES / PC-polyurethane hybrid dispersion (Alberdingk Boley); Overcoat

[0273] o Bondthane™ UD-620 — self-crosslinking polyurethane is ideally suited for hard, clear or pigmented coatings for rigid plastics (BPI); Overcoat

[0274] o CrystalCoat® PR 670 — water-based emulsion (SDC); Primer

[0275] o Hi-Gard HP 1500 — thermal cured coating for hard coatings (PPG); Primer

[0276] • Resin Solvent Based Solutions:

[0277] o Versamid®PUR 1010 — Primer

[0278] o Laroflex®HS-9000 — Primer.

[0279] Solvents: low evaporation rate / low vapor pressure

[0280] • TPM (Tripropylene glycol methyl ether, CAS 25498-49-1)

[0281] • PPH (Ph-O-CH2-CHMe-OH, CAS 770-35-4)

[0282] • DBA (2-(2-Butoxyethoxy)ethyl acetate, CAS 124-17-4)

[0283] • TPnB (Tripropylene glycol n-butyl ether, CAS 55934-93-5)

[0284] • DPnP (Pr-O-[CH2-CHMe-O]2-H, CAS 29911-27-1)

[0285] • Augeo® (HO-CH2-Me2 Acetal, CAS 100-79-8)

[0286] • DPnP (Pr-O-[CH2-CHMe-O]2-H, CAS 29911-27-1)

[0287] • Butyl Carbitol (CAS 112-34-5)

[0288] Equipment

[0289] • Coating Equipment

[0290] o Ink-Jet Printer: Xaar Nitrox GS6 Elite printhead; 1 to 7 droplets per drop; each droplet approximately 6 pL

[0291] o Microvalve: electromagnetically actuated (Fritz Gyger AG); nozzle diameter — 0.1mm, pressure 0.5-2.0 bar

[0292] o Spin coater: MUTECH pCoater (Mutech Microsystems SAS)

[0293] o UV LED Curing System: FJ100 Gen 2, 395nm, 12W / cm2(Phoseon Technology)o Thermal Curing System: Venticell ECO Forced air oven (MMM) o Surface Activation: Corona Treatment Device Electrical Surface Treatment HF SpotTEC Single (Tantec).

[0294] • Testing Equipment

[0295] o Spectrophotometer: Cary 4000 UV-Vis. double-beam spectrophotometer, ISO / EN 8980-3:2013 (Agilent)

[0296] o Light Transmittance and Haze Measuring Meter: TH-100, ASTM D1003 / D1044 (Hangzhou CHN Spec Technology Co., Ltd.)

[0297] o Thickness measurements: ThetaMetrisis layer thickness analyzer.

[0298] EXAMPLE 1: Corona Surface Treatment Procedure

[0299] The head of the corona treatment device (Tantec) was set at 1cm from the surface of the ophthalmic lens and then was activated for 10 seconds. The process was performed twice before various coating materials were applied on the ophthalmic lens.

[0300] EXAMPLE 2: Procedure for Primer Application using Spin-Coating The ophthalmic lens was attached to the vacuum chuck of the spin coating apparatus. The spinning of the ophthalmic lens was performed at a spinning speed of 3000 rpm, an acceleration of 1000 rpm / sec, for 10 seconds.

[0301] EXAMPLE 3:

[0302] Procedure for Application of post-Hardcoat Layers using Spin-Coating The ophthalmic lens was attached to the vacuum chuck of the spin coating apparatus. The spinning of the ophthalmic device was performed at a spinning speed of 1500 rpm, an acceleration of 500 rpm / sec, for 10 seconds.

[0303] EXAMPLE 4: Optimization of Ink- Jetting Parameters

[0304] A Xaar Nitrox GS6 Elite printhead was utilized for the inkjetting operations.

[0305] The ink delivery system was typically pre-heated to 30°C. The drop characteristics were then optimized for each ink using a Jet Expert stroboscope (Image Expert) mounted on the printer (camera and light source synchronized with the jetting frequency). The waveform was optimized for each ink, jetted at a frequency of 0.5-7.0kHz. The resolution was 360 dots per inch (dpi).

[0306] EXAMPLE 5: Microvalving a Film-Forming Ink onto a Lens Substrate An optical construction having at least one of various functionalities (hardcoats, primer, overcoat, post-hardcoat coatings, etc.) was prepared by microvalving a film-forming ink onto a lens substrate. The microvalve was mounted on a controllable X-Y-Z stage, with a PLCsynchronizing between the actuation of the microvalve and the positioning of the lens. Both frequency and relative velocity between the stage and the microvalve were maintained at fixed values. The microvalving was performed according to any one of various pre-determined digital patterns.

[0307] EXAMPLE 6 A: Drying

[0308] Drying and curing of the primer, overcoat, and colorant ink layers was typically performed at 60°C for 30 minutes. Partial drying of the continuous, inkjetted layer(s) was tailored to the particular solvents in the ink, but was typically performed at 60°C for 2 to 5 minutes.

[0309] EXAMPLE 6B: Thermal Curing

[0310] Thermal curing of the hardcoat was typically performed at 120°C for 3 hours.

[0311] EXAMPLE 6C: UV Curing

[0312] UV curing was performed for 10 seconds using the UV LED Curing System: FJ100 Gen 2, 395nm, 12W / cm2(Phoseon Technology).

[0313] EXAMPLE 7

[0314] 39.54 grams of TPM solvent were heated to 80°C and mixed in a 150ml glass beaker equipped with a magnetic stirrer. 6.98 grams of BA20S polymer were gradually added to the heated solvent, while stirring. The beaker was covered with aluminum foil and mixed under heating for 8 hours. After 8 hours the mixture was clear and homogenous, the temperature was lowered to 70°C, and the following components were added during stirring: TPM solvent (4.8 grams); PMA solvent (44.34 grams); and dye mixture, composed of pre-mixed: solvent red 122 (0.35 grams), solvent yellow 82 (0.23 grams), and solvent black 27 (0.66 grams). After mixing the components for 1 hour, the ink was removed, cooled down to room temperature, and filtered with a syringe filter (0.45 micrometer).

[0315] EXAMPLE 8

[0316] 45.0 grams of TPM solvent were heated to 80°C and mixed in a 150ml glass beaker equipped with a magnetic stirrer. 5.0 grams of BA20S polymer were gradually added to the heated solvent, while stirring. After 8 hours of mixing as in Example 7, the temperature was lowered to 70°C, and the following components were added during stirring: TPM solvent (2.0 grams); PMA solvent (46.95 grams); and the dye mixture of Example 7 (1.05 grams). The processing was according to Example 7.

[0317] EXAMPLE 9

[0318] 45.0 grams of TPM solvent were heated to 80°C and mixed in a 150ml glass beaker equipped with a magnetic stirrer. 5.0 grams of BA20S polymer were gradually added to theheated solvent, while stirring. After 8 hours of mixing as in Example 7, the temperature was lowered to 70°C, and the following components were added during stirring: ethyl acetate solvent (24.5 grams); PMA solvent (24.5 grams); and the dye mixture of Example 7 (1.05 grams). The processing was according to Example 7.

[0319] EXAMPLE 10

[0320] 44.97 grams of TPM solvent were heated to 80°C and mixed in a 150ml glass beaker equipped with a magnetic stirrer. 5.0 grams of BA20S polymer were gradually added to the heated solvent, while stirring. After 8 hours of mixing as in Example 7, the temperature was lowered to 70°C, and the following components were added during stirring: ethyl acetate solvent (34.6 grams); PMA solvent (14.53 grams); and the dye mixture of Example 7 (0.9 grams). The processing was according to Example 7.

[0321] EXAMPLE 11

[0322] 45.0 grams of TPM solvent were heated to 80°C and mixed in a 150ml glass beaker equipped with a magnetic stirrer. 5.0 grams of BA20S polymer were gradually added to the heated solvent, while stirring. After 8 hours of mixing as in Example 7, the temperature was lowered to 70°C, and the following components were added during stirring: TPM solvent (8.10 grams); ethyl acetate solvent (40.85 grams); and the dye mixture of Example 7 (1.05 grams). The processing was according to Example 7.

[0323] EXAMPLE 12

[0324] 45.0 grams of TPM solvent were heated to 80°C and mixed in a 150ml glass beaker equipped with a magnetic stirrer. 5.0 grams of BA20S polymer were gradually added to the heated solvent, while stirring. After 8 hours of mixing as in Example 7, the temperature was lowered to 70°C, and the following components were added during stirring: TPM solvent (1.98 grams); ethyl acetate solvent (46.98 grams); and the dye mixture of Example 7 (1.05 grams). The processing was according to Example 7.

[0325] EXAMPLE 13

[0326] The procedure of Example 7 was performed, to produce the following composition: 45% TPM, 48% Texanol, 5% Mowital PVB16 H, 2% Magenta Dye.

[0327] EXAMPLE 14

[0328] The procedure of Example 7 was performed, to produce the following composition: 45% 2-m ethyl butanol, 48% 2-Ethylhexanol, 5% Mowital PVB16 H, 2% Magenta Dye.

[0329] EXAMPLE 15

[0330] The procedure of Example 7 was performed, to produce the following composition: 45% 2-m ethyl butanol, 47% DMM, 6% Mowital PVB16 H, 2% Magenta Dye.EXAMPLE 16

[0331] The procedure of Example 7 was performed, to produce the following composition: 45% 2-methyl butanol, 47% ethyl lactate, 6.5% Mowital PVB16 H, 1.5% Magenta Dye.

[0332] EXAMPLE 17

[0333] The procedure of Example 7 was performed, to produce the following composition: 45% 2-methyl butanol, 48% PMA, 5% Mowital PVB16 H, 2% Magenta Dye.

[0334] EXAMPLE 18

[0335] The procedure of Example 7 was performed, to produce the following composition: 48% PM, 45% Texanol, 5% Mowital PVB16 H, 2% Magenta Dye.

[0336] EXAMPLE 19

[0337] The procedure of Example 7 was performed, to produce the following composition: 48% TPM, 36% PM, 14% Joncryl 587, 2% Magenta Dye.

[0338] EXAMPLE 20

[0339] The procedure of Example 7 was performed, to produce the following composition: 50% Texanol, 36% PM, 12% Joncryl 587, 2% Magenta Dye.

[0340] EXAMPLE 21

[0341] The procedure of Example 7 was performed, to produce the following composition: 40% TPM, 48% PMA, 10% Joncryl 587, 2% Magenta Dye.

[0342] EXAMPLE 22

[0343] The procedure of Example 7 was performed, to produce the following composition: 64% Texanol, 24% PM, 10% Joncryl 587, 2% Magenta Dye.

[0344] EXAMPLE 23

[0345] 49 grams of TPM solvent were mixed with 46.8 grams of ethyl acetate solvent in a 200ml glass beaker equipped with a magnetic stirrer. After mixing the components for 5 minutes at room temperature, 0.2 grams of surfactant BYK®-358 were added to the solvent mixture while mixing. 2 grams of Reversacol Leather Brown dye were then added, along with 2 grams of Laropal A-81 as a binder, while mixing. Mixing was continued for another 20 minutes at 60°C to produce the photochromic ink, which was subsequently filtered with the syringe filter.

[0346] EXAMPLE 24

[0347] 67.4 grams of TPM solvent were mixed with 24.5 grams of methyl isobutyl ketone solvent in a 200ml glass beaker equipped with a magnetic stirrer. After mixing the components for 5 minutes at room temperature, 0.2 grams of surfactant BYK®-358 were added to the solvent mixture while mixing. 2 grams of Reversacol Midnight Gray dye and 2 grams of Reversacol Amazon Green dye were then added, along with 3.8 grams of Laropal A-81 as a binder, whilemixing. Mixing was continued for another 20 minutes at 60°C to produce the photochromic ink, which was subsequently filtered with the syringe filter.

[0348] EXAMPLE 25

[0349] 59.8 grams of TPM solvent were mixed with 35.6 grams of methyl propyl ketone solvent in a 200ml glass beaker equipped with a magnetic stirrer. After mixing the components for 5 minutes at room temperature, 0.2 grams of surfactant BYK®-358 were added to the solvent mixture while mixing, followed by 2 grams of Reversacol Midnight Gray dye, 1 gram of Emoltene™3GO plasticizer, and 1.4 grams of SETALUX® 2127 XX-60. Mixing was continued for another 20 minutes at 60°C to produce the photochromic ink, which was subsequently filtered with the syringe filter.

[0350] EXAMPLE 26

[0351] 42 grams of TPM solvent were mixed with 48.8 grams of PM A and 5 grams of ethyl acetate solvent in a 200ml glass beaker equipped with a magnetic stirrer. 1 gram of Pearlcoat DIPP 119 was added and mixing ensued for 2 hours at 60°C. 0.2 grams of surfactant BYK®-358 were added, while mixing, followed by 2 grams of Reversacol Amazon Green dye along with 2 grams of Pearlbond™ 360. Mixing was continued for another 20 minutes at 60°C to produce the photochromic ink, which was subsequently filtered with the syringe filter.

[0352] EXAMPLE 27

[0353] 39.5 grams of Augeo® (HO-CH2-Me2Acetal) solvent were mixed with 51.8 grams of isopropyl acetate solvent in a 200ml glass beaker equipped with a magnetic stirrer. After mixing the components for 5 minutes, 0.2 grams of surfactant BYK®-358 were added to the solvent mixture while mixing. 2 grams of Reversacol Midnight Gray dye, 2 grams of Reversacol Amazon Green dye, 3.5 grams of Pearlcoat DIPP 119 was added and mixing ensued for 2 hours at 60°C. and 1 gram of Emoltene™ 3GO plasticizer were then added while mixing. Mixing was continued for another 20 minutes at 60°C to produce the photochromic ink, which was subsequently filtered with the syringe filter.

[0354] EXAMPLE 28

[0355] 64.8 grams of TPM solvent were mixed with 31 grams of isobutyl acetate solvent in a 200ml glass beaker equipped with a magnetic stirrer. 2 grams of Laropal® A-81 dispersion were added and mixing ensued for 2 hours at 60°C. 0.2 grams of surfactant BYK®-358 were added to the mixture while mixing, followed by 2 grams of Reversacol Corn Yellow dye. Mixing was continued for another 20 minutes at 60°C to produce the photochromic ink, which was subsequently filtered with the syringe filter.EXAMPLE 29

[0356] 65 grams of Joncryl®1532 were mixed with 20 grams of water in a 200ml glass beaker equipped with a magnetic stirrer. Then 9.5 grams of EB solvent, 4.8 grams of DPM solvent and 0.2 grams of BYK®024 were added while mixing. After mixing the components for 5 minutes, 0.5 grams of surfactant BYK®-346 were added to the mixture and the mixing was continued for another 10 minutes at 30°C, to produce a primer formulation.

[0357] EXAMPLE 30

[0358] 70 grams of Joncryl®1534 were mixed with 15 grams of water in a 200ml glass beaker equipped with a magnetic stirrer. Then 9.5 grams of EB solvent, 4.8 grams of DPM solvent and 0.2grams of BYK®024 were added while mixing. After mixing the components for 5 minutes, 0.5 grams of surfactant EFKA®3200 were added to the mixture and the mixing was continued for another 10 minutes at 30°C, to produce a primer formulation.

[0359] EXAMPLE 31

[0360] The corona surface treatment procedure was performed on a Trivex® (PPG) lens made of urethane-based pre-polymer, according to Example 1.

[0361] EXAMPLE 32

[0362] The corona surface treatment procedure was performed on a polycarbonate lens according to Example 1.

[0363] EXAMPLE 33

[0364] The corona surface treatment procedure of Example 1 was performed on a polycarbonate lens that was pre-coated with a hardcoat.

[0365] EXAMPLE 34

[0366] Onto a polycarbonate lens was applied Versamid®PUR 1010 as a primer. Microvalving was effected according to Example 5, and a calculated (average) wet thickness of 1.55pm was obtained. The wet layer was then subjected to thermal drying and curing in a Venticell ECO forced air oven at 60°C for 10 minutes and then at 100°C for 10 minutes, to produce the primer layer.

[0367] EXAMPLE 35

[0368] Onto a polycarbonate lens was applied Laroflex®HS-9000 as a primer. Microvalving was effected according to Example 5, and a calculated wet thickness of 2.2pm was obtained. The wet layer was then subjected to thermal drying and curing in a Venticell ECO forced air oven at 60°C for 10 minutes and then at 100°C for 10 minutes, to produce a primer layer having a thickness of about 1.5pm.EXAMPLE 36

[0369] Onto various lenses was applied PROCAM™ HPR-160 as a primer. Microvalving was effected according to Example 5, and the wet layer was then subjected to thermal drying and curing in a Venticell ECO forced air oven to produce a primer layer having a thickness of about 2-3.5pm.

[0370] EXAMPLE 36A: Inkjetting onto a Lens Substrate

[0371] An optical construction having at least one of various functionalities (hardcoats, primer, overcoat, post-hardcoat coatings, etc.) was prepared by microvalving a film-forming ink onto a lens substrate. The microvalve was mounted on a controllable X-Y-Z stage, with a PLC synchronizing between the actuation of the microvalve and the positioning of the lens. Both frequency and relative velocity between the stage and the microvalve were maintained at fixed values. The microvalving was performed according to any one of various pre-determined digital patterns.

[0372] EXAMPLES 37-58: Inkjetting a Colorant-Containing Ink onto Curved Lens Surfaces The colorant-containing ink formulations of Examples 7-28 were inkjetted onto various lens substrates according to Example 4, using the Xaar Nitrox GS6 Elite printhead (2-7 droplets per drop, typically 4-7). All of the ink formulations had 25°C viscosities within the range of 6cP to lOOcP (corresponding to operating temperature viscosities of about 6cP to 95cP), and more typically, within the range of lOcP to 45cP. In practice, inks having a viscosity below lOcP tended to flow uncontrollably on the curved lens surface, particularly at higher curvatures (e.g., base numbers). The lens substrates of Examples 7-28 had base curves of 2, 4, 6, and 8, respectively. In one trial, a 70mm base curve of 12 was utilized. However, increased flow to the periphery of the lens was observed in the dried and cured coating, as shown in Figure 17D, in which the inner area 1750 is noticeably lighter than peripheral area 1760.

[0373] In some of Examples 37-58, the lens substrates were subjected to surface energy treatment (plasma or corona). In others, the lens substrates were primed with a primer formulation of Examples 34, 35, and 36. In yet others, the lens substrates were both subjected to the surface energy treatment and primed with the primer formulation. Partial drying of the continuous, inkjetted layer(s) was typically performed at 60°C for 2 to 5 minutes. Thermal curing was performed as detailed hereinabove. The general conditions are provided in Table 1 below:

[0374]

[0375] EXAMPLE 59: Measuring Elaze & % Transmitance

[0376] After calibrating the T-100 instrument, the Target lens was measured (uncoated reference lens). In Sample mode, the coated lens was then tested. The instrument then displayed the following results of the coated and uncoated lenses: % Transmittance, A % Transmittance, Haze,and A Haze. Lower delta values between the coated and uncoated lens indicate good optical clarity / transparency.

[0377] EXAMPLE 60: Measuring Tinting properties

[0378] Spectrophotometric studies were conducted using a Cary 4000 UV-Vis. double-beam spectrophotometer. The light source was a UV-LED lamp (395 nm). In the spectrophotometric studies, the coated samples were characterized against an uncoated reference slide or lens. Spectrum data were normally collected in the range 350-700nm at a resolution of Inm. Transmittance measurements were performed at the wavelength of maximal absorbance for each tinting dye.

[0379] As used herein in the specification and in the claims section that follows, volatile liquids are divided into 5 categories, as follows:

[0380] LLevap < 0.022 (e.g.: TPM, 2,2, 4-trimethyl-l,3-pentanediol monoisobutyrate, 2-ethylhexanol, ethylene glycol monobutyl ether, DPnB).

[0381] 0.022 Levap < 0.1 (e.g.:, DPM, EB, NMP, DMSO, Augeo, ethylene glycol monobutyl ether, DPM acetate).

[0382] 0.1 Mevap < 0.85 (e.g.: EEP, EP, PP, DMM, PMA, 2 methyl butanol, 1-pentanol, n-butyl proprionate, n-butanol, ethyl lactate, amyl acetate, PM, isobutanol, water).

[0383] 0.85 <: Hevap < 1.8 (e.g.: xylene, n-butyl acetate, isobutyl acetate, methyl isobutyl ketone, isopropanol, ethanol).

[0384] 1.8 HHevap (e.g.: toluene, methanol, n-propyl acetate, isopropyl acetate, ethyl acetate, methyl propyl ketone, methyl ethyl ketone).

[0385] The designated standard material, n-butyl acetate, is assigned a vaporization or evaporation rate of 1.0. Thus, the term “relative evaporation rate” and the like is used with reference to n-butyl acetate.

[0386] As used herein in the specification and in the claims section that follows, the term “percent”, or “%”, with regard to composition or the like, refers to percent by weight, unless specifically indicated otherwise.

[0387] As used herein in the specification and in the claims section that follows, the terms “antiglare”, “anti-reflectance”; “anti-fog”; “hardcoat”; “ultraviolet absorber”; “photochromic”, “tinting” “blue-light absorber”, and the like, unless otherwise specified, are meant as used in the art of optical substrate coatings.

[0388] The term “ratio”, as used herein in the specification and in the claims section that follows, refers to a weight ratio, unless specifically indicated otherwise.

[0389] As used herein in the specification and in the claims section that follows, the term “nonvolatile component”, with respect to a formulation or formulation on a lens / optical substrate,relates to the residue left after driving off some or all of the solvents and carrier liquids from the lens / optical surface after subjecting the lens / optical substrate, coated with the formulation, to oven-drying at 120°C for 3 hours. The residue includes the solid particles within the formulation, along with dissolved solids that remain after the solvent has been removed.

[0390] The “thickness” of a layer or a plurality of layers at a particular location is measured in the direction that is normal (N) to the lens substrate at that location.

[0391] Various types of thin-film thickness measurements are know to those of skill in the art. For example, single-spot thickness measurements may be performed by spectral reflectance or by spectroscopic ellipsometry.

[0392] In addition, mapping of thin-film surfaces and calculation of average thicknesses of such films may be performed using these techniques.

[0393] The “average thickness” of a wet layer may be determined as follows: when a volume of material vol covers a surface area of a surface having an area SA with a wet layer - the thickness of the wet layer is assumed to be vol / SA. If the weight of the materials is known, vol may be calculated by dividing by the material’s specific gravity. Typically, the specific gravity of the various coating materials may safely be approximated as 1.00.

[0394] The “average thickness” of a dried film may be calculated as follows: when a volume of material vol that is x% liquid, by weight, wets or covers a surface area SA of a surface, and all the liquid is evaporated away to convert the wet layer into a dry film, the thickness of the dry film is calculated as:

[0395] Vol / Pwet layer (100- x) / (SA*pdry layer)

[0396] where pWet layer is the specific gravity of the wet layer and pary layer is the specific gravity of the dry layer. This calculation requires a knowledge of various properties of the wet coating material of the film, e.g., the specific gravity. As mentioned above, typically, the specific gravities may be assumed to be 1.

[0397] Similarly, an average diameter of drops such as jetted or microvalved drops (Ddrop) may be calculated by weighing a large number of the jetted drops, converting the total weight into volume using the specific gravity, dividing by the number of drops, and utilizing the equation relating spherical drop diameter to sphere volume: D = (6*V / TT)1 / 3.

[0398] As used herein in the specification and in the claims section that follows, the term “drop diameter”, or Ddrop, is defined and calculated in this fashion.

[0399] It will be appreciated by those of skill in the art that the various layers disposed on the optical or ophthalmic surface (e.g., the lens surface) of the present invention are generally of a substantially even thickness, hence, the “average thickness” may be determined by evaluating one or more representative spot thicknesses on the film or layer.As used herein, and as will be appreciated by those of skill in the art, the “target surface” lies within the “wet continuous ink layer” produced by the inkjetting operation.

[0400] As used herein, the term “base curve” refers to the theoretical base curve, or “true curve”. As used herein, the term “disposed in fixed relative position with respect to the jetting direction”, and the like, means that the minimum distance remains constant between (i) a first plane passing through at least some of the nozzles and orthogonal to the jetting direction of the nozzles, and (ii) a second plane defined by a face, parallel to said first plane, of the smallest virtual rectangular prism containing the lens and comprising said face.

[0401] Typically, and more simply put, the inkjet nozzles and the optical substrate are disposed in fixed relative position in the vertical or z-direction, while there may or may not be relative movement between them along the x-y plane.

[0402] As is well known, a two-dimensional convex region (such as a silhouette or projection) produced by a three-dimensional contour (e.g., that of a lens) is one where any line segment connecting two points within the shape lies entirely inside it, containing no indents or "inward" pointing features. For a lens (or lens blank, or any portions thereof), having a continuous ink layer disposed thereon, the maximum convex region represents the filled silhouette of the 3-D object's extreme outward points.

[0403] The printed ink density on an optical substrate such as an eyeglass lens, or of a region thereof, may be calculated by summing the volume of each drop (e.g. on said region of the eyeglass lens) and dividing by the top (ink-receiving) surface area of that region. The surface area may be calculated substantially as described hereinabove with respect to Figure 16, or by known methods. The volume of the drops may calculated by summing up the volume of each drop (SVdrop(i) from 1 to the total number of drops), or for drops of substantially the same volume, multiplying the number of drops by the drop volume. Alternatively, a known number of drops can be printed into a tared vessel, and the average drop weight determined. Dividing by the specific gravity of the ink, the volume of the ink may be determined. All of these methods have been found to yield very similar results, such that any of them may be used.

[0404] As used herein in the specification and in the claims section that follows, the term “transparent”, typically with respect to a material, e.g., a material used in a coating, or as a substrate, may be determined according to ASTM D1003. Utilizing ASTM D1003, a material having a haze measurement of less than 2% and a total transmittance (T) of at least 85% is considered “transparent”. More typically, the haze is at most 1.5% or at most 1.0%. More typically, Tf is at least 90% or at least 95%. Yet more typically, the haze is at most 1.0% and Tf is at least 95%.

[0405] In the context of the present application and claims, the phrase "at least one of A and B" is equivalent to an inclusive "or", and includes any one of "only A", "only B", or "A and B".Similarly, the phrase "at least one of A, B, and C" is equivalent to an inclusive "or", and includes any one of "only A", "only B", "only C", "A and B", "A and C", "B and C", or "A and B and C".

[0406] As used herein in the specification and in the claims section that follows, the terms “top”, “bottom”, “above”, “below”, “upper”, “lower”, “height” and “side” and the like are utilized for convenience of description or for relative orientation, and are not necessarily intended to indicate an absolute orientation in space.

[0407] Inventive Concepts

[0408] The present disclosure includes, inter alia, the following Inventive Concepts (“ICs”), which are listed below for convenient reference. While some concepts disclosed hereinabove may not summarized in this section, this should not be taken as an indication that such concepts are not inventive or not within the scope of the embodiments. Some of the Inventive Concepts are introduced below for the first time for the sake of conciseness.

[0409] IC1. A method of producing a continuous optical layer or coating on a curved optical substrate, the method comprising:

[0410] (a) inkjetting drops of an ink formulation, by means of an inkjet nozzle, onto a target surface of a curved optical surface of the optical substrate, to form a wet continuous ink layer; (b) treating the wet continuous ink layer to produce a dried continuous ink layer on said optical surface;

[0411] wherein, over the entire course of said inkjetting, said inkjetting of said drops is performed while said inkjet nozzle and the optical substrate are disposed in fixed relative position with respect to the jetting direction;

[0412] and wherein, at at least one location on the target surface, the inkjet nozzle discharges a jetted drop at a gap distance of at least 2.5mm between the nozzle and the target surface, the gap distance being measured in the direction of the jetting direction.

[0413] IC1A. A method of producing a continuous optical layer or coating on a curved optical substrate, the method comprising:

[0414] (a) inkjetting drops of an ink formulation, by means of an inkjet nozzle, onto a target surface of a curved optical surface of the optical substrate, to form a wet continuous ink layer; (b) treating the wet continuous ink layer to produce a dried continuous ink layer on said optical surface;

[0415] wherein, over the entire course of said inkjetting, said inkjetting of said drops is performed while said inkjet nozzle and the optical substrate are disposed in fixed relative position with respect to the jetting direction, for any given jetting direction;and wherein, at at least one location on the target surface, the inkjet nozzle discharges a jetted drop at a gap distance of at least 2.5mm between the nozzle and the target surface, the gap distance being measured in the direction of the jetting direction, for any given jetting direction.

[0416] ICIB. A method of producing a continuous optical layer or coating on a curved optical substrate, the method comprising:

[0417] (a) inkjetting drops of an ink formulation, by means of an inkjet nozzle, onto a target surface of a curved optical surface of the optical substrate, to form a wet continuous ink layer; (b) treating the wet continuous ink layer to produce a dried continuous ink layer on said optical surface;

[0418] wherein:

[0419] GDmin is defined as the smallest gap distance between the inkjet nozzle and the curved optical surface during the inkjetting;

[0420] GDmax is defined as the largest gap distance between the inkjet nozzle and the curved optical surface during the inkjetting; and

[0421] AGDmax is the maximum gap differential defined by the subtraction of GDmin from GDmax; and wherein AGDmax is within a range of 2.8mm to 12mm.

[0422] ICIC. The method of any one of the preceding ICs, wherein an average diameter of the inkjetted drops (Ddrop) is within a range of 18 to 60 micrometers (pm).

[0423] ICID. The method of any one of the preceding ICs, wherein the inkjetting is performed so as to effectuate at least one of the following printing patterns:

[0424] i) a ratio of a mean volume of the inkjetted ink formulation per unit of area of the target surface in an edge portion thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surface and a perimeter thereof, is between 0.58 and 0.95 times a maximum ratio of a volume the inkjetted ink formulation per unit of area of the target surface; and ii) a ratio of a mean volume of the inkjetted ink formulation per unit of area of the target surface in an edge portion thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surface and a perimeter thereof, is between 0.58 and 0.95 times a mean ratio of a volume of the inkjetted ink formulation per unit of area in a central area characterized by lying between 0% and 10% of a distance from the centroid of the target surface and the perimeter.

[0425] ICIE. The method of any one of claims 1 to 19 provided hereinbelow.

[0426] ICIF. The method of any one of the preceding ICs, wherein the curved optical substrate is a curved polymeric optical substrate.IC1G. The method of any one of the preceding ICs, wherein the curved optical substrate is a glass.

[0427] IC2. The method of any one of the preceding ICs, wherein an or the average diameter of the inkjetted drops (Ddrop) is at least 20pm.

[0428] IC3. The method of IC2, wherein Ddrop is at least 22pm.

[0429] IC4. The method of IC2, wherein Ddrop is at least 24pm.

[0430] IC5. The method of IC2, wherein Ddrop is at least 27pm.

[0431] IC6. The method of IC2, wherein Ddrop is at least 30pm.

[0432] IC6A. The method of any one of the preceding ICs, wherein Ddrop is at most 55pm.

[0433] IC6B. The method of IC6A, wherein Ddrop is at most 50pm.

[0434] IC6C. The method of IC6A, wherein Ddrop is at most 45pm.

[0435] IC7. The method of any one of the preceding ICs, wherein the SAG number of the curved optical surface is at least 2 mm.

[0436] IC8. The method of IC7, wherein the SAG number is at most 12mm.

[0437] IC8A. The method of IC7, wherein the SAG number is at least 3mm.

[0438] IC9. The method of IC7, wherein the SAG number is at least 3.5mm.

[0439] IC10. The method of IC7, wherein the SAG number is at least 4mm.

[0440] IC 11. The method of IC7, wherein the SAG number is at least 4.5mm.

[0441] IC12. The method of IC7, wherein the SAG number is at least 5mm.

[0442] IC13. The method of IC7, wherein the SAG number is at least 6mm.

[0443] IC14. The method of IC7, wherein the SAG number is at least 7mm.

[0444] IC15. The method of IC7, wherein the SAG number is at least 8.5mm.

[0445] IC16. The method of any one of the preceding ICs, wherein the SAG number is at most 10.5mm.

[0446] IC17. The method of IC16, wherein the SAG number is at most 9.5mm.

[0447] IC18. The method of IC16, wherein the SAG number is at most 8.7mm.

[0448] IC18A. The method of any one of ICs 1 to 14, wherein the SAG number is at most 8mm.

[0449] IC18B. The method of any one of the preceding ICs, the ink formulation containing at least one solvent.

[0450] IC18C.The method of any one of the preceding ICs, wherein the ink formulation is a solventbased ink formulation.

[0451] IC18C1. The method of any one of the preceding ICs, the ink formulation containing at least one colorant such as a photochromic dye.

[0452] IC18C2. The method of IC18C1, wherein the colorant includes a tint dye.IC18D.The method of any one of the preceding ICs, wherein the ink formulation contains a dissolved colorant or dye and a dissolved polymer resin.

[0453] IC18D1. The method of IC18D, wherein the dissolved polymer resin concentration within the ink formulation is at least 2%.

[0454] IC18D2. The method of IC18D1, wherein the dissolved polymer resin concentration is at least 3.5% and optionally, at most 10%.

[0455] IC18E. The method of any one of ICs 18B to 18D, wherein the dissolved dye is or includes a photochromic dye.

[0456] IC18F. The method of any one of ICs 18B to 18E, wherein the ink formulation is a photochromic ink formulation comprising a resin, a photochromic dye, and a solvent system.

[0457] IC18G.The method of IC18F, wherein the photochromic ink formulation includes a softening agent for softening the resin, the softening agent forms a single liquid phase with the solvent system, the resin, and the photochromic dye.

[0458] IC19C.The method of any one of the preceding ICs, and in particular, the method of any one of ICs 18C1 to 18G, wherein the wet continuous ink layer is continuous at least over a region having an area of at least 1cm2.

[0459] IC19D.The method of IC19C, wherein the region has an area of at least 4cm2.

[0460] IC19E. The method of IC19C or IC19D, wherein the region is a convex region.

[0461] IC19F. The method of any one of the preceding ICs, wherein the treating of the wet continuous ink layer to produce a dried continuous ink layer is performed in a drying station.

[0462] IC19G.The method of IC19F, wherein the treating in the drying station is performed such that the residual solvent content (RS) remaining in the dried continuous ink layer, with respect to the solvent content in the ink formulation, is at most 20% or at most 15% (by weight).

[0463] IC19H.The method of IC19G, wherein RS is at most 10%.

[0464] IC19H1. The method of IC19G, wherein RS is at most 7%.

[0465] IC19I. The method of IC19G, wherein RS is at most 5%.

[0466] IC19J. The method of any one of ICs 19Gto 191, wherein RS is at least 1%.

[0467] IC19K.The method of IC19J, wherein RS is at least 2%.

[0468] IC19L. The method of IC19J, wherein RS is at least 3%.

[0469] IC19M. The method of IC19J, wherein RS is at least 4.5%.

[0470] IC19M1. The method of any one of ICs 19G to 19H1, wherein RS is at least 6%.

[0471] IC19N. The method of any one of the preceding ICs, further comprising, following step (a) and prior to step (b): repeating step (a) to produce a stack having at least a second wet continuous ink layer on top of the initially produced wet continuous ink layer.IC190. The method of IC19N, wherein, prior to step (b), the repeating is performed at least twice, to produce a stack of at least three wet continuous ink layers.

[0472] IC19P. The method of IC19N or IC19O, wherein, prior to step (b), the stack contains at most five wet continuous ink layers.

[0473] IC19Q. The method of IC19P, wherein, prior to step (b), the stack contains at most four wet continuous ink layers.

[0474] IC19R. The method of IC19P, wherein, prior to step (b), the stack contains at most three wet continuous ink layers.

[0475] IC19S. The method of IC19N, wherein, prior to step (b), the stack contains at most two wet continuous ink layers.

[0476] IC19S1. The method of any one of the preceding ICs, wherein the total thickness of the stack of wet continuous ink layers is at most 35 micrometers.

[0477] IC19S2. The method of IC19S1, wherein the total thickness is at most 28 micrometers.

[0478] IC19S3. The method of IC19S1, wherein the total thickness is at most 22 micrometers.

[0479] IC19S4. The method of any one of the preceding ICs, wherein the total thickness of the stack of wet continuous ink layers is at least 5 micrometers.

[0480] IC19S5. The method of IC19S4, wherein the total thickness is at least 8 micrometers.

[0481] IC19S6. The method of IC19S4, wherein the total thickness is at least 12 micrometers.

[0482] IC19T. The method of any one of the preceding ICs, further comprising, following step (b): repeating step (a) to produce at least one additional wet continuous ink layer on the stack including the at least one dried continuous ink layer produced in step (b).

[0483] IC19U. The method of IC19T, wherein, following the production of the final wet continuous ink layer of the at least one additional wet continuous ink layer, drying the stack to produce a dried stack on the optical surface.

[0484] IC19V. The method of any one of the preceding ICs, further comprising, after the topmost or final layer of the stack has been dried, curing the stack of dried continuous ink layer(s) to produce a cured stack.

[0485] IC19X. The method of IC19V, further comprising applying a wet overcoat layer on the cured stack.

[0486] IC19Y. The method of IC19X, further comprising drying the wet overcoat layer to produce a dried overcoat layer.

[0487] IC19Z. The method of IC19X or IC19Y, further comprising curing the wet overcoat layer or the dried overcoat layer to produce a cured overcoat-covered stack.IC20. The method of any one of ICs 19X to 19Z, wherein the formulation forming the wet overcoat is an aqueous polymeric dispersion.

[0488] IC20A. The method of IC20, wherein the aqueous polymeric dispersion is a polyurethane dispersion.

[0489] IC20B. The method of any one of ICs 19V to 20A, further comprising applying a wet hardcoat layer onto the cured stack or onto the cured overcoat-covered stack.

[0490] IC20C. The method of IC20B, further comprising drying the wet hardcoat layer to produce a dried hardcoat layer.

[0491] IC20D. The method of IC20B or IC20C, further comprising curing the wet hardcoat layer or the dried hardcoat layer to produce a cured hardcoat-covered stack.

[0492] IC20E. The method of any one of the preceding ICs, further comprising, prior to the inkjetting, subjecting the target surface of the curved optical surface to at least one surface treatment.

[0493] IC21. The method of IC20E, wherein the at least one surface treatment includes an energy treatment for raising the surface energy of the target surface.

[0494] IC22. The method of IC20E, wherein the energy treatment includes at least one energy treatment selected from the group consisting of corona, plasma, electron beam and electrical discharge treatments.

[0495] IC23. The method of IC21 , wherein the energy treatment includes a corona treatment.

[0496] IC24. The method of IC21, wherein the energy treatment includes a plasma treatment.

[0497] IC25. The method of any one of ICs 22 to 24, wherein the surface treatment raises the surface energy of the optical substrate by at least 2 mN / m.

[0498] IC26. The method of IC25, wherein the surface energy increase is at least 5 mN / m.

[0499] IC27. The method of IC25, wherein the surface energy increase is at least 10 mN / m.

[0500] IC28. The method of any one of ICs 25 to 27, wherein the surface energy increase is at most 30 mN / m.

[0501] IC29. The method of IC28, wherein the surface energy increase is at most 20 mN / m.

[0502] IC30. The method of IC28, wherein the surface energy increase is at most 14 mN / m.

[0503] IC31. The method of any one of ICs 20 to 30, wherein said surface treatment includes applying a primer to a first surface of the optical substrate to form a wet primer coating, and treating (including drying and / or curing) the wet primer coating to form the optical surface of the optical substrate.

[0504] IC32. The method of IC31, wherein the treating of the wet primer coating produces a fully-cured primer coating, prior to applying the ink formulation.

[0505] IC33. The method of IC31 or 32, wherein the cured primer coating has a thickness (Tp) of at least 0.4pm.IC34. The method of IC33, wherein Tp is at least 0.6pm.

[0506] IC35. The method of IC33, wherein Tp is at least 0.8pm.

[0507] IC36. The method of IC33, wherein Tp is at least 1.0pm.

[0508] IC37. The method of any one of ICs 33 to 36, wherein Tp is at most 3pm.

[0509] IC38. The method of IC37, wherein Tp is at most 2.5pm.

[0510] IC39. The method of IC37, wherein Tp is at most 2.0pm.

[0511] IC40. The method of IC37, wherein Tp is at most 1.7pm.

[0512] IC41. The method of IC37, wherein Tp is at most 1.4pm.

[0513] IC42. The method of any of ICs 33 to 41, wherein Tp is at least one of a local thickness and an average thickness.

[0514] IC43. The method of any one of ICs 31 to 42, wherein the treated primer coating has a non-tacky upper surface.

[0515] IC44. The method of any one of ICs 31 to 43, wherein the treating (including drying and / or curing) of the wet primer coating is performed only after the entire continuous layer of primer has been applied.

[0516] IC45. The method of any one of the preceding ICs, wherein a gap distance differential (AGD), is defined as the gap distance between the nozzle and the target surface, at any point i on the target surface (GD,), less the minimum gap distance between the nozzle and the target surface (GDmin), the gap distances being measured in the direction of the vertical axis:

[0517] AGD = GD, - GDmin

[0518] and wherein, at at least one location on said target surface, AGD is at least 3mm.

[0519] IC46. The method of IC45, wherein for the at least one location, AGD is at least 3.5mm.

[0520] IC47. The method of IC45, wherein for the at least one location, AGD is at least 4mm.

[0521] IC48. The method of IC45, wherein for the at least one location, AGD is at least 4.5mm.

[0522] IC49. The method of IC45, wherein for the at least one location, AGD is at least 5mm.

[0523] IC50. The method of IC45, wherein for the at least one location, AGD is at least 5.5mm.

[0524] IC51. The method of IC45, wherein for the at least one location, AGD is at least 6mm.

[0525] IC52. The method of IC45, wherein for the at least one location, AGD is at least 6.5mm.

[0526] IC53. The method of IC45, wherein for the at least one location, AGD is at least 7.5mm.

[0527] IC54. The method of IC45, wherein for the at least one location, AGD is at least 9mm.

[0528] IC55. The method of any one of ICs 45 to 54, wherein for the at least one location, AGD is at most 11mm.

[0529] IC56. The method of IC55, wherein for the at least one location, AGD is at most 10mm.

[0530] IC57. The method of IC55, wherein for the at least one location, AGD is at most 9.5mm.IC57A. The method of any one of the preceding ICs, wherein AGDmax at least equals AGD. IC58. The method of any one of the preceding ICs, wherein the inkjetting of the drops is performed while the inkjet nozzle and the optical substrate move relative to one another along an plane orthogonal to the jetting direction.

[0531] IC59. The method of IC58, wherein the velocity of the relative movement between the inkjet nozzle and the optical substrate is at least 50mm / s.

[0532] IC60. The method of IC58, wherein the velocity is at least 90mm / s.

[0533] IC61. The method of IC58, wherein the velocity is at least 130mm / s.

[0534] IC62. The method of IC58, wherein the velocity is at least 180mm / s.

[0535] IC63. The method of any one of ICs 58 to 62, wherein the velocity is at most 450mm / s.

[0536] IC64. The method of IC63, wherein the velocity is at most 350mm / s.

[0537] IC65. The method of IC63, wherein the velocity is at most 300mm / s.

[0538] IC66. The method of IC63, wherein the velocity is at most 250mm / s.

[0539] IC67. The method of IC63, wherein the velocity is at most 225mm / s.

[0540] IC68. The method of any one of the preceding ICs, wherein Ddrop is at most 50pm.

[0541] IC69. The method of IC68, wherein Ddrop is at most 45pm.

[0542] IC70. The method of any one of the preceding ICs, wherein the jetting direction is within 10° of vertical.

[0543] IC71. The method of any one of the preceding ICs, wherein the optical surface is an ophthalmic surface.

[0544] IC72. The method of any one of the preceding ICs, wherein the optical substrate is an ophthalmic substrate.

[0545] IC73. The method of IC71 or 72, wherein the optical surface or ophthalmic surface is the front surface of the substrate.

[0546] IC74. The method of IC71 or 72, wherein the optical surface or ophthalmic surface is the back surface of the substrate.

[0547] IC75. The method of any one of ICs 71 to 74, wherein the optical surface or ophthalmic surface is a convex surface.

[0548] IC76. The method of any one of ICs 71 to 74, wherein the optical surface or ophthalmic surface is a concave surface.

[0549] IC77. The method of any one of the preceding ICs, wherein the optical substrate has a diameter Ds of at least 40mm.

[0550] IC78. The method of IC77, wherein Ds is at least 50mm.

[0551] IC79. The method of IC77, wherein Ds is at least 60mm.

[0552] IC80. The method of IC77, wherein Ds is at least 70mm.IC81. The method of IC77, wherein Ds is at least 80mm.

[0553] IC82. The method of any one of ICs 77 to 81, wherein Ds is at most 90mm.

[0554] IC83. The method of IC77, wherein Ds is within a range of 50mm to 80mm.

[0555] IC84. The method of any one of the preceding ICs, wherein the optical substrate is a lens blank. IC85. The method of any one of ICs 1 to 83, wherein the lens blank is semi-finished.

[0556] IC86. The method of any one of ICs 1 to 83, wherein the lens blank is finished.

[0557] IC87. The method of any one of ICs 1 to 83, wherein the optical substrate is a lens (e.g., an edged lens).

[0558] IC88. The method of any one of the preceding ICs, wherein the wet continuous ink layer is continuous over a contiguous area of at least 400mm2.

[0559] IC89. The method of IC88, wherein the contiguous area is at least 900mm2.

[0560] IC90. The method of any one of the preceding ICs, further comprising mounting the optical substrate having the dried ink-containing layer into eyeglasses frames (e.g. as a lens thereof). IC91. The method of any one of the preceding ICs, wherein the ink formulation includes an electrochromic dye.

[0561] IC92. The method of any one of the preceding ICs, wherein the ink formulation includes thermochromic dye.

[0562] IC93. The method of any one of the preceding ICs, wherein the ink formulation is not a hardcoat formulation.

[0563] IC94. The method of any one of the preceding ICs, wherein a 25°C surface tension ct of the ink formulation is at most 35 dyne / cm.

[0564] IC95. The method of IC94, wherein a is at most 32 dyne / cm.

[0565] IC96. The method of IC94, wherein a is at most 30 dyne / cm.

[0566] IC97. The method of IC94, wherein a is at most 29 dyne / cm.

[0567] IC98. The method of any one of ICs 94 to 97, wherein ct of the ink formulation is at least 24 dyne / cm.

[0568] IC99. The method of IC98, wherein <j is at least 25 dyne / cm.

[0569] IC100. The method of IC98, wherein a is at least 26 dyne / cm.

[0570] IC101. The method of any one of the preceding ICs, wherein at least 85 weight% of the total polymer content within the ink formulation is a film-forming polymer.

[0571] IC102. The method of IC101, wherein at least 90 weight% of the total polymer content within the ink formulation is a film-forming polymer.

[0572] IC103. The method of any one of the preceding ICs, wherein, on an n-butyl acetate normalized 25°C evaporation rate scale, at least 75% of the total solvent within the formulation is at most a high vapor-pressure solvent (Hevap), on a weight basis.IC104. The method of IC103, at least 80% of the total solvent being at most Hevap. IC105. The method of IC103, at least 85% of the total solvent being at most Hevap.

[0573] IC106. The method of IC103, at least 90% of the total solvent being at most Hevap.

[0574] IC107. The method of IC103, at least 95% of the total solvent being at most Hevap.

[0575] IC108. The method of any one of the preceding ICs, wherein, on an n-butyl acetate normalized 25°C evaporation rate scale, at least 70% of the total solvent within the formulation is at most a medium vapor-pressure solvent (Mevap), on a weight basis.

[0576] IC109. The method of IC108, at least 75% of the total solvent being at most Mevap.

[0577] IC110. The method of IC108, at least 80% of the total solvent being at most Mevap.

[0578] IC111. The method of IC108, at least 85% of the total solvent being at most Mevap.

[0579] IC112. The method of IC108, at least 90% of the total solvent being at most Mevap.

[0580] IC113. The method of any one of the preceding ICs, wherein, on an n-butyl acetate normalized 25°C evaporation rate scale, at least 45% of the total solvent within the formulation is at most a low vapor-pressure solvent (Levap), on a weight basis.

[0581] IC114. The method of IC113, at least 50% of the total solvent being at most Levap.

[0582] IC115. The method of IC113, at least 55% of the total solvent being at most Levap.

[0583] IC116. The method of IC113, at least 60% of the total solvent being at most Levap.

[0584] IC117. The method of IC113, at least 70% of the total solvent being at most Levap.

[0585] IC118. The method of IC113, at least 80% of the total solvent being at most Levap.

[0586] IC119. The method of IC113, at least 90% of the total solvent being at most Levap.

[0587] IC120. The method of any one of the preceding ICs, wherein, on an n-butyl acetate normalized 25°C evaporation rate scale, at least 15% of the total solvent within the formulation is a very low vapor-pressure solvent (LLevap), on a weight basis.

[0588] IC121. The method of IC120, at least 20% of the total solvent being LLevap.

[0589] IC122. The method of IC120, at least 25% of the total solvent being LLevap.

[0590] IC123. The method of IC120, at least 30% of the total solvent being LLevap.

[0591] IC124. The method of IC120, at least 40% of the total solvent being LLevap.

[0592] IC125. The method of IC120, at least 50% of the total solvent being LLevap.

[0593] IC126. The method of IC120, at least 60% of the total solvent being LLevap.

[0594] IC127. The method of IC120, at least 70% of the total solvent being LLevap.

[0595] IC128. The method of any one of the preceding ICs, wherein, on an n-butyl acetate normalized 25°C evaporation rate scale (Snba), at least 30% of the total solvent (Ts) within the formulation has a relative evaporation rate (Rev) of at most 0.05, on a weight basis.

[0596] IC129. The method of IC128, wherein, for at least 40% of Ts, Rev is at most 0.05.

[0597] IC130. The method of IC128, wherein, for at least 50% of Ts, Rev is at most 0.05.IC131. The method of IC128, wherein, for at least 60% of Ts, Rev is at most 0.45.

[0598] IC132. The method of IC128, wherein, for at least 80% of Ts, Rev is at most 0.45.

[0599] IC133. The method of IC128, wherein, for at least 70% of Ts, Rev is at most 0.75.

[0600] IC134. The method of IC128, wherein, for at least 85% of Ts, Rev is at most 0.75.

[0601] IC135. The method of any one of the preceding ICs, wherein the relative evaporation rate of LLevap (RLL) is at most 0.01.

[0602] IC136. The method of IC135, wherein RLL is at most 0.007.

[0603] IC137. The method of IC135, wherein RLL is at most 0.005.

[0604] IC138. The method of IC135, wherein RLL is at most 0.003.

[0605] IC139. The method of any one of ICs 1 to 138, wherein the relative evaporation rate of LLevap (RLL) is at least 0.0015.

[0606] IC140. The method of any one of the preceding ICs, wherein a weight ratio (WR1) of the colorant or dye to the total non-volatile content of the ink formulation is at least 0.10:1.

[0607] IC141. The method of IC140, wherein WR1 is at least 0.2:1.

[0608] IC142. The method of IC140, wherein WR1 is at least 0.25:1.

[0609] IC143. The method of IC140, wherein WR1 is at least 0.3:1.

[0610] IC144. The method of IC140, wherein WR1 is at least 0.35:1.

[0611] IC145. The method of IC140, wherein WR1 is at least 0.4:1.

[0612] IC146. The method of any one of ICs 140 to 145, wherein WR1 is at most 0.75:1.

[0613] IC148. The method of IC146, wherein WR1 is at most 0.60:1.

[0614] IC149. The method of IC146, wherein WR1 is at most 0.55:1.

[0615] IC150. The method of IC146, wherein WR1 is at most 0.50:1.

[0616] IC151. The method of IC146, wherein WR1 is at most 0.45:1.

[0617] IC152. The method of any one of ICs 140 to 144, wherein WR1 is at most 0.40:1.

[0618] IC153. The method of any one of ICs 140 to 143, wherein WR1 is at most 0.35:1.

[0619] IC154. The method of any one of ICs 140 to 142, wherein WR1 is at most 0.3:1.

[0620] IC155. The method of any one of ICs 140 to 141, wherein WR1 is at most 0.25:1.

[0621] IC156. The method of IC140, wherein WR1 is at most 0.2:1.

[0622] IC157. The method of IC140, wherein WR1 is at most 0.15:1.

[0623] IC157A. The method of any one of the preceding ICs, wherein the inkjet nozzle is a plurality of inkjet nozzles.

[0624] IC157B. The method of IC157A, wherein the plurality of inkjet nozzles includes at least 20 inkjet nozzles.

[0625] IC157C. The method of IC157A, wherein the plurality of inkjet nozzles includes at least 100 inkjet nozzles.IC157D. The method of any one of ICs 157A to 157C, wherein the operation of the nozzles is substantially independent of the surface geometry of the substrate or lens.

[0626] IC157E. The method of any one of ICs 157A to 157D, wherein, from a quantitative standpoint, at least 75% of the nozzles have identical or substantially identical (within ±10% or within ±5%) operating parameters.

[0627] IC157F. The method of IC157E, wherein from the quantitative standpoint, at least 90% of the nozzles have identical or substantially identical operating parameters.

[0628] IC157G. The method of IC157E, wherein from the quantitative standpoint, all of the nozzles have identical or substantially identical operating parameters.

[0629] IC158. The method of any one of the preceding ICs, wherein the ink formulation has a viscosity (Vop) of at most lOOcP at the inkjetting temperature.

[0630] IC159. The method of IC158, Vop being at most 80cP.

[0631] IC160. The method of IC158, Vop being at most 60cP.

[0632] IC161. The method of IC158, Vop being at most 40cP.

[0633] IC162. The method of IC158, Vop being at most 30cP.

[0634] IC163. The method of any one of ICs 158 to 162, Vop being at least 5cP.

[0635] IC164. The method of IC163, Vop being at least 7cP.

[0636] IC165. The method of IC163, Vop being at least lOcP.

[0637] IC166. The method of IC163, Vop being at least 12cP.

[0638] IC167. The method of IC163, Vop being at least 15cP.

[0639] IC168. The method of IC163, Vop being at least 18cP.

[0640] IC169. The method of IC163, Vop being at least 20cP.

[0641] IC170. The method of IC163, Vop being at least 23cP.

[0642] IC171. The method of any one of ICs 1 to 157, wherein the ink formulation has a viscosity at 25°C (V25) of at most 120cP.

[0643] IC172. The method of IC171, V25 being at most 90cP.

[0644] IC173. The method of IC171, V25 being at most 70cP.

[0645] IC173A. The method of IC171, V25 being at most 50cP.

[0646] IC174. The method of IC171, V25 being at most 40cP.

[0647] IC175. The method of IC171, V25 being at most 30cP.

[0648] IC176. The method of any one of ICs 171 to 175, V25 being at least 5cP.

[0649] IC177. The method of IC176, V25 being at least 7cP.

[0650] IC178. The method of IC176, V25 being at least lOcP.

[0651] IC179. The method of IC176, V25 being at least 12cP.

[0652] IC180. The method of IC176, V25 being at least 15cP.IC181. The method of IC176, V25 being at least 18cP.

[0653] IC182. The method of IC176, V25 being at least 20cP.

[0654] IC183. The method of IC176, V25 being at least 23cP.

[0655] IC184. The method of any one of the preceding ICs, wherein the ink formulation has at most 0.2% surfactant, by weight.

[0656] IC185. The method of IC184, wherein the ink formulation has at most 0.1% surfactant.

[0657] IC186. The method of IC184, wherein the ink formulation has at most 0.04% surfactant.

[0658] IC186A. The method of IC184, wherein the ink formulation is devoid of surfactant.

[0659] IC186B. The method of any one of the preceding ICs, wherein the ink formulation contains a light absorber in a non-visible-light portion of the spectrum.

[0660] IC186C. The method of IC186B, wherein the light absorber is a UV absorber.

[0661] IC186D. The method of IC186B, wherein the light absorber is a blue light absorber.

[0662] IC186E. The method of IC186B, wherein the light absorber absorbs light at at least a portion of the 380-450 nm range.

[0663] IC187. The method of any one of the preceding ICs, wherein, during printing, the stage of the optical substrate moves solely in the X-Y plane with respect to the inkjet nozzle.

[0664] IC188. The method of any one of the preceding ICs, wherein the inkjetting is drop-on-demand jetting.

[0665] IC189. The method of any one of the preceding ICs, wherein the inkjetting is piezo-actuated jetting.

[0666] IC190. The method of any one of the preceding ICs, further including any feature contained in the coating system ICs provided hereinbelow.

[0667] IC191. The method of any one of the preceding ICs, further including any feature contained in the Specification.

[0668] INVENTIVE CONCEPTS - SYSTEM (“ICS”)

[0669] ICS1. A coating system comprising:

[0670] (a) an ink-formulation-application station including inkjet apparatus configured to inkjet droplets of an ink-formulation onto a target surface of an optical substrate to form a wet ink layer on the target surface; and(b) a drying and / or curing station configured to dry and / or cure the wet ink layer to produce a cured ink coating on the target surface.

[0671] ICS2. The system of ICS1, further comprising:

[0672] (c) an optical-substrate transfer apparatus configured to transfer the optical substrate having the wet ink layer on the target surface thereof from the ink-formulation- application station to the drying and / or curing station.

[0673] ICS3. The system of either preceding ICS, wherein the optical-substrate-transfer apparatus includes at least one of a robotic arm, a gripper, a conveyer belt, and an elevator for raising or lowering an elevation of the optical substrate on the target surface thereof.

[0674] ICS4. The system of any preceding ICS, further comprising a controller programmed or programmable to regulate the optical-substrate-transfer apparatus such that the transfer of the optical substrate is contingent upon a detection that the wet ink layer has been formed on the target surface of the optical substrate at the ink-formulation-application station.

[0675] ICS5. The system of any preceding ICS, wherein the drying and / or curing station includes at least one of a heat lamp, an oven, and a UV-curing mechanism.

[0676] ICS6. The system of any preceding ICS, wherein the drying and / or curing station includes an oven which: (i) is open when the optical substrate having the wet layer on the target surface thereof is transferred thereinto, and (ii) is closed, subsequent to transfer of the optical substrate to the oven, and remains closed during the drying and / or curing.

[0677] ICS7. The system of any preceding ICS, comprising a primer application station configured to apply droplets of a primer formulation onto the target surface before inkjetting ink-formulation thereupon.

[0678] ICS8. The system of ICS7, wherein the primer application station includes a microvalve apparatus for applying drops of the primer formulation.

[0679] ICS9. The system of any preceding ICS, further comprising at least one of: (i) a treatment station for increasing the surface energy of the target surface before application thereon of the primer or the ink formulation; and (ii) a cleaning station for subjecting the target surface to a cleaning process before inkjet-application thereon of the ink formulation.

[0680] ICS10. The system of ICS9, further comprising the surface energy treatment station, said surface energy station including at least one of a corona-treatment-apparatus and a plasma-treatment apparatus.

[0681] ICS11. The system of any preceding ICS, wherein the ink-formulation-application station includes a reservoir of the ink formulation and is configured to inkjet, onto the target surface of the optical substrate, ink formulation stored in the reservoir.ICS 12. The system of any preceding ICS, wherein the system is further configured to apply, by inkjetting, at least one additional ink formulation (e.g., a tint formulation or a photochromic formulation) to the target surface of the optical substrate before the application thereon of the wet layer of the first ink formulation.

[0682] ICS13. The system of any preceding ICS, wherein the system is devoid of dip coating apparatus. ICS 14. The system of any preceding ICS, wherein the system is devoid of spin coating apparatus.

[0683] ICS 15. The system of any preceding ICS, including a controller configured or programmed to control the inkjetting of the droplets of the ink formulation onto the target surface.

[0684] ICS16. The system of any preceding ICS, wherein the target surface is curved.

[0685] ICS17. The system of any preceding ICS, wherein the target surface has a SAG number of at least 2.5mm.

[0686] ICS18. The system of any one of ICS 15 to 17, wherein the controller is configured or programmed to control the inkjetting such that a ratio of a volume of formulation applied per unit of area of a two-dimensional projection of the target surface is constant.

[0687] ICS19. The system of any one of ICS 15 to 17, wherein the controller is configured or programmed to control the inkjetting such that a ratio of a volume of formulation applied per unit of area of a two-dimensional projection of the target surface, within any subdivision of said two-dimensional projection having an area of 5% or more of an area of the projection, is within ±10%, or within ±5%, or within ±2%, or within ±1% of a mean value of said ratio for all of said two-dimensional projection.

[0688] ICS20. The system of any one of the preceding ICSs, wherein the controller is configured or programmed to generate a or the two-dimensional projection of the target surface, before the inkjetting.

[0689] ICS21. The system of any one of ICSs 15 to 20, wherein the controller is configured or programmed to calculate or select a ratio of the volume of formulation per unit of area of the two-dimensional projection of the target surface, before the inkjetting.

[0690] ICS22. The system of ICS21, wherein the controller is configured or programmed to control the inkjetting such that a ratio of a volume of formulation applied per unit of area of a two-dimensional projection of the target surface, within any subdivision of said two-dimensional projection having an area of 5% or more of an area of the projection, is within ±10%, or within ±5%, or within ±2%, or within ±1% of said calculated or selected ratio.

[0691] ICS23. The system of any preceding ICS, wherein the inkjetting is such that a ratio of a mean volume of formulation applied per unit of area of the target surface in an edge portion thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surfaceand a perimeter thereof, is between 0.58 and 0.95 times a maximum ratio of a volume of formulation applied per unit of area of the target surface.

[0692] ICS24. The system of any preceding ICS, wherein the inkjetting is such that a ratio of a mean volume of formulation applied per unit of area of the target surface in an edge portion thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surface and a perimeter thereof, is between 0.58 and 0.95 times a mean ratio of a volume of formulation applied per unit of area in a central area characterized by lying between 0% and 10% of a distance from said centroid of the target surface and said perimeter.

[0693] ICS25. The system of ICS23 or 24, wherein the SAG number of the target surface is at least 2.5mm and at most 12mm.

[0694] ICS26. The system of ICS25, wherein the SAG number is at least 3mm.

[0695] ICS27. The system of ICS25, wherein the SAG number is at least 3.5mm.

[0696] ICS28. The system of ICS25, wherein the SAG number is at least 4.5mm.

[0697] ICS29. The system of ICS25, wherein the SAG number is at least 5mm.

[0698] ICS30. The system of ICS25, wherein the SAG number is at least 6mm.

[0699] ICS31. The system ofICS25, wherein the SAG number is at least 7mm.

[0700] ICS32. The system of ICS25, wherein the SAG number is at least 9mm.

[0701] ICS33. The system of any one of ICSs 25 to 32, wherein the SAG number is at most 13.5mm. ICS34. The system of ICS33, wherein the SAG number is at most 12mm.

[0702] ICS35. The system of ICS33, wherein the SAG number is at most 10.5mm.

[0703] ICS36. The system of any one of ICSs 25 to 31, wherein the SAG number is at most 8mm.

[0704] ICS37. The system of any one of ICSs 23 to 36, wherein the ratio in the edge portion is between 0.6 and 0.9 times the maximum ratio.

[0705] ICS38. The system of any one of ICSs 23 to 36, wherein the ratio in the edge portion is between 0.6 and 0.85 times the maximum ratio.

[0706] ICS39. The system of any one of ICSs 23 to 36, wherein the ratio in the edge portion is between 0.8 and 0.96 times the ratio in the central area.

[0707] ICS40. The system of any one of ICSs 23 to 36, wherein the ratio in the edge portion is between 0.9 and 0.96 times the ratio in the central area.

[0708] ICS41. The system of any one of ICSs 13 to 22, wherein the SAG number of the target surface is between 7mm and 9mm, and the inkjetting is such that a ratio of a volume of formulation applied per unit of area of the target surface near an edge thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surface and a perimeter thereof, is between 0.70 and 0.94 times a maximum ratio of a volume of formulation applied per unit of area of the target surface.ICS42. The system of any one of ICSs 13 to 22, wherein the SAG number of the target surface is between 7mm and 9mm, and the inkjetting is such that a ratio of a volume of formulation applied per unit of area of the target surface near an edge thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surface and a perimeter thereof, is between 0.72 and 0.92 times a maximum ratio of a volume of formulation applied per unit of area of the target surface.

[0709] ICS43. The system of any one of ICSs 13 to 22, wherein the SAG number of the target surface is between 5mm and 7mm, and the inkjetting is such that a ratio of a volume of formulation applied per unit of area of the target surface near an edge thereof characterized by lying between 90% and 100% of a distance from a centroid of the target surface and a perimeter thereof, is between 0.82 and 0.96 times a maximum ratio of a volume of formulation applied per unit of area of the target surface.

[0710] ICS44. The system of any one of ICSs 13 to 22, wherein the inkjetting is such that a ratio of a mean volume of formulation applied per unit of area of the target surface at a given point on the target surface, is equal to a reduction factor times a maximum ratio of a volume of formulation applied per unit of area at any point on the target surface, said reduction factor being equal to a cosine of an acute angle formed between (i) a plane that is tangent to the target surface at said given point and (ii) a horizontal plane.

[0711] ICS45. The system of ICS44, wherein the reduction factor at any point on a perimeter of the curved surface is between 0.63 and 0.96.

[0712] ICS46. The system of any one of ICSs 13 to 45, wherein for any point on the target surface, a maximum acute angle formed between (i) a plane that is tangent to the target surface at said given point and (ii) a horizontal plane is between 10° and 40°.

[0713] ICS47. The system of any one of ICSs 13 to 45, wherein for any point on the target surface, a maximum acute angle formed between (i) a plane that is tangent to the target surface at said given point and (ii) a horizontal plane is between 5° and 50°.

[0714] ICS48. The system of any one of ICSs 13 to 45, wherein for any point on the target surface, a maximum acute angle formed between (i) a plane that is tangent to the target surface at said given point and (ii) a horizontal plane is between 15° and 40°.

[0715] ICS49. The system of any one of ICSs 13 to 45, wherein for any point on the target surface, a maximum acute angle formed between (i) a plane that is tangent to the target surface at said given point and (ii) a horizontal plane is between 5° and 20°.

[0716] ICS50. The system of any preceding ICS, wherein wherein the system is configured to perform the inkjetting without any relative vertical z-axis movement between the inkjet apparatus and the target surface.ICS51. The system of any preceding ICS, wherein the system is not configured to perform the inkjetting while causing relative vertical z-axis movement between the inkjet apparatus and the target surface.

[0717] ICS52. The system of any preceding ICS, wherein the system is not configured to perform the inkjetting while causing relative vertical z-axis movement between the inkjet apparatus and the target surface.

[0718] ICS53. The system of any preceding ICS, wherein the system is configured to perform the inkjetting without any relative rotational movement on a horizontal x-y plane between the inkjet apparatus and the target surface during the forming of the wet layer.

[0719] ICS54. The system of any preceding ICS, wherein the system is not configured to perform the inkjetting while causing relative rotational movement on a horizontal x-y plane between the inkjet apparatus and the target surface during the forming of the wet layer.

[0720] ICS55. The system of ICS54, wherein the ink-formulation-application station comprises a nonrotating optical-substrate holder.

[0721] ICS56. The system of any preceding ICS, wherein the inkjet apparatus is drop-on-demand.

[0722] ICS57. The system of any preceding ICS, further comprising a microvalve apparatus.

[0723] ICS58. The system of any preceding ICS, wherein for any point on the target surface, an acute angle formed between (i) a plane that is tangent to the target surface at said given point and (ii) a horizontal plane, is an angle (a), wherein the maximum a on the target surface is amax, and wherein a max is at least 5°.

[0724] ICS59. The system of ICS58, wherein amaxis at least 10°.

[0725] ICS60. The system of ICS58, wherein amaxis at least 15°.

[0726] ICS61. The system of ICS58, wherein amaxis at least 20°.

[0727] ICS62. The system of ICS58, wherein amaxis at least 25°.

[0728] ICS63. The system of ICS58, wherein amaxis at least 30°.

[0729] ICS64. The system of ICS58, wherein amaxis at most 50°.

[0730] ICS65. The system of any one of ICSs 58 to 64, wherein amaxis within a range of 30-40°, and wherein RDI is at most 0.90, or within a range of 0.62 to 0.90.

[0731] ICS66. The system of any one of ICSs 58 to 64, wherein amax is within a range of 19-27°, and wherein RDI is at most 0.93, or within a range of 0.85 to 0.93.

[0732] ICS67. The system of any one of ICSs 58 to 64, wherein amaxis within a range of 15-20°, and wherein RDI is at most 0.97 or within a range of 0.90 to 0.97.

[0733] ICS68. The system of any preceding ICS, further comprising any feature or features of the features provided in the method ICs hereinabove.ICS69. The system of any preceding ICS, further comprising any feature or features as described herein.

[0734] OPTICAL CONSTRUCTION EMBODIMENTS

[0735] Embodiment 1. An optical construction, as described herein.

[0736] Embodiment 2. An optical construction comprising any of the structural features disclosed in the above-provided method ICs.

[0737] Embodiment 3. An optical construction comprising any of the structural features disclosed in the above-provided system ICSs.

[0738] Embodiment 4. The optical construction of any of Embodiments 1 to 3, wherein the optical construction is or includes an eyeglass lens.

[0739] Embodiment 5. Eyeglasses comprising an eyeglass frame and at least one eyeglass lens of Embodiment 4.

[0740] It will be appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

[0741] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification, are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

Claims

WHAT IS CLAIMED IS1. A method of producing a continuous optical coating on a curved optical substrate, the method comprising:(a) inkjetting drops of a colorant-containing ink formulation, by means of an inkjet nozzle, onto a target surface of a curved optical surface of the optical substrate, to form a wet continuous ink layer having a continuous area of at least 1cm2; and(b) treating the wet continuous ink layer to produce a dried continuous ink layer on said optical surface;wherein the optical substrate is an eyeglass lens or lens blank, the optical substrate having a diameter of at least 40mm;wherein, over the entire course of said inkjetting, said inkjetting of said drops is performed while said inkjet nozzle and the optical substrate are disposed in fixed relative position with respect to the jetting direction, said inkjetting being performed while said inkjet nozzle and the optical substrate move relative to one another solely in the horizontal (X-Y) plane, and wherein, during said inkjetting, the relative movement between the inkjet nozzle and the optical substrate has velocity of at least 90mm / s;wherein GDmin is defined as the smallest gap distance between the inkjet nozzle and the curved optical surface during the inkjetting; GDmax is defined as the largest gap distance between the inkjet nozzle and the curved optical surface during the inkjetting; and AGDmax is the maximum gap differential defined by the subtraction of GDmin from GDmax, AGDmax being within a range of 2.8mm to 12mm;wherein an average diameter of the inkjetted drops (Ddrop) is within a range of 18 to 60 micrometers;wherein a peripheral printing density (PDp) is defined as a mean volume of the inkjetted ink formulation per unit of the area within a peripheral edge portion of the target surface disposed between 90% and 100% of a distance from a centroid of the target surface and a perimeter of the target surface;wherein a central printing density (PDcen) is defined as a mean volume of the inkjetted ink formulation per unit of the area within a central area disposed between 0% and 10% of a distance from the centroid of the target surface and the perimeter of the target surface;and wherein the ratio PDp to PDcen is between 0.58 and 0.95.

2. The method of claim 1, wherein the treating of the wet continuous ink layer to produce a dried continuous ink layer is performed in a drying station, wherein the treating in the drying station is performed such that the residual solvent content (RS) remaining in the dried continuous ink layer, with respect to the solvent content in the ink formulation, is at most 15% (by weight).

3. The method of claim 2, wherein RS is at least 1% or at least 3%.

4. The method of claim 3, wherein said drying is initiated after said wet continuous ink layer has been inkjetted.

5. The method of claim 4, further comprising, following step (a) and prior to step (b): repeating step (a) to produce a stack having at least a second wet continuous ink layer on top of the initially produced wet continuous ink layer.

6. The method of claim 5, wherein, prior to step (b), the stack contains at most three wet continuous ink layers.

7. The method of any one of the preceding claims, wherein the total thickness of the stack of wet continuous ink layers is at most 28 micrometers.

8. The method of claim 7, wherein the total thickness of the stack of wet continuous ink layers is at least 5, at least 8, or at least 12 micrometers.

9. The method of any one of the preceding claims, further comprising, following step (b): repeating step (a) to produce at least one additional wet continuous ink layer on the stack, the stack including the at least one dried continuous ink layer produced in step (b).

10. The method of claim 9, further comprising, following the production of the final wet continuous ink layer of the at least one additional wet continuous ink layer: drying the stack to produce a dried stack on the optical surface, and curing the dried stack to produce a cured stack.

11. The method of claim 10, further comprising: applying a wet overcoat layer to the cured stack, and drying and curing the wet overcoat layer to produce a cured overcoat-covered stack.

12. The method of claim 11, further comprising: applying a wet hardcoat layer onto the cured overcoat-covered stack, and drying and curing to produce a cured hardcoat-covered stack.

13. The method of any one of the preceding claims, wherein the controller is configured or programmed to calculate or select a ratio of the volume of formulation per unit of area of a two-dimensional projection of the target surface, before said inkjetting.

14. The method of any one of the preceding claims, wherein the ratio PDp to PDcen is at least 0.8.

15. The method of any one of the preceding claims, wherein the colorant-containing ink formulation contains a photochromic dye.

16. The method of any one of the preceding claims, wherein, on an n-butyl acetate normalized 25°C evaporation rate scale, the formulation has at least one of the following features: (a) at least 45% of the total solvent within the formulation is at most a low vaporpressure solvent (Levap), at least 15% of the total solvent within the formulation is a very low vapor-pressure solvent (LLevap); and (b) at least 70% of the total solvent within the formulation is at most a medium vapor-pressure solvent (Mevap).

17. The method of claim 16, wherein at least 80% of the total solvent within the formulation is at most a high vapor-pressure solvent (Hevap).

18. The method of any one of the preceding claims, wherein with respect to the ink formulation, the operating viscosity is within a range of 10 to 70cP, and the operating surface tension is within a range of 24 to 35 dyne / cm.

19. The method of claim 18, wherein, the operating viscosity is within a range of 10 to 45cP.

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