Functional membranes printed by 3D printing

Abstract

A method for manufacturing an optical lens (417, 901), comprising: (S301) obtaining a transparent thermoplastic (TP) carrier (410, 1210) having at least one smooth surface; (S305) using a thermoplastic filament (403) to print at least one transparent layer (420, 1220) on a side opposite to the at least one smooth surface of the transparent TP carrier (410, 1210) via a 3-D printer, each transparent layer (420, 1220) having predetermined filtering properties, thereby forming a functional layer (420, 1220); and (S307) performing an injection overmolding process (415) to fuse the functional layer (420, 1220) to a thermoplastic substrate, thereby forming the optical lens, wherein the at least one smooth surface of the transparent TP carrier (410, 1210) forms the smooth surface of the manufactured optical lens (417, 901).

Description

background Technical Field

[0002] This disclosure relates to a method for manufacturing functional membranes suitable for producing optical lenses using conventional injection molding processes using additive manufacturing methods. For example, an FDM 3D printing process using a smooth thermoplastic substrate is proposed to produce a membrane with optical filtering function. Background Art

[0004] The "Background" description provided herein is intended to generally introduce the context of the present disclosure. To the extent that the work of the presently named inventors is described in this Background section, and for aspects of this description that may not be identified as prior art at the time of filing, no admission is made, either explicitly or implicitly, that it is prior art against the present invention.

[0005] Corrective lenses, including glasses and contact lenses, are used to treat refractive errors of the eye, such as nearsightedness, farsightedness, astigmatism, and presbyopia. Glasses are worn on the face, a short distance in front of the eyes. Contact lenses are worn directly on the surface of the eye.

[0006] Materials commonly used for lenses include glass and plastic. Glass lenses are less common due to their relatively high weight compared to plastic lenses. Plastic lenses are by far the most commonly prescribed lenses due to their relative safety, lower cost, ease of production, and high optical quality. The main disadvantages of many types of plastic lenses are that the lenses can be easily scratched and the limitations and costs of producing higher refractive index lenses. Polycarbonate is lighter in weight than normal plastics. It blocks UV rays, resists breakage, and is used in sports eyewear and eyewear for children and teenagers. Because polycarbonate is soft and will scratch easily, an anti-scratch coating is usually applied to the lenses after they are formed and polished.

[0007] Fused Deposition Modeling TM FDM (Fused Filament Fabrication; sometimes also called Fused Filament Fabrication or FFF) is a cost-effective method for producing customized three-dimensional (3-D) thermoplastic parts and prototypes. Figure 1 Schematic diagram of an FDM 3-D printer. A filament spool 101 containing filament 103 is fed into an extruder 105 , heated in a heater head 107 , and then fed through a nozzle 109 to print a part 111 on a print bed 113 .

[0008] The FDM 3-D printer also includes a programmable controller. The programmable controller controls the movement of the nozzle 109 in the XY plane and applies layers by moving in the Z direction. Furthermore, the programmable controller controls the ejection of heated filament. By controlling the movement of the nozzle and the ejection of heated filament, various patterns can be formed at each level of the XY plane of the layer, and applying layers in the Z direction allows for the formation of various 3-D shapes. Furthermore, the filament material can be varied to produce layers of different materials.

[0009] The main disadvantage of FDM 3-D printing is its inability to produce with a resolution fine enough to achieve optical quality. FDM's layered approach results in many rigid edges (or sometimes small holes) on the part surface that strongly scatter light (see Figure 2 FDM printing of the functional membrane 201 in the example above results in a rough and opaque appearance. Furthermore, the layer bonding mechanism causes the FDM part itself to be anisotropic and have poor impact strength. Therefore, FDM 3-D printing is currently generally considered unsuitable for the production of optical lenses in the optical industry. Summary of the Invention

[0010] A first aspect is a method for manufacturing an optical lens. The method includes: obtaining a transparent thermoplastic (TP) carrier having at least one smooth surface; using thermoplastic filament to print at least one transparent layer on a side of the transparent TP carrier opposite the at least one smooth surface via a 3-D printer, each transparent layer having predetermined light filtering properties, thereby forming a functional layer; and performing an injection overmolding process to fuse the functional layer to a thermoplastic substrate, thereby forming the optical lens, wherein the at least one smooth surface of the transparent TP carrier forms the smooth surface of the manufactured optical lens.

[0011] It should be noted that the transparent TP carrier is retained by this manufacturing method and is therefore included in the final manufactured lens, the smooth surface of this carrier also being present in the lens.

[0012] The at least one smooth surface may exhibit a roughness average parameter Ra greater than or equal to 50 nm.

[0013] In a second aspect, the printing includes printing a plurality of transparent layers via the 3-D printer, each transparent layer having different filtering properties to form a multifunctional layer, wherein the filtering property is one selected from the group consisting of: ultraviolet (UV) cutoff, blue light cutoff, color enhancement, photochromic, and near infrared (NIR) cutoff.

[0014] In a third aspect, the transparent TP carrier has at least one predetermined filtering property.

[0015] In a fourth aspect, the thermoplastic filaments include a filament material that is compatible with the material of the transparent TP carrier so as to strengthen the bonding of the transparent layer to the transparent TP carrier.

[0016] In a fifth aspect, the filament material is selected from the group consisting of: polycarbonate (PC), alicyclic polycarbonate copolymers, poly(methyl methacrylate) (PMMA), poly(methacrylimide) (PMMI), polyamide (PA), polyester, copolyester, polysulfone (PSU), cellulose triacetate (TAC), thermoplastic polyurethane (TPU) and cyclic olefin copolymer (COC).

[0017] In a sixth aspect, the thermoplastic substrate has a material that is compatible with the material of the outermost layer of the functional layer so as to strengthen the bonding between the thermoplastic substrate and the functional layer.

[0018] In a seventh aspect, the transparent TP carrier is a polarizing laminate of multiple layers, wherein two or more of the layers are composed of different materials selected from the group consisting of: polycarbonate (PC), polyvinyl alcohol (PVA), cellulose triacetate (TAC), polyamide (PA), cyclic olefin copolymer (COC), thermoplastic polyurethane (TPU) and multilayer optical film (MOF).

[0019] In an eighth aspect, the transparent TP carrier is a photochromic laminate of multiple layers, wherein two or more of the layers are composed of different materials selected from the group consisting of: polycarbonate (PC), polyurethane (PU), polyether block amide (PEBA), cellulose triacetate (TAC), polyamide (PA), cyclic olefin copolymer (COC) and thermoplastic polyurethane (TPU).

[0020] In a ninth aspect, the printing further comprises heating the TP support to a temperature higher than its glass transition temperature (T g，载体 ) Temperature lower than 50℃ (T 载体 ), making 0℃<T g，载体 -T 载体 ≤50℃, and heating is preferably such that 5℃≤T g，载体 -T 载体 ≤30℃.

[0021] In a tenth aspect, the printing further comprises incorporating a specific pattern into the at least one transparent layer.

[0022] In an eleventh aspect, the specific pattern includes data related to the lens manufacturer and is bonded using an IR absorbing dye.

[0023] In the twelfth aspect, the specific pattern is used to scatter light and is a group of rings, each ring is concentric and is made of a pitch circle shape with a diameter of 0.3 mm or less, and the refractive index of the transparent TP carrier is different from the refractive index of the material of the specific pattern.

[0024] In a thirteenth aspect, the at least one transparent layer is printed as a grid made of:

[0025] - a set of diffuse points having a refractive index different from the refractive index of the thermoplastic substrate,

[0026] - a set of light scattering dots, the size of which is between 100 nm and 10 μm.

[0027] Fourteenth aspect:

[0028] - the step of obtaining the transparent TP carrier is such that the transparent TP carrier is curved and both sides of the transparent TP carrier are smooth surfaces; and

[0029] - The printing step is carried out via the 3-D printer on the concave side of the curved transparent TP carrier.

[0030] In a fifteenth aspect, at least one smooth surface of the transparent TP carrier faces a concave insert of an injection mold, and the injection overmolding process is performed in the injection mold.

[0031] The foregoing general description and the following detailed description of the illustrative embodiments are merely exemplary aspects of the teachings of the present disclosure and are not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] A more complete understanding of the present disclosure and many of its attendant advantages will be readily obtained as the present disclosure may be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0033] Figure 1 This is a schematic diagram of an FDM 3-D printer;

[0034] Figure 2 It is an FDM 3-D printed functional diaphragm;

[0035] Figure 3 is a flow chart of a method for manufacturing an optical lens using an FDM 3-D printer and injection overmolding according to an exemplary aspect of the present disclosure;

[0036] Figure 4 is a schematic diagram of a system for manufacturing an optical lens using an FDM 3-D printer and injection overmolding according to an exemplary aspect of the present disclosure;

[0037] Figure 5 is a schematic diagram of the injection overmolding process;

[0038] Figure 6 According to exemplary aspects of the present disclosure Figure 3 A flow chart of a method comprising printing a transparent layer;

[0039] Figure 7 yes Figure 3 A flow chart of a method comprising heating a TP support to a temperature below a glass transition temperature;

[0040] Figure 8 yes Figure 3 A flow chart of a method comprising printing a transparent layer in a pattern of a diffused dot grid;

[0041] Figure 9 shows the microlenses arrayed on the lenses of single-vision glasses;

[0042] Figure 10 yes Figure 3 A flow chart of a method comprising combining a specific geometric pattern;

[0043] Figure 11 A functional film having a specific pattern according to an exemplary aspect of the present disclosure is shown; and

[0044] Figure 12 is a schematic diagram of a system for manufacturing an optical lens using an FDM 3-D printer and injection overmolding according to an exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0045] In the drawings, like reference numerals designate identical or corresponding parts throughout the several views. Furthermore, as used herein, the terms "a," "an," and the like generally have the meaning of "one or more" unless otherwise indicated. The drawings are generally drawn to scale unless otherwise indicated or to show schematic structures or flow diagrams.

[0046] Furthermore, the terms "approximately," "approximately," "about," and similar terms generally refer to ranges that include the identified value within a margin of 20%, 10%, or preferably 5%, and any values ​​therebetween.

[0047] 3D printing offers benefits such as being more cost-effective for low-volume and rapid prototyping tasks. FDM can be used to quickly and cost-effectively produce functional membranes from thermoplastic filaments with specific dyes and / or filters such as UV cutoff, blue light cutoff, NIR cutoff, color enhancement, and photochromic.

[0048] One possible way to form optical quality parts using FDM is to integrate the functional film onto the front surface of an ophthalmic lens through a conventional injection overmolding process (or film insert molding process). In this approach, during the conventional injection overmolding process, the front surface of the functional film (convex surface) is aligned with the cavity wall (concave insert surface) of the ophthalmic lens at a temperature well below its glass transition temperature, T g The glass transition temperature characterizes the secondary transformation of an amorphous polymer from a brittle, glassy solid to a viscous or rubbery substance. The cavity temperature T in the injection mold 模腔 Must be lower than the glass transition temperature T of the membrane g，膜片 , so that the functional membrane maintains its shape when embedded in the mold cavity. 模腔 Must be below the glass transition temperature (T g，镜片 ), so that the resulting lens is in a solid form that is rigid enough to be ejected without deformation. In this method, T 模腔 ≤T g，镜片 -20 (℃). In addition, the diaphragm material and the lens material should be the same to ensure the compatibility between the diaphragm and the lens to achieve good bonding. In this case, T g，膜片 =T g，镜片 .

[0049] However, using this method, even though the back surface (concave surface) of the diaphragm is melted by the molten lens material and becomes an integral part of the resulting lens, the front surface remains solid throughout the injection overmolding process and retains its surface texture. Therefore, the surface of the optical lens with integrated functional diaphragms produced by FDM 3-D printing will not be smooth.

[0050] One purpose of this disclosure is to describe a method for producing functional films for producing optical lenses using an FDM 3-D printer. In one aspect, the functional films printed by FDM 3-D printing are used together with a conventional injection overmolding process to produce optical lenses.

[0051] The reason why conventional injection overmolding processes using FDM 3D printed functional films have not yet been able to achieve optical quality lenses is that the front surface of the functional film remains well below its glass transition temperature, T gtemperature and thus remain solid throughout the entire process. It has been determined that this problem can be overcome by at least first obtaining a single-layer or multi-layer functional thermoplastic carrier with at least a smooth front surface, and then sintering the additional (multiple) functional layers of 3D printing onto the rear surface of the carrier. At least the front surface of the thermoplastic carrier is smooth. The resulting 3D printed product retains the smooth front surface of the functional carrier while adding new functions through the additional (multiple) layers. The 3D printed product can be used as a functional membrane together with conventional injection overmolding to produce optical products with smooth surfaces.

[0052] In some embodiments, a flat, multi-layered, transparent thermoplastic (TP) carrier is obtained, and a transparent layer is printed on one side of the carrier using an FDM 3-D printer. The transparent layer can be printed using TP filaments with specific filtering (such as blue light cutoff (BCT), color enhancement, photochromic (PhCh), and near-infrared (NIR) light cutoff) to prepare a functional membrane. This functional membrane can then be used with a conventional injection overmolding process to produce an optical lens with a specific filtering function. In some aspects, several layers of different filters can be printed on a carrier to prepare a membrane with multiple functions (such as PhCh / BCT, BCT / NIR cutoff, PhCh / BCT / NIR cutoff, and other filtering functions).

[0053] Figure 3 1 is a flow chart of a method for manufacturing an optical lens using an FDM 3-D printer and injection overmolding according to an exemplary aspect of the present disclosure. The method for manufacturing an optical lens includes: S301, obtaining a transparent thermoplastic (TP) substrate having at least one smooth surface; S303, using thermoplastic filament to print at least one transparent layer on a side opposite to the at least one smooth surface of the transparent TP substrate via an FDM 3-D printer, each transparent layer having predetermined light filtering properties to form a functional layer; and S307, performing an injection overmolding process to fuse the functional layer to the thermoplastic substrate to form the optical lens.

[0054] Figure 4is a schematic diagram of a system for manufacturing an optical lens using an FDM 3-D printer and injection overmolding according to an exemplary aspect of the present disclosure. A filament spool 101 of thermoplastic (TP) filament 403 is supplied to an extruder 105, heated in a heater end 107, and then passed through a nozzle 109 to print a functional layer 420 on a TP carrier 410. In some embodiments, the transparent TP carrier 410 is flat and has a smooth surface on at least the front side (i.e., the side facing away from the nozzle 109). The FDM 3-D printer prints a transparent layer 420 on the back side of the carrier 410 using the TP filament 403. The TP filament 403 can have specific filtering (such as blue light cutoff (BCT), color enhancement, photochromic (PhCh), and NIR cutoff) to produce a functional film 413. In some embodiments, at 419, the functional layer 413 can be thermoformed into a lens shape to achieve desired optical properties. This functional diaphragm 413 or 419 can be used with a conventional injection overmolding process 415 (e.g. Figure 9 shown) are used together to produce an optical lens 417 with a specific filtering function.

[0055] In some embodiments, several layers of different filters can be printed on the TP carrier 410 to produce a film 413 with multiple functions (such as PhCh / BCT, BCT / NIR cutoff, PhCh / BCT / NIR cutoff, and other optical functions). Furthermore, the TP carrier 410 can be made of a TP film that itself has specific filters to introduce additional functions.

[0056] Preferably, the filament 403 and the TP carrier 410 used to print the functional layer 420 are made of the same material or made of materials that are compatible with each other to ensure good bonding and optical transparency of the functional layer / carrier interface of the resulting membrane 413. Examples of identical filament materials and carrier materials include, but are not limited to, polycarbonate (PC), alicyclic polycarbonate copolymers, poly(methyl methacrylate) (PMMA), poly(methacrylimide) (PMMI), polyamide (PA), copolyesters, cellulose triacetate (TAC), thermoplastic polyurethane (TPU) and cyclic olefin copolymers (COC). Examples of unpreferred filament / carrier pairs include, but are not limited to, PMMA / PC, copolyesters / PC, polyester alloys / PC and alicyclic polycarbonate / PC. Non-limiting examples of PMMA include Evonik Arkema and ChiMei Non-limiting examples of PMMI include Evonik Non-limiting examples of copolyesters include Eastman TRITAN TM and SK Chemical Non-limiting examples of polyester alloys include Sabic XYLEX TM Non-limiting examples of alicyclic polycarbonates include DURABIO from Mitsubishi Chemical Corporation. TM and Teijin Non-limiting examples of PC include Sabic Lexan TM , Teijin and Covestro

[0057] Furthermore, in order to use the 3D printed functional film 413 together with the injection overmolding 415, the lens material and the outermost layer of the rear portion of the functional film 413 can be the same or compatible to ensure good bonding and good transparency of the resulting optical lens. The above examples of filament materials and carrier materials also apply to the lens material.

[0058] Figure 5 Schematic diagram of the injection overmolding process. The injection overmolding process 415 is used to integrate a functional film onto a thermoplastic lens. The entire process is carried out at a constant mold cavity temperature (T 模腔 ), the constant cavity temperature is basically kept below the glass transition temperature (T g，膜片 ). In 501, the mold is opened. In 503, the functional film 413 is inserted into the mold. In 505, the mold is closed. In 507, molten lens material 520 is injected into the mold and sintered to the functional film 413. In 509, the lens 417 is ejected from the mold.

[0059] In some embodiments, the process can start with a 3-layer flat laminate with a smooth surface on at least one side as a carrier 410 to prepare a functional film 413 using FDM 3-D printing. Typical examples of laminates include PC / PVA / PC and TAC / PVA / TAC polarizing laminates, PC / PU / PC and PC / TPU / PC photochromic laminates, PC / MOF (multilayer optical film) / PC polarizing and / or blue light cutoff and / or reflector laminates. These types of laminates (especially PVA polarizing or MOF) often have functions that are difficult to achieve by 3D printing alone. By combining with FDM 3-D printing, additional functions can be added to such laminates without having to modify the constituent layers. For example, a color enhancement layer can be printed on a PC / PVA / PC polarizing carrier to produce a polarizing film with color enhancement function. A similar method can be used to provide a color enhancement photochromic film by printing a color enhancement layer on a PC / PU / PC carrier.

[0060] In some embodiments, the transparent TP carrier is a polarizing laminate of multiple layers, wherein two or more layers are made of different materials. Polarizing laminates include, but are not limited to, polycarbonate (PC) / polyvinyl alcohol (PVA) / PC, cellulose triacetate (TAC) / PVA / TAC, polyamide (PA) / PVA / PA, cyclic olefin copolymer (COC) / PVA / COC, thermoplastic polyurethane (TPU) / PVA / TPU, and PC / multilayer optical film (MOF) / PC. Although these laminates are symmetrical, asymmetric laminates may also be used.

[0061] In some embodiments, the transparent TP carrier is a photochromic laminate of multiple layers, wherein two or more layers are made of different materials. Photochromic laminates include, but are not limited to, polycarbonate (PC) / polyurethane (PU) / PC, PC / polyether block amide (PEBA) / PC, triacetyl cellulose (TAC) / PU / TAC, TAC / PEBA / TAC, polyamide (PA) / PU / PA, PA / PEBA / PA, cyclic olefin copolymer (COC) / PU / COC, COC / PEBA / COC, and thermoplastic polyurethane (TPU) / PU / TPU, and TPU / PEBA / TPU. Although these laminates are symmetrical, asymmetric laminates may also be used.

[0062] Figure 6 According to exemplary aspects of the present disclosure Figure 3 Flowchart of a method for printing a transparent layer. As mentioned above, several layers of different filters can be printed on a TP carrier 410 to produce a membrane 413 with multiple functions. In S601, an FDM 3-D printer prints several transparent layers 420, each with different filtering properties, to form a multifunctional layer.

[0063] Figure 7 yes Figure 3 Flowchart of a method for 3D printing, which includes heating the TP carrier to a temperature below the glass transition temperature. In particular, in order to improve the quality of the 3D printed layer and to enhance the bonding strength between the 3D printed functional layer 420 and the TP carrier 410, it is preferred that during 3D printing (S303), in S701, the carrier is heated to and maintained at a temperature higher than its glass transition temperature (T g，载体 ) Temperature lower than 50℃ (T 载体 ), that is, 0<T g，载体 -T 载体 ≤50℃, more preferably, 5℃≤T g，载体 -T 载体≤30° C. Such temperature conditions can be achieved by using a heated print bed and / or performing 3D printing in a heated chamber.

[0064] One advantage of the present disclosure is that a conventional injection overmolding process with a constant mold temperature is used, which has a much less complex mold design and a much shorter cycle time than a heating / cooling process. Furthermore, supplementary functions and / or complementary functions can be added to existing functional carriers, which significantly shortens the time and reduces the cost of developing new functional membranes. Moreover, because filament extrusion and FDM 3-D printing are typically performed at lower material temperatures, lower material shear, and shorter material residence times than injection molding processes, the present method is more suitable for preparing functional membranes with heat-sensitive dyes / filters than injection molding.

[0065] In some embodiments, FDM can 3D print specific patterns rather than adding uniform layers. These patterns can be used to directly write data related to lens manufacturing, such as using IR-absorbing dyes in the FDM-deposited material. These patterns can also include microlenses, bifocal lenses, trifocal lenses, and progressive lenses.

[0066] In one embodiment, a specific pattern may be formed for myopia control purposes. Figure 8 yes Figure 3 Flowchart of a method for printing a transparent layer into a grid of diffused dots. In S801, a grid made of a set of diffused dots can be printed as a solution to reduce the contrast at the periphery of the lens (for example, to slow the progression of myopia in children, see US2011 / 0313058). Figure 9 A diagram shows microlenses arranged on a single vision lens. The set of diffused dots can be microlenses, which typically have diameters ranging from about one-tenth of a millimeter to about 1.1 millimeters and heights of about 1 micron. The optical power is located at the center 905 of the lens 901, while the microlenses form an array 903 in a specific pattern.

[0067] In this embodiment, the refractive index (RI) of the FDM material needs to be different from the refractive index of the injected lens material to provide optical scattering. For example, using a dot with a thickness of 0.3 mm and a width or diameter of 0.3 mm, with a refractive index difference of ΔRI = 0.01 will be sufficient to provide optical scattering (0.3 mm x 0.01 >> wavelength of visible light). Smaller dots may be preferred to increase the scattering angle of the dot. For example, a 0.2 mm diameter will be at (3 / 2) 2 =2.25 scatters light over a larger angle area.

[0068] In one embodiment, an FDM filament material with scattering properties can be added. This material can be PC mixed with pigments, with a size between 100nm and 10μm.

[0069] In some embodiments, other patterns may be printed. Figure 10 yes Figure 3 Flowchart of a method for printing a transparent layer into a specific geometric pattern, the method comprising: In S1001, a transparent layer can be printed into a specific geometric pattern. Figure 11 A functional film having a specific geometric pattern according to an exemplary aspect of the present disclosure is shown. Figure 11 In FIG, a diaphragm 1101 includes a specific geometric pattern 1103 deposited via FDM for scattering light. Specifically, the specific geometric pattern is a set of rings (each ring is concentric) and is made of a pitch circle shape with a diameter of 0.3 mm or less, and the RI of the TP carrier ≠ the RI of the FDM patterned material.

[0070] Experimental Implementation 1

[0071] As an experimental embodiment, color enhancement polarizing films and lenses were made. In the embodiment, a 650 μm thick PC / PVA / PC neutral gray polarizing laminate with a transmission of 35% from Onbitt was die cut to Circular carrier.

[0072] Sabic OQ3820 is a UV stabilized polycarbonate (PC) grade for ophthalmic lenses. This PC resin has a glass transition temperature of 145°C and a UV cutoff of approximately 380 nm as measured through a 2 mm thick lens. OQ3820 PC resin is compounded with two color enhancing dyes with absorption peaks around 495 nm and 585 nm, respectively, and then extruded into filament.

[0073] Using this filament, a 0.1 mm thick color-enhancing layer was then printed onto a PC / PVA / PC polarizing support using an FDM 3-D printer in a heated chamber maintained at 120°C to produce a color-enhancing polarizing film. The resulting flat film had a rough surface on the 3D-printed side but a smooth surface on the other side.

[0074] In order to produce polarized lenses with color enhancement function, the film is applied to Figure 5 The injection overmolding process demonstrated here uses OQ3820 PC resin as the lens material, with the smooth side facing the concave insert and the rough color enhancement layer facing the melt. Key parameters are listed below:

[0075]

[0076]

[0077] The resulting 1.50 base semi-finished (SF) lens was 10 mm thick, optically clear, had smooth front and back surfaces, and exhibited both polarization and color enhancement functions.

[0078] Experimental Implementation 2

[0079] As a second experimental embodiment, a blue light cutoff film and a lens were manufactured.

[0080] A commercially available transparent PC film of 250 μm thickness with a total transmittance of 91% and a UV cutoff of <300 nm was die-cut into Circular carrier.

[0081] Sabic OQ3820 is a UV stabilized polycarbonate (PC) grade for ophthalmic lenses. This PC resin has a glass transition temperature of 145°C and a UV cutoff of approximately 380 nm as measured through a 2 mm thick lens. OQ3820 PC resin was mixed with 1.0% of 326UV absorber compounded and then extruded into filament.

[0082] Using this filament, a 0.25 mm thick layer was then printed onto the PC support using an FDM 3-D printer in a heated chamber maintained at 120° C. to produce a blue-light-cutting membrane. The resulting flat membrane had a rough surface on the 3D-printed side but a smooth surface on the other side.

[0083] In order to produce a blue light cut-off lens, the film is applied to Figure 4 In the demonstrated injection overmolding process, the smooth side faces the concave insert, while the rough blue-light cutoff layer faces the melt. OQ3820 PC resin is used as the lens material. The key parameters are listed below:

[0084]

[0085] The resulting 1.50mm thick semi-finished lens (SF) is not only optically transparent with smooth front and back surfaces, but also achieves a UV cutoff of approximately 402nm after surface processing to a 2mm flat surface. Furthermore, a blue light cutoff performance (BVC B') of approximately 30% was measured.

[0086] Figure 12 The process of making functional lenses by FDM 3D printing (multiple) thermoplastic (TP) functional layers on a curved single-layer TP carrier using a functional film is demonstrated.

[0087] exist Figure 12 In the embodiment, a curved transparent TP carrier 1210 with a smooth surface on the back or both sides is used together with an FDM 3-D printer to print a transparent layer 1220 on the concave side of the carrier 1210 using TP filament 403 with specific light filtering (such as blue light cutoff (BCT), color enhancement, photochromic (PhCh) and NIR cutoff) to produce a functional film 1213. This functional film 1213 can then be used with a conventional injection overmolding process 415 (such as Figure 5 In some embodiments, the optical lens 417 is used together with the optical lens 417 to produce a specific filtering function. Figure 4 Similar to the above situation in , several layers of different filters can be printed on the carrier 1210 to produce a membrane 1213 with multiple functions (such as PhCh / BCT, BCT / NIR cutoff, PhCh / BCT / NIR cutoff, etc.). Furthermore, the carrier 1210 can be made of a TP film with specific filters to introduce more functions.

[0088] In some embodiments, the FDM 3-D printer used to print on the curved TP carrier 1210 can be a 3-D printer that is specifically configured to print on surfaces other than flat surfaces. For example, the specialized 3-D printer can include control over the angle of the nozzle 109 so that the nozzle is continuously adjusted to face a direction perpendicular to a tangent line of the curved surface.

[0089] (1) A method for manufacturing an optical lens, comprising:

[0090] obtaining a transparent thermoplastic (TP) support having at least one smooth surface;

[0091] Printing at least one transparent layer on a side opposite to at least one smooth surface of the transparent TP carrier using a thermoplastic filament via a 3-D printer, each transparent layer having predetermined light filtering properties, thereby forming a functional layer; and

[0092] An injection overmolding process is performed to fuse the functional layer to the thermoplastic substrate, thereby forming the optical lens.

[0093] (2) The method according to (1), wherein the printing comprises:

[0094] Multiple transparent layers are printed out through the 3-D printer, each transparent layer having different light filtering properties to form a multifunctional layer.

[0095] Wherein the light filtering property is one selected from the group consisting of ultraviolet (UV) cut-off, blue light cut-off, color enhancement, photochromic, and near infrared (NIR) cut-off.

[0096] (3) The method according to (1) or (2), wherein the transparent TP carrier has at least one predetermined filtering property.

[0097] (4) The method according to any one of (1) to (3), wherein the thermoplastic filament comprises a filament material that is compatible with the material of the transparent TP carrier so as to strengthen the bonding of the transparent layer to the transparent TP carrier.

[0098] (5) The method according to any one of (1) to (4), wherein the filament material is selected from the group consisting of: polycarbonate (PC), alicyclic polycarbonate copolymers, poly(methyl methacrylate) (PMMA), poly(methacrylimide) (PMMI), polyamide (PA), polyester, copolyester, polysulfone (PSU), cellulose triacetate (TAC), thermoplastic polyurethane (TPU) and cyclic olefin copolymer (COC).

[0099] (6) The method according to any one of (1) to (5), wherein the thermoplastic substrate has a material compatible with the material of the outermost layer of the functional layer so as to strengthen bonding of the thermoplastic substrate to the functional layer.

[0100] (7) A method according to any one of (1) to (6), wherein the transparent TP carrier is a polarizing laminate of multiple layers, wherein two or more of the layers are composed of different materials selected from the group consisting of: polycarbonate (PC), polyvinyl alcohol (PVA), cellulose triacetate (TAC), polyamide (PA), cyclic olefin copolymer (COC), thermoplastic polyurethane (TPU) and multilayer optical film (MOF).

[0101] (8) The method according to any one of (1) to (7), wherein the transparent TP carrier is a photochromic laminate of multiple layers, wherein two or more of the layers are composed of different materials selected from the group consisting of: polycarbonate (PC), polyurethane (PU), polyether block amide (PEBA), cellulose triacetate (TAC), polyamide (PA), cyclic olefin copolymer (COC) and thermoplastic polyurethane (TPU).

[0102] (9) The method according to any one of (1) to (8), wherein the printing further comprises heating the TP support to a temperature higher than its glass transition temperature (T g，载体 ) Temperature lower than 50℃ (T 载体 ).

[0103] (10) The method according to (9), wherein during the printing, the TP carrier is heated to a temperature such that 0°C < T g，载体 -T 载体≤50℃.

[0104] (11) The method according to (10), wherein during the printing, the TP carrier is heated to a temperature such that 5°C ≤ T g，载体 -T 载体 ≤30℃.

[0105] (12) The method according to any one of (1) to (11), wherein the printing further includes incorporating a specific pattern into the at least one transparent layer.

[0106] (13) The method according to (12), wherein the specific pattern includes data related to the lens manufacturer and is bonded using an IR absorbing dye.

[0107] (14) The method according to any one of (1) to (13), wherein the at least one transparent layer is printed as a grid made of a set of diffuse dots having a refractive index different from the refractive index of the thermoplastic substrate.

[0108] (15) A method according to any one of (1) to (14), wherein the at least one transparent layer is printed into a grid made of a set of light scattering dots, the size of which is between 100 nm and 10 μm.

[0109] (16) A method for manufacturing an optical lens, comprising:

[0110] obtaining a curved transparent thermoplastic (TP) carrier having smooth surfaces on both sides;

[0111] Printing at least one transparent layer on the concave side of the curved transparent TP carrier using a thermoplastic filament via a 3-D printer, each transparent layer having predetermined light filtering properties, thereby forming a functional layer; and

[0112] An injection overmolding process is performed to fuse the functional layer to the thermoplastic substrate, thereby forming the optical lens.

[0113] (17) The method according to (16), wherein the printing comprises:

[0114] Multiple transparent layers are printed out through the 3-D printer, each transparent layer having different light filtering properties to form a multifunctional layer.

[0115] Wherein the light filtering property is one selected from the group consisting of ultraviolet (UV) cut-off, blue light cut-off, color enhancement, photochromic, and near infrared (NIR) cut-off.

[0116] (18) The method according to (16) or (17), wherein the curved transparent TP carrier has at least one predetermined filtering property.

[0117] (19) The method according to any one of (16) to (18), wherein the thermoplastic filament comprises a filament material that is compatible with the material of the curved transparent TP carrier so as to strengthen the bonding of the transparent layer to the curved transparent TP carrier.

[0118] (20) The method according to (19), wherein the filament material is selected from the group consisting of: polycarbonate (PC), alicyclic polycarbonate copolymers, poly(methyl methacrylate) (PMMA), poly(methacrylimide) (PMMI), polyamide (PA), polyester, copolyester, polysulfone (PSU), cellulose triacetate (TAC), thermoplastic polyurethane (TPU) and cyclic olefin copolymer (COC).

[0119] Many modifications and variations of the present invention are possible in light of the above teachings.It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

Claims

1. A method for manufacturing an optical lens (417, 901), comprising: (S301) obtaining a transparent thermoplastic (TP) carrier (410, 1210) having at least one smooth surface; (S305) using a thermoplastic filament (403) to print at least one transparent layer (420, 1220) on a side opposite to at least one smooth surface of the transparent TP carrier (410, 1210) via a 3-D printer, wherein each transparent layer (420, 1220) has predetermined light filtering properties, thereby forming a functional layer (420, 1220); as well as (S307) An injection molding process (415) is performed to fuse the functional layer (420, 1220) to the thermoplastic substrate, thereby forming the optical lens, wherein at least one smooth surface of the transparent TP carrier (410, 1210) forms a smooth surface of the manufactured optical lens (417, 901), so that the transparent TP carrier (410, 1210) is included in the manufactured optical lens (417, 901).

2. The method according to claim 1, wherein The printing (S305) includes: Printing a plurality of transparent layers (420, 1220) via the 3-D printer, each transparent layer (420, 1220) having different light filtering properties to form a multifunctional layer, The light filtering property is one selected from the group consisting of ultraviolet (UV) cutoff, blue light cutoff, color enhancement, photochromic, and near infrared (NIR) cutoff.

3. The method according to claim 1, wherein The transparent TP carrier (410, 1210) has at least one predetermined filtering property.

4. The method according to claim 1, wherein The thermoplastic filaments (403) include a filament material that is compatible with the material of the transparent TP carrier (410, 1210) so as to strengthen the bonding of the transparent layer (420, 1220) to the transparent TP carrier (410, 1210).

5. The method according to claim 4, wherein The filament material is selected from the group consisting of polycarbonate (PC), alicyclic polycarbonate copolymers, poly(methyl methacrylate) (PMMA), poly(methacrylimide) (PMMI), polyamide (PA), polyester, copolyester, polysulfone (PSU), cellulose triacetate (TAC), thermoplastic polyurethane (TPU) and cyclic olefin copolymer (COC).

6. The method according to claim 1, wherein The thermoplastic substrate has a material that is compatible with the material of the outermost layer of the functional layer (420, 1220) so as to strengthen the bonding between the thermoplastic substrate and the functional layer (420, 1220).

7. The method according to claim 1, wherein The transparent TP carrier (410, 1210) is a polarizing laminate of multiple layers, wherein two or more of the layers are composed of different materials selected from the group consisting of: polycarbonate (PC), polyvinyl alcohol (PVA), cellulose triacetate (TAC), polyamide (PA), cyclic olefin copolymer (COC), thermoplastic polyurethane (TPU) and multilayer optical film (MOF).

8. The method according to claim 1, wherein The transparent TP carrier (410, 1210) is a photochromic laminate of multiple layers, wherein two or more of the layers are composed of different materials selected from the group consisting of: polycarbonate (PC), polyurethane (PU), polyether block amide (PEBA), cellulose triacetate (TAC), polyamide (PA), cyclic olefin copolymer (COC) and thermoplastic polyurethane (TPU).

9. The method according to claim 1, wherein The printing (S305) further includes heating the TP carrier (410, 1210) to a temperature higher than its glass transition temperature (T g，载体 ) Temperature lower than 50℃ (T 载体 ), making 0℃<T g，载体 -T 载体 <50℃.

10. The method according to claim 1, wherein The printing (S305) further includes (S801, S1001) incorporating a specific pattern (903, 1103) into the at least one transparent layer (420, 1220).

11. The method according to claim 10, wherein: The specific pattern (903) includes data related to the manufacturer of the lens (417, 901) and is bonded using an IR absorbing dye.

12. The method according to claim 10, wherein: The specific pattern (1103) is used to scatter light and is a group of rings, each ring is concentric and is made of a pitch circle shape with a diameter of 0.3 mm or less, and the refractive index of the transparent TP carrier (410) is different from the refractive index of the material of the specific pattern (1103).

13. The method according to claim 1, wherein The at least one transparent layer (420, 1220) is printed as a grid made of: - a set of diffuse points having a refractive index different from the refractive index of the thermoplastic substrate, - a set of light scattering dots, the size of the set of light scattering dots being between 100 nm and 10 μm.

14. The method of claim 1, wherein: - the step of obtaining the transparent TP carrier (1210) makes the transparent TP carrier (1210) curved and both sides of the transparent TP carrier (1210) are smooth surfaces; and - The printing step (S305) is performed on the concave side of the curved transparent TP carrier (1210) via the 3-D printer.

15. The method according to claim 1 or 14, wherein: At least one smooth surface of the transparent TP carrier (410, 1210) faces a concave insert of an injection mold in which the injection overmolding process (415) is performed.

16. The method according to claim 9, wherein Heat to make 5℃≤T g，载体 -T 载体 ≤30℃.

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