Electronic eyewear for ophthalmics

Abstract

Methods, devices, and systems for use in integrating an electronic device in an ophthalmic article to produce, e.g., electronic eyewear such as electrochromic eyewear, that reduces susceptibility to structural damage during thermal forming, that is scalable for mass manufacturing, and that exhibits the requisite conductivity, sheet resistance, and optical transparency for ophthalmic uses.

Description

ELECTRONIC EYEWEAR FOR OPHTHALMICSRELATED APPLICATIONS

[0001] This application claims benefit of and priority to U.S. Provisional Application Serial No. 63 / 570,671 filed March 27, 2024 entitled Electronic Eyewear For Ophthalmics, which is hereby incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION

[0002] Electronic devices are increasingly incorporated in eyewear for ophthalmics for a wide range of purposes, including vision correction, monitoring, enhancement, light filtering, light emission, treatment of conditions such as migraines or photosensitivity, and the like. Examples of electronic eyewear in ophthalmics includes smart glasses, augmented reality glasses, virtual reality headsets, eye tracking devices, ERG devices, electronic visual aids, and spectral filtering.

[0003] The integration of such electronic devices in ophthalmics typically requires a combination of high optical transparency and low electrical resistance. Additionally, most ophthalmic applications require formation of such electronic devices on a curved surface.

[0004] A first approach is to form the electronic device on a preformed curved surface. However, such an approach may present challenges for many devices and thus would not be easily scaled up to mass manufacturing due to differences in curvature for different corrective powers (e.g., prescriptions). Furthermore, the electronic device may then be exposed to the external environment; making it more prone to damage from the environment or physical damage such as scratches.

[0005] A second approach is to form the electronic device on a flat sheet which is easily scaled to mass manufacturing practices and then subsequently form the device to a curved surface using, e.g., thermal or vacuum forming. The flat sheet may be part of a laminate structure which allows the device to be embedded, which may offer protection from damage. The device for an individual lens, which may be cut from a sheet to form a wafer, can then be embedded in a lens, or adhered to the front of anexisting lens. However, this approach may present challenges in forming the curve without causing damage to the electronic device.

[0006] A key weakness in the second approach is the propensity of cracking of the electronic device during forming, especially if metal oxide type coatings are employed in the electronic device. A common metal oxide type coating used in such applications is indium tin oxide (ITO), which is used as a transparent conductor. Key metrics of ITO are transparency and conductivity, expressed as sheet resistance.

[0007] The sheet resistance can be expressed as Rs = rho / d, where rho is the material resistivity and d is the thickness of the layer. Material resistivity is a property of the layer and thus not easily modified, at least in a positive direction. To achieve a high level of conductivity, such as through resistance being less than 100 ohm and preferably less than 40 ohm, the thickness of the ITO may be increased. However, the increase in thickness may increase the susceptibility of the brittle metal oxide to cracking during the formation process. Furthermore, increasing the thickness can make the ITO’s effect on clarity more pronounced by, e.g., imparting color and decreasing transmission.

[0008] This fundamental issue for ITO has limited its use in certain applications. It is possible to incorporate buffer layers which are more ductile or additional layers to improve optical matching and increase transmission. However, the benefit of such approaches is limited and does not overcome the fundamental issue.

[0009] While materials other than ITO are available, they also suffer from various shortcomings. Zinc oxide (ZnO) has inferior conductivity, even when doped with aluminum, and also can be susceptible to brittle fracture. Conductive polymers such as poly(3,4-ethylenedioxythiophene), commonly referred to as PEDOT, are also available. However, PEDOT achieves limited sheet resistance, effectively being limited to about 100 ohm / sq for a thick layer. The use of silver nanowire (AgNW) or rods to enhance conductivity can achieve lower sheet resistance with acceptable clarity, but at a higher price and potentially inferior durability.

[0010] There is thus a need for alternative options that exhibit the desired sheet resistance in a cost effective, scalable manner while reducing susceptibility to brittlefracture or other potential defects common when integrating electronic devices in curved articles.SUMMARY OF THE INVENTION

[0011] Disclosed herein are various methods, devices, and systems for use in integrating an electronic device in an ophthalmic article to produce, e.g., electronic eyewear, that reduces susceptibility to structural damage during thermal forming, that is scalable for mass manufacturing, and that exhibits the requisite conductivity, sheet resistance, and optical transparency for ophthalmic uses.

[0012] In some aspects, the techniques described herein relate to an electronic eyewear device, including: a first polycarbonate layer; a first metallic grid layer adhered to an inner surface of the first polycarbonate layer; one or more electronic device layers; a second metallic grid layer; and a second polycarbonate layer, wherein the second metallic grid layer is adhered to an inner surface of the second polycarbonate layer.

[0013] In some aspects, the techniques described herein relate to an electronic eyewear device, wherein the one or more electronic device layers include an electrochromic layer.

[0014] In some aspects, the techniques described herein relate to an electronic eyewear device, wherein the one or more electronic device layers include an ion storage layer.

[0015] In some aspects, the techniques described herein relate to an electronic eyewear device, wherein the one or more electronic device layers include an ion conductor layer.

[0016] In some aspects, the techniques described herein relate to an electronic eyewear device, wherein the electrochromic layer is included of a gel.

[0017] In some aspects, the techniques described herein relate to a method of fabricating an electronic eyewear device, including: adhering a first patterned metallic grid to a first polycarbonate film; adhering a second patterned metallic grid to a secondpolycarbonate film; positioning one or more electronic device layers between the first polycarbonate film and the second polycarbonate film to form a laminate; curing the laminate; cutting the laminate to form a wafer; thermal forming the wafer to impart a curvature; and incorporating the wafer onto the front of a lens.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which

[0019] Fig. 1 is a partial top view of a patterned metallic grid for use in forming electronic eyewear in accordance with an example embodiment.

[0020] Fig. 2 is a side view illustrating the layers of a sheet for forming electronic eyewear in accordance with an example embodiment.DETAILED DESCRIPTION

[0021] Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements.

[0022] The present disclosure relates to various methods, devices, and systems for use in integrating an electronic device in an ophthalmic article to produce, e.g., electronic eyewear, that reduces susceptibility to structural damage during thermal forming, that is scalable for mass manufacturing, and that exhibits the requisite conductivity, sheet resistance, and optical transparency for ophthalmic uses.

[0023] In an example embodiment, a metallic grid may be introduced to the lens stack of an ophthalmic article having an electronic device. The conductivity of the metal may be sufficiently high that, even in grid form, the sheet resistance can be sufficiently low to allow desired conductivity.

[0024] By controlling the line size (i.e., width) and density of the lines, the transmission can also be sufficiently high to benefit both metrics - low resistance and high transmission. Such approaches have been previously used for applications such as missile domes which require optical clarity for infrared imaging systems and in conductive surfaces for EMI shielding and patterned to allow radio wave transmission over selective bands.

[0025] The use of a metallic grid such as, for example, Nanoweb Transparent Conductive Film offered by Meta Materials, Inc., may provide high visible clarity (e.g., greater than 85% or, preferably, greater than 95%) with low sheet resistance (e.g., lower than 40 ohm / sq or, preferably, lower than 20 ohm / sq). Furthermore, the wires in such metallic grids may be patterned in such a way to prevent optical diffraction which may degrade clarity. Additionally, such a metallic grid may be sufficiently flexible to allow a very small bend radius (e.g., less than 10 cm or, preferably, less than 5 cm) without damaging conductivity.

[0026] Fig. 1 is a partial top view of a patterned metallic grid 110 for use in forming electronic eyewear in accordance with an example embodiment. Such a metallic grid may be utilized in a wide variety of electronic eyewear devices, such as but not limited to electrochromic eyewear devices.

[0027] Such devices could be formed from a pair of opposing flat films, with a metallic grid on the respective inner surfaces of each flat film. The electronically active layer()s, such as electrochromic active layer(s), may then be applied between the films. As an example, such an electrochromic material may comprise a gel form electrochromic (commonly referred to as a laminate electrochromic). Alternatively, a solid state electrochromic may be used in which the layers are solid and don’t require controlled film spacing and sealing to prevent leakage.

[0028] Generally, a metallic grid 1 10 may be formed by one or more wires formed into a flat, patterned grid pattern. The patterned grid pattern of one or more wires 115 may be implemented in a flat sheet, the thickness, length, and width of which can vary in different examples. It should be appreciated that the grid pattern illustrated in Fig. 1 is merely an illustrative example and that, in some example embodiments, the number of wires 115 and resulting pattern may vary than what is shown. Thus, the scope should not be construed as limited to the pattern illustrated in Fig. 1 .

[0029] Fig. 2 is a side view illustrating the layers of a sheet for forming electronic eyewear in accordance with an example embodiment. In an example of an electrochromic device, a sheet may be formed from a plurality of layers including, from top to bottom, a first polycarbonate film layer 100A, a first metallic grid layer 110A, an ion storage layer 120, an ion conductor (electrolyte) layer 130, an electrochromic layer 140, a second metallic grid layer 110B, and a second polycarbonate film layer 100B. One or more of the layers may be secured by an optical adhesive such as polyurethane.

[0030] It should be appreciated that the specific layers utilized may vary depending on the type of electronic device being integrated in the ophthalmic device, as well as other factors including the desired corrective power, the shape of the ophthalmic device, the type of ophthalmic device, etc. Thus, it should be appreciated that the specific configuration illustrated in Fig. 2 is specific only to one contemplated example, and that the scope should not be limited to that specific configuration, as a metallic grid 110 may be utilized in combination with various other layer configurations to implement different applications.

[0031] In an example such as shown in Fig. 2, an electrochromic device may be constructed from polycarbonate film having two opposing layers 100A, 100B, with the inner surfaces of the polycarbonate film layers each including a metallic grid pattern 110A, 110B. A series of layers, such as an ion storage layer 120, ion conductor (electrolyte) layer 130, and electrochromic layer 140, may be deposited on one side.

[0032] In another example, other material approaches could be utilized wherein single layers are employed where the charge injection and electrochromic layers are formed in molecular pairs or regions to simply device design.

[0033] In another example, an electronic device, such as an electrochromic device, could be built on a single polycarbonate sheet coated with a patterned metallic grid. The electrochromic device may then be construed layer-by-layer on top of the single polycarbonate sheet, ending with the opposing electrode being the last deposited layer. The final polycarbonate sheet may then be laminated to the coating stack using an optical adhesive, such as a polyurethane.

[0034] In any of the preceding examples, the resulting laminate may be cured to improve device adhesion and durability. Curing may comprise, e.g., thermal or ultraviolet curing. Ultraviolet curing may be appropriate where ultraviolet initiators are included in the formulation. The final sheet may then be cut into the desired wafer shapes and formed using thermal forming to the desired curve. The use of the patterned metallic grid, as opposed to ITO, for example, may reduce or eliminate susceptibility to cracking or other structural damage during thermal forming.

[0035] Solid state materials may not require a curing step. Solid state devices may be prone to cracking, but organic type film structures have been shown to be compliant to forming due to the inherent ductility of organic chain molecules, depending upon degree of cross linking.

[0036] Gel-based devices may require edge sealing to protect and isolate the electrochromic material.

[0037] The formed wafer may then be incorporated into the front of a lens using, e.g., overmolding where the wafer is included in the cavity during molding. The increased temperature and pressure from the wafer may match the adjacent cavity surface and fuse to the polycarbonate material filling the cavity during the injection cycle. The above processes may result in a lens with electrochromic functionality on a curved surface without the brittleness inherent with the use of materials such as ITO.

[0038] Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of exampleto facilitate comprehension of the invention and should not be construed to limit the scope thereof.

Claims

What is claimed is:1 . An electronic eyewear device, comprising: a first polycarbonate layer; a first metallic grid layer adhered to an inner surface of the first polycarbonate layer; one or more electronic device layers; a second metallic grid layer; and a second polycarbonate layer, wherein the second metallic grid layer is adhered to an inner surface of the second polycarbonate layer.

2. The electronic eyewear device of claim 1 , wherein the one or more electronic device layers comprise an electrochromic layer.

3. The electronic eyewear device of claim 2, wherein the one or more electronic device layers comprise an ion storage layer.

4. The electronic eyewear device of claim 3, wherein the one or more electronic device layers comprise an ion conductor layer.

5. The electronic eyewear device of claim 2, wherein the electrochromic layer is comprised of a gel.

6. A method of fabricating an electronic eyewear device, comprising: adhering a first patterned metallic grid to a first polycarbonate film; adhering a second patterned metallic grid to a second polycarbonate film; positioning one or more electronic device layers between the first polycarbonate film and the second polycarbonate film to form a laminate; curing the laminate; cutting the laminate to form a wafer; thermal forming the wafer to impart a curvature; and incorporating the wafer onto the front of a lens.

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