Electroactive lens having multiple electrode layers

Abstract

The concentric ring electrodes in a conventional electroactive lens are arranged in the same layer and spaced apart from each other to prevent electrical shorts. The spacing between the electrodes depends on the substrate material and the process used to make the electrodes. Ideally, the electrodes should be as close together as possible to prevent vortices or discontinuities in the electric field that the electrodes apply to the electroactive material in the electroactive lens. These vortices or discontinuities degrade the optical quality of the electroactive lens. Unfortunately, current photolithographic patterning processes are unable to produce gaps less than about 5 micrometers on plastic substrates. To compensate for this constraint, electrodes can be arranged on the substrate in two or more staggered layers, with the electrodes in one layer appearing to fill the gaps in the other layer when viewed through the electroactive lens. This eliminates the apparent gaps between the electrodes, even with plastic substrates and coarse patterning resolution.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority under 35 USC 119(e) to U.S. patent application Ser. No. 63 / 340,134, filed May 10, 2022, which is incorporated by reference in its entirety for all purposes. [Background technology]

[0002] Electro-active lenses can be made by several methods, including patterning a series of concentric electrodes of conductive material on a first substrate and sandwiching a layer of liquid crystal between the first substrate and a second substrate opposite the first substrate. The second substrate may have one or more circular patterns of conductive material patterned on it, or any other shape that matches or exceeds the area of ​​the patterned electrodes, allowing for the formation of an electrical circuit that creates a voltage field between the two substrates. When an electric field is applied across the electrodes, the liquid crystal material between the two substrates changes its refractive index.

[0003] By applying a voltage field gradient at different electrode locations on the lens, a refractive index gradient can be created to create the lens. The more electrodes used, the finer the resolution of the refractive index gradient can be created. This results in a smoother wavefront curvature and therefore provides higher quality optical properties.

[0004] However, increasing the number of electrodes also increases the complexity of the electronic circuitry and the light blocking elements that power the electrodes, so methods have been developed that allow a voltage gradient to be applied across a larger number of electrodes with fewer power supply lines. In particular, N power supply lines can be used to apply a voltage gradient across M>N electrodes with resistive bridges between the electrodes. In these electro-active lenses, every M / Nth electrode is connected to a power supply line, and the other electrodes are connected to each other with resistive bridges.

[0005] U.S. Patent No. 9,280,020 to Bos et al., which is incorporated herein by reference, discloses an electroactive lens with resistive bridges fabricated in the same plane as the electrodes. These resistive bridges are in gaps in the electrode rings. Unfortunately, these gaps degrade the optical quality of the electroactive lens. Reducing the gap size would improve optical performance, but may make the manufacture of the resistive bridges more complicated. In addition, the electroactive lens of U.S. Patent No. 9,280,020 consumes too much power to be practical because the resistive bridges provide a short path for current to flow from one drive channel to the other. This extra current flow leads to an undesirable increase in the power consumption of the electroactive lens.

[0006] Van Heugten et al., U.S. Pat. No. 10,599,006, incorporated herein by reference, also addresses these problems by providing electro-active lenses with larger, higher resistive bridges that do not degrade the optical performance of the lens. In these designs, the electrodes are on one layer and the resistive bridges are on another layer, with a layer of insulating material between the electrode layer and the resistive bridge layer so that the electrodes can remain continuous and close to each other. In addition, no surface area needs to be removed or sacrificed from the electrodes to make room for these "raised" resistive bridges. As a result, the raised resistive bridges can have larger, higher resistive values, allowing the electro-active lens to operate with lower power consumption. Summary of the Invention [Problem to be solved by the invention]

[0007] When fabricated on glass substrates, electroactive lenses such as those disclosed in U.S. Pat. No. 10,599,006 can have concentric ring electrodes separated by a gap of 1.5 to 2 micrometers to prevent the electrodes from electrically shorting. Although these electrodes provide excellent electrical and optical performance, electroactive lenses with glass substrates are not as suitable for mass production as electroactive lenses with plastic, polymeric, or other non-glass substrates. Unfortunately, current lithographic processes for patterning electrodes on plastic substrates cannot produce concentric ring electrodes with a gap of less than about 5.5 micrometers. This large gap reduces the optical performance of the electroactive lens. [Means for solving the problem]

[0008] The present technology addresses the problem of wide gaps between adjacent electrodes in electroactive lenses fabricated on plastic substrates. In fact, it can be used to eliminate gaps between adjacent electrodes on any type of substrate. Instead of forming the electrodes in a single layer, the electrodes are fabricated in two or more layers separated by respective layers of insulating material, and the gap between the electrodes in each layer can be as large as needed. Similar to a shadow box or board-on-board fence, the electrodes in each layer are arranged in a staggered fashion on different sides of the insulating layer, with the electrodes on one side spanning the gap between the electrodes on the other side of the insulating layer. However, when viewed along the optical axis of the electroactive lens, there may be no visible gap between the electrodes. The electrodes are connected to resistive bridges and / or bus lines (i.e., providing bridges or bus lines, or both) on separate layers to provide good electrical performance. While a gap of 1.5-2.0 micrometers is good with current technology, if the gap could be made zero in this way, the optical quality would be further improved. This new approach allows for zero gap along the optical axis while maintaining electrical isolation.

[0009] To see how, consider an electro-active lens with two layers of concentric ring electrodes centered on the optical axis of the electro-active lens and numbered consecutively from the innermost ring to the outermost ring. The first electrode layer contains the odd electrodes and the second electrode layer contains the even electrodes. A thin layer of insulating material separates the first and second electrode layers. In each layer, each electrode is separated from the adjacent electrode by a gap of x micrometers width and filled with insulating material (i.e., there is a gap of x micrometers between the first and third electrodes in the first layer, and there is a gap of x micrometers between the second and fourth electrodes in the first layer). This gap can be 5.5 micrometers or more, depending on the resolution of the photolithography process used to fabricate the electrodes. However, if the electrodes are the same width as the gap or wider, there will appear to be no gaps between the consecutively numbered electrodes when viewing the electro-active lens along its optical axis. Eliminating the gap between the electrodes along the line of sight of the optical axis improves the optical performance of the electro-active lens.

[0010] In a preferred embodiment of electrode sizing and spacing, the width of the electrodes is progressively narrower the further away from the center of the optical axis of the electro-active lens. In one example, the second electrode from the center is 151 micrometers wide, the third electrode is 118 micrometers wide, and the fourth electrode is 99 micrometers wide. When the second and fourth electrodes are at the top level and the third electrode is at the bottom level, the gap between the second and fourth electrodes is 118 micrometers, and the width of the third electrode is the same as the gap between the second and fourth electrodes (i.e., 118 micrometers in this example). The inner edge of the third electrode is aligned with the outer edge of the second electrode, and the outer edge of the third electrode is aligned with the inner edge of the fourth electrode.

[0011] As will be readily appreciated by those skilled in the art of optical design, the dimensions, spacing, and alignment of the electrodes can be calculated using MATLAB® or other suitable programming language. MATLAB code such as the following can be used to calculate the radius and position of the lens electrodes for a given design wavelength and optical path distance (OPD) per electrode:

number

[0012] The inventive electroactive lenses disclosed herein are suitable for use as intraocular lenses, contact lenses, spectacle lenses, or lenses for augmented or virtual reality systems. Such electroactive lenses may include a first substantially transparent substrate, a first electrode on the first substantially transparent substrate, a first insulating layer on the first electrode, a second electrode on the first insulating layer, and a second insulating layer on the second electrode. The lens also includes a resistive bridge on the second insulating layer that connects one of the first electrodes with one of the second electrodes through holes patterned in the first insulating layer (and optionally the second insulating layer).

[0013] The first electrode may be radially staggered relative to the second electrode. The first electrode includes a first ring electrode and the second electrode includes a second ring electrode concentric with the first ring electrode. When viewed along an optical axis of the electro-active lens, no gap is seen between the first ring electrode and the concentric second ring electrode. The first ring electrode may have an outer radius at least equal to an inner radius of the second ring electrode.

[0014] There may be gaps between adjacent pairs of the first electrodes and gaps between adjacent pairs of the second electrodes. At least one of the gaps between adjacent pairs of the first electrodes may be at least 5.5 micrometers wide. Insulating material may be present in the gaps between adjacent pairs of the first electrodes and the gaps between adjacent pairs of the second electrodes.

[0015] The electro-optic lens may also include a second substantially transparent substrate liquid crystal material sandwiched between the first and second substantially transparent substrates, the liquid crystal material changing the focus of the electro-active lens in response to actuation by the first and / or second electrodes.

[0016] Another inventive electro-active lens may include a first plastic substrate, a second plastic substrate, a liquid crystal material disposed between the first plastic substrate and the second plastic substrate, first electrodes disposed on the first plastic substrate and separated from each other by a first gap of 5 micrometers, an insulating layer disposed on the first electrodes, and a second electrode disposed on the insulating layer and separated from each other by a second gap of 5 micrometers and staggered with respect to the first electrodes. In operation, the first and second electrodes apply an electric field to the liquid crystal material, thereby changing the focus of the electro-active lens.

[0017] The first and second electrodes can be first and second concentric ring electrodes, respectively. When viewed along the optical axis of the electro-active lens, the first concentric ring electrode can be seen to occupy the second gap, and the second concentric ring electrode can be seen to occupy the first gap. One of the first concentric ring electrodes can have a first inner radius and a first outer radius, and one of the second concentric ring electrodes can have a second inner radius that is larger (e.g., ≦2.0 μm larger) than the first inner radius and smaller (e.g., ≦2.0 μm smaller) than the first outer radius.

[0018] The insulating layer can be a first insulating layer including a first insulating material disposed on the first concentric ring electrodes and in the first gap, the first insulating material electrically isolating the first concentric ring electrodes from each other and from the second concentric ring electrode, and there can be a second insulating material disposed on the second concentric ring electrode and in the second gap, electrically isolating the second concentric ring electrodes from each other.

[0019] The electro-active lens can also include one or more (raised) resistive bridges disposed on the second insulating material, each of which is electrically connected to a corresponding subset of the first and second concentric ring electrodes.

[0020] Alternatively, the electroactive lens can include a resistive arc. For example, there can be a first resistive arc formed on the first plastic substrate and connecting one of the first concentric ring electrodes with one of the second concentric ring electrodes through a first via in the first insulating layer. Similarly, there can be a second resistive arc formed on the first insulating layer and connecting another one of the second concentric ring electrodes with another one of the first concentric ring electrodes through a second via in the first insulating layer.

[0021] The electroactive lens of the present invention can be made by forming a first electrode on a substantially transparent substrate with a first gap therebetween. A first insulating layer can be disposed on the first electrode and in the first gap. A second electrode is formed on the first insulating layer in a radially staggered arrangement with respect to the first electrode with a second gap therebetween. A second insulating layer is disposed on the second electrode and in the second gap. A bus line is formed connecting at least a portion of the first electrode through the first insulating layer and the second insulating layer, and / or at least a portion of the second electrode through the second insulating layer. The substantially transparent substrate can be a plastic substrate, and forming the first electrode can include photolithographically patterning the first electrode with a feature size of at least 5 micrometers. Optionally, a resistive bridge can be electrically connected to a subset of the first electrodes and a subset of the second electrodes. Alternatively, each resistive arc may be formed in the plane of the first and second electrodes and connected to the respective first or second electrode through a via or hole in the first insulating layer.

[0022] All combinations of the foregoing concepts and additional concepts discussed in more detail below (provided such concepts are not mutually inconsistent) are contemplated as part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as part of the inventive subject matter disclosed herein. Terms explicitly used herein that may also appear in any disclosure made a part of this specification by reference should be given the meaning most consistent with the particular concepts disclosed herein. [Brief description of the drawings]

[0023] Those skilled in the art will appreciate that the drawings are primarily for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale, and in some instances, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and / or structurally similar elements).

[0024] [Figure 1] FIG. 1 shows a view along the optical axis of a single layer of concentric ring electrodes for a conventional electro-active lens with a glass substrate. [Diagram 2] FIG. 1 shows a view along the optical axis of a single layer of concentric ring electrodes for a conventional electro-active lens with a plastic substrate. [Figure 3a] FIG. 2 is a view along the optical axis of a first layer of concentric ring electrodes for use in an electro-active lens having a pair of staggered layers of concentric ring electrodes. [Figure 3b] FIG. 13 is a view along the optical axis of a second layer of concentric ring electrodes for use in an electro-active lens having a pair of staggered layers of concentric ring electrodes. [Figure 4] FIG. 2 is a view along the optical axis of an electro-active lens having first and second staggered layers of concentric ring electrodes. [Diagram 5]FIG. 1 is a perspective view of an electro-active lens having a pair of staggered layers of concentric ring electrodes. [Figure 6] FIG. 1 is a cross-sectional view of an electro-active lens having a pair of staggered layers of concentric ring electrodes separated by an insulating material. [Figure 7] 1 shows a cross section of an electro-active lens having a single layer of raised resistive bridges and a single layer of electrodes. [Figure 8] FIG. 1 is a cross-sectional view of an electro-active lens having a pair of staggered layers of concentric ring electrodes separated by an insulating material and connected by a resistive bridge. [Figure 9] 9 shows a plan view of the electro-active lens of FIG. 8. [Figure 10A] An electro-active lens having staggered electrodes is a layer of different electrodes connected by resistive arcs. [Figure 10B] An electro-active lens having staggered electrodes is a layer of different electrodes connected by resistive arcs. [Figure 10C] An electro-active lens having staggered electrodes is a layer of different electrodes connected by resistive arcs. [Figure 10D] An electro-active lens having staggered electrodes is a layer of different electrodes connected by resistive arcs. [Figure 11A] 10A-10D show an electro-active lens with electrodes and resistive arcs. [Figure 11B] 11B illustrates via and bus electrodes for the electro-active lens of FIG. 11A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] (Electroactive Lens with a Single Layer of Electrodes) FIG. 1 shows a plan view of an electro-active lens 100 having a single layer of concentric annular or ring-shaped electrodes 5 on a glass substrate. The electrodes 5 conduct electricity and are almost completely transparent. They can be made of indium tin oxide (ITO), silver nanowires, carbon nanotubes, or any other suitable material. The electrodes 5 are lithographically patterned and separated by thin gaps 10 that are easily seen when looking through the electro-active lens 100 along its optical axis (in and out of the plane of FIG. 1). A layer of transparent insulating material (not shown) covers the electrodes 5 and fills the gaps 10. The insulating layer should be electrically insulating (non-conductive), thin (e.g., 0.25 μm to 0.5 μm thick), and transparent. Suitable materials for the insulating layer include silicon dioxide (SiO 2 ) and transparent photoresists such as SU-8, but many other suitable materials could be used as long as they are transparent, thin, and electrically insulating. The gap 10 and insulating material electrically isolate the electrodes 5 from one another. The bus lines 20 on top of the insulating layer connect to the electrodes 5 through via holes 15 patterned in the insulating layer. This allows each bus line 20 to connect to a corresponding electrode 5 without connecting and shorting to other electrodes 5.

[0026] Each of these electro-active lenses 100, 200 also includes a liquid crystal layer and another transparent substrate coated with a ground electrode (not shown) parallel to the plane of the concentric ring electrodes. The liquid crystal layer is sandwiched between the transparent substrates, which may be coated with an alignment layer to fix and / or align the liquid crystal material. Applying a voltage to the concentric ring electrodes 5, 220 creates an electric field that extends into the liquid crystal material. This field re-aligns the liquid crystal material and changes the refractive index of the electro-active lens along the optical axis. Changing the shape and amplitude of the electric field changes the focusing properties of the electro-active lens. If the electric field is curved or shaped, for example like a Fresnel lens, the electro-active lens 100, 200 focuses light. If the electric field is tilted or slanted, the electro-active lens 100 behaves as a prism.

[0027] Unfortunately, the gaps 10 between the concentric ring electrodes 5 introduce gaps, eddies, or discontinuities in the electric field. These gaps, eddies, or discontinuities prevent the electric field from aligning the liquid crystal material in the desired direction, resulting in discontinuities in the refractive index profile of the electro-active lens. To a person viewing the electro-active lens, these discontinuities in the refractive index profile can appear as blurry spots or areas.

[0028] For better optical performance, the gaps 10 between the electrodes 5 should be as narrow as possible. The gaps 10 between lithographically patterned electrodes 5 on glass substrates can be 1.5-2.0 micrometers. However, it is not possible to make the gaps narrow on substrates made of polymers and other materials that are currently commonly used to make spectacle lenses, contact lenses, intraocular lenses, and other ophthalmic lenses. For example, FIG. 2 illustrates an electro-active lens 200 having concentric ring electrodes 220 lithographically patterned on a plastic substrate and separated by wider gaps 225. (The bus lines 20 connect to each electrode 220 through via holes in an insulating layer that covers the electrodes 220 and the gaps 225.) These gaps 225 between the electrodes 220 are about three times as wide (e.g., about 4.5-6.0 μm) as the gaps created when performing lithography on glass. Larger gaps 225 would degrade the optical performance of the electro-active lens 200 with plastic substrates.

[0029] Electro-active lenses with staggered layers of electrodes By reducing or eliminating the apparent gap between the concentric ring electrodes, undesirable discontinuities in the electric field applied by the concentric ring electrodes are reduced or eliminated, so that the liquid crystal material actuated by the electrodes is perfectly aligned by the electric field, thereby improving the optical performance of the electro-active lens and reducing or eliminating the blur experienced when looking through the electro-active lens.

[0030] Figures 3A, 3B, 4, and 5 show concentric ring electrodes that address the problem of being unable to create electrodes separated by narrow gaps with plastic lithography processes. Figure 3A shows a single layer of concentric ring electrodes 35 separated by a very wide gap 60 (e.g., a gap of about 5 micrometers wide or wider). Figure 3B shows a second single layer of concentric ring electrodes 40 (the central electrode is circular rather than annular) separated by a very wide gap 65 (again, e.g., about 5 micrometers wide or wider). Figures 4 and 5 show plan and perspective views, respectively, of these two electrode layers 35 and 40 stacked together in a single electro-active lens 400. Both sets of electrodes 35 and 40 are aligned concentrically with the optical axis of the electro-active lens 400.

[0031] Electrode 35 is on the bottom layer and electrode 40 is on the top layer which is on the bottom layer. (The bottom and top layers may be staggered in the opposite order if desired.) When viewed along the optical axis of the electro-active lens (i.e., the top view of FIG. 4), each electrode 35 on the bottom level appears to be between a corresponding pair of electrodes 40 on the top level. In other words, the electrodes 35 on the bottom level appear to fill the gaps 65 between the electrodes 40 on the top level, and the electrodes 40 on the top level appear to fill the gaps 60 between the electrodes 35 on the bottom level. If the electrodes 35 and 40 were not as wide as the gaps 60 and 65, there would appear to be a very narrow gap 67 (e.g., a gap of about 1.5 to 2 micrometers wide or narrower) between the apparently adjacent electrodes 35 and 40, as shown in FIG. 4. Even if the electrodes 35 and 40 are on a plastic substrate, the apparent gap 67 between the electrodes 35 and 40 can be as narrow as a gap that can be formed on a glass substrate.

[0032] Manufacturing tolerances may be considered to ensure that apparent gap 67 is as thin as possible (i.e., a thinner apparent gap results in better optical performance). Some dimensional tolerances in the lithography used to pattern electrodes 35 and 40 may cause deviations in the inner diameter, outer diameter, and / or location of the electrodes. Dimensional deviations may also occur when forming an upper layer of electrode 40 over an lower layer of electrode 35.

[0033] For example, if an overall deviation of 4 microns is expected, but the maximum allowable apparent gap 67 is 2 microns, the diameters of electrodes 35 and 40 can be altered to compensate. In this example, the outer diameter of the electrode at the lower level can be increased by 2 microns and the inner diameter of the electrode at the upper level can be decreased by 2 microns, or the inner and / or outer diameter of both sets of electrode diameters can be altered to compensate.

[0034] In another embodiment, each electrode has an outer diameter slightly larger than the inner diameter of the next largest adjacent electrode and an inner diameter slightly smaller than the outer diameter of the next smallest adjacent electrode. In other words, each electrode may overlap its neighbor by, for example, 1.5 to 2.0 μm, to allow for the offset of the electrode layers relative to one another. Small overlaps (e.g., about 2.0 μm or less) should not affect the optical performance of the electro-active lens. Larger overlaps between adjacent electrodes may cause the electric fields applied by the adjacent electrodes to interfere or collide with one another, causing discontinuities or vortices in the net electric field experienced by the liquid crystal, degrading the optical performance of the electro-active lens.

[0035] 4 and 5 also show bus lines 20 connecting the electrodes 35 and 40 to a voltage source (not shown) for actuating the electro-active material in the electro-active lens 400. In this embodiment, there is one bus line 20 per electrode 35 or 40, although in other embodiments there may be fewer bus lines than electrodes, with resistors (e.g., resistive bridges) connecting adjacent sets of electrodes. The bus lines 20 are deposited on an insulating material (not shown) that covers the electrodes 35 and 40 and fills the gaps 60 and 65 between the electrodes 35 and 40. The bus lines 20 connect to the bottom electrode 35 through a deeper via or hole 45 that extends through the insulating material all the way to the bottom electrode 35, and connect to the top electrode 40 through a shallower via or hole 50 that extends through the insulating material part way to the top electrode 40.

[0036] FIG. 6 shows a portion of an electro-active lens 400 in cross section. A bottom electrode 35 is patterned on the top surface of a transparent substrate 75. (Orientations are relative to the orientation shown in FIG. 6.) A first insulating layer 80 is applied over the bottom electrode 35, with a top electrode 40 patterned over the first insulating layer 80. A second insulating layer 85 is applied over the top electrode 40. (FIG. 6 shows only three top electrodes and three bottom electrodes, each with only one label.) More than three electrodes per level can be used, for example, tens to hundreds or thousands of electrodes, although more electrodes generally produce an electro-active lens with better optical quality.

[0037] Two layers are patterned into insulating layers 80 and 85 through holes 45 to reach bottom electrode 35. Bus line 20 conducts electricity through these two layers through holes 45 to bottom electrode 35, but does not connect to top electrode 40. Monolayers through holes 50 are patterned into second insulating layer 85 and do not extend into or through first insulating layer 80 or connect to any of bottom electrodes 35. Monolayers through holes 50 conduct power to top electrode 40.

[0038] Above the bus lines 20 and the second insulating layer 85 is an alignment layer 90. The alignment layer 90 structures the liquid crystal molecules in layer 95. Above the liquid crystal layer 95 is a second alignment layer 100. Above the alignment layer 100 is a conductive layer 105, which may act as a ground plane for actuating the liquid crystal layer 95 in conjunction with the electrodes 35 and 40. Above the conductive layer 105 is a second clear or transparent substrate 110 (e.g., made of plastic or another transparent polymer). The substrates 75 and 110 sandwich other layers between them. Although FIG. 6 shows the sides of the electro-active lens 400 as open, in reality they are sealed to prevent leakage of material (e.g., liquid crystal material) into or out of the electro-active lens 400.

[0039] Electro-active Lens with Raised Resistive Bridges and Single Layer of Electrodes FIG. 7 shows a cross section of a portion of an electroactive lens 700 having a raised resistive bridge 725 connecting selected concentric ring electrodes 710 arranged in a single layer. The electroactive lens 700 includes concentric ring electrodes 710 (e.g., made of ITO or another transparent conductor) formed in a single layer on a transparent substrate 705 (e.g., a glass or plastic substrate). The concentric ring electrodes are coplanar with each other and concentric about the optical axis of the electroactive lens, which is perpendicular to the plane of the transparent substrate 705. Because the concentric ring electrodes 710 are in the same layer on the substrate 705, they are separated by gaps 715, which may be approximately 1.5 to 5.5 micrometers wide, depending on the substrate material and the resolution of the (photolithography) process used to form the electrodes 710. The concentric ring electrodes 710 are coated with a layer 720 of insulating material, which may be disposed in the gaps 715. Resistive bridges 725 on the insulating layer 720 connect the electrodes 710 through vias or holes 730 in the insulating layer 720.

[0040] (Resistance bridge for connecting multiple staggered electrode layers) Staggering the electrodes in different layers addresses the inability to create gaps less than 2 micrometers when lithographically patterning electrodes on plastic substrates. Staggered electrode layers also address another challenge of electro-active lenses: utilizing a large number of electrodes with less than one bus line per electrode phase to create a smoother wavefront. If an electro-active lens includes one bus line per electrode phase, the electro-active lens may include a large number of bus lines (e.g., hundreds of bus lines), which creates at least two problems. First, the bus lines cause visual impairment in the electro-active lens, and as the number of bus lines increases, the optical performance of the lens decreases. Second, as the number of bus lines increases, the complexity of the electronics also increases, increasing the size, weight, power consumption (reducing battery life), and cost (SWAP-C) of the electronics package. In general, electro-active eyeglasses, contacts, and intraocular lenses should be as light and small as possible while still having good battery life and economic cost.

[0041] For better performance, an electro-active lens should have as many electrodes as possible and as few bus lines as possible. One way to reduce the number of bus lines is to use a resistive bridge divider network. However, current resistive bridge designs are limited to a single plane, whereas the staggered electrode designs described herein have electrodes in at least two planes.

[0042] 8 and 9 show cross-sectional and plan views, respectively, of an electro-active lens 800 having multiple layers of staggered electrodes 835, 840 connected by a resistive bridge 120. The electrodes 835, 840 are staggered to reduce or eliminate the apparent gap between the electrodes and any associated blurring. The electro-active lens 800 includes a first layer 835 of concentric ring electrodes on a transparent substrate 875, which can be made of plastic or glass. The concentric ring electrodes 835 are made of a patterned conductive material (e.g., ITO) and can be spaced apart by relatively wide gaps, e.g., gaps of 5.5 micrometers or more, which is possible with photolithography on a plastic transparent substrate. The first layer of concentric ring electrodes 835 is covered with a first layer 880 of insulating material, which separates the first layer of concentric ring electrodes 835 from the second layer of concentric ring electrodes 840. This prevents the concentric ring electrodes 835, 840 on different layers from contacting each other and causing a short circuit.

[0043] A second layer 885 of insulating material separates the second layer 840 of concentric ring electrodes from the layer 120 of raised resistive bridges. The resistive bridge 120 is connected to the first and second layer concentric ring electrodes 835, 840 through vias or holes 845, 850 that extend through both insulating layers. In the portion of the electro-active lens 800 shown in Figures 8 and 9, a single resistive bridge 120 connects all of the concentric ring electrodes 835, 840 to each other, even though the electrodes are on different layers. The innermost electrode 840 and the outermost electrode 835 are connected to the bus lines 125 and 115, respectively. The resistive bridge 120 can be used to create a voltage gradient between the bus lines 125 and 115, as described in detail in U.S. Patent No. 10,599,006 to Van Heugten et al., which is incorporated herein by reference.

[0044] The concentric ring electrodes 835, 840 in the first and second layers are concentric with the optical axis (and with each other) and are alternately or staggered. If the concentric ring electrodes were numbered consecutively based on their distance from the optical axis, the first layer would include the even ring electrodes 835 and the second layer would include the odd ring electrodes 840 (or vice versa). The even ring electrodes 835 are positioned to "fill" the gaps 865 between their respective odd ring electrodes 840, and the odd ring electrodes 840 are positioned to "fill" the gaps 860 between their respective even ring electrodes 835. In this embodiment, the electrodes 835, 840 and the gaps 860, 865 have the same width, but are aligned such that no gaps are visible when the electro-active lens 800 is viewed along the optical axis of the electro-active lens. The gaps 860 , 865 between the concentric ring electrodes 835 , 840 in the first and second layers may be filled with the same insulating material used to form the insulating layers 880 , 885 .

[0045] The electro-active lens 800 may include more electrodes and more layers of electrodes (e.g., three layers with one-third of the electrodes in each layer and staggered accordingly). Similarly, it may include more resistive bridges, each resistive bridge electrically connected to a number of adjacent electrodes (e.g., 5-10 electrodes per resistive bridge). It may also include more bus lines (e.g., one bus line for every 5-10 electrodes). More electrodes typically result in better optical performance.

[0046] Electro-active lens 800 also includes a liquid crystal material confined between transparent substrate 875 and another transparent substrate (not shown). Applying a voltage to concentric ring electrodes 835, 840 actuates electro-active lens 800 by altering the liquid crystal orientation and the refractive index profile of the lens. Because there is no apparent radial gap between electrodes 835 and 840 when electro-active lens 800 is viewed along its optical axis, the electric field applied to the liquid crystal material does not suffer from the discontinuities that affect electro-active lenses with electrodes in a single layer.

[0047] A preferred embodiment of the resistive bridge includes first and second layers of resistive arcs on the same plane as the first and second electrodes, respectively, with the resistive arcs on the first plane electrically connected to electrodes on the second plane, and the resistive arcs on the second plane electrically connected to electrodes on the first plane. These resistive arcs can be made of the same material as the electrodes are made of and can be made during the same step when the electrodes are formed, simplifying the manufacturing process. The electrodes on different planes (layers) can be connected by patterning a series of vias through an insulating layer at the locations where the resistive bridge should connect electrodes on different levels, and filling the vias with a conductive material when manufacturing the bus lines. The electrodes act as etch stops for the vias.

[0048] 10A-10D, 11A, and 11B illustrate an electroactive lens having two electrode layers connected by an arc or resistive bridge. FIGS. 10A and 10B each show different electrode layers and corresponding several arcs. In FIG. 10A, resistive arc 145 is patterned on electrode 130, resistive arc 150 is patterned on electrode 135, and electrode 140 depends on resistive arc 180 shown in FIG. 10B. In FIG. 10B, resistive arc 170 is patterned on electrode 155, resistive arc 175 is patterned on electrode 160, and resistive arc 180 is patterned on electrode 165. FIGS. 10C and 10D show close-ups of the resistive arcs of FIGS. 10A and 10B, respectively.

[0049] FIG. 11A shows a front view (i.e., view along the optical axis) of an electro-active lens in which two layers of electrodes and arcs of FIGS. 10A-10D are stacked on top of each other. The insulating layers are not shown. FIG. 11B shows the location of vias, where vias 190, 192, 194, 195, and 199 electrically connect the lower layer electrodes and resistive arcs to the upper layer electrodes and resistive arcs. FIG. 11B also shows bus lines 115 and 125 that power the electro-active lens 1000. In this configuration, the two bus lines 115 and 125 power six electrodes without a raised resistive bridge.

[0050] Fabrication of Electroactive Lenses with Staggered Electrode Layers The electroactive lens 400 shown in Figure 6 can be fabricated using the following process. First, the transparent substrates 75 and 110 are coated with a transparent, conductive material (e.g., ITO), typically using a sputtering process or one of several other types of thin film deposition processes known to those skilled in the art. If ITO is used, it can be deposited on each substrate to form a transparent, conductive layer having a thickness of 5 to 100 nanometers.

[0051] Photolithography is typically used to pattern electrodes from a conductive layer on one of the substrates. (The conductive layer on the other substrate can remain unpatterned and function as a ground plane.) To create the first (lower) layer of electrodes using a photolithography process, the surface of the conductive layer to be patterned is coated with photoresist (e.g., in a spin-coating process). The photoresist is masked with a patterned mask, exposed to ultraviolet (UV) light, and developed. The UV-exposed photoresist then dissolves, and the unexposed photoresist remains on the substrate undissolved. The remaining photoresist covers the portions of the conductive layer that will become the electrodes in the first electrode layer. The photoresist does not cover other portions of the conductive layer. These exposed portions are etched, for example, using acid or plasma. After etching, the remaining photoresist is stripped away to leave the patterned electrodes. If the transparent substrate is plastic, the minimum feature size of the patterned electrodes (e.g., the width of the gap between the electrodes) is typically about 5 micrometers or larger.

[0052] A first insulating layer is then deposited, for example, using sputtering or spin coating, over the patterned electrodes and in the gaps between the patterned electrodes. A second conductive layer is formed on the first insulating layer and patterned using photolithography to form a second electrode (top) layer. A second insulating layer is deposited, for example, using sputtering or spin coating, over the top electrodes and in the gaps between the top electrodes. Vias or holes are then patterned through the insulating layer using photolithography, with the top electrodes acting as etch stops for the single layer vias.

[0053] The bus lines may be formed on the same plane as the resistive bridge, or on a different plane. For example, the bus lines may be formed by depositing a third layer of conductive material on the second insulating layer and into the vias, and photolithographically patterning the conductive material using the process described above for the electrodes. In a preferred embodiment, the bus lines are made of a low resistivity, opaque material such as nickel or aluminum to promote more consistent voltage distribution when bus lines of different lengths are used. Other high resistivity materials can be used if voltage drop is considered when the lenses and electronics are designed.

[0054] To create the raised resistive bridge, another layer of resistive bridge material is deposited and photolithographically patterned into the desired shape. The raised resistive bridge can be made from a material with high resistivity to reduce current flow between the bus lines to minimize power consumption. Some exemplary materials are ITO or PDOT. The bus lines can be fabricated before the resistive bridge, or vice versa.

[0055] The resistive arc bridge can be formed when forming the electrodes. During the via patterning step, additional vias are formed (during the same process step) to electrically connect the arc bridge to the electrodes on the two layers.

[0056] Once the electrodes, bus lines, and insulating layers (and possibly raised resistive bridges) have been formed, an alignment layer is applied to the top of the stack on each substrate, for example by a spin-coating process. The alignment layer is rubbed in one direction with a felt cloth or exposed to polarized UV light to define the pretilt angle of the liquid crystal material. The two substrates are bonded together, typically separated by transparent spacer beads, to form a cavity. The liquid crystal material is introduced into the cavity, typically by vacuum or capillary action. The cavity is sealed to contain the liquid crystal material and obtain the completed electro-active lens.

[0057] The electrodes can vary in width from 2 mm to 5 micrometers and thickness from 10 nanometers to 150 nanometers. The insulating layer can be 20 nanometers to 1 micrometer thick. The vias can have diameters of 1 to 20 micrometers and depths of 20 nanometers to 1 micrometer. The bus lines can be 1 micrometer to 20 micrometers wide and 10 nanometers to 1 micrometer thick.

[0058] Because electroactive lenses with staggered electrode layers can tolerate relatively large gaps between the electrodes, the electrodes themselves can be made using manufacturing processes, substrates, and / or materials with coarser resolution. For example, they can be made on more flexible surfaces using simpler lithography or inkjet printing. The electrodes of the different layers can also be made of different materials. They can also be of different shapes and overlap when viewed along the optical axis. For example, the rings of the first (second) layer can be wider than the gaps of the second (first) layer.

[0059] (Conclusion) While various inventive embodiments have been described and illustrated herein, those skilled in the art will readily envision a variety of other means and / or structures for performing the functions and / or obtaining one or more of the results and / or advantages described herein, and each of such variations and / or modifications are deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the particular use or application for which the teachings of the present invention are / are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. Thus, the foregoing embodiments are presented by way of example only, and it will be understood that within the scope of the appended claims and their equivalents, the inventive embodiments may be practiced otherwise than as specifically described and claimed. The inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods is within the inventive scope of the present disclosure, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

[0060] The above-described embodiments can be implemented in any of numerous ways. For example, the embodiments of designing and creating the techniques disclosed herein can be implemented using hardware, software, or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided on a single computer or distributed across multiple computers.

[0061] Further, it should be understood that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. Additionally, a computer may be embedded in a device not generally considered a computer but having suitable processing capabilities, such as a personal digital assistant (PDA), a smart phone, or any other suitable portable or fixed electronic device.

[0062] A computer may also have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include a printer or display screen for visual presentation of output, and a speaker or other sound generating device for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards and pointing devices such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information via voice recognition or other audible format.

[0063] Such computers may be interconnected by one or more networks of any suitable form, including local area networks or wide area networks, such as enterprise networks, and intelligent networks (INs) or the Internet. Such networks may be based on any suitable technology and operate according to any suitable protocol, and may include wireless networks, wired networks, or fiber optic networks.

[0064] The various methods or processes outlined herein (e.g., designing and making the techniques disclosed above) may be coded as software executable on one or more processors employing any one of a variety of operating systems or platforms. Further, such software may be written using any of a number of suitable programming languages ​​and / or programming or scripting tools, and compiled as executable machine language code or intermediate code that runs on a framework or virtual machine.

[0065] In this regard, the various inventive concepts may be embodied as a computer-readable storage medium (or multiple computer-readable storage media) (e.g., a computer memory, one or more floppy disks, compact disks, optical disks, magnetic tapes, flash memories, circuitry in field programmable gate arrays or other semiconductor devices, or other non-transitory or tangible computer storage media) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement the various embodiments of the invention as described above. The computer-readable medium or media may be transportable such that the program or programs stored thereon can be loaded into one or more different computers or other processors to implement various aspects of the invention, as described above.

[0066] As used herein, the terms "program" or "software" are used in a general sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to perform various aspects of the embodiments as described above. It should be further understood that, according to one aspect, one or more computer programs that, when executed, perform the methods of the present invention need not reside on a single computer or processor, but may be distributed in a modular manner among several different computers or processors to perform various aspects of the present invention.

[0067] Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.

[0068] Additionally, data structures may be stored on computer-readable media in any suitable form. For ease of illustration, data structures may be shown as having fields that are related through their location within the data structure. Such relationships may be achieved by allocating storage for the fields with locations within the computer-readable media that similarly convey the relationship between the fields. However, any suitable mechanism may be used to establish relationships between information within fields of a data structure, including the use of pointers, tags, or other mechanisms that establish relationships between data elements.

[0069] Also, various inventive concepts may be embodied as one or more methods, examples of which are provided. The acts performed as part of a method may be ordered in any suitable manner. Thus, although an exemplary embodiment shows acts as sequential, embodiments may be constructed in which acts are performed in an order different from that illustrated, which may include performing some acts simultaneously.

[0070] All definitions and those used herein should be understood to control for any dictionary definitions, definitions in documents incorporated herein by reference, and / or ordinary meaning of the defined terms.

[0071] As used in this specification and the claims, the indefinite articles "a" and "an" should be understood to mean "at least one," unless clearly indicated to the contrary.

[0072] As used in the present specification and claims, the term "and / or" should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctive in some cases and disjunctive in other cases. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" of the elements so conjoined. Optionally, other elements may be present other than the elements specifically identified by the "and / or" clause, whether or not related to the elements specifically identified. Thus, as a non-limiting example, a reference to "A and / or B," when used in conjunction with an open-ended expression such as "comprising," can refer in one embodiment to only A (optionally including elements other than B), in another embodiment to only B (optionally including elements other than A), in yet another embodiment to both A and B (optionally including other elements), etc.

[0073] As used herein and in the claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be interpreted as inclusive, i.e., including at least one, but not two or more, of a number or list of elements, and, optionally, including additional items not in the list. Only terms clearly indicating the contrary, such as "only one of," "exactly one of," or, when used in the claims, "consisting of," refer to the inclusion of exactly one element of a number or list of elements. Generally, as used herein, the term "or" shall be interpreted as indicating exclusive alternatives (i.e., "one or the other, but not both") only when preceded by a term indicating exclusivity, such as "either," "one of," "only one of," or "exactly one of." As used in the claims, "consisting essentially of" shall have its ordinary meaning as used in the field of patent law.

[0074] As used herein and in the claims, the phrase "at least one" in reference to a list of one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. This definition also allows that elements other than those specifically identified in the list of elements to which the phrase "at least one" refers may optionally be present, whether or not related to the specifically identified element. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B" or, equivalently, "at least one of A and / or B") can refer in one embodiment to at least one A, optionally including more than one, in the absence of B (and optionally including elements other than B); in another embodiment to at least one B, optionally including more than one, in the absence of A (and optionally including elements other than A); in yet another embodiment to at least one A, optionally including more than one, and at least one B, optionally including more than one (and optionally including other elements), etc.

[0075] In the claims, as well as in the above specification, all transitional phrases, such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "consisting of," and the like, are to be understood to be open ended, i.e., meaning including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" must be closed or semi-closed transitional phrases, respectively, as provided in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

1. A first plastic substrate; a second plastic substrate; a liquid crystal material disposed between the first plastic substrate and the second plastic substrate; first electrodes disposed on the first plastic substrate and separated from each other by a first gap of 5 micrometers; an insulating layer disposed on the first electrode; a second electrode disposed on the insulating layer, the second electrode being separated from the first electrode by a second gap of 5 micrometers and staggered with respect to the first electrode; An electroactive lens comprising:

2. The electro-active lens of claim 1 , wherein the first electrode is a first concentric ring electrode and the second electrode is a second concentric ring electrode.

3. 3. The electro-active lens of claim 2, wherein, when viewed along an optical axis of the electro-active lens, the first concentric ring electrode appears to occupy the second gap and the second concentric ring electrode appears to occupy the first gap.

4. 3. The electro-active lens of claim 2, wherein one of the first concentric ring electrodes has a first inner radius and a first outer radius, and one of the second concentric ring electrodes has a second inner radius greater than the first inner radius and less than the first outer radius.

5. 5. The electro-active lens of claim 4, wherein the insulating layer is a first insulating layer comprising a first insulating material disposed on the first concentric ring electrode and in the first gap, electrically isolating the first concentric ring electrodes from each other and from the second concentric ring electrode.

6. 6. The electro-active lens of claim 5, further comprising a second insulating material disposed on said second concentric ring electrodes and in said second gap, said second concentric ring electrodes electrically isolating said second concentric ring electrodes from each other.

7. 7. The electro-active lens of claim 6, further comprising a resistive bridge disposed on the second insulating material and electrically connected to the first subset of concentric ring electrodes and the second subset of concentric ring electrodes.

8. a first resistive arc formed on the first plastic substrate and connecting one of the first concentric ring electrodes with one of the second concentric ring electrodes through a first via in the first insulating layer; 7. The electro-active lens of claim 6, further comprising: a second resistive arc formed on the first insulating layer and connecting another one of the second concentric ring electrodes with another one of the first concentric ring electrodes through a second via in the first insulating layer.

9. a first substantially transparent substrate; a first electrode disposed on the first substantially transparent substrate; a first insulating layer disposed on the first electrode; a second electrode disposed on the first insulating layer; a second insulating layer disposed on the second electrode; a resistive bridge connecting one of the first electrodes with one of the second electrodes through a hole patterned in the first insulating layer; An electroactive lens comprising:

10. The electro-active lens of claim 9 , wherein the first electrodes are radially staggered relative to the second electrodes.

11. The electro-active lens of claim 9 , wherein the first electrode comprises a first ring electrode and the second electrode comprises a second ring electrode concentric with the first ring electrode.

12. The electro-active lens of claim 11 , wherein no gap is visible between the first ring electrode and the second concentric ring electrode when viewed along an optical axis of the electro-active lens.

13. The electro-active lens of claim 11 , wherein the first ring electrode has an outer radius at least equal to an inner radius of the second ring electrode.

14. the resistive bridge being a first resistive arc formed in the plane of the first electrode, the hole being a first hole; 10. The electro-active lens of claim 9, further comprising a second resistive arc formed in the plane of the second electrodes and connecting another one of the first electrodes to another one of the second electrodes through a second hole patterned in the first insulating layer.

15. 10. The electro-active lens of claim 9, further comprising a gap between adjacent pairs of the first electrodes and a gap between adjacent pairs of the second electrodes.

16. 16. The electro-active lens of claim 15, wherein at least one of the gaps between the adjacent pairs of the first electrodes is at least 5 micrometers wide.

17. 16. The electro-active lens of claim 15, further comprising an insulating material disposed in the gaps between the adjacent pairs of the first electrodes and in the gaps between the adjacent pairs of the second electrodes.

18. a second substantially transparent substrate; and a liquid crystal material sandwiched between the first and second substantially transparent substrates to change the focus of the electro-active lens in response to actuation by the first and / or second electrodes; The electro-active lens of claim 9 further comprising:

19. forming a first electrode on a substantially transparent substrate with a first gap therebetween; disposing a first insulating layer over the first electrode and in the first gap; forming a second electrode on the first insulating layer, the second electrode being radially staggered with respect to the first electrode such that there is a second gap therebetween; disposing a second insulating layer over the second electrode and in the second gap; forming a bus line connecting to at least a portion of the first electrodes through the first insulating layer and the second insulating layer and / or to at least a portion of the second electrodes through the second insulating layer; A method of making an electro-active lens comprising:

20. 20. The method of claim 19, wherein the substantially transparent substrate is a plastic substrate and forming the first electrode comprises photolithographic patterning the first electrode with a feature size of at least 5 micrometers.

21. 20. The method of claim 19, further comprising forming a resistive bridge electrically connected to the first subset of electrodes and the second subset of electrodes.

22. 22. The method of claim 21, wherein the step of forming a resistive bridge comprises forming a resistive arc in a plane of the first electrode.

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