HK1190194B - Lens with multi-concave meniscus wall - Google Patents

Description

Lens with multi-concave meniscus wall

Related patent application

The present application claims the priority of U.S. patent application serial No. 13/401,962 filed on day 22/2/2012, 2011, U.S. provisional patent application serial No. 61/454,212 filed on day 18/3/2011 and entitled "lens and vehicle systems" (the contents of which are trusted and incorporated by reference), and U.S. patent application serial No. 13/095,786 filed on day 27/4/2011, entitled "accucutanellid systems", the contents of each of which are trusted and incorporated by reference.

Technical Field

The present invention relates generally to a liquid meniscus lens, and more particularly, to an arcuate liquid meniscus lens with a meniscus wall comprising a plurality of concave segments.

Background

Liquid meniscus lenses are well known in the industry. As discussed more fully below in connection with fig. 1A and 1B, known liquid meniscus lenses are designed in a cylindrical shape with a peripheral surface formed by points at a fixed distance from an axis that is a straight line. The design of known liquid meniscus lenses is defined as having a first inner surface substantially parallel to a second inner surface and each perpendicular to the cylinder axis. Known examples of uses of liquid meniscus lenses include devices such as electronic cameras and cell phones.

Traditionally, ophthalmic devices (e.g., contact lenses and intraocular lenses) include biocompatible devices having corrective, cosmetic, or therapeutic properties. For example, a contact lens may provide one or more of the following effects: vision correction functionality, cosmetic enhancement and therapeutic effects. Each function is provided by a physical characteristic of the lens. Designs incorporating refractive properties into the lens may provide vision correction functions. Pigments incorporated into the lens can provide cosmetic enhancement. The active agent incorporated into the lens may provide therapeutic functionality.

More recently, electronic components have been incorporated into contact lenses. Some of the elements may include semiconductor devices. However, physical limitations including size, shape and control of the liquid meniscus lens make it difficult to apply in an ophthalmic lens. Generally, the cylindrical shape of the liquid meniscus lens (sometimes referred to as the "puck" shape) does not facilitate the shape of articles that can be used in the human eye.

Furthermore, the physical challenges involved with a curved liquid meniscus lens are not necessarily present in conventional designs of liquid meniscus lenses with parallel sidewalls.

Disclosure of Invention

Accordingly, the present invention provides a liquid meniscus lens including an arcuate front curve lens and an arcuate back curve lens. The present invention includes meniscus walls having a physical structure that facilitates one or both of: attraction and repulsion of a liquid contained within the lens and formation of a meniscus with another liquid.

According to the invention, the first arcuate optic is immediately adjacent the second arcuate optic with a cavity formed therebetween. A saline solution and oil are maintained within the cavity. Applying an electrical charge to a meniscus wall located substantially in a peripheral region of one or both of the first arcuate optic and the second arcuate optic changes the physical shape of a meniscus formed between the saline solution and the oil held within the cavity.

The present invention includes a meniscus wall shaped substantially as a compound shape including a plurality of concave segments, the meniscus wall in cross-section including a plurality of ring segments in mechanical communication with each other.

Drawings

Fig. 1A illustrates a prior art example of a cylindrical liquid meniscus lens in a first state.

Fig. 1B illustrates a prior art example of a cylindrical liquid meniscus lens in a second state.

Fig. 2 illustrates a tangential sectional profile of an exemplary liquid meniscus lens, according to some embodiments of the invention.

Fig. 3 illustrates a cross section of a portion of an exemplary arcuate liquid meniscus lens, according to some embodiments of the invention.

Fig. 4 illustrates additional exemplary aspects of an arcuate liquid meniscus lens.

Fig. 5 illustrates a meniscus wall element within an arcuate liquid meniscus lens according to some embodiments of the present invention.

Fig. 6A illustrates a multi-concave meniscus wall within a liquid meniscus lens, showing the liquid meniscus boundary in its unpowered state.

Fig. 6B illustrates a multi-concave meniscus wall within a liquid meniscus lens, showing the liquid meniscus boundary in its powered state.

Fig. 6C illustrates a multi-concave meniscus wall within a liquid meniscus lens, with the powered and unpowered states of the liquid meniscus boundary shown in a single diagram for comparison.

Fig. 7A illustrates a cross-section of a multi-concave meniscus wall viewed separately from the rest of an arcuate liquid meniscus lens.

Fig. 7B illustrates a cross-section of a segment of a meniscus wall that is concave from an optical axis formed in the lens, where the resulting shape includes a segment of a torus when viewed from the rest of the arcuate liquid meniscus lens.

Detailed Description

A liquid meniscus lens with at least one of a front curve lens and a back curve lens defining a meniscus cavity of the liquid meniscus lens is provided.

Term(s) for

In this specification and claims relating to the invention, the terms used are defined as follows:

contact angle: the angle at which the oil/saline solution interface (also referred to as the liquid meniscus boundary) contacts the meniscus wall. In the case of a linear meniscus wall, the contact angle is the angle measured between the meniscus wall and a line tangent to the liquid meniscus boundary where the liquid meniscus boundary contacts the meniscus wall. In the case of a curved meniscus wall, the contact angle is the angle measured between a line tangent to the meniscus wall and the liquid meniscus boundary when they are in contact.

Liquid meniscus boundary: an arcuate surface interface between the saline solution and the oil. Generally, the surface will form a lens that is concave on one side and convex on the other side.

A meniscus cavity: a space in the arcuate liquid meniscus lens between the front curve lens and the back curve lens, having an oil and saline solution retained therein.

Meniscus wall: a particular area on the interior of the front curve lens such that it is within the meniscus cavity along which the liquid meniscus boundary moves.

Optical zone: as used herein, refers to the area of an ophthalmic lens through which a wearer of the ophthalmic lens views.

Sharp edge: the geometry of the inner surface of either the front curve lens piece or the back curve lens piece is sufficient to encompass the location of the two predetermined fluid contact lines on the optical piece. Sharp edges are typically external angles rather than internal angles. With reference to the fluid, it is an angle greater than 180 degrees.

Referring now to fig. 1A, a cross-sectional view depicting a prior art lens 100 in which an oil 101 and saline solution 102 are contained within a cylinder 110. The cylinder 110 comprises two plates 106 of optical material. Each plate 106 includes a flat inner surface 113. The cylinder 110 includes a substantially rotationally symmetric inner surface. In some prior art embodiments, one or more surfaces may include a hydrophobic coating. Electrodes 105 are also included on or around the periphery of the cylinder. An electrical insulator may also be used in close proximity to the electrode 105.

According to the prior art, each of the inner surfaces 113 is substantially flat or planar. An interface surface 112A is defined between the brine solution 102A and the oil 101. As shown in fig. 1A, the shape of the interface 112A is combined with the refractive index characteristics of the saline solution 102A and the oil 101 to receive incident light 108 through a first inner surface 113 and provide divergent light 109 through a second inner surface 113. The shape of the interface surface between the oil 101 and the brine solution 102 is changed by applying a current to the electrode 105.

FIG. 1A shows a perspective view of a prior art lens shown at 100.

Referring now to fig. 1B, a prior art lens 100 is shown in an energized state. The energized state is accomplished by applying a voltage 114 across the electrodes 115. The shape of the interface surface 112B between the oil 101 and the brine solution 102 is changed by applying a current to the electrode 115. As shown in fig. 1B, incident light 108B passing through the oil 101 and the brine solution 102B is focused into a converging light pattern 111.

Referring now to fig. 2, a cross-sectional view of a liquid meniscus lens 200 with a front curve lens 201 and a back curve lens 202 is shown. The front curve lens 201 and the back curve lens 202 are positioned next to each other and form a cavity 210 therebetween. The front curve lens includes a concave arcuate inner lens surface 203 and a convex arcuate outer lens surface 204. The concave arcuate lens surface 203 may have one or more coatings (not shown in fig. 2). The coating may comprise, for example, one or more of an electrically conductive or insulating material, a hydrophobic material, or a hydrophilic material. One or both of the concave arcuate lens surface 203 and the coating are in liquid and optical communication with an oil 208 contained in a cavity 210.

The back curve lens 202 includes a convex arcuate inner lens surface 205 and a concave arcuate outer lens surface 206. The convex arcuate lens surface 205 may have one or more coatings (not shown in fig. 2). The coating may comprise, for example, one or more of an electrically conductive or insulating material, a hydrophobic material, or a hydrophilic material. At least one of the convex arcuate lens surface 205 and the coating is in liquid and optical communication with a saline solution 207 contained in a cavity 210. The saline solution 207 contains one or more salts or other conductive components and thus may be attracted or repelled by electrical charges.

In accordance with the present invention, a conductive coating 209 is positioned along at least a portion of the perimeter of one or both of the front curve lens 201 and the back curve lens 202. The conductive coating 209 may comprise gold or silver and is preferably biocompatible. Applying an electrical charge to the conductive coating 209 causes the conductive salts or other components in the saline solution to be attracted or repelled.

The front curve lens 201 has an optical power associated with light passing through a concave arcuate inner lens surface 203 and a convex arcuate outer lens surface 204. The optical power may be 0, or may be positive or negative power. In some preferred embodiments, the optical power is that which is typically present in corrective contact lenses, such as a power between-8.0 and +8.0 diopters, as a non-limiting example.

The back curve lens 202 has an optical power associated with light passing through a convex arcuate inner lens surface 205 and a concave arcuate outer lens surface 206. The optical power may be 0, or may be positive or negative power. In some embodiments, the optical power is that power typically present in corrective contact lenses, such as a power between-8.0 and +8.0 diopters as a non-limiting example. An optical axis 212 is formed through the back curve lens 202 and the front curve lens 201.

Various embodiments may also include a change in optical power associated with a change in shape of a liquid meniscus 211 formed between the saline solution 207 and the oil. In some embodiments, the change in optical power may be relatively small, for example between 0 to 2.0 diopter change. In other embodiments, the change in optical power associated with the change in shape of the liquid meniscus may be a change in diopter of up to about 30 or more. Generally, a larger change in optical power associated with a change in shape of the liquid meniscus 211 is associated with a relatively thicker lens thickness 213.

According to some embodiments of the present invention, such as those that may be included in an ophthalmic lens, such as a contact lens, the cross-cut lens thickness 213 of the arcuate liquid meniscus lens 200 will be at most about 1,000 microns thick. An exemplary lens thickness 213 of the relatively thin lens 200 may be up to about 200 microns thick. A preferred embodiment may include a liquid meniscus lens 200 having a lens thickness 213 of about 600 microns thick. Generally, the front curve lens 201 can have a cross-sectional thickness of between about 35 microns and about 200 microns, and the back curve lens 202 can also have a cross-sectional thickness of between about 35 microns and 200 microns.

According to the present invention, the cumulative optical power is the sum of the optical powers of the front curve lens 201, the back curve lens 202, and the liquid meniscus 211 formed between the oil 208 and the saline solution 207. In some embodiments, the optical power of the lens 200 will also include a refractive index difference between one or more of the front curve lens 201, the back curve lens 202, the oil 208, and the saline solution 207.

In those embodiments that include an arcuate liquid meniscus lens 200 incorporated into a contact lens, it is also desirable that the relative positions of the saline 207 and oil 208 within the curved liquid meniscus lens 200 remain stable as the contact lens wearer moves. Generally, it is preferable to prevent the oil 208 from flowing and moving relative to the saline 207 while the wearer is moving. Thus, the combination of oil 208 and brine solution 207 selected preferably have the same or similar densities. Further, the oil 208 and the brine solution 207 preferably have a relatively low immiscibility such that the brine solution 207 does not mix with the oil 208.

In some preferred embodiments, the volume of saline solution contained within the cavity is greater than the volume of oil contained within the cavity. In addition, some preferred embodiments include a saline solution 207 in contact with substantially the entire inner surface 205 of the back curve lens 200. Some embodiments may include a volume of oil 208 that is about 66% or more by volume compared to an amount of saline solution 207. Some additional embodiments may include an arcuate liquid meniscus lens, wherein the volume of oil 208 is about 90% or less by volume compared to the amount of saline solution 207.

Referring now to fig. 3, a cross-sectional view of an edge portion of an arcuate liquid meniscus lens 300 is shown. As described above, the arcuate liquid meniscus lens 300 includes combined front curve lens 301 and back curve lens 302 elements. The front curve lens 301 and the back curve lens 302 may be formed of one or more at least partially transparent materials. In some embodiments, one or both of the front curve lens 301 and the back curve lens 302 comprise a plastic that is generally optically transparent, such as one or more of the following: PMMA, Zeonor and TPX.

For example, one or both of the front curve lens 301 and the back curve lens 302 may be formed by one or more of the following methods: single point diamond turning lathe processing, injection molding and free forming of the digital micro-mirror device.

One or both of the front curve lens 301 and the back curve lens 302 may include a conductive coating 303, as shown, the conductive coating 303 extending along a peripheral portion from 309 to 310. In some preferred embodiments, the conductive coating 303 comprises gold. The gold may be applied by sputtering, vapor deposition or other known methods. As a non-limiting example, alternative conductive coating 303 can include aluminum, nickel, and indium tin oxide. Generally, the conductive coating 303 will be applied to the peripheral region of one or both of the front curve lens 301 and the back curve lens 302.

In some embodiments of the present invention, the back curve lens 302 has a conductive coating 304 applied to specific areas. For example, a portion around the perimeter of the back curve lens 302 may be coated from the first boundary 304-1 to the second boundary 304-2. For example, the gold coating may be applied by a sputtering method or vapor deposition. In some embodiments, a mask may be used to coat gold or other conductive material in a predetermined pattern around one or more peripheral portions of the front curve lens 301 or the back curve lens 302. Alternative conductive materials may be applied and cover different areas of the back curve lens 302 using a variety of methods.

In some embodiments, the conductive flow path, such as one or more holes or slits in the back curve lens 302, may be filled with a conductive filling material, such as a conductive epoxy. The conductive filler may provide electrical conduction to a conductive coating on the inner surface of one or both of the front curve lens 301 and the back curve lens 302.

In another aspect of the present invention, one or both of the front curve lens 301 and the back curve lens 302 may be formed from a variety of different materials, wherein the optical zone (not shown) that is typically located in the central region of the front curve lens 301 and the back curve lens 302 may comprise an optically transparent material, and the peripheral region may comprise an optically opaque region comprising an electrically conductive material. The optically opaque region may further comprise one or more of a control circuit and an energy source.

In another aspect, in some embodiments, an insulator coating 305 is applied to the front curve lens 301. By way of non-limiting example, the insulator coating 305 may be applied to a region extending from the first region 305-1 into the second region 305-2. The insulator may comprise, for example, parylene c, teflon af, or other materials having a variety of electrical and mechanical properties, as well as electrical resistance.

In some specific embodiments, the insulator coating 305 creates a boundary region to maintain separation between the saline solution 306 and the conductive coating 303 contained in the cavity between the front curve lens 301 and the back curve lens 302. Accordingly, some embodiments include an insulator coating 305 patterned and positioned in one or more areas of one or both of the front curve lens 301 and the back curve lens 302 to prevent the positively charged conductor 303 from coming into contact with the negatively charged saline solution 306, wherein contact of the conductor 303 with the saline solution 306 could cause a short circuit in the circuit. An embodiment may include a positively charged saline solution 306 and a negatively charged conductor 303.

Other embodiments may allow a short circuit to occur between conductor 303 and saline solution 306 as a reset function of the circuitry associated with the operation of lens 300. For example, a short circuit condition may interrupt the power to the lens and cause the saline solution 306 and oil 307 to return to a default position.

Some preferred embodiments include conductors 303 that extend from regions 309 on the interior of cavity 311 to regions 310 outside of cavity 311. Other embodiments may include a channel 312 through the front curve lens or the back curve lens that may be filled with a conductive material 313, such as a waterproof conductive epoxy. The conductive material 313 may form or be connected to an electrical terminal outside the cavity. An electrical charge may be applied to the terminal and conducted through the conductive material 313 in the via 312 to the coating.

The thickness of the insulator coating 305 can vary as a parameter of lens performance. According to the present invention, the charged components, including the saline solution 306 and the conductor 303, are generally held on either side of the insulator coating 305. The present invention provides an indirect relationship between the thickness of the insulator coating 305 and the electric field between the saline solution 306 and the conductor 303, wherein the farther apart the saline solution 306 is held from the conductor 303, the weaker will be its electric field.

In general, the present invention provides that the electric field strength can be significantly reduced as the thickness of the insulator coating 305 increases. The closer the electric field, the more energy will generally be available to move with the spherical liquid meniscus boundary 308. As the distance between the saline solution 306 and the conductor 303 increases, the farther apart the saline solution 306 is from the electric field of the conductor coating 303, and thus the more difficult it is to move the spherical meniscus boundary 308. Conversely, the thinner the insulator coating 305, the more susceptible the spherical liquid meniscus 308 is to defects in the insulator coating 305. Generally, even relatively small holes in the insulator coating 305 will short the lens 300.

In some embodiments, it is desirable to include a saline solution 306 having a density that is about the same as the density of the oil 307 also contained within the lens 300. For example, the density of the brine solution 306 may preferably be within 10% of the density of the oil 307, more preferably, the density of the brine solution 306 will be within 5% of the density of the oil, most preferably within about 1%. In some embodiments, the density of the brine solution 306 may be adjusted by adjusting the concentration of salts or other components within the brine solution 306.

In accordance with the present invention, the arcuate liquid meniscus lens 300 will provide more stable optical properties by limiting the movement of the oil 307 relative to the front curve lens 301 and the back curve lens 302. One way to stabilize the movement of the oil 307 relative to one or both of the arcuate front curve lens 301 and the back curve lens 302 is to maintain a relatively consistent density of the oil 307 and the saline solution 306. Furthermore, the relative depth or thickness of the layer of saline solution 306 is reduced as compared to conventional cylindrical lens designs, since the inner surfaces of both the front curve lens 301 and the back curve lens 302 are of curved design. Accordingly, the position of the oil within the lens 300 becomes more stable in order to avoid movement of the oil and possible damage to the meniscus between the oil 306 and the saline solution 307.

In some preferred embodiments, the saline solution 306 provides a lower refractive index than the oil 307, which provides a relatively higher refractive index. However, in some embodiments, a saline solution 306 having a higher refractive index than the oil 307 may be included, in which case the oil provides a relatively lower refractive index.

The front curve lens 301 and the back curve lens 302 may be secured in place proximate to each other using an adhesive 314, thereby retaining the oil 307 and the saline solution 306 therebetween. The adhesive 314 acts as a seal so that the saline 306 or oil 307 does not leak from the curved liquid meniscus lens 300.

Referring now to fig. 4, a curved liquid meniscus lens 400 is shown with a liquid meniscus boundary 401 between a saline solution 406 and an oil 407. According to some preferred embodiments, a first angular break in the arcuate wall extending between 402 and 403 defines a meniscus wall 405 in the front curve lens 404. When an electrical charge is applied and removed along the one or more conductive coatings or conductive materials 408, the liquid meniscus boundary 401 will move up and down the meniscus wall 405.

In some preferred embodiments, the conductive coating 403 will extend from an area inside the cavity 409 holding the saline solution 406 and oil 407 to an area outside the cavity 409 containing the saline solution 406 and oil 407. In such embodiments, the conductive coating 403 may be a conduit for the electrical charge applied to the conductive coating 403 at a point outside the cavity 409 to the area of the conductive coating within the cavity and in contact with the saline solution 406.

Referring now to fig. 5, a cross-sectional view of an edge portion of an arcuate liquid meniscus lens 500 with a front curve lens 501 and a back curve lens 502 is shown. An arcuate liquid meniscus lens 500 may be used to contain a saline solution 503 and oil 504. The geometry of the arcuate liquid meniscus lens 500 and the properties of the saline solution 503 and the oil 504 facilitate the formation of a liquid meniscus boundary 505 between the saline solution 503 and the oil 504.

In general, a liquid meniscus lens may be considered a capacitor with one or more of the following: conductive coatings, insulator coatings, vias, and materials that are present on or through the front curve lens 501 and the back curve lens 502. In accordance with the present invention, the shape of the liquid meniscus boundary 505 and, thus, the contact angle between the liquid meniscus boundary 505 and the front curve lens 501 changes as an electrical charge is applied to the surface of at least a portion of one or both of the front curve lens 501 and the back curve lens 502.

In accordance with the present invention, a change in the current applied to the saline solution through the conductive coating or material changes the position of the liquid meniscus boundary 505 along the meniscus wall 506. This movement occurs between first sharp edge 506-1 and second sharp edge 506-2.

In a preferred embodiment, when a current of a first magnitude (e.g., a voltage and current associated with an unpowered state or a sleep state) is applied to the lens, the liquid meniscus boundary 505 will be at or near the first sharp 506-1.

Application of a second magnitude of current (sometimes referred to as a first powered state) may be associated with movement of the liquid meniscus boundary 505 along the meniscus wall 506 in a direction generally toward the second sharp 506-2, thereby causing a change in the shape of the liquid meniscus boundary. As discussed in more detail below, each of the plurality of sharp edges included along the meniscus wall may be associated with a respective energized state in accordance with the present invention.

In some embodiments, the meniscus wall 506 will be a smooth surface. A smooth meniscus wall 506 surface may minimize defects in the insulator coating. In addition, a smooth meniscus wall 506 is preferred because random irregularities in surface texture when the lens is powered on or off can cause unstable fluid motion, thereby causing unstable or unpredictable meniscus motion. In some preferred embodiments, the smooth meniscus wall includes a peak to valley measurement in the range of about 1.25 nanometers to 5.00 nanometers along the meniscus wall 506.

In another aspect, in some embodiments it is desirable for the meniscus wall 506 to be hydrophobic, in which case a defined texture, such as a nano-textured surface, may be incorporated into the design of an arcuate liquid meniscus lens.

In another aspect, in some embodiments, the meniscus wall 506 may be angled with respect to the optical axis of the lens. The angle may range from 0 ° (or parallel to the optical axis) to at or near 90 ° (or perpendicular to the optical axis). As shown, and in some preferred embodiments, the meniscus wall 506 angle is typically between about 30 ° and 50 ° such that an arcuate liquid meniscus lens functions according to the contact angle currently between the liquid meniscus boundary 505 and the insulator coated meniscus wall 506. The angle of the meniscus wall 506 may approach 0 or 90, due to the use of different materials or for different optical purposes, such as telescopic vision.

In accordance with the present invention, the angle of the meniscus wall 506 may be designed to accommodate the magnitude of motion along the meniscus wall 506 that occurs upon application of a specified voltage and current. In some embodiments, as the meniscus wall 506 angle increases, the ability to change the lens power generally decreases within given lens size and voltage parameters. Furthermore, if the meniscus wall 506 is at or near 0 ° with respect to the optical axis, the liquid meniscus boundary 505 will advance almost straight onto the front optic. The meniscus wall angle is one of a number of parameters that may be adjusted to provide various lens performance effects.

In some preferred embodiments, the length of the meniscus wall 506 is about 0.265 mm. However, in various designs, the angle of the meniscus wall 506, along with the size of the entire lens, will naturally affect the length of the meniscus wall 506.

It is believed that the arcuate liquid meniscus lens 500 will fail if the oil 504 contacts the back curve lens 502. Thus, in a preferred embodiment, the meniscus wall 506 is designed to allow a minimum gap of 50 microns between the first sharp 506-1 and the back curve lens 502 at its closest point. In other embodiments, the minimum gap may be less than 50 microns, although the risk of lens failure increases as the gap decreases. In other embodiments, the gap may be increased to reduce the risk of lens failure, but the overall lens thickness will also increase, which may be undesirable.

In another aspect of some preferred embodiments of the present invention, the behavior of the liquid meniscus boundary 505 as it travels along the meniscus wall 506 may be inferred using young's equations. Although young's equation defines the force balance that a droplet induces on a dry surface and assumes a perfectly flat surface, the basic properties may still apply to the electrowetting lens environment created within the arcuate liquid meniscus lens 500.

A first magnitude of electrical energy may be applied to the lens, such as when the lens is in an unpowered state. During the application of the first magnitude of electrical energy, a balance of interfacial energy between the oil 504 and the brine solution 503 is achieved. This state may be referred to herein as a liquid meniscus boundary 505. The oil 504 and the meniscus wall 506, and the saline solution 503 and the meniscus wall 506, form an equilibrium contact angle between the liquid meniscus boundary 505 and the meniscus wall 506. As the magnitude of the voltage applied to the arcuate liquid meniscus lens 500 changes, the balance of the interface energy will change, causing the contact angle between the liquid meniscus boundary 505 and the meniscus wall 506 to change accordingly.

The contact angle of the liquid meniscus boundary 505 with the insulator coated meniscus wall 506 is a major factor in the design and function of the arcuate liquid meniscus lens 500, not only due to its role in young's equation in the motion of the liquid meniscus boundary 505, but also due to the contact angle in combination with other structures of the arcuate liquid meniscus lens 500 to limit meniscus motion.

Discontinuities across the meniscus wall 506, such as sharp edges 506-1, 506-2, act as boundaries for the motion of the liquid meniscus 505 because they require a significant change in voltage to effect a sufficient change in the contact angle of the liquid meniscus to move the liquid meniscus boundary 505 across one of the sharp edges. By way of non-limiting example, in some embodiments, the contact angle of the liquid meniscus boundary 505 with the meniscus wall 506 is in the range of 15 to 40 °, whereas the contact angle of the liquid meniscus boundary 505 with the step 507 below the second sharp 506-2 may be in the range of 90 to 130 °, and in some preferred embodiments is about 110 °.

A voltage applied to the lens may cause the liquid meniscus boundary 505 to move along the meniscus wall 506 towards the second sharp 506-2. The natural contact angle between the liquid meniscus boundary 505 and the insulator coated meniscus wall 506 will cause the liquid meniscus boundary 505 to stop at the second sharp 506-2 unless a significantly higher voltage is provided.

At one end of the meniscus wall 506, the first sharp 506-1 generally defines a limit beyond which the liquid meniscus boundary 505 generally does not move. In some embodiments, first sharp 506-1 is configured as a sharp edge. In other preferred embodiments, first sharp 506-1 has a defined small radial surface that is less likely to be defective during manufacturing. Electrical conductors, insulators, and other potentially desirable coatings may not deposit uniformly and as expected on sharp edge edges, but the radial edges of the defined radial surfaces may be more reliably coated.

In some embodiments, first sharp 506-1 is configured at an angle of about 90 ° and has a defined radius of about 10 microns. The sharp edge may also be manufactured to have an angle of less than 90 °. In some embodiments, sharp edges having an angle greater than 90 ° may be used to increase the robustness of the sharp edge, but the design takes up more lens space.

In various embodiments, sharp edges 506-1, 506-2 may define a radius in the range of 5 microns to 25 microns. Larger defined radii can be used to improve coating reliability, but at the expense of taking up more space in the tight tolerances of the lens design. In this regard, as in many other lens design areas, there is a trade-off between ease of manufacture, optimization of lens function, and minimization of size. Various variables may be used to fabricate a practical, reliable arcuate liquid meniscus lens 500.

Second sharp 506-2 comprises a structure designed to limit oil movement when a voltage is applied to arcuate liquid meniscus lens 500. In some embodiments, second sharp 506-2 may also comprise a sharp having a generally pointed end, or in other embodiments, second sharp 506-2 may comprise a defined radius of between 5 and 25 microns, most preferably 10 microns. A radius of 10 microns works well as a sharp edge and can be manufactured using a single point diamond turning lathe or injection molding process.

A vertical or near vertical step 507 extending to the beginning of the optical zone 508 of the front curve lens 501 may be included on the opposite side of the second sharp 506-2 from the meniscus wall 506. In some embodiments, the height of the step 507 is 120 microns, but it may also be in the range of 50 microns to 200 microns.

In some embodiments, the step 507 may be at an angle of about 5 ° to the optical axis. In other embodiments, the angle of the step 507 may be only 1 ° or 2 °, or may be an angle greater than 5 °. A step 507 at a smaller angle to the optical axis will generally act as a more effective meniscus motion limiter as it requires a greater change in the contact angle of the liquid meniscus boundary 505 to move the meniscus wall 506 away and onto the step 507. The radius of the transition from step 507 to the beginning of the optical zone 508 is 25 microns. A larger radius will unnecessarily take up more space in the lens design. Smaller radii are possible and may be implemented if space is to be gained. In this and other lens fields, decisions to use defined radii rather than theoretical sharp edges are based in part on the potential movement of the injection molding process used for the lens elements. The bend between step 507 and the beginning of optical zone 508 will improve plastic flow during the injection molding process and give the lens optimal strength and stress handling characteristics.

Referring now to fig. 6A, a multi-concave meniscus wall 601 is depicted in some embodiments, which may be included in a liquid meniscus lens. The multi-concave meniscus wall 601 includes multiple segments that are concave with respect to the optical axis formed through the liquid meniscus lens. The plurality of segments that are concave with respect to the optical axis may or may not be interspersed with segments of the meniscus wall that comprise other shapes with respect to the optical axis, such as linear, convex, or stepped. Other shapes of structures and sections may also be interspersed.

In some embodiments, the multi-concave meniscus wall may be positioned at an angle of approximately forty-five degrees (45 °) from the optical axis in an arcuate liquid meniscus lens, which contains the oil 602 and the saline solution 603. In some embodiments, the liquid meniscus boundary 604A contacts the multi-concave meniscus wall 601 at 605A in a first state where power is applied to the multi-concave meniscus wall 601, e.g., in an unpowered state. Generally, in some exemplary embodiments, the first powered state includes the liquid meniscus boundary proximate the end of the multi-concave meniscus wall 601 closest to the first sharp 607.

Fig. 6B illustrates a position of a liquid meniscus boundary 604B in a second powered state, e.g., a powered state where current is applied to the meniscus wall 601. Relative to a first state, including an unpowered state, the liquid meniscus boundary 604B moves generally along the multi-concave meniscus wall 601 towards the front curve lens 606. The powered state may also include the liquid meniscus boundary 604B substantially closer to the break 609 between concave segments in the multi-concave meniscus wall 601.

Referring now to fig. 7A, a perspective view of a multi-concave meniscus wall 701 assembly of an arcuate liquid meniscus lens is shown separately from the rest of the arcuate liquid meniscus lens. In the illustrated embodiment, the multi-concave meniscus wall 701 includes four concave meniscus wall segments 701-1 through 701-4. The concave wall section is generally concave with respect to an optical axis 703 through the lens. Other embodiments may also include more or fewer concave meniscus wall segments 701-1 through 701-4. Many wall segments may be based on, for example, the physical size of the liquid meniscus lens, many setting positions of the meniscus where the lens is desired to be deployed, or other factors.

The multi-concave meniscus wall 701 has a uniform length around the entire lens between the first sharp 702-1 and the second sharp 702-2. Fig. 7B illustrates a perspective view of a concave meniscus wall segment 701-1 shaped to include a segment of a ring.

Fig. 6C, in conjunction with fig. 6A and 6B, illustrates the position of the liquid meniscus boundary in both the unpowered 604A state and the powered 604B state. In accordance with the present invention, a liquid meniscus lens with a multi-concave meniscus wall 601 placed at a given angle with respect to the optical axis (as shown in fig. 6C) provides more consistent and repeatable control of liquid meniscus motion produced by the application of electrical current to the meniscus wall portions, as compared to a liquid meniscus lens with a linear meniscus wall placed at a similar angle with respect to the optical axis. An example of a lens including a linear meniscus wall is described in U.S. patent application serial No. 61,359,548, entitled "lens system and lens system, filed on 29/6/2010, which is incorporated herein by reference.

In some preferred embodiments, a voltage is applied to the liquid meniscus wall and the corresponding liquid meniscus boundary moves along the multi-concave meniscus wall 601 towards the front curve lens 606. The discontinuity 609 between concave meniscus wall segments functions to slow and stop the liquid meniscus motion in a given region to achieve an increased specific power change. As the liquid meniscus boundary travels along each concave segment, the travel of the liquid meniscus boundary will slow and more easily stop proximate each discontinuity 609 due to the change in liquid meniscus boundary contact angle on either side of the discontinuity 609. In accordance with the present invention, if the liquid meniscus boundary 604 stops near the break 609, the liquid meniscus boundary 604 moves slightly to settle at the second sharp 608 side of the break 609 due to the channeling of the break 609 over the liquid meniscus boundary 604.

While the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof.

Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims.

Claims (27)

1. An optical lens, comprising:

a front curve lens comprising a front curve lens outer surface and a front curve lens inner surface, wherein the front curve lens outer surface and the front curve lens inner surface each comprise an arcuate shape;

a back curve lens comprising a back curve lens inner surface and a back curve lens outer surface, the back curve lens positioned proximate to the front curve lens such that the front curve lens inner surface and the back curve lens inner surface form a cavity therebetween;

a volume of saline solution and a volume of oil contained within a cavity formed between the front curve lens interior surface and the back curve lens interior surface, the volume of saline solution and the volume of oil forming a meniscus therebetween; and

a meniscus wall comprising a general shape consisting essentially of a plurality of segments of a torus that is concave with respect to an optical axis formed in one or both of the front curve lens and the back curve lens and abutting a meniscus formed between the saline solution and oil.

2. The optical lens of claim 1 wherein the back curve lens inner surface and the back curve lens outer surface each comprise an arcuate shape.

3. The optical lens of claim 2 further comprising a conductive coating on at least a portion of the meniscus wall.

4. The optical lens of claim 3 wherein the volume of oil is less than the volume of saline solution contained within the cavity.

5. The optical lens of claim 3 wherein the volume of oil is 66% or more of the volume of saline solution.

6. The optical lens of claim 4 wherein the volume of oil is 90% or less of the volume of saline solution.

7. The optical lens of claim 3 wherein the density of the oil is equal to the density of the saline solution.

8. The optical lens of claim 3 wherein the density of the oil is within 10% of the density of the saline solution.

9. The optical lens of claim 3 wherein the density of the oil is within 5% of the density of the saline solution.

10. The optical lens of claim 3 wherein the conductive coating extends from a region inside the cavity to a region outside the cavity.

11. The optical lens of claim 10 wherein the area of conductive coating outside the cavity forms an electrical terminal for providing an electrical charge to the optical lens.

12. The optical lens of claim 10 wherein application of an electrical charge to a region of conductive coating outside the cavity causes a change in the location of contact of the peripheral edge of the meniscus and the meniscus wall.

13. The optical lens of claim 12 wherein the electrical charge comprises a direct current.

14. The optical lens of claim 12 wherein the electrical charge is 20.0 volts.

15. The optical lens of claim 12 wherein the electrical charge is 18.0 to 22.0 volts.

16. The optical lens of claim 12 wherein the charge is 5.0 volts.

17. The optical lens of claim 12 wherein the electrical charge is 3.5 to 7.5 volts.

18. The optical lens of claim 4 wherein the front curve lens outer surface comprises an optical power other than 0.

19. The optical lens of claim 4 wherein the front curve lens interior surface comprises an optical power other than 0.

20. The optical lens of claim 4 wherein the back curve lens outer surface comprises an optical power other than 0.

21. The optical lens of claim 4 wherein the back curve lens interior surface comprises an optical power other than 0.

22. The optical lens of claim 4 further comprising a channel through one or both of the front curve lens and the back curve lens and a conductive material filling the channel.

23. The optical lens of claim 22 further comprising a terminal in electrical communication with the conductive material filling the channel.

24. The optical lens of claim 23 wherein applying an electrical charge to the terminal causes a change in the shape of the meniscus.

25. The optical lens of claim 4 further comprising an insulator coating along at least a portion of an inner surface of the front curve lens, wherein the insulator coating comprises an electrical insulator.

26. The optical lens of claim 25 wherein the insulator comprises one of parylene c and teflon af.

27. The optical lens of claim 25 wherein the insulator provides separation between the saline solution and the conductive coating.