Fluid filled lenses and mechanisms of inflation thereof

An actuator for a fluid-filled lens including a housing having a first and a second end; a reservoir disposed within the housing. In an embodiment, a slider is slidingly disposed within the housing and disposed adjacent to the reservoir. In an embodiment, the actuator further includes a compression arm having a first end that is fixed and a second end that is not fixed, wherein the compression arm is disposed adjacent to the reservoir. Sliding the slider from one end of the housing to the other causes the slider to push the second end of the compression arm so as to compress the reservoir. In an embodiment, the slider includes a first end having a wedge shape configured to compress the reservoir. Sliding of the slider from one end of the housing to the other causes the first end of the slider to compress the reservoir.

BACKGROUND

Embodiments of the present invention relate to fluid-filled lenses and in particular to variable fluid-filled lenses.

2. Background Art

Basic fluid lenses have been known since about 1958, as described in U.S. Pat. No. 2,836,101, incorporated herein by reference in its entirety. More recent examples may be found in “Dynamically Reconfigurable Fluid Core Fluid Cladding Lens in a Microfluidic Channel” by Tang et al., Lab Chip, 2008, vol. 8, p. 395, and in WIPO publication WO2008/063442, each of which is incorporated herein by reference in its entirety. These applications of fluid lenses are directed towards photonics, digital phone and camera technology and microelectronics.

Fluid lenses have also been proposed for ophthalmic applications (see, e.g., U.S. Pat. No. 7,085,065, which is incorporated herein by reference in its entirety). In all cases, the advantages of fluid lenses, such as a wide dynamic range, ability to provide adaptive correction, robustness, and low cost have to be balanced against limitations in aperture size, possibility of leakage, and consistency in performance. The '065 patent, for example, has disclosed several improvements and embodiments directed towards effective containment of the fluid in the fluid lens to be used in ophthalmic applications, although not limited to them (see, e.g., U.S. Pat. No. 6,618,208, which is incorporated by reference in its entirety). Power adjustment in fluid lenses has been effected by injecting additional fluid into a lens cavity, by electrowetting, application of ultrasonic impulse, and by utilizing swelling forces in a cross-linked polymer upon introduction of a swelling agent such as water.

BRIEF SUMMARY

In an embodiment, an actuator for a fluid-filled lens comprises: a housing; a reservoir disposed within the housing; a compression arm having a first end that is fixed and a second end that is not fixed, wherein the compression arm is disposed adjacent to the reservoir; and wherein the compression arm flexes to compress the reservoir.

In another embodiment, an actuator for a fluid-filled lens comprises: a housing having a first end and a second end; a reservoir disposed within the housing; and a slider slidingly disposed within the housing and disposed adjacent to the reservoir, wherein the slider includes a first end having a wedge shape configured to compress the reservoir, and wherein sliding of the slider from the second end of the housing to the first end of the housing causes the first end of the slider to compress the reservoir.

DETAILED DESCRIPTION

Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present invention. It will be apparent to a person skilled in the pertinent art that this invention can also be employed in a variety of other applications.

Fluid lenses have important advantages over conventional means of vision correction, such as rigid lenses and contact lenses. First, fluid lenses are easily adjustable. Thus, a presbyope who requires an additional positive power correction to view near objects can be fitted with a fluid lens of base power matching the distance prescription. The user can then adjust the fluid lens to obtain additional positive power correction as needed to view objects at intermediate and other distances.

Second, fluid lenses can be adjusted continuously over a desired power range by the wearer. As a result, the wearer can adjust the power to precisely match the refractive error for a particular object distance in a particular light environment. Thus, fluid lenses allow adjustment of power to compensate for alteration of the natural depth of focus of the eye that depends on the wearer's pupil size, which is in turn dependent on the ambient light level.

Third, although 20/20 vision, which corresponds to an image resolution of 1 minute of arc ( 1/60 degree) is generally acknowledged to represent an acceptable quality of vision, the human retina is capable of finer image resolution. It is known that a healthy human retina is capable of resolving 20 seconds of arc ( 1/300 degree). Corrective eyeglasses designed to enable a patient to achieve this superior level of vision have a resolution of about 0.10 D or better. This resolution can be achieved with continuously adjustable fluid lens elements.

In an embodiment of a fluid lens assembly, one or more fluid lenses may be provided with its own actuation system, so that a lens for each eye can be adjusted independently. This feature allows wearers, such as anisometropic patients, to correct any refractive error in each eye separately, so as to achieve appropriate correction in both eyes, which can result in better binocular vision and binocular summation.

FIG. 1illustrates a perspective view of a caliper actuator assembly100, according to an embodiment of the present invention. Caliper actuator assembly100includes temple cover110, which includes a hollow outer portion and a hollow inner portion formed together to enclose additional pieces of caliper actuator assembly100. Distal end160of temple cover110is shaped to fit over a wearer's ear. Caliper actuator assembly100further includes temple chassis120, wheel130, and slider140. In an embodiment, wheel130and slider140are longitudinally slidably disposed within temple chassis120. Caliper actuator assembly100operates to compress reservoir150and transfer fluid between reservoir150and a fluid lens (not shown). The compressing force may be applied in various ways, such as for example, by rotating wheel130or by translating the wheel along a slot. Additional methods of applying compressing force are also described herein. The compression of reservoir150may be effected either by compressing reservoir150in a vertical or horizontal direction against a ceiling or inner wall of temple chassis120, as described in detail below.

FIG. 2illustrates an exploded perspective view of an embodiment of caliper actuator assembly100. In an embodiment, slider subassembly295(described below with respect toFIGS. 3-4) is configured to translate along one or more of temple cover110and temple chassis120in order to compress reservoir150. In operation, a user rotates wheel130, which moves slider block255, which in turn compresses a relatively stiff metal plate, such as compression arm270, that is in contact with a first side surface265of reservoir150. A second side surface (not shown) of reservoir150is placed against inner wall285of temple chassis120, a portion of temple cover110, or any other suitable surface. Slider140presses against compression aim270, which compresses reservoir150in a controllable manner. In an embodiment, the length of the lateral movement of wheel130is proportional to the magnitude of compression of the compression arm, and is proportional to the magnitude of compression of the reservoir.

In an embodiment, wheel130has a knurled edge in order to provide secure contact with the finger of the user as well more precise control over the translation of wheel130.

Lens module200is connected via outlet port245to a connecting tube (not shown), which is connected to reservoir150. Lens module200may further include a flexible back surface provided by, for example, a flexible membrane (not shown) stretched flat over the edge of a rigid optical lens. To change the optical power of fluid filled lens module200, the membrane may be inflated through the addition of a fluid from reservoir150.

The connecting tube delivers fluid from lens module200to reservoir150and vice versa. The connecting tube is designed to be relatively impermeable to the fluid contained therein. In an embodiment, the connecting tube is configured to allow a minimum flow rate at all times in order to ensure a minimum speed of response to the user moving wheel130in order to change the optical power of fluid filled lens module200. The connecting tube is connected at one end to outlet port245of lens module200and at the other end to reservoir150. In an embodiment, the overall assembly including the lens module200, the connecting tube, and reservoir150is designed to maintain a seal excluding fluids and air for an overall use period of two years or more. In an embodiment, the connecting tube is thin in order to be accommodated within a hinge cavity. In an embodiment, it is less than 2.0 mm in outer diameter and less than 0.50 mm in wall thickness, in order to maintain an adequate flow of fluid. In an embodiment, it is capable of being bent by an angle of no less than 60 degrees. In an embodiment, it is capable of being bent by an angle of no less than 45 degrees without crimping. In an embodiment, it is durable to repeated flexing of the hinge.

Hinge block250and spring230are enclosed within a covered area between inner block210and outer block240. Additional embodiments of the hinge and spring are described in U.S. application Ser. No. 12/904,769. Caliper actuator assembly100includes wheel130held in place by axle280, slider140, slider block255, spacer block290, and compression arm270. These parts are assembled into a temple chassis subassembly (which is described further with respect toFIGS. 7 and 8) and are held in place by screws235. Rubber strip205includes a flexible surface upon which wheel130may move. In an embodiment, wheel130may rotate. In another embodiment it may translate, and in yet another embodiment it may rotate and translate.

In an embodiment, slider140maintains reservoir150in its compressed state as it moves away from distal end160. As slider140is moved towards distal end160, the compressing force on reservoir150is released, and reservoir150springs back to its original shape, temporarily creating low pressure on the fluid, and thus pulling fluid back from lens module200.

Materials

The pieces of the various actuator assemblies described herein, for example, but not limited to, the temple cover, temple chassis, wheel, slider, spring, screws, inner block, outer block, axle, compression arm, spacer block, etc, may be manufactured through any suitable process, such as metal injection molding (MIM), cast, machining, plastic injection molding, and the like. The choice of materials may be further informed by the requirements of mechanical properties, temperature sensitivity, optical properties such as dispersion, moldability properties, or any other factor apparent to a person having ordinary skill in the art.

The fluid used in the fluid lens may be a colorless fluid, however, other embodiments include fluid that is tinted, depending on the application, such as if the intended application is for sunglasses. One example of fluid that may be used is manufactured by Dow Corning of Midland, Mich., under the name “diffusion pump oil,” which is also generally referred to as “silicone oil.”

The fluid lens may include a rigid optical lens made of glass, plastic, or any other suitable material. Other suitable materials include, for example and without limitation, Diethylglycol bisallyl carbonate (DEG-BAC), poly(methyl methacrylate) (PMMA), and a proprietary polyurea complex, trade name TRIVEX (PPG).

The fluid lens may include a membrane made of a flexible, transparent, water impermeable material, such as, for example and without limitation, clear and elastic polyolefins, polycycloaliphatics, polyethers, polyesters, polyimides and polyurethanes, for example, polyvinylidene chloride films, including commercially available films, such as those manufactured as MYLAR or SARAN. Other polymers suitable for use as membrane materials include, for example and without limitation, polysulfones, polyurethanes, polythiourethanes, polyethylene terephthalate, polymers of cycloolefins and aliphatic or alicyclic polyethers.

The connecting tube may be made of one or more materials such as TYGON (polyvinyl chloride), PVDF (Polyvinyledene fluoride), and natural rubber. For example, PVDF may be suitable based on its durability, permeability, and resistance to crimping.

The temple cover may be any suitable shape, and may be made of plastic, metal, or any other suitable material. In an embodiment, the temple cover is made of a lightweight material such as, for example and without limitation, high impact resistant plastics material, aluminum, titanium, or the like. In an embodiment, the temple cover may be made entirely or partly of a transparent material.

The reservoir may be made of, for example and without limitation, Polyvinyledene Difluoride, such as Heat-shrink VITON®, supplied by DuPont Performance Elastomers LLC of Wilmington, Del., DERRY-KYF 190 manufactured by DSG-CANUSA of Meckenheim, Germany (flexible), RW-175 manufactured by Tyco Electronics Corp. of Berwyn, Pa. (formerly Raychem Corp.) (semirigid), or any other suitable material. Additional embodiments of the reservoir are described in U.S. application Ser. No. 12/904,736.

Assembly

FIGS. 3-4illustrate a set of steps for assembling an embodiment of slider subassembly295. Beginning withFIG. 3, axle280is first placed within hole297located in the center of wheel130. Next, slider140is placed onto axle280with slider tab310on the same side of slider140as wheel130. Next, slider140is laser welded to axle280. The slider subassembly continues withFIG. 4, which illustrates a second set of steps for assembling an embodiment of the slider subassembly. Slider block255is assembled to slider140by snapping and pressing various tabs410protruding from slider block255into corresponding slots420located in slider140.

FIG. 5illustrates a set of steps for assembling an embodiment of a temple cover subassembly500. First, an adhesive (not shown) is applied to rubber strip205. Although strip205is referred to herein as a rubber strip, one of skill in the art will recognize that strip205may be made from any elastic or semi-elastic material. Next, rubber strip205is applied to ramped surface510of temple cover110. Next, wheel130of slider subassembly295is inserted into corresponding slot520of temple cover110. Friction between rubber strip205and wheel130allows wheel130to rotate around axle280while translating within temple cover110.

FIG. 6illustrates a set of steps for assembling compression arm subassembly263, according to an embodiment of the present invention. First, backing260is placed onto compression arm270. Next backing260is laser welded to compression arm270.

FIGS. 7-8illustrate a set of steps for assembling an embodiment of a temple chassis subassembly. Beginning withFIG. 7, spacer block290is placed onto temple chassis120. Next, spacer block290is welded onto temple chassis120along edges710and720. Next, hinge block250is placed onto temple chassis120. Next, hinge block250is welded onto temple chassis120along edges730and740. The temple chassis subassembly continues withFIG. 8, which illustrates a second set of steps for assembling an embodiment of temple chassis subassembly800. A backing (not shown) may be removed from tape810on both sides of reservoir150. Reservoir150is placed against temple chassis120. Compression arm270is then placed onto spacer block290. Compression aim270is then welded onto spacer block290.

FIG. 9illustrates a set of steps for assembling temple subassembly900, according to an embodiment. First, tabs920of temple chassis subassembly800are slid into rear slot930of temple cover110. Next, temple chassis subassembly800is rotated within temple cover110until it snaps into place. It is recommended that slider subassembly295be positioned as far distally as possible within temple cover110. Further, it is recommended that when snapping temple chassis subassembly800into temple cover110, tube940does not become pinched between hinge block250and temple cover110or temple chassis subassembly800.

FIG. 10illustrates a set of steps for assembling lens module subassembly1000, according to an embodiment. First, a suitable piece of 2-sided tape1010is applied on an outward facing side of reservoir150. This process is repeated for the opposite side of reservoir150. The backing of tape1010is then removed when lens module subassembly1000is in position within caliper actuator assembly100.

FIG. 11is a perspective view of a portion of an embodiment of caliper actuator assembly100.FIG. 12shows an embodiment of caliper actuator assembly100.FIG. 13shows additional views of an embodiment of caliper actuator assembly100.FIG. 14shows an embodiment of caliper actuator assembly100with a portion of temple cover110removed to show temple chassis subassembly800.

FIG. 15illustrates a portion of an embodiment of a caliper actuator assembly, showing the rotation of the wheel with respect to the temple cover.

FIG. 16shows charts with data corresponding to breadboard actuator performance for an embodiment. The charts show the changes in optical power of a fluid lens module connected to a reservoir in contact with an actuator, according to an embodiment. The charts show optical power at the optical center of the exemplary lens as a function of the position of the wheel within the slot with respect to diopter readings S, C, and D+0.5C. The linearity in response demonstrates that a wearer of an embodiment of the fluid-filled lenses will be able to achieve the desired level of correction by adjusting the location of the wheel within the slot.

FIGS. 17aand17billustrate two embodiments of caliper actuator assemblies wherein the position of slider block255is changed in order to shorten the length of the lever arm.FIG. 18shows charts with data corresponding to breadboard actuator performance between the embodiments ofFIGS. 17aand17b. The charts show the reversibility of optical power in an exemplary fluid lens module with respect to diopter readings S, C, and D+0.5C. The data shows that while the changes in optical power are reversible, the rate of change is variable, and depends on the initial location of the wheel within the slot. This data indicates that reversibility of the fluid lens module is improved with increased stiffness of the compression arm. However, as would be apparent to one having ordinary skill in the art, less stiff compression arms may also have beneficial properties.

Additional embodiments of actuators will now be described. Similarly to the caliper actuator embodiments described above, each of the following actuator embodiments serve to compress a reservoir located in one or more temples of a fluid-filled lens assembly in order to adjust the optical power of a fluid-filled lens.

FIG. 19aillustrates a side view of an embodiment of roll and translate actuator1900with vertical compression of reservoir1930. Roll and translate actuator1900includes wheel1910, slider1920, reservoir1930, and temple chassis1940. In roll and translate actuator1900, wheel1910translates along track1960. Slider1920slides with wheel1910and compresses reservoir1930against temple chassis ceiling1950of temple chassis1940.FIG. 19billustrates a top view of the roll and translate actuator ofFIG. 19a.FIG. 19cillustrates a side view of the roll and translate actuator ofFIG. 19awhen compressed.

FIG. 20aillustrates a side view of an embodiment of roll and translate actuator2000with horizontal compression of reservoir2030. Roll and translate actuator2000includes wheel2010, slider2020, reservoir2030, and temple chassis2040. In roll and translate actuator2000, wheel2010translates along temple chassis2040. Slider2020slides with wheel2010and compresses reservoir2030against a vertical inner side surface2050of temple chassis2040. In an embodiment, slider2020includes a wedge2060to facilitate the horizontal compression of reservoir2030.FIG. 20billustrates a top view of the roll and translate actuator ofFIG. 20a.FIG. 20cillustrates a side view of the roll and translate actuator ofFIG. 20cwhen compressed.

FIG. 21ais a side perspective view of reservoir2030ofFIG. 20a.FIG. 21billustrates a front view of reservoir2030ofFIG. 20a.FIG. 21cillustrates a front view of reservoir2030when horizontally compressed.

FIG. 22aillustrates a front view of an embodiment of a rack and pinion actuator assembly2200, according to an embodiment of the present invention. Rack and pinion actuator assembly2200includes slider bar2270, rack portion2210of slider bar2270, pinion2220, wheel2230, temple cover2240, and reservoir2260. Wheel2230and pinion2220are coupled together so that when wheel2230is rotated, pinion2220is also rotated. Teeth2225of pinion2220engage with teeth2215of rack portion2210of slider bar2270. As a result, when wheel2230is rotated, slider bar2270moves to compress reservoir2260against temple chassis ceiling2255of temple chassis2250.FIG. 22billustrates a side view of the rack and pinion actuator assembly ofFIG. 22awhen compressed.

FIGS. 23a-cand24illustrate an embodiment of rack and pinion actuator assembly2300with horizontal compression of reservoir2360.FIG. 23aillustrates a side view of rack and pinion actuator assembly2300. Wheel2330and pinion2320are coupled together so that when wheel2330is rotated, pinion2320is also rotated. Teeth2325of pinion2320engage with teeth2310of slider bar2370. When wheel2330of rack and pinion actuator assembly2300is rotated, slider bar2370compresses reservoir2360against a vertical inner side surface2340of temple chassis2350. In an embodiment, slider bar2370includes a wedge2380to facilitate the horizontal compression of reservoir2030.FIG. 23billustrates a top view of the rack and pinion actuator assembly ofFIG. 23a.FIG. 23cillustrates a side view of the rack and pinion actuator assembly ofFIG. 23awhen compressed.

FIG. 24illustrates a perspective exploded view of an embodiment of rack and pinion actuator assembly2400. When wheel2430of rack and pinion actuator assembly2400is rotated, slider bar2470pushes stiff plate2490. Reservoir2460is placed between stiff plate2490and inner wall2410of temple cover2440so that reservoir2460is compressed when wheel2430is rotated.

FIG. 25shows an embodiment of a rack and pinion actuator assembly.FIG. 26illustrates a portion of an embodiment of a temple including a rack and pinion actuator showing the rotation of the wheel relative to the temple cover, according to an embodiment.

FIG. 27aillustrates a side view of screw actuator assembly2700with vertical compression of reservoir2740. Slider bar2710works in a similar way to the slider bars of previous embodiments. However, instead of a rack and pinion or other arrangement, screw actuator assembly2700provides for a worm gear arrangement between screw2720and slider bar2710. When screw2720is rotated by rotation of dial2730by a user, slider bar2710moves to compress reservoir2740against temple chassis ceiling2750of temple chassis2760.FIG. 27billustrates a side view of the screw actuator assembly ofFIG. 27awhen compressed.

FIG. 28aillustrates a side view of an embodiment of rotation actuator assembly2800with a pulley-type track2810with vertical compression of reservoir2860. Slider bar2820works in a similar way to the slider bars of previous embodiments, except it is adhered to track2810. When wheel2830is rotated, it moves track2810around pulleys2840and2850. When track2810moves around pulleys2840and2850, slider bar2820moves to compress reservoir2860against temple chassis ceiling2880of temple chassis2870. In an embodiment, as shown inFIG. 28a, slider bar2820is configured to bend around pulley2850.FIG. 28bis a view of the screw actuator assembly along line A ofFIG. 28a.

FIG. 29aillustrates a side view of an embodiment of slide and translate actuator2900with horizontal compression of its reservoir (not shown). When slider button2910is translated along temple arm2920, the slider bar (not shown) moves to compress the reservoir against the temple chassis.FIG. 29bis a sectional view of the actuator assembly along an axis of temple arm2920. Specifically,FIG. 29bis a sectional view of the slider compressing the reservoir as it translates along the axis of the temple arm.