Abstract:
In an embodiment, a hinge for a fluid-filled lens assembly includes a base having a first end configured to connect to a temple arm of the lens assembly and a second end configured to connect to a frame of the lens assembly, wherein the base includes a gap that is shaped to allow for tubing to pass from the first end to the second end of the base. In an embodiment, the first end of the base includes a cammed surface configured to engage a surface of the temple arm. In an embodiment, the first and second ends of the base are configured to flex around a rotation axis of the hinge.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. application Ser. No. 13/739,780, filed Jan. 11, 2013, now U.S. Pat. No. 8,876,283 which is a continuation application of U.S. application Ser. No. 12/904,769 filed Oct. 14, 2010, now U.S. Pat. No. 8,353,593 which claims priority to U.S. Provisional Patent Application No. 61/251,819, filed Oct. 15, 2009, all of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field 
     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 &#39;065 patent, 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, a hinge fluid-filled lens assembly includes a base having a first end configured to connect to a temple arm of the lens assembly and a second end configured to connect to a frame of the lens assembly, wherein the base includes a gap that is shaped to allow for tubing to pass from the first end to the second end of the base. In an embodiment, the first end of the base includes a cammed surface configured to engage a surface of the temple arm. In an embodiment, the first and second ends of the base are configured to flex around a rotation axis of the hinge. 
     In another embodiment, a fluid-filled lens assembly comprises: a temple arm; a reservoir disposed within the housing; a frame; a fluid-filled lens disposed within the frame; tubing connecting the reservoir to the fluid-filled lens; and a hinge attached to the temple arm and to the frame. The hinge includes a base having a gap that is shaped to allow for tubing to pass from a first end to a second end of the base. 
     Further embodiments, features, and advantages of the present invention, as well as the structure and operation of the various embodiments of the present invention, are described in detail below with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES 
       The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. 
         FIG. 1  illustrates a perspective view of an embodiment of a caliper actuator assembly. 
         FIG. 2  illustrates an exploded perspective view of an embodiment of a caliper actuator assembly. 
         FIG. 3  illustrates a first set of steps for assembling an embodiment of a temple chassis subassembly. 
         FIG. 4  illustrates a second set of steps for assembling an embodiment of a temple chassis subassembly. 
         FIG. 5  illustrates a set of steps for assembling a temple subassembly, according to an embodiment. 
         FIG. 6  illustrates a first set of steps for assembling a frame assembly, according to an embodiment. 
         FIG. 7  illustrates a second set of steps for assembling a frame assembly, according to an embodiment. 
         FIG. 8  illustrates a completed frame assembly, according to an embodiment. 
         FIG. 9  illustrates a spring connected to a temple arm, according to an embodiment. 
         FIG. 10  illustrates a spring connected to a temple arm, according to an embodiment. 
         FIG. 11  shows a hinge, according to an embodiment. 
         FIG. 12  shows a hinge, according to an embodiment. 
         FIG. 13  shows a view of a leaf spring hinge embodiment. 
         FIG. 14  shows further views of a leaf spring hinge embodiment. 
         FIG. 15  shows further views of a leaf spring hinge embodiment. 
         FIG. 16  shows a further view of a leaf spring hinge embodiment. 
         FIG. 17  illustrates an exploded view of a leaf spring hinge embodiment. 
         FIG. 18  shows a view of a sheet metal spring hinge, according to an embodiment. 
         FIG. 19  shows further views of a sheet metal spring hinge, according to an embodiment. 
         FIG. 20  shows further views of a sheet metal spring hinge, according to an embodiment. 
         FIG. 21  shows a further view of a sheet metal spring hinge, according to an embodiment. 
         FIG. 22  illustrates an exploded view of a sheet metal spring hinge embodiment. 
         FIG. 23  shows multiple views of an assembled pair of eyeglasses, according to an embodiment. 
     
    
    
     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. 
     It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described can include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of one skilled in the art to affect such feature, structure or characteristic in connection with other embodiments whether or not explicitly described. 
     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 an individual 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&#39;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 filled lens in a pair of eyeglasses, the optical power of the fluid filled lens may be adjusted by moving an actuator attached to a reservoir located in a temple arm of the eyeglass frame. The reservoir is attached to the fluid filled lens via a connecting tube. Moving the actuator a first way compresses the reservoir and pushes fluid into the fluid lens. Moving the actuator a second way allows the reservoir to expand and pull fluid from the fluid lens. The compression and expansion of the reservoir changes the optical power of the fluid filled lens. In an embodiment, one or more fluid lenses may be provided, each with its own actuation system, so that a lens for each eye may be adjusted independently. This feature allow wearers, such as anisometropic patients, to correct any refractive error in each eye separately, so as to achieve appropriate correction in both eves, which can result in better binocular vision and binocular summation. Further description and additional embodiments of the reservoir are described in U.S. application Ser. No. 12/904,736. 
     In such fluid filled lens designs, the fluid must pass from the reservoir located in the temple arm of the eyeglasses through a hinge located at the juncture between the temple arm and the lens frame located on the front of the eyeglasses. Because the hinge is subject to repeated bending, the connecting tube may prematurely fail if made of a weak material. Further, if the connecting tube is bent beyond a certain level, the fluid pressure in the lens may be affected. Accordingly, a fluid filled lens assembly according to an embodiment of the present invention provides ample space within the temple and end piece for the connecting tube to bend without kinking. In addition, according to an embodiment, the entire hinge mechanism may be located within the volume of the temple arm and frame. 
       FIG. 1  illustrates a perspective view of a caliper actuator assembly  100 , according to an embodiment of the present invention. Caliper actuator assembly  100  includes temple cover  110 , which includes a hollow outer portion and a hollow inner portion formed together to enclose additional pieces of caliper actuator assembly  100 . Distal end  160  of temple cover  110  is shaped to fit over a wearer&#39;s ear. Caliper actuator assembly  100  further includes temple chassis  120 , wheel  130 , and slider  140 . In an embodiment, wheel  130  and slider  140  are longitudinally slidably disposed within temple chassis  120 . Caliper actuator assembly  100  operates to compress reservoir  150  and transfer fluid between reservoir  150  and a fluid lens (not shown). The compressing force may be applied in various ways, such as for example, by rotating wheel  130  or by translating the wheel along a slot. Additional methods of applying compressing force are also described herein. The compression of reservoir  150  may be effected either by compressing reservoir  150  in a vertical or horizontal direction against a ceiling or inner wall of temple chassis  120 , as described in detail below. 
       FIG. 2  illustrates an exploded perspective view of an embodiment of caliper actuator assembly  100 . In an embodiment, slider subassembly  295  (described below with respect to  FIGS. 3-4 ) is configured to translate along one or more of temple cover  110  and temple chassis  120  in order to compress reservoir  150 . In operation, a user rotates wheel  130 , which moves slider block  255 , which in turn compresses a relatively stiff metal plate, such as compression arm  270 , that is in contact with a first side surface  265  of reservoir  150 . A second side surface (not shown) of reservoir  150  is placed against inner wall  285  of temple chassis  120 , a portion of temple cover  110 , or any other suitable surface. Slider  140  presses against compression arm  270 , which compresses reservoir  150  in a controllable manner. In an embodiment, the length of the lateral movement of wheel  130  is proportional to the magnitude of compression of the compression arm, and is proportional to the magnitude of compression of the reservoir. Further description and additional embodiments of the actuator are described in U.S. application Ser. No. 12/904,720. 
     In an embodiment, wheel  130  has a knurled edge in order to provide secure contact with the finger of the user as well more precise control over the translation of wheel  130 . 
     Lens module  200  is connected via outlet port  245  to a connecting tube (not shown), which is connected to reservoir  150 . Lens module  200  may further include a flexible back surface provided by, for example, a flexible membrane (not shown) stretched flat over the edge of rigid optical lens. To change the optical power of fluid filled lens module  200 , the membrane may be inflated through the addition of a fluid in communication with reservoir  150 . 
     The connecting tube delivers fluid from lens module  200  to reservoir  150  and 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 wheel  130  in order to change the optical power of fluid filled lens module  200 . The connecting tube is connected at one end to outlet port  245  of lens module  200  and at the other end to reservoir  150 . In an embodiment, the overall assembly including the lens module  200 , the connecting tube, and reservoir  150  is 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 has to be thin in order to be accommodated within the 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 block  250  and spring  230  are enclosed within a covered area between inner block  210  and outer block  240 . Hinge block  250  includes a gap that is shaped to allow the connecting tube to pass through hinge block  250 . Additional embodiments of the spring are described below with respect to  FIGS. 9-22 . Caliper actuator assembly  100  includes wheel  130  held in place by axle  280 , slider  140 , slider block  255 , spacer block  290 , and compression arm  270 . These parts are assembled into a temple chassis subassembly and are held in place by screws  235 . Rubber strip  205  includes a flexible surface upon which wheel  130  may move. In an embodiment, wheel  130  may rotate. In other embodiments it may translate, and in other embodiments it may rotate and translate. 
     Assembly 
       FIGS. 3-4  illustrate a set of steps for assembling an embodiment of a temple chassis subassembly. Beginning with  FIG. 3 , spacer block  290  is placed onto temple chassis  120 . Next, spacer block  290  is welded onto temple chassis  120  along edges  310  and  320 . Next, hinge block  250  is placed onto temple chassis  120 . Next, hinge block  250  is welded onto temple chassis  120  along edges  330  and  340 . The temple chassis subassembly continues with  FIG. 4 , which illustrates a second set of steps for assembling an embodiment of temple chassis subassembly  400 . A backing (not shown) may be removed from tape  410  on both sides of reservoir  150 . Reservoir  150  is placed against temple chassis  120 . Compression arm  270  is then placed onto spacer block  290 . Compression arm  270  is then welded onto spacer block  290 . 
       FIG. 5  illustrates a set of steps for assembling temple subassembly  500 , according to an embodiment. First, tabs  520  of temple chassis subassembly  400  are slid into rear slot  530  of temple cover  110 . Next, temple chassis subassembly  400  is rotated within temple cover  110  until it snaps into place. It is recommended that slider subassembly  295  be positioned as far distally as possible within temple cover  110 . Further, it is recommended that when snapping temple chassis subassembly  400  into temple cover  110 , tube  540  does not become pinched between hinge block  250  and temple cover  110  or temple chassis subassembly  400 . 
       FIGS. 6-7  illustrate a set of steps for assembling a frame assembly, according to an embodiment. Beginning with  FIG. 6 , in an embodiment, an adhesive, such as glue, is applied to the inside edge of frame  610 . Next, spring  230  is placed against hinge block  250 . In an embodiment, frame  610  is then pulled over lens module  200  so that upper portion  620  and lower portion  630  of frame  610  are coupled with lens module  200 . An adhesive, such as glue, may be used to bond lens module  200  to frame  610 . One of skill in the art will recognize that, in another embodiment, lens module  200  may be added to frame  610  after assembly of frame assembly  600  is complete. The frame assembly continues with  FIG. 7 , which shows a second set of steps for assembling an embodiment of frame assembly  600 . In an embodiment, screws  235  are inserted into respective screw holes  710  in frame  610  into hinge block  250 .  FIG. 7  shows the frame assembled with spring  230 , showing the addition of cover  720  to seal off the hinge mechanism and prevent access of water or contaminants to connecting tube  540 . The steps shown in  FIGS. 6 and 7  may be repeated for the second temple subassembly. In an embodiment, after frame assembly  600  is assembled, adequate time is allowed for any glue or adhesive to cure. 
       FIG. 8  illustrates completed frame assembly  600  including temple chassis  120 , frame  610  and lens module  200 . 
     Additional embodiments of hinge springs will now be described.  FIG. 9  illustrates an embodiment of a spring that may be used in frame assembly  600 . In an embodiment, spring  910  includes an end  920 . Additional embodiments of end  920  may include a canned surface. When temple arm  900  rotates, end  920  rides up against a small peak  930 . Force on end  920  from flexing creates stored energy that releases when temple arm  900  causes end  920  to move from peak  930 . Temple arm  900  then accelerates and rotates to either folded or unfolded position. A hard stop  960  may be provided to prevent temple arm  900  from flexing too far. During assembly, the connecting tube (not shown) is routed through the center of hinge  970  through gap  950 . 
       FIG. 10  shows another embodiment of a spring that may be used in frame assembly  600 . In an embodiment, spring  1010  is a sheet metal hinge that uses a folded sheet metal arm  1020  to provide spring force. End  1030 , which is closest to lens module  200  is fixed within frame  610  (not shown). End  1040  is attached to temple arm  1050 . The flexure of spring  1010  occurs primarily within the bend (i.e., folded sheet metal arm  1020 ). During assembly, the connecting tube (not shown) is routed through the center of spring  1010  through gap  1060 . Although spring  1010  is referred to herein as a “sheet metal” hinge, one of skill in the art will recognize that spring  1010  may be made of any material, even a non-metallic material, that satisfies the balance between flexibility and rigidity needed for spring  1010  to operate. 
       FIG. 11  shows another embodiment of a hinge  1100 . Hinge  1100  is configured to rotate around rotation axis A-A′ with respect to a temple arm (not shown). As hinge  1100  rotates around rotation axis A-A′, cantilever tab  1110  engages with a corresponding ridge on the temple arm (not shown). 
       FIG. 12  shows another embodiment of a hinge  1200 . Hinge  1200  is configured to rotate around rotation axis B-B′ with respect to a temple arm (not shown). As hinge  1200  rotates around rotation axis B-B′, cantilever tab  1210  engages with a corresponding ridge on the temple arm (not shown). 
       FIGS. 13-16  show views of a leaf spring hinge from different perspectives, according to an embodiment of the present invention. 
       FIG. 17  illustrates an exploded view of a leaf spring hinge above a breadboard, according to an embodiment of the present invention. 
       FIGS. 18-21  show views of a sheet metal spring hinge from different perspectives, according to an embodiment of the present invention. 
       FIG. 22  illustrates an exploded view of a sheet metal spring hinge above a breadboard, according to an embodiment of the present invention. 
       FIG. 23  shows several views of an assembled embodiment of a pair of eyeglasses from different perspectives that includes a spring in accordance with an embodiment of the present invention. 
     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, for example and without limitation, 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 (such as heat-shrunk flexible 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 Polyvinyledene Difluoride, such as Heat-shrink VITON®, supplied by DuPont Performance Elastomers LLC of Wilmington, Del., DERAY-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. 
     The screws used in the frame assembly may include, for example and without limitation, Visottica 07V120037017 shoulder screws produced by Visottica Industrie S.P.A. of Susegana, Italy. Other suitable types of screws or other attachment means, such as rivets, may be used. 
     Although various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. 
     Further, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is not intended to be limiting as to the scope of the present invention in any way.