SYSTEMS AND METHODS FOR INSERT PLACEMENT TO FABRICATE HYBRID CONTACT LENSES
20250319678 ยท 2025-10-16
Inventors
- Yang ZHENG (Redmond, WA, US)
- Cornelius Daniel Niculas (Suwanee, GA, US)
- Yuan Chang (Chicago, IL, US)
- Junhao Ge (Shanghai, CN)
- Steve Yun Zhang (Sugar Hill, GA)
- Justin Joel Aguayo (Duluth, GA, US)
- David Andrew Icenogle (Brookhaven, GA, US)
- Muhammad Waqas Asif (Madison, WI, US)
- Daryl Reece (Atlanta, GA, US)
Cpc classification
B29D11/00038
PERFORMING OPERATIONS; TRANSPORTING
B29K2083/00
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
Systems, devices, and methods are disclosed for fabricating a hybrid contact lens product having a lens insert embedded at a precisely controlled location within a lens body. A mold engagement and support base engages and retains a lens forming mold in a substantially fixed position. An insert placement and positioning device includes an insert pickup head with a contact face configured for releasable engagement of the lens insert and at least one suction opening in the contact face for applying suction to engage the insert on the contact face. A positioning housing interacts with the mold and/or the support base to provide precise locational positioning of the lens insert within the mold. A lens body forming material is delivered to the mold to encapsulate the lens insert.
Claims
1-30. (canceled)
31. A method of fabricating a hybrid contact lens product having a lens insert embedded within a lens body, the lens insert comprising a first material and having a concave back surface and an opposite convex front surface, the method comprising: obtaining a lens forming mold element which is a female mold half having a circular and concave central mold receptacle and a circumferential flange defining an internal geometry and surrounding the central mold receptacle; releasably engaging a lens insert comprising a first material onto an insert contact face of an insert placement and positioning device, wherein the insert placement and positioning device comprises a positioning housing, a suction conduit connected to an external suction source and extending centrally and axially through the positioning housing from top to base, an insert pick-up head mounted to the suction conduit, and a positioning ring coupling the suction conduit with the positioning housing at the top of the positioning housing, wherein the insert pickup head comprises the insert contact face configured for cooperative releasable engagement of the lens insert, at least one suction opening in fluid communication with the suction conduit. and at least one pressure relief channel, wherein the positioning housing comprises at least one positioning feature which comprises an external geometry and outside diameter around its base that is configured for a clearance or interference fit within the internal geometry of the circumferential flange of the lens forming mold element to provides precise locational positioning of the insert pickup head relative to the lens forming mold element both in an axial dimension and in a transverse dimension orthogonal to the axial dimension; delivering a first quantity of a second material different from the first material into the circular and concave central mold receptacle of the lens forming mold element; precisely positioning the lens insert in contact with the first quantity of the second material within the circular and concave central mold receptacle of the lens forming mold element, wherein the precise positioning of the lens insert is at least partially controlled by positional interaction between said_at least one positioning feature of the positioning housing of the insert placement and positioning device and the lens forming mold element; releasing the lens insert from engagement with the insert contact face; delivering a second quantity of the second material into the circular and concave central mold receptacle of the lens forming mold element to encapsulate the lens insert within the second material; and curing the second material to form a lens body with the lens insert encapsulated within the lens body.
32. The method of claim 31, further comprising the step of at least partially curing the first quantity of the second material within the mold receptacle before releasing the lens insert from engagement with the insert contact face.
33. The method of claim 31, wherein the lens insert is releasably engaged on the insert contact face of the insert placement and positioning device by delivery of suction through at least one suction opening in the insert contact face.
34. The method of claim 31, wherein the precise positioning the lens insert is at least partially controlled by a sensor and feedback controller configured to position the insert placement and positioning device relative to the lens forming mold element.
35. The method of claim 31, further comprising engaging the lens forming mold element onto a mold engagement and support base_which comprises a body having planar top and bottom surface and at least one mold engagement feature configured to engage the lens forming mold element and retain the lens forming mold element in a substantially fixed position relative to the mold engagement and support base.
36. The method of claim 35, wherein said at least one mold engagement feature comprises a collar projecting axially from the planar top surface of the mold engagement and support base, the collar being configured for engagement within a cooperatively configured receiver of the lens forming mold element.
37. The method of claim 36, wherein the collar comprises an at least partially annular structure and projects axially upward from the planar top surface of the mold engagement and support base.
38. The method of claim 37, wherein the female mold half comprises an annular rim with a flat upper positioning surface surrounding the central mold receptacle near the outer periphery of the female mold half, and a peripheral recess surrounding the central mold receptacle adjacent the rim, wherein the female mold half comprises a L-shaped (in cross-section) external circumferential flange having a generally horizontal base ring portion and a vertical upright cylindrical or tubular wall portion, wherein the female mold half comprises an inverted annular recess beneath the upper positioning surface and between the peripheral recess and the upright wall portion forms a receiver for engagement over the collar of the mold engagement and support base when the female mold half is mounted onto the mold engagement and support base.
39. The method of claim 38, wherein the lens forming mold element comprises a diametrically opposed pair of engagement wings, and wherein at least one mold engagement feature of the mold engagement and support base comprises a diametrically opposed pair of slots, each slot configured to receive a corresponding engagement wing.
40. The method of claim 35, wherein the positioning ring comprises a locking nut that can be manually loosened and tightened by hand to allow adjustment and locking of the axial position of the insert pick-up head relative to the positioning housing.
41. The method of claim 35, wherein the body of the mold engagement and support base is cylindrical in shape and comprises at least one partially annular or ring-shaped collar extended upwardly from the planar top surface and an open chamber extending through the body to a top opening bounded by the collar.
42. The method of claim 31, wherein insert contact face comprises a smoothly radiused convex surface configured to generally match and closely conform to the back surface of the lens insert.
43. The method of claim 31, wherein the insert pickup head is positionally adjustable relative to the positioning housing.
44. The method of claim 43, wherein the positional adjustment of the insert pickup head relative to the positioning housing is provided by a threaded coupling between the insert pickup head and the suction conduit.
45. The method of claim 31, wherein the insert pickup head comprises a plurality of suction openings in fluid communication with the suction conduit.
46. The method of claim 45, wherein the plurality of suction openings are arranged in a circular array.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0024] The present invention may be understood more readily by reference to the following detailed description of example embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions, or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein.
[0025] Also, as used in the specification including the appended claims, the singular forms a, an, and the include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from about or approximately one particular value and/or to about or approximately another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent about, it will be understood that the particular value forms another embodiment.
[0026] With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,
[0027] In the depicted example embodiment, the support base or pedestal 20 comprises a cylindrical or otherwise shaped body portion having generally planar or flat top and bottom surfaces 22, 24, an at least partially annular or ring-shaped collar 26 extending upwardly from the top surface 22, and an open chamber 30 extending through the body to a top opening bounded by the collar 26. In example forms the support base or pedestal 20 may be fabricated from stainless steel, aluminum or other metal(s), plastic or other polymeric materials, ceramic, composites, and/or other substantially rigid and durable material(s) of construction.
[0028] In the depicted example embodiment, the mold 40 is a lens forming mold element comprising a female or front curve (FC) mold portion or mold half having a generally circular and concave central mold receptacle 42, an annular rim with a flat upper positioning surface 44 surrounding the mold receptacle near the outer periphery of the mold, and a peripheral recess 46 surrounding the mold receptacle adjacent the rim. The mold further comprises a generally L-shaped (in cross-section) external circumferential flange having a generally horizontal base ring portion 48 and a generally vertical upright cylindrical or tubular wall portion 50. An inverted annular recess or channel beneath the upper positioning surface 44 and between the peripheral recess 46 and the upright wall portion 50 forms a receiver 52 for engagement over the collar 26 of the support base 20 when the mold 40 is mounted onto the base. In example forms, the mold 40 may be at least partially formed of a resilient material, and/or the receiver 52 may be configured to closely conform to the collar 26, to retain the mold 40 generally fixed in position relative to the base 20 when mounted, for precise locational control. In further example forms, the mold 40 is at least partially formed from a transparent, translucent, or light-transmissive material to allow UV light to pass through the mold to cure lens-forming material contained in the mold receptacle 42. Alternatively or additionally, the mold 40 is at least partially formed from a thermally conductive material for heat curing of lens forming material contained therein.
[0029] In the depicted example embodiment, the insert placement and positioning device 60 comprises a positioning housing 62, a vacuum or suction tube or conduit 64 extending generally centrally and axially through the positioning housing, an insert pick-up head 66 mounted to the vacuum conduit, and a positioning ring 68 coupling the vacuum conduit with the positioning housing. The positioning housing 62 has an external geometry and size (outside diameter) around its base that is configured for a clearance fit (locational, sliding, close running or running) or light interference fit within the inside diameter and geometry of the upright wall portion 50 of the mold 40, thereby providing precise radial or transverse (horizontal) positioning registration between the mold and the positioning housing during use (i.e., a horizontal or X-axis datum location reference). The positioning housing 62 also has a lower contact surface configured and positioned for abutment or contact with the upper positioning surface 44 of the mold 40, thereby providing precise axial (vertical) positioning registration between the mold and the positioning housing during use (i.e., a vertical or Y-axis datum location reference). In example embodiments, these positioning features provide radial placement accuracy or tolerance of about 0.050 mm or better, and axial placement accuracy or tolerance of about 0.010 mm or better, and a fixture vertical (axial) tolerance for the distance between the apex and hard stop of about 0.005 mm or better.
[0030] The insert pick-up head 66 has an insert contact face 72 and at least one suction passage or opening 74 formed therein, which is in fluid engagement with the internal lumen 76 of the vacuum tube 64. The insert contact face 72 preferably comprises a smoothly radiused convex surface configured to generally match and closely conform to the back surface of the lens insert or other insert body to be embedded during the molding process, for example having a diameter and a radius of curvature substantially equal to the diameter and radius of curvature of the insert body. A threaded connection 78 between the insert pick-up head 66 and the vacuum tube 64 allows fine and accurate axial adjustment of the relative positioning and spacing between the insert contact face 72 of the pick-up head and the inner surface of the mold receptacle 42 when the positioning housing 62 is fully engaged in registration with the mold 40 for precise axial positioning of the insert during the molding process. The vacuum tube 64 has an internal lumen 76 extending therethrough, and a coupling or connection for attachment via a tube or other conduit to an external vacuum or suction source. The positioning ring or locker 68 may comprise a locking nut that can be manually loosened and tightened by hand to allow adjustment and locking of the axial position of the tip of the pick-up head 66 relative to the hard axial stop of the lower contact surface of the positioning housing at the Y-axis datum location reference. A screw or threaded coupling may be provided between the vacuum tube 64 and the pick-up head 66 for further fine adjustment of the tip positioning in the axial direction. The vacuum tube 64 may be mounted to the housing with a threaded bushing 82 that is press-fit or glued into the fixture housing. In this manner, height adjustment may be provided between the tip of the pick-up head and the apex of the mold, for example by bringing the parts into contact and then backing the tip of the pick-up head away from the mold by a known amount to set the desired offset with the mold apex while holding an embedded insert on the pick-up head.
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[0032] The lens insert 180 may then be transferred to a centering jig or fixture 210, as shown in
[0033] The insert placement and positioning device 60 is then lowered into the centering jig or fixture 210 as shown in
[0034]
[0035] A hydrogel or hydrogel material refers to a crosslinked polymeric material which is insoluble in water, but can hold at least 10 percent by weight of water in its three-dimensional polymer networks (i.e., polymer matrix) when it is fully hydrated.
[0036] As used in this application, the term non-silicone hydrogel refers to a hydrogel that is theoretically free of silicon.
[0037] Numerous non-silicone hydrogel lens formulations have been described in numerous patents and patent applications published by the filing date of this application and have been used in producing commercial non-silicone hydrogel contact lenses. Examples of commercial non-silicone hydrogel contact lenses include, without limitation, alfafilcon A, acofilcon A, bufilcon A, crofilcon A, deltafilcon A, etafilcon A, focofilcon A, helfilcon A, helfilcon B, hilafilcon B, hioxifilcon A, hioxifilcon B, hioxifilcon D, lidofilcon A, lidofilcon B, mafilcon A, methafilcon A, methafilcon B, nelfilcon A, nesofilcon A, netrafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, perfilcon A, phemfilcon A, polymacon, samfilcon A, surfilcon A, tefilcon A, tetrafilcon A, vasurfilcon A, and vilfilcon A.
[0038] As used in this application, the term silicone hydrogel refers to a hydrogel containing silicone. A silicone hydrogel typically is obtained by copolymerization of a polymerizable composition comprising at least one silicone-containing vinylic monomer or at least one silicone-containing vinylic macromer or at least one silicone-containing prepolymer having ethylenically unsaturated groups.
[0039] Numerous SiHy lens formulations have been described in numerous patents and patent applications published by the filing date of this application and have been used in producing commercial SiHy contact lenses. Examples of commercial SiHy contact lenses include, without limitation, asmofilcon A, balafilcon A, comfilcon A, delefilcon A, efrofilcon A, enfilcon A, fanfilcon A, galyfilcon A, kalifolcon A, lehfilcon A, lotrafilcon A, lotrafilcon B, narafilcon A, narafilcon B, samfilcon A, senofilcon A, senofilcon B, senofilcon C, sifilcon A, somofilcon A, stenfilcon A, verofilcon A.
[0040] The insert placement and positioning device 60 then delivers and positions the lens insert 180 into the desired position within the mold 40, as shown in
[0041] The lens insert 180 is preferably precisely centered on the contact face 72 of the pick-up head 66 by a centering and pick-up process, for example as described above. Also, as described above, the radial (horizontal) positioning of the lens insert 180 is precisely controlled during placement due to the alignment and registration of the positioning housing 62 within the upright wall portion 50 of the mold 40. And the axial (vertical) positioning of the lens insert 180 is precisely controlled during placement by abutment or contact between the lower contact surface of positioning housing 62 against the upper positioning surface 44 of the mold 40. If necessary, the axial (vertical) positioning can be fine tuned by adjustment of the threaded coupling between the insert pick-up head 66 and the vacuum tube 64.
[0042] The first quantity of lens body forming material 310 may optionally be at least partially cured or stabilized while the lens insert 180 is retained in the desired position within the mold 40 by the placement and positioning device 60. For example, ultraviolet light from a light source UV may be directed through a light transmissive portion of the mold 40 to at least partially cure the lens body forming material 310 as shown in
[0043] The vacuum or suction that was previously applied through the vacuum tube 64 and the at least one suction passage or opening 74 of the pick-up head 66 is then discontinued and any negative pressure is released to allow the lens insert 180 to separate from the contact face 72 of the pick-up head 66. Optionally a small positive pressure air delivery may be delivered through the vacuum tube 64 and the at least one suction passage or opening 74 to ensure separation of the lens insert 180 from the pick-up head 66. The insert placement and positioning device 60 is then raised out of engagement with the mold 40, leaving the lens insert 180 positioned on the first quantity of lens body forming material 310 as shown in
[0044] An additional second quantity of uncured lens body forming material 310 is then dosed or delivered to fill the mold receptacle 42 sufficiently to form the final lens product, as shown in
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[0052] In an example manner of use, the mold 1240 is axially placed, for example by axial operation of the insert placement and positioning device, onto the arbor press pedestal 1210 (
[0053] Example methods and associated equipment as disclosed herein may be utilized to fabricate hybrid products including hybrid contact lenses, such as for example a hybrid contact lens having a rigid gas permeable (RGP) lens insert fully enclosed or encapsulated by a silicone hydrogel (SiHy) carrier lens body, with intact external surfaces not having holes or discontinuities. In example forms, the fabricating methods use a specially designed vacuum pick tool to precisely place lens inserts in the desired location in the carrier molds, resulting hybrid lenses of intact surfaces. Precise placement of a lens insert is during the fabrication of hybrid contact lenses is advantageous. Having post structures on the front curve of the hybrid lens molds to support the inserts will leave holes on the surface of the hybrid lenses, making them prone to bacteria growth, which is disadvantageous. Example fabrication processes and systems according to the present invention may be used to precisely pick and place the insert in the desired position without the need of post structures. As a result, embedded lenses with intact surfaces can be made. Further, some example fabrication processes and systems according to the present invention may be implemented with minimum modification required to typical contact lens-making processes and systems. Additionally, some example fabrication processes and systems according to the present invention may use traditional contact lens molds to make hybrid contact lenses, with no mold change required. Example fabrication processes and systems according to the present invention may be used to fabricate next-generation contact lens products for astigmatism masking, diffractive multifocal, health monitoring, or other purposes and functions.
[0054] The radial accuracy of placement of an embedded element within a hybrid contact lens assembly is highly important to the performance of some particular lens assemblies. Example devices and processes according to the present invention allow precisely accurate placement of embedded elements to be accomplished by using the same locating surfaces on the insert creation mold, as well as the hybrid lens assembly construction mold to pick and then place the insert. Some example embodiments of the invention incorporate a mechanical only placement solution that achieves high radial and axial insert placement accuracy without complex active placement compensation schemes. In further example embodiments, active axial position feedback may be used with the same fixture to ensure micron level accuracy of placement of the inserts within the lens assembly. In some particular examples, the lens insert-interfacing surface of the insert placement and positioning device will have a matching profile to the back side design of the lens insert to ensure minimal deformation of the insert (which may be important for optical elements) and to form a vacuum seal to prevent ingress of lens body liquid formulation into the vacuum system. The vacuum pickup head may include single or multiple holes to optimize the pickup, placement, and curing processes. Placement of the insert within the hybrid lens assembly is a difficult challenge to control with good radial and height position. Example systems and methods of the present invention leverage the insert creation accuracy to enhance the accuracy placement of the insert. For example, a vacuum tip of the insert lens pickup head may remove an insert lens from a mold and place it accurately in the center of another mold to be embedded within a lens body formulation, while holding it in place for UV curing. Some example systems and methods according to the present invention advantageously provide a mechanically simple and scalable solution to the insert placement problems recognized with previously known systems and methods for fabricating hybrid lens products.
[0055] While the invention has been described with reference to example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.