HK1171419B - Methods, devices, and systems for moving wet ophthalmic lenses during their manufacture - Google Patents

Description

Method, device and system for moving wet spectacle lenses during their manufacture

Technical Field

The present invention relates to methods, devices and systems for manufacturing ophthalmic lenses, such as contact lenses. More particularly, methods, devices, and systems for moving wet eyeglass lenses are described.

Background

During the manufacture of ophthalmic lenses, including contact lenses such as hydrogel contact lenses and silicone hydrogel contact lenses, polymerizable lens-forming compositions containing reactive components are polymerized to form polymerized lenses. The polymeric lens can be cleaned to remove uncrosslinked or partially crosslinked material from the polymeric lens to produce a cleaned polymeric lens. The washing step can comprise contacting the polymerized lens with alcohol or other organic solvent, contacting the polymerized lens with an aqueous liquid that may or may not contain alcohol or solvent, solute, or combinations thereof. The cleaned polymeric lens is finally provided in a package (e.g., a blister package) which is then sealed and sterilized with a sealing element. In some processes, the cleaning is performed in the package, and in other processes, the cleaning is performed with the polymerized lenses in a cleaning tray or carrier. Additional steps may include inspecting the lens for defects prior to sealing the package.

When polymerized lenses are cleaned in a cleaning tray or lens carrier, the lenses must be individually transported to the lens packages so that one lens is placed in one package. Although these steps may be performed manually, many of the steps are automated in an economical manufacturing process.

Disclosure of Invention

New methods, devices, and systems for manufacturing ophthalmic lenses are described. Existing methods, devices, and systems can efficiently transport wet cleaned lenses from a lens carrier to a lens package. The yield of a batch of lenses manufactured using the method, apparatus and system can be improved. For example, with the lens carrier of the present invention, wet lenses can remain centered in the wells of the carrier, which helps ensure that the lenses are accurately picked up by the wet lens pickup head, and the number of missed wet lenses can be reduced compared to methods, devices, and systems that use different carriers. Further, the yield may be improved by reducing damage to the wet lens caused by the wet lens pickup head contacting and moving the wet lens. In another example, acceptable packaged lens yield may be improved by reducing the amount of liquid transferred to the lens package with the wet lens from the lens carrier well, which helps maintain a target osmotic volume concentration (osmolarity) of packaged liquid in the lens package. Furthermore, with existing methods, devices and systems, the wet lens can be centered in the lens package if desired, which is useful in downstream inspection processes.

In one aspect, the present invention provides a method of manufacturing an ophthalmic lens.

In another aspect, the invention provides a lens carrier.

In another aspect, the present invention provides a wet lens pickup head.

Additional aspects and details of the invention are also described in the detailed description below and the appended claims.

Various embodiments of the present invention are described in detail in the following detailed description and claims. Any feature or combination of features described herein is included within the scope of the present invention, and the invention provides that features included in any such combination are not mutually inconsistent, as will be apparent to the context, this specification, and those skilled in the art. Furthermore, any feature or combination of features may be specifically excluded from any embodiment of the present invention.

Drawings

FIG. 1 is a schematic view of an exemplary eyeglass lens packaging system provided in accordance with aspects of the present invention;

FIG. 2A is a schematic view of the transfer module of FIG. 1 showing additional features of an exemplary pick and place system;

FIG. 2 is a schematic diagram of a transfer module, which is a subassembly of the system of FIG. 1;

FIG. 3 is a schematic partial front view of an end effector located at an end of the pick and place robot of FIG. 2;

FIG. 4 is a perspective view of a pick head mountable on the end effector of FIG. 3;

FIG. 5 is a cross-sectional side view of the pickup head of FIG. 4;

FIG. 6 is a perspective view of a transfer tray that can be used to transfer eyeglass lenses according to aspects of the present invention;

FIG. 7 is a perspective view of the transfer tray of FIG. 6 from a different perspective;

FIG. 8 is a cross-sectional side view of the transfer tray of FIG. 6 taken along line 8-8;

FIG. 9 is a partially exploded plan view of the tray of FIG. 6 showing details of the interior of the cavity;

FIG. 10 is a perspective view of a feeding tray moving on a transport module and carrying a plurality of blister packs;

FIG. 11 is an array of blister packs that may be used with the feeding tray of the present invention; and

FIG. 12 is a perspective view of another blister pack that may be used with the infeed trays described herein.

Detailed Description

Fig. 1 is a schematic view of an exemplary eyeglass lens packaging system, generally designated 10, provided in accordance with aspects of the present invention. Broadly, the system 10 includes a number of modules having a number of devices and tools for performing the functions of transferring, moving, pushing, dosing, centering, and sealing trays and packages, and other functions related to the manufacture of ophthalmic lenses in blister packages such as those shown in fig. 11 and 12. The system 10 is configured to place an eyeglass lens manufactured elsewhere on a production line or factory in a blister package that is also manufactured elsewhere on a production line or factory and is bonded together with the eyeglass lens. Ophthalmic lenses suitable for use in the systems of the present invention include hydrogel contact lenses. A silicone hydrogel contact lens is a hydrogel contact lens that includes a silicone component. Examples of silicone hydrogel contact lenses that can be packaged in the present packages include, but are not limited to, silicone hydrogel contact lenses having the following U.S. adopted names (U.S. adhered name, usa): lotrafilcon A, lotrafilcon B, balafilcon A, galyfilcon A, senofilcon A, comfilcon A, and enfilcon A. A non-silicone hydrogel contact lens is a hydrogel contact lens without a silicone component. Examples of non-silicone hydrogel contact lenses that can be packaged in the present packages include hydrogel contact lenses having the following USANs: omafilcon A, ocufilcon B, ocufilcon C, ocufilcon D, ocufilcon E, methafilcon A, and methafilcon B.

The system 10 includes a plurality of modules that are each configured to perform one or more tasks of placing ophthalmic lenses manufactured elsewhere in a production line or plant in blister packages also manufactured elsewhere. In one exemplary embodiment, the system 10 includes a feed (fed) tray loading module 12 for feeding and moving rows of feed trays containing blister packs configured to receive contact lenses. As discussed further below, the trays each include a plurality of cavities having a blister package disposed therein to receive an eyeglass lens. The system further comprises a transfer module 18 comprising a robot arm (robot arm) for picking up the spectacle lenses supplied by the infeed transfer tray loading module 16. The loading module 16 may include a transfer system for moving a plurality of transfer trays including a plurality of eyeglass lenses to the transfer module 18 for pick up, as discussed further below. Finally, an unload module 26 is provided that includes inspection, transfer and sealing components for completing the packaging process. However, the system is not limited to the modules explicitly disclosed, and one of ordinary skill in the art may modify the system to remove, add, or replace different modules to complete a packaging system for placing individual eyeglass lenses in individual lens packages.

Referring now to FIG. 2A, which shows an exploded schematic view of the transfer module 18 of FIG. 1, the module 18 includes a pick and place system 20 for picking and placing ophthalmic lenses in individual blister packs 40 located in a feed tray 36, as discussed further below. The pick and place system 20 includes a robotic arm 46; a motor 22 to move the robotic arm 46 and other pick and place components such as belts, gears, connectors; an end effector 62 and a plurality of pick-up heads 64; and one or more controllers 24. The term "pick and place robot" as used herein may be considered to be a controllable robot arm that is movable to pick up and lower an ophthalmic lens.

Referring now to fig. 2 and 10, there are shown schematic views of transfer module 18, transport module 14, and transfer cart (cart) 30. The transport module 14 is configured to move a plurality of infeed trays 36 (fig. 2) or a contiguous set of infeed trays 36 (fig. 10) through the processing system. The infeed trays 36 each include a storage area 38 (fig. 10) for receiving blister packs 40. In a particular embodiment, eight slots 42 are formed in the storage area 38 in a 1 × 8 arrangement or array to receive eight blister packs 40, with greater or lesser numbers of arrays also being contemplated. The feed tray 36 may be made of a metal such as hard anodized steel or aluminum. In other embodiments, the infeed tray is made of a thermoplastic material, such as polypropylene or polyethylene and the like.

Any number of blister packages may be used with the feeding tray 36 of the present invention. In one embodiment, the blister packages (fig. 11) are each formed with a holding cavity 52 having a spherical distal section 54 and an aspherically tapered proximal section 56. The cavity 52 is sized and shaped such that when it is filled with an encapsulation solution and an ophthalmic lens is placed therein, the shape allows the placed lens to center itself in the cavity. This in turn facilitates inspection and other processes that rely on lenses that are centered relative to the cavity. The blister package 40 further includes a flange 58 configured to mate with a peelable seal layer (not shown), and optional bumps or protrusions 60 for gripping purposes as well as aesthetic appeal. Another embodiment of the blister package is illustrated by the blister package of fig. 12, wherein, similar to blister package 40 described above, blister package 300 comprises or consists essentially of a plastic base member that includes a cavity 303 for storing a hydrogel contact lens and encapsulating liquid, as will be understood by those skilled in the art.

The pick and place robot 46 is programmed to traverse along the z-axis to move between a first working envelope or region 58 and a second working envelope or region 60. The first working envelope may be considered to cover an entire area located above one or more infeed trays 36 and the second working envelope may be considered to cover an entire area located above one or more transfer trays 34. Thus, as described herein, the pick and place robot 46 is configured to move between the second working area 60 where a set of eyeglass lenses are picked and the first working area 58 where the eyeglass lenses are placed in the corresponding blister packs 40. Additional embodiments of the present system include a pick and place robot 46 movable along the x-z plane, the x-axis, and/or the y-axis.

Movement along the y-axis enables the pick and place robot 46 to raise and lower its end effector 62 while positioned within either the first or second working envelope. This in turn allows the robot to apply a vacuum to the end effector to pick up a plurality of eyeglass lenses or to disable the vacuum to drop the eyeglass lenses into corresponding blister packs, as discussed further below.

Referring now to fig. 3-5 in addition to fig. 2, a pick-up head 64 is shown incorporated into the end effector 62 to pick up an eyeglass lens. In one embodiment, eight individual pick-up heads 64_1-n(where n is any integer greater than 1) is incorporated on the end effector 62 to pick up eight eyeglass lenses in a single pick up operation. The number of pick-up heads 64 on the end effector 62 should correspond to the number of cavities in the transfer tray 34 and the infeed tray 36, and soThe number of cavities corresponds to the number of spectacle lenses to be picked up in each transfer operation, as discussed further below. The pick-up heads 64 may each be made of 316 stainless steel and include an arcuate distal end profile 66 that approximately matches the base curve of the eyeglass lens to promote an approximate dimensional corresponding fit when the pick-up heads pick up the eyeglass lens. In a particular embodiment, the pick-up head 64 incorporates four intersecting tabs or wings 68 that appear like a "+" symbol when viewed normally along the distal end of the pick-up head and its longitudinal axis (i.e., the end that contacts the contact lens). Preferably, the wings are equally spaced from each other, and in the most preferred embodiment are at right angles to each other. However, fewer wings may be incorporated, such as three, or more than four wings may be incorporated, such as five wings. In one embodiment, the wings are equally spaced from each other.

Wing 68 is formed with a flange 70 having an enlarged flange section 72, a reduced flange section 74 and a shoulder 76 therebetween. Threaded holes are incorporated into the upper surface 78 of the flange 70 to threadably engage the pick head 64 with threaded male rods protruding from a headstock (head) connector block 80 (fig. 3), which are part of the end effector 62. However, the reverse arrangement is possible where a threaded male pin is incorporated on the pick head 64 and a threaded bore is incorporated on the connector block 80, and other connecting means for connecting the pick head to the header connector block are possible without departing from the spirit and scope of the present invention.

Referring now in detail to fig. 4 and 5, each wing 68 incorporates a plurality of radial holes 81-83 each having two ends terminating in an opening. The holes are configured to create a negative pressure or vacuum to enable the pickup head 64 to pick up an eyeglass lens, as discussed further below. A first or outer opening 84 of each hole is located at the distal outline 66 of the wing 68, and a second or inner opening 86 is located along a central hole 88. In one embodiment, three radial holes 81-83 are formed in each wing 68, wherein each hole has the same inner diameter. In another example, the holes are sized to create a substantially similar vacuum at the outer openings 84 such that a similar level of negative pressure is applied to the eyeglass lenses from all openings. In one embodiment, the diameter of the holes generally decreases from the outermost holes 83 to the innermost holes 81 due to the decrease in hole length, which results in a smaller pressure drop and thus a relatively smaller diameter. In another embodiment, the bore has a constant diameter along its length.

The central bore 88 extends generally longitudinally from the entrance to the threaded bore (not shown) where the pick head 64 is connected to the header connector block 80 and extends through the intersection of the four wings 68. In one embodiment, a pressure reducer 96 is incorporated at the terminal or distal end 94 of the central bore 88 to provide a large pressure drop across a central outer opening 98 of the central bore. The outer openings 84 cooperate to pick up an eyeglass lens when a vacuum source is supplied to the central bore 88, as discussed further below. The central bore 88 acts as a vacuum head to the plurality of radial bores 81-83. In one embodiment, the central bore 88 is sized about 2.5 to about 4 times larger than the diameter of the largest radial bore.

In the example shown in FIG. 5, the three outer openings 84 are equally spaced along the outer periphery 66 of each wing, although other configurations are possible. As shown at the example center of fig. 4, a relief area 100 is provided by forming a lip 102 at the inner end of each wing 68. The central opening 98 is recessed from the innermost opening 84 of the innermost radial bore 81 as it terminates in the undercut region 100. This allows the central opening 98 to draw in areas and surfaces in the inverted concave region of the pickup head 64 and not in contact with the surface of an eyeglass lens simultaneously with the other openings 84 of the wings 68, as discussed further below. As used herein, the term "concave" or "recessed" is understood to be away from or offset from the same general plane or contour of another item or structure.

The partial cut-away view of fig. 4 also shows an eyeglass lens 90 having a periphery 92. In one embodiment, the outermost openings 84 of the four wings 68 are sized and positioned such that the lens periphery 92 is recessed from the outer edges of the four outer openings 84 when the eyeglass lens 90 is picked up by the pick-up head 64. Thus, the outer opening 84 will not be completely obscured or covered by the eyeglass lens when a vacuum is applied. This allows the pickup head 64 to lift the outer edge of the eyeglass lens and draw fluid around the lens during a pickup operation, as discussed further below. In another embodiment, the outermost opening 84 is sized and placed such that it is recessed from the periphery 92 of the eyeglass lens 90 and covered by the lens. However, since the central opening 98 is recessed from the inner opening 84, it is not sealed or directly covered by the posterior surface of the lens when suction is applied. Thus, fluid and possible particles from unreacted or partially reacted monomers may be sucked away by the central opening 98 regardless of whether the outer openings are covered.

In one embodiment, a plurality of bypass openings 104 are incorporated along a sidewall 106 of one or more wings 68. Referring to fig. 5 in addition to fig. 4, each bypass opening 104 is formed along the path of and communicates with the outermost radial bore 83. The bypass opening 104 is thus recessed from the end profile 66 of the pickup head 64 and, in the embodiment shown, is positioned along a plane perpendicular to the plane defining the central opening 98. In this embodiment, since the bypass opening 104 and the central opening 98 are not in contact with the lens surface, they have open ends that enable the pick-up head to suck away fluids and the like. Accordingly, one aspect of the present invention is a pick-up head comprising a plurality of openings, a subset of which are configured to draw a common surface of an ophthalmic lens and the remaining number of which are configured to draw fluid and possibly suspended solids from a tray cavity during a pick-up operation, as discussed further below. The pick-up head provided herein may also be viewed as providing a spaced-apart suction region bounded by internal suction openings formed along the plug-shaped region, and wherein different sets of openings may be used to provide a continuous negative pressure. In this description, the pick-up head is also considered to provide a contoured periphery that is sized and shaped to form a spherical fit with the lens back surface of the eyeglass lens.

Referring now to FIG. 6, a transfer tray or lens carrier 34 provided in accordance with aspects of the present invention is shown. As previously discussed with reference to fig. 2, the transfer tray 34 is configured to temporarily store ophthalmic lenses after a lens demolding (delensing) step or a cleaning step such as a hydration step or a combination of hydration/extraction steps. While robots or other assemblies may be used to transfer the eyeglass lenses into the cavities of the transfer tray, in one embodiment, the eyeglass lenses are transferred manually to the transfer tray with the lens back surface or base curve facing the opening of the cavities. The tray 34 may be formed from a thermoplastic material, for examplePolypropylene (Total Petrochemicals, Courbevoie, France) or other polypropylene resin, and it is contemplated that smaller or larger arrays may be used in a 4 x 8 array of lens cavities. More particularly, the tray 34 has a length L and a width W and is molded with a plurality of cavities or wells 108 aligned in a 4 x 8 array along the length and width. In one embodiment, the wells depend from a substantially planar upper surface 109 along the length and width in an equally spaced manner. The cavities 108 are each sized and configured to hold a single wet eyeglass lens and each have a receiving area configured to hold an upwardly facing lens back surface of the eyeglass lens and a lens front surface facing a bottom wall surface of the cavity.

Referring to fig. 9 in addition to fig. 6, the cavity 108 has an opening 110 defined by an edge having a multi-sided clover configuration (e.g., an eight-leaf clover configuration). As shown in fig. 8, which is a cross-sectional view of fig. 6 along line 8-8, the cavity 108 tapers radially inward as it extends toward the cavity base 114. Thus, the inner surface 112 (FIG. 6) of the cavity 108 is wavy and tapered. Inside, a cylindrical inner section 116 (fig. 8) is formed by a generally square or vertical (i.e., non-tapered) wall 118, the wall 118 being disposed below the tapered section of the cavity. A generally spherically shaped wall section forming the base surface 114 is disposed adjacent the generally square shaped wall section 118. Thus, when an eyeglass lens 90 is placed in one of the cavities 108, the inner contour of the cavity is structured to align the lens so that it is centered within the cavity. In one embodiment, the lens cavities 108 are each filled with a sufficient amount of deionized water prior to placing the ophthalmic lenses therein. When an eyeglass lens is placed in one of the cavities, it sinks to the bottom of the cavity and is self-aligned by the structure of the inner wall surface 112. As shown in fig. 8 and 9, the periphery 92 of the eyeglass lens 90 fits against the edge of the square wall section 118 near the transition with the base 114. In one embodiment, the diameter of the square wall section is about 16mm and the diameter of the eyeglass lens is about 14.5mm for a curved lens and about 14.0mm for a spherical lens. In another embodiment, the diameter of the square wall section is about 0.1mm to about 0.3mm greater than the diameter of the eyeglass lens to facilitate alignment within a smaller tolerance. Accordingly, one aspect of the present invention is a transfer tray comprising a plurality of cavities formed in an array, the cavities each comprising an undulating surface and a tapered surface that tapers to a smaller diameter base surface to center the eyeglass lens. Another embodiment of the invention is a system comprising a 1 x 8 array of cavities on a transfer tray, a 1 x 8 array of pick heads on an end effector, and a 1 x 8 array of cavities on an infeed tray, wherein the infeed tray, the spacing between two adjacent cavity centers of the transfer tray, and the spacing between two pick heads are substantially the same, within 0.1mm to 0.3 mm.

Fig. 7 is a bottom perspective view of the tray 34 of fig. 6. As shown, the tray has an outer edge wall 120, a recessed outer edge wall 122, and a stacking area 124 (fig. 6) formed therebetween. The stacking area 124 is configured to support another tray 34 placed thereon to form a stack of transfer trays 34. Fig. 7 also shows four depressed areas 126 formed along the length of the tray. The depressed areas 126 are formed to promote alignment on the package board (palette)32 (fig. 1). Typically the trays are arranged in a planar arrangement in a production line so that each tray is adjacent to each other without being stacked on top of each other. In some embodiments, the trays can be stacked on top of each other. The plurality of ribs 128, 130 are incorporated to provide added structural rigidity and planarity for molding purposes. Short ribs 130 are provided to connect adjacent outer cavity wall surfaces 132, while long ribs 128 are provided to connect the outer edge walls 120, 122 together. In one embodiment, the well or cavity 108 is about 27.3mm in the center, the tray height is about 15mm high, the tray width is about 243mm wide, and the tray length is about 129mm long. The well depth measured from the top surface 109 to the tray floor or base 114 is about 13.57 mm.

The operation of the system provided herein can be understood as follows:

a thermoplastically formed or injection molded transfer tray 34 is first prepared by placing a transfer solution in the tray cavity 108. In one embodiment, the transfer solution may be deionized water or other aqueous solutions, such as saline solution, including contact lens packaging solutions. The eyeglass lenses 90 are then manually placed in the cavities 108, one lens per cavity, with the base curve (back surface) facing upward to form a ready-to-transfer tray 134, which is considered to be a tray with the eyeglass lenses disposed therein. The trays may be placed in a row that is one stack high, or in a stack of multiple trays, such as a stack of five or an integer number of trays.

The stack of transfer-ready trays 134 is then moved onto the transfer module 18 (fig. 1 and 2), or transported using a transport system or otherwise, such as by manual handling. The process may be a continuous process or a batch process. If a continuous process and cart are used to transport the transfer-ready tray 134 stack to the transfer module 18, care must be taken to ensure that sufficient stacks of trays 134 are available at the second work area 60 for pick-up by the pick and place robot 46 so as not to interrupt the continuous process.

The pick and place robot 46 is programmed to move between a first work area 58 and a second work area 60. In the exemplary sequence, the pick and place robot 46 moves along the x-z coordinate to move over the second work area 60 transfer ready tray 134. The pick and place robot 46 then lowers the end effector 62 along the y-axis toward the tray 134 (fig. 2 and 3). The pickup head 64_1-8(numbered the same as and spaced a distance corresponding to the cavity 108 on the tray 134) is lowered into the cavity 108 and into the fluid contained therein to pick up the eyeglass lens 90. Simultaneously with or slightly before the pickheads are lowered into the cavities, a vacuum is applied to the end effector 62, which places the header connector block 80 under vacuum and provides a vacuum to each of the central bores 88 of the eight pickheads 64.

Referring now to fig. 5, as the pick-up heads 64 are lowered into the cavities of the transfer-ready tray 134, a vacuum is created and causes a negative fluid flow (e.g., gas and/or liquid) into each pick-up head, which is indicated by the arrows. Since the cavity is filled to a predetermined level with liquid, the liquid is evacuated by the vacuum. The pick heads 64 pick and hold the lenses from the wet tray while vacuum is still applied, one on each pick head. The applied vacuum also draws Deionized (DI) water from the wet tray. In one embodiment, the robot 46 is programmed to move directly toward the tray and the pick head 64 picks up the lens before the liquid is completely emptied from the cavity. As such, residual liquid may remain in the cavity even after the end effector 62 is withdrawn from the tray and the ophthalmic lens is aspirated to the end 66 of the pick head 64.

Referring now to fig. 4 in addition to fig. 2, as the end effector 62 withdraws from the transfer-ready tray 134 and moves to the first work area 58, the vacuum applied to the pickup head 64 causes excess liquid on the surface of the ophthalmic lens to be drawn away through the central opening 98 and the bypass opening 104 of the pickup head. Thus, excess liquid present with the ophthalmic lens is removed from the ophthalmic lens by the vacuum at the central opening and the bypass opening before the lens is placed in the blister package. This removal of excess liquid allows for more effective control of the volumetric osmolarity of the final encapsulation solution (which may be, for example, a buffered saline solution) in the blister package by limiting the amount of transfer liquid (e.g., deionized water) that will contact and dilute the encapsulation solution.

Referring again to fig. 6 in addition to fig. 4, since the cavities 108 are structured to center the eyeglass lenses 90 within each cavity and the spacing between each cavity is known, the robot 46 can be programmed to pick up lenses with repetitive precision. However, in the event that the ophthalmic lens is misaligned such that it is off-center when picked up by the pickup head 64, the bypass holes 104 and the central opening 98 on the pickup head allow the holes and openings to draw excess transfer liquid away from the lens surface so that it does not affect the bulk osmotic concentration of the encapsulation solution.

Referring to fig. 10 and 11, after the eyeglass lenses are picked up and the pick and place robot 46 returns to the first work area 58, it is programmed with coordinates that enable the pick head 64 to be positioned and aligned over the blister pack 40 or cavity 52 of blister pack 300, as illustrated in fig. 12. The blister pack moves within the feed tray 36 along the delivery module 14 and is pre-filled with a packaging solution as it passes through the dosing module. The pick and place robot 46 is then activated to descend along the y-coordinate to lower the pick head into the corresponding blister pack.

When the pick-up head with the contact lens is positioned over the blister pack, the vacuum is turned off or otherwise stopped. The lens may remain attached to the pick-up head by surface tension provided by the wet lens surface and the pick-up head surface. The lens attached to the pick-up head is then immersed in the encapsulation solution in a blister pack. Contacting the lens with the packaging solution causes the lens to release from the pick-up head and become immersed in the packaging solution in the blister pack.

In another embodiment, during the release operation, both the pick-up head 64 and the lens are lowered below the surface of the encapsulation solution before the vacuum is turned off. Once closed, the eyeglass lenses separate from the pickup head 64 and float to the bottom of the blister pack. This process may be incorporated in conjunction with overfilling the blister package with the packaging solution and/or providing a means to avoid drawing all or a portion of the packaging solution.

Fig. 10 shows blister packages 40 each having a peelable foil cover 136, as reflected by the reflective cross-hatching. The foil cover 136 is placed over the blister pack after the eyeglass lenses are placed in the blister pack one lens per pack.

In view of the disclosure herein, it can be appreciated that with the present inventive tray 34, the ophthalmic lenses present in the liquid in the cavities of the tray 34 remain centered or are substantially centered in the cavities. This self-centering effectively reduces variability in the position of the lens within the cavity and thus reduces the likelihood that the pickup head will inadvertently miss the lens during the pickup process. Ideally, the centering of the spectacle lenses provided by the cavities results in zero errors of the pick-up head and achieves a yield of 100% of the lens batch being transferred. As discussed herein, the cavities of the illustrated embodiments have corrugated or undulating conical sidewalls that taper from a wider dimension at the cavity opening to a narrower dimension near the cavity bottom. The cavity has a cylindrical bottom sidewall disposed between a conical sidewall and a bottom surface of the cavity. The bottom surface of the cavity may be defined by a spherically curved surface in the illustrated embodiment. Furthermore, by providing a corrugated or undulating conical sidewall, portions of the sidewall may act as channels along which liquid may flow.

Further, with the pick-up head of the present invention, vacuum pressure can be used to pick up wet hydrogel lenses without damaging the lenses, controlling the amount of liquid transferred with the lenses from the tray to the blister pack, or both. The reduction in damage to the lens compared to other pick heads used to transfer wet hydrogel lenses can be attributed to the unique hole design of the pick head, where the vacuum pressure does not become excessive, causing pits and/or other damage to the lens. Similarly, in embodiments of the unique aperture configuration having the ability to remove excess liquid during transfer, the removal of excess liquid helps to reduce contamination of the encapsulated liquid in the blister package and thus helps to maintain a predetermined condition of the encapsulated liquid, such as the bulk osmotic concentration of the encapsulated liquid. In the illustrated embodiment, the maximum amount of liquid transferred with the lens attached to the pick-up head is 60 μ L. However, the amount of liquid may even be less than 60 μ L. Thus, in the illustrated embodiment, the dilution of the encapsulating liquid is 4% or less due to the transfer of the lenses and any residual liquid from the lens tray. Using the systems, assemblies, and processes of the present invention, the osmolality of the packaged liquid can be maintained at a value of about 325mOsm +/-10 mOsm. In other embodiments, the osmolarity of the encapsulating liquid is about 316mOsm +/-19mOsm when the lens is inserted into the blister package.

With the pick-up head and tray of the present invention, the lens can also be effectively centered in the depression of the blister pack because the original position of the lens in the tray cavity is known. Ophthalmic lenses can be transferred into blister packages that already contain a liquid in the blister package cavity to reduce bubble formation that can result from placing the lens and liquid in the blister package. The centering lenses preferably do not contact the sidewalls of the blister pack cavity when in the packaging liquid. By reducing the amount of contact between the lens and the blister pack cavity side walls, it is easier to obtain reliable images of the lens in the blister pack during the lens inspection process and to reduce the number of false positive defects detected (i.e., resulting from contact between the lens and the side walls as compared to the actual defects of the lens).

Once in the blister package cavity, the lens may be inspected manually or automatically using a camera and various computer software programs configured to detect lens defects.

While the disclosure herein refers to certain specific embodiments, it is to be understood that these embodiments are presented by way of example and not limitation. The foregoing detailed description, while discussing exemplary embodiments, is to be understood as encompassing all changes, modifications and equivalents of the embodiments as may be within the spirit and scope of the invention as defined by the claims.

Claims (15)

1. A method of manufacturing an eyeglass lens, comprising:

providing an ophthalmic lens in a volume of liquid in a well of a lens carrier such that the ophthalmic lens is considered a wet lens;

removing the wet lens from the well using a wet lens pick-up head comprising a periphery sized and shaped to form a fit with a posterior concave surface of the wet lens;

moving the wet lens pickup head toward a blister pack having a cavity to receive the wet lens, the posterior concave surface of the wet lens being secured to the periphery of the wet lens pickup head; and

releasing the wet lens from the wet lens pick-up head into the cavity of the blister pack,

wherein, during the moving, the wet lens is secured to a first set of holes in the periphery of the wet lens pickup head and held by vacuum, and excess liquid is removed from the wet lens through a second set of holes that are recessed from the periphery of the wet lens pickup head that is not in contact with the wet lens surface.

2. The method of claim 1, wherein the step of releasing the wet lens comprises releasing the wet lens into a volume of packaging solution.

3. The method of claim 1, wherein the lens picking head comprises spaced wings, each wing comprising an end surface comprising a curved end profile, and wherein the first set of holes are formed on the end surface and are used to apply vacuum to the wet lens during movement of the lens.

4. The method of claim 1, wherein the step of releasing the wet lens comprises releasing the lens into the volume of liquid in the well with the base curve of the lens facing upward.

5. The method of claim 1, wherein the sidewall portion of the well comprises a contoured and tapered surface that effectively centers the wet lens in the well.

6. An ophthalmic lens carrier suitable for use in manufacturing ophthalmic lenses, comprising:

a body member having a substantially planar upper surface;

a plurality of wells depending from the substantially planar upper surface, wherein each well includes an opening having a multilateral clover configuration, a sidewall portion including undulating and tapered surfaces, and a bottom surface in contact with the sidewall portion, the bottom surface structured to center an eyeglass lens in the well when the lens is positioned in a volume of liquid provided in the well.

7. The eyeglass lens carrier of claim 6, further comprising a cylindrical inner section located between the sidewall portion and the bottom surface.

8. The eyeglass lens carrier of claim 6, wherein the bottom surface is curved.

9. The eyeglass lens carrier of claim 6, wherein the plurality of wells comprise equal spacing.

10. The eyeglass lens carrier of claim 6, further comprising a stacking area between the lower concave outer edge wall and the outer edge wall.

11. A wet lens pickup head suitable for use in manufacturing ophthalmic lenses, comprising:

a flange having a substantially planar surface;

a plurality of wings depending from the flange and contacting each other at intersections having undercut regions formed by lips at inner ends of each wing, the wings each including an end surface including a curved end profile for picking up a curved surface of an eyeglass lens, the end surface including a plurality of end openings formed thereon and a central opening at the undercut regions; and

wherein at least one of the wings has a bypass opening formed thereon that is recessed from the end opening, and wherein the central opening is recessed from the end opening.

12. The wet lens pickup head of claim 11, wherein the flange includes an upper surface having a threaded bore formed therein or a male threaded bore formed thereon.

13. The wet lens pickup head of claim 11, wherein a central bore is formed at the intersection and communicates with the plurality of end openings.

14. The wet lens pickup head according to claim 11, wherein each of the wings has at least one bypass opening.

15. The wet lens pickup head of claim 11 made of a stainless steel material.