GB2619575A - A packaged contact lens - Google Patents

Abstract

A hermetically sealed blister package for a contact lens comprises a base member 100 with a well 103 and a rectangular plastics flange 101 having two longer edges 102 and two shorter edges 104, an upper side 110 and a lower side (112, fig. 3B). A sealing member is sealed to the base to form a blister cavity for a contact lens and solution. The base has a first half 140 containing the well and a second half 130 comprising the majority of the flange. The lower side of the flange includes elongate protrusions (119, 120 and 122), a planar lower region (121) and four recesses (124, 126). Recesses 124 are smaller and triangular and are located on opposite corners of the first half, and recesses 126 are larger and located on opposite corners of the second half, and are defined by a bridge (154), a part of the perimeter and an area of the lower planar region that corresponds to a sealing region 105. The bridge connects the perimeter to the area of the lower planar region and has a broadest section that is positioned centrally along the width of the flange.

Description

A packaged contact lens.

Field of the Invention

The present invention concerns a packaged contact lens. More particularly, but not exclusively, this invention concerns a sealed blister package including a base member and a sealing member sealed to the base member to form a blister cavity arranged to hold an unworn contact lens and an aqueous solution. The invention also concerns a blister package including a base member which has four recesses on a lower planar region.

Background of the Invention

Soft contact lenses, for example hydrogel and silicone hydrogel contact lenses, are stored in an aqueous solution in order to keep them hydrated and in a useable condition. Contact lenses are typically sold individually packaged in sealed blister packaging. A molded blister package for storing and dispensing a contact lens is disclosed in Martinez US 4,691,820. Blister packages provide a sterile and secure environment for an unused contact lens, allowing it to be transported and stored safely until such time as it is required by the end user. A conventional blister package comprises a base member made of a plastics material and a sealing member that is sealed to that base member to form a blister cavity, in which the unused contact lens is stored. The base member also typically provides a handle that can be held between the finger and thumb of the user. The blister cavity is often configured as a well in the base member, the well being capable of holding a volume of contact lens packaging solution and the contact lens itself. Contact lenses are typically packaged in the blister package in a manufacturing process that includes the steps of placing the contact lens in the well of the base member, filling the well with a volume of contact lens packaging solution, sealing the well with a sealing member to seal the contact lens and the solution into the packaging and then autoclaving the sealed blister package in order to sterilize the contact lens and solution within the blister cavity.

Many people use daily, weekly, fortnightly or monthly disposable contact lenses, packaged in that way. This means that a large number of blister packages are transported to customers across the world on a daily basis. The cost and fossil fuel emissions associated with transporting contact lenses are significantly increased due to the additional weight of the blister packaging and contact lens packaging solution. Furthermore, although the plastics material of the blister pack may be recyclable, it is preferable to recycle less rather than more plastics material. It is therefore desirable to create a blister package that provides the same functionality for storage of contact lenses, whilst reducing the weight of the blister packaging. An object of this invention is to provide a lightweight blister pack that is still able to perform the functionality of a traditional blister package. The blister package must maintain enough structural integrity to avoid problematic deformation and to adequately protect a contact lens during transportation and storage. In addition, the blister package must be able to maintain a hydrogel contact lens or a silicone hydrogel contact lens in a packaging solution so that the lens remains hydrated prior to use by a contact lens wearer; otherwise, the hydrogel contact lens or silicone hydrogel contact lens may dry out and become unusable.

Summary of the Invention

The present invention provides according to a first aspect, a hermetically sealed blister package for a contact lens having the features set out in claim 1 below. Preferred but optional features are set out in the dependent claims.

The recesses are thinned regions of the flange that act to reduce the amount of plastics material contained in the base member. The recesses thereby reduce the weight of the base member without compromising the base member's structural integrity and without having to alter the position of locations where pick-up heads may attach to the base member during manufacture. This avoids the wastage associated with re-tooling. The recesses do not extend through the full thickness of the flange; i.e., the recesses are not holes in the flange. Thus, the recesses on the lower side of the flange do not interrupt the upper planar region on the upper side of the flange that supports the sealing member. The upper planar region may provide locations for pick-up heads to attach to the base member during manufacture. The bridge portion of the lower planar region may provide a location for a pickup head to attach to the base member during manufacture. The remaining thickness of material that is present above the recesses provides an upper planar region on the upper side of the flange that is flat, smooth and continuous and can be used as a handle by a user and can be used as a surface for supporting a portion of the sealing member. The remaining thickness of material also allows the structural integrity of the base member to be maintained, reducing the susceptibility of the base member to deformation.

The upper side of the flange may include a flat, smooth and continuous upper planar region and an annular sealing region. The sealing member may be joined to the base member at the sealing region. The majority of the upper side of the second half of the base member may be the upper planar region. The second half of the base member may form a handle for gripping by a user during use. The upper side of the second half of the base member may also include part of the sealing region. The upper planar region of the flange may provide structural support to the sealing member. The sealing member may rest against the flat, smooth and continuous upper planar region, preventing the sealing member from being damaged during storage and transportation. This may allow the sealing member to have a portion that extends away from the sealing region that can be grabbed by the user when opening the blister package.

In the recesses the flange is thinner than in the lower planar region. The lower side of the flange may include six elongate protrusions. The lower side of the flange includes four recesses. Each recess may be located adjacent to a corner of the lower side of the flange. The lower planar region includes a bridge portion, a perimeter portion and an area that corresponds to the sealing region on the upper side of the flange. The perimeter portion may run around the perimeter of the lower side of the flange and may have a varying width.

FIG. IA shows the base member from above, i.e., looking down on the upper side of the flange. FIG. 1B shows the base member from below, i.e., looking up at the lower side of the flange. The upper planar region may provide locations for pick-up heads to attach to the base member during manufacture. Approximate pick-up locations are shown in FIG. 1A, and are indicated by dashed circles centred on signs.

The bridge portion of the lower planar region may also provide a location for a pick-up head to attach to the base member during manufacture, as shown in FIG. 1B.

A pick-up head may attach to the bridge portion from the lower side of the flange.

The dashed circle centred on the +' indicates an approximate pick-up location.

The perimeter portion of the lower planar region may increase the structural integrity of the base member. The bridge portion may be centred on a midway point located approximately 116th of the distance between the shorter edge of the second half of the base member and the shorter edge of the first half of the base member. The bridge portion may be centred on a midway point located 14.0mm to 17.0mm from the notional dividing line (as shown in FIG. 3A as dashed line 107) between the first half and the second half of the base member.

The bridge portion may provide structural integrity to the flange of the base member. The bridge portion may provide structural integrity to the base member such that the risk of unwanted deformation when the base member is contacted by a pickup head during manufacture is reduced. The bridge portion may increase the rigidity of the flange of the base member. The bridge portion of the lower planar region may provide a location at which a pick-up head can attach to the base member during manufacture. The location may be on the lower planar region of the lower side of the flange.

The recesses are described herein as having some "linear" walls. As used herein, a linear wall is a straight wall, or a straight portion of a wall. Where lengths are given for these linear walls, the length is measured over the straight section of the wall, and does not include any additional length provided by rounded corners of the recesses. FIG. 2 includes dashed lines indicating the end points of the linear walls of the recesses.

The smallest pair of recesses may be substantially triangular. The smallest pair of recesses may be identical, and one of the pair is now described, and is referred to as "the smallest recess". The smallest recess may have rounded corners. The smallest recess may have three rounded corners. A first linear wall may join two of the corners of the smallest recess. The first linear wall may be parallel to the longer edges of the flange. The first linear wall may have a length of 2.0mm to 7.0mm (between the dashed lines 178 and 180 as shown in FIG. 2). The first linear wall may have a length of 3.0mm to 4.5mm. The first linear wall may have a length of 3.8mm. A second linear wall may join two of the corners of the smallest recess and may be parallel to the shorter edges of the flange. The second linear wall may have a length of 2.0mm to 7.0mm (between the dashed lines 182 and 184 as shown in FIG. 2). The second linear wall may have a length of 3.0mm to 5.0mm. The second linear wall may have a length of 4.0mm. A curved wall may complete the triangle by joining up two corners.

The curved wall may be an arc of a circle with a diameter of 31.0mm to 33.0mm centred at the centre of the well. The curved wall may be an arc of a circle with a diameter of 32.5mm centred at the centre of the well. The curved wall may abut the area of the lower planar region that corresponds to the sealing region on the upper side of the flange. Two of the three rounded corners of the smallest recess may have a radius of curvature of 0.5mm to 1.0mm. Two of the three rounded corners of the smallest recess may have a radius of curvature of 0.75mm. The corner between the first linear wall and the second linear wall of the smallest recess may have a radius of curvature of 1.5mm to 2.5mm. The corner between the first linear wall and the second linear wall of the smallest recess may have a radius of curvature of 2.0mm.

An area of the upper planar region that corresponds to the smallest pair of recesses may provide a location on which a pair of pick-up heads can attach to the base member during manufacture (as shown in FIG. 1A). Locations on the upper planar region corresponding to the smallest recesses may still be used for attachment to a pick-up head during manufacture, despite the thin flange in the region of the recesses, because the perimeter portion and the sealing region act to increase the structural integrity of the base member around the smallest recesses. The perimeter portion may provide structural integrity to the location on the upper planar region where the pick-up heads can attach to the base member. The sealing region on the upper side of the flange may provide structural integrity to the location on the upper planar region where the pick-up heads can attach to the base member. The perimeter portion and the sealing region may act to reduce any deformation that occurs when pick-up points attach to the base member during manufacture.

The largest pair of recesses may be identical, and one of the pair is now described, and is referred to as "the largest recess". The largest recess is larger than the smallest recess. The largest recess may have a first linear wall. The first linear wall may be parallel to the shorter edge of the flange. The first linear wall may be adjacent to the shorter edge of the flange in the second half of the base member. The first linear wall may be defined by a part of the perimeter portion of the lower planar region. The first linear wall may have a length of 6.5mm to 10.5mm (between the dashed lines 174 and 176 as shown in FIG. 2). The first linear wall may have a length of 7.5mm to 9.5mm. The first linear wall may have a length of 8.6mm. The largest recess may have a second linear wall. The second linear wall may be parallel to the longer edge of the flange. The second linear wall may be adjacent to the longer edge of the flange. The second linear wall may have a length of 18.0mm to 22.0mm (between dashed lines 170 and 172 as shown in FIG. 2). The second linear wall may have a length of 19.0mm to 21.0mm. The second linear wall may have a length of 20.0mm. The second linear wall may be defined by a part of the perimeter portion.

The first and second linear walls may be joined by a corner. The comer may have a radius of curvature of 1.5mm to 2.5mm. The corner may have a radius of curvature of 2.0mm. Opposite the first linear wall the largest recess may have a first curved wall. The first curved wall may be joined to the second linear wall by a rounded corner. The rounded corner may have a radius of curvature of 1.5mm to 3.0mm. The rounded corner may have a radius of curvature of 2.0mm. The rounded corner may have a centre of curvature between the well and the nearest longer edge of the flange. The rounded corner may abut a part of the perimeter portion of the lower planar region. The rounded comer may abut the area of the lower planar region that corresponds to the sealing region on the upper side of the flange. The rounded corner may be shaped so as to maximise the area of the recess, thereby reducing the material required by the base member. The first curved wall may be defined by an arc of a circle that is centred at the centre of the well. The circle may have a diameter of 31.0mm to 33.0mm. The circle may have a diameter of 32.5mm. The first curved wall may be defined by the area of the lower planar region that corresponds to the sealing region on the upper side of the flange. A fourth wall of the largest recess may join the first curved wall to the first linear wall. The fourth wall may include a curved corner, a second curved wall and an angled linear wall. The curved comer may have a radius of curvature of 1.0mm to 2.5mm. The curved corner may have a radius of curvature of 1.75mm. The curved corner may be joined at one end to the first linear wall. The second curved wall may be joined at one end to the curved comer and at its other end to the angled wall. The second curved wall may be defined by the bridge portion. The second curved wall may have a radius of curvature of 5.0mm to 7.0mm about two central points. The second curved wall may have a radius of curvature of 6.0mm about two central points that are 1.6mm apart. The second curved wall may be an arc of an oval. The angled linear wall may be angled so that as it gets closer to the well it gets closer to the nearest longer edge of the flange. The angled linear wall may be joined at one end to the curved wall and at its other end to the second portion.

The fourth wall of the largest recess may be defined by the bridge portion of the lower planar region. A first region of the bridge portion may abut the curved corners of the fourth walls of the largest recesses. The bridge portion may have a generally circular region that abuts the second curved walls of the largest recesses. The generally circular region of the bridge portion may be connected to the area of the lower planar region that corresponds to the sealing region by a third region of the bridge portion. The third region of the bridge portion may abut the angled linear walls of the largest recesses. The third region of the bridge portion may taper outwards towards the longer edges of the flange.

The recesses allow the weight of the base member to be reduced without reducing or eliminating the area of the base member that is required to interface with manufacturing apparatus.

The thickness of the flange may be 0.5mm to 1.5mm. The thickness of the flange in regions that are not recessed or raised may be 0.9mm to 1.1mm. The thickness of the flange in regions that are not recessed or raised may be 1.0mm. The thickness of the flange in the recesses, which are thinned compared to the rest of the flange, may be 0.2mm to 0.8mm. The thickness of the flange in the recesses may be 0.4mm. The recesses do not extend all the way through the thickness of the flange.

The substantially rectangular flange may have rounded corners. The longer edges of the flange may be joined to the shorter edges of the flange by rounded corners. The rounded corners may have a radius of curvature of 3.0mm to 5.0mm. The rounded corners may have a radius of curvature of 4.0mm. The shorter edges of the flange may have a length of 25.0mm to 41.0mm. The shorter edges of the flange may have a length of 33.0mm to 34.0mm. The shorter edges of the flange may have a length of 33.2mm to 33.6mm. The longer edges of the flange may have a length of 20 45.0mm to 61.0mm. The longer edges of the flange may have a length of 53.0mm to 54.0 mm. The longer edges of the flange may have a length of 53.2mm to 53.6mm. "Substantially rectangular" is to be understood to mean the shape of a rectangle with some minor alterations such as rounded corners. "Substantially triangular" is to be understood to mean the shape of a triangle with some minor alterations such as rounded corners or curved edges.

The sealing member may have a side with an area equal to the area of the upper side of the flange. The sealing member may have a side with an area greater than the area of the upper side of the flange. The sealing member may have a side with an area smaller than the area of the upper side of the flange. The sealing member has a portion that corresponds to the sealing region. The sealing member may have a portion that corresponds to the upper planar region of the upper side of the flange. The sealing member may be arranged to be sealed to the sealing region and have a portion that rests against the upper planar region of the flange. The upper planar region of the flange does not have any holes extending through it and is therefore able to provide support and protection to the sealing member.

The sealing region on the upper side of the base member may provide one or more locations for interacting with manufacturing apparatus. The sealing region on the upper side of the base member may provide one or more locations for interacting with a pick-up head within the manufacturing process (as shown in FIG. 1A).

The area of the lower planar region that corresponds to the sealing region may provide increased structural integrity to the sealing region on the upper side of the flange and to the base member as a whole.

The elongate protrusions allow the base member to be located within a machine pallet before sealing of the sealing member during manufacture of the blister package. The elongate protrusions also act to provide an increased surface area for mating two or more base members together, which acts to increase the pack rigidity of a multiple pack of blister packages. The elongate protrusions also act to increase the structural integrity of the base member, making the base member less susceptible to deformation. The elongate protrusions increase the base member's structural integrity such that the base member is able to withstand the force provided by a user during manual removal of the sealing member from the sealing region.

The elongate protrusions may extend from the lower side of the flange adjacent to the longer edges of the flange. The elongate protrusions may extend away from the lower planar region of the flange in a direction perpendicular to the lower planar region. The elongate protrusions may extend to a height of 0.7mm to 1.5mm from the lower planar region. The elongate protrusions may extend to a height of 0.9mm to 1.1mm from the lower planar region. The elongate protrusions may extend to a height of 1.0mm from the lower planar region. The flange may have three pairs of elongate protrusions, wherein a member of each pair is located adjacent to each longer edge of the flange so that the elongate protrusions are arranged symmetrically about a central axis running longitudinally through the flange. Each pair may comprise two identical elongate protrusions.

A first pair of elongate protrusions may each have a length of 3.0mm to 4.5mm. The first pair of elongate protrusions may each have a length of 3.4mm to 4.0mm. The first pair of elongate protrusions may each have a length of 3.4mm. The first pair of elongate protrusions may be located in the first half of the base member. Each elongate protrusion in a second and third pair of elongate protrusions may have a length of 3.0mm to 6.0mm. Each elongate protrusion in the second and third pair of elongate protrusions may have a length of 4.5mm to 5.5mm. Each elongate protrusion in the second and third pair of elongate protrusions may have a length of 5.0mm. Each elongate protrusion in the second and third pair of elongate protrusions may be located in the second half of the base member. Along each long edge of the flange, the elongate protrusion of the second pair is positioned between an elongate protrusion of the first pair and an elongate protrusion of the third pair. Along each long edge of the flange, there is a greater distance between the first and second pair of elongate protrusions than the distance between the second and third pair of elongate protrusions.

The first pair of elongate protrusions may be adjacent to the smallest pair of recesses. The second and third pairs of elongate protrusions may be adjacent to the largest pair of recesses.

The third pair of elongate protrusions may be located 3.0mm to 4.0mm from the shorter edge of the flange in the second half of the base member. The third pair of elongate protrusions may be located 3.2mm to 3.8mm from the shorter edge of the flange. The distance between the second elongate protrusion and the first elongate protrusion along each longer edge of the flange may be 22.0mm to 28.0mm. The distance between the second elongate protrusion and the first elongate protrusion along each longer edge of the flange may be 24.0mm to 25.5mm. The distance between the second elongate protrusion and the third elongate protrusion along each longer edge of the flange may be 3.0mm to 8.0mm. The distance between the second elongate protrusion and the third elongate protrusion along each longer edge of the flange may be 4.0mm to 7.0mm. The distance between the second elongate protrusion and the third elongate protrusion along each longer edge of the flange may be 5.0mm.

Each elongate protrusion may be adjacent to a recess.

The sealing region may be annular in plan view. The sealing region may have an inner diameter of 24.0mm to 26.0mm. The sealing region may have an inner diameter of 24.6mm to 25.2mm. The sealing region may have an outer diameter of 31.0mm to 33.0mm. The sealing region may have an outer diameter of'31.5mm to 32.5mm. The sealing region may be raised above the upper planar region of the upper side of the flange by 0.05mm to lmm. The sealing region may be raised above the upper planar region of the upper side of the flange by 0.1mm to 0.3mm.

The well may have an inner well surface that extends from the upper side of the flange. The well may have an outer well surface that extends from the lower side of the flange. The well may have a well base and a perimeter wall. The perimeter wall may be a cylindrical wall, which may have a non-circular cross section. The perimeter wall may be a conical wall, which may have a non-circular cross section. The perimeter wall may extend away from the lower side of the flange in a direction perpendicular to the lower side of the flange. The cross-section of the perimeter wall may be a major segment of a circle which has an arc portion and a linear portion. The arc portion may be the arc of a circle centred on the centre of the well in plan view.

The linear portion may be linear in plan view. The linear portion of the perimeter wall may be parallel to the shorter edges of the flange. The linear portion may be aligned with the notional dividing line between the first half and the second half of the base member. The arc portion of the perimeter wall may extend 260 to 280 degrees around the well base. The arc portion of the perimeter wall may extend 270 degrees around the well base. The linear portion may be connected at either end to the arc portion.

The well base may be substantially parallel to the upper side of the base member. The well base may have the same shape in plan view as the cross-section of the perimeter wall. The well base may have the shape of a major segment of a circle in plan view. The perimeter of the well base may be surrounded by the perimeter wall. The perimeter wall may extend beyond the well base to form a stand. The perimeter wall and the well base may be contiguous portions of the well. The inner well surface may be defined by an upper side of the well base and an inner side of the perimeter wall. The outer well surface may be defined by an outer side of the perimeter wall and a lower side of the well base. The opening in the flange that is the mouth of the well may have the same shape as the well base in plan view. The opening in the flange that is the mouth of the well may have a shape of a major segment of a circle in plan view. The arc portion of the perimeter wall may be an arc of a circle with a diameter of 24.0mm to 26.0mm where the perimeter wall meets the upper side of the flange. The perimeter wall may have the shape of a cone with a non-circular base. The well base may have a perimeter that is smaller than the perimeter of the opening in the flange that is the mouth of the well. The arc portion of the perimeter wall may be an arc of a circle with a diameter of 24.6mm to 25.2mm. The perimeter wall of the well may have a thickness of 0.5mm to 1.5mm. The perimeter wall of the well may have a thickness of 0.7mm to 1.3mm. The centre point of the arc that defines the arc portion of the perimeter wall may be located 7.5mm to 9.5mm from the linear portion of the perimeter wall in a plane that runs longitudinally through the centre of the base member. The centre point of the arc that defines the arc portion of the perimeter wall may be located 8.0mm to 9.0mm from the linear portion of the perimeter wall in a plane that runs longitudinally through the centre of the base member. The centre point of the arc that defines the arc portion of the perimeter wall may be located 8.7mm from the linear portion of the perimeter wall.

The well base may have a thickness of 0.5mm to 1.5mm. The well base may have a thickness of 0.7mm to 1.3mm. The distance between the upper planar region of the upper side of the flange and the outer well surface may be 8.0mm to 10.0mm along a vertical axis that is perpendicular to the well base and runs through the centre of the well. The distance between the upper planar region of the flange and the outer well surface may be 8.7mm to 9.4rnm along the vertical axis as described above. The distance between an outer edge of the stand and the upper planar region of the flange may be 8.0mm to 10.0mm along the vertical axis as described above. The distance between an outer edge of the stand and the upper planar region of the flange may be 8.7mm to 9.4mm. The well base may curve towards the upper planar region of the flange so that on the outer well surface the well base meets the perimeter wall 1.8mm to 2.2mm from the outer edge of the stand. The well base may meet the perimeter wall 1.9mm to 2.1mm from the outer edge of the stand. The inner well surface of the well base may have a radius of curvature of 28.0mm to 30mm. The inner well surface of the well base may have a radius of curvature of 29.0mm.

The base member may have a weight of less than 2.0g. The base member may have a weight of less than 1.90g. The base member may have a weight of less than 1.86g. The base member may have a weight less than or equal to 1.85g. The base member may have a weight of less than 1.82g. The base member may have a weight of less than 1.80g. The base member may have a weight less than or equal to 90% of the weight of an identical base member that does not have recesses on its lower side. The base member may have a thickness of 0.4mm in the recesses. The base member may have a thickness of 0.9mm to 1.1mm in the regions that do not include a recess or an elongate protrusion. The base member may comprise a polypropylene material. The contact lens may be a hydrogel contact lens or a silicone hydrogel contact lens. The base member may be made from a recyclable plastics material. This means that the base member may be recycled rather than being sent to land-fill. The base member may be made from a polypropylene material. The base member may be made from a thermoplastic material.

The well may hold a volume of contact lens packaging solution of 0.5mL to 3.5mL. The well may hold a volume of contact lens packaging solution of 1.5mL to 3.0mL. The well may hold a volume of contact lens packaging solution of 1.7mL.

The well may hold a volume of contact lens packaging solution of 2.5mL The present invention provides, according to a second aspect, a method of manufacturing a packaged contact lens having the features set out in claim 16 below. The step of sealing a sealing member to the sealing region of the base member may be carried out by pressing a foil laminate sealing member against a plastic base member under heat, to melt the layer of plastic of the foil laminate and the sealing region of the base member together. The step of sealing a sealing member to the sealing region may be done at a temperature of 210 degrees to 240 degrees Celsius. The step of sealing a sealing member to the sealing region may be done for example using a heated die pressing the sealing member against the sealing region of the base member at a pressure of 25 PSI to 60 PSI. The heated die may for example press the sealing member against the sealing region for a time of I 00ms to I I 00ms.

Desirably, the sealing region provides a sufficient seal between the base member and the sealing member to withstand separation forces that occur during a contact lens autoclave sterilization process, and also is relatively easy for a person to peel open using the person's fingers. If a lower separation force is required to separate the sealing member from the sealing region, the base member can have a reduced structural integrity (and can therefore be made lighter) without reducing the protection that the blister package provides to a contact lens.

For example, the sealing region may be configured to provide an average separation force of less than 15 Newtons (N). In some embodiments, the sealing region is configured to provide a separation force from about 4 N to about 14 N. In further embodiments, the sealing region is configured to provide a separation force from about 6 N to about 11 N. In yet further embodiments, the sealing region is configured to provide a separation force from about 8 N to about 10 N. The peel strength can be measured using an INSTRON Model 5943 machine. For purposes of these measurements, the angle of pull is set at 45 degrees The load cell of the machine is calibrated prior to testing the peel strength. Generally, the operating instructions are set by the manufacturer.

The sealing configuration can be adjusted by controlling the temperature of a heat sealing head surface that is pressed against the sealing member on the upper side of the flange of the base member, controlling the pressure with which the sealing head is applied to the sealing member, or controlling the time for which the sealing head is applied to the sealing member, or combinations thereof, as described above.

It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.

Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: FIG.1A shows a top view of a contact lens package base member according to a first embodiment of the invention with dashed circles indicating approximate pick-up locations; FIG. 1B shows a bottom view of a contact lens package base member according to a first embodiment of the invention with dashed circles indicating approximate pick-up locations; FIG. 2 shows a bottom view of a contact lens package base member according to a first embodiment of the invention with dashed lines indicating the end points of the linear walls of the recesses; FIG. 3A shows a top view of a contact lens package base member according to a first embodiment of the invention; FIG.3B shows a bottom view of the base member of FIG.3A; FIG.3C shows a region 125 in more detail indicated in FIG.3B as a dashed box; FIG.3D shows a region 118 in more detail indicated in FIG.3B as a dashed box; FIG.4 shows a cross-sectional view of the base member of FIG.3A taken along line A-A'; FIG.5 shows a cross-sectional view of the base member of FIG.3A taken along line B-B'; FIG.6 shows the steps of a method of manufacturing a packaged contact lens according to a second embodiment of the invention.

Detailed Description

A contact lens blister package according to the present invention includes a base member, a sealing member, a contact lens and a contact lens solution. A first example embodiment of the invention will now be described with reference to FIGS. 1 to 5.

FIG.3A shows a base member 100 formed from a plastics material The base member 100 comprises a substantially rectangular flange 101 and a well 103 for receiving a contact lens and contact lens solution. The flange 101 has two parallel shorter edges 104 and two parallel longer edges 102. The shorter edges 104 have a length of 33.6mm. The longer edges 102 have a length of 53.5mm. An upper side 110 of the flange 101 and an inner surface of the well 103 is shown in FIG.3A. The flange 101 defines an opening 114 that is the mouth of the well 103.

The well 103 is defined by a well base 108 and a perimeter wall 106. The perimeter wall 106 is attached at one end to the flange 101 and at its other end to the well base 108. The well 103 has an inner well surface 166. The perimeter wall 106 extends away from the flange 101 in a direction perpendicular to the flange 101. The perimeter wall 106 surrounds the perimeter of the well base 108. The perimeter wall 106 is a cylindrical wall with a cross section of a major segment of a circle. The perimeter wall 106 has a portion 106a that is an arc of a circle in plan view and extends for approximately 270 degrees around the well base 108. The portion 106a is an arc of circle that has a diameter of 25.2mm. The perimeter wall 106 has a portion 106b that is linear in plan view and extends the remaining distance around the well base 108. The well base 108 is correspondingly shaped, being a major segment of a circle with a diameter of 25.2mm in plan view. The linear portion 106b of the perimeter wall 106 extends parallel to the shorter edges 104 of the flange 101. The linear portion 1061) of the perimeter wall 106 is approximately aligned with a point along the longer edges 102 of the flange 101 that is halfway between the two shorter edges 104 of the flange 101. In plan view, base member 100 can be conceptually split into a first half 140 and a second half 130 (divided by dashed line 107 in the drawings). The linear portion 106b of the perimeter wall 106 lies on the boundary 107 between the two halves.

The upper side 110 of the flange 101 is flat, smooth and continuous, save for the opening 114 in the flange that defines the mouth of the well and an annular sealing region 105 that is concentric with the opening 114. The flat, smooth and continuous area of the upper side 110 is referred to as the upper planar region 115. The opening 114 in the flange has the same shape in plan view as the well base 108. The annular sealing region 105 has an inner diameter of 25.2mm and an outer diameter of 32.5 mm.

FIG.3B shows a lower side 112 of the flange 101 and an outer well surface 164. The lower side 112 of the flange 101 includes a lower planar region 121, six elongate protrusions (119, 120 and 122) and four recesses (124 and 126). The lower planar region 121 includes a bridge portion 154, a perimeter portion 155 and an area 159 that corresponds to the sealing region 105 on the upper side 110 of the flange.

The perimeter portion 155 of the lower planar region 121 runs around the perimeter of the lower side of the flange 101 and has a varying width.

The bridge portion 154 of the lower planar region 121 connects the perimeter portion 155 to the area 159 that corresponds to the sealing region 105. The bridge portion 154 has a broadest section that is positioned centrally along the width of the lower side 112. The broadest section tapers towards the shorter edge 104 of the flange 101 in the second half 130 of the base member 100. The bridge portion is centred on a midway point located approximately 116th of the way between the shorter edge 104 of the flange 101 in the first half 140 of the base member 100 and the shorter edge 104 in the second half 130 of the base member 100.

In the first half 140 which includes the well 103, there are two approximately triangular recesses 124 each located in opposite corners of the first half 140. The triangular recesses 124 are also referred to herein as "the smallest recesses-. The triangular recesses are defined by a part of the perimeter portion 155 of the lower planar region 121 nearest to the shorter edge 104 of the flange 101 and the area 159 of the lower planar region 121 that corresponds to the sealing region 105.

FIG.3C shows a region 125 defined by a dashed box in FIG.3B, containing one of the triangular recesses 124. Triangular recess 124 has three rounded corners 128a, 128b and 128c. A first linear wall 132 of recess 124 joins two of the comers 128c and 128a. The first linear wall 132 is parallel to the longer edges 102 of the flange 101. The first linear wall 132 has a length of 3.8mm (between dashed lines 178 and 180 as shown in FIG. 2) in the direction of the longer edge 102 of the flange 101. A second linear wall 133 of recess 124 joins two of the comers (128a and 128b) and is parallel to the shorter edges 104 of the flange 101. The second linear wall 133 has a length of 4.0mm (between dashed lines 182 and 184 as shown in FIG. 2) in the direction of the shorter edge 104 of the flange 101. A curved wall 134 of the recess 124 completes the triangle by joining up two corners 128b and 128c. The curved wall 134 is an arc of a circle with a diameter of 32.5mm centred at the centre of the well 103. The curved wall 134 abuts the area 159 of the lower planar region 121 that corresponds to the sealing region 105 on the upper side 110 of the flange 101. Two of the rounded corners 128b and 128c have a radius of curvature of 0.75mm. The corner 128a between the first linear wall 132 and the second linear wall 133 has a radius of curvature of 2.0mm.

In the second half 130 of the base member 100, which does not include the well 103, there are two largest recesses 126, each located in a corner of the base member 100. The recesses 126 are also referred to herein as "the largest recesses".

Each of these largest recesses 126 is defined by the bridge portion 154, a part of the perimeter portion 155 and the area 159 that corresponds to the sealing region 105. The smallest recesses 124 and the largest recesses 126 are both located on the lower side 112 of the flange 101.

FIG.3D shows a region 118 defined by a dashed box in FIG.3B, containing one of the largest recesses 126. The largest recesses 126 are identical mirror images of each other. One of the largest recesses U6 will now be described. The largest recess 126 has a first linear wall 146 that is parallel to the shorter edge 104 of the flange 101 and that has a length of 8.6mm (between dashed lines 174 and 176 as shown in FIG. 2) and is defined by a part of the perimeter portion 155. The largest recess 126 has a second linear wall 150 that is parallel and adjacent to the longer edge 102 of the flange 101 and that has a length of 20.0mm (between dashed lines 170 and 172 as shown in FIG. 2) and is defined by a part of the perimeter portion 155. The first 146 and second 150 linear wails are joined by a corner 148 with a radius of curvature of 2.0mm. Opposite the first linear wall 146 the recess is defined by a first curved wall 138. The first curved wall 138 is joined to the second linear wall by a rounded corner 136 with a radius of curvature of 2.0mm. The rounded corner 136 has a centre of curvature between the well 103 and the nearest longer edge 102 of the flange 101. The rounded corner may be shaped so as to maximise the area of the recess, thereby reducing the weight of the base member. The first curved wall 138 is an arc of a circle that is centred at the centre of the well 103 and has a diameter of 32.5mm. The first curved wall 138 is defined by the area 159 of the lower planar region 121 that corresponds to the sealing region 105. A fourth wall 142 of the recess 126 joins the first curved wall 138 to the first linear wall 146. The fourth wall 142 includes a curved corner 144, a second curved wail 141 and an angled linear wall 143. The curved corner 144 has a radius of curvature of 1.75mm and is joined at one end to the first linear wall 146. The second curved wall 141 is joined at one end to the curved corner 144 and at its other end to the angled linear wall 143. The second curved wall 141 is defined by the bridge portion 154 and has a radius of curvature of 6.0mm about two central points that are 2.0mm apart along a longitudinal axis naming through the centre of the base member 100. The angled linear wall 143 is angled so that as it gets closer to the well 103 it gets closer to the nearest longer edge 102 of the flange 101. The angled linear wall 143 is joined at one end to the second curved wall 141 and at its other end to the first curved wall 138.

As just described, the fourth wall 142 of the largest recess U6 is defined by the bridge portion 154 (as shown in FIG. 3B and 3D). The bridge portion 154 connects the part of the perimeter portion 155 of the lower planar region 121 adjacent to the shorter edge 104 of the first half 140 of the base member with the area 159 of the lower planar region 121 that corresponds to the sealing region 105. A first region of the bridge portion 154 abuts the curved corners 144 of the recesses 126. The bridge portion 154 tapers out to a generally circular region of the bridge portion 154 that abuts the second curved walls 141 of the recesses 126. The generally circular region includes the broadest section of the bridge portion 154. The circular region of the bridge portion 154 is connected to the area 159 of the lower planar region 121 that corresponds to the sealing region 105 by a third region of the bridge portion 154 that abuts the angled linear walls 143 of the larger recesses 126. This third region of the bridge portion 154 tapers outwards towards the longer edges 102 of the flange 101. The four recesses (124 and 126) define an area of the lower side 112 of the flange 101 that is set back from the lower planar region 121. The base member 100 has a thickness of 0.4mm in the recesses. The base member 100 has a thickness of 1.0mm in the lower planar region 121.

The recesses (124 and 126) are sized and positioned to reduce the amount of material used in the base member 100 whilst maintaining an upper planar region 115 of the flange 101. The upper planar region 115 may be designed to come into contact with pick-up heads during the manufacturing process. FIG. lA shows the locations where the pick-up heads can attach to the base member on the upper side of the flange. The lower planar region 121 may be designed to come into contact with pick- up heads during the manufacture process. FIG. 1B shows the location where the pick-up heads can attach to the base member on the lower planar region. The recesses (124 and 126) are shaped so that the lower planar region 121 of the flange 101 can provide structural integrity to the base member 100 to allow pick-up heads to attach to the base member 100 during manufacture.

The elongate protrusions (119, 120 and 122) extend adjacent to the longer edges 102 of the flange 101 and extend away from the lower planar region 121 of the flange 101 in a direction perpendicular to the lower planar region 121. There are three pairs of elongate protrusions (119, 120 and 122). The second 120 and third 119 pairs of elongate protrusions each extend 5.0mm of the way along the flange 101 adjacent to the longer edges 102. The second and third pair of elongate protrusions 119 and are located in the second half HO of the base member 100. The third 119 pair of elongate protrusions are each located 3.8mm from the shorter edge 104 in the second half 130 of the base member 100. Each of the first pair of elongate protrusions 122 extends 4.0mm along opposite longer edges 102 of the flange 101. The distance between each of the first pair of elongate protrusions 122 and each of the second pair of elongate protrusions 120 along each longer edge 102 of the flange 101 is 25.1mm. The first pair of elongate protrusions 122 are located in the first half 140 of the base member 100 which contains the well and are positioned close to the shorter edge 104.

Each elongate protrusion (119, 120 and 122) is adjacent to a recess (124 and 126). Each recess is located adjacent to a corner of the lower side 112 of the flange 101.

The recesses (124 and 126) and elongate protrusions (119, 120 and 122) are sized and positioned so that the base member 100 is sufficiently stiff to allow manufacture of the blister package. The base member 100 is designed to have sufficient structural integrity so that during use by a user (for example when the sealing member is removed from the blister package by a user) the risk of deformation is limited.

FIG.4 shows a cross-sectional view of the base member 100 along the line A-A' as shown in FIG.3A. An elongate protrusion of the third pair of elongate protrusions 119 and an elongate protrusion of the second pair of elongate protrusions 120 is shown in FIG.4 extending from the lower side 112 of the flange. The thickness of the flange 101 (the distance between the upper side 110 and the lower side 112) is 1.0mm in the regions that do not have a recess, a raised region or an elongate protrusion.

The perimeter wall 106 and the well base 108 define the inner well surface 166. The perimeter wall 106 and the well base 108 define the outer well surface 164. The perimeter wall 106 extends beyond a point where it meets the well base 108 to form a stand 162. The perimeter wall 106 has a thickness of 1.0mm. The centre point of the arc that defines portion 106a of the perimeter wall 106 is 8.7mm from the linear portion 106b along a plane defined by the line A-A' (as shown in FIG.3A) which passes centrally through the base member in the longitudinal direction in plan view. The distance from the upper planar region 115 to the outer well surface 164 is 9.4mm along an axis that is perpendicular to the flange 101 and passes through a centre point of the arc that defines portion 106a. The distance between an outer edge of the stand 162 and the upper planar region 115 is 9.4mm in the plane shown in FIG. 4. FIG.5 shows a cross-sectional view of the base member 100 along the line B-B' as shown in FIG.3A. The well base 108 has a thickness of 1.0mm. The well base 108 curves towards the upper planar region 115 so that the well base 108 meets the perimeter wall 106 on the outer well surface 164, 2.1mm from an outer end of the stand 162.

The inner well surface 166 of the well base 108 has a radius of curvature of 29.3mm. The base member 100 of the present blister packages can be formed by injection molding polypropylene or other suitable plastics material into a blister base member cavity of an injection molding machine, as understood by persons skilled in the art.

In a method 200 of manufacturing a packaged contact lens according to a second embodiment (FIG. 6) a base member 100 of a blister package for a contact lens according to the first aspect of the invention is provided in a first step 202. A contact lens is placed into the well 103 of the base member 100 of the blister package in a second step 204. A volume of liquid contact lens packaging solution is placed into the well 103 of the base member 100 in a third step 206. A sealing member is sealed to the sealing region 105 of the base member 100 in a fourth step 208. The sealed contact lens blister package is autoclaved to sterilize the contact lens and the packaging solution in a fifth step 2W.

In use, a person will hold the flange and will peal away the sealing member from the flange to expose the unworn contact lens in its packaging solution. The contact lens will be removed from the packaging solution and placed on a person's eye.

Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein.

Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims (16)

1. Claims 1. A hermetically sealed blister package for a contact lens, the blister package comprising: a) a base member comprising a well and a substantially rectangular flange made of plastics material, the flange having two parallel longer edges and two parallel shorter edges, an upper side and a lower side; b) a sealing member sealed to the base member to form a blister cavity; and c) an unworn contact lens and a contact lens packaging solution contained within the blister cavity; wherein: i) the base member has a first half containing the well and a second half comprising the majority of the flange; ii) the flange defines an opening that is the mouth of the well; the opening is surrounded on the upper side of the flange by an annular sealing region; iii) the upper side of the flange includes the sealing region and a flat upper planar region; iv) the lower side of the flange includes a lower planar region, elongate protrusions and four recesses; v) the lower planar region includes a bridge portion, a perimeter portion, and an area that corresponds to the sealing region on the upper side of the flange; vi) the bridge portion connects the perimeter portion to the area of the lower planar region that corresponds to the sealing region; vii) the bridge portion has a broadest section that is positioned centrally along the width of the flange, the bridge portion tapering from the broadest section towards the shorter edge of the flange in the second half of the base member; viii) a smallest pair of recesses are substantially triangular and are each located in opposite corners of the first half of the base member, the smallest pair of recesses being defined by a part of the perimeter portion nearest to the shorter edge of the flange and the area of the lower planar region that corresponds to the sealing region; and ix) a largest pair of recesses are each located in opposite corners of the second half of the base member, the largest pair of recesses being defined by the bridge portion, a part of the perimeter portion, and the area of the lower planar region that corresponds to the sealing region.
2. 2. A hermetically sealed blister package for a contact lens according to claim 1, wherein the base member has a width of 33.2mm to 33.6mm and a length of 53.2mm to 53.6mm.
3. 3. A hermetically sealed blister package for a contact lens according to claims 1 or 2, wherein the contact lens is a hydrogel contact lens or a silicone hydrogel contact lens.
4. 4. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the base member is made from a recyclable plastics material.
5. 5. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the base member has a weight of less than 1.86g.
6. 6. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the base member has a weight less than or equal to 90% of the weight of an identical base member that does not have recesses on its lower side.
7. 7. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the elongate protrusions extend adjacent to the longer edges of the flange.
8. 8. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the elongate protrusions extend perpendicular to the lower planar region to a height of 0.9mm to 1.1mm from the lower planar region
9. 9. A hermetically sealed blister package for a contact lens according to any preceding claim, including three pairs of elongate protrusions, a first pair having a length of 3.4mm to 4.0mm located in the first half of the base member and a second and third pair each having a length of 3.0mm to 6.0mm located in the second half of the base member; the elongate protrusions being arranged symmetrically about a central axis running longitudinally through the base member.
10. 10. A hermetically sealed blister package for a contact lens according to claim 9, wherein the first pair of elongate protrusions are adjacent to the pair of smallest recesses and the second and third pair of elongate protrusions are adjacent to the pair of largest recesses.
11. 11. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the sealing region has an inner diameter of 24.6mm to 25.2mm and an outer diameter of'31.5mm to 32.5ium.
12. 12 A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the well includes a perimeter wall and a well base; the well base being shaped in plan view as a major segment of a circle and being connected around its entire perimeter to the perimeter wall; the perimeter wall being a cylindrical wall having a non-circular cross section and attaching at one end to the flange
13. 13. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the flange has a thickness of 0.4mm in the recesses.
14. 14. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the flange has a thickness of 0.9mm to 11mm in the regions that do not include either a recess or an elongate protrusion.
15. 15. A hermetically sealed blister package for a contact lens according to any preceding claim, wherein the base member comprises a polypropylene material.
16. 16 A method of manufacturing a packaged contact lens, comprising: providing a base member of a blister package for a contact lens according to any preceding claim; placing a contact lens into the well of the base member; placing a volume of liquid contact lens packaging solution into the well of the base member; sealing a sealing member to the sealing region of the base member, and autoclaving the sealed contact lens blister package to sterilize the contact lens and the packaging solution.