Special receptacle or package – Including ancillary article contacting medium – For tool or appliance
Reexamination Certificate
2000-01-27
2002-06-04
Foster, Jim (Department: 3728)
Special receptacle or package
Including ancillary article contacting medium
For tool or appliance
C206S005100, C220S501000
Reexamination Certificate
active
06398018
ABSTRACT:
The present invention relates to a container, in particular a container for an ophthalmic lens, more especially, a container for a hydrophilic or “soft” contact lens.
Packages for storing, transporting and dispensing soft contact lenses may comprise a container having a cavity in which the contact lens is housed in a saline solution.
EP-A-0 223 581 describes such a package. The base of the cavity has an inclined surface to aid removal of the lens.
EP-A-0 604 177 also describes such a package. The base of the cavity is concave, and has a radius of curvature which is greater than the radius of curvature of the lens, while being sufficiently small to cause the lens to settle at the lowermost portion of the base, i.e., to centre.
Soft contact lenses are generally manufactured by moulding. After moulding, the contact lens is subjected to various hydrating, washing and conditioning processes. In order to minimise handling of the lens, it is desirable to carry out those processes while the lens is in its final package, that is, while the lens is in the container. However, it is then necessary to be able to introduce and to remove treating fluids from the container without damaging the lens.
Fluid may be introduced to the cavity in which the lens is housed by directing the fluid into the centre of the upturned lens, and then allowing the fluid to overflow into the cavity. (Contact lenses are usually concavo—convex; in this specification a lens is described as “upturned” when its concave face is uppermost.) This method of fluid introduction avoids damage to the lens, and has the added advantage that it locates the lens at the base of the cavity, and prevents it from floating in the fluid.
Avoiding damage to the lens on fluid removal, however, is more difficult, particularly where the maximum diameter of the cavity is not much greater than the diameter of the lens. This will often be the case as it is desirable to minimise the size of the cavity in order to minimise manufacturing costs and production time, and to aid lens extraction by the user.
EP-A-0 618 063 describes a nozzle for removing fluid from a container containing a lens. The nozzle includes a fluid entrance passage and at least one fluid exit passage. The nozzle is placed in sealing contact with the container. Purging fluid is introduced to the container through the fluid entrance passage so that the fluid in the container is forced out through the fluid exit passage. The arrangement of the fluid entrance passage and the fluid exit passage is such that fluid flow is symmetrical about the central axis of the lens, so preventing migration of the lens from the centre.
It is an object of the present invention to provide a container which minimises or prevents damage to a lens on removal of fluid from the cavity housing the lens.
The present invention provides a container comprising at most two first cavities for receiving an ophthalmic lens, and a second cavity for the removal of fluid from the or each first cavity, the second cavity being laterally spaced from, and in communication with, the or each first cavity, wherein each cavity has an opening on the same face of the container.
Fluid removal is carried out by inserting a fluid removal device into the second cavity, either from above or from below, and then withdrawing fluid through the device. Insertion of the device in the second cavity avoids contact between the device and the or each lens, so reducing the possibility of damage to the or each lens. It will be appreciated that the second cavity may also be used to accommodate other devices used in the hydrating, washing or conditioning processes, for example, an ultrasonic probe to agitate the fluid, a device to heat the fluid, or a device to measure the fluid level.
The invention further provides a container comprising at most two first cavities for receiving an ophthalmic lens, and a second cavity for the removal of fluid from the or each first cavity, the second cavity being laterally spaced from, and in communication with, the or each first cavity, wherein each cavity has an opening, the openings being such that the cavities are capable of retaining fluid even when the openings are not sealed.
The invention further provides a container comprising at most two first cavities for receiving an ophthalmic lens, and a second cavity for the removal of fluid from the or each first cavity, the second cavity being laterally spaced from, and in communication with, the or each first cavity, wherein each cavity has an opening, the openings being such that the cavities form a closed system when the openings are sealed.
The invention further provides a container comprising at least one first cavity for receiving an ophthalmic lens, and a second cavity for the removal of fluid from the or each first cavity, the second cavity being laterally spaced from, and in communication with, the or each first cavity, wherein each cavity has an opening on one face of the container, the cross-sectional area of the opening of the or each first cavity being greater than that of the second cavity.
Soft contact lenses are subject to an inspection process as well as to hydrating, washing and conditioning processes. In the inspection process, an illuminating beam is transmitted through the lens. That beam is then focused on a screen to produce an image of the lens. That image is inspected (by eye or automatically) to determine whether or not the lens contains any irregularities which would make the lens unacceptable for consumer use.
In order to minimise handling of the lens, it is desirable to carry out the inspection process while the lens is in the container. Where that is the case, however, it is important to minimise the optical power of the base of the first cavity to minimise the effect that the container has on the illuminating beam. The base of the first cavity has zero optical power when it is flat. However, some curvature of the base is desirable to cause the lens to centre consistently. Accordingly, at least the lower portion of the inner wall of the or each first cavity is preferably concave.
The invention further provides a container comprising at least one first cavity for receiving an ophthalmic lens, and a second cavity for the removal of fluid from the or each first cavity, the second cavity being in communication with the or each first cavity, wherein at least a lower portion of the inner wall of the or each first cavity is concave.
Preferably, the second cavity is laterally spaced from the or each first cavity.
Where the lower portion of the inner wall of the first cavity is curved, it is desirable to maximise the radius of curvature of that portion to minimise the optical power of the base of the cavity. However, if the radius of curvature of the whole of the inner wall of the first cavity is such that it is just sufficient to cause the lens to centre, the first cavity would have to be extremely large in order to contain sufficient fluid to cover the lens. Accordingly, the inner wall of the or each first cavity advantageously comprises an upper portion and a lower portion, the radius of curvature of the lower portion being greater than the radius of curvature of the upper portion. This allows the first cavity to have a base of low optical power, while being able to contain sufficient fluid to cover the lens.
Preferably, the radius of curvature of the lower portion is between 9 mm and 35 mm. If the radius of curvature of the lower portion is less than 9 mm, the lens may not sit with its centre touching the centre of the lower portion. If the radius of curvature is greater than 35 mm, the lens may not centre.
Preferably, the radius of curvature of the upper portion is such that the maximum diameter of the or each first cavity is between 15 mm and 30 mm. A diameter that falls within this range allows sufficient volume for washing, while minimising package size.
Preferably, the depth of the or each first cavity is between 6 mm and 12 mm. A depth that falls within this range ensures that the entire lens will be covered by solution, while
Livesley David John
Townsend Christopher Andrew
Tyldesley William Frank
Foster Jim
Ocular Sciences, Inc.
Stout, Uxa Buyan & Mullins, LLP
Uxa Frank J.
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