US-20260124815-A1 - PRODUCTION LINE FOR THE PRODUCTION OF OPHTHALMIC LENSES

US20260124815A1US 20260124815 A1US20260124815 A1US 20260124815A1US-20260124815-A1

Abstract

An automated production line for the production of ophthalmic lenses comprises: a production line front end comprising: a first and a second injection-molding machine, a casting module, a filling station and a capping station, a stacking module and a curing module, a destacking module and a demolding and delensing module a production line back end comprising: a treatment module, and inspection module, wherein self-driving shuttles in the inspection module can form a queue and act as a buffer for the primary packaging module if an interruption of the primary packaging module and variations of the cycle time in the primary packaging module are buffered so that the extraction module is able to operate largely independently from the upstream and downstream components of the manufacturing line.

Inventors

Matthias Schwab
Matthias Braun
Roger Biel
Nils Schweizer
Nicholas Gollas
Shu Zong

Assignees

ALCON INC.

Dates

Publication Date: 20260507
Application Date: 20260105

Claims (20)

1 . A method for the automated production of ophthalmic lenses, in particular contact lenses such as soft contact lenses, for example silicone hydrogel contact lenses, the method being capable of being carried out in a production line according to any one of the preceding claims , the method comprising: concurrently producing a plurality of front curve plastic lens molds (FCM) by injection-molding the front curve plastic lens molds in the production line within a predetermined cycle time of less than ten seconds, in particular less than five seconds, and preferably in two to five seconds; concurrently producing a corresponding plurality of base curve plastic lens molds (BCM) by injection-molding the base curve plastic lens molds (BCM) in the production line within the same predetermined cycle time of less than ten seconds, in particular less than five seconds, and preferably in two to five seconds; filling a predetermined amount of a lens-forming material into a predetermined number of the front curve plastic lens molds (FCM); placing a corresponding number of base curve plastic lens molds (BCM) having the same age as the predetermined number of front curve plastic lens molds (FCM) onto the front curve plastic lens molds (FCM) containing the lens-forming material to form a corresponding number of closed plastic lens molds (BCM/FCM) containing the lens-forming material; transferring the corresponding number of closed plastic lens molds (BCM/FCM) containing the lens-forming material and placing them onto a lens mold tray; stacking a plurality of lens mold trays loaded with the closed plastic lens molds containing the lens-forming material to form a stack of lens mold trays; loading the stack of lens mold trays loaded with the plastic lens molds (BCM/FCM) containing the lens-forming material into a heatable chamber of an oven; heating the chamber of the oven to a predetermined temperature to effect curing of the lens-forming material to form cured lenses (CL) in the closed plastic lens molds (BCM/FCM); removing a said stack of lens mold trays loaded with the closed plastic lens molds (BCM/FCM) containing the cured lenses from the chamber; destacking the individual trays from the stack of lens mold trays removed from the chamber for allowing access to the closed plastic molds (BCM/FCM) of each individual lens mold tray; transferring a predetermined number of the closed plastic lens molds (BCM/FCM) containing the cured lenses (CL) from a said individual lens mold tray in order for the closed molds (BCM/FCM) being opened and the cured lenses (CL) being released; opening the closed lens molds (BCM/FCM) by separating the base curve plastic lens molds (BCM) and the front curve plastic lens molds (FCM) from each other; releasing the cured lenses (CL) from the base curve plastic lens molds (BCM) or the front curve plastic lens molds (FCM); transferring the released cured lenses (CL) to a treatment carrier tray; treating the cured lenses (CL) in a treatment bath to obtain the ophthalmic lenses; inspecting the ophthalmic lenses in a lens inspection module comprising: a closed-loop rail, a plurality of self-driving shuttles arranged on the closed-loop rail, each self-driving shuttle carrying a plurality of inspection cuvettes arranged thereon, a plurality of inspection stations arranged along the closed-loop rail; and packaging those ophthalmic lenses that have successfully passed the inspection in primary packaging containers.
2 . The method according to claim 1 , wherein in case the ophthalmic lenses to be manufactured by the production line are different from those presently manufactured by the production line, at least one of the first tooling plate, the second tooling plate, the third tooling plate and the fourth tooling plate is pulled out of the first slot, the second slot, the third slot or the fourth slot, respectively, and at least one of a new first tooling plate, a new second tooling plate, a new third tooling plate and a new fourth tooling plate having optical tool inserts or back pieces mounted to the respective first sleeves, second sleeves, third sleeves and fourth sleeves pre-mounted thereto is slid into at least one of the first slot, the second slot, the third slot and the fourth slot.
3 . The method according to claim 1 , wherein further the toric angle (α) of the base curve plastic molds (BCM) and the front curve plastic molds (FCM) relative to each other is verified prior to transferring the corresponding number of closed plastic lens molds (BCM/FCM) containing the lens-forming material and placing them on a lens mold tray.
4 . The method according to claim 1 , further comprising temporarily placing the stack of lens mold trays removed from the heatable chamber or the stack of lens mold trays to be loaded into the heatable chamber in an intermediate storage station in case such stack of lens mold trays removed from the heatable chamber cannot be directly destacked or in case such stack of lens mold trays cannot be directly loaded into the heatable chamber.
5 . An automated production line for the production of ophthalmic lenses, the production line comprising: a production line front end; and a production line back end comprising: a treatment module for a liquid bath treatment of cured lenses (CL) carried by a treatment carrier tray to obtain the ophthalmic lenses; an inspection module for the inspection of the ophthalmic lenses, the inspection module comprising: a closed-loop rail; a plurality of self-driving shuttles arranged on the closed-loop rail, each self-driving shuttle carrying a plurality of inspection cuvettes arranged thereon; a plurality of inspection stations arranged along the closed-loop rail; and a primary packaging module for packaging in primary packaging containers the ophthalmic lenses that have successfully passed the inspection.
6 . The automated production line of claim 5 , wherein the production line front end comprises: a first injection-molding machine arranged in the production line and configured to concurrently produce a plurality of front curve plastic lens molds (FCM) within a predetermined cycle time of less than ten seconds; and a second injection-molding machine arranged in the production line and configured to concurrently produce a corresponding plurality of base curve plastic lens molds (BCM) within the same predetermined cycle time of less than ten seconds.
7 . The automated production line of claim 5 , wherein the production line front end comprises: a casting module comprising: a filling station configured to dose a predetermined amount of lens-forming material into a predetermined number of the front curve plastic lens molds (FCM), and a capping station configured to place a corresponding number of the base curve plastic lens molds (BCM) having substantially the same age as the predetermined number of front curve plastic lens molds (FCM) on the predetermined number of front curve plastic lens molds (FCM) containing the predetermined amount of lens-forming material, to form a corresponding number of closed plastic lens molds (BCM/FCM) containing the lens-forming material.
8 . The automated production line of claim 5 , wherein the production line front end comprises: a transfer robot configured to transfer a corresponding number of closed plastic lens molds (BCM/FCM) containing lens-forming material from a casting module to a stacking module.
9 . The automated production line of claim 5 , wherein the production line front end comprises: a stacking module comprising: a plurality of lens mold trays, each lens mold tray configured for being loaded with a multiple of a corresponding number of closed plastic lens molds (BCM/FCM) transferred by a transfer robot and containing a lens-forming material, a stacking robot for stacking a plurality of lens mold trays comprising the closed plastic lens molds comprising the lens-forming material to form a stack of lens mold trays.
10 . The automated production line of claim 5 , wherein the production line front end comprises: a curing module comprising a plurality of ovens, a stack handling robot, wherein each individual oven of the plurality of ovens comprises a heatable chamber sized to accommodate a stack of lens mold trays carrying closed plastic lens molds (BCM/FCM) as well as a door for opening and closing the chamber, to allow the stack handling robot to load a said stack of lens mold trays loaded with closed plastic lens molds (BCM/FCM) containing lens-forming material into the heatable chamber when the door is open.
11 . The automated production line of claim 5 , wherein the production line front end comprises: a destacking module comprising a destacking robot configured to destack individual lens mold trays from a stack of lens mold trays removed from a heatable chamber of an oven for allowing access to closed plastic molds (BCM/FCM) of each individual lens mold tray; and a transfer robot configured to transfer a predetermined number of the closed plastic lens molds (BCM/FCM) containing the cured lenses (CL) from said individual lens mold tray to a demolding and delensing module.
12 . The automated production line of claim 5 , wherein the production line front end comprises: a demolding and delensing module comprising: a demolding station configured to open a predetermined number of closed plastic lens molds (BCM/FCM) by separating base curve plastic lens molds (BCM) and front curve plastic lens molds (FCM) from each other, with cured lenses adhering either to the base curve plastic lens molds (BCM) or to the front curve plastic lens molds (FCM).
13 . The automated production line of claim 5 , wherein the production line front end comprises: a delensing station configured to release cured lenses from base curve plastic lens molds (BCM) or from the front curve plastic lens molds (FCM), and a transfer gripper configured to transfer the cured lenses released from the delensing station to the treatment carrier tray.
14 . The automated production line of claim 5 , wherein the treatment module comprises: a treatment carrier tray stacking station for stacking a plurality of individual treatment carrier trays one above the other to form a stack of treatment carrier trays carrying the cured lenses (CL).
15 . The automated production line of claim 5 , wherein the treatment module comprises: a plurality of treatment baths, each treatment bath of the plurality of treatment baths comprising a tank sized to accommodate a stack of treatment carrier trays and containing a treatment liquid.
16 . The automated production line of claim 5 , wherein the treatment module comprises: a handling robot configured to pick a stack of treatment carrier trays and to place the stack of treatment carrier trays into a first treatment bath of a plurality of treatment baths for a predetermined period of time.
17 . The automated production line of claim 16 , wherein the handling robot is further configured to: remove the said stack of treatment carrier trays from the first treatment bath after the predetermined period of time and lift the stack of treatment carrier trays to a position above a tank of the first treatment bath, tilt the lifted stack of treatment carrier trays about a pivot shaft with the tilted stack of treatment carrier trays still being arranged above the tank of the first treatment bath to allow the treatment liquid remaining in the stack of treatment carrier trays to flow back from the tilted stack of treatment carrier trays into the tank of the first treatment bath, tilt the lifted stack of treatment carrier trays back, and move the stack of treatment carrier trays from the first treatment bath to a second treatment bath of the plurality of treatment baths or to an ophthalmic lens transfer station where the individual treatment carrier trays of the stack of treatment carrier trays are destacked and the ophthalmic lenses obtained by the liquid bath treatment of the cured lenses (CL) are transferred from the destacked individual treatment carrier trays to the inspection module.
18 . The automated production line according to claim 5 , wherein the plurality of inspection stations of the inspection module comprises: a cuvette filling station configured to fill the plurality of cuvettes with water, the plurality of cuvettes being arranged on a said shuttle in a handling position, and a lens insertion station configured to insert the ophthalmic lenses transferred from the treatment module into the plurality of filled cuvettes arranged on the shuttles, one said ophthalmic lens into one said cuvette.
19 . The automated production line according to claim 18 , wherein the plurality of inspection stations of the inspection module further comprises: a first cuvette tilting station configured to tilt the plurality of cuvettes arranged on the shuttle from the handling position to an inspection position, and a lens inspection station configured to inspect the ophthalmic lenses in the plurality of cuvettes.
20 . The automated production line according to claim 19 , wherein the plurality of inspection stations of the inspection module comprises: a first cuvette tilting-back station for tilting the plurality of cuvettes containing the inspected ophthalmic lenses from the inspection position back to the handling position, and an ophthalmic lens transfer station for transferring those inspected ophthalmic lenses that have successfully passed the inspection to the primary packaging module.

Description

FIELD The present invention generally deals with the manufacture of ophthalmic lenses, in particular contact lenses such as soft contact lenses, for example silicone hydrogel contact lenses. More specifically, the invention deals with a production line for the manufacture of such lenses using plastic lens molds which are produced using injection-molding techniques. BACKGROUND Contact lenses, in particular soft contact lenses such as silicone hydrogel contact lenses, are produced using mass-manufacturing techniques, in particular since these contact lenses are typically worn only once (single use) and are subsequently disposed of. Obviously, therefore, very large numbers of such contact lenses must be produced in more or less fully automated mass-manufacturing production lines. In this regard, two general types of fully automated production lines are known which are fundamentally different regarding the type of lens molds used for forming the contact lenses. In the first type of production line, the lens molds for forming the contact lenses are re-usable and are actually used thousands of times in the production line before they are removed from the production line and replaced by different re-usable lens molds. This means that after one contact lens has been produced using these lens molds, these re-usable lens molds are cleaned, rinsed and dried in the production line, and are subsequently used again in the next production run to form the next contact lens. Such re-usable lens molds are typically made of glass, e.g. quartz glass, and are very expensive (this is one reason why the glass lens molds must be re-used to produce large numbers of contact lenses), and curing of the lens-forming material may be effected with the aid of UV-light and UV-photoinitiators contained in the lens-forming material, these UV-photoinitiators triggering photopolymerization and/or crosslinking of the lens-forming material (which may be a monomer or a prepolymer) upon being exposed to UV-light to form the contact lenses. In the second type of production line, the lens molds for forming the contact lenses are single-use lens molds. This means that after one contact lens has been produced in one production run using such single-use lens mold, the same lens mold is not used anymore, but rather a new single-use lens mold is used in the next production cycle for producing the next contact lens. The used lens molds are typically returned to the recycling process after having been used. Obviously, since the lens molds are used only once they must be cheap both with respect to the material the lens molds are made of as well as with respect to the process of their manufacture. Nevertheless, they must be capable of producing contact lenses of top quality. Single-use lens molds are plastic lens molds which are typically made of polyolefines, in particular polypropylene, and they can be reliably and cost-effectively produced using injection-molding machines. In injection-molding machines, a flowable hot thermoplastic material is injected at high pressure into casting dies through so-called hot runners (i.e. channels or pipes through which the flowable hot thermoplastic material is injected). The casting dies are shaped such that after curing of the hot thermoplastic material in the casting dies by cooling down, the plastic lens molds having the desired geometry (defined by the casting dies) are formed. Typically, an injection-molding machine comprises two tool halves which are movable towards and away from each other. When the two tool halves are moved towards each other until they are in a closed position, the casting dies are formed between the two tool halves and the flowable hot thermoplastic material is injected into the casting dies at high pressure. After the flowable hot thermoplastic material has cooled down to form the plastic lens molds, the two tool halves are moved away from each other to an open position that allows for the removal of the plastic lens molds once they have been formed. Thousands of such single use plastic lens molds are produced in injection-molding machines or apparatuses which are arranged separate from the contact lens production lines. Typically, large numbers of plastic lens molds having different geometries are produced and stored until they are needed to produce contact lenses having the respective geometries whereupon the respective plastic lens molds needed are supplied to the production lines. Known production lines using plastic lens molds are capable of producing only one lot (a first lot) of contact lenses at a time, that is to say the contact lenses produced at a time all have the same properties. This means that the plastic lens molds supplied to the production line to produce this one lot of contact lenses all have the same specifications (e.g. geometry, lens-forming material, etc.). These plastic lens molds are actually supplied to the production line some time before starting production of thi