Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates to equipment used to manufacture ophthalmic devices, and, in particular, to equipment used to manufacture contact lenses.
2. Description of Related Art
Soft hydrogel contact lenses have increased in popularity since they were first introduced in the 1970s. Such contact lenses are conventionally formed through a process in which the material used to make the lenses is placed between two halves of a casting mold, and the entire assembly is then cured to form the desired contact lens shape. After the curing process, the lens is removed from the casting mold and is immersed in a series of fluids to remove impurities therefrom. While still immersed in fluid, the lens is taken to an examination station where it is inspected for foreign particles, holes, and/or deformations caused by the manufacturing process.
Existing systems for the inspection of contact lenses typically include a lens transportation device, a camera, a viewing monitor, and a computer. The computer is configured to run lens examination software which controls the camera during a lens inspection process. In examining the lens, the camera and, in particular, the software, can inspect the lens surfaces for the foreign particles, holes, and deformities discussed above, and the software can control the inspection system to reject a lens if such deformities are found thereon.
Although existing inspection systems have some utility in a contact lens production environment, reliance on such systems can result in a large number of false lens rejections during production. For example, the camera and, in particular, the camera software can not be capable of distinguishing a hole, a foreign particle, or other lens deformities from gas bubbles that have adhered to the surface of the lens. Bubbles can be formed by, for example, turbulent working fluid 42 flow within the various systems used for impurity removal. In such systems, air and other gases can become entrained within the working fluid 42 and high fluid pressures can not allow the entrained air to expand and escape from the working fluid 42. Depending on the type of contact lens being examined and the throughput of the manufacturing line, false lens rejections caused by existing camera inspection systems can dramatically increase production costs and can severely hinder manufacturing efficiency.
Accordingly, the disclosed systems and methods are directed towards overcoming one or more of the problems set forth above.
In an exemplary embodiment of the present disclosure, an ophthalmic device forming system includes an inspection station configured to receive a plurality of ophthalmic devices, a fluid supply fluidly connected to the inspection station, the fluid supply containing a working fluid 42, and a degassing assembly fluidly connected between the fluid supply and the inspection station. The degassing assembly includes a housing, a vacuum device, and a membrane. The vacuum device is fluidly connected to the housing adjacent to the membrane.
In another exemplary embodiment of the present disclosure, a method of degassing a working fluid 42 includes directing a flow of pressurized working fluid 42 across a membrane disposed within the housing, releasing entrained gas from the pressurized working fluid 42, and collecting the released gas in a low-pressure gas region adjacent to the membrane. The method also includes removing the released gas from the low pressure gas region and directing the flow to an ophthalmic device inspection station.
In still another exemplary embodiment of the present disclosure, a method of degassing a working fluid 42 includes directing a flow of pressurized working fluid 42 across a membrane of a degassing assembly, forming a low pressure gas region adjacent to the membrane, and removing released gas from the low pressure gas region with a vacuum device. The method also includes directing the flow to an ophthalmic device inspection station.
In forming an ophthalmic device such as, for example, a contact lens, casting molds can be dosed with a monomer, a polymer, and/or other lens forming materials. The entire casting mold assembly can then be placed into a curing apparatus where the ophthalmic device can be formed and/or otherwise cured. Once the lens is formed, a posterior portion of the casting mold can be removed and discarded, and the formed lens can be substantially adhered to the remaining or anterior portion of the casting mold. The lens and the anterior portion of the casting mold can then be placed in, for example, a solvent reduction oven where the lens and the anterior portion of the casting mold are immersed in a solvent to assist in separation. A plunger mechanism can then be used to apply a pressure to a portion of the anterior portion of the casting mold and a vacuum device can be used to remove the separate lens. The anterior portion of the casting mold can then be discarded and the formed lens can be transported to an edge forming apparatus wherein at least a portion of the substantially circular edges of the lens are rounded. The lens can then be coated with a plasma and/or other lens coating materials, and the coated lens can be transported to one or more machines configured to assist in removing impurities and inspecting the condition of the lens.
In an exemplary embodiment, a coated lens can first be transported to the water bath 12 via the transport device 18. The transport device 18 can be any apparatus and/or collection of machines or devices useful in transporting items having optical quality surfaces from one machine to another machine in an assembly and/or manufacturing environment. The transport device 18 can include one or more gripping devices such as, for example, fingers, hooks, graspers, and/or any other gripping devices known in the art. Such gripping devices (not shown) can be configured to delicately grasp a fragile item such as, for example, a partially formed ophthalmic device and safely transport the fragile item from machine to machine without causing damage thereto. In an exemplary embodiment, the transport device 18 can also include one or more vacuum devices (not shown). The vacuum devices can be configured to handle and/or otherwise grasp the ophthalmic devices while not causing any damage to the one or more optical quality surfaces of the ophthalmic devices during transport. In an additional exemplary embodiment of the present disclosure, the ophthalmic devices formed and/or inspected by the system 10 can be housed in one or more carrying trays, and the carrying trays can be transported from, for example, the water bath 12 to the cleanser 14 and then to the inspection station 16 by the transport device 18. In such an exemplary embodiment, the transport device 18 can be configured to transport the carrying trays between the components of the system 10 without causing any damage to, for example, the carrying trays and/or the ophthalmic devices carried thereby. Alternatively, as discussed above, the transport device 18 can also be configured to transport ophthalmic devices individually between the components of the system 10. In such an alternative exemplary embodiment, the carrying trays can be omitted.
The water bath 12 can be any device known in the art configured to assist in fluidly removing debris, contaminants, and/or other foreign materials from an ophthalmic device such as, for example, a contact lens. Such foreign materials may be adhered to and/or otherwise carried with the ophthalmic device in an ophthalmic device forming process, and the foreign materials can be, for example, dirt, dust, and/or pieces of polymer or monomer material left over from upstream ophthalmic device forming and/or curing processes. The water bath 12 can also be configured to remove, for example, isopropyl alcohol or other cleansing agents supplied to the ophthalmic devices by components of the system 10 disposed upstream of the water bath 12. The water bath 12 can be configured to receive ophthalmic devices and/or other devices or carrying trays transported by the transport device 18. The water bath 12 can include a housing and/or other components configured to receive and retain working fluid 42 such as, for example, water, saline solution and/or other cleansing agents. The housing of the water bath 12 can be made from any metal and/or alloy know in the art such as, for example, FDA approved 316 stainless steel.
The water bath 12 can be fluidly connected to a fluid supply 52 configured to store the working fluid 42 discussed above and/or direct a pressurized flow of the working fluid 42 to the water bath 12. The water bath 12 can also include one or more pressurization devices (not shown) configured to direct the working fluid 42 supplied from the fluid supply 52 towards the ophthalmic devices delivered by the transportation device 18. In an exemplary embodiment, the pressurization devices can include one or more nozzles or other like structures.
The fluid supply 52 can be any drum, container, sump, or other fluid storage device known in the art configured to house and/or otherwise store a large volume of working fluid 42. In an exemplary embodiment, fluid supply 52 can be a fluid supply of the manufacturing facility in which the system 10 is operating. In such an exemplary embodiment, the fluid supply 52 can be a water tower or other like fluid storage device. As shown in
A pump 50 can be fluidly connected between the fluid supply 52 and the water bath 12. The pump 50 can be configured to draw working fluid 42 from the fluid supply 12 and supply a pressurized flow of the working fluid 42 to the water bath 12 via the supply lines 34. The pump 50 can be any fluid pressurization device known in the art such as, for example, a positive displacement pump or a rotodynamic pump. The pump 50 can also include a power source such as, for example, an electric motor configured to supply rotary power to, for example, an input shaft of the pump 50.
As illustrated in
The housing 28 of the degassing assembly 26 can be any substantially rigid housing configured to supply a flow of pressurized fluid between two components in a manufacturing environment. In an exemplary embodiment, the housing 28 can be a pipe, hose, or other known structure configured to transmit a pressurized flow of working fluid 42 and, in such an exemplary embodiment, the housing 28 can be mechanically similar to the supply lines 34. The housing 28 can be any shape, size, and/or other configuration known in the art. For example, the housing 28 can be substantially cylindrical and can have a diameter similar to the diameter of the supply lines 34 connected thereto. In addition, the housing 28 can have any desirable length known in the art and it is understood that extending a length of the housing 28 can assist in forming a laminar flow of working fluid 42 within the housing 28. Forming such a laminar flow may assist in substantially removing gases entrained within a pressurized flow of working fluid 42.
The membrane 32 of the degassing assembly 26 can be any semi-permeable membrane known in the art configured to allow a flow of pressurized working fluid 42 to travel therethrough, and the membrane 32 can be configured to assist in removing gases entrained within the working fluid 42. The membrane 32 and the housing 28 can be made from any metal and/or alloy known in the art and, in an exemplary embodiment, the membrane 32 and the housing 28 can be made from the same materials discussed above with respect to the supply lines 34. In an exemplary embodiment, the membrane 32 and the housing 28 can both be made from the same material and, in such an exemplary embodiment, the membrane 32 and the housing 28 can be made from FDA approved 3/16 stainless steel. The membrane 32 can be rigidly connected to the housing 28 by any means known in the art such as, for example, weldments, bolts, brackets, soldering, and/or other devices.
The membrane 32 can have any configuration known in the art to assist in removing entrained gases from a pressurized flow of working fluids 42. For example, the membrane 32 can be substantially disc-shaped or substantially bowl-shaped. In an exemplary embodiment, the membrane 32 can be a wire and/or metal mesh. In such an exemplary embodiment, the mesh can be comprised of one or more wires woven together to form a semi-permeable structure. The wires of the mesh can be configured in any way known in the art and can form a plurality of orifices 40 configured to allow working fluid 42 to pass therethrough. The orifices 40 can be configured to assist in removing gases entrained within the pressurized flow of working fluid 42 and the orifices 40 can be any shape, size, and/or other configuration known in the art. For example, the orifices 40 can be square, round, rectangular, diamond shaped, triangular, and/or any other shape known in the art. The orifices 40 can also be desirably sized so as to allow the flow of pressurized working fluid 42 to pass through the membrane 32 without causing an undesirable pressure drop across the membrane 32. In an exemplary embodiment, each orifice 40 can have a diameter between approximately 0.02 microns and approximately 0.05 microns. At such diameters, entrained gases can be removed from the flow of working fluid 42, without removing substantially any of the working fluid 42 from the system 10, by applying a negative pressure to the orifices 40.
In an alternative embodiment, the membrane 32 can be a single piece of material that has been machined and/or otherwise formed to define the orifices 40. In such an exemplary embodiment, the orifices 40 can be formed by any known process such as, for example, drilling, laser etching, or chemical etching. The orifices 40 formed by such processes can have any of the shapes, sizes, and/or other configurations discussed above with respect to the orifices 40 of the mesh-type membrane 32. In addition, it is understood that, regardless of the configuration of the membrane 32, the orifices 40 can be desirably arranged on a surface of the membrane 32 to assist in removing entrained gases from the flow of working fluid 42 without removing the working fluid 42 from the system 10. To accomplish this, the orifices 40 can be positioned on a surface of the membrane 32 substantially in line with the flow of working fluid 42 passing therethrough. In an exemplary embodiment, the orifices 40 can be disposed substantially uniformly about a surface of the membrane 32 and, in an alternative exemplary embodiment, the orifices 40 can be concentrated in a desired region of the membrane 32. In such an exemplary embodiment, the orifices 40 can be concentrated in a center portion of the membrane 32 and/or about a rim portion of the membrane 32.
It is understood that the embodiments of the housing 28 and membrane 32 discussed above are exemplary in nature and that the housing and membrane 32 can have additional configurations not disclosed by the figures included herein. For example, in an additional embodiment of the present disclosure, the membrane 32 can be substantially conical or substantially cylindrical.
As shown in
The vacuum device 30 can be, for example, a vacuum, a pump, and/or any other mechanical or electro-mechanical device configured to deliver a negative pressure within a substantially fluidly sealed environment. In an exemplary embodiment, the vacuum device 30 can be a vacuum having a capacity of, approximately 0 psia to approximately 10.0 psia. In an exemplary embodiment, the vacuum device 30 can be a vacuum line and/or other negative pressure device of the manufacturing or production facility in which the system 10 (
As shown in
Referring again to
As discussed above with respect to the water bath 12, the cleanser 14 can be fluidly connected to a fluid supply 54. The fluid supply 54 can be, for example, a tank, container and/or any other device configured to store and/or retain a supply of fluid such as, for example, water or other working fluids 42. As shown in
As shown in
The inspection station 16 can be disposed adjacent to the cleanser 14 and cleaned ophthalmic devices and/or other ophthalmic device handling components can be transported from the cleanser 14 to the inspection station 16 by the transport device 18. The inspection station 16 can be any conventional inspection station or apparatus known in the art. The inspection station 16 can include, for example, a housing similar to the housings described above with respect to the water bath 12 and the cleanser 14. The inspection station 16 can be configured to receive a pressurized flow of working fluid 42 from the fluid supply 54. As shown in
The inspection station 16 can include at least one sensor 17. The sensor 17 can be any diagnostic device such as, for example, a thermocouple, a camera, and/or a pressure sensor. In an exemplary embodiment, the sensor 17 can be a high resolution camera and/or other video, photographic, or image sensing device configured to sense and/or otherwise analyze a surface of an ophthalmic device delivered in proximity thereto. The inspection station 16 can be configured to direct and/or otherwise immerse ophthalmic devices delivered thereto via the transport device 18 in a flow of working fluid 42 supplied by the fluid supply 54. Accordingly, the sensor 17 can be configured to obtain images of the ophthalmic devices in a substantially aqueous environment. In an embodiment in which the sensor 17 comprises a camera, the camera can have between approximately 1 M Pixel and 10 M Pixel. In such an exemplary embodiment, the sensor 17 can be, for example, a 4 M Pixel camera.
It is understood that the transport device 18 can enable the ophthalmic devices transported thereby to be movable relative to the inspection station 16. It is further understood that the sensor 17 can be configured and/or otherwise mounted within the inspection station 16 to be controllably movable relative to the transport device 18 and/or the ophthalmic devices transported thereby. The sensor 17 can be mounted to tracks, motors, belts, robot arms, and/or other devices (not shown) configured to enable relative movement between the sensor 17 and ophthalmic devices delivered to the inspection station 16.
The sensor 17 can be electrically connected to a controller 62 of the system 10. The controller 62 can be any type of controller known in the art configured to assist in manipulating and/or otherwise controlling a group of electrical and/or electromechanical devices. For example, the controller 62 can include an ECU, a computer, and/or any other electrical control device known in the art. The controller 78 can include one or more operator interfaces 64 such as, for example, a monitor, a keyboard, a mouse, a touch screen, and/or any other devices useful in entering, reading, storing, and/or extracting data from the devices to which the controller 62 is connected. The controller 62 can be configured to exercise one or more control algorithms and/or control the devices to which it is connected based on one or more preset programs. For example, the controller 62 can be configured to control the sensor 17 to obtain images of ophthalmic devices delivered to the inspection station 16 via the transport device 18. The controller 62 can also be configured to operate and/or otherwise execute image software loaded thereon and configured to inspect the images obtained by the sensor for defects in the ophthalmic devices. The controller 62 can also be configured to store and/or collect images and/or other data regarding the ophthalmic devices that are observed. Such data can assist a user in determining the quality and/or usability of the observed ophthalmic device.
The controller 62 can be connected to, for example, the sensor 17 via one or more connection lines 63. The controller 62 can also be connected to, for example, the vacuum devices 30 of the degassing assemblies 26. The pumps 50, the motors (not shown) connected to pumps 50, and/or other devices of the system 10 can also be electrically connected to the controller 62 via connection lines 63 (not shown). The connection lines 63 can consist of any conventional electrical connection means known in the art such as, for example, wires or other like connection structures, as well as wireless communication means. Through these electrical connections, the controller 62 can be configured to receive, for example, sensed image data from the sensor 17. In particular, the controller 62 can be configured to receive images of the optical quality surfaces of the ophthalmic devices delivered to the inspection station 16 by the transport device 18. Based on the sensed images, the controller 62 can be configured to control the system 10 to accept the inspected ophthalmic for commercial sale or reject the ophthalmic devices based on one or more detected impurities or lens deformations. The transport device 18 can be configured to direct accepted ophthalmic devices from the inspection station 16 to one or more packaging components of the system 10 configured to package the accepted ophthalmic devices for commercial sale. The inspection station 16 can also be configured to direct the rejected ophthalmic devices to a bin 24 via a transport device 22. The transport device 22 can be substantially similar in configuration to the transport device 18 and the bin 24 can be, for example, a reject bin of the system 10. Ophthalmic devices directed to the bin 24 can be melted down and/or otherwise recycled for use in future ophthalmic device forming processes. Alternatively, the ophthalmic devices directed to bin 24 can be discarded.
The ophthalmic device forming system 10 of the present disclosure can be used with a series of other machines for the inspection and/or formation of ophthalmic devices such as, for example, contact lenses. The system 10 can be configured for use with and/or otherwise included in, for example, an assembly line used to manufacture contact lenses and, in an exemplary embodiment, the system 10 can be used to inspect one or more ophthalmic devices prior to packaging for commercial sale. In particular, one or more degassing assemblies 26 of the present disclosure can be utilized to remove and/or substantially release gases entrained within pressurized flows of working fluid 42 used in the ophthalmic device inspection process. Degassing the working fluids 42 utilized by the system 10 can increase the accuracy with which defects are detected by components of the system 10 such as, for example, the sensor 17. Improving the reliability and/or accuracy with which ophthalmic device defects are detected by the sensor 17 and, in particular, reducing the number of false rejects detected by the sensor 17 can be accomplished by degassing, for example, the working fluid 42 supplied by the fluid supply 52 and/or the working fluid 42 supplied by the fluid supply 54.
It is understood that, due to the turbulent flow of the working fluid 42, gases such as, for example, air can become entrained within the working fluid 42 delivered to, for example, the water bath 12, the cleanser 14, and/or the inspection station 16. Once entrained within the working fluid 42 these gases form the bubbles 44 illustrated in
In an exemplary ophthalmic device forming process of the present disclosure, the transport device 18 can deliver one or more ophthalmic devices to the water bath 12. Upon receiving the ophthalmic devices, the pump 50 can be activated to supply a pressurized flow of working fluid 42 from the fluid supply 52, through supply line 34, to the water bath 12. The working fluid 42 can be, for example, water (de-ionized) or another lens cleaning agent. The water bath 12 can substantially immerse and/or otherwise wash the ophthalmic devices therein with the pressurized flow of working fluid 42 such that substantially all impurities and/or other foreign objects are removed from the optical quality surfaces of the ophthalmic devices. In addition, the water bath 12 can assist in removing isopropyl alcohol carried by the ophthalmic devices. It is understood that, in an exemplary embodiment, isopropyl alcohol may be deposited on the ophthalmic devices by system components disposed upstream of the water bath 12. A portion of the working fluid 42 supplied to the water bath 12 can return to the fluid supply 52 via the return line 58.
In an exemplary embodiment, a degassing assembly 26 can be used to substantially remove gases entrained within the pressurized flow of working fluid 42 supplied to the water bath 12. In particular, the membrane 32 of the degassing assembly 26 can substantially eliminate bubbles 44 formed within the pressurized flow of working fluid 42 as the working fluid 42 passes therethrough. By eliminating the bubbles 44, the membrane 32 can release entrained gases from the working fluid 42 and the released gases can collect within the low pressure gas region A of the housing 28. The vacuum device 30 can be activated to assist in removing at least a portion of the released gases collected within the low pressure gas region A. The vacuum device 30 can also be activated to assist in drawing the working fluid 42 across the membrane 32 and/or releasing the entrained gases from the working fluid 42. In such an exemplary embodiment, the pressurized flow of working fluid 42 supplied to the water bath 12 can be substantially bubble free and, in particular, substantially no bubbles may be allowed to adhere to the surfaces of the ophthalmic devices acted on and/or otherwise cleaned by the water bath 12.
As illustrated by arrow 20 in
In an exemplary embodiment, a degassing assembly 26 can assist in releasing gases entrained within a pressurized flow of working fluid 42 directed to the cleanser 14. As discussed above with respect to the degassing assembly 26 disposed upstream of the water bath 12, a portion of the housing 28 of the degassing assembly 26 disposed upstream of the cleanser 14 can collect gases released from the pressurized flow of working fluid 42 in, for example, the low pressure gas region A. The vacuum device 30 connected thereto can be activated to assist in removing at least a portion of the released gases collected within the low pressure gas region A. The vacuum device 30 can also be activated to assist in drawing the working fluid 42 across the membrane 32 and/or releasing the entrained gases from the working fluid 42. Once the pressurized flow of working fluid 42 has been supplied to the cleanser 14, a portion of the working fluid 42 can be returned to the fluid supply 54 via the return line 58.
After the ophthalmic devices have been acted upon by the cleanser 14, the ophthalmic devices can then be transferred to the inspection station 16 by the transport device 18. The ophthalmic devices can again be immersed in working fluid 42 within the inspection station 16 so as not to dehydrate the ophthalmic devices during inspection. As discussed above with respect to the water bath 12 and the cleanser 14, the flow of working fluid 42 directed to the inspection station 16 can be pressurized and, in an exemplary embodiment, a degassing assembly 26 can be used to release gases entrained within the pressurized flow of working fluid 42 delivered from the fluid supply 54. In an exemplary embodiment, due to the degassing assembly 26, substantially no bubbles 44 can be entrained within the working fluid 42. In such an exemplary embodiment, substantially no bubbles 44 can adhere to the surfaces of the ophthalmic devices being examined in the inspection station 16.
Once immersed in bubble-free working fluid 42 within the inspection station 16, the sensor 17 can obtain one or more images of the ophthalmic devices being examined and can transmit the obtained images to the controller 62 whereby the controller 62 may, through the use of preloaded examination software, determine the status, health, and/or quality of the ophthalmic device being examined. In particular, the software being executed by the controller 62 can determine whether or not the examined ophthalmic device contains any defects. Based on this defect determination, the controller 62 can make the determination whether or not to allow the ophthalmic device to be passed on from the inspection station 16 for packaging and commercial sale or whether to reject the examined ophthalmic device and pass the rejected device to the bin 24 via the transport device 22.
Other embodiments of the disclosed system 10 will be apparent to those skilled in the art from consideration of this specification. It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being indicated by the following claims.
This application claims benefit of Provisional Patent Application No. 61/01 2,568 filed Dec. 10, 2007 which is incorporated by reference herein.
Number | Date | Country | |
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61012568 | Dec 2007 | US |