Patent Description:
Blue light at a wavelength range of <NUM>-<NUM>, more specifically <NUM>-<NUM> and especially <NUM>-<NUM> is harmful to human eyes and has been described as playing a role in certain ocular diseases such as age-related macular degeneration (AMD).

To implement a blue-cut in an ophthalmic lens, blue blocking filters can be incorporated into the bulk of the lens substrate. However, due to the varying center-to-edge thickness of the resulting lenses of plus or minus diopter powers and the intrinsic color of the filters, the lenses can include a center-to-edge color difference, and inconsistency of the blue-cut level. <CIT> describes blue-cut lenses of the prior art.

According to the invention, a blue-cut wafer includes one or more of blue blocking dyes blended with a thermoplastic resin injection molded into the blue-cut wafer or a thermoplastic blue-cut film thermoformed into a blue-cut wafer. The blue-cut wafer is coupled to a lens, such that the blue-cut wafer is configured to reduce by absorption at least a portion of light having a first wavelength range from <NUM> nanometers to <NUM> nanometers, preferably from <NUM> nanometers to <NUM> nanometers, and preferably permits light having a second wavelength range, the second wavelength range including wavelengths greater than <NUM> nanometers. According to the invention, the blue-cut wafer is configured to reduce by absorption at least a portion of light having a first wavelength range from <NUM> nanometers to <NUM> nanometers, and homogenize a color appearance and a blue-cut performance level of the blue-cut wafer, wherein the blue-cut wafer has center thickness and edge thickness, the center-to-edge thickness variation of the bluecut wafer being within twenty percent, in such a manner as ΔE ≤ <NUM>, where ΔE is the color difference between the wafer center and the wafer edge calculated using the CIE76 color-difference formula.

The description set forth below in connection with the appended drawings is intended as a description of various embodiments of the disclosed subject matter and is not necessarily intended to represent the only embodiment(s). In certain instances, the description includes specific details for the purpose of providing an understanding of the disclosed subject matter. However, it will be apparent to those skilled in the art that embodiments may be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form in order to avoid obscuring the concepts of the disclosed subject matter.

Reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, characteristic, operation, or function described in connection with an embodiment is included in at least one embodiment of the disclosed subject matter. Thus, any appearance of the phrases "in one embodiment" or "in an embodiment" in the specification is not necessarily referring to the same embodiment. Further, the particular features, structures, characteristics, operations, or functions may be combined in any suitable manner in one or more embodiments. Further, it is intended that embodiments of the disclosed subject matter can and do cover modifications and variations of the described embodiments.

That is, unless clearly specified otherwise, as used herein the words "a" and "an" and the like carry the meaning of "one or more. " Additionally, it is to be understood that terms such as "left," "right," "top," "bottom," "front," "rear," "side," "height," "length," "width," "upper," "lower," "interior," "exterior," "inner," "outer," and the like that may be used herein, merely describe points of reference and do not necessarily limit embodiments of the disclosed subject matter to any particular orientation or configuration. Furthermore, terms such as "first," "second," "third," etc., merely identify one of a number of portions, components, points of reference, operations and/or functions as described herein, and likewise do not necessarily limit embodiments of the disclosed subject matter to any particular configuration or orientation.

<FIG> depicts a side view of a blue-cut lens <NUM>. The blue-cut lens <NUM> can include a blue-cut wafer <NUM> and a lens <NUM>. A wafer can be a thin, round, and curved article that can be integrated onto a front surface of the lens <NUM> to introduce specific functions including blue-cut, photochromic, polarizing, and the like. More specifically, the blue-cut wafer <NUM> can include clear thermoplastics, the thermoplastics including dyes, pigments, or other absorbers that absorb blue light of a predetermined wavelength range. For example, the blue-cut wafer <NUM> cuts (e.g. absorb, reflect, etc.) blue light in the range of <NUM> nanometers to <NUM> nanometers, and preferably in the range of <NUM> nanometers to <NUM> nanometers. The blue-cut wafer <NUM> can have a maximum thickness and minimum thickness within twenty percent of a nominal thickness. Although the blue-cut wafer <NUM> can have non-uniform thickness to integrate with the lens <NUM>, when the thickness variation of the blue-cut wafer <NUM> is less than a predetermined amount (e.g., <NUM>%), the blue-cut wafer <NUM> can have a homogeneous color appearance and blue-cut performance level. The blue-cut performance level can be the success rate at which the blue-cut wafer <NUM> prevents at least a portion of the predetermined wavelength range of blue-light from passing through the blue-cut wafer <NUM>.

The lens <NUM> is an ophthalmic lens comprising a lens having a diopter power, such as a plus lens or a minus lens of various diopter powers, for example.

<FIG> depicts a side view of the blue-cut wafer <NUM>. The blue-cut wafer <NUM> includes an edge thickness <NUM>, a center thickness <NUM>, a front radius <NUM>, and a back radius <NUM>.

The center-to-edge thickness variation being within <NUM>%, as determined by measurements of the edge thickness <NUM> and the center thickness <NUM>, results in a homogeneous color appearance and blue-cut performance level. Because the blue-cut wafer <NUM> is responsible for cutting the blue-light rather than the lens <NUM>, the lens <NUM> can be various diopter powers without issue because the effect of light path differences become negligible.

A selection of edge thickness <NUM> and center thickness <NUM> can be based on how much tolerance of a wafer thickness can be controlled during wafer manufacturing (e.g., injection molding, film extrusion, etc.). The tolerance can be based on a processing control, timing, and/or cost, for example.

The front radius <NUM> represents the top of the wafer. The back radius <NUM> represents the bottom on the wafer. For wafers by injection molding, the front radius <NUM> and back radius <NUM> are used to arrive at the thickness values for the wafer. For wafers of extruded or solvent casted films, the front radius <NUM> and back radius <NUM> are substantially equal. The thickness of a wafer including any variations is thus determined by the film fabrication process.

The blue-cut wafer <NUM> can be made of a clear thermoplastic substrate, such as polycarbonate (PC), polymethyl methacrylate (PMMA), cellulose triacetate (TAC), and the like. The blue-cut wafer <NUM> can be manufactured from a thermoplastic blue-cut film prepared via a film extrusion process or solvent casting. Alternatively, the blue-cut wafer <NUM> can be manufactured from a thermoplastic blue-cut resin injection molded into blue-cut wafers <NUM>. In another aspect, the lens <NUM> can be made by machining (e.g. shaving portions of the lens to reduce the size of the lens) a thicker lens to reduce the size of the lens to a lens with a predetermined thickness. The thickness of the lens <NUM> can be based on the functionality required of the lens (e.g., improving eyesight) as would be known by one of ordinary skill in the art.

The blue-cut wafer <NUM> can be color balanced, and the color balancing can include calculating L, a*, and b* after mixing the color balancing dyes with blue blocking filters. The L, a*, and b* values can correspond to the Lab color space as would be known by one of ordinary skill in the art. The concentration of the dyes can be adjusted until a predetermined color balanced target is reached. For example, <NUM> ppm of ABS420 can be used as a predetermined concentration as further described herein.

<FIG> is an exemplary work flow for producing the blue-cut lens <NUM> according to one or more aspects of the disclosed subject matter.

The blue-cut lens <NUM> is able to absorb at least a portion of a predetermined wavelength range corresponding to blue light, such that the absorbed blue light is prevented from passing through the blue-cut lens <NUM>.

To produce the blue-cut lens <NUM>, a nominal thickness of the blue-cut wafer can be selected in S302. The nominal thickness can be used as the thickness measurement to which the thickness variation can be compared.

In S330, various measurements corresponding to the thickness of the blue-cut wafer <NUM> can be calculated using processing circuitry, for example (see <FIG>). The thickness calculations include a thickness variation range <NUM>, a minimum edge thickness <NUM>, and a maximum edge thickness <NUM>. The thickness variation range can be within <NUM>% of a nominal thickness of the blue-cut wafer <NUM> to homogenize color appearance and the blue-cut performance level of the blue-cut wafer <NUM>. Additionally, the thickness variation range <NUM> can include measurements of the center thickness <NUM> to assist in determining/calculating the thickness variation range <NUM>.

In S305, the blue cut wafer <NUM> can be prepared. The blue-cut wafer <NUM> can be manufactured from a blue-cut film <NUM> or via injection molding <NUM>. The blue-cut film <NUM> can be manufactured via film extrusion <NUM> or via solvent casting <NUM> as further described herein. The blue-cut wafer <NUM> can be prepared having a center thickness <NUM> at the nominal thickness and the edge thickness being within the maximum edge thickness <NUM> and the minimum edge thickness <NUM>, wherein according to the invention the maximum edge thickness <NUM> and minimum edge thickness <NUM> are based on being within the twenty percent thickness variation.

In S350, the blue-cut wafer <NUM> can be integrated onto the lens <NUM>. Various techniques for integrating the blue-cut wafer <NUM> onto the lens <NUM> can include front side lamination (FSL) <NUM>, direct injection <NUM>, in-mold lamination IML <NUM>, and bi-injection <NUM>. Additionally, IML <NUM> can include a first technique of coating the blue-cut wafer <NUM> with adhesive and inserting the blue-cut wafer <NUM> into the mold. In another aspect, the IML <NUM> can include using liquid glue for bonding the blue-cut wafer <NUM> to the lens <NUM>. Once the blue-cut wafer <NUM> is secured to the lens <NUM>, the blue-cut lens <NUM> can include blue-cut functionality with a homogenous color appearance and blue-cut performance level.

For example, the values listed below in Table <NUM>, Table <NUM>, and Table <NUM>, Table <NUM> can correspond to the results of an exemplary blue-cut lens, such as the blue-cut lens <NUM>, that includes a blue-cut wafer <NUM> having a nominal thickness of <NUM> millimeters produced via injection molding (e.g., injection molding <NUM>) of a mixture of three parts per million of ABS420 in Sabic Lexan polycarbonate (PC). The resulting wafer can have thickness values ranging from <NUM> millimeters to <NUM> millimeters across the whole wafer, and show a uniform color appearance and blue-cut performance level. However, the values could range from <NUM> millimeters to <NUM> millimeters to maintain a thickness variation within <NUM>% of the nominal thickness. Additionally, the thickness variation can be within <NUM>% of the nominal thickness while still maintaining ΔE = <NUM>, where ΔE is a measure of color difference.

Table <NUM> and Table <NUM> describe the results based on the formulation of ABS420 with color balancing in a PC wafer, which can be based on determining/calculating the maximum edge thickness and the minimum edge thickness as further described herein.

<FIG> can include the same steps as <FIG>. However, preparing the blue-cut wafer in S305 can be the first step in the work flow. Additionally, S348 can follow S330 and occur before S350. In S348, the blue-cut wafer <NUM> can be selected based on the various wafer thickness calculations in S330.

Steps S302, S305, S330, and S350 of <FIG> are represented in the description for <FIG> (except where explicitly indicated as different).

<FIG> is a work flow for manufacturing a blue-cut wafer from a film.

In S405, a blue-cut film can be manufactured. The blue-cut film can be manufactured via a film extrusion system or via solvent-casting. For film extrusion, blue blocking filters and a thermoplastic resin in the form of pellets or powder are extruded together through a die onto a chill-roller to produce a blue-cut film. The ratio of resin to blue blocking filters can be based on the types of blue blocking filters and the desired blue cut performance. The combination of the thermoplastic resin and blue-blocking filters can be converted into a film by the film extrusion system as would be known by one of ordinary skill in the art. For solvent-casting, blue blocking filters and a thermoplastic resin are first dissolved in a solvent to form film dope. The film dope can then be casted onto a carrier film. After a drying step for the solvent to evaporate, the thermoplastic blue-cut film is formed. The solvent-casting process can be suitable for blue blocking filters that are thermally sensitive because less heating is involved in the solvent-casting process. Similarly to film extrusion, the ratio of resin to blue blocking filters can be based on the types of blue blocking filters and the desired blue cut performance.

The blue-cut film can include various thermoplastics including one or more of polyacrylics, polyols, polyamines, polyamides, polyanhydrides, polycarboxilic acids, polyepoxides, polyisocyanates, polynorbornenes, polysiloxanes, polysilazanes, polystyrenes, polyolefinics, polyesters, polyimides, polyurethanes, polythiourethanes, polycarbonates, polyallylics, polysulfides, polyvinyl esters, polyvinylethers, polyarylenes, polyoxides, polysulfones, poly cyclo olefins, polyacrylonitriles, polyethylene terephtalates, polyetherimides, polypentenes, and cellulose triacetate.

In S410, multi-layer blue-cut laminates can be made by laminating the blue-cut film. The optional lamination step can be used to construct a multi-layer laminate from the blue-cut film. The one or more additional layers can be used to protect the blue-cut film from exposure to extensive heat or solvent, to provide compatibility to other thermoplastics for fuse-bonding, add additional functions including polarizing, NIR-cut, etc., and the like.

In S415, the blue-cut film can be cut to a predetermined size. The predetermined size can be based on various sizes of lenses <NUM> to which the blue-cut film will be attached, for example.

In S420, the blue-cut film can be thermoformed to create the blue-cut wafer <NUM>. The thermoforming process can be used to create a curved wafer, such that the curve can match the curve of the various lenses <NUM> to which the blue-cut wafer <NUM> will be attached.

In S425, an adhesive can optionally be applied to laminate the blue-cut wafer <NUM> onto a lens <NUM>.

<FIG> is a work flow for manufacturing a blue-cut wafer <NUM> via injection-molding.

In S505, an injection molded blue-cut wafer <NUM> can be manufactured. Blue blocking filters can be blended with a thermoplastic resin and then injection-molded to create the blue-cut wafer <NUM>. Further specifics of injection-molded thin wafers can be found in <CIT>.

In S510, an adhesive can optionally be applied to laminate the blue-cut wafer <NUM> onto the lens <NUM>.

<FIG> is a work flow for manufacturing a blue-cut lens <NUM>.

In S605, the blue-cut wafer <NUM> can be manufactured as described in one of <FIG> or <FIG>.

In S610, a thickness variation range of the blue-cut wafer <NUM> can be calculated. ΔE ≤ <NUM>, where ΔE is the color difference calculated using the CIE76 formula as would be known by one of ordinary skill in the art, can be used as criteria to determine the wafer thickness variation range based on ΔE = <NUM> being the smallest color difference a human eye can detect. In other words, the thickness variation range should result in a homogenous color appearance of the bluecut wafer <NUM> because any difference in color is too small to be detected by the human eye. If the thickness variation range were greater than a predetermined variation, the color of the bluecut wafer <NUM> would be heterogeneous (i.e., at least one noticeable color difference).

In S615, a maximum edge thickness of the blue-cut wafer <NUM> can be calculated. The maximum edge thickness can have a ΔE of <NUM> compared to the wafer center thickness <NUM>. To determine the maximum edge thickness, the light absorption from transmission at each wavelength can be calculated. The wafer thickness can then be increased by <NUM> millimeters and the light absorptions can be calculated. A color spectrum at the current thickness of the wafer can be determined. The color spectrum can then be converted to Lab color space. ΔE can then be calculated between the original thickness and the current thickness. If ΔE < <NUM>, then the wafer thickness can be increased by <NUM> millimeters until ΔE = <NUM>. When ΔE = <NUM>, the maximum edge thickness of the wafer can be determined.

In S620, the minimum edge thickness can be calculated. The minimum edge thickness can have a ΔE of <NUM> compared to the wafer center thickness <NUM>. The minimum edge thickness can be calculated similarly to the maximum edge thickness as described in S615. However, rather than increasing the thickness by <NUM> millimeters until ΔE = <NUM>, the thickness can be decreased by <NUM> millimeters until ΔE = <NUM> to determine the minimum edge thickness.

In S625, the blue-cut wafer <NUM> can be integrated onto the lens <NUM>. The blue-cut wafer <NUM> can be integrated onto the lens <NUM> through various techniques including front-side lamination, direct injection, in-mold lamination, and bi-injection. The integration of the blue-cut wafer <NUM> onto the lens <NUM> can create the blue-cut lens <NUM>. The blue-cut lens <NUM> can absorb the predetermined wavelength range of blue light rather than reflecting it. In other words, the blue-cut lens <NUM> can absorb the predetermined wavelength range of blue light, while also permitting the wavelength ranges outside of the predetermined wavelength range of blue light.

Front-side lamination can include a blue-cut wafer <NUM> pre-coated with adhesive and laminated onto the lens <NUM> under pressure and heat to conform to the front surface of the lens <NUM>.

Direct injection can include a blue-cut wafer <NUM> inserted into a mold cavity followed by injection of a molten thermoplastic that is fuse-bonded to the blue-cut wafer <NUM>. In this process, the blue-cut wafer <NUM> can be subjected to high melt temperatures and high shear during injection molding.

In-mold lamination can include opening a mold and inserting a blue-cut wafer <NUM> coated with adhesive. The mold can then be closed to laminate the blue-cut wafer <NUM> onto the front surface of the lens <NUM> utilizing the clamping pressure and heat from the mold. The bluecut wafer <NUM> experiences a low mold temperature which can be beneficially for heat sensitive blue blocking filters. Additionally, there is no shear involved. Further specifics relating to in-mold lamination can be found in <CIT>.

Alternatively, the injection-molded lenses can include liquid glue to bond the blue-cut wafer <NUM> to the lens <NUM>.

It should be appreciated that the steps of <FIG>, <FIG>, <FIG>, <FIG>, and <FIG> can be performed in another order, and/or the steps can be performed simultaneously.

Bi-injection can include making the blue-cut wafer <NUM> in-situ by using two injection units. A first injection unit to inject the top blue-cut wafer <NUM> layer using a mixture of blue blocking filters and a thermoplastic, and a second injection unit to injection the thermoplastic lens substrate.

Typical prescription blue-cut lenses typically have a center-to-edge thickness variation of greater than <NUM>%, especially for high minus or plus lenses. Therefore, an advantage of manufacturing the blue-cut lens <NUM> is that the resulting lenses can have a homogeneous color appearance and blue-cut level regardless of the diopter power of the lens. According to the invention, the homogenous color appearance and blue-cut performance level of the blue-cut wafer are achieved by the center-to-edge thickness variation of the blue-cut wafer <NUM> being within <NUM>%, in such a manner as ΔE ≤ <NUM>, where ΔE is the color difference between the wafer center and the wafer edge calculated using the CIE76 color-difference formula. The homogenous color appearance improves the aesthetic appearance of the blue-cut lens <NUM>.

Additionally, the existing monomer formulation or thermoplastic resin does not need to be altered to manufacture the blue-cut lenses <NUM>.

Further, additional functions (e.g., polarizing, NIR cut, other specific light filters, color balancing, etc.) can easily be added to the resulting blue-cut lenses <NUM> through the use of multilayered wafers.

The heat sensitive blue blocking dyes that typically would not survive a thermoset casting process or thermoplastic injection-molding process can also be used because the processes for preparing the blue-cut wafer <NUM> and integrating the blue-cut wafer <NUM> onto the lens <NUM> are typically at a much lower temperature, especially when the blue-cut layer is protected in the case of a multi-layer wafer.

Next, a hardware description of a processing device <NUM>, according to exemplary embodiments is described with reference to <FIG>. The processing device <NUM> can include a computer, a server, smart phone, laptop, PDA, any processor or processing circuitry, and the like. In <FIG>, the processing device <NUM> includes a CPU <NUM> which performs the processes described above/below. The process data and instructions may be stored in memory <NUM>. These processes and instructions may also be stored on a storage medium disk <NUM> such as a hard drive (HDD) or portable storage medium or may be stored remotely. Further, the claimed advancements are not limited by the form of the computer-readable media on which the instructions of the inventive process are stored. For example, the instructions may be stored on CDs, DVDs, in FLASH memory, RAM, ROM, PROM, EPROM, EEPROM, hard disk or any other information processing device with which the processing device <NUM> communicates, such as a server or computer.

Further, the claimed advancements may be provided as a utility application, background daemon, or component of an operating system, or combination thereof, executing in conjunction with CPU <NUM> and an operating system such as Microsoft Windows <NUM>, UNIX, Solaris, LINUX, Apple MAC-OS and other systems known to those skilled in the art.

The hardware elements in order to achieve the processing device <NUM> may be realized by various circuitry elements, known to those skilled in the art. For example, CPU <NUM> may be a Xenon or Core processor from Intel of America or an Opteron processor from AMD of America, or may be other processor types that would be recognized by one of ordinary skill in the art. Alternatively, the CPU <NUM> may be implemented on an FPGA, ASIC, PLD or using discrete logic circuits, as one of ordinary skill in the art would recognize. Further, CPU <NUM> may be implemented as multiple processors cooperatively working in parallel to perform the instructions of the inventive processes described above.

The processing device <NUM> in <FIG> also includes a network controller <NUM>, such as an Intel Ethernet PRO network interface card from Intel Corporation of America, for interfacing with network <NUM>. As can be appreciated, the network <NUM> can be a public network, such as the Internet, or a private network such as an LAN or WAN network, or any combination thereof and can also include PSTN or ISDN sub-networks. The network <NUM> can also be wired, such as an Ethernet network, or can be wireless such as a cellular network including EDGE, <NUM> and <NUM> wireless cellular systems. The wireless network can also be WiFi, Bluetooth, or any other wireless form of communication that is known.

The processing device <NUM> further includes a display controller <NUM>, such as a NVIDIA GeForce GTX or Quadro graphics adaptor from NVIDIA Corporation of America for interfacing with display <NUM>, such as a Hewlett Packard HPL2445w LCD monitor. A general purpose I/O interface <NUM> interfaces with a keyboard and/or mouse <NUM> as well as a touch screen panel <NUM> on or separate from display <NUM>. General purpose I/O interface also connects to a variety of peripherals <NUM> including printers and scanners, such as an OfficeJet or DeskJet from Hewlett Packard.

A sound controller <NUM> is also provided in the processing device <NUM>, such as Sound Blaster X-Fi Titanium from Creative, to interface with speakers/microphone <NUM> thereby providing sounds and/or music.

The general purpose storage controller <NUM> connects the storage medium disk <NUM> with communication bus <NUM>, which may be an ISA, EISA, VESA, PCI, or similar, for interconnecting all of the components of the processing device <NUM>. A description of the general features and functionality of the display <NUM>, keyboard and/or mouse <NUM>, as well as the display controller <NUM>, storage controller <NUM>, network controller <NUM>, sound controller <NUM>, and general purpose I/O interface <NUM> is omitted herein for brevity as these features are known.

Moreover, the present disclosure is not limited to the specific circuit elements described herein, nor is the present disclosure limited to the specific sizing and classification of these elements. For example, the skilled artisan will appreciate that the circuitry described herein may be adapted based on changes on battery sizing and chemistry, or based on the requirements of the intended back-up load to be powered.

Having now described embodiments of the disclosed subject matter, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Thus, although particular configurations have been discussed herein, other configurations can also be employed.

Claim 1:
An ophthalmic lens (<NUM>) comprising:
a lens (<NUM>) having a diopter power,
a blue-cut wafer (<NUM>) attached to the lens,
one or more of blue blocking dyes blended with a thermoplastic resin injection molded into the blue-cut wafer, or a thermoplastic blue-cut film thermoformed into the blue-cut wafer,
wherein the blue-cut wafer is configured to reduce by absorption at least a portion of light having a first wavelength range from <NUM> nanometers to <NUM> nanometers, and homogenize a color appearance and a blue-cut performance level of the blue-cut wafer,
wherein the blue-cut wafer has center thickness and edge thickness, the center-to-edge thickness variation of the blue-cut wafer being within twenty percent, in such a manner as ΔE ≤ <NUM>, where ΔE is the color difference between the wafer center and the wafer edge calculated using the CIE76 color-difference formula.