Mandrels for machining ophthalmic lenses

Abstract

A mandrel (1) for holding an ophthalmic lens blank (52) during processing is disclosed. The mandrel (1) comprises a front surface (6) for receiving an ophthalmic lens blank (52) to be processed; a back surface (8) opposite the front surface (6); and one or more through-holes (10) extending between the front and back surfaces (6, 8). In use, wax applied to the back surface (8) contacts the ophthalmic lens blank (52) received on the front surface 6 via the one or more through-holes (10). A method for producing an ophthalmic lens using the mandrel and a lens produced using the mandrel are also disclosed.

Description

Technical Field

[0001] The present disclosure relates to a mandrel for machining ophthalmic lenses, and more particularly, but not exclusively, contact lenses. The present disclosure relates to a mandrel for holding an ophthalmic lens blank during machining, a kit of parts including such a mandrel, a method of mounting an ophthalmic lens blank on a mandrel, a method of machining an ophthalmic lens blank, and an ophthalmic lens machined using such a mandrel and / or method. Background Art

[0002] Ophthalmic lenses are typically produced by machining an ophthalmic lens blank, for example, to provide a desired shape or surface finish. A high degree of accuracy in such operations is necessary to ensure that the finished lens possesses the desired properties. Mandrels are used to hold an ophthalmic lens blank during machining, for example, to mount the lens blank on a lathe for cutting, or to hold the lens blank during polishing or grinding.

[0003] Typically, a block of wax is provided on the front surface of the mandrel, and the lens blank is pushed into the wax, which then solidifies and holds the lens blank in place. Accurate placement of the lens blank on the wax and consistent wax thickness can be difficult to achieve. This can lead to processing errors due to misalignment or tilting of the lens blank relative to the mandrel. The wax can also leave residue on the surface of the lens, which creates a hazy or cloudy effect on the surface and thereby affects the optical performance of the lens. This wax residue must then be cleaned. If cleaning is unsuccessful or if cleaning frequently scratches the lens, the lens will not achieve the desired optical performance (due to scratches or wax residue). It would be advantageous to provide a method for holding ophthalmic lens blanks during processing that reduces processing errors, resulting in lenses with improved optical performance and / or reduced error rates in the produced lenses.

[0004] Recently, ophthalmic lens assemblies have been proposed in which optical components are housed within a lens. Examples of optical components include diffractive optical elements and electrically switchable components, including liquid crystal cells. Such assemblies can be produced by encapsulating the optical components between a first lens member and a second lens member. The first and second lens members may define the front and back surfaces of the lens between them, or the first and second lens members may define an encapsulated component that is then encapsulated within the lens material to form the front and / or back surfaces of the lens. It would be advantageous to provide an efficient way to process such lens assemblies. Such assemblies may require more accurate processing in order to achieve the desired dimensions, given the number of components involved (e.g., due to tolerance stacking), and / or may require a higher level of processing precision in order to allow the optical components to provide the desired effect. Therefore, more accurate processing techniques may be particularly advantageous when applied to such ophthalmic lens assemblies.

[0005] An alternative to using wax is to provide a mandrel with a recess that closely corresponds to the dimensions of the lens blank, so that the lens is held on the mandrel with an interference fit between the recess and the blank. However, the tight fit between the lens blank and the recess can produce excessive forces on the blank as it is processed, resulting in a deformed lens after cutting. Furthermore, this technique can be limited by the shapes of the blanks that can be used with it. For example, blanks with very thin edges can be difficult to process in this manner because it is difficult to position the thin edge against the side of the recess. It would be advantageous to provide a method for holding ophthalmic lens blanks during processing that reduces error rates, provides lenses with improved optical performance, and / or allows for processing a wider range of lens blank shapes.

[0006] The present disclosure is directed to alleviating the above-mentioned problems.Alternatively or additionally, the present disclosure is directed to providing improved apparatus and / or methods for processing ophthalmic lenses. Summary of the Invention

[0007] In a first aspect, the present disclosure provides a mandrel for holding an ophthalmic lens member blank during processing, the mandrel comprising:

[0008] a front surface for receiving an ophthalmic lens member blank to be processed;

[0009] a rear surface opposite the front surface; and

[0010] one or more through-holes extending between the front and rear surfaces;

[0011] Such that, in use, wax applied to the posterior surface contacts an ophthalmic lens member blank received on the anterior surface via the one or more through-holes.

[0012] In a second aspect, the present disclosure provides a kit of parts comprising a mandrel according to the first aspect, the mandrel having a socket in a front surface for receiving a joint; and one or more of:

[0013] a fitting including a male end, the fitting configured to be received in the socket such that the male end defines a portion of the front surface of the mandrel;

[0014] a fitting including a concave end portion, the fitting being configured to be received in the socket such that the concave end portion defines a portion of the front surface of the mandrel;

[0015] A joint includes a flat end configured to be received in the socket such that the flat end defines a portion of the front surface of the mandrel.

[0016] In a third aspect, the present disclosure provides a method for mounting an ophthalmic lens component blank on a spindle, the spindle comprising a front surface, a back surface, and one or more through holes extending between the front and back surfaces, the method comprising: holding the ophthalmic lens component blank against the front surface of the spindle, and while holding the ophthalmic lens component blank against the front surface of the spindle, applying wax to the back surface of the spindle and flowing the wax through the one or more through holes to contact the back surface of the ophthalmic lens component blank at the through holes.

[0017] In a fourth aspect, the present disclosure provides a method of processing an ophthalmic lens component blank, the method comprising mounting the ophthalmic lens component blank on a spindle according to the method of the third aspect, releasing the retaining and holding the lens component blank on the spindle by the wax; and then processing the front surface of the lens component blank while holding the lens component blank on the spindle.

[0018] In a fifth aspect, the present disclosure provides a batch of one thousand ophthalmic lenses, each lens being processed using the mandrel of the first and / or second aspects and / or produced using the method of the third and / or fourth aspects, wherein each lens includes a central optical zone and an annular peripheral zone surrounding the central optical zone, and the central optical zone of each lens is free of wax residue and scratches, and at least one of the lenses has an annular peripheral zone, the annular peripheral zone including a surface having wax residue and / or scratches thereon.

[0019] In a sixth aspect, the present disclosure provides an ophthalmic lens produced using the spindle processing of the first and / or second aspects and / or using the method of the third and / or fourth aspects, wherein the lens includes a central optical zone and a peripheral zone surrounding the central optical zone, wherein the central optical zone is free of wax residues and scratches and the peripheral zone includes a surface having wax residues and / or scratches thereon.

[0020] Optional but preferred features are set out in the dependent claims.

[0021] Of course, it will be appreciated that features described with respect to one aspect of the disclosure may be incorporated into other aspects of the disclosure. For example, the method of the disclosure may incorporate any of the features described with reference to the apparatus of the disclosure, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Example embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

[0023] Figure 1A showing a cross-sectional view of a mandrel according to an embodiment of the present disclosure;

[0024] Figure 1B exhibit Figure 1A A front view of the mandrel;

[0025] Figure 1C Display having an ophthalmic lens blank assembly mounted thereon Figure 1A a cross-sectional view of a mandrel;

[0026] Figure 2A A perspective view showing a mandrel according to an embodiment of the present disclosure;

[0027] Figure 2B exhibit Figure 2A A front view of the mandrel;

[0028] Figure 2C exhibit Figure 2A a cross-sectional view of a mandrel;

[0029] Figure 3A A perspective view showing a mandrel according to an embodiment of the present disclosure;

[0030] Figure 3B exhibit Figure 3A A front view of the mandrel;

[0031] Figure 3C exhibit Figure 3A a cross-sectional view of a mandrel;

[0032] Figure 4 shows a schematic cross-sectional view of a mandrel with an ophthalmic lens member blank mounted thereon, the mandrel being mounted on a lathe for machining the lens member blank in accordance with an embodiment of the present disclosure;

[0033] Figure 5 a flow chart showing a method of mounting an ophthalmic lens member blank on a mandrel according to the present disclosure;

[0034] Figure 6 showing a support assembly for mounting a lens member blank on a spindle according to an embodiment of the present disclosure;

[0035] Figure 7 Photographs showing ophthalmic lens members produced using mandrels according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0036] According to a first aspect of the present disclosure, a mandrel for holding an ophthalmic lens blank during processing may be provided. The mandrel may include a front surface for receiving an ophthalmic lens blank to be processed; a back surface opposite the front surface; and / or one or more through-holes extending between the front and back surfaces. The mandrel may be configured such that, during use, wax applied to the back surface contacts the ophthalmic lens blank mounted on the front surface via the one or more through-holes.

[0037] Using such a mandrel can allow wax to be applied to an ophthalmic lens blank at one or more discrete locations, such as defined by the through-holes. The lens blank positioned against the front surface can be contacted (and subsequently held) by the wax at the opening to the through-holes on the front surface of the mandrel. This can improve the accuracy of the lens blank's positioning on the mandrel and thereby reduce processing errors by eliminating the variability introduced by the need to apply a wax layer having a certain thickness and / or push the lens blank into the wax layer to a certain depth. Additionally or alternatively, controlling and limiting the area where wax contacts the lens blank can reduce the impact of wax residue on the optical performance of the lens.

[0038] The term machining may refer to cutting, grinding, polishing and / or other machining processes. Examples of machine tools to which the present disclosure may be applied include lathes, grinders, polishers and / or other machine tools.

[0039] The front surface of the mandrel may include an optic zone and a peripheral zone, and the one or more through-holes may be located in the peripheral zone. Positioning the through-holes in the peripheral zone may improve the optical performance of the lens because any wax residue will then be located outside the optic zone. The optic zone of the front surface may be centered on the front surface. The mandrel may be configured so that when the blank is received on the front surface, the optic zone of the front surface is aligned with the optic zone of the lens component blank. The peripheral zone of the front surface may be radially outside the optic zone; for example, the peripheral zone may be annular and surround the optic zone. The mandrel may be configured so that when the blank is received on the front surface, the peripheral zone of the front surface is aligned with the peripheral zone of the lens component blank. The through-holes of the mandrel may be confined to the peripheral zone. Any through-holes extending between the front and back surfaces may be located in the peripheral zone. The front surface of the mandrel may be convex, concave, or flat in the optic zone.

[0040] The front surface of the mandrel may include, for example, a concave bowl-shaped surface region in the optic zone configured to receive the convex surface of a lens member blank. The front surface of the mandrel may include, for example, a convex dome-shaped surface region in the optic zone configured to receive the concave surface of a lens member blank. The bowl-shaped or dome-shaped region may be surrounded by a flat surface region. The front surface in the peripheral region may include a substantially flat surface. Thus, the shape of the front surface may conform to the shape of the front or back surface of the lens member blank.

[0041] The spindle may include a rod for mounting the spindle on a machine tool. The rod may include an elongated body configured to be received in a chuck of the machine tool. The spindle may include a flange extending radially from the rod (e.g., at one end of the rod). The flange may include a front surface, a rear surface (e.g., on a surface of the flange opposite the front surface), and / or one or more through-holes. The diameter of the rod may be less than 50% of the diameter of the flange. The front and / or rear surfaces may be substantially perpendicular to the rod (notwithstanding any notches formed therein). When mounted on the machine tool, the longitudinal axis of the through-hole may be substantially parallel to the longitudinal axis of the rod and / or the axis of rotation of the spindle.

[0042] The spindle may include a plurality of through holes. The plurality of through holes may be circumferentially spaced about the longitudinal axis of the spindle and / or rod. The through holes may be equally spaced about the longitudinal axis.

[0043] The front surface of the mandrel may include a front recess shaped to receive an ophthalmic lens blank. The front recess may be configured to receive the lens blank, for example, with a locating fit rather than an interference fit. A locating fit may be defined as a fit in which the dimensions of the recess match the blank such that the blank is substantially immovable radially within the recess, but in the absence of wax to hold the blank in place, the blank will fall out of the recess when the mandrel is inverted. This is in contrast to an interference fit, in which the blank will be retained in the recess when the mandrel is inverted in the absence of wax. The dimensions of the front recess may closely match the dimensions of the ophthalmic lens blank. Providing a front recess having a shape that closely matches the shape of the lens blank may improve the accuracy and reliability of positioning the lens blank on the mandrel (and thereby reduce manufacturing errors). The front recess may have a diameter from 4 mm to 20 mm (inclusive), for example, from 10 mm to 20 mm (inclusive). The optic zone of the mandrel may be substantially circular in shape and may have a diameter ranging from 2 mm to 10 mm, inclusive. In some embodiments, the anterior recess has a diameter ranging from 13 mm to 15 mm, and the optic zone of the mandrel has a diameter ranging from 7 mm to 9 mm. The depth of the anterior recess may be less than or equal to 1 mm, for example, the depth may be from 0.8 mm to 0.2 mm at the outer edge of the anterior recess. The depth of the anterior recess may be less than the thickness of the lens member blank at the outer edge of the anterior recess. For example, if the front surface includes a convex or concave area in the optic zone, the depth of the anterior recess may vary with the radius. Providing a shallow recess may allow the mandrel to be used with a wider range of lens thicknesses while still allowing the entire surface of the lens blank to be processed. The depth may be measured at the outer edge of the anterior recess relative to the front of the mandrel (for example, at the outer edge of the anterior recess relative to the front of the flange). In cases where the longitudinal position of the front of the mandrel at the outer edge of the anterior recess varies around the circumference, the average position of the front edge should be used to measure the depth of the recess. The front notch can be defined by a raised area (e.g., an annular raised area). The raised area can be centered on the axis, e.g., centered on the front surface. The raised area can be concentric with the front notch, the optic zone, and / or the peripheral zone.

[0044] The rear surface of the mandrel may include a rear recess, such as an annular recess. The rear recess may be centered on the rear surface and / or concentric with the rear surface. The rear recess may be centered on the flange and / or concentric with the flange and / or the longitudinal axis of the mandrel. The depth of the rear recess may be greater than the depth of the front recess. The depth of the rear recess may be less than or equal to 5 mm, for example, the depth may be from 0.5 mm to 0.4 mm. The depth may be measured at the outermost edge of the rear recess relative to the rear surface (for example, at the outer edge of the rear recess relative to the rear portion of the flange). In the case where the longitudinal position of the rear surface at the outer edge of the rear recess varies around the circumference, the average position of the rear edge should be used to measure the depth of the recess. Multiple through-holes (for example, each through-hole or all through-holes) may be in fluid communication with the rear recess and / or in fluid communication with each other via the rear recess. Therefore, the wax dispensed into the rear recess may flow into the multiple through-holes. Providing a rear recess through which wax can be applied to the plurality of through-holes means that the user can simply dispense wax into the rear recess rather than individually dispensing wax to each hole. This can help provide a more even distribution of the wax, thereby improving the reliability of the hold provided by the mandrel during use and / or increasing ease / efficiency of use (e.g., by reducing the number of wax dispensing steps).

[0045] Each through hole may have a first opening on the front surface and a second opening on the rear surface. The first opening may be located in the front recess and / or the second opening may be located in the rear recess. The through hole may extend between the first opening and the second opening. Thus, the first and second openings may define the ends of the through hole. The first opening may be located in the base of the front recess. The second opening may be located in the base of the rear recess. The through hole has a longitudinal axis. When viewed in a cross-section perpendicular to its longitudinal axis, the through holes may be substantially circular, kidney-shaped, and / or arcuate, for example, an arc having a constant radius relative to the center of the front surface. The perimeters of the first and second openings (i.e., the edges of the openings) may be curved and, for example, may not include any discontinuities, such as sharp corners.

[0046] The front surface of the mandrel may include one or more drainage channels through which wax and / or air can flow from the front recess. Providing drainage channels can allow excess wax to escape the area of ​​the through-hole and thereby reduce variations in the amount of wax protruding beyond the opening of the through-hole on the front surface, which could affect the position of the lens member blank on the front surface and thereby increase the risk of machining errors. Additionally or alternatively, providing drainage channels can reduce the risk of air bubbles forming between the blank and the mandrel. The drainage channels can extend from an edge of the front recess. The drainage channels can extend from an edge of the through-hole (e.g., the opening of the through-hole). Drain channels extending directly from the through-hole at the front surface can be particularly advantageous in reducing the accumulation of excess wax.

[0047] The front surface may include a raised area defining a front recess. The front surface may further include a reservoir, for example, located radially outward from the raised area. The reservoir may be connected to the front recess via the one or more drainage channels, such that excess wax in the front recess can flow to the reservoir via the drainage channels. The front surface of the raised area may be substantially flat (despite the presence of any drainage channels). Providing a reservoir on the front surface may be a mechanically simple way to collect excess wax and thereby prevent wax from contacting the lens member blank in areas other than the intended area. The reservoir may be deeper than the front recess. The drainage channels may extend radially and linearly from the front recess to the reservoir. This arrangement may facilitate the flow of wax from the front recess to the reservoir. The reservoir may take the form of an annular channel defining the outer perimeter of the raised area.

[0048] In some embodiments, the front recess is substantially circular, the raised area is substantially annular and the reservoir is substantially annular.The front recess, raised area and reservoir may be concentric and in the following order from innermost to outermost: front recess, raised area, reservoir.

[0049] In a second aspect of the present disclosure, a component kit is provided, comprising a spindle having any of the features described above in conjunction with the first aspect. The spindle may include a socket in the front surface for receiving a joint. The component kit may further include one or more of the following: a joint including a convex (dome-shaped) end, the joint being configured to be received in the socket so that the convex end defines a portion of the front surface of the spindle; a joint including a concave (bowl-shaped) end, the joint being configured to be received in the socket so that the concave end defines a portion of the front surface of the spindle; a joint including a flat end, the joint being configured to be received in the socket so that the flat end defines a portion of the front surface of the spindle. Thus, the joint can be used to provide a convex or concave area of ​​the front surface as described above in the first aspect. This reconfigurable spindle / kit can provide increased manufacturing efficiency and / or ease of manufacturing.

[0050] In a third aspect of the present disclosure, a method is provided for mounting an ophthalmic lens component blank (e.g., a contact lens component blank) on a mandrel for machining (i.e., as part of a machining process). The mandrel may include a front surface, a back surface, and one or more through holes extending between the front and back surfaces. The method may include holding the ophthalmic lens component blank against the front surface of the mandrel, for example, holding the back surface of the lens component blank against the front surface. The method may include applying wax to the back surface of the mandrel while holding the ophthalmic lens component blank against the front surface. The method may include flowing the wax through the one or more through holes to contact the back surface of the blank at the through holes while holding the ophthalmic lens component blank against the front surface.

[0051] The method may include contacting the back surface of the ophthalmic lens member blank with the wax only at the through-hole. The method may include allowing the wax to solidify. The method may include releasing the hold on the lens member blank (e.g., after the wax has solidified) with the blank being held by the wax.

[0052] The method may include placing the ophthalmic lens component blank on a support, such as a support including a bowl-shaped recess or a dome-shaped protrusion on its upper surface to conform to the front surface of the blank. The method may include placing the mandrel on top of the lens component blank on the support, such as such that the weight of the mandrel itself holds the lens component blank against the front surface of the mandrel. The method may include dispensing wax onto the back surface, such as when the back surface of the mandrel is uppermost while the mandrel rests on top of the lens component blank. The method may include holding the mandrel before and / or during dispensing of the wax, and optionally pressing the mandrel downward. It will be apparent that the force required to hold the blank against the mandrel will depend in part on the pressure, flow rate, and volume of wax dispensed. When wax is dispensed slowly at low pressure and in a volume substantially equal to the volume of the through-hole, the wax does not force the blank away from the front surface, and little or no force is required to hold the blank in place. If higher rates, pressures, and volumes are involved, some force may be required to hold the blank against the surface. The method may include using a fixture, for example, having a cavity configured to receive a portion of a rod, to hold the mandrel in place, for example, while the wax is dispensed. Using a support and fixture can assist in maintaining alignment between the mandrel and the lens member while the wax is applied, thereby reducing the risk of machining errors.

[0053] In a fourth aspect of the present disclosure, a method for processing an ophthalmic lens component blank is provided, the method comprising mounting the ophthalmic lens component blank on a mandrel according to the method of the third aspect. The method may comprise mounting the mandrel (to which the blank is attached by the wax) on a machine tool. For example, the mandrel may be mounted on the machine tool by inserting the rod of the mandrel into a chuck. The method may comprise processing the front surface of the lens component blank. The method may comprise releasing the hold of the ophthalmic lens component blank (which may be referred to as an ophthalmic lens component when forming is complete) from the mandrel, for example by melting the wax. The method may comprise performing other finishing steps on the ophthalmic lens component.

[0054] The method may include receiving the ophthalmic lens member blank in the front recess of the mandrel with a registered fit.The method may include dispensing wax into the rear recess of the mandrel.

[0055] An ophthalmic lens component blank may have a front surface, i.e., the front surface when the lens is in use on the eye. An ophthalmic lens component blank may have a back surface, i.e., the back surface when the lens is applied to the eye. The back surface may include, for example, a concave (bowl-shaped) area surrounded by a flat area. The front surface may include, for example, a convex (dome-shaped) area surrounded by a flat area. Either the front or back surface may be positioned adjacent to the front surface of the spindle to enable machining of the other of the front or back surfaces. In this context, the surface of the lens component blank adjacent to the front surface of the spindle is referred to herein as the back surface of the lens component blank, and the other surface of the lens component blank is referred to as the front surface. Therefore, depending on the orientation of the blank on the spindle, the front surface of the blank may be referred to as the front surface and the back surface at different times. When the front surface of the lens component blank is machined and the back surface is adjacent to the front surface, the spindle may have a convex (dome-shaped) surface area. When the front surface of the lens member blank is machined and the back surface is adjacent to the front surface, the mandrel may have a concave (bowl-shaped) surface area. Providing a front surface that conforms to the shape of the machined lens member blank may provide improved accuracy in positioning the lens member on the mandrel.

[0056] The method may include holding one of the front and back surfaces of the lens component blank against the front surface of the mandrel and applying wax as described in the method of the third aspect, and then machining the other of the front and back surfaces (and optionally performing any of the other method steps described above, wherein the lens component blank is mounted on the mandrel in that orientation). The method may include removing the lens component blank from the mandrel after machining of that surface is completed. The method may then be repeated to machine the other of the front and back surfaces of the same lens component blank. The method may include holding the machined one of the front and back surfaces of the lens component blank against the front surface of the mandrel and applying wax as described in the method of the third aspect, and then machining the other of the front and back surfaces (and optionally performing any of the other method steps described above, wherein the lens component blank is mounted on the mandrel in that orientation). The method may include removing the lens component blank from the mandrel after machining is completed. Thus, the method can provide a method for mounting and / or machining a lens component blank to provide a lens component.

[0057] The method may include holding the front surface of a first lens component blank against the front surface of a mandrel and applying wax as described in the method of the third aspect, and then machining the back surface (and optionally performing any of the other method steps described above, wherein the first lens component blank is mounted on the mandrel in that orientation). The method may then include removing the first lens component blank from the mandrel after machining of that surface is completed. The method may then include holding the machined back surface of the first lens component blank against the front surface of a mandrel and applying wax as described in the method of the third aspect. The method may include mounting one or more optical components on the first lens component blank, for example, on the front surface of the lens component blank. The method may include securing a second lens component blank to the first lens component blank. The method may then include machining the front surface of the second lens member blank while the second lens member blank is secured to the first lens member blank and thereby held on the spindle (and optionally carrying out any of the other method steps described above in which the second lens member blank is mounted on the spindle). Thus, the method may provide a method of mounting and / or machining a lens member assembly.

[0058] Machining may include cutting (eg, on a lathe), polishing or grinding, or any other machining operation in which the lens must be held and supported.

[0059] The following paragraphs describe aspects of ophthalmic lenses related to any of the aspects of the present disclosure as described above or below.

[0060] The ophthalmic lens may include a central optic zone and an annular peripheral zone surrounding the central optic zone, wherein the first and second regions having wax residue thereon are located in the peripheral zone. The lens may have a plurality of regions having wax residue thereon, the regions being located in and spaced apart in the peripheral zone.

[0061] The ophthalmic lens may include one or more optical components, such as a diffractive optical element, and an electrically switchable component, including a liquid crystal cell.The ophthalmic lens may include one or more optical components located between first and second ophthalmic lens members.

[0062] An ophthalmic lens may include an ophthalmic lens produced by processing an ophthalmic lens component blank. An ophthalmic lens may include a lens component blank processed on its front surface (i.e., the front surface when used on the eye) and / or its back surface (i.e., the back surface when used on the eye). An ophthalmic lens may include a single lens component blank processed on its front surface and / or its back surface. Alternatively, an ophthalmic lens may include two (or more) lens component blanks, each of which is processed on its front surface and / or its back surface. An ophthalmic lens may include a first lens component processed on its back surface and a second lens component processed on its front surface, for example, wherein the second lens component is fixed to the first lens component, with one or more optical components optionally located therebetween. In some embodiments, the first and second lens components define an encapsulation assembly, which is then itself encapsulated in a lens material to form a lens. In other embodiments, an ophthalmic lens may be formed solely of the first and second lens components.

[0063] The visual zone of a lens component may be centered on the optical axis. The optical axis may be aligned with the center of the lens component. The visual zone of a lens or lens component encompasses the portion of the lens that is optically functional during use. The visual zone may be configured to be positioned above or in front of the pupil of the eye during use. In a plan view, a lens component may have a visual zone surrounded by a peripheral zone. The peripheral zone is not part of the visual zone but is located outside the visual zone. When the lens component is worn, the peripheral zone may be located above the iris. The peripheral zone may provide mechanical functions, such as increasing the size of the lens component, thereby making the lens easier to handle. The peripheral zone may extend to the edge of the lens component. The peripheral zone may provide ballast to prevent the lens component from rotating and / or provide a shaped area that improves the comfort of the lens wearer.

[0064] As used herein, an ophthalmic lens can be a spectacle lens or a contact lens. A lens can include one or more lens components produced by processing one or more lens component blanks. A contact lens can include one or more contact lens components produced by processing one or more contact lens component blanks.

[0065] The contact lens can be a hard contact lens or a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens. As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the front surface of the eye. It will be understood that such a contact lens will provide clinically acceptable on-eye movement and will not bind to the person's eye.

[0066] Contact lenses can be used to correct or improve vision associated with myopia, presbyopia, hyperopia, astigmatism, or another refractive error. Contact lenses can be soft contact lenses, such as hydrogel contact lenses or silicone hydrogel contact lenses. Contact lenses can be hard gas permeable contact lenses. Contact lenses can be scleral contact lenses.

[0067] The contact lens (and thus the contact lens component blank) may comprise an elastomeric material, a silicone elastomeric material, a hydrogel material, or a silicone hydrogel material, or a combination thereof. As understood in the contact lens art, a hydrogel is a material that holds water in equilibrium and is free of silicone-containing chemicals. A silicone hydrogel is a hydrogel that contains silicone-containing chemicals. As described in the context of the present disclosure, hydrogel materials and silicone hydrogel materials have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). In some embodiments, the hydrogel material or silicone hydrogel material has an EWC of from about 30% to about 70% (wt / wt). In contrast, as described in the context of the present disclosure, silicone elastomeric materials have a water content of from about 0% to less than 10% (wt / wt). Typically, the silicone elastomeric material used with the method or apparatus of the present disclosure has a water content of from 0.1% to 3% (wt / wt). Examples of suitable lens formulations include those with the following United States Adopted Names (USAN): methafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon A, senofilcon A, senofilcon B, senofilcon C, narafilcon A, narafilcon B, balafilcon A, samfilcon A, lotrafilcon A, lotrafilcon B, somofilcon A, riofilcon A, delefilcon A, verofilcon A, kalifilcon A, and the like.

[0068] Alternatively, the lens (and thus the lens member blank) may comprise, consist essentially of, or consist of a silicone elastomeric material. For example, the lens may comprise, consist essentially of, or consist of a silicone elastomeric material having a Shore A hardness of from 3 to 50. As will be understood by one of ordinary skill in the art, Shore A hardness may be determined using conventional methods (e.g., using method DIN 53505). For example, other silicone elastomeric materials are available from NuSil Technology or The Dow Chemical Company.

[0069] Alternatively, the lens (and thus the lens member blank) may comprise polymethyl methacrylate (PMMA).

[0070] The contact lens may be substantially circular in shape. The contact lens may have a diameter of from 4 mm to 20 mm (inclusive), for example, from 10 mm to 20 mm (inclusive). The optic zone of the contact lens may be substantially circular in shape and may have a diameter of from 2 mm to 10 mm (inclusive). In some embodiments, the contact lens has a diameter of from 13 mm to 15 mm, and the optic zone has a diameter of from 7 mm to 9 mm. The contact lens may have a convex front surface. The contact lens may have a concave rear surface.

[0071] In a fifth aspect of the present disclosure, a batch of one thousand ophthalmic lenses (e.g., contact lenses) is provided. Each lens in the batch can be processed using the mandrel of the first and / or second aspects and / or the method of the third and / or fourth aspects. Each lens can include a central optic zone and a peripheral zone surrounding the central optic zone, and the central optic zone of each lens can be free of wax residue and / or scratches, while one of the lenses can have a peripheral zone comprising a surface having wax residue and / or scratches thereon. The peripheral zone can be an annular peripheral zone.

[0072] Prior art methods of manufacturing lenses using wax to hold the lens member on a mandrel produce a large number of lenses with wax residue in the optic zone and / or scratches in the optic zone (caused by the removal of the wax residue). Known methods using wax do not produce an error rate of less than 1 in 1000 lenses for these defects. Lenses produced using the mandrel of the present disclosure can avoid such defects by limiting the area where the wax contacts the lens blank to the peripheral zone.

[0073] At least 10% (eg, at least 20%) of the lens may have an annular peripheral zone comprising a surface having wax residue and / or scratches thereon.

[0074] It will be appreciated that a batch of lenses is produced sequentially. As used herein, "sequentially produced" means that the batch consists of lenses produced one after the other without any intervening lenses that do not form part of the batch.

[0075] As used herein, 'wax residue' refers to the remaining wax on the surface of the lens / lens component that is visible to the naked eye.

[0076] As used herein, 'scratch' refers to one or more scratches on the surface of a lens or lens component that are visible to the naked eye.

[0077] When the lens is held against the front surface of the mandrel, the region having wax residue thereon may correspond to the location of the through-hole. The peripheral region may include a surface having a first region having wax residue thereon and a second region having wax residue thereon, the first region being spaced apart from the second region. Each region may correspond to the location of the through-hole.

[0078] Each ophthalmic lens may include a first ophthalmic lens component, a second ophthalmic lens component, and one or more optical components located between the first and second ophthalmic lens components. The optical zone of each of the first and second lens components may be free of wax residue and / or scratches. The at least one lens may include the first and / or second lens components having an annular peripheral zone including a surface having wax residue and / or scratches thereon.

[0079] In a sixth aspect of the present disclosure, an ophthalmic lens is provided that is processed using the mandrel of the first and / or second aspects and / or the method of the third and / or fourth aspects. The lens may include a central optic zone and a peripheral zone surrounding the central optic zone. The central optic zone may be free of wax residue and scratches, and the peripheral zone may include a surface having wax residue and / or scratches thereon. The lens of the sixth aspect may have any of the features described above with respect to the fifth (or any other) aspect of the present disclosure.

[0080] refer to Figure 1A 、 Figure 1B and Figure 1C , shows a spindle 1 according to an embodiment of the present disclosure. The spindle comprises a rod 2 and a flange 4 at one end of the rod 2 and extending radially outward from the rod 2. The flange 4 defines a portion of a front surface 6 of the spindle located on the side of the flange 4 opposite the rod 2, and a rear surface 8 located on the side of the flange 4 opposite the front surface 6. Two through-holes 10 extend through the flange 4 between the front surface 6 and the rear surface 8. The through-holes 10 are located on opposite sides of the rod 2 and when Figure 1B Circular when viewed in plan view in FIG. A front recess 12 is formed in the front surface 6 by a rim 14 extending around the circumference of the flange 4. A rear recess 16 is formed in the rear surface 8 by a rim 18 extending around the circumference of the flange 4. A through hole 10 extends between the base of the front recess 12 and the base of the rear recess 16. The spindle 1 includes a dome 20 that defines part of the front surface 6. The dome 20 is located concentrically with the flange 4 and the rod 2 and is located on the side of the flange 4 opposite the rod 2. The dome 20 is centered in the viewing area 22 of the front surface and the through hole 10 is located in an annular peripheral area 24, which is located outside the viewing area 24. The domed line indicates Figure 1B The range of the viewing area 22 in.

[0081] Figure 1C exhibit Figure 1ASchematic cross-sectional view of a mandrel 1 with a contact lens component assembly 50 secured thereto using wax (not shown). The contact lens component assembly 50 includes a first lens component blank 52 and a second lens component blank 54. The second lens component blank 54 is concentrically mounted on the first lens component blank 52 with an optical component 56 encapsulated between the first and second lens component blanks 52, 54. Each of the first and second lens component blanks 52, 54 includes an optic zone 53 centered on the lens component and an annular peripheral zone 55 concentrically positioned with and surrounding the optic zone 53. Figure 1C , the contact lens component assembly 50 is arranged with the back surface of the first lens component blank 52 against the front surface 6 of the mandrel 1 so that the front surface of the second lens component blank 54 is the front surface 60 of the assembly 50 and can then be processed. Thus, the back surface 58 of the first lens component blank 52 is concave in the optic zone 53 and flat in the peripheral zone 55, and thus conforms to the shape of the front surface 6 as defined by the flange 4 and the dome 20. The through hole 10 is located in the peripheral zone 55. Although Figure 1C While the following embodiments relate to contact lens members and contact lens member assemblies, it will be appreciated that other ophthalmic lens members / lens member assemblies may be machined using the mandrels of the present disclosure. Figure 1C A contact lens assembly formed of two contact lens members is shown, but it will be understood that a single contact lens member or a contact lens assembly formed of more than two lens members can be processed using the mandrel of the present disclosure. A batch may include one thousand contact lenses, each lens being formed of a plurality of contact lenses. Figure 1C The contact lens component assembly 50 shown in FIG.

[0082] In use, wax is dispensed into the rear recess 16 and flows into the through-hole 10 to contact the rear surface 58 of the first lens member 52. In this way, the lens assembly is fixed in place on the spindle, but the wax contacts the rear surface 58 only at the location where the through-hole 10 passes through to the front surface 6. This enables the location where the wax contacts the lens assembly to be controlled and, for example, limited to non-optical areas of the lens. For example, Figure 1C In the embodiment of the present invention, the through hole 10 is located in the peripheral zone 55 so that any blurring on the lens caused by the wax does not affect the visual zone 53.

[0083] refer to Figure 2A 、 Figure 2B and Figure 2C, showing a mandrel 1 according to a second example embodiment of the present disclosure. Only those aspects of the second embodiment that differ from the first embodiment will be discussed herein. As between the first and second embodiments, similar reference numerals have been used to denote similar elements (e.g., through-holes 10). Compared to the first embodiment, the mandrel 1 of the second embodiment has six through-holes 10—four through-holes 10a that are kidney-shaped when viewed in plan (kidney-shaped through-holes) and two through-holes 10b that are circular when viewed in plan (circular through-holes). The two circular through-holes 10b are located opposite each other in the peripheral region 24 around the circumference of the front recess 12 (e.g., Figure 2B ), and the four kidney-shaped through holes 10a form two opposite pairs on opposite sides of the peripheral area 24. The viewing area 22 (as shown in FIG. Figure 2B An annular raised area 60 extends around the outside of the peripheral region 24 and an annular reservoir 62 extends around the outside of the peripheral region 24. The annular raised area 60 includes a plurality of radially extending flow channels 64, each extending from the through hole 10 to the annular reservoir 62.

[0084] In use, excess wax can flow from the through-hole 10 to the annular reservoir via the radially extending grooves 64, thereby preventing excess wax from contacting the rear surface of the lens member located on the spindle.

[0085] Figure 3A 、 Figure 3B and Figure 3C A mandrel 1 is shown according to a third example embodiment of the present disclosure. Only those aspects of the third embodiment that differ from the first embodiment will be discussed herein. As between the first and third embodiments, similar reference numerals have been used to denote similar elements (e.g., through-holes 10). Compared to the first embodiment, the mandrel 1 of the third embodiment has three kidney-shaped through-holes 10 (e.g., equidistantly spaced around the circumference of the flange 4) in the peripheral region 24. Figure 3B ). As in the second embodiment, an annular raised area 60 extends around the outside of the peripheral region 24 and an annular reservoir 62 extends around the outside of the peripheral region 24. The annular raised area 60 includes three radially extending grooves 64, each extending from the outer edge of the front recess 12 adjacent one of the through-holes 10 to the annular reservoir 62.

[0086] In use, excess wax can flow from the through-hole 10 to the annular reservoir via the radially extending grooves 64, thereby reducing the accumulation of excess wax in the area of ​​the through-hole 10. Although the radially extending grooves 64 are not directly connected to the through-hole 10 in the third embodiment, they can still provide benefits in reducing contact between wax and the back surface of the lens member outside the area of ​​the through-hole 10.

[0087] like Figure 3CAs shown more clearly in FIG, an axial cavity 66 extends along the length of the spindle 1. The axial cavity 66 provides a socket into which a fitting 67 including a domed end 69 can be inserted so as to define a convex portion of the front surface 6 and support a lens member mounted thereon. The provision of the axial cavity 66 thus provides a more flexible spindle that can be reconfigured for machining both the front and back surfaces of lens member blanks.

[0088] Figure 4 The mandrel 1 according to an example embodiment of the present disclosure is shown mounted in a chuck 68 of a lathe (not shown) for cutting using a cutting tool 70. Wax 72 fills the through hole 10 and the rear recess 16 and contacts the rear surface 58 of the first lens member blank 52 received in the front recess 12. In use, the cutting tool 70 cuts the front surface 74 of the first lens member. Figure 4 The front surface of the lens element. Figure 4 The spindle 1 is shown in a lathe, but it will be appreciated that other machining operations, such as polishing and / or grinding, may be performed using the spindle of the present disclosure.

[0089] Figure 5 A flow chart showing an example method according to the present disclosure is shown. A lens member blank is held 100 against the front surface of a mandrel. Wax is then dispensed 102 onto the back surface of the mandrel, flowing 104 into the through hole and contacting the back surface of the lens member blank adjacent to the front surface of the mandrel. Optionally, the method may include the following additional steps (individually or in combination), wherein the optional step is: Figure 5 10. The lens blank is then machined 114 (e.g., cut) by the mandrel. The wax is then melted to release 116 the lens blank from the mandrel.

[0090] In the event that the lens member is to be machined on both the front and back surfaces, the steps discussed above are then performed, wherein the wax contacts the front surface of the lens member and the back surface of the lens member is machined. After the lens member is released 116 from the mandrel, the steps discussed above are then performed, wherein the wax contacts the back surface of the lens member and the front surface of the lens member is machined (or vice versa). The resulting lens member is then sent for finishing. Reconfiguration of the mandrel (e.g., by changing between different shaped joints) or a different shaped mandrel may be required to support the lens depending on whether the front or back surface is being machined.

[0091] If a lens component assembly comprising two lens components is desired, the steps discussed above are then performed, wherein the front surface of the first lens component is contacted by wax and the back surface of the first lens component is machined. The method may then include repeating steps 100 to 110 as described above, wherein the first lens component blank is held with its back surface against the front surface of the mandrel. Optionally, steps 112 and 114 are repeated to machine the front surface of the first lens component. An optical component (e.g., an optoelectronic component) is then mounted on the front surface of the first lens component blank. A second lens component blank is then secured to the first lens component blank, with the front surface of the second lens component blank in proximity to the first lens component blank. Steps 112 and 116 are then repeated to machine the back surface of the second lens component blank and release the assembly from the mandrel. The resulting lens component assembly is then sent for finishing.

[0092] Figure 6 An exploded view of a mandrel 1, a lens member blank 52, a first support 80, and a second support 82 is shown according to an embodiment of the present disclosure. The lens member blank 52 is shown above the first support 80, the uppermost surface of which includes a front surface corresponding to the front surface of the lens member blank 52 (which is Figure 6 The spindle 1 is shown above the lens component blank 52 with the front surface of the spindle 1 facing downward and the second support 82 is shown above the spindle 1. The lowermost surface of the second support 82 includes a cylindrical cavity 84 corresponding to the shape of the stem of the spindle. In use, the lens component blank 52 is placed on top of the first support 80, with the dome of the front surface of the lens component blank 52 being received in the bowl shaped cavity 84. The spindle is then placed on top of the lens component blank 52 with the front surface of the spindle against the back surface of the lens component blank 52. The second support 82 is then placed on top of the spindle 1 with the stem of the spindle 1 being received in the cylindrical cavity 86. The second support 82, together with the first support 80, holds the spindle 1 in alignment with the lens component blank 52 while wax is applied to the spindle 1. Figure 6 , the lens component blank is shown with the front surface arranged for processing. It will be appreciated that if the back surface is to be processed, it may be desirable to replace the bowl-shaped cavity 84 with a domed surface in order to better support the lens component blank 52.

[0093] Figure 7 A photograph showing a contact lens member according to an embodiment of the present disclosure. Wax residue 99 is shown as three discrete areas on the peripheral area of ​​the lens member. For clarity, dotted lines have been added to the photograph to indicate the approximate extent of the areas. Figure 7 The lens component is shown combined with a second lens component to form an encapsulated assembly, and then subsequently encapsulated within a lens material to form a lens.

[0094] While the present disclosure has been described and illustrated with reference to particular embodiments, it will be apparent to those skilled in the art that the present disclosure lends itself to many different variations not specifically illustrated herein.

[0095] In the foregoing description, reference is made to wholes or elements that have known, obvious or foreseeable equivalents, and such equivalents are then incorporated herein as if individually stated. Reference should be made to the claims to determine the true scope of the present disclosure, which should be interpreted as encompassing any such equivalents. The reader will also understand that wholes or features of the present disclosure that are described as preferred, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Furthermore, it should be understood that such optional wholes or features, while potentially beneficial in some embodiments of the present disclosure, may be undesirable in other embodiments and therefore may not exist.

Claims

1. A mandrel for holding an ophthalmic lens member blank during processing, the mandrel comprising: a front surface for receiving an ophthalmic lens member blank to be processed; a rear surface opposite to the front surface; and one or more through-holes extending between the front surface and the rear surface; such that, in use, wax applied to said posterior surface contacts an ophthalmic lens member blank received on said anterior surface via said one or more through-holes; The spindle comprises a rod for mounting the spindle on a machine tool and a flange radially extending from the rod, wherein the flange comprises the front surface, the rear surface and the one or more through holes. 2 . The mandrel of claim 1 , wherein the front surface comprises a central viewing region and an annular peripheral region, and the one or more through-holes are located in the peripheral region.

3. The mandrel of claim 2, wherein the front surface of the mandrel is convex, concave, or flat in the central viewing area.

4. The mandrel of any one of claims 1-3, having a longitudinal axis and comprising a plurality of through-holes circumferentially spaced about the longitudinal axis.

5. The mandrel of claim 4, wherein the through-holes are equally spaced about the longitudinal axis.

6. The mandrel of claim 1, wherein the front surface comprises a front recess shaped to receive the ophthalmic lens member blank.

7. The mandrel of claim 6, wherein the front recess is shaped to receive the ophthalmic lens member blank in a register fit.

8. The mandrel of claim 1, wherein the rear surface includes a rear notch.

9. The mandrel of claim 8, wherein the rear recess is an annular recess.

10. The mandrel of any one of claims 6-9, wherein each through-hole has a first opening on the front surface and a second opening on the rear surface.

11. The spindle of any one of claims 6 or 7, wherein each through-hole has a first opening on the front surface and a second opening on the rear surface, and wherein the first opening is located in the front recess.

12. The spindle of any one of claims 8 or 9, wherein each through-hole has a first opening on the front surface and a second opening on the rear surface, and wherein the second opening is located in the rear recess.

13. A core shaft according to claim 6 or 7, wherein the front surface includes a raised annular area that defines the front recess and an annular reservoir located radially outside the raised annular area, and the reservoir is connected to the front recess by one or more discharge channels so that excess wax in the front recess can flow to the reservoir via the discharge channels.

14. The spindle of any one of claims 1-3 and 6-9, wherein the through-holes have a longitudinal axis and are circular, kidney-shaped and / or arcuate when viewed in a cross-section perpendicular to their longitudinal axis.

15. The mandrel of claim 14, wherein the through holes, when viewed in cross-section perpendicular to their longitudinal axes, are arcs of constant radius relative to the center of the front surface.

16. The mandrel of any one of Claims 1-3 and 6-9, wherein the ophthalmic lens component blank is a contact lens component blank.

17. The mandrel of claim 16, wherein the ophthalmic lens member blank is a contact lens member blank for a soft contact lens.

18. The mandrel of claim 16, wherein the ophthalmic lens member blank is a contact lens member blank for a rigid gas permeable contact lens.

19. A kit of parts comprising a mandrel according to any one of claims 1 to 18, the mandrel having a socket in a front surface for receiving a joint; and one or more of: a fitting including a male end, the fitting configured to be received in the socket such that the male end defines a portion of the front surface of the mandrel; a fitting including a concave end portion, the fitting being configured to be received in the socket such that the concave end portion defines a portion of the front surface of the mandrel; A joint includes a flat end configured to be received in the socket such that the flat end defines a portion of the front surface of the mandrel.

20. A method of mounting an ophthalmic lens member blank on a mandrel, the mandrel comprising a front surface, a back surface, and one or more through holes extending between the front and back surfaces, wherein the mandrel comprises a rod for mounting the mandrel on a machine tool and a flange extending radially from the rod, the flange comprising the front surface, the back surface, and the one or more through holes, the method comprising: The ophthalmic lens component blank is held against the front surface of the mandrel, and while the ophthalmic lens component blank is held against the front surface of the mandrel, wax is applied to the back surface of the mandrel and caused to flow through the one or more through holes to contact the back surface of the ophthalmic lens component blank at the through holes.

21. The method of claim 20, wherein the ophthalmic lens component blank is a contact lens component blank.

22. The method of claim 20 or 21, wherein the ophthalmic lens member blank is received in a front recess formed in the front surface of the mandrel with a locating fit and the wax is dispensed into a rear recess formed in the rear surface of the mandrel, and the one or more through holes extend between the front recess and the rear recess.

23. A method of machining an ophthalmic lens component blank, the method comprising mounting the ophthalmic lens component blank on a mandrel according to the method of any one of claims 20-22, releasing the retaining and holding the ophthalmic lens component blank on the mandrel by the wax; and then machining the front surface of the ophthalmic lens component blank while holding the ophthalmic lens component blank on the mandrel.

24. The method according to claim 23, comprising: While holding a first ophthalmic lens member blank against the anterior surface, wax is applied to the posterior surface of the mandrel and flows through the one or more through holes to contact the posterior surface of the first ophthalmic lens member blank at the through holes, and then, While holding said first ophthalmic lens member blank on said mandrel by said wax: mounting one or more optical components on said first ophthalmic lens member blank; affixing a second ophthalmic lens component blank to the first ophthalmic lens component blank such that the optical component is located between the first and second ophthalmic lens component blanks, and then The front surface of the second ophthalmic lens member blank is machined.

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