Eyeglass component engraving device

Abstract

A laser cutting tool whose position, aiming direction and cutting duration are controlled by a programmable microprocessor, is housed in a cabinet above a platen equipped with a number of component-holding stations. Each of the stations has a plurality of vises sized to grasp an eyeglass component including lenses or lens blanks, a eyeglass frame, temple pieces, a nose bridge, a carrying case or a lens cleaning swatches. Program data sets specify the edging out of blanks of a particular optical property, and the engraving of the lens and other components with decorative patterns. A cylindrical cutting wheel mounted on a position-controlled carriage has a circular groove is also programmed to bevel the edges of the lenses.

Description

PRIOR APPLICATIONS

This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/889,798 filed Jul. 13, 2004, and a continuation-in-part of co-pending PCT Application No. PCT/US05/24663 filed Jul. 13, 2005.

FIELD OF THE INVENTION

This invention relates to the machining of eyeglass components including the edging of lenses out of lens blanks, and the decorative engraving of lenses, frames, temple pieces, nose bridges, carrying cases and cleaning swatches.

BACKGROUND

The manufacture of eyeglass lenses is a time-consuming, multi-step process which generally includes the measuring of a patient's condition to derive a prescription for each eye, the measuring or tracing of the size and shape of the desired eyeglass frame, the selection of a lens blank for each eye which will accommodate the prescription for that eye and the frame, measuring or otherwise determining the optical parameters of each blank such as its power, and for cylindrical lenses, its optical axis orientation, and blocking or otherwise properly orienting each lens blank according to its optical parameters and the prescription parameters in a machine or number of machines which can further process the blank into the final lens. The processing includes edging or cutting away material from the lens blank so that the finished lens may fit the selected eyeglass frame, beveling or grooving the peripheral edge to snugly fit the frame, drilling attachment holes for temples or earpieces and nose bridges for so-called “rimless” eyeglasses, and tinting the lenses for sunglasses.

In general, most eyeglass lenses fall into two categories, namely spherical lenses and cylindrical lenses, each being suited to correct different patient conditions. Referring now to FIGS. 1 and 2, a spherical lens blank 1 is typically shaped to have a convex front surface 2, a concave rear surface 3, and a circular perimeter 4 having a lower edge 5 which lies substantially within a plane 6 substantially perpendicular to a central axis 7 which can be spaced apart a distance R_oc from the optical center 8 in spherical lens blanks having a decentration of greater than zero. Each spherical lens blank is sized to be about 7.5 centimeters (3 inches) in diameter and has a thickness contour which allows it to serve as the lens stock for a wide variety of eyeglass frames.

Referring now to FIG. 3, cylindrical lenses differ from spherical lenses in that the curvature of its surfaces can change according to meridian or angular direction from the central axis 10. As such, the lower edge 11 may have a saddle shape. The meridian or direction of least curvature can be defined as the cylindrical or optical axis 12 of a cylindrical lens.

Each lens blank, whether spherical or cylindrical in type is characterized by its lens blank parameters which can include the material from which the blank is made such as glass, acrylic or polycarbonate plastic materials, and the optical parameters which define the shape contour of the front and rear surfaces, which can include its diopter values, decentration of the optical center and cylindrical axis orientation. Even non-prescription lens blanks can be said to have such parameters though they may have zero values such as zero optical power values. The parameters which describe the lens blank are collectively referred to as “lens blank parameters”. A difference in even one parameter may result in a different type of lens blank. Such lens blanks are commercially available from a number of sources such as the Sola Lens company of Pensacola, Fla., or the Younger Optical company of Torrance, Calif. Depending on the prescription, a “stock” lens blank may have to be “customized” or further ground and polished to provide the desired front and back surface shapes. It has been found that most prescriptions can be filled by commercially available finished lens blanks without further grinding and polishing of the optical surfaces.

Referring back to FIGS. 1 and 2, the lens blank 1 is then “edged” or cut along a path 12 whose shape is generally defined by the shape of the selected frame. Eyeglass frames come in numerous shapes, primarily dictated by fashion. The translational and rotational position of the path on the lens blank is determined by the lens blank parameters and the eventual user's prescription. As disclosed in Kennedy U.S. Pat. No. 5,462,475, incorporated herein by this reference, accounting for the lens blank parameters generally requires the so-called “blocking” or holding of the lens blank in a specific orientation so that proper “edging” can occur. This is a time-consuming process which requires special skill by the operator who will typically use a lensometer to determine the lens blank parameters, temporarily mark the blank with one or more ink dots to represent the location and or orientation of those parameters, and precisely attaching a temporary blocking or holding structure in accordance with the markings. Attempts have been made to further automate the edging process by providing machines known as “self-blocking” devices which analyze a blank to determine its optical parameters, and “block” the blank automatically. Such devices tend to be expensive and handle lenses individually.

So called “rimless” eyeglasses have recently gained popularity. Rimless eyeglasses are typically formed by drilling through-holes in the peripheral edge portions of each of the edged lenses to facilitate the fastening of nose bridge and temple or earpiece structures thereon. A significant advantage of “rimless” lenses is that they do not require quite as accurate edging in order to adequately fit a given frame. However, because of the absence of the structurally stiffening and strengthening surrounding frame, many “rimless” designs can have a greater susceptibility to damage than their “rimmed” counterparts. Another disadvantage is that the mechanical drilling of the through-holes can cause stress damage to the lenses.

Another disadvantage of “rimless” eyeglasses is that they typically do not offer the same potential for frame ornamentation that “rimmed” eyeglasses do.

Lasers and abrasive water jet-type cutting devices have been used in the past to machine manufactured parts made from a number of different materials such as metal and plastic. Laser and abrasive jet machining typically requires time consuming programming for each part shape being made. Further, use of lasers and abrasive jets can induce heat and residual artifacts which can damage parts or require further machining.

It is often desirable to mark eyeglasses with a monogram or other identifying indicium in order to guard against theft or as a fashion feature. Some fashionable styles also requires engraving the various components of eyeglasses including the frame, the temple pieces and the nose bridge with decorative patterns, sometimes customly specified by the purchaser. Today there is no device or process that can fulfill these various tasks.

Therefore, there is a need for the more automated and economical edging of eyeglass and sunglass lenses which address some or all of the above described disadvantages.

SUMMARY

The instant invention provides a eyeglass component machining device that is programmed to edge prescription lenses out of standard blanks, bevel the edges of the lenses, drill attachment holes in lenses, frames, temple pieces and nose bridges. The device can engrave the periphery of the lenses and all the other eyeglass components with decorative of identifying designs. The device groups in a single enclosure, a laser cutting tool, a grinding tool, a platen equipped with a plurality of eyeglass component holding structures, and a programmable microprocessor. The tools are mounted on a position controllable carriage positioned above the platen. The microprocessor is programmed with edging, grinding, drilling and engraving routines that operate as a function of various parameters data sets including component location parameters, blank optical parameters, lens prescription optical parameters, and decoration parameters. Multiple tasks are performed on a complete array of eyeglass component in a single machining session.

Some embodiments provide a device for machining eyeglass components including lenses, frames, temple pieces, nose bridges, cases and cleaning swatches, which comprises: a holding platen including a plurality of component holding stations; each of said stations being shaped and dimensioned to fixedly hold one of said components; an electronic controlled cutting tool mounted about said platen; and a programmable microprocessor adapted to control the location, aim and cutting duration of said tool with respect to said stations according to component parameter data sets.

In some embodiments said machining of eyeglass lenses comprises edging lenses out of cylindrical or spherical lens blanks along edging paths selected as a function of defined optical parameters; and wherein said component parameter data sets comprise lens blank parameters and lens optical parameters.

In some embodiments said data set comprise lens engraving parameters. In some embodiments said data sets comprise frame engraving parameters. In some embodiments said data sets comprises temple piece engraving parameters. In some embodiments said data sets comprise eyeglass case engraving parameters. In some embodiments said data sets comprise cleaning swatch engraving parameters. In some embodiments said data sets comprises lens, frame, temple piece, nose bridge, case, and cleaning swatch engraving parameters. In some embodiments said data sets further comprise lens, frame, temple piece, nose bridge, case and cleaning swatch engraving parameters.

In some embodiments the machining device further comprises a position controllable grinding tool mounted about said platen; and wherein said programmable microprocessor is adapted to apply said grinding tool to peripheral areas of lenses.

In some embodiments said grinding tool comprises a cylindrical abrasive head having an axial spinning movement and a peripheral groove. In some embodiments said groove is shaped and dimensioned to bevel the edges of lenses.

In some embodiments said data sets comprise lens edging, beveling and engraving parameters. In some embodiments said lens engraving data sets comprise program routines for creating a dye-retaining tooth pattern in a marginal peripheral zone of said lenses.

In some embodiments said machining of lenses comprises drilling component attachment holes through said lenses; and said data sets comprise drill location parameters.

In some embodiments said platen comprises a plurality of vises sized to grasp a plurality of said components.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a prior art top plan view of a lens blank;

FIG. 2 is a prior art cross-sectional side view of the blank of FIG. 1 taken along line 2-2;

FIG. 3 is a prior art diagrammatic perspective view of a cylindrical lens blank;

FIG. 4 is a perspective view of an exemplary embodiment of an eyeglass component machining device;

FIG. 5 is a perspective view of the lens blank or lens-holding structure;

FIG. 6 is a cross-sectional frontal view of an alternate lens-holding structure;

FIG. 7 is a frontal view of an alternate lens-holding structure and lens beveling tool;

FIG. 8 is a perspective view of a machining instrument carriage;

FIG. 9 is a top plan view of engraved lens components; and

FIG. 10 is a map of the machining parameter data sets.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With further reference to the drawing, there is shown in FIG. 4 an eyeglass component machining device 13 housed in a cabinet 14 provided with an access opening 15 closed by a flap-door 16. A programmable microprocessor 17 is packaged in the bottom part of the enclosure. A pull-out tray 18 carries a platen 19 equipped with a plurality of eyeglass component-holding structures 20-24. A processing tool assembly 25 including a laser-cutting tool, a grinding tool, and an inking tool among others is mounted in the upper part of the cabinet 14.

It should be noted that the holding structures of the platen are positioned and dimensioned to fixedly hold the top surfaces of the various components—lens blanks or pre-edged lenses 26, frame 27, temple pieces 28, carrying case 29 and cleaning swatch 30—in about the same horizontal plane in order to facilitate access by the processing tools such as cutting, grinding and inking tools.

As illustrated in FIG. 5, each of the two lens-holding structures 20 comprises a substantially hollow cylindrical base 90. A “cookie-cutter” style lens-holding template piece 91 is secured elevationally and angularly to the top of the base by a bayonet style releasable connector 92. A pit 93 is set into the upper surface 94 of the template piece having a peripheral edge 95 shaped similarly to the pre-edged lens 96 and slightly oversized to accept and indicate a unique angular orientation of the lens. A set of three adjustable lens-supporting posts 31,32,33 project vertically from the bottom of the pit 93. An oval slot 97 through the upper surface and bottom of the pit allows the lens to be readily grasped along its top and bottom edges by the thumb and finger of an operator. The posts are threaded into mating threaded holes 98 so that their height can be adjusted by a screwing motion. It should be noted that the posts can be adjusted to support a pre-edged lens in the “concave-side-up” or “convex-side-up” orientation depending on the surfaces to be processed. Each post 31,32,33 is capped by a lens-supporting capital 34 having a top surface 35 made from a layer of an elastomeric material. Each capital is rockingly mounted on its post so that it will conveniently adjust the geometry of the bottom surface of the supported component. The top surface is optionally coated with a tacky substance that provides detachable adhesion to the lens.

It should be noted that for processing a single pair of eyeglass components the two lens-holding templates will have pits which are essentially mirror images of each other. Further, it shall be understood that a set of interchangeable template pieces are provided, each having a differently shaped pit so that the set can accommodate a number of different pre-edged lens shapes.

As shown in FIG. 6, an alternate lens-holding structure 100 is provided without a template piece. Instead posts 102,103 having rockingly mounted capitals support either a pre-edged lens or a lens blank 101 above a surface 104 of the lens-holding structure. A sensing tool senses the orientation and lens parameters during processing.

Referring now to FIG. 7, there is shown an alternate lens-holding structure which is adapted to releasably secure a pre-edged lens or lens blank 60 in either a “concave-surface-up” or “convex-surface-up” orientation. The lens is temporarily mounted to a blocking structure 82 having a generally cylindrical body 83 and an arcuate cup portion 84 often referred to as the “block” fastened to the top. The bottom surface of the cup portion is preferably shaped to have a keyed prominence 85 which engages a correspondingly shaped depression 86 in the top of the body in a specified angular orientation. A magnet 88 located adjacent to and below the depression releasably secures the ferro-magnetic material cup portion to the body.

The use of an angularly keyed interlocking structure between the cup portion and the body allows a lens blank to be optically “blocked” or just merely held in place by the blocking structure. If the blank is optically “blocked”, some of the lens blank parameters can be ignored during processing. The cup supports an arcuate leap pad 87 made of resilient material such as foam rubber. The top and bottom surfaces of the pad have sticky layers 81 for contacting the blank and cup, and securing them against unwanted relative movement. The blocking structure is releasably bonded to the platen 19 by means of a magnet 89 located at the bottom end of the body where the platen is made at least partially from a ferro-magnetic material.

Referring back to FIG. 4, the frame-holding structure 21 is essentially a vise which clamps the frame 27 between a back ledge 36 and a post 37 sized to nest against the nose bridge of the frame. A pair of height adjustable prongs 36B extend from the back ledge and support the frame. In the case of a rimless set of eyeglasses, the holding structure 21 is used to simply hold a nose bridge. It should be noted that the positioning of the frame 27 can be adjusted by moving a pair of wedge elements 63 which, as they progress under the frame force it to tilt upward. Optionally, an additional pair of wedge elements may be provided to extend from the back ledge 36 in place of the support prongs 36B to prove further adjustment of the part of the frame opposite the first pair of wedge elements 63.

The temple piece holding structure 22 consists essentially of twin vises in which each temple piece is clamped between a central wall 38 and a pair of jaws 39 astride the wall 38.

The case-holding structure 23 consists essentially of two resiliently flexible plates 40, 41 between which the case 29 is clamped. Alternately, or in addition to the plates, a number of spacers 29A can be used to adjust the height of the case. The cleaning swatch holding structure 24 consists essentially in a horizontal table.

As illustrated in FIG. 7, the cylindrical wheel 55 of the grinding tool has a circular, peripheral groove 58 whose profile is configured to form a double bevel 59 on the periphery of a lens 60.

A pair of rulers 61, 62 mounted orthogonally to one another on the platen in the working plane of the top surface of the various components provide a convenient reference for mapping the location of the various components about the platen by way of a locator program that analyses a digital image provided by a camera 77 mounted over the platen.

The tool assembly 25 includes a X-Y carriage 42 as illustrated in FIG. 8. The front-to-back movement of the carriage is provided by two synchronized motors 43, 44 driving a pair of threaded stems 45,46 through supporting blocks 47,48. One of the blocks 48 holds two synchronized motors 49,50 driving two threaded shafts 51,52 orthogonal to the aforesaid threaded stems 45,46. The two shafts engage a first platform 53 carrying a laser-cutting tool 57, a vacuum tool 57B for extracting fumes, and an ink jet tool 82, and a second platform 54 carrying a grinding tool 55B, a dry air blower tool 55C for cleaning off dust and debris, an optional sensor tool 55D comprising a measurement laser or camera 55E for locating various components or component features and a removable/replaceable automated protective dust cover 55F. It is understood that any of the tools may utilize an automatically retractable protective cover if necessary to avoid dust or debris fouling the tool head.

Each of the platforms has a internal clutch that allows it to be optionally engaged with the shafts 51, 52. Accordingly, by coordinating the operation of the various motors and internal clutches, any or all of the tools can be positioned at any coordinate location above the components held on the platen 19. The grinding tool is also provided with a depth adjustment mechanism whereby a cylindrical abrasive grinding wheel 55 that spins axially can be accurately lowered against the edges of the lenses.

The head 56 of the laser cutting tool is mounted on a controllable universal joint 57A that allows the laser beam to be accurately aimed toward its target.

The aforesaid machining device 13 can perform a variety of edging, engraving, beveling, sensing, cleaning and drilling operations of which exemplary results are illustrated in FIG. 9.

The laser-cutting tool 57 can be used to edge a pair of eyeglass lenses from lens blanks as a function of lens location parameters, the optical property parameters of the blanks and of the desired lens according to the techniques described in the background of this specification. Additionally, and in the case of rimless eyeglasses, the laser tool can drill attachment holes 64, 65 on either side of the lens. The laser tool can also be used to drill holes 66, 67 in the nose bridge. The tool can also be used to drill holes 68 in the temple pieces and holes 69, 70 in the frame.

The laser tool 54 can also be used to engrave the surface of a peripheral marginal zone 71 of a lens with a fine tooth that will retain a dye into which the lens is later dipped, or retain ink deposited by the ink jet head 82. The colored zone provides a decorative element which, in the case of a frame-less eyeglass assembly, simulates a frame around the lens. Alternately, the engraving can create a decorative pattern consisting of cross-hatching 72, series of circles or stars 73 or other whimsical designs 74 on either or all of the peripheral zones of the lenses, the sides of the temple pieces, the frame or the nose bridge. A monogram 75 can also be engraved in a corner of one of the lenses.

In order to perform the various above-described machining tasks the microprocessor 17 is programmed with a number of routines including a routine for edging lenses, a routine for beveling the edge of a lens, a routine for etching a dye-retaining or ink-retaining tooth on the surface of a lens or components, routines for engraving the surface of components, routines for ink-jet printing on the surface of lenses or components, routines for cleaning the surface of lenses or components, hole drilling routines, and routines for protecting unused tool head against fouling. The microprocessor also stores the parameter data sets 115 that are listed on the map of FIG. 10. The data base of the computer must be provided with component location parameters 116 that define the coordinates of each of the various components that constitute the work piece for the cutting, grinding or coloring tool. These component locations are preferably obtained by processing a digital picture of the fully loaded platen taken by a digital camera 77 mounted against the ceiling of the enclosure 14 as shown in FIG. 4, or by the sensing tool 55D if present. The picture is scanned to define the coordinates of shape-defining-pixels for each component. These coordinates are then used to direct the position and aim of the laser-cutting tool 57 and the position and height of the grinding tool 55, and the position of the inking tool 82.

In the case where lenses must be cut from blanks, the data base must include the optical characteristics of the blanks 118, the desired optical properties 119 of the lens, and a definition of the edging path to be followed by the cutting tool.

The data base must also include the exact drilling location coordinates 120 for the various work pieces.

Finally, the coordinates of the areas to be engraved 121 of the various components must also be provided.

While the preferred embodiment of the invention has been described, modifications can be made and other embodiments may be devised without departing from the spirit of the invention and the scope of the appended claims.

Claims

1. A device for machining eyeglass components including lenses, frames, temple pieces, nose: bridges, cases and cleaning swatches, which comprises:

a holding platen including a plurality of component holding stations;

each of said stations being shaped and dimensioned to fixedly hold one of said components;

an electronic controlled cutting tool mounted about said platen; and

a programmable microprocessor adapted to control the location, aim and cutting duration of said tool with respect to said stations according to component parameter data sets.

2. The device of claim 1, wherein said machining of eyeglass lenses comprises edging lenses out of cylindrical or spherical lens blanks along edging paths selected as a function of defined optical parameters; and

wherein said component parameter data sets comprise lens blank parameters and lens optical parameters.

3. The device of claim 1, wherein said data set comprise lens engraving parameters.

4. The device of claim 1, wherein said data sets comprise frame engraving parameters.

5. The device of claim 1, wherein said data sets comprises temple piece engraving parameters.

6. The device of claim 1, wherein said data sets comprise eyeglass case engraving parameters.

7. The device of claim 1, wherein said data sets comprise cleaning swatch engraving parameters.

8. The device of claim 1, wherein said data sets comprises lens, frame, temple piece, nose bridge, case, and cleaning swatch engraving parameters.

9. The device of claim 2, wherein said data sets further comprise lens, frame, temple piece, nose bridge, case and cleaning swatch engraving parameters.

10. The device of claim 1 which further comprises a position controllable grinding tool mounted about said platen; and

wherein said programmable microprocessor is adapted to apply said grinding tool to peripheral areas of lenses.

11. The device of claim 10, wherein said grinding tool comprises a cylindrical abrasive head having an axial spinning movement and a peripheral groove.

12. The device of claim 11, wherein said groove is shaped and dimensioned to bevel the edges of lenses.

13. The device of claim 12, wherein said data sets comprise lens edging, beveling and engraving parameters.

14. The device of claim 3,wherein said lens engraving data sets comprise program routines for creating a dye-retaining tooth pattern in a marginal peripheral zone of said lenses.

15. The device of claim 1, wherein said machining of lenses comprises drilling component attachment holes through said lenses; and

said data sets comprise drill location parameters.

16. The device of claim 1, wherein said platen comprises a plurality of vises sized to grasp a plurality of said components.