Dual ophthalmic lens machining platform and simultaneous ophthalmic lens manufacturing method

A dual ophthalmic lens machining platform comprises a blocked lens mounting structure constructed to simultaneously receive a first and a second blocked lens blank, and configured to rotationally and linearly move each lens blank, wherein the first and second lens blank have at least one common axis of movement on the mounting structure; and at least one machine tool adapted to machine each lens blank. A method of manufacturing ophthalmic lens comprises the steps of mounting at least a first and a second blocked lens blank on the machining platform; and simultaneously performing at least one machining process on the two blocked lens blanks on the machining platform. The dual ophthalmic lens machining platform is configured to simultaneously receive and machine a left and a right blocked lens blank for forming a left and a right lens of a pair of eyeglasses.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the manufacture of ophthalmic lenses. Specifically this invention relates to a dual ophthalmic lens machining platform and a method of simultaneously manufacturing pairs of ophthalmic lens.

2. Background Information

In the art of ophthalmic lens manufacture, finished ophthalmic lenses are usually made from finished uncut lenses or from semi-finished lens blanks. Finished uncut lenses are lenses that are optically finished on both front and back surfaces and only need to be edged to the proper shape and edge contour to become finished lenses. Semi-finished lens blanks have optically finished front surfaces; however, the back surfaces of these blanks need to be generated and fined and are then polished and/or coated to produce finished uncut lenses. The finished uncut lenses are then edged to the proper frontal shape and edge contour to fit into spectacle frames or other mounting structures. Within the meaning of the present application the terms spectacle, eyeglasses, or glasses can be used interchangeably. Single vision lenses that are outside the normal range of inventoried finished uncut lenses, and most multi-focal lenses, are made from semi-finished lens blanks. Semi-finished lens blanks are made with various front surface curve radii, and have various topographies including spherical, aspheric, hyperbolic, irregular aspheric such as progressive add lenses, and poly-spheric, such as executive type segmented bifocals and trifocals. Any specific semi-finished lens blank can be finished into a range or species of finished lens whereby each blocked lens blank is associated with a species of eyeglass prescriptions.

In order to generate a desired lens according to a specific prescription, calculations are required to determine the topography of the back surface of the lens. Such calculations typically involve variables that include the front surface radii of the semi-finished blank, the index of refraction of the lens blank material, prescription values of the desired lens, statutory values regarding minimum lens thickness, and the physical dimensions of the frame or mounting structure. In the art, various mechanisms have been devised to accomplish the physical process of producing a back surface of optical quality. Most of these methods begin by generating a back surface that approximates the desired back surface topography and surface smoothness. This approximate surface is then fined to a more perfect approximation in both curvature and surface smoothness. After the appropriate accuracy and smoothness is achieved in the fining process, the surface is then polished or surface coated to produce a surface of optical quality. The optically finished lens blank is then edged to the proper shape and edge profile to fit into the frame for which it was made. Finished lens may be further coated with tinting coatings, photo-chromic coatings, scratch resistant coatings (i.e. hard coats).

Many business entities that sell ophthalmic lenses do lens finishing as a profit center activity and as a way to expedite delivery of single vision lenses. Only a small percentage of these entities also do surfacing of ophthalmic lenses. The business volume of most of these entities cannot justify the costs of acquiring and operating a conventional surfacing laboratory as known in the art. Surfacing laboratory setup costs have heretofore been several times the cost of setting up a laboratory for edging only.

Hiring qualified technicians for ophthalmic lens finishing or training personnel to perform ophthalmic lens finishing is relatively easy. However, hiring and training optical technicians to operate a surfacing laboratory is not easy. In many communities it is very difficult to find personnel that are trained in surfacing on conventional equipment. Technicians who are qualified to do surfacing are generally remunerated at higher pay scales than technicians skilled only in edging.

In addition to the significantly higher equipment and personnel costs of a surfacing lab, there are also higher ongoing costs for the additional lab space required. At least several hundred square feet of operational space and storage space have heretofore been required for a full service surfacing and edging ophthalmic lens laboratory. Consequently there is a need for a system and method of ophthalmic lens manufacture that would significantly reduce the investment required to acquire a surfacing and edging laboratory. There is a further need for a system and method of ophthalmic lens manufacture that significantly reduces the costs associated with operating a surfacing and edging laboratory. Further, there is a need for a system and method of ophthalmic lens manufacture that is operative to perform surfacing and edging by an operator with little skill in the art.

Further, in the prior art, the processes of surfacing and edging are done on at least two separate machines. In the prior art, blocking for surfacing and edging required two separate blocking devices. Also in the prior art, the individual processes of lap tool surfacing and lens cribbing and safety beveling and edge grooving and edge polishing and lens engraving each requires its own machine or device or machine augmentation. Consequently, there is therefore a need for a system and method of ophthalmic lens manufacture that reduces the need to employ a plurality of expensive and complex machines to manufacture lenses.

Prescription lenses for patients are generally generated in pairs (i.e. right and left lenses) for a spectacle frame. Prior art systems typically generate each lens independently. Production cycle times for generating lenses may be reduced by employing multiple, independent, surfacing and edging machines in the laboratory to generate pairs of lenses, however duplication of equipment at least doubles the acquisition and operational costs of the laboratory. Thus there exists a need for a system and method of ophthalmic lens manufacture that provides for reduced production cycle times for pairs of prescription lens without significantly increasing costs for the laboratory.

SUMMARY OF THE INVENTION

It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent. For the purposes of this specification, unless otherwise indicated, all No.s expressing any parameters used in the specification and claims are to be understood as being modified in all instances by the term “about.” All numerical ranges herein include all numerical values and ranges of all numerical values within the recited numerical ranges.

The various embodiments and examples of the present invention as presented herein are understood to be illustrative of the present invention and not restrictive thereof and are non-limiting with respect to the scope of the invention. It is an object of the present invention to overcome the deficiencies in the prior art and to provide for efficient, effective simultaneous manufacture of ophthalmic lens using remotely a dual ophthalmic lens machining platform. It is a further object of the exemplary form of the present invention to provide a system and method for ophthalmic lens manufacture that is operative to perform surfacing of both lenses of a pair of lenses at the same time. It is a further object of the exemplary form of the present invention to provide a system and method for ophthalmic lens manufacture that is operative to perform edging of both lenses of a pair of lenses at the same time.

The above stated objects are achieved at least in part with a method of manufacturing ophthalmic lens according to one non-limiting aspect of the present invention. The method of manufacturing ophthalmic lens comprising the steps of: providing a machining platform that is operative to concurrently machine two ophthalmic lens and wherein the machining platform has at least one common axis of motion for the two ophthalmic lens being machined; mounting at least a first and a second blocked lens blank on the machining platform; and simultaneously performing at least one machining process on the two blocked lens blanks on the machining platform.

In one non-limiting aspect of the method of manufacturing ophthalmic lens according to the invention the step of simultaneously performing at least one machining process on the two blocked lens blanks on the machining platform includes simultaneously machining left and right ophthalmic lens from the blocked lens blanks on the machining platform.

In one non-limiting aspect of the method of manufacturing ophthalmic lens according to the invention, the step of simultaneously performing at least one machining process on the two blocked lens blanks on the machining platform includes back surface generation of the lens blanks and edging of the lens blanks. The back surface generation of each lens blank may include machining a back surface of the lens blank responsive to data representative of an eyeglass prescription. The edging of each lens blank may include machining an edge of the lens blank to include a contour adapted to be mounted in the lens receiving portion of an eyeglass frame responsive to data representative of the lens receiving portion. Each lens blank may remain blocked throughout the back surface generation and the edging of the lens blanks.

In one non-limiting aspect of the method of manufacturing ophthalmic lens according to the invention, the lens blanks are mounted on the lens blocks without regard to specific lens prescription data.

In one non-limiting aspect of the method of manufacturing ophthalmic lens according to the invention, the at least one common axis of motion for the two ophthalmic lens blanks being machined includes a common rotary axis for each lens blank, or a common linear axis, or both. In one non-limiting aspect of the method of manufacturing ophthalmic lens according to the invention, the common axis of motion for the two ophthalmic lens blanks being machined includes two common linear axes for each lens blank.

The above stated objects are achieved at least in part with a method of manufacturing ophthalmic lens according to one non-limiting aspect of the present invention. The method of manufacturing a pair of ophthalmic lens for a pair of eyeglasses comprising the steps of: providing a machining platform that is operative to concurrently machine two ophthalmic lenses; mounting a left and a right blocked lens blank on the machining platform adapted to form a left and a right lens for a pair of eyeglasses; and simultaneously performing at least one machining process on the left and right blocked lens blanks on the machining platform.

The above stated objects are achieved at least in part with a dual ophthalmic lens machining platform according to one non-limiting aspect of the present invention. The dual ophthalmic lens machining platform comprises: a blocked lens mounting structure constructed to simultaneously receive a first and a second blocked lens blank, and configured to rotationally and linearly move each lens blank, wherein the first and second lens blank have at least one common axis of movement on the mounting structure; and at least one machine tool adapted to machine each lens blank.

In one non-limiting aspect of the dual ophthalmic lens machining platform according to the invention the blocked lens mounting structure includes an arbor that rotationally supports both blocked lens blanks. In one non-limiting aspect of the dual ophthalmic lens machining platform according to the invention the blocked lens mounting structure includes a first mounting stage that receives the first lens blank and a second mounting stage that receives the second lens blank and wherein the first and second stages share a common linear actuator. Machine tools may be provided for each lens blank that are configured to perform back surface generation of the lens blanks and edging of the lens blanks. The blocked lens mounting structure may be configured to simultaneously receive and machine a left and a right blocked lens blank for forming a left and a right lens of a pair of eyeglasses.

These and other advantages of the present invention will be clarified in the brief description of the preferred embodiment taken together with the drawings in which like reference numerals represent like elements throughout.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-7illustrate and highlight the dual ophthalmic lens machining platform and simultaneous ophthalmic lens manufacturing method to which the present invention is directed. However, the blocking technique for the pre-blocked lens blanks, the machine tool configuration and control (e.g., tool path generation) and the machining particulars are described in U.S. Pat. Nos. 7,086,928; 6,953,381; and 6,568,990 as well as publication No.s 2006-0166609, 2005-0266772, 2003-0181133 and 2001-0051490 which are incorporated herein by reference in their entirety. The present disclosure focuses on the particulars of the dual ophthalmic lens machining platform and simultaneous ophthalmic lens manufacturing method.

FIG. 1shows an exemplary machining platform10that is operative to concurrently surface and edge two ophthalmic lenses from blocked lens blanks12and14. The exemplary machining platform10may be further operative to machine both custom blocks for blocking lens blanks and both surface lap tools for polishing and fining ophthalmic lenses generated by the machining platform10.

The exemplary machining platform10includes an articulation shaft16and a mounting stage18in operative connection with the articulation shaft16. In the exemplary embodiment a computer system of the present invention is operative to selectively rotate the articulation shaft16to raise or lower the position of the mounting stage18. The exemplary mounting stage18includes an arbor20which is selectively rotatable responsive to the computer processor. The arbor20is operative to receive two mounting blocks or blocked lens blanks12and14positioned at opposed ends of the arbor20.

The machining platform10further comprises at least one ball slide carriage22, at least two machining tools24and26and two spindle motors28and30. The spindle motors28and30are in operative connection with the at least one ball slide carriage22and are positioned adjacent the opposed ends of the arbor20. Each tool24and26is in releasable connection with a spindle motor28and30as will be understood by those of ordinary skill in the art. The spindle motors28and30are operative to rotate the tools24and26and are independently operative responsive to the computer processor to move toward and away from the arbor ends along the ball slide carriage22. In the exemplary embodiment the articulation shaft16is turned by a planetary gear motor32mounted on the end of the articulation shaft16. The arbor20is turned by the right angle gear motor34responsive to the computer processor.

In the exemplary embodiment of the machining platform10, the computer processor is operative to selectively move the machining tools24and26relative the ends of the arbor20through a plurality of tool paths for machining custom blocks, surfacing and edging lens blanks12and14, and surfacing lap tools. In addition to machining two lenses from lens blanks12and14simultaneously, two lap tools simultaneously, or two mounting blocks simultaneously, the exemplary embodiment of the machining platform may further be used to simultaneously machine both a block and a lap tool for a particular lens. In addition the exemplary machine may be used to simultaneously machine a lens and a corresponding lap tool for the lens.

FIG. 2shows the exemplary machining platform10in a configuration that enables an operator to more easily mount and remove blocked lens blanks12and14, lap tools and finished lenses from the machine platform10. Here the articulation shaft arbor16responsive to the computer processor has rotated the mounting stage18upwardly to move the arbor20away from the machining tools24and26. In this exemplary orientation, the tools24and26may also be more easily removed.

An alternative exemplary embodiment of a machining platform for the present invention is shown inFIGS. 3-5.FIG. 3shows a top plan view of the machining platform400andFIG. 4shows a front view of the machining platform400. The machining platform400includes an arbor402mounted on a mounting stage404. The arbor402is rotated by a servo-motor412in operative connection with the arbor402.

The arbor402is operative to receive two blocked lens blanks406and408on opposed ends of the arbor402. By selectively rotating the arbor with the servo motor412, the angular orientation of the lenses can be changed. The machining platform400also includes two spindles414and416, with tools418and419that are positioned adjacent to each of the lens blanks406and408. In this described exemplary embodiment the axis of rotation of the tools418and419is orientated parallel to the axis of rotation of the arbor shaft. However, in other alternative embodiments other angular relationships between the spindles414and416and the arbor shaft may be used depending on the shape of the machining tool and the type of machining operation being performed.

Each of the spindles414and416is operative to move independently of each other toward and away from the lens blanks406and408respectively. This enables the machining platform400to machine the back surfaces of the lens blanks406and408simultaneously according to different prescription specifications for each lens being generated.

FIG. 5shows a side view of machining platform400. As shown inFIG. 5the machining platform400is operative to selectively move the arbor in a plane perpendicular to the axis of rotation of the arbor shaft. In this described exemplary embodiment this is accomplished by having the mounting stage pivot at pivot point432of a pivot support428. The amount of pivot angular rotation is selectively controlled by a stage-moving device420. In this described exemplary embodiment the stage moving device420includes a ball slide422in operative connection with an end portion426of the mounting stage. The ball slide422is selectively driven along a ball screw423with a servo motor424that is operatively configured to selectively rotate the ball screw423. The end portion426of the mounting stage moves up or down responsive to the movement of the ball slide422. As a result the angular position of the mounting stage404can be selectively adjusted to move the arbor402and the lens blanks406and408relative to the machining tools.

In this described exemplary embodiment the pivot point432is located between the stage moving device420and the arbor402. However, in alternative embodiments the arbor402may be located between the pivot point432and the stage moving device420or the stage moving device420may be located between the pivot point432and the arbor402. The mounting stage may also include an encoder430at the pivot point432that is operative to measure the amount of angular rotation of the mounting stage relative the pivot support428. Alternatively, a linear encoder could be used to monitor the linear position of a portion of the mounting stage. The feedback output of the encoder is used by the machining platform to control the operation of the servo motor of the stage moving device. This enables the system to accurately place the arbor in the proper position for machining the lens blanks according to the calculated tool paths.

FIG. 6shows a schematic view of a further alternative exemplary embodiment of a machining platform800of the present invention. Here the machining platform800includes two mounting stages802and804upon which blocked semi-finished lenses806and808are mounted for back surface generating and edging, and upon which reusable lap tools are mounted for surfacing. With two mounting stages802and804, both right and left lenses are surfaced and edged at the same time from lens blanks806and808. Similarly both the right and left mounting blocks and right and left lap tools for lenses may also be surfaced simultaneously with machining platform800.

In this described embodiment the machining platform800includes an x-axis ball slide810and two y-axis ball slides812and814. The x-axis ball slide810comprises a servo or stepper motor816, a right handed ball screw818, a flexible coupling820, and a left handed ball screw822. The mounting stage804for right lenses and right lap tools is driven by the left handed ball screw822and the mounting stage802for left lenses and left lap tools is driven by the right handed ball screw818. The two stages802and804travel along the x-axis in synchronized opposing motion. The two ball screws are in operative connection with a flexible connector which couples the motion of the right-handed ball screw that is in direct connection with the drive motor with the motion of the left-handed ball screw. This arrangement enables the single motor816to drive both mounting stages802and804in coordinated opposing motion.

As shown inFIG. 7, the single x-axis ball slide810is mounted on the two parallel y-axis ball slides812and814so both stages always move together in the y-axis. The y-axis ball slides812and814are also driven by a single servo or stepper motor (not shown). With this exemplary configuration, when one stage performs a circular motion in the x-y plane moving clockwise, the other stage performs precisely the same circular motion but moving counterclockwise.

In this described embodiment, the machining platform includes two high speed spindles824and826with corresponding tools828and830. Spindle824for machining a left lens or left lap tool is in operative connection with a left z-axis ball slide832. Spindle826for machining a right lens or right lap tool is in operative connections with a right z-axis ball slide834. The two stages802and804move under the z-axis spindles824and826for simultaneous edging of both right and left lenses and for simultaneous surfacing of both right and left lenses. The two z-axis ball slides832and834are positioned generally perpendicular to the two y-axis ball slides812and814. The z-axis position of each spindle tool is driven by its own servo motor or stepping motor836and838. The motion of one tool can be and usually is independent of the other tool.

For all the described embodiments, the tools should rotate in opposite directions for the best results. Consequently, the tools affixed to each spindle require right or left isometric edge configurations appropriate for its spindle rotational direction and normal tool path direction. This allows both tools to cut uphill at the same time with conventional milling. Without opposing rotation, one spindle would be performing conventional milling while the other would be performing so called “climb” cutting. This opposing rotational direction is necessary in order to get similar finishes on the edges of the lenses.

Although the present invention has been described with particularity herein, the scope of the present invention is not limited to the specific embodiment disclosed. It will be apparent to those of ordinary skill in the art that various modifications may be made to the present invention without departing from the spirit and scope thereof. The scope of the present invention is defined in the appended claims and equivalents thereto.