Patent Publication Number: US-2023162469-A1

Title: Device (system) and method for determining edge profile of lens

Description:
CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM TO PRIORITY 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/282,765 filed Nov. 24, 2021 by Debus et al., which is incorporated herein by reference in its entirety and to which priority is claimed. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to processing ophthalmic (or optical) lenses in general and, more particularly, to a device and process for detecting the exact location and 3D profile of an outer peripheral edge of an edged lens. As a result of the shape and dimensions of the edge/profile, an exact 3D representation of the outer peripheral edge profile is obtained to be used in subsequent processing steps, such as application of liquid to (or coating with a liquid) an outer peripheral profile of a finished optical lens. 
     2. Description of the Related Art 
     Typically, peripheral features are machined onto an ophthalmic (or eyeglass) lens for settling the ophthalmic lens in an eyeglass frame selected by an eyeglass wearer. Eyeglass frames may have a groove or a bevel or some other configuration for seating with the edged lens. Correspondingly, the periphery of the lens will be shaped to complement the frame, to allow the lens to seat with the frame. The term ophthalmic (or eyeglass) lens as used below, is an optical lens or lens blank for eyeglasses made of the usual materials, i.e., inorganic glass or plastics, such as polycarbonate, CR-39®, Spectralite®, etc., and with a circumferential (or outer) lens edge of any shape, which lens or lens blank may be machined or generated on an optically effective surface prior to machining of the lens edge. 
     The purpose of ophthalmic lens edge machining is to make the ophthalmic lens ready for insertion into an eyeglass frame. Consequently, the ophthalmic lens is provided, when viewed in plan, with a circumferential contour which is substantially complementary to the circumferential contour of the eyeglass frame. Also, it may be necessary, depending on the type of lens holder, to form a groove or bevel at the ophthalmic lens edge, which serves for securing the ophthalmic lens to the eyeglass frame. To ensure that the ophthalmic lens fits into the eyeglass frame after edge-machining, or to be able to determine the position of the groove or bevel on the ophthalmic lens edge, the edge of the ophthalmic lens is measured after a preliminary machining stage, which is then finalized taking account of the measured edge data, optionally with formation of the groove or bevel. 
     The ophthalmic lens edge or a portion thereof may be coated with at least one functional layer formed by a substance (such as UV curing polymer blend) that is applied in liquid form to the outer edge of the ophthalmic lens, is chemically cured or radiation-cured, and is integrally bonded with the eyeglass lens upon curing. 
     Currently there is no system known that is able to accurately provide all geometric data related to the 3D outer peripheral edge profile of an ophthalmic lens. There are two basic systems available in different styles and executions that provide part of the information obtained by the invention: probing/measuring system in lens edger and tracer system. 
     Probing/measuring in lens edger: Every patternless lens edger requires measuring the ophthalmic lens edge positions (front and back edge of the lens) at some point during the processing. This is necessary to be able to position bevel, groove, safety bevel, etc., correctly on the lens edge. Most edgers perform this measurement after the initial rough cut with a tactile (or mechanical contact) method illustrated in  FIG.  1   . The QM-X4 edger available from National Optronics implements such a technique. However, none of the edgers measures ophthalmic lenses with lens edge profiles different from just a flat edge. Additionally, only Z axial information is retrieved, for axial lens edge location the edgers rely on their CNC positions from cutting the ophthalmic lens in the roughing step. 
     Tracer: Tracers, such as the 4Tx tracer available from National Optronics, are configured to measure the shape of the eyeglass frame and/or the shape of original (or unfinished) ophthalmic lenses (dummy lens and pattern). Existing tracers are available with tactile systems using a stylus (as illustrated in  FIGS.  2 A and  2 B ) or an optical measuring system. While tactile tracers measure the frame itself wherever possible (such as the lens edges with V-Bevel) and only rely on a demo lens for rimless/groove edges, optical tracers use the demo lens for all lens edge types. If an eyeglass frame is measured, the obtained frame shape data can be two- or three-dimensional, depending on the make and model of the tracer. The 3rd dimension is related to the groove in the eyeglass frame, not the ophthalmic lens itself. If a demo lens is measured, the obtained shape data is most often two-dimensional, although some tracers are capable of providing axial data for the center of a bevel feature. Even if axial data is obtained from tracing a demo lens, this data does not include any information about the lens edge profile. Axial data is also of relatively low accuracy and is used only for calculating lens edge circumference. When tracing a beveled lens, radial data is only collected at the apex of the bevel of the lens edge profile, and no information about bevel shape (height, angle, etc.) is collected. When tracing a grooved shape of the lens edge profile, only the rimless shape is measured; no information about the groove (width, axial position, etc.) is collected. 
     Moreover, none of the existing systems provides an exact 3D edge profile of ophthalmic lenses. As described before, some of the information is available from the lens tracers, some from the measuring step in the lens edger, but the full 3D edge profile cannot be established with existing solutions. While one might attempt to calculate the full 3D profile of the final lens from edger tool and tool path data, this data is not commonly available. Further, even if it would be available, the accuracy is not sufficiently high given inaccuracies in the tool geometry descriptions, machine calibrations, and flexing of the lens while clamped in the edger and force is applied to the edge by the machining cutter during edging. 
     BRIEF SUMMARY OF THE INVENTION 
     According to a first aspect of the invention, a machine for processing an edge profile of an ophthalmic lens is disclosed. The ophthalmic lens includes first and second opposite optical surfaces, and an outer peripheral edge defined therebetween. The machine defines mutually perpendicular X, Y and Z axes. The machine includes a machine frame, and a lens holder unit for selectively holding the ophthalmic lens. A laser scanner unit is provided for determining a profile of the outer peripheral edge of the ophthalmic lens when mounted to the lens holder unit. A main controller is operatively connected to each of the lens holder unit and the laser scanner unit for controlling and operating the lens holder unit and the laser scanner unit. Each of the lens holder unit and the laser scanner unit are mounted to the machine frame. The lens holder unit is moveable relative to the machine frame between a home position in which the ophthalmic lens is held away from the laser scanner unit, and a working position in which the ophthalmic lens is positioned adjacent the laser scanner unit. The lens holder unit is configured to selectively rotate the ophthalmic lens around a C-axis of the lens holder unit, to tilt the ophthalmic lens relative to the laser scanner unit, and to move rectilinearly relative to the machine frame in the direction of the Y axis. The laser scanner unit is selectively moveable rectilinearly relative to the machine frame in the X and Z axes. 
     According to a second aspect of the invention, a method for processing an edge profile of an ophthalmic lens is disclosed. The ophthalmic lens includes first and second opposite optical surfaces, and a continuous outer peripheral edge defined therebetween. The method includes the steps of securing an ophthalmic lens to a lens holder unit. The lens is then positioned in a working position adjacent a laser scanner unit A laser scan is conducted by a lens scanner by the laser scanner unit. The laser scanning includes directing a diffused laser beam projected from the laser scanner unit onto an outer peripheral edge of an ophthalmic lens from the laser scanner unit, sensing a reflected laser beam from the outer peripheral edge by the laser scanner unit, and determining an edge profile of the outer peripheral edge of the ophthalmic lens. 
     Yet another aspect is a machine for application of liquid to an edge profile of an ophthalmic lens. The ophthalmic lens includes first and second opposite optical surfaces, and a continuous outer peripheral edge defined therebetween. The machine defines mutually perpendicular X, Y and Z axes. The machine includes a machine frame, a lens holder unit for selectively holding the ophthalmic lens, and a laser scanner unit for determining a profile of the outer peripheral edge of the ophthalmic lens mounted to the lens holder unit. A liquid dispensing unit is moveably mounted to the machine frame, and is configured to apply a liquid coating to at least a portion of the outer peripheral edge of an ophthalmic lens. A UV light curing unit is mounted to the machine frame, and is configured to cure the liquid applied to the outer peripheral edge of the ophthalmic lens based on the profile of the outer peripheral edge of the ophthalmic lens determined by the laser scanner unit. The machine further includes a main controller operatively connected to each of the lens holder unit, the laser scanner unit, the liquid dispensing unit and the UV light curing unit for controlling and operating the lens holder unit, the laser scanner unit, the liquid dispensing unit and the UV light curing unit. The lens holder unit is moveable relative to the machine frame between a home position in which the ophthalmic lens is held away from the laser scanner unit, and a working position in which the ophthalmic lens is positioned adjacent the laser scanner unit. The lens holder unit is configured to selectively rotate the ophthalmic lens around a C axis of the lens holder unit, to tilt the ophthalmic lens relative to the laser scanner unit around a B axis, and to move rectilinearly relative to the machine frame in the directions of the Y axis. The laser scanner unit selectively moveable rectilinearly relative to the machine frame in the X and Z axes. 
     Other aspects of the invention, including system, devices, methods, and the like which constitute parts of the invention, will become more apparent upon reading the following detailed description of the exemplary embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are incorporated in and constitute a part of the specification. The drawings, together with the general description given above and the detailed description of the exemplary embodiments and methods given below, serve to explain the principles of the invention. The objects and advantages of the invention will become apparent from a study of the following specification when viewed considering the accompanying drawings, in which like elements are given the same or analogous reference numerals. In these drawings: 
         FIG.  1    illustrates a probing/measuring system in lens edger of the prior art; 
         FIG.  2 A  illustrates a tracer system of the prior art for an ophthalmic lens with V-bevel; 
         FIG.  2 B  illustrates a tracer system of the prior art for an ophthalmic lens with groove; 
         FIG.  3    illustrates an ophthalmic lens with a standard bevel edge; 
         FIGS.  4   a - i    illustrate ophthalmic lenses with different edge structures; 
         FIG.  5 A  is a perspective view of a machine for determining the peripheral shape and dimensions of a lens edge and for application of liquid to the edge profile of an ophthalmic lens in accordance with an exemplary embodiment of the present invention with the ophthalmic lens in a home position; 
         FIG.  5 B  is a partial perspective view of the machine of  FIG.  5 A  with the ophthalmic lens in a working position; 
         FIG.  6    is a block diagram of a control system of the machine of  FIG.  5 A  according to exemplary embodiment of the present invention; 
         FIG.  7    is an enlarged partial perspective view of the machine of  FIG.  5 B  showing a laser scanner unit and a lens holding unit in the working position; 
         FIG.  8    is an enlarged partial side view of the machine of  FIG.  5 B  showing the laser scanner unit and the lens holding unit in the working position; 
         FIG.  9    is a front view of the laser scanner unit scanning the ophthalmic lens; 
         FIG.  10    is a side view of the laser scanner unit scanning the ophthalmic lens; 
         FIG.  11 A  is a front view of the laser scanner unit scanning an ophthalmic lens having a concave section; 
         FIG.  11 B  is a front view of the laser scanner unit scanning the ophthalmic lens having the concave section, which is rotated with respect to the position of the ophthalmic lens in  FIG.  11 A ; 
         FIG.  12 A  is a front view of the laser scanner unit scanning the ophthalmic lens, wherein an angle of a projected laser line with respect to the outer peripheral edge of the ophthalmic lens is significantly less than 90°; 
         FIG.  12 B  is a front view of the laser scanner unit scanning the ophthalmic lens, wherein the ophthalmic lens is rotated and offset from the projected laser line in Y-direction relative to a position of the ophthalmic lens in  FIG.  12 A ; 
         FIG.  13 A  is a side view of the laser scanner unit scanning the ophthalmic lens, wherein an angled safety bevel of the ophthalmic lens reflects the projected laser line away from the laser scanner unit; 
         FIG.  13 B  is a front view of the laser scanner unit scanning the ophthalmic lens, wherein the ophthalmic lens is tilted so that the laser line projected to the angled safety bevel is reflected back to the laser scanner unit; and 
         FIGS.  14 A,  14 B and  14 C  show outer peripheral edges of rimless, beveled and grooved ophthalmic lenses, respectively, as scanned by the laser scanner unit. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments and methods of the invention as illustrated in the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the drawings. It should be noted, however, that the invention in its broader aspects is not limited to the specific details, representative devices and methods, and illustrative examples shown and described in connection with the exemplary embodiments and methods. 
     This description of exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “inner” and “outer”, “inside” and “outside,” “horizontal” and “vertical,” “front” and “rear,” “upper” and “lower,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion and to the orientation relative to a vehicle body. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. The term “integral” (or “unitary”) relates to a part made as a single part, or a part made of separate components fixedly (i.e., non-moveably) connected together. Additionally, the words “a” and/or “an” as used in the claims mean “at least one” and the word “two” as used in the claims mean “at least two”. For the purpose of clarity, some technical material that is known in the related art has not been described in detail in order to avoid unnecessarily obscuring the disclosure. 
     As illustrated in  FIG.  3   , an ophthalmic lens  10  to be seated in a frame includes first (convex) and second (concave) opposite optical surfaces  12  and  14 , respectively, and a shaped, continuous outer peripheral edge  16  defined therebetween. The shaped outer peripheral edge  16  of the ophthalmic lens  10 , as used hereinbelow, is a surface (or area) of the ophthalmic lens  10  between a first edge line  19   1  (delimiting the first optical surface  12 ) and a second edge line  19   2  (delimiting the second optical surface  14 ) that is shaped during processing of a blank (or unfinished) ophthalmic lens with a flat (i.e., original or unshaped) edge  15  by an edger to ensure that the ophthalmic lens  10  is able to be well secured and centered in an eyeglass frame as is well known in the art. Different edge structures are machined into the lens periphery, some of the main ones of which are shown in  FIG.  4   . Moreover, the first and/or second edge lines  19   1 ,  19   2  define a perimeter of the ophthalmic lens  10  (or of the outer peripheral edge  16  of the ophthalmic lens  10 ). 
       FIG.  4    illustrates ophthalmic lenses with various types of circumferential (or outer) lens edges commonly used in the optical industry, such as (a) unfinished ophthalmic lens  10   a  with a flat (i.e., original or unshaped) edge  15 , (a) shows a finished lens (b) finished ophthalmic lens  10   b  with T-bevel edge  16   b , (c) finished ophthalmic lens  10   c  with a standard groove edge  16   c , (d) finished ophthalmic lens  10   d  with an inclined standard groove edge  16   d , (e) finished ophthalmic lens  10   e  with inclined groove edge  16   e , (f) finished ophthalmic lens  10   f  with standard bevel edge  16   f , (g) finished ophthalmic lens  10   g  with inclined bevel edge  16   g , (h) finished ophthalmic lens  10   h  with step V-bevel edge  16   h , and (i) finished ophthalmic lens  10   i  with safety bevel edge  16   i . In other words, the edge  16  of the ophthalmic lens  10  may be provided with a groove or an outwardly extending V-bevel  17  having an apex  18  on the outer peripheral edge  16  of the ophthalmic lens  10 , as best shown in  FIGS.  3  and  4   . As further illustrated in  FIG.  4   , V-bevels can have different angles, widths and heights. The grooves and T-bevels can vary in width and depth, same as step backs (shelves). Safety bevels, such as the safety bevel edge  16   i  shown in  FIG.  4 ( i ) , can have different widths and appear or disappear around a lens perimeter based on the thickness of the lens edge  16   i.    
       FIGS.  5 A and  5 B  illustrate an exemplary embodiment of a machine  20  for determination of the shape and dimensions of the lens periphery and for application of liquid to (or coating of) at least a portion of the outer peripheral edge  16  of an ophthalmic lens  10  in accordance with an exemplary embodiment of the present invention. The machine  20  comprises a machine frame  22 , a lens holder unit  24 , a laser scanner unit  26 , a liquid dispensing unit (or dosing mechanism)  28 , and a UV light curing unit  30 . Each of the lens holder unit  24 , the laser scanner unit  26 , the liquid dispensing unit  28  and the UV light curing unit  30  is mounted to the machine frame  22 , as best shown in  FIGS.  5 A and  5 B . 
       FIGS.  5 A and  5 B  show partial perspective views of the machine  20 , wherein a width direction of the machine  20  is set as the X-direction (also described as “X-axis direction” hereinbelow), a length direction of the machine  20  is set as the Y-direction (also described as “Y-axis direction” hereinbelow), and a height direction (upper and lower direction) of the machine  20  is set as the Z-direction (also described as “Z-axis direction” hereinbelow). In the description hereinbelow, an axis parallel to the X-direction is set as the X-axis, an axis parallel to the Y-direction is set as a Y-axis, and an axis parallel to the Z-direction is set as the Z-axis. The X-direction, the Y-direction, and the Z-direction are set orthogonal to each other. Similarly, the X-axis, the Y-axis, and the Z-axis are set orthogonal to each other. In other words, the machine  20  is defined by Cartesian coordinate system of mutually perpendicular (i.e., orthogonal) X, Y and Z axes. 
     The lens holder unit  24  is configured to selectively hold the ophthalmic lens  10 . The lens holder unit  24  is moveable relative to the machine frame  22  between a home position holding the ophthalmic lens  10  away from the laser scanner unit  26 , as shown in  FIG.  5 A , and a working position positioning the ophthalmic lens  10  adjacent, such as below, the laser scanner unit  26 , as shown in  FIG.  5 B . The lens holder unit  24 , according to the exemplary embodiment, includes a support chuck  32  and a hold-down chuck  34 , as best shown in  FIG.  7   , which is selectively rectilinearly moveable toward and away from the support chuck  32 . Moreover, the support chuck  32  and the hold-down chuck  34  are coaxial with one another. The lens holder unit  24  is configured to selectively clamp and non-movably secure the ophthalmic lens  10  between the support chuck  32  and the hold-down chuck  34 . Accordingly, the support chuck  32  of the lens holder unit  24  engages one of the first and second opposite optical surfaces  12  and  14  of the ophthalmic lens  10 , while the hold-down chuck  34  of the lens holder unit  24  engages another of the first and second opposite optical surfaces  12  and  14  of the ophthalmic lens  10 . Rather than clamping the lens  10 , the lens holder unit  24  may include a suction cup securing the front optical surface or the back optical surface of the lens  10 . Moreover, lens holder unit  24  includes a motor  36 , such as an electric motor, such as a stepper motor, for rotating the ophthalmic lens  10  secured by the lens holder unit  24  about a holder axis C (or C-axis of the lens holder unit  24 ), as best shown in  FIG.  7   . The C-axis of the lens holder unit  24  defines a center of rotation O of the ophthalmic lens  10 , which coincides with the center of rotation of the ophthalmic lens  10 , as best shown in  FIG.  9   . Furthermore, the lens holder unit  24 , and thus the ophthalmic lens  10  as well, is tiltable (or pivotable) about an axis B (or B-axis) of the lens holder unit  24 , as best shown in  FIG.  8   . Also, the lens holder unit  24  with the ophthalmic lens  10  may rectilinearly reciprocate along the Y-axis. Preferably, the B-axis is parallel to the Y-axis when the lens holder unit  24  is in the working position. 
     As illustrated in  FIG.  6   , the machine  20  further comprises a main controller  38  operatively connected to each of the laser scanner unit  26 , to the liquid dispensing unit  28  and to the UV light curing unit  30 , each of the liquid dispensing unit  28  and the UV curing unit  30  is rectilinearly moveably mounted to the machine frame  22  for movement in the X and Z axes. The main controller  38  includes hardware, software, and firmware for controlling operation of machine  20  and its components. The machine  20  further comprises a motion control system and motor drivers  48  (best shown in  FIG.  6   ) operatively connected to, controlled by, and operated by the main controller  38 . The motion control system and motor drivers  48  cooperate to selectively rotate the ophthalmic lens  10  about the lens holder axis C, selectively tilt the ophthalmic lens  10  about the axis B relative to the laser scanner unit  26 , and move the lens  10  rectilinearly along the Y axis (front to back in the machine  20 ). The motion control system and motor drivers  48  are also selectively move the laser scanner unit  26 , the liquid dispensing unit  28 , and the UV light curing unit  30  rectilinearly along the X-axis (left/right in the machine  20 ) and Z-axis (up/down). The laser scanner unit  26  is operatively connected to the main controller  38  through a laser scanner interface  50 , while the UV light curing unit  30  is operatively connected to the main controller  38  through a UV light interface  52 , as best shown in  FIG.  6   . 
     The laser scanner unit  26  is known in the art and includes a laser beam transmitter  40  and a laser sensor  42  in a casing  27 . The laser beam transmitter  40  is configured to generate and emit (or project) a diffused laser beam (or projected laser line)  41  outwardly from the laser scanner unit  26  onto the outer peripheral edge  16  of the ophthalmic lens  10 . The laser sensor  42  includes a highly sensitive sensor matrix and is configured to receive laser reflections (or reflected laser line)  43  from the outer peripheral edge  16  of the ophthalmic lens  10  viewable by the laser sensor  42 , as best shown in  FIGS.  7 - 10   . As best shown in  FIGS.  5 B,  7  and  10   , the laser beam transmitter  40  is diffused alongside the laser line (X axis). The laser beam transmitter  40  is a semiconductor laser, preferably a blue laser, although other laser types can be used. Commercially available laser scanners suitable for measuring a 3D edge profile of the outer peripheral edge  16  of the ophthalmic lens  10  are 3D line laser scanners from Micro-Epsilon, such as the scanCONTROL and surfaceCONTROL lines of laser scanners, e.g., scanCONTROL LLT3000-25/BL-SI. The sensor matrix of the laser sensor  42  typically includes a charge-coupled device (CCD), which is a light-sensitive integrated circuit that captures images by converting photons to electrons. The CCD sensor breaks the image elements into pixels. 
     As shown in  FIGS.  5 B,  7  and  10   , the diffused laser beam  41  has a trapezoidal shape and is diffused in a direction perpendicular to the outer peripheral edge  16  between the first and second opposite optical surfaces  12  and  14  of the ophthalmic lens  10  and perpendicular to the first and second edge lines  19   1  and  19   2 , respectively. As best shown in in  FIGS.  7 - 10   , the diffused laser beam  41  is projected toward the outer peripheral edge  16  of the ophthalmic lens  10  by the laser scanner unit  26 , then reflected back toward the laser sensor  42  of the laser scanner unit  26 . As further shown in  FIGS.  9  and  10   , the projected laser line  41  reflected from the outer peripheral edge  16  of the ophthalmic lens  10  as the reflected laser line  43  is strong and detectable by the laser sensor  42 , while the projected laser line  41  projected toward areas  11  outside the outer peripheral edge  16  of the ophthalmic lens  10  produces either weak or no reflected laser line  43 ′, which cannot be detected by the laser sensor  42  of the laser scanner unit  26 . 
     From the image acquired by the sensor matrix of the laser sensor  42 , a processing unit internal to the laser sensor  42  processes the image and reports the X, Z coordinates to the main controller  38 , which calculates the distance (Z-axis) and the position alongside the laser line (X-axis). The measured values are then output in a two-dimensional coordinate system (X, Z) that is fixed with respect to the laser scanner unit  26 . In the case of moving objects or traversing scanners, it is possible to obtain 3D measurement values. In other words, a plurality of 2D scans (measurement values) are acquired, then converted to 3D measurement values around the entire outer peripheral edge  16  of the ophthalmic lens  10 . Software available from Micro-Epsilon, for example, may be used to implement the conversion. Accurate measuring data at any location around the lens perimeter requires an additional 4th degree of freedom to maintain the projected laser line  41  normal to at least a portion of the outer peripheral edge  16  at all times. The 4 th  degree of freedom is the Y-axis, allowing the laser line  41  to be projected so that it does not pass through the center C of rotation of the ophthalmic lens  10 . The laser  41  is offset so that it does not intersect the C axis for the fine scan. Because the chuck is a fixed size and orientation in the machine, and because the chuck  32  is preferably made of materials that do not provide a specular reflection, reflections from the chuck  32  can be excluded from the collected data set during the fine scan. The machine  20  of the present invention can also use a 5 th  axis in the form of the B axis, allowing the projected laser line  41  to be projected normal to features such as the angled surface of the bevel  17  rather than only normal to the flat (in the direction parallel to axis of the ophthalmic lens  10 ) edged portion of the lens edge  16 . 
     The main controller  38  is connected to the laser scanner unit  26  and exchanges various signals and data, including control signals for controlling operation of the laser scanner unit  26 , measuring the 3D edge profile of the outer peripheral edge  16  of the ophthalmic lens  10 , moving the laser scanner unit  26  relative to the ophthalmic lens  10  when the lens holder unit  24  is in the working position, and measurement (or geometric) data from the laser scanner unit  26 , between the laser scanner unit  26  and the main controller  38 . 
     Sometimes, an ophthalmic lens  10 ′ may have concave sections or other geometry in which the reflected laser line  43 ′ may be blocked by the lens itself, as shown in  FIG.  11 A . In this case it is necessary to rotate the lens  10 ′ and create an offset K 1  of the projected laser line  41  with respect to the C-axis (i.e., the axis of rotation of the ophthalmic lens  10 ′) in the Y-direction, as shown in  FIG.  11 B , in order to allow the sensor  42  to receive the reflected laser light  43 . 
     In other cases, the angle of the projected laser line  41  with respect to the outer peripheral edge  16  of the ophthalmic lens  10  or the edge line  19  is significantly less than 90°, as shown in  FIG.  12 A . In such a case, particularly on a highly polished lens edge, the laser sensor  42  of the laser scanner unit  26  may not receive a strong enough reflected laser line  43  to create a clear image of the outer peripheral edge  16 . Only weak reflected laser line  43 ′, which cannot be detected by the laser sensor  42  of the laser scanner unit  26 , is reflected toward the laser sensor  42 , as shown in  FIG.  12 A . Please note that the reference numeral  55  in  FIG.  12 A  marks a normal (i.e., line perpendicular) to the outer peripheral edge  16  and the lens edge line  19  of the ophthalmic lens  10 . Accordingly, the ophthalmic lens  10  must be rotated and the C-axis of the lens  10  offset by an offset K 2  from the projected laser line  41  in Y-direction in order to provide a strong reflected laser line  43  detectable by the laser sensor  42 , as best shown in  FIG.  12 B . Please note that the projected laser line  41  in  FIG.  12 B  is normal (i.e., line perpendicular) to the outer peripheral edge  16  and the lens edge line  19  of the ophthalmic lens  10 . 
     Various features of the edge profile of the outer peripheral edge  16  of the ophthalmic lens  10 , such as safety bevels  17   i , may be angled with respect to the laser scanner unit  26 . The laser scanner unit  26  may be perfectly positioned to measure the finished edge profile of a rimless lens, but the angled safety bevel  17   i  may reflect the projected laser line  41  away from the laser sensor  42 , as shown in  FIG.  13 A  as the weak reflected laser line  43 ′. In order to obtain good readings (i.e., readings detectable by the laser sensor  42 ) from these features, the ophthalmic lens  10  is tilted so that the laser line  41   i  projected onto the angled safety bevel  17   i  is reflected back to the laser sensor  42 , as shown in  FIG.  13 B  as a reflected laser line  43   i . Please note that the reference numeral  56  in  FIGS.  13 A and  13 B  marks a normal (i.e., line perpendicular) to the angled safety bevel  17   i  of the outer peripheral edge  16  of the ophthalmic lens  10 . 
     The laser scanner unit  26  is mounted to the machine frame  22  so as to be rectilinearly moveably along the Z-axis of the machine  20  toward and away from the outer peripheral edge  16  of the ophthalmic lens  10  when the lens holder unit  24  is in the working position. 
     In operation, the shaped ophthalmic lens  10  is held by the lens holder unit  24  and moved into the diffused laser beam  41  projected by the laser scanner unit  26 . The laser scanner unit  26  uses the laser triangulation principle for two-dimensional profile detection on different target surfaces. The laser triangulation means distance measurement by angle calculation. In measurement technology, a laser beam transmitter projects a laser beam onto a measurement object. The laser reflection (or reflected light) falls incident onto the laser sensor (or receiving element) at a certain angle depending on the distance. From the position of the light spot on the laser sensor and the distance from the laser beam transmitter to the laser sensor, the distance to the measurement object is calculated via basic principles of geometry in the laser scanner unit. The measurement object is a body whose movement, position, or dimension is to be measured by the laser scanner unit. In other words, the laser scanner unit uses the laser triangulation principle for two-dimensional profile detection on different target surfaces. By using lenses, a laser beam is enlarged to form a static laser line and is projected onto the target surface, such as an outer peripheral edge of an ophthalmic lens. The laser beam transmitter projects the diffusely reflected light of the laser line onto the targeted surface, from which it is reflected onto a laser sensor including a highly sensitive sensor matrix. From a matrix image, the controller calculates the distance information (Z-axis) and the position alongside the laser line (X-axis). These measured values are then output in a two-dimensional coordinate system that is fixed with respect to the laser scanner unit. In the case of moving objects or a traversing laser scanner unit, it is therefore possible to obtain 3D measurement values. 
     The laser beam transmitter  40  projects the diffused laser beam  41  onto the outer peripheral edge  16  of the ophthalmic lens  10 . Then, the reflected laser line  43  from the outer peripheral edge  16  of the ophthalmic lens  10  is received by the sensor matrix of the laser sensor  42 , based on which a matrix image of the outer peripheral edge  16  of the ophthalmic lens  10  is formed. Then, the main controller  38  calculates the distance information (Z-axis) and the position alongside the laser line (X-axis) of the outer peripheral edge  16  of the ophthalmic lens  10  from the matrix image of the outer peripheral edge  16  of the ophthalmic lens  10 . 
     These measured values are then output in a two-dimensional coordinate system (X and Z) that is fixed with respect to the laser scanner unit  26 . Accurate measurement data (i.e., scan data) at any location around the lens perimeter requires the additional 4th degree of freedom to maintain the projected laser line  41  normal to the outer peripheral edge  16  of the ophthalmic lens  10  at all times. The projected laser line  41  is maintained normal to the outer peripheral edge  16  of the ophthalmic lens  10 , as shown in  FIG.  12 B , by calculating the normal direction from the scan data or job data, rotating the lens  10  to orient a scan point (or point of measurement) normal to the laser beam transmitter  40  of the laser scanner unit  26 , and moving the lens  10  so that the scan point is underneath the laser beam transmitter  40  of the laser scanner unit  26 . As a result, the machine  20  of the present invention generates an accurate 3D-profile of the outer peripheral edge  16  of any given ophthalmic lens for subsequent processing. 
     The method of operation of the machine  20  is as follows. First, the ophthalmic lens  10  is secured in the lens holder unit  24  between the support chuck  32  and the hold-down chuck  34 . Then, the ophthalmic lens  10  is moved from the home position to the working position beneath the laser sensor  42  of the laser scanner unit  26 . 
     Next, a rough (or initial) lens scan of the outer peripheral edge  16  of the ophthalmic lens  10  along the perimeter of the ophthalmic lens  10  is conducted to acquire an approximate lens shape of the outer peripheral edge  16  of the ophthalmic lens  10  by the laser scanner unit  26  while rotating the ophthalmic lens  10 . The approximate lens shape (or profile) is obtained by scanning the lens periphery with the laser scanner unit  26  at a first predetermined number N1 (for example 32) of initial points of measurement (or initial scan points) spaced equiangularly around the circumference (or perimeter) of the ophthalmic lens  10  for the initial lens scan. Specifically, the initial scan points are spaced at 360°/N1 between the initial scan points. 
     At each measurement point the X-axis and Z-axis measurement data of the outer peripheral edge  16  are determined by the laser scanner unit  26 . The ophthalmic lens  10  is then moved (rotated) to the next point and the laser scanner unit  26  moved in X-direction and Z-direction, if required, so that the scanned outer peripheral edge  16  of the lens  10  is maintained within a measurement field of the laser scanner unit  26  for each measurement. The ophthalmic lens  10  is not moved in the Y direction during the initial lens scan. The measurement field is defined by a rectangle (W M ×L M ), wherein W M  is a width of the diffused laser beam  41  in the vicinity of the outer peripheral edge  16  of the ophthalmic lens  10 , while L M  is the height of a portion of the diffused laser beam  41  in the vicinity of the outer peripheral edge  16 , as shown in  FIG.  10   . According to the exemplary embodiment, W M  is in a range between 20 to 30 mm, preferably 25 mm, and L M  is in a range between 20 to 10 mm, preferably 15 mm. Moreover, the measurement field is oriented so that the outer peripheral edge  16  of the ophthalmic lens  10 , disposed within the measurement field, is spaced from the laser scanner unit  26  an optimal reading (or measuring) distance L B , at which the reflected laser line  43  is optimal and easily detectable by the laser sensor  42  of the laser scanner unit  26 . According to the exemplary embodiment, the measuring distance L B  is in a range of between 80 to 90 mm, preferably 85 mm. 
     As noted above, the machine  20  for scanning the outer peripheral edge  16  of the ophthalmic lens  10  has 5 axes defined as follows:
         the axis X is the Left to Right axis used to maintain the outer peripheral edge  16  centered within the measurement field of the laser scanner unit  26 ;   the axis Y is the In and Out (or Front and Back) axis used to position the outer peripheral edge  16  normal and also non-normal to the laser scanner unit  26 ;   the axis Z is the up and down axis used to position the outer peripheral edge  16  centered within the measurement field of the laser scanner unit  26 ;   the axis B is the Tilt/Rotation axis around the Y-axis used to position the outer peripheral edge  16  in appropriate orientation to allow optimum scanning/detection of the reflected laser line  43 ; and   the axis C is the Rotation axis of the ophthalmic lens  10  used to rotate the ophthalmic lens  10  in relation to the laser scanner unit  26  when the lens holder unit  24  is in the working position.       

     The ophthalmic lens  10  is mounted to the lens holder unit  24  such that, when the lens holder unit  24  is in the working position, the first (convex) optical surface  12  is normal (or perpendicular) to the X axis, and the laser scanner unit  26  is moveable along axes X and Z of the machine  20 . 
     During the rough lens scan, the ophthalmic lens  10  is first positioned so that the projected laser line  41  intersects the center of rotation of the ophthalmic lens  10 , and the laser scanner unit  26  is positioned so that the outer peripheral edge  16  of the largest ophthalmic lens  10  that can be processed in the machine  20  is inside the laser scanner measurement field. If the laser scanner unit  26  does not find the outer peripheral edge  16  of the ophthalmic lens  10  based on the measurement data (for example if the lens radius is smaller than the maximum scannable lens radius), then the laser scanner unit  26  is lowered along the Z-axis until the outer peripheral edge  16  of the ophthalmic lens  10  is found by the laser scanner unit  26 . Then, the outer peripheral edge  16  of the ophthalmic lens  10  is centered in the measurement field, both in the X-axis and the Z-axis. 
     The ophthalmic lens  10  is measured a second time by the laser scanner unit  26  to ensure that it is completely centered in the measurement field, and then re-centered in the measurement field in both the X-axis and Z-axis. This second measurement and centering operation is undertaken in case some portion of the lens peripheral edge  16  is outside of the measurement field prior to the first centering operation. 
     Next measurement data of the outer peripheral edge  16  of the ophthalmic lens  10  is acquired by sequentially rotating, step by step, the ophthalmic lens  10  via the C-axis and acquiring measurement data at the first predetermined number N1, preferably 32, of the initial points of measurement on the perimeter of the ophthalmic lens  10 . The N1 measurement points are equiangularly spaced about the lens  10 . At each point of measurement, the X-axis and Z-axis measurement data of the outer peripheral edge  16  are obtained by the laser scanner unit  26  and the ophthalmic lens  10  is moved, e.g. rotated, to the next point of the measurement. The ophthalmic lens  10  moves incrementally, i.e., the ophthalmic lens  10  stops at each of the 32 points of measurement to take each measurement. The outer peripheral edge  16  of the ophthalmic lens  10  is maintained inside the measurement field at all times by moving the laser scanner unit  26  as required. Consequently, the approximate (or rough) lens shape is acquired. Once the rough (or initial) profile of the outer peripheral edge  16  of the ophthalmic lens  10  has been acquired, it is then correlated to known traced perimeter data for the scanned lens  10 , downloaded from connected tracer machines, an ophthalmic laboratory management server, or another data source. This is the same data that is used by the edger to cut the lens, and should be a good but not perfect representation of the actual lens shape. The correlation process preferably uses an iterative technique fitting method to match the scanned shape data to the trace shape data. The distance from each scanned point to the trace shape is calculated, and those distances are summed to a quality of fit parameter. The trace shape data is translated and rotated until an optimal (minimum) value for the quality of fit parameter is achieved. After this fitting process is complete, the scanned data is no longer used. The rotated and translated trace data is used as the basis for all further calculations. The trace data is also known as “job data” though the job data includes not only the trace data but other information about the ophthalmic lens  10  (right/left eye, prescription, material etc.). 
     The modified trace data is then offset outwardly using known mathematical techniques for inflating polygons and creating an enlarged shape. The enlarged trace data is smoothed using known mathematical techniques, such as Fourier transform smoothing. A second predetermined number N2 of main points of measurement (or main scan points) (for example 64) are generated equally spaced around this enlarged perimeter shape of the ophthalmic lens  10 . The enlarged shape and points are then offset inwardly using known mathematical techniques for deflating polygons, thus recreating the initial trace shape that has now been smoothed. The impact of this inward offset is to alter the spacing of the N2 main scan points, depending upon the local curvature of the ophthalmic lens  10 . In areas of the ophthalmic lens  10  with small radius corners, for example, the main scan points become more closely spaced. This is desirable to create a fine scan that fully captures the true edge shape of the ophthalmic lens  10  by in essence increasing relative scan resolution in highly curved areas of the lens peripheral edge  16  and decreasing relative scan resolution in areas of the lens peripheral edge  16  having more gradual curves. 
     Alternatively, for ophthalmic lenses having concave sections or other geometry that block the laser reflection, e.g., as shown in  FIG.  11 A , an alternative method of acquiring the lens shape may be employed. Specifically, the ophthalmic lens is moved in the Y-axis direction incrementally between the N1 initial points of measurement. At every increment the reflected laser line  43  is recorded and once there is no reflected laser line  43  detected by the laser sensor  42  of the laser scanner unit  26 , the ophthalmic lens  10  is rotated such that the last point of measurement, where no reflected laser line  43  was detected, is now vertically below the laser beam transmitter  40 . This is repeated until an overlap in measured points has been detected. Data collected using this method is then processed as previously mentioned to create a set of N2 points for the subsequent fine scan. 
     Alternatively, if a single scan data point in the rough scan is missed, that skip point can be skipped or disregarded, and the analysis continue on to the next measurement point. If two scan data points in a row are missed, the scan can be terminated and the lens repositioned by the operator before a rescan. 
     Profile data is generated and stored as part of the process for manufacturing the edged lenses. The trace data is obtained from a tracer (such as from the 4Tx of National Optronics), and is then used by the edger (such as the QM-X4 from National Optronics) to create the finished edged lens. The rough/initial lens scan is done without any reference to this trace data. The trace data can also be known as “job data” though job data includes not only the trace but other information about the lens (right/left eye, prescription, material, etc). The trace data is used in the previous steps, and must be used. 
     Next, using the processed trace data of the ophthalmic lens  10 , a main or fine lens scan along the perimeter of the ophthalmic lens  10  is conducted. From the approximate profile of the outer peripheral edge  16  of the ophthalmic lens  10  obtained during the initial lens scan, the normal relative to the lens edge  16  is determined so that the fine lens scan can be taken by scanner  42  for a more accurate edge reading. 
     The lens edge profile is obtained by scanning the lens periphery with the laser scanner unit  26  at the second predetermined number N2 of the main points of measurement (or main scan points) spaced around the circumference (or perimeter) of the ophthalmic lens  10  for the accurate lens scan. Those main scan points have been determined by previous calculations above. This measurement is referred to as the fine lens scan. The number N2 of the main points of measurement is significantly larger (such as twice larger) than the number N1 of the initial points of measurement. The main (or fine) lens scan of the outer peripheral edge  16  of the ophthalmic lens  10  along the perimeter of the ophthalmic lens  10  is conducted to acquire an accurate lens shape of the outer peripheral edge  16  of the ophthalmic lens  10  by the laser scanner unit  26  while rotating the ophthalmic lens  10 . The fine scan data is more accurate for at least the following reasons: (a) there are more points being scanned, essentially increasing the resolution of the scan result; (b) using the position data from the rough scan, the lens peripheral edge  16  can be positioned more nearly in the center of the laser measuring field where the laser measurement errors are at a minimum; (c) using the trace data, the projected laser line  41  can be arranged normal to the lens peripheral edge  16  at every scan point (which is more accurate); and (d) scan points are placed more densely in places where the lens shape changes quickly (e.g., the corners of lenses), increasing scan fidelity in these sections. Moreover, the main controller  38  spaces the measurement points a first distance around low curvature portions of the lens periphery and a second distance around high curvature portions of the lens periphery, wherein the first distance exceeds the second distance. 
     During the fine scan of the outer peripheral edge  16  of the ophthalmic lens  10  is positioned in the center of the measurement field so that the projected laser line  41  of the laser scanner unit  26  is normal (i.e., perpendicular) to the perimeter of the outer peripheral edge  16  of the ophthalmic lens  10  by using the X, Y, Z, B and C axes, i.e., by rotating and tilting the ophthalmic lens  10  and rectilinearly moving the ophthalmic lens  10  forwards and backwards along the Y-axis, by rectilinearly moving the laser scanner unit  26  up and down along the Z-axis, and by rectilinearly moving the laser scanner unit  26  left and right along the X-axis. A scan normal to the lens edge  16  is needed because the ophthalmic lens  10  may possess geometry that could obstruct the laser reflection if positioned appropriately (see  FIGS.  11 A- 13 B ). 
     The outer peripheral edge  16  of the ophthalmic lens  10  recorded during the rough lens scan is used to determine any tilt angle needed to position the lens edge  16  normal to the projected laser line  41  of the laser scanner unit  26  with the B-axis. This is done for all N2 main points of measurement, and the laser measurement data is then recorded for each of these main points of measurements. 
     The measurement data recorded by the laser scanner unit  26  during the fine lens scan is then smoothed by known mathematical techniques, such as conversion to nonuniform ration B-splines (NURBS). Smooth splines are function estimates obtained from a set of noisy observations of the target in order to balance a measure of goodness of fit of with a derivative based measure of the smoothness of the function estimates. They provide a means for smoothing noisy x, y data so that the measurement data of the outer peripheral edge  16  of the ophthalmic lens, such as the local radius from the center of lens rotation to the lens outer peripheral edge  16  and the lens edge features (i.e., edge features marked  16 ,  17 ,  18 ,  19   1  and  19   2  in  FIG.  3   ), for any angle around the C-axis provides an accurate profile of the outer peripheral edge  16  of the ophthalmic lens  10 . 
     Examples of the accurate profiles of the outer peripheral edge  16  of the ophthalmic lens  10  obtained during the fine lens scan are illustrated in  FIGS.  14 A,  14 B and  14 C  showing outer peripheral edges of the rimless, beveled and grooved ophthalmic lenses, respectively. 
     Once the measuring data is retrieved from the laser scanner unit  26  and synchronized with the points of measurement on the perimeter of the ophthalmic lens  10 , the 3D profile of the outer peripheral edge  16  of the ophthalmic lens  10  is created. This edge profile allows for calculation of e.g. the lens edge surface size in discrete locations around the lens perimeter. Additionally, any tool can be positioned with high accuracy in relation to the ophthalmic lens  10  and potential collisions can be avoided. 
     It should be noted that in the event the ophthalmic lens  10  has drill notches or similar features that cause discontinuity in the outer peripheral edge  16  of the ophthalmic lens  10 , a more precise scan is needed to accurately find the drill feature. For this case, the number of points of measurement is increased, because for discontinuities in the outer peripheral edge  16  of the lens  10 , such as drill notches and screw holes, it is necessary to know more precisely where the lens edge becomes discontinuous (so that machine  20  can stop dosing fluid onto the lens edge exactly at the drill notch). 
     The following describes the most important steps of the measuring process. Please note that not all of these features are mandatory for all lens edge profiles and might change accordingly:
     a) projected laser line from the laser beam transmitter is normal to the outer peripheral edge of the ophthalmic lens to avoid shading at corners and reflection away from the laser sensor, especially for rectangular lenses with high width/length ratio; and   b) tilting the ophthalmic lens towards the laser scanner unit when slope between segments differ significantly to catch light reflected away from the lens edge (especially on small segments).   

     Therefore, the machine  20  of the present invention generates an accurate 3D-profile of an outer peripheral edge of any given ophthalmic lens for subsequent processing. The ophthalmic lens  10  is held by the lens holder unit  24  into the projected laser line  41  of the laser scanner unit  26 . The laser scanner unit  26  uses the laser triangulation principle for two-dimensional profile detection on the outer edge  16  of the ophthalmic lens  10 . 
     Moreover, eyeglass consumers often request treatments of ophthalmic lens  10  to enhance the functionality and appeal (fashion) of their glasses. These lens treatments may involve coating the outer edge  16  of the ophthalmic lens  10 . In order to apply the coating properly, the lens edge profile around the lens perimeter must be known with high accuracy to:
         position the liquid dispensing unit  28  correctly and accurately at a predetermined distance relative to the outer peripheral edge  16  of the ophthalmic lens  10 ;   calculate the correct dosing amount for any specific location around the perimeter of the ophthalmic lens  10  (avoid over- or under-dosing of the coating liquid substance);   avoid any collisions between the liquid dispensing unit  28  and the outer edge  16  of the ophthalmic lens  10 .       

     In this specific use case, a dosing needle of the liquid dispensing unit  28  must be positioned normal to the outer peripheral edge  16  of the ophthalmic lens  10  with a very high degree of accuracy, such as +/−20 microns, and the amount of dosed liquid must be calculated, taking into account rheological properties of the dosing liquid, based also on size of the outer peripheral edge  16  of the ophthalmic lens  10  at a specific location. The outer peripheral edge  16  of the ophthalmic lens  10  is usually coated along segments of the lens edge. The coat needs to be regular and in a very specific thickness range: not too thin for durability and cosmetic reasons, and not too thick for curability, inserting lens into the eyeglass frame). The path of the liquid dispensing unit  28  and dosing parameters determine the thickness and position of the coating, depending on the lens edge type and the width of the segments on the outer peripheral edge  16 . The correct distance between the dosing needle and the outer peripheral edge  16  is important to avoid uneven surfaces and lines in the coating as well as to avoid uncoated areas. The segment width and profile and exact position are the base for the amount of fluid dosed and the positioning of each line of coating. This avoids uneven surfaces as well as uncoated parts on the outer peripheral edge  16 . Other use cases could be considered as well. 
     After the step of coating the outer peripheral edge  16  of the ophthalmic lens  10  with the appropriate liquid substance is complete, the UV light curing unit  30  may be positioned adjacent to the coated outer peripheral edge  16  of the ophthalmic lens  10  and activated to cure the liquid substance applied to the outer peripheral edge  16  of the ophthalmic lens  10 . 
     The foregoing description of the exemplary embodiments of the present invention has been presented for the purpose of illustration in accordance with the provisions of the Patent Statutes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments disclosed hereinabove were chosen in order to best illustrate the principles of the present invention and its practical application to thereby enable those of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated, as long as the principles described herein are followed. Thus, changes can be made in the above-described invention without departing from the intent and scope thereof. It is also intended that the scope of the present invention be defined by the claims appended thereto.