Abstract:
An invention uses three-dimension frame scanning to create a 3D model of the lens openings so that a finished lens cut data file can be created by a noncontact mapping of the frame in which the lens will be installed by a noncontact method combination of articulation and sensor measurements.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    An invention that provides eye frame scanning to create a 3D model of the lens openings so that a finished lens cut data file can be created with precision of less than 300 microns by a noncontact method combination of articulation and sensor measurements. 
       BACKGROUND OF THE INVENTION 
       [0002]    Existing techniques to measure eyeglass frame dimensions employ a mechanical stylus. See, for example, US20140020254, US20130067754, and U.S. Pat. No. 8,578,617, which all describe mechanical contact methods to measure the shape and dimensions of the frame needed to fit the glass. These patents describe measuring the groove of the frame to get information about the shape and dimensions of the frame which assists an eyeglass maker to decide on the dimensions to cut a lens and its bevel to fit a frame. 
         [0003]    There are a number of problems that remain in the prior art. 
         [0004]    Measurements with a stylus in the tracer machine at a optician&#39;s office location result in errors in the lens cut at a lab which has the cut/edger machine due to calibration errors between the different instruments. The mechanical instrument needs to be calibrated often in the optician&#39;s office to ensure accurate measurements. 
         [0005]    The tracer stylus often falls out of the groove and fails to accurately measure the depth due to groove width or sharp curving turns around the frame corner. The resulting lens may end up with gaps between the frame and the lens in corners. 
         [0006]    Frame shapes can be easily distorted, especially thin plastic frames, because the lenses (dummy or actually used) are removed for enabling stylus-based measurement. 
         [0007]    Frame bending can occur as a result of bevel incorrectly positioned on the lens edge. This results in the frame user feeling that the frame does not look like what he expected while trying on the frame with dummy lenses. 
         [0008]    Additional time and shipping charges result from the need to ship frames to the remote lab for tracing, cutting, edging and fitting of the lens to the selected frame. Any delay can impact frame scheduling, sometimes for multiple opticians, piling up in the labs for measurement and processing. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention is an apparatus which uses an automated process to examine and map the contour of the grooves in a set of eyeglasses, providing the data to a lens-cutting device for fast turn-around and more precise and accurate lens fitting. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is an orthogonal view of one embodiment of the apparatus. 
           [0011]      FIG. 2  is a side view of the embodiment of  FIG. 1 . 
           [0012]      FIG. 3  is an example of a Scan Platform Stage. 
           [0013]      FIG. 4  is a front view of the invention as in  FIG. 1 . 
           [0014]      FIG. 5  is a top view of the invention as in  FIG. 1 . 
           [0015]      FIG. 6  is a flow chart of the operation of one embodiment of the invention. 
           [0016]      FIG. 7A  is a front view of the region of interest showing standard scanning method. 
           [0017]      FIG. 7B  is a front view of the region of interest showing an optional scanning method. 
           [0018]      FIGS. 8A, 8B, and 8C  shows a side view, a bottom view and a rear view of one embodiment of the Diverter  35 . 
           [0019]      FIG. 9A  shows one possible embodiment of a Diverter Mount  39  (without the Diverter  35 ). 
           [0020]      FIG. 9B  shows the embodiment of the Diverter Mount  39  while holding the Diverter  35 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    As shown in the drawings, an eyeglass Frame  11  is positioned in a horizontal orientation upside-down on a Scanning Platform  21  with the temples facing the user at the front of the invention. The Frame&#39;s bridge is aligned to an Index Key  23 . The Frame  11  is typically oriented with its top facing down to maximize its stability while it is being processed. 
         [0022]    The invention operates in two stages, a Front Frame Scan stage and a Groove Scan stage. The Front Frame Scan stage creates a mapping of the front view of the Frame  11 . This is accomplished by using a Sensor  25  that is moved along the horizontal (x-axis, running generally parallel to the plane of the frame lenses) and vertical (z-axis) space in front of the frames. This scan can optionally track the wrap of the Frame by determining its change in depth from the frontmost portion of the Frame, located at the Index Key  23 . 
         [0023]    The Sensor  25  sends data to a CPU  31  which is programmed to accept the information and create a multi-dimensional Frame Map  41  of a front view of the frame. 
         [0024]    As shown in  FIG. 1 , the current embodiment uses a camera as the Sensor  25 . In this embodiment, the Sensor  25  is moved using a three-dimensional motorized xyz linear translation Stage  27 . The entire area in which the Sensor can be moved in the x-z plane is the Region of Interest  29 , the boundary of which is indicated by a dotted line. 
         [0025]    Though a custom three-dimensional Stage  27  can be constructed, the industry more commonly uses commercially available x-y two-stage platform with the addition of an z-axis lift stage. There are many such constructions that are available commercially that can position the Sensor  25  in front of the Frame  11  and move the camera over the Region of Interest  29 , as this rectangular area envelopes the potential front view of a conventional Frame  11 . 
         [0026]    The CPU  31  directs the Stage  27  to move the Sensor  25  which begins at one corner of the Region of Interest  29 , takes a picture of the space directly in front of the camera, is moved in small steps along one axis until it reaches the far side of its motion, then moves perpendicular in one step, and travels back the other way, so that the until the Region of Interest  50  is covered, and the Sensor  21  input is fed to the CPU  31 , which can then use industry available techniques to convert the Sensor&#39;s input to a single image Frame Map  41  of the Region of Interest  50  and the Frame  11  within it. 
         [0027]      FIG. 7A  demonstrates one potential Scan Path  50  for the Sensor  25  as it travels through the Region of Interest  29 . This path makes no assumption regarding symmetry of the Frame  11 , or centralized position. 
         [0028]    To more quickly create the Frame Map  41 , an assumption can be made during the scan process that the Frame  11  is symmetrical along the y-axis. Using that assumption and building up the Map  51  during the scan process, the time necessary to build up a Map  51  can be almost halved by keeping track of where the Frame  11  appears in the Map  51 , and then after scanning that entire x-axis, calculating the exact middle of the Frame  11  in the x-axis by averaging the mapping of the Frame  11  at its far sides (typically at the temples). The calculation can be conducted for more than one row of scanning, and repeating the calculation for each row. 
         [0029]    Employing the symmetrical assumption approach explained above,  FIG. 7B  shows one potential Optimized Scan Path  51  for the Sensor  25 . This path first takes the Sensor  25  across the middle of the Region of Interest  29  to establish the extent of the Frame  11 , so the Program  33  can calculate the location of the middle of the Frame  11 , and then merely scan one half of the Region of Interest, and using the scanned information from the left half of the Region of Interest, the Program can create a Frame Map  41 . 
         [0030]    To further ensure that the invention has calculated the middle of the Frame  11 , the Program  33  can repeat the calculation or add scan paths across the entirety of the Region of Interest  29 , until the margin of error is acceptable. 
         [0031]    In the current embodiment, the Program  33  starts the scan at the lower left, and then sends input to the CPU, which uses that input to detect the presence of the Frame  11  directly in front of the Sensor  25 . As the invention completes the first three rows of scans, the CPU can use the data of the first three rows to determine the middle. 
         [0032]    By taking three calculations, the Program  33  first determines whether it received helpful data by comparing the middle calculation of each row. If one row is dramatically different from the others, for example, if the CPU calculates that the Frame  11  is 5.5″ wide, but the CPU determines from the input from the third scan calculates and finds a 6.5″ wide Frame  11 , clearly one of the sensor readings is in error. The Program  33  discards the data from the third scan, and conducts an additional full line scan on additional lines until the Program determines that it has sufficient information to be sure that the correct location of the middle of the Frame  11  is known to the degree desired, or that it is malfunctioning and reports an error to the user. The allowable variation between the calculations can vary with a user setting, but in the current embodiment, the Program  33  will find a difference of more than one millimeter to be unacceptable. 
         [0033]    Given the extent of the Frame  11  from the calculations of the Program  33  and its middle, the invention determines how inaccurate the Frame  11  placement is, and calculates where the Frame  11  is sitting in relation to the Index Key  23 . 
         [0034]    The invention can scan the entire Region of Interest  50  and ensure that any non-symmetrical elements of the Frame  11  is noted, as shown in  FIG. 7A . Alternatively, the invention could employ a more efficient scan by first scanning horizontally along the middle of the Region of Interest  50 , and establishing the middle of the Frame  11  by determining where the images show the extent of the Frame  11 , and then taking advantage of the symmetry of the Frame. 
         [0035]      FIG. 7B  demonstrates the efficient approach, showing the full length scan paths. The Stage  27  can move the Sensor  25  along only one side of the Region of Interest  50 , feeding that information to the Program  33 , which then creates the Frame Map  41  from the scanned side of the Frame  11 , and then uses the known data to complete the Frame Map  51 . 
         [0036]    The Control System  31  can validate the Map  51  built using the above scheme by moving to the location where the second side of the Frame  11  should end on one or more initially unscanned ends of rows, based on the assumption that the Frame  11  is symmetrical and the Sensor-collected data can be used by the Program  33  to complete the Frame Map  41  from the area already scanned. 
         [0037]    In this validation process, the Frame Map  41  can account for a miscentered Frame  11  by traveling the width of the Frame and assuming it is symmetrical, and thereby detect the amount by which it is not centered, and then adjust the mapping. For example, assuming that the Index Key  23  middle of the camera-scannable area is given the point (0,0), the Program  33  determines that the extent of the Frame  11  is (−3.0″, 0″) to (2.5,0), concluding that the Frame is 5.5″ wide from temple to temple, and that the Frame  11  is positioned 0.25″ to the left. The Program  33  uses that information to tell the Stage  27  to move the Sensor  25  so it starts on the left side of the Frame  11 , travels along the Frame  11  until it has scanned past the frame middle (physically identified as the middle of the Bridge  15 ), and then travels back to the left side again. 
         [0038]    As the Program  33  receives data from the Sensor  25 , the Program creates the Frame Map  41  using the left-side data to draw the right side of the Frame  11 . 
         [0039]    In the Groove Scan Stage, a Sensor  25  (usually a camera) is centered in the middle of a Frame Lens Area  17  by the Stage  27 . Instead of using a Sensor  25  to map the front view of the Frame  11 , the Sensor will now create a frame Lens Groove Map  43 . It is that Lens Groove Map  43  that is provided to a lens maker in order to cut the lenses to fit the Frame  11 . 
         [0040]    To obtain the necessary data, the Program first uses the Frame Map  43  to determine the middle of each Frame Lens Area  17  using industry-known techniques. It is not critical that the exact middle of the Frame Lens Area  17  is located; the salient issue is to locate a position in the Frame Lens Area  17  in which the Sensor  25  can be placed so it can rotate and easily scan the Lens Groove  19  from roughly in the middle of the Lens Area  17 . 
         [0041]    To construct the Lens Groove Map  43 , the Program collects image information from the Sensor  25  as it rotates within the Frame Lens Area  17 . In the current embodiment, the Sensor  25  used in this stage is a camera as discussed in stage one, with a Diverter  35  that turns the Sensor angle of operation by 90° so the camera serving as the Sensor  25  can scan images of the Lens Groove  19 . 
         [0042]    In the current embodiment, the Diverter  35  is a mirror that sits at the end of the camera that serves as the Sensor  25  and is directed along the y-axis, held in an extended position by a Rotational Element  37  that operates to correctly turn the Sensor  25  (camera) during the Groove Scan Stage of the invention&#39;s operation. 
         [0043]    The Diverter  35  only operates during the Groove Scan stage of the invention&#39;s operation. A user can be prompted by the invention after the Front Frame Scan Stage to place the Diverter  35  on the end of the Sensor  25 . Alternatively, the Diverter  35  can be kept on a Diverter Mount  39 . Upon beginning the Groove Scan stage, the invention moves the Sensor  25  to engage the Diverter, which can be affixed on the Sensor by a friction hold, a snap-in connection, or other means for holding the Diverter  35  on the end of the Sensor  25 . 
         [0044]    When the Groove Scan Stage is completed, the Diverter  35  must be removed prior to performing a Front Frame Scan. This removal can be by hand or an automated process in which the invention&#39;s Program  33  instructs the Sensor  25  to move so that the Diverter  35  is placed back on the Diverter Mount  39 . 
         [0045]    There are many methods of holding the Diverter  35  on the Mount  39  that are known in the art, including the use of a simple lip on the Mount  39 . To install the Diverter  35 , the invention pushes the Sensor  25  onto a Diverter  35 , and then lifts it off of the Mount  39 , so the Diverter  35  does not catch the lip of the Mount  39 . 
         [0046]    To uninstall the Diverter  35  from the Sensor, the Program  33  moves the Sensor to place the Diverter  35  on the Mount  39 , and then use the lip on the Mount  39  so the Mount  39  catches the edge of the Diverter  35  and dislodges it so it remains on the Mount as the Sensor  25  moves from the Mount  39 . 
         [0047]    An example of one possible construction of the Diverter  35  is shown in  FIGS. 8A, 8B and 8C . An example of one possible embodiment of a Diverter Mount  39  without the Diverter  35  is shown in  FIG. 9A . One embodiment of a Diverter Mount  39  while holding Diverter  35  is shown in  FIG. 9B . 
         [0048]    To control the Sensor  25  so it tracks the Lens Groove  19 , the three-dimensional Stage  27  is supplemented with up to three extra degrees of controlled movement—rotate, yaw, and pitch (r-y-p), constructed with commercially available motion control stages. 
         [0049]    The rotation of the Sensor  25  is required to collect images from the Lens Groove  19 . To track the wrap of the Frame  11 , the “yaw” must correct for the Frame wrap while the scan is in process and make adjustments during the scan to maximize the accuracy of the mapping of the Lens Groove  19 . 
         [0050]    To ease this difficult process, the first stage of the operation can track the bend of the Frame  11  during its scans while the invention develops the Frame Map  41 . Using the depth of the Frame  11  as it is intended to wrap around a user&#39;s head, the invention can turn the direction of the Sensor  25  so it is continuously perpendicular to the part of the Lens Groove  19  that the Sensor is facing as it rotates. 
         [0051]    The Sensor  25  again sends data to the Program  33 , which compiles the data and creates the Lens Groove Map. This data is compiled and used to model the fit of the lens so that a lens-cutting device can cut the lens without error. 
         [0052]    The Region of Interest  29  is the rectangular maximum area in both length and width which envelopes the Frame outline and defined by the extent of the Sensor  25  movement. 
         [0053]    This disclosure thus far includes a possibility of a six-axis (xyz-rpy) articulation to be used to position the Sensor  25  within a eye frame lens opening. The Region of Interest  29  for scanning will be the Lens Groove  19  that the lens is seated in such that the width and depth of the Grove  19  may be used to create the Lens Groove Map  43 . 
         [0054]    The width of the scan is determined by the size of the field of view of the Sensor  25 . The number of passes that the Sensor  25  requires to cover the Region of Interest  50  is based on the size of the field of view, as a Sensor  25  (a miniature camera in the current embodiment) with a small field of view will require more scans than a Sensor  25  with a wider field of view. 
         [0055]    For purposes of this embodiment of the invention, the x-axis is parallel to the frame length, the y-axis is the depth of the Frame  11  (starting at the Bridge  15  and going straight, and the z-axis is used to indicate elevation from the Scanning Platform  21 . 
         [0056]    In the embodiment shown in the figures, the invention may be constructed to change the pitch (p) and yaw (y) of the Scanning Platform  21  to align the Sensor  25  and Lens Groove  19  with an optimal scanning position. 
         [0057]    During the Groove Scan Stage of the invention use, the Sensor  25  is operated so it gathers images from the Lens Groove  19  by rotating the Sensor  25  around an axis as it is positioned to analyze the Lens Groove  19  in 360 degrees from a fixed position (specified in terms of xyz or xyz-py). 
         [0058]    Additional transposition movements in (xyz or xyz-py) may be utilized to best utilize the measurement range of the sensor during a rotation and scan procedure. 
         [0059]    The drawings show the Scanning Platform  21  as either a non-moving element, or an element with limited pitch and yaw motion. However, the invention can be completely operated with the xyz and pitch positioning provided by the Scanning Platform  21  that is constructed with an appropriate multi-dimension Scan Platform Stage  26  such as shown in  FIG. 3 . 
         [0060]    The invention is not limited by the disclosed construction; it is known in the art to use motion control stages to move the Sensor  25  or the Scanning Platform  21  so that the spatial relationship between the Frame  11  and the Sensor  25  is maintained and image data properly collected. Therefore the invention is not limited to the x-, y-, and z-axis motion to the Sensor  25  apparatus, and the pitch and yaw to the Scanning Platform  21 —all five directions of motion could be handled by the Scanning Platform  21  and the Sensor  25  merely handle the rotation aspect. 
         [0061]    Though the embodiment uses a camera for the Sensor  25  element capable of creating data mapping of the Lens Groove  19  to 300 microns, the invention is not limited to the use of a camera; a laser/sensor combination can be employed to detect distance and create the necessary images. 
         [0062]    Similarly, the invention is not limited to the embodiment disclosed in any other aspect. For example, the Diverter  35  can employ a threaded mount onto the Sensor  25 , or some sort of quarter-turn lock, or any number of methods well-known in the industry. 
         [0000]    
       
         
               
             
               
               
             
           
               
                   
               
               
                 Legend: 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 11 Frame 
               
               
                   
                 15 Bridge 
               
               
                   
                 17 Frame Lens Area 
               
               
                   
                 19 Lens Groove 
               
               
                   
                 21 Scanning Platform 
               
               
                   
                 23 Index Key 
               
               
                   
                 25 Sensor 
               
               
                   
                 27 Stage (Sensor) 
               
               
                   
                 28 Scan Platform Stage 
               
               
                   
                 29 Region of Interest 
               
               
                   
                 31 CPU 
               
               
                   
                 33 Program 
               
               
                   
                 35 Diverter 
               
               
                   
                 37 Rotational Element 
               
               
                   
                 39 Diverter Mount 
               
               
                   
                 41 Frame Map 
               
               
                   
                 43 Lens Groove Map 
               
               
                   
                 50 Scan Path 
               
               
                   
                 51 Optimized Scan Path