Patent Publication Number: US-2016231103-A1

Title: Laser frame tracer

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/018,311, filed Sep. 4, 2013, to be issued as U.S. Pat. No. 9,316,489 on Apr. 19, 2016, which is a Continuation of U.S. Ser. No. 13/683,484, filed Nov. 21, 2012, now abandoned, of which the entirety of all is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates in general to automated measurement units, and in particular to units for optically measuring eyeglass frames. 
     BACKGROUND 
     Prior art eyeglass frame measurement units have been provided for measuring eyeglass frames to determine the dimensions for cutting lenses for fitting the frames. Prior art units have included units with mechanical measurement probes which make contact with and push against the eyeglass frames to trace the frames and thereby determine dimensions of the frames. The measured dimensions are then stored for later use to cut the lenses to size. Problems often arises with measurement probes running across surfaces of the frames, and debris can also interfere with obtaining accurate measurements. 
     SUMMARY 
     A laser frame tracer is provided for optically measuring dimensions for eyeglass frames. The laser frame tracer includes an enclosure with an on-board computer which interfaces with a touch screen monitor for operator input. A laser measuring unit has a laser which emits laser light along a line and cameras which are mounted for receiving light emitted by the laser and reflected off the frame. A frame carrier is provided for mounting eyeglass frames and moving the eyeglass frames through the laser line emitted from the laser. The frame carrier includes a linear carriage and a rotary carriage mounted to the linear carriage. Movement of the linear carriage and the rotary carriage are controlled by the onboard computer which collects image data from the cameras. The image data is processed to determine a solid 3D model for the frames from which selected dimensions for the eyeglass frame may be digitally measured. The dimensions may be stored in a cloud database for access by others in cutting lenses to fit other eyeglass frames of the same model. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS 
       For a more complete understanding of the embodiments of the laser frame tracer disclosed herein and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying Drawings in which  FIGS. 1 through 6  show various aspects for a laser frame tracer, as set forth below: 
         FIG. 1  is a perspective view of the laser frame tracer; 
         FIG. 2  is a partially exploded view of a laser measuring unit of the laser frame tracer; 
         FIG. 3  is a perspective view of a frame carrier shuttle of the laser frame tracer; 
         FIG. 4  is an exploded view of the frame carrier shuttle of the laser frame tracer; 
         FIG. 5  is a flow chart illustrating operation of the laser frame tracer for collecting image data for a frame; and 
         FIG. 6  is a flow chart illustrating operation of the laser frame tracer for processing the image data to provide selected frame measurements. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Detailed embodiments of laser frame tracers are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the laser frame tracers, which may be embodied in various forms. Therefore, specific functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure. 
       FIG. 1  is a perspective view of the laser frame tracer  12  for measuring the geometry of an eye wear frame  10  for cutting lenses to fit the frame  10 . The laser frame tracer  12  includes an enclosure  14  with a first compartment  15  and a second compartment  17 . The first compartment  15  houses a laser measuring unit  20  and a frame carrier shuttle  22 . The laser measuring unit  20  is located in a fixed position within the housing  14  and the frame carrier shuttle  22  moves the frames beneath the laser measuring unit  20 . The laser measuring unit  20  has a laser  36  which emits laser light, for example, in a line, and one or more cameras, for example, cameras  38  and  40 , which measure the reflection of the laser light off the frame  10 . The frame carrier shuttle  22  includes a linear carriage  44  and a rotary carriage  88  which is mounted to the linear carriage  44 . The frames  10  are mounted to the rotary carriage  88 . The linear carriage  44  moves the frames  10  beneath the laser  36 , and the rotary carriage  88  moves the frames  10  to a different angular position between each pass through the laser  36 . The frame carrier shuttle  22  sequentially moves the frames  10  beneath the laser  36  and the cameras  38  and  40  with the rotary carriage  88  indexing the frames  10  into different angular positions, such that a complete geometry of the peripheral surfaces of the frames  10  may be determined by recording the light from the laser reflected from the frames  10 . 
     The second compartment  17  houses onboard electronics  16  which include an onboard computer  116 , a hard drive  118 , a power supply  120  and interface boards  122 . The interfaces boards  122  contain circuitry and drivers for operating the laser measuring unit  20  and the frame carrier  22 . The onboard computer  116  and the hard drive  118  together define a data processing unit. The onboard computer  116  has a data processor and memory, and may be connected to a computer or computer network, for example, a global computer network for sharing information. The data processor in the onboard computer  116  emits control signals which control operation of the laser frame tracer  12  and processes recorded images to determine a 3D model for a frame  10  from which selected measurements for the frame  10  may be calculated. A touch screen monitor  18  is provided for data display and user input into the onboard computer  116  for controlling operation of the laser frame tracer  12 . A data link is provided between the cameras  38  and  40  and the onboard computer  116  for storing images from the cameras  38  and  40 . The cameras  38  and  40  may be directly connected to the motherboard of the computer  116 , or in some embodiments connected through the interface boards  122 . The interface boards  122  can apply electric power for operating a motor  56 , for example, a stepper motor, for the linear carriage  44  and a motor  93 , for example, a servo motor, for the rotary carriage  88  in response to control signals from the computer  116 . 
       FIG. 2  is a partially exploded view of the laser measuring unit  20 . The laser measuring unit  20  includes a mount  26  which is secured in fixed position relative to the enclosure  14 . The mount  26  has a frame  28  which includes a centrally disposed laser mounting bracket  30  and camera mounts  33  and  35 , which are located on opposite sides of the laser mounting bracket  30 . The laser  36  is mounted to the laser mounting bracket  30 . The laser  36  emits laser light, for example, along a line. Mounting brackets  32  and  34  are provided for releasably securing to respective ones of the camera mounts  33  and  35  for securing the cameras  38  and  40 , respectively, in fixed position relative to the frame  28 , on opposite sides of the laser  36 . 
       FIG. 3  is a perspective view of the frame carrier shuttle  22 . The shuttle  22  is mounted to the housing  14  by two slides  42 , allowing the frame carrier shuttle  22  to easily be removed from the housing  14  to provide access to a user for installation and removal of the frames  10  from the shuttle  22 . The frame carrier shuttle  22  includes the linear carriage  44  and the rotary carriage  88 , with the rotary carriage  88  mounted atop the linear carriage  44 . The linear carriage  44  has a platform  46  which is slidably mounted to two rods  48 . The platform  46  is threadingly secured to a lead screw  50  such that rotation of the lead screw  50  in opposite angular directions will linearly move the platform  46  in respective ones of two different linear directions, parallel to the two rods  48 . The two rods  48  extend with axes which are generally horizontal, such that the platform  46  slides in horizontal directions. A drive motor  56  is preferably provided, for example, as a stepper motor and is coupled to the lead screw  50  for rotating the lead screw  50  in selected angular directions. The onboard computer  116  provides a data processing unit which emits linear position control signals for operating the drive motor  56  and turning the lead screw  50  to move the platform  46  beneath the measuring unit  20  and to selected positions. The rotary carriage  88  includes a carrier  90  which is connected to a motor  92 , which is preferably provided, for example, as a servo motor. The eye glass frames  10  are mounted to the carrier  90 , and rotated to selected angular positions by the motor  92 . 
       FIG. 4  is a partially exploded view showing various components of the frame carrier shuttle  22  of the laser frame tracer  12 . The platform  46  of the linear carriage  44  is slidably secured to two rods  48 , and rotatably secured to a lead screw  50 . The rods  48  are fixedly secured, that is secured in fixed positions, with two spaced apart carriage brackets  52  and  54 . The carriage brackets  52  and  54  include through-holes with adjacent slots  66  for slidably receiving respective ends of the rods  48 , and fasteners  68  are tightened across the slots  66  to fixedly secure the ends of the rods  48  within the holes and the adjacent slots  66 . The lead screw  50  preferably includes threads, for example, acme threads, and is rotatably secured between the two carriage brackets  52  and  54  by means of collars  62  and bearings  64  in a conventional fashion. The lead screw  50  and the two rods  48  are spaced apart and extend in parallel to one another. A motor coupling  60  secures the lead screw  50  to the drive shaft of the motor  56 . A motor mount bracket  58  secures the motor  56  to the carriage bracket  54 , here, in a direction projecting outward from between the two carriage brackets  54  and  56 . 
     The platform  46  has a through-hole  74  for receiving a drive nut  70 , which is preferably secured in fixed position within the through-hole  74  by threaded fasteners  72 . As illustrated, there are three threaded fasteners  72 , however it should be appreciated that less than or more than three threaded fasteners may be used. The fasteners  72  secure the drive nut  70  in the through hole  74  in a fixed angular and linear position relative to the platform  46 . The lead screw  50  is threadingly received within the drive nut  70  such that rotation of the lead screw  50  within the nut  70  will linearly move the platform  46  along the rods  48 . Two bearings  76  are slidingly secured to the rods  48  with snap rings  78 . The platform  46  has through openings  80  for receiving and securing respective ones of the bearings  76  therein. The openings  80  extend on an underside of the platform  46 , defined by grooves  84  against which clam shells  82  are secured to fixedly secure the bearings  76  there-between and within the openings  80 . 
     The rotary carriage  88  includes two brackets  94  and  96  which are mounted atop the platform  46 . The bracket  94  also includes a motor mount  98  to which the motor  92  is secured. The motor  92  may be, for example, a servo motor, and its angular position is controlled by angular position control signals from the computer  116  in the second compartment  17 . A carrier  90  is provided as a rod  108  which is formed to have a U-shape. The carrier  90  includes an end  102  which is non-rotatably secured, or fixedly secured, to the drive shaft  100  of the motor  92 . The end  102  and the opposite end of the carrier  90  are rotatably secured within the bearing mounting holes  106  of the brackets  94  and  96 , respectively, by bearings  104 . A mounting boss  110  is fixedly secured to the rod  108  and provides a platform to which a clamp  112  is fixedly secured. As illustrated, the clamp  112  is U-shaped and secures the eyewear frame  10  to the carrier  90 . However, it should be appreciated that other securing mechanisms may be used instead of or in addition to the clamp  112  to secure the eyewear frame  10  to the carrier  90 . The motor  92  will rotate the carrier  90  to selected positions, to align the frame in different angular positions as it is moved by the linear carriage  44  for different passes beneath the laser measuring unit  20 . 
     In operation the eyeglass frame  10  is placed in the clamp  112 . The frame  10  is then shuttled beneath the laser  36  and through the emitted laser light by means of the linear carriage  44  making multiple passes moving in linear directions through the laser light, and the rotary carriage  88  moving in angular directions to index the frame  10  into different angular positions between the different passes through the laser light. The laser light is reflected from the frame  10  during the multiple passes and images of the frame  10  passing through the laser light at different angles are recorded by the cameras  38  and  40 . The recorded images are processed by the on board electronics  16  to determine a 3D model from which selected dimensions for the eyeglass frame  10  may be electronically measured. The traced dimensions may then be stored in a database which may also be accessed by others, for example, via a wired or wireless network, such as the Internet. 
       FIG. 5  is a flow chart illustrating operation of the laser frame tracer  12  for collecting image data for the frame  10  being traced. The process starts in step  126 , and in step  128  the frame  10  is secured to the frame carrier  22  by means of the clamp  112 . In step  130 , the motor  56  is powered to move the frame  10  through the laser light, which may be a laser line, emitted by the laser  36 , as the two cameras  38  and  40  digitally record images of the frame  10  passing through the laser line emitted by the laser  36 . In step  132 , data representing the digital images is stored, for example, in a database. In step  134 , the motor  92  is powered to rotate the rotary carriage  88  and angularly move the frame  10  through an incremental angle for recording images of the frame  10  at a different angle from prior images. In step  136 , the motor  56  moves the platform  46  back to a home position. In step  138 , the process determines whether a complete data set of images has been collected for building a solid 3D model for the frame  10 . If not, the process returns to step  130  to move the frame  10  across the laser line emitted by the laser  36 , stores camera images in step  132 , and proceeds through the steps  134  and  136 . When in step  138  a determination is made that a complete set of images has been acquired to construct a 3D model of the frame  10 , the process proceeds to the end step  140 . 
       FIG. 6  is a flow chart illustrating operation of the laser frame tracer  12  for processing the image data to provide selected frame measurements. In one embodiment, the image data is processed in the onboard electronics  16 , including the onboard computer  116 , but in other embodiments the raw image data may be exported from the onboard computer  116  into a local or remote database for processing by a local or remote processing unit to determine a solid 3D model for the frame  10 . Selected measurements, for example, a height, a width, and other dimensions of the portion of the frame  10  that holds a lens, may be electronically measured from the 3D model by a processing unit for cutting lenses to size for fitting the frame. The process starts in step  142 , and in step  144  the raw image data is acquired from a scanning module, or from a database in which the data is stored. In step  146 , the image data is processed to detect, for various image frames, the position of the laser line emitted by the laser  36 . Reflection and noise filters may then be applied in step  148 . In step  150 , detected data points from selected data frames are converted into 2D data points. In step  152 , the 2D data points are compiled into a 3D cloud of data points (“COP”). In step  154 , the 3D COP is calibrated into metric coordinates, which are then converted in step  156  into a 3D model for the frame  10  being traced. In step  158 , selected measurements are extracted from the solid 3D model. In step  160 , the measurements are formatted, for example, for sharing, and in step  161 , the selected measurements are loaded into a remote database. The measurements stored in the remote database may be used for cutting lenses locally, for example, by a lens manufacturer, or sharing with others at remote locations for use in cutting lenses. Additionally, the entire 3D model may be loaded into the remote database for sharing with others. 
     The disclosure provides a laser frame tracer  12  having a rotary carriage  90  mounted atop a linear carriage  44 . An eyeglass frames  10  is mounted atop the rotary carriage  88 . The onboard electronics  16  control movement of the rotary carriage  88  and the linear carriage  44  to pass the eyeglass frame  10  through the laser line emitted by the laser  36  and beneath the cameras  38  and  40 . Light reflected off the frame  10  is recorded as digital images by the cameras  38  and  40 , and the digital images are processed to detect the position of the laser line on the frame  10  in the digital images. Based on the detected positions of the laser line a 3D model of the frame  10  is constructed. Measurements may then be digitally taken from the 3D model of the eyeglass frame  10 . 
     Although certain embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the disclosure. The present disclosure is thus not to be limited to the precise details of methodology or construction set forth above as such variations and modification are intended to be included within the scope of the present disclosure. 
     Although the laser frame tracer  12  is described as having the laser measuring unit  20 , including the laser  36  and cameras  38  and  40 , located in a fixed position and a frame carrier shuttle  22  that moves the frame  10  beneath the laser measuring unit  20 , the frame  10  may disposed in a fixed position and the laser measuring unit  20  may move above and around the frame  10 . Although the laser  36  is described as emitting laser light in a line, such as provided by a line laser, other types of lasers may be used, for example, including a point laser. Further, although the laser frame tracer  12  is described as measuring one frame  10  at a time, the laser frame tracer  12  may be adapted to measure more than one frame  10  at the same time, for example, in parallel or in series. 
     Further, as used in the disclosure, the term “a” or “one” may include one or more items unless specifically stated otherwise. The phrase “based on” is intended to mean “based at least in part on” unless specifically stated otherwise. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are merely used to distinguish one element from another.