Laser marking system

Abstract

A laser energy microinscribing system, comprising a semiconductor excited Q-switched solid state laser energy source; a cut gemstone mounting system, allowing optical access to a mounted workpiece; an optical system for focusing laser energy from the laser energy source onto a cut gemstone; a displaceable stage for moving said gemstone mounting system with respect to said optical system so that said focused laser energy is presented to desired positions on said gemstone, having a control input; an imaging system for viewing the gemstone from a plurality of vantage points; and a rigid frame supporting said laser, said optical system and said stage in fixed relation, to resist differential movements of said laser, said optical system and said stage and increase immunity to vibrational misalignments. The laser energy source is preferably a semiconductor diode excited Q-switched Nd:YLF laser with a harmonic converter having an output of about 530 nm. The system may further comprise an input for receiving marking instructions; a processor for controlling said displaceable stage based on said marking instructions and said imaging system, to selectively generate a marking based on said instructions and a predetermined program; and a storage system for electronically storing information relating to images of a plurality of workpieces. A secure certificate of authenticity of a marked workpiece is also provided.

1 - 101 . (canceled)  
   
   
       102 . A gemstone produced by a method comprising the steps of: 
 receiving marking instructions;    mounting a gemstone in a mounting system;    imaging the mounted gemstone from at least one vantage point to produce optical feedback;    directing a focused laser energy onto a desired portion of the mounted gemstone;    controlling the directing of focused laser energy from a laser energy source based on the marking instructions and the imaging, to selectively generate a surface microinscription marking on the gemstone corresponding to the instructions, to produce a modified surface portion without damaging a bulk portion, said modified surface portion extending less than about 10 microns deep and producing a minimum line width of about 9-12 microns.    
   
   
       103 . The gemstone according to  claim 102 , wherein said method is carried out on a plurality of gemstones, and information relating to images of the plurality of gemstones including the markings generated thereon are stored for later use.  
   
   
       104 . The gemstone according to  claim 102 , said method further comprising the steps of storing an image of the generated markings on the gemstone and printing a hard copy of the stored image.  
   
   
       105 . The gemstone according to  claim 102 , said method further comprising the steps of storing physical attributes associated with the gemstone.  
   
   
       106 . The gemstone according to  claim 105 , said method further comprising the steps of storing physical attributes associated with the gemstone, and printing a hard copy of the stored image and said associated physical attributes to create a certificate of authenticity for said gemstone.  
   
   
       107 . The gemstone according to  claim 102 , wherein said gemstone has a curved surface, and wherein said imaging controls a focal plane of the focused laser energy.  
   
   
       108 . The gemstone according to  claim 102 , wherein said imaging reports a success of a surface marking, and said controlling repeats a marking process at a location of the surface marking was unsuccessful.  
   
   
       109 . The gemstone according to  claim 102 , wherein a directed position of the focused laser energy from the laser energy source is based on an optically determined position of a prior microinscribed position.  
   
   
       110 . The gemstone according to  claim 102 , wherein a directed position of the focused laser energy from the laser energy source is positioned based on optical feedback from said imaging to overlap a prior microinscribed position.  
   
   
       111 . The gemstone according to  claim 102 , wherein said focused laser energy has a shallow depth of field to produce an ablation on a girdle of a cut diamond having a depth shallower than a diameter, wherein a focal plane of said focused laser energy is controlled based on said imaging to align the focal plane with a surface of the gemstone.  
   
   
       112 . The gemstone according to  claim 102 , wherein said marking instructions comprise an alphanumeric string translated into a corresponding raster pattern.  
   
   
       113 . The gemstone according to  claim 102 , wherein the gemstone is a diamond, and the modified surface portion comprises a graphitization.  
   
   
       114 . A gemstone microinscribed by a laser energy microinscribing system, produced by a process comprising: 
 providing a laser energy source;    mounting a gemstone in a mounting system, allowing optical access to the mounted gemstone;    providing an optical system for focusing laser energy from the laser energy source, onto the gemstone to create a marking thereon;    directing said focused laser energy onto a desired portion of the gemstone;    viewing the gemstone from at least one vantage point to obtaining image information from the gemstone;    controlling said directing based on said marking instructions and said image information, to selectively generate a marking based on said marking instructions and a predetermined program, to produce a modified surface portion without damaging a bulk portion, said modified surface portion extending less that about 10 microns deep and producing a minimum line width of about 9-12 microns.    
   
   
       115 . The gemstone according to  claim 114 , wherein the gemstone comprises a diamond and the modified surface portion comprises a graphitization.  
   
   
       116 . A gemstone microinscribed by laser energy microinscribing system, produced by a process comprising: 
 providing a laser energy source;    mounting a cut gemstone in a mounting system, allowing optical access thereto;    focusing laser energy from the laser energy source onto a cut gemstone with an optical system;    moving said gemstone mounting system with respect to said optical system with a displaceable stage so that said focused laser energy is presented to desired positions on said gemstone:    viewing the gemstone from at least one vantage point with an imaging system;    supporting said laser, said optical system and said stage in fixed relation on a rigid frame, to resist differential movements of said laser, said optical system and said stage and increase immunity to vibrational misalignments;    receiving marking instructions; and    controlling said displaceable stage based on said marking instructions and said imaging system, to selectively generate an optically corrected marking based on said instructions and a predetermined program, to modify a surface portion without damaging a bulk portion, said modified surface portion extending less than about 10 microns deep and producing a minimum line width of about 9-12 microns.    
   
   
       117 . The gemstone according to  claim 116 , wherein the gemstone comprises a diamond and the modified surface portion comprises a graphitization.  
   
   
       118 . A laser microinscribed gemstone produced by a method comprising the steps of: 
 providing an apparatus comprising a laser energy source; a gemstone mounting system, allowing optical access to a mounted gemstone; and an optical system for focusing laser energy from the laser energy source onto said gemstone to create an ablation pattern thereon, the ablation pattern altering a surface portion without damaging a bulk portion, said ablation pattern extending less than about 10 microns deep and producing a minimum line width of about 9-12 microns:    positioning said gemstone mounting system with respect to said optical system so that said focused laser energy is presented to desired positions on said gemstone; and    supporting said laser, said optical system and said stage in fixed relation with a rigid frame, to resist differential movements of said laser, said optical system and said stage and increase immunity to vibrational misalignments to thereby produce said gemstone with a laser marking with reduced vibration-induced artifacts.    
   
   
       119 . The laser-microinscribed gemstone according to  claim 118 , wherein said gemstone comprises a diamond, and said ablation pattern is associated with a local graphitization of the diamond.  
   
   
       120 . A laser energy microinscribed gemstone produced by a method comprising the steps of: 
 providing a laser inscription system comprising: a laser energy source; a gemstone mounting system, allowing optical access to a mounted gemstone; an optical system for focusing laser energy from the laser energy source onto said gemstone to create an ablation pattern thereon, adapted to ablate a surface portion without damaging a bulk portion said graphitization extending less than about 10 microns deep and producing a minimum line width of about 9-12 microns; a stage for positioning said gemstone mounting system with respect to said optical system so that said focused laser energy is presented to desired positions on said gemstone; and an optical imager for imaging the mounted gemstone from at least one vantage point;    receiving a set of marking instructions defining desired marking positions for a marking to be inscribed on said gemstone;    positioning said gemstone mounting system with respect to said optical system so that said focused laser energy is presented to said desired positions on said gemstone;    imaging the mounted gemstone from at least one vantage point;    said positioning being controlled based on said set of marking instructions and an output of said optical imager, to produce an optically corrected microinscription corresponding to the marking instructions.    
   
   
       121 . The laser energy microinscribed gemstone according to  claim 120 , wherein the gemstone is a diamond, and said ablation is associated with a graphitization of the diamond.  
   
   
       122 . An authenticated gemstone produced by a process comprising: 
 (a) applying a microinscribed marking to a portion of the gemstone, the microinscribed marking having a fixed relation to a predetermined portion of the gemstone, to modify a surface portion without damaging a bulk portion, said modified surface portion extending less than about 10 microns deep and producing a minimum line width of about 9-12 microns;    (b) recording an image of the microinscribed marking and the predetermined portion of the gemstone, having sufficient resolution and scope to record a relationship of the microinscribed marking to the predetermined portion;    (c) storing information from the recorded image; and    (d) comparing a putative authentic gemstone to the recorded image to determine a corresponding thereof, a high degree of correspondence indicating that the gemstone is authentic.    
   
   
       123 . The authenticated gemstone according to  claim 122 , produced by the further step of recording the image of the microinscribed marking contemporaneously with applying the microinscribed marking.  
   
   
       124 . The authenticated gemstone according to  claim 122 , produced by a process further comprising the steps of storing a set of physical attributes of the gemstone and comparing a putative authentic gemstone with the stored physical attributes.  
   
   
       125 . The authenticated gemstone according to  claim 122 , further comprising a certificate of authenticity for said authenticated gemstone having printed thereon said stored image and said associated physical attributes.  
   
   
       126 . The authenticated gemstone according to  claim 122 , wherein said authenticated gemstone is produced by a process further comprising the steps of imaging the gemstone while applying the microinscribed marking, and controlling the applying based on the imaging.  
   
   
       127 . A microinscribed diamond produced by a method consisting of the steps of: 
 (a) illuminating a surface of the diamond with a harmonically converted pulse infrared laser, filtered to remove long wavelengths, through a focusing lens having a depth of field sufficiently short to form an ablation pattern at the focus of the lens at the surface of the diamond, without substantially altering the bulk diamond below the surface, to graphitize a surface portion without damaging a bulk portion, said graphitization extending less than 10 microns deep and producing a minimum line width of about 9-12 microns; and    (b) precisely repositioning the surface of the diamond with respect to the focusing of the of the focusing lens, in a series of pixel locations, to produce a microinscription pattern on the diamond of a plurality of symbolic images, and    (c) using optical feedback from an imager to ensure that the microinscription corresponds to a predetermined pattern.    
   
   
       128 . The microinscribed diamond according to  claim 127 , wherein said precisely repositioning step produces a symbolic image having a lower limit of symbol size of about 15-20 microns.  
   
   
       129 . The microinscribed diamond according to  claim 128 , wherein said symbolic image comprises alphanumeric symbols.  
   
   
       130 . A microinscribed diamond produced by a method consisting of the steps of: 
 (a) illuminating a surface of the diamond with a focused laser beam, having an intensity, duration, and depth of field sufficiently shallow to graphitize a surface portion without damaging a bulk portion, said graphitization extending less than about 10 microns deep and producing a minimum line width of about 9-12 microns; and    (b) precisely positioning the diamond using optical closed loop feedback from an imager to produce a predetermined microinscription pattern on the diamond.    
   
   
       131 . The microinscribed diamond according to  claim 130 , wherein the predetermined microinscription pattern comprises a symbolic image having a lower limit of symbol size of about 15-20 microns.  
   
   
       132 . The microinscribed diamond according to  claim 131 , wherein said symbolic image comprises alphanumeric symbols.  
   
   
       133 . A microinscribed diamond having a laser-inscribed microinscription formed on a surface thereof said microinscription comprising graphitized surface portions, without associated damage to a bulk portion, said graphitization extending less than about 10 microns deep and producing a minimum line width of about 9-12 microns.  
   
   
       134 . The microinscribed diamond according to  claim 133 , wherein the microinscription comprises a symbolic image having a lower limit of symbol size of about 15-20 microns.  
   
   
       135 . The microinscribed diamond according to  claim 133 , wherein said symbolic image comprises alphanumeric symbols.  
   
   
       136 . A gemstone produced by a method comprising the steps of: 
 receiving marking instructions for producing at least one symbol on a gemstone;    mounting a gemstone in a mounting system;    imaging the mounted gemstone from at least one vantage point to produce optical feedback;    directing a focused laser energy onto a desired portion of the mounted gemstone;    controlling the directing of focused laser energy from a laser energy source based on the marking instructions and the imaging, to selectively generate a surface microinscription marking on the gemstone in accordance with the instructions and corresponding to the symbol, said inscription producing a symbol having a lower limit of symbol size of about 15-20 microns.    
   
   
       137 . The gemstone according to  claim 136 , wherein the symbol is an alphanumeric symbol.  
   
   
       138 . The gemstone according to  claim 137 , said method further comprising the steps of determining physical attributes associated with the gemstone, and storing the physical attributed in association with the at least one alphanumeric symbol.  
   
   
       139 . The gemstone according to  claim 138 , said method further comprising the steps of printing a hard copy of an image of the at least one alphanumeric symbol and the associated physical attributes to create a certificate of authenticity for said gemstone.  
   
   
       140 . The gemstone according to  claim 136 , wherein said gemstone has a curved surface, and wherein said imaging controls a focal plane of the focused laser energy.  
   
   
       141 . The gemstone according to  claim 136 , further comprising the step of detecting a location of an unsuccessful surface marking, and repeating said controlling step to remark the gemstone at the detected location.  
   
   
       142 . The gemstone according to  claim 136 , wherein a directed position of the focused laser energy from the laser energy source is based on an optically determined position of a prior microinscribed position.  
   
   
       143 . The gemstone according to  claim 136 , wherein a directed position of the focused laser energy from the laser energy source is positioned based on optical feedback from said imaging to overlap a prior microinscribed position, said at least one symbol being formed of overlapping microinscribed portions.  
   
   
       144 . The gemstone according to  claim 136 , wherein said focused laser energy has a shallow depth of field to produce an ablation on a girdle of a cut diamond having a depth shallower than a diameter, wherein a focal plane of said focused laser energy is controlled based on said imaging to align the focal plane with a surface of the gemstone.  
   
   
       145 . The gemstone according to  claim 136 , wherein said marking instructions comprise an alphanumeric string translated into a corresponding raster pattern.  
   
   
       146 . A gemstone microinscribed by a laser energy microinscribing system, produced by a process comprising: 
 providing a laser energy source;    mounting a gemstone in a mounting system, allowing optical access to the mounted gemstone;    providing an optical system for focusing laser energy from the laser energy source, onto the gemstone to create a marking thereon;    directing said focused laser energy onto a desired portion of the gemstone;    viewing the gemstone from at least one vantage point to obtaining image information from the gemstone;    controlling said directing based on said marking instructions and said image information, to selectively generate a marking based on said marking instructions and a predetermined program, to produce at least one alphanumeric symbol having a lower limit of symbol size of about 15-20 microns.    
   
   
       147 . The gemstone according to  claim 146 , wherein the gemstone comprises a diamond and the at least one alphanumeric symbol comprises graphitization of a surface portion of the diamond.  
   
   
       148 . A gemstone microinscribed by laser energy microinscribing system, produced by a process comprising: 
 providing a laser energy source;    mounting a cut gemstone in a mounting system, allowing optical access thereto;    focusing laser energy from the laser energy source onto a cut gemstone with an optical system;    moving said gemstone mounting system with respect to said optical system with a displaceable stage so that said focused laser energy is presented to desired positions on said gemstone:    viewing the gemstone from at least one vantage point with an imaging system;    supporting said laser, said optical system and said stage in fixed relation on a rigid frame, to resist differential movements of said laser, said optical system and said stage and increase immunity to vibrational misalignments;    receiving marking instructions; and    controlling said displaceable stage based on said marking instructions and said imaging system, to selectively generate an optically corrected marking based on said instructions and a predetermined program, to produce at least one alphanumeric symbol having lower limit of symbol size of about 15-20 microns.    
   
   
       149 . The gemstone according to  claim 148 , wherein the gemstone comprises a diamond and the at least one alphanumeric symbol comprises graphitization of a surface portion of the diamond.  
   
   
       150 . A laser microinscribed gemstone produced by a method comprising the steps of: 
 providing an apparatus comprising a laser energy source; a gemstone mounting system, allowing optical access to a mounted gemstone; and an optical system for focusing laser energy from the laser energy source onto said gemstone to create an ablation pattern thereon corresponding to at least one alphanumeric symbol, having a lower limit of symbol size of about 15-20 microns;    positioning said gemstone mounting system with respect to said optical system so that said focused laser energy is presented to desired positions on said gemstone; and    supporting said laser, said optical system and said stage in fixed relation with a rigid frame, to resist differential movements of said laser, said optical system and said stage and increase immunity to vibrational misalignments to thereby produce said gemstone with a laser marking with reduced vibration-induced artifacts.    
   
   
       151 . A laser energy microinscribed diamond produced by a method comprising the steps of: 
 providing a laser inscription system comprising a laser energy source; a diamond mounting system, allowing optical access to a mounted diamond; an optical system for focusing laser energy from the laser energy source onto said diamond to create a graphitization pattern thereon corresponding to at least one alphanumeric symbol having a lower limit of symbol size of about 15-20 microns; a stage for positioning the diamond mounting system with respect to said optical system so that said focused laser energy is presented to desired positions on the diamond; and an optical imager for imaging the mounted diamond from at least one vantage point;    receiving a set of marking instructions defining the at least one alphanumeric symbol for a marking to be inscribed on the diamond;    positioning said diamond gemstone mounting system with respect to said optical system so that said focused laser energy is presented to said desired positions on the diamond;    imaging the mounted diamond from at least one vantage point;    sand positioning being controlled based on said set of marking instructions and an output of said optical imager, to produce an optically corrected microinscription corresponding to the marking instructions and representing the at least one alphanumeric symbol.    
   
   
       152 . An authenticated gemstone produced by a process comprising: 
 (a) applying a microinscribed symbolic marking to a portion of the gemstone, the microinscribed symbolic marking having a fixed relation to a predetermined portion of the gemstone, said microinscribed symbolic marking having a lower limit of symbol size of about 15-20 microns;    (b) recording an image of the microinscribed marking and the predetermined portion of the gemstone, having sufficient resolution and scope to record a relationship of the microinscribed symbolic marking to the predetermined portion;    (c) storing information from the recorded image; and    (d) comparing a putative authentic gemstone to the recorded image to determine a corresponding thereof, a high degree of correspondence indicating that the gemstone is authentic.    
   
   
       153 . The authenticated gemstone according to  claim 152 , produced by a process further comprising the steps of storing a set of physical attributes of the gemstone associated with the microinscribed symbolic marking and comparing a putative authentic gemstone with the stored physical attributes associated with the corresponding symbolic marking.  
   
   
       154 . The authenticated gemstone according to  claim 152 , further comprising a printed certificate of authenticity for said authenticated gemstone comprises said stored image and said associated physical attributes.  
   
   
       155 . A microinscribed diamond produced by a method consisting of the steps of: 
 (a) illuminating a surface of the diamond with a harmonically converted pulse infrared laser, filtered to remove long wavelengths, through a focusing lens having a depth of field sufficiently short to form an ablation pattern at the focus of the lens at the surface of the diamond, without substantially altering the bulk diamond below the surface, to graphitize a surface portion without damaging a bulk portion; and    (b) precisely repositioning the surface of the diamond with respect to the focusing of the of the focusing lens, in a series of pixel locations, to produce a microinscription pattern on the diamond of a plurality of symbolic images having a lower limit of symbol size of about 15-20 microns, and    (c) using optical feedback from an imager to ensure that the microinscription corresponds to a predetermined pattern.    
   
   
       156 . A microinscribed diamond produced by a method consisting of the steps of: 
 (a) illuminating a surface of the diamond with a focused laser beam, having an intensity, duration, and depth of field sufficiently shallow to graphitize a surface portion without damaging a bulk portion; and    (b) precisely positioning the diamond with respect to the laser beam using optical closed loop feedback from an imager to produce a predetermined microinscription pattern on the diamond corresponding to a predetermined alphanumeric symbolic image, having a lower limit of symbol size of about 15-20 microns.    
   
   
       157 . A microinscribed diamond having a laser-inscribed alphanumeric symbolic microinscription formed on a surface thereof, said microinscription comprising graphitized surface portions, without associated damage to a bulk portion, said alphanumeric symbolic microinsciption having a lower limit of alphanumeric symbol size of about 15-20 microns.