Substrate onto which images are direct laser engraved

Abstract

An optical scanning system and method for laser engraving a plurality of data subrasters into a substrate to form a raster of engraved data defining an image on the substrate. Each subraster has a length dimension and a width dimension. The system includes a transport assembly having an objective lens and a mirror, the mirror capable of reflecting a substantially collimated scanning beam incident thereon in a direction transverse to an axis of the incident beam such that it is directed to the objective lens. The objective lens is capable of focusing the scanning beam on the substrate to engrave a set of data in the width dimension of the subraster and the objective lens and mirror combination is capable of moving along the axis of the incident beam to allow subsequent engraving of other sets of data in the width dimension until a complete subraster is formed along its length dimension. The objective lens and mirror combination is also capable of returning to its starting position to begin engraving of a subsequent subraster of the plurality of subrasters forming the raster of engraved data. A thermoset plastic substrate is also identified as being particularly suitable for use with the aforementioned system and method.

What is claimed is:  
     
         1 . A substrate for use with a direct laser engraving process to create an intaglio printing substrate, the substrate consisting essentially of a thermoset plastic which substantially vaporizes in response to an impinging laser beam that engraves portions of the substrate, thereby substantially eliminating the formation of slag material adjacent to engraved portions of the substrate.  
     
     
         2 . The substrate of  claim 1 , further including a mineral filler.  
     
     
         3 . The substrate of  claim 2 , wherein the mineral filler is silica.  
     
     
         4 . The substrate of  claim 2 , wherein the mineral filler has a grain size smaller than a smallest feature of the engraved portions of the substrate.  
     
     
         5 . The substrate of  claim 3 , wherein the grain size is in the range of about 3 to 5 microns.  
     
     
         6 . The substrate of  claim 1 , further including a flame retardant.  
     
     
         7 . The substrate of  claim 1 , wherein the thermoset plastic material is selected from the group consisting of an epoxy, an unsaturated polyester, a phenolic, an amino resin, an alkyd, an allyl, a silicone molding compund, and a polyimide.  
     
     
         8 . An optical scanning system for laser engraving of a plurality of subrasters of data into a substrate to form a raster of engraved data, each subraster having a length dimension and a width dimension, the system comprising: 
 a scanner capable of deflecting an input laser beam incident thereon from a first beam direction to create a scanning beam;    a beam expander capable of receiving the scanning beam and expanding it to create an expanded scanning beam; and    a transport assembly having an objective lens and a mirror, the mirror capable of reflecting the expanded scanning beam in a second beam direction transverse to the first beam direction such that it is incident on the objective lens, the objective lens and mirror capable of moving along an axis defined by the first beam direction;    wherein the objective lens is capable of focusing the expanded scanning beam on the substrate to engrave a set of data oriented in the width dimension of the subraster;    wherein the objective lens and mirror combination is capable of moving along the first beam axis to allow subsequent engraving of other sets of data oriented in the width dimension until a complete subraster is formed to define the length dimension; and    wherein the objective lens and mirror combination is capable of returning to its starting position to initiate engraving of a subsequent subraster.    
     
     
         9 . The system of  claim 8 , further including a receptor assembly disposed substantially parallel to the objective lens of the transport assembly and capable of supporting the substrate and translating it relative to the transport assembly along the width dimension of the subraster.  
     
     
         10 . The system of  claim 8 , wherein the scanner and the beam expander are in a fixed position relative to the substrate during engraving of a subraster.  
     
     
         11 . The system of  claim 8 , wherein the beam expander reduces a scanned angle of the input beam when the input beam is expanded.  
     
     
         12 . The system of  claim 8 , wherein the scanner is positioned a distance away from the movable objective lens and the system simulates an effect of the scanner being positioned at the movable objective lens.  
     
     
         13 . The system of  claim 8 , wherein the scanning beam has a scan angle of about ±20° and the expanded scanning beam has a scan angle of about ±1°.  
     
     
         14 . The system of  claim 8 , wherein each set of data oriented in the width dimension comprises a set of dots, each dot representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         15 . The system of  claim 8 , wherein each set of data in the width dimension comprises 40 dots, each dot representing one of either an engraved point or a unengraved point on the substrate across the width dimension.  
     
     
         16 . The system of  claim 8 , wherein each set of data in the width dimension comprises 80 dots, each dot representing one of either an engraved point or a unengraved point on the substrate across the width dimension.  
     
     
         17 . The system of  claim 8 , wherein the raster of engraved data has a resolution of 1200 dpi.  
     
     
         18 . The system of  claim 8 , wherein the raster of engraved data has a resolution of 2400 dpi.  
     
     
         19 . The system of  claim 8 , wherein the width dimension of the subrasters is about 33 mils.  
     
     
         20 . The system of  claim 8 , wherein the beam expander comprises a first lens having a first focal length and a second lens having a second focal length and spaced a distance from the focal point of the first lens.  
     
     
         21 . The system of  claim 20 , wherein the first focal length is about 15 mm and the second focal length is about 300 mm.  
     
     
         22 . An optical scanning system for laser engraving of a plurality of subrasters of data into a substrate to form a raster of engraved data, each subraster having a length dimension and a width dimension that is substantially less than the length dimension, the system comprising: 
 a polygon scanner capable of deflecting an input laser beam incident thereon from a first beam direction to create a scanning beam;    a beam expander capable of receiving the scanned beam and expanding it to create an expanded scanning beam;    a transport assembly having an objective lens and a mirror, the mirror capable of reflecting the expanded scanning beam in a second beam direction transverse to the first beam direction such that it is incident on the objective lens, the objective lens and mirror being movable in a direction along the length dimension of the subraster; and    a receptor assembly disposed substantially parallel to the objective lens of the transport assembly and capable of supporting the substrate and translating it relative to the transport assembly in the direction along the width dimension of the subraster;    wherein the objective lens focuses the expanded scanning beam on the substrate to engrave a set of data in the width dimension of the subraster;    wherein the objective lens and mirror combination moves in the direction along the length dimension of the subraster to allow subsequent engraving of other sets of data in the width direction until a complete subraster is formed; and    wherein the objective lens and mirror combination returns to its starting position and the substrate is translated to initiate engraving of a subsequent subraster.    
     
     
         23 . The system of  claim 22 , wherein the scanner and the beam expander are in a fixed position relative to the substrate during engraving of a subraster.  
     
     
         24 . The system of  claim 22 , wherein the beam expander reduces a scanned angle of the input beam when the input beam is expanded to maintain a substantially collimated beam.  
     
     
         25 . The system of  claim 22 , wherein the scanner is positioned a distance away from the movable objective lens and the system simulates an effect of the scanner being positioned at the movable objective lens.  
     
     
         26 . The system of  claim 22 , wherein the scanning beam has a scan angle of about ±20° and the expanded scanning beam has a scan angle of about ±1°.  
     
     
         27 . The system of  claim 22 , wherein each set of data oriented in the width dimension comprises a set of dots, each dot representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         28 . The system of  claim 22 , wherein each set of data in the width dimension comprises 40 dots, each dot representing one of either an engraved point or a unengraved point on the substrate across the width dimension.  
     
     
         29 . The system of  claim 28 , wherein the 40 dots across the width dimension is made up of 5 subsets of 8 dots, each dot representing a data bit and each subset representing a data byte.  
     
     
         30 . The system of  claim 22 , wherein each set of data in the width dimension comprises 80 dots, each dot representing one of either an engraved point or a unengraved point on the substrate across the width dimension.  
     
     
         31 . The system of  claim 30 , wherein the 80 dots across the width dimension is made up of 10 subsets of 8 dots, each dot representing a data bit and each subset representing a data byte.  
     
     
         32 . The system of  claim 22 , wherein the raster of engraved data has a resolution of 1200 dpi.  
     
     
         33 . The system of  claim 22 , wherein the raster of engraved data has a resolution of 2400 dpi.  
     
     
         34 . The system of  claim 22 , wherein the beam expander comprises a first lens having a first focal length and a second lens having a second focal length and spaced a distance from the focal point of the first lens.  
     
     
         35 . The system of  claim 34 , wherein the first focal length is about 15 mm and the second focal length is about 300 mm.  
     
     
         36 . The system of  claim 35 , wherein the movable objective lens and mirror combination is movable within a range of 8 inches along the first beam direction, the 8 inch range corresponding to the length dimension of the subrasters.  
     
     
         37 . The system of  claim 36 , wherein the objective lens and mirror combination is nominally positioned about 270 mm from the second lens of the beam expander and movable about 4 inches therefrom along the first beam direction.  
     
     
         38 . The system of  claim 22 , wherein the width dimension of the subrasters is about 33 mils.  
     
     
         39 . A method of making a substrate for use in a printing process, the method comprising the steps of: 
 directing a laser beam onto a scanner to create a scanning beam;    directing the scanning beam through a beam expander to create an expanded scanning beam having a beam axis;    directing the expanded scanning beam to an objective lens that is movable along the beam axis;    focusing the expanded scanning beam onto the substrate and engraving a set of subraster data along a width dimension equal to the width of the beam scan;    moving the objective lens along the beam axis to a subsequent position relative to the substrate and engraving a subsequent set of subraster data adjacent to a previous set of subraster data;    repeating the steps of moving the objective lens and engraving until a complete subraster is created; and    incrementing the substrate and engraving an additional subraster adjacent to a previous subraster;    repeating the steps of incrementing the substrate and engraving an additional subraster until a complete raster is created defining an engraved image on the substrate.    
     
     
         40 . The method of  claim 39 , wherein the sets of subraster data each comprise a set of dots each representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         41 . The method of  claim 39 , wherein the movement of the objective lens is continuous throughout the method.  
     
     
         42 . A method of laser engraving a substrate for use in a printing process, the method comprising the steps of: 
 directing a substantially collimated scanning beam having a beam axis to an objective lens that is movable along the beam axis, the scanning beam defining a scan width;    focusing the scanning beam through the objective lens and onto the substrate;    engraving onto the substrate a set of subraster width data having a width equal to the scan width of the beam;    moving the objective lens along the beam axis to a subsequent position relative to the substrate and engraving a subsequent set of subraster width data adjacent to the previously engraved set of subraster width data;    repeating the steps of moving the objective lens and engraving until a complete subraster made up of a plurality of sets of subraster width data is created;    incrementing the substrate and engraving an additional subraster adjacent to the previously completed subraster; and    repeating the steps of incrementing the substrate and engraving an additional subraster until a complete raster made up of a plurality of subrasters is created that defines an engraved image on the substrate.    
     
     
         43 . The method of  claim 42 , wherein the sets of subraster width data each comprise a set of dots each representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         44 . The method of  claim 42 , wherein the movement of the objective lens is continuous throughout the method.  
     
     
         45 . A method of laser engraving a substrate for use in a printing process, the method comprising the steps of: 
 directing a substantially collimated scanning beam having a beam axis to an objective lens that is movable along the beam axis, the scanning beam defining a scan width;    focusing the scanning beam through the objective lens and onto the substrate;    engraving onto the substrate a set of subraster width data having a width equal to the scan width of the beam;    continuously moving the objective lens along the beam axis to subsequent positions relative to the substrate and engraving subsequent sets of subraster width data to form a complete subraster;    incrementing the substrate and engraving an additional subraster adjacent to the previously completed subraster; and    repeating the steps of incrementing the substrate and engraving an additional subraster until a complete raster made up of a plurality of subrasters is created that defines an engraved image on the substrate.    
     
     
         46 . An optical scanning system for laser engraving a plurality of data subrasters into a substrate to form a raster of engraved data defining an image on the substrate, each subraster having a length dimension and a width dimension that is substantially less than the length dimension, the system including a transport assembly having an objective lens and a mirror, the mirror capable of reflecting a substantially collimated scanning beam incident thereon in a direction transverse to an axis of the incident beam such that it is directed to the objective lens; wherein the objective lens is capable of focusing the scanning beam on the substrate to engrave a set of data in the width dimension of the subraster; wherein the objective lens and mirror combination is capable of moving along the axis of the incident beam to allow subsequent engraving of other sets of data in the width dimension until a complete subraster is formed along its length dimension; and wherein the objective lens and mirror combination is capable of returning to its starting position to begin engraving of a subsequent subraster of the plurality of subrasters forming the raster of engraved data.  
     
     
         47 . The system of  claim 46 , wherein each set of data oriented in the width dimension comprises a set of dots, each dot representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         48 . The system of  claim 46 , wherein each set of data in the width dimension comprises 40 dots, each dot representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         49 . The system of  claim 46 , wherein each set of data in the width dimension comprises 80 dots, each dot representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         50 . The system of  claim 46 , wherein the raster of engraved data has a resolution of 1200 dpi.  
     
     
         51 . The system of  claim 46 , wherein the raster of engraved data has a resolution of 2400 dpi.  
     
     
         52 . The system of  claim 46 , wherein the width dimension of the subrasters is about 33 mils.  
     
     
         53 . The system of  claim 46 , wherein the system is capable of engraving at two different resolutions.  
     
     
         54 . An optical scanning system for laser engraving of a plurality of data subrasters into a substrate to form a raster of engraved data, each subraster having a length dimension and a width dimension, the system including a transport assembly having an objective lens and a mirror, the objective lens disposed parallel to the substrate, the mirror capable of reflecting a substantially collimated scanning beam incident thereon from a first direction in a second direction transverse to the first direction such that the scanning beam is incident on the objective lens, wherein the objective lens is capable of focusing the scanning beam on the substrate to engrave a set of data oriented in the width dimension of the subraster; wherein the objective lens and mirror combination is capable of moving in the direction along the length dimension of the subraster to allow subsequent engraving of other sets of data oriented in the width dimension until a complete subraster is formed; and wherein the objective lens and mirror combination is capable of returning to its starting position to begin engraving of a subsequent subraster.  
     
     
         55 . The system of  claim 54 , wherein each set of data oriented in the width dimension comprises a set of dots, each dot representing one of either an engraved point or a unengraved point on the substrate.  
     
     
         56 . The system of  claim 55 , wherein each set of data in the width dimension comprises 40 dots.  
     
     
         57 . The system of  claim 55 , wherein each set of data in the width dimension comprises 80 dots.  
     
     
         58 . The system of  claim 54 , wherein the system is capable of engraving at two different resolutions.  
     
     
         59 . A substrate for use in an intaglio printing process, the substrate having an engraved image created by laser engraving a plurality of subrasters each having a width and a length, each subraster defined by a plurality of data point sets each scanned across the width of the subraster by a scanning beam incident to the substrate, each of the data point sets having data points that create one of either an engraved point or an unengraved point defined by a state of the scanning beam, the plurality of subrasters combining to form a raster defining the engraved image.  
     
     
         60 . The substrate of  claim 59 , wherein the substrate is made from a thermoset plastic.  
     
     
         61 . The substrate of  claim 60 , wherein the thermoset plastic material is selected from the group consisting of an epoxy, an unsaturated polyester, a phenolic, an amino resin, an alkyd, an allyl, a silicone molding compound, and a polyimide.