Laser radiation source

Abstract

In a system or method for forming ink holding indicia at a processing surface of a printing form associated with a printing cylinder, a laser beam source is provided creating a laser beam. A rotatable mount rotates the cylinder. A modulator modulates the laser beam to control engraving of the ink holding indicia at the processing surface. Focusing optics focuses the laser beam to create a processing spot on the processing surface. Between the focusing optics and the processing surface a base member having an inner cavity through which said laser beam passes on its way to said processing surface, and at least one extraction channel which extracts unwanted material from said cavity.

1 - 263 . (canceled)  
   
   
       264 . A rotogravure laser engraver system engraving ink holding receptacles at a processing surface of a rotogravure printing cylinder, comprising: 
 a laser beam source creating a laser beam;    a rotatable mount which rotates the rotogravure cylinder;    a modulator which modulates the laser beam to control engraving of the ink holding receptacles at the processing surface;    a focusing optics which focuses the laser beam to create a processing spot on the rotogravure cylinder processing surface to create said ink holding receptacles by removing material from said processing surface with said laser beam; and    between said focusing optics and said processing surface of said cylinder a base member having an inner cavity through which said laser beam passes on its way to said processing surface through said cavity, at least one extraction channel which extracts unwanted eroded material in a region of said processing surface, and at least one admission channel which directs an airflow at said cavity to reduce presence of said unwanted eroded material which can interfere with the laser beam on its way to said processing surface.    
   
   
       265 . A system of  claim 264  wherein the cavity comprises an entrance and an exit for said laser beam wherein the exit is narrower than the entrance, and having near said entrance for said laser beam an airflow from said admission channel.  
   
   
       266 . A system of  claim 265  wherein at a region of said exit an airflow is provided from said admission channel.  
   
   
       267 . A system of  claim 264  wherein said cavity comprises a conical bore having a bypass bore from said admission channel near an entrance of the conical bore and a nozzle bore from said admission channel at an exit end of said conical bore, and wherein said at least one extraction channel lies in a cylindrical processing space after said exit end of said conical bore.  
   
   
       268 . A system of  claim 264  wherein a transparent plate is provided at an entrance end of said inner cavity for said laser beam, said laser beam passing through said transparent plate.  
   
   
       269 . A system of  claim 268  wherein said transparent plate is mounted to said base member and said base member is secured by a removable connection.  
   
   
       270 . A system of  claim 264  wherein said base member has two extraction channels at opposite sides of the laser beam where it strikes the processing surface.  
   
   
       271 . A system of  claim 264  wherein an admission channel is provided which supplies a gas to said cavity, and wherein said at least one extraction channel has a suction applied thereto.  
   
   
       272 . A system of  claim 264  wherein the admission channel is located between the extraction channel and a transparent plate.  
   
   
       273 . A system of  claim 264  wherein said laser beam source comprises a fiber laser.  
   
   
       274 . A system of  claim 264  wherein said processing surface comprises metal.  
   
   
       275 . A rotogravure laser engraver system engraving ink holding receptacles at a processing surface of a rotogravure printing cylinder, comprising: 
 a laser beam source creating a laser beam;    a rotatable mount which rotates the rotogravure cylinder;    a modulator which modulates the laser beam to control engraving of the ink holding receptacles at the processing surface;    a focusing optics which focuses the laser beam to create a processing spot on the rotogravure cylinder processing surface to create said ink holding receptacles by removing material from said processing surface with said laser beam; and    between said focusing optics and said processing surface of said cylinder a base member having an inner cavity having an entrance and an exit wherein the exit is narrower than the entrance and wherein at least one extraction channel is located between said exit and said processing surface with a vacuum which extracts unwanted eroded material from a region of said processing surface.    
   
   
       276 . A rotogravure laser engraver method for engraving ink holding receptacles at a processing surface of a rotogravure printing cylinder, comprising the steps of: 
 providing a laser beam source creating a laser beam;    providing a rotatable mount which rotates the rotogravure cylinder;    modulating the laser beam to control engraving of the ink holding receptacles at the processing surface;    focusing the laser beam to create a processing spot on the rotogravure cylinder processing surface to create said ink holding receptacles by removing material from said processing surface with said laser beam; and    between said focusing optics and said processing surface of said cylinder providing a base member having an inner cavity through which said laser beam passes on its way to said processing surface, before said processing surface at least one extraction channel which extracts unwanted eroded material from a region of said processing surface, and an admission channel which supplies gas to said cavity to reduce flow of eroded material back through said cavity which could interfere with said laser beam.    
   
   
       277 . A system for forming ink holding indicia at a processing surface of a printing form associated with a printing cylinder, comprising: 
 a laser beam source creating a laser beam;    a rotatable mount which rotates the printing cylinder;    a modulator which modulates the laser beam to control engraving of the ink holding receptacles at the processing surface;    a focusing optics which focuses the laser beam to create a processing spot on the processing surface to create said printing indicia by removing material from said processing surface with said laser beam; and    between said focusing optics and said processing surface of said cylinder a base member having an inner cavity through which said laser beam passes on its way to said processing surface through said cavity, at least one extraction channel which extracts unwanted eroded material in a region of said processing surface, and at least one admission channel which directs an airflow at said cavity to reduce presence of said unwanted eroded material which can interfere with the laser beam on its way to said processing surface.