Method and apparatus for making a high resolution light pattern generator on a transparent substrate

Abstract

A light pattern generator that can be used to form a gobo for use in a projection optical system. A transparent plate is coated with a stack that is absorptive and reflective. The stack is formed to be ablatable in the form of a pattern. The stack can have multiple different layers with multiple different characteristics, all of which are ablated by the laser.

What is claimed is: 
     
         1 . A light pattern generator substrate comprising:
 a transparent plate with front and rear sides;   a coating stack bonded to one of said sides of the transparent plate, said coating stack comprising:   a dark coating which absorbs ultraviolet; and   a reflector layer, coupled to said dark coating.   
     
     
         2 . A substrate as in  claim 1 , wherein portions of the coating stack bonded to the rear side of the transparent plate have been removed in the shape of a pattern. 
     
     
         3 . A substrate as in  claim 2 , further comprising a light beam generator, producing a light beam through said pattern. 
     
     
         4 . A substrate as in  claim 1 , wherein said reflector layer has multiple layers of reflector material. 
     
     
         5 . A substrate as in  claim 1 , wherein said dark coating includes a first layer absorptive to radiation at a first range, and a second layer absorptive to radiation in a second range. 
     
     
         6 . A substrate as in  claim 1  wherein said coating stack is formed of first and second layers are formed of materials that are ablated by a UV laser. 
     
     
         7 . A substrate as in  claim 1 , further comprising an anti-reflection coating bonded to the front side of the transparent plate, said coating being substantially transmissive to radiation. 
     
     
         8 . A substrate as in  claim 7 , wherein said coating stack is on said rear side of said transparent plate. 
     
     
         9 . A substrate as in  claim 1 , wherein said coating stack is on said front side of said transparent plate. 
     
     
         10 . A substrate as in  claim 7 , wherein said anti reflection coating is at least 95% transmissive to radiation in a 350 nm to 700 nm region. 
     
     
         11 . A light pattern generator for use in a projection optical system, comprising:
 a transparent plate with front and rear sides;   an anti-reflection coating bonded to the front side of the transparent plate, said coating being substantially transmissive to radiation;   a coating stack bonded to the rear side of the transparent plate, said coating stack comprising:   a first layer absorptive to radiation at a first range;   a second layer absorptive to radiation in a second range; and   a third layer reflective to radiation in a third range;   said first, second and third layers are formed of materials that are ablated by a UV laser, and wherein portions of the coating stack bonded to the rear side of the transparent plate have been removed.   
     
     
         12 . A system as in  claim 11 , wherein said anti reflection coating is at least 95% transmissive to radiation in a 350 nm to 700 nm region. 
     
     
         13 . A system as in  claim 11 , wherein said first range is within 10% of 355 nm. 
     
     
         14 . A system as in  claim 11 , wherein said second layer is at least 90% absorptive. 
     
     
         15 . A system as in  claim 11 , wherein said second range is from 400 nm to 700 nm. 
     
     
         16 . A system as in  claim 15 , wherein said third range is from 400 nm to 700 nm. 
     
     
         17 . A system as in  claim 11 , wherein said third layer is at least 90% reflective. 
     
     
         18 . A light pattern generator for use in a projection optical system, comprising:
 a transparent plate with front and rear sides;   a coating stack bonded to the rear side of the transparent plate, comprising;   a first layer absorptive to first radiation;   a second layer substantially reflective to a second range of radiation; and   a third layer substantially absorptive to radiation in a third range of the spectrum;   wherein portions of the coating stack bonded to the rear side of the transparent plate have been removed and patterned.   
     
     
         19 . A system as in  claim 18 , wherein said first radiation is within 10% of 355 nm. 
     
     
         20 . A system as in  claim 18 , wherein said second layer is at least 90% absorptive. 
     
     
         21 . A system as in  claim 18 , wherein said second range is from 400 nm to 700 nm. 
     
     
         22 . A system as in  claim 21 , wherein said third range is from 400 nm to 700 nm. 
     
     
         23 . A system as in  claim 18 , wherein said third layer is at least 90% reflective.