Transparent light emitting members and method of manufacture

Abstract

Illuminators include transparent light emitting members having a pattern of rounded shallow notches or grooves in one or more surfaces of the members for causing internally reflected light to be emitted from the members. The notches or grooves may be cut using a circular cutting tool. The relative speed of the cutting tool and feed rate of the cutting tool relative to the members may be controlled to produce a roughened surface on the notches or grooves.

1 . A method of making an illuminator comprising cutting a pattern of shallow notches or grooves in at least one surface of a transparent member using a circular cutting tool, and controlling the relative speed of the cutting tool and the feed rate of the cutting tool relative to the member to produce a roughened surface on the notches or grooves.  
     
     
         2 . The method of  claim 1  wherein at least one of the relative speed of the cutting tool and the feed rate of the cutting tool relative to the member is varied during cutting of at least some of the notches or grooves to vary the amount of roughening of the surface on the notches or grooves.  
     
     
         3 . The method of  claim 2  wherein at least one of the relative speed of the cutting tool and the feed rate of the cutting tool relative to the member is progressively varied during cutting of at least some of the notches or grooves to progressively vary the amount of roughening of the surface of the notches or grooves.  
     
     
         4 . The method of  claim 3  wherein the amount of roughening of the surface of at least some of the notches or grooves is progressively varied along the length of the notches or grooves.  
     
     
         5 . The method of  claim 3  wherein the amount of roughening of the surface of at least some of the notches or grooves progressively varies along the length of the member.  
     
     
         6 . The method of  claim 1  wherein the notches or grooves are cut in more than one surface of the member.  
     
     
         7 . The method of  claim 1  wherein the depth of the cutting tool is varied during cutting of at least some of the notches or grooves to vary the depth of such notches or grooves.  
     
     
         8 . The method of  claim 1  wherein the depth of the cutting tool is progressively varied during cutting of at least some of the notches or grooves to progressively vary the depth of such notches or grooves along the length of the member.