Methods of separating a glass web

Abstract

Methods of separating a glass web that is moving at a glass web velocity. The method includes exposing a separation path on the glass web to at least one laser beam spot that moves with a laser beam spot velocity vector that is equal to a glass web velocity vector in a conveyance direction. The method also includes creating a defect on the separation path while the separation path is under thermal stress from the laser beam spot, whereupon the glass web spontaneously separates along the separation path in response to the defect. In further examples, a glass web separation apparatus includes a first reflector that rotates such that a laser beam spot repeatedly passes along a separation path and a second reflector that rotates such that the laser beam spot moves in a conveyance direction of the glass web.

What is claimed is: 
     
         1 . An apparatus for separating a moving glass web comprising:
 at least one laser beam generator;   a first reflector including a first reflective surface rotatable about a first axis, the laser beam generator aligned with the first reflector such that a laser beam produced by the at least one laser beam generator will produce a laser beam spot that repeatedly passes along a separation path on the glass web when the first reflector is rotated;   a second reflector including a second reflective surface rotatable about a second axis, the second reflector aligned with the first reflector such that the laser beam spot will move in a conveyance direction of the glass web when the second reflector is rotated;   wherein the first reflector is positioned upstream from the second reflector such that the laser beam produced by the laser beam generator reflects off the first reflective surface of the first reflector prior to reflecting off the second reflective surface of the second reflector.   
     
     
         2 . The apparatus of  claim 1 , further comprising an actuator configured to rotate the second reflective surface about the second axis. 
     
     
         3 . The apparatus of  claim 2 , further comprising a sensor configured to sense a velocity of the moving glass web in the conveyance direction. 
     
     
         4 . The apparatus of  claim 3 , further comprising a controller configured to receive the sensed velocity from the sensor, calculate a target rotational rate of the second reflective surface based on the sensed velocity, and instruct the actuator to rotate the second reflective surface about the second axis at the target rotational rate. 
     
     
         5 . The apparatus of  claim 3 , wherein the sensor comprises a thermal sensor or an optical sensor. 
     
     
         6 . The apparatus of  claim 1 , wherein the first axis is perpendicular to the second axis. 
     
     
         7 . The apparatus of  claim 1 , wherein the at least one laser beam generator is configured to produce a plurality of laser beam spots that each produce thermal stress along a corresponding segment of the separation path. 
     
     
         8 . An apparatus for separating a moving glass web comprising:
 at least one laser beam generator;   a second reflector including a second reflective surface rotatable about a second axis, the laser beam generator aligned with the second reflector such that a laser beam produced by the at least one laser beam generator will produce a laser beam spot that will move in a conveyance direction of the glass web when the second reflector is rotated;   a first reflector including a first reflective surface rotatable about a first axis, the first reflector aligned with the second reflector such that the laser beam spot produced by the at least one laser beam will repeatedly pass along a separation path on the glass web when the first reflector is rotated; and   wherein the second reflector is positioned upstream from the first reflector such that the laser beam produced by the laser beam generator will reflect off the second reflective surface of the second reflector prior to reflecting off the first reflective surface of the first reflector.   
     
     
         9 . The apparatus of  claim 8 , further comprising an actuator configured to rotate the second reflective surface about the second axis. 
     
     
         10 . The apparatus of  claim 9 , further comprising a sensor configured to sense a velocity of the moving glass web in the conveyance direction. 
     
     
         11 . The apparatus of  claim 10 , further comprising a controller configured to receive the sensed velocity from the sensor, calculate a target rotational rate of the second reflective surface based on the sensed velocity, and instruct the actuator to rotate the second reflective surface about the second axis at the target rotational rate. 
     
     
         12 . The apparatus of  claim 3 , wherein the sensor comprises a thermal sensor or an optical sensor. 
     
     
         13 . The apparatus of  claim 8 , wherein the first axis is perpendicular to the second axis. 
     
     
         14 . The apparatus of  claim 8 , wherein the at least one laser beam generator is configured to produce a plurality of laser beam spots that each produce thermal stress along a corresponding segment of the separation path.