Abstract: A method is disclosed for scribing a contained crack or vent in a chemically strengthened glass sheet. The glass has shallow surface regions under compressive stress, bounding a central region under tensile stress. The vent is formed by rapidly bulk-heating the glass, using radiation from a carbon monoxide laser, to a depth just below a surface compressive region and extending marginally into the tensile stress region then rapidly cooling the heated region with a water mist spray. The glass sheet can be subsequently divided along the vent by application of mechanical or thermal stress.

Abstract: A method is disclosed for scribing a contained crack or vent in a chemically strengthened glass sheet. The glass has shallow surface regions under compressive stress, bounding a central region under tensile stress. The vent is formed by rapidly bulk-heating the glass, using radiation from a carbon monoxide laser, to a depth just below a surface compressive region and extending marginally into the tensile stress region then rapidly cooling the heated region with a water mist spray. The glass sheet can be subsequently divided along the vent by application of mechanical or thermal stress.

Abstract: Powder-delivery apparatus for delivering powdered cladding-material into the vicinity of a laser-beam spot includes a plurality of powder-delivery modules. Each of the modules is arranged to receive the cladding-material and deliver the cladding-material through a plurality of nozzles. The position of the nozzles in the modules with respect to the laser-beam spot is adjustable in three Cartesian axes. The modules are selectively removable from, and attachable to the apparatus. Nozzles in any one of the modules can be selectively prevented from delivering cladding-material.