Method and apparatus for laser scribing glass sheet substrate coatings

A method for laser scribing comprising:

• providing a glass sheet substrate having oppositely facing surfaces one of which is uncoated and the other of which has a coating with different layers;
• conveying the coated glass sheet substrate in a vertical orientation along a direction of conveyance adjacent a vanadate laser source that provides a pulsed laser beam of a selected power with a wavelength at its near-infrared fundamental frequency and having a pulse frequency of at least 50 kilohertz and a pulse duration of no greater than 70 nanoseconds;
• positioning the vertically oriented substrate by gas pressure and vacuum positioners;
• and
• reflecting the pulsed laser beam from the vanadate laser source by an XYZ galvanometer controlled mirror system toward the uncoated surface of the glass sheet substrate for passage therethrough to the coating on the other surface to provide overlapping ablations through certain layers of the coating and scribing thereof at a speed of at least about 1000 millimeters per second.