Patent ID: 6184917
Filing Date: 2001-02-06
Classification: B23K

Abstract:
A laser marking method in which a liquid crystal mask formed of a heat-resistant high-molecular liquid crystal having thereon a desired pattern to be marked is scanned with a laser beam to mark an object with the pattern by the laser beam having passed through the liquid crystal mask, which comprises:a first step of putting the liquid crystal mask in a non-light permeable state to prevent the laser beam from passing though the liquid crystal mask before the marking operation and preheating the liquid crystal mask by irradiating the laser beam onto the liquid crystal mask so as to raise a temperature of the liquid crystal mask to a first predetermined temperature higher than a room temperature; anda second step of performing a marking operation on the crystal object while adjusting a temperature of the liquid crystal mask to maintain the liquid crystal mask raised to the first predetermined temperature in a predetermined temperature range between the first predetermined temperature and a second predetermined temperature which is lower than the first predetermined temperature and higher than the room temperature.