| 摘要 |
PROBLEM TO BE SOLVED: To prevent excess glass peeling and to obtain distinct markings on a glass surface by repetitively irradiating the glass surface plural times with a carbon dioxide laser regulated to specific intensity and forming microcracks on the glass surface by an abrupt temp. change of the parts to be irradiated and chipping such surface, thereby forming the markings. SOLUTION: The glass surface is repetitively scanned plural times with the carbon dioxide laser regulated to the intensity to avoid the generation of such cracks exceeding a line width of, for example, 0.2 mm if largest, and usually about 0.1 mm, to be marked on the marking part if the character size is preferably <=1 mm×1 mm per character and further, >=0.5 mm×0.5 mm when the identification by naked eyes is required. The irradiation is preferably executed by adjusting the spot diameter of the carbon dioxide laser to <=1/2 the line width to be marked. Then, weak thermal strains are repetitively applied at the same parts, by which the occurrence of the elongation of the large cracks in one direction is averted. |
