| 摘要 |
PURPOSE:To enable a discriminable mark to be provided extremely easily and speedily, by providing a light-absorptive layer having excellent light absorptivity on a surface of an object, and converting the energy of laser light into heat by the light-absorptive layer to thereby melt the surface of the object. CONSTITUTION:A light-shielding mask 3 having a light-transmitting part 3c in a predetermined pattern is produced, and a light-absorptive layer 2 is provided on a surface of an object 1 in a region to be marked. The mask 3 is disposed between the object 1 and a light source 4, and a pulse of electric current is supplied to the light source 4 a predetermined number of times, whereby laser light is emitted from the light source 4. The light is reflected in area corresponding to a chromium film 3b of the mask 3, whereas in an area corresponding to the light-transmitting part 3c, the light is absorbed into the light-absorptive layer 2, and is converted into thermal energy. The thermal energy is transmitted from the light-absorptive layer 2 to the surface of the object 1 making close contact with the layer 2, thereby melting the surface of the object 1. By regulating the number of times the pulse of current is supplied, it is possible to provide a mark having a required depth. |
