METHOD OF EFFECTING LASER MARKING HAVING A SPECIAL EFFECT ON PLASTIC PRODUCT IN ANY FORM

摘要

PURPOSE: To form a mark which one can see at a specified illumination angle and observation angle but can not see at other angles by using MoS₂ as an additive and specifying the wavelength of a laser parameter, pulse energy density, and pulse amplitude. ;CONSTITUTION: In a method of marking, a plastic product is sensitive to radiation, contains an additive which induces a change in light reflection, and is irradiated with a laser beam pulse so that the laser beams are converged on the surface of the product corresponding to the shape of a mark to be formed to produce visual effects in the irradiated area without being damaged. In this laser marking method, MoS₂ is used as the additive, the wavelength of a laser parameter, pulse energy density, and pulse amplitude are controlled to form the effect mark the contrast of which is changed visually by an irradiation angle.;COPYRIGHT: (C)1991,JPO