| 摘要 |
PURPOSE:To make it possible to mark any material with a bar code by applying a sublimable coating material to the surface of a component part, and irradiating the coating material with laser beams to sublime the coating material at only the irradiated parts. CONSTITUTION:A component part 6 is coated with a sublimable coating material 11. The coating 11 may be, for example, an acrylic resin coating material for a white color or an aluminum-containing epoxy resin coating material for a silvery color. The coating material 11 on the component part 6 is scanned, along a plane, with a laser beam emitted from a YAG laser to mark a bar code in the coating material 11. The energy density of the laser beam is so selected as to be sufficient for sublimation of the coating material 11 but not to cause any change in the component part itself. Upon the irradiation, the coating material 11 is completely sublimed at the irradiated parts, leaving the ground of the component part 6 exposed. The laser beam does not cause any change in the ground itself. Therefore, a light flux B from a light-emitting source of a bar code reader is not reflected irregularly, and accurate reading can be achieved. |
