| 摘要 |
PURPOSE:To decrease troubles and to stabilize the change-over of the optical path of a laser beam by using a non-mechanical optical switch means for changing over of the optical path of the laser beam. CONSTITUTION:Electricity is conducted to conductive films 6, 7 to heat the films, then the liquid at the point along the inside surface thereof evaporates to form thin vapor layers along the films 6, 7. The refractive index of the vapor layer between the film 6 and the liquid 12 is approximately 1 and the refractive index of a glass substrate and the film is about 1.5 and therefore, the optical path of the incident laser beam 2 on the glass substrate 4 is reflected by the vapor layers and is changed over to the laser beam 13 side connected to a marking optical system 19. A power source 10 is time-dividedly operated to heat the conductive films 6, 7, by which the optical path of the laser beam 2 is selectively changed over to either of marking optical systems 19, 21, by which the marking operation is efficiently executed. |
