The improved ring seal includes an annularly shaped body element having a radial inner surface, a radial outer surface, a first axial end surface and a second axial end surface. To do so, a method for fusing toner to a printing material is provided, in which case the printing material is guided in a contacting manner below the toner’s glass transition temperature and in a non-contacting manner above the toner’s glass transition temperature. The transparent electrodes are laminated over the light shielding film via a single insulating layer. Forces from the drive motors of both the window frame guide and the stage are transmitted through the center of gravity of the stage, thereby eliminating unwanted moments of inertia. The bus interface is coupled between the interface controller and the control unit and is for inputting the video data from the control unit to the interface controller. In an actively mode-locked laser, a dynamic wavelength tuning control and a dynamic cavity length control are implemented to maintain mode locking during tuning of the laser wavelength.