The invention relates to a color display device comprising an electron gun for generating three electron beams, and convergence means for dynamically influencing the convergence of the electron beams. The gold plating bath has high deposition selectivity. During polishing, the semiconductor substrate is not radially oscillated over the surface of the polishing pad, and as a result a more uniform polishing rate is achieved across the semiconductor substrate. Analysis algorithms may also be run on the acquisition device. The reduction gear device has at least a first idle gear wheel which is pivoted on the first train-carrier and which engages two wheels of the planetary wheels in order to allow force balancing.