The invention relates to a method of controlling a pixel-oriented display device, for a railway control system, whereby a representation, of a traffic situation on a railway track installation, is represented on a screen of the display device, in such a way that an observer of the screen may recognise the situation and take control measures to influence said situation. In a preferred embodiment, the relaxed semiconductor material is 80:20 Si:Ge and the strained semiconductor material is substantially Si. The phase change materials are disposed between the top and bottom electrodes, and each of the PC materials is conducted with one of the top electrodes and one of the bottom electrodes. The resulting structure may permit an applied compressive force to result in a tensile force applied in the envelope material. The light guide element includes a second attraction element attracted to the first attraction element. At least one of the heating or retaining parts has a first permanent magnet cooperating with a second, opposing permanent magnet belonging to its housing, the second permanent magnet being mounted in phase with the first.