of 2 mm from the surface to be coated the disk is provided with a central opening of a 0 2 1 cm diameter for feeding the coating compound the axes of rotation of display 1 and disk 4 are of course concentric disk and display now are put in rotation equidirectionally with 800 rpm and 5 ml of coating solution added all at once through the central opening the coating solution has the following composition 32 g of och 3 4 si och 3 4 88 ml of ethanol 1 ml of hcl and 27 ml of h 2 o after the addition of the coating solution disk and display can rotate for about 10 more seconds the display is removed from the holding device dried at 150 u00b0 c and then the coating is baked on at 400 u00b0 450 u00b0 c the layer produced on the display surface had a thickness of 91 nm u00b1 2 nm over the entire surface the drying of the coating solution on the display surface can also take place when the picture tube is still clamped in the holding device by e g the disk being tilted away and warm or hot air being blown at the entire disk surface the display can rotate or stand still here after the drying of the first layer corresponding other layers can be applied.