Abstract: A display sign of the type comprising a back-lighted panel having a plurality of discrete light-transmitting areas and an equal number of controlled opaque disks which move between alternate stable positions. One position of each disk overlies the light-transmitting area associated therewith. The other position of each disk is offset to one corresponding side of its associated light-transmitting area. The disks are operated by electromagnets or other noncontacting means mounted to a carriage rearward of the panel. Selected disks are shifted from one position to the other during relative movement between the carriage and panel. The improvement comprises a magnetic drum which precedes the electromagnets to momentarily reset all of the disks in their first position overlying the individual light-transmitting area associated therewith in a progressive pattern just forward of the disks being set by the electromagnets.