Electrical display device

An electrically controlled display device for selectively displaying a desired value along a graduated base line display according to a selectable one of a plurality of displayable scales comprising:

• two opposed planar electrode screens disposed across an optically active display medium;
• a first one of said electrode screens includes a first electrode means for defining said base line display with a plurality of spaced graduation points therealong and said first electrode means is electrically connected to an electrode terminal, a second electrode means for defining a linear array of individual display points adjacent and along said defined graduated base line and each individual point in said array is electrically connected to a corresponding electrode terminal, a third electrode means for defining a first of said selectably displayable scales of values over a predetermined range and containing a plurality of numerical marking elements indicative of said values positioned adjacent alternate ones of said graduation points on said base line display, said first scale numerical marking elements are interconnected by a first common electrical conductor for a corresponding electrode terminal, a fourth electrode means for defining a second of said selectably displayable scales of values over a predetermined range and containing a plurality of numerical marking elements indicative of said values positioned adjacent to the other ones of said alternate graduation points between the numerical marking elements of said third electrode means, said second scale numerical marking elements are interconnected by a second common electrical conductor to a corresponding electrode terminal;
• and
• a second one of said electrode screens includes a single conducting electrode formed to be disposed directly opposite said graduated base line, said linear array and said first and second scale elements to provide a counter electrode for displaying said oppositely disposed elements.