Apparatus for displaying waveforms on a matrix display

Claim 1

Apparatus for displaying waveforms comprising: (i) an electro optic display having a layer of display material between two dielectric substrates, a first series of m strip electrodes on one substrate and a second series of n strip electrodes on the other substrate arranged to define an m×n plurality of elements across which an electric signal may be applied to change the layer from one state to another thereby causing an observable display effect; (ii) means for generating m different reference waveforms from different L-bit, N'-ary numbers whereby each waveform has a different shape over a period t, L and N' being integers greater than 1; (iii) means for simultaneously applying a different one of said reference waveforms to each electrode in the first series of electrodes; (iv) sampling means for providing a series of discrete amplitude values of the waveform signal to be displayed; (v) means for selectively generating and storing ones of the m different reference waveforms, the generated waveforms representing the value of each amplitude sample relative to the order of the reference waveforms applied to the first set of electrodes, and for selectively applying such selectively generated waveforms concurrently to a plurality of the second series of electrodes; (vi) whereby an alternating voltage with an rms value greater than a display effect threshold voltage is maintained across some non-selected elements of the display so that these elements are in a first state and a substantially zero rms voltage exists simultaneously across selected elements which are defined by one electrode of said first series of electrodes and by one electrode of said second series of electrodes to which the same waveforms are applied so that these elements are in their second state and collectively display the waveform signal.