Power supply for sequentially energizing segments of an electroluminescent panel to produce animated displays

Claim 1

Apparatus for selectively powering or not powering respective segments of a selected one of a plurality of electroluminescent (EL) display devices, each of said EL display devices being of a different physical size and shape and each EL display device defining a different and distinct segment pattern characterizing a different and distinct graphic display, said graphic display including one or more numbers, letters, symbols, patterns, images, said apparatus comprising: means for generating an alternate wave voltage having a predetermined magnitude to provide a first voltage potential to a common electrode of the EL display device, wherein said alternating wave generating means further comprises: circuit means for generating a triangular waveform voltage; first comparator circuit means having an input coupled to said triangular waveform voltage generating circuit for producing a first voltage pulse signal; second comparator circuit means having an input coupled to said triangular waveform generating circuit for producing a second voltage pulse signal 180° out of phase with respect to said first voltage pulse signal; voltage transformer circuit means having a primary winding and a secondary winding, said primary winding being centertapped and having one end driven by said first voltage pulse signal and an opposite end driven by said second voltage pulse signal to induce alternating wave voltage across said secondary winding, said transformer circuit means having a transformation ratio for stepping-up said voltage pulse signals driving said primary winding to a predetermined voltage magnitude across said secondary winding sufficient to excite said segments of said EL display device; controllable electronic switching means having an electrically conductive ON switching condition and an electrically non-conductive OFF switching condition, said switching means coupled one-for-one to an associated respective segment of the EL display device for providing electrical continuity between the segment electrode of the EL display device and a second voltage reference potential to illuminate a said associated respective segment for a time duration corresponding to the time said switching means is electrically conductive; at least one of a number of addressable memory means for storing at least one addressable location for identification and subsequent retrieval binary coded data information defining the segments to be energized in the selected one of the plurality of different and distinct EL display devices, said at least one addressable memory means having output means coupled to said controllable electronic switching means for selectively operating said switching means to its respective ON switching condition and OFF switching condition; addressing means coupled to said at least one of said number of addressable memory means for sequentially accessing said at least one addressable location to retrieve the binary coded data information stored therein; timing means coupled to said at least one of said number of addressing means for producing timing pulses in a predetermined timed relationship with respect to one another and in a random timed relationship with respect to one another whereby said segments of the selected EL display device are energized in accordance with the binary coded data information stored in said selected at least one addressable memory means and retrieved from said addressable memory locations in said selected one of said addressable memory means in accordance with a selected one of a possible number of programmed sequences defining the respective segments of the selected EL display device to selectively power the segments to produce the desired animated graphic display.