Electro-chromic display driving circuit

A display driving circuit comprising in combination electro-chromic display means comprising a first conductor means adapted to be referenced to a first potential, and second conductor means spaced apart from said first conductor means and adapted to be referenced to one of a second potential and a third potential, wherein said third potential is greater than said first potential, and said second potential is less than said first potential, and an oxidation-reduction sensitive compound disposed between said first and second spaced apart conductor means, said compound being normally at a first level of transparency in response to a first predetermined potential difference between said first potential and said second potential, and being altered to a second level of transparency in response to a second predetermined potential difference between said third potential and said first potential, and injection type transistor means for alternately and successively applying said second and third potential to said second conductor means, said injection transistor means effecting a transient characterized by an initial sharp increase in current in response to said first predetermined potential difference and a sharp negative decrease to a negative value following said initial sharp increase from a zero level, followed in turn by a return to a zero level, in response to said second predetermined potential difference.