Electrochromic display device

An electrochromic display device comprising:

• a first and a second substrates disposed substantially parallel to each other with a predetermined gap space in between, the peripheral parts of said substrates being sealed by a sealing means thereby closing said gap space, at least one of said substrates being at least partly transparent,
• seven-segment type indication electrodes disposed on the inner face of said first substrate, responsive to driving signals selectively applied thereto, for displaying a character by selective energization thereof,
• a counter-electrode disposed on the inner face of said second substrate,
• an auxiliary electrode, responsive to a signal which is complementary to the driving signal to a predetermined segment of said indication electrodes to energize said auxiliary electrode concurrently with predetermined combinations of segments of said indication electrodes,
• lead-out terminals connected to said indication electrodes, said counter electrode and said auxiliary electrode, and
• an electrochromic solution confined in said gap space, said electrochromic solution containing organic electrochromic substance which makes coloring-discoloring by cathode-reduction and anode-oxidation on said indication electrodes, and auxiliary electrode and said counter electrode.

An electrochromic display device comprising:

• first and second substrates disposed to form a cavity therebetween, said second substrate being at least partially transparent;
• an electrochromic solution retained in said cavity;
• a plurality of individually actuable indicator electrode segments disposed on the interior surface of said first substrate in contact with said solution;
• an opaque counter electrode disposed on the interior surface of said second substrate in contact with said solution, said counter electrode including an aperture disposed in registry with said transparent portion to provide visual access to said indicating electrode segments;
• an auxiliary area compensation electrode, disposed on said first substrate interior surface in contact with said solution underlying said opaque counter electrode;
• and
• control means for selectively generating a current between said counter electrode and respective combinations of individual indicator electrode segments to form designated characters, including area compensation means for selectively generating a current between said counter electrode and said auxiliary area compensation electrode concurrently with generation of currents between said counter electrode and predetermined combinations of said individual indicator electrode segments to compensate for changes in total actuated indicator electrode area between said respective combinations.