Electro-transmissive display device

• US 4,023,890 A
• Filed: 07/31/1975
• Issued: 05/17/1977
• Est. Priority Date: 08/07/1974
• Status: Expired due to Term

• Current Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Nomura, Yasushi, Shirasu, Shinichi
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Hille, Rolf
• Application Number:
  US05/600,574
• Time in Patent Office: 656 Days
• Field of Search: 350/160 LC, 340/336
• US Class Current: 349/142
• CPC Class Codes: G02F 1/134327 Segmented, e.g. alpha numeric display

Abstract

A digital display device for forming one or more electro-transmissive display patterns, which comprises a pair of oppositely disposed electrodes to which a signal is supplied for energization. Each of the electrodes includes a number of electro-conductive sections which are disposed with a lower distribution density at the central portion and with a higher distribution density at the contour portion. This mode of distribution of the sections gives an equivalent visual contrast to the situations in which all the sections are disposed with a uniform distribution while at the same time reducing the power consumption rate.

Claims

1. In a display device of the light transmitting type, wherein the device includes at least one pattern having a periphery and central portion within the periphery;

first and second substrates of insulating material having inner surfaces facing one another.

a layer of light transmitting material disposed between the substrates;

a plurality of segment electrodes deposited on the inner surface of the first substrate between the first substrate and the layer of light transmitting material wherein each segment electrode contains the pattern having a periphery and central portion;

a common electrode deposited on the inner surface of the second substrate between the second substrate and the layer of light transmitting material; and

a plurality of electro-conductive sections forming segment electrodes, wherein said sections adjacent the periphery have a higher distribution density than those forming the central portions, so that the periphery of the pattern is brighter than the central portion and the pattern has the same visual impact as a pattern with a constant distribution density.

2. A display device, as claimed in claim 1, wherein said light transmitting substance is an electrochromatic display element.

3. A display device, as claimed in claim 1, wherein said light transmitting substance is liquid crystal material.

4. A display device as claimed in claim 1, wherein the distribution density gradually decreases toward said central part from said contour part.