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Reversible image display medium

  • US 6,686,940 B2
  • Filed: 11/15/2001
  • Issued: 02/03/2004
  • Est. Priority Date: 11/16/2000
  • Status: Active Grant
First Claim
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1. A reversible image display medium comprising:

  • two substrates opposed to each other with a gap therebetween;

    one or more developer accommodating cells formed between the two substrates, each having a periphery surrounded by a partition wall; and

    a dry developer contained in each of the cell(s), wherein the dry developer contains at least two kinds of frictionally chargeable dry developing particles having different chargeable polarities and different optical reflection densities, and whereinthe dry developer has an average charge quantity of 1.0 μ

    C/g to 10 μ

    C/g as determined by an electric field separation measuring method.

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