×

Color display device

  • US 9,170,468 B2
  • Filed: 05/15/2014
  • Issued: 10/27/2015
  • Est. Priority Date: 05/17/2013
  • Status: Active Grant
First Claim
Patent Images

1. A display layer comprising an electrophoretic medium, a first surface on a viewing side, and a second surface on the opposite of the first surface, the electrophoretic medium being sandwiched between the first and the second surfaces and comprising a first type of positive particles, a first type of negative particles, a second type of positive particles, and a second type of negative particles, all dispersed in a solvent or solvent mixture, the four type of particles having respectively optical characteristics differing from one another, such that:

  • (a) application to a pixel of an electric field having the same polarity as the first type of positive particles will cause the optical characteristics of the first type of positive particles to be displayed at the first surface;

    or(b) application to a pixel of an electric field which has the same polarity as the first type of negative particles will cause the optical characteristic of the first type of negative particles to be displayed at the first surface;

    or(c) once a pixel is driven to display the optical characteristic of the first type of positive particles, application to a pixel of an electric field having the same polarity as the second type of negative particles, which electric field is not strong enough to overcome the attraction force between the first type of positive particles and the first type of negative particles, but sufficient to overcome the attraction forces between other oppositely charged particles, will cause the optical characteristic of the second type of negative particles to be displayed at the first surface;

    or(d) once a pixel is driven to display the optical characteristic of the first type of negative particles, application to a pixel of an electric field having the same polarity as the second type of positive particles, which electric field is not strong enough to overcome the attraction force between the first type of positive particles and the first type of negative particles, but sufficient to overcome the attraction forces between other oppositely charged particles, will cause the optical characteristic of the second type of positive particles to be displayed at the first surface.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×