Electrophoretic display film for anti-counterfeit application
AssigneeE Ink California, LLC
InventorsYu Li, HongMei Zang
Life of this patent
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Abstract
The present invention is directed to an electrophoretic display film which can be controlled to malfunction permanently within a period of time. It provides an elegant method to utilize an electrophoretic film for anti-counterfeit purposes. The concept involves the removal of strong barrier layer(s) from the film to allow the solvent in the electrophoretic fluid within the film to evaporate through weak barrier layer(s), and within a period of time, the performance of the display film will be significantly degraded and the film cannot be re-used.
Claims14
A method for protecting against counterfeit, comprising:
- providing a module comprising an electrophoretic display film which film comprises a microcup layer having (i) partition walls, (ii) a microcup bottom layer, and (iii) microcups filled with an electrophoretic fluid comprising charged pigment particles dispersed in a solvent, and the microcup layer is sandwiched between a first stack of layers and a second stack of layers, wherein the partition walls and the microcup bottom layer are weak barrier layers, and each of the two stacks comprises at least a strong barrier layer, and
- removing one or more the strong barrier layers from the first stack of layers or removing one or more the strong barrier layers from the second stack of layers, or both, allowing the solvent to evaporate from the display film.
A method for protecting against counterfeit, comprising:
- providing a module comprising an electrophoretic display film which film comprises a microcup layer having (i) partition walls, (ii) a microcup bottom layer, and (iii) microcups filled with an electrophoretic fluid comprising charged pigment particles dispersed in a solvent, wherein the microcup layer is sandwiched between a first stack of layers and a second stack of layers, the partition walls and the microcup bottom layer are strong barrier layers and the first stack of layers comprises at least one strong barrier layer and a sealing layer which is a weak barrier;
- and
- removing one or more strong barrier layers in the first stack of layers, allowing the solvent to evaporate from the display film.
Dependencies are inferred from the claim text.