Electrophoretic displays in portable devices and systems for addressing such displays
AssigneeE Ink Corporation
InventorsRobert W. Zehner, Gregg M. Duthaler, Richard J. Paolini, Jr., Ian Morrison
Life of this patent
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Abstract
A card may include a photoconductive layer and an electrophoretic layer. The impedance of the photoconductive layer is lowered when struck by light from the light-emitting layer. Where the impedance of the photoconductive layer is lowered, the electrophoretic layer may be addressed by an applied electric field to update an image on the card. The image on a card may be updated by a system of updating an image on a card and a method of updating an image on a card that are presented.
Claims41
A system of updating an image on a card, the system comprising:
- (a) a light system generating a pattern of light;
- and
- (b) a card comprising an electrophoretic layer and a photoconductive layer, the photoconductive layer adjacent the electrophoretic layer;
- wherein the pattern of light generated by the light system reduces the impedance of the photoconductive layer, permitting an applied electric field to address the electrophoretic layer where the impedance is reduced.
A card comprising:
- a photoconductive layer;
- and
- an electrophoretic layer, the photoconductive layer adjacent the electrophoretic layer;
- wherein the photoconductive layer impedance is reduced when the photoconductive layer is exposed to a pattern of light, permitting an applied electric field to address the electrophoretic layer where the impedance is reduced.
A method of updating an image on a card, the method comprising the steps of:
- (a) providing a card comprising an electrophoretic layer and a photoconductive layer, the photoconductive layer adjacent the electrophoretic layer, the photoconductive layer providing impedance;
- (b) lowering the impedance of the photoconductive layer by exposing the photoconductive layer to a pattern of light;
- (c) addressing the electrophoretic layer by applying an electric field, the image of the card changing in response to the applied electric field and the lowered impedance of the photoconductive layer.
Dependencies are inferred from the claim text.