Rewritable sign system

A rewritable sign comprising:

• a first panel that is transparent;
• a second panel;
• and
• a cholesteric liquid crystal layer disposed between the first panel and the second panel;
• wherein the rewritable sign is adapted to electrically couple to external electrical circuitry for establishing localized electric fields to the cholesteric liquid crystal layer.

A rewritable information presentation medium comprising:

• a first transparent panel comprising:
• a first side, and
• a second side;
• a second panel comprising:
• a first side, and
• a second side;
• a cholesteric liquid crystal layer disposed between the first transparent panel and the second panel, the cholesteric liquid crystal layer including:
• a first side of the cholesteric liquid crystal layer that faces the second side of the first transparent panel;
• and
• a second side of the cholesteric liquid crystal layer that faces the first side of the second transparent panel;
• and
• a first plurality conductors for applying electric fields to the cholesteric liquid crystal layer, the first plurality of conductors including first terminal portions that are adapted to electrically and disengageably couple to an external drive signal source for establishing localized electric fields to the cholesteric liquid crystal layer.

A method for writing information on a rewritable sign having a cholesteric liquid crystal layer, the method comprising the steps of:

• holding an information writer in proximity to the rewritable sign;
• applying one or more voltage signals to one or more electrodes within the information writer;
• establishing one or more electric fields between the pixel electrodes and a ground plane of the rewritable sign;
• and
• passing the one or more electric fields through a cholesteric liquid crystal layer of the rewritable sign thereby altering a phase of the cholesteric liquid crystal layer in localized regions thereby writing information on the rewritable sign.