Patent ID: 7030854

Claim:
An apparatus for displaying a drawing, said apparatus comprising: a display member having a viewing surface; support means for supporting said display member above a horizontal floor with said viewing surface facing upwardly; an electro-optic medium having first and second display states differing in at least one optical property, said medium being chanced from its first to its second display state by application of an electric field to said medium, said electro-optic medium being disposed on said display member so as to be visible to an observer viewing said viewing surface; a writing head arranged to write on said electro-optic medium an image visible to the observer viewing said viewing surface; and drive means for moving said writing head relative to said electro-optic medium, wherein said display member has the form of a hollow box, said electro-optic medium is disposed on an internal surface of said box, the portion of said box adjacent said electro-optic medium being substantially transparent so as to enable an observer to see said electro-optic medium through said viewing surface, and said writing head comprises an elongate member arranged to move within said box so as to write on said electro-optic medium.