Patent ID: 7843440

Claim:
A scrolling electronic whiteboard, comprising: a thin-film antenna board, with a thin-film as a substrate, a plurality of wires equally-spaced and arranged on said thin-film to form a two-dimensional matrix of antenna loops; a scrolling mechanism cassette, for housing said thin-film antenna board, said thin-film antenna board being able to be pulled out from or retracted into said scrolling mechanism cassette; at least an electromagnetic signal transmitter, with each said electromagnetic signal transmitter having a resonant circuit for transmitting an electromagnetic signal of a specific frequency; and a main control board, having a signal processing and control circuit and a microprocessor, for receiving antenna loop signals from said thin-film antenna board, and electromagnetic signals from each said electromagnetic signal transmitter; wherein said main control board enables said electromagnetic signal transmitter, activates a plurality of Y-axis antenna loop in said two-dimensional matrix of antenna loops one by one for receiving a respective antenna loop signal, and a length of said thin-film antenna board being pulled out is determined by the Y-axis antenna loop that has the antenna loop signal with a largest amplitude.