Light pen tracking method and apparatus
First Claim
1. A method for use in a display system which includes a display medium (100) comprised of a plurality of selectively energizable display sites, means (105, 110, 111, 115, 116, 130) for causing selected ones of said display sites to flash in a selected order, a light pen (150) adapted to be moved adjacent to said display medium, said light pen generating a signal when a display site adjacent thereto flashes, and means (105, 115, 116, 130, 154) responsive to said signal for identifying as the current location of said light pen the location of said adjacent display site, said method being comprised of the step ofselecting as said ones of said display sites the display sites in a region of said display medium which includes a predicted future location of said pen.
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Accused Products
Abstract
An initial location of a light pen (150) placed on the surface of an ac plasma panel (100) is determined by scanning the panel with a two-step finder mode. In the first step, the display sites of every seventh row of display sites of the panel are caused to flash in groups of sixteen until the pen signals that it has detected a flash. The sites in a 60-by-60 site region (306) of the panel are then caused to flash individually to determine the precise pen location (302). A second pen location (312) is determined by scanning the sites of a 32-by-32 scanning patch (311) centered around the initial pen location. Subsequent pen locations are then predicted based on the most recent and second most recent pen locations. Each predicted location (317) is used to determine where a subsequent 32-by-32 scanning patch (316) is to be positioned. The direction in which the pen is moving determines the order in which the sites of each patch are scanned. As each pen location is determined, a line (313,319) is generated in the displayed image connecting it to the previously-determined pen location. This creates the subjective impression of "writing" with the pen.
42 Citations
32 Claims
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1. A method for use in a display system which includes a display medium (100) comprised of a plurality of selectively energizable display sites, means (105, 110, 111, 115, 116, 130) for causing selected ones of said display sites to flash in a selected order, a light pen (150) adapted to be moved adjacent to said display medium, said light pen generating a signal when a display site adjacent thereto flashes, and means (105, 115, 116, 130, 154) responsive to said signal for identifying as the current location of said light pen the location of said adjacent display site, said method being comprised of the step of
selecting as said ones of said display sites the display sites in a region of said display medium which includes a predicted future location of said pen.
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9. A method for use in a display system which includes a display medium (100), a light pen (150) adapted to be moved adjacent to the surface of said display medium and means (105, 110, 111, 115, 116, 130) operative for scanning said display medium to determine the location of said light pen, said method comprising the step of
operating said scanning means to scan the sites in a region of said display medium which includes a predicted future location of said light pen.
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17. A display system which includes
a display medium (100) comprised of a plurality of selectively energizable display sites, control means (105, 110, 111, 115, 116, 130) for causing selected ones of said display sites to flash in a selected order, a light pen (150) adapted to be moved adjacent to said display medium, said light pen generating a signal when a display site adjacent thereto flashes, and means (105, 115, 116, 130, 154) responsive to said signal for identifying as the current location of said light pen the location of said adjacent display site, said control means characterized by means (260, 290) for selecting as said ones of said display sites the display sites in a region of said display medium which includes a predicted future location of said pen.
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25. A display system which includes,
a display medium (100), a light pen (150) adapted to be moved adjacent to the surface of said display medium and means (105, 110, 111, 115, 116, 130) for scanning a selected region of said display medium to determine the location of said light pen, said scanning means characterized by means (260, 290) for selecting as said region a region of said display medium which includes a predicted future location of said light pen.
Specification