Eraser for use with optical interactive surface

摘要

An eraser is usable in a display system having a display surface. The eraser includes one or more optical detection elements for determining the coordinates of the eraser relative to the display surface.

主权项

1. An erasing device for reducing eraser ghosting in an electronic whiteboard system comprising a writing surface and two or more optical detection elements, the erasing device comprising:
a body; at least two retro-reflectors configured to retro-reflect light beams incident at an angle within a predetermined cone of accurate retro-reflection; and an orientation identification system wherein the retro-reflectors are disposed on the body of the erasing device such that each optical detection unit of the electronic whiteboard system detects retro-reflected light beams from no more than one of the retro-reflectors in substantially all orientations of the erasing device when the body of the erasing device is in proximity to the writing surface.