초록

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.

대표청구항 ▼

1. An electronic whiteboard system comprising: a writing surface;a first optical detection element;a second optical detection element; andan erasing device with an orientation identification system, the orientation identification system comprising at least two reflectors positioned such that each op

1. An electronic whiteboard system comprising: a writing surface;a first optical detection element;a second optical detection element; andan erasing device with an orientation identification system, the orientation identification system comprising at least two reflectors positioned such that each optical detection unit detects retro-reflected light beams from no more than one of the reflectors in substantially all orientations of the erasing device when the erasing device is in contact with the writing surface;wherein the at least two reflectors each comprise a retro-reflective surface;wherein the retro-reflective surfaces are configured to retro-reflect light beams incident at an angle within a predetermined cone of accurate retro-reflection;wherein the first optical detection element, the second optical detection element, and the orientation identification system work together to eliminate eraser ghosting. 2. The system of claim 1, wherein each retro-reflective surface faces a different direction from the other retro-reflective surfaces. 3. The system of claim 1, the first reflector adapted to retro-reflect a light beam emitted from the first optical detection element back to the first optical detection element and the second reflector adapted to retro-reflect a light beam emitted from the second optical detection element back to the second optical detection element. 4. The system of claim 1, the orientation identification system comprising at least two windows, each window comprising at least two angled surfaces, and one of the at least two reflectors. 5. The system of claim 4, wherein each window is primarily formed two surfaces at a 90° angle to each other. 6. The system of claim 5, wherein each retro-reflecting portion faces a different direction from the retro-reflecting other portions. 7. The system of claim 5, wherein the at least two windows are four windows. 8. The system of claim 1, further comprising a retro-reflective perimeter surrounding at least three edges of the writing surface for reflecting light beams emitted from the optical detection elements along a parallel path. 9. The system of claim 1, the optical detection elements each comprising an optical emitter and an optical receiver. 10. An electronic whiteboard assembly comprising: a writing surface having a first side, a second side, a third side, and a fourth side;a perimeter disposed along the first, second, and third sides of the first writing surface;a first optical detection element;a second optical detection element; andan erasing device comprising a body, the erasing device with an orientation identification system, the orientation identification system comprising one or more windows;wherein each window comprises a concave cavity in the body primarily comprising two planar surfaces at a predetermined angle to each other, at least a portion of which surfaces are retro-reflecting;wherein the first optical detection element, the second optical detection element, and the orientation identification system work together to eliminate eraser ghosting. 11. The system of claim 10, wherein each optical detection element detects retro-reflected light from no more than one retro-reflecting portion of the one or more windows when the erasing device is in contact with the writing surface. 12. The system of claim 10, wherein each retro-reflective portion faces a different direction from the other retro-reflective portions. 13. The system of claim 10, the orientation identification system comprising a first retro-reflective surface and a second retro-reflective surface. 14. The system of claim 13, the first retro-reflective surface adapted to retro-reflect a light beam emitted from the first optical detection element back to first optical detection element and the second retro-reflective surface adapted to retro-reflect a light beam emitted from the second optical detection element back to the second optical detection element. 15. The system of claim 10, wherein the two planar surfaces of a window are angled at approximately 90° to each other. 16. The system of claim 10, the perimeter being a retro-reflective perimeter surrounding at least three edges of the writing surface for reflecting light beams emitted from the optical detection elements along a parallel path. 17. The system of claim 10, the optical detection elements each comprising an optical emitter and an optical receiver. 18. An electronic whiteboard assembly comprising: a writing surface having a first side, a second side, a third side, and a fourth side;a perimeter disposed along the first, second, and third sides of the first writing surface;two optical detection elements, each optical detection element configured to detect retro-reflected light;an erasing device comprising a body, the erasing device with an orientation identification system comprising one or more windows;wherein each window comprises a concave cavity in the body formed of at least two angled surfaces, at least a portion of which surfaces are retro-reflecting;wherein the retro-reflecting portions are configured such that cones of accurate reflection of any two retro-reflecting portions do not overlap at a location on the writing surface when the erasing device is in contact with the writing surface; andwherein the optical detection elements, and the orientation identification system work together to eliminate eraser ghosting. 19. The system of claim 18, wherein each retro-reflecting surface faces a different direction from the other retro-reflecting surfaces. 20. The system of claim 19, wherein the one or more windows are four windows.