发明名称 |
Marking device for electronic presentation board |
摘要 |
A presentation board digitizer system for large boards preferably employs at least three spaced-apart ultrasound receivers assemblies. A current position of an ultrasound transmitter is assigned as a weighted centroid of time-of-flight position measurements based on at least two pairs of receiver assemblies. The weighting used varies as a function of the transmitter across the board. A preferred structure of an ultrasound receiver assembly for use in the system employs a pair of ultrasound receivers arranged side-by-side in a line perpendicular to the surface of the presentation board. The receives are connected so as to generate a total output signal corresponding to the instantaneous sum of the ultrasound signals received at each, such that the receiver assembly is most sensitive to ultrasound signals incident from a plane adjacent to the presentation board. Also described are a transmitter device for use with a conventional pen in which the ultrasound transmitter is a cylindrical element lying coaxial with the pen and adjacent to its tip, and a jointed eraser structure. |
申请公布号 |
AU6544298(A) |
申请公布日期 |
1998.09.22 |
申请号 |
AU19980065442 |
申请日期 |
1998.03.05 |
申请人 |
ELECTRONICS FOR IMAGING, INC. |
发明人 |
RAFI HOLTZMAN;ISAAC ZLOTER |
分类号 |
G06F3/043;G06F3/033;G06F3/041 |
主分类号 |
G06F3/043 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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