公开(公告)号：US06404340B1

公开(公告)日：2002-06-11

申请号：US09596618

申请日：2000-06-19

申请人： Joseph A. Paradiso ,  Kai-Yuh Hsiao

发明人： Joseph A. Paradiso ,  Kai-Yuh Hsiao

IPC分类号： G08B1314

CPC分类号： G06K7/10336

摘要： A preferred reader circuit for energizing the coils and detecting loading variations is shown in FIGS. 3A and 3B. It was designed for tabletop operation at relatively low frequencies; the amplitudes, frequencies, and time constraints listed below can be shifted as desired for other applications. The depicted schematic includes driver circuitry for three coils, it being understood that further drivers can be added as indicated in the figure. Each driver circuit includes an inductive bridge wherein a search coil 3051, 3052, 3053 is balanced against a series of reference inductors 3071, 3072, 3073; 3091, 3092, 3093; and 3311, 3112, 3113 (the latter being variable to trim residuals in the search coil's inductance). A representative pair of search coils 3051, 3052 are identically wound and driven together, and the sensing volume between them is once again indicated at 200. Coil 3053 may be one of another coil pair, or may instead be a non-aligned search coil used to resolve orientation-related ambiguities with respect to coils 3051, 3052.

摘要翻译： 用于激励线圈和检测负载变化的优选读取器电路在图1和图2中示出。 图3A和3B。 它设计用于较低频率的桌面操作; 下面列出的幅度，频率和时间约束可以根据其他应用的要求进行移位。 所描绘的原理图包括用于三个线圈的驱动器电路，应当理解，可以如图所示添加另外的驱动器。 每个驱动器电路包括电感桥，其中搜索线圈3051,3052,3053与一系列参考电感器3071,3072,3073平衡; 3091,3092,3093; 和3311,31212,3133（后者可以修整搜索线圈的电感中的残差）。 一对代表性的搜索线圈3051,3052被一体地卷绕和驱动，并且它们之间的感测体积再次以200表示。线圈3053可以是另一个线圈对中的一个，或者可以替代地是使用的非对齐搜索线圈 以解决相对于线圈3051,3052的取向相关歧义。