| 摘要 |
A visually and remotely readable apparatus is provided which comprises a plurality of sensing units, a control unit and a flexible printed cable (FPC) to connect two units for exchanging information therebetween. A preferable structure of the sensing unit includes a fixed part secured to the body of the apparatus and two oppositely positioned rotatable parts, where two rotatable parts mounted on a common shaft with the fixed part arranged therebetween forming two angular position sensors. Each sensor is based on the capacitive coupling between two working surfaces of the rotatable part and the respective working surfaces of the fixed part with the electrodes are secured thereto. Two working surfaces of one part are confronted with two respective working surfaces of another part forming two working surface pair. Each sensor has two working surface pairs, one working surface pair is sensing pair for sensing angular position; another is coupling pair for coupling sensing signals. A plurality of transmitting electrodes are secured to the working surface of the sensing pair of the fixed part; a receiving electrode is secured to the working surface of the sensing pair of the rotatable part; an output electrodes is secured to the working surface of the coupling pair of the fixed part; a coupling electrode connected to the receiving electrode is secured to the working surface of the coupling pair of the rotatable part. To each of the plurality of the transmitting electrodes is applied a respective one of polyphase squarewave voltages. The capacitive coupling between the electrodes of the sensing pair is dependent on the relative positions of two rotatable part, and the output signal voltages on the output electrode which coupled from the coupling electrode represents the angular position of the rotatable part. In the first embodiment provided for the sensors, the shape of working surfaces is in a conical frustum; the second embodiment, the shape of working surfaces is a cylinder; the third embodiment, the shape of working surfaces is a disc; the fourth embodiment, with a cylinder-shaped working surface and a disk-shaped working surface, is a combination of the second and the third embodiments provided as an example of the application of the embodiments. A circuit of the control unit is provided for processing data, generating control signals for the sensors. By using radio frequency identification (RFID) technique to exchange information with the reader station outside of the apparatus and power the system are also disclosed in the invention. |
| 主权项 |
1. An apparatus for visually and remotely determining an angular position of a relative rotation of parts as it rotates about an axis comprising:
first and second relatively rotatable parts, one is fixed as a fixed part, another, relatively rotatable one, rotated about an axis as a rotating part, each of said parts having two working surfaces which geometrically generated by rotating a two-dimensional polygon about said axis, said two-dimensional polygon parallel to said axis but not intersect said axis; one of two working surfaces is for sensing position purpose called sensing surface, another is for coupling sensing signals called coupling surface; each of said two working surfaces of one of said parts is equispaced from, and lies closely adjacent to, a respective one of said two working surfaces of another one of said parts; each of said two working surfaces of one part forms a working surface pair with a respective one of said two working surfaces of another part, one of the formed two working surface pairs is sensing surface pair, another is coupling surface pair; said sensing surface of said fixed part having secured thereto a plurality of transmitting electrodes and a respective one of said rotating part having secured thereto a receiving electrode; said coupling surface of said fixed part having secured thereto an output electrode and the respective one of said rotating part having secured thereto a coupling electrode which connected to said receiving electrode of said rotating part with a conductor; said plurality of transmitting electrodes on said sensing surface of said fixed part being positioned in confronting, spaced relation to, but in no way mechanically or electrically connected to said receiving electrode on said sensing surfaces of said rotating part within any rotatable positions of said rotating part, other than that said receiving electrode is capacitive coupled to a portion of said plurality of transmitting electrodes; said output electrode on said coupling surface of said fixed part being positioned in confronting, spaced relation to, but in no way mechanically or electrically connected to said coupling electrode on said coupling surface of said rotating part other than that said output electrode is capacitive coupled to said coupling electrode; means for mounting said fixed and rotating parts for relative rotational movement so as to cause said receiving electrode secured to the sensing surface of said rotating part to move along a predetermined path relative to said plurality of transmitting electrodes, a capacitive coupling between said receiving electrode and said plurality of transmitting electrodes being dependent on a relative rotational position of said parts and said electrodes; a source of n phase polyphase squarewave voltages being supplied to said plurality of transmitting electrodes, said n equal to the number of said plurality of transmitting electrodes, successive ones of said transmitting electrodes being connected to successive said polyphase squarewave voltages; the capacitive coupling between said transmitting electrodes and said receiving electrode inducing a coupling signal on said receiving electrode, said coupling signal providing only one electrical cycle per complete mechanical rotation of said relatively rotatable parts; said coupling signal received by said coupling electrode and coupled to said output electrode with an output sensing signal produced thereon. |
