| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rotation detection apparatus suitable for the detection of high-speed rotation, which may be difficult by a magnetic sensor, and to achieve also a low-cost apparatus excellent in environment resistance. <P>SOLUTION: The high-speed rotation detection apparatus includes: a first signal generator 9 for generating a first signal of a frequency based on a resonance frequency of a circuit including inductance (or also capacitance is available) reacting to a counter distance from a target 1 and a second signal generator 10 for generating a second signal of a frequency to be a reference. The first signal generator 9 includes a voltage controlled oscillator 2. A phase synchronizing circuit 12 applies control voltage to the voltage controlled oscillator 2 so that the phases and frequencies of the first signal and the second signal respectively coincide with each other. An output circuit 8 outputs a rectangular wave signal taking a period in which the control voltage is changed, i.e. a signal corresponding to a recessed part or a projected part of the target 1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
