| 摘要 |
PURPOSE:To obtain a displacement converter, which does not have errors and phase fitter due to delay in a circuit system and does not require adjustment, by detecting light transmitted through a code plate by a specified image sensor, counting the detected signal by a counter through a bandpass filter, and processing the result. CONSTITUTION:Image sensor 4 is driven by a reference clock fc and detects light transmitted through a code plate. The detected signal undergoes phase modulation through a bandpass filter 6. A signal e6 becomes a rectangular wave signal e7 through a wave shaping circuit 51 of a phase measuring means 50. The signal e7 is inputted to the D terminal of an FF52, which receives the reference clock fc as a clock input. An output e8 of the FF52 is inputted to a control circuit 53. A pulse e9 is generated at every cycle of the signal e7 and inputted to a counter 54. The clocks fc of the one cycle are counted. Output D1 of the counter is inputted to an operation circuit 55, where operation is performed. Then the output corresponding to the change in the code plate can be obtained. Since the signal e8 is synchronized with the clock fc, errors are not computed. |
