| 摘要 |
PROBLEM TO BE SOLVED: To provide a speed detection device capable of reducing costs without producing a speed operation error. SOLUTION: The speed detection device includes a latch signal generation part 21 for detecting the edge of an output pulse from an encoder; a time counter 23 for measuring a time synchronously with a speed operation period; data latches 25-1 to 25-4 of a first latch part 41 for holding a time measured value by a first latch signal output from the latch signal generation part 21; data latches 28-1 to 28-4 of a second latch part 42 for holding by a second latch signal a time measured value held by the first latch part 41;a concurrent signal detecting means 35 for generating a concurrent detection signal when the edge is generated concurrently with a speed operation period signal; a second latch signal selecting means 36 for providing the second latch part 42 with an adjusting signal which is the speed operation period signal shifted by a predetermined period as the second latch signal at the time of generation of the concurrent detection signal; and a CPU 30 for operating a rotational speed by using the time measured value held by the second latch part 42. COPYRIGHT: (C)2010,JPO&INPIT
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