Title:
COUNTER OF INCREMENTAL ENCODER
Document Type and Number:
Japanese Patent JP3538261
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a counter of incremental encoder wherein the count output values are logically examined and their errors can be automatically detected.
SOLUTION: A reference pulse is output from a first comparator 1 according to slide-motion of a main scale, and also a comparison pulse having a phase difference less than 180 degrees with respect to the reference pulse is output from a second comparator 2. An up-down counter 3 adds counted output values every time it detects a change in signal state of the reference pulse and the comparison pulse since it received a 0-set signal. Therefore, incremented numbers during a period of the reference pulses are always constant. An initial phase latch circuit 4 holds the signal state of the reference pulses and the comparison pulses at the time of receiving the 0-set signal. A count error detection circuit 6 calculates the difference between a remainder wherein the counted output value of the up-down counter 3 is divided by the number of increments during the one period and the number of changes calculated by a phase comparison circuit 5 as an error.
Inventors:
Matsumoto, Mitsuhiro
Application Number:
JP17220095A
Publication Date:
June 14, 2004
Filing Date:
July 07, 1995
Export Citation:
Assignee:
ASAHI OPTICAL CO LTD
International Classes:
G01D5/245; G01D5/244; G01D5/36; (IPC1-7): G01D5/245; G01D5/36
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