McGuireWoods LLP
Method of processing signals of encoders and apparatus employing the same
 The present invention provides a method of processing signals of encoders and an apparatus employing the same by each of which increase and decrease of a counter value can be made to match an angle of a rotational angle of two-phase incremental encoders all the time. The apparatus includes: first and second change point detecting units for detecting the changes of output signals of Ach and Bch, respectively, which are outputted from incremental type encoders; first and second storage units for storing therein, at a time point when the change of one of the output values is detected by the first and second change point detecting units, the other output value; a past value storing unit for storing therein the value which is stored in at least one storage unit of the values which are stored last time in the first and second storage units; a logical judgement unit for determining the up/down direction of a counter on the basis of the values stored in the first and second storage units and in the past value storing unit; and a logical judgement unit for sending a clock. 
NEC Corporation
H G
H03M G05B
inventional inventional
Takuji
Nakano