| 摘要 |
PURPOSE:To enable to provide a high precision without a wide change in a constitution, by a method wherein a lattice pattern of a code plate and a group of sensors are arranged in an array, which equalize in an arrangement frequency, are are positioned so that they can cross each other. CONSTITUTION:A code plate 1, in which light and dark information is periodically arranged in a longitudinal direction, and a linar sensor 2 are located within a plane, being perpendicular to a paper surface, and tilting at an angle theta to each other. The arrangement of the light and dark pattern of the plate 1 and the arrangement of a group of the sensors 2 have the same period. The output of the sensor 2 produced resulting from the relative movement of the plate 1 to the sensor 2 is added to a signal distributor 13 after being amplified. The distributor 13 distributes the signals of the sensor 2 into signals of even-numbered elements and signals of odd-numbered elements, and the signals are sent to envelope curve detectors 14 and 15. Output signals from detectors 14 and 15 are compared by means of a comparator 16, and a comparision output is generated at a point where the two signals produce the same electrical potential. The comparison output is added to a counter 17 which feeds counting values to a conversion circuit 12, and a micro reading result of a movement amount is obtained from the circuit 12. |
