Substrate for an induction sensor
AssigneeNEC Corporation
InventorTakeshi Ikemoto
Life of this patent
Estimating the term…
Abstract
In an electromagnetic induction type displacement sensor, two coil patterns are formed on a substrate included in a scale. The coil patterns alternate with each other in the sensing direction of the sensor and are deviated in spatial phase from each other by a quarter pitch. An idle pattern portion is included in one or both of the two coil patterns in order to provide them with the same impedance. Even when sinusoidal voltages, which are different in phase by 90 degrees, are respectively applied to the coil patterns, the resulting magnetic fields are identical and insure accurate displacement detection.
Claims6
A substrate provided in scale of an electromagnetic induction type displacement sensor, wherein said substrate comprises:
- a first and second coil pattern provided on said substrate, said first and second coil patterns having at least one double path, wherein said double paths of said first and second coil patterns extend toward the other of said first and second coil patterns in a direction perpendicular to a sensing direction of said displacement sensor, said double paths of said first and second coil patterns alternate with each other in the sensing direction of said displacement sensor, said first and second coil patterns are deviated in spatial phase from each other by a quarter pitch, and wherein sinusoidal currents different in phase from each other by 90 degrees are respectively applied to said first and second coil patterns;
- and
- means for equalizing the impedances of said first and second coil patterns.
An electromagnetic induction type displacement sensor having a substrate provided in a scale, wherein said substrate comprises:
- a first and second coil pattern provided on said substrate, said first and second coil patterns having at least one double path, wherein said double paths of said first and second coil patterns extend toward the other of said first and second coil patterns perpendicular to a sensing direction of said displacement sensor, said double paths of said first and second coil patterns alternate with each other in the sensing direction of said displacement sensor, and said first and second coil patterns are deviated in spatial phase from each other by a quarter pitch;
- and
- means for equalizing impedances of said first and second coil patterns.
Dependencies are inferred from the claim text.