Electronic linear scale using a reduced offset high accuracy induced current position transducer

US6049204A · kind A · utility

Assignee

• Mitutoyo Corporation · JP

Inventors

• Nils Ingvar Andermo · Kirkland, US
• Karl G. Masreliez · Stockholm, SE

Key dates

• Filing date: Nov 21, 1997
• Grant date: Apr 11, 2000
• Expiry date: Nov 21, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/2086
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An electronic linear scale having a reduced offset position transducer that uses at least one coupling loop on a scale to inductively couple a transmitter winding on a read head to one or more receiver windings on the read head. The transmitter winding generates at least one primary magnetic field. The transmitter winding is inductively coupled to first loop portions of the coupling loops by the primary magnetic field. Second loop portions of the coupling loops generate secondary magnetic fields. Each receiver winding is inductively coupled to the second loop portions of the coupling loops by the secondary magnetic fields. At least one of the transmitter winding or the receiver windings is formed in a periodic pattern complementary to the dimensions of the coupling loops. Prescribed winding configurations are used to reduce the effects of extraneous inductive coupling in the device. Depending on the relative position between the read head and the scale, the receiver windings inductively couple to the second loop portions of the coupling loops to various degrees. A compact, high accuracy, high resolution inductive position sensor results. Low power operation is possible.