Position measuring apparatus with reflection

US5079418A · kind A · utility

Assignee

• DR. JOHANNES HEIDENHAIN GMBH · DE

Inventors

• Dieter Michel · Traunstein, DE
• Erwin Spanner · Traunstein, DE

Key dates

• Filing date: Feb 20, 1990
• Grant date: Jan 7, 1992
• Expiry date: Feb 20, 2010

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/38
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A position measuring apparatus for measuring the position of a first object relatively movable with respect to a second object. The position measuring apparatus includes a first deflection element, a light source positioned to scan the first deflection element with a light beam, a second deflection element, and a reflection element. The second deflection element and the reflection element are adapted with respect to each other and with respect to the first deflection element so that partial beam bundles deflected from the first deflection element are deflected by the second deflection element and emerge converging from the second deflection element into the reflection element, are reflected by the reflection element, and emerge diverging from the reflection element, impinge again on a deflection element, are deflected again and are brought into interference. The movement of the first object connected to the first deflection element with respect to the second object connected to the second deflection element can be determined by detection of the interference.