Scale and method for making a scale

US5880882A · kind A · utility

Assignee

• DR. JOHANNES HEIDENHAIN GMBH · DE

Inventors

• Dieter Michel · Traunstein, DE
• Georg Flatscher · Schneizlreuth, DE

Key dates

• Filing date: Dec 13, 1996
• Grant date: Mar 9, 1999
• Expiry date: Dec 13, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/34707
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A scale for opto-electrical linear or angular measuring systems. A gradation in the form of a phase grating is embodied on the scale and has alternating raised and stepped areas. A continuous compensating layer of chrome and on it a continuous highly reflective layer of titanium nitride are applied to one side of a step-like structured base body. The material and the layer thickness of the compensating layer is selected in such a way that it counteracts the mechanical stresses of the reflecting surface layer and thus, in the finished state of the scale, the deposited layers no longer exert stresses on the base body.