One-dimension position encoder

US8698892B2 · kind B2 · utility

Assignee

• CSEM CENTRE SUISSE D'ELECTRONIQUE ET DE MICROTECHNIQUE SA—RECHERCHE ET DÉVELOPPEMENT · CH

Inventors

• David Hasler · Neuchâtel, CH
• Peter Masa · La Chaux-de-Fonds, CH
• Pascal Heim · Bevaix, CH
• Edoardo Franzi · Cheseaux-Noréaz, CH

Key dates

• Filing date: Apr 3, 2009
• Grant date: Apr 15, 2014
• Expiry date: May 28, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03M1/202
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A one-dimension position measurement system includes: a first ruler having a first one-dimension binary code si applied thereon, a camera for acquiring a picture of a portion of the code si, the portion having a length of I bits, and some processing elements. Each codeword of length I of the one-dimension code si is unique within the whole code si. A codeword ai is read from the acquired picture, and the processing elements are implemented for computing an absolute position p of the codeword ai of the code si from: (I). An ad-hoc interpolation method is used to obtain a precision way below the distance between two bits of the codewords. The code si may be applied on the ruler by using some geometric primitives, a geometric primitive for encoding a “1” being different from a geometric primitive for encoding a “0”, both having the same horizontal projection. The horizontal projection is then used for fine interpolation, achieving nanometer-scale resolution.