Method for 3D, measurement of the surface of an object, in particular for dental purposes

US8615128B2 · kind B2 · utility

Assignee

• SIRONA Dental Systems GmbH · DE

Inventors

• Axel Schwotzer · Groß-Gerau, DE
• Konrad Klein · Dortmund, DE

Key dates

• Filing date: Dec 23, 2009
• Grant date: Dec 24, 2013
• Expiry date: Sep 22, 2030

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B1/24
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

For the purpose of 3D scanning the surface of an object by optical double triangulation using the phase-shifting method, more particularly for dental purposes, at least two 3D scans of the same object (1) are carried out at different triangulation angles (θ1, θ2), the first angle of which is known and the second angle of which is known at least approximately. For each pixel (Bi) of the phase related image (φ1(x,y)), a wave number (wz(xi,yi) is determined using the second phase related image, the integral portion of which is equal to the order (n) of the uniqueness range (E1) in which the respective pixel (Bi) is located. The wave number (wz(x,y)) is optimized, at least for a random sample of m pixels (Bi), by minimizing a non-integral portion of the wave number (wz (xi,yi)−[wz(xi,yi)]).