Sensor unit, process and device for inspecting the surface of an object

US6449036B1 · kind B1 · utility

Assignee

• Baumer Optronic GmbH · DE

Inventors

• Christian Wollmann · Radeberg, DE
• Lutz Wenert · Dresden, DE
• Joachim Ihlefeld · Dresden, DE
• Ralf Grieser · Dresden, DE

Key dates

• Filing date: Jan 10, 2000
• Grant date: Sep 10, 2002
• Expiry date: Jan 10, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S17/48
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor unit (50), a device, and a process for inspection of a surface (10′, 10&Dgr;) of an object (10) for the purpose of identifying surface characteristics, such as structural defects. The device contains an emitting module (51) and a receiving module (52). The emitting module emits at least one beam bundle (6, 6′, 6″). The receiving module has at least one light receiver (15, 16, 20). A rotating polygonal mirror wheel (2) is located in the focal point of a parabolic mirror (1). A beam bundle (6) of the laser (3, 4) is directed onto the mirror (1) by means of a telecentric lens, which guides the emitter and receiver beam on the same optical axis, whereby the parabolic mirror (1) guides the deflected beam bundle (6, 6′, 6″) under a constant angle relative to the axis of symmetry (7) of the parabolic mirror (1) along a scanning line (23, 24) over the object (10). The diffusely reflected beam bundle, after being deflected out of the common beam path, impinges on the processing unit (5).