Modular surface inspection method and apparatus using optical fibers

An apparatus for inspecting the surface of an object moving in a direction of travel relative to said apparatus, said apparatus comprising:

• light source means for generating a line of light on the surface of the object generally transverse to the direction of travel, with the line of light impinging the surface of the object at an angle of incidence lying in an illumination plane generally upstanding from the surface of the object;
• first optical detector means for detecting light scattered from the line of light by the surface of the object along a first path lying in a first detection plane generally upstanding from the surface of the object;
• and
• second optical detector means for detecting light scattered from the line of light by the surface of the object along a second path lying in a second detection plane generally upstanding from the surface of the object,
• wherein said first and second optical detector means each comprise a plurality of sensors for creating electronic signals and fiber optic means for communicating scattered light to said sensors, said apparatus further comprising multiplexor means associated with said sensors for multiplexing said signals.

An apparatus for inspecting the surface of an object comprising:

• means for generating a source of light;
• means for shining the source of light onto the surface of the object to project a line of light on the surface of the object;
• first means for detecting light scattered from the line of light by the surface of the object in a first detection plane generally upstanding from the surface of the object;
• second means for detecting light scattered from the line of light by the surface of the object in a second detection plane generally upstanding from the surface of the object;
• means for converting the scattered light detected by said first and second means for detecting light for creating first and second electrical signals, respectively;
• means for filtering the first and second electrical signals to remove noise therefrom;
• means for multiplexing the first and second electrical signals;
• and
• means for processing the first and second electrical signals to detect the existence of a defect on the surface of the object.

A method for inspecting the surface of an object comprising the steps of:

• (a) generating a source of light;
• (b) shining the source of light onto the surface of the object to project a line of light on the surface of the object;
• (c) detecting light scattered from the line of light by the surface of the object in a first detection plane generally upstanding from the surface of the object;
• (d) detecting light scattered from the line of light by the surface of the object in a second detection plane generally upstanding from the surface of the object;
• (e) converting the scattered light detected in the first and second detection planes to first and second electrical signals, respectively;
• (f) filtering the first and second electrical signals to remove noise;
• (g) multiplexing the first and second electrical signals;
• and
• (h) processing the first and second electrical signals to detect the existence of a defect on the surface of the object.