Method and apparatus for distinguishing regions where a material is present on a surface.
AssigneeKoninklijke Philips Electronics N.V.
InventorEGBERT F.A. LAND
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Abstract
A property of the surface such as height is sensed as a function of position on the surface. A statistical spread in the sensed property as a function of the position is computed. Regions where the material is present are distinguished from other regions on the basis of the spread, e.g. conductor tracks on a PCB assembly are distinguished from a PCB substrate by having lower spread.
Claims8
A method of distinguishing regions where a material is present on a surface, the method comprising the steps of
- sensing a property of the surface as a function of position on the surface;
- distinguishing regions where said material is present from other regions on the basis of said sensed property,
- characterized by the steps of
- computing a measure of statistical spread in said sensed property as a function of the position;
- distinguishing regions where said material is present from other regions on the basis of said measure of statistical spread.
An apparatus containing a detector for distinguishing regions where a material is present on a surface, the detector comprising
- a sensor for sensing a property of the surface as a function of position on the surface;
- a discriminator for discriminating regions where said material is present from other regions on the basis of said sensed property, characterized in that the discriminator is arranged for computing a measure of statistical spread in said sensed property as a function of the position and for discriminating regions where said material is present from other regions on the basis of said measure of statistical spread.
Dependencies are inferred from the claim text.