Measuring method and apparatus
AssigneeWalter AG
InventorAndreas Meier
Life of this patent
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Abstract
A method of measuring selected values of a specimen having at least one edge is performed with an apparatus which positions the specimen in the path of a light beam such that the specimen at least partially interrupts the light beam and the edge borders a shadow cast by the specimen. Further, the apparatus rotates the specimen about a rotary axis through at least one predetermined angle; monitors, by an observing apparatus, a boundary of the shadow cast by the edge; generates, by the observing apparatus, signals representing positions of the boundary; and evaluates the signals for determining the selected values.
Claims19
A method of measuring selected values of a specimen having at least one edge, comprising the following steps:
- (a) positioning the specimen in the path of a light beam such that the specimen at least partially interrupts the light beam and said edge borders a shadow cast by the specimen;
- (b) rotating the specimen about a rotary axis through at least one predetermined angle;
- (c) monitoring, by an observing apparatus, a boundary of the shadow cast by said edge;
- (d) generating, by said observing apparatus, signals representing positions of said boundary;
- and
- (e) evaluating said signals for determining said values.
A measuring apparatus for measuring selected values of a specimen having at least one edge, comprising
- (a) an illuminating device emitting a light beam having a light beam path;
- (b) a specimen-receiving chuck holding and positioning the specimen in the light beam path for causing the specimen, including an edge thereof, to cast a shadow;
- (c) means for rotating said chuck for rotating the specimen about a predetermined axis;
- (d) a sensor device coupled to the chuck for emitting first signals representing angular positions of said chuck and the specimen;
- (e) an observing apparatus receiving the shadow cast by the edge and emitting second signals representing positions of the shadow;
- and
- (f) an evaluating device connected to said sensor device and said observing apparatus for receiving and evaluating said first and second signals.
Dependencies are inferred from the claim text.