Optical measuring apparatus for measuring objects on machines
AssigneeRenishaw PLC
InventorsVictor G Stimpson, Jon P Fuge, William K Davies, Norman J Leete, Colin T Bell
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Abstract
The present invention teaches a method and apparatus for making measurement of an object on a machine, such as a machine tool, using an optical measuring apparatus which includes a light source for generating a beam of light which is incident on a detector. A detection signal is generated within the detector each time the beam is interrupted. The duration and/or frequency of the detection signals are evaluated and an output signal is emitted from the detection only if a further detection signal is present within the detector in a specified time interval from the generation of an earlier detection signal.
Claims11
A method of making measurements of an object using an optical measuring apparatus which includes a light source which generates a beam of light, and a detector, upon which is incident the beam of light, the method comprising the steps, in any suitable order, of:
- causing a beam of light to be emitted from the light source;
- generating a first detection signal within the detector when the beam of light from the light source is interrupted;
- providing a first time interval when the first detection signal is generated;
- providing a second time interval wherein the second time interval is shorter than the first time interval and commences at the end of the first time interval;
- emitting an output signal from the detector if a further detection signal is present within the detector during the second time interval.
Optical apparatus for measuring objects comprising a light source for generating a beam of light and comprising a detector arranged to receive the said beam and for generating a signal when the beam is interrupted, wherein the detector in use:
- generates a first detection signal within the detector when the beam of light from the light source, incident on the detector is interrupted;
- provides a first time interval when the first detection signal is generated,
- provides a second time interval wherein the second time interval is shorter than the first time interval and commences at the end of the first time interval;
- and
- emits an output signal from the detector if a further detection signal is present within the detector during the second time interval.
A method of making measurements of an object on a machine using an optical measuring apparatus which includes a light source which generates a beam of light which is incident upon a detector and a detector, the method comprising upon a detector and a detector, the method comprising the steps, in any suitable order, of:
- rotating the object;
- causing light to be emitted from the light source;
- generating a first detection signal within the apparatus when the beam of light from the light source, incident on the detector, is interrupted;
- generating a first time interval when the first detection signal is generated;
- evaluating whether there is a further occurrence of the detection signal during a second time interval, which commences at the end of the first time interval and is shorter than the first time interval;
- and
- emitting an output signal from the apparatus only if a further detection signal is present within the apparatus during the second time interval.
Dependencies are inferred from the claim text.