Error detection apparatus and method for use with engravers

An image system for imaging engraved areas on workpieces comprising:

• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• and
• a processor coupled to said imager for using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said processor locates at least one pair of said engraved areas using said pixel array and generates said calibration factor corresponding thereto, said processor generating said calibration factor using a scaling variable;
• and
• wherein said scaling variable comprises a count of the number of pixels situated between centroids of said plurality of engraved areas.

An image system for imaging engraved areas on workpieces comprising:

• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• and
• a processor coupled to said imager for using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said processor locates at least one pair of said engraved areas using said pixel array and generates said calibration factor corresponding thereto, said processor generating said calibration factor using a scaling variable and a known screen variable associated with said plurality of engraved areas;
• wherein said calibration factor comprises a ratio of said scaling variable and said known screen variable;
• wherein said known screen variable comprises a distance defined by a desired screen;
• and
• wherein said at least one scaling variable comprises a count of the number of pixels between centroids of said plurality of engraved areas and said known screen variable comprises an actual distance between said engraved areas as defined by said screen associated with said plurality of engraved areas.

An image system for imaging engraved areas on workpieces comprising:

• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• and
• a processor coupled to said imager for using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said processor locates at least one pair of said engraved areas using said pixel array and generates said calibration factor corresponding thereto, said processor generating said calibration factor using a scaling variable and a known screen variable associated with said plurality of engraved areas;
• and
• wherein said processor determines a pixel span between at least one pair of engraved areas and determines said scaling variable using said pixel span.

An image system for imaging engraved areas on workpieces comprising:

• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• and
• a processor coupled to said imager for using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said image calibration factor comprises a ratio defined by the following formula:
• M=D/P
• where M is said calibration factor;
• P comprises a count of a number of pixels between a first point on a first engraved area and a second point on a second engraved area, wherein a relationship between said first point relative to said first engraved area substantially corresponds to a second relationship of said second point to said second engraved area;
• and
• D comprises a distance between said first engraved area and said second engraved area as defined by a desired screen.

An image system for imaging engraved areas on workpieces comprising:

• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• and
• a processor coupled to said imager for using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said image calibration factor comprises a ratio defined by the following formula:
• M=D/P
• where M is said calibration factor;
• P comprises an average count of a number of pixels between corresponding points of a plurality of pairs of engraved areas;
• and
• D comprises an distance between said plurality of pairs of said engraved areas as defined by a desired screen.

An engraver for engraving a cylinder comprising:

• an engraving head for engraving a plurality of engraved areas on said cylinder;
• a processor for controlling the operation of the engraving head;
• and
• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• said processor using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said processor locates at least one pair of said engraved areas using said pixel array and generates said calibration factor corresponding thereto, said processor generating said calibration factor using a scaling variable and a known screen variable associated with said plurality of engraved areas;
• wherein said calibration factor comprises a ratio of said scaling variable and said known screen variable;
• and
• wherein said scaling variable comprises a number of pixels between said engraved areas.

An engraver for engraving a cylinder comprising:

• an engraving head for engraving a plurality of engraved areas on said cylinder;
• a processor for controlling the operation of the engraving head;
• and
• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• said processor using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said processor locates at least one pair of said engraved areas using said pixel array and generates said calibration factor corresponding thereto, said processor generating said calibration factor using a scaling variable and a known screen variable associated with said plurality of engraved areas;
• wherein said scaling variable comprises a count of the number of pixels situated between centroids of said plurality of engraved areas.

An engraver for engraving a cylinder comprising:

• an engraving head for engraving a plurality of engraved areas on said cylinder;
• a processor for controlling the operation of the engraving head;
• and
• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• said processor using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said processor locates at least one pair of said engraved areas using said pixel array and generates said calibration factor corresponding thereto, said processor generating said calibration factor using a scaling variable and a known screen variable associated with said plurality of engraved areas;
• wherein said calibration factor comprises a ratio of said scaling variable and said known screen variable;
• wherein said known screen variable comprises a distance defined by a desired screen;
• and
• wherein said at least one scaling variable comprises a count of the number of pixels between centroids of said plurality of engraved areas and said known screen variable comprises an actual distance between said engraved areas as defined by said screen associated with said plurality of engraved areas.

An engraver for engraving a cylinder comprising:

• an engraving head for engraving a plurality of engraved areas on said cylinder;
• a processor for controlling the operation of the engraving head;
• and
• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• said processor using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• wherein said processor locates at least one pair of said engraved areas using said pixel array and generates said calibration factor corresponding thereto, said processor generating said calibration factor using a scaling variable and a known screen variable associated with said plurality of engraved areas;
• and
• wherein said processor determines a pixel span between at least one pair of engraved areas and determines said scaling variable using said pixel span.

An engraver for engraving a cylinder comprising:

• an engraving head for engraving a plurality of engraved areas on said cylinder;
• a processor for controlling the operation of the engraving head;
• and
• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• said processor using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• and
• wherein said image calibration factor comprises a ratio defined by the following formula:
• M=D/P
• where M is said calibration factor;
• P comprises a count of a number of pixels between a first point on a first engraved area and a second point on a second engraved area, wherein a relationship between said first point relative to said first engraved area substantially corresponds to a second relationship of said second point to said second engraved area;
• and
• D comprises a distance between said first engraved area and said second engraved area as defined by a desired screen.

An engraver for engraving a cylinder comprising:

• an engraving head for engraving a plurality of engraved areas on said cylinder;
• a processor for controlling the operation of the engraving head;
• and
• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto:
• said processor using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• and
• wherein said image calibration factor comprises a ratio defined by the following formula:
• M=D/P
• where M is said calibration factor;
• P comprises an average count of a number of pixels between corresponding points of a plurality of pairs of adjacent engraved areas of said CCD array;
• and
• D comprises an distance between said plurality of pairs of said engraved areas as defined by a desired screen.

An engraver for engraving a cylinder comprising:

• an engraving head for engraving a plurality of engraved areas on said cylinder;
• a processor for controlling the operation of the engraving head;
• and
• an imager for imaging a plurality of engraved areas on a workpiece and for generating a pixel array corresponding thereto;
• said processor using said pixel array to generate a calibration factor for use when determining actual measurements for engraved areas subsequently imaged by said imager;
• and
• wherein said processor further comprises:
• means for generating error signals representing differences between commanded values for said engraved areas and actual measurements for said engraved areas;
• means for indicating a warning when a magnitude of said error signals exceeds a predetermined limit value.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• and
• wherein said scaling variable comprises a number of pixels between a pair of said engraved areas.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• and;
• wherein said method further comprises the steps of:
• locating centroids for a plurality of said engraved areas;
• using said centroids to generate said calibration factor.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• and
• wherein said scaling variable comprises a count of the number of pixels situated between centroids of said plurality of engraved areas.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• and
• wherein said scaling variable comprises a count of the number of pixels between centroids of said plurality of engraved areas and said known screen variable comprises an actual distance between said engraved areas as defined by said screen associated with said plurality of engraved areas.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• and
• determining a pixel span between at least one pair of engraved areas;
• generating said scaling variable using said pixel span.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• and
• determining an average of a plurality of pixel spans to determine said scaling variable, each of said plurality of pixel spans comprising a horizontal pixel span between a pair of engraved areas which are situated in a substantially common horizontal row within said pixel array.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• and
• determining an average of a plurality of pixel spans to determine said scaling variable, each of said plurality of pixel spans comprising a vertical pixel span between a pair of engraved areas which are situated in a substantially common vertical column within said pixel array.

A method of calibrating an image system for imaging engraved areas on a workpiece, said method comprising the steps of:

• capturing an image of said engraved areas and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• and
• determining said calibration factor using a ratio defined by the following formula:
• M=D/P
• where M is said calibration factor;
• P comprises a count of a number of pixels between a first point on a first engraved area and a second point on a second engraved area, wherein a relationship between said first point relative to said first engraved area substantially corresponds to a second relationship of said second point to said second engraved area;
• and
• D comprises a distance between said first engraved area and said second engraved area as defined by a desired screen.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• wherein said scaling variable comprises a number of pixels between a pair of said engraved areas.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• and
• locating centroids for a plurality of said engraved areas;
• using said centroids to generate said calibration factor.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• wherein said scaling variable comprises a count of the number of pixels situated between centroids of said plurality of engraved areas.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• wherein said scaling variable comprises a count of the number of pixels between centroids of said plurality of engraved areas and said known screen variable comprises an actual distance between said engraved areas as defined by said screen associated with said plurality of engraved areas.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• wherein said method further comprises the steps of:
• determining a pixel span between at least one pair of engraved areas;
• generating said scaling variable using said pixel span.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• wherein said method further comprises the steps of:
• determining an average of a plurality of pixel spans to determine said scaling variable, each of said plurality of pixel spans comprising a horizontal pixel span between a pair of engraved areas which are situated in a substantially common horizontal row within said pixel array.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• wherein said method further comprises the steps of:
• determining an average of a plurality of pixel spans to determine said scaling variable, each of said plurality of pixel spans comprising a vertical pixel span between a pair of engraved areas which are situated in a substantially common vertical column within said pixel array.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• determining said calibration factor using a ratio defined by the following formula:
• M=D/P
• where M is said calibration factor;
• P comprises a count of a number of pixels between a first point on a first engraved area and a second point on a second engraved area, wherein a relationship between said first point relative to said first engraved area substantially corresponds to a second relationship of said second point to said second engraved area;
• and
• D comprises a distance between said first engraved area and said second engraved area as defined by a desired screen.

A method of engraving comprising the steps of:

• mounting a workpiece on an engraver;
• capturing an image of engraved areas on said workpiece and generating a pixel array in response thereto;
• generating a calibration factor using said pixel array and a screen variable associated with a desired screen for said engraved areas;
• and
• using said calibration factor to determine a measurement for at least one engraved area;
• adjusting said engraver in response to said measurement;
• engraving second engraved areas after performing said adjusting step;
• generating command signals corresponding to commanded dimensions for engraving said engraved areas;
• determining said measurement;
• adjusting said command signals in correspondence with differences between said measurement and a commanded dimensions.