Vision metrology system

A vision unit, comprising:

• a vision head,
• said vision head comprising:
• a prism,
• a primary objective lens,
• zoom optics means comprising a plurality of lenses,
• a sensor,
• said prism, primary objective lens, and said zoom optics means comprising an optical path through which the image of an object may pass onto said sensor,
• said primary objective lens and said zoom optics means being located along said optical path between said prism and said sensor,
• a reseau pattern means having a plurality of reseaus formed in a given pattern, and
• light means for projecting an image of said reseaus to said prism and then through said optical path onto said sensor for use for correcting in real-time, optical distortion of the image of the object passing through said plurality of lenses of said zoom optics means.
• mount means for mounting said vision head at a position where two perpendicular axes intersect each other,
• said mount means mounting said vision head for rotational movement about each of said two axes at the intersection of said two axes,
• a first position adjusting means coupled to said mount means for controlling movement of said vision head about one of said axes,
• a second position adjusting means coupled to said mount means for controlling movement of said vision head about the other of said axes, and
• control means coupled to first and second position adjusting means for automatically controlling movement of said vision head about said two perpendicular axes.

In an optical system comprising a primary prism, a primary objective lens, zoom optics means comprising a plurality of lenses, an area array sensor, light means, and a reseau pattern means comprising a two-dimensional pattern of reseaus wherein said primary prism, said primary objective lens, and said zoom optics means comprise an optical path through which an image of an object may pass onto said sensor, said primary prism comprising structure positioned to allow light to pass therethrough by way of a first path which coincides with said optical path and by way of a second path having an initial portion which is different from said first path and which intercepts said first path and then merges with said first path, said light means and said reseau pattern means being located such that said light means, when actuated, projects an image of said predetermined pattern of said reseaus through said primary prism by way of said second path, a process of obtaining information for correcting in real-time, optical distortion of the image of the object passing through said plurality of lenses of said zoom optics means comprising the steps of:

• projecting the image of an object onto said sensor through said optical path and hence through said first path by way of said primary prism, said primary objective lens, and said plurality of said lenses of said zoom optics means, and
• actuating said light means to project the image of said predetermined two-dimensional pattern of said reseaus through said second path onto said sensor by way of said primary prism, said primary objective lens, and said plurality of said lenses of said zoom optics means for use for correcting for said distortion.

In an optical system comprising a primary prism, a primary objective lens, zoom optics means comprising a plurality of lenses, and an area array sensor wherein said primary prism, said primary objective lens, and said zoom optic means comprise an optical path through which an image of an object may pass onto said sensor, a process of correcting in real-time, optical distortion of the image of the object passing through said plurality of lenses of said zoom optics means, comprising the steps of:

• projecting the image of an object onto said sensor by way of said primary prism, said primary objective lens, and said plurality of said lenses of said zoom optics means,
• projecting an image of a predetermined two-dimensional pattern of reseaus onto said sensor by way of said primary prism, said primary objective lens, and said plurality of said lenses of said zoom optics means,
• said reseaus of said predetermined pattern, prior to passing through said primary prism, having known coordinates,
• determining the coordinates of the image of the reseaus detected by said sensor,
• determining the coordinates of the image of points of interest of the object detected by said sensor,
• determining distortion-corrected image coordinates of the imaged object points of interest from their detected sensor coordinates by employing coordinates of the imaged reseaus detected by said sensor and said known coordinates of said reseaus.

A measuring system, comprising:

• a vision head,
• said vision head comprising:
• a primary prism,
• a primary objective lens,
• zoom optics means comprising a plurality lenses, and
• an area array sensor,
• said primary prism, said primary objective lens, and said zoom optics means comprising a primary optical path through which an image of an object may pass onto said sensor,
• a reseau pattern means having a plurality of reseaus formed in a given pattern,
• light means for projecting an image of said reseaus through said primary optical path onto said sensor for use for correcting in real-time, optical distortion of the image of the object passing through said plurality of lenses of said zoom optics means,
• said primary objective lens being adjustable in position along said primary optical path relative to said sensor,
• primary objective lens adjusting means for adjusting the position of said primary objective lens along said primary optical path relative to said sensor,
• said plurality of lenses of said zoom optics means having an adjustable magnification,
• zoom optics adjusting means for adjusting the magnification of said plurality of lenses of said zoom optics means,
• said light means and said reseau pattern means being located such that said light means, when actuated, projects the image of said reseaus along a secondary optical path to said primary prism and then through said primary prism and through said primary optical path onto said sensor,
• said reseau pattern means being adjustable in position along said secondary optical path,
• reseau pattern adjusting means for adjusting the position of said reseau pattern means along said secondary optical path corresponding with the adjustment of said primary objective lens along said primary optical path,
• aperture means located in said primary optical path for allowing light to pass along said primary optical path to said sensor,
• said aperture means having an aperture with an adjustable size for controlling the passage of light therethrough,
• aperture adjusting means for adjusting the size of said aperture,
• mount means for mounting said vision head for movement about a first axis and a second axis perpendicular to said first axis,
• first head orientation adjusting means coupled to said mount means for controlling movement of said vision head about said first axis,
• second head orientation adjusting means coupled to said mount means for controlling movement of said vision head about said second axis,
• an optically collimated reference mark on said mount means for allowing precise measurements along said first and second head position axes,
• a programmable computer means, and control means responsive to said programmable computer means for controlling each of said primary objective lens adjusting means, said zoom optics adjusting means, said reseau pattern adjusting means, said aperture adjusting means, and said first and second head orientation adjusting means.

A servo system for controlling movement of a device about an axis, comprising:

• a servo motor for rotating said device about said axis,
• a control means for producing a position control signal representative of a desired angular position of said device relative to said axis,
• a low-resolution control counter responsive to said position control signal for producing a low-resolution output representative of the desired angular position of said device relative to said axis,
• encoder means for converting the actual angular position of said device relative to said axis to an actual position signal,
• means for transforming said actual position signal into a low-resolution feedback signal and a high-resolution feedback signal,
• a low-resolution feedback counter responsive to said low-resolution feedback signal for producing a low-resolution output representative of the actual angular position of said device relative to said axis,
• a control feedback error register for comparing the output of said low-resolution control counter and the output of said low-resolution feedback counter for producing a low-resolution position error output,
• a high-resolution counter responsive to said high-resolution feedback signal for producing a high-resolution output representative of the actual angular position of said device relative to said axis,
• an error encoder multiplexer for combining said low-resolution position error output and the output of said high-resolution counter to produce a position error signal, and
• means for applying said position error signal to said servo motor for causing rotation of said device about said axis so as to minimize said position error signal.