The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 15, 1977
Filed:
Dec. 15, 1975
William F Marantette, Torrance, CA (US);
Ruth B Marantette, Torrance, CA (US);
Other;
Abstract
A system for providing exact centering of an art work target at a given point to thereby provide exact positioning of a printed circuit board to be drilled, by way of example, combines visual as well as automatic electronic means for effecting the centering. The art work target in the form of an annular opaque pad with a clear center is projected onto a rear projection screen on which there are provided X and Y orthogonal axes the intersection point of which defines the exact point for centering of the art work target. Elongated photo cells are positioned quadrilaterally about the intersection point on the orthogonal axes, part of each of the photo cells lying in the opaque area of the target and the remaining portions lying in the clear center portion of the target. Shadows cast by these photo cells are visible on the rear projection screen so that a viewer can observe precisely what the photo cells 'see.' When the target image is precisely centered at the intersection point of the orthogonal axes, all of the signals from the photo cells will be equal. By utilizing difference signals between opposite photo cells aligned with X axis to drive an X servo motor and difference signals between the photo cells aligned on the Y axis to drive a Y servo motor, a table supporting the art work can be automatically moved in the X and Y directions to effect the desired precise centering automatically.