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US 4,307,498 AGranted
One piece astigmatic grid for color picture tube electron gun and method of making same
AssigneeNorth American Philips Consumer Electronics Corp.
InventorDonald L. Say
Life of this patent
Estimating the term…
Abstract
A one-piece astigmatic lens is formed in a grid by lancing a section threeof, coining the lanced section to a dimension wider than the trough formed by the lanced section and providing a beam aperture in the lanced and coined section.
Claims4
In a method of making a one piece grid which provides an astigmatic lens for a cathode ray tube electron gun, said grid having a functional grid area defined by a perimeter and upper and lower surfaces defining a given thickness therebetween, the steps comprising:
- lancing said functional grid area to form a lanced section whose upper surface lies below said lower surface of said functional grid area, said upper surface of said functional grid area and the upper surface of said lanced section defining a trough having a given width;
- and coining said lanced section to decrease its thickness and increase its width to a dimension greater than said given width.
Dependencies are inferred from the claim text.