Projection printing system with an improved mask configuration
AssigneeInternational Business Machines Corporation
InventorsGerard Abraham, Gaston Bergasse
Life of this patent
Estimating the term…
Abstract
In a projection printing system the pattern mask, whose image is projected onto a light sensitive layer, is encased in a glass sandwich so that any dirt particles on the surfaces of the sandwich are out of focus and are not printed in the light sensitive layer.
Claims8
In a projection printing system for forming an image on a light sensitive substrate, which system includes a mask including a transparent substrate with a pattern of opaque and transparent areas formed on one surface thereof, an illuminating system for directing light through the mask to the light sensitive substrate, and optical means for forming a focussed image of the mask pattern on the light sensitive substrate, the improvement which comprises means for maintaining the images of any dirt particles on the surfaces of the mask out of focus so that the dirt particle images will not be printed on the light sensitive substrate, said means comprisng a transparent layer bonded to said substrate, said layer completely covering said pattern to prevent scratching and contamination thereof, with the thicknesses of the transparent layer and the substrate being such that the images of any dirt particles on the free surfaces of the transparent layer and the substrate are not printed on the light sensitive substrate.
A projection printing mask comprising a pattern of opaque and transparent areas encased between bonded transparent layers whose outer surfaces are spaced from 1 to 10 millimeters from said pattern, such that the pattern is protected against damage and dirt and the images of any dirt on said outer surfaces are maintained out of focus so that the images will not be printed when the pattern is printed on a light sensitive substrate.
In a projection printing system for forming an image on a light sensitive substrate, which system includes a mask including a transparent substrate with a pattern of opaque and transparent areas formed on one surface thereof, an illuminating system for directing light through the mask to the light sensitive substrate, and optical means for forming a focussed image of the mask pattern on the light sensitive substrate, the improvement which comprises means for maintaining the images of any dirt on the surfaces of the mask out of focus so that the images will not be printed on the light sensitive substrate, said means comprising a transparent layer bonded to said substrate, said layer completely covering said pattern to prevent damage and contamination thereof, with the distance that the outer surface of the transparent layer is spaced from said pattern and the thickness of said substrate being such that the images of any dirt on the outer surfaces of the transparent layer and the substrate are not printed on the light sensitive substrate.
A projection printing system for forming an image on a light sensitive substrate, which system includes a mask having a pattern of opaque and transparent areas and means to prevent damage and contamination to said pattern, an illuminating system for directing light through the mask to the light sensitive substrate, and an optical means for forming a focussed image of the mask pattern on the light sensitive substrate, said means to prevent damage and contamination to said pattern including transparent layers encasing said pattern, with the distances that the outer surfaces of said transparent layers are spaced from said pattern being such that the images of any dirt particles on said surfaces are maintained out of focus so that the dirt particle images will not be printed on the light sensitive substrate.
Dependencies are inferred from the claim text.