Method of making an electron sensitive mosaic color screen

Claim 2

IN THE MANUFACTURE OF A COLOR SCREEN FOR A COLOR PICTURE TUBE HAVING A SHADOW MASK WITH APERTURES THEREIN, THE METHOD WHICH INCLUDES: DEPOSITING A LAYER OF PHOTORESIST MATERIAL OF THE POSITIVE TYPE OVER THE FACE OF THE TUBE; MOUNTING A SHADOW MASK HAVING APERTURES OF THE SAME DIAMETER AS THE SHADOW MASK OF THE FINISHED TUBE IN SPACED RELATION IN FRONT OF SAID FACE OF SAID TUBE; IRRADIATING LIGHT ON SAID LAYER THROUGH SAID APERTURES OF SAID MASK, SUCCESSIVELY ROTATING THE SOURCE OF SAID LIGHT ABOUT THE DIFFERENT APPARENT COLOR CENTERS OF THE TUBE, THE RADIUS OF GYRATION BEING SUCH AS TO FORM AN ANNULUS OF LIGHT, AND WHEREIN THE RADIUS R OR GYRATION IS SELECTED AS R>N/N - 1 A; WHEREIN N IS THE RATIO OF THE LIGHT SOURCE-TO-FACE PLATE SPACING TO THE LIGHT SOURCE-TO-MASK SPACING AND A IS THE RADIUS OF SAID APERTURES, THEREAFTER DEVELOPING THE PHOTOREIST LAYER TO REMOVE THE PORTIONS THEREOF WHERE THE ANNULUS OF LIGHT FELL; COATING A GRAPHITE SOLUTION OVER THE ENTIRE AREA OF THE FACE OF SAID TUBE INCLUDING THE REMAINING PORTIONS OF THE PHOTORESIST LAYER; IRRADIATING THE OPPOSITE FACE OF THE FACE PLATE OF SAID TUBE BY LIGHT TO SENSITIVE THE SAID REMAINING PORTIONS OF SAID PHOTORESIST LAYER AND THE PORTIONS OF THE GRAPHITE LAYER OVER-

Claim 3

In the method of claim 1, wherein said apertures are larger in diameter than the portions remaining where said annulus of light did not fall.

Claim 4

In the manufacture of a color screen for a color picture tube having a shadow mask having apertures therein, the method which includes: depositing a layer of photoresist material of a negative type over the face of a tube; mounting a shadow mask with apertures of the same diameter as the shadow mask of the finished tube in spaced relation in front of said face of said tube; irradiating light on said layer through said apertures of said mask, successively rotating the source of said light about the different apparent color centers of the tube, the radius of gyration being such as to form a spot of light on said tube face which is smaller than the apertures of said mask through which the light passes, and wherein the radius r of gyration is selected as 0<R< lambda / lambda - 1 a, where lambda is the ratio of the light source-to-face plate spacing to the light source-to-mask spacing and a is the radius of said apertures, thereafter developing the photoresist layer to remove the portions thereof where the spot of light did not fall; coating a graphite solution over the entire area of the face of the tube; removing the remaining portion of the photoresist layer; and coating the regions of the face plate not now covered by the graphite layer with phosphor slurry of desired colors to form a mosaic of multi-colored grouping on the face of said tube.

Claim 5

In the manufacture of a color screen for a color picture tube having a shadow mask having apertures therein, the method which includes: depositing a layer of photoresist material of a negative type over the face of a tube; mounting a shadow mask with apertures of the same diameter as the shadow mask of the finished tube in spaced relation in front of said face of said tube; irradiating light on said layer through said apertures of said mask, successively rotating the source of said light about the different apparent color centers of the tube, the radius of gyration being such as to form a spot of light on said tube face which is smaller than the apertures of said mask through which the light passes, and wherein the radius r of gyration is selected as 0<R< lambda / lambda - 1 a, where lambda is the ratio of the light source-to-face plate spacing to the light source-to-mask spacing and a is the radius of said apertures, thereafter developing the photoresist layer to remove the portions thereof where the spot of light did not fall; coating a graphite solution over the entire area of the face of the tube; removing the remaining portion of the photoresist layer; and coating the regions of the face plate not now covered by the graphite layer with phosphor slurry of desired colors to form a mosaic of multi-colored grouping on the face of said tube.

Claim 6

In the method of claim 3, wherein said apertures are larger in diameter than the portions of light where said annulus oF light did not fall.