Cathode-ray tube and method of making same

Claim 1

THE TUBE FACE OF A CATHODE RAY TUBE OF THE TYPE HAVING A FLUORESCENT SCREEN AND AN ELECTRON GUN FOR BOMBARDING SAID FLUORESCENT SCREEN TO PRODUCE A LUMINOUS IMAGE TO BE VIEWED BY AN OBSERVER, SAID TUBE COMPRISING A PORTION OF RELATIVELY RIGID TRANSPARENT MATERIAL SUPPORTING ON THE INNER SIDE SURFACE THEREOF THE FLUORESCENT SCREEN WHEREBY, WHEN IN USE LIGHT FROM SAID LUMINUOUS IMAGE MAY BE TRANSMITTED THERETHOUGH TO BE VISIBLE TO THE OBSERVER''S EYES, SAID TUBE FACE HAVING, ON THE OUTER SIDE SURFACE THEREOF, A COATING OF TRANSPARENT MATERIAL HAVING AN EFFECTIVE INDEX OF REFRACTION AND OPTICAL THICKNESS SUCH AS TO SUBSTANTIALLY INCREASE TRANSMISSION OF LIGHT RAYS STRIKING SAID OUTER SURFACE FROM A LIGHT SOURCE EXTERIORLY THEREOF AND WHEREBY THE REFLECTION OF SAID LIGHT RAYS TO THE OBSERVER''S EYES WILL BE MATERIALLY REDUCED, AND SAID TUBE FACE FURTHER HAVING LIGHT-DIFFUSING MEANS ON SAID INNER SAID SURFACE WHICH IS SUCH AS TO BREAK UP SPECULAR REFLECTION OF LIGHT FROM SAID LIGHT SOURCE EXTERIORLY THEREOF WHICH MIGHT OTHERWISE BE VISIBLE TO THE OBSERVER''S EYES, SAID LIGHT-DIFFUSING MEANS BEING DISPOSED BETWEEN SAID INNER SIDE OF THE TUBE FACE AND THE FLUORESCENT SCREEN AND IN INTIMATE CONTACT THEREWITH WHEREBY IT IS IN SUCH CLOSE PROXIMITY WITH THE LUMINOUS IMAGE PRODUCED ON BOMBARDMENT OF THE FLUORESCENT SCREEN, WHEN THE TUBE IS IN USE, AS TO HAVE SUBSTANTIALLY NO EFFECT UPON THE DEFINITION OF THE IMAGE, SAID TRANSPARENT COATING ON SAID OUTER SURFACE OF THE TUBE FACE SIMULTANEOUSLY INCREASING THE TRANSMISSION OF LIGHT FROM SAID LUMINOUS IMAGE THROUGH SAID OUTER SURFACE WHEREBY THE AMOUNT OF LIGHT FROM SAID IMAGE REFLECTED BACK TOWARD THE INNER SURFACE OF THE TUBE FACE IS REDUCED, AND SAID REDUCED AMOUTN REFLECTED BACK BEING BROKEN UP BY THER LIGHT-DIFFUSING MEANS ON SAID INNER SURFACE THEREBY HALATION IS SUBSTANTIALLY ELIMINATED AND INCREASED DEFINITION AND CONTRAST OF THE IMAGE AS VIEWED BY THE OBSERVER IS OBTAINED.