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Specular Reflection Reduction by Etching

IP.com Disclosure Number: IPCOM000049053D
Original Publication Date: 1982-May-01
Included in the Prior Art Database: 2005-Feb-09

Publishing Venue

IBM

Related People

Authors:
Beeteson, JS Sowter, BR [+details]

Abstract

Color cathode ray tubes (CRTs) are usually made with a black matrix coating the inside surface of the glass. Photolithographic techniques are used to form holes in the black matrix for subsequent coatings of phosphor dots. Approximately 70 percent of the screen surface is covered by the black matrix. A major problem in color tubes is that of specular reflections from the glass black matrix surface. This is because the high stipple that is used on mono tubes to scatter ambient light into diffuse reflections presents process problems on color tubes. The problem is that irregular holes are formed in the matrix. Consequently, color tubes use a low stipple which causes specular reflections.