Thomson Licensing S.a.

Thomson Consumer Electronics Inc.

Jeffrey Herbert Harrell

Himanshu Mukundray Patel

Charles Henry Knepfler

A method of manufacturing a luminescent screen assembly for a color cathode-ray tube (CRT) is disclosed. The luminescent screen assembly is formed on an interior surface of a faceplate panel of the CRT. The luminescent screen assembly includes color-emitting phosphors that are sequentially deposited over portions of the interior surface of the faceplate panel of the CRT. A filming composition is electrostatically sprayed over the color-emitting phosphors. The filming composition comprises an acrylic polymer dissolved in a solvent mixture of one or more high-volatility solvents combined with one or more low-volatility solvents.

Filming process for electrophotographic screen (EPS) formation

In accordance with the present invention, shown in FIG. 3, a method of electrophotographically manufacturing a phosphor screen, comprises the steps of coating 44 an interior surface of a viewing faceplate panel to form a volatilizable organic conductive (OC) layer and overcoating 46 the OC layer to form a volatilizable organic photoconductive (OPC) layer. The OPC layer is electrostatically charged 48 and selected areas of the OPC layer are exposed to light to form a charge image 50. The charge image is developed with at least one phosphor material 52 which is fixed 58 to the OPC layer by spraying a fixing solution comprising two solvents, having substantially different rates of evaporation onto the phosphor material on the OPC layer to affect the solubility thereof and to make the OPC layer tacky. At least a portion or all of the solvent with the higher rate of evaporation is allowed to evaporate while the solvent with the lower rate of evaporation retains the tackiness of the OPC layer. The phosphor material on the OPC layer is resprayed with the fixing solution comprising the two solvents having the substantially different rates of evaporation to uniformly fix the phosphor material to said OPC layer. Then, the fixed phosphor material is filmed 62 and an aluminum layer is deposited thereon 66 to form the screen assembly which is baked at an elevated temperature to drive off the volatilizable constituents thereof.

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Marion, IN, United States of America

Jeffrey Herbert Harrell