Method for making high resolution phosphorescent output screens
AssigneeGeneral Electric Company
InventorWalter P. Sarvas
Life of this patent
Estimating the term…
Abstract
A screen for converting an electron image to an optical image is made by coating a transparent substrate with 1 micron mean particle size phosphor in fluid thermoplastic material using a spinning method. When the thermoplastic is set it is heated to near melting and additional fine phosphor is driven into its surface with an ultrafine sponge. After baking, this first layer is coated with a slurry of coarser grain phosphor suspended in water and a silicate compound and the substrate is centrifuged. After this second layer is dry, a thin coat of lacquer is applied and dried followed by aluminizing the lacquer. The coated screen is then baked to drive off the lacquer volatiles.
Claims8
A method of making phosphorescent screens comprising the steps of:
- coating a substrate with a slurry composed of substantially uniformly fine phosphor particles having a first degree of fineness suspended in a thermoplastic fluid,
- spinning said substrate to remove any excess slurry and to reduce the coating to the thickness desired, and permitting said thermoplastic fluid to set,
- heating said substrate and the coated layer formed as aforesaid until the thermoplastic softens or begins to melt,
- pressing onto said softened thermoplastic with a fine low durometer sponge more phosphor having said first degree of fineness and removing any excess phosphor particles which are not adhered,
- heating said substrate and the coating thereon to drive out the volatile constituents of the thermoplastic,
- depositing on said coating another coating of slurry composed of substantially uniformly fine phosphor particles having a second degree of fineness, which is more coarse that the first, suspended in a water and silicate mixture, and centrifuging the substrate to reduce said other coating to the desired thickness,
- drying said other coating, applying a thin coating of lacquer over said other coating and letting the lacquer dry,
- depositing a thin aluminum layer on said lacquer, and
- heating the coated substrate to drive off the volatile constituents of said lacquer.
Dependencies are inferred from the claim text.