A new thin CRT

Abstract

Abstract— A description of the principles, the operation, the underlying physics, the technology, system aspects, and the performance of a new flat thin CRT, as invented and realized in the Philips Research Laboratories, is given. The panel operation is based on controlled electron (“hop”) transport in vacuum through insulating structures, enabling the use of mechanical supports inside the envelope to withstand the atmospheric pressure. The resulting flat panel has a thickness of about 1 cm for any panel size, a relatively low mass, and a reduced number of outside connections. The “hop”‐transport process is based on a self‐regulating secondary‐emission process. This process involves charge deposition by electrons landing on insulating surfaces. These modify the potential distribution until a steady state is reached in which exactly one electron leaves the surface for each electron impinging on the insulator. This process is used throughout the panel to guide the electrons from the cathodes to the addressed dots at the phosphor screen. The techniques and the processes used for making the panels are described. These include a refined powder‐blast process for three‐dimensional structuring of thin glass plates, a wet‐chemical process for realizing metal tracks on glass plates, and a low‐cost process for depositing thin MgO layers. System aspects concerning the application of the flat panel in TV sets are discussed, and some of the electronic circuitry, including newly developed ICs needed for driving the panel, is described. A two‐step addressing system allows the implementation of a novel multiplexing scheme, which leads to a more than three‐fold reduction in the number of outside connections. Experimental 17‐in. panels show good performance in terms of luminance, contrast, color purity, luminous efficacy, and viewing angle. Picture‐uniformity aspects deserve further investigation, but already some good results have been obtained. The same can be said for the lifetime of the panel.