U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Dieter Wadow

Jacqueline Merikhi

Michael Bredol

Cornelis Reinder Ronda

Herfried Karl Wieczorek

Ulrich Schiebel

Helmut Bechtel

Markus Haase

Albert A Comberg

Wolfram Czarnojan

Gunter Zeitler

Heinrich A Oepen

Irmgard Kohler

Herbert Schreinemachen

Alwin Knops

The present invention is directed to a GdOS:M fluorescent ceramic material with a very short afterglow, wherein M represents at least one element selected from the group Pr, Th, Yb, Dy, Sm and/or Ho and the GdOS:M fluorescent ceramic material comprises further:

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A method of manufacturing a phosphor composition of a phosphor comprising a pigment coating of hematite, includes a first step in which the phosphor is coated with an iron-containing starting compound for hematite, and a second step, in which the phosphor with the coating is calcined, thereby converting the iron-containing starting compound for hematite into hematite. The calcining operation is carried out in an atmosphere of a gas mixture of water vapor and an oxidizing gas.

Manufacture of a phosphor composition with hematite

A color display screen having a coating which comprises at least a greend an/or a red phosphor as well as at least a pigment having the following composition:

Color display screen comprising a contrast-enhancing pigment

A color display screen comprising a coating which contains at least a green and/or a red phosphor and at least a pigment having the composition Zn.sub.3-3x In.sub.2xy Ga.sub.2x-2xy S.sub.3, wherein 0.2&lt;x&lt;0.97 and 0.1&lt;y.ltoreq.1.0, yields a high-contrast and low-reflection picture, because the solid-solution properties of the pigmentation in accordance with the invention enable its absorption properties to be accurately adapted to the emission spectrum of the phosphor. The solid solutions having the above-mentioned composition are characterized by steep absorption edges in the yellow-orange spectral range and by a high absorptivity. This permits thin pigment-containing layers and small quantities of pigment to be used.

The invention relates to a display screen comprising a phosphor composition of a sulphide and/or selenide-containing phosphor which is provided with a coating which is composed of germanium disulphide and/or germanium diselenide. In such a display screen, in particular a low-energy cathode ray display screen, the advantages of the efficient sulphide or selenide-containing phosphors can be used and said display screen remains bright and rich in contrast for a long period of time because the coating, which is composed of germanium disulphide and/or germanium diselenide, surprisingly acts as a stabilizing protective coating which limits the corrosion processes in sulphide and/or selenide-containing phosphors induced by low-energy radiation.

Luminescent screen

A projection television display tube having an evacuated envelope (1) with a display window (4) which has a display screen (5) on its inside and in front of which a light-permeable second window (6) is provided on the outside, a cooling liquid flowing through the space (7) between the display window (4) and the second window (6) from at least one inlet aperture to at least one outlet aperture. When in such a projection television display tube a cooling jacket(8) is provided at the area of the windows (4, 6) and around the said space (7) and is provided with at least one duct (9) and one pump (16) with connecting nipples (17,18) which transport the cooling liquid from the outlet aperture to the inlet aperture or apertures of the said space (7), an effective cooling is obtained with a power up to 40 W without outer pipes and without heat exchangers. By the forced circulation of the cooling liquid a good temperature compensation is obtained so that fewer stresses occur in the glass of the display window.

Projection television display tube

In electrophotography or electroradiography charge images are formed which are customarily made visible by means of toners. The invention provides an electrostatic probe device for the electric scanning of charge images. The device, therefore, is particularly suitable for use in conjunction with digital image processing and storage. The device in accordance with the invention comprises a large number of electrode tracks which are provided on a flat substrate and on which there is provided an insulating layer on which a conductive layer is provided. The latter layer comprises cut-outs at the area of the electrostatic probe electrode heads. This device is suitable for the simultaneous measurement of the charge distribution at some hundreds of measuring locations.

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Aachen, Germany

Dieter Wadow