U.S. Philips Corporation

Jan Hendrik Duistermaat

Jan Gerritsen

Johannes C Van Nes

Constantius Johannes Panis

A CRT display device including an envelope having a faceplate of a predetermined light transmissivity, a luminescent screen disposed on an inner surface of the faceplate and electron beam producing means disposed within the envelope for exiting the screen to effect production of a luminescent image, a neutral density transmissivity filter means disposed adjacent an outer surface of the faceplate, wherein for viewing under high ambient light conditions the total transmissivity T.sub.t is 10%.ltoreq.T.sub.t .ltoreq.30%, and during operation of the display device the electron beam producing means produce a beam current density on the screen such that the contrast C.sub.4000 is 4.ltoreq.C.sub.4000 .ltoreq.8.

CRT display device for use in high ambient light

An exposure device for establishing the phosphor dots of a shadow mask color television tube. The apertures in the shadow mask are optically projected from a light source onto a photosensitive layer on the window of the tube. Arranged between the light source and the shadow mask is a cylinder lens with its axis in the direction of one of the main directions of the deflection coil system.

Method for manufacturing the picture display screen of a color

A degaussing device for a color television display tube having three electron guns arranged in one horizontal plane and vertically directed phosphor strips on the display screen, comprising degaussing coils which envelop a major part of the conical surface of the tube and are arranged such as to generate a vertically directed magnetic field, and a capacitor connected parallel to the degaussing coils, the impedance of the capacitor being high at the frequency of the degaussing current and low at the frequency of the line deflection current.

Growing community of inventors

Eindhoven, Netherlands

Jan Hendrik Duistermaat