U.S. Philips Corporation

Johannes C Van Nes

Johannes Penninga

Leendert Vriens

Herman F Van Heek

Jan Hendrik Duistermaat

Constant J Geenen

Frank Gersmann

Marcus T Crooymans

A display device having a cathode ray tube which comprises a display window. The radius of curvature of the inside of the display window along the diagonal (R.sub.diag) is greater than 1.6.times.1.767.times.D and smaller than 3.0.times.1.767.times.D, where D is the length of the diagonal of the display window. For the inside surface it holds that the quotient of the sagittal height at the end of the diagonal (21) and the sum of the sagittal heights at the end of the long axis (22) and at the end of the short axis (23) ranges between 0.75 and 0.95. In embodiments, the inside surface also complies with the formula 1.5&lt;R.sub.x (0,0)/R.sub.x (x.sub.max, O)&lt;4, where R.sub.x (0,0) and R.sub.x (x.sub.max, 0) are the radii of curvature along the long axis in the centre of the display window and at the end of the long axis, respectively. By virtue thereof, an improved picture display as regards reflection, local doming and raster distortion can be obtained.

Display device having a display window

A color cathode ray tube of the type having a color selection electrode arranged in front of the display screen, is characterized in that the inner surface of the screen exhibits a deviation from an arc shape along the long X axis such that, in operation, the effect of doming is reduced. Preferably, the deviation decreases as the distance to the long axis increases. In an embodiment, the inner surface also exhibits a deviation from an arc shape along the short y-axis.

Cathode ray tube having a curved display window and a color display

A cathode ray tube comprising a rectangular display window whose thickness increases from the center of the display window along the long and the short axes. The thickness D (x) of the display window along the long axis (x) is defined by:

Cathode ray tube having strong display window and display device

An exposure device for the manufacture of cathode-ray tubes for displaying colored pictures comprises an elongate light source shaped so that the amount of light radiated by said light source increases linearly from zero at the ends of the light source to a maximum at the center of the light source, so that a triangular light profile is obtained. The device may be used to manufacture cathode-ray tubes wherein the display screen is composed of triplets of phosphor lines of very constant width.

Exposure device for the manufacture of cathode-ray tubes for displaying

A window part for a color CRT is coated with a photosensitive layer which is exposed through the apertures of a shadow mask to a rotating light source having a direction of greatest light intensity directed to the center of rotation.

Method of optically projecting a pattern of substantially circular

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

The method of manufacturing a striped screen for a colored cathode-ray tube having a shadow mask with rows of elongate apertures. Adjacent apertures in each row are separated by a solid bridge. The photosensitized screen is exposed to light from a elongate light source parallel to the longitudinal directions of the apertures. By moving the light source uniformly during the exposure over a distance substantially equal to an integral number of times the length of the light source and the direction of the longitudinal axis, a line structure is exposed on the photosensitized screen, and the width of the lines is very constant.

Method of manufacturing a cathode ray tube for displaying colored

A liquid-cooled high-pressure metal vapor discharge lamp, to be used in particular in a method of manufacturing a color television display tube in which a cooling jacket is secured around the discharge tube and on which a thin metal mirror is provided on the inside. The mirror comprises apertures through which light rays of a given intensity as a function of the location emanate without disturbing reflections.

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Eindhoven, Netherlands

Johannes C Van Nes