Nokia Technology Gmbh

Standard Elektrik Lorenz Ag

Joachim Hassler

Zeljko Sernhorst

Rolf Schmidt

Dieter Forker

Rudi Lenk

Bernhard Lau

Gunter Wessels

Michael Neusch

Herbert Kilgus

Jurgen Reinknecht

Kurt Ringer

A calibration step is carried out on a calibration tube in which magnetizations which cause beam displacements in x and y directions are determined for all the magnet poles and beams, and the adjustments of sensitivity of each beam from the x/y values is determined. A beam deviation of a production tube is then adjusted by determining its initial error in x and y directions and then starting a calculation sequence in which the magnetization currents are calculated by linear superposition of the individual currents on the basis of the known adjustment sensitivities. An additional rotating and decreasing auxiliary field is active during the magnetization of the poles in the rings of the calibration tube and of the production tube. It is also possible to correct twist errors using the invention.

Process and device for magnetizing a magnet ring in the neck of a color

A process for measuring a targeting of an electron beam that passes through a slot in a shadow mask in a multiple-beam color picture tube and strikes a phosphor stripe on a screen of the tube includes: exciting a luminous stripe in the phosphor stripe, recording an image of the luminous stripe with an image converter, determining outer edges of the phosphor stripe, generating an electron beam in the picture tube to illuminate a luminous spot on the phosphor stripe, recording an image of the luminous spot, determining positions of outer edges by analyzing the image of the luminous spot, and comparing locations of the outer edges of the phosphor stripe with the positions of the outer edges of the luminous spot to determine the targeting of the electron beam. If the respective outer edges do not substantially coincide, then the process includes generating a displaced electron beam with an auxiliary deflector to illuminate a displaced luminous spot having two outer edges perceptible by the image converter, and determining from a width and displacement of the displaced luminous spot the position of the outer edges of the displaced luminous.

Process and device for measuring targeting in color picture tubes

A color TV convergence measurement device and process for measuring a position of an electron beam of a multiple-beam color picture tube relative to a field of view of an image converter, in which an electron beam generation system provides the electron beam which generates a brightness distribution pattern on a screen of a tube, the screen has phosphor stripes for different colors, and a shadow mask is arranged in front of the screen and has elongated slots in the direction of the phosphor stripes. The process includes generating a predefined electron distribution pattern on the shadow mask; recording an associated brightness distribution pattern on the screen using the image converter which converts the brightness distribution pattern into an electrical charge pattern; and analyzing the charge pattern to obtain a value for a variable characterizing the position of the charge pattern within the field of view of the image converter; generating the electron distribution pattern with dimensions on an order of a few millimeters and with at least one edge extending obliquely to the direction of elongation of the mask slots; and generating the associated brightness distribution pattern on the image converter so that it fits completely into the field of view.

Process and device for convergence measurement in a color picture tube

The invention concerns the measurement of the radiant density of electron beams from shadow mask tubes. According to a known process, the beam is displaced on the screen and pictures are taken of the light spot areas, as they are detected by the effect of apertures when the beam has been displaced. The pictures are then evaluated with respect to their luminance distribution. This process requires an extraordinary number of adjustments. For that reason the invention states that the pictures are taken by an image converter camera, that light spots are produced over the entire field of view of the image converter, which serve as simulated apertures for the detection of light spot sections and that, to determine the luminous density distribution, the displacement width is selected so that the light spot sections that were detectable before a displacement step can no longer be detected after the displacement step, that the camera takes a picture before the first and after each displacement step, and that all the pictures are stored and composed into a total picture of the light spot distribution.

Device and process for measuring an electron density distribution in a

Measuring apparatus for measuring the position of a light source inside a lighthouse as used in the manufacture of phosphor screens of color picture tubes comprises a base plate and two optical projection devices which are directed on to the light source, and which each contain at least two position diodes. An evaluating circuit connected thereto ascertains the position of the light source and the result is fed to a display device.

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Esslingen, Germany

Joachim Hassler