International Business Machines Corporation

Peter Burr

Brian D Chase

James F Ziegler

Richard C Joy

Brian R Sowter

Andrew Paton

The dimensions and light output of a beam in a shadow mask cathode-ray tube are determined by means of an optical system 7 focussed on a phosphor dot to pick up and record the light generated by a ray 4 passing through a single aperture 6 in the shadow mask 2. The cathode-ray beam 1 is moved so that the whole cross-section of the beam passes the aperture 4. The detected light outputs are plotted to provide an accurate representation of the whole beam. Repeating the procedure for each gun gives a precise record of the misconvergence of the beam

Method and apparatus for determining beam dimensions at the screen of a

Convergence of the beams of an in-line gun shadow mask cathode-ray tube is provided by windings on a common core and generating pairs of quadruple and six-pole magnetic fields, respectively. The core is provided with non-magnetic ribs each having a projection for the purpose of locating the windings.

Convergence unit for cathode-ray tube

The device structure is a bi-polar transistor having a region of inert atoms located in the collector adjacent to the base-collector junction. Another embodiment of the invention is a complementary insulated gate field effect transistor (IGFET) structure having N and P channel IGFETs with regions of implanted ions beneath the source and drain of one or both transistors, and/or annular regions projecting inwardly from the surface that surround or separate the different types of IGFETs.

Growing community of inventors

Winchester, United Kingdom

Peter Burr