Browse Prior Art Database

Electrical Output Storage Tube with Vertical Beam Landing

IP.com Disclosure Number: IPCOM000081548D
Original Publication Date: 1974-Jun-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Langner, GO: AUTHOR

Abstract

This Electrical Output Storage Tube (EOST), uses a focusing and deflection system achieving vertical landing of the electron beam on the target regardless of position.

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Electrical Output Storage Tube with Vertical Beam Landing

This Electrical Output Storage Tube (EOST), uses a focusing and deflection system achieving vertical landing of the electron beam on the target regardless of position.

Monocrystalline silicon wafers with thermally grown and photoetched silicon dioxide targets have significant manufacturing advantages, but are very sensitive to nonvertical landing of the writing as well as the reading beam. Differences in the landing angle cause brightness nonuniformity (shading), and displacement of the beam position on the target between the read and erase phases and the write phase, because the electrons travel along a different parabola between the collector mesh grid and the target.

Vertical landing is provided over the whole target area, regardless of the potentials on grids which are very critical with common vidicon-coil assemblies.

Vertical landing of the electron beam regardless of position is accomplished by a beam control field arrangement shown in Fig. 1. The beam emerging from the crossover 3 in the electron gun 2 of the storage tube 1 is focused by an airgap (short field) focus coil 4, preferably using a low-coercive force MN-ferrite A suitable compromise between tube length and spot size is attained when the focus field is halfway between the crossover and target. Between focus field 5 and collector mesh grid 6, two deflection fields 7 and 8 are generated by two identical deflection yokes either electromagne...