Browse Prior Art Database

Electron Beam Readout for a Magnetic Memory

IP.com Disclosure Number: IPCOM000094723D
Original Publication Date: 1965-May-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Speliotis, DE: AUTHOR [+3]

Abstract

Information can be stored magnetically using magnetic heads at 50, 000 bpi without demagnetization occurring. Readout is accomplished with an electron beam scanning system. The information is detected by measuring any one or all of the following parameters: secondary electrons, fluorescent X rays, reflected electrons and degree of beam current absorption.

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Electron Beam Readout for a Magnetic Memory

Information can be stored magnetically using magnetic heads at 50, 000 bpi without demagnetization occurring. Readout is accomplished with an electron beam scanning system. The information is detected by measuring any one or all of the following parameters: secondary electrons, fluorescent X rays, reflected electrons and degree of beam current absorption.

Information is recorded in the NRZI or other encoding mode on a plated tape or particulate magnetic recording medium. A recorded pattern is developed using a Bitter technique. Bitter particles 2 collect at the regions of high magnetic pole density in the NRZI mode. Particles 2 collect for the recorded 1's. They do not collect for the recorded 0's.

For information readout, medium 1 is moved serially past a focused beam of electrons 3 provided by electron gun 4. As beam 3 passes from a recorded 1 to a recorded 0, that is, from a Bitter to a non-Bitter region, there is a distinct difference in the number of electrons reflected from the surface of medium 1. The reflected electrons are monitored by detector 5 which provides the indication of the recorded information.

In a similar manner, there is a difference in the number of secondary electrons that are produced and in the quantity and character of the fluorescent X rays that are produced, when the electron beam impinges on medium 1. The variations in these parameters can also be monitored by a detector for readout of the...