Browse Prior Art Database

Electron Beam Read Only Memory Tube

IP.com Disclosure Number: IPCOM000094737D
Original Publication Date: 1965-May-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Harris, TJ: AUTHOR [+2]

Abstract

High-density, read-only information storage is performed in an electron beam tube. Storage operation is accomplished using the comparative secondary emission characteristics of metals that are bombarded by the tube' s beam. Servo control of the beam of electrons assures that readout scanning is performed at a particular location of a storage device.

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Electron Beam Read Only Memory Tube

High-density, read-only information storage is performed in an electron beam tube. Storage operation is accomplished using the comparative secondary emission characteristics of metals that are bombarded by the tube' s beam. Servo control of the beam of electrons assures that readout scanning is performed at a particular location of a storage device.

Information target 1 is disposed in a cathode ray tube. Readout operation occurs in response to the bombardment of target 1 by a beam of primary electrons 7 provided by electron gun 8. Target 1 is maintained at a fixed potential in the electron gun. Bombarding beam 7 strikes target 1 with a given electron volt energy level. Beam 7 can be controlled by positioning positively charged collector grid 12 in the path of beam 7. The magnitude of the current flow through output resistor 9 is approximately one half the beam current striking target 1. The output signal is produced at terminal 10. Its polarity is determined by the particular metal bombarded.

Target 1 is formed by depositing a thin layer of one metal 3, such as platinum, on substrate 2, such as glass. A thin layer of a second metal 4, such as cadmium, is deposited on platinum 3. Evaporation techniques can be employed for depositing the metals. By photoetching the assembly, certain areas of cadmium 4 are removed to provide alternating platinum and cadmium strips 3 and 4 on each side of information strip 5. Each strip 5 is formed of random pla...