Browse Prior Art Database

Cathode Ray Tube Storage Reading

IP.com Disclosure Number: IPCOM000098387D
Original Publication Date: 1960-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Friest, DT: AUTHOR

Abstract

The apparatus reads magnetic bits stored on the magnetizable surface 10 of a cathode ray tube 11. The system utilizes the electron mirror principle in which a beam of electrons is accelerated toward the target surface 10. The target 10 is biased slightly positive with respect to the cathode 12 so that, initially, the system is in delicate balance, and the energy of the electron beam is just sufficient for the electrons to reach target 10 at substantially zero velocity.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 86% of the total text.

Page 1 of 2

Cathode Ray Tube Storage Reading

The apparatus reads magnetic bits stored on the magnetizable surface 10 of a cathode ray tube 11. The system utilizes the electron mirror principle in which a beam of electrons is accelerated toward the target surface 10. The target 10 is biased slightly positive with respect to the cathode 12 so that, initially, the system is in delicate balance, and the energy of the electron beam is just sufficient for the electrons to reach target 10 at substantially zero velocity.

With a magnetic bit present on target 10, however, the magnetic field surrounding this bit reacts with the moving electrons to provide a deflecting force acting in a direction normal to the direction of motion. Hence, the beam is deflected to one side according to fundamental theory defining electron motion in a magnetic field. Each deflected electron is now required to travel a further distance than before in order to reach target 10. There is, however, insufficient energy for the electron to travel farther since the system was initially in balance. In accordance with electron mirror theory, the electron does not reach the target, but reverses its direction and is collected by the accelerating anode. Thus, with a bit present and with no electrons reaching the target, no current is produced through resistor 13.

As the electron beam is swept across the target surface, the beam either strikes the target or is deflected from it, depending upon whether a bit is present ...