Browse Prior Art Database

Optically Compatible CRT

IP.com Disclosure Number: IPCOM000090859D
Original Publication Date: 1969-Jul-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

McDowell, AW: AUTHOR

Abstract

Certain display cathode ray tubes have a requirement for optical and Electron beam paths which are substantially coaxial. By locating the electron gun in an off-axis position and bending the resulting electron beam into coincidence with the optical beam path, exact axial coincidence of the two beams is provided.

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 96% of the total text.

Page 1 of 2

Optically Compatible CRT

Certain display cathode ray tubes have a requirement for optical and Electron beam paths which are substantially coaxial. By locating the electron gun in an off-axis position and bending the resulting electron beam into coincidence with the optical beam path, exact axial coincidence of the two beams is provided.

CRT 10 has screen 12 upon which image information is recorded by electron beam 14 under the control of deflection yoke 16. CRT 10 can be of the type in which the image information is in the form of electrostatic charges on the beam side of screen 12, enabling development of an image on the other side by use of toner. Alternatively, the tube can be of the type in which electrostatic charges operate to deform a polymer layer or the like on screen 12. In either case, the resulting image information can be projected by optics 18 and 20 defining light path 22 passing through screen 12.

Electron beam 14 originates in gun structure 24 in neck 26 extending from the side of main neck 28 of CRT 10. A bending magnet 30 provides a field which reorients the electron bean 14 from its initial direction in gun 24 into alignment with the main axis of CRT 10.

Yoke 16 can be a two-part type so that it can be assembled onto main neck 28 inboard of appendix neck 26. Alternatively, the deflection yoke 16 can be applied to neck 26 and a larger bending magnet 30 can be utilized for redirecting the electron beam after deflection by such yoke.

1

Page 2 of...