Method of extending the life of a cathode ray tube
US4336478A · kind A · utility
50Cited by
4References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1980 |
| Grant date | Jun 22, 1982 |
| Priority date | — |
| Expiry date | Apr 21, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/257
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A luminous trace of varying length is produced upon a first non-centralized portion of the screen of a cathode ray tube used in a phototypesetter for generating characters, and is precisely imaged upon positions of a photosensitive medium. The concentration of the electron beam to generate the required trace eventually burns out the phosphor. The life of the tube is greatly extended by thereafter rotating it to position a second non-centralized portion of the screen at the optical projection axis, and so on, and thus, the cathode ray tube life is greatly extended.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.