Patent · US Expired

Flat image display device utilizing digital modulation

US4030090A · kind A · utility

8Cited by
3References
13Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 17, 1975
Grant dateJun 14, 1977
Priority date
Expiry dateDec 17, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N3/122
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An evacuated envelope having therein a vertical by horizontal matrix of cells. Each cell includes a line electron source; a digital modulation section; an electron accelerating and focusing region; and a cathodoluminescent phosphor screen. The digital modulation section includes a modulation mask disposed between the line electron sources and the electron accelerating and focusing region. The modulation mask comprises a metal sheet having a plurality of slots therein. Each slot is aligned within a cell and is surrounded by a sensing pad disposed on a surface of the modulation mask which faces the line electron sources, and by a modulation electrode disposed on the opposite surface. A digitally pulsed flow of electrons, produced by the line electron sources, is directed toward the modulation mask. A series of digital voltage pulses are applied to the modulating electrodes. The voltage pulses are synchronized with the digitally pulsed electron flow such that when a voltage pulse appears on the modulating electrodes the corresponding pulse from the line electron source will be denied passage through the slot in the modulation mask. The sensing pads are charged to a desired voltage in …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.