Patent · US Expired

Interactive viewgraph system

US4503468A · kind A · utility

37Cited by
2References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 9, 1981
Grant dateMar 5, 1985
Priority date
Expiry dateOct 9, 2001

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/42
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

At each of a pair of linked terminals, an image is generated at local and remote input devices. The generated image is projected onto a viewing screen and, while exhibited, further locally or remotely generated data is used to alter the generated image and, consequently, to alter the projected image. Data can, for example, be generated by means of a document scanner and a manually operated X-Y pen digitizer.

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