Patent · US Expired

Graphics light pen and method for raster scan CRT

US4367465A · kind A · utility

50Cited by
6References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 4, 1980
Grant dateJan 4, 1983
Priority date
Expiry dateApr 4, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F3/04892
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A graphics system for a raster scan CRT implements a light pen tracked by a cursor. Hits corresponding to the cursor are distinguished from those corresponding to background data by a selective interlacing technique. A threshold level shifting technique providing accurate measurement of a horizontal component of the cursor allows accurate prediction of the location of the center of the field of view during the next frame.

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