Patent · US Expired

Graphic communications apparatus

US4177354A · kind A · utility

55Cited by
6References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 17, 1978
Grant dateDec 4, 1979
Priority date
Expiry dateApr 17, 1998

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F3/0386
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A light-spot-emitting stylus (21) is utilized by an operator to write graphical information on the surface of a simple multilayer planar transducer device (10) that includes a photoconductive layer (16) sandwiched between a transparent conductive layer (14) and a resistive layer (18) that includes spaced-apart electrodes (23 through 32 . . . ). In response to the writing spot, the transducer device generates electrical output signals indicative of successive coordinate positions of the spot on the transducer surface. In turn, these signals are transmitted to a remote location where the originally written graphical information is reconstructed. Moreover, by positioning the transducer on the face of a display unit (51), the information being written on the transducer can be viewed by the operator during the writing process.

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