Patent · US Expired

Deformable touch sensitive surface

US4542375A · kind A · utility

206Cited by
13References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 11, 1982
Grant dateSep 17, 1985
Priority date
Expiry dateFeb 11, 2002

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2203/04109
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A touch sensitive device is arranged with substantially parallel surfaces inside which light from a synchronized source, such as a CRT, can become trapped by total internal reflection. The screen is fitted with photodetectors which respond to the entrapment of light within the surfaces. The device is compliant so that a touch of the device at a particular point will cause an inward deflection of the surface at that point. The deflection causes light to become entrapped within the surface by total internal reflection thus making it possible, by comparing the photodetector output with the CRT raster position, to determine the exact surface position of the touch.

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