Patent · US Expired

Photo-image memory panel and activating method therefor

US4024389A · kind A · utility

4Cited by
5References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 7, 1975
Grant dateMay 17, 1977
Priority date
Expiry dateAug 7, 1995

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C13/047
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Disclosed is a photo-image memory panel composed of an electroluminescent element which exhibits electrical polarization effects upon light excitation. Under the conditions when the panel is biased by DC voltage or DC offset voltage, light irradiation is applied to the panel to establish a light-activated polarized electric field of which the intensity is controllable in dependence upon a photo-image desired to be written into the panel. Then, the photo-image written into the panel is held while maintaining the polarized electric field. Thereafter, application of a predetermined voltage pulse enables the reading out of the photo-image in the form of light emission. Alternatively, in case of an electroluminescent element of which the light emission versus applied voltage characteristics involve the hysteresis phenomenon, a train of alternating current pulses are employed as reading-out pulses to maintain light emission corresponding to the read-out image.

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