Sharp Kabushiki Kaisha Corporation

Mikio Takeda

Masaru Yoshida

Hiroshi Kishishita

Kinichi Isaka

Yukihiko Nakata

Yoshinobu Kakihara

Hiroyuki Kawabata

A ZnS thin-film electroluminescent element which exhibits the hysteresis phenomenon within the light emission versus applied voltage characteristics, the electric current versus applied alternating voltage characteristics, or the electric current phase versus applied alternating voltage characteristics. The ZnS element comprises a ZnS EL thin-film including Mn serving as a luminescent center with a concentration of 0.05-5.0 wt. %, and a pair of dielectric layers made of rare earth oxides or oxides groups of III, IV and V of the Periodic Table. The EL thin-film is sandwiched between the pair of the dielectric layers. The ZnS EL thin-film is made by applying the electron-beam heating evaporation technology to a ZnS pellet.

ZnS:Mn Thin-film electroluminescent element with memory function

At least one light-absorption layer is disposed between a thin electroluminescent film and a counter electrode for absorbing light applied through a transparent electrode. According to the light-absorption layer, less light is reflected by the counter electrode, thereby preventing a visual contrast provided by electroluminescence from lowering owing to the reflected light. A plurality of light-absorption layers may be formed in the same arrangement. Materials useful for the light-absorption layers are Al.sub.2 O.sub.3, Al.sub.2 O.sub.3-x, Mo, Zr, Ti, Y, Ta, Ni, Al or the like with a thickness of about 10-300 A.

Light-absorption film for rear electrodes of electroluminescent display

Growing community of inventors

Nara, Japan

Mikio Takeda