Output luminance of an RGB‐LED backlight for an LCD‐TV was adaptively dimmed along with input video signal in fashions of 0D (uniform dimming), 1D (line dimming), and 2D (local dimming). It has been proven experimentally that the backlight power can be reduced to 83%, 71%, and 50%, respectively, for a typical sample movie having 8.0% post‐gamma average picture level (which is equal to the average luminance level). Further simulation study revealed that the power consumption can be reduced to the value equal to that of the post‐gamma APL.

High-luminance electroluminescent devices have been newly developed using a Ga 2 O 3 :Mn thin film prepared by a sol-gel process. The sol-gel process, which eliminates the need for vacuum processes, enabled the inexpensive preparation of Ga 2 O 3 :Mn thin films on large-area thick ceramic sheet insulators. Gallium acethylacetonate, a relatively inexpensive and easy to handle material, was used as the Ga source material. Thin-film electroluminescent (TFEL) devices with a Ga 2 O 3 :Mn thin-film emitting layer prepared by the sol-gel process at a deposition temperature of 900 • C and a postannealing temperature of 1000 • C exhibited luminances of 1271 and 401 cd/m 2 when driven at 1 kHz and 60 Hz, respectively.

A new multicomponent oxide phosphor, Mn-activated Y 2 O 3 -GeO 2 , is demonstrated to be very promising as the thin-film emitting layer for thin-film electroluminescent (TFEL) devices. High-luminance yellow emissions were obtained in TFEL devices using (Y 2 O 3 -GeO 2 ):Mn thin films prepared with a GeO 2 content of 0 to 100 mol%: 1756, 2500, 758 and 1629 cd/m 2 in 1-kHz-driven TFEL devices fabricated using Y 2 O 3 :Mn, Y 4 GeO 8 :Mn, Y 2 GeO 5 :Mn and Y 2 Ge 2 O 7 :Mn phosphor thin films, i.e., a GeO 2 content of 0, 33, 50 or 67 mol%, respectively. In addition, high luminous efficiencies of 2.8, 3.4, 1.5 and 4.5 lm/W, respectively, were obtained in these TFEL devices using a driving voltage at 60 Hz.

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Ga2O3:Mn and (Ga2O3-SnO2):Eu thin films have been prepared by a sol-gel process. High luminance emissions were obtained in TFEL devices: green using a Ga2O3:Mn and red using a Ga2O3:Eu or a SnO2:Eu thin-film emitting layer. These sol-gel prepared devices were produced without using any vacuum processes and always exhibited higher luminances than equivalent devices prepared by r.f. magnetron sputtering: 40, 309 and above 1000 cd/m2 using SnO2:Eu, Ga2O3:Eu and Ga2O3:Mn phosphor thin films, respectively, in TFEL devices prepared by the sol-gel process and driven at 1kHz.

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