Abstract: A color liquid crystal display device fitted with a liquid crystal panel having a pixel formed with a plurality of primary color pixel components combined so that a reference white is reproduced, each of the primary color pixel components further having a corresponding liquid crystal shutter; and a back light unit disposed in the rear of the liquid crystal panel and used to give light in such a manner as to have the light pass through the liquid crystal shutters. In the color liquid crystal display device, the transmission factors of the liquid crystal shutters corresponding to the primary color pixel components are set substantially equal and the reference white is reproduced on the liquid crystal panel by means of the transmission factors thus set. With this arrangement, it becomes possible to set high the luminance of the reference white, to equalize the gradation levels depending on the primary color and to simplify the configuration of its driving circuit.

Abstract: Disclosed is a fluorescent lamp which comprises a mixture of a phosphor (i) comprising an alkaline earth metal halophosphate phosphor activated with divalent europium, represented by the general formula:M.sub.5-x X(PO.sub.4).sub.3 :Eu.sup.2+ (x)wherein M consists of Ba, Ca and Mg, containing 3 to 4.5 gram-atom of Ba, 0.5 to 2 gram-atom of Ca and 0.01 to 1 gram-atom of Mg each; X is one or more of F, Cl or Br; and 0.01<x.ltoreq.0.2and having the emission peak at the wavelength region of 480 to 500 nm, and a phosphor (ii) having the emission peak at the wavelength region of 620 to 640 nm and having the half width of 120 to 160 nm.

Abstract: A flourescent lamp, having a vacuum tight radiation transmitting envelope comprising mercury and rare gas, provided with electrodes between which the discharge takes place during operation and a luminescent layer which comprises a mixture of phosphors having different densities wherein the greater the density of the phosphor, the smaller its particle size.