Abstract: It is sought to improve the image contrast of plasma panel type display screens. A plasma panel comprises a front plate (D1) bearing photoluminescent elements (LB1, LV1) constituted by grains (GL1, GLn) of luminophor material. According to one characteristic, the grains (GL1, GLn) have a diameter of less than 1.5 micrometer. This, in relation to the prior art, constitutes a substantial reduction of the diameter of the luminophor grains, which leads to reducing the coefficient of reflectance, the result of which is an improvement of the contrast of the image.

Abstract: A diffusing display screen resulting from the combination of a cell comprising a polymer dispersed liquid crystal material which can be made diffusing, and of a cell comprising an electrochromic material which can be made absorbing and reflecting. Outside the operating mode, the display screen according to the invention has the advantage of being transparent, and thus capable of being fixed onto any surface (window, wall, etc.).