| abstract |
A colour electroluminescent, EL, display device comprising an array of pixels (11) each comprising sub-pixels (1) of two or more colours (R, G, B). For at least one of the colours (R, G, B), the pixel (11) comprises a first sub-pixel (RL, GL, BL) comprising a first EL material and a second sub-pixel (Rc, Gc, Bc) comprising a second EL material. The first EL material is of higher lifetime than the second EL material; the second EL material has better colour points and/or better colour rendition properties than the first EL material. In some embodiments a pixel comprises two red sub-pixels (RL, Rc), two green subÂpixels (GL, Gc) and two blue sub-pixels (BL, Bc), one sub-pixel of each colour (RL, GL, BL) comprising relatively high lifetime EL material and the other sub pixel of each colour (Rc, Gc, Bc) comprising relatively good colour points EL material. In other embodiments a pixel comprises two blue sub-pixels (BL, Bc) but only one red sub-pixel and one green sub-pixel. |