A flat panel display comprising: a plurality of pixels, each pixel including a plurality of sub-pixels (R, G, B), the sub-pixels (R, G, B) having different colours and each sub-pixel (R, G, B) comprising an electro-luminescent element and a driving thin film transistor (20r, 20g, 20b), wherein each driving thin film transistor (20r, 20g, 20b) is electrically connected to one of the electro-luminescent elements, wherein said each driving thin film transistor (20r, 20g, 20b) has a semiconductor active layer (21 r, 21 g, 21 b) having a channel region, the semiconductor active layer (21 r, 21 g, 21 b) being formed of polycrystalline silicon, the polycrystalline silicon having primary grain boundaries parallel to one another and side grain boundaries of anisotropic grains each approximately perpendicular to the primary grain boundaries and located between adjacent primary grain boundaries, characterised in that the channel regions of the driving thin film transistors (20r, 20g, 20b) of at least two different sub-pixels (R, G, B) of one pixel are arranged in different directions with respect to the direction of the primary grain boundaries of the polycrystalline silicon, wherein the different directions of the channel regions of the sub-pixels (R, G, B) are determined by an amount of current flowing in the self-luminescent element of the sub-pixels (R, G, B) of different colors when a substantially identical driving voltage is applied to the sub-pixels (R, G, B) of different colors, such that, when the active layers are substantially identical in size and a substantially identical driving voltage is applied to all sub-pixels, a white balance is be achieved. a plurality of pixels, each pixel including a plurality of sub-pixels (R, G, B), the sub-pixels (R, G, B) having different colours and each sub-pixel (R, G, B) comprising an electro-luminescent element and a driving thin film transistor (20r, 20g, 20b), wherein each driving thin film transistor (20r, 20g, 20b) is electrically connected to one of the electro-luminescent elements, wherein said each driving thin film transistor (20r, 20g, 20b) has a semiconductor active layer (21 r, 21 g, 21 b) having a channel region, the semiconductor active layer (21 r, 21 g, 21 b) being formed of polycrystalline silicon, the polycrystalline silicon having primary grain boundaries parallel to one another and side grain boundaries of anisotropic grains each approximately perpendicular to the primary grain boundaries and located between adjacent primary grain boundaries, characterised in that the channel regions of the driving thin film transistors (20r, 20g, 20b) of at least two different sub-pixels (R, G, B) of one pixel are arranged in different directions with respect to the direction of the primary grain boundaries of the polycrystalline silicon, wherein the different directions of the channel regions of the sub-pixels (R, G, B) are determined by an amount of current flowing in the self-luminescent element of the sub-pixels (R, G, B) of different colors when a substantially identical driving voltage is applied to the sub-pixels (R, G, B) of different colors, such that, when the active layers are substantially identical in size and a substantially identical driving voltage is applied to all sub-pixels, a white balance is be achieved.