Colour control for active matrix electroluminescent display
AssigneeKoninklijke Philips Electronics N.V.
InventorMark Childs
Life of this patent
Estimating the term…
Abstract
A colour active matrix EL display device has a row and column array of colour pixels (1) which each comprise an electroluminescent display element (2) connected in series with a drive transistor (22) to a power line (26). The different colour pixels in a row are connected to respective and separate power lines (26, 26″, 26″′). The respective power supplies to each of the separate power lines associated with a row of pixels is individually switchable (45,48) to enable control of the duty cycles of the differently coloured pixels in the row. In this way, different efficiencies of different colour EL material used in the display elements can be accommodated and and adjustment of the relative brightness of each colour can be achieved.
Claims11
A colour active matrix electroluminescent display device comprising a row and column array of display pixels (1), each pixel comprising an electroluminescent display element (2) and a drive transistor (22) for driving a current through the display element, the drive transistor and the display element being connected in series between a power line (26) for supplying or drawing a controllable current to or from the display element and a common potential line (30), wherein each row of display pixels (1) comprises different colour display pixels for producing different colour light outputs, wherein the display pixels of each colour in a row are associated with a respective and separate power line (26′, 26″, 26′″), and wherein the power supply to each power line is individually switchable (40, 45, 48) so as to control the duty cycle of the associated display pixels.
A display device according to any one of the preceding claims, wherein each row of display pixels comprises red, green, and blue pixels, the different colour pixels being connected to respective power lines.
Dependencies are inferred from the claim text.