Organic light emitting diode display device

An organic light emitting display device (OLED) has a substrate 501 and pixel regions P1, each having an electrode 520. Pixel regions P1 in a column emit the same colour (figure 11). A bank 550 between each pixel region P1 includes a step 552 on either side of a first part 551, wherein the step height is smaller than that of the first part 551. An organic light emitting layer 570 is on the electrode 520 of a pixel region P1 and also on the bank steps, and may be laminated using a soluble process such as inkjet or nozzle printing, and may have thickness uniformity. The bank 550 may have equal width between pixel regions in a row which emit different colours. The OLED may also have an auxiliary electrode connected to a power line, which may reduce sheet resistance and width of the power line, reducing aperture ratio.