Organic Light Emitting Diode (OLED) display technology has advantages such as low energy consumption. However, The OLED has a short lifespan as luminance of the emitted light is frequently changed according to displayed contents in operation. For this, there is a technology combining OLED display and Liquid Crystal Display (LCD). In a display device of such display device, an OLED substrate is provided, which comprises a plurality of OLEDs configured to emit light of different colors, a LCD panel which comprises a plurality of sub-pixels configured to filter light is disposed outside of the OLED substrate, light emitted from the respective OLED is filtered by the sub-pixels so as to have a desired luminance and to perform display. In such a display device, the luminance is controlled by filtering light through the sub-pixels of the LCD panel. Thus, the luminance of light emitted from the OLEDs is not required to be changed frequently, and the lifespan of OLEDs will be elongated.
Obviously, in order for normal operation, both the OLED substrate and the LCD panel require a driving circuit for supplying driving signal (for example, gate scanning signals, data voltage signals, common voltage signals, and the like) thereto. Conventional driving circuits are integrated in a Driver IC which is disposed on a printed circuit board (PCB) and is electrically connected to the OLED substrate and the LCD panel through a flexible printed circuit (FPC).
Clearly, in such a display device, the OLED substrate and the LCD panel are respectively controlled by different driving circuits, and two different driver IC and two flexible printed circuits are required, thereby causing a large amount of elements, a complex structure and high cost.