An Organic Light-Emitting Diode (OLED) display is one of focuses in the research field of displays at present time. OLED has low power consumption, a low production cost, self-light-emission, a wide angle of view, a high response speed, and other advantages as compared with a Liquid Crystal Display (LCD). OLED screens have come to take the place of the traditional LCD screens in the display fields of mobile phones, Personal Digital Assistants (PDA), digital cameras, etc., where design of pixel circuits are a core technology in the OLED display, and a research thereon is of great significance.
An existing pixel circuit structure, as shown in FIG. 1, includes six transistors: M01˜M06, one driving transistor M0 and one capacitor C0. FIG. 2 shows an input timing diagram corresponding to the pixel circuit as shown in FIG. 1. Such pixel circuit can be used to address the problem of uneven display due to drift of the threshold voltage of the driving transistor M0 which results from some different technologies or aging of the transistors by its internally compensation mechanism, but there still exists a problem of brightness inconsistency in the first frame after switching between high and low gray scales. Moreover, after the pixel circuit has been used for light emitting for some period, because a bias stress may cause the occurrence of a shift in the threshold voltage of the driving transistor, hysteresis effect may happen due to different influences from the drift variation, further causing the occurrence of ghosting image.