1. Field
Exemplary embodiments of the present invention relate to a pixel circuit and a display device using the pixel circuit. More particularly, exemplary embodiments of the present invention relate to a pixel circuit that can be driven at a high speed and display an image of uniform luminance, and a display device using the pixel circuit.
2. Discussion of the Background
Various kinds of flat display devices developed in recent years are capable of reducing detriments of cathode ray tubes (CRT), such as their heavy weight and large size. Examples of flat panel displays are a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting diode (OLED) display, and the like.
Among the flat panel displays, the organic light emitting diode display which uses an organic light emitting diode (OLED), generates light by recombining electrons and holes, has a fast response speed, is driven with low power consumption, and has excellent emission efficiency, luminance, and viewing angle, such that it has recently been in the limelight.
In general, a plurality of pixels emitting light in the organic light emitting diode (OLED) display include an organic light emitting diode (OLED), and the organic light emitting diode (OLED) generates light of a predetermined luminance corresponding to a data current supplied from a pixel circuit.
Digital driving, which is one method of expressing grayscale of the organic light emitting diode display, controls an on time of a pixel. When the digital driving is used in the organic light emitting diode, one frame is divided into a plurality of sub-frames, and a light emitting period of each sub-frame is set in order to display grayscale. Among a plurality of sub-frames constituting one frame, the pixel emits light during the selected sub-frame depending on an image signal for grayscale expression. That is, the sub-frame is selected according to the image signal, and is turned on to express the grayscale.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.