Organic light emitting diode display and method for controlling luminance thereof

A method for controlling a luminance of an organic light emitting diode display including pixels, in which an amount of current flowing in an organic light emitting diode of each pixel is determined depending on a difference between a data voltage and a reference voltage, the method comprising:

• differently generating a screen brightness control signal depending on a driving mode;
• independently adjusting a reference voltage register value and a gamma register value from a reference voltage default value and a gamma default value, respectively, at each of red (R), green (G), and blue (B) pixels depending on the screen brightness control signal;
• generating the reference voltage of each of the R, G, and B colors based on the adjusted reference voltage register value;
• generating the data voltage of each of the R, G, and B colors based on the adjusted gamma register value,
• loading a plurality of bands, which correspond to some of digital brightness values input from a user and in which optical compensation is previously set on the gamma register value and the reference voltage register value of each band;
• and
• in response to receiving the screen brightness control signal for an increase in brightness, increasing the gamma register value of each of the R, G, and B colors from the gamma default value of a default band while decreasing the reference voltage register value of each of the R, G, and B colors from the reference voltage default value of the default band based on the digital brightness value.

An organic light emitting diode display comprising:

• pixels each including an organic light emitting diode, an amount of current flowing in the organic light emitting diode being determined depending on a difference between a data voltage and a reference voltage;
• a control signal generator configured to differently generate a screen brightness control signal depending on a driving mode;
• a register adjusting unit configured to independently adjust a reference voltage register value and a gamma register value at each of red (R), green (G), and blue (B) colors depending on the screen brightness control signal;
• a reference voltage generator configured to generate the reference voltage of each of the R, G, and B colors based on the adjusted reference voltage register value;
• and
• a data voltage generator configured to generate the data voltage of each of the R, G, and B colors based on the adjusted gamma register value,
• wherein the reference voltage generator includes:
• a first reference voltage generator configured to generate an R reference voltage depending on an R reference voltage register value;
• a second reference voltage generator configured to generate a G reference voltage depending on a G reference voltage register value;
• and
• a third reference voltage generator configured to generate a B reference voltage depending on a B reference voltage register value.