Method of determining OLED driving signal

A method of determining driving signals for a organic electroluminescence device having a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel, the driving signals including a white signal, a red signal, a green signal, and a blue signal, the method comprising following steps in order:

• shutting the white sub-pixel and using the red sub-pixel, the green sub-pixel, and the blue sub-pixel to display a predetermined color;
• recording the lowest value among the red reference signal, the green reference signal, and the blue reference signal;
• turning on the white sub-pixel and defining the white signal equal to said lowest value;
• adjusting the values of the red signal, the green signal, or the blue signal to display the predetermined color by the pixel, wherein the adjusting step includes a white balance process including:
• detecting a difference between a first color displayed while only turning on the white sub-pixel of a four-color organic electroluminescence device and a pure white;
• compensating the first color to the pure white by using one or combination of the red sub-pixel, the green sub-pixel and the blue sub-pixel;
• and
• recording the values of the red sub-pixel, the green sub-pixel and the blue sub-pixel to be a compensating red signal, a compensating green signal, and a compensating blue signal;
• and
• recording values of the red signal, the green signal, and the blue signal.

A method of determining driving signals for a pixel of a four-color organic electroluminescence device, wherein said driving signals include a white signal, a first-color signal, a second-color signal and a third-color signal to drive the pixel presenting a predetermined color, a three-color organic electroluminescence device being used as a reference, a pixel of the three-color organic electroluminescence device driven by a first-color reference signal, a second-color reference signal and a third-color reference signal to present said predetermined color, the method comprising following steps:

• defining a value of the white signal equal to one of the first-color reference signal, the second-color reference signal and the third-color reference signal that having the lowest value;
• defining a value of the first-color signal equal to the value difference between the first-color reference signal and the white signal, defining a value of the second-color signal equal to the value difference between the second-color reference signal and the white signal, defining a value of the third-color signal equal to the value difference between the third-color reference signal and the white signal;
• and
• performing an adjusting step to adjust the values of the first-color signal, the second-color signal or the third-color signal for compensating color shifting resulted from a white OLED of the pixel, wherein the adjusting step includes a white balance process including:
• detecting a difference between a first color displayed while only turning on the white sub-pixel of a four-color organic electroluminescence device and a pure white;
• compensating the first color to the pure white by using one or combination of the red sub-pixel, the green sub-pixel and the blue sub-pixel;
• and
• recording the values of the red sub-pixel, the green sub-pixel and the blue sub-pixel to be a compensating red signal, a compensating green signal, and a compensating blue signal.