TFT pixel threshold voltage compensation circuit with short one horizontal time

A method of operating a pixel circuit for a display device comprising the steps of:

• providing a pixel circuit comprising:
• a drive transistor configured to control an amount of current to a light-emitting device during the emission phase depending upon a voltage input applied to a gate of the drive transistor;
• a second transistor and a third transistor, wherein the second transistor is connected between the gate of the drive transistor and the third transistor, and the third transistor is connected between the second transistor and a second terminal of the drive transistor, such that when the second and third transistors are in an on state the drive transistor becomes diode-connected such that the gate and the second terminal of the drive transistor are electrically connected through the second and third transistors;
• a storage capacitor having a first plate connected to a third terminal of the drive transistor that receives a second voltage input, and a second plate connected to the gate of the drive transistor, and
• a programming capacitor having a first plate connected to the second and third transistors, and a second plate of the programming capacitor is electrically connectable to a data voltage input;
• performing a compensation phase to compensate a threshold voltage of the drive transistor comprising diode-connecting the drive transistor through the second and third transistors and applying the reference voltage at the second plate of the programming capacitor while the drive transistor is diode connected, wherein the programming capacitor is isolated from the reference voltage at the end of the compensation phase;
• performing a data programming phase to program the data voltage to the programming capacitor comprising applying the data voltage at a second plate of the programming capacitor while the second transistor is in an on state;
• and
• performing an emission phase during which light is emitted from the light-emitting device comprising isolating the programming capacitor from the storage capacitor and the drive transistor, and applying the second voltage input through the drive transistor to the light emitting device.