New pixel circuits for controlling threshold voltage by back-gate bias voltage using crystalline oxide semiconductor FETs

We devised a threshold voltage compensation pixel circuit using back‐gate bias voltage. Variation in threshold voltages can be reduced to 10% in simulation while improving the saturation characteristics of a driving transistor. The pixel circuit can compensate not only threshold variation but also mobility variation. We fabricated a 5.29‐in Quad‐VGA organic light emitting diode display using this pixel circuit. We devised a threshold voltage compensation pixel circuit using back‐gate bias voltage. Variation in threshold voltages can be reduced to 10% in simulation while improving the saturation characteristics of a driving transistor. The pixel circuit can compensate not only threshold variation but also mobility variation. We fabricated a 5.29‐in Quad‐VGA organic light emitting diode display using this pixel circuit.