Pixel Circuit with Dual Capacitors for Threshold Voltage Sampling

The threshold voltage sampling is performed in advance during the second period before the data writing operation in the third period. By completing the sampling action preliminarily, the circuit ensures that the threshold voltage is captured with sufficient time even when the overall horizontal period is compressed for high-speed driving. This preliminary action allows the sampling to be completed before the time constraint becomes critical.

The pixel circuit operates through periodic cycles divided into multiple distinct periods: first period for initialization, second period for threshold voltage sampling, and third period for data writing. This periodic structure with clearly defined phases ensures that the sampling operation receives dedicated time allocation within each cycle, maintaining adequate sampling time while enabling high-speed operation through efficient periodic repetition.

The first capacitor serves multiple functions: it stores the threshold voltage during the sampling period and subsequently provides this stored voltage during the data writing period to enable proper pixel operation. This multi-functionality reduces the need for additional dedicated components, as the same capacitor handles both the sampling storage and the subsequent voltage provision, thereby limiting the increase in device complexity while still achieving sufficient sampling time.

The circuit merges the threshold voltage storage function and the data holding function into a coordinated sequence using the capacitors and switches. The first capacitor stores threshold voltage, and the second capacitor stores data voltage, with their operations merged in time but separated in function. This merging approach allows efficient use of components while achieving the goal of separate sampling and writing periods with sufficient time allocation.