Pixel Circuit Segmentation for Threshold Voltage Compensation
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Solution Overview
Problem
In high-resolution display panels, the short data writing time for pixel circuits limits the effectiveness of threshold voltage compensation, leading to decreased image quality due to the influence of threshold voltage on display images.
Innovation Solution
A pixel circuit is designed to operate in separate voltage compensation and data writing periods, using a voltage setting circuit with transistors and capacitors to adjust compensation time independently of data writing time, allowing for improved image quality by isolating these processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the pixel circuit operates with combined voltage compensation and data writing in a single period, then the device complexity is reduced, but the compensation time length is insufficient in high-resolution displays leading to poor image quality
Solution Approach 1:
The patent divides the pixel circuit operation into two separate periods: a voltage compensation period and a data writing period. The voltage compensation period is dedicated solely to compensating for threshold voltage variations, while the data writing period handles data input. This temporal segmentation allows sufficient compensation time even in high-resolution displays with short overall pixel periods, thereby improving image quality without significantly increasing device complexity.
2Productivity
If the data writing time is shortened to increase pixel density in high-resolution displays, then the productivity is improved, but the compensation time length is reduced leading to threshold voltage influence on display quality
Solution Approach 1:
The patent segments the pixel operation timeline into distinct compensation and data writing phases. By dedicating a specific voltage compensation period before the data writing period, the circuit ensures that threshold voltage compensation is completed independently of the shortened data writing time required for high-resolution displays. This allows fast data writing while maintaining adequate compensation time.
Solution Approach 2:
The voltage compensation operation is performed in advance during a dedicated compensation period before the data writing begins. This preliminary action ensures that the threshold voltage is compensated prior to data input, so that subsequent data writing can proceed quickly without compromising compensation quality. The compensation effect is established beforehand and maintained during the emission period.
Data Source
AI summary
A pixel circuit is provided. The pixel circuit includes a light emitting element, first to third transistors, first to second capacitors and a voltage setting circuit. The light emitting element receives a system low voltage. The first transistor receives a system high voltage and controlled by an emission signal. The second transistor is coupled between the first transistor and the light emitting device. The first capacitor is coupled to the second transistor. The second capacitor is coupled between the first capacitor and the first transistor. The voltage setting circuit receives first to second scan signals, a source driving signal and a data voltage to remove charges stored in the first capacitor according to the first to second scan signal, and writes the data voltage to the first capacitor according to the source driving signal. The third transistor is controlled by the second scan signal and receives a first reference voltage.