Pixel Structure with Pre-Charged Storage Capacitor for Fast Charging
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Solution Overview
Problem
High-resolution and high-refresh-rate liquid crystal displays face challenges in charging pixel units within the scanning time of one line due to the need for AC voltage driving, which results in prolonged charging times.
Innovation Solution
A pixel structure is introduced with two or three gate lines arranged to allow early setting of the pixel unit's voltage to a reference voltage during one period of line scanning time, utilizing a storage capacitor formed by overlapping gate lines and a pixel electrode to shorten charging time and increase speed without reducing aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If AC voltage driving is adopted to prevent polarization, then liquid crystal display reliability is improved, but pixel unit charging time increases
Solution Approach 1:
The patent applies preliminary action by pre-charging the storage capacitor during the previous frame period before the current line scanning begins. This allows the pixel unit to start with a pre-established voltage foundation, reducing the actual charging time needed during the current frame while maintaining AC voltage driving for polarization prevention.
Solution Approach 2:
The charging process is segmented into two phases: pre-charging during the previous frame period and final charging during the current frame period. This segmentation allows the charging to start earlier without extending the critical display period, effectively reducing the perceived charging time while maintaining reliability.
2Productivity
If high resolution and high refresh rate are implemented, then display quality is improved, but pixel unit charging speed becomes insufficient
Solution Approach 1:
The storage capacitor is pre-charged during the previous frame period before the current line scanning begins. This preliminary charging action provides a head start for the pixel unit voltage establishment, enabling high refresh rates to be achieved without compromising charging speed within the constrained scanning time.
Solution Approach 2:
The charging action continues across frame boundaries, with the storage capacitor being charged during the previous frame and completing during the current frame. This continuous charging approach ensures that high resolution and high refresh rate requirements are met by eliminating idle charging time.
3Loss of time
If storage capacitor is charged within one line scanning period, then charging time is reduced, but voltage stabilization to reference voltage is compromised
Solution Approach 1:
The storage capacitor is pre-charged to a preliminary voltage level during the previous frame period. This preliminary action establishes a voltage foundation that is closer to the target reference voltage, reducing the time needed for final stabilization while ensuring voltage stability is achieved within the current line scanning period.
Solution Approach 2:
The voltage setting process uses periodic action by alternating between pre-charging phases in previous frames and final stabilization phases in current frames. This periodic approach ensures that voltage stabilization is achieved within each line scanning period while maintaining overall voltage stability across multiple frames.
Data Source
AI summary
The present invention provides a structure of a pixel, which has a simple structure and employs an arrangement where a terminal of the storage capacitor Cst is of the same potential as the gate line. In other words, under a condition of not reducing aperture ratio, an arrangement of two (or three) gate lines is used, of which one is used to early set the voltage of the pixel electrode to a reference voltage by one period of line scanning time and, also, which is set to partly overlap the pixel electrode of a structure of another pixel to provide a storage capacitor, so as to shorten the charging time of the pixel unit and increase the charging speed of the pixel unit.