Pixel Circuit Light Energy Precharge for LCD Charging Bottlenecks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Liquid Crystal Displays (LCDs), high scan frequencies lead to insufficient charging times for pixels, and existing precharge methods cause interference and excessive load on IC or GOA units due to simultaneous signal input into multiple scan lines.
Innovation Solution
A pixel circuit with a first and optional second precharge unit that converts light energy into electric energy, allowing for precharging and charging of the display unit under control of specific scan and control lines, reducing the need for simultaneous signal input into multiple scan lines and mitigating interference and load issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If precharge is implemented by turning on the gate enable signal in advance to output signals early from the scan line, then the pixels can be charged to the desired potential more quickly within the actual charging time period, but signals need to be input into multiple scan lines simultaneously causing interference between scan lines and excessive load on the IC or GOA unit
Solution Approach 1:
The pixel circuit uses its own emitted light to precharge itself and adjacent pixels through the photosensitive transistor and capacitor, eliminating the need for external precharge signals. This self-service mechanism reduces the signal input load on IC or GOA units while maintaining fast charging performance.
Solution Approach 2:
The patent implements alternating precharge modes where odd-numbered pixels precharge in one direction during odd frames, and even-numbered pixels precharge in the opposite direction during even frames. This periodic action distributes the signal load over time rather than requiring simultaneous input to all scan lines, reducing interference while maintaining charging speed.
2Productivity
If high scan frequency is used to increase display refresh rate, then the display can show updates more frequently, but the charging time for each pixel becomes insufficient
Solution Approach 1:
The pixel circuit performs preliminary charging using stored light energy from previous frames before the actual data writing occurs. This preliminary action ensures that pixels are already partially charged when the high-frequency scan arrives, eliminating the charging time deficit caused by high scan frequencies.
Solution Approach 2:
The photosensitive capacitor continuously accumulates light energy from the display unit across multiple frames, providing a continuous charging source that operates independently of the scan frequency. This continuous energy accumulation ensures sufficient charging time even at high refresh rates.
3Productivity
If multiple scan lines receive signals simultaneously for precharging, then all pixels can be prepared in advance, but interference occurs between adjacent scan lines and the load on driving units becomes too large
Solution Approach 1:
The patent divides the pixel array into alternating groups (odd and even numbered pixels) that operate in different frames. This segmentation prevents simultaneous signal input to adjacent scan lines by spatially separating the precharge operations, eliminating interference while maintaining overall precharge efficiency.
Solution Approach 2:
The patent implements time-division multiplexing where odd pixels precharge during odd frames and even pixels precharge during even frames. This periodic alternation ensures that adjacent scan lines never receive precharge signals simultaneously, eliminating interference while keeping the driving unit load manageable through temporal distribution.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables quick charging of pixels to desired potentials without scan frequency limitations, reducing interference and load on IC or GOA units, and alternately charging liquid crystals to prevent aging and extend display life.
Implementation Method 1
a first precharge unit (20) connected to the display unit (10), the (N-1)th scan line Scan N-1 and a control line CL, and configured to convert light energy into electric energy
Data Source
AI summary
Embodiments of the present disclosure provide a pixel circuit, a driving method thereof and a display device comprising the pixel circuit. The pixel circuit comprises a display unit and a first precharge unit; the first precharge unit is connected to the display unit, a (N−1)th scan line and a control line, and is configured to convert light energy into electric energy and to precharge the display unit with the converted electric energy under the control of the control line and the (N−1)th scan line; the display unit is further connected to the Nth scan line and a data line and is configured to charge the display unit through the data line under the control of the Nth scan line; wherein N≥2.