Liquid Crystal Display Common Potential Feedback Accuracy
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Solution Overview
Problem
Conventional methods for stabilizing the common potential in liquid crystal display devices suffer from low accuracy due to interference from intersection capacitances and noise, particularly when measuring and feeding back the common voltage, leading to irregularities in image quality and potential instability.
Innovation Solution
The liquid crystal display device incorporates a common sensing line and a scanning-signal-drive-circuit-use power source line formed along one side of the display panel, with the common sensing line placed between the common-voltage-supply-use line and the driver-power-source supply line, allowing for improved detection and stabilization of the common potential by reducing noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the common potential is measured at a portion close to the voltage input position, then the measurement is easier to implement, but the accuracy in stabilizing the potential is low due to influence from intersection capacitances
Solution Approach 1:
The patent extracts the common potential measurement function from the conventional location near the voltage input and relocates it to a dedicated sensing line that extends to the periphery of the display region. This separation allows the measurement to be performed at a location less influenced by intersection capacitances, thereby improving measurement accuracy while maintaining implementation feasibility through the use of a dedicated sensing pathway.
Solution Approach 2:
The patent introduces a dedicated common sensing line as an intermediary element between the common electrode and the measurement point. This sensing line acts as a mediator that transports the common potential signal to the periphery of the display region, where it can be measured with higher accuracy without being affected by intersection capacitances at the voltage input location.
2Reliability
If a long line is used for detecting and feeding back the common potential outside the display region, then the feedback path is established, but the detected potential is influenced by peripheral equipments reducing accuracy
Solution Approach 1:
The patent merges the common sensing line with the periphery of the display region, allowing the measurement to be performed at the boundary between the display region and the peripheral equipment area. This positioning enables the feedback path to be established while minimizing the length of the line exposed to peripheral equipment interference, thereby maintaining measurement accuracy.
Solution Approach 2:
The patent applies local quality by creating a dedicated sensing region at the periphery of the display region where the common potential is measured. This localized measurement area is specifically positioned to be less influenced by peripheral equipment, providing a stable measurement point that maintains accuracy while establishing the necessary feedback path.
3Device complexity
If the common voltage supply lines intersect scanning signal lines or video signal lines stereoscopically, then the display structure is compact, but intersection capacitances generate noises causing potential irregularities
Solution Approach 1:
The patent extracts the common potential measurement function from the area affected by intersection capacitances and relocates it to the periphery of the display region. By measuring the common potential at this removed location, the system maintains the compact stereoscopic intersection structure of the voltage supply lines while eliminating the harmful noise influence from the measurement process.
Solution Approach 2:
The patent introduces a dedicated common sensing line as an intermediary that separates the measurement function from the noisy intersection regions. This sensing line acts as a mediator that transports the common potential signal away from the intersection capacitances, allowing the compact structural design to be maintained while reducing noise influence on the measurement.
Data Source
AI summary
The present invention provides a liquid crystal display device which can enhance the accuracy in feeding back a common potential applied to common voltage supply lines. A display panel includes a common bus line electrically connected to common electrodes and formed annularly on a periphery of the display region, a common sensing line for feeding back a voltage of the common bus line to a control printed circuit board, a scanning-signal-drive-circuit-use power source line for supplying electricity for driving a scanning signal drive circuit, and a common-voltage-supply-use line for supplying a common voltage to the common bus line. The common-voltage-supply-use line, the common sensing line and the scanning-signal-drive-circuit-use power source line are formed along one side of the display panel to which at least the scanning signal drive circuit is connected. The common sensing line is formed between the common-voltage-supply-use line and the scanning-signal-drive-circuit-use power source line on one side of the display panel.