Liquid Crystal Display Residual Voltage Elimination
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Solution Overview
Problem
Conventional liquid crystal display devices experience persistence due to residual voltages between pixel electrodes and common electrodes, which are not efficiently eliminated, leading to delayed white display in all liquid crystal pixels.
Innovation Solution
A liquid crystal display device with a display control circuit that simultaneously drives all scanning lines and transitions signal line potentials to match the common electrode potential within a one-frame period, then turns off the power source after a preset time, allowing for rapid elimination of residual voltages across all pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the scan driver and signal driver operate to eliminate residual voltage sequentially row by row, then the residual voltage is reduced to approximately zero, but a one-frame period or more is required to cause all liquid crystal pixels to perform white display
Solution Approach 1:
The patent merges the residual voltage elimination process with the white display process by simultaneously driving all scanning lines to transition signal line potentials to match the common electrode potential. This combined approach eliminates residual voltages across all pixels while achieving white display in a single operation, reducing the time required from one-frame period or more to within one-frame period.
2Speed
If the potential of signal lines is transitioned to match common electrode potential simultaneously, then residual voltages are eliminated rapidly within 10 ms or less, but the display control circuit requires precise timing control
Solution Approach 1:
The patent applies preliminary action by pre-configuring the display control circuit to simultaneously drive all scanning lines at the appropriate timing. The control circuit is designed to transition signal line potentials to match the common electrode potential before the power source is turned off, ensuring residual voltages are eliminated rapidly within 10 ms or less without requiring complex real-time adjustments.
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 approach enables the rapid setting of pixel electrode potentials equal to the common electrode potential, reducing persistence and ensuring almost immediate white display without the need for prolonged pixel row transitions, thus eliminating residual voltages within 10 ms or less.
Implementation Method 1
the alignment direction of liquid crystal molecules in the pixel region is controlled by an electric field corresponding to drive voltage retained between the pixel electrode and the common electrode
Implementation Method 2
The pixel electrode reflects ambient light incident thereon via the liquid crystal layer from the counter-substrate side as reflection light
Data Source
AI summary
A liquid crystal display device is composed of a liquid crystal display panel which includes liquid crystal pixels arranged in a matrix form and each having liquid crystal held between a pixel electrode and a common electrode, scanning lines arranged along the rows of pixels, signal lines arranged along the columns of pixels and pixel switching elements arranged near intersections between the scanning lines and the signal lines and each driven via a corresponding scanning line, and a display control circuit which controls the display panel. The display control circuit is configured to simultaneously drive all of the scanning lines, transition the potentials of the signal lines to a value substantially equal to potential of the common electrode in a state where the scanning lines are driven within a one-frame period, and turn off a power source after a preset period of time required for the transition has elapsed.