Touch-Control Liquid Crystal Display Electrode Multiplexing
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Solution Overview
Problem
Existing touch-control technologies for liquid crystal display devices increase thickness and weight, and can deteriorate the display effect by either separating the touch-control panel from the display device or reducing the display area.
Innovation Solution
A touch-control method that switches between display and touch-control modes using existing electrodes in a time division multiplex way, where the common or signal electrode is defined as the receiving electrode to perform touch-control functions without affecting the display, allowing for a lighter and thinner product with preserved light transmittance and display area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate touch-control panel is used, then touch-control functionality is achieved, but the device thickness and weight increase
Solution Approach 1:
The patent merges the touch-control panel with the display panel by integrating the touch-control electrodes into the same substrate as the display electrodes. The signal electrode serves dual purposes: as a signal electrode for display and as a receiving electrode for touch control, eliminating the need for separate touch-control panel layers and reducing overall device weight.
Solution Approach 2:
The signal electrode is designed to perform multiple functions simultaneously - it acts as both a display signal electrode and a touch-control receiving electrode. This multi-functionality allows the electrode structure to support both display and touch control operations without requiring additional dedicated components, thereby reducing device weight.
2Adaptability or versatility
If a separate touch-control panel is used, then touch-control functionality is achieved, but the device thickness increases
Solution Approach 1:
The touch-control panel and display panel are merged into a single integrated structure where the signal electrode serves as both the display signal electrode and the touch-control receiving electrode. This integration eliminates additional touch-control panel layers, thereby reducing device thickness.
Solution Approach 2:
The patent utilizes the same planar dimension for both display and touch-control electrodes, arranging them in the same XY plane rather than stacking them in different Z-height layers. This approach allows touch-control functionality to be achieved without adding thickness in the Z-dimension.
3Adaptability or versatility
If sensing units are embedded into pixels, then touch-control function is integrated, but the display area is reduced
Solution Approach 1:
The patent segments the electrode functions by direction rather than embedding sensing units within pixels. The signal electrode extends across the entire display area without being confined to pixel boundaries, allowing full utilization of the display area for both display and touch control purposes.
Solution Approach 2:
The signal electrode serves dual purposes as both a display signal electrode and a touch-control receiving electrode across the entire display area. This multi-functionality allows the full display area to be utilized without reduction, as the same electrode structure supports both display and touch control operations simultaneously.
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
Enables touch-control functionality without increasing the device's thickness or weight, maintaining the display effect by separating touch-control and display functions in time rather than in space, thus allowing for a lighter and thinner product with improved performance.
Implementation Method 1
a touch is determined based on the mutual capacitance by detecting a coupling capacitance between a driving electrode and a receiving electrode
Data Source
AI summary
A touch-control method for a liquid crystal display device, includes: switching from a display mode to a touch-control mode; determining whether there is a touch made by an object or whether there is an input made by an active pen; in the case where there is the input made by the active pen, starting an active pen detecting sub-mode in which an X-axis direction common electrode of the liquid crystal display device is defined as an X-axis direction receiving electrode, and a Y-axis direction common electrode or a signal electrode is defined as a Y-axis direction receiving electrode; and determining a position or an action of the active pen according to amplitudes of signals of the X-axis direction receiving electrode and the Y-axis direction receiving electrode. A touch-controllable liquid crystal display device is further provided.