Integrated Common Electrode Blocks for LCD Touch Sensing
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Solution Overview
Problem
Existing LCD devices with integrated touch screens have a complex manufacturing process and increased thickness due to the separate formation of the touch screen on top of the liquid crystal panel.
Innovation Solution
The LCD device incorporates a common electrode block that functions as both a sensing electrode for touch input and a component for generating an electric field to drive liquid crystals, eliminating the need for a separate touch screen layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate touch screen is formed on top of the liquid crystal panel, then touch sensing capability is achieved, but device thickness increases and manufacturing complexity increases
Solution Approach 1:
The patent merges the touch sensing function with the liquid crystal display structure by integrating sensing electrodes directly into the LCD panel layers. The common electrode is divided into multiple common electrode blocks that serve dual purposes: generating electric fields for liquid crystal control and sensing touch positions through capacitance changes, thereby eliminating the need for a separate touch screen layer.
Solution Approach 2:
The common electrode blocks perform multiple functions simultaneously: they generate electric fields to drive the liquid crystal molecules and act as sensing electrodes to detect touch positions. This multi-functionality reduces the overall device complexity by eliminating dedicated touch sensing components.
2Adaptability or versatility
If a separate touch screen is formed on top of the liquid crystal panel, then touch sensing capability is achieved, but device thickness increases
Solution Approach 1:
The touch sensing function is merged into the existing LCD panel structure by integrating sensing electrodes within the liquid crystal layer boundaries. This eliminates the need for an additional touch screen layer on top, thereby reducing overall device thickness while maintaining touch sensing capability.
3Area of stationary object
If sensing lines are electrically connected to multiple common electrode blocks, then sensing coverage is improved, but electrical insulation between blocks is compromised
Solution Approach 1:
The common electrode is segmented into multiple isolated common electrode blocks, each connected to sensing lines. This segmentation allows each block to be independently connected to sensing lines for comprehensive coverage while maintaining electrical insulation between blocks through physical separation and insulating layers, preventing signal interference.
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 simplifies the manufacturing process, reduces the device thickness, and lowers production costs while maintaining the capability to detect touch positions on an X-Y plane using a single-direction sensing line.
Implementation Method 1
the alignment of liquid crystal in the liquid crystal layer is adjusted with an electric field, and thus, light transmittance of the liquid crystal layer is adjusted
Implementation Method 2
a liquid crystal layer formed between the lower substrate and the upper substrate
Implementation Method 3
when a user touches a certain position, a capacitance between the first and second sensing electrodes is changed at the touched position, and thus, the touch screen senses the position at which the capacitance has been changed
Data Source
AI summary
An LCD device includes a plurality of gate lines and data lines cross-arranged on a lower substrate to define a plurality of pixels, a pixel electrode disposed in each of the pixels, a plurality of common electrode blocks pattern-formed that generate an electric field with the pixel electrode and sensing a touch of a user, a plurality of sensing lines, a plurality of pad parts arranged to be separated from each other at predetermined intervals along a corresponding sensing line, and having a line width thicker than the sensing line, and a contact part disposed between a corresponding pad part and a corresponding common electrode block, and electrically connecting a corresponding sensing line and the common electrode block. When the sensing lines are electrically connected to one of the common electrode blocks, the sensing lines are electrically insulated from the other common electrode blocks.