Liquid Crystal Display with Integrated Capacitive Touch Electrodes
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Solution Overview
Problem
The high manufacturing costs and complex assembly processes of liquid crystal display devices with tactile keys, including separate production and assembly of the display and control components, as well as time-consuming electrical connections, hinder the development of cost-effective and efficient display devices.
Innovation Solution
Integrating all electrodes, including those for optical property modification and capacitive touch, on the same transparent substrate, with conductive tracks and connection pins allowing direct electrical connection to an external control device, reducing the need for separate components and simplifying the manufacturing and connection processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a separate touch-sensitive control device is manufactured and laminated to the display, then the display can be easily integrated into wearable devices, but the manufacturing costs increase significantly
Solution Approach 1:
The patent merges the display and touch-sensitive control device into a single integrated unit by structuring all electrodes (display electrodes and touch-sensitive electrodes) on the same front substrate. This eliminates the need for separate manufacturing and lamination processes, reducing manufacturing costs while maintaining integration ease.
Solution Approach 2:
The front substrate serves multiple functions: it supports both the display electrodes for liquid crystal control and the touch-sensitive electrodes for user input. This multi-functionality reduces the number of separate components needed, thereby lowering manufacturing costs while keeping the device easily integrable.
2Adaptability or versatility
If separate flexible film and connection cable components are used for the touch-sensitive control device, then the device can be manufactured separately, but the manufacturing costs increase
Solution Approach 1:
The patent combines the functions of flexible film and connection cables into the substrate itself. The substrate provides both the structural base for electrodes and the electrical connection pathways, eliminating the need for separate flexible films and connection cables, thereby reducing component costs while maintaining manufacturing flexibility.
3Adaptability or versatility
If electrical connection is performed in two separate steps for display and touch-sensitive control device, then the components can be connected to different external control devices, but the connection process becomes very time-consuming
Solution Approach 1:
The patent merges the electrical connection process into a single step by providing a unified set of connection pins that connect both display electrodes and touch-sensitive electrodes to external control devices simultaneously. This reduces connection time while maintaining the flexibility to connect to different external control devices.
4Device complexity
If all electrodes are structured on the same substrate using same techniques, then manufacturing costs are reduced, but the device structure becomes more complex
Solution Approach 1:
The patent applies local quality by structuring different electrodes (display and touch-sensitive) on different surfaces or regions of the same substrate using the same manufacturing techniques. This approach reduces component quantity and manufacturing complexity while maintaining the precision required for each electrode type through localized optimization of the structuring process.
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 significantly reduces manufacturing costs and time by allowing all electrodes to be produced using the same techniques and materials, enabling a more streamlined production process and easy connection to external control devices through connection pins, resulting in a cost-effective and efficient liquid crystal display device with capacitive touch functionality.
Implementation Method 1
By applying an appropriate electrical voltage between the electrode and the counter electrode, it is possible to modify the optical properties of the liquid crystal at the point where the electrodes intersect
Implementation Method 2
Each of these tactile buttons forms one plate of a capacitor, the other plate of which is formed by the portion of the upper surface of the flexible or rigid film that faces the tactile button. By placing a finger on one of these touch-sensitive keys, the user changes the capacitance value detected by that key
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a liquid crystal display device comprising a front substrate (2) and a rear substrate (4) extending parallel to and at a distance from the front substrate (2), the front substrates (2) and rear substrate (4) being joined together by means of a sealing frame (8) which delimits a sealed enclosure (10) for the confinement of a liquid crystal, at least a first electrode (12) being structured on a lower face (14) of the front substrate (2), and at least a second opposing electrode (16) being structured on a upper face (18) of the rear substrate (6), the optical properties of the liquid crystal being modified by applying an appropriate electrical voltage to the crossing point of the first and second electrodes (12, 16) considered,at least one first electrode (12) and at least one second electrode (16) being made of an electrically conductive transparent material and being extended outwards from the liquid crystal display device (1) by a first, respectively a second electrically conductive tracks (20, 14) structured on the lower face (14) of the front substrate (2), at least one third electrode (26) defining a capacitive touch area being structured on an upper face (28) of the front substrate (2), this third electrode (26) being made of an electrically conductive transparent material and being extended by a third electrically conductive track (32) with which a connecting pin (40) is in electrical contact to connect the third electrode (26) with an external control device (30),at least one protective layer or polarizer (34) being fixed to the upper face (28) of the front substrate (2) and covering the third electrode (26).