Blocking Layer Reduces Parasitic Capacitance in Touch Display
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Solution Overview
Problem
Liquid crystal display devices face issues with touch sensitivity due to parasitic capacitances formed by sensing electrodes and sensing lines, which affect the overall thickness and performance of the device.
Innovation Solution
A display device design that includes a lower panel with a first substrate and an upper panel with a first touch conductive layer, sensing electrodes, and sensing lines, where a blocking layer overlaps the sensing electrodes and lines to prevent parasitic capacitance formation, and a connection electrode connects the sensing lines to reduce the electric field influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If sensing electrodes and sensing lines are added to enable touch functionality, then touch recognition capability is improved, but parasitic capacitances are formed causing deviation in touch sensitivity
Solution Approach 1:
A blocking layer is introduced as an intermediary component between the sensing electrodes/lines and the lower panel. This blocking layer acts as a mediator that prevents direct capacitive coupling, thereby reducing parasitic capacitance while maintaining the touch sensing functionality of the electrodes and lines
2Length of stationary object
If the overall thickness of the liquid crystal display device is reduced, then device compactness is improved, but the influence of electric field between sensing electrode and lower panel increases
Solution Approach 1:
The blocking layer serves as a protective intermediary that shields the sensing electrodes from the electric field generated by the lower panel. Even when the overall device thickness is reduced, this blocking layer maintains electrical isolation and prevents harmful electric field interactions, allowing compact design without compromising sensing performance
3Reliability
If blocking layer is added to reduce parasitic capacitance, then touch sensitivity is improved, but device structure complexity increases
Solution Approach 1:
The blocking layer is designed to serve multiple functions simultaneously: it reduces parasitic capacitance, blocks electric field interference, and provides structural support. By consolidating these functions into a single layer, the design achieves improved touch sensitivity without proportionally increasing overall device complexity
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
The solution effectively reduces the impact of parasitic capacitances, enhancing touch sensitivity and maintaining a reduced overall thickness of the display device.
Implementation Method 1
a blocking layer overlapping the sensing electrodes and the sensing lines
Implementation Method 2
a connection electrode overlapping the first sensing electrode, the first sensing line, and the second sensing line
Data Source
AI summary
A display device includes a lower panel including a first substrate and at least one transistor disposed on the first substrate; and an upper panel facing the lower panel and including a first touch conductive layer including a second substrate, sensing electrodes disposed on the second substrate and including a first sensing electrode, and sensing lines including a second sensing line, a first insulating layer disposed on the first touch conductive layer, and a second touch conductive layer disposed on the first insulating layer including a blocking layer overlapping the sensing electrodes and the sensing lines and a connection electrode overlapping the first sensing electrode, the first sensing line, and the second sensing line.