Display Device Force Detection via Shared Common Electrode
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Solution Overview
Problem
Conventional touchscreen display devices face challenges in detecting force applied to the display surface at a low cost, as they require additional layers and increased processes, which can complicate the configuration and increase costs.
Innovation Solution
A display device configuration that includes a display region with pixels, gate lines, signal lines, pixel electrodes, first electrodes, auxiliary wiring lines, and a second electrode in the same layer as the signal lines or gate lines, utilizing a detection circuit to detect force based on capacitance generated between these elements, allowing for force detection without a separate force detection electrode layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate force detection electrode layer is added to detect force applied to the display surface, then force detection capability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the force detection electrode with the common electrode of the liquid crystal display, eliminating the need for a separate force detection layer. The common electrode serves dual purposes: driving the liquid crystal display and detecting force applied to the display surface through capacitance changes.
Solution Approach 2:
The common electrode is given multiple functions: it acts as both the driving electrode for the liquid crystal display and the sensing electrode for force detection. This multi-functional design reduces the overall number of components and simplifies the device structure.
2Illumination intensity
If a direct-type backlight unit is used with increased distance between detection electrode and reference potential layer, then backlight performance is improved, but capacitance change detection capability deteriorates
Solution Approach 1:
The patent introduces a reference electrode positioned between the detection electrode and the backlight unit. This reference electrode serves as an intermediary that maintains a constant potential, allowing the detection electrode to sense force-induced capacitance changes without being affected by the backlight unit's presence or distance variations.
3Measurement precision
If additional layers are added for force detection, then force detection accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent combines the force detection electrode with the existing common electrode structure, eliminating the need for additional manufacturing layers and processes. This merging approach maintains force detection accuracy while significantly reducing manufacturing complexity and cost.
Solution Approach 2:
By making the common electrode serve dual purposes as both display driver and force sensor, the patent avoids the need for separate force detection layers, thereby reducing the number of manufacturing steps and associated costs while maintaining detection accuracy.
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 configuration enables effective force detection on the display surface at a lower cost by integrating force detection capabilities within the existing display structure, enhancing detection accuracy and reducing the need for additional layers or processes.
Implementation Method 1
a detection circuit configured to detect force applied to the display region based on at least first capacitance generated between the second electrode and the signal lines
Implementation Method 2
a detection circuit configured to detect force applied to the display region based on at least first capacitance generated between the second electrode and the gate lines
Implementation Method 3
a detection circuit that detects force applied to the display region based on at least first capacitance generated between the second electrode and the first reference electrode
Data Source
AI summary
According to an aspect, a display device includes: a display region in which a plurality of pixels are arrayed in a row direction and a column direction; a plurality of gate lines extending in the row direction and coupled to the pixels; a plurality of signal lines extending in the column direction and coupled to the pixels; a plurality of pixel electrodes provided in the pixels; a plurality of first electrodes facing the pixel electrodes; a plurality of auxiliary wiring lines coupled to the respective first electrodes; a second electrode provided in the same layer as the auxiliary wiring lines and overlapping with the signal lines; and a detection circuit configured to detect force applied to the display region based on at least first capacitance generated between the second electrode and the signal lines.