Touch Sensing Electrode Layout to Reduce Display Reflection
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Solution Overview
Problem
The visibility of display devices is compromised due to light reflection from conductive materials in the sensing electrode array, which are visible to users.
Innovation Solution
A display device design featuring a first and second conductive pattern layer separated by a sensing insulating layer, with bridge wiring electrically insulated from the sensing electrode array and exposing an insulating layer through bridge openings, and dummy contact holes to reduce visibility of reflected light patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensing electrode array with conductive materials is used to sense touch input, then touch sensing capability is achieved, but light reflection from the conductive materials becomes visible and deteriorates display visibility
Solution Approach 1:
The sensing electrode array is segmented into multiple separate sensing electrodes arranged in an interdigitated pattern, with bridge wirings connecting corresponding electrodes. This segmentation allows the conductive structures to be distributed more evenly, reducing localized reflection intensity while maintaining sensing functionality.
Solution Approach 2:
A bridge wiring structure with bridge openings is introduced as an intermediary element to connect sensing electrodes across the display area. The bridge openings expose the underlying insulating layer, creating non-conductive gaps that reduce continuous light reflection paths while maintaining electrical connectivity for touch sensing.
2Reliability
If bridge wiring is added to connect sensing electrodes, then electrical connectivity is improved, but the complexity of the conductive pattern structure increases
Solution Approach 1:
The bridge wiring structure merges multiple functions into a single element: it provides electrical connectivity between sensing electrodes, defines bridge openings for insulating layer exposure, and serves as part of the touch sensing electrode array itself. This integration reduces the need for separate components and simplifies the overall structure.
Solution Approach 2:
The bridge wiring serves multiple purposes simultaneously: it acts as a conductive connector for electrical connectivity, creates openings that expose the insulating layer to reduce reflection, and functions as part of the sensing electrode array for touch detection. This multi-functionality reduces structural complexity despite adding connectivity features.
Data Source
AI summary
A display device includes a display layer including pixels. An input sensing layer is on the display layer, and includes a first conductive pattern layer, a second conductive pattern layer and a sensing insulating layer. The second conductive pattern layer includes a first sensing electrode array extending in a first direction, and second-first and second-second sensing electrodes that are separated in a second direction with the first sensing electrode array interposed therebetween. The first conductive pattern layer includes a bridge wiring connected to the second-first and second-second sensing electrodes through bridge contact holes defined in the sensing insulating layer and is electrically insulated from and intersects the first sensing electrode array. The bridge wiring includes a bridge opening exposing an insulating layer disposed under the bridge wiring. The first sensing electrode array directly contacts the insulating layer exposed by the bridge opening, through a dummy contact hole.